cyclin-d1 and Hyperplasia

Primary hyperparathyroidism (pHPT), generally caused by a monoclonal parathyroid adenoma, is a common endocrinopathy. Until recently, the genesis of the disease was poorly understood but during the past decade the molecular pathology of parathyroid tumor development has begun to be unveiled. This review summarizes recent advances in our understanding of genetic predisposition to pHPT, and the role of vitamin D receptor gene (VDR) variants in development of the disease. It has been shown that the multiple endocrine neoplasia tumor suppressor gene (MEN1) is mutated in parathyroid adenomas, and overexpression of the cyclin D1 oncogene [PRAD1 (parathyroid adenoma 1)] seems to contribute to parathyroid tumorigenesis. Several familial hyperparathyroid disorders have been studied, and the identification and characterization of the disease-causing genes have contributed to our understanding of parathyroid physiology and pathophysiology.

Topics: Adenoma; Cyclin D1; Genetic Predisposition to Disease; Humans; Hyperplasia; Multiple Endocrine Neoplasia Type 1; Mutation; Parathyroid Glands; Parathyroid Neoplasms; Receptors, Calcitriol

Columnar cell lesions (CCLs) are recognised breast cancer precursor lesions. Intraductal papillomas are usually lined by benign (polyclonal) cells. Although papillomas with monoclonal lesions (atypical ductal hyperplasia (ADH)/ductal carcinoma in situ (DCIS)) have been described, CCLs have not been described in papillomas.. We present two papillary breast lesions lined by a single layer of luminal cells resembling atypical CCL/flat epithelial atypia (FEA). We compared these two lesions with 13 benign intraductal papillomas, and 2 papillomas with ADH/DCIS grade 1 features as controls were immunohistochemically stained for the oestrogen receptor alpha (oestrogen receptor) and progesterone receptors (PR), cytokeratin 5 (CK5) and cyclin D1.. Oestrogen receptor/PR expression was variable, with areas with ≥85% hormone receptor positivity in both morphologically normal papillomas and papillomas with ADH. In ADH areas, CK5 expression was seen in ≤5% of cells while cyclin D1 expression was high (>60%). The two papillary lesions with FEA were 100% oestrogen receptor and 90% cyclin D1 positive, and low on PR/CK5. There was only one morphologically normal papilloma with similar areas of low CK5 (5%) and high cyclin D1 expression; in all other morphologically benign papillomas CK5 expression varied between 10% and 50% and cyclin D1 expression was ≤50%. The papillary lesion with FEA that could be tested showed 16q losses, the hallmark genetic change in low nuclear grade breast neoplasias, in contrast to nine morphologically benign papillomas that could be tested.. We present two papillomatous breast lesions with atypical CCL morphology and 16q loss, for which we propose the term papillary FEA.

Topics: Breast; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Intraductal, Noninfiltrating; Cyclin D1; Female; Humans; Hyperplasia; Papilloma; Papilloma, Intraductal; Receptors, Estrogen

With the continuous discovery of new borderline thyroid lesions and benign and malignant "gray areas", coupled with the limitations of traditional immune indicators, the differential diagnosis of papillary thyroid carcinoma (PTC) has become more difficult. Cyclin D1 and P21 are cell cycle regulators involved in the occurrence and metastasis of multiple tumors, including PTC, but their specific functions are unclear.. In our study, immunohistochemical staining was used to explore the expression of Cyclin D1 and P21 in PTC, paracancerous tissue, follicular adenoma (FA) and papillary thyroid hyperplasia. In addition, their relationship with the clinicopathological features of PTC and their differential diagnostic value in distinguishing between intralymph node PTC metastases and intralymph node ectopic thyroid tissue were studied.. Among 200 primary PTC lesions, Cyclin D1 and P21 were found to be expressed in 186 (93.00%) and 177 (88.50%), respectively, and their expression levels were significantly higher in PTC tissue than in adjacent tissue, FA tissue and papillary thyroid hyperplasia tissue (P < 0.05). The expression levels of Cyclin D1 and P21 were positively correlated with tumor size and lymph node metastasis (P < 0.05) but not with sex, age, number of tumor lesions, histological subtype, chronic lymphocytic thyroiditis or TNM stage (P < 0.05). The expression levels of Cyclin D1 and P21 were significantly correlated (P < 0.05). The positivity rates of Cyclin D1 and P21 in intralymph node PTC metastases were 97.96% (48/49) and 89.80% (44/49), respectively, which were significantly higher than those in intralymph node ectopic thyroid tissue (P < 0.05). The sensitivity (Se) and negative predictive value (NPV) of Cyclin D1 and P21 detection alone or in combination were higher than those of the combined detection of the classical antibody markers CK19, HBME-1 and Galectin-3. Besides, the Se, Sp, PPV and NPV of Cyclin D1 and P21 in differentiating intralymph node PTC metastases and intralymph node ectopic thyroid tissue were higher.. The results of our study show that Cyclin D1 and P21 are highly sensitive and specific markers for the diagnosis of PTC that are superior to traditional classical antibodies. And, these two markers are of great value in the differential diagnosis of intralymph node PTC metastases and intralymph node ectopic thyroid tissue.

Topics: Adenoma; Biomarkers, Tumor; Carcinoma, Papillary; Cyclin D1; Diagnosis, Differential; Humans; Hyperplasia; Thyroid Cancer, Papillary; Thyroid Dysgenesis; Thyroid Neoplasms

Intimal hyperplasia is a common feature of vascular remodelling disorders. Accumulation of synthetic smooth muscle cell (SMC)-like cells is the main underlying cause. Current therapeutic approaches including drug-eluting stents are not perfect due to the toxicity on endothelial cells and novel therapeutic strategies are needed. Our preliminary screening for dysregulated cyclic nucleotide phosphodiesterases (PDEs) in growing SMCs revealed the alteration of PDE10A expression. Herein, we investigated the function of PDE10A in SMC proliferation and intimal hyperplasia both in vitro and in vivo.. RT-qPCR, immunoblot, and in situ proximity ligation assay were performed to determine PDE10A expression in synthetic SMCs and injured vessels. We found that PDE10A mRNA and/or protein levels are up-regulated in cultured SMCs upon growth stimulation, as well as in intimal cells in injured mouse femoral arteries. To determine the cellular functions of PDE10A, we focused on its role in SMC proliferation. The anti-mitogenic effects of PDE10A on SMCs were evaluated via cell counting, BrdU incorporation, and flow cytometry. We found that PDE10A deficiency or inhibition arrested the SMC cell cycle at G1-phase with a reduction of cyclin D1. The anti-mitotic effect of PDE10A inhibition was dependent on cGMP-dependent protein kinase Iα (PKGIα), involving C-natriuretic peptide (CNP) and particulate guanylate cyclase natriuretic peptide receptor 2 (NPR2). In addition, the effects of genetic depletion and pharmacological inhibition of PDE10A on neointimal formation were examined in a mouse model of femoral artery wire injury. Both PDE10A knockout and inhibition decreased injury-induced intimal thickening in femoral arteries by at least 50%. Moreover, PDE10A inhibition decreased ex vivo remodelling of cultured human saphenous vein segments.. Our findings indicate that PDE10A contributes to SMC proliferation and intimal hyperplasia at least partially via antagonizing CNP/NPR2/cGMP/PKG1α signalling and suggest that PDE10A may be a novel drug target for treating vascular occlusive disease.

Topics: Animals; Bromodeoxyuridine; Cell Proliferation; Cells, Cultured; Cyclic GMP; Cyclic GMP-Dependent Protein Kinase Type I; Cyclin D1; Endothelial Cells; Guanylate Cyclase; Humans; Hyperplasia; Mice; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Phosphoric Diester Hydrolases; RNA, Messenger; Vascular Remodeling; Vascular System Injuries

Colorectal cancer is related to ulcerative colitis. This study aimed to investigate the effects of aspirin on non-specific inflammation developing into cancer.. Ulcerative colitis model was generated by administrating azoxymethane/dextran sulfate sodium to mice. Weight, tumor size/ amount, and intestinal mucositis scores were analyzed. Inflammatory cell infiltration and atypical hyperplasia were determined with hematoxylin-eosin staining. Immunohistochemical assay was used to detect the proliferating cell nuclear antigen. Interleukin-6 and interleukin-10 were detected using enzyme-linked immunosorbent assay. Signal transducer and activator of transcription 3, phosphorylated-STAT3, cyclin D1, and suppressor of cytokine signaling 3 were examined with western blotting.. Aspirin remarkably decreased tumor size/amount compared to those of the ulcerative colitis model group (P < .05). Interleukin-6 was increased and interleukin-10 was decreased in mice of ulcerative colitis model group compared with the control group (P < .05). Aspirin markedly reduced interleukin-6 and enhanced interleukin-10 compared to the ulcerative colitis model group (P < .05) induced Azoxymethane/dextran sulfate sodium inflammation (3 weeks) and atypical hyperplasia (8 weeks). Aspirin predominantly inhibited the "inflammation-atypical hyperplasia-cancer" process and alleviated inflammatory cell infiltration of mice in the ulcerative colitis model group. Aspirin promoted apoptosis and alleviated proliferating cell nuclear antigen of atypical hyperplastic intestinal mucosal cells at 8 weeks post-modeling. The expression of phosphorylated-STAT3, signal transducer and activator of transcription 3, cyclin D1, and suppressor of cytokine signaling 3 was significantly increased in mice of ulcerative colitis model group compared to the control group (P < .05). Aspirin remarkably decreased phosphorylated-STAT3, signal transducer and activator of transcription, and cyclin D1 expression compared with ulcerative colitis model group (P < .05).. Aspirin inhibited carcinogenesis of intestinal mucosal cells in the ulcerative colitis model by inhibiting the interleukin-6/ Janus kinase/signal transducer and activator of transcription 3 signaling pathway and promoted apoptosis, thereby suppressing proliferation.

Topics: Animals; Apoptosis; Aspirin; Azoxymethane; Carcinogenesis; Cell Proliferation; Colitis, Ulcerative; Colorectal Neoplasms; Cyclin D1; Dextran Sulfate; Hyperplasia; Inflammation; Interleukin-10; Interleukin-6; Janus Kinases; Mice; Proliferating Cell Nuclear Antigen; Signal Transduction; STAT3 Transcription Factor

As a result of thrombosis or intimal hyperplasia, synthetic artificial vascular grafts had a low success rate when they were used to replace small-diameter arteries (inner diameter < 6 mm). C-type natriuretic peptides (CNP) have anti-thrombotic effects, and can promote endothelial cell (EC) proliferation and inhibit vascular smooth muscle cell (SMC) over-growth. In this study, poly(ε-caprolactone) (PCL) vascular grafts loaded with CNP (PCL-CNP) were constructed by electrospinning. The PCL-CNP grafts were able to continuously release CNP at least 25 days in vitro. The results of scanning electron microscopy (SEM) and mechanical testing showed that the loading of CNP did not change the microstructure and mechanical properties of the PCL grafts. In vitro blood compatibility analysis displayed that PCL-CNP grafts could inhibit thrombin activity and reduce platelet adhesion and activation. In vitro cell experiments demonstrated that PCL-CNP grafts activated ERK1/2 and Akt signaling in human umbilical vein endothelial cells (HUVECs), as well as increased cyclin D1 expression, enhanced proliferation and migration, and increased vascular endothelial growth factor (VEGF) secretion and nitric oxide (NO) production. The rabbit arteriovenous (AV)-shunt ex vitro indicated that CNP loading significantly improved the antithrombogenicity of PCL grafts. The assessment of vascular grafts in rat abdominal aorta implantation model displayed that PCL-CNP grafts promoted the regeneration of ECs and contractile SMCs, modulated macrophage polarization toward M2 phenotype, and enhanced extracellular matrix remodeling. These findings confirmed for the first time that loading CNP is an effective approach to improve the hemocompatibility and vascular regeneration of synthetic vascular grafts. STATEMENT OF SIGNIFICANCE: Small-diameter (< 6 mm) vascular grafts (SDVGs) have not been made clinically available due to their prevalence of thrombosis, limited endothelial regeneration and intimal hyperplasia. The incorporation of bioactive molecules into SDVGs serves as an effective solution to improve hemocompatibility and endothelialization. In this study, for the first time, we loaded C-type natriuretic peptides (CNP) into PCL grafts by electrospunning and confirmed the effectiveness of loading CNP on improving the hemocompatibility and vascular regeneration of artificial vascular grafts. Regenerative advantages included enhancement of endothelialization, modulation of macrophage po

Topics: Animals; Biocompatible Materials; Blood Vessel Prosthesis; Caproates; Cyclin D1; Human Umbilical Vein Endothelial Cells; Humans; Hyperplasia; Lactones; Natriuretic Peptide, C-Type; Nitric Oxide; Polyesters; Proto-Oncogene Proteins c-akt; Rabbits; Rats; Regeneration; Thrombin; Thrombosis; Vascular Endothelial Growth Factor A

Rheumatoid arthritis, a recurrent incendiary autoimmune joint syndrome, features by prominent synovial hyperplasia. Fibroblast-like synoviocytes are the executive components in the pathogenesis of rheumatoid arthritis. It is generally accepted that excessive proliferation and reduced apoptosis of fibroblast-like synoviocytes lead to synovial hyperplasia. Our previously studies found that sorafenib could inhibit adjuvant arthritis in rats and induced adjuvant arthritis fibroblast-like synoviocytes apoptosis. Presently, we aim to investigate the inhibitory effect with mechanisms of action of sorafenib on adjuvant arthritis fibroblast-like synoviocytes proliferation.. Cell counting kit-8 and flow cytometry detection were conducted to monitor FLSs proliferation and cell cycle. Western blotting and qPCR assays were performed to detect P21, P53, CDK4, CyclinD1 and proliferating cell nuclear antigen content levels.. Sorafenib significantly inhibited adjuvant arthritis fibroblast-like synoviocytes proliferation with an IC50 value of 4 µmol/L by a concentration-dependent pattern, which accompanies by G1 cell cycle arrest. Also, sorafenib significantly decreased the levels of P21, CyclinD1, CDK4 and proliferating cell nuclear antigen, as well as up-regulated P53 expression in adjuvant arthritis fibroblast-like synoviocytes.. Sorafenib could inhibit adjuvant arthritis fibroblast-like synoviocytes proliferation via arresting G1/S cell cycle progression, which was partially through CDK4/CyclinD1-mediated pathway, as well as up-regulating P53 and down-regulating proliferating cell nuclear antigen expressions. These results suggest that sorafenib may provide a new paradigm for rheumatoid arthritis treatment.

Topics: Animals; Antirheumatic Agents; Apoptosis; Arthritis, Experimental; Arthritis, Rheumatoid; Cell Culture Techniques; Cell Cycle; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Down-Regulation; Fibroblasts; G1 Phase Cell Cycle Checkpoints; Hyperplasia; Mice; Proliferating Cell Nuclear Antigen; Protein Kinase Inhibitors; Rats, Sprague-Dawley; Sorafenib; Synovial Membrane; Synoviocytes

Cardiovascular diseases are associated with proliferation and phenotypic switch. Platelet-derived growth factor-BB (PDGF-BB) is a major initiating factor for proliferative vascular diseases, such as neointimal lesion formation, restenosis after angioplasty, and atherosclerosis. Ruxolitinib, a potent Janus kinase (JAK) 1 and 2 inhibitor, has been reported to significantly block the proliferation-related signaling pathway of JAK2/signal transducers and activators of transcription 3 (STAT3) and harbor a broad spectrum of anti-cancer activities, including proliferation inhibition, apoptosis induction, and anti-inflammation. However, the role of ruxolitinib in regulating PDGF-BB-induced VSMC proliferation remains to be elucidated. Thus, this study investigates the role of ruxolitinib in regulating PDGF-BB-induced VSMC proliferation and its underlying mechanisms.. In vivo, the medial thickness of the carotid artery was evaluated using a mouse carotid ligation model, ruxolitinib was administered orally to the mice every other day, and the mice were euthanized on day 28 to evaluate the therapeutic effects of ruxolitinib. Cell proliferation markers were measured using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting. In vitro, VSMCs were treated with ruxolitinib with or without PDGF-BB at an indicated time and concentration. Cell proliferation and apoptosis were measured using Cell Counting Kit-8 assay, MTS assays and flow cytometry. The JAK2/STAT3 signaling pathway involved in the effects of ruxolitinib on VSMCs was detected by western blotting with the specific pathway inhibitor AG490.. In vivo, ruxolitinib significantly decreased the ratio-of-intima ratio (I/M ratio) by inhibiting the expression of PCNA and cyclinD1 (p <0.05). In vitro, ruxolitinib inhibited PDGF-BB-induced VSMC proliferation compared with the PDGF-BB treatment group (p <0.05). In addition, ruxolitinib inhibited the PDGF-BB-induced activation of the JAK2/STAT3 signaling pathway and decreased the expression of proliferation related-proteins cyclinD1 and PCNA in VSMCs (p <0.05).. Our findings suggest that ruxolitinib inhibits VSMC proliferation in vivo and in vitro by suppressing the activation of the JAK2/STAT3 signaling pathway. Therefore, ruxolitinib has a therapeutic potential for proliferative vascular diseases.

Topics: Animals; Becaplermin; Carotid Artery, Common; Carotid Stenosis; Cells, Cultured; Cyclin D1; Disease Models, Animal; Hyperplasia; Janus Kinase 2; Janus Kinase Inhibitors; Male; Mice, Inbred C57BL; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Neointima; Nitriles; Proliferating Cell Nuclear Antigen; Pyrazoles; Pyrimidines; Signal Transduction; STAT3 Transcription Factor

The high rate of vein graft failure due to neointimal hyperplasia is a major challenge for cardiovascular surgery. Finding novel approaches to prevent neointimal hyperplasia is important. Thus, the purpose of this study was to investigate whether dedicator of cytokinesis 2 (DOCK2) plays a role in the development of neointima formation in the vein grafts.. We found that DOCK2 levels were significantly elevated in the vein grafts following grafting surgery. In addition, overexpression of DOCK2 promoted venous smooth muscle cell (SMC) proliferation and migration. Conversely, knocking-down endogenous DOCK2 expression in venous SMCs inhibited SMC proliferation and migration. Consistent with this, knocking-down DOCK2 expression in the grafted veins significantly reduced neointimal formation compared with the controls 28 days after vein transplantation. Moreover, DOCK2 silencing treatment improved hemodynamics in the vein grafts. Mechanistically, knockdown of DOCK2 significantly alleviated the vein graft-induced down regulation of SMC contractile protein expression and impeded the vein graft-induction of both Cyclin D1 and PCNA expression. In particular, to ensure high efficiency when transferring the DOCK2 short hairpin RNA (shDOCK2) into the grafted veins, a 30% poloxamer F-127 gel incorporated with 0.25% trypsin was smeared around the vein grafts to increase the adenovirus contact time and penetration.. DOCK2 silencing gene therapy effectively attenuates neointimal hyperplasia in vein grafts. Knock-down of DOCK2 would be a potential therapeutic approach for the treatment of vein graft failure.

Topics: Animals; Cardiovascular Surgical Procedures; Cyclin D1; Gene Expression Regulation, Developmental; Graft Rejection; Guanine Nucleotide Exchange Factors; Humans; Hyperplasia; Myocytes, Smooth Muscle; Neointima; Poloxamer; Proliferating Cell Nuclear Antigen; Rats; Transplants; Veins

Neointimal hyperplasia is characterized by excessive accumulation of vascular smooth muscle cells (SMCs) leading to occlusive disorders, such as atherosclerosis and stenosis. Blood vessel injury increases growth factor secretion and matrix synthesis, which promotes SMC proliferation and neointimal hyperplasia via FAK (focal adhesion kinase).. To understand the mechanism of FAK action in SMC proliferation and neointimal hyperplasia.. Using combined pharmacological FAK catalytic inhibition (VS-4718) and SMC-specific FAK kinase-dead (Myh11-Cre-ER. Nuclear enrichment of FAK by inhibition of FAK catalytic activity during vessel injury blocks SMC proliferation and neointimal hyperplasia through regulation of GATA4-mediated cyclin D1 transcription.

Topics: Active Transport, Cell Nucleus; Animals; Cell Nucleus; Cell Proliferation; Cells, Cultured; Cyclin D1; Focal Adhesion Kinase 1; GATA4 Transcription Factor; Hyperplasia; Mice; Mice, Inbred C57BL; Myocytes, Smooth Muscle; Tunica Intima

Topics: Cell Proliferation; Coronary Restenosis; Cyclin D1; Focal Adhesion Protein-Tyrosine Kinases; GATA4 Transcription Factor; Humans; Hyperplasia; Muscle, Smooth, Vascular

Vascular smooth muscle cell (VSMC) proliferation and migration are crucial events in the pathological course of restenosis after percutaneous coronary intervention (PCI). N-oleoylethanolamide (OEA) is a bioactive lipid amide released upon dietary fat digestion with many reported actions. However, the effect of OEA on restenosis after vascular injury remains unknown. Here, we investigated the effects of OEA on intimal hyperplasia after balloon injury in vivo, its effect on VSMC proliferation and migration induced by platelet-derived growth factor (PDGF) stimulation in vitro, and the underlying mechanism underlying these effects. The results showed that OEA-treated rats displayed a significant reduction in neointima formation after balloon injury. In cultured VSMCs, treatment with OEA decreased cell proliferation and migration induced by PDGF. OEA treatment both in vivo and in vitro led to an increase in adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and peroxisome proliferator-activated receptor alpha (PPARα), and a decrease in proliferating cell nuclear antigen (PCNA) and cyclinD1 expression. Pharmacological inhibition of AMPK and PPARα reversed the suppressive effects of OEA on VSMC proliferation and migration, suggesting that the suppressive effect of OEA on VSMC proliferation and migration is mediated through the activation of AMPK and PPARα. In conclusion, our present study demonstrated that OEA attenuated neointima formation in response to balloon injury by suppressing SMC proliferation and migration through an AMPK and PPARα-dependent mechanism. Our data suggests that OEA may be a potential therapeutic agent for restenosis after PCI.

