kiss1-protein--human and Melanoma

Melanoma is a highly metastatic cancer that accounts for the majority of skin cancer deaths. Unfortunately, very few improvements have been made during the last 20 years in the management of melanoma metastases, which is the major cause of melanoma deaths. Therefore, identification of molecular targets that can be exploited in the clinic to treat metastatic disease is desperately needed. The KISS1 metastasis suppressor gene has emerged as a promising molecular target for the management of metastatic disease. This review compiles data regarding the molecular and biochemical properties of KISS1 and its cognate receptor, focusing on the properties believed to be most pertinent to the use of KISS1 in the clinical setting. In addition, clinical data that supports KISS1 as having a dual role as a prognostic indicator and a therapeutic target for the management of metastatic disease will be highlighted.

Topics: Animals; Carrier Proteins; Gene Expression Regulation, Neoplastic; Genes, Tumor Suppressor; Humans; Kisspeptins; Melanoma; Models, Biological; Neoplasm Metastasis; Prognosis; Protein Structure, Tertiary; Proteins; Receptors, G-Protein-Coupled; Receptors, Kisspeptin-1; Signal Transduction; Skin Neoplasms; Tumor Suppressor Proteins

Metastatic disease is the most critical impediment to cancer patient survival. However, comparatively little is known concerning the intricate pathways which govern the complex phenotypes associated with metastasis. The KISS1 metastasis suppressor gene inhibits metastasis in both in vivo melanoma and breast carcinoma models. Despite its clear physiological activity, the mechanism of KISS1 remains unclear. Recent identification of a 54 amino acid peptide of KISS1, termed metastin or kisspeptin-54, and its cognate G-protein coupled receptor (hOT7T175, AXOR12, GPR54) have provided additional clues and avenues of research. While studies have attributed KISS1 with modulation of NFkappaB regulation, experiments with metastin and its receptor implicate MAP kinase pathways and also suggest the potential of autocrine, paracrine and endocrine roles. Impacts on motility, chemotaxis, adhesion and invasion have each been documented in disparate cell lines and conflicting observations require resolution. Nevertheless, mounting clinical evidence, particularly the loss of KISS1 in metastases, correlates KISS1 and metastin receptor expression with human tumor progression. Together, the data substantiate roles for these molecules in metastasis regulation.

Topics: Breast Neoplasms; Chromosomes, Human, Pair 6; Genes, Tumor Suppressor; Humans; JNK Mitogen-Activated Protein Kinases; Kisspeptins; MAP Kinase Kinase 4; Melanoma; Mitogen-Activated Protein Kinase Kinases; Neoplasm Metastasis; Proteins; Receptors, G-Protein-Coupled; Receptors, Kisspeptin-1; Receptors, Neuropeptide; Signal Transduction; Tumor Suppressor Proteins

Melanoma is a kind of skin cancer that is begun by the alteration of melanocytes. miRNAs are small non-coding RNA molecules that regulate a variety of biological processes. KISS1, the metastasis-suppressor gene, encodes kisspeptins which inhibits migration and proliferation of cancers. This study was aimed to determine the role of Let-7i and KISS1 in melanoma cell migration and proliferation. At first, the expression of Let-7i and KISS1 was determined in patients with melanoma. In the in vitro part of the study, Let-7i mimics were transfected and the impact of its restoration on target gene expression, proliferation, migration and apoptosis of SK-MEL-3 melanoma cell line was assessed by real-time PCR and Western blotting, MTT assay, wound-healing assay and flow cytometry, respectively. Besides, KISS1 inhibitor siRNA alone and along with Let-7i was transfected to determine their probable correlation. The results revealed that either Let-7i or KISS1 were down-regulated in patients with melanoma. The results obtained from the in vitro part of the study revealed that restoration of Let-7i reduced the expression of metastasis- and proliferation-related target genes. Moreover, it was revealed that up-regulation of Let-7i attenuated migration and proliferation capability of SK-MEL-3 cells. Besides, it was demonstrated that Let-7i restoration induced apoptosis in melanoma cells. More importantly, the KISS1 inhibitor caused a prominent cell migration and proliferation, attenuated by Let-7i re-expression. To sum up, the present study revealed the impressive role of Let-7i restoration along with its correlation with KISS1 on melanoma carcinogenicity which may be applicable in future in vivo studies.

