cyclin-d1 and Melanoma

Cyclin D1 is a protein encoded by the CCND1 gene, located on 11q13 chromosome, which is a key component of the physiological regulation of the cell cycle. CCND1/cyclin D1 is upregulated in several types of human tumors including melanoma and is currently classified as an oncogene that promotes uncontrolled cell proliferation. Despite the demonstrated importance of CCND1/cyclin D1 as a central oncogene in several types of human tumors, its knowledge in melanoma is still limited. This review examines data published on upregulation of the CCND1 gene and cyclin D1 protein in the melanoma setting, focusing on the pathways and molecular mechanisms involved in the activation of the gene and on the clinical and therapeutic implications.

Topics: Animals; Biomarkers, Tumor; Cyclin D1; Humans; Melanocytes; Melanoma; Molecular Targeted Therapy; Skin Neoplasms

Melanoma has one of the highest somatic mutational burdens among solid malignancies. Although the rapid progress in genomic research has contributed immensely to our understanding of the pathogenesis of melanoma, the clinical significance of the vast array of genomic alterations discovered by next-generation sequencing is far from being fully characterized. Most mutations prevalent in melanoma are simply neutral "passengers," which accompany functionally significant "drivers" under transforming conditions. The delineation of driver mutations from passenger mutations is critical to the development of targeted therapies. Novel advances in genomic data analysis have aided in distinguishing true driver mutations involved in tumor progression. Here, the authors review the current literature on important somatic driver mutations in melanoma, along with the implications for treatment. Cancer 2017;123:2104-17. © 2017 American Cancer Society.

Topics: Cyclin D1; GTP Phosphohydrolases; GTP-Binding Protein alpha Subunits; GTP-Binding Protein alpha Subunits, Gq-G11; Guanine Nucleotide Exchange Factors; High-Throughput Nucleotide Sequencing; Humans; Melanoma; Membrane Proteins; Metalloproteins; Microphthalmia-Associated Transcription Factor; Mutation; Neurofibromin 1; Nuclear Proteins; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-kit; PTEN Phosphohydrolase; rac1 GTP-Binding Protein; Ribosomal Proteins; RNA-Binding Proteins; Sequence Analysis, DNA; Skin Neoplasms; Telomerase; Tumor Suppressor Protein p53; Uveal Neoplasms

Clear cell melanoma is a rare clear cell malignancy. Accurate diagnosis of clear cell melanoma requires integration of immunohistochemical and morphologic findings, with molecular studies to rule out clear cell sarcoma. The differential diagnosis includes melanoma, carcinoma, perivascular epithelioid cell tumor, and epidermotropic clear cell sarcoma. We use a case of a lesion on the helix of an 86-year-old man as an example. Histologic examination revealed an ulcerated clear cell malignant tumor. Tumor cell cytoplasm contained periodic acid-Schiff-positive, diastase-sensitive glycogen. Tumor cells showed positive labeling for S100, HMB-45, and Melan-A, and negative labeling for cytokeratins, p63, and smooth muscle actin. Molecular studies demonstrated BRAF V600E mutation, copy gains at the 6p25 (RREB1) and 11q13 (CCND1) loci, and absence of EWSR1-ATF1 fusion. These findings supported a diagnosis of clear cell melanoma. The rare pure clear cell morphology occurs due to accumulation of intracytoplasmic glycogen. We review the differential diagnosis of clear cell melanoma and describe the utility of immunohistochemical and molecular studies in confirming this diagnosis.

Topics: Aged, 80 and over; Amino Acid Substitution; Biomarkers, Tumor; Cyclin D1; Diagnosis, Differential; DNA-Binding Proteins; Ear Auricle; Gene Dosage; Glycogen; Humans; Male; Melanoma; Mutation; Perivascular Epithelioid Cell Neoplasms; Proto-Oncogene Proteins B-raf; Sarcoma, Clear Cell; Skin; Skin Neoplasms; Transcription Factors; Up-Regulation

The Clark model for melanoma progression emphasizes a series of histopathological changes beginning from benign melanocytic nevus to melanoma via dysplastic nevus. Several models of the genetic basis of melanoma development and progression are based on this Clark's multi-step model, and predict that the acquisition of a BRAF mutation can be a founder event in melanocytic neoplasia. However, our recent investigations have challenged this view, showing the polyclonality of BRAF mutations in melanocytic nevi. Furthermore, it is suggested that many melanomas, including acral and mucosal melanomas, arise de novo, not from melanocytic nevus. While mutations of the BRAF gene are frequent in melanomas on non-chronic sun damaged skin which are prevalent in Caucasians, acral and mucosal melanomas harbor mutations of the KIT gene as well as the amplifications of cyclin D1 or cyclin-dependent kinase 4 gene. Amplifications of the cyclin D1 gene are detected in normal-looking 'field melanocytes', which represent a latent progression phase of acral melanoma that precedes the stage of atypical melanocyte proliferation in the epidermis. Based on these observations, we propose an alternative genetic progression model for melanoma.

Topics: Animals; Cell Transformation, Neoplastic; Cyclin D1; Gene Expression Regulation, Neoplastic; Genetic Predisposition to Disease; Humans; Melanoma; Mutation; Nevus, Pigmented; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-kit; Skin Neoplasms

The Wnt/beta-catenin pathway is involved in various cellular activities--including determination, proliferation, migration and differentiation--in embryonic development and adult homeostasis. The deregulation or constitutive activation of the Wnt/beta-catenin pathway may lead to cancer formation. This review focuses on the role of the Wnt/beta-catenin canonical signaling pathway in the melanocyte lineage, and more specifically, in melanoma. Several components of the Wnt/beta-catenin pathway, such as APC, ICAT, LEF1 and beta-catenin are modified in melanoma tumors and cell lines, leading to activation of this signaling. A hallmark of the activation of this pathway is the presence of beta-catenin in the nucleus. Indeed, beta-catenin is found in about 30% of human melanoma nuclei, indicating a potentially specific role for this signaling pathway in this aggressive type of cancer. Beta-catenin can induce ubiquitous genes such as myc or cyclinD1, cell lineage-restricted genes such as Brn2 and melanocyte-specific genes such as Mitf-M and Dct. The Mitf-M and Brn-2 genes encode transcription factors. Mitf plays a critical role in melanocyte survival, proliferation and differentiation. Brn-2 is involved in melanoma proliferation. Determining how the Wnt/beta-catenin signaling pathway, alone or with other pathways, orchestrates the induction of target genes involved in a diverse range of activities represents a major challenge in research into melanoma formation and tumor progression.

Topics: beta Catenin; Cell Adhesion Molecules; Cell Differentiation; Cell Lineage; Cell Membrane; Cell Movement; Cell Nucleus; Cell Proliferation; Cyclin D1; Cytoplasm; Hepatocytes; Homeodomain Proteins; Humans; Intramolecular Oxidoreductases; Melanocytes; Melanoma; Microphthalmia-Associated Transcription Factor; Neural Crest; POU Domain Factors; Signal Transduction; Transcription, Genetic; Wnt Proteins

Because skin lesions are visible and easily accessible, skin cancers provide us with an excellent in vivo model to study the development of cancers. Cutaneous malignant melanoma and squamous cell carcinoma (SCC) both arise from the epidermis and have an initial progression stage in which proliferation of the neoplastic cells is confined to the epidermis. This stage is called melanoma in situ or SCC in situ. Molecular analyses of melanoma in situ and of solar keratosis, a prototype of early SCC in situ, show that loss of p16(INK4a)/p14(ARF) and dysfunction of p53 play a critical role, respectively. Furthermore, there seems to be potential precursor cells to these in situ lesions, which are not discernible with conventional hematoxylin and eosin-stained sections. The precursor cells have minimal but critical genetic alterations, such as cyclin D1 amplification and p53 mutation, and can be identified using fluorescent in situ hybridization and immunostaining with p53 antibodies, respectively. These precursor cells may be defective in repair response to DNA damage, and would have proliferative or survival advantages over their normal neighboring counterparts in the presence of growth factor stimulation or genotoxic events, such as ultraviolet irradiation. Such precursor clones may be induced at a rather young age, and their number and size increase with accumulating carcinogenic stimuli. If these lesions acquire additional mutations, they could progress to clinically visible lesions of in situ carcinoma. Precise molecular analyses of early stages of skin cancers may have a strong impact on our understanding of in vivo development of cancers in other human organs.

Topics: Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Cyclin D1; Early Diagnosis; Gene Expression Regulation, Neoplastic; Humans; Keratinocytes; Melanocytes; Melanoma; Mutation; Skin Neoplasms; Tumor Suppressor Protein p53

Transformation of normal melanocytes into melanoma cells is accomplished by the activation of growth stimulatory pathways, typically leading to cellular proliferation, and the inactivation of apoptotic and tumor suppressor pathways. Small molecule inhibitors of proteins in the growth stimulatory pathways are under active investigation, and their application to melanoma patients would represent a new treatment strategy to inhibit cell proliferation or induce cell death. We provide a general overview of the mechanisms of oncogene activation and the functions of oncogenes. Lastly, we review oncogenic events in melanoma.

Topics: Apoptosis; Cell Nucleus; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinases; Gene Expression Regulation, Neoplastic; Genes, myc; Growth Substances; Humans; Melanoma; Nuclear Proteins; Oncogenes; Proto-Oncogene Proteins; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-mdm2; Proto-Oncogene Proteins c-raf; ras Proteins; Receptors, Growth Factor; Signal Transduction

Dabrafenib is a selective inhibitor of V600-mutant BRAF kinase, which recently showed improved progression-free survival (PFS) as compared with dacarbazine, in metastatic melanoma patients. This study examined potential genetic markers associated with response and PFS in the phase I study of dabrafenib.. Baseline (pretreatment or archival) melanoma samples were evaluated in 41 patients using a custom genotyping melanoma-specific assay, sequencing of PTEN, and copy number analysis using multiplex ligation amplification and array-based comparative genomic hybridization. Nine patients had on-treatment and/or progression samples available.. All baseline patient samples had BRAF(V600E/K) confirmed. Baseline PTEN loss/mutation was not associated with best overall response to dabrafenib, but it showed a trend for shorter median PFS [18.3 (95% confidence interval, CI, 9.1-24.3) vs. 32.1 weeks (95% CI, 24.1-33), P=0.059]. Higher copy number of CCND1 (P=0.009) and lower copy number of CDKN2A (P=0.012) at baseline were significantly associated with decreased PFS. Although no melanomas had high-level amplification of BRAF, the two patients with progressive disease as their best response had BRAF copy gain in their tumors.. Copy number changes in CDKN2A, CCND1, and mutation/copy number changes in PTEN correlated with the duration of PFS in patients treated with dabrafenib. The results suggest that these markers should be considered in the design and interpretation of future trials with selective BRAF inhibitors in advanced melanoma patients.

Topics: Comparative Genomic Hybridization; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Disease Progression; Disease-Free Survival; DNA Copy Number Variations; Humans; Imidazoles; Melanoma; Mutation; Neoplasm Staging; Oximes; Proto-Oncogene Proteins B-raf; PTEN Phosphohydrolase

Bardoxolone methyl, a novel synthetic triterpenoid and antioxidant inflammation modulator, potently induces Nrf2 and inhibits NF-κB and Janus-activated kinase/STAT signaling. This first-in-human phase I clinical trial aimed to determine the dose-limiting toxicities (DLT), maximum tolerated dose (MTD), and appropriate dose for phase II studies; characterize pharmacokinetic and pharmacodynamic parameters; and assess antitumor activity.. Bardoxolone methyl was administered orally once daily for 21 days of a 28-day cycle. An accelerated titration design was employed until a grade 2-related adverse event occurred. A standard 3 + 3 dose escalation was then employed until the MTD was reached. Single dose and steady-state plasma pharmacokinetics of the drug were characterized. Assessment of Nrf2 activation was examined in peripheral blood mononuclear cells (PBMC) by measuring NAD(P)H:quinone oxidoreductase (NQO1) mRNA levels. Immunohistochemical assessment of markers of inflammation, cell cycle, and apoptosis was carried out on tumor biopsies.. The DLTs were grade 3 reversible liver transaminase elevations. The MTD was established as 900 mg/d. A complete tumor response occurred in a mantle cell lymphoma patient, and a partial response was observed in an anaplastic thyroid carcinoma patient. NQO1 mRNA levels increased in PBMCs, and NF-κB and cyclin D1 levels decreased in tumor biopsies. Estimated glomerular filtration rate (eGFR) was also increased.. Bardoxolone methyl was well tolerated with an MTD of 900 mg/d. The increase in eGFR suggests that bardoxolone methyl might be beneficial in chronic kidney disease. Objective tumor responses and pharmacodynamic effects were observed, supporting continued development of other synthetic triterpenoids in cancer.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Carcinoma, Renal Cell; Colorectal Neoplasms; Cyclin D1; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Humans; Janus Kinases; Kidney Neoplasms; Lymphoma; Male; Maximum Tolerated Dose; Melanoma; Middle Aged; NAD(P)H Dehydrogenase (Quinone); Neoplasms; NF-E2-Related Factor 2; NF-kappa B; Oleanolic Acid; RNA, Messenger; STAT Transcription Factors; Thyroid Neoplasms; Young Adult

Sorafenib monotherapy in patients with metastatic melanoma was explored in this multi-institutional phase II study. In correlative studies the impact of sorafenib on cyclin D1 and Ki67 was assessed.. Thirty-six patients treatment-naïve advanced melanoma patients received sorafenib 400 mg p.o. twice daily continuously. Tumor BRAF(V600E) mutational status was determined by routine DNA sequencing and mutation-specific PCR (MSPCR). Immunohistochemistry (IHC) staining for cyclin D1 and Ki67 was performed on available pre- and post treatment tumor samples. The main toxicities included diarrhea, alopecia, rash, mucositis, nausea, hand-foot syndrome, and intestinal perforation. One patient had a RECIST partial response (PR) lasting 175 days. Three patients experienced stable disease (SD) with a mean duration of 37 weeks. Routine BRAF(V600E) sequencing yielded 27 wild-type (wt) and 6 mutant tumors, whereas MSPCR identified 12 wt and 18 mutant tumors. No correlation was seen between BRAF(V600E) mutational status and clinical activity. No significant changes in expression of cyclin D1 or Ki67 with sorafenib treatment were demonstrable in the 15 patients with pre-and post-treatment tumor samples.. Sorafenib monotherapy has limited activity in advanced melanoma patients. BRAF(V600E) mutational status of the tumor was not associated with clinical activity and no significant effect of sorafenib on cyclin D1 or Ki67 was seen, suggesting that sorafenib is not an effective BRAF inhibitor or that additional signaling pathways are equally important in the patients who benefit from sorafenib.. Clinical Trials.gov NCT00119249.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Benzenesulfonates; Cyclin D1; DNA Mutational Analysis; Female; Humans; Ki-67 Antigen; Male; Melanoma; Middle Aged; Mutation; Neoplasm Metastasis; Niacinamide; Phenylurea Compounds; Proto-Oncogene Proteins B-raf; Pyridines; Sequence Analysis, DNA; Signal Transduction; Sorafenib

The diagnostic role of preferentially expressed antigen in melanoma (PRAME) immunohistochemistry has not been thoroughly evaluated for acral melanocytic tumors. The objective of this study was to evaluate the utility of this modality for the diagnosis of acral melanocytic tumors compared with other potential markers. Melanocytic tumors were classified as either acral nevi, challenging melanocytic tumors (superficial atypical melanocytic proliferation of uncertain significance (SAMPUS)-favor benign (SAMPUS-FB), SAMPUS-favor malignant (SAMPUS-FM)) or acral melanomas. A total of 106 acral melanocytic tumors including acral nevi (n = 32), SAMPUS-FB (n = 17), SAMPUS-FM (n = 20), and acral melanomas (n = 37) were included. Diagnostic power, assessed using an area under the receiver operating characteristic curve (AUC) for distinguishing acral melanomas and acral nevi, was highest for PRAME (AUC = 0.997), followed by c-Myc (AUC = 0.755), cyclin D1 (AUC = 0.652), and c-Kit (AUC = 0.573). At a PRAME expression level ≥30% as a positive test for acral melanoma, the sensitivity and specificity of this marker for discriminating acral melanoma from acral nevus were 100% and 96.9%, respectively. PRAME immunohistochemistry also discriminated SAMPUS-FM from SAMPUS-FB with a sensitivity and specificity of 90.0% and 76.5%, respectively. In conclusion, PRAME immunohistochemistry can be used effectively to distinguish between various spectra of acral melanocytic neoplasms.

Topics: Antigens, Neoplasm; Cyclin D1; Diagnosis, Differential; Humans; Immunohistochemistry; Melanoma; Melanoma, Cutaneous Malignant; Nevus, Pigmented; Proto-Oncogene Proteins c-kit; Skin Neoplasms

Topics: Antigens, Neoplasm; Cyclin D1; Humans; Immunohistochemistry; Melanoma; Skin Neoplasms

Genomic analysis is an important tool in the diagnosis of histologically ambiguous melanocytic neoplasms. Melanomas, in contrast to nevi, are characterized by the presence of multiple copy number alterations. One such alteration is gain of the proto-oncogene CCND1 at 11q13. In melanoma, gain of CCND1 has been reported in approximately one-fifth of cases. Exact frequencies of CCND1 gain vary by melanoma subtype, ranging from 15.8% for lentigo maligna to 25.1% for acral melanoma. We present a cohort of 72 cutaneous melanomas from 2017-2022 in which only 6 (8.3%) showed evidence of CCND1 gain by chromosomal microarray. This CCND1 upregulation frequency falls well below those previously published and is significantly lower than estimated in the literature ( P < 0.05). In addition, all 6 melanomas with CCND1 gain had copy number alterations at other loci (most commonly CDKN2A loss, followed by RREB1 gain), and 5 were either thick or metastatic lesions. This suggests that CCND1 gene amplification may be a later event in melanomagenesis, long after a lesion would be borderline or equivocal by histology. Data from fluorescence in situ hybridization, performed on 16 additional cutaneous melanomas, further corroborate our findings. CCND1 gain may not be a common alteration in melanoma and likely occurs too late in melanomagenesis to be diagnostically useful. We present the largest chromosomal microarray analysis of CCND1 upregulation frequencies in cutaneous melanoma, conjecture 3 hypotheses to explain our novel observation, and discuss implications for the inclusion or exclusion of CCND1 probes in future melanoma gene panels.

Topics: Cyclin D1; Genomics; Humans; In Situ Hybridization, Fluorescence; Melanoma; Melanoma, Cutaneous Malignant; Skin Neoplasms

Malignant melanoma is one of the most aggressive and lethal skin cancer. At present, the treatment methods for melanoma have shortcomings. Glucose is the primary energy source of cancer cells. However, it is unclear whether glucose deprivation can be used to treat melanoma. Herein, we first found glucose played an essential role in melanoma proliferation. We then further found a drug combination of niclosamide and quinacrine could inhibit melanoma proliferation and glucose intake. Thirdly, we revealed the mechanism of anti-melanoma effect of the drug combination, which suppressed the Akt pathway. In addition, the first-rate limiting enzyme HK2 of glucose metabolism was inhibited. This work also disclosed that the decrease of HK2 inhibited cyclin D1 by reducing the activity of transcription factor E2F3, which further suppressed the proliferation of melanoma cells. The drug combination treatment also resulted in significant tumor regression in the absence of obvious morphologic changes in primary organ in vivo. In summary, our study demonstrated that the drug combination treatment created glucose deprivation to inactive the Akt/HK2/cyclin D1 axis, thereby inhibited the proliferation of melanoma cells, providing a potential anti-melanoma strategy.

Topics: Cell Line, Tumor; Cell Proliferation; Cyclin D1; Glucose; Humans; Melanoma; Niclosamide; Proto-Oncogene Proteins c-akt; Quinacrine; Signal Transduction

Nucleotide excision repair (NER) eliminates highly genotoxic solar UV-induced DNA photoproducts that otherwise stimulate malignant melanoma development. Here, a genome-wide loss-of-function screen, coupling CRISPR/Cas9 technology with a flow cytometry-based DNA repair assay, was used to identify novel genes required for efficient NER in primary human fibroblasts. Interestingly, the screen revealed multiple genes encoding proteins, with no previously known involvement in UV damage repair, that significantly modulate NER uniquely during S phase of the cell cycle. Among these, we further characterized Dyrk1A, a dual specificity kinase that phosphorylates the proto-oncoprotein cyclin D1 on threonine 286 (T286), thereby stimulating its timely cytoplasmic relocalization and proteasomal degradation, which is required for proper regulation of the G1-S phase transition and control of cellular proliferation. We demonstrate that in UV-irradiated HeLa cells, depletion of Dyrk1A leading to overexpression of cyclin D1 causes inhibition of NER uniquely during S phase and reduced cell survival. Consistently, expression/nuclear accumulation of nonphosphorylatable cyclin D1 (T286A) in melanoma cells strongly interferes with S phase NER and enhances cytotoxicity post-UV. Moreover, the negative impact of cyclin D1 (T286A) overexpression on repair is independent of cyclin-dependent kinase activity but requires cyclin D1-dependent upregulation of p21 expression. Our data indicate that inhibition of NER during S phase might represent a previously unappreciated noncanonical mechanism by which oncogenic cyclin D1 fosters melanomagenesis.

Topics: Carcinogenesis; Cells, Cultured; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; DNA Damage; DNA Repair; Dyrk Kinases; Fibroblasts; G1 Phase; HeLa Cells; Humans; Melanoma; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; S Phase; Ultraviolet Rays

黑色素瘤恶性程度高，发病机制复杂。细胞周期蛋白D1（cyclin D1）和细胞周期蛋白依赖性激酶4（cyclin-dependent kinases 4，CDK4）是细胞周期进程中的重要分子，可形成复合物发挥功能促进细胞从G

Topics: Cyclin D1; Cyclin-Dependent Kinase 4; Humans; Melanoma; Melanoma, Cutaneous Malignant; Skin Neoplasms

Melanoma is a notoriously radioresistant type of skin cancer. Elucidation of the specific mechanisms underlying radioresistance is necessary to improve the clinical efficacy of radiation therapy. To identify the key factors contributing to radioresistance, five melanoma cell lines were selected for study and genes that were upregulated in relatively radioresistant melanomas compared with radiosensitive melanoma cells determined via RNA sequencing technology. In particular, we focused on cyclin D1 (CCND1), a well known cell cycle regulatory molecule. In radiosensitive melanoma, overexpression of cyclin D1 reduced apoptosis. In radioresistant melanoma cell lines, suppression of cyclin D1 with a specific inhibitor or siRNA increased apoptosis and decreased cell proliferation in 2D and 3D spheroid cultures. In addition, we observed increased expression of γ-H2AX, a molecular marker of DNA damage, even at a later time after γ-irradiation, under conditions of inhibition of cyclin D1, with a response pattern similar to that of radiosensitive SK-Mel5. In the same context, expression and nuclear foci formation of RAD51, a key enzyme for homologous recombination (HR), were reduced upon inhibition of cyclin D1. Downregulation of RAD51 also reduced cell survival to irradiation. Overall, suppression of cyclin D1 expression or function led to reduced radiation-induced DNA damage response (DDR) and triggered cell death. Our collective findings indicate that the presence of increased cyclin D1 potentially contributes to the development of radioresistance through effects on RAD51 in melanoma and could therefore serve as a therapeutic target for improving the efficacy of radiation therapy.

Topics: Apoptosis; Cell Line, Tumor; Cyclin D1; DNA Repair; Humans; Melanoma; Rad51 Recombinase; Radiation Tolerance

Numerous cells with very large and irregular nuclei ("monster" cells) have not hitherto been reported in desmoplastic melanoma (DM). Their prognostic significance in melanomas is a matter of debate, although some authors have associated them with more aggressive tumor behavior. We report a mixed DM on the scalp of an 88-year-old woman imitating an atypical fibroxanthoma. Tumor cells stained positive for SOX10, S100, and cyclin D1; BRAF mutation status was negative, and fluorescence in situ hybridization analysis showed copy number gains in 11q13 (cyclin D1) and 6p25 (RREB1), and loss in 6q23 (MYB). Cyclin D1 amplification is associated with poor prognosis in melanoma.

Topics: Aged, 80 and over; Cyclin D1; Female; Humans; In Situ Hybridization, Fluorescence; Melanoma; Scalp; Skin Neoplasms

Malignant melanoma (MM) is known to avoid the host's immune response. Studies on in vitro melanoma cell lines link the microphthalmia-associated transcription factor (MITF) with the regulation of the PD-L1 expression. It seems that MITF affects the activation of the gene responsible for PD-L1 protein expression. Several proteins, including Bcl-2 and Cyclin D1, play major roles in malignant melanoma cell cycle regulation and survival. Our study aims to assess the relationship between MITF, Bcl-2, and cyclin D1 protein expression and the expression of the PD-L1 molecule. Additionally, we examined the association of BRAF mutation, MITF, and CCND1 gene amplification with PD-L1 protein expression. We performed immunohistochemical staining on fifty-two tumour samples from patients diagnosed with nodular melanoma (NM). BRAF V600 mutation, MITF, and CCND1 gene amplification analyses were analyzed by the Sanger sequencing and QRT-PCR methods, respectively. Statistical analyses confirmed the significant inverse correlation between cyclin D1 and PD-L1 expression (p = 0.001) and correlation between PD-L1 and MITF protein expression (p = 0.023). We found a statistically significant inverse correlation between the present MITF gene amplification and PD-L1 (p = 0.007) and MITF protein expression (p = 3.4 ×10-6), respectively. Our study, performed on clinical NM materials, supports the in vitro study findings providing a rationale for the potential MITF-dependent regulation of PD-L1 expression in malignant melanoma.

Topics: B7-H1 Antigen; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Microphthalmia-Associated Transcription Factor; Proto-Oncogene Proteins c-bcl-2; Retrospective Studies; Skin Neoplasms

Distinguishing benign lesion from early malignancy in melanocytic lesions of the nail unit still remains a diagnostic challenge, both clinically and histopathologically. While several immunohistochemistry (IHC) stainings have been suggested to help discriminate benign subungual melanocytic proliferation (SMP) and subungual melanoma in situ (MIS), the diagnostic utility of IHC staining for cyclin D1 and PRAME has not been thoroughly investigated in melanocytic lesions of nail unit.. This retrospective study included cases of benign SMP and subungual MIS confirmed by biopsy at Asan Medical Center from January 2016 to December 2020. Cases of melanocytic activation without proliferation and melanoma where dermal invasion was identified were excluded. Cyclin D1 and PRAME expression was assessed by counting proportion of melanocytes with nuclear positivity under 200x magnification.. A total of 14 patients with benign SMP and 13 patients with subungual MIS were included in this study. 11 patients with benign SMP (71.4%) and 5 patients with subungual MIS (38.5%) showed > 60% nuclear immunostaining for cyclin D1, respectively. While 13 patients with benign SMP (92.9%) showed totally negative staining for PRAME, 10 patients with subungual MIS (76.9%) exhibited > 50% nuclear immunostaining for PRAME. Using the cutoff of 10%, PRAME exhibited good overall discrimination between benign SMP and subungual MIS (AUC = 0.849, 95% CI = 0.659-0.957).. This study suggests that PRAME IHC staining as a reliable discriminator in distinguishing subungual MIS from benign SMP.

Topics: Antigens, Neoplasm; Cell Proliferation; Cyclin D1; Humans; Melanoma; Melanoma, Cutaneous Malignant; Nail Diseases; Retrospective Studies; Skin Neoplasms

Uveal melanoma (UM) is the most common intraocular malignancy in adults with a poor prognosis and a high recurrence rate. Currently there is no effective treatment for UM. Multi-kinase inhibitors targeting dysregulated pro-tumorigenic signalling pathways have revolutionised anti-cancer treatment but, as yet, their efficacy in UM has not been established. Here, we identified the multi-kinase inhibitor afatinib as a highly effective agent that exerts anti-UM effects in in vitro, ex vivo and in vivo models.. We assessed the anti-cancer effects of afatinib using cell viability, cell death and cell cycle assays in in vitro and ex vivo UM models. The signaling pathways involved in the anti-UM effects of afatinib were evaluated by Western blotting. The in vivo activity of afatinib was evaluated in UM xenograft models using tumour mass measurement, PET scan, immunohistochemical staining and TUNEL assays.. We found that afatinib reduced cell viability and activated apoptosis and cell cycle arrest in multiple established UM cell lines and in patient tumour-derived primary cell lines. Afatinib impaired cell migration and enhanced reproductive death in these UM cell models. Afatinib-induced cell death was accompanied by activation of STAT1 expression and downregulation of Bcl-xL and cyclin D1 expression, which control cell survival and cell cycle progression. Afatinib attenuated HER2-AKT/ERK/PI3K signalling in UM cell lines. Consistent with these observations, we found that afatinib suppressed tumour growth in UM xenografted mice.. Our data indicate that afatinib activates UM cell death and targets the HER2-mediated cascade, which modulates STAT1-Bcl-xL/cyclin D1 signalling. Thus, targeting HER2 with agents like afatinib may be a novel therapeutic strategy to treat UM and to prevent metastasis.

Topics: Afatinib; Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Humans; Melanoma; Mice; Protein Kinase Inhibitors; Uveal Neoplasms; Xenograft Model Antitumor Assays

Distinction of superficial spreading melanoma (SSM) from compound nevi (CN) sometimes poses difficult diagnostic challenges. Herein, we studied cyclin D1 protein expression by immunohistochemistry in SSM and CN and evaluated the results by digital image analysis.. A total of 13 CN and 12 SSM cases were retrospectively reviewed and cyclin D1 immunohistochemistry was performed. Immunohistochemical stained slides were evaluated by digital imaging analysis that included quantification and staining intensity of the cyclin D1 expressing dermal cells.. Cyclin D1 expression was observed in all CN and SSM. CN-positive staining was present in 30% to 93% of the dermal nevocytes, more positive in the upper (mean 85%), than lower half (mean 57%). SSM-positive staining was present in 44% to 96% of the dermal lesion, more positive in the upper (mean 88%) than lower half (mean 49%). When analyzed based on 3+ strong staining intensity, similar regional differences in cyclin D1 expression were observed.. Digital image analysis of Cyclin D1 expression showed no differences between CN and SSM. Quantity and regional distribution of cyclin D1 positivity were found to be similar in both lesions. Our findings argue against the routine use of cyclin D1 immunohistochemistry as a diagnostic tool for differentiating CN from SSM.

Topics: Cyclin D1; Humans; Melanoma; Melanoma, Cutaneous Malignant; Nevus; Retrospective Studies; Skin Neoplasms

Topics: Cyclin D1; Humans; Melanoma; Republic of Korea; Skin Neoplasms

Ocular melanoma is a disorder that is rarely found but is deadly. Four tissues in the eye that can be attacked by melanoma include the uveal tract, conjunctiva, eyelids, and orbit. Uveal melanoma is the most common case, while melanoma conjunctiva is very rare.. This study aimed to investigate the effect of giving genistein on cyclin D1 expression in malignant melanoma.. When confluent, CRL1872 malignant melanoma cells will be divided into treatment groups, the group giving genistein dose 25 μM, the group giving genistein a dose of 50 μM, and the group giving genistein a dose of 100 μM. Cyclin D1 analysis was measured by immunofluorescence using confocal laser scan microscopy.. There was a significant increase in the expression of cyclin D1, in the group given genistein 25 μM and 50 μM (p < 0.05). For the administration of the genistein dose of 100 μM, cyclin D1 expression decreased significantly compared to the control group (p < 0.05).. It was concluded that genistein had a biphasic effect on cyclin D1 expression in malignant melanoma cells. Thus, genistein at the right dose can be a treatment of malignant melanoma.