Topics: AMP-Activated Protein Kinases; Animals; Cardiovascular Agents; Carotid Artery Injuries; Carotid Artery, Common; Cell Movement; Cell Proliferation; Cell Survival; Cyclin D1; Endocannabinoids; Endothelial Cells; Hyperplasia; Male; Muscle, Smooth, Vascular; Neointima; Oleic Acids; Phosphorylation; Platelet-Derived Growth Factor; PPAR alpha; Primary Cell Culture; Proliferating Cell Nuclear Antigen; Rats; Rats, Sprague-Dawley; Tunica Intima

o-Nitroanisole is an intermediate in the manufacture of azo dyes. In a National Toxicology Program stop-exposure study,o-nitroanisole induced hyperplasia, papillomas, and papillary carcinomas in the urinary bladder of Fischer 344/N rats.o-Nitroanisole was investigated since occupational or environmental exposure to aniline and azo dyes is a risk factor for urinary bladder cancer in humans. The current study describes the morphology of urinary bladder neoplasms seen in rats with respect to those observed in humans. This study also evaluated immunohistochemical expression of the cell cycle-related proteins cyclin D1 and p53 and the differentiation markers cytokeratin 20 and uroplakin III in hyperplastic (n= 11) and neoplastic (n= 6 papillomas,n= 11 carcinomas) lesions of the urinary bladder epithelium from rats treated with o-nitroanisole and in normal (n= 6) urinary bladders from untreated rats. The tumors observed were more similar to the papillary type rather than the muscle-invasive type of urinary bladder cancer in humans. The preneoplastic and neoplastic lesions observed suggest progression from hyperplasia to papilloma to papillary carcinoma. With neoplastic progression (hyperplasia to papilloma to carcinoma), cyclin D1 immunoreactivity progressively increased in intensity, percentage of cells staining, and distribution. Overexpression of p53 was not found. Cytokeratin 20 staining decreased in superficial cells, while uroplakin III staining increased in intermediate and basal cells with progression from hyperplasia to carcinoma. The results are consistent with increased cell cycle dysregulation or proliferation (cyclin D1), decreased differentiation (cytokeratin 20), and abnormal differentiation (uroplakin III) as lesions progress toward malignancy.

Topics: Animals; Anisoles; Biomarkers, Tumor; Carcinoma, Papillary; Cyclin D1; Disease Models, Animal; Female; Humans; Hyperplasia; Immunohistochemistry; Keratin-20; Male; Papilloma; Precancerous Conditions; Rats; Rats, Inbred F344; Tumor Suppressor Protein p53; Urinary Bladder; Urinary Bladder Neoplasms; Uroplakin III

Signal transducer and activator of transcription 6 (STAT6) is involved in epithelial cell growth. However, little is known regarding the STAT6 phosphorylation status in Graves' disease (GD) and its role in thyroid epithelial cells (TECs). In this study, we found that STAT6 phosphorylation (p-STAT6) was significantly increased in TECs from both GD patients and experimental autoimmune Graves' disease mice and that STAT6 deficiency ameliorated GD symptoms. Autocrine IL-4 signalling in TECs activated the phosphorylation of STAT6 via IL-4 R engagement, and the downstream targets of STAT6 were Bcl-xL and cyclin D1. Thus, the IL-4-STAT6-Bcl-xL/cyclin D1 pathway is crucial for TEC hyperplasia, which aggravates GD. More importantly, in vitro and in vivo experiments demonstrated that STAT6 phosphorylation inhibited by AS1517499 decreased TEC hyperplasia, thereby reducing serum T3 and T4 and ameliorating GD. Thus, our study reveals that in addition to the traditional pathogenesis of GD, in which autoantibody TRAb stimulates thyroid-stimulating hormone receptors and consequently produces T3, T4, TRAb could also trigger TECs producing IL-4, and IL-4 then acts in an autocrine manner to activate p-STAT6 signalling and stimulate unrestricted cell growth, thus aggravating GD. These findings suggest that STAT6 inhibitors could be potent therapeutics for treating GD.

Topics: Animals; bcl-X Protein; Cyclin D1; Graves Disease; Humans; Hyperplasia; Interleukin-4; Mice, Inbred BALB C; Models, Biological; Phosphorylation; Pyrimidines; Receptors, Interleukin; Severity of Illness Index; STAT6 Transcription Factor; Thyroid Epithelial Cells; Up-Regulation

Microglandular hyperplasia (MGH) is a common endocervical alteration that in most cases presents no diagnostic difficulty. However, MGH rarely shows atypical features that may mimic endocervical neoplasia, while conversely endometrial carcinomas can show deceptively bland MGH-like appearances. It has been suggested that immunohistochemical analysis is useful in this context, but relatively few studies have specifically investigated microglandular pattern lesions and the results have been conflicting. In this study, we have examined a series of MGH (n=24), atypical MGH (n=2), and endometrial microglandular-like carcinomas (EMC, n=8), with a panel of antibodies including PAX2, cyclin D1, p16, vimentin, and Ki67. Loss of PAX2 staining was identified only in EMC but had relatively poor sensitivity for a malignant diagnosis (3/8 cases). Seven EMCs showed p16 expression and staining was diffuse (≥50% cells) in 6 cases, whereas all conventional MGH lesions were negative. However, 1 case of atypical MGH was also p16-positive. Cyclin D1, vimentin, and Ki67 did not reliably distinguish the benign and malignant microglandular lesions because of considerable overlap in staining patterns. In summary, none of the antibodies examined proved completely sensitive and specific, but a p16-positive/PAX2-negative phenotype favored a diagnosis of EMC. Pathologists should be aware that EMC, like some other types of endometrial carcinoma, are commonly p16-positive to avoid misinterpretation as a primary endocervical neoplasm. In practice, correlation of the histologic, immunohistologic, and clinical findings is necessary for accurate interpretation of microgandular-pattern lesions, particularly in small biopsy samples.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Biopsy; Cervix Uteri; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Diagnosis, Differential; Endometrial Neoplasms; Endometrium; Female; Humans; Hyperplasia; Ki-67 Antigen; Middle Aged; Neoplasm Proteins; PAX2 Transcription Factor; Phenotype; Sensitivity and Specificity; Vimentin

To identify the role of gene products associated with apoptosis and cell cycle in the pathogenesis of thyroid follicular neoplasm.. Thirty follicular adenomas (FAs), 16 follicular carcinomas (FCs), and 20 adenomatous nodules (ANs) were investigated with immunohistochemical staining of p16, p21, p27, p53, Bcl-2, Bax, Bcl-xL, and cyclin D1 via a tissue microarray method.. Bcl-2 showed a significant difference between the benign groups (AN and FA) and the malignant group (FC). Bax was significantly higher in the FC group. p53 was lowest in the AN group and highest in the FC group with significant differences between the groups. p16 was significantly higher in the FC group than in the other groups. There was a significant difference between the AN group and neoplastic lesions in terms of p21 staining. The number of cases with positive p27 was lower in the AN group than the neoplastic groups. There was no significant difference in terms of Bcl-xL and cyclin D1.. Cell cycle modulators, led by the Bcl-2 family, played an important role in the pathogenesis of thyroid follicular neoplasm, and p53, p16, and p21 in particular played a role in the carcinogenesis of FC.

Topics: Adenocarcinoma, Follicular; Adenoma; Adult; Apoptosis; bcl-2-Associated X Protein; Cell Cycle Checkpoints; Cell Cycle Proteins; Cyclin D1; Female; Humans; Hyperplasia; Immunohistochemistry; Male; Middle Aged; Thyroid Neoplasms; Thyroid Nodule; Tissue Array Analysis

The histopathology of premalignant laryngeal lesions does not provide reliable information on the risk of malignant transformation, hence we examined new molecular markers which can easily be implemented in clinical practice. Dual-target fluorescence in situ hybridisation (FISH) for chromosome 1 and 7 centromeres was performed on tissue sections of laryngeal premalignancies in 69 patients. Chromosome instability was indicated by numerical imbalances and/or polysomy for chromosomes 1 and 7. Additionally, immunostainings for p53, Cyclin D1 and (p)FADD expression were evaluated. Malignant progression was recorded. Eighteen patients with carcinoma in situ (CIS) were treated after diagnosis and excluded from follow-up. Chromosome instability was strongly associated with a high risk of malignant transformation, especially in lower grade lesions (hyperplasia, mild and moderate dysplasia; odds ratio = 8.4, p = 0.004). Patients with lesions containing chromosome instability showed a significantly worse 5-year progression-free survival than those with premalignancies without chromosome instability (p = 0.002). Neither histopathology nor the protein markers predicted progression in univariate analysis, although histopathological diagnosis, p53 and FADD contributed positively to chromosome instability in multivariate analysis. Chromosome instability is associated with malignant progression of laryngeal premalignancies, especially in lower grade lesions. These results may contribute to better risk counselling, provided that they can be validated in a larger patient set.

Topics: Adult; Aged; Chromosomal Instability; Cyclin D1; Disease Progression; Disease-Free Survival; Fas-Associated Death Domain Protein; Female; Humans; Hyperplasia; In Situ Hybridization, Fluorescence; Kaplan-Meier Estimate; Laryngeal Neoplasms; Larynx; Male; Middle Aged; Precancerous Conditions; Young Adult

Previous analysis of the Cerberus like 2 knockout (Cerl2-/-) mouse revealed a significant mortality during the first day after birth, mostly due to cardiac defects apparently associated with randomization of the left-right axis. We have however, identified Cerl2-associated cardiac defects, particularly a large increase in the left ventricular myocardial wall in neonates that cannot be explained by laterality abnormalities. Therefore, in order to access the endogenous role of Cerl2 in cardiogenesis, we analyzed the embryonic and neonatal hearts of Cerl2 null mutants that did not display a laterality phenotype. Neonatal mutants obtained from the compound mouse line Cer2-/-::Mlc1v-nLacZ24+, in which the pulmonary ventricle is genetically marked, revealed a massive enlargement of the ventricular myocardium in animals without laterality defects. Echocardiography analysis in Cerl2-/- neonates showed a left ventricular systolic dysfunction that is incompatible with a long lifespan. We uncovered that the increased ventricular muscle observed in Cerl2-/- mice is caused by a high cardiomyocyte mitotic index in the compact myocardium which is mainly associated with increased Ccnd1 expression levels in the left ventricle at embryonic day (E) 13. Interestingly, at this stage we found augmented left ventricular expression of Cerl2 levels when compared with the right ventricle, which may elucidate the regionalized contribution of Cerl2 to the left ventricular muscle formation. Importantly, we observed an increase of phosphorylated Smad2 (pSmad2) levels in embryonic (E13) and neonatal hearts indicating a prolonged TGFβs/Nodal-signaling activation. Concomitantly, we detected an increase of Baf60c levels, but only in Cerl2-/- embryonic hearts. These results indicate that independently of its well-known role in left-right axis establishment Cerl2 plays an important role during heart development in the mouse, mediating Baf60c levels by exerting an important control of the TGFβs/Nodal-signaling pathway.

Topics: Animals; Animals, Newborn; Cardiomyopathies; Cyclin D1; Female; Gene Expression Regulation, Developmental; Heart Ventricles; Hyperplasia; Intercellular Signaling Peptides and Proteins; Mice; Myocytes, Cardiac; Nodal Protein; Signal Transduction; Smad2 Protein; Transforming Growth Factor beta; Ventricular Dysfunction, Left

Depletion of early growth response factor-1 (Egr-1) by a DNA enzyme, ED5, inhibits neointimal hyperplasia (NH) following vascular injury by an unknown mechanism. The aim of this study was to characterize the effects of ED5 in a rat carotid injury model in order to elucidate the mechanism by which ED5 inhibits NH.. ED5 was transfected into the arterial wall of Wistar rats using FuGENE6 transfection reagent following artery balloon injury. Hematoxylin and eosin staining, immunohistochemistry, real-time reverse transcription polymerase chain reaction and Western blotting analysis were used to characterize the response to ED5.. NH decreased significantly in the ED5- plus FuGENE6-treated rats (p < 0.05) compared with the control groups, and this was accompanied by a reduced inflammatory response. Egr-1 mRNA and protein levels were significantly decreased in the ED5-treated group, as expected. The decrease in Egr-1 was accompanied by decreases in the mRNA and protein levels of PDGF-BB, Cyclin D1, CDK4, MCP-1, and ICAM-1 (p < 0.05).. Transfection of the Egr-1-specific synthetic DNA enzyme ED5 significantly reduced NH after injury in rats, at least in part, as a result of decreased expression of downstream proliferative genes such as PDGF-BB, Cyclin D1, CDK4, and the inflammatory factors MCP-1 and ICAM-1.

Topics: Animals; Becaplermin; Carotid Arteries; Carotid Artery Injuries; Cyclin D1; DNA, Single-Stranded; Early Growth Response Protein 1; Hyperplasia; Male; Neointima; Proto-Oncogene Proteins c-sis; Random Allocation; Rats; Rats, Wistar

Laminin-5 is an important protein in the establishment of an intact basement membrane. The aims of this study were to assess the expression of laminin-5 (γ2 chain) using cyclin D1 and Ki-67 in hyperplastic oral mucosal lesions, oral dysplasia, and squamous cell carcinoma (SCC).. Paraffin-embedded tissue blocks of 134 patients were stained for laminin-5, cyclin D1, and Ki-67 using immunohistochemistry and assessed by virtual microscopy. Statistical analysis was performed using Kruskal-Wallis tests and Mann-Whitney U tests for post hoc assessment.. Laminin-5, cyclin D1, and Ki-67 were found to have significant differences in expression for the different categories of dysplasia, SCC, and hyperplasia (P < .001). Cyclin D1 and Ki-67 expression levels were significantly increased in moderate and severe dysplasia and SCC, with no significant difference in expression between hyperplasia and mild dysplasia or between biopsies of severe dysplasia and SCC. Laminin-5 expression was only significantly increased in SCC, confirming it as a marker of malignant transformation and invasion.. The results of this study indicate that overexpression of laminin-5 is found only in SCC and not dysplastic lesions. Therefore, laminin-5 has potential as a marker for the intraoperative assessment of cancer excision margins and could be used as a target for chemotherapeutic agents.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Carcinoma, Squamous Cell; Cell Adhesion Molecules; Cell Nucleus; Cell Transformation, Neoplastic; Cyclin D1; Cytoplasm; Epithelium; Female; Humans; Hyperplasia; Image Processing, Computer-Assisted; Immunohistochemistry; Kalinin; Ki-67 Antigen; Laminin; Male; Middle Aged; Mouth Mucosa; Mouth Neoplasms; Neoplasm Invasiveness; Precancerous Conditions

The conversion of plasminogen into plasmin by interstitial urokinase plasminogen activator (uPA) is potentially important in asthma pathophysiology. In this study, the effect of uPA-mediated plasminogen activation on airway smooth muscle (ASM) cell proliferation was investigated.. Human ASM cells were incubated with plasminogen (0.5-50 μg·mL(-1) ) or plasmin (0.5-50 mU·mL(-1) ) in the presence of pharmacological inhibitors, including UK122, an inhibitor of uPA. Proliferation was assessed by increases in cell number or MTT reduction after 48 h incubation with plasmin(ogen), and by earlier increases in [(3) H]-thymidine incorporation and cyclin D1 expression.. Plasminogen (5 μg·mL(-1) )-stimulated increases in cell proliferation were attenuated by UK122 (10 μM) or by transfection with uPA gene-specific siRNA. Exogenous plasmin (5 mU·mL(-1) ) also stimulated increases in cell proliferation. Inhibition of plasmin-stimulated ERK1/2 or PI3K/Akt signalling attenuated plasmin-stimulated increases in ASM proliferation. Furthermore, pharmacological inhibition of cell signalling mediated by the EGF receptor, a receptor trans-activated by plasmin, also reduced plasmin(ogen)-stimulated cell proliferation. Knock down of annexin A2, which has dual roles in both plasminogen activation and plasmin-signal transduction, also attenuated ASM cell proliferation following incubation with either plasminogen or plasmin.. Plasminogen stimulates ASM cell proliferation in a manner mediated by uPA and involving multiple signalling pathways downstream of plasmin. Targeting mediators of plasminogen-evoked ASM responses, such as uPA or annexin A2, may be useful in the treatment of asthma.

Topics: Annexin A2; Bronchi; Cell Proliferation; Cells, Cultured; Cyclin D1; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Fibrinolysin; Humans; Hyperplasia; Muscle, Smooth; Myocytes, Smooth Muscle; Phosphatidylinositol 3-Kinase; Phosphoinositide-3 Kinase Inhibitors; Plasminogen; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; RNA Interference; Serine Proteinase Inhibitors; Signal Transduction; Time Factors; Transfection; Urokinase-Type Plasminogen Activator

Our prior studies have indicated that ochratoxin A (OTA), a mycotoxin, has skin tumor initiating activity. In the present investigation, skin tumor promoting activity of OTA and the mechanism/(s) involved therein was undertaken. A single topical application of OTA (100 nmol/mouse) caused significant enhancement in short-term markers of skin tumor promotion such as ornithine decarboxylase activity, DNA synthesis, hyperplasia as well as expression of cyclin-D1 and COX-2 in mouse skin. In a two-stage mouse skin tumorigenesis protocol, twice-weekly exposure of OTA (50 nmol/mouse) to 7,12-dimethylbenz[α]anthracene (120 nmol/mouse) initiated mice skin for 24 weeks leads to tumor formation. Further, exposure of primary murine keratinocytes (PMKs) with non-cytotoxic dose of OTA (5.0 µM) caused (i) significant enhancement of DNA synthesis, (ii) enhanced phosphorylation and subsequent activation of epidermal growth factor receptor (EGFR) and its downstream signaling pathways viz Akt, ERK1/2, p38 and JNK mitogen-activated protein kinases (MAPKs), (iii) overexpression of c-jun, c-fos, cyclin-D1 and COX-2 and (iv) increased binding of nuclear factor-kappaB (NF-κB) and AP-1 transcription factors to the promoter region of cyclin-D1 and COX-2 genes. It was also observed that knocking down the messenger RNA expression of NF-κB, c-jun, c-fos, cyclin-D1 and COX-2 results in significant inhibition in OTA-induced PMKs proliferation. These results suggest that OTA has cell proliferative and tumor-promoting potential in mouse skin, which involves EGFR-mediated MAPKs and Akt pathways along with NF-κB and AP-1 transcription factors and that cyclin-D1 and COX-2 are the target genes responsible for tumor-promoting activity of OTA.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinogens; Cell Proliferation; Cell Survival; Cells, Cultured; Cyclin D1; Cyclooxygenase 2; Enzyme Activation; Epidermis; ErbB Receptors; Female; Gene Knockdown Techniques; Hyperplasia; Keratinocytes; Mice; Mitogen-Activated Protein Kinases; NF-kappa B; Ochratoxins; Ornithine Decarboxylase; Phosphorylation; Primary Cell Culture; Promoter Regions, Genetic; Protein Binding; Protein Processing, Post-Translational; Proto-Oncogene Proteins c-akt; RNA, Small Interfering; Skin Neoplasms; Transcription Factor AP-1; Transcriptional Activation

Chronic renal failure (CRF) is associated with increased cardiovascular mortality, and medial vascular smooth muscle cell (VSMC) hypertrophy, proliferation, and calcification play a pivotal role in uremic vasculopathy. Glucose transporter-1 (GLUT1) facilitates the transport of glucose into VSMCs, and GLUT1 overexpression associated with high glucose influx leads to a stimulation of VSMC proliferation. However, the role of GLUT1 in uremic vasculopathy remains unclear. This study aimed to identify changes in the expression of GLUT1 in VSMCs in the setting of experimental uremia and investigate whether Akt/tuberous sclerosis complex subunit 2 (TSC2)/mammalian target of rapamycin (mTOR)/ribosomal S6 protein kinase (S6K) signaling, which plays a crucial role in VSMC proliferation and glucose metabolism, is involved in the regulation of GLUT1 expression.. In vivo experimental CRF was induced in Wistar rats by 5/6 nephrectomy, and the GLUT1 expression in aortic tissue was determined by the reverse transcriptase-polymerase chain reaction, immunoblotting, and immunohistochemical staining. Indoxyl sulfate (IS) is a uremic retention solute proven with pro-proliferative effect on rat VSMCs, and we further studied the expression of GLUT1 in rat A7r5 rat embryonic aortic cells stimulated by IS in the presence or absence of phloretin, a GLUT1 inhibitor, to explore the pathogenic role of GLUT1 in uremic vasculopathy. The contribution of Akt/TSC2/mTOR/S6K signaling in modifying the GLUT1 expression was also assessed.. Eight weeks after 5/6 nephrectomy, aortic tissue obtained from CRF rats exhibited increased wall thickness and VSMC hypertrophy, hyperplasia, and degeneration. Compared with the sham-operated control group, the messenger (m)RNA and protein abundance of GLUT1 were both markedly increased in CRF rats. In vitro, IS induced a significant increase in expression of GLUT1 protein as well as pro-proliferative cyclin D1 and p21 mRNA and a modest increase in expression of antiapoptotic p53 mRNA in A7r5 cells, whereas inhibition of GLUT1 mediated glucose influx reduced the pro-proliferative and antiapoptotic effects of IS. In addition to increased GLUT1 expression, IS significantly suppressed Akt and TSC2 phosphorylation after 6-hour and 12-hour treatment, but increased S6K phosphorylation after 3-hour treatment. Inactivation of mTOR downstream signaling by rapamycin treatment inhibited S6K phosphorylation and abolished the stimulatory effect of IS on GLUT1 expression.. In vivo and in vitro experimental CRF displayed prominent GLUT1 upregulation in VSMCs. The uremic toxin IS stimulated proliferation of VSMCs possibly through induction of GLUT1 expression. The Akt/TSC/mTOR/S6K signaling pathway may be one of the mechanisms underlying the upregulation of GLUT1 expression in uremic VSMCs.