Topics: Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Female; Humans; Kisspeptins; Male; Melanoma; MicroRNAs; Middle Aged; Skin Neoplasms; Up-Regulation

To determine how daylight exposure in mice affects melatonin protein expression in blood and Kiss1 gene expression in the hypothalamus. The second aim was to assess the relationship between skin cancer formation, daylight exposure, melatonin blood level, and kisspeptin gene expression level.. New-born mice (n=96) were assigned into the blind group or daylight group. The blind group was raised in the dark and the daylight group was raised under 12 hours light/12 hours dark cycle for 17 weeks. At the end of the 11th week, melanoma cell line was inoculated to mice, and tumor growth was observed for 6 weeks. At the end of the experiment, melatonin level was measured from blood serum and Kiss1 expression from the hypothalamus.. The blind group had significantly higher melatonin and lower Kiss1 expression levels than the daylight group. Tumor volume was inversely proportional to melatonin levels and directly proportional to Kiss1 expression levels. Tumor growth speed was lower in the blind than in the daylight group.. Melatonin and Kiss1 were shown to be nvolved in tumor suppression. They were affected by daylight and were mutually affected by each other.

Topics: Animals; Animals, Newborn; Female; Gene Expression Regulation; Hypothalamus; Kisspeptins; Melanoma; Melatonin; Mice; Mice, Inbred BALB C; Photoperiod; Skin Neoplasms

Melanoma is a very aggressive tumor that does not respond well to standard therapeutic approaches, such as radio- and chemotherapies. Furthermore, acquiring the ability to metastasize in melanoma and many other tumor types is directly related to incurable disease. The B1 kinin receptor participates in a variety of cancer-related pathophysiological events, such as inflammation and angiogenesis. Therefore, we investigated whether this G protein-coupled receptor plays a role in tumor progression. We used a murine melanoma cell line that expresses the kinin B1 receptor and does not express the kinin B2 receptor to investigate the precise contribution of activation of the B1 receptor in tumor progression and correlated events using various in vitro and in vivo approaches. Activation of the kinin B1 receptor in the absence of B2 receptor inhibits cell migration in vitro and decreases tumor formation in vivo. Moreover, tumors formed from cells stimulated with B1-specific agonist showed several features of decreased aggressiveness, such as smaller size and infiltration of inflammatory cells within the tumor area, higher levels of pro-inflammatory cytokines implicated in the host anti-tumor immune response, lower number of cells undergoing mitosis, a poorer vascular network, no signs of invasion of surrounding tissues or metastasis and increased animal survival. Our findings reveal that activation of the kinin B1 receptor has a host protective role during murine melanoma tumor progression, suggesting that the B1 receptor could be a new anti-tumor GPCR and provide new opportunities for therapeutic targeting.

Topics: Analysis of Variance; Blotting, Western; Cell Line, Tumor; Fluorescent Dyes; Gene Expression Profiling; Humans; Immunohistochemistry; Kisspeptins; Melanoma; Neoplasm Metastasis; Receptor, Bradykinin B1; Tetrazolium Salts; Thiazoles

The objective of this study was to use the established xenograft model of human melanoma (C8161.9) to test a pharmacological approach to the effect of the metastasis suppressor KISS1. A KISS1 analog was used to inhibit the metastatic development of C8161.9 cells in nude mice. Further experiments were performed to test the validity of the C8161.9 model and test the connection between KISS1 expression and loss of metastatic potential. New clones of C8161.9 cells were obtained, with or without KISS1 expression, and were tested for metastasis formation. The absence of benefit in survival with the KISS1 analog compared with PBS prompted us to revisit the C8161.9 model. We found that the cells expressing KISS1, used in the previous study and obtained by transfection and single-cell cloning, were defective for both formation of orthotopic tumors and metastases. In mixing experiments, these cells could not suppress orthotopic tumor growth of KISS1-negative C8161.9 cells, suggesting that the suppression of metastasis by C8161.9-KISS1 cells may be intrinsic to the selected clone rather than related to KISS1 expression. Isolation of clones from parental C8161.9 cells in soft agar yielded cell populations that phenotypically and genotypically mimicked the KISS1-positive clone. In addition, new clones expressing KISS1 did not show any decrease in metastatic growth. These data demonstrate the heterogeneity of cell types in the C8161.9 cell line and the high risk of artifact linked to single-cell selection. A different xenograft model will be necessary to evaluate the use of KISS1 analogs as antimetastatic therapy.