Topics: Cyclin D1; Genistein; Humans; Melanoma; Skin Neoplasms; Uveal Neoplasms

Rivoceranib, a novel tyrosine kinase inhibitor, exhibits anti-tumour effects by selectively blocking vascular endothelial growth factor receptor-2 (VEGFR2) in cancer cells. Recently, the therapeutic effects of rivoceranib on solid tumours have been elucidated in human patients. However, the anti-tumour effects of rivoceranib against canine cancer remain unclear. Here, we investigated the anti-tumour effects of rivoceranib using in vitro and in vivo mouse xenograft models.. We performed cell proliferation, cell cycle, and migration assays to determine the effects of rivoceranib on canine solid tumour cell lines in vitro. Furthermore, apoptosis and angiogenesis in tumour tissues were examined using a TUNEL assay and immunohistochemistry methods with an anti-cluster of differentiation-31 antibody, respectively. Additionally, the expression levels of cyclin-D1 and VEGFR2 activity were determined using western blot analysis.. Rivoceranib treatment showed anti-proliferative effects and mediated cell cycle arrest in the canine melanoma cell line (LMeC) and the mammary gland tumour (MGT) cell line (CHMp). In animal experiments, rivoceranib decreased the average volume of LMeC cells compared to that following control treatment, and similar results were observed in CHMp cells. Histologically, rivoceranib induced apoptosis and exerted an anti-angiogenic effect in tumour tissues. It also downregulated the expression of cyclin-D1 and inhibited VEGFR2 activity.. Our results show that rivoceranib inhibits proliferation and migration of tumour cells. These findings support the potential application of rivoceranib as a novel chemotherapeutic strategy for canine melanoma and MGTs.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Movement; Cell Proliferation; Cyclin D1; Dog Diseases; Dogs; Female; Gene Expression Regulation, Neoplastic; Mammary Neoplasms, Animal; Melanoma; Mice; Neovascularization, Pathologic; Pyridines; Vascular Endothelial Growth Factor Receptor-2; Xenograft Model Antitumor Assays

Histologically undetermined early acral melanoma in situ (HUAMIS) is rare but a diagnostic challenge, being clinically and dermoscopically MIS (late onset, a large size (>7 mm), parallel ridges pattern) but microscopically without recognizable cytological atypia. Cyclin D1 (CCND1) gene amplification is a genetic aberration occurring in the early radial growth phase of AMs and could thus help determine malignancy for this disease. We determine the value of CCND1 amplification by FISH as a diagnostic marker for HUAMIS. CCND1 amplification was examined in paraffin-embedded skin biopsies and excisions using a dual-probes fluorescence in situ hybridization (FISH) (11q13 and CEP11). One FISH-negative case 6 was additionally examined by Mypath Melanoma (qRT-PCR). Seventeen cases (12 dysplastic nevi, 3 AMIS, and 2 invasive AM) were served as negative controls for FISH. All six patients (4 females and 2 males) were Hispanic. Pigment lesions were on the left plantar foot (4), right third finger palm (1), and right thumb subungual (1). All cases showed similar clinical and dermoscopical characteristics, including late onset (50 to 74 years old), long duration (from 2 to 15 years), large-sized pigments (from 16 to 40 mm), and a parallel ridge pattern. Junctional melanocytes with no or minimal atypia from five cases showed CCND1 amplifications. Four of 5 cases were received 1st or/and 2nd wide excisions, which demonstrated foci of histologically overt MIS. One FISH-negative case 6 demonstrated "likely malignancy" scores (>2) by Mypath Melanoma (qRT-PCR). None of negative controls showed the amplification. We propose here a simple CCND1 FISH is a practical diagnostic test to determine the malignancy of the very early progression phase of AM preceding histopathologically defined MIS. Cases presented here could be an indolent subtype of AMIS characterized by carrying a long latent radial growth phase without vertical growth, mimicking lentigo maligna.

Topics: Aged; Biopsy; Cyclin D1; Dermoscopy; Female; Follow-Up Studies; Gene Amplification; Hispanic or Latino; Humans; In Situ Hybridization, Fluorescence; Male; Melanocytes; Melanoma; Melanoma, Cutaneous Malignant; Middle Aged; Skin; Skin Neoplasms; Treatment Outcome

Topics: Animals; Biomarkers, Tumor; Cell Cycle; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Shape; Cortactin; Cyclin D1; Extracellular Matrix; Focal Adhesions; Humans; Hyaluronic Acid; Lumican; Lung Neoplasms; Melanoma; Mice, Inbred C57BL; Neoplasm Metastasis; Phosphorylation; Podosomes; Signal Transduction; Skin Neoplasms; Snail Family Transcription Factors; Vinculin

CCND1 copy number increase is characteristic of acral melanoma and is useful in distinguishing benign and malignant acral melanocytic lesions. Increase of the gene copy number may result in protein overexpression. This raises the possibility that detection of high expression of cyclin D1 by immunohistochemistry (IHC) may be used as a surrogate for direct evaluation of increase in the CCND1 gene copy number.. We examined increases in CCND1 copy number with fluorescence in situ hybridization (FISH), and examined cyclin D1 protein expression with IHC in 61 acral melanomas.. Using FISH, 29 acral melanomas (29/61, 47.5%) showed increase in the CCND1 copy number, including 8 (8/61, 13.1%) which showed low-level increase in the CCND1 copy number and 21 (21/61, 34.4%) with high-level increase in the CCND1 copy number. By analysis of IHC, the median IHC score was 15% (range: 1-80%) in acral melanomas with no CCND1 copy number alteration. In acral melanomas with low-level CCND1 copy number increase, the median IHC score was 25% (range: 3-90%). In acral melanomas with high-level CCND1 copy number increase, the median IHC score was 60% (range: 1-95%). Comparing FISH and IHC, cyclin D1 protein expression level has no corelation with the CCND1 copy number in acral melanomas which have no CCND1 copy number alteration and low-level CCND1 copy number increase (P = 0.108). Cyclin D1 protein expression level correlated positively with CCND1 copy number in acral melanomas with high-level CCND1 copy number increase (P = 0.038). The sensitivity, specificity and positive predictive value of using cyclin D1 IHC to predict CCND1 FISH result was 72.4, 62.5 and 63.6%. Increase in CCND1 copy number was associated with Breslow thickness in invasive acral melanoma.. High-level increase in the CCND1 copy number can induce high cyclin D1 protein expression in acral melanomas. However low-level increase and normal CCND1 copy number have no obvious correlation with protein expression. Cyclin D1 IHC cannot serve as a surrogate for CCND1 FISH in acral melanomas.

Topics: Adult; Aged; Aged, 80 and over; China; Cohort Studies; Cyclin D1; DNA Copy Number Variations; Female; Gene Amplification; Gene Dosage; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Male; Melanoma; Melanoma, Cutaneous Malignant; Middle Aged; Skin Neoplasms

Early differential diagnosis between malignant and benign tumors and their underlying intrinsic differences are the most critical issues for life-threatening cancers. To study whether human acral melanomas, deadly cancers that occur on non-hair-bearing skin, have distinct origins that underlie their invasive capability, we develop fate-tracing technologies of melanocyte stem cells in sweat glands (glandular McSCs) and in melanoma models in mice and compare the cellular dynamics with human melanoma. Herein, we report that glandular McSCs self-renew to expand their migratory progeny in response to genotoxic stress and trauma to generate invasive melanomas in mice that mimic human acral melanomas. The analysis of melanocytic lesions in human volar skin reveals that genetically unstable McSCs expand in sweat glands and in the surrounding epidermis in melanomas but not in nevi. The detection of such cell spreading dynamics provides an innovative method for an early differential diagnosis of acral melanomas from nevi.

Topics: Animals; Cell Movement; Cell Proliferation; Cyclin D1; Disease Models, Animal; Epidermis; Gene Amplification; Genomic Instability; Melanocytes; Melanoma; Mice, Inbred C57BL; Nevus; Risk Factors; Skin; Skin Pigmentation; Stem Cells; Sweat Glands; Ultraviolet Rays

Canine oral melanoma (COM) is the most frequent tumour with oral localization in dogs. Copy number gains and amplifications of CCND1, a gene coding for Cyclin D1, are the most frequent chromosomal aberrations described in human non-UV induced melanomas. Twenty-eight cases of COM were retrieved from paraffin-blocks archives. A total of 4 μm thick sections were immunostained with an antibody against human Cyclin D1 and Ki-67. Cyclin D1 and Ki-67 expressions were scored through two counting methods. DNA was extracted from 20 μm thick sections of formalin-fixed paraffin-embedded blocks. Pathological and surrounding healthy tissue was extracted independently. Cyclin D1 immunolabelling was detected in 69% (18/26) while Ki-67 was present in 88.5% (23/26) of cases. Statistical analysis revealed correlation between two counting methods for Cyclin D1 (r = 0.54; P = .004) and Ki-67 (r = 0.56; P = .003). The correlation found between Ki-67 and Cyclin D1 indexes in 16/26 cases labelled by both antibodies (r = 0.7947; P = .0002) suggests a possible use of Cyclin D1 index as prognostic marker. Polymerase chain reaction analysis on CCND1 coding sequence revealed the presence of nine somatic mutations in seven samples producing synonymous, missense and stop codons. Since none of the single-nucleotide polymorphisms was found to be recurrent, it is suggested that overexpression of Cyclin D1 may be the consequence of alterations of CCND1 upstream regions or other genetic aberrations not detectable with the methodology used in this study. Future studies are needed to verify the potential use of Cyclin D1 index as prognostic indicator and to highlight the molecular events responsible for Cyclin D1 overexpression in COMs.

Topics: Animals; Cyclin D1; Dog Diseases; Dogs; Gene Expression Regulation, Neoplastic; Immunohistochemistry; Ki-67 Antigen; Melanoma; Mouth Neoplasms; Mutation

Reliable biomarkers are necessary for assessment of treatment responses. Acral and mucosal melanomas are commonly associated with copy number (CN) alterations rather than specific point mutations, with CN alterations inKIT, CDK4, and CCND1 occurring frequently. Cell-free DNA is released to peripheral blood by both normal and tumor cells, and therefore contains the same genetic alterations present in the source tumor.. To investigate the usefulness of detecting CN alterations in oncogenes in cell-free DNA for monitoring treatment response in acral and mucosal melanomas.. We isolated cell-free DNA from peripheral blood and assessed the CN alterations in the cell-free DNA. Using droplet digital PCR, we examined CN alterations ofKIT, CDK4, and CCND1 in tumors from 37 melanoma patients (acral, n = 27; mucosal, n = 10) and peripheral blood from 24 melanoma patients (acral, n = 17; mucosal, n = 7).. CN gain was detected in at least one of the genes examined in 62.9 % (17/27) of acral melanomas and 70 % (7/10) of mucosal melanomas. CN gains were also detected in the plasma of some patients. Furthermore, plasma CN ratio was correlated with clinical condition. This correlation was especially clear in patients with high CN ratios in tumors and high tumor burdens.. Plasma CN ratios may be useful for evaluating treatment responses in patients with acral and mucosal melanoma.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Cell-Free Nucleic Acids; Cyclin D1; Cyclin-Dependent Kinase 4; Disease Progression; DNA Copy Number Variations; Female; Humans; Male; Melanoma; Middle Aged; Mucous Membrane; Proto-Oncogene Proteins c-kit; Response Evaluation Criteria in Solid Tumors; Skin; Skin Neoplasms; Tomography, X-Ray Computed

Despite their low individual metastatic potential, thin melanomas (≤1 mm Breslow thickness) contribute significantly to melanoma mortality overall. Therefore, identification of prognostic biomarkers is particularly important in this subgroup of melanoma. Prompted by preclinical results, we investigated cyclin D1 protein and Ki-67 expression in in-situ, metastatic and non-metastatic thin melanomas.. Immunohistochemistry was performed on 112 melanoma specimens, comprising 22 in situ, 48 non-metastatic and 42 metastatic thin melanomas. Overall, epidermal and dermal cyclin D1 and Ki-67 expression were semiquantitatively evaluated by three independent investigators and compared between groups. Epidermal Ki-67 expression did not differ statistically in in-situ and invasive melanoma (P = 0.7). Epidermal cyclin D1 expression was significantly higher in thin invasive than in in-situ melanoma (P = 0.003). No difference was found in cyclin D1 expression between metastatic and non-metastatic invasive tumours. Metastatic and non-metastatic thin melanomas did not show significant differences in epidermal expression of Ki-67 and cyclin D1 (P = 0.148 and P = 0.611, respectively). In contrast, strong dermal expression of Ki-67 was more frequent in metastatic than non-metastatic samples (28.6 versus 8.3%, respectively, P = 0.001). The prognostic value of dermal Ki-67 expression was confirmed by multivariate analysis (P = 0.047).. We found an increased expression of cyclin D1 in invasive thin melanomas compared to in-situ melanomas, which supports a potential role of this protein in early invasion in melanoma, as suggested by preclinical findings. Moreover, our results confirm that high dermal Ki-67 expression is associated with an increased risk of development of metastasis in thin melanoma and could possibly serve as a prognostic biomarker in clinical practice, especially if combined with additional methods.

Topics: Adult; Aged; Biomarkers, Tumor; Cyclin D1; Female; Humans; Ki-67 Antigen; Male; Melanoma; Melanoma, Cutaneous Malignant; Middle Aged; Neoplasm Invasiveness; Prognosis; Skin Neoplasms

Topics: Aged; Bone Marrow; Cyclin D1; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoid Enhancer-Binding Factor 1; Male; Melanoma; Neoplasms, Second Primary

Tryptophan metabolites: kynurenine (KYN), kynurenic acid (KYNA) and 6-formylindolo[3,2-b]carbazole (FICZ) are considered aryl hydrocarbon receptor (AhR) ligands. AhR is mainly expressed in barrier tissues, including skin, and is involved in various physiological and pathological processes in skin. We studied the effect of KYN, KYNA and FICZ on melanocyte and melanoma A375 and RPMI7951 cell toxicity, proliferation and cell death. KYN and FICZ inhibited DNA synthesis in both melanoma cell lines, but RPMI7951 cells were more resistant to pharmacological treatment. Tested compounds were toxic to melanoma cells but not to normal human adult melanocytes. Changes in the protein level of cyclin D1, CDK4 and retinoblastoma tumor suppressor protein (Rb) phosphorylation revealed different mechanisms of action of individual AhR ligands. Importantly, all tryptophan metabolites induced necrosis, but only KYNA and FICZ promoted apoptosis in melanoma A375 cells. This effect was not observed in RPMI7951 cells. KYN, KYNA and FICZ in higher concentrations inhibited the protein level of AhR but did not affect the gene expression. To conclude, despite belonging to the group of AhR ligands, KYN, KYNA and FICZ exerted different effects on proliferation, toxicity and induction of cell death in melanoma cells in vitro.

Topics: Basic Helix-Loop-Helix Transcription Factors; Carbazoles; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Cyclin-Dependent Kinase 4; Gene Expression Regulation, Neoplastic; Humans; Kynurenic Acid; Kynurenine; Melanocytes; Melanoma; Phosphorylation; Receptors, Aryl Hydrocarbon; Retinoblastoma Protein

The aim of this study was to evaluate the inhibitory effects of resveratrol (RSV) in A375 and A431 melanoma cells, by assessing cell viability (CCK-8 assay), apoptosis through flow cytometer and cell morphology, cell cycle assay by flow cytometer and western blot (Cyclin D1, Rac1 and PCDH9). Our results demonstrated that RSV strongly inhibited A375 cells proliferation, by decreasing cell viability, promoting apoptosis and arresting cell cycle. Besides, to clarify the main factor - duration or concentration of RSV, the double variance analysis of independent factors was operated after Bartlett's test for homogeneity by R project. According to the outcomes obtained from statistical analyses, Cyclin D1 and PCDH9 were strongly affected by RSV duration while Rac1 was not influenced. In conclusion, RSV can inhibit A375 proliferation and trigger apoptosis by influencing cell cycle proteins; for these effects, treatment duration of RSV played more important role than concentration.

Topics: Apoptosis; Cell Cycle; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Humans; Melanoma; Resveratrol

Rottlerin is a cytostatic and cytotoxic drug in a variety of cancer cells. Our previous experience demonstrated that depending upon the genetic/biochemical background of cancer cells, rottlerin is able to induce both apoptotic and autophagic cell death, or dramatically disturb protein homeostasis leading to lethal cellular atrophy. In the current study, we investigated the cytotoxic effects and mechanisms of rottlerin against human amelanotic A375 melanoma cells. In this cell line, rottlerin exhibits its main and newest cytotoxic properties, that is, growth arrest, apoptosis induction, and translation shutoff. In fact, the drug, time-, and dose-dependently, markedly inhibited cell proliferation through cyclin D1 downregulation and induced apoptotic cell death as early as after 18 h treatment. Mechanistically, rottlerin triggered apoptosis by both intrinsic and extrinsic pathways. Both pathways are likely activated by the downregulation of the antiapoptotic B-cell lymphoma 2 (Bcl-2) protein, which simultaneously affects mitochondrial and endoplasmic reticulum (ER) membranes stability. Concomitantly to extrinsic apoptosis induction, the rottlerin-activated ER stress/eukaryotic initiation factor 2 (eIF2) α axis blocked the translational apparatus. The altered proteostasis precluded the complete cells' rescue from death in the presence of apoptosis inhibitors.

Topics: Acetophenones; Antineoplastic Agents; Apoptosis; Benzopyrans; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Mitochondria; Reactive Oxygen Species; Signal Transduction

Aberrant extra-vascular expression of VE-cadherin (VEC) has been observed in metastasis associated with vasculogenic mimicry (VM); however, the ultimate reason why non-endothelial VEC favors the acquisition of this phenotype is not established. In this study, we show that human malignant melanoma cells have a constitutively high expression of phoshoVEC (pVEC) at Y658; pVEC is a target of focal adhesion kinase (FAK) and forms a complex with p120-catenin and the transcriptional repressor kaiso in the nucleus. FAK inhibition enabled kaiso to suppress the expression of its target genes and enhanced kaiso recruitment to KBS-containing promoters. Finally we have found that ablation of kaiso-repressed genes WNT11 and CCDN1 abolished VM. Thus, identification of pVEC as a component of the kaiso transcriptional complex establishes a molecular paradigm that links FAK-dependent phosphorylation of VEC as a major mechanism by which ectopical VEC expression exerts its function in VM.

Topics: Antigens, CD; Cadherins; Catenins; Cell Line, Tumor; Cyclin D1; Delta Catenin; Focal Adhesion Kinase 1; Gene Expression; Gene Knockout Techniques; HEK293 Cells; Human Umbilical Vein Endothelial Cells; Humans; Melanoma; Neovascularization, Pathologic; Phosphorylation; Skin Neoplasms; Transcription Factors; Transduction, Genetic; Wnt Proteins

Cutaneous melanoma (CM) is one of the most prevalent skin cancers, which lacks both a prognostic marker and a specific and lasting treatment, due to the complexity of the disease and heterogeneity of patients. Reflectance confocal microscopy (RCM) in vivo analysis is a versatile approach offering immediate morphological information, enabling the identification of four primary cutaneous RCM CM types. Whether RCM CM types are associated with a specific protein and molecular genetic profiles at the tissue level remains unclear. The current pilot study was designed to identify potential correlations between RCM CM types and specific biological characteristics, combining immunohistochemistry (IHC) and molecular analyses. Eighty primary CMs evaluated at patient bedside with RCM (type 1 [19, 24%], type 2 [12, 15%], type 3 [7, 9%] and type 4 [42, 52%]) were retrospectively evaluated by IHC stains (CD271, CD20, CD31, cyclin D1), fluorescence in situ hybridization FISH for MYC gain and CDKN2A loss and molecular analysis for somatic mutations (BRAF, NRAS and KIT). RCM CM types correlated with markers of stemness property, density of intra-tumoral lymphocytic B infiltrate and cyclin D1 expression, while no significant association was found with blood vessel density nor molecular findings. RCM CM types show a different marker profile expression, suggestive of a progression and an increase in aggressiveness, according to RCM morphologies.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Cyclin D1; Dermatology; Female; GTP Phosphohydrolases; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Male; Melanoma; Melanoma, Cutaneous Malignant; Membrane Proteins; Microscopy, Confocal; Middle Aged; Mutation; Neoplasm Invasiveness; Pilot Projects; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-kit; Retrospective Studies; Skin Neoplasms

Melanoma is one of the most malignant skin tumours with constantly increasing incidence worldwide. Previous studies have demonstrated that microRNA-374 (miR-374) is a novel biomarker for cancer therapy. Therefore, this study explores whether miR-374 targeting tyrosinase (TYR) affects melanoma and its underlying mechanism. We constructed subcutaneous melanoma models to carry out the following experiments. The cells were transfected with a series of miR-374 mimics, miR-374 inhibitors or siRNA against TYR. Dual luciferase reporter gene assay was used for the verification of the targeting relationship between miR-374 and TYR. Reverse transcription quantitative polymerase chain reaction and western blot analysis were conducted to determine the expression of miR-374, TYR, β-catenin, B-cell leukaemia 2 (Bcl-2), Bcl-2 associated X protein (Bax), Low-density lipoprotein receptor-related protein 6 (LRP6), Leucine-rich repeat G protein-coupled receptor 5 (LGR5) and CyclinD1. Cell proliferation, migration, invasion, cell cycle distribution and apoptosis were evaluated using cell counting kit-8 assay, scratch test, transwell assay and flow cytometry respectively. TYR was proved as a putative target of miR-374 as the evidenced by the result. It was observed that up-regulated miR-374 or down-regulated TYR increased expression of Bax and decreased expressions of TYR, β-catenin, LRP6, Bcl-2, CyclinD1 and LGR5, along with diminished cell proliferation, migration, invasion and enhanced apoptosis. Meanwhile, cells with miR-374 inhibitors showed an opposite trend. These findings indicated that up-regulated miR-374 could inhibit the expression of TYR to suppress cell proliferation, migration, invasion and promote cell apoptosis in melanoma cells by inhibiting the Wnt signalling pathway.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; beta Catenin; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; Low Density Lipoprotein Receptor-Related Protein-6; Male; Melanoma; Mice; Mice, Nude; MicroRNAs; Monophenol Monooxygenase; Proto-Oncogene Proteins c-bcl-2; Receptors, G-Protein-Coupled; RNA, Small Interfering; S Phase Cell Cycle Checkpoints; Skin Neoplasms; Transplantation, Heterologous; Wnt Signaling Pathway

Melanoma is responsible for the majority of deaths caused by skin cancer. Antitumor activity of microRNA-329 (miR-329) has been seen in several human cancers. In this study, we identify whether miR-329 serves as a candidate regulator in melanoma. Melanoma-related differentially expressed genes were screened with its potential molecular mechanism predicted. Melanoma tissues and pigmented nevus tissues were collected, where the levels of miR-329 and high-mobility group box 2 (HMGB2) were determined. To characterize the regulatory role of miR-329 on HMGB2 and the β-catenin pathway in melanoma cell activities, miR-329 mimics, miR-329 inhibitors, and siRNA-HMGB2 were transfected into melanoma cells. Cell viability, migration, invasion, cell cycle, and apoptosis were assessed. miR-329 was predicted to influence melanoma by targeting HMGB2 via the β-catenin pathway. High level of HMGB2 and low miR-329 expression were observed in melanoma tissues. HMGB2 was targeted and negatively regulated by miR-329. In melanoma cells transfected with miR-329 mimics or siRNA-HMGB2, cell proliferation, migration, and invasion were impeded, yet cell cycle arrest and apoptosis were promoted, corresponding to decreased levels of β-catenin, cyclin D1, and vimentin and increased levels of GSK3β and E-cadherin. Collectively, our results show that miR-329 can suppress the melanoma progression by downregulating HMGB2 via the β-catenin pathway.

Topics: Antigens, CD; Apoptosis; beta Catenin; Cadherins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3 beta; HMGB2 Protein; Humans; Male; Melanoma; MicroRNAs; Middle Aged; Neoplasm Invasiveness; Signal Transduction; Skin Neoplasms; Vimentin

Very recently, we have produced new resveratrol derived compounds, especially labruscol by culture of elicited grapevine cell suspensions (Vitis labrusca L.). This new polyphenolic oligomer could function as cancer chemopreventive agent in similar manner of resveratrol. In this study, we have determined the efficiency of resveratrol, ε-viniferin and the labruscol on human melanoma cell with or without metastatic phenotype. Our results show a differential activity of the three compounds where the resveratrol remains the polyphenolic compound with the most effective action compared to other oligomers. These three compounds block cell cycle of melanoma cells in S phase by modulating key regulators of cell cycle i.e. cyclins A, E, D1 and their cyclin-dependent kinases 1 and 2. These effects are associated with an increase of cell death while these compounds have no cytotoxic action on normal human dermal fibroblasts.

Topics: Anticarcinogenic Agents; Benzofurans; CDC2 Protein Kinase; Cell Line, Tumor; Cell Proliferation; Cyclin A; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 2; Fibroblasts; Humans; Melanoma; Resveratrol; S Phase; Skin; Stilbenes; Vitis

Accumulating evidence has indicated that MEG3 can serve as a tumor suppressive lncRNA in various tumors. It is aberrantly expressed in multiple cancers. However, the biological roles of MEG3 in melanoma are poorly understood. Therefore, in our study, we concentrated on the biological mechanism of MEG3 in melanoma progression. First, we observed that MEG3 was obviously decreased in melanoma cells including A375, SK-MEL-1, B16, and A2058 cells compared to human epidermal melanocytes HEMa-LP. MEG3 was restored by transfecting LV-MEG3 in to A375 and A2058 cells. Subsequently, we found that overexpression of MEG3 was able to inhibit cell proliferation and colony formation capacity. Meanwhile, melanoma cell apoptosis was induced by up-regulation of MEG3. Overexpression of MEG3 greatly repressed melanoma cell migration and invasion ability. In addition, Wnt signaling pathway has been identified in the progression of various cancers. Here, in our study, it was indicated that Wnt signaling was highly activated in melanoma cells with β-catenin expression significantly increased and GSK-3β decreased. Interestingly, MEG restoration strongly inactivated Wnt signaling pathway by reducing β-catenin and CyclinD1, elevating GSK-3β levels in vitro. Finally, in vivo experiments were carried out to confirm the inhibitory roles of MEG3 in vivo. Taken these together, we suggested that MEG3 can inhibit melanoma development through blocking Wnt signaling pathway.

Topics: Animals; beta Catenin; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Disease Progression; Female; Glycogen Synthase Kinase 3 beta; Humans; Melanoma; Melanoma, Cutaneous Malignant; Mice; Mice, Inbred BALB C; Mice, Nude; RNA, Long Noncoding; Skin Neoplasms; Wnt Signaling Pathway; Xenograft Model Antitumor Assays

BACKGROUND MicroRNA-365 (miR-365) is involved in the development of a variety of cancers. However, it remains largely unknown if and how miRNAs-365 plays a role in melanoma development. MATERIAL AND METHODS In this study, we overexpressed miR-365 in melanoma cell lines A375 and A2058, via transfection of miR-365 mimics oligos. We then investigated alterations in a series of cancer-related phenotypes, including cell viability, cell cycle, apoptosis, colony formation, and migration and invasion capacities. We also validated cyclin D1 (CCND1) and BCL2 apoptosis regulator (BCL2) as direct target genes of miR-365 by luciferase reporter assay and investigated their roles in miR-365 caused phenotypic changes. To get a more general view of miR-365's biological functions, candidate target genes of miR-365 were retrieved via searching online databases, which were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses for potential biological functions. We then analyzed The Cancer Genome Atlas (TCGA) Skin Cutaneous Melanoma (SKCM) dataset for correlation between miR-365 level and clinicopathological features of patients, and for survival of patients with high and low miR-365 levels. RESULTS We found that miR-365 was downregulated in melanoma cells. Overexpression of miR-365 remarkably suppressed cell proliferation, induced cell cycle arrest and apoptosis, and compromised the migration and invasion capacities in A375 and A2058 cell lines. We also found that the phenotypic alterations by miR-365 were partially due to downregulation of CCND1 and BCL2 oncogenes. The bioinformatics analysis revealed that predicted targets of miR-365 were widely involved in transcriptional regulation and cancer-related signaling pathways. However, analysis of SKCM dataset failed to find differences in miR-365 level among melanoma patients at different clinicopathologic stages. The Kaplan-Meier analysis also failed to discover significant differences in overall survival and disease-free survival between patients with high and low miR-365 levels. CONCLUSIONS Our findings suggested that miR-365 might be an important novel regulator for melanoma formation and development, however, the in vivo roles in melanoma developments need further investigation.

Topics: Apoptosis; Cell Cycle; Cell Cycle Checkpoints; Cell Growth Processes; Cell Line, Tumor; Cyclin D1; Down-Regulation; Humans; Melanoma; Melanoma, Cutaneous Malignant; MicroRNAs; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; Skin Neoplasms

The identification and targeting of key molecular drivers of melanoma and breast and lung cancer have substantially improved their therapy. However, subtypes of each of these three common, lethal solid tumors lack identified molecular drivers, and are thus not amenable to targeted therapies. Here we show that pleckstrin homology domain-interacting protein (PHIP) promotes the progression of these "driver-negative" tumors. Suppression of PHIP expression significantly inhibited both tumor cell proliferation and invasion, coordinately suppressing phosphorylated AKT, cyclin D1, and talin1 expression in all three tumor types. Furthermore, PHIP's targetable bromodomain is functional, as it specifically binds the histone modification H4K91ac. Analysis of TCGA profiling efforts revealed PHIP overexpression in triple-negative and basal-like breast cancer, as well as in the bronchioid subtype of nonsmall cell lung cancer. These results identify a role for PHIP in the progression of melanoma and breast and lung cancer subtypes lacking identified targeted therapies. The use of selective, anti-PHIP bromodomain inhibitors may thus yield a broad-based, molecularly targeted therapy against currently nontargetable tumors.

Topics: Animals; Breast; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; Intracellular Signaling Peptides and Proteins; Lung Neoplasms; Melanoma; Pleckstrin Homology Domains; Proto-Oncogene Proteins c-akt; Triple Negative Breast Neoplasms

Neokestose has superior prebiotic effects compared with the commercial fructooligosaccharides (FOS). In addition, the branched structure of neokestose, a type of neo‑FOS, confers improved chemical stability compared with conventional FOS; therefore, the investigation of the branched structure by the present study may be of high biomedical value. The present study aimed to determine whether neokestose may suppress growth of the A2058 melanoma cell line. The cells were initially treated with neokestose; subsequently, in vitro cytotoxicity was assessed using MTT, and cell cycle progression and apoptosis were detected using flow cytometry. The protein expression levels of cyclin D1, phosphorylated (p)‑inhibitor of κB (IκB) and nuclear factor‑κB (NF‑κB) were determined using western blotting. Treatment with neokestose led to a dose‑dependent inhibition of cell viability. Flow cytometry data indicated that neokestose increased the sub‑G1 cell population, and induced early and late apoptosis. Western blot analysis revealed that neokestose treatment reduced the expression levels of p‑IκB and cyclin D1. These findings suggest that neokestose treatment may induce suppression of A2058 melanoma cell viability via inhibition of the NF‑κB pathway. The present findings support the requirement for further investigation into the potential use of neokestose as an additional or chemopreventive therapeutic agent for the treatment of melanoma.

Topics: Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Gene Expression; Humans; Melanoma; NF-kappa B; Phosphorylation; Signal Transduction; Transforming Growth Factor beta; Trisaccharides

Malignant melanoma is the most dangerous form of skin cancer, with a rapidly increasing incidence rate. Despite recent advances in melanoma research following the approval of several novel targeted and immuno-therapies, the majority of oncological patients will ultimately perish from the disease. Thus, new effective drugs are still required. Starfish steroid glycosides possess different biological activities, including antitumor activity. The current study focused on the determination of the in vitro inhibitory activity and the mechanism of action of cyclic steroid glycosides isolated from the starfish

Topics: Animals; Antineoplastic Agents; Apoptosis; Caspase 3; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Glycosides; Humans; Inhibitor of Apoptosis Proteins; Melanoma; Poly(ADP-ribose) Polymerases; Proto-Oncogene Proteins c-bcl-2; Skin Neoplasms; Starfish; Steroids

P-REX1 (PIP3-dependent Rac exchange factor-1) is a guanine nucleotide exchange factor that activates Rac by catalyzing exchange of GDP for GTP bound to Rac. Aberrant up-regulation of P-REX1 expression has a role in metastasis however, copy number (CN) and function of P-REX1 in cutaneous melanoma are unclear. To explore the role of P-REX1 in melanoma, SNP 6.0 and Exon 1.0 ST microarrays were assessed. There was a higher CN (2.82-fold change) of P-REX1 in melanoma cells than in melanocytes, and P-REX1 expression was significantly correlated with P-REX1 CN. When P-REX1 was knocked down in cells by P-REX1 shRNA, proliferation, colony formation, 3D matrigel growth, and migration/invasiveness were inhibited. Loss of P-REX1 inhibited cell proliferation by inhibiting cyclin D1, blocking cell cycle, and increased cell apoptosis by reducing expression of the protein survivin. Knockdown of P-REX1 expression inhibited cell migration/invasiveness by disrupting P-REX1/RAC1/PAK1/p38/MMP-2 pathway. Assessment of patient tumors and disease outcome demonstrated lower distant metastasis-free survival among AJCC stage I/II/III patients with high P-REX1 expression compared to patients with low P-REX1 expression. These results suggest P-REX1 plays an important role in tumor progression and a potential theranostic target.

Topics: Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Guanine Nucleotide Exchange Factors; Humans; Inhibitor of Apoptosis Proteins; MAP Kinase Signaling System; Melanoma; Melanoma, Cutaneous Malignant; Neoplasm Invasiveness; RNA, Messenger; Skin Neoplasms; Up-Regulation

Though Astragalin (kaempferol-3-glucoside) contained in Paeonia lactiflora and other plants was known to have anti-oxidant, antiinflammatory, and anti-tumor activity, the anti-tumor mechanism of Astragalin has never been reported in melanomas until now. Thus, in the present study, the underlying apoptotic mechanism of Astragalin isolated from Aceriphyllum rossii was elucidated in A375P and SK-MEL-2 melanoma cells. Astragalin exerted cytotoxicity in A375P and SK-MEL-2 cells in a concentration-dependent manner. Also, Astragalin significantly increased the number of TdT-mediated dUTP nick end labeling positive cells and sub-G1 population as a feature of apoptosis in A375P and SK-MEL-2 cells compared with untreated control. Consistently, western blotting revealed that Astragalin activated caspase 9/3 and Bax, cleaved poly (ADP-ribose) polymerase, and attenuated the expression of cyclin D1, Mcl-1, and Sry-related HMg-Box gene 10 (SOX10) in A375P and SK-MEL-2 cells. Of note, ectopic expression of SOX10 reduced the apoptotic ability of Astragalin to inhibit proliferation, cleave poly (ADP-ribose) polymerase, and caspase 3 in A375P and SK-MEL-2 melanoma cells. Overall, our findings provide evidence that Astragalin induces apoptosis in A375P and SK-MEL-2 melanoma cells via activation of caspase9/3 and inhibition of SOX10 signaling. Copyright © 2017 John Wiley & Sons, Ltd.