Topics: Animals; Aorta; Apoptosis; Blotting, Western; Cell Line; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Disease Models, Animal; Glucose; Glucose Transporter Type 1; Hyperplasia; Hypertrophy; Immunohistochemistry; Indican; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Nephrectomy; Phloretin; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Renal Insufficiency; Reverse Transcriptase Polymerase Chain Reaction; Ribosomal Protein S6 Kinases; RNA, Messenger; Signal Transduction; Sirolimus; Time Factors; TOR Serine-Threonine Kinases; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Protein p53; Tumor Suppressor Proteins; Up-Regulation; Uremia

Gingival lesions of squamous hyperplasia, cystic keratinizing hyperplasia (CKH), and squamous cell carcinoma (SCC) can be induced in rats treated by chronic gavage with 10-100 mg/kg 3,3',4,4'-tetrachloroazobenzene. We evaluated gingival squamous hyperplasia (GSH), CKH, and SCC for the immunohistochemical pattern of expression of carcinogenesis-associated markers. The 3 types of lesions and controls were stained with proliferation markers (proliferating cell nuclear antigen [PCNA] and cyclin-D1), tumor-suppressor markers (β-catenin and mammary serine protease inhibitor [maspin]) and stroma-related markers (α-smooth muscle actin [SMA] and osteonectin/SPARC). The lesions had common immunohistochemical characteristics that differed in their expression patterns among the various diagnoses. PCNA and cyclin-D1 expression was higher in GSH, CKH, and SCC than in controls. The normal membranous expression of β-catenin was lower in GSH, and almost absent in CKH and SCC. Maspin expression was similar in GSH and controls, whereas both CKH and SCC showed decreased expression. SMA and/or osteonectin/SPARC were seen in stromal cells in CKH and SCC. Collectively, there appears to be a progression from hyperplastic and cystic lesions toward malignancy based on the morphological changes, supported by the expression of carcinogenesis-associated proteins. The exact sequence of events leading to SCC remains to be defined in a time-dependent manner.

Topics: Analysis of Variance; Animals; Azo Compounds; Biomarkers, Tumor; Carcinoma, Squamous Cell; Chlorobenzenes; Cyclin D1; Epithelium; Female; Gingiva; Gingival Neoplasms; Hyperplasia; Immunohistochemistry; Male; Proliferating Cell Nuclear Antigen; Rats; Rats, Sprague-Dawley; Statistics, Nonparametric

The Ron receptor tyrosine kinase (macrophage stimulating 1 receptor) is overexpressed in approximately 50% of human breast cancers. Transgenic mice overexpressing Ron in the mammary epithelium [mouse mammary tumor virus driven (MMTV)-Ron expressing mice] develop mammary tumors that exhibit up-regulation of β-catenin and β-catenin target genes. β-Catenin has been shown to be a mediator of mammary tumorigenesis in various breast cancer models, including downstream of Ron. However, the in vivo impact of a conditional loss of β-catenin downstream of Ron receptor overexpression on the onset, growth, turnover, and metastasis of mammary tumors has not been addressed. To determine the significance of β-catenin in the context of Ron overexpression, we conditionally deleted β-catenin in mammary epithelial cells of MMTV-Ron mice. Conditional deletion of β-catenin in the mammary epithelium, through the use of whey acidic protein (WAP)-Cre transgenic mice, significantly delayed the onset of mammary hyperplastic nodules, the presence of palpable mammary tumors, and ultimately decreased liver metastasis. β-Catenin loss in this model was also associated with decreased expression of cyclin D1. In total, these studies support an important role for β-catenin downstream of Ron receptor signaling during the development of mammary tumorigenesis.

Topics: Animals; beta Catenin; Blotting, Western; Cell Transformation, Neoplastic; Cyclin D1; Epithelial Cells; Female; Gene Expression Regulation, Neoplastic; Hyperplasia; Liver Neoplasms; Male; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mice; Mice, Knockout; Mice, Transgenic; Receptor Protein-Tyrosine Kinases; Reverse Transcriptase Polymerase Chain Reaction; Time Factors

Proliferation of smooth muscle cells (SMC) in response to vascular injury is central to neointimal vascular remodeling. There is accumulating evidence that histone acetylation constitutes a major epigenetic modification for the transcriptional control of proliferative gene expression; however, the physiological role of histone acetylation for proliferative vascular disease remains elusive.. In the present study, we investigated the role of histone deacetylase (HDAC) inhibition in SMC proliferation and neointimal remodeling. We demonstrate that mitogens induce transcription of HDAC 1, 2, and 3 in SMC. Short interfering RNA-mediated knockdown of either HDAC 1, 2, or 3 and pharmacological inhibition of HDAC prevented mitogen-induced SMC proliferation. The mechanisms underlying this reduction of SMC proliferation by HDAC inhibition involve a growth arrest in the G(1) phase of the cell cycle that is due to an inhibition of retinoblastoma protein phosphorylation. HDAC inhibition resulted in a transcriptional and posttranscriptional regulation of the cyclin-dependent kinase inhibitors p21(Cip1) and p27(Kip). Furthermore, HDAC inhibition repressed mitogen-induced cyclin D1 mRNA expression and cyclin D1 promoter activity. As a result of this differential cell cycle-regulatory gene expression by HDAC inhibition, the retinoblastoma protein retains a transcriptional repression of its downstream target genes required for S phase entry. Finally, we provide evidence that these observations are applicable in vivo by demonstrating that HDAC inhibition decreased neointima formation and expression of cyclin D1 in a murine model of vascular injury.. These findings identify HDAC as a critical component of a transcriptional cascade regulating SMC proliferation and suggest that HDAC might play a pivotal role in the development of proliferative vascular diseases, including atherosclerosis and in-stent restenosis.

Topics: Acetylation; Animals; Cell Cycle; Cell Cycle Proteins; Cell Proliferation; Cells, Cultured; Chromatin Assembly and Disassembly; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Disease Models, Animal; E2F Transcription Factors; Epigenesis, Genetic; Histone Deacetylase Inhibitors; Histone Deacetylases; Histones; Hydroxylamines; Hyperplasia; Mice; Mice, Inbred C57BL; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Phosphorylation; Quinolines; Rats; Retinoblastoma Protein; RNA Interference; Time Factors; Transcription, Genetic; Tunica Media; Vascular System Injuries

Syndecan-4 (Syn4) is a heparan sulfate proteoglycan and works as a coreceptor for various growth factors. We examined whether Syn4 could be involved in the development of neointimal formation in vivo.. Wild-type (WT) and Syn4-deficient (Syn4-/-) mice were subjected to wire-induced femoral artery injury. Syn4 mRNA was upregulated after vascular injury in WT mice. Neointimal formation was attenuated in Syn4-/- mice, concomitantly with the reduction of Ki67-positive vascular smooth muscle cells (VSMCs). Basic-fibroblast growth factor- or platelet-derived growth factor-BB-induced proliferation, extracellular signal-regulated kinase activation, and expression of cyclin D1 and Bcl-2 were impaired in VSMCs from Syn4-/- mice. To examine the role of Syn4 in bone marrow (BM)-derived vascular progenitor cells (VPCs) and vascular walls, we generated chimeric mice by replacing the BM cells of WT and Syn4-/- mice with those of WT or Syn4-/- mice. Syn4 expressed by both vascular walls and VPCs contributed to the neointimal formation after vascular injury. Although the numbers of VPCs were compatible between WT and Syn4-/- mice, mobilization of VPCs from BM after vascular injury was defective in Syn4-/- mice.. Syn4 deficiency limits neointimal formation after vascular injury by regulating VSMC proliferation and VPC mobilization. Therefore, Syn4 may be a novel therapeutic target for preventing arterial restenosis after angioplasty.

Topics: Animals; Apoptosis; Becaplermin; Bone Marrow Transplantation; Cell Movement; Cell Proliferation; Cyclin D1; Disease Models, Animal; Extracellular Signal-Regulated MAP Kinases; Femoral Artery; Fibroblast Growth Factor 2; Hyperplasia; Ki-67 Antigen; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Platelet-Derived Growth Factor; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-sis; Signal Transduction; Stem Cells; Syndecan-4; Time Factors; Tunica Intima; Vascular System Injuries

Cholestasis contributes to hepatocellular injury and promotes liver carcinogenesis. We created a mouse model of chronic cholestasis to study its effects on progression of cholangiocarcinoma and the oncogenes involved.. To induce chronic cholestasis, Balb/c mice were given 2 weekly intraperitoneal injections of diethylnitrosamine (DEN); 2 weeks later, some mice also received left and median bile duct ligation (LMBDL) and, then 1 week later, were fed DEN, in corn oil, weekly by oral gavage (DLD). Liver samples were analyzed by immunohistochemical and biochemical assays; expression of Mnt and c-Myc was reduced by injection of small inhibitor RNAs.. Chronic cholestasis was induced by DLD and accelerated progression of cholangiocarcinoma, compared with mice given only DEN. Cystic hyperplasias, cystic atypical hyperplasias, cholangiomas, and cholangiocarcinoma developed in the DLD group at weeks 8, 12, 16, and 28, respectively. LMBDL repressed expression of microRNA (miR)-34a and let-7a, up-regulating Lin-28B, hypoxia-inducible factor (HIF)-1α, HIF-2α, and miR-210. Up-regulation of Lin-28B might inhibit let-7a, which is associated with development of cystic hyperplasias, cystic atypical hyperplasias, cholangiomas, and cholangiocarcinoma. Knockdown of c-Myc reduced progression of cholangiocarcinoma, whereas knockdown of Mnt accelerated its progression. Down-regulation of miR-34a expression might up-regulate c-Myc. The up-regulation of miR-210 via HIF-2α was involved in down-regulation of Mnt. Activation of the miR-34a-c-Myc and HIF-2α-miR-210-Mnt pathways caused c-Myc to bind the E-box element of cyclin D1, instead of Mnt, resulting in cyclin D1 up-regulation.. DLD induction of chronic cholestasis accelerated progression of cholangiocarcinoma, which is mediated by down-regulation of miR-34a, up-regulation miR-210, and replacement of Mnt by c-Myc in binding to cyclin D1.

Topics: Animals; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Basic Helix-Loop-Helix Transcription Factors; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cholangiocarcinoma; Cholestasis; Cyclin D1; Diethylnitrosamine; Disease Models, Animal; Disease Progression; Gene Expression Regulation, Neoplastic; Hyperplasia; Hypoxia-Inducible Factor 1, alpha Subunit; Ligation; Liver; Male; Mice; Mice, Inbred BALB C; MicroRNAs; Proto-Oncogene Proteins c-myc; Repressor Proteins; RNA Interference; RNA-Binding Proteins; Signal Transduction; Time Factors; Transcription Factors

Lung cancer is the leading cause of cancer-related mortality worldwide. Early detection or prevention strategies are urgently needed to increase survival. Hyperplasia is the first morphologic change that occurs in the bronchial epithelium during lung cancer development, followed by squamous metaplasia, dysplasia, carcinoma in situ, and invasive tumor. This study was designed to determine the molecular mechanisms that control bronchial epithelium hyperplasia. Using primary normal human tracheobronchial epithelial (NHTBE) cells cultured by using the 3-dimensional (3D) organotypic method, we found that the epidermal growth factor receptor (EGFR) ligands, EGF, TGF-α, and amphiregulin induced hyperplasia, as determined by cell proliferation and multilayered epithelium formation. We also found that EGF induced increased cyclin D1 expression, which plays a critical role in bronchial hyperplasia; this overexpression was mediated by activating the mitogen-activated protein kinase pathway but not the phosphoinositide 3-kinase/Akt signaling pathway. Erlotinib, an EGFR tyrosine kinase inhibitor, and U0126, a MAP/ERK kinase (MEK) inhibitor, completely inhibited EGF-induced hyperplasia. Furthermore, a promoter analysis revealed that the activator protein-1 transcription factor regulates EGF-induced cyclin D1 overexpression. Activator protein-1 depletion by using siRNA targeting its c-Jun component completely abrogated EGF-induced cyclin D1 expression. In conclusion, we showed that bronchial hyperplasia can be modeled in vitro by using primary NHTBE cells maintained in a 3D organotypic culture. EGFR and MEK inhibitors completely blocked EGF-induced bronchial hyperplasia, suggesting that they have a chemopreventive role.

Topics: Bronchi; Butadienes; Cell Line, Tumor; Cyclin D1; Enzyme Inhibitors; ErbB Receptors; Erlotinib Hydrochloride; Humans; Hyperplasia; Luciferases; Lung Neoplasms; MAP Kinase Kinase Kinases; Models, Biological; Nitriles; Organ Culture Techniques; Quinazolines; RNA, Small Interfering

Long-term dialysis for patients with end stage renal disease leads to an unavoidable common complication, which is secondary hyperparathyroidism. Two histological patterns (nodular and diffuse hyperplasia) are detected, indicating that continuous uremia-related stimulation promotes parathyroid cell proliferation from diffuse to nodular growth. However, the key molecular mechanism is not fully understood, which narrows the range of therapeutic options for advanced secondary hyperparathyroidism. To address this issue, we utilized surgically resected normal and hyperplastic parathyroid glands to perform immunohistochemical analysis of a multifunctional cell cycle modulator, CCAAT enhancer binding protein (C/EBP)β. In contrast to normal parathyroid tissue and diffuse hyperplasia, the intensity of C/EBPβ staining was homogeneously increased in the parathyroid cells from nodules, along with a higher cyclin D1 labeling index (108.0 ± 19.5, mean ± SEM) and Ki-67 labeling index (31.70 ± 0.49). Normal and diffuse hyperplastic parathyroid glands had far fewer cyclin D1- and Ki-67-positive cells (P < 0.001). Immunofluorescent double staining showed abundant coexpression of Th235 (mitogen-activated protein kinase [MAPK] phosphorylation site) C/EBPβ, along with upregulation of cytoplasmic Ras in nodular hyperplasia. In conclusion, hyperplastic parathyroid cells in nodules have an autonomous proliferation mechanism similar to that of cancer, in which C/EBPβ is upregulated and phosphorylated to interact with the oncogenic Ras/MAPK pathway. C/EBPβ may be a novel target molecule for blocking the growth circuit that underlies parathyroid tumorigenesis in secondary hyperparathyroidism.

Topics: CCAAT-Enhancer-Binding Protein-beta; Cell Proliferation; Cyclin D1; Fluorescent Antibody Technique; Humans; Hyperparathyroidism, Secondary; Hyperplasia; Ki-67 Antigen; Mitogen-Activated Protein Kinases; Parathyroid Glands; Phosphorylation; ras Proteins; Staining and Labeling; Up-Regulation

The mucosa of gallbladder stimulated with gallstones and accompanied with abnormalities in bile composition, is the origin of biliary disease, which could induce metaplasia, simple hyperplasia, atypical hyperplasia and even carcinoma in situ and invasive carcinoma in gallbladder mucosa.. To determine the disorder of the balance between cell proliferation and cell cycle or apoptosis in gallbladder cancer accompanied with gallstones, removal of the gallbladder due to gallstones specimens of 88 cases were collected randomly, including a variety of 54 cases for hyperplasia, 27 cases for gallbladder cancer and 7 cases for normal gallbladder. The expressions of key cell cycle factors were detected by in situ hybridization, immunohistochemistry and Western blot.. The expressions of CDK4 and Cyclin D1 increased along with progression of gallbladder mucosa hyperplasia; and showed highest expression in cancer group. On the contrary, p16 decreased to the lowest level in gallbladder cancer. The increased apoptotic index analyzed by TUNEL assay rose along with malignant degree to the highest level in undifferentiated carcinoma.. Our results suggest that changes of these signals have effect on breaking the balance of proliferation and death of gallbladder epithelial cells, even on inducing gallbladder cancer.

Topics: Apoptosis; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p16; Epithelial Cells; Epithelium; Fluorescence; Gallbladder Neoplasms; Gallstones; Gene Expression Regulation, Neoplastic; Humans; Hyperplasia; Mucous Membrane; Retinoblastoma Protein; Risk Factors; RNA, Messenger; Signal Transduction

Pituitary tumor transforming gene (PTTG)-binding factor (PBF or PTTG1IP) is a little characterized proto-oncogene that has been implicated in the etiology of breast and thyroid tumors. In this study, we created a murine transgenic model to target PBF expression to the thyroid gland (PBF-Tg mice) and found that these mice exhibited normal thyroid function, but a striking enlargement of the thyroid gland associated with hyperplastic and macrofollicular lesions. Expression of the sodium iodide symporter (NIS), a gene essential to the radioiodine ablation of thyroid hyperplasia, neoplasia, and metastasis, was also potently inhibited in PBF-Tg mice. Critically, iodide uptake was repressed in primary thyroid cultures from PBF-Tg mice, which could be rescued by PBF depletion. PBF-Tg thyroids exhibited upregulation of Akt and the TSH receptor (TSHR), each known regulators of thyrocyte proliferation, along with upregulation of the downstream proliferative marker cyclin D1. We extended and confirmed findings from the mouse model by examining PBF expression in human multinodular goiters (MNG), a hyperproliferative thyroid disorder, where PBF and TSHR was strongly upregulated relative to normal thyroid tissue. Furthermore, we showed that depleting PBF in human primary thyrocytes was sufficient to increase radioiodine uptake. Together, our findings indicate that overexpression of PBF causes thyroid cell proliferation, macrofollicular lesions, and hyperplasia, as well as repression of the critical therapeutic route for radioiodide uptake.

Topics: Animals; Cell Proliferation; Cyclin D1; Gene Expression Regulation; Goiter, Nodular; Humans; Hyperplasia; Intracellular Signaling Peptides and Proteins; Iodine; Iodine Radioisotopes; Membrane Proteins; Mice; Mice, Transgenic; Proto-Oncogene Mas; Symporters; Thyroid Gland

We have demonstrated that a synthetic DNA enzyme targeting early growth response factor-1 (Egr-1) can inhibit neointimal hyperplasia following vascular injury. However, the detailed mechanism of this inhibition is not known. Thus, the objective of the present study was to further investigate potential inhibitory mechanisms. Catalytic DNA (ED5) and scrambled control DNA enzyme (ED5SCR) were synthesized and transfected into primary cultures of rat vascular smooth muscle cells (VSMCs). VSMC proliferation and DNA synthesis were analyzed by the MTT method and BrdU staining, respectively. Egr-1, TGF-beta1, p53, p21, Bax, and cyclin D1 expression was detected by RT-PCR and Western blot. Apoptosis and cell cycle assays were performed by FACS. Green fluorescence could be seen localized in the cytoplasm of 70.6 +/- 1.52 and 72 +/- 2.73% VSMCs 24 h after transfection of FITC-labeled ED5 and ED5SCR, respectively. We found that transfection with ED5 significantly inhibited cultured VSMC proliferation in vitro after 24, 48, and 72 h of serum stimulation, and also effectively decreased the uptake of BrdU by VSMC. ED5 specifically reduced serum-induced Egr-1 expression in VSMCs, further down-regulated the expression of cyclin D1 and TGF-beta1, and arrested the cells at G0/G1, inhibiting entry into the S phase. FACS analysis indicated that there was no significant difference in the rate of apoptosis between ED5- and ED5SCR-transfected cells. Thus, ED5 can specifically inhibit Egr-1 expression, and probably inhibits VSMC proliferation by down-regulating the expressions of cyclin D1 and TGF-beta1. However, ED5 has no effect on VSMC apoptosis.