Topics: Agar; Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Survival; Culture Media, Conditioned; Enzyme-Linked Immunosorbent Assay; Humans; Kisspeptins; Melanoma; Mice; Mice, Nude; Neoplasm Metastasis; Neoplasm Transplantation; Nucleic Acid Hybridization

Metastatic melanoma is a fatal disease due to the lack of successful therapies and biomarkers for early detection and its incidence has been increasing. Genetic studies have defined recurrent chromosomal aberrations, suggesting the location of either tumor suppressor genes or oncogenes. Transcription factor 21 (TCF21) belongs to the class A of the basic helix-loop-helix family with reported functions in early lung and kidney development as well as tumor suppressor function in the malignancies of the lung and head and neck. In this study, we combined quantitative DNA methylation analysis in patient biopsies and in their derived cell lines to demonstrate that TCF21 expression is downregulated in metastatic melanoma by promoter hypermethylation and TCF21 promoter DNA methylation is correlated with decreased survival in metastatic skin melanoma patients. In addition, the chromosomal location of TCF21 on 6q23-q24 coincides with the location of a postulated metastasis suppressor in melanoma. Functionally, TCF21 binds the promoter of the melanoma metastasis-suppressing gene, KiSS1, and enhances its gene expression through interaction with E12, a TCF3 isoform and with TCF12. Loss of TCF21 expression results in loss of KISS1 expression through loss of direct interaction of TCF21 at the KISS1 promoter. Finally, overexpression of TCF21 inhibits motility of C8161 melanoma cells. These data suggest that epigenetic downregulation of TCF21 is functionally involved in melanoma progression and that it may serve as a biomarker for aggressive tumor behavior.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Basic Helix-Loop-Helix Transcription Factors; Blotting, Western; Cell Cycle; Cell Differentiation; Cell Movement; Child; Chromatin Immunoprecipitation; DNA Methylation; Epigenomics; Female; Gene Expression Regulation, Neoplastic; Gene Silencing; Humans; Immunoenzyme Techniques; In Situ Hybridization, Fluorescence; Kisspeptins; Luciferases; Male; Melanoma; Middle Aged; Promoter Regions, Genetic; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Skin Neoplasms; Young Adult

Melanoma progression occurs through three major stages: radial growth phase (RGP), confined to the epidermis; vertical growth phase (VGP), when the tumor has invaded into the dermis; and metastasis. In this work, we used suppression subtractive hybridization (SSH) to investigate the molecular signature of melanoma progression, by comparing a group of metastatic cell lines with an RGP-like cell line showing characteristics of early neoplastic lesions including expression of the metastasis suppressor KISS1, lack of alphavbeta3-integrin and low levels of RHOC.. Two subtracted cDNA collections were obtained, one (RGP library) by subtracting the RGP cell line (WM1552C) cDNA from a cDNA pool from four metastatic cell lines (WM9, WM852, 1205Lu and WM1617), and the other (Met library) by the reverse subtraction. Clones were sequenced and annotated, and expression validation was done by Northern blot and RT-PCR. Gene Ontology annotation and searches in large-scale melanoma expression studies were done for the genes identified.. We identified 367 clones from the RGP library and 386 from the Met library, of which 351 and 368, respectively, match human mRNA sequences, representing 288 and 217 annotated genes. We confirmed the differential expression of all genes selected for validation. In the Met library, we found an enrichment of genes in the growth factors/receptor, adhesion and motility categories whereas in the RGP library, enriched categories were nucleotide biosynthesis, DNA packing/repair, and macromolecular/vesicular trafficking. Interestingly, 19% of the genes from the RGP library map to chromosome 1 against 4% of the ones from Met library.. This study identifies two populations of genes differentially expressed between melanoma cell lines from two tumor stages and suggests that these sets of genes represent profiles of less aggressive versus metastatic melanomas. A search for expression profiles of melanoma in available expression study databases allowed us to point to a great potential of involvement in tumor progression for several of the genes identified here. A few sequences obtained here may also contribute to extend annotated mRNAs or to the identification of novel transcripts.