Topics: Apoptosis; bcl-2-Associated X Protein; Caspase 3; Caspase 9; Cell Line, Tumor; Cyclin D1; Humans; Kaempferols; Melanoma; Myeloid Cell Leukemia Sequence 1 Protein; Poly(ADP-ribose) Polymerases; Signal Transduction; Skin Neoplasms; SOXE Transcription Factors

Topics: Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Melanoma; Nevus, Blue; Staining and Labeling

Diagnostic confirmation of spindle-cell melanoma (SM) or desmoplastic melanoma (DM) as a melanoma can be challenging. In conventional melanoma (CM), a recently established fluorescence in situ hybridization (FISH) assay for RREB1, MYB, CCND1 can be helpful. Here, we determined the presence of RREB1, MYB, and CCND1 abnormalities in an SM/DM/mixed cohort.. We assembled 49 cases and performed 3 separate hybridizations for RREB1/MYB/CCND1. We assessed clinical utility in diagnostically challenging cases and performed a cost and turnaround time analysis.. With regard to the diagnosis of melanoma, the FISH assay is 76% sensitive (n = 31/41 true positives melanomas) and 88% specific (n = 1/8 false positive desmoplastic nevi). The prevalence of abnormalities in DM is lower (12/19 cases, 63%; P = .03) than in SM (15/18 cases, 83%; P = .27), mixed (4 of 4 cases), or the reported sensitivity in CM (345/411 cases, 84%). The implied genetic differences in DM result in a higher false negative rate in DM (37%). Despite these limitations, when restricted to diagnostically challenging cases (n = 23), the FISH assay and, in particular, RREB1 was able to confirm melanoma in 70% (n = 16/23). Individual probe sensitivities ( RREB1 > MYB > CCND1) and a cost and turnaround time analysis argues for a 2-step test algorithm that reduces the economic impact of FISH testing considerably (~55%; n = 69 vs 123 hybridizations).. We propose a step-by-step genetic testing algorithm to support the diagnosis of melanoma in the setting of SM/DM and show that FISH testing is useful in diagnostically challenging cases.

Topics: Adult; Aged; Algorithms; Biomarkers, Tumor; Cyclin D1; DNA-Binding Proteins; Female; Gene Dosage; Genes, myb; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Male; Melanoma; Melanoma, Cutaneous Malignant; Middle Aged; Sensitivity and Specificity; Skin Neoplasms; Transcription Factors

Malignant melanoma is the deadliest form of all skin cancers. Itraconazole, a commonly used systemic antifungal drug, has been tested for its anti-tumor effects on basal cell carcinoma, prostate cancer, and non-small cell lung cancer. Whether itraconazole has any specific anti-tumor effect on melanoma remains unknown. However, the goal of this study is to investigate the effect of itraconazole on melanoma and to reveal some details of its underlying mechanism. In the in vivo xenograft mouse model, we find that itraconazole can inhibit melanoma growth and extend the survival of melanoma xenograft mice, compared to non-itraconazole-treated mice. Also, itraconazole can significantly inhibit cell proliferation, as demonstrated by Ki-67 staining in itraconazole-treated tumor tissues. In in vitro, we show that itraconazole inhibits the proliferation and colony formation of both SK-MEL-28 and A375 human melanoma cells. Moreover, we demonstrate that itraconazole significantly down-regulates Gli-1, Gli-2, Wnt3A, β-catenin and cyclin D1, while it up-regulates Gli-3 and Axin-1, indicating potent inhibitory effects of itraconazole on Hedgehog (Hh) and Wnt signaling pathways. Furthermore, itraconazole significantly suppresses the PI3K/mTOR signaling pathway - indicated by the down-regulated phosphorylation of p70S6K, 4E-BP1 and AKT - but has no effect on the phosphorylation of MEK or ERK. Our data suggest that itraconazole inhibits melanoma growth through an interacting regulatory network that includes Hh, Wnt, and PI3K/mTOR signaling pathways. These results suggest that this agent has several potent anti-melanoma features and may be useful in the synergesis of other anti-cancer drugs via blockage of the Hh, Wnt and PI3K/mTOR signaling pathways.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Disease Models, Animal; Female; Gene Expression Regulation, Neoplastic; Hedgehog Proteins; Humans; Itraconazole; Melanoma; Mice; Phosphatidylinositol 3-Kinases; Signal Transduction; TOR Serine-Threonine Kinases; Tumor Stem Cell Assay; Wnt Proteins; Xenograft Model Antitumor Assays

Encorafenib (LGX818) is a new-generation BRAF inhibitor that is under evaluation in clinical trials. However, the underlying mechanism remains to be elucidated. Here we show that LGX818 potently decreased ERK phosphorylation and inhibited proliferation in BRAFV600E melanoma cell lines. Moreover, LGX818 downregulated CyclinD1 in a glycogen synthase kinase 3β-independent manner and induced cell cycle arrest in the G1 phase, Surprisingly, LGX818 triggered cellular senescence in BRAFV600E melanoma cells, as evidenced by increased β-galactosidase staining, while no appreciable induction of apoptosis was detected, as determined by Annexin V and propidium iodide staining and immunoblot analysis of caspase-3 processing and poly (ADP-ribose) polymerase cleavage. Increased p27KIP1 expression and retinoblastoma protein activation were detected during LGX818-induced senescence. Additionally, inhibition of dual-specificity tyrosine phosphorylation-regulated kinase 1B by AZ191 reversed LGX818-induced CyclinD1 turnover and senescence. Interestingly, autophagy is triggered through inhibition of the mTOR/70S6K pathway during LGX818-induced senescence. Moreover, autophagy inhibition by pharmacological and genetic regulation attenuates LGX818-induced senescence. Notably, combining LGX818 with autophagy modulators has anti-proliferative effect in LGX818-resistant BRAF mutant melanoma cells. Altogether, we uncovered a mechanism by which LGX818 exerts its anti-tumor activity in BRAFV600E melanoma cells.

Topics: Autophagy; Carbamates; Cell Line, Tumor; Cellular Senescence; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Dyrk Kinases; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; MAP Kinase Signaling System; Melanoma; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Proto-Oncogene Proteins B-raf; Retinoblastoma Protein; Sulfonamides; TOR Serine-Threonine Kinases

Newly appearing or changing melanocytic lesions (MLs) are a recently reported toxicity of BRAF inhibitor (BRAFi) therapy. Morphologically, MLs associated with BRAFi therapy (BRAFi-MLs) may demonstrate alarming features of melanoma with an epithelioid cell phenotype with notable cytologic atypia. We sought to characterize the clinicopathological and molecular features of BRAFi-MLs. A retrospective review over a 4-year period revealed 20 patients in which 44 MLs (including 11 control nevi) were characterized by histopathology, review of clinical medical records, and immunohistochemical (IHC) studies (with anti-BRAF V600E, anti-BAP1, anti-cyclin D1, and anti-p16); the percentage of IHC+ cells was scored. Of the 20 patients, 3 (15%) whose BRAFi-MLs were biopsied had a second primary cutaneous melanoma. Of the 44 BRAFi-MLs tested, 37 (100%) of 37 MLs available for BRAF V600E testing lacked expression in contrast to 1 (9%) of 11 control nevi (lesions not associated with targeted therapy). A significantly higher level of cyclin D1 expression (>50% IHC+ cells) was more commonly seen in BRAFi-MLs (44%) than in control nevi (9%). No difference in p16 expression in melanocytes was seen between the 2 groups. BRAF mutation status distinctly differs between BRAFi-MLs from melanomas and nevi biopsied in patients who do not receive BRAFi therapy. Morphologically, BRAFi-MLs demonstrate a greater degree of atypia than do control nevi. Furthermore, BRAFi-MLs with coexisting cutaneous keratinocyte toxicity developed during fewer days of targeted therapy. Paradoxical activation of the MAPK pathway in BRAF(WT) melanocytes may account for ~15% to 21% of patients developing a second new primary melanoma within a year of starting BRAFi therapy; thus, close clinical surveillance is warranted.

Topics: Adult; Aged; Antineoplastic Agents; Biopsy; Cyclin D1; Female; Humans; Immunohistochemistry; Male; Melanocytes; Melanoma; Middle Aged; Mutation; Neoplasms, Second Primary; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Retrospective Studies; Skin Neoplasms; Time Factors; Treatment Outcome; Up-Regulation; Young Adult

Activity of both c-Jun and cyclin D1 is deemed critical for melanoma cell proliferation. This functionality is corroborated by frequently elevated expression and activity of these proteins in human melanomas. Correspondingly, alleviating c-Jun and cyclin D1 function is vital to the success of antimelanoma therapeutics.. To understand the role of the c-Jun N-terminal kinase (JNK) signalling pathway in melanoma cell proliferation and survival.. The effect of JNK inhibitors SP600125 and JNK-IN-8 on the proliferation and survival of genetically highly representative human melanoma cell lines was studied in assays of proliferation and apoptosis. Changes in c-Jun and cyclin D1 protein and mRNA levels in response to JNK and mitogen-activated protein kinase kinase (MEK) inhibition were investigated through immunoblotting and quantitative reverse-transcription polymerase chain reaction. The effects of JNK and MEK inhibitors on cell-cycle distribution were assessed by flow cytometry.. We demonstrate the requirement of JNK signalling in melanoma cell proliferation and survival. While JNK inhibition suppressed the expression and activity of c-Jun, it failed to suppress cyclin D1 levels. Consistently with its inability to downregulate cyclin D1, JNK inhibition failed to induce G1 arrest. In contrast, the blockade of MEK-extracellular signal-regulated kinase (ERK) signalling, although unable to suppress c-Jun activity and expression, paradoxically abated cyclin D1 levels and triggered G1 arrest. This previously unreported dual disconnect between JNK-cyclin D1 and ERK-c-Jun levels was confirmed by concomitant JNK and BRAF inhibition, which suppressed both c-Jun and cyclin D1 levels and exhibited a heightened antiproliferative response.. Dual disjunction between JNK-cyclin D1 and ERK-c-Jun signalling forms the basis for further investigation of combined JNK and MAPK signalling blockade as a more effective therapeutic approach in human melanoma.

Topics: Anthracenes; Cell Proliferation; Cyclin D1; Humans; JNK Mitogen-Activated Protein Kinases; Melanoma; Protein Kinase Inhibitors; Signal Transduction; Skin Neoplasms; Tumor Cells, Cultured

Background Malignant melanoma of the nail apparatus is exceedingly rare. Increasingly, genetic studies have been employed to aid in distinguishing between malignant melanoma and benign melanocytic nevi. Methods Archived nail apparatus melanomas were analyzed by fluorescence in situ hybridization (FISH) using probes targeting the genes at 6p25 (RREB1), 11q13 (CCND1), 8q24.1 (MYC), 6q23 (MYB), 9p21 (CDKN2A) and the centromeres of chromosomes 8 (D8Z2) and 6 (D6Z1). The results were correlated with clinical and demographic information. Results Mean patient age was 57.8 years (range 23-92 years). In all, 5 of 7 (71%) cases involved the upper extremity digits. RREB1 gain was seen in all cases. CCND1 gain was seen in 6 of 7 (86%) cases, 3 of which were amplified. MYB loss and MYC gain were both seen in 5 of 7 (71%) cases. Homozygous loss of CDKN2A was not observed in any case. Two of 7 (28.6%) patients had lymph node metastasis and died of widely metastatic disease. These 2 patients harbored the most genetic aberrations: gains of RREB1, CCND1, and MYC, and MYB loss. Both benign melanocytic nevi controls showed normal FISH results. Conclusions RREB1 and CCND1 gains are common in nail apparatus melanoma as in most melanomas, and an increased number of genetic aberrations may be associated with a poorer prognosis, though the limited number of cases precludes definitive correlation. FISH appears to be a useful adjunct in the diagnosis of nail apparatus melanomas and improves diagnostic confidence even in the setting of unambiguous histomorphology.

Topics: Adult; Aged; Aged, 80 and over; Cyclin D1; DNA-Binding Proteins; Female; Humans; In Situ Hybridization, Fluorescence; Male; Melanoma; Middle Aged; Nail Diseases; Skin Neoplasms; Transcription Factors; Young Adult

Previous research indicates that microRNA-25 (miR-25) regulates carcinogenesis and the progression of various cancers, but the role of miR-25 in melanoma remains unclear. We observed that miR-25 was significantly upregulated in melanoma cell lines and tissue samples. Downregulation of miR-25 markedly suppressed invasion and proliferation of melanoma cells in vitro; however, overexpression of miR-25 markedly increased melanoma cell invasion and proliferation. Moreover, we observed Dickkopf-related protein 3 (DKK3) as a direct target of miR-25 in vitro. Upregulation of DKK3 partially attenuated the oncogenic effect of miR-25 on melanoma cells. Ectopic expression of miR-25 in melanoma cells induced β-catenin accumulation in nuclear and inhibited TCF4 (T cell factor 4) activity, as well as the expression of c-Myc and Cyclin D1. In a nude xenograft model, miR-25 upregulation significantly increased A375 melanoma growth. In summary, miR-25 is upregulated in melanoma and promotes melanoma cell proliferation and invasion, partially by targeting DKK3. These results were indicated that miR-25 may serve as a potential target for the treatment of melanoma in the future.

Topics: Adaptor Proteins, Signal Transducing; Animals; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; beta Catenin; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Chemokines; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; Intercellular Signaling Peptides and Proteins; Melanoma; Mice; MicroRNAs; Neoplasm Invasiveness; Proto-Oncogene Proteins c-myc; Transcription Factor 4; Transcription Factors; Wnt Signaling Pathway; Xenograft Model Antitumor Assays

At least 17 genomic regions are established as harboring melanoma susceptibility variants, in most instances with genome-wide levels of significance and replication in independent samples. Based on genome-wide single nucleotide polymorphism (SNP) data augmented by imputation to the 1,000 Genomes reference panel, we have fine mapped these regions in over 5,000 individuals with melanoma (mainly from the GenoMEL consortium) and over 7,000 ethnically matched controls. A penalized regression approach was used to discover those SNP markers that most parsimoniously explain the observed association in each genomic region. For the majority of the regions, the signal is best explained by a single SNP, which sometimes, as in the tyrosinase region, is a known functional variant. However in five regions the explanation is more complex. At the CDKN2A locus, for example, there is strong evidence that not only multiple SNPs but also multiple genes are involved. Our results illustrate the variability in the biology underlying genome-wide susceptibility loci and make steps toward accounting for some of the "missing heritability."

Topics: Chromosome Mapping; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Genetic Loci; Genetic Predisposition to Disease; Humans; Melanoma; Polymorphism, Single Nucleotide; Telomerase

Melanoma is an aggressive disease with limited therapeutic options. Here, we determined the effects of honokiol (HNK), a biphenolic natural compound on melanoma cells and stemness. HNK significantly inhibited melanoma cell proliferation, viability, clonogenicity and induced autophagy. In addition, HNK significantly inhibited melanosphere formation in a dose dependent manner. Western blot analyses also demonstrated reduction in stem cell markers CD271, CD166, Jarid1b, and ABCB5. We next examined the effect of HNK on Notch signaling, a pathway involved in stem cell self-renewal. Four different Notch receptors exist in cells, which when cleaved by a series of enzymatic reactions catalyzed by Tumor Necrosis Factor-α-Converting Enzyme (TACE) and γ-secretase protein complex, results in the release of the Notch intracellular domain (NICD), which then translocates to the nucleus and induces target gene expression. Western blot analyses demonstrated that in HNK treated cells there is a significant reduction in the expression of cleaved Notch-2. In addition, there was a reduction in the expression of downstream target proteins, Hes-1 and cyclin D1. Moreover, HNK treatment suppressed the expression of TACE and γ-secretase complex proteins in melanoma cells. To confirm that suppression of Notch-2 activation is critical for HNK activity, we overexpressed NICD1, NICD2, and performed HNK treatment. NICD2, but not NICD1, partially restored the expression of Hes-1 and cyclin D1, and increased melanosphere formation. Taken together, these data suggest that HNK is a potent inhibitor of melanoma cells, in part, through the targeting of melanoma stem cells by suppressing Notch-2 signaling.

Topics: ADAM Proteins; ADAM17 Protein; Amyloid Precursor Protein Secretases; Autophagy; Basic Helix-Loop-Helix Transcription Factors; Biomarkers, Tumor; Biphenyl Compounds; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Homeodomain Proteins; Humans; Lignans; Melanoma; Neoplastic Stem Cells; Receptor, Notch2; Receptors, Notch; Signal Transduction; Transcription Factor HES-1

Uveal melanoma (UM) is an intraocular malignant tumor in adults that is characterized by rapid progression and recurrence. Irradiation has become the primary therapy for UM patients who are not candidates for surgery. However, after large-dose fraction irradiation treatment, some patients undergo subsequent enucleation because of radiotherapy-related complications. This situation has raised concerns on how to optimize the effectiveness of radiation treatment. Recent investigations of microRNAs are changing our understanding of UM tumor biology and are helping to identify novel targets for radiotherapy. The radioresistant UM cell lines OM431 and OCM1 were selected and exposed to irradiation, and let-7b was found to be downregulated after exposure. We then confirmed that let-7b mimics could inhibit UM growth both in vitro and in vivo. More specifically, transfection with let-7b mimics markedly resensitized OCM1 and OM431 cells to irradiation by reducing the population of S-phase cells. Cyclin D1 plays a vital role in cell cycle arrest, which is induced by let-7b overexpression. Cyclin D1 is also a target of let-7b and its expression is suppressed by upregulation of let-7b. Collectively, our results indicate that let-7b overexpression can in turn downregulate cyclin D1 expression and enhance the radiosensitivity of UM through cell cycle arrest. Let-7b could serve as a marker for radiosensitivity and could enhance the therapeutic benefit of UM cell irradiation.

Topics: Animals; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Dose-Response Relationship, Radiation; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Mice, Nude; MicroRNAs; S Phase Cell Cycle Checkpoints; Time Factors; Transfection; Tumor Burden; Up-Regulation; Uveal Neoplasms; Xenograft Model Antitumor Assays

Malignant melanoma remains the most life-threatening skin cancer to date. What makes it worse is the incidence keeps increasing worldwide, including in China. Notably, clinical studies revealed the distinct features in the Chinese population differing from those in Caucasians, which give hints to variant mechanisms underlying. Therefore, it is of great importance to generate a cell line with similar background for melanoma research in Chinese even Asian patients. However, most melanoma cell lines in use are derived from Caucasians, thus, we established one novel metastatic melanoma cell line, FLFMM-34, derived from a Han Chinese woman. The cell line showed positive for S100, HMB45, vimentin and melan-A. Chromosome analysis revealed multiple structural aberrations. Gene-mutation analysis identified that FLFMM-34 cells had BRAF(V600E) mutation and deletions of exon 2 and 3 in p16/CDKN2A. Importantly, two novel mutations including TP53(P33R) and TP53(R142H) have been detected. RT-PCR results showed that FLFMM-34 cells expressed a higher mRNA level of cyclinD1 than three other melanoma cell lines, WM793B, 1205Lu and A2058. In addition, in vivo mice model demonstrated that the cells could be transplanted into the subcutis of nude mice and produced tumors associated with lymphoid node metastases. In conclusion, these data indicate that FLFMM-34 cell line can be employed as a suitable model for melanoma research in Chinese Han population.

Topics: Animals; Cell Line, Tumor; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Exons; Female; Humans; Karyotyping; Lymph Nodes; Lymphatic Metastasis; Melanoma; Mice; Mice, Nude; Middle Aged; Mutation; Proto-Oncogene Proteins B-raf; RNA, Messenger; Skin Neoplasms; Transplantation, Heterologous

Approximately 20% of melanomas contain a mutation in NRAS. However no direct inhibitor of NRAS is available. One of the main signaling pathways downstream of NRAS is the MAPK pathway. In this study we investigated the possibility of blocking oncogenic signaling of NRAS by inhibiting two signaling points in the MAPK pathway.. Fourteen NRAS mutated human melanoma cell lines were treated with a pan-RAF inhibitor (PRi, Amgen Compd A), a MEK inhibitor (MEKi, trametinib) or their combination and the effects on proliferation, cell cycle progression, apoptosis, transcription profile and signaling of the cells were investigated.. The majority of the cell lines showed a significant growth inhibition, with high levels of synergism of the PRi and MEKi combination. Sensitive cell lines showed induction of apoptosis by the combination treatment and there was a correlation between p-MEK levels and synergistic effect of the combination treatment. Proliferation of sensitive cell lines was blocked by the inhibition of the MAPK pathway, which also blocked expression of cyclin D1. However, in resistant cell lines, proliferation was blocked by combined inhibition of the MAPK pathway and cyclin D3, which is not regulated by the MAPK pathway. Resistant cell lines also showed higher levels of p-GSK3β and less perturbation of the apoptotic profile upon the treatment in comparison with the sensitive cell lines.. The combination of PRi + MEKi can be an effective regimen for blocking proliferation of NRAS mutant melanomas when there is higher activity of the MAPK pathway and dependence of proliferation and survival on this pathway.

Topics: Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin D3; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; GTP Phosphohydrolases; Humans; MAP Kinase Signaling System; Melanoma; Membrane Proteins; Mutation; raf Kinases; Signal Transduction; Transcription, Genetic

To explore the utility of fluorescence in situ hybridization as a diagnostic tool for cutaneous melanoma.. Twenty cutaneous melanomas and 20 cutaneous nevi from pathology files were selected and analyzed by Vysis melanoma FISH probe kit targeting 3 loci on chromosome 6 (MYB, CEP6 and RREB1) and 1 locus on 11q (CCND1) and data were interpreted based on the Abbott criteria provided by the kit.. Informative FISH results were obtained in 16 melanomas and 18 nevi. Chromosomal aberrations were detected in 12 of the 16 melanomas and only 1 of 18 nevi.. FISH is a useful diagnostic tool and able to distinguish cutaneous nevus from melanoma with good sensitivity and specificity.

Topics: Chromosome Aberrations; Cyclin D1; Diagnosis, Differential; Humans; In Situ Hybridization, Fluorescence; Melanoma; Melanoma, Cutaneous Malignant; Nevus; Sensitivity and Specificity; Skin Neoplasms

Spitzoid neoplasms may represent a difficult diagnosis in the practice of dermatopathology. We evaluated the concordance of the fluorescence in-situ hybridization (FISH) assay, histopathology, and dermoscopy in a group of adults and in a group of children with spitzoid neoplasms. The FISH assay, designed to detect the copy number of the RREB1 (6p25), MYB (6q23), and CCND1 (11q13) genes and of centromere 6 (Cep 6), was performed in a group of children and in a group of adults with a histopathologic diagnosis of spitzoid neoplasms. FISH data were compared with dermoscopy and histopathology. Fifteen spitzoid neoplasms were collected from 13 patients (five children and eight adults): nine lesions were histologically diagnosed as typical Spitz nevi; three lesions were melanomas and three were atypical Spitz nevi. The conventional FISH criteria were concordant with the clinical and histopathologic diagnosis of Spitz nevi in four adults and in three children. FISH criteria of the other neoplasms showed a concordance with the histopathologic diagnosis in three cases. Discordant results were obtained in five cases (two children, three adults). The FISH melanoma assay proved more reliable in spitzoid lesions found in adults than in children. This assay should be interpreted carefully in pediatric patients with Spitz nevi in the context of histological features as melanomas in the pediatric population may show distinct chromosomal aberrations.

Topics: Adolescent; Adult; Child; Child, Preschool; Cyclin D1; Cytogenetic Analysis; Diagnosis, Differential; DNA Copy Number Variations; DNA-Binding Proteins; Female; Humans; In Situ Hybridization, Fluorescence; Male; Melanocytes; Melanoma; Middle Aged; Nevus, Epithelioid and Spindle Cell; Proto-Oncogene Proteins c-myb; Skin Neoplasms; Transcription Factors; Young Adult

Metastatic process accounts for the vast majority of melanoma associated mortality, and also results in difficulties in the effective treatment. Therefore, identification of novel biomarkers could contribute to melanoma prognosis, and may also provide new opportunities for efficient cancer treatment. Several signaling pathways have been identified as key regulators in melanoma progression, including the frequent activation of Ras/MAPK signaling pathway through the mutant BRAF or NRAS genes. Besides, alterations of CCND1 may also be of great importance. The oncogene plays a significant role in the G1/S phase transition of the cell cycle, and its transcriptional activation is primarily carried out by the Ras/MAPK cascade. One of our aims was to determine the genetic and gene expression alterations of CCND1 during melanoma progression, considering the mutation status of BRAF and NRAS genes. Analysis of CCND1 copy number alterations revealed significant association with poor clinical outcome in primary melanomas, which was influenced by the mutation status of BRAF or NRAS in the term of sun exposure. Regarding gene expression, CCND1 mRNA level decreased in lesions with multiple metastases and were correlated with both the mRNA levels and mutation status of BRAF and NRAS. CCND1 protein expression was associated with Breslow thickness, metastasis formation and shorter survival time. However, the proportion of cells expressing the protein showed a heterogeneous distribution, influencing the association with clinical-pathological parameters. Therefore melanoma cell lines with different biological behavior were also analyzed for protein expression. These experiments revealed an increasing CCND1 protein level throughout primary cancer progression, which then decreased in the metastasis. The other purpose of our study was to determine the role of 7q31 region in melanoma progression, which was found frequently altered using array comparative genomic hybridization (aCGH). 7q31 is a gene dense locus, including the FRA7G fragile site, which serves as a mutation hot spot. In its close vicinity TES (focal adhesions) and CAV1 (lipid rafts) genes are located. Using interphase FISH, significant associations were found between 7q31 copy number alterations and poor clinical outcome. Both mRNA and protein levels of CAV1 decreased in thick lesions whereas primary melanomas forming multiple metastases were featured by decreased TES mRNA level.. A melanoma okozta halálozások legfõbb oka a metasztázisok megjelenése, mely a túlélésen túl jelentõsen csökkenti az alkalmazott terápiák hatékonyságát is. Ezért szükséges olyan biomarkerek felkutatása, melyek hozzájárulnak a melanoma prognózisához, és sikeresen alkalmazhatók a terápiás hatékonyság növelésére. Számos jelátviteli útvonal szerepét bizonyították már a melanoma progressziójában. Ezek közül kiemelkedõ jelentõségû a Ras/MAPK útvonal aktivációja. A BRAF- és NRAS-mutációk korai megjelenése mellett fontos, hogy az útvonal egyik fõ célmolekulája a sejtciklus G1/S fázis átmenetét szabályozó CCND1. Vizsgálataink egyik részében a CCND1 genetikai és génexpressziós eltéréseit tanulmányoztuk a melanomaprogresszió során, figyelembe véve a BRAF és NRAS gének mutációs státuszát. Eredményeink a CCND1-kópiaszám eltéréseinek szignifikáns összefüggését tárták fel a kedvezõtlen klinikai kimenetellel primer melanomákban, mely összefüggést befolyásolta a BRAF és NRAS gének mutációs státusza a napsugárzásnak való kitettség függvényében. Génexpressziós vizsgálataink során a CCND1 mRNS-szintjének szignifikáns csökkenését figyeltük meg a többszörös áttétképzõ primer tumorokban, mely korrelációt mutatott mind a BRAF és NRAS mRNS-szintekkel, mind pedig ez utóbbi gének mutációs státuszával. A CCND1 protein fokozott expressziója pedig áttétképzéssel, rövidebb túléléssel és nagyobb Breslow-vastagsággal társult. A CCND1-et kifejezõ sejtek aránya azonban heterogén eloszlást mutatott, mely befolyásolta a klinikopatológiai paraméterekkel való összefüggést. Kísérleteinket ezért eltérõ biológiai karakterû sejtvonalakon végzett vizsgálatokkal egészítettük ki. Ez alapján a progresszió elõrehaladtával a CCND1-expresszió fokozódik, majd az áttétben lecsökken. További célunk volt az array komparatív genomhibridizációs (aCGH) vizsgálatok során gyakori eltérést mutató 7q31-es régió szerepének vizsgálata a melanoma progressziójában. A lókusz rendkívül géndenz, mely magában foglalja a mutációs forrópontként mûködõ FRA7G fragilis helyet. Ennek környezetében lokalizálódik a fokális adhéziók egy kulcsmolekuláját kódoló TES gén, valamint a membrán-lipidtutajok multifunkciós alapköve, a CAV1. Interfázisos FISH-vizsgálataink szignifikáns összefüggést mutattak a 7q31 kópiaszám-eltérései és a kedvezõtlen prognózis között. A CAV1 mRNS-expresszió lecsökkent vastag melanomákban, mely változás fehérjeszinten is tapasztalható volt, míg a TES mRNS-szint csökkenése a többszörös áttétképzõ primer mintáka

Topics: Caveolin 1; Cyclin D1; Cytoskeletal Proteins; Gene Expression Regulation, Neoplastic; GTP Phosphohydrolases; Humans; In Situ Hybridization, Fluorescence; LIM Domain Proteins; Melanoma; Membrane Proteins; Mutation; Predictive Value of Tests; Prognosis; Proto-Oncogene Proteins B-raf; RNA-Binding Proteins; Signal Transduction; Tissue Array Analysis

The incidence of skin cancer is increasing worldwide and cutaneous squamous cell carcinomas (SCCs) are associated with considerable morbidity and mortality, particularly in immunosuppressed individuals ('carcinomatous catastrophy'). Yet, molecular mechanisms are still insufficiently understood. Besides ultraviolet (UV)-indicative mutations, chromosomal aberrations are prominent. As telomeres are essential in preserving chromosome integrity, and telomere erosion as well as aberrant spatial telomere distribution contribute to genomic instability, we first established telomere length profiles across the whole tissue and identified normal skin (10/30) harboring discrete epidermal sites (stem cell territories) of evenly short telomeres. Precancerous actinic keratoses (AKs) (17) and SCCs (27) expressed two telomere phenotypes: (i) tissue-wide evenly short to intermediate and (ii) longer and tissue-wide heterogeneous telomere lengths, suggesting two modes of initiation, with one likely to originate in the epidermal stem cells. Although tumor histotype, location, patient gender or age failed to distinguish the two SCC telomere phenotypes, as did telomerase activity, we found a trend for a higher degree of aberrant p53 and cyclin D1 expression with long/heterogeneous telomeres. In addition, we established an association for the short/homogeneous telomeres with a simpler and the heterogeneous telomeres with a more complex karyotype correlating also with distinct chromosomal changes. SCCs (13) from renal transplant recipients displayed the same telomere dichotomy, suggesting that both telomere subtypes contribute to 'carcinomatous catastrophy' under immunosuppression by selecting for a common set (3, 9p and 17q) and subtype-specific aberrations (e.g., 6p gain, 13q loss). As a second mechanism of telomere-dependent genomic instability, we investigated changes in telomere distribution with its most severe form of telomeric aggregates (TAs). We identified a telomere length-independent but progression-dependent increase in cells with small telomere associations in AKs (17/17) and additional TAs in SCCs (24/32), basal cell carcinomas (30/31) and malignant melanomas (15/15), and provide evidence for a reactive oxygen species-dependent mechanism in this UV-induced telomere organization-dependent genomic instability.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Carcinoma, Squamous Cell; Cell Line, Tumor; Child; Cyclin D1; Disease Progression; Genomic Instability; Humans; Male; Melanoma; Middle Aged; Skin Neoplasms; Telomerase; Telomere; Tumor Suppressor Protein p53; Ultraviolet Rays; Young Adult

The INK4A locus codes for two independent tumor suppressors, p14ARF and p16/CDKN2A, and is frequently mutated in many cancers. Here we report a novel deletion/substitution from CC to T in the shared exon 2 of p14ARF/p16 in a melanoma cell line. This mutation aligns the reading frames of p14ARF and p16 mid-transcript, producing one protein which is half p14ARF and half p16, chimera ARF (chARF), and another which is half p16 and half non-p14ARF/non-p16 amino acids, p16-Alternate Carboxyl Terminal (p16-ACT). In an effort to understand the cellular impact of this novel mutation and others like it, we expressed the two protein products in a tumor cell line and analyzed common p14ARF and p16 pathways, including the p53/p21 and CDK4/cyclin D1 pathways, as well as the influence of the two proteins on growth and the cell cycle. We report that chARF mimicked wild-type p14ARF by inducing the p53/p21 pathway, inhibiting cell growth through G2/M arrest and maintaining a certain percentage of cells in G1 during nocodazole-induced G2 arrest. chARF also demonstrated p16 activity by binding CDK4. However, rather than preventing cyclin D1 from binding CDK4, chARF stabilized this interaction through p21 which bound CDK4. p16-ACT had no p16-related function as it was unable to inhibit cyclin D1/CDK4 complex formation and was unable to arrest the cell cycle, though it did inhibit colony formation. We conclude that these novel chimeric proteins, which are very similar to predicted p16/p14ARF chimeric proteins found in other primary cancers, result in maintained p14ARF-p53-p21 signaling while p16-dependent CDK4 inhibition is lost.