Topics: Animals; Apoptosis; Blotting, Western; Catalytic Domain; Cell Proliferation; Cyclin D1; DNA; Down-Regulation; Early Growth Response Protein 1; Hyperplasia; Intercellular Signaling Peptides and Proteins; Muscle, Smooth, Vascular; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; Transforming Growth Factor beta1; Tunica Intima

A major determinant of the progression from insulin resistance to the development of overt type 2 diabetes is a failure to mount an appropriate compensatory beta-cell hyperplastic response to maintain normoglycemia. We undertook the present study to directly explore the significance of the cell cycle protein cyclin D2 in the expansion of beta-cell mass in two different models of insulin resistance.. We created compound knockouts by crossing mice deficient in cyclin D2 (D2KO) with either the insulin receptor substrate 1 knockout (IRS1KO) mice or the insulin receptor liver-specific knockout mice (LIRKO), neither of which develops overt diabetes on its own because of robust compensatory beta-cell hyperplasia. We phenotyped the double knockouts and used RT-qPCR and immunohistochemistry to examine beta-cell mass.. Both compound knockouts, D2KO/LIRKO and D2KO/IRS1KO, exhibited insulin resistance and hyperinsulinemia and an absence of compensatory beta-cell hyperplasia. However, the diabetic D2KO/LIRKO group rapidly succumbed early compared with a relatively normal lifespan in the glucose-intolerant D2KO/IRS1KO mice.. This study provides direct genetic evidence that cyclin D2 is essential for the expansion of beta-cell mass in response to a spectrum of insulin resistance and points to the cell-cycle protein as a potential therapeutic target that can be harnessed for preventing and curing type 2 diabetes.

Topics: Animals; Cyclin D1; Cyclin D2; Diabetes Mellitus, Experimental; Genotype; Homozygote; Hyperglycemia; Hyperplasia; Insulin Resistance; Insulin-Secreting Cells; Liver; Mice; Mice, Knockout; Receptor, Insulin; Reverse Transcriptase Polymerase Chain Reaction

Accumulating evidence indicated that smoking might directly induce pulmonary vascular remodeling at the initial stage of chronic obstructive pulmonary disease (COPD). However, the molecular mechanism underlying this process remains poorly understood. To investigate the role of cyclin D1 in pulmonary vascular remodeling, we constructed a plasmid-based short hairpin RNA (shRNA) to knock down the expression of cyclin D1 in smoking rats. Specific shRNA against cyclin D1 significantly prevented the cyclin D1 expression and the cell proliferation in rat pulmonary artery smooth muscle cells (rPASMCs). Furthermore, the plasmid-based shRNA successfully decreased the cyclin D1 protein in intra-pulmonary arteries of smoking rats and subsequently decreased the wall thickness of pulmonary vessels and the percentage of muscularized vessels. We conclude that the plasmid-based shRNA against cyclin D1 gene attenuated pulmonary vascular remodeling in smoking rats. Cyclin D1 might play a critical role in cigarette smoke-induced pulmonary vascular remodeling via regulating rPASMCs proliferation.

Topics: Animals; Arteries; Blood Pressure; Cell Proliferation; Cells, Cultured; Cyclin D1; Green Fluorescent Proteins; Hyperplasia; Lung; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Nicotiana; Plasmids; Pulmonary Artery; Rats; Rats, Wistar; RNA, Small Interfering; Smoke; Smoking; Transfection

Estrogen and progesterone are the defining hormones of normal female development, and both play critical roles in breast carcinogenesis. Cyclin D1 is a breast cancer oncogene whose amplification is linked to poor prognosis in estrogen and progesterone receptor-positive breast cancers. Here we report that cyclin D1 regulates progesterone receptor expression, consequently enhancing responses to estrogen and progesterone. Estrogen treatment of cyclin D1 transgenic mice increased progesterone receptor expression and induced mammary hyperplasias that were stimulated by progesterone and blocked by a progesterone antagonist. Progesterone receptor levels decreased in cyclin D1 knockout mice. Cyclin D1 regulated progesterone receptor expression through a novel estrogen- and cyclin D1-responsive enhancer in DNA encoding part of the 3' untranslated region of the progesterone receptor gene. Small inhibitory RNAs for cyclin D1 decreased progesterone receptor expression and estrogen receptor binding to the 3' enhancer region in human breast cancer cells. Since estrogen and progesterone regulate cyclin D1, our results suggest that cyclin D1's participation in a feed-forward loop could contribute to increased breast cancer risks associated with estrogen and progesterone combinations. Additionally, its regulation of the progesterone receptor identifies a novel role for cyclin D1 in ovarian hormone control of breast development and breast carcinogenesis.

Topics: Animals; Binding Sites; Breast Neoplasms; Cell Line, Tumor; Cyclin D1; Enhancer Elements, Genetic; Estradiol; Estrogens; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Hyperplasia; Mammary Glands, Animal; Mice; Mice, Transgenic; Progesterone; Promoter Regions, Genetic; Protein Binding; Receptors, Estrogen; Receptors, Progesterone; RNA, Small Interfering; Signal Transduction

Proliferation of vascular smooth muscle cells (VSMCs) is a crucial event in the pathogenesis of intimal hyperplasia, the main cause of restenosis following vascular reconstruction. Here, the impact of sonic hedgehog (Shh)/Gli family zinc finger 2 (Gli2) signaling on VSMC proliferation was assessed.. Increased Shh signaling was detected in VSMCs in the neointima of vein grafts obtained from mice undergoing restenosis. Comparable results were found in primary cultured human VSMCs (hVSMCs) obtained from patients undergoing coronary bypass surgery, which were used to further assess the impacts of Shh signaling on VSMC proliferation. Inhibition of Shh signaling in hVSMCs through treatment with cyclopamine or knockdown of Gli2 results in G(1) arrest and reduced cyclin D1, cyclin E, and phosphorylated retinoblastoma (pRB) levels. In contrast, activation of Shh/Gli2 signaling in hVSMCs results in increased levels of G(1) cyclins and promotes G(1)-S transition. Stimulation of hVSMC proliferation by Shh is abolished by cyclin D1 knockdown.. Combined, these results demonstrate that Shh/Gli2 signaling stimulates VSMC proliferation via regulation of the G(1) cyclin-retinoblastoma axis and suggest that antagonists that target the Shh pathway may be therapeutically beneficial in the prevention of intimal hyperplasia.

Topics: Animals; Cell Proliferation; Cells, Cultured; Cyclin D1; Cyclin E; Disease Models, Animal; G1 Phase; Graft Occlusion, Vascular; Hedgehog Proteins; Humans; Hyperplasia; Jugular Veins; Kruppel-Like Transcription Factors; Mice; Mice, Inbred C57BL; Muscle, Smooth, Vascular; Phosphorylation; Recombinant Fusion Proteins; Retinoblastoma Protein; RNA Interference; S Phase; Saphenous Vein; Signal Transduction; Veratrum Alkaloids; Zinc Finger Protein Gli2

Cyclin D1, an important component of cell cycle machinery and a protein with known oncogenic potential, is downregulated in normal mature B lymphocytes. Its expression detected in a number of malignancies, including B-cell lymphomas, may be important for oncogenesis.. In our work, we determined the level of cyclin D1 expression in various B-cell lymphomas (i.e., mantle cell lymphoma, B-cell chronic lymphocytic leukemia, diffuse large B-cell lymphoma, follicular lymphoma, and marginal zone lymphoma) and compared it with normal B cells. For cyclin D1 level evaluation, the real-time quantitative polymerase chain reaction data was normalized. We tested five reference genes for stability on our sample set and using the three most stable ones (YWHAZ, ubiquitin c, and HPRT) obtained rather small intra-group variance for cyclin D1 expression in most lymphomas. This allowed their statistically significant ranking according to cyclin D1 expression level.. Median values of normalized cyclin D1 expression determined by real-time quantitative polymerase chain reaction were 1.32 for mantle cell lymphoma, 0.02 for B-cell chronic lymphocytic leukemia, 0.009 for diffuse large B-cell lymphoma, 0.004 for marginal zone lymphoma, 0.002 for follicular lymphoma compared with 0.0003 for reactive lymphoid tissue, and 0.00004 for sorted B cells of healthy donors.. Our data demonstrate that mantle cell lymphoma, a lymphoma with t(11;14)(q13;q32) translocation, has the level of cyclin D1 increased by four orders of magnitude, while other B-cell lymphomas without t(11;14)(q13;q32) translocation still have the level of cyclin D1 significantly elevated above that of normal lymphocytes (2 orders for B-cell chronic lymphocytic leukemia and an order for other lymphomas) and suggests more than one method of its upregulation in malignant B cells.

Topics: Aged; B-Lymphocytes; Cyclin D1; Flow Cytometry; Gene Expression Regulation, Neoplastic; Humans; Hyperplasia; Immunohistochemistry; Leukemia, Lymphocytic, Chronic, B-Cell; Leukocytes, Mononuclear; Lymph Nodes; Lymphoma, B-Cell; Lymphoma, B-Cell, Marginal Zone; Lymphoma, Follicular; Lymphoma, Large B-Cell, Diffuse; Lymphoma, Mantle-Cell; Middle Aged; Reverse Transcriptase Polymerase Chain Reaction; Spleen

Cyclin D1b is an alternative transcript of the cyclin D1 gene (CCND1) expressed in human tumors. Its abundance is regulated by a single base pair polymorphism at the exon 4/intron 4 boundary (nucleotide 870). Epidemiological studies have shown a correlation between the presence of the G870A allele (that favors the splicing for cyclin D1b) with increased risk and less favorable outcome in several forms of cancer. More recently, it has been shown that, unlike cyclin D1a, the alternative transcript D1b by itself has the capacity to transform fibroblasts in vitro. In order to study the oncogenic potential of cyclin D1b, we developed transgenic mice expressing human cyclin D1b under the control of the bovine K5 promoter (K5D1b mice). Seven founders were obtained and none of them presented any significant phenotype or developed spontaneous tumors. Interestingly, K5D1b mice do not develop the fatal thymic hyperplasia, which is characteristic of the cyclin D1a transgenic mice (K5D1a). Susceptibility to skin carcinogenesis was tested in K5D1b mice using two-stage carcinogenesis protocols. In two independent experiments, K5D1b mice developed higher papilloma multiplicity as compared with wild-type littermates. However, when K5D1b mice were crossed with cyclin D1KO mice, the expression of cyclin D1b was unable to rescue the carcinogenesis-resistant phenotype of the cyclin D1 KO mice. To further explore the role of cyclin D1b in mouse models of carcinogenesis we carried out in silico analysis and in vitro experiments to evaluate the existence of a mouse homologous of the human cyclin D1b transcript. We were unable to find any evidence of an alternatively spliced transcript in mouse Ccnd1. These results show that human cyclin D1b has different biological functions than cyclin D1a and confirm its oncogenic properties.

Topics: Animals; Base Sequence; Cell Transformation, Neoplastic; Cyclin D1; DNA Primers; Exons; Hyperplasia; Introns; Mice; Mice, Transgenic; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Skin Neoplasms; Thymus Gland

Utilizing the Citrobacter rodentium (CR)-induced transmissible murine colonic hyperplasia (TMCH) model, we provide mechanistic basis of changes in beta-catenin/APC/CKIepsilon leading to progression and/or regression of hyperplasia in vivo. In response to CR-induced TMCH, crypt lengths increased significantly between days 6-27 post-infection, followed by a steep decline by day 34. beta-Cat(45)/total beta-catenin were elevated on day 1 post-infection, preceding changes in crypt length, and persisted for 27 days before declining by day 34. Importantly, cellular CKIepsilon and beta-catenin co-immunoprecipitated and exhibited remarkable parallel changes in kinetics during hyperplasia/regression phases. beta-catenin, phosphorylated at Ser33,37 and Thr41 (beta-cat(33,37/41)), was low till day 12, followed by gradual increase until day 27 before declining by day 34. GSK-3beta exhibited significant Ser(9)-phosphorylation/inactivation at days 6-12 with partial recovery at days 27-34. Wild type (wt) APC (p312) levels increased at day 6 with transient proteolysis/truncation to p130 form between days 12 and 15; p312 reappeared by day 19 and returned to baseline by day 34. The kinetics of beta-Cat(45)/beta-catenin nuclear accumulation and acetylation (Ac-beta-Cat(Lys49)) from days 6 to 27, followed by loss of phosphorylation/acetylation by day 34 was almost identical; Tcf-4 co-immunoprecipitated with beta-Cat(45)/beta-catenin and localized immunohistochemically to beta-Cat(41/45)-positive regions leading to elevated cyclin D1 expression, during the hyperproliferative, but not regression phases of TMCH. CKIepsilon mediated phosphorylation of beta-Cat(45), resulting in stabilization/nuclear translocation of beta-Cat(45) may be critical for maintaining proliferation at days 6-27. Reversal of GSK-3beta phosphorylation and APC changes may be equally critical during the regression phase from days 27 to 34.

Topics: Acetylation; Adenomatous Polyposis Coli Protein; Animals; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; beta Catenin; Cell Nucleus; Cell Proliferation; Colon; Cyclin D1; Epithelial Cells; Frozen Sections; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hyperplasia; Immunohistochemistry; Immunoprecipitation; Mice; Models, Biological; Nerve Tissue Proteins; Phenotype; Phosphorylation; Proliferating Cell Nuclear Antigen; Protein Stability; Protein Transport; Stem Cells; TCF Transcription Factors; Transcription Factor 4

The retinoblastoma (RB) tumor suppressor pathway is likely important in primitive neuroectodermal tumors (PNET) of the brain. In fact, 10% to 15% of children born with RB mutations develop brain PNETs, commonly in the pineal gland. Cyclin D1, which in association with cyclin-dependent kinase (Cdk) 4 and Cdk6 phosphorylates and inactivates the RB protein, is expressed in 40% of sporadic medulloblastoma, a PNET of the cerebellum. To understand tumorigenic events cooperating with RB pathway disruption in brain PNET, we generated a transgenic mouse where cyclin D1 was expressed in pineal cells. Cyclin D1 enhanced pinealocyte proliferation, causing pineal gland enlargement. However, proliferation ceased beyond 2 weeks of age with reversal of Cdk4-mediated Rb phosphorylation despite continued expression of the transgene, and the pineal cells showed heterochromatin foci suggestive of a senescent-like state. In the absence of the p53 tumor suppressor, cell proliferation continued, resulting in pineal PNET that limited mouse survival to approximately 4 months. Interestingly, the Cdk inhibitor p18(Ink4c) was induced in the transgenic pineal glands independently of p53, and transgenic mice that lacked Ink4c developed invasive PNET, although at an older age than those lacking p53. Analogous to our mouse model, we found that children with heritable RB often had asymptomatic pineal gland enlargement that only rarely progressed to PNET. Our finding that the Cdk4 inhibitor p18(Ink4c) is a tumor suppressor in cyclin D1-driven PNET suggests that pharmacologic interventions to inhibit Cdk4 activity may be a useful chemoprevention or therapeutic strategy in cancer driven by primary RB pathway disruption.

Topics: Animals; Brain Neoplasms; Cell Growth Processes; Child, Preschool; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinase Inhibitor p18; Cyclin-Dependent Kinase Inhibitor p21; Disease Progression; Eye Proteins; Genes, bcl-1; Genes, p53; Humans; Hyperplasia; Infant; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neuroectodermal Tumors, Primitive; Phosphorylation; Pineal Gland; Retinoblastoma; Retinoblastoma Protein; Retinol-Binding Proteins

The tumour necrosis factor (TNF) family member TWEAK activates the Fn14 receptor and has pro-apoptotic, proliferative and pro-inflammatory actions that depend on the cell type and the microenvironment. We explored the proliferative actions of TWEAK on cultured tubular cells and in vivo on renal tubules. Additionally, we studied the role of TWEAK in compensatory proliferation following unilateral nephrectomy and in an inflammatory model of acute kidney injury (AKI) induced by a folic acid overdose. TWEAK increased the proliferation, cell number and cyclin D1 expression of cultured tubular cells, in vitro. Exposure to serum increased TWEAK and Fn14 expression and the proliferative response to TWEAK. TWEAK activated the mitogen-activated protein kinases ERK and p38, the phosphatidyl-inositol 3-kinase (PI3K)/Akt pathway and NF-kappaB. TWEAK-induced proliferation was prevented by inhibitors of these protein kinases and by the NF-kappaB inhibitor parthenolide. TWEAK-induced tubular cell proliferation as assessed by PCNA and cyclin D1 expression in the kidneys of adult healthy mice in vivo. By contrast, TWEAK knock-out mice displayed lower tubular cell proliferation in the remnant kidney following unilateral nephrectomy, a non-inflammatory model. This is consistent with TWEAK-induced proliferation on cultured tubular cells in the absence of inflammatory cytokines. Consistent with our previously published data, in the presence of inflammatory cytokines TWEAK promoted apoptosis, not proliferation, of cultured tubular cells. In this regard, TWEAK knock-out mice with AKI displayed less tubular apoptosis and proliferation, as well as improved renal function. In conclusion, TWEAK actions in tubular cells are context dependent. In a non-inflammatory milieu TWEAK induces proliferation of tubular epithelium. This may be relevant for compensatory renal hyperplasia following nephrectomy.

Topics: Animals; Apoptosis; Cell Proliferation; Cyclin D1; Cytokine TWEAK; Epithelium; Folic Acid; Hyperplasia; Kidney; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Nephrectomy; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factors; TWEAK Receptor

We recently reported a critical role of NFkappaB in mediating hyperproliferative and anti-apoptotic effects of progastrin on proximal colonic crypts of transgenic mice overexpressing progastrin (Fabp-PG mice). We now report activation of beta-catenin in colonic crypts of mice in response to chronic (Fabp-PG mice) and acute (wild type FVB/N mice) progastrin stimulation. Significant increases were measured in relative levels of cellular and nuclear beta-catenin and pbeta-cat45 in proximal colonic crypts of Fabp-PG mice compared with that in wild type littermates. Distal colonic crypts were less responsive. Interestingly, beta-catenin activation was downstream of IKKalpha,beta/NFkappaB, because treatment of Fabp-PG mice with the NFkappaB essential modulator (NEMO) peptide (inhibitor of IKKalpha,beta/NFkappaB activation) significantly blocked increases in cellular/nuclear levels of total beta-catenin/pbeta-cat45/and pbeta-cat552 in proximal colons. Cellular levels of pbeta-cat33,37,41, however, increased in proximal colons in response to NEMO, probably because of a significant increase in pGSK-3betaTyr216, facilitating degradation of beta-catenin. NEMO peptide significantly blocked increases in cyclin D1 expression, thereby, abrogating hyperplasia of proximal crypts. Goblet cell hyperplasia in colonic crypts of Fabp-PG mice was abrogated by NEMO treatment, suggesting a cross-talk between the NFkappaB/beta-catenin and Notch pathways. Cellular proliferation and crypt lengths increased significantly in proximal but not distal crypts of FVB/N mice injected with 1 nM progastrin associated with a significant increase in cellular/nuclear levels of total beta-catenin and cyclin D1. Thus, intracellular signals, activated in response to acute and chronic stimulation with progastrin, were similar and specific to proximal colons. Our studies suggest a novel possibility that activation of beta-catenin, downstream to the IKKalpha,beta/NFkappaB pathway, may be integral to the hyperproliferative effects of progastrin on proximal colonic crypts.

Topics: Animals; beta Catenin; Cell Proliferation; Colon; Cyclin D1; Gastrins; Gene Expression Regulation; Goblet Cells; Homozygote; Hyperplasia; Mice; Mice, Transgenic; Models, Biological; NF-kappa B; Protein Precursors; Signal Transduction

High-throughput microarray technologies were used to study DNA methylation accompanied by transcriptional changes in follicular lymphoma (FL). Using Methylated CpG Island Amplification with Microarrays to study CpG Island DNA methylation in FL, we discovered widespread hypermethylation of homeobox genes and previously identified targets of polycomb repressive complex 2 (PRC2) in cell lines and primary tumors, but not in benign follicular hyperplasia (BFH). DNA methylation for HOXA11, HOXD10, HOXB7, HOXC12, PAX6, LHX9, SFMBT2, EN2, and PAX7 was independently validated in the RL cell line and HOXA11, HOXD10, PAX6, and EN2 in primary tumors. Combined Bisulfite Restriction Analysis (COBRA) also established DNA methylation for the previously identified PRC2 targets DCC, DES, GAD2, AQP5, GPR61, GRIA4, GJD2, and AMPH in FL but not in BFH. Gene expression analyses revealed 411 genes that were hypermethylated and transcriptionally repressed in RL, 74% of which were reactivated by the demethylating agent 5-aza-2'-deoxycytidine (5-azaD) plus or minus the histone deacetylase inhibitor trichostatin A (TSA). Forty genes were also downregulated in primary FL. Our results suggest that extensive hypermethylation in promoters of polycomb target genes is a characteristic of FL and that loss of expression of certain SUZ12 target genes could be functionally relevant for lymphomagenesis.