Topics: Cell Line, Tumor; Clone Cells; Disease Progression; DNA, Complementary; Gene Expression Regulation, Neoplastic; Genetic Markers; HLA-DR alpha-Chains; HLA-DR Antigens; Humans; Integrin alphaVbeta3; Kisspeptins; Melanoma; Neoplasm Staging; rho GTP-Binding Proteins; rhoC GTP-Binding Protein; Tumor Suppressor Proteins

Uveal melanoma (UM) is the most common primary malignant intraocular tumour in adults. Forty-five percent of UM patients develop metastasis within 15 years of initial diagnosis. KISS1, a human metastasis suppressor gene, has been reported to play a role in various human malignancies. The purpose of this study was to investigate the expression of KISS1 in UM and its potential value as a prognostic marker.. Thirty-seven cases of paraffin-embedded human UM specimens were immunostained with a KISS1 antibody. Clinical-pathological data were obtained. The relationship between the clinical-pathological data and the expression of KISS1 was evaluated. Moreover, the survival rates of the patients were also assessed. Five UM cell lines (92.1, OCM-1, MKTBR, UW1 and SP6.5) were assayed for KISS1 expression. In addition, real-time PCR was used to determine mRNA levels of KISS1and its receptor GPR54in these cell lines.. The immunohistochemical results of KISS1 expression displayed cytoplasmic staining in 84% of UM specimens. Low KISS1 expression was associated with a higher risk of metastatic disease (P<0.05). Furthermore, we found that KISS1 was expressed in all five UM cells lines. Real-time PCR analysis confirmed the presence of both KISS1and its receptor GPR54in all five human UM cell lines.. To the best of our knowledge, this is the first time that KISS1has been characterized in UM. The correlation between KISS1 expression and UM survival rate suggests an important role for KISS1as a prognostic marker in this particular tumour.

Topics: Biomarkers, Tumor; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Kisspeptins; Melanoma; Polymerase Chain Reaction; RNA, Messenger; Tumor Suppressor Proteins; Uveal Neoplasms

Loss of the metastasis suppressor gene, KiSS-1 has been strongly correlated to the progression of metastases in numerous types of cancers. The mechanism through which KiSS-1 is lost during metastasis, however, is still not completely known. Previous studies have shown that genetic material on human chromosome 6q16.3-q23 is essential for KiSS-1 expression in normal tissues. Additionally, microcell-mediated transfer of this chromosome in cancerous tissue results in rescued expression of KiSS-1 and reduced metastatic phenotype. Here, we show that loss of Sp1-coactivator protein DRIP-130, which is encoded by human chromosome 6q16.3-q23, results in reduced KiSS-1 promoter activation in highly malignant melanoma cells. Co-expression of Sp1 and DRIP-130 not only rescues KiSS-1 expression, but also induces an inhibition of the invasive and migratory behavior in highly metastatic melanoma cells, similar to the overexpression of KiSS-1 metastasis suppressor gene in those cells. Furthermore, we demonstrate that KiSS-1 expression is regulated by Sp1 elements within the first 100-bp region of the KiSS-1 promoter and that targeted deletion of a single GC-rich region spanning -93 to -58 interrupts Sp1- and DRIP-130-modulated transcriptional control of KiSS-1 expression. Our results thus suggest that DRIP-130 is a key regulator in KiSS-1 transactivation in normal tissue, and that the loss of DRIP-130 expression, as a result of the gross loss of human chromosome 6q16.3-q23, provokes increased tumor metastasis.

Topics: Base Sequence; Blotting, Western; Cell Line, Tumor; DNA Primers; Electrophoretic Mobility Shift Assay; Gene Expression Regulation, Neoplastic; Humans; Kisspeptins; Mediator Complex; Melanoma; Neoplasm Metastasis; Promoter Regions, Genetic; Reverse Transcriptase Polymerase Chain Reaction; Sp1 Transcription Factor; Trans-Activators; Transcription, Genetic; Tumor Suppressor Proteins