Topics: Base Sequence; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p16; Exons; Humans; Melanoma; Mutant Chimeric Proteins; Mutation; Tumor Suppressor Protein p14ARF; Tumor Suppressor Protein p53

Human beta-defensin-2 (hBD-2) is an antimicrobial cationic peptide capable to control human carcinoma cell growth via cell cycle regulation. The present study was aimed on determination of hBD-2 influence on the growth patterns and malignant potential of cultured human melanoma cells.. The study was performed on cultured human melanoma cells of mel Z and mel Is lines treated with recombinant hBD-2 (rec-hBD-2); cell viability, proliferation, cell cycle distribution, and anchorage-independent growth were analyzed using MTT test, direct cell counting, flow cytometry, and colony forming assay respectively. Expression and/or phosphorylation levels of proteins involved in cell cycle control were evaluated by Western blotting.. The treatment of mel Z and mel Is cells with rec-hBD-2 in a concentration range of 100-1000 nM resulted in a concentration-dependent suppression of cell proliferation, viability, and colony forming activity. It has been shown that rec-hBD-2 exerts its growth suppression effects via significant downregulation of B-Raf expression, activation of pRB and upregulation of p21(WAF1) expression, downregulation of cyclin D1 and cyclin E resulting in cell cycle arrest at G1/S checkpoint.. According to obtained results, hBD-2 exerts its growth suppression effect toward human melanoma cells via downregulation of B-Raf, cyclin D1 and cyclin E expression, upregulation of p21(WAF1) expression and activation of pRB.

Topics: Antimicrobial Cationic Peptides; Apoptosis; beta-Defensins; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Proto-Oncogene Proteins B-raf

Alterations in key-regulator genes of disease pathogenesis (BRAF, cKIT, CyclinD1) have been evaluated in patients with multiple primary melanoma (MPM).. One hundred twelve MPM patients (96 cases with two primary melanomas, 15 with three, and 1 with four) were included into the study. Paired synchronous/asynchronous MPM tissues (N=229) were analyzed for BRAF mutations and cKIT/CyclynD1 gene amplifications.. BRAF mutations were identified in 109/229 (48%) primary melanomas, whereas cKIT and CyclinD1 amplifications were observed in 10/216 (5%) and 29/214 (14%) tumor tissues, respectively. While frequency rates of BRAF mutations were quite identical across the different MPM lesions, a significant increase of cKIT (p<0.001) and CyclinD1 (p=0.002) amplification rates was observed between first and subsequent primary melanomas. Among the 107 patients with paired melanoma samples, 53 (49.5%) presented consistent alteration patterns between first and subsequent primary tumors. About one third (40/122; 32.8%) of subsequent melanomas presented a discrepant pattern of BRAF mutations as compared to incident primary tumors.. The low consistency in somatic mutation patterns among MPM lesions from same patients provides further evidence that melanomagenesis is heterogeneous and different cell types may be involved. This may have implications in clinical practice due to the difficulties in molecularly classifying patients with discrepant primary melanomas.

Topics: Adult; Cyclin D1; Female; Humans; Male; Melanoma; Middle Aged; Mutation; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-kit

Determination of the niche for early-stage cancer remains a challenging issue. Melanoma is an aggressive cancer of the melanocyte lineage. Early melanoma cells are often found in the epidermis around sweat ducts of human volar skin, and the skin pigmentation pattern is an early diagnostic sign of acral melanoma. However, the niche for melanoma precursors has not been determined yet. Here, we report that the secretory portion (SP) of eccrine sweat glands provide an anatomical niche for melanocyte-melanoma precursor cells. Using lineage-tagged H2B-GFP reporter mice, we found that melanoblasts that colonize sweat glands during development are maintained in an immature, slow-cycling state but renew themselves in response to genomic stress and provide their differentiating progeny to the epidermis. FISH analysis of human acral melanoma expanding in the epidermis revealed that unpigmented melanoblasts with significant cyclin D1 gene amplification reside deep in the SP of particular sweat gland(s). These findings indicate that sweat glands maintain melanocyte-melanoma precursors in an immature state in the niche and explain the preferential distribution of early melanoma cells around sweat glands in human volar skin.

Topics: Animals; Cell Cycle; Cyclin D1; Gene Amplification; Green Fluorescent Proteins; Humans; Melanocytes; Melanoma; Mice; Neoplastic Stem Cells; Skin; Skin Neoplasms; Stem Cell Niche; Sweat Glands

Considering that nodular melanoma (NM) has the potential to show an early distant metastasis, there is an urgent need for the discovery and evaluation of new diagnostic and prognostic biomarkers. We aimed to investigate the protein expression of membrane and nuclear epidermal growth factor receptor (EGFR), cyclin D1, and the corresponding gene status in NM samples and correlate the results obtained with clinicopathological parameters and overall survival of patients. Immunohistochemical and fluorescence in-situ hybridization analyses were carried out on tissue microarrays constructed from 110 NM samples, 30 compound nevi, and 38 dysplastic nevi. NM samples showed 24% strong cyclin D1 and 37% strong Ki67 protein expression compared with 3 and 0% strong cyclin D1 and Ki67 expression in the control group. Membrane EGFR expression was detected in 50% of NM cases, whereas EGFR gene amplification was detected in only 4% of NM cases. Multiple NM samples presented simultaneous membrane and nuclear EGFR expression. We found a negative correlation between tumor thickness and membrane EGFR expression. It was also observed that membrane EGFR 3+ NM samples presented ulceration significantly more often than membrane EGFR-negative (0) NM samples. In univariate analysis, carried out on 44 patients with follow-up data, both nuclear and membrane EGFR overexpression showed a correlation with a shorter overall survival. Nuclear EGFR (++, +++) showed 3.06 and membrane EGFR (2+, 3+) showed 2.76 higher risk of mortality compared with patients with low and negative nuclear and membrane EGFR expression (P<0.05).

Topics: Adult; Aged; Biomarkers, Tumor; Cell Nucleus; Cyclin D1; ErbB Receptors; Female; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Male; Melanoma; Middle Aged; Skin Neoplasms; Survival Analysis

Primary malignant melanoma of sinonasal tract is a rare but severe form of melanoma. We retrospectively analyzed 17 cases and focused on the histologic presentation and the expression of c-Kit, epidermal growth factor receptor (EGFR), cyclin D1/Bcl-1, PS100, and HMB45 and searched for BRAF, NRAS, and KIT mutations that are known to be associated with melanoma subtypes, together with amplifications of KIT, cyclin D1, cyclin-dependent kinase 4, MDM2, and microphthalmia-associated transcription factor using quantitative polymerase chain reaction. In most cases (78%), an in situ component was evidenced. Invasive components were composed of diffuse areas of rhabdoid, epithelioid, or spindle cells and, in most cases, lacked inflammatory reaction, suggesting that an immune escape phenomenon probably develops when the disease progresses. EGFR was rarely and weakly expressed in the in situ component of 2 cases. None of the investigated case showed BRAF V600E, but 1 had a D594G mutation. NRAS mutations in exon 2 (G12D or G12A) were found in 3 cases (18%), and a KIT mutation in exon 11 (L576P), in 1, whereas c-Kit was expressed at the protein level in half of the cases. Amplifications of cyclin D1 were evidenced in 5 cases, confirmed in 3 by fluorescence in situ hybridization, but this was not always correlated with protein expression, found in 8 patients (62.5%), 3 having no significant amplification. In conclusion, primary malignant melanoma of sinonasal tract is not associated with BRAF V600E mutations. Instead, NRAS or KIT mutations and cyclin D1 amplification can be found in a proportion of cases, suggesting that primary malignant melanoma of sinonasal tract is heterogeneous at the molecular level and should not be sensitive to therapeutic approaches aiming at BRAF.

Topics: Aged; Aged, 80 and over; Cyclin D1; DNA Mutational Analysis; DNA, Neoplasm; Female; Gene Amplification; GTP Phosphohydrolases; Humans; Male; Melanoma; Membrane Proteins; Middle Aged; Mutation; Paranasal Sinus Neoplasms; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-kit; Retrospective Studies

Intraocular melanocytoma is a rare naevus variant that can be located at the optic disc or within the uvea, and belongs to the group of non-epithelial-associated melanocytic lesions. We wanted to gain an understanding of the role of GNAQ, GNA11 and BRAF V600E in the pathogenesis of uveal melanocytoma and in cases of transformation to uveal melanoma and also to perform a differential immunohistochemical study comparing melanocytoma with uveal melanoma.. Two patients were identified with melanocytoma, one of which had transformed to melanoma. In the latter case, the melanocytoma exhibited an immunophenotype that featured nuclear p27 and no HMB45 staining, with very low Cyclin D1 expression compared with the melanoma that featured little nuclear but more cytoplasmic p27 positivity, much higher Cyclin D1 expression and HMB45 positivity. The melanocytomas were negative for CD68 allowing distinction from melanophages. Both melanocytomas and the melanoma harboured mutations in GNAQ, with no mutations of GNA11 or BRAF V600E.. GNAQ mutations are present in uveal melanocytomas and in a case of transformation to melanoma, implicating GNAQ-dependent mitogen activation signals, in the pathogenesis of uveal melanocytoma. This assists in explaining why a proportion of uveal melanocytoma can transform to uveal melanoma, known to harbour high-frequency GNAQ mutations at exon 5, codon 209.

Topics: Adolescent; Adult; Cell Transformation, Neoplastic; Chromosomes, Human, Pair 3; Chromosomes, Human, Pair 8; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; gp100 Melanoma Antigen; GTP-Binding Protein alpha Subunits; GTP-Binding Protein alpha Subunits, Gq-G11; Humans; Immunoenzyme Techniques; In Situ Hybridization, Fluorescence; Male; MART-1 Antigen; Melanoma; Melanoma-Specific Antigens; Mutation; Nevus, Pigmented; Polymerase Chain Reaction; Proto-Oncogene Proteins B-raf; Retrospective Studies; Uveal Neoplasms

Human malignant melanoma is one of the most aggressive forms of skin cancer with an exceptionally bad prognosis. Melanoma often displays constitutively activated MAPK pathway through BRAF or NRAS mutations. It is also known that these mutations are almost never simultaneously present and that they appear at early stages and preserved throughout tumor progression, although it is proved that these alterations alone are insufficient to cause tumor progression. Therefore the first aim of our study was to evaluate those distinct genetic alterations which can properly differentiate the three important molecular subtypes of primary melanomas with a) BRAF, b) NRAS mutation and c) WT (wild type for both loci). High-resolution array comparative genomic hybridization (array CGH) was used to assess genome-wide analysis of DNA copy number alterations. Primary melanomas with BRAF mutation more frequently exhibited losses on 10q23-10q26 and gains on chromosome 7 and 1q23-1q25 compared to melanomas with NRAS mutation. Loss on the 11q23-11q25 sequence was found mainly in conjunction with NRAS mutation. Based on these results, we proved the existence of marked differences in the genetic pattern of the BRAF and NRAS mutated melanoma subgroups, which might suggest that these mutations contribute to the development of malignant melanoma in conjunction with distinct cooperating oncogenic events. In general, it is an interesting phenomenon suggesting that these mutations provide probably the "guiding force" for these tumors and it also suggests that there are alternative genetic pathways to melanoma. These additional oncogenic events which are associated with BRAF or NRAS mutations can provide rational additional targets for a combination therapy with kinase inhibitors. In this study we also investigated the specific dynamic activities among different signalling pathways highlighting the frequent alterations of genes involved in the signalling interactions between the MAPK-JAK pathways in BRAF mutated melanomas. Using a data mining algorithm we also found a gene alteration signature in the MAPK pathway that was commonly related to the presence of BRAF mutation in our melanoma cohorts. The second aim of this study was to develop an accurate Q-PCR method for determining the co-amplification pattern of six candidate genes that reside in the 11q13 amplicon core. We found that co-amplification of these candidate genes or the CCND1 amplification along with either BRAF or NRAS mutatio. A malignus melanóma a legrosszabb indulatú bõrdaganat, mely fokozott metasztázisképzéssel és gyógyszer-rezisztenciával jellemezhetõ. Kialakulásában és progressziójában számos genomeltérést azonosítottak. Ezek közül kiemelkedõ jelentõségû a MAP-kináz jelátviteli útvonal konstitutív aktivációját eredményezõ NRAS és BRAF onkogének mutációja, melyek a tumorgenezis korai fázisában jelennek meg. Ezekhez a mutációkhoz a daganatprogresszió során újabb genomikai eltérések társulnak, melyek együttesen eredményezik az agresszív fenotípust. Vizsgálataink során elsõdleges célunk volt a BRAF- és NRAS-mutációt hordozó primer melanómákat jellemzõ molekuláris eltérések feltérképezése. A melanómagenom genetikai alterációinak analízisére array komparatív genomhibridizációt (array-CGH) alkalmaztunk. Eredményeink szerint a BRAF-mutációt hordozó daganatok leggyakoribb eltérései az 1-es kromoszóma hosszú karja (1q25-1q25), valamint a teljes 7-es kromoszóma DNS-többlete, és a 10-es kromoszóma hosszú karjának (10q23-10q26) DNS-hiánya voltak. Az NRAS-mutációt hordozó daganatokat a 11q22.3-11q25 régió gyakori deléciója jellemezte. Eddigi adataink alapján feltételezhetjük, hogy annak ellenére, hogy az NRAS és a BRAF onkogének aktivációs mutációi ugyanazt a szignáltranszdukciós útvonalat aktiválják, a primer melanómák tumorgenezise során eltérõ genetikai eltéréseket hordozó molekulákkal kooperálnak. Eredményeink elemzése során a különbözõ szignáltranszdukciós útvonalak részletesebb vizsgálatával felderítettük, hogy a BRAF-mutációt hordozó daganatokban leggyakrabban a MAPK-JAK jelátviteli útvonalak közötti interakcióban részt vevõ fehérjék génjei sérülnek, majd különbözõ adatbányászati algoritmusok segítségével további BRAF-mutációval összefüggésbe hozható géneltéréseket azonosítottunk a MAPK-útvonalból. Vizsgálataink másik szakaszában részletesen tanulmányoztuk a 11q13 amplifikációs klaszter géneltéréseit, melyet array-CGH vizsgálataink során a melanóma egyik leggyakoribb genetikai eltéréseként azonosítottunk. Eredményeink arra utalnak, hogy a 11q13 régióban lokalizálódó onkogének koamplifikációja, a BRAF- vagy NRAS-mutáció CCND1-amplifikációval társulva gyakrabban jellemzõ rossz prognózisú daganatokra, mint e genetikai eltérések jelenléte külön-külön.

Topics: Chromosomes, Human, Pair 10; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 7; Comparative Genomic Hybridization; Cyclin D1; DNA Copy Number Variations; GTP Phosphohydrolases; Heterozygote; Humans; MAP Kinase Signaling System; Melanoma; Membrane Proteins; Mutation; Polymerase Chain Reaction; Proto-Oncogene Proteins B-raf; Skin Neoplasms

Cyclin D1-cyclin-dependent kinase 4/6 (CDK4/6) dysregulation is a major contributor to melanomagenesis. Clinical evidence has revealed that p16(INK4A), an allosteric inhibitor of CDK4/6, is inactivated in over half of human melanomas, and numerous animal models have demonstrated that p16(INK4A) deletion promotes melanoma. FBXO4, a specificity factor for the E3 ligase that directs timely cyclin D1 proteolysis, has not been studied in melanoma. We demonstrate that Fbxo4 deficiency induces Braf-driven melanoma and that this phenotype depends on cyclin D1 accumulation in mice, underscoring the importance of this ubiquitin ligase in tumor suppression. Furthermore, we have identified a substrate-binding mutation, FBXO4 I377M, that selectively disrupts cyclin D1 degradation while preserving proteolysis of the other known FBXO4 substrate, TRF1. The I377M mutation and Fbxo4 deficiency result in nuclear accumulation of cyclin D1, a key transforming neoplastic event. Collectively, these data provide evidence that FBXO4 dysfunction, as a mechanism for cyclin D1 overexpression, is a contributor to human malignancy.

Topics: Amino Acid Substitution; Animals; Cell Line, Tumor; Cyclin D1; F-Box Proteins; Gene Deletion; Humans; Melanoma; Mice; Point Mutation; Proto-Oncogene Proteins B-raf; Tumor Suppressor Proteins; Ubiquitination

Although the 'gold standard' for melanoma diagnosis remains histopathological analysis, presently dermoscopists play a significant role in the diagnostic process. However, even a combined approach may not allow a clear-cut judgment on equivocal melanocytic lesions. Fluorescence in-situ hybridization (FISH) can offer assistance in the evaluation of chromosome abnormalities associated with malignancies, and its role is emerging in melanoma diagnosis. The aim of this study was to evaluate the diagnostic role of the FISH in the assessment of controversial lesions, defined as those lesions showing discrepancies between dermatoscopic and histological evaluations. Twenty clinically and histologically ambiguous melanocytic lesions were selected. After the first histopathologic diagnosis, a second pathologist examined the specimens in a blinded review for a second opinion and to identify the most suitable areas to hybridize using probes specific to RREB1, MYB, and CCND1 genes and the centromere of chromosome 6. The first histopathological evaluation led to the diagnosis of melanoma in seven cases, whereas the second identified eight cases of malignant melanoma and was in agreement with the first in 65% of cases and with dermoscopy in 40% of cases. Cytogenetic abnormalities detected by FISH are markers of malignancy that can be useful in the characterization of difficult-to-diagnose melanocytic tumors, when the dermatologist and the pathologist have a different opinions.

Topics: Adult; Aged; Aged, 80 and over; Centromere; Chromosome Aberrations; Cyclin D1; Dermoscopy; DNA-Binding Proteins; Female; Humans; In Situ Hybridization, Fluorescence; Male; Melanocytes; Melanoma; Melanoma, Cutaneous Malignant; Middle Aged; Nevus; Proto-Oncogene Proteins c-myb; Skin Neoplasms; Transcription Factors; Young Adult

We previously demonstrated that α-mangostin, γ-mangostin, and 8-deoxygartanin have significant cytotoxic effects on human melanoma SK-MEL-28 cell line. The current study revealed the underlying mechanisms. α-Mangostin (7.5  μg/mL) activated caspase activity, with a 3-fold and 4-fold increased caspase 8 and 9 activity, respectively. The molecular mechanisms were investigated by qRT-PCR for mRNA related to cell cycle arrest in G1 phase (p21(WAF1) and cyclin D1), apoptosis (cytochrome C, Bcl-2, and Bax), and survival pathways (Akt1, NFκB, and IκBα). α-Mangostin significantly upregulated mRNA expression of cytochrome C and p21(WAF1) and downregulated that of cyclin D1, Akt1, and NFκB. γ-Mangostin significantly downregulated mRNA expression of Akt1 and NFκB and upregulated p21(WAF1) and IκBα. 8-Deoxygartanin significantly upregulated the mRNA expression of p21(WAF1) and downregulated that of cyclin D1 and NFκB. The three xanthones significantly inhibited the mRNA expression of the BRAF V600E mutation. Moreover, α-mangostin and γ-mangostin significantly downregulated Akt phosphorylation at Ser473. In conclusion, the three xanthones induced an inhibitory effect on SK-MEL-28 cells by modulating the molecular targets involved in the apoptotic pathways.

Topics: Apoptosis; Caspase 8; Caspase 9; Cell Line, Tumor; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; I-kappa B Kinase; Melanoma; Phosphorylation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; RNA, Messenger; RNA, Neoplasm; Up-Regulation; Xanthones

Metastasis, a multistep process, is a major cause of mortality in cancer patients. Thus, it is hoped that inhibition of metastasis at any step, such as proliferation, migration, or invasion, using small-molecule inhibitors will reduce this mortality. Recent study suggests that the Janus kinase/signal transducer and activator of transcription 3 signal transduction pathway is a central pathway that regulates tumor progression and metastasis and can be blocked using tyrosine kinase inhibitors. In this study we used a synthetic tyrosine kinase inhibitor, AG490, to block the constitutive activation of the Janus kinase/signal transducer and activator of transcription 3 pathway in A549 lung carcinoma and A375 melanoma cell lines. Our results show that AG490 at subtoxic doses can effectively suppress tumor cell proliferation by limiting the expression of cyclin D1. Furthermore, AG490 is seen to induce apoptosis, inhibit cellular migration by disrupting actin organization, and suppress matrix metalloproteinase 2 activity. Taken together, these data demonstrate that AG490 can exert antimetastatic activity by inhibiting cellular proliferation, invasion, and migration.

Topics: Actins; Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Dose-Response Relationship, Drug; Enzyme Inhibitors; Humans; In Vitro Techniques; Janus Kinase 2; Lung Neoplasms; Matrix Metalloproteinase 2; Melanoma; Protein-Tyrosine Kinases; STAT3 Transcription Factor; Tyrphostins

Activation of the mitogen-activated protein kinase (MAPK) pathway targets the putative tumor suppressor protein inducible cAMP early repressor (ICER) to ubiquitin-mediated proteasomal degradation [Yehia et al. JBC 2001; 276: 35272-35279]. We demonstrate that ICER proteasomal degradation is implicated in Ras/MAPK-mediated melanoma tumorigenesis. In a system using Tyr/Tet-Ras INK4a-/- transgenic mice and melanoma cells in culture termed R545 cells isolated from Tyr/Tet-Ras INK4a-/- mice [Chin et al. Nature 1999; 400: 468-472], melanoma genesis and melanoma maintenance is strictly dependent upon expression of H-RasV12G. We found that ICER protein was not expressed during melanoma genesis but was strongly expressed in regressing melanomas. Similarly in R545 cells, ICER protein expression was negatively regulated by H-RasV12G. The expression of ICER mRNA was not affected by H-RasV12G expression, suggesting that ICER regulation was post-translational. Indeed, pharmacological inhibition of Ras activity or the proteasome abolished the degradation of ICER caused by H-RasV12G expression indicating that RAS oncogene regulates the expression of ICER protein by targeting ICER to proteasomal degradation. By engineering clones of R545 melanoma cells stably transfected with ICER we were able to determine the prerequisite for Ras-induced tumorigenesis. The reconstitution of physiological levels of ICER showed a significant decrease in cell growth, as well as inhibition of anchorage-independent cell growth and tumorigenicity in nude mice. ICER was found to efficiently repress the expression of cyclin D1 in R545 cells due to the binding of ICER to the CRE in the cyclin D1 promoter. Taken together, we postulate that ICER protein might be targeted to degradation in human tumors where Ras is mutated.

Topics: Animals; Cell Line, Tumor; Cell Transformation, Neoplastic; Cyclic AMP Response Element Modulator; Cyclin D1; Genes, ras; HeLa Cells; Humans; Male; Melanoma; Mice; Mice, Nude; Mice, SCID; Mice, Transgenic; Mitogen-Activated Protein Kinases; Promoter Regions, Genetic; Proteasome Endopeptidase Complex; Protein Processing, Post-Translational; Repressor Proteins; Tumor Suppressor Proteins

Primary sinonasal mucosal melanomas are aggressive tumors with a poor clinical control by current treatments, raising the urgent need of novel strategies.. By fluorescence in situ hybridization (FISH), direct sequencing, and immunohistochemistry, we investigate the spectrum of molecular abnormalities in a cohort of 32 cases of primary sinonasal mucosal melanomas.. We found that all primary sinonasal mucosal melanomas lack BRAF V600E mutation; in addition, they are characterized by somatic mutations of NRAS (22%) and KIT (12.5%), together with amplification of RREB1 (100%) and loss of MYB (76%). The large majority of cases showed KIT protein expression (96.9%). Among tumor suppressor genes, primary sinonasal mucosal melanomas showed loss of PTEN (48.1%) and p16/INK4a (55.2%). All tested cases showed expression of pAkt and pErk, suggesting a combined activation of PI3K/Akt and RAS-mitogen-activated protein kinase (MAPK) pathways.. This molecular fingerprint strongly argues against the clinical efficacy of BRAF-inhibitors, but could candidate primary sinonasal mucosal melanomas to therapeutic strategies targeting RAS and KIT mutations or inhibiting PI3K-Akt-mTOR pathway.

Topics: Adult; Aged; Aged, 80 and over; Cohort Studies; Cyclin D1; DNA-Binding Proteins; Female; Genes, myb; Genes, p16; Genes, ras; Humans; Male; Melanoma; Middle Aged; Mutation; Nasal Mucosa; Paranasal Sinus Neoplasms; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-kit; PTEN Phosphohydrolase; Transcription Factors

The molecular mechanisms mediating cylindromatosis (CYLD) tumor suppressor function appear to be manifold. Here, we demonstrate that, in contrast to the increased levels of phosphorylated c-Jun NH(2)-terminal kinase (pJNK), CYLD was decreased in a majority of the melanoma cell lines and tissues examined. Exogenous expression of CYLD but not its catalytically deficient mutant markedly inhibited melanoma cell proliferation and migration in vitro and subcutaneous tumor growth in vivo. In addition, the melanoma cells expressing exogenous CYLD were unable to form pulmonary tumor nodules following tail-vein injection. At the molecular level, CYLD decreased β1-integrin and inhibited pJNK induction by tumor necrosis factor-α or cell attachment to collagen IV. Moreover, CYLD induced an array of other molecular changes associated with modulation of the "malignant" phenotype, including a decreased expression of cyclin D1, N-cadherin, and nuclear Bcl3, and an increased expression of p53 and E-cadherin. Most interestingly, coexpression of the constitutively active MKK7 or c-Jun mutants with CYLD prevented the above molecular changes, and fully restored melanoma growth and metastatic potential in vivo. Our findings demonstrate that the JNK/activator protein 1 signaling pathway underlies the melanoma growth and metastasis that are associated with CYLD loss of function. Thus, restoration of CYLD and inhibition of JNK and β1-integrin function represent potential therapeutic strategies for treatment of malignant melanoma.

Topics: Antigens, CD; B-Cell Lymphoma 3 Protein; Cadherins; Cell Adhesion; Cell Line, Tumor; Cell Proliferation; Collagen Type IV; Cyclin D1; Deubiquitinating Enzyme CYLD; Disease Progression; Humans; Integrin beta1; MAP Kinase Kinase 7; MAP Kinase Signaling System; Melanoma; Mutation; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-jun; Skin Neoplasms; Transcription Factor AP-1; Transcription Factors; Tumor Necrosis Factor-alpha; Tumor Suppressor Protein p53; Tumor Suppressor Proteins

Even in experienced hands, the classification of some melanocytic lesions of the conjunctiva remains challenging. In skin pathology, the recent application of fluorescence in situ hybridisation (FISH) has been demonstrated to be of use for the analysis and diagnosis of ambiguous melanocytic neoplasms of the skin. This study set out to evaluate this method on seven prospective conjunctival cases that were histologically equivocal.. 18 unequivocal retrospective melanocytic controls were exposed to FISH. Commercially available probes assessing copy numbers of RREB1 (6p25), MYB (6q23) and CCND1 (11q13) genes compared with CEP6 (a chromosome six centromeric reference point) were used. After control verification, seven prospective, equivocal cases were identified and exposed to FISH.. There was complete correlation between FISH result and the control section histopathology report. Control cases of melanoma cases were all positive for FISH and control benign lesions were negative. Of the seven equivocal cases, five were positive and classed as invasive melanoma or melanoma-in situ, one was negative and one tetraploid, classed as negative (these last two cases were classed as naevi with careful clinical observation).. FISH is very useful in classifying equivocal conjunctival melanocytic lesions, especially those with atypical junctional activity and naevoid melanocytic proliferations of the conjunctiva.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Conjunctival Neoplasms; Cyclin D1; DNA Probes; DNA-Binding Proteins; Female; Humans; In Situ Hybridization, Fluorescence; Male; Melanoma; Middle Aged; Neoplasm Proteins; Nevus, Pigmented; Prospective Studies; Proto-Oncogene Proteins c-myb; Retrospective Studies; Transcription Factors; Young Adult

Markedly pleomorphic epithelioid cells with high mitotic activity, giant cell formation, very large atypical nuclei, multiple nucleoli and abundant cytoplasm characterize 'monster' cells and may indicate aggressive tumor behavior. Very rare reports of melanomas comprised of 'monster cells' or cells with comparable histomorphological features, found in tissue samples from skin, lymph nodes, CNS, oral cavity and ileum have been published in the literature. This case is the first such description in the lung, and it is characterized with a battery of immunohistochemical stains; BRAF mutation status was negative, and fluorescence in situ hybridization analysis revealed increased copy number gains in 11q (cyclin D1), which is associated with poor prognosis in melanoma. The presence of monster cells in melanoma was associated with aggressive behavior in the reported patient.

Topics: Cyclin D1; Fatal Outcome; Female; Giant Cells; Humans; Lung Neoplasms; Melanoma; Middle Aged; Skin Neoplasms

Melanoma is one of the most aggressive and extremely resistant to conventional therapies neoplasms. Recently, cellular resistance was linked to the cancer stem cell phenotype, still controversial and not well-defined. In this study, we used a Rhodamine 123 (Rh123) exclusion assay to functionally identify stem-like cells in metastatic human melanomas and melanoma cell lines. We demonstrate that a small subset of Rh123-low-retention (Rh123(low)) cells is enriched for stem cell-like activities, including the ability to self-renew and produce nonstem Rh123(high) progeny and to form melanospheres, recapitulating the phenotypic profile of the parental tumor. Rh123(low) cells are relatively quiescent and chemoresistant. At the molecular level, we show that melanoma Rh123(low) cells overexpress HIF1α, pluripotency factor OCT4, and the ABCB5 marker of melanoma stem cells and downregulate the expression of Cyclin D1 and CDK4. Interestingly, a short treatment with LY294002, an inhibitor of the PI3K/AKT pathway, specifically reverts a subset of Rh123(high) cells to the Rh123(low) phenotype, whereas treatment with inhibitors of mammalian target of rapamycin, phosphatase and tensin homolog or mitogen-activated protein kinase signaling does not. This phenotypic switching was associated with reduced levels of the HIF1α transcript and an increase in the level of phosphorylated nuclear FOXO3a preferentially in Rh123(low) cells. Moreover, the Rh123(low) cells became less quiescent and displayed a significant increase in their melanosphere-forming ability. All the above indicates that the Rh123(low) melanoma stem cell pool is composed of cycling and quiescent cells and that the PI3K/AKT signaling while maintaining the quiescence of Rh123(low) G0 cells promotes the exit of cycling cells from the stem cell compartment.

Topics: ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cell Cycle; Cell Line, Tumor; Chromones; Cyclin D1; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Immunohistochemistry; Melanoma; Morpholines; Neoplastic Stem Cells; Octamer Transcription Factor-3; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Reverse Transcriptase Polymerase Chain Reaction; Rhodamine 123; Signal Transduction; Tumor Cells, Cultured

Studies integrating clinicopathological and genetic features have revealed distinct patterns of genomic aberrations in Melanoma. Distributions of BRAF or NRAS mutations and gains of several oncogenes differ among melanoma subgroups, while 9p21 deletions are found in all melanoma subtypes. In the study, status of genes involved in cell cycle progression and apoptosis was evaluated in a panel of 17 frozen primary acral melanomas. NRAS mutations were found in 17% of the tumors. In contrast, BRAF mutations were not found. Gains of AURKA gene (20q13.3) were detected in 37.5% of samples, gains of CCND1 gene (11q13) or TERT gene (5p15.33) in 31.2% and gains of NRAS gene (1p13.2) in 25%. Alterations in 9p21 were identified in 69% of tumors. Gains of 11q13 and 20q13 were mutually exclusive, and 1p13.2 gain was associated with 5p15.33. Our findings showed that alterations in RAS-related pathways are present in 87.5% of acral lentiginous melanomas.

Topics: Apoptosis; Aurora Kinase A; Aurora Kinases; Cell Cycle; Chromosome Deletion; Cluster Analysis; Cyclin D1; Gene Dosage; Gene Expression Regulation, Neoplastic; Genes, ras; Genetic Variation; GTP Phosphohydrolases; Humans; Melanoma; Membrane Proteins; Mutation; Mutation, Missense; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins B-raf; Signal Transduction; Skin Neoplasms; Telomerase

Melanoma is one of the most common cancers, and its incidence has continued to increase over the past few decades. Chemotherapy resistance and related defects in apoptotic signaling are critical for the high mortality of melanoma. Effective drugs are lacking because apoptosis regulation in this tumor type is not well understood. The folate pathway has been considered an interesting target for anticancer therapies, and approaches targeting this pathway have recently been extended to melanoma treatment. In this study, the intracellular apoptosis signaling pathways of two melanoma cells lines (SK-MEL-2 and SK-MEL-28) were investigated after treatment with a new experimental antifolate substance (MR36) that targets thymidylate synthase. In both melanoma cell lines, apoptosis induction was triggered by a p53-independent mechanism. MR36-induced apoptosis was associated with a loss of both mitochondrial membrane potential and caspase-3 activation. Induction of cell cycle arrest by MR36 was associated with changes in the expression of key cell cycle regulators, such as p21 and cyclin D1, and the hypophosphorylation of pRb. In addition, Fas signaling was also analyzed. These findings suggest that, unlike classical antifolates, MR36 exerted an inhibitory effect on both the enzymatic function and expression of thymidylate synthase, thereby inducing apoptosis through the activation of the extrinsic and intrinsic pathways in the melanoma cell lines. MR36 showed a different mechanism of action from the known antifolates (Nolatrexed and Pemetrexed) that resulted in higher anticancer activity. Therefore, MR36 should be included as a potential new therapeutic treatment in melanoma research.

Topics: Apoptosis; Blotting, Western; Caspase 3; Cell Cycle; Cell Line, Tumor; Coumarins; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Enzyme Inhibitors; Folic Acid Antagonists; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Models, Biological; Phosphorylation; Polyglutamic Acid; Retinoblastoma Protein; RNA, Messenger; Signal Transduction; Thymidylate Synthase; Tumor Suppressor Protein p53

The E3 ligase Rad18 is a key regulator for the lesion bypass pathway, which plays an important role in genomic stability. However, the status of Rad18 expression in melanoma is not known. Using melanoma tissue microarray (TMA), we showed that nuclear Rad18 expression was upregulated in primary and metastatic melanoma compared to dysplastic nevi. Rad18 expression was significantly reduced in sun-exposed sites compared to the sun-protected sites. Strong Rad18 expression correlated with worse 5-year patient survival and was an independent prognostic factor for melanoma found in the sun-protected sites. Furthermore, we showed that melanoma cell proliferation and the expression of pAkt and cyclin D1 were reduced upon Rad18 knockdown. We, for the first time, showed that Rad18 is significantly increased in melanoma and predicts the poor outcome for melanoma in the sun-protected sites. Rad18 is involved in the regulation of melanoma cell proliferation, which can be exploited in designing new strategy for melanoma treatment.