Topics: Carrier Proteins; Cell Line, Tumor; Cluster Analysis; CpG Islands; Cyclin D1; DNA Methylation; Epigenesis, Genetic; Female; Genes, Homeobox; Homeodomain Proteins; Humans; Hyperplasia; Lymph Nodes; Lymphoma, Follicular; Male; Middle Aged; Neoplasm Proteins; Nuclear Proteins; Oligonucleotide Array Sequence Analysis; Polycomb Repressive Complex 2; Polycomb-Group Proteins; Promoter Regions, Genetic; Repressor Proteins; Reproducibility of Results; Transcription Factors; Transcription, Genetic

Low levels of serum adiponectin have been reported to be associated with obesity, diabetes, and non-alcoholic steatohepatitis (NASH), as well as several malignancies. Adiponectin knockout (KO) mice have been reported to cause insulin resistance and neointimal formation of the artery. We used adiponectin KO mice fed a high fat (HF) diet, and investigated the effect of adiponectin on the progression of steatohepatitis and carcinogenesis in vivo.. Adiponectin KO mice and wild type (WT) mice were fed a HF diet or normal chow for the periods of 24 and 48 weeks. The HF diet contained 60% of calories from fat.. The adiponectin KO mice on the HF diet showed obesity, marked elevation of serum transaminase levels, and hyperlipidemia. At 24 weeks, hepatic expression of tumor necrosis factor-alpha and procollagen alpha (I) was higher in KO mice as compared with WT mice. At 48 weeks, liver triglyceride contents in KO mice on normal chow were significantly higher than those in WT mice. Hepatocyte ballooning, spotty necrosis, and pericellular fibrosis around central veins were observed in KO mice on the HF diet. The pericellular fibrosis was more severe in KO mice on the HF diet than that in WT mice (1.62% vs 1.16%, P = 0.033). Liver adenoma and hyperplastic nodules developed in a KO mouse on the HF diet at 48 weeks (12.5%, n = 1/8), whereas no tumor was detected in WT mice (n = 10).. Adiponectin may play a protective role in the progression of NASH in the early stages by suppressing tumor necrosis factor-alpha expression and liver fibrosis.

Topics: Adenoma; Adiponectin; Alanine Transaminase; Animals; Aspartate Aminotransferases; Collagen Type I; Collagen Type I, alpha 1 Chain; Cyclin D1; Dietary Fats; Disease Models, Animal; Disease Progression; Fatty Liver; Hyperlipidemias; Hyperplasia; Liver; Liver Cirrhosis, Experimental; Liver Neoplasms; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; RNA, Messenger; Time Factors; Triglycerides; Tumor Necrosis Factor-alpha

We previously showed that antral gastric tumors develop in gastrin-deficient (Gas(-/-)) mice. Therefore Gas(-/-) mice were studied sequentially over 12 months to identify molecular mechanisms underlying gastric transformation. Fundic atrophy developed by 9 months in Gas(-/-) mice. Antral mucosal hyperplasia developed coincident with the focal loss of TFF1 and Muc5AC. Microarray analysis of 12 month Gas(-/-) tumors revealed an increase in follistatin, an activin/BMP antagonist. We found that elevated follistatin expression occurred in the proliferative neck zone of hyperplastic antrums, in antral tumors of Gas(-/-) mice, and also in human gastric cancers. Follistatin induced cyclin D1 and the trefoil factors TFF1 and TFF2 in a gastric cancer cell line. We concluded that antral hyperplasia in Gas(-/-) mice involves amplification of mucous cell lineages due to follistatin, suggesting its role in the development of antral gastric tumors.

Topics: Animals; Cell Line, Tumor; Cell Transformation, Neoplastic; Cyclin D1; Follistatin; Gastric Mucosa; Gastrins; Hyperplasia; Mice; Mice, Knockout; Mucins; Muscle Proteins; Peptides; Pyloric Antrum; Stomach Neoplasms; Trefoil Factor-1; Trefoil Factor-2

The postnatal heart responds to biomechanical stress with hypertrophy. The fetal heart may also undergo hyperplasia, but the percentage of mitotically active cardiomyocytes decreases throughout gestation. The signaling pathways controlling growth and proliferation in the fetal heart are poorly understood.. To determine whether activation of the mitogen-activated protein kinases and Akt in the acute response to pressure loading in the fetal heart is developmentally regulated.. Pulmonary artery banding (PAB) was performed in 100- or 128-day fetuses of twin gestation (n = 6 per group) for 6 h. One twin served as a control. Right ventricular (RV) and left ventricular (LV) mitogen-activated protein kinase, Akt, and cyclin D1 protein levels were determined by Western blot.. Within each gestational age group, hemodynamic and arterial blood gas values were similar between PAB and control fetuses. The total mitogen-activated protein kinase and Akt protein levels were unchanged by PAB at both gestational ages, as were active p38 and JNK levels. The RV levels of active ERK tended to decrease in 128-day PAB fetuses as compared with controls, and LV active ERK normalized to total ERK was significantly decreased. At gestational age (GA) 100 days, RV active ERK levels were significantly higher in PAB animals as compared with controls, with a trend towards increased active Akt levels. No differences were seen in the 100-day LV. The levels of the cell cycle promoter cyclin D1 were unchanged in all animals.. Pressure loading of the fetal sheep heart leads to developmentally regulated cell signaling profiles. ERK and possibly Akt may be important regulators of in vivo cardiomyocyte hyperplasia.

Topics: Animals; Blood Gas Analysis; Blood Pressure; Cyclin D1; Enzyme Activation; Female; Fetus; Heart; Heart Rate; Hyperplasia; Immunoblotting; Mitogen-Activated Protein Kinases; Myocardium; Organ Size; Pregnancy; Proto-Oncogene Proteins c-akt; Pulmonary Artery; Pulmonary Circulation; Sheep; Vascular Surgical Procedures

p27(Kip1), an important regulator of Cdk2 activity and G1/S transition, is tightly regulated in a cell-type and condition-specific manner to integrate mitogenic and differentiation signals governing cell cycle progression. We show that p27 protein levels progressively declined from mid-G1 through late-G2 phase as density-arrested 3T3-L1 preadipocytes synchronously reentered the cell cycle during early stages of adipocyte differentiation. This dramatic fall in p27 protein accumulation was due, at least in part, to a decrease in protein stability. Specific inhibitors of the 26S proteasome were shown to completely block the decrease in p27 protein levels throughout G1, increase the abundance of ubiquitylated p27 protein, and inhibit G1/S transition resulting in G1 arrest. It is further demonstrated that p27 was phosphorylated on threonine 187 during S phase progression by Cdk2 and that phosphorylated p27 was polyubiquitylated and degraded. Furthermore, we demonstrate that Skp2 and Cks1 dramatically increased during S/G2 phase progression concomitantly with the maximal fall in p27 protein. Complete knockdown of Skp2 with RNA interference partially prevented p27 degradation equivalent to that observed with Cdk2 blockade suggesting that the SCF(Skp2) E3 ligase and other proteasome-dependent mechanisms contribute to p27 degradation during preadipocyte replication. Interestingly, Skp2-mediated p27 degradation was not essential for G1/S or S/G2 transition as preadipocytes shifted from quiescence to proliferation during adipocyte hyperplasia. Finally, evidence is presented suggesting that elevated p27 protein in the absence of Skp2 was neutralized by sequestration of p27 protein into Cyclin D1/Cdk4 complexes.

Topics: 3T3-L1 Cells; Adipocytes; Animals; Cyclin D1; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p27; G2 Phase; Gene Expression Regulation; Hyperplasia; Mice; Phosphorylation; Phosphothreonine; Proteasome Endopeptidase Complex; Protein Kinase Inhibitors; Protein Processing, Post-Translational; RNA, Messenger; S Phase; S-Phase Kinase-Associated Proteins; Ubiquitin

Cyclin D1/cyclin-dependent kinase 2 (Cdk2) complexes are present at high frequency in human breast cancer cell lines, but the significance of this observation is unknown. This report shows that expression of a cyclin D1-Cdk2 fusion protein under the control of the mouse mammary tumor virus (MMTV) promoter results in mammary gland hyperplasia and fibrosis, and mammary tumors. Cell lines isolated from MMTV-cyclin D1-Cdk2 (MMTV-D1K2) tumors exhibit Rb and p130 hyperphosphorylation and up-regulation of the protein products of E2F-dependent genes. These results suggest that cyclin D1/Cdk2 complexes may mediate some of the transforming effects that result from cyclin D1 overexpression in human breast cancers. MMTV-D1K2 cancer cells express the hepatocyte growth factor (HGF) receptor, c-Met. MMTV-D1K2 cancer cells also secrete transforming growth factor beta (TGFbeta), but are relatively resistant to TGFbeta antiproliferative effects. Fibroblasts derived from MMTV-D1K2 tumors secrete factors that stimulate the proliferation of MMTV-D1K2 cancer cells, stimulate c-Met tyrosine phosphorylation, and stimulate the phosphorylation of the downstream signaling intermediates p70(s6k) and Akt on activating sites. Together, these results suggest that deregulation of the Cdk/Rb/E2F axis reprograms mammary epithelial cells to initiate a paracrine loop with tumor-associated fibroblasts involving TGFbeta and HGF, resulting in desmoplasia. The MMTV-D1K2 mice should provide a useful model system for the development of therapeutic approaches to block the stromal desmoplastic reaction that likely plays an important role in the progression of multiple types of human tumors.

Topics: Animals; Cyclin D1; Cyclin-Dependent Kinase 2; Disease Progression; Enzyme Activation; Female; Fibroblasts; Hepatocyte Growth Factor; Hyperplasia; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mammary Tumor Virus, Mouse; Mice; Mice, Transgenic; Promoter Regions, Genetic; Recombinant Fusion Proteins; Retinoblastoma Protein; Retinoblastoma-Like Protein p130; Transforming Growth Factor beta

One hundred twenty eight patients with irritated bowel syndrome (IBS) were included in the study and divided into two equal groups. Group one consisted of patients with type II IBS (without atrophic changes in the colon mucosa, CM); group II consisted of patients with type II IBS (with atrophic changes in the CM); the control group consisted of 24 practically healthy individuals. All the subjects, including the healthy ones, were examined using clinical, endoscopic, immunohistochemical methods, and electron microscopy. The study found that the development of type IIBS was connected with hyperplasia and hyperfunction of serotonin-producing cells with intensification of apoptosis. The number of colonocytes with nuclei that are immunopositive to D1 cycline increases, and the number of colonocyte nuclei that are immunopositive to proliferating cell nuclear antigen decreases. The onset of type II IBS is associated with hyperplasia and hyperfunction of all apudocyte populations, including those producing melatonin and serotonin, and simultaneous reduction of the number and functional exhaustion of VIP-producing and mast cells. Colonocyte apoptosis intensifies; their proliferative potential decreases.

Topics: Adult; Apoptosis; Cell Proliferation; Colon; Cyclin D1; Enterocytes; Enteroendocrine Cells; Humans; Hyperplasia; Intestinal Mucosa; Irritable Bowel Syndrome; Mast Cells; Microscopy, Electron, Transmission; Proliferating Cell Nuclear Antigen; Serotonin

Pigment epithelium-derived factor (PEDF) inhibits cytokine-induced endothelial cell activation through its antioxidative properties. However, the effect of PEDF on restenosis remains to be elucidated. Because the pathophysiological feature of restenosis is characterized by increased superoxide formation and accumulation of smooth muscle cells (SMCs), PEDF may inhibit this process via suppression of reactive oxygen species generation. We investigated here whether PEDF could prevent neointimal formation after balloon injury. PEDF levels were decreased in balloon-injured arteries. Adenoviral vector encoding human PEDF (Ad-PEDF) prevented neointimal formation. Expression and superoxide generation of the membrane components of NADPH oxidase, p22(phox) and gp91(phox), in the neointima were also suppressed by Ad-PEDF. Ad-PEDF reduced G(1) cyclin (cyclin D1 and E) expression and increased p27, a cyclin-dependent kinase inhibitor. In vitro, PEDF inhibited platelet-derived growth factor-BB-induced SMC proliferation and migration by blocking reactive oxygen species generation through suppression of NADPH oxidase activity via down-regulation of p22(PHOX) and gp91(PHOX). PEDF down-regulated G(1) cyclins and up-regulated p27 levels in platelet-derived growth factor-BB-exposed SMCs as well. These results demonstrate that PEDF could inhibit neointimal formation via suppression of NADPH oxidase-mediated reactive oxygen species generation. Our present study suggests that substitution of PEDF may be a novel therapeutic strategy for restenosis after balloon angioplasty.

Topics: Animals; Aorta; Becaplermin; Catheterization; Cell Movement; Cell Proliferation; Cells, Cultured; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase Inhibitor p27; Eye Proteins; Humans; Hyperplasia; Male; Myocytes, Smooth Muscle; NADPH Oxidases; Nerve Growth Factors; Platelet-Derived Growth Factor; Proto-Oncogene Proteins c-sis; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Serpins; Tunica Intima

Targeting MAPK kinase (MEK) in the MAPK pathway is a potentially effective therapeutic strategy for thyroid cancer.. The objective of the study was to investigate genotype-dependent therapeutic potential of the MEK inhibitor CI-1040 for thyroid cancer.. We examined the effects of CI-1040 on proliferation, apoptosis, transformation, thyroid gene reexpression, and xenograft tumor growth with respect to genotypes in 10 thyroid tumor cell lines.. Cell proliferation was potently inhibited by CI-1040 in cells harboring BRAF or RAS mutations but not in cells harboring RET/PTC rearrangement or wild-type alleles. For example, the IC50 values for BRAF mutation-harboring KAT10 cells and DRO cells and H-RAS mutation-harboring C643 cells were 0.365, 0.031, and 0.429 microm, respectively, whereas the IC50 values for RET/PTC1-harboring TPC1 cells and the wild-type MRO and WRO cells were 44, 46, and 278 microm, respectively. Proapoptotic effect of CI-1040 was seen in DRO cells, and cytostatic effect was seen in other cells. Down-regulation of cyclin D1 and reexpression of some thyroid genes were induced by CI-1040 in some BRAF mutation-harboring cells, and transformation was inhibited in all cells. CI-1040 also inhibited the growth of xenograft tumors in nude mice derived from KAT10 or C643 cells but not that derived from MRO cells.. We for the first time demonstrated potent inhibitory effects of a MEK inhibitor, CI-1040, on thyroid cancer cells, some of which, particularly cell proliferation and tumor growth, seemed to be BRAF mutation or RAS mutation selective. Our data encourage a clinical trial on CI-1040 in thyroid cancer patients.

Topics: Animals; Benzamides; Blotting, Western; Cell Line, Tumor; Cell Proliferation; Cyclin D1; DNA Fragmentation; Enzyme Inhibitors; Genes, ras; Humans; Hyperplasia; Mice; Mice, Nude; Mitogen-Activated Protein Kinase Kinases; Mutation; Proto-Oncogene Proteins B-raf; RNA; Thyroid Neoplasms; Xenograft Model Antitumor Assays

The role of aberrant crypt foci (ACF) as preneoplastic lesions in colon carcinogenesis is not clear. In Min/+ mice and their wild-type littermates treated with azoxymethane (AOM), we previously identified a subgroup of flat ACF that seem more immediate precursors of tumors than the classical elevated ACF. In the present study, we identified a similar subgroup of flat ACF in AOM-treated A/J mice and compared them with nascent tumors and classical elevated ACF. At week 1 and 2 after birth, A/J mice were injected subcutaneously with AOM (10 mg/kg bw/injection). At weeks 7-14, we examined the luminal surface of unsectioned colon preparations stained with methylene blue in the inverse light microscope. The lesions were also examined by histopathology and immunohistochemistry. Surface examination revealed flat ACF, classical elevated ACF and nascent tumors. Since flat ACF were not observed as elevated structures, their bright blue appearance and compressed pit pattern of crypt openings seen with transillumination were used as criteria for their identification. Flat ACF and nascent tumors displayed a uniform picture of severe dysplasia, compressed pit pattern, overexpression of cytoplasmic/nuclear beta-catenin and nuclear overexpression of cyclin D1. Apparently, flat ACF and tumors represented the same type of dysplastic lesions at different stages of crypt multiplication. In contrast, classical elevated ACF did not seem to be as clearly related to tumorigenesis. They infrequently (1/20) possessed severe dysplasia, overexpression of cytoplasmic/nuclear beta-catenin, or nuclear overexpression of cyclin D1, and they did not have compressed crypt openings. Furthermore, flat ACF grew significantly faster than classical elevated ACF. In conclusion, our data indicate a development from flat ACF to adenoma characterized by aberrant activation of the Wnt signaling pathway and fast crypt multiplication. Classical elevated ACF do not seem to be as closely related to tumorigenesis.

Topics: Animals; Azoxymethane; beta Catenin; Carcinogens; Cell Nucleus; Colonic Neoplasms; Cyclin D1; Female; Hyperplasia; Male; Mice; Mice, Inbred A; Precancerous Conditions

Smad4 is the common mediator for TGFbeta signals, which play important functions in many biological processes. To study the role of Smad4 in skin development and epidermal tumorigenesis, we disrupted this gene in skin using the Cre-loxP approach. We showed that absence of Smad4 blocked hair follicle differentiation and cycling, leading to a progressive hair loss of mutant (MT) mice. MT hair follicles exhibited diminished expression of Lef1, and increased proliferative cells in the outer root sheath. Additionally, the skin of MT mice exhibited increased proliferation of basal keratinocytes and epidermal hyperplasia. Furthermore, we provide evidence that the absence of Smad4 resulted in a block of both TGFbeta and bone morphogenetic protein (BMP) signaling pathways, including p21, a well-known cyclin-dependent kinase inhibitor. Consequently, all MT mice developed spontaneous malignant skin tumors from 3 months to 13 months of age. The majority of tumors are malignant squamous cell carcinomas. A most notable finding is that tumorigenesis is accompanied by inactivation of phosphatase and tensin homolog deleted on chromosome 10 (Pten), activation of AKT, fast proliferation and nuclear accumulation of cyclin D1. These observations revealed the essential functions of Smad4-mediated signals in repressing skin tumor formation through the TGFbeta/BMP pathway, which interacts with the Pten signaling pathway.

Topics: Alopecia; Animals; Bone Morphogenetic Proteins; Carcinoma, Squamous Cell; Cell Differentiation; Cell Nucleus; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Enzyme Activation; Epidermis; Female; Hair Follicle; Hyperplasia; In Situ Hybridization; Integrases; Keratinocytes; Male; Mice; Mice, Knockout; Mice, Transgenic; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Skin; Skin Neoplasms; Smad4 Protein; Transforming Growth Factor beta

A common feature of human breast oncogenesis is cell cycle deregulation. The expression of cyclins D1 and D3 was examined during estradiol-17beta (E(2))-induced mammary tumorigenesis in female August Copenhagen Irish (ACI) rats. Low serum E(2) levels ( approximately 60-120 pg/ml) were sufficient to induce mammary gland tumors (MGTs) that remarkably resemble human ductal breast cancer (BC) at the histopathologic and molecular levels. Western blot analysis of the E(2)-induced MGTs revealed a marked rise in cyclins D1 (24-fold), D3 (9-fold) and cdk4 (3-fold) expression compared with age-matched untreated controls. Small focal dysplasias with large, pale staining nuclei were commonly seen at 3-3.6 months, large focal dysplasias, including atypical ductal hyperplasia at 3.6-4.3 months, ductal carcinoma in-situ (DCISs) at 4.3-5.0 months, and 100% incidence of invasive ductal BC/frank tumors at 5-6 months were detected after E(2) treatment. Immunohistochemical analysis of serial sections of focal dysplasias, DCISs and invasive ductal carcinomas showed overexpression of cyclins D1, D3, estrogen receptor-alpha (ERalpha) and progesterone receptor (PR). However, cyclin D3 expression, unlike D1, was confined essentially to early pre-malignant lesions (focal dysplasias and DCISs) and primary MGTs with <1-5% of resting and normal hyperplastic breast cells staining positive. The kinase activity for cyclins D1 and D3, using retinoblastoma (Rb) as a substrate, in E(2)-induced MGTs and their binding to cdk4 was significantly elevated. Semi-quantitative reverse transcriptase PCR analysis of the E(2)-induced MGTs exhibited increased expression of cyclins D1 (2.9-fold) and D3 (1.4-fold) mRNA, indicating that their elevated protein expression was due in part to an increase in mRNA transcription. However, when analyzed by quantitative real-time Q-PCR, these genes were not amplified. These data indicate that in female ACI rat mammary glands, E(2)-induced pre-malignant lesions differentially and selectively express cyclins D1 and D3, thus contributing to a distinct growth advantage of these pre-neoplasias relative to E(2)-elicited normal hyperplasia.

Topics: Animals; Carcinoma, Intraductal, Noninfiltrating; Cell Cycle; Cell Transformation, Neoplastic; Cyclin D1; Cyclin D3; Cyclins; Estradiol; Female; Gene Amplification; Gene Expression Profiling; Hyperplasia; Immunohistochemistry; Mammary Neoplasms, Animal; Polymerase Chain Reaction; Precancerous Conditions; Rats; Rats, Inbred ACI

To investigate the relationship between cell cycle protein (cyclin D1 and p16) expression and vulvar white lesion.. Biopsies from 34 cases with vulvar white lesion, including 12 cases with lichen sclerosus (LS), 18 with squamous hyperplasia (SH) and 4 SH accompanied with LS, were examined for protein expression of cyclin D1 and p16 using immunohistochemical techniques. Normal vulvar tissues from 11 patients with other benign gynecologic diseases were used as control.. Fifty-six percent of patients with vulvar white lesion were immunopositive for cyclin D1 protein, which was significantly higher than that of control group (9%, P < 0.05); but there was no significant difference between LS (58%) and SH patients (50%, P > 0.05) in expression of cyclin D1 protein. Immunopositive expression of p16 protein in patients was 6%, with no significant difference from the control group (0, P > 0.05).. Cyclin D1 and p16 are important factors modulating cell cycle. The interrupt of balance between these two factors derived from abnormal expression of cyclin D1 may be one of the causes of vulvar white lesion.