The KISS1 protein suppresses metastasis of several tumor models without blocking orthotopic tumor growth, but the mechanism remains elusive. For its role in human sexual maturation, KISS1 protein is secreted and processed to kisspeptins, which bind to the G protein-coupled receptor GPR54. We tested the hypothesis that KISS1 secretion is required for metastasis suppression via GPR54.. KISS1 containing an internal FLAG epitope with (KFM) or without (KFMdeltaSS) a signal sequence was transfected into C8161.9 human melanoma cells, which do not express endogenous KISS1. Whole-cell lysates and conditioned medium from C8161.9(KFM) and C8161.9(KFMdeltaSS) cells were collected and analyzed for kisspeptins by immunoprecipitation and enzyme-linked immunosorbent assay. GPR54 levels were measured using real-time reverse transcription-polymerase chain reaction. The ability of conditioned medium from C8161.9(KFM) and C8161.9(KFMdeltaSS) cells to stimulate calcium mobilization in GPR54-expressing Chinese hamster ovary cells (CHO-G) and in C8161.9 cells was evaluated. Metastasis was monitored in athymic mice (groups of 10 per experiment) that were injected with C8161.9(KFM) or C8161.9(KFMdeltaSS) cells labeled with enhanced green fluorescent protein. Survival of mice injected with C8161.9 or C8161.9(KFM) cells was analyzed by Kaplan-Meier methods.. Full-length KFM and KFMdeltaSS were detected in whole-cell lysates of C8161.9(KFM) and C8161.9(KFMdeltaSS) cells, respectively, but kisspeptins were detected only in conditioned medium of C8161.9(KFM) cells. In vivo, C8161.9(KFM), but not C8161.9(KFMdeltaSS), cells were suppressed for metastasis to lung, eye, kidney, and bone, with corresponding differences in mouse survival (median > 120 versus 42 days). C8161.9(KFM) cells seeded mouse lungs but did not form macroscopic metastases. Conditioned medium from C8161.9(KFM), but not C8161.9(KFMdeltaSS), cells stimulated calcium mobilization in CHO-G cells. GPR54 expression was low in C8161.9 cells, which were not stimulated by conditioned medium from C8161.9(KFM) cells.. KISS1 secretion was required for multiple organ metastasis suppression and for maintenance of disseminated cells in a dormant state. The absence of GPR54 expression in C8161.9 cells (whose metastatic spread was suppressed by KFM) suggests that metastasis suppression is not mediated through this receptor. The results imply the existence of another KISS1 receptor and/or paracrine signaling. The findings raise the possibility that soluble KISS1, kisspeptins, or mimetics could be used to maintain tumor dormancy, rendering treatment of already disseminated tumor cells (i.e., micrometastases) a legitimate target.

Topics: Animals; Cell Line, Tumor; CHO Cells; Cricetinae; Cricetulus; Fluorescent Antibody Technique; Gene Expression Regulation, Neoplastic; Green Fluorescent Proteins; Humans; Kaplan-Meier Estimate; Kisspeptins; Melanoma; Mice; Receptors, G-Protein-Coupled; Receptors, Kisspeptin-1; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Tumor Suppressor Proteins

The participation of BRCA1 (breast cancer 1) in DNA repair is well established, especially in mammary and ovarian cells. Our purpose was to develop a new in vivo radio-sensitizing therapy for melanoma. We therefore investigated the effect of downregulation of BRCA1 on irradiated melanoma cells using an anti-BRCA1 ribozyme. Our results show that BRCA1 downregulation increased radio-sensitivity of the A375 cell line, suggesting that BRCA1 could act as a caretaker in melanoma; however, as BRCA1 functions are not limited to maintaining genomic integrity but also regulate transcription and the cell cycle, we confirmed that the proliferative rate of BRCA1 downregulated clones did not change. We also demonstrate that: (1) among the major pro-angiogenic genes, FGF-2 was not increased before or after irradiation and vascular endothelial growth factor strongly inhibited after irradiation; (2) expression of two important metalloproteinases, matrix metalloproteinase 2 and 9, involved in melanoma metastasis were decreased before and after irradiation; (3) expression of their major inhibitor, tissue inhibitor of metalloproteinase, was mainly upregulated; and (4) that invasion of BRCA1 downregulated cells was modified. Together these data suggest that BRCA1 downregulation in melanoma cells did not make them more aggressive and could lead to new therapeutic strategies for this tumor, which is so difficult to control once metastasized.