Topics: Cell Line, Tumor; Cell Proliferation; Cyclin D1; DNA-Binding Proteins; Female; Humans; Male; Melanoma; Middle Aged; Multivariate Analysis; Proportional Hazards Models; Proto-Oncogene Proteins c-akt; Skin Neoplasms; Survival Analysis; Ubiquitin-Protein Ligases

Spitz naevi are difficult to diagnose, because of significant overlap with melanomas. It has been recently demonstrated that the LSI RREB1(6p25)/LSI MYB(6q23)/LSI CCND1(11q13)/CEP6 fluorescence in-situ hybridization (FISH) assay is a reliable tool with which to distinguish benign naevi and melanomas. Little is known about its diagnostic usefulness in Spitz naevi.. We investigated 51 patients with Spitz naevi and long-term median follow-up (8.18 years) with the multicolour FISH probe. Control groups included 11 benign naevi and 14 melanomas. Spitz naevi from 32 (63%) patients did not show cytogenetic abnormalities (FISH-). In contrast, Spitz naevi from 19 (37%) patients showed changes in the investigated loci (FISH+). Spitz naevi with the FISH+ profile showed chromosome X polysomy in 14/18 (78%) patients. All Spitz naevi with the FISH- profile were disomic. All melanomas displayed a FISH+ profile, and 4/11 (36%) showed chromosome X polysomy. No differences in clinicopathological features were detected between Spitz naevi with and without genetic abnormalities.. The presence of gene copy number changes in Spitz naevi as detected by FISH is higher than expected, and Spitz naevi at the genetic level represent a heterogeneous group. The findings of similar cytogenetic alterations in Spitz naevi and melanomas suggest that there should be cautious interpretation of FISH analysis in this setting.

Topics: Adolescent; Adult; Biopsy; Child; Child, Preschool; Chromosome Aberrations; Chromosomes, Human, X; Cyclin D1; Diagnosis, Differential; DNA-Binding Proteins; Female; Follow-Up Studies; Gene Dosage; Humans; In Situ Hybridization, Fluorescence; Male; Melanoma; Middle Aged; Nevus, Epithelioid and Spindle Cell; Oncogene Proteins v-myb; Retrospective Studies; Skin; Skin Neoplasms; Transcription Factors; Young Adult

Resistance to therapies develops rapidly for melanoma leading to more aggressive disease. Therefore, agents are needed that specifically inhibit proteins or pathways controlling the development of this disease, which can be combined, dependent on genes deregulated in a particular patient's tumors. This study shows that elevated sphingosine-1-phosphate (S-1-P) levels resulting from increased activity of sphingosine kinase-1 (SPHK1) occur in advanced melanomas. Targeting SPHK1 using siRNA decreased anchorage-dependent and -independent growth as well as sensitized melanoma cells to apoptosis-inducing agents. Pharmacological SPHK1 inhibitors SKI-I but not SKI-II decreased S-1-P content, elevated ceramide levels, caused a G2-M block and induced apoptotic cell death in melanomas. Targeting SPHK1 using siRNA or the pharmacological agent called SKI-I decreased the levels of pAKT. Furthermore, SKI-I inhibited the expression of CYCLIN D1 protein and increased the activity of caspase-3/7, which in turn led to the degradation of PARP. In animals, SKI-I but not SKI-II retarded melanoma growth by 25-40%. Thus, targeting SPHK1 using siRNAs or SKI-I has therapeutic potential for melanoma treatment either alone or in combination with other targeted agents.

Topics: Animals; Apoptosis; Cell Adhesion; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Down-Regulation; Fibroblasts; G1 Phase Cell Cycle Checkpoints; Humans; Lysophospholipids; Melanocytes; Melanoma; Mice; Molecular Targeted Therapy; Phosphotransferases (Alcohol Group Acceptor); Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Resting Phase, Cell Cycle; RNA, Small Interfering; Skin Neoplasms; Sphingosine; Staurosporine; Thiazoles; Up-Regulation; Xenograft Model Antitumor Assays

GNAQ mutations at codon 209 have been recently identified in approximately 50% of uveal melanomas (UM) and are reported to be oncogenic through activating the MAPK/Erk1/2 pathway. Protein kinase C (PKC) is a component of signaling from GNAQ to Erk1/2. Inhibition of PKC might regulate GNAQ mutation-induced Erk1/2 activation, resulting in growth inhibition of UM cells carrying GNAQ mutations. UM cells carrying wild type or mutant GNAQ were treated with the PKC inhibitor enzastaurin. Effects on proliferation, apoptosis, and signaling events were evaluated. Enzastaurin downregulated the expression of several PKC isoforms including PKCβII PKCθ, PKCε and/or their phosphorylation in GNAQ mutated cells. Downregulation of these PKC isoforms in GNAQ mutated cells by shRNA resulted in reduced viability. Enzastaurin exhibited greater antiproliferative effect on GNAQ mutant cells than wild type cells through induction of G1 arrest and apoptosis. Enzastaurin-induced G1 arrest was associated with inhibition of Erk1/2 phosphorylation, downregulation of cyclin D1, and accumulation of cyclin dependent kinase inhibitor p27(Kip1). Furthermore, enzastaurin reduced the expression of antiapoptotic Bcl-2 and survivin in GNAQ mutant cells. Inhibition of Erk1/2 phosphorylation with a MEK specific inhibitor enhanced the sensitivity of GNAQ wild type cells to enzastaurin, accompanied by p27(Kip1) accumulation and/or inhibition of enzastaurin-induced survivin and Bcl-2 upregulation. PKC inhibitors such as enzastaurin have activity against UM cells carrying GNAQ mutations through inhibition of the PKC/Erk1/2 pathway and induction of G1 arrest and apoptosis. Inhibition of the PKC pathway provides a basis for clinical investigation in patients with UM.

Topics: Apoptosis; Bromodeoxyuridine; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Drug Screening Assays, Antitumor; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; GTP-Binding Protein alpha Subunits; GTP-Binding Protein alpha Subunits, Gq-G11; Humans; Indoles; Isoenzymes; Melanoma; Mitogen-Activated Protein Kinase Kinases; Molecular Sequence Data; Mutation; Protein Kinase C; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Uveal Neoplasms

The acquisition of abnormalities at G1/S is considered a crucial step in the genesis and progression of melanoma. The expression of cell cycle regulators has also been used in various neoplasms as an adjunct to diagnosis. The aim of this study was to compare the expression of p16, p21, p27 and cyclin D1 in oral nevi and melanomas. Expression of these cell cycle regulatory proteins was evaluated by immunohistochemistry in 51 oral melanocytic lesions, including 38 intramucosal nevi and 13 primary oral melanomas. p16 and p27 were highly expressed in intramucosal nevi, whereas p21 and cyclin D1 expression was higher in oral melanomas. The results indicate that p21 and cyclin D1 may be involved in the development of oral melanomas, and eventually they may be useful in the differential diagnoses of oral benign and malignant melanocytic lesions.

Topics: Adolescent; Adult; Aged; Biomarkers, Tumor; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Female; Humans; Immunohistochemistry; Male; Melanoma; Middle Aged; Mouth Neoplasms; Neoplasm Proteins; Nevus; Young Adult

The purpose of this preclinical study was to determine the effectiveness of RAF265, a multikinase inhibitor, for treatment of human metastatic melanoma and to characterize traits associated with drug response.. Advanced metastatic melanoma tumors from 34 patients were orthotopically implanted to nude mice. Tumors that grew in mice (17 of 34) were evaluated for response to RAF265 (40 mg/kg, every day) over 30 days. The relation between patient characteristics, gene mutation profile, global gene expression profile, and RAF265 effects on tumor growth, mitogen-activated protein/extracellular signal-regulated kinase (MEK)/extracellular signal-regulated kinase (ERK) phosphorylation, proliferation, and apoptosis markers was evaluated.. Nine of the 17 tumors that successfully implanted (53%) were mutant BRAF (BRAF(V600E/K)), whereas eight of 17 (47%) tumors were BRAF wild type (BRAF(WT)). Tumor implants from 7 of 17 patients (41%) responded to RAF265 treatment with more than 50% reduction in tumor growth. Five of the 7 (71%) responders were BRAF(WT), of which 1 carried c-KIT(L576P) and another N-RAS(Q61R) mutation, while only 2 (29%) of the responding tumors were BRAF(V600E/K). Gene expression microarray data from nonimplanted tumors revealed that responders exhibited enriched expression of genes involved in cell growth, proliferation, development, cell signaling, gene expression, and cancer pathways. Although response to RAF265 did not correlate with pERK1/2 reduction, RAF265 responders did exhibit reduced pMEK1, reduced proliferation based upon reduced Ki-67, cyclin D1 and polo-like kinase1 levels, and induction of the apoptosis mediator BCL2-like 11.. Orthotopic implants of patient tumors in mice may predict prognosis and treatment response for melanoma patients. A subpopulation of human melanoma tumors responds to RAF265 and can be characterized by gene mutation and gene expression profiles.

Topics: Animals; Apoptosis; Base Sequence; bcl-X Protein; Cell Cycle Proteins; Cell Proliferation; Cyclin D1; Extracellular Signal-Regulated MAP Kinases; Female; Gene Expression Profiling; Humans; Imidazoles; Ki-67 Antigen; Male; MAP Kinase Signaling System; Melanoma; Mice; Mice, Nude; Mutation; Oligonucleotide Array Sequence Analysis; Polo-Like Kinase 1; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-kit; Proto-Oncogene Proteins p21(ras); Pyridines; Sequence Analysis, DNA; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Homogeneous staining regions (HSRs) have been previously shown to confer a worse prognosis in solid tumors and myelodysplastic syndromes. We previously reported a single case of melanoma with HSR for cyclin D1 and postulated that HSR for cyclin D1 is an independent poor prognostic indicator. Herein, we report 7 cases of melanoma with HSR for cyclin D1. The cases occurred in elderly men and women with an average age of 65 years. Three cases occurred in areas of intermittent sun exposure, 2 cases occurred in chronically sun-damaged areas, and 2 cases were acral. HSR correlated with aggressive histology. The average Breslow depth was 2.7 mm (range, 1-11 mm), the average mitotic index was 5.1 per square millimeter, and 5 of the 7 cases were ulcerated. Clinical follow-up was available for 6 of the 7 cases. Five of the 6 cases for which clinical follow-up was available metastasized, and 1 patient died of metastatic melanoma. Three cases with metastatic disease occurred in primary melanomas with lower Breslow depths, ranging from 1.0 to 1.4 mm. These additional cases of melanoma with an aggressive clinical course provide further evidence of the prognostic significance of HSR for cyclin D1 in melanoma. Larger cohort studies are needed to validate this observation.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Chicago; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; In Situ Hybridization, Fluorescence; Male; Melanoma; Middle Aged; Mitotic Index; Prognosis; Retrospective Studies; Skin; Skin Neoplasms; Time Factors

This paper aims to evaluate the anti-tumour properties of elatol, a compound (sesquiterpene) isolated from algae Laurencia microcladia.. In-vitro and in-vivo anti-tumour properties of elatol were investigated using: MTT assays to assess the cytotoxic effects; flow cytometry analysis to examine the cell cycle and apoptosis; Western blot analysis for determination of the expression of cell cycle and apoptosis proteins; and study of in-vivo tumour growth in mice (C57Bl6 mice bearing B16F10 cells).. Elatol exhibited a cytotoxic effect, at least in part, by inducing cell cycle arrest in the G(1) and the sub-G(1) phases, leading cells to apoptosis. Western blot analysis demonstrated that elatol reduced the expression of cyclin-D1, cyclin-E, cyclin-dependent kinase (cdk)2 and cdk4. A decrease in bcl-xl and an increase in bak, caspase-9 and p53 expression was also observed. In the in-vivo experiment, treatment with elatol was able to reduce tumour growth in C57Bl6 mice.. Elatol promotes a delay in the cell cycle, probably in the G(1)/S transition, activating the apoptotic process and this could be responsible, at least in part, for the in-vivo effects observed. Taken together, the in-vitro and in-vivo experiments suggested that elatol has anti-tumour properties. Further studies should be conducted to clarify the mechanism of action.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein; Caspase 9; Cell Cycle Checkpoints; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 4; Female; Humans; Laurencia; Male; Melanoma; Mice; Mice, Inbred C57BL; Neoplasms; Phytotherapy; Plant Extracts; Spiro Compounds

The differential diagnosis between Spitz naevus and spitzoid melanoma can be extremely difficult, or even impossible. In recent years, many attempts have been made to find specific histopathological or immunohistochemical markers, although none has proved successful. Because the prognosis and treatment of each are very different, it is important to distinguish between these entities. We evaluated the ability of the fluorescence in situ hybridization (FISH) assay-designed to detect the copy number of the RREB1 (6p25), MYB (6q23) and CCND1 (11q13) genes and of centromere 6 (Cep 6)-in order to distinguish between Spitz naevus and spitzoid melanoma.. We evaluated 12 spitzoid melanomas and six Spitz naevi from our records. The diagnosis of both conditions was based on previously described histopathological criteria. We obtained valuable results for FISH in eight spitzoid melanomas and five Spitz naevi. Chromosomal aberrations were detected in seven of the eight spitzoid melanomas (FISH-positive) and in none of the five Spitz naevi. The FISH-negative spitzoid melanoma was the least typical in its group.. FISH was able to distinguish between Spitz naevus and spitzoid melanoma, with a sensitivity of 87.5% and a specificity of 100%. Our findings suggest that FISH could prove a useful tool in the differential diagnosis between these entities.

Topics: Adult; Child; Chromosome Aberrations; Cyclin D1; Diagnosis, Differential; DNA-Binding Proteins; Female; Gene Dosage; Genes, myb; Humans; In Situ Hybridization, Fluorescence; Male; Melanoma; Middle Aged; Nevus, Epithelioid and Spindle Cell; Skin Neoplasms; Transcription Factors; Young Adult

It is well demonstrated that CCND1 amplification is a frequent event in the acral subtype of cutaneous malignant melanoma; however, its role in the other subtypes of the disease is still controversial. The objectives of this study were to evaluate genetic and expression alterations of CCND1 with a focus on primary cutaneous melanomas, to define BRAF and NRAS mutation status, and correlate the data with clinical-pathological parameters. CCND1 amplification was associated with ulceration and the localization of the metastasis. After correction for the mutation state of BRAF and NRAS genes, CCND1 amplification in samples without such mutations was associated with ulceration and sun exposure. The cyclin D1 (CCND1) mRNA level decreased in lesions with multiple metastases and was correlated with both the mRNA levels and mutation state of BRAF and NRAS genes. Primary melanomas with BRAF(V600) or NRAS(Q61 ) mutations exhibited lower CCND1 mRNA level. CCND1 protein expression was associated with Breslow thickness, metastasis formation, and shorter survival time. These observations suggest that CCND1 alterations are linked to melanoma progression and are modified by BRAF and NRAS mutations. Our data show that CCND1 amplification could have a prognostic relevance in cutaneous melanoma and highlight that altered CCND1 gene expression may influence the metastatic progression, survival, and the localization of metastases.

Topics: Adult; Comparative Genomic Hybridization; Cyclin D1; Disease Progression; Female; Follow-Up Studies; Genes, ras; Humans; Immunoenzyme Techniques; In Situ Hybridization, Fluorescence; Lymphatic Metastasis; Male; Melanoma; Middle Aged; Mutation; Neoplasm Staging; Prognosis; Proto-Oncogene Proteins B-raf; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Skin Neoplasms; Survival Rate; Young Adult

Malignant melanoma is a relatively rare but potentially aggressive tumor in children and adolescents. We report the case of a metastatic malignant melanoma in a 17-year-old girl, first diagnosed on cytological features of a fine-needle lymph node aspiration and then histologically confirmed by both examination of the metastatic adenopathy and a clinically harmless skin lesion of the scalp, which harbored focal microscopic pattern of melanoma. A fluorescent in situ hybridization study revealed that both metastatic and primary cutaneous tumours contained the same and pejorative chromosomal aberration consisting in CCND1 amplification (11q13). This observation raises actual limits and challenges in the fields of diagnosis and treatment of fast-killing melanomas.

Topics: Adolescent; Antibodies, Monoclonal; Antineoplastic Agents, Alkylating; Back Pain; Combined Modality Therapy; Cyclin D1; Dacarbazine; Drug Resistance, Neoplasm; Fatal Outcome; Female; Gene Amplification; Head and Neck Neoplasms; Humans; Immunotherapy; In Situ Hybridization, Fluorescence; Ipilimumab; Lymphatic Metastasis; Melanoma; Nausea; Neoplasm Proteins; Neoplasms, Second Primary; Nevus; Osteolysis; Scalp; Skin Neoplasms; Weight Loss

Melanomas are aggressive neoplasms with limited therapeutic options. Therefore, developing new therapies with low toxicity is of utmost importance. Honokiol is a natural compound that recently has shown promise as an effective anticancer agent.. The effect of honokiol on melanoma cancer cells was assessed in vitro. Proliferation and physiologic changes were determined using hexosaminidase assay and transmission electron microscopy. Protein expression was assessed by immunoblotting.. Honokiol treatment inhibited cell proliferation and induced death. Electron microscopy showed autophagosome formation. Reduced levels of cyclin D1 accompanied cell-cycle arrest. Honokiol also decreased phosphorylation of AKT (known as protein kinase B) and mammalian target of rapamycin, and inhibited γ-secretase activity by down-regulating the expression of γ-secretase complex proteins, especially anterior pharynx-defective 1.. Honokiol is highly effective in inhibiting melanoma cancer cells by attenuating AKT/mammalian target of rapamycin and Notch signaling. These studies warrant further clinical evaluation for honokiol alone or with present chemotherapeutic regimens for the treatment of melanomas.

Topics: Amyloid Precursor Protein Secretases; Animals; Antineoplastic Agents, Phytogenic; Autophagy; Biomarkers, Tumor; Biphenyl Compounds; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Dose-Response Relationship, Drug; Down-Regulation; Immunoblotting; Lignans; Melanoma; Mice; Proto-Oncogene Proteins c-akt; Signal Transduction; TOR Serine-Threonine Kinases

A decrease in the level of the ROC1 protein, which is involved in cyclin D1 degradation, might explain an increase in cyclin D1 protein in the absence of gene overexpression. This study aimed to investigate the relationship between ROC1 and cyclin D1 expression in skin melanomas. A total of 62 cases of primary skin melanomas and 58 cases of compound melanocytic nevi were assessed. Immunohistochemistry was performed using cyclin D1 and ROC1 antibodies, and fluorescent in situ hybridization was used to assess the amplification of the CCND1 gene. ROC1 was expressed in >50% of cells in 87.9% of the melanocytic nevus cases and in 45.2% of the melanoma cases (p=0.0014). There was a significant negative correlation between ROC1 and cyclin D1 expression in all cases (p=0.0008985). In comparison with cyclin D1, ROC1 expression was increased in 86.2% of the melanocytic nevi and in 45.2% of the melanomas (p<0.001). Among the non-amplified melanomas, 50% expressed cyclin D1 in >50% of the cells and expressed ROC1 in <25%. ROC1 expression is negatively correlated with cyclin D1 expression, demonstrating its importance in the degradation of cyclin D1 in melanomas.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Brazil; Carrier Proteins; Chi-Square Distribution; Child; Child, Preschool; Cyclin D1; Gene Amplification; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Melanoma; Middle Aged; Nevus, Pigmented; Skin Neoplasms; Young Adult

The mitogen-activated protein kinase (MAPK) signaling pathway is one of the major cascades that are crucial for the initiation and progression of melanoma; however, the influence of these signaling molecules on patient survival has not been clarified.. The purpose of this study was to analyze the protein expression of MAPK signaling molecules in melanoma, and to correlate the expression status with clinicopathologic parameters.. Expression of c-Kit, phosphorylated ERK (p-ERK), and cyclin D1 was examined by immunohistochemistry in 78 primary melanomas, 24 metastatic lesions, and in 42 benign nevi. The following clinicopathologic variables were evaluated: age, gender, histologic type, tumor site, Breslow thickness, Clark's level, ulceration, and survival period. Statistical analyses were performed for assessment of associations and melanoma-specific survival.. The expression of c-Kit, p-ERK, and cyclin D1 was significantly higher in primary melanomas than in nevi. c-Kit immunoreactivity was highest in thin (Tis-pT2) melanomas, and showed a significant reduction with tumor progression and metastasis. The expression of p-ERK was high in all stages of melanoma. Cyclin D1 positivity increased significantly according to tumor progression, but decreased in metastases. A significant correlation between p-ERK and cyclin D1 expression was observed. Survival analysis failed to detect any trends towards shorter or longer survival among patients expressing either c-Kit, p-ERK or cyclin D1.. The expression of c-Kit, p-ERK, and cyclin D1 might help to differentiate thin melanoma from melanocytic nevus, but it appears to lack prognostic potential.

Topics: Adult; Aged; Aged, 80 and over; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Male; MAP Kinase Signaling System; Melanoma; Middle Aged; Mitogen-Activated Protein Kinase 3; Neoplasm Metastasis; Phosphorylation; Prognosis; Proto-Oncogene Proteins c-kit; Signal Transduction; Skin Neoplasms

Relating specific genetic alterations to prognosis may help improve prognostication in melanoma, may identify key oncogenic drivers in cancer, and may assist in developing targeted therapies. Characteristic genetic alterations in melanoma include chromosomal copy number aberrations. We evaluated 97 melanomas (55 metastasizing and 42 nonmetastasizing) after a minimum 5-year follow-up in a case-control study using fluorescence in situ hybridization, targeting commonly altered chromosomal loci in melanoma. Eight probes arranged in two panels were used, and 11 parameters were evaluated. Parameters showing a statistically significant difference between the metastasizing and nonmetastasizing groups were evaluated with multivariate logistic regression analysis to compare their prognostic potential with other traditional prognostic markers used by the American Joint Committee on Cancer. Four of 11 parameters evaluated, including CCND1 (alias Bcl-1) gain, CCND1 r-gain, MYC (alias c-myc) gain, and MYC r-gain, had a statistically significant difference in the metastasizing versus nonmetastasizing group. All four parameters maintained statistical significance when evaluated in separate multivariate logistic regression analyses that included the seven currently used American Joint Commission on Cancer prognosticators in melanoma. In multivariate analyses, these four parameters were second only to ulceration in their prognostic potential. Copy number changes at 11q13 and 8q24 [corrected] harboring CCND1 and MYC, respectively, are highly associated with prognosis. Fluorescence in situ hybridization targeting these loci may be a useful standardized prognostic marker in melanoma skin cancer.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Case-Control Studies; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 8; Cyclin D1; DNA Copy Number Variations; Female; Humans; Male; Melanoma; Middle Aged; Neoplasm Staging; Prognosis; Proto-Oncogene Proteins c-myc; Skin Neoplasms; Young Adult

RAS mutations occur in more than 30% of all human cancers but efforts to directly target mutant RAS signaling as a cancer therapy have yet to succeed. As alternative strategies, RAF and MEK inhibitors have been developed to block oncogenic signaling downstream of RAS. As might be expected, studies of these inhibitors have indicated that tumors with RAS or BRAF mutations display resistance RAF or MEK inhibitors. In order to better understand the mechanistic basis for this resistance, we conducted a RNAi-based screen to identify genes that mediated chemoresistance to the RAF kinase inhibitor RAF265 in a BRAF (V600E) mutant melanoma cell line that is resistant to this drug. In this way, we found that knockdown of protein kinase D3 (PRKD3) could enhance cell killing of RAF and MEK inhibitors across multiple melanoma cell lines of various genotypes and sensitivities to RAF265. PRKD3 blockade cooperated with RAF265 to prevent reactivation of the MAPK signaling pathway, interrupt cell cycle progression, trigger apoptosis, and inhibit colony formation growth. Our findings offer initial proof-of-concept that PRKD3 is a valid target to overcome drug resistance being encountered widely in the clinic with RAF or MEK inhibitors.

Topics: Cell Cycle; Cell Line, Tumor; Cyclin D1; Extracellular Signal-Regulated MAP Kinases; Humans; Imidazoles; MAP Kinase Signaling System; Melanoma; Mitogen-Activated Protein Kinase Kinases; Phosphatidylinositol 3-Kinases; Poly(ADP-ribose) Polymerases; Protein Kinase C; Pyridines; raf Kinases; RNA, Small Interfering

RASSF1A gene, found at the 3p21.3 locus, is a tumor suppressor gene frequently hypermethylated in human cancers. In this study, we report that compared with melanocytes in normal choroid, RASSF1A is downregulated in uveal melanoma samples and in uveal melanoma cell lines. LOH at 3p21.3 was detected in 50% of uveal melanoma. Moreover, methylation of the RASSF1A promoter was detected in 35 of 42 tumors (83%) and RASSF1A was also weakly expressed at the mRNA level. These data indicate that LOH at the RASSF1A locus or RASSF1A promoter methylation may partly account for the suppression of RASSF1A expression observed in uveal melanoma. Furthermore, following ectopic expression in three RASSF1A-deficient melanoma cell lines (OCM-1, Mel270, and 92.1), RASSF1A weakly reduces cell proliferation and anchorage-independent growth of uveal melanoma cells without effect on ERK1/2 activation, cyclin D1 and p27(Kip1) expression. This study explored biological functions and underlying mechanisms of RASSF1A in the ERK1/2 pathway in normal uveal melanocytes. We showed that siRNA-mediated depletion of RASSF1A increased ERK1/2 activation, cyclin D1 expression, and also decreased p27(Kip1) expression in normal uveal melanocytes. Moreover, that the depletion of RASSF1A induced senescence-associated β-galactosidase activity and increased p21(Cip1) expression suggests that RASSF1A plays a role in the escape of cellular senescence in normal uveal melanocytes. Interestingly, we found that RASSF1A was epigenetically inactivated in long-term culture of uveal melanocytes. Taken together, these data show that depletion of RASSF1A could be an early event observed during senescence of normal uveal melanocytes and that additional alterations are acquired during malignant transformation to uveal melanoma.

Topics: Cell Line, Tumor; Cell Proliferation; Cellular Senescence; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; DNA Methylation; Gene Expression Regulation, Neoplastic; Humans; Loss of Heterozygosity; MAP Kinase Signaling System; Melanocytes; Melanoma; Promoter Regions, Genetic; RNA, Small Interfering; Tumor Suppressor Proteins; Uveal Neoplasms

MicroRNAs play important roles in gene regulation, and their expression is frequently dysregulated in cancer cells. In a previous study, we reported that miR-193b represses cell proliferation and regulates cyclin D1 in melanoma cells, suggesting that miR-193b could act as a tumor suppressor. Herein, we demonstrate that miR-193b also down-regulates myeloid cell leukemia sequence 1 (Mcl-1) in melanoma cells. MicroRNA microarray profiling revealed that miR-193b is expressed at a significantly lower level in malignant melanoma than in benign nevi. Consistent with this, Mcl-1 is detected at a higher level in malignant melanoma than in benign nevi. In a survey of melanoma samples, the level of Mcl-1 is inversely correlated with the level of miR-193b. Overexpression of miR-193b in melanoma cells represses Mcl-1 expression. Previous studies showed that Mcl-1 knockdown cells are hypersensitive to ABT-737, a small-molecule inhibitor of Bcl-2, Bcl-X(L), and Bcl-w. Similarly, overexpression of miR-193b restores ABT-737 sensitivity to ABT-737-resistant cells. Furthermore, the effect of miR-193b on the expression of Mcl-1 seems to be mediated by direct interaction between miR-193b and seed and seedless pairing sequences in the 3' untranslated region of Mcl-1 mRNA. Thus, this study provides evidence that miR-193b directly regulates Mcl-1 and that down-regulation of miR-193b in vivo could be an early event in melanoma progression.

Topics: Antimetabolites, Antineoplastic; Apoptosis; Binding Sites; Biphenyl Compounds; Cell Line, Tumor; Cyclin D1; Down-Regulation; Drug Resistance, Neoplasm; Growth Inhibitors; Humans; Melanoma; MicroRNAs; Myeloid Cell Leukemia Sequence 1 Protein; Nitrophenols; Piperazines; Proto-Oncogene Proteins c-bcl-2; Skin Neoplasms; Sulfonamides

Cyclin D-dependent kinases (CDK4 and CDK6) are positive regulators of cell cycle entry and they are overactive in the majority of human cancers. However, it is currently not completely understood by which cellular mechanisms CDK4/6 promote tumorigenesis, largely due to the limited number of identified substrates. Here we performed a systematic screen for substrates of cyclin D1-CDK4 and cyclin D3-CDK6. We identified the Forkhead Box M1 (FOXM1) transcription factor as a common critical phosphorylation target. CDK4/6 stabilize and activate FOXM1, thereby maintain expression of G1/S phase genes, suppress the levels of reactive oxygen species (ROS), and protect cancer cells from senescence. Melanoma cells, unlike melanocytes, are highly reliant on CDK4/6-mediated senescence suppression, which makes them particularly susceptible to CDK4/6 inhibition.

Topics: Cell Transformation, Neoplastic; Cellular Senescence; Cyclin D1; Cyclin D3; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinases; Forkhead Box Protein M1; Forkhead Transcription Factors; G1 Phase; HEK293 Cells; Humans; Melanocytes; Melanoma; Molecular Sequence Data; Phosphorylation; Piperazines; Proteome; Pyridines; S Phase; Signal Transduction; Substrate Specificity

The serine/threonine kinase, B-RAF, is frequently mutated in melanoma and is required for cell proliferation. Proteasomal turnover of cyclins and cyclin-dependent kinase inhibitors via E3 ubiquitin ligases regulates cell cycle progression. We previously showed that B-RAF regulates Cks1, a co-factor for the F-box protein Skp2. Recently, a second F-box protein cofactor was identified, alphaB-crystallin, that binds Fbx4 and promotes cyclin D1 degradation. Here, we demonstrate that alphaB-crystallin is down-regulated in mutant B-RAF melanoma cells compared to melanocytes in a B-RAF and MEK-dependent manner. In a subset of lines, MEK inhibition was sufficient to up-regulate alphaB-crystallin protein levels; whereas in other lines combined MEK and proteasome inhibition was required. alphaB-crystallin knockdown partially stabilized cyclin D1 in melanocytes. Expression of alphaB-crystallin in mutant B-RAF melanoma cells did not promote cyclin D1 turnover under normal conditions, but did enhance turnover following etoposide-induced DNA damage. Together, these data show that alphaB-crystallin is highly expressed in melanocytes contributing, in part, to cyclin D1 turnover. Furthermore, alphaB-crystallin is down-regulated in a B-RAF-dependent manner in melanoma cells and its re-expression regulates cyclin D1 turnover after DNA damage.

Topics: alpha-Crystallin B Chain; Bleomycin; Butadienes; Cells, Cultured; Cyclin D1; Cycloheximide; DNA Damage; Etoposide; Humans; Leupeptins; Melanocytes; Melanoma; Mutant Proteins; Mutation; Nitriles; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Structure-Activity Relationship; Tetracycline

We evaluated the usefulness of immunohistochemical examination for E-cadherin, p16, and cyclin D1 in discriminating melanoma from Spitz tumors. Immunoperoxidase staining was performed on formalin-fixed tissue specimens from 46 Spitz tumors and 42 concurrent melanoma specimens. The percentages of immunoreactive melanocytes in the epidermis and dermis were estimated semiquantitatively. Qualitatively abnormal immunoreactivity patterns were also tabulated. Dermal p16 immunoreactivity was the best quantitative discriminator: decreased nuclear immunoreactivity (<25% of dermal melanocytes) was 3-fold more likely in melanoma than in Spitz tumors (P = .004). Loss of both nuclear and cytoplasmic dermal p16 immunoreactivity was 8-fold more likely in melanoma (P = .01). Qualitative irregularities in the zonal distribution of E-cadherin immunoreactivity were 2-fold higher in melanoma (P = .01), but these were often focal or subtle. There was no statistically significant difference in cyclin D1 immunoreactivity. In atypical Spitz tumors, the dermal p16 immunoreactivity and frequency of qualitative E-cadherin abnormalities were intermediate between those of ordinary Spitz nevi and melanoma. Also, contrasting immunoreactivity patterns were helpful in determining Breslow thickness in specimens containing melanoma and contiguous dermal nevi.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Cadherins; Chi-Square Distribution; Child; Child, Preschool; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Male; Melanoma; Middle Aged; Nevus, Epithelioid and Spindle Cell; Skin Neoplasms

To evaluate the diagnostic sensitivity of fluorescence in situ hybridization (FISH) using probes targeting 6p25, 6q23, 11q13, and Cep6 in melanoma subtypes.. Blinded comparison of chromosomal copy number changes detected using FISH targeting 6p25, 6q23, 11q13, and Cep6 in benign nevi and melanoma subtypes.. Dermatopathology Laboratory, Department of Dermatology, Northwestern University, Chicago, Illinois.. One hundred ten individuals with benign nevi and 123 with melanoma (70 superficial spreading, 28 lentigo maligna, 22 nodular, and 3 acral lentiginous melanomas).. Sensitivity of previously developed criteria using FISH using probes targeting 6p25, 6q23, 11q13, and Cep6 in the melanoma subtypes.. Overall, sensitivity was 83.0% and specificity was 94.0%. The 6p25 gain criterion had the highest sensitivity overall and in each subtype. The assay was most sensitive in the subgroups of nodular and acral melanomas and least sensitive in the superficial spreading subtype. The 11q13 gain was more commonly seen in chronically sun-damaged skin and infrequently in non-chronically sun-damaged skin.. Heterogeneous changes in melanoma occur at the molecular level, and the changes are different among melanoma subtypes. Clonal abnormalities in chromosome 6 with increased copies of the short arm relative to the long arm are common in all melanoma subtypes, suggesting that isochromosome 6 is common in all variants of cutaneous melanoma subtypes. An increase in copy number of 11q13 is most frequent in chronically sun-damaged melanomas.