Topics: Adult; Aged; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Female; Humans; Hyperplasia; Immunohistochemistry; Middle Aged; Retrospective Studies; Vulva; Vulvar Diseases; Vulvar Lichen Sclerosus

To investigate the role of Wnt/beta-catenin signaling transduction pathway in rat hepatocarcinogenesis.. The mRNAs of Wnt1, beta-catenin, APC, cyclin D1 and c-myc genes were amplified by using of semiquantitative reverse transcription polymerase chain reaction (RT-PCR) from normal rat livers, atypical hyperplasia livers and hepatoma tissues, respectively. Then the proteins expression of beta-catenin, APC and cyclin D1 was examined by immunohistochemical staining.. In normal rat livers, the mRNAs of Wnt1, cyclin D1 and c-myc genes were not detected and only beta-catenin protein was observed to have low expression at cellular membrane. However, 14 weeks after cancer induction in atypical hyperplasia livers, beta-catenin protein and APC protein were accumulated in cytoplasm. Meanwhile, cyclin D1 protein was detected in cytoplasm and/or nucleus in some cells. 16 weeks after cancer induction in hepatoma tissues, the mRNAs and protein expression of beta-catenin, APC, cyclin D1 and c-myc genes were detected except Wnt1.. The activation of Wnt/beta-catenin signaling transduction pathway might be one of the reasons for rat hepatocarcinogenesis.

Topics: Animals; beta Catenin; Carcinoma, Hepatocellular; Cell Transformation, Neoplastic; Cyclin D1; Cytoskeletal Proteins; Gene Expression Regulation, Neoplastic; Genes, myc; Hyperplasia; Immunohistochemistry; Liver; Liver Neoplasms, Experimental; Male; Rats; RNA, Messenger; Signal Transduction; Wnt Proteins

Here we report a new model of pre-clinical breast cancer which has been generated by overexpressing the steroid receptor coactivator AIB1 at moderate levels in breast epithelium. Transgenic female mice display mammary hyperplasia at the onset of puberty, consistent with enhanced proliferation of primary mammary epithelial cultures and augmented levels of cyclin D1 and E-cadherin. Studies of BrdU incorporation revealed that AIB1 localizes to the nucleus during or after S phase, implicating a new role for AIB1 in cell-cycle progression subsequent to G1. Our findings suggest that moderate overexpression of AIB1 may represent one of the pre-neoplastic changes in breast tissue.

Topics: Active Transport, Cell Nucleus; Animals; Cadherins; Cell Nucleus; Cell Transformation, Neoplastic; Cyclin D1; Epithelium; Female; G1 Phase; Gene Expression; Histone Acetyltransferases; Hyperplasia; Mammary Glands, Animal; Mice; Mice, Transgenic; Nuclear Receptor Coactivator 3; S Phase; Sexual Maturation; Trans-Activators

Here, we investigate the role of caveolin-1 (Cav-1) in breast cancer onset and progression, with a focus on epithelial-stromal interactions, ie, the tumor microenvironment. Cav-1 is highly expressed in adipocytes and is abundant in mammary fat pads (stroma), but it remains unknown whether loss of Cav-1 within mammary stromal cells affects the differentiated state of mammary epithelia via paracrine signaling. To address this issue, we characterized the development of the mammary ductal system in Cav-1-/- mice and performed a series of mammary transplant studies, using both wild-type and Cav-1-/- mammary fat pads. Cav-1-/- mammary epithelia were hyperproliferative in vivo, with dramatic increases in terminal end bud area and mammary ductal thickness as well as increases in bromodeoxyuridine incorporation, extracellular signal-regulated kinase-1/2 hyperactivation, and up-regulation of STAT5a and cyclin D1. Consistent with these findings, loss of Cav-1 dramatically exacerbated mammary lobulo-alveolar hyperplasia in cyclin D1 Tg mice, whereas overexpression of Cav-1 caused reversion of this phenotype. Most importantly, Cav-1-/- mammary stromal cells (fat pads) promoted the growth of both normal mammary ductal epithelia and mammary tumor cells. Thus, Cav-1 expression in both epithelial and stromal cells provides a protective effect against mammary hyperplasia as well as mammary tumorigenesis.

Topics: Adipose Tissue; Animals; Caveolin 1; Cell Proliferation; Cyclin D1; Enzyme Activation; Epithelial Cells; Female; Hyperplasia; Male; Mammary Glands, Animal; Mammary Neoplasms, Animal; Mammary Tumor Virus, Mouse; Mice; Mice, Knockout; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Phenotype; Protective Agents; Signal Transduction; STAT5 Transcription Factor; Stromal Cells

Tumors can become lethal when they progress from preinvasive lesions to invasive carcinomas. Here, we identify candidate tumor progression genes using gene array analysis of preinvasive and invasive tumors from mice, which were then evaluated in human cancers. Immediate early response protein IEX-1, small stress protein 1 (HSPB8), and tumor necrosis factor-associated factor-interacting protein mRNAs displayed higher expression levels in invasive lesions than in preinvasive lesions using samples obtained by laser capture microdissection (LCM) from transgenic erbB2, ras, and cyclin D1 mice. LCM-isolated tissues from patient-matched normal, ductal carcinoma in situ, and invasive ductal carcinoma revealed similar increased expression in invasive human cancers compared with preinvasive and normal samples. These genes induced anchorage independence, increased cell proliferation, and protected against apoptosis, singly or in collaboration with erbB2. Surprisingly, they were all up-regulated by 17beta-estradiol and cyclin D1, and cyclin D1 overexpression increased p300/CBP binding to their promoters, supporting the model that cyclin D1-estrogen receptor (ER) coactivator interactions may be important to its role in ER-positive breast cancer. Additionally, an irreversible dual kinase inhibitor of ErbB signaling inhibited expression of the same genes. The up-regulation of genes contributing to increased invasiveness of ER-positive cancers offers a novel explanation for the contribution of cyclin D1 to a worse prognosis in ER-positive cancers. As targets of estrogen, cyclin D1, and erbB2 signaling, these candidates offer insights into the nature of the second events involved in breast cancer progression, regulatory events contributing to invasion, and potential targets of combined inhibition of hormone and growth factor signaling pathways.

Topics: 3T3 Cells; Animals; Breast; Breast Neoplasms; Cyclin D1; Disease Progression; Estrogens; Female; Gene Expression Regulation, Neoplastic; Humans; Hyperplasia; Mice; Mice, Transgenic; Reference Values; RNA, Messenger; RNA, Neoplasm

Urinary bladder hyperplasia associated with terephthalic acid (TPA) treatment was examined with concomitant use of sodium bicarbonate (NaHCO3) or hydrochlorothiazide to allow assessment of the relationship among bladder stones, epithelial hyperplasia, and corresponding cell cycle checkpoint gene expression in Sprague-Dawley (SD) rat.. A total of 112 weanling male SD rats that divided between six groups were given basal diet (control), diets containing 5% TPA or in combination with either 4% sodium NaHCO3 or 0.02% hydrochlorothiazide. After 90-day feeding, bladder samples were collected for histopathological diagnoses, and immunohistochemical method was used to characterize the expression of p16Ink4a cyclin D1, CDK4, EGFr and cyclin E in relation to that of proliferating cell nuclear antigen (PCNA).. In TPA treatment groups, bladder stone incidence was 40% (21/52) with 14 cases of proliferative bladder. In control and other groups, neither stone nor epithelial cell proliferation was diagnosed. PCNA-positive focal hyperplasic lesions involved all epithelial layers. Overexpressions of cyclin D1, CDK4, EGFr are found in the corresponding lesion. p16Ink4a nuclear staining reduced in proliferative bladders especially with a great quantity of stone. In addition, no positive expression was detected on cyclin E.. The present study provides a strong evidence of a link between induction of bladder hyperplasia, deregulation of the p16Ink4a-cyclin D1/CDK4 pathway, and abnormal EGFr mediated signal transduction pathway.

Topics: Animals; Cell Division; Cocarcinogenesis; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinases; Epithelial Cells; ErbB Receptors; Free Radical Scavengers; G1 Phase; Hydrochlorothiazide; Hyperplasia; Immunohistochemistry; Male; Phthalic Acids; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins; Random Allocation; Rats; Rats, Sprague-Dawley; S Phase; Sodium Bicarbonate; Urinary Bladder; Urinary Bladder Calculi

A conditional tetracycline-responsive transgenic mouse model with deregulated estrogen receptor alpha expression in mammary epithelial cells developed ductal hyperplasia (DH), lobular hyperplasia, and ductal carcinoma in situ (DCIS) by 4 months of age. Higher proliferative rates were found in both normal and abnormal ductal and lobular structures. DH and DCIS but not normal ductal structures showed an increased percentage of cells with nuclear-localized cyclin D1. No differences in either the prevalence or extent of these phenotypes following exogenous 17beta-estradiol treatment were found suggesting that alteration of ERalpha expression was the rate-limiting factor in initiation of DH, lobular hyperplasia, and DCIS.

Topics: Animals; Carcinoma in Situ; Carcinoma, Ductal; Cell Nucleus; Cell Proliferation; Cell Transformation, Neoplastic; Cyclin D1; Estradiol; Estrogen Receptor alpha; Female; Gene Expression Regulation; Gene Expression Regulation, Neoplastic; Hyperplasia; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mice; Mice, Inbred C57BL; Mice, Transgenic; RNA, Messenger

Cyclin D1 can stimulate proliferation by driving cells from the G1 into the S-phase of the mammalian cell cycle. Previous animal studies have implicated the G1-S transition as a key regulatory checkpoint governing the proliferation of pancreatic islet cells. We expressed cyclin D1 in the beta-cells of mice and islet hyperplasia developed in a time-dependent manner. The hyperplastic beta-cells exhibited higher rates of proliferation. However, blood glucose levels in fasting as well as nonfasting conditions remained normal. Furthermore, glucose tolerance tests demonstrated nearly normal responses, and diabetes did not develop in any of the animals. No islet cell tumors were observed, even among animals >2 years of age. Under our experimental conditions, the proliferative stimulus provided by cyclin D1 is not tumorigenic, does not result in diabetes, and does not result in hypoglycemia. Cyclin D1 may thus be considered a potential candidate to augment the beta-cell population ex vivo as a prelude to islet transplantation for diabetes.

Topics: Aging; Animals; Blood Glucose; Cell Proliferation; Cyclin D1; Gene Expression; Glucose Tolerance Test; Hyperplasia; Hypoglycemia; Islets of Langerhans; Male; Mice; Mice, Transgenic

Proteins controlling cell growth, differentiation, apoptosis, and oncogenic stress are often deregulated in tumor cells. However, whether such deregulations affect tumor behavior remains poorly understood in many tumor types. We recently showed that the urothelium-specific expression of activated H-ras and SV40 T antigen in transgenic mice produced two distinctive types of tumors strongly resembling the human superficial papillary tumors and carcinoma in situ of the bladder, respectively. Here we assessed the expression of a key set of cell cycle regulators in these mouse tumors and in a new transgenic line expressing a cyclin D1 oncogene in the urothelium. We found that urothelia of the wild-type and cyclin D1 transgenic mice exhibited a profile of cell cycle regulators found in quiescent (G(0)) cells, indicating that urothelium overexpressing the cyclin D1 (an 8-fold increase) is reminiscent of normal urothelium and remains slow-cycling. Low-grade superficial papillary tumors induced by activated H-ras had no detectable Rb family proteins (Rb, p107, and p130) and late cell cycle cyclins and kinases (cyclin A, E, and CDK1), but had increased level of p16, p53, and MDM2. These data suggest that the inactivation of the Rb pathway plays an important role in H-ras-induced superficial papillary tumors and that oncogenic H-ras can induce a compensatory activation of alternative tumor suppressor pathways. In contrast, carcinoma in situ of the bladder induced by SV40 T antigen had increased expression of cell cycle regulators mainly active in post-G(1) phases. The fact that phenotypically different bladder tumors exhibit different patterns of cell cycle regulators may explain why these tumors have different propensity to progress to invasive tumors. Our results indicate that the transgenic mouse models can be used not only for studying tumorigenesis but also for evaluating therapeutic strategies that target specific cell cycle regulators.

Topics: Animals; Antigens, Polyomavirus Transforming; Carcinoma, Papillary; Cell Cycle; Cell Cycle Proteins; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Genes, ras; Hyperplasia; Mice; Mice, Transgenic; Proliferating Cell Nuclear Antigen; Retinoblastoma Protein; Tumor Suppressor Proteins; Urinary Bladder Neoplasms; Urothelium

Aromatase transgenic mice exhibit hyperplastic and dysplastic changes, attesting to the importance of local estrogen in breast carcinogenesis. These mice also show increased levels of the estrogen receptor alpha and beta (ERalpha, ERbeta) suggesting that this receptor may play an important role in the initiation of estrogen-mediated mammary hyperplasia observed in these mice. To address the specific role of ERalpha in the mammary development and in the induction of estrogen-mediated hyperplasia in aromatase transgenic mice, we have generated MMTV-aromatase x ERalpha knockout cross (referred as aromatase/ERKO). Even though ERbeta is expressed in aromatase/ERKO mice, lack of ERalpha leads to impaired mammary growth in these mice. The data suggest that ERalpha plays an important role in the mammary gland development as well as in the induction of mammary hyperplasia in aromatase transgenic mice. Lack of ERalpha expression in the aromatase/ERKO mice resulted in a decrease in the expression of Cyclin D1, PCNA and TGFbeta relative to the aromatase parental strain. The studies involving aromatase/ERKO mice show that lack of ERalpha results in impaired mammary development even in the presence of continuous tissue estrogen, suggesting estrogen/ERalpha-mediated actions are critical for mammary development and carcinogenesis.

Topics: Animals; Aromatase; Cyclin D1; Estrogen Receptor alpha; Hyperplasia; Male; Mammary Glands, Animal; Mice; Mice, Knockout; Mice, Transgenic; Proliferating Cell Nuclear Antigen; RNA, Messenger; Transforming Growth Factor beta

Overwhelming evidence has demonstrated tobacco smoke (TS) is causally associated with various types of cancers, especially lung cancer. Sustained epithelial cell hyperplasia and squamous metaplasia are considered as preneoplastic lesions during the formation of lung cancer. The cellular and molecular mechanisms leading to lung cancer due to TS are not clear. Mitogen-activated protein kinases (MAPK)/activator protein-1 (AP-1) can be activated by various stimuli and play a critical role in the control of cell proliferation and differentiation. To date, information on the response of the MAPK/AP-1 pathway during hyperplasia and squamous metaplasia induced by TS is lacking. We therefore investigated the effects of TS on the development of epithelial hyperplasia and squamous metaplasia, regulation of MAPK/AP-1 activation, and expression of AP-1-regulated cell cycle proteins and differentiation markers in the lungs of rats. Exposure of rats to TS (30 mg/m(3) or 80 mg/m(3), 6 h/day, 3 days/week for 14 weeks) dramatically induced cell proliferation and squamous metaplasia in a dose-dependent manner, effects that paralleled the activation of AP-1-DNA binding activity. Phosphorylated ERK1/2, JNK, p38 and ERK5 were significantly increased by exposure to TS, indicating the activation of these MAPK pathways. Expression of Jun and Fos proteins were differentially regulated by TS. TS upregulated the expression of AP-1-dependent cell cycle proteins including cyclin D1 and proliferating cell nuclear antigen (PCNA). Among the AP-1-dependent cell differentiation markers, keratin 5 and 14 were upregulated, while loricrin, filaggrin and involucrin were downregulated following TS exposure. These findings suggest the important role of MAPK/AP-1 pathway in TS-induced pathogenesis, thus providing new insights into the molecular mechanisms of TS-associated lung diseases including lung cancers.

Topics: Animals; Cell Proliferation; Cyclin D1; Enzyme Activation; Filaggrin Proteins; Hyperplasia; Intermediate Filament Proteins; JNK Mitogen-Activated Protein Kinases; Keratins; Lung Neoplasms; Male; Membrane Proteins; Metaplasia; Mitogen-Activated Protein Kinases; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Proliferating Cell Nuclear Antigen; Protein Precursors; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-jun; Rats; Rats, Inbred WKY; Signal Transduction; Smoking; Transcription Factor AP-1

The tumor suppressor phosphatase and tensin homologue (PTEN) is involved in cell proliferation, adhesion, and apoptosis. PTEN overexpression in mammary epithelium leads to reduced cell number and impaired differentiation and secretion. In contrast, overexpression of the proto-oncogene Wnt-1 in mammary epithelium leads to mammary hyperplasia and subsequently focal mammary tumors. To explore the possibility that PTEN intersects with Wnt-induced tumorigenesis, mice that ectopically express PTEN and Wnt-1 in mammary epithelium were generated. PTEN overexpression resulted in an 11% reduction of Wnt-1-induced tumors within a 12-month period and the onset of tumors was delayed from an average of 5.9 to 7.7 months. The rate of tumor growth, measured from 0.5 cm diameter until the tumors reached 1.0 cm diameter, was increased from 8.4 days in Wnt-1 mice to 17.7 days in Wnt-1 mice overexpressing PTEN. Here we show for the first time in vivo that overexpression of PTEN in the Wnt-1 transgenic mice resulted in a marked decrease in the insulin-like growth factor (IGF)-I receptor levels leading to a reduced IGF-I-mediated mitogenesis. Moreover, the percentage of BrdUrd-positive epithelial nuclei was decreased by 48%. beta-Catenin immunoreactivity was significantly decreased and the percentage of signal transducer and activator of transcription 5a (stat5a)-positive mammary epithelial cells was increased by 2-fold in Wnt-1 mice overexpressing PTEN. The present study shows that PTEN can partially inhibit the Wnt-1-induced mammary tumorigenesis in early neoplastic stages by blocking the AKT pathway and by reducing the IGF-I receptor levels in mammary gland. This study identifies the PTEN as a therapeutic target for the treatment of mammary cancer and presumably other types of cancer.

Topics: Animals; beta Catenin; Cadherins; Cell Growth Processes; Cell Transformation, Neoplastic; Cyclin D1; Cytoskeletal Proteins; DNA-Binding Proteins; Down-Regulation; Female; Hyperplasia; Intercellular Signaling Peptides and Proteins; Male; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Mice, Transgenic; Milk Proteins; Protein Serine-Threonine Kinases; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Protein Tyrosine Phosphatases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Receptor, IGF Type 1; Signal Transduction; STAT5 Transcription Factor; Trans-Activators; Transgenes; Tumor Suppressor Proteins; Wnt Proteins; Wnt1 Protein

A diagnosis of atypical ductal hyperplasia (ADH) after breast core biopsy usually is followed by an excisional biopsy to exclude the presence of a more significant lesion. To determine whether the immunohistochemical expression of cyclin D1 (CyD1) and Ki-67 can aid in case stratification for the likelihood of finding ductal carcinoma in situ (DCIS) on subsequent excision, we immunohistochemically stained 21 consecutive ADH cases diagnosed by core biopsy, and proliferation indices (PIs) were calculated for each case. Fluorescence in situ hybridization to detect CCND1 amplification was performed in 10 cases. In 5 cases, DCIS (with or without invasive carcinoma) was identified in the subsequent excision. The mean PICyD1 and PIKi-67 for these cases were significantly higher than in the remainder (P = .03 and P = .05, respectively). The sensitivities of PICyD1 and PIKi-67 for the presence of DCIS on subsequent excision were 100%, and the specificities were 75% and 69%, respectively. The specificity of the 2 markers combined was 88%. The number of cells with CCND1 amplification was higher in cases with DCIS or ADH on subsequent excision. Immunostaining for CyD1 and Ki-67 might help stratify cases of ADH on core biopsy and identify patients unlikely to have DCIS found on excision.

Topics: Aged; Biomarkers, Tumor; Biopsy, Needle; Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Cyclin D1; Female; Humans; Hyperplasia; Immunohistochemistry; In Situ Hybridization, Fluorescence; Ki-67 Antigen; Middle Aged; Precancerous Conditions

Malignant transformation of parathyroid tumours is rare. Nevertheless, this small subset of malignant tumours often creates diagnostic and therapeutic problems. In this work, the morphological characteristics of 26 primary parathyroid carcinomas and seven metastases have been studied. Furthermore, immunohistochemical expression profiles for the calcium sensing receptor (CASR), cyclin D1 (CCND1), and Ki-67 were determined for parathyroid carcinomas and compared with adenomas and hyperplasias using a tissue microarray. Loss of heterozygosity (LOH) of the chromosome 1q region containing the HRPT2 gene and chromosome 11q (MEN1) was determined in the carcinomas. In contrast to the adenomas and hyperplasias, 31% of carcinomas demonstrated down-regulation of CASR. A significant correlation was found between CASR expression and the Ki-67 proliferation index. Chromosome 1q and chromosome 11q LOH were found in 12 of 22 (55%) and 11 of 22 (50%) carcinomas tested, respectively. Combined 1q and 11q LOH was seen in 8 of 22 (36%) carcinomas, in contrast to the low percentage of LOH reported in both regions in adenomas. In conclusion, this study demonstrates that combined 1q and 11q LOH in parathyroid tumours is suggestive of malignant behaviour. Strong down-regulation of the CASR protein is seen in a proportion of parathyroid carcinomas with a high proliferation index.