Topics: Benzothiazoles; Carrier Proteins; Cell Division; Cell Line, Tumor; Cell Survival; Diamines; Down-Regulation; Fibroblast Growth Factor 2; Fluorescent Dyes; Gene Expression Regulation, Neoplastic; Humans; Kisspeptins; Matrix Metalloproteinase 1; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Melanoma; Neovascularization, Pathologic; Organic Chemicals; Proteins; Quinolines; Reverse Transcriptase Polymerase Chain Reaction; Skin Neoplasms; Thrombospondin 1; Thrombospondins; Tissue Inhibitor of Metalloproteinase-1; Tumor Suppressor Proteins; Ubiquitin-Protein Ligases; Vascular Endothelial Growth Factor A

There is a growing body of evidence to support the efficacy of topical imiquimod in the treatment of primary skin carcinomas. Conflicting data exist concerning the use of imiquimod for the treatment of skin melanoma metastases. To date, only the impact of imiquimod on cytokines involved in immunological processes has been studied extensively. We report a woman successfully treated with imiquimod (once daily for 8 weeks) for skin melanoma metastases in whom we investigated the expression of molecules involved in metastasis and angiogenesis. Before and after treatment, a skin lesion was biopsied and the expression of the following molecules was investigated using real-time reverse transcription-polymerase chain reaction: matrix metalloproteinase (MMP)-1, 2 and 9 and their inhibitors KiSS-1 and tissue inhibitor of metalloproteinase (TIMP)-1, vascular endothelial growth factor (VEGF), fibroblast growth factor-2, and angiogenesis inhibitors (thrombospondin-1 and 2). Interferon (IFN)-alpha was also investigated as an in vivo marker of imiquimod activity. IFN-alpha was upregulated by the treatment. Under imiquimod, the following molecules were upregulated: TIMP-1, KiSS-1 and MMP-1. MMP-2 expression was not modified. MMP-9 expression was dramatically decreased. The expression of angiogenesis inhibitors was slightly increased but VEGF expression remained at a basal level. These results suggest that imiquimod could downregulate metastasis invasion and angiogenesis. However, these data were obtained at a transcriptional level and from a single case, and further investigations should include migration assays and additional cases in order to confirm that imiquimod may be safely used for treatment of melanoma metastases.

Topics: Administration, Topical; Aged; Aminoquinolines; Angiogenesis Inhibitors; Antineoplastic Agents; Female; Gene Expression Regulation; Humans; Imiquimod; Interferon-alpha; Kisspeptins; Matrix Metalloproteinases; Melanoma; Neovascularization, Pathologic; Proteins; Skin Neoplasms; Tissue Inhibitor of Metalloproteinase-1; Tumor Suppressor Proteins; Vascular Endothelial Growth Factors

Loss of genetic material on chromosome 6 has been associated with progression of human melanomas. We showed previously that introducing chromosome 6 into metastatic human melanoma cell lines suppresses metastasis without affecting the ability of the hybrids to form progressively growing tumors. By subtractive hybridization comparing nonmetastatic chromosome 6-containing (neo6/C8161) versus parental (C8161) metastatic cells, the KISS1 metastasis suppressor gene was isolated. However, KISS1 mapped to chromosome 1q32. To identify upstream regulator(s) of (and downstream effectors of) KISS1, microarray hybridization comparing C8161 and neo6/C8161 variants was performed. TXNIP/VDUP1, a thioredoxin-binding protein, was expressed more highly in neo6/C8161 and in nonmetastatic melanomas. Increased TXNIP expression inhibited metastasis and up-regulated KISS1. Surprisingly, TXNIP also mapped to chromosome 1q. PCR karyotyping that refined the region on chromosome 6 identified CRSP3/DRIP130, a transcriptional coactivator, as a metastasis suppressor. CRSP3 transfectant cells had up-regulated KISS1 and TXNIP expression and were suppressed for metastasis. Quantitative real-time reverse-transcription PCR of clinical melanoma samples showed that loss of CRSP3 expression correlated with decreased KISS1 expression and increased metastasis. Thus, we implicated a specific gene on chromosome 6 in the etiology of melanoma metastasis and identified potential up-stream regulators of KISS1 and TXNIP.

Topics: Animals; Carrier Proteins; Chromosome Mapping; Chromosomes, Human, Pair 6; Female; Gene Expression Regulation, Neoplastic; Genes, Tumor Suppressor; Humans; Kisspeptins; Mediator Complex; Melanoma; Mice; Mice, Nude; Oligonucleotide Array Sequence Analysis; Protein Biosynthesis; Proteins; Thioredoxins; Trans-Activators; Transcription Factors; Transfection; Transplantation, Heterologous; Tumor Cells, Cultured; Tumor Suppressor Proteins