Topics: Aged; Chromosome Aberrations; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 6; Cyclin D1; Diagnosis, Differential; DNA Probes; DNA-Binding Proteins; DNA, Neoplasm; Female; Genetic Predisposition to Disease; Humans; In Situ Hybridization, Fluorescence; Male; Melanoma; Middle Aged; Proto-Oncogene Proteins c-myb; Sensitivity and Specificity; Skin Neoplasms; Transcription Factors; Zinc Fingers

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Cyclin D1; Diagnosis, Differential; DNA-Binding Proteins; Female; Fluorescent Dyes; Humans; In Situ Hybridization, Fluorescence; Male; Melanoma; Middle Aged; Nevus, Pigmented; Proto-Oncogene Proteins c-myb; Skin Neoplasms; Transcription Factors; Young Adult

Cutaneous melanoma is an aggressive form of human skin cancer characterized by high metastatic potential and poor prognosis. To better understand the role of microRNAs (miRNAs) in melanoma, the expression of 470 miRNAs was profiled in tissue samples from benign nevi and metastatic melanomas. We identified 31 miRNAs that were differentially expressed (13 up-regulated and 18 down-regulated) in metastatic melanomas relative to benign nevi. Notably, miR-193b was significantly down-regulated in the melanoma tissues examined. To understand the role of miR-193b in melanoma, functional studies were undertaken. Overexpression of miR-193b in melanoma cell lines repressed cell proliferation. Gene expression profiling identified 314 genes down-regulated by overexpression of miR-193b in Malme-3M cells. Eighteen of these down-regulated genes, including cyclin D1 (CCND1), were also identified as putative miR-193b targets by TargetScan. Overexpression of miR-193b in Malme-3M cells down-regulated CCND1 mRNA and protein by > or = 50%. A luciferase reporter assay confirmed that miR-193b directly regulates CCND1 by binding to the 3'untranslated region of CCND1 mRNA. These studies indicate that miR-193b represses cell proliferation and regulates CCND1 expression and suggest that dysregulation of miR-193b may play an important role in melanoma development.

Topics: Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cluster Analysis; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; Melanoma; MicroRNAs; Models, Biological; Oligonucleotide Array Sequence Analysis; Reverse Transcriptase Polymerase Chain Reaction; Skin Neoplasms

Cyclins, cyclin-dependent kinases, as well as proteins cooperating with them are responsible for cell cycle regulation which is crucial for normal development, injury repair, and tumorigenesis. D-type cyclins regulate G1 cell cycle progression by enhancing the activities of cyclin-dependent kinases, and their expression is frequently altered in tumors. Disturbances in cyclin expression were also reported in melanocytic skin lesions. The objective of the study was to evaluate the expression of cyclins D1 and D3 in common, dysplastic, and malignant melanocytic skin lesions. Forty-eight melanocytic skin lesions including common nevi (10), dysplastic nevi (24), and melanomas (14) were diagnosed by dermoscopy and excised. Expression of cyclin D1 and D3 was detected by immunohistochemistry and quantified as percentage of immunostained cell nuclei in each sample. In normal skin, expression of cyclins D1 and D3 was not detected. The mean percentage of cyclin D1-positive nuclei was 7.75% for melanoma samples, 5% for dysplastic nevi samples, and 0.34% for common nevi samples. For cyclin D3, the respective values were 17.8, 6.4, and 1.8%. Statistically significant differences in cyclin D1 expression were observed between melanomas and common nevi as well as between dysplastic and common nevi (p = 0.0001), but not between melanomas and dysplastic nevi. Cyclin D3 expression revealed significant differences between all investigated lesion types (p = 0.0000). The mean cyclin D1 and D3 scores of melanomas with Breslow thickness <1 mm and >1 mm were not significantly different. G1/S abnormalities are crucial for the progression of malignant melanoma, and enhanced cyclin D1 and D3 expression leading to increased melanocyte proliferation is observed in both melanoma and dysplastic nevi. In histopathologically ambiguous cases, lower cyclin D3 expression in dysplastic nevi can be a diagnostic marker for that lesion type.

Topics: Biomarkers; Cell Proliferation; Cyclin D1; Cyclin D3; Dermoscopy; Diagnosis, Differential; Dysplastic Nevus Syndrome; Humans; Immunohistochemistry; Melanocytes; Melanoma; Precancerous Conditions; Skin; Skin Neoplasms

Melanoma is the most deadly form of skin cancer without effective treatment. Methylthioadenosine (MTA) is a naturally occurring nucleoside with differential effects on normal and transformed cells. MTA has been widely demonstrated to promote anti-proliferative and pro-apoptotic responses in different cell types. In this study we have assessed the therapeutic potential of MTA in melanoma treatment.. To investigate the therapeutic potential of MTA we performed in vitro proliferation and viability assays using six different mouse and human melanoma cell lines wild type for RAS and BRAF or harboring different mutations in RAS pathway. We also have tested its therapeutic capabilities in vivo in a xenograft mouse melanoma model and using variety of molecular techniques and tissue culture we investigated its anti-proliferative and pro-apoptotic properties.. In vitro experiments showed that MTA treatment inhibited melanoma cell proliferation and viability in a dose dependent manner, where BRAF mutant melanoma cell lines appear to be more sensitive. Importantly, MTA was effective inhibiting in vivo tumor growth. The molecular analysis of tumor samples and in vitro experiments indicated that MTA induces cytostatic rather than pro-apoptotic effects inhibiting the phosphorylation of Akt and S6 ribosomal protein and inducing the down-regulation of cyclin D1.. MTA inhibits melanoma cell proliferation and in vivo tumor growth particularly in BRAF mutant melanoma cells. These data reveal a naturally occurring drug potentially useful for melanoma treatment.

Topics: Adenosine; Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Dose-Response Relationship, Drug; Genes, ras; Humans; Male; Melanoma; Mice; Mutation; Phosphorylation; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-akt; Ribosomal Protein S6; Skin Neoplasms; Thionucleosides; Time Factors; Tumor Burden; Xenograft Model Antitumor Assays

A putative tumor suppressor gene at chromosome 10p15, which contains KLF6 and other genes, is predicted to be lost during melanoma development, and its identity is unknown. In this study, we investigated the biological roles and identity of this tumor suppressor gene.. The human UACC 903 melanoma cell line containing introduced DNA fragments from the 10p15 region with (10E6/3, 10E6/11, and 10E6/18) and without (10ER4S.2/1) the tumor suppressor gene was used. Xenograft tumors were generated in a total of 40 mice with melanoma cell lines, and tumor size was measured. Cells were cultured on plastic or a gel of type I collagen. Viability, proliferation, and apoptosis were assessed. Expression of KLF6 protein was assessed by immunohistochemistry and immunoblot analysis. Expression of phosphorylated Erk1/2 and cyclin D1 was assessed by immunoblot analysis. Protein expression of KLF6 was inhibited with small interfering RNA (siRNA). KLF6 protein expression was assessed in 17 human nevi and human melanoma specimens from 29 patients. Statistical analyses were adjusted for multiple comparisons by use of Dunnett method. All statistical tests were two-sided.. Melanoma cells containing KLF6 generated smaller subcutaneous xenograft tumors with fewer proliferating cells than control cells. When grown on collagen 1, viability of cells with ectopic KLF6 expression (72%) was lower than that of control cells (100%) (group difference = -28%, 95% confidence interval = -31.3% to -25.2%, P < .001). Viability of melanoma cells with or without the KLF6 tumor suppressor gene on plastic dishes was similar. When KLF6 expression was inhibited with KLF6 siRNA, viability of cells with the tumor suppressor gene on collagen I gel increased compared with that of control cells carrying scrambled siRNA. KLF6 protein was detected in all nevi examined but not in human metastatic melanoma tissue examined. Ectopic expression of KLF6 protein in melanoma cells grown on collagen I decreased levels of phosphorylated Erk1/2 and cyclin D1 in the mitogen-activated protein kinase signaling pathway.. In melanoma cells, the tumor suppressor gene at 10p15 appears to be KLF6. Signaling from the collagen I-rich extracellular matrix appears to be involved in the tumor suppressive activity of KLF6 protein.

Topics: Adult; Aged; Animals; Apoptosis; Base Sequence; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chromosomes, Human, Pair 10; Collagen Type I; Cyclin D1; DNA Fragmentation; DNA, Complementary; Female; Gelatin; Gene Expression Regulation, Neoplastic; Humans; Immunoblotting; Immunohistochemistry; Kruppel-Like Factor 6; Kruppel-Like Transcription Factors; Male; Matrix Metalloproteinases; Melanoma; Mice; Mice, Inbred BALB C; Mice, Nude; Microscopy, Electron, Transmission; Middle Aged; Mitogen-Activated Protein Kinase 3; Molecular Sequence Data; Nevus; Phosphorylation; Polymerase Chain Reaction; Proto-Oncogene Proteins; RNA, Small Interfering; Signal Transduction; Skin Neoplasms; Transplantation, Heterologous; Tumor Suppressor Proteins

Activating mutations in the NRAS gene, which occur predominantly in codon 61 (Q61R, Q61K) are among the most common genetic events in malignant melanoma. NRAS protein with oncogenic codon 61 mutations may therefore be good therapeutic targets. In the present study, we used gene expression profiling as a method for global characterization of gene expression alterations that resulted from treatment of melanoma cells with siRNA specifically targeting NRAS(Q61R). Sixteen probe sets representing 15 unique genes were identified whose expression was significantly altered by siRNA against NRAS(Q61R) in 2 melanoma cell lines. The genes with altered expression are involved in several functions, including modulation of cell growth, invasion and migration. The results suggest that downregulation of cyclin E2 and cyclin D1 and also upregulation of the negative cell-cycle regulator HBP1 in NRAS(Q61R) knockdown cells contribute to the inhibition of cell proliferation. Furthermore, suppression of oncogenic NRAS results in reduced migration and invasion, which is accompanied by downregulation of EphA2 (a receptor tyrosine kinase), uPAR (urokinase receptor) and cytoskeleton proteins such as leupaxin, paxillin and vinculin. These studies support the concept that suppression of oncogenic NRAS by siRNA can induce growth arrest and inhibit invasion of human melanoma cells by modulating the levels of these gene products.

Topics: Cell Adhesion Molecules; Cell Line, Tumor; Cyclin D1; Cyclins; Cytoskeleton; Gene Expression Regulation, Neoplastic; Genes, ras; Humans; Melanoma; Mutation; Oncogene Protein p21(ras); Paxillin; Phenotype; Phosphoproteins; Skin Neoplasms; Vinculin

Primary melanoma of the iris, for reasons unknown has a lower metastatic rate compared with primary ciliary-body melanoma. Six histology cases of ciliary-body melanoma were identified that had spread onto the iris surface and into the stroma, representing a change in tumour microenvironment from aqueous humour non-exposure (ciliary-body component) to aqueous humour exposure (iris surface component). This provided an ideal paradigm for investigating the effects of different environments on melanoma.. Conventional light microscopy was performed on stained paraffin sections of the identified cases, followed by immunohistochemistry to cell cycle proteins p27 and Cyclin D1. Fluorescence in situ hybridisation (FISH) analysis was conducted on the paraffin sections for changes of chromosomes 3 and 8, associated with poor uveal melanoma prognosis.. Iris surface melanoma cells were smaller compared with the adjacent deeper iris stromal melanoma cells and with those in the ciliary body. Fewer iris surface melanoma cells expressed Cyclin D1 protein, but more expressed p27 protein, compared with the larger iris stromal melanoma cells (paired Wilcoxon signed ranks test: Cyclin D1 p = 0.028; p27 p = 0.046) and with the ciliary-body melanoma cells (paired Wilcoxon signed ranks test: Cyclin D1 p = 0.028; p27 p = 0.028). With FISH, chromosome 3 and 8 alterations were less common among the iris surface melanoma cells than the deeper iris stromal melanoma cells and the ciliary-body melanoma cells, which were consistently characterised by a relative genetic imbalance for chromosomes 3 and 8.. These data suggest that there are tumour-modulatory factors within the anterior chamber environment that probably select populations of ciliary-body melanoma cells, with a less aggressive, better-differentiated status. Furthermore, it may help explain why iris melanomas generally have a less aggressive course than ciliary-body and choroidal melanomas.

Topics: Aged; Aged, 80 and over; Anterior Chamber; Chromosomes, Human, Pair 3; Chromosomes, Human, Pair 8; Ciliary Body; Cyclin D1; Female; Humans; In Situ Hybridization, Fluorescence; Iris; Male; Melanoma; Middle Aged; Neoplasm Invasiveness; Neoplasm Proteins; Proliferating Cell Nuclear Antigen; Tissue Fixation; Uveal Neoplasms

High malignancy and early metastasis are hallmarks of melanoma. Here, we report that the transcription factor Snail1 inhibits expression of the tumor suppressor CYLD in melanoma. As a direct consequence of CYLD repression, the protooncogene BCL-3 translocates into the nucleus and activates Cyclin D1 and N-cadherin promoters, resulting in proliferation and invasion of melanoma cells. Rescue of CYLD expression in melanoma cells reduced proliferation and invasion in vitro and tumor growth and metastasis in vivo. Analysis of a tissue microarray with primary melanomas from patients revealed an inverse correlation of Snail1 induction and loss of CYLD expression. Importantly, tumor thickness and progression-free and overall survival inversely correlated with CYLD expression. Our data suggest that Snail1-mediated suppression of CYLD plays a key role in melanoma malignancy.

Topics: Animals; B-Cell Lymphoma 3 Protein; Blotting, Western; Cadherins; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Deubiquitinating Enzyme CYLD; Down-Regulation; Female; Gene Expression Regulation, Neoplastic; Humans; Male; Melanoma; Melanoma, Experimental; Mice; Mice, Inbred Strains; Mice, Nude; Neoplasm Invasiveness; Proto-Oncogene Proteins; Proto-Oncogene Proteins B-raf; Reverse Transcriptase Polymerase Chain Reaction; Snail Family Transcription Factors; Transcription Factors; Transplantation, Heterologous; Tumor Suppressor Proteins

Accurate classification of primary melanocytic tumours as benign or malignant is crucial for prognostic prediction and appropriate patient management. Several chromosomal aberrations have been frequently identified in melanomas, but are absent in melanocytic naevi. We performed four-colour fluorescence in situ hybridisation (FISH) analysis of melanocytic tumours to determine the accuracy of the technique in classifying melanocytic tumours as benign or malignant.. FISH was performed on paraffin-embedded tissue from 40 histologically unequivocal melanocytic tumours (10 metastatic melanomas, 10 primary melanomas and 20 benign melanocytic naevi) using the product Vysis LSI RREB1/LSI MYB/LSI CCND1/CEP 6 probes (Abbott Molecular Laboratories, USA), which is designed to detect the copy number of the RREB1 (6p25), MYB (6q23), and CCND1 (11q13) genes and FISH positivity is defined by means of a scoring algorithm.. FISH distinguished the melanomas and the naevi with a sensitivity of 90% (10/10 primary melanoma cases and 8/10 metastatic melanoma cases, respectively), and a specificity of 95%. The most common abnormalities in the melanomas were increased copies of 11q (70%) and 6p (70%), followed by 6q loss relative to cep6 (50%). Fifteen of the 18 positive melanomas were positive by more than one criterion.. The results of this study show that FISH, using a panel of four probes, is a sensitive and specific method of classifying benign and malignant melanocytic tumours. The four-colour FISH technique has the potential to assist in the stratification of the subgroup of melanocytic tumours which are difficult to classify using conventional histology.

Topics: Adolescent; Adult; Aged; Child; Cyclin D1; DNA-Binding Proteins; Female; Gene Dosage; Genes, myb; Humans; In Situ Hybridization, Fluorescence; Male; Melanoma; Middle Aged; Nevus, Pigmented; Sensitivity and Specificity; Skin Neoplasms; Transcription Factors; Young Adult

In response to DNA damage, eukaryotic cells initiate a complex signalling pathway, termed the DNA damage response (DDR), which coordinates cell cycle arrest with DNA repair. Studies have shown that oncogene-induced senescence, which provides a barrier to tumour development, involves activation of the DDR. Using a genome-wide RNA interference (RNAi) screen, we have identified 17 factors required for oncogenic BRAF to induce senescence in primary fibroblasts and melanocytes. One of these factors is an F-box protein, FBXO31, a candidate tumour suppressor encoded in 16q24.3, a region in which there is loss of heterozygosity in breast, ovarian, hepatocellular and prostate cancers. Here we study the cellular role of FBXO31, identify its target substrate and determine the basis for its growth inhibitory activity. We show that ectopic expression of FBXO31 acts through a proteasome-directed pathway to mediate the degradation of cyclin D1, an important regulator of progression from G1 to S phase, resulting in arrest in G1. Cyclin D1 degradation results from a direct interaction with FBXO31 and is dependent on the F-box motif of FBXO31 and phosphorylation of cyclin D1 at Thr 286, which is known to be required for cyclin D1 proteolysis. The involvement of the DDR in oncogene-induced senescence prompted us to investigate the role of FBXO31 in DNA repair. We find that DNA damage induced by gamma-irradiation results in increased FBXO31 levels, which requires phosphorylation of FBXO31 by the DDR-initiating kinase ATM. RNAi-mediated knockdown of FBXO31 prevents cells from undergoing efficient arrest in G1 after gamma-irradiation and markedly increases sensitivity to DNA damage. Finally, we show that a variety of DNA damaging agents all result in a large increase in FBXO31 levels, indicating that induction of FBXO31 is a general response to genotoxic stress. Our results reveal FBXO31 as a regulator of the G1/S transition that is specifically required for DNA damage-induced growth arrest.

Topics: Acetylcysteine; Ataxia Telangiectasia Mutated Proteins; Cell Cycle Proteins; Cell Line, Tumor; Cyclin D1; Cysteine Proteinase Inhibitors; DNA Damage; DNA-Binding Proteins; F-Box Proteins; G1 Phase; Humans; Melanoma; Proteasome Endopeptidase Complex; Protein Serine-Threonine Kinases; Transcriptional Activation; Tumor Suppressor Proteins; Ubiquitination

We present the case of 10-year-old girl who have had from birth a plane tumor, of tan color, 3-4 mm of diameter, localized on the face on the cutaneous part of the superior lip. This tumor has been stabile until 8-year-old. Then, after repeated sunlight exposures, the lesion has become more stark, hemispheric in shape, has increased in size becoming about 5-6 mm, with irregular borders, and after an accidental traumatism it began to bleed. We have performed the electroexcision of the lesion for diagnostic and therapeutic purpose. The histopathologic exam distinguished typical images of Spitz nevus on some of the histological sections but also of melanocytary tumor with uncertain malignant potential on the others where atypical mitoses localized in the deeper component of the tumor are being noticed. The immunohistochemical assessment of the tumoral cells showed positivity for the melanocytic markers HMB45 and Melan A, within junctional intraepidermic nevic cells and in the nevic cells from superficial dermis, and also for CD44 protein (belonging to the adhesion molecules family). However, cyclin D1 was positive in rare nevic cells, and the proliferation rate of the tumor was small, with a proliferation index for Ki67 lesser than 5%. The correlation between histopathological and immunohistochemical data conducive to final diagnosis of Spitz nevus with uncertain malignant potential. The clinical evolution confirmed the histopathological diagnosis by the fact that the patient did not presented clinical signs of local recurrences or metastasis at three years after the excision of the tumor.

Topics: Antigens, Neoplasm; Biomarkers, Tumor; Child; Cyclin D1; Diagnosis, Differential; Female; Humans; Hyaluronan Receptors; Ki-67 Antigen; MART-1 Antigen; Melanoma; Melanoma-Specific Antigens; Neoplasm Proteins; Nevus, Epithelioid and Spindle Cell; Skin Neoplasms

Topics: Aged, 80 and over; Cyclin D1; Female; Gene Dosage; Humans; In Situ Hybridization, Fluorescence; Melanoma; Skin Neoplasms

Amplification of the 11q13 chromosomal region is a common event in primary melanomas. Several candidate genes are localized at this sequence; however, their role in melanoma has not been clearly defined. The aim of this study was to develop an accurate method for determining the amplification pattern of six candidate genes that map to this amplicon core and to elucidate the possible relationship between BRAF, NRAS mutations and CCND1 copy number alterations, all of which are key components of the MAP kinase pathway. Characterization of gene copy numbers was performed by quantitative PCR and, as an alternative method, fluorescence in situ hybridization was used to define the CCND1 amplification pattern at the single cell level. Samples with amplified CCND1 (32%) were further analyzed for copy number alterations for the TAOS1, FGF3, FGF19, FGF4 and EMS1 genes. Co-amplification of the CCND1 and TAOS1 was present in 15% of tumors and was more frequent in ulcerated lesions (P=0.017). Furthermore, 56% of primary melanomas had either BRAF or NRAS mutations, but these two mutations were not present in any of the lesions analyzed. Of these cases, 34% also had CCND1 amplification. There was a significant relationship between NRAS activating mutations and UV exposure (P=0.005). We did not find correlations between CCND1 gene amplification status and any of the patients' clinicopathological parameters. However, CCND1 amplification simultaneously with either BRAF or NRAS activation mutations was observed mainly in primary tumors with ulcerated surfaces (P=0.028). We assume that co-amplification of these candidate genes in the 11q13 region or CCND1 gene alterations along with either BRAF or NRAS mutations might be more important for prognosis than the presence of these alterations alone.

Topics: Adult; Chromosomes, Human, Pair 11; Cortactin; Cyclin D1; Female; Fibroblast Growth Factor 3; Fibroblast Growth Factor 4; Fibroblast Growth Factors; Gene Amplification; Gene Dosage; Gene Expression Regulation, Neoplastic; Genes, ras; Genetic Association Studies; Humans; In Situ Hybridization, Fluorescence; Male; Melanoma; Middle Aged; Mutation; Neoplasm Proteins; Neoplasm Staging; Polymerase Chain Reaction; Prognosis; Proto-Oncogene Proteins B-raf; Reproducibility of Results; Skin Neoplasms; Young Adult

Topics: Animals; Cell Cycle; Cell Line; Cyclin D1; DNA Damage; F-Box Proteins; Humans; Melanoma; Tumor Suppressor Proteins

The immunohistochemical expression of cell cycle proteins p16, cyclin D1, and pRb was assessed in 112 benign and malignant melanocytic tumors and correlated with tumor progression, prognosis, and outcome. Comparing benign and malignant tumors, there were significant differences in the median score for all 3 proteins, with decreased p16 (P = .000001), increased cyclin D1 (P = .01), and increased pRb in melanomas (P = .01). There was a progressive loss of expression of p16 with progression from benign naevi to primary melanomas and to metastases. p16 was significantly decreased in primary tumors from melanoma patients who developed recurrent disease (P = .0000013). Cyclin D1 and pRb showed a progressive increase in expression from benign to malignant tumors but with relative decreases in the more advanced tumors (thick primaries and metastatic melanomas). Alterations in cell cycle proteins involved in G1/S transition are implicated in melanocytic tumor progression and have a potential role in diagnosis and prognostication.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Cell Nucleus; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Disease Progression; Female; Humans; Immunoenzyme Techniques; Lymph Nodes; Lymphatic Metastasis; Male; Melanocytes; Melanoma; Middle Aged; Neoplasm Recurrence, Local; Nevus; Prognosis; Retinoblastoma Protein; Skin Neoplasms

Nevoid melanoma may resemble benign compound or intradermal nevi by their silhouette and profile on low power. Higher power usually reveals nuclear atypia, confluence of cells, incomplete maturation and dermal mitotic activity. However, to some extent all of these features maybe seen in benign compound or intradermal nevi and no single criteria can be used to differentiate nevoid melanoma from a benign nevus. The distinction can be particularly problematic in nevi that show mitotic activity and we have noted a recent trend in diagnosis of melanocytic neoplasms with dermal mitosis as nevoid melanoma despite the presence of normal maturation in the dermis and lack of significant nuclear atypia. Therefore in this study we evaluated 10 nevoid melanomas, 4 of which resulted in metastasis and 10 mitotically active nevi with fluorescence in situ hybridization targeting key chromosomal loci previously shown to effectively discriminate been malignant and benign melanocytic neoplasms. All 10 nevoid melanomas showed copy number abnormalities by fluorescence in situ hybridization in either chromosome 6 or 11 while none of the 10 mitotically active nevi did. The results demonstrate that fluorescence in situ hybridization targeting key chromosomal loci on chromosomes 6 and 11 can be effective in discriminating nevoid melanomas from mitotically active nevi. Additionally, our study presents further evidence that dermal mitoses alone without other diagnostic features such as nuclear atypia and lack of maturation does not constitute sufficient evidence alone for a diagnosis of melanoma.

Topics: Adolescent; Adult; Aged, 80 and over; Chromosome Aberrations; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 6; Cyclin D1; Dermis; Diagnosis, Differential; DNA-Binding Proteins; Female; Gene Expression Regulation, Neoplastic; Humans; In Situ Hybridization, Fluorescence; Male; Melanoma; Middle Aged; Mitosis; Nevus; Nevus, Intradermal; Predictive Value of Tests; Prognosis; Proto-Oncogene Proteins c-myb; Skin Neoplasms; Time Factors; Transcription Factors; United States; Young Adult

Recent studies have shown that there is a considerable heterogeneity in the response of melanoma cell lines to MEK and BRAF inhibitors. In the current study, we address whether dysregulation of cyclin-dependent kinase 4 (CDK4) and/or cyclin D1 contribute to the BRAF inhibitor resistance of melanoma cells. Mutational screening identified a panel of melanoma cell lines that harbored both a BRAF V600E mutation and a CDK4 mutation: K22Q (1205Lu), R24C (WM39, WM46, and SK-Mel-28), and R24L (WM902B). Pharmacologic studies showed that the presence of a CDK4 mutation did not alter the sensitivity of these cell lines to the BRAF inhibitor. The only cell line with significant BRAF inhibitor resistance was found to harbor both a CDK4 mutation and a CCND1 amplification. Array comparative genomic hybridization analysis showed that CCND1 was amplified in 17% of BRAF V600E-mutated human metastatic melanoma samples, indicating the clinical relevance of this finding. As the levels of CCND1 amplification in cell lines are lower than those seen in clinical specimens, we overexpressed cyclin D1 alone and in the presence of CDK4 in a drug-sensitive melanoma line. Cyclin D1 overexpression alone increased resistance and this was enhanced when cyclin D1 and CDK4 were concurrently overexpressed. In conclusion, increased levels of cyclin D1, resulting from genomic amplification, may contribute to the BRAF inhibitor resistance of BRAF V600E-mutated melanomas, particularly when found in the context of a CDK4 mutation/overexpression.

Topics: Amino Acid Substitution; Base Sequence; Cell Line, Tumor; Cyclin D1; Cyclin-Dependent Kinase 4; DNA Mutational Analysis; Drug Resistance, Neoplasm; Gene Amplification; Glutamic Acid; Humans; Imidazoles; Melanoma; Molecular Sequence Data; Mutation; Proto-Oncogene Proteins B-raf; Valine

Topics: Aged; Cheek; Cyclin D1; Humans; In Situ Hybridization, Fluorescence; Lymphatic Metastasis; Male; Melanoma; Neoplasm Invasiveness; Skin; Skin Neoplasms

A microRNA expression screen was performed analyzing 157 different microRNAs in laser-microdissected tissues from benign melanocytic nevi (n = 10) and primary malignant melanomas (n = 10), using quantitative real-time PCR. Differential expression was found for 72 microRNAs. Members of the let-7 family of microRNAs were significantly downregulated in primary melanomas as compared with benign nevi, suggestive for a possible role of these molecules as tumor suppressors in malignant melanoma. Interestingly, similar findings had been described for lung and colon cancer. Overexpression of let-7b in melanoma cells in vitro downregulated the expression of cyclins D1, D3, and A, and cyclin-dependent kinase (Cdk) 4, all of which had been described to play a role in melanoma development. The effect of let-7b on protein expression was due to targeting of 3'-untranslated regions (3'UTRs) of individual mRNAs, as exemplified by reporter gene analyses for cyclin D1. In line with its downmodulating effects on cell cycle regulators, let-7b inhibited cell cycle progression and anchorage-independent growth of melanoma cells. Taken together, these findings not only point to new regulatory mechanisms of early melanoma development, but also may open avenues for future targeted therapies of this tumor.

Topics: Cell Cycle; Cyclin A; Cyclin D1; Cyclins; Fluorescent Antibody Technique; Humans; Immunoblotting; Melanoma; MicroRNAs; Polymerase Chain Reaction

Familial acquired dysplastic nevi carry a risk for the development of melanoma. However, the results in various studies regarding the significance of sporadic dysplastic nevi as a precursor of malignant melanoma (MM), are controversial. The aim of this study is to investigate cyclin D1 expression and Ki67 proliferative index in a group of melanocytic lesions to address the biologic significance of sporadic dysplastic nevi in the progression of melanocytic lesions. Formalin-fixed paraffin-embedded material from 21 common melanocytic nevi, 42 dysplastic nevi, and 17 primary cutaneous MMs were examined. Standard streptavidin-biotin immunoperoxidase method was used for immunostaining with cyclin D1 and Ki-67 antibody. Nuclear cyclin D1 immunostaining was scored and Ki-67 proliferative index was calculated. Cyclin D1 expression was significantly higher in melanoma than those in other lesions. However, there was no significant difference between dysplastic nevi and common melanocytic nevi in terms of cyclin D1 expression. Ki-67 index was significantly higher in dysplastic nevi compared with common melanocytic nevi and to melanoma compared with dysplastic nevi. There was a significant positive correlation between cyclin D1 expression and Ki-67 proliferative index for each group. The present study indicates significant differences in cyclin D1 expressions and Ki-67 indices among melanocytic lesions. We think that dysplastic nevi are biologically separate from common melanocytic nevi in terms of proliferative activity. Additionally, our results suggest that cyclin D1 expression may be related to malignant phenotype and is associated with high proliferation rate in MM.

Topics: Biomarkers, Tumor; Cyclin D1; Dysplastic Nevus Syndrome; Humans; Immunohistochemistry; Ki-67 Antigen; Melanoma; Nevus, Pigmented

The tumour suppressor gene product, p16, is often inactivated during melanoma malignant progression. Although the importance of p16 in melanomas is well documented, its relationship with cyclin D1, beta-catenin and ultraviolet radiation (UVR) remains unclear.. To determine the role of these cell cycle-related proteins and high-risk sun exposure in the biological behaviour of melanocytic lesions.. We used immunohistochemistry to examine 28 melanocytic naevi (MN; 9 congenital and 19 acquired types) and 24 primary cutaneous malignant melanomas (CMM; 19 nodular melanomas, 3 lentigo maligna melanomas, 1 acral lentiginous melanoma and 1 superficial spreading melanoma) for the presence of p16, cyclin D1 and beta-catenin. The melanocytic lesions were classified into two groups to examine the effects of UVR on these three proteins: high risk of sun exposure (chronically sun damaged; CSD), or low risk of sun exposure (nonchronically sun damaged; non-CSD). We evaluated the relationship between the production of these proteins and the histopathological and clinical characteristics of the lesions.. Production of p16 was repressed in most CMM, but not in MN (P < 0.0001). Cyclin D1 was overproduced in CMM but not in MN, and beta-catenin was frequently overproduced both in MN and CMM. Overproduction of beta-catenin was not common in CSD melanocytic lesions, but was more frequent in non-CSD melanocytic lesions (P = 0.027).. An immunohistochemical panel including melanocytic markers enriched by p16 and cyclin D1 could be used to differentiate some borderline melanocytic lesions. In addition, the Wnt/beta-catenin pathway was more frequently activated in non-CSD than in CSD melanocytic lesions.