Topics: Adenoma; Adult; Aged; Aged, 80 and over; Carcinoma; Chromosomes, Human, Pair 1; Chromosomes, Human, Pair 11; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; Hyperplasia; Immunohistochemistry; Ki-67 Antigen; Loss of Heterozygosity; Lymphatic Metastasis; Male; Middle Aged; Oligonucleotide Array Sequence Analysis; Parathyroid Glands; Parathyroid Neoplasms; Receptors, Calcium-Sensing

Tumorigenesis is a multistep process that involves a series of genetic changes or "multiple hits," leading to alterations in signaling, proliferation, immortalization, and transformation. Many of the molecular factors that govern tumor initiation and progression remain unknown. Here, we evaluate the transformation suppressor potential of caveolin-1 (Cav-1) and its ability to cooperate with a well established tumor suppressor, the INK4a locus. To study the effects of loss of caveolin-1 on cellular transformation, we established immortalized primary mouse embryonic fibroblasts (MEFs) expressing and lacking caveolin-1 by interbreeding Cav-1 (+/+) and Cav-1 (-/-) mice with INK4a (-/-) mice. Analysis of these cells reveals that loss of caveolin-1 confers a significant growth advantage, as measured via cellular proliferation and cell cycle analysis. Loss of caveolin-1 in the INK4a (-/-) genetic background results in constitutive hyperactivation of the p42/44 MAP kinase cascade, decreased expression of p21(Cip1), as well as cyclin D1 and PCNA overexpression, consistent with their hyperproliferative phenotype. Importantly, in cells lacking Cav-1 expression, transformation by activated oncogenes (H-Ras(G12V) or v-Src) results in increased tumor growth in vivo (up to >40-fold). Finally, INK4a (-/-)/Cav-1 (-/-) mice demonstrate disturbed mammary epithelial ductal morphology, with hyperplasia, increased side-branching, and fibrosis. Our results provide important new evidence for the transformation suppressor properties of Cav-1 and the first molecular genetic evidence that Cav-1 cooperates with a tumor suppressor, namely the INK4a genetic locus.

Topics: Animals; Blotting, Western; Caveolin 1; Caveolins; Cell Division; Cell Line, Transformed; Cell Transformation, Neoplastic; Cells, Cultured; Crosses, Genetic; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Disease Progression; Enzyme Activation; Epithelial Cells; Fibroblasts; Flow Cytometry; Gene Expression Regulation, Neoplastic; Genes, Reporter; Hyperplasia; Immunoblotting; Mammary Glands, Animal; Mice; Mice, Inbred C57BL; Mice, Nude; Mice, Transgenic; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Models, Genetic; Neoplasm Transplantation; Phenotype; Retroviridae; RNA, Messenger; Signal Transduction; src-Family Kinases; Time Factors

Heterogeneous nuclear ribonucleoprotein B1 (hnRNP B1), an RNA binding protein, is a useful marker for early detection of lung squamous cell carcinoma because it is overexpressed in the early stages of lung cancer, including bronchial dysplasia, a premalignant lesion of lung squamous cell carcinoma. In the case of adenocarcinoma, we investigated the utility of hnRNP B1 for both detection of early adenocarcinoma and discrimination of non-invasive lesion, atypical adenomatous hyperplasia (AAH) from adenocarcinoma. hnRNP B1, cyclin D1, p16, and Ki-67 were analyzed in lung adenocarcinoma tissues and divided into early and overt adenocarcinoma and AAH, using immunohistochemistry. The intensity of these molecular markers was compared among three groups and also analyzed for 4 patients who showed both adenocarcinoma and AAH. Thirty-six of 54 (67%) adenocarcinoma patients showed positive staining of hnRNP B1: 14/20 (70%) early adenocarcinoma and 22/34 (65%) overt adenocarcinoma. In contrast, overexpression of hnRNP B1 in non-invasive lesion, AAH was observed in only 9% (1/11). Overexpression of cyclin D1 and decrease of p16 were frequently observed in both adenocarcinoma and AAH. These results suggest that hnRNP B1 would be a candidate of molecular marker for detection of early lung adenocarcinoma. In addition, combined analysis of hnRNP B1 and cell cycle-related genes, such as cyclin D1 and p16, might aid in discrimination of AAH from early adenocarcinoma.

Topics: Adenocarcinoma; Aged; Biomarkers, Tumor; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Disease Progression; Female; Heterogeneous-Nuclear Ribonucleoprotein Group A-B; Humans; Hyperplasia; Immunoenzyme Techniques; Ki-67 Antigen; Lung; Lung Neoplasms; Male; Middle Aged; Neoplasm Proteins; Precancerous Conditions

Beta-catenin plays dual important roles in epithelial cell-cell adhesion in cytoplasm as well as in the nuclear T-cell factor (TCF)/lymphoid enhancing factor-1 (LEF-1) signaling pathway. Abnormal nuclear accumulation of beta-catenin promotes colorectal carcinogenesis by triggering the expression of cyclin D1 gene through the TCF/LEF-1 pathway. The purpose of this study was to investigate the possible involvement of the TCF/LEF-1 pathway in endometrial carcinogenesis.. Immunohistochemical localization of beta-catenin and cyclin D1 in normal endometrium, hyperplastic endometrium and endometrial carcinoma were assessed on serial tissue sections.. Nuclear accumulation of beta-catenin was observed in endometrial carcinomas compared with normal endometria. Cyclin D1-positive endometrial cancer cases were beta-catenin-positive in the nuclei, especially in 70% (7/10) of G1 and 55.6% (5/9) of G2 differentiated endometrial carcinomas, but never in G3 undifferentiated ones.. These results imply that the simultaneous nuclear accumulation of beta-catenin and cyclin D1--suggesting the activation of the TCF/LEF-1 pathway--may be a potential marker for the progression of Type 1 endometrial carcinogenesis.

Topics: Adult; Aged; beta Catenin; Cyclin D1; Cytoskeletal Proteins; Endometrial Neoplasms; Endometrium; Female; Humans; Hyperplasia; Immunohistochemistry; Middle Aged; Trans-Activators

Caveolin-1 is the principal protein component of caveolae membrane domains, which are located at the cell surface in most cell types. Evidence has accumulated suggesting that caveolin-1 may function as a suppressor of cell transformation in cultured cells. The human CAV-1 gene is located at a putative tumor suppressor locus (7q31.1/D7S522) and a known fragile site (FRA7G) that is deleted in a variety of epithelial-derived tumors. Mechanistically, caveolin-1 is known to function as a negative regulator of the Ras-p42/44 MAP kinase cascade and as a transcriptional repressor of cyclin D1, possibly explaining its transformation suppressor activity in cultured cells. However, it remains unknown whether caveolin-1 functions as a tumor suppressor gene in vivo. Here, we examine the tumor suppressor function of caveolin-1 using Cav-1 (-/-) null mice as a model system. Cav-1 null mice and their wild-type counterparts were subjected to carcinogen-induced skin tumorigenesis, using 7,12-dimethylbenzanthracene (DMBA). Mice were monitored weekly for the development of tumors. We demonstrate that Cav-1 null mice are dramatically more susceptible to carcinogen-induced tumorigenesis, as they develop skin tumors at an increased rate. After 16 weeks of DMBA-treatment, Cav-1 null mice showed a 10-fold increase in tumor incidence, a 15-fold increase in tumor number per mouse (multiplicity), and a 35-fold increase in tumor area per mouse, as compared with wild-type littermate mice. Moreover, before the development of tumors, DMBA-treatment induced severe epidermal hyperplasia in Cav-1 null mice. Both the basal cell layer and the suprabasal cell layers were expanded in treated Cav-1 null mice, as evidenced by immunostaining with cell-type specific differentiation markers (keratin-10 and keratin-14). In addition, cyclin D1 and phospho-ERK1/2 levels were up-regulated during epidermal hyperplasia, suggesting a possible mechanism for the increased susceptibility of Cav-1 null mice to tumorigenesis. However, the skin of untreated Cav-1 null mice appeared normal, without any evidence of epidermal hyperplasia, despite the fact that Cav-1 null keratinocytes failed to express caveolin-1 and showed a complete ablation of caveolae formation. Thus, Cav-1 null mice require an appropriate oncogenic stimulus, such as DMBA treatment, to reveal their increased susceptibility toward epidermal hyperplasia and skin tumor formation. Our results provide the first genetic evidence that caveolin-1 inde

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinogens; Caveolin 1; Caveolins; Cell Division; Cyclin D1; Epidermis; Hyperplasia; Immunohistochemistry; Keratinocytes; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Electron; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Neoplasms, Experimental; Phosphorylation; Skin; Time Factors; Up-Regulation

Alterations of cell cycle proteins contribute to the development and biological behaviour of malignant tumours. We evaluated the distribution and prognostic significance of immunohistochemically detected proteins p53, p21, Rb, and cyclin D1 in 101 laryngeal and hypopharyngeal squamous cell carcinomas (SCC) and adjacent epithelial hyperplastic lesions (EHL). Protein expression was correlated with tumour grade and stage. Varying patterns of protein expression were found in SCC. A significant correlation (p<0.05) was found between Rb expression and tumour grade. Different grades of EHL exhibited randomly distributed p53 and cyclin D1 positive cell clusters with no association to the pattern of their expression in SCC. Our study demonstrated derailment of cell cycle regulation in almost all cases of SCC of the larynx and hypopharynx. However, only cyclin D1 expression had an independent prognostic value for cancer-specific survival. The results also suggest that Rb gene inactivation, although rare, might be more important in the development of SCC than previously thought.

Topics: Adult; Aged; Aged, 80 and over; Carcinoma, Squamous Cell; Cell Cycle Proteins; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Enzyme Inhibitors; Female; Humans; Hyperplasia; Hypopharyngeal Neoplasms; Hypopharynx; Immunohistochemistry; Laryngeal Neoplasms; Larynx; Male; Middle Aged; Prognosis; Respiratory Mucosa; Retinoblastoma Protein; Tumor Suppressor Protein p53

UVB radiation is a complete carcinogen able to initiate, promote, and progress keratinocyte cells toward carcinogenesis. Exposure to UVB leads to the propagation of a number of signal transduction pathways resulting in increased DNA binding of transcription factors, including activator protein-1 (AP-1), and subsequent gene expression. To test the hypothesis that AP-1 activation plays a role in the promotion of UVB-induced skin tumors, a dominant negative c-jun (TAM67) mutant transgene was expressed in the epidermis of SKH-1 hairless mice and bred with mice expressing an AP-1 luciferase reporter gene. Single UVB exposure experiments showed a significant decrease in AP-1 activity, as measured by luciferase levels, in mice expressing TAM67 72 h postexposure. Transgenic and nontransgenic littermates were placed into a chronic UVB exposure experiment, three exposures per week for 25 weeks. Expression of TAM67 reduced the number of tumors per mouse by 58% and tumor sizes were 79% smaller than the tumors present in the nontransgenic study group. These tumors were histologically identified as squamous cell carcinomas. TAM67 had no effect on UVB-induced hyperplasia because comparable epidermal thickening was observed in both study groups over a 5-day period post-UVB exposure. Immunohistochemical analysis showed a reduction in the number of cyclin D(1)-expressing cells in squamous cell carcinoma samples removed from the TAM67 study group. These data show that TAM67 can inhibit UVB-induced squamous cell carcinoma formation, suggesting that AP-1 is a good candidate target for the development of new chemoprevention strategies to prevent sunlight-induced skin cancers.

Topics: Animals; Carcinoma, Squamous Cell; Cyclin D1; Disease Models, Animal; Genes, jun; Hyperplasia; Mice; Mice, Inbred Strains; Mice, Transgenic; Neoplasms, Radiation-Induced; Peptide Fragments; Proto-Oncogene Proteins c-jun; Reverse Transcriptase Polymerase Chain Reaction; Skin Neoplasms; Time Factors; Transcription Factor AP-1; Transgenes; Ultraviolet Rays

Diet plays an important role in promoting and/or preventing colon cancer; however, the effects of specific nutrients remain uncertain because of the difficulties in correlating epidemiological and basic observations. Transmissible murine colonic hyperplasia (TMCH) induced by Citrobacter rodentium, causes significant hyperproliferation and hyperplasia in the mouse distal colon and increases the risk of subsequent neoplasia. We have recently shown that TMCH is associated with an increased abundance of cellular beta-catenin and its nuclear translocation coupled with up-regulation of its downstream targets, c-myc and cyclin D1. In this study, we examined the effects of two putatively protective nutrients, calcium and soluble fibre pectin, on molecular events linked to proliferation in the colonic epithelium during TMCH. Dietary intervention incorporating changes in calcium [high (1.0%) and low (0.1%)] and alterations in fibre content (6% pectin and fibre-free) were compared with the standard AIN-93 diet (0.5% calcium, 5% cellulose), followed by histomorphometry and immunochemical assessment of potential oncogenes. Dietary interventions did not alter the time course of Citrobacter infection. Both 1.0% calcium and 6% pectin diet inhibited increases in proliferation and crypt length typically seen in TMCH. Neither the low calcium nor fibre-free diets had significant effect. Pectin diet blocked increases in cellular beta-catenin, cyclin D1 and c-myc levels associated with TMCH by 70%, whereas neither high nor low calcium diet had significant effect on these molecules. Diets supplemented with either calcium or pectin therefore, exert anti-proliferative effects in mouse distal colon involving different molecular pathways. TMCH is thus a diet-sensitive model for examining the effect of specific nutrients on molecular characteristics of the pre-neoplastic colonic epithelium.

Topics: Adhesins, Bacterial; Animals; beta Catenin; Calcium, Dietary; Carrier Proteins; Cell Division; Citrobacter rodentium; Colon; Cyclin D1; Cytoskeletal Proteins; Dietary Fiber; Escherichia coli Proteins; Hyperplasia; Mice; Pectins; Proto-Oncogene Proteins c-myc; Trans-Activators

The restriction of energy intake has documented beneficial effects on numerous diseases including cancer, yet the mechanism(s) that accounts for these effects is unknown. Recently, we showed that the inhibitory activity against mammary carcinogenesis mediated by energy restriction (ER) is accompanied by an increase in the secretion of adrenal cortical steroids. However, ER caused a concomitant reduction in circulating levels of insulin-like growth factor-1, which also may be involved in inhibiting carcinogenesis. To determine what cellular and molecular effects may be because of corticosterone per se, detailed mechanistic studies were performed in vitro using a mouse mammary hyperplastic cell line (TM10). The following questions were addressed: (a) is corticosterone-mediated growth inhibition accounted for by disruption of cell cycle machinery; (b) is growth inhibition accompanied by the induction of apoptosis; and (c) is growth inhibition reversible? At doses of corticosterone (50-200 micro M for 24-72 h) that resulted in inhibition (up to 76%; P < 0.001) of growth, a dose- and time-dependent G(1) arrest in cell cycle progression was observed. In the studies analyzing cell cycle regulatory molecules, corticosterone treatment of cells resulted in a strong induction (up to approximately 10-fold over control; P < 0.01) of KIP1/P27 together with a decrease (up to 98%; P < 0.01) in cyclin-dependent kinase 4 (CDK4) and cyclin D1 protein levels. Cells treated with corticosterone also showed an increased binding (up to 2.6-fold over control; P < 0.01) of KIP1/P27 with CDK4, together with a strong decrease (up to 89%; P < 0.01) in the kinase activity of the CDK4-cyclin D1 complex. Treatment of cells with KIP1/P27 antisense oligonucleotides reversed the growth inhibitory effects of corticosterone. Treatment of cells with RU 486, a glucocorticoid receptor blocker, reversed the effects of corticosterone on cell growth and KIP/P27 protein levels suggesting the involvement of the glucocorticoid receptor in accounting for these effects. Additional studies assessing the biological fate of cells after corticosterone treatment showed that corticosterone exerted reversible growth inhibitory effects with limited apoptotic cell death. Together, these findings show a reversible cytostatic effect of corticosterone via perturbations in cell cycle regulators causing a G(1) arrest in the absence of increased levels of apoptosis. These data provide evidence for a role of corticost

Topics: Animals; Cell Cycle; Cell Cycle Proteins; Cell Division; Corticosterone; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p27; Cyclin-Dependent Kinases; Energy Intake; Hyperplasia; Insulin-Like Growth Factor I; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mice; Mifepristone; Proto-Oncogene Proteins; Tumor Suppressor Proteins

Cyclin D1 and E2F-1 proteins are essential for the regulation of the G1/S transition through the cell cycle. Cyclin D1, a product of the bcl-1 gene, phosphorylates the retinoblastoma protein, releasing E2F-1, which in turn activates genes involved in DNA synthesis. Expression patterns of E2F-1 protein in thyroid proliferations have not been reported. This study used monoclonal antibodies for cyclin D1 and E2F-1 proteins to immunostain sections of normal thyroid, hyperplastic (cellular) nodules, follicular adenomas, follicular carcinomas, and papillary carcinomas. The proliferation rate was examined using an antibody specific for the Ki-67 antigen. Fluorescence in situ hybridization (FISH) methods and chromosome 11-specific probes were also employed to determine chromosome copy number and to assess for evidence of amplification at the 11q13 locus in papillary and follicular carcinomas with cyclin D1 overexpression. Concurrent overexpression of Ki-67, cyclin D1, and E2F-1 was found in the majority of benign and malignant thyroid lesions, compared with normal thyroid tissue. Cyclin D1 up-regulation was not due to extra copies of chromosome 11, or bcl-1 gene amplification. Malignant tumours showed the highest expression for all three markers, particularly papillary carcinomas. E2F-1 was detected at the same or slightly lower levels than cyclin D1. It was only found when cyclin D1 was overexpressed. Because cyclin D1 normally activates E2F-1, up-regulation of cyclin D1 may lead to E2F-1 overexpression in benign and malignant thyroid lesions.

Topics: Adenocarcinoma, Follicular; Adenoma; Carcinoma, Papillary; Cell Cycle Proteins; Cell Division; Cyclin D1; DNA-Binding Proteins; E2F Transcription Factors; E2F1 Transcription Factor; Humans; Hyperplasia; In Situ Hybridization, Fluorescence; Ki-67 Antigen; Neoplasm Proteins; Thyroid Gland; Thyroid Neoplasms; Transcription Factors

Verrucous carcinoma (VC) is a locally invasive, nonmetastasizing variant of squamous cell carcinoma (SCC) with distinct clinical and histologic features. Molecular alterations detectable by immunohistochemical analyses in VC have not been extensively studied. This study investigates the expression of p53, epidermal growth factor receptor (EGFR), transforming growth factor-alpha (TGF-alpha), and cyclin D1 in VC, verrucous hyperplasia (VH), and classic SCC of the head and neck. Twenty-six cases of VC, 12 cases of SCC of various differentiations, and 4 cases of VH were studied. Formalin-fixed, paraffin-embedded archival material was used for immunohistochemistry (avidin-biotin immunoperoxidase technique) to study the expression of oncogenes and their tumor markers. Identification of p53 protein was found in 100% of VH, 88% of VC, and 100% of SCC. EGFR expression was noted in 25% of VH, 54% of VC, 40% of well-differentiated SCC (WDSCC), and 100% of moderately and poorly differentiated SCC (MDSCC/PDSCC). TGF-alpha was detected in 25% of VH, 88% of VC, 80% WDSCC, and 100% of MDSCC/PDSCC. Cyclin-D1 expression was seen in 75% of VH, 35% of VC, 100% of WDSCC, 67% of MDSCC, and 50% of PDSCC. Correlation between the level of expression of all markers and the grade of this group of squamous lesions revealed statistically significant correlation coefficients for p53 and EGFR but not for TGF-alpha and cyclin D1.

Topics: Biomarkers, Tumor; Carcinoma, Squamous Cell; Carcinoma, Verrucous; Cell Differentiation; Cyclin D1; Epithelium; ErbB Receptors; Head and Neck Neoplasms; Humans; Hyperplasia; Immunohistochemistry; Transforming Growth Factor alpha; Tumor Suppressor Protein p53

Endometrioid carcinoma is often preceded by characteristic histopathologic lesions known as endometrial hyperplasia. Estrogen appears to be involved in the development of endometrioid carcinoma. Other mechanisms of endometrial carcinogenesis include mutations in p53 and PTEN tumor suppressor genes and overexpression of cyclin D1. However, the pattern of cyclin D1 expression is not well defined in normal, hyperplastic, neoplastic, and metaplastic endometrium.. Cyclin D1 immunohistochemical analysis was used to evaluate 108 fixed, paraffin-embedded endometrial biopsy specimens and uterine resections obtained from 108 patients. Specimens included proliferative and secretory endometria, simple and complex hyperplastic lesions, and endometrioid adenocarcinoma. Normal and metaplastic surface epithelia were also evaluated independently of glandular morphologic features.. Cyclin D1 was significantly overexpressed in glands with complex hyperplasia and endometrioid adenocarcinoma compared with proliferative or secretory endometrium and simple hyperplasia. Significant overexpression was also noted in papillary, syncytial, and squamous metaplasias compared with normal surface epithelium or epithelium with tubal metaplasia.. Overexpression of cyclin D1 increases from normal endometrium to hyperplasia and carcinoma, suggesting that it may play a role in endometrial carcinogenesis. Overexpression of cyclin D1 in endometrial glands was independent from overexpression of cyclin D1 in surface metaplastic epithelium.