A novel human G protein-coupled receptor named AXOR12, exhibiting 81% homology to the rat orphan receptor GPR54, was cloned from a human brain cDNA library. Heterologous expression of AXOR12 in mammalian cells permitted the identification of three surrogate agonist peptides, all with a common C-terminal amidated motif. High potency agonism, indicative of a cognate ligand, was evident from peptides derived from the gene KiSS-1, the expression of which prevents metastasis in melanoma cells. Quantitative reverse transcriptase-polymerase chain reaction was used to study the expression of AXOR12 and KiSS-1 in a variety of tissues. The highest levels of expression of AXOR12 mRNA were observed in brain, pituitary gland, and placenta. The highest levels of KiSS-1 gene expression were observed in placenta and brain. A polyclonal antibody raised to the C terminus of AXOR12 was generated and used to show localization of the receptor to neurons in the cerebellum, cerebral cortex, and brainstem. The biological significance of these expression patterns and the nature of the putative cognate ligand for AXOR12 are discussed.

Topics: Amino Acid Sequence; Animals; Brain; CHO Cells; Cricetinae; Female; Genes, Tumor Suppressor; Heterotrimeric GTP-Binding Proteins; Humans; Kinetics; Kisspeptins; Ligands; Melanoma; Molecular Sequence Data; Nephropidae; Neurons; Organ Specificity; Peptide Fragments; Pituitary Gland; Placenta; Pregnancy; Proteins; Rats; Receptors, Cell Surface; Receptors, G-Protein-Coupled; Receptors, Kisspeptin-1; Receptors, Neuropeptide; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; Sea Anemones; Sequence Alignment; Sequence Homology, Amino Acid; Transfection; Tumor Suppressor Proteins

KiSS1 is a putative melanoma metastasis suppressor gene, the expression of which may be regulated by another gene(s) mapping to chromosome 6q16.3-q23. To additionally elucidate the role of KiSS1 in the progression of human melanoma in vivo, we examined KiSS1 mRNA expression in 51 melanocytic tumors with various stages of progression by in situ hybridization. We also examined a correlation between loss of KiSS1 mRNA expression and loss of heterozygosity (LOH) of 6q16.3-q23 in 27 melanoma metastases. All of the four nevocellular nevi and eight primary melanomas <4 mm in thickness showed KiSS1 mRNA expression, whereas only 50% (6 of 12) of primary melanomas >4 mm in thickness expressed KiSS1. Loss of KiSS1 mRNA was equally frequent in metastases; 44% (12 of 27) of tumors lost KiSS1 expression. LOH of 6q16.3-q23 was observed in 52% (14 of 27) of metastases. There was a strong association between LOH and loss of KiSS1 expression (P = 0.03); nine metastases with LOH of 6q16.3-q23 lost KiSS1 expression, whereas 10 tumors with no LOH showed positive KiSS1 mRNA expression. The findings in this study show, for the first time, KiSS1 down-regulation during the progression of melanoma in vivo and strongly suggest that inactivation of a tumor suppressor gene(s) mapping to 6q16.3-q23 by deletion or mutation coupled with LOH may lead to the down-regulation of KiSS1.

Topics: Adult; Aged; Aged, 80 and over; Chromosomes, Human, Pair 6; Disease Progression; Female; Humans; In Situ Hybridization; Kisspeptins; Loss of Heterozygosity; Male; Melanoma; Middle Aged; Nevus; Protein Biosynthesis; Proteins; RNA, Messenger; Skin; Tumor Suppressor Proteins

The identification and sequence of KiSS-1 (HGMW-approved symbol, KISS1), a human malignant melanoma metastasis-suppressor gene, was recently published. In this report, we present a corrected genomic sequence, genomic structure, and refined chromosomal location for KiSS-1. The genomic organization of the sequence reveals a gene consisting of four exons. The first two exons are not translated; the third exon contains 38 5' noncoding bases followed by the translational start site and another 100 translated bases. The terminal exon contains a further 332 translated bases, the translational stop codon, and the polyadenylation signal. The gene maps to chromosome 1q32 as determined by radiation hybrid mapping and FISH analysis. The relatively simple organization of this gene will facilitate analyses for mutations and abnormal expression in human tumors.

Topics: Amino Acid Sequence; Base Sequence; Chromosome Mapping; Chromosomes, Human, Pair 1; DNA, Complementary; Exons; Genes, Tumor Suppressor; Humans; In Situ Hybridization, Fluorescence; Introns; Kisspeptins; Melanoma; Molecular Sequence Data; Neoplasm Metastasis; Proteins; Tumor Suppressor Proteins