Topics: Adult; Aged; beta Catenin; Biomarkers, Tumor; Cell Cycle Proteins; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Disease Progression; Female; Gene Expression; Humans; Male; Melanoma; Middle Aged; Neoplasm Proteins; Nevus, Pigmented; Skin Neoplasms; Sunlight

Mutated B-Raf-mediated constitutive activation of ERK1/2 is involved in about 66% of cutaneous melanoma. By contrast, activating mutations in B-RAF are rare in ocular melanoma. This study aimed to determine the role of wild-type B-Raf ((WT)B-Raf) in uveal melanoma cell growth. We used cell lines derived from primary tumors of uveal melanoma to assess the role of (WT)B-Raf in cell proliferation and to characterize its upstream regulators and downstream effectors. Melanoma cell lines expressing (WT)B-Raf and (WT)Ras grew with similar proliferation rates, showed constitutive activation of ERK1/2, and had similar levels of B-Raf expression and B-Raf kinase activity as melanoma cell lines expressing the activating V600E mutation ((V600E)B-Raf). They were equally as sensitive to pharmacological inhibition of MEK1/2 for cell proliferation and transformation as (V600E)B-Raf cells. siRNA-mediated depletion of Raf-1 did not affect either ERK1/2 activation, whereas siRNA-mediated depletion of B-Raf reduced cell proliferation by up to 65% through the inhibition of ERK1/2 activation, irrespective of the mutational status of B-Raf. Pharmacological inhibition of cAMP-dependent protein kinase (PKA) and siRNA-mediated depletion of PKA greatly reduced B-Raf activity, ERK1/2 activation, and cell proliferation in (WT)B-Raf cells, whereas it did not affect (V600E)B-Raf cells, demonstrating a key role of PKA in mediating (WT)B-Raf/ERK signaling for uveal melanoma cell growth. Moreover, inactivation or depletion of PKA did not affect Rap-1 activity, and Rap-1 depletion did not affect either B-Raf activity or ERK1/2 activation. This ruled out a role for Rap1 in the PKA-mediated B-Raf/ERK activation in (WT)B-Raf cells. Finally, we demonstrated the importance of cyclin D1 in mediating PKA/(WT)B-Raf signaling for cell proliferation. Altogether, our results suggest that the PKA/B-Raf pathway is a potential target for therapeutic strategies against (WT)B-Raf-expressing uveal melanoma.

Topics: Cell Proliferation; Cell Transformation, Neoplastic; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cyclin D1; Extracellular Signal-Regulated MAP Kinases; Humans; Isoenzymes; Melanoma; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-raf; Signal Transduction; Tumor Cells, Cultured; Uveal Neoplasms

Topics: Adult; Apoptosis; Biopsy, Needle; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Case-Control Studies; Caspases; Cell Cycle; Confidence Intervals; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Genetic Variation; Humans; Incidence; Melanoma; Middle Aged; Multivariate Analysis; Odds Ratio; Polymorphism, Genetic; Probability; Prognosis; Reference Values; Risk Assessment; Sensitivity and Specificity; Skin Neoplasms

The transformation of melanocytes to melanoma cells is characterised by abnormal proliferation resulting from alterations in cell cycle regulatory mechanisms. This occurs through alterations in the two major cell cycle regulatory pathways, the retinoblastoma (Rb) and p53 tumour suppressor pathways. This review summarises the current knowledge of alterations in these two pathways at G1/S transition and specifically the role of the key cell cycle regulatory proteins pRb, p16INK4a (p16), cyclin D1, p27Kip1 (p27), p53 and p21Waf1/Cip1 (p21) in the pathogenesis of melanoma. It also considers their prognostic significance. Current data indicate that alterations of cyclin kinase inhibitor (cdki) levels are implicated in the pathogenesis of melanoma and may be useful prognostic markers. However, large validation studies linked to comprehensive clinical follow up data are necessary to clarify the prognostic significance of cell cycle regulatory proteins in individual patients.

Topics: Animals; Cell Cycle; Cell Cycle Proteins; Cell Proliferation; Cell Transformation, Neoplastic; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Disease Progression; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Prognosis; Retinoblastoma Protein; Skin Neoplasms; Tumor Suppressor Protein p53

The majority of human melanomas harbor activating mutations in either the BRAF or NRAS gene. To date, the role of oncogenic NRAS in melanoma remains poorly defined and no current therapies are directed at specifically suppressing oncogenic NRAS in human melanoma tumors. The aim of our study, therefore, was to investigate the effects of suppressing oncogenic NRAS in human melanoma cell lines in vitro. Using both small interfering RNA- and plasmid based-RNA interference techniques, oncogenic NRAS was specifically suppressed in 2 human melanoma cell lines, 224 and BL, which harbor a codon 61 CAA (glutamine) to CGA (arginine) NRAS mutation. Suppression of oncogenic NRAS in these cell lines resulted in increased apoptosis. Furthermore, in 224 cells we demonstrated decreased phosphorylation of extracellular signal-regulated kinase (ERK) and Akt, and reduced expression of NF-kappaB and cyclin D1 in the N-Ras signaling pathway. In contrast, RNA interference directed at wild-type (WT) NRAS had no significant effect on apoptosis of 224 cells or 2 human melanoma cell lines (A375 and 397) containing WT NRAS but a codon 600 GTG (valine) to GAG (glutamate) mutation in BRAF. These data suggest that oncogenic NRAS is important for avoidance of apoptosis in melanomas that harbor the codon 61 NRAS mutation and emphasizes oncogenic NRAS as a therapeutic target in patients with tumors that harbor this mutation.

Topics: Apoptosis; Cell Line, Tumor; Cell Proliferation; Codon; Coloring Agents; Cyclin D1; Down-Regulation; Ethidium; Genes, ras; Genetic Vectors; Humans; Immunoblotting; In Situ Nick-End Labeling; Melanoma; Microscopy, Fluorescence; Mitogen-Activated Protein Kinase 3; Mutation; Plasmids; Proto-Oncogene Proteins p21(ras); RNA Interference; RNA, Small Interfering; Signal Transduction; Time Factors; Transfection

Mutations in BRAF, a component of extracellular signal-regulated kinases 1 and 2 (ERK) cascade, are frequent in melanoma. It is important to understand how BRAF mutations contribute to malignant traits including anchorage- and growth factor-independence. We have previously shown that efficient activation of ERK in normal human epidermal melanocytes (NHEM) requires both adhesion to the extracellular matrix and growth factors. Mutant V599E BRAF is sufficient to promote ERK activation independent of adhesion and growth factors. Here, we analysed regulation of G1 cell cycle events in NHEM and human melanoma cells. We show that S phase entry in NHEM requires both adhesion and growth factor signaling through the MEK-ERK pathway. This control correlates with induction of cyclin D1 and downregulation of p27Kip1, two key G1 cell cycle events. In melanoma cells expressing V599E BRAF, cyclin D1 was constitutively expressed independent of adhesion but dependent upon MEK activation and nuclear accumulation of ERK. Reduction of cyclin D1 levels by RNA interference inhibited S phase entry in melanoma cells. Importantly, expression of V599E BRAF in NHEM was sufficient to promote cyclin D1 promoter activity in the absence of adhesion. Additionally, p27Kip1 levels were downregulated in V599E BRAF-expressing melanoma cells and active BRAF was sufficient to downregulate p27Kip1 in serum-starved NHEM. Thus, adhesion-growth factor cooperation, leading to efficient activation of ERK, regulates cyclin D1 and p27Kip1 levels in human melanocytes and mutant BRAF overrides adhesion-growth factor control of these two G1 cell cycle proteins in melanomas. These findings provide important insight into how BRAF mutations contribute to aberrant human melanocyte proliferation.

Topics: Cell Adhesion; Cell Cycle; Cell Cycle Proteins; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; DNA Mutational Analysis; Down-Regulation; Extracellular Signal-Regulated MAP Kinases; Genes, Tumor Suppressor; Humans; MAP Kinase Kinase Kinases; Melanocytes; Melanoma; Promoter Regions, Genetic; Proto-Oncogene Proteins B-raf; Signal Transduction; Skin Neoplasms; Tumor Suppressor Proteins

Progression through the cell cycle is controlled by cyclins, cyclin-dependent kinases, and cyclin-dependent kinase inhibitory proteins. The role of cyclin D1 in the development and progression of melanomas is controversial. The goal of this study is to evaluate the role of cyclin D1 in benign and malignant melanocytic lesions of the skin.. A total of 126 pigmented lesions of the skin including compound nevi (21), intradermal nevi (18), melanoma in situ (28), primary invasive melanomas (30), and metastatic melanoma (29) were evaluated for cyclin D1 expression. The following tiered system was used for scoring: 0% nuclear staining (score 0), 1% to 19% nuclear staining (score 1), 20% to 49% nuclear staining (score 2), and 50% or greater nuclear staining (score 3).. Average scores were significantly higher for primary melanomas compared with nevi and for in situ melanomas compared with primary invasive melanomas. The average score for metastatic melanomas was not significantly different compared with primary invasive melanomas. Scores for primary invasive melanomas did not correlate with depth of invasion or presence of metastases. Compound nevi exhibited a slightly higher level of cyclin D1 expression compared with intradermal nevi.. Although primary melanomas show a higher level of cyclin D1 expression compared with nevi, cyclin D1 appears to have little role in development of a metastatic phenotype. It is not clear why lesions localized near the dermal-epidermal junction express higher levels of cyclin D1. Further studies are indicated to ascertain the biologic role and practical utility of cyclin D1 in melanocytic lesions of the skin.

Topics: Biomarkers, Tumor; Cyclin D1; Humans; Immunohistochemistry; Melanocytes; Melanoma; Nevus, Pigmented; Skin Neoplasms

One of the most attractive clinical targets for melanoma is the mitogen-activated protein kinase (MAPK) signaling pathway. In this study, we examined MAPK signaling activation in a total of 28 acral melanoma samples, consisting of 13 primary tumors and 15 metastases. In line with the previous reports, NRAS/BRAF mutations were rare; only one metastatic tumor had an NRAS E61R mutation, and one primary tumor and two metastases harbored BRAF V599E mutations. Western blot analyses, however, revealed phosphorylated extracellular signal-regulated kinase (ERK)1/2 proteins in 11 of 14 (78.5%) of the acral melanoma tumors. Furthermore, fluorescence in situ hybridization analyses revealed the prominent amplification of the cyclin D1 (CCND1) gene, which is an important down-stream effecter of the MAPK pathway, in 5 of 21 (23.8%) tumors examined. Interestingly, two of three tumors that were negative for phosphorylated ERK proteins according to western blot harbored CCND1 amplifications, suggesting that the increased gene dosage of CCND1 may exert effects similar to phosphorylated ERK proteins in cell growth. We conclude that, despite the low frequency of BRAF/NRAS mutations, the MAPK signaling pathway is constitutively activated in the majority of acral melanomas. This provides a rational basis to include acral melanomas into the clinical trials with MAPK inhibitors.

Topics: Adult; Aged; Aged, 80 and over; Cyclin D1; Female; Genes, ras; Humans; Male; MAP Kinase Signaling System; Melanoma; Middle Aged; Proto-Oncogene Proteins B-raf; Skin Neoplasms

Exposure to ultraviolet light is a major causative factor in melanoma, although the relationship between risk and exposure is complex. We hypothesized that the clinical heterogeneity is explained by genetically distinct types of melanoma with different susceptibility to ultraviolet light.. We compared genome-wide alterations in the number of copies of DNA and mutational status of BRAF and N-RAS in 126 melanomas from four groups in which the degree of exposure to ultraviolet light differs: 30 melanomas from skin with chronic sun-induced damage and 40 melanomas from skin without such damage; 36 melanomas from palms, soles, and subungual (acral) sites; and 20 mucosal melanomas.. We found significant differences in the frequencies of regional changes in the number of copies of DNA and mutation frequencies in BRAF among the four groups of melanomas. Samples could be correctly classified into the four groups with 70 percent accuracy on the basis of the changes in the number of copies of genomic DNA. In two-way comparisons, melanomas arising on skin with signs of chronic sun-induced damage and skin without such signs could be correctly classified with 84 percent accuracy. Acral melanoma could be distinguished from mucosal melanoma with 89 percent accuracy. Eighty-one percent of melanomas on skin without chronic sun-induced damage had mutations in BRAF or N-RAS; the majority of melanomas in the other groups had mutations in neither gene. Melanomas with wild-type BRAF or N-RAS frequently had increases in the number of copies of the genes for cyclin-dependent kinase 4 (CDK4) and cyclin D1 (CCND1), downstream components of the RAS-BRAF pathway.. The genetic alterations identified in melanomas at different sites and with different levels of sun exposure indicate that there are distinct genetic pathways in the development of melanoma and implicate CDK4 and CCND1 as independent oncogenes in melanomas without mutations in BRAF or N-RAS.

Topics: Adult; Aged; Aged, 80 and over; Cyclin D1; Cyclin-Dependent Kinase 4; DNA, Neoplasm; Environmental Exposure; Female; Genes, ras; Genome, Human; Humans; Male; Melanoma; Middle Aged; Mitogen-Activated Protein Kinases; Mutation; Nucleic Acid Hybridization; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins B-raf; PTEN Phosphohydrolase; Risk Factors; Signal Transduction; Skin Neoplasms; Ultraviolet Rays

Spitz nevi are benign melanocytic nevi that overlap histopathologically with melanoma. We previously found copy number increases of chromosome 11p frequently paralleled by mutations in the HRAS oncogene mapping to this region. In this study, we explored mechanisms that inhibit proliferation in the presence of HRAS activation. We analyzed MAP-kinase activation using immunohistochemistry for phospho-ERK, cyclin D1, and microphthalmia transcription factor expression in 17 Spitz nevi with and 18 Spitz nevi without 11p copy number increase. We found relatively high levels of phospho-ERK and cyclin D1 expression suggesting MAP-kinase pathway activation in both groups of Spitz nevi. However, Spitz nevi with 11p copy number increases showed significantly higher levels of cyclin D1 expression and lower levels of microphthalmia transcription factor expression suggesting stronger MAP-kinase pathway activation in this group. Contrasting this apparent activation, the proliferation rate as assessed by Mib1 expression was low in both groups. An analysis of cell-cycle inhibitory proteins including p16, p21, and p27 showed that the majority of Spitz nevus cells expressed high levels of p16, with cells of the cases that had increased copy number of 11p expressing significantly higher levels than those of Spitz nevi with normal copy number of 11p. We propose that in benign nevi with constitutive activation of the MAP-kinase pathway, p16 functions as an essential mediator of oncogene-induced senescence preventing progression to melanoma.

Topics: Calibration; Cell Cycle; Cell Division; Cyclin D1; Disease Progression; DNA-Binding Proteins; Enzyme Activation; Humans; Immunohistochemistry; MAP Kinase Signaling System; Melanoma; Microphthalmia-Associated Transcription Factor; Mitogen-Activated Protein Kinases; Nevus, Epithelioid and Spindle Cell; Transcription Factors

Lumican is a member of the small leucine-rich proteoglycan (SLRP) family. It contributes to the organisation of the collagen network and plays an important role in cell migration and tissue repair. The present study aimed to determine the influence of lumican expression on adhesion, anchorage-dependent and -independent growth, migration, in vitro invasion and in vivo melanoma growth. For that purpose, B16F1 mouse melanoma cells were stably transfected with an expression plasmid containing the complete lumican cDNA. Lumican expression by tumor cells did not change the proliferative activity of mouse melanoma cells in monolayer culture and did not influence either cell adhesion to extracellular matrix gel or type I collagen or cell spreading on these substrates. In contrast, lumican-transfected cells were characterized by a strong reduction of their anchorage-independent proliferation in agarose gel and capacity to invade extracellular matrix gel. After subcutaneous injections of transfected B16F1 cells in syngenic mice, lumican expression significantly decreased subcutaneous tumor formation in vivo, with a concomitant decrease of cyclin D1 expression. Lumican induced and/or increased the apoptosis of B16F1 cells. The results suggest that lumican is involved in the control of melanoma growth and invasion and may be considered, like decorin, as an anti-tumor factor from the extracellular matrix.

Topics: Animals; Apoptosis; Cell Adhesion; Cell Division; Cell Line, Tumor; Chondroitin Sulfate Proteoglycans; Cyclin D1; Disease Progression; Female; Humans; Keratan Sulfate; Lumican; Melanoma; Mice; Mice, Inbred C57BL; Neoplasm Invasiveness; Neoplasm Transplantation; Transfection

A(3) adenosine receptor (A(3)AR) activation was shown to inhibit the growth of various tumor cells via the down-regulation of nuclear factor kappaB and cyclin D1. To additionally elucidate whether A(3)AR is a specific target, a survey of its expression in tumor versus adjacent normal cells was conducted.. A(3)AR mRNA expression in various tumor tissues was tested in paraffin-embedded slides using reverse transcription-PCR analysis. A comparison with A(3)AR expression in the relevant adjacent normal tissue or regional lymph node metastasis was performed. In addition, A(3)AR protein expression was studied in fresh tumors and was correlated with that of the adjacent normal tissue.. Reverse transcription-PCR analysis of colon and breast carcinoma tissues showed higher A(3)AR expression in the tumor versus adjacent non-neoplastic tissue or normal tissue. Additional analysis revealed that the lymph node metastasis expressed even more A(3)AR mRNA than the primary tumor tissue. Protein analysis of A(3)AR expression in fresh tumors derived from colon (n = 40) or breast (n = 17) revealed that 61% and 78% had higher A(3)AR expression in the tumor versus normal adjacent tissue, respectively. The high A(3)AR expression level in the tumor tissues was associated with elevated nuclear factor kappaB and cyclin D1 levels. High A(3)AR mRNA expression was also demonstrated in other solid tumor types.. Primary and metastatic tumor tissues highly express A(3)AR indicating that high receptor expression is a characteristic of solid tumors. These findings and our previous data suggest A(3)AR as a potential target for tumor growth inhibition.

Topics: Blotting, Western; Breast Neoplasms; Carcinoma, Ductal, Breast; Cell Line, Tumor; Colonic Neoplasms; Cyclin D1; Down-Regulation; Humans; Lung Neoplasms; Lymphatic Metastasis; Melanoma; Neoplasm Metastasis; Neoplasms; NF-kappa B; Receptor, Adenosine A3; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

Melanoma differentiation-associated gene-7 (mda-7), also referred to as IL-24, is a novel growth regulatory cytokine that has been shown to regulate the immune system by inducing the expression of inflammatory cytokines, such as TNF, IL-1, and IL-6. Whether the induction of these cytokines by MDA-7 is mediated through activation of NF-kappaB or whether it regulates cytokine signaling is not known. In the present report we investigated the effect of MDA-7 on NF-kappaB activation and on TNF-induced NF-kappaB activation and apoptosis in human embryonic kidney 293 cells. Stable or transient transfection with mda-7 into 293 cells failed to activate NF-kappaB. However, TNF-induced NF-kappaB activation was significantly enhanced in mda-7-transfected cells, as indicated by DNA binding, p65 translocation, and NF-kappaB-dependent reporter gene expression. Mda-7 transfection also potentiated NF-kappaB reporter activation induced by TNF receptor-associated death domain and TNF receptor-associated factor-2. Cytoplasmic MDA-7 with deleted signal sequence was as effective as full-length MDA-7 in potentiating TNF-induced NF-kappaB reporter activity. Secretion of MDA-7 was not required for the potentiation of TNF-induced NF-kappaB activation. TNF-induced expression of the NF-kappaB-regulated gene products cyclin D1 and cyclooxygenase-2, were significantly up-regulated by stable expression of MDA-7. Furthermore, MDA-7 expression abolished TNF-induced apoptosis, and suppression of NF-kappaB by IkappaBalpha kinase inhibitors enhanced apoptosis. Overall, our results indicate that stable or transient MDA-7 expression alone does not substantially activate NF-kappaB, but potentiates TNF-induced NF-kappaB activation and NF-kappaB-regulated gene expression. Potentiation of NF-kappaB survival signaling by MDA-7 inhibits TNF-mediated apoptosis.

Topics: Adjuvants, Immunologic; Alkaline Phosphatase; Amino Acid Sequence; Apoptosis; Carrier Proteins; Cell Differentiation; Cell Line; Cyclin D1; Cyclooxygenase 2; Drug Synergism; Gene Expression Regulation; Genes, Reporter; Genes, Tumor Suppressor; Humans; I-kappa B Kinase; Interleukins; Isoenzymes; Melanoma; Membrane Proteins; Molecular Sequence Data; NF-kappa B; Prostaglandin-Endoperoxide Synthases; Proteins; Receptors, Tumor Necrosis Factor; Trans-Activators; Transfection; Tumor Necrosis Factor-alpha; Up-Regulation

Cell cycle regulating proteins are important in tumour development. To investigate whether alterations in Cyclin D1, p14, CDK4 and Rb are associated with tumour cell proliferation, tumour progression and patient survival in malignant melanoma, we examined 202 vertical growth phase tumours and 68 corresponding metastases for expression of Cyclin D1, p14, CDK4 and Rb, and compared the results with Ki-67 expression, p16 and p53 expression, clinico-pathological variables, and survival data. Nuclear staining of Cyclin D1 was strong in 35% of cases, and correlated with high levels of Rb (p=0.05), but not with survival or other markers tested. Strong staining of p14 was found in 63% of nodular melanomas and was associated with strong p53 expression (p=0.014), and with high levels of CDK4 (p<0.0001). Low p14 expression was associated with increased tumour thickness (p=0.008) and increasing level of invasion (p=0.020). Strong nuclear staining for CDK4 was found in 81% of cases and was associated with tumour thickness below the median value of 3.7 mm and improved survival (log-rank test, p=0.024). Further, 56% of the tumours showed strong nuclear staining for Rb, and these cases were significantly associated with absent/low levels of p16 staining (p=0.030), high levels of p14 (p=0.010), as well as high Ki-67 expression (p=0.005). Our results seem to confirm that the p16-Rb pathway plays an important role in tumour progression and prognosis in vertical growth phase melanomas, whereas alterations in the p14-p53 pathway might be less important.

Topics: Cell Cycle; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinases; Disease Progression; Gene Expression Profiling; Humans; Immunohistochemistry; Melanoma; Oligonucleotide Array Sequence Analysis; Prognosis; Proto-Oncogene Proteins; Retinoblastoma Protein; Skin Neoplasms; Survival Analysis

In contrast with melanocytes, melanomas display constitutive expression of HLA-DR (HLA-DR+). This abnormal expression has been associated with tumour progression and metastatic dissemination. We have previously reported that this deregulation of HLA-D genes is due to the abnormal constitutive expression of the lymphocyte-specific isoform of class II transactivator (B-CIITA), in addition to its fibroblast form (F-CIITA), which is usually expressed in major histocompatibility complex (MHC) class II-negative interferon-gamma-induced cell types, such as melanocytes. In this study, we investigated the abnormal expression of B-CIITA in a panel of melanoma cell lines displaying differential HLA-DR expression profiles, and analysed whether such a molecular event can participate in tumour progression. Our results showed that the abnormal expression of B-CIITA did not have any particular effect, in comparison with F-CIITA, on the classical activity of CIITA HLA-D gene regulation. As CIITA has also been shown to regulate genes other than HLA-D, we evaluated the modulation of those encoding cyclin D1, YARS (tyrosyl-tRNA synthetase) and TRIP1 (transforming growth factor (TGF)-beta receptor-interacting protein), proteins involved in cell cycle/apoptosis balance, angiogenesis and resistance to TGF-beta, respectively. In contrast with other cell types, neither B-CIITA nor F-CIITA was able to modulate these genes in melanoma cell lines. Thus, the activity of CIITA, whether lymphocyte-specific or fibroblast-specific, is restricted to HLA-D gene expression in these tumours. Accordingly, our data suggest that CIITA is not involved per se in tumour progression; rather, it is the MHC class II molecules themselves, through tumour antigen presentation and the induction of tumour antigen-specific CD4 lymphocyte anergy, that may participate in immune escape and melanoma progression.

Topics: Animals; B-Lymphocytes; Chlorocebus aethiops; COS Cells; Cyclin D1; Disease Progression; Eukaryotic Initiation Factor-3; Fibroblasts; Gene Expression Regulation, Neoplastic; Genes, MHC Class II; HLA-DR Antigens; Humans; Melanoma; Nuclear Proteins; Protein Isoforms; Proteins; Skin Neoplasms; Trans-Activators; Tumor Cells, Cultured; Tyrosine-tRNA Ligase

Activation of the Gi protein-coupled A3 adenosine receptor (A3AR) has been implicated in the inhibition of melanoma cell growth by deregulating protein kinase A and key components of the Wnt signaling pathway. Receptor activation results in internalization/recycling events that play an important role in turning on/off receptor-mediated signal transduction pathways. Thus, we hereby examined the association between receptor fate, receptor functionality, and tumor growth inhibition upon activation with the agonist 1-deoxy-1-[6-[[(3-iodophenyl)-methyl]amino]-9H-purine-9-yl]-N-methyl-beta-D-ribofuranuronamide (IB-MECA). Results showed that melanoma cells highly expressed A3AR on the cell surface, which was rapidly internalized to the cytosol and "sorted" to the endosomes for recycling and to the lysosomes for degradation. Receptor distribution in the lysosomes was consistent with the down-regulation of receptor protein expression and was followed by mRNA and protein resynthesis. At each stage, receptor functionality was evidenced by the modulation in cAMP level and the downstream effectors protein kinase A, glycogen synthase kinase-3beta, c-Myc, and cyclin D1. The A3AR antagonist MRS 1523 counteracted the internalization process as well as the modulation in the expression of the signaling proteins, demonstrating that the responses are A3AR-mediated. Supporting this notion are the in vivo studies showing tumor growth inhibition upon IB-MECA treatment and reverse of this response when IB-MECA was given in combination with MRS 1523. In addition, in melanoma tumor lesions derived from IB-MECA-treated mice, the expression level A3AR and the downstream key signaling proteins were modulated in the same pattern as was seen in vitro. Altogether, our observations tie the fate of A3AR to modulation of downstream molecular mechanisms leading to tumor growth inhibition both in vitro and in vivo.

Topics: Adenosine; Animals; Cell Division; Cell Line, Tumor; Cyclin D1; Down-Regulation; Melanoma; Mice; Mice, Inbred C57BL; Neoplasm Proteins; Neoplasms, Experimental; Protein Transport; Proto-Oncogene Proteins c-myc; Receptor, Adenosine A3; Signal Transduction

The purpose of the present work was to analyze the expression of beta-catenin in a panel of superficial and nodular spreading primary and metastatic melanomas, and to correlate the level of immunohistochemical staining to clinicopathological parameters.. Expression of beta-catenin was examined by immunohistochemistry in 106 superficial and 58 nodular spreading primary melanomas, as well as in 66 metastatic lesions.. Membrane-associated staining was detected in nearly all of the cases, and no association to clinical parameters could be revealed. When cytoplasmic localization of the protein was recorded, a significant higher fraction of the superficial than the nodular spreading primary lesions expressed the protein in the majority of the cells (P < 0.0001). Interestingly, metastatic lesions from superficial melanomas demonstrated down-regulated expression of the protein, and in agreement with this a significant inverse correlation between protein expression and the vertical thickness of the primary lesion was detected (P = 0.012). Furthermore, a significant correlation between cytoplasmic localization and disease-free survival (P = 0.0006) was revealed, but beta-catenin did not have any significant impact on overall survival for this group of patients (P = 0.0824). No association was detected between beta-catenin expression and clinicopathological parameters in the nodular subgroup of melanomas, indicating that the protein may play different roles in the malignant progression of the two main types of melanomas.. In summary, we hypothesize that cytoplasmic beta-catenin has a protective role in early melanoma development.

Topics: Adult; Aged; Aged, 80 and over; beta Catenin; Cell Cycle Proteins; Cell Line, Tumor; Cell Membrane; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Cytoplasm; Cytoskeletal Proteins; Disease-Free Survival; Humans; Immunohistochemistry; Melanoma; Middle Aged; Neoplasm Metastasis; Recurrence; Skin Neoplasms; Time Factors; Trans-Activators; Tumor Suppressor Proteins

Activation of the Gi-protein-coupled A3 adenosine receptor (A3AR) has been reported to be involved in the inhibition of tumor cell growth. A3AR is highly expressed in tumor cells whereas lower expression was noted in a variety of normal cells. Recently we showed that A3AR activation in melanoma cells resulted in growth inhibition via a direct anti-proliferative effect which entailed cell cycle arrest in the G0/G1 and down-regulation of cyclin D1 and c-Myc. In the present study we present an additional mechanism demonstrating that A3AR agonists activate natural killer (NK) cells which further enhance the anti-tumor effect of this group of molecules. NK cells mediate the natural cytotoxicity and their number and function is reduced in cancer patients. We show Cl-IB-MECA to inhibit tumor development via the activation of NK cells is an additional mechanism which accounts for the anti-tumor effect of A3AR agonists. This effect was noted at a low dose of 10 micro g/kg, demonstrating that the response is exclusively A3AR mediated. Treatment of naïve mice for four days yielded the highest effect on NK cell potentiation. In mice inoculated with B16-F10 melanoma cells and treated each orally with Cl-IB-MECA, melanoma growth inhibition correlated with higher serum level of IL-12 and potentiation of NK cells. Moreover, in adoptive transfer experiments in melanoma bearing mice, marked inhibition of lung metastatic foci was noted upon engraftment with splenocytes derived from Cl-IB-MECA treated mice. Taken together, the ability of Cl-IB-MECA to inhibit tumor development via the activation of NK cells is an additional mechanism which accounts for the anti-tumor effect of A3AR agonists.

Topics: Adenosine A3 Receptor Agonists; Animals; Cell Line, Tumor; Cyclin D1; Dose-Response Relationship, Drug; G1 Phase; Interleukin-12; Killer Cells, Natural; Kinetics; Melanoma; Mice; Neoplasm Transplantation; Proto-Oncogene Proteins c-myc; Resting Phase, Cell Cycle; Spleen

To examine the expression of proteins in the Rb and p53 tumor suppressor pathways in uveal melanomas following plaque radiotherapy.. Immunohistochemistry and cell culture studies. Immunohistochemistry for Rb, p16, cyclin D1, p53, HDM2, and Bcl-2 was performed on twelve eyes containing posterior uveal melanomas that were enucleated following plaque radiotherapy. Cell culture studies were performed in three cases.. The irradiated eyes were enucleated for radiation complications (five cases), local tumor recurrence (three cases), and other reasons (four cases). On histopathologic examination, all cases showed evidence of tumor cell loss. However, residual tumor cells were present in all cases, including those that were clinically regressed. Residual cells from three of the clinically regressed cases were cultured and demonstrated minimal cell division, marked cell death, and extensive chromosomal damage. Strong p53 staining was observed in six cases (50%) and was significantly associated with recent radiotherapy (P = .04). Abnormal cytoplasmic staining for Rb was observed in four cases (33%).. Plaque radiotherapy of uveal melanomas induces DNA damage, inhibits cell division, and promotes cell death. These changes may be due, at least in part, to induction of p53, which activates genes involved in both cell cycle arrest and apoptosis. Plaque radiotherapy can also cause alterations in the expression of Rb, but the significance of this finding will require further study.

Topics: Adult; Aged; Brachytherapy; Cobalt Radioisotopes; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; DNA Damage; DNA, Neoplasm; Eye Enucleation; Female; Humans; Immunoenzyme Techniques; Iodine Radioisotopes; Male; Melanoma; Middle Aged; Nuclear Proteins; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-mdm2; Retinoblastoma Protein; Tumor Cells, Cultured; Tumor Suppressor Protein p53; Uveal Neoplasms

Members of the mitogen-activated protein kinase (MAPK) superfamily, including p38 kinase and SAPK/JNK, play a central role in mediating cellular response to environmental stress, growth factors and cytokines. Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional cytokine capable of eliciting mitogenic, motogenic and morphogenetic activities in responsive cells, and has been implicated in tumor development and metastasis. Binding of HGF/SF to its tyrosine kinase receptor c-Met stimulates multiple signal transduction pathways, leading to the activation of numerous transcription factors. We here report that HGF/SF can induce cyclin D1 expression in mouse melanoma cells, and that this up-regulation is mediated in part by the activating transcription factor-2 (ATF-2). HGF/SF-mediated phosphorylation of ATF-2 was reduced in the presence of either the p38 kinase-specific inhibitor SB203580, a dominant negative p38 mutant, the SAPK/JNK inhibitor JNK-interacting protein-1 (JIP-1), or the phosphatidylinositol 3-kinase (PI3K)-specific inhibitor LY294002. Activation of p38 kinase by HGF/SF was partially blocked by the PI3K-specific inhibitor as well. The upstream kinases for p38, MKK3/6, did not become activated following HGF/SF exposure, and ATF-2 activation was undiminished by transient transfection of a dominant negative MKK6 mutant. However, transcriptional up-regulation of cyclin D1 by HGF/SF was partially inhibited by the p38 kinase-specific inhibitor, and cyclin D1 protein induction was partially blocked by a dominant negative ATF-2 mutant. Notably, the p38 kinase-specific inhibitor was able to block melanoma cell proliferation but not motility. We conclude that the ATF-2 transcription factor becomes activated by HGF/SF through p38 MAPK and SAPK/JNK. Moreover, the p38-ATF-2 pathway can help mediate proliferation signals in tumor cells through transcriptional activation of key cell cycle regulators.

Topics: Activating Transcription Factor 2; Animals; Cell Division; Cell Movement; Cyclic AMP Response Element-Binding Protein; Cyclin D1; Hepatocyte Growth Factor; Kinetics; Melanoma; Mice; Mitogen-Activated Protein Kinases; p38 Mitogen-Activated Protein Kinases; Phosphatidylinositol 3-Kinases; RNA, Messenger; Signal Transduction; Transcription Factors; Transcriptional Activation; Tumor Cells, Cultured; Up-Regulation

The retinoblastoma pathway has been implicated in melanoma; however, previous studies of one of the key components of this pathway, cyclin D1 (CD1), failed to find amplification of this gene in a large series of melanomas. We have recently shown that a particular subtype of melanoma, acral melanoma (AM), has frequent amplification of the CD1 locus. This suggested that CD1 might be important in AM and that it may also be important in other melanoma types, even though its copy number may not be altered. We compared CD1 gene copy number and protein expression in 137 invasive primary cutaneous melanomas (71 superficial spreading melanomas, 17 nodular melanomas, 19 lentigo maligna melanomas, 18 AMs, and 12 unclassifiable melanomas) using fluorescence in situ hybridization and immunohistochemistry. We found frequent amplification of CD1 in AM (44.4%) and occasional amplification in lentigo maligna melanoma (10.5%) and superficial spreading melanoma (5.6%). CD1 protein was overexpressed in all cases with amplifications and in an additional 20% of cases without amplification. We tested the importance of CD1 in cell growth in melanoma by using adenovirus-mediated antisense treatment targeted to CD1 in two melanoma cell lines, one with and the other without CD1 amplification and overexpression. Antisense mediated down-regulation of CD1 induced apoptosis in vitro and led to significant tumor shrinkage of melanoma xenografts in severe combined immunodeficient mice. However, it did not alter the growth of normal melanocytes. Together, these results suggest that CD1 may be an oncogene in melanoma and that targeting its expression may be therapeutically beneficial.

Topics: Apoptosis; Cell Division; Cyclin D1; Gene Amplification; Gene Dosage; Humans; In Situ Hybridization, Fluorescence; Melanoma; Oncogenes; Skin Neoplasms; Transduction, Genetic; Tumor Cells, Cultured

The frequent loss of both INK4a and ARF in melanoma raises the question of which INK4a-ARF gene product functions to suppress melanoma genesis in vivo. Moreover, the high incidence of INK4a-ARF inactivation in transformed melanocytes, along with the lack of p53 mutation, implies a cell type-specific role for INK4a-ARF that may not be complemented by other lesions of the RB and p53 pathways. A mouse model of cutaneous melanoma has been generated previously through the combined effects of INK4a(Delta2/3) deficiency (null for INK4a and ARF) and melanocyte-specific expression of activated RAS (tyrosinase-driven H-RAS(V12G), Tyr-RAS). In this study, we made use of this Tyr-RAS allele to determine whether activated RAS can cooperate with p53 loss in melanoma genesis, whether such melanomas are biologically comparable to those arising in INK4a(Delta2/3-/-) mice, and whether tumor-associated mutations emerge in the p16(INK4a)-RB pathway in such melanomas. Here, we report that p53 inactivation can cooperate with activated RAS to promote the development of cutaneous melanomas that are clinically indistinguishable from those arisen on the INK4a(Delta2/3) null background. Genomewide analysis of RAS-induced p53 mutant melanomas by comparative genomic hybridization and candidate gene surveys revealed alterations of key components governing RB-regulated G(1)/S transition, including c-Myc, cyclin D1, cdc25a, and p21(CIP1). Consistent with the profile of c-Myc dysregulation, the reintroduction of p16(INK4a) profoundly reduced the growth of Tyr-RAS INK4a(Delta2/3-/-) tumor cells but had no effect on tumor cells derived from Tyr-RAS p53(-/-) melanomas. Together, these data validate a role for p53 inactivation in melanomagenesis and suggest that both the RB and p53 pathways function to suppress melanocyte transformation in vivo in the mouse.

Topics: Animals; cdc25 Phosphatases; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; G1 Phase; Gene Expression Regulation, Neoplastic; Gene Silencing; Genes, ras; In Situ Hybridization; Melanoma; Mice; Mice, Mutant Strains; Proteins; Proto-Oncogene Proteins c-myc; Retinoblastoma Protein; S Phase; Tumor Suppressor Protein p14ARF; Tumor Suppressor Protein p53

Malignant uveal melanoma is the commonest primary intraocular tumour in adults. It metastasizes frequently and 50% of patients die within 10 years of diagnosis. The expression of cyclin D1, p53, and MDM2 in uveal melanoma and their relationship to metastasis-free 5-year survival was determined, in order to investigate whether these proteins help to distinguish those patients with a favourable prognosis from those with a poorer one. Ninety-six eyes enucleated for uveal melanomas were immunohistochemically analysed for the protein expression of cyclin D1 and related cell-cycle markers, p53 and MDM2. The evaluation of the specimens was undertaken by two independent pathologists without knowledge of the outcome. Statistical analysis of clinical, morphological, and immunohistological features was performed. A 'favourable outcome' was defined as survival of at least 5 years after diagnosis, without metastases (n=57). An 'unfavourable outcome' was defined as death from metastases within the first 5 years after diagnosis of uveal melanoma (n=39). Cyclin D1 positivity (>15% positive tumour cells) as well as p53 positivity (>15% positive tumour cells) was associated with an unfavourable outcome (for cyclin D1: odds ratio=4. 2, 95% confidence interval 1.5-11.8, p=0.006; for p53: odds ratio=3. 2, 95% confidence interval 1.1-9.3, p=0.03). In addition, cyclin D1 positivity was associated with the presence of extraocular extension of the tumour (p=0.01), with the mixed or epithelioid cell type (p=0. 02), and with the tumour cell MIB-1 positivity (p=0.0001). MDM2 immunoreactivity of the tumour cells showed a potential correlation with clinical outcome (odds ratio=2.1, 95% confidence interval 0.8-5. 8, p=0.13). Multiple logistic regression models showed that cyclin D1 positivity is an independent prognostic factor after control for other prognostic markers. The expression of cyclin D1 in uveal melanoma is associated with a more aggressive course and histologically unfavourable disease. This could serve as a further independent prognostic factor in uveal melanoma.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Confidence Intervals; Cyclin D1; Disease-Free Survival; Female; Humans; Male; Melanoma; Middle Aged; Neoplasm Metastasis; Nuclear Proteins; Odds Ratio; Predictive Value of Tests; Prognosis; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-mdm2; Regression Analysis; Tumor Suppressor Protein p53; Uveal Neoplasms

The incidence of cutaneous malignant melanoma is undergoing a dramatic increase in persons with light-color skin in all parts of the world. The prognosis for individuals with advanced disease is dismal due to the lack of effective treatment options. Thus, there is a need for new approaches to control tumor progression. Epidemiological, experimental, and mechanistic data implicate omega-6 polyunsaturated fatty acids (PUFAs) as stimulators and long-chain omega-3 PUFAs as inhibitors of development and progression of a range of human cancers, including melanoma. The aim of this study was to assess the mechanisms by which docosahexaenoic acid (DHA), an omega-3 PUFA, affects human melanoma cells. Exponentially growing melanoma cell lines were exposed in vitro to DHA and then assessed for (a) inhibition of cell growth; (b) expression of cyclins and cyclin-dependent kinase inhibitors in individual cells by flow cytometry and immunocytochemistry using specific monoclonal antibodies to cyclin D1, cyclin E, p21WAF1/CIP1, or p27(KIP1); and (c) expression of total pRb(T) independent of phosphorylation state and hypophosphorylated pRb(P-) in fixed cells by flow cytometry and immunocytochemistry using specific monoclonal antibodies to pRb(T) or pRb(P-), respectively. After treatment with increasing concentrations of DHA, cell growth in a majority of melanoma cell lines (7 of 12) was inhibited, whereas in 5 of 12 cell lines, cell growth was minimally affected. Two melanoma cell lines were examined in detail, one resistant (SK-Mel-29) and one sensitive (SK-Mel-110) to the inhibitory activity of DHA. SK-Mel-29 cells were unaffected by treatment with up to 2 microg/ml DHA whether grown in the absence or presence of 1% fetal bovine serum (FBS). No appreciable change was observed in cell growth, cell cycle distribution, the status of pRb phosphorylation, cyclin D1 expression, or the levels of the cyclin-dependent kinase inhibitors p21 and p27. In contrast, SK-Mel-110 cell growth was inhibited by DHA with the cells accumulating either in G1 or S phase: 0% in SK-Mel-29 versus 13.3 or 41.2% in SK-Mel-110 in the absence or presence of FBS, respectively. In the absence of serum, considerable death occurred by apoptosis. In addition, DHA treatment resulted in increasing numbers of SK-Mel-110 cells (from 12 to >40%) expressing hypophosphorylated pRb, whereas the levels of cyclin D1 and p21 changed little. Expression of p27 in these cells increased >2.5 times when grown in the absenc

Topics: Animals; Apoptosis; Cattle; Cell Cycle; Cell Cycle Proteins; Cell Division; Culture Media, Serum-Free; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Cyclins; Docosahexaenoic Acids; Flow Cytometry; Growth Inhibitors; Humans; Melanoma; Microtubule-Associated Proteins; Phosphorylation; Retinoblastoma Protein; Skin Neoplasms; Tumor Cells, Cultured; Tumor Suppressor Proteins

We examined 172 primary (110 superficial and 62 nodular) and 73 metastatic melanomas, as well as 10 benign nevi, for protein expression of cyclin D1 and cyclin D3 and evaluated the relationship between deregulated protein levels and clinical outcome. For both proteins, a heterogeneous nuclear staining pattern was observed. Cyclin D3 was expressed by 96% of primary and 97% of metastatic melanomas. The corresponding percentages for cyclin D1 were 62% and 29%, respectively. In benign nevi, only rare cyclin D3-positive cells and no cyclin D1-positive cells were observed. High levels of cyclin D3 (>5% of the cells stained) were detected in 26 of 62 (42%) nodular melanomas and in 22 of 110 (20%) superficial tumors, whereas no such difference was observed with respect to cyclin D1. In superficial melanomas, a significant concordant staining pattern was observed between cyclin D1 and cyclin D3 (P = 0.0009), cyclin D1 and Ki-67 (P = 0.0001), cyclin D1 and cyclin A (P = 0.02), cyclin D3 and Ki-67 (P < 0.00001), and cyclin D3 and cyclin A (P = 0.002). Kaplan-Meier analysis revealed that high levels of cyclin D3 were an indicator of early relapse and decreased overall survival for patients with superficial (P = 0.001 and P = 0.009, respectively) but not nodular (P = 0.64 and P = 0.23) melanoma. Cyclin D1 did not have any impact on disease-free and overall survival for either of the subtypes. In conclusion, our results suggest that deregulation of cyclin D3 expression leading to increased proliferation may be a prognostic factor for superficial melanoma, whereas deregulated cell cycle machinery seems to have little impact on disease progression of nodular melanoma.

Topics: Biomarkers, Tumor; Cell Cycle; Cell Division; Cyclin A; Cyclin D1; Cyclin D3; Cyclins; Disease-Free Survival; Humans; Immunohistochemistry; Ki-67 Antigen; Melanoma; Nevus; Skin Neoplasms; Survival Analysis

Telomerase plays a key role in carcinogenesis. It is activated in most immortal cell lines and human cancers, including cutaneous melanoma (CM). Increased cell proliferation and deregulation of the cell cycle occur in human cancers. Links between telomerase activity (TA), cell proliferation, cell death and expression of cell-cycle regulators have not been extensively elucidated in CM. In this study, we investigated TA, mitotic index (MI), apoptotic index (AI), Ki-67 and nuclear positivity of cyclins D1 and A (Ki-67+ N/1,000, cyclin D1+N/1,000, cyclin A+N/1,000) in 42 primary cutaneous melanomas (PCMs). TA was detected in all cases and directly correlated with MI, Ki-67+N/1,000, cyclin D1+N/1,000 and cyclin A+N/1,000 (p < 0.001); it was not correlated with AI. When subdividing PCMs into radial and vertical growth phase melanomas (RGPMs, VGPMs), a correlation was maintained only with MI (p < 0.005) and cyclin D1 +N/1,000 (p < 0.005). Although MI and Ki-67+N/1,000 were highly correlated with cyclin D1+N/1,000 and cyclin A+N/1,000 (p < 0.001) when considering all cases together, a high correlation was found in the RGPM and VGPM groups between cyclin A+N/1,000 and Ki-67+N/1,000 only (p < 0.001), thus suggesting that cyclin A is more closely correlated with cell proliferation than cyclin D1. Our results further support the association between TA, tumor cell proliferation and cyclin D1 and A expression in PCM, though it is possible that links between TA and proliferation, on the one hand, and TA and cyclin D1 expression, on the other, might occur following various pathways.

Topics: Apoptosis; Cyclin A; Cyclin D1; Humans; Ki-67 Antigen; Melanoma; Mitosis; Skin Neoplasms; Telomerase

Uveal melanoma is the most common primary eye cancer, yet its molecular pathogenesis is poorly understood. In this study, we investigated the immunohistochemical expression of proteins in the Rb and p53 tumor suppressor pathways in 33 uveal melanomas from enucleated eyes. Strong nuclear staining for Rb was present in most tumors. However, a few cases displayed weak nuclear staining and strong cytoplasmic staining (possibly indicating Rb mutation), and this aberrant staining correlated strongly with failed radiotherapy or thermotherapy before enucleation. Staining for cyclin D1 was positive in most tumors and was associated with advanced age and larger tumor size, which are both poor prognostic factors. Generally, immunostaining for p53 was weak (suggesting a lack of p53 mutations), although p53 positivity correlated strongly with staining for phosphorylated Rb, supporting the notion that inappropriate phosphorylation of Rb can induce p53. Strong immunostaining for MDM2, which can functionally block p53 activity, was observed in most tumors and correlated significantly with female sex. Strong cytoplasmic staining was observed for Bcl2, which can inhibit both p53-dependent and -independent apoptosis. We conclude that Rb and p53 are mutated infrequently in uveal melanoma, but their respective pathways may be functionally inactivated.

Topics: Adult; Aged; Cell Nucleus; Cyclin D1; Female; Humans; Immunohistochemistry; Male; Melanoma; Middle Aged; Nuclear Proteins; Phosphorylation; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-mdm2; Retinoblastoma Protein; Sex Characteristics; Tumor Suppressor Protein p53; Uveal Neoplasms

The morphologic distinction between Spitz nevus and malignant melanoma can be difficult. Because cyclin D1 has been reported to be overexpressed in malignant melanomas, but not in common acquired nevi, we hypothesized that cyclin D1 might be a useful marker to distinguish Spitz nevi from malignant melanoma. Thus, we assessed for cyclin D1 expression in 11 Spitz nevi (10 compound and 1 intradermal) and 9 malignant melanomas (4 Clark stages I-III and 5 Clark stages IV-V) using an immunohistochemical method and routinely fixed and processed tissues. The cyclin D1 results were arbitrarily divided into three groups: 0% to 10%, >10% to 25%, and >25%. We confirmed the observations reported previously by others that cyclin D1 is expressed in malignant melanomas but not in common acquired nevi. Unexpectedly, a relatively high number of cyclin D1-positive cells (i.e., >10%) was also found in all cases of Spitz nevus. However, unlike malignant melanoma, the cyclin D1 positivity in Spitz nevi was present in a zonal pattern. In other words, the number of cyclin D1-positive cells decreased as the lesion extended more deeply, with the number of positive cells in the reticular dermis being less than that in the papillary dermis. Fluorescence in situ hybridization methods were used to assess amplification of 11q13, the locus harboring the cyclin D1 gene, in four cases of Spitz nevus; all were disomic. Using the antibody MIB-1, we compared cyclin D1 expression to the proliferation rate in Spitz nevi. Despite the high cyclin D1 positivity, all Spitz nevi had a relatively low number of MIB-1-positive cells (mean=3.2%), which was significantly lower than that of malignant melanomas (mean=15.3%) (p < 0.001). Thus, unlike malignant melanoma, there appears to be a dissociation between cyclin D1 overexpression and cell proliferation in Spitz nevi.

Topics: Carrier Proteins; Cell Cycle Proteins; Cyclin D1; Diagnosis, Differential; DNA-Binding Proteins; E2F Transcription Factors; Humans; Immunohistochemistry; Ki-67 Antigen; Melanoma; Nevus; Nevus, Epithelioid and Spindle Cell; Retinoblastoma-Binding Protein 1; Skin; Skin Neoplasms; Transcription Factor DP1; Transcription Factors

Cancer cells have abnormal cell cycle regulation which favors accelerated proliferation, chromosomal instability, and resistance to the senescence response. Although the p16INK4a locus is the most prominent susceptibility locus for familial melanomas, the low frequency of p16 mutations in sporadic melanomas suggests additional alterations in other cell cycle regulatory genes. Here we used primary melanoma tumors to reveal early cell cycle alterations that could be masked in advanced metastatic lesions due to their inherently high genetic instability. Unexpectedly, the cyclin-dependent kinase inhibitors p27KIP1 and/or p21Waf-1/SDI-1 were found to be expressed in 13 of 18 (72%) of the primary melanomas with a Breslow thickness greater than 0.076 mm. In general, p27 and/or p21 staining in the primary tumors correlated with low Ki-67 index. Importantly, most of the p21- and p27-positive tumors expressed high levels of cyclin D1 and cyclin E. In proliferating cells p27 is predominantly associated with cyclin D-CDK4 complexes, but does not inhibit the kinase activity, whereas in quiescent cells p27 is found associated with inactive CDK2 complexes. p27 was also expressed at high levels in proliferating primary melanomas in culture, and found to be associated with active cyclin E-CDK2 complexes containing high levels of cyclin E. It is thus likely that accumulation of cyclin E overcomes the potent inhibitory activity of p27 and p21 in CDK2 complexes. Of the primary melanomas with no indication of invasiveness, only three of 15 (20%) were positive for p27 and/or p21. We propose that high levels of p27 and p21 may confer upon melanoma tumors their characteristic resistance to conventional therapies. In turn, high levels of cyclins E and D1 may contribute to unlimited proliferation in primary melanomas that express the tumor suppressor p16INK4. J Invest Dermatol 113:1039-1046 1999

Topics: CDC2-CDC28 Kinases; Cell Cycle Proteins; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase Inhibitor p27; Cyclin-Dependent Kinases; Humans; Immunohistochemistry; Melanoma; Microfilament Proteins; Microtubule-Associated Proteins; Muscle Proteins; Protein Serine-Threonine Kinases; Tumor Suppressor Proteins

While investigating the mechanism of synergistic cytotoxicity between tamoxifen (TAM) and cisplatin (DDP) we developed a TAM-resistant variant of the human melanoma cell line T-289. We sought to characterize this cell line with respect to the effect of TAM resistance on a variety of different intracellular cell cycle control and apoptotic pathways. A TAM-resistant variant cell line (289 TAMs) was developed and the technique of Western analysis was to determine the changes in protein expression that occurred as a result of the development of TAM resistance. In this model, TAM resistance resulted in an increase in the detectable basal levels of cyclin E, GADD 153, p16, BAX, Bcl-XL, and wild-type and mutant p53, an increase in TAM induction of p16, and a decrease in the detectable basal levels of cyclin D1, p21 and p27. There were no detectable changes in the levels of pRb. In the TAM-resistant variant, p21 levels were essentially undetectable, while p27 was present and maintained its response to TAM Induction, albeit at a much lower level. This investigation demonstrates that the development of TAM resistance is associated with a change in the detectable levels of a variety of cell cycle control and apoptosis-related proteins. While the exact role that each change plays in the development of tamoxifen resistance remains to be determined, these data suggest that the development of resistance to a particular agent results in changes in multiple, seemingly unrelated pathways. These data have implications for future studies in both the laboratory and the clinic.

Topics: Antineoplastic Agents, Hormonal; Apoptosis; bcl-2-Associated X Protein; bcl-X Protein; Cell Cycle Proteins; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p15; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Cyclin-Dependent Kinases; Cyclins; Drug Resistance, Neoplasm; Humans; Melanoma; Microtubule-Associated Proteins; Neoplasm Proteins; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Receptors, Estrogen; Tamoxifen; Transcription Factors; Tumor Cells, Cultured; Tumor Suppressor Protein p53; Tumor Suppressor Proteins

Because betulinic acid was recently described as a melanoma-specific inducer of apoptosis, we investigated whether this agent was comparably effective against metastatic tumors and those in which metastatic ability and 92-kD gelatinase activity had been decreased by introduction of a normal chromosome 6. Human metastatic C8161 melanoma cells showed greater DNA fragmentation and growth arrest and earlier loss of viability in response to betulinic acid than their non-metastatic C8161/neo 6.3 counterpart. These effects involved induction of p53 without activation of p21WAF1 and were synergized by bromodeoxyuridine in metastatic Mel Juso, with no comparable responses in non-metastatic Mel Juso/neo 6 cells. Our data suggest that betulinic acid exerts its inhibitory effect partly by increasing p53 without a comparable effect on p21WAF1.

Topics: Antineoplastic Agents, Phytogenic; Betulinic Acid; Cell Death; Cyclin D1; Cyclin D3; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; DNA Damage; Drug Resistance, Neoplasm; Gelatinases; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Neoplasm Metastasis; Pentacyclic Triterpenes; Triterpenes; Tumor Cells, Cultured; Tumor Suppressor Protein p53

A checkpoint mechanism in late G1, whose regulation via loss of retinoblastoma protein (pRB) or p16, or overexpression of cyclin D1 or cyclin dependent kinase 4 (CDK4), has been proposed to constitute a common pathway to malignancy. The aims of this study were (a) to compare markers of cell cycle G1-S phase transition in an intraocular tumour with known pRB deficiency (retinoblastoma) and compare it with one with an apparently functional pRB (uveal melanoma); (b) to determine if one of these markers may have a role in the pathogenesis of uveal melanoma; and (c) to determine if there is a difference in cell cycle marker expression following treatment of uveal melanoma and retinoblastoma.. 90 eyes were enucleated from 89 patients for retinoblastoma (n = 24) or for choroidal or ciliary body melanoma (n = 66). Conventional paraffin sections were assessed for cell type and degree of differentiation. Additional slides were investigated applying standard immunohistochemical methods with antibodies specific for cyclin D1 protein, pRB, p53, p21, p16, BCL-2, and MIB-1.. Cyclin D1 protein and pRB were negative in retinoblastoma using the applied antibodies. In contrast, cyclin D1 protein expression was observed in 65% of uveal melanomas; a positive correlation between cyclin D1 cell positivity and tumour cell type, location, growth fraction, as well as with pRB positivity was observed. p53, p21, and p16 could be demonstrated in both tumours. An inverse relation between p53 and p21 expression was demonstrated in most choroidal melanomas and in some retinoblastomas. Apart from a decrease in the growth fractions of the tumours as determined by MIB-1, a significant difference in the expression of G1-S phase transition markers in vital areas of uveal melanoma and retinoblastoma following treatment with radiotherapy and/or chemotherapy was not observed.. Retinoblastomas and uveal melanomas, two tumours of differing pRB status, differ also in their immunohistochemical pattern for markers of the G1-S phase transition of the cell cycle. The results of the present study support the concept of (a) an autoregulatory loop between pRB and cyclin D1 in tumours with a functional pRB and the disruption of this loop in the presence of pRB mutation, as well as (b) a checkpoint mechanism in late G1, whose regulation via loss of p16 or pRB, or overexpression of cyclin D1 constitutes a common pathway to malignancy. Further, the results raise the possibility of cyclin D1 overexpression having a role in the pathogenesis of uveal melanoma.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Cyclin D1; Female; G1 Phase; Humans; Immunoenzyme Techniques; Infant; Male; Melanoma; Neoplasm Proteins; Retinal Neoplasms; Retinoblastoma; Retinoblastoma Protein; S Phase; Uveal Neoplasms

Retinoic acid (RA) induces growth arrest and differentiation of many different tumor cells. RA activates RA receptors, which function as ligand-dependent transcriptional modulators. S91 murine melanoma cells stop proliferating and then reversibly differentiate into a melanocytic cell type after the administration of RA. The genetic changes that take place during this process serve as an excellent model for the etiology of melanoma. The use of subtractive hybridization techniques yielded several differentially expressed cDNAs that are associated with RA-induced growth arrest. One clone, cyclin D1, is repressed and is probably a differentiation marker. Two other cDNAs represent novel, RA-inducible genes. Expression of another cDNA, clone 10d, is strongly down-regulated. It is the homologue of the human gene BM28 (CDCL1) that is indispensable for entry into S phase and cell division. S91 cells that are permanently transfected with a plasmid that constitutively expresses clone 10d become significantly more resistant to RA, suggesting that repression of this gene is a critical event in RA-induced growth arrest. The use of reverse transcription-PCR for the detection of expression in human melanoma in vitro was performed to study the potential role of clone 10d/BM28 in this disease. It is expressed in 80% of melanoma cell lines but is virtually undetectable in primary melanocytes. The expression of BM28 is not regulated by RA in human, RA-resistant melanoma cells. These results suggest that clone 10d/BM28 functions as an important tumor cell growth promoter. The regulation of clone 10d may be directly mediated by RA receptors, and escape from negative regulation may, thus, contribute to the etiology of melanoma.

Topics: Base Sequence; Cell Cycle Proteins; Cell Division; Cyclin D1; DNA, Complementary; DNA, Neoplasm; Down-Regulation; Drug Resistance, Neoplasm; Humans; Melanoma; Minichromosome Maintenance Complex Component 2; Molecular Sequence Data; Nuclear Proteins; Receptors, Retinoic Acid; Sequence Analysis, DNA; Tretinoin; Tumor Cells, Cultured

Biopsies from 61 sporadic metastatic malignant melanomas and five melanoma cell lines were examined for homozygous deletions and mutations in the CDKN2 gene (p16). As the p16 protein is involved in a cell cycle regulatory pathway consisting of at least pRb, cdk4 and cyclin D1, the tumours were also screened for amplifications of the last two genes. Moreover, the transcript levels of the genes were determined and the results compared with the immunohistochemically assessed expression of pRb. Altogether, homozygous deletions of CDKN2 were found in seven tumours (11%) and two of five cell lines, whereas a mutation was detected in only one biopsy, indicating that in sporadic melanomas the former mechanism is predominant for inactivating this gene. Notably, in total 59% of the metastatic lesions lacked detectable expression of p16 mRNA, whereas all the biopsies were found to express pRb. In accordance with the postulated negative feedback loop between p16 and pRb, one melanoma cell line showed overexpression of CDKN2 mRNA together with very low levels of the Rb protein. Amplification of the other two genes may not be important in the tumorigenesis of melanomas, as only one CDK4 and no CCND1 amplification was observed. However, highly elevated CDK4 mRNA levels, compared with that seen in a panel of normal tissues, were observed in 76% of the tumours, accompanied in 71% of the cases by high expression of the CCND1 cyclin activator. Although a low frequency of CDKN2 DNA aberrations was observed, the high number of tumours that lacked CDKN2 expression but showed overexpression of CDK4 and/or CCND1, suggest that functional inactivation of pRb through this pathway may be involved in the development or progression of sporadic human melanomas.

Topics: Base Sequence; Carrier Proteins; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinases; Cyclins; DNA, Neoplasm; Genes, Retinoblastoma; Humans; Melanoma; Molecular Sequence Data; Mutation; Oncogene Proteins; Proto-Oncogene Proteins; Retinoblastoma Protein; RNA, Messenger

Overexpression of cyclin D1 and p53 protein has been reported in many types of malignant tumors.. We investigated whether cyclin D1 was detected immunohistochemically in various types of malignant tumors of the skin, comparable with p53 protein.. Immunohistochemical staining of cyclin D1 and p53 protein was applied to squamous cell carcinoma, malignant melanoma and malignant fibrous histiocytoma and various kinds of benign skin tumors.. Cyclin D1 was positive only in malignant tumors at the same incidence as p53 protein.. Cyclin D1 immunohistochemical staining may be a malignant marker for various skin tumors.

Topics: Biomarkers; Biopsy, Needle; Carcinoma, Squamous Cell; Cyclin D1; Cyclins; Histiocytoma, Benign Fibrous; Humans; Immunohistochemistry; Melanoma; Oncogene Proteins; Sensitivity and Specificity; Skin Neoplasms; Tumor Suppressor Protein p53

Adaptive survival responses (ASRs) are observed when cells become more resistant to a high dose of a cytotoxic agent after repeated low dose exposures to that agent or another genotoxic agent. Confluent (G0/G1) human normal (GM2936B, GM2937A, AG2603, IMR-90), cancer-prone (XPV2359), and neoplastic (U1-Mel, HEp-2, HTB-152) cells were primed with repeated low doses of X-rays (ranging from 0.05-10 cGy/day for 4 days), then challenged with a high dose (290-450 cGy) on day 5. U1-Mel and HEp-2 cells showed greater than 2-fold transient survival enhancement when primed with 1-10 cGy. ASRs in U1-Mel or HEp-2 cells were blocked by cycloheximide or actinomycin D. Increases in cyclins A and D1 mRNAs were noted in primed compared to unirradiated U1-Mel and HEp-2 cells; however, only cyclin A protein levels increased. Cyclin D1 and proliferating cell nuclear antigen (PCNA) protein levels were constitutively elevated in HEp-2 and U1-Mel cells, compared to the other human normal and neoplastic cells examined, and were not altered by low or high doses of radiation. Low dose primed U1-Mel cells entered S-phase 4-6 h faster than unprimed U1-Mel cells upon low-density replating. Similar responses in terms of survival recovery, transcript and protein induction, and altered cell cycle regulation were not observed in the other human normal, cancer-prone or neoplastic cells examined. We hypothesize that only certain human cells can adapt to ionizing radiation by progressing to a point later in G1 (the A point) where DNA repair processes and radioresistance can be induced. ASRs in human cells correlated well with constitutively elevated levels of PCNA and cyclin D1, as well as inducibility of cyclin A. We propose that a protein complex composed of cyclin D1, PCNA, and possibly cyclin A may play a role in cell cycle regulation and DNA repair, which determine ASRs in human cells.

Topics: Adaptation, Physiological; Carcinoma; Cell Cycle; Cells, Cultured; Cyclin D1; Cyclins; DNA Repair; Dose-Response Relationship, Radiation; G1 Phase; Gamma Rays; Humans; Melanoma; Oncogene Proteins; Proliferating Cell Nuclear Antigen; Proteins; RNA, Messenger; Transcription, Genetic; Tumor Cells, Cultured

The growth of malignant melanoma cells is inhibited by 12-O-tetradecanoylphorbol-13-acetate (TPA) while the growth of normal melanocytes is stimulated. We previously demonstrated that TPA inhibits the growth of Demel melanoma cells and leads to arrest at both at the G1/S and G2/M cell cycle transitions. To investigate the mechanism by which TPA arrests melanoma cell growth at the G1/S transition we have examined its effects on the levels of cyclins and cyclin dependent kinases (CDKs) and activation of CDK2 kinase activity. Addition of TPA in G1 blocked the increase in the level of p34cdc2 mRNA, but not of CDK2 mRNA. When TPA was added in G1, it inhibited the mobility shift of CDK2 reflecting a change in phosphorylation state. This corresponded to inhibition of the increase in CDK2 histone H1 kinase activity. There was little effect on the level of CDK4. Treatment with TPA during G1 caused a three to four fold increase in cyclin D1 mRNA expression, but blocked the increase in the expression of cyclin A and cyclin B mRNAs later in the cell cycle. TPA caused a small increase in levels of cyclin D1 and had little effect on cyclin E, suggesting these G1 cyclins were not limiting. Addition of TPA in G1 prevented an increase in cyclin A levels, suggesting cyclin A might play an important role in mediating the growth inhibition. Examination of the levels of the CDK inhibitors p21Cip1 and p27Kip1 showed that the level of these inhibitors was higher in G1 and dropped as cells entered S phase. In the presence of TPA this decrease did not occur. These results demonstrate that TPA blocks the G1/S transition in Demel melanoma cells in late G1 by mechanisms which regulate phosphorylation and activation of the CDK2 kinase. These mechanisms include preventing the decrease in p21Cip1 and p27Kip1 kinase inhibitors and limiting the amount of cyclin A.

Topics: CDC2 Protein Kinase; CDC2-CDC28 Kinases; Cell Cycle; Cell Cycle Proteins; Cyclin D1; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Cyclin-Dependent Kinases; Cyclins; Enzyme Inhibitors; G1 Phase; Gene Expression Regulation, Neoplastic; Humans; Melanoma; Microtubule-Associated Proteins; Oncogene Proteins; Phosphorylation; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; RNA, Messenger; S Phase; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured; Tumor Suppressor Proteins

Cell division is controlled by a series of positive and negative regulators which act at sequential points throughout the cell cycle. Disturbance of these checks could contribute to cancer by allowing excessive cell proliferation. The point in G1 at which cells irrevocably commit to DNA synthesis is controlled by protein complexes consisting of cyclin-dependent kinases (CDK4 or CDK6) and cyclins (D1, D2 or D3). These complexes are inhibited by low molecular weight proteins, such as p16INK4 (refs 1,2), p15INK4B (ref. 3) and p18 (ref. 4). Deletion or mutation of these CDK-inhibitors could lead to unchecked cell growth, suggesting that members of the p16INK4 family may be tumour suppressor genes. The recent detection of p16INK4 (MTS1) mutations in familial melanoma kindreds, many human tumour cell lines, and primary tumours is consistent with this idea. Previously, we described eight germline p16INK4 substitutions in 18 familial melanoma kindreds. Genetic analyses suggested that five mutations predisposed carriers to melanoma, whereas two missense mutations had no phenotypic effect. We now describe biochemical analyses of the missense germline mutations and a single somatic mutation detected in these families. Only the melanoma-predisposing mutants were impaired in their ability to inhibit the catalytic activity of the cyclin D1/CDK4 and cyclin D1/CDK6 complexes in vitro. Our data provide a biochemical rationale for the hypothesis that carriers of certain p16INK4 mutations are at increased risk of developing melanoma.

Topics: Animals; Carrier Proteins; Cell Line; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinases; Cyclins; Humans; Insecta; Melanoma; Mutagenesis, Site-Directed; Mutation; Oncogene Proteins; Phosphorylation; Protein Binding; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Recombinant Fusion Proteins