Topics: Carcinoma, Endometrioid; Cell Nucleus; Cyclin D1; Endometrial Neoplasms; Endometrium; Female; Humans; Hyperplasia; Immunoenzyme Techniques; Metaplasia; Precancerous Conditions

To investigate tumorigenesis in the gastric hyperplastic polyp (HP), we evaluated 19 HPs with and 50 HPs without dysplasia (including carcinoma in situ), as compared with normal mucosa and fundic gland polyps. Helicobacter pylori density was highest in HPs without dysplasia. Apoptotic activity and Ki-67 and p53 expression also were higher in dysplasia in HPs than in normal mucosa, fundic gland polyps, or HPs themselves. The p21WAF1/CIP1 and cyclin D1 levels, in contrast, were highest in HPs. In HPs without dysplasia, size was correlated positively with the degree of stromal inflammation and with p53 and cyclin D1 expression. p53 and c-Ki-ras mutations were detected in 41% (8/19) and 5% (1/19) of dysplasia (including carcinoma in situ) in HPs. Our results demonstrate that the HP enlarges with enhanced cell turnover and overexpression of p53, p21WAF1/CIP1, and cyclin D1, associated with H pylori-related inflammation, and that p53 but not c-Ki-ras mutations may have an important role in dysplastic change in HPs.

Topics: Adult; Aged; Aged, 80 and over; Apoptosis; Carcinoma in Situ; Cell Transformation, Neoplastic; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; DNA, Neoplasm; Down-Regulation; Female; Helicobacter pylori; Humans; Hyperplasia; Immunoenzyme Techniques; Ki-67 Antigen; Male; Middle Aged; Mutation; Polymerase Chain Reaction; Polyps; Proto-Oncogene Proteins p21(ras); Stomach Neoplasms; Tumor Suppressor Protein p53

Activation of Akt by the phosphatidylinositol 3'-OH kinase (PI3K) results in the inhibition of proapoptotic signals and the promotion of survival signals (L. P. Kane et al., Curr. Biol. 9:601-604, 1999; G. J. Kops et al., Nature 398:630-634, 1999). Evidence supporting the importance of the PI3K/Akt signaling pathway in tumorigenesis stems from experiments with transgenic mice bearing polyomavirus middle T antigen under the control of the mouse mammary tumor virus long terminal repeat promoter. Mammary epithelium-specific expression of polyomavirus middle T antigen results in the rapid development of multifocal metastatic mammary tumors, whereas transgenic mice expressing a mutant middle T antigen decoupled from the phosphatidylinositol 3'-OH kinase (MTY315/322F) develop extensive mammary gland hyperplasias that are highly apoptotic. To directly assess the role of Akt in mammary epithelial development and tumorigenesis, we generated transgenic mice expressing constitutively active Akt (HAPKB308D473D or Akt-DD). Although expression of Akt-DD interferes with normal mammary gland involution, tumors were not observed in these strains. However, coexpression of Akt-DD with MTY315/322F resulted in a dramatic acceleration of mammary tumorigenesis correlated with reduced apoptotic cell death. Furthermore, coexpression of Akt-DD with MTY315/322F resulted in phosphorylation of the FKHR forkhead transcription factor and translational upregulation of cyclin D1 levels. Importantly, we did not observe an associated restoration of wild-type metastasis levels in the bitransgenic strain. Taken together these observations indicate that activation of Akt can contribute to tumor progression by providing an important cell survival signal but does not promote metastatic progression.

Topics: Animals; Antigens, Polyomavirus Transforming; Cell Survival; Cyclin D1; DNA-Binding Proteins; Enzyme Activation; Epithelium; Female; Forkhead Box Protein O1; Forkhead Transcription Factors; Hyperplasia; I-kappa B Proteins; Lung Neoplasms; Male; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mice; Mice, Transgenic; Phosphatidylinositol 3-Kinases; Phosphorylation; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Signal Transduction; Transcription Factors

Cyclin D1 is associated with cell cycle regulation and has more recently been shown to stimulate the transcriptional functions of the oestrogen receptor (ER). Furthermore, in normal breast there is a negative association between expression of ER and the proliferation marker Ki67 indicating that either ER positive cells are non-dividing or that the receptor is down-regulated as cells enter cycle. This important relationship breaks down in many ER-positive cancers and precancerous breast lesions where the receptor is often detected on proliferating cells. The aims of the present study were to determine the interplay between ER, Ki67 and cyclin D(1)in individual cells within the spectrum of human breast lesions ranging from normal to invasive carcinoma by using dual staining immunofluorescence. We found that in normal breast there was a strong positive association between ER and cyclin D(1)expression. In contrast there was a strong negative association between cyclin D(1)and Ki67 expression. Similar findings were seen for the other precancerous and cancerous breast lesions. Thus immunodetectable cyclin D(1)within individual cells does not appear to be associated with cell cycle progression in the benign or malignant breast but instead may have important interactions with ER.

Topics: Antibodies, Monoclonal; Antibody Specificity; Breast; Breast Neoplasms; Cyclin D1; Humans; Hyperplasia; Immunohistochemistry; Ki-67 Antigen; Mitosis; Neoplasm Invasiveness; Precancerous Conditions; Receptors, Estrogen

Post-initiation ethanol modification on N-nitrosomethylbenzylamine (NMBA)-induced rat esophageal carcinogenesis model was investigated in male, 6-week-old, F344 rats that received s.c. injections, 3 times per week, of 0.5 mg/kg NMBA for the first 5 weeks and then were treated with 0% (Group 1), 3.3% (Group 2), and 10% (Group 3) ethanol in the drinking water for up to 20 weeks. Group 4 received 10% ethanol without NMBA administration and Group 5 was maintained without any chemical treatment. There were no statistical differences in the incidence and multiplicity of esophageal tumors among Groups 1 to 3. However, the multiplicity of hyperplasias was statistically greater in Group 3 than in Groups 1 or 2. Esophageal epithelia of all rats in Groups 4 and 5 demonstrated a normal histology. BrdU labelling indices of tumors and hyperplasias in NMBA-treated groups were essentially similar, although cycline D1 was overexpressed to a greater extent in tumors and also hyperplasias of Group 3 than in Groups 1 or 2. The results indicated ethanol to exert weak promotion effects through cycline D1 overexpression on rat esophageal tumorigenesis initiated with NMBA.

Topics: Animals; Bromodeoxyuridine; Carcinogens; Cyclin D1; Dimethylnitrosamine; Disease Progression; Epithelium; Esophageal Neoplasms; Esophagus; Ethanol; Hyperplasia; Immunohistochemistry; Male; Rats; Rats, Inbred F344

The differentiation of neuronal cells in the developing mammalian retina is closely coupled to cell cycle arrest and proceeds in a highly organized manner. Cyclin D1, which regulates cell proliferation in many cells, also drives the proliferation of photoreceptor progenitors. In the mouse retina, cyclin D1 protein normally decreases as photoreceptors mature. To study the importance of the down-regulation of cyclin D1 during photoreceptor development, we generated a transgenic mouse in which cyclin D1 was persistently expressed in developing photoreceptor cells. We observed numerous abnormalities in both photoreceptors and other nonphotoreceptor cells in the retina of these transgenic mice. In particular, we observed delayed opsin expression in developing photoreceptors and alterations in their number and morphology in the mature retina. These alterations were accompanied by disorganization of the inner nuclear and plexiform layers. The expression of cyclin D1 caused excess photoreceptor cell proliferation and apoptosis. Loss of the p53 tumor suppressor gene decreased cyclin D1-induced apoptosis and led to microscopic hyperplasia in the retina. These findings are distinct from other mouse models in which the retinoblastoma gene pathway is disrupted and suggest that the IRBP-cyclin D1 mouse model may recapitulate an early step in the development of retinoblastoma.

Topics: Animals; Apoptosis; Cell Differentiation; Cell Division; Cyclin D1; Genes, p53; Hyperplasia; Immunohistochemistry; In Situ Nick-End Labeling; Mice; Mice, Inbred C57BL; Mice, Transgenic; Retina; Retinoblastoma; Transgenes

Overexpression of ornithine decarboxylase (ODC) has been shown to be characteristic of tumor development and progression in humans and experimental animals. Therefore, we have examined the effects of 1, 3-diaminopropane dihydrochloride (DAP), a potent inhibitor of ODC, on rat two-stage urinary bladder carcinogenesis initiated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). In experiment 1 (36 weeks), 6-week-old F344 male rats were administered 0.05% BBN in drinking water for 4 weeks and then divided into four groups. Animals of groups 1 and 2 received basal diet and drinking water supplemented with or without DAP (2 g/l). Groups 3 and 4 were given diet containing 5% sodium L-ascorbate (NaAsA), a typical urinary bladder tumor promoter, and drinking water with or without DAP. Administration of DAP to group 1 significantly reduced tumor size, multiplicity and incidence, particularly of papillomas, when compared with group 2 values. DAP together with NaAsA (group 3) also decreased tumor size relative to the group 4 case. To determine the effects of DAP on the early stages of bladder carcinogenesis and its mechanisms, a similar protocol was conducted (experiment 2) with death after 20 weeks. DAP treatment caused complete inhibition (0% incidence) of papillary and/or nodular hyperplasia in group 1 but was without influence in group 3, as compared with the respective controls. Moreover, the ODC activity, bromodeoxyuridine labeling indices and mRNA expression levels of cyclin D1 in the urinary bladder mucosa, determined by northern blotting, were markedly lower in group 1 than in group 2, but values were comparable for both groups administered NaAsA. Assessment of mRNA expression levels of the angiogenic vascular endothelial growth factor suggested no involvement in the inhibitory effects of DAP on urinary bladder carcinogenesis. The results indicate that inhibition of ODC could reduce urinary bladder carcinogenesis in rats, particularly in the early stages, through antiproliferative mechanisms.

Topics: Acetyltransferases; Animals; Anticarcinogenic Agents; Apoptosis; Ascorbic Acid; Butylhydroxybutylnitrosamine; Carcinogens; Carcinoma; Cocarcinogenesis; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinases; Diamines; Endothelial Growth Factors; Hydrogen-Ion Concentration; Hyperplasia; Lymphokines; Male; Ornithine Decarboxylase; Ornithine Decarboxylase Inhibitors; Papilloma; Polyamines; Proto-Oncogene Proteins; Rats; Rats, Inbred F344; RNA, Messenger; Urinary Bladder; Urinary Bladder Neoplasms; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

The cell cycle regulatory gene, Cyclin D1, plays a critical role in the growth and progression of several types of human cancer, including breast cancer. Immunohistochemical study of Cyclin D1 expression has been extensively reported in invasive ductal carcinoma (IDC). In contrast, there have been few reports concerning Cyclin D1 expression in ductal carcinoma in situ (DCIS) and their positive rates are variable. The differences in the reported frequency may be largely due to the differences in antibodies used, immunohistochemical methods and the positive cut-off point. However, we speculated that the strictness of diagnosis of DCIS might be somewhat responsible for these differences in frequency. Therefore, we selected cases of DCIS by carefully eliminating cases of predominantly intraductal carcinoma (PIC). Moreover, to clarify whether Cyclin D1 expression is involved in multistep carcinogenesis or the progression of human breast cancer, we immunohistochemically investigated Cyclin D1 expression in 57 DCIS, 10 atypical ductal hyperplasia (ADH), 70 usual ductal hyperplasia (UDH), 44 PIC and 92 IDC. Cyclin D1 expression was detected in 41 DCIS cases (72%), 22 PIC cases (50%) and 40 IDC cases (43%). No expression of Cyclin D1 was observed in either ADH or UDH. There were no significant correlations between Cyclin D1 expression and histological grade or estrogen receptor expression in DCIS. These results suggest that Cyclin D1 expression may play an important role in the early stages of carcinogenesis, and that immunohistochemical detection of Cyclin D1 expression may be helpful in differentiating low-grade DCIS from ADH.

Topics: Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Cyclin D1; Female; Fluorescent Antibody Technique, Indirect; Humans; Hyperplasia; Immunoenzyme Techniques; Lymph Nodes; Lymphatic Metastasis; Neoplasm Staging; Receptor, ErbB-2; Receptors, Estrogen; Tumor Suppressor Protein p53

Abstract. Hyperplasia of mesangial cells (MC) is a frequent finding in glomerulonephritis. The control and function of cyclin D1, a regulator of cell cycle progression, in MC proliferation in vivo and in vitro were investigated. In a rat model of mesangioproliferative glomerulonephritis, increases in the number of cyclin D1-positive MC nuclei were prominent on day 5 of the disease, preceding the peak of MC hyperplasia. In growth-arrested rat MC in culture, mitogenic stimulation with serum or platelet-derived growth factor (PDGF) led to rapid increases in cyclin D1 protein expression. Transforming growth factor-beta1 inhibited PDGF induction of cyclin D1 protein at 12 h. In an examination of the subcellular distribution of cyclin D1, it was observed that stimulation of MC with PDGF for 6 h caused translocation of cyclin D1 from the cytoplasm into the nucleus. Coincubation with PDGF and transforming growth factor-beta1 completely inhibited this effect, without altering the cellular cyclin D1 protein abundance at that time point. To test whether reduction of cyclin D1 protein levels was sufficient to inhibit mitogenesis, MC were transfected with antisense oligonucleotides (ODN) complementary to rat cyclin D1 mRNA. Antisense ODN against cyclin D1 reduced the serum- or PDGF-induced protein expression of cyclin D1 to 27 or 10% of control levels, respectively. These inhibitory effects were correlated with diminished cyclin-dependent kinase 4 activity. Antisense ODN against cyclin D1 also decreased the PDGF-induced increase in p21(Waf-1) protein levels. The MC proliferation caused by serum or PDGF was markedly inhibited by antisense ODN against cyclin D1, as measured by [(3)H]thymidine uptake and cell counts. It is concluded that increased cyclin D1 protein expression of MC is required for MC proliferation. Targeting cyclin D1 expression may represent an effective means to inhibit MC proliferation in vitro and in vivo.

Topics: Animals; Biological Transport; Cattle; Cell Nucleus; Cells, Cultured; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinases; Cyclins; DNA; Fetal Blood; Glomerular Mesangium; Glomerulonephritis, Membranoproliferative; Hyperplasia; Male; Mitosis; Oligonucleotides, Antisense; Platelet-Derived Growth Factor; Proto-Oncogene Proteins; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

Breast cancer is probably the result of a series of genetic events, each with its own histopathologic correlate in the hyperplasia to carcinoma sequence. The expression of breast cancer markers in hyperplasia and tumors are well known, but few studies have investigated their sequential expression among hyperplastic and cancerous lesions within the same breast. Using breast tissue obtained from a single procedure, we correlated the immunohistochemical expression of several breast cancer markers with the histopathologic stage of proliferative breast disease. We selected 14 cases in which various degrees of hyperplasia coexisted with carcinoma. Serial sections were reacted with antibodies to DF3, c-erbB-2, p53 (DO7 and CM1), B72.3, and cyclin D1. We found that within an individual breast, the number of breast cancer markers expressed increased with progression from hyperplasia to atypical hyperplasia to carcinoma. Cytoplasmic DF3 was first expressed at the level of simple hyperplasia, followed by c-erbB-2 in atypical hyperplasia. Overexpression of p53 was confined to carcinomas, and thus appeared to be a late event. B72.3 was expressed in three carcinomas and in one atypical hyperplasia, although the associated carcinoma was negative. Carcinomas that expressed cytoplasmic DF3 and c-erbB-2 were associated with atypical hyperplasias that also expressed cytoplasmic DF3 and c-erbB-2, with one and two exceptions, respectively. No specific cyclin D1 staining pattern was observed.

Topics: Antibodies; Antigens, Neoplasm; Biomarkers, Tumor; Breast; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Carcinoma, Lobular; Cyclin D1; Female; Glycoproteins; Humans; Hyperplasia; Immunohistochemistry; Receptor, ErbB-2; Tumor Suppressor Protein p53

Hyperplasia of mesangial cells (MCs) is a frequent finding in glomerulonephritis. Heat shock protein 90 (HSP90) is a major cellular chaperone that assists protein folding under physiological and stress conditions.. To identify genes that are potentially involved in the pathogenesis of glomerulonephritis, we analyzed glomerular gene expression in mesangioproliferative rat anti-Thy1.1 nephritis by representational difference analysis (RDA). Expression of HSP90beta in anti-Thy1.1 nephritis was studied by Northern and Western blot analyses and immunohistochemistry. In cultured rat MCs, the requirement of HSP90 for mitogenic signaling steps and MC replication was studied by incubation with the specific HSP90 inhibitor geldanamycin.. By RDA, a cDNA fragment homologous to HSP90beta was identified. Glomerular mRNA and protein expression of HSP90beta was markedly and transiently up-regulated during the course of anti-Thy1.1 nephritis, with a maximum at day 6, coinciding with the peak of MC proliferation. By immunohistochemistry, HSP90beta expression in normal glomeruli was detected in podocytes. However, in anti-Thy1.1 nephritis, glomerular HSP90beta protein expression was strongly and transiently increased in mesangial localization. In vitro, mitogenic stimulation of rat MCs led to the induction of HSP90beta mRNA and protein. Incubation of MCs with geldanamycin dose-dependently inhibited DNA synthesis and replication. Moreover, geldanamycin interfered with mitogen-induced phosphorylation of extracellular signal-regulated kinase and transcription of c-fos and Egr-1, but not with transactivation of STAT1 transcription factor. Cell cycle analysis of serum-stimulated MCs revealed that geldanamycin inhibited kinase activity of cyclin D1/CDK4 complexes and blocked progression in the G0/G1 phase and at the S/G2 phase transition.. The up-regulation of HSP90beta in anti-Thy1.1 nephritis may reflect its functional involvement in phenotypical alterations of MCs in mesangioproliferative glomerulonephritis. Our in vitro studies indicate that HSP90 governs the capacity of MCs to respond to proliferative stimuli by regulating critical mitogenic signaling steps necessary for G1 entry and S-phase progression.

Topics: Animals; Antibodies; Benzoquinones; Blood Proteins; Cell Division; Cells, Cultured; Cicatrix; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinases; DNA-Binding Proteins; Dose-Response Relationship, Drug; Enzyme Inhibitors; G1 Phase; G2 Phase; Gene Expression; Glomerular Mesangium; Glomerulonephritis; HSP90 Heat-Shock Proteins; Hyperplasia; Lactams, Macrocyclic; Male; Mitogen-Activated Protein Kinases; Protein Folding; Proto-Oncogene Proteins; Quinones; Rats; Rats, Sprague-Dawley; Resting Phase, Cell Cycle; RNA, Messenger; S Phase; STAT1 Transcription Factor; Thy-1 Antigens; Trans-Activators

In primary hyperparathyroidism, certain genetic abnormalities responsible for parathyroid tumorigenesis are proposed, and it has been reported that the overexpression of PRAD1/cyclin D1 induced by a DNA rearrangement of the parathyroid hormone (PTH) gene is one of the genetic disorders in a number of primary parathyroid adenomas. However, in secondary hyperparathyroidism caused by uremia, the mechanism of monoclonal proliferation in nodular parathyroid hyperplasia is not well understood. To elucidate the mechanism, we examined the expression of PRAD1/cyclin D1, retinoblastoma gene products, and Ki67 in primary adenoma and secondary hyperplasia.. In adenomas (N = 15) and associated glands (N = 7) with normal histology obtained from patients with primary hyperparathyroidism and in diffuse (N = 14), multinodular (N = 58), and single nodular (N = 28) glands from patients who underwent parathyroidectomy for renal hyperparathyroidism, the expression of these cell cycle regulators was evaluated by immunohistochemical technique. A labeling index was used to define the proportion of cells with positive nuclear staining by each antibody.. In 6 out of 15 (40%) primary adenomas, PRAD1/cyclin D1 was overexpressed (a labeling index of more than 500), possibly because of the PTH gene rearrangement, but not in secondary hyperplasia, including single nodular glands. Compared with diffuse hyperplasia, nodular hyperplasia showed a significantly higher expression of PRAD1/cyclin D1 (P < 0.05), retinoblastoma gene products (P < 0.05), and Ki67 (P < 0.05). However, no statistically significant correlation between the expression of PRAD1/cyclin D1 and that of Ki67 was observed in both primary adenoma and secondary hyperplasia.. These results suggest that in secondary hyperplasia caused by uremia, at least remarkable overexpression of PRAD1/cyclin D1 induced by PTH gene rearrangement may be not the major genetic abnormality responsible for tumorigenesis. Heterogenous genetic changes seem to contribute to monoclonal proliferation of parathyroid cells induced by the expression of PRAD1/cyclin D1 or by some other mechanism independent of the amplification of the proto-oncogene.

Topics: Adenoma; Biomarkers, Tumor; Cell Nucleus; Cyclin D1; Humans; Hyperplasia; Immunohistochemistry; Ki-67 Antigen; Kidney Failure, Chronic; Middle Aged; Parathyroid Glands; Parathyroid Neoplasms; Proto-Oncogene Mas; Retinoblastoma Protein

In this study, we assessed the frequency of cyclin D1 protein expression in normal and neoplastic parathyroid tissue (10 parathyroid carcinomas, 28 adenomas, 18 hyperplasias, and 32 normal parathyroid glands) with use of a monoclonal anticyclin D1 antibody and a heat-induced epitope retrieval method. Overexpression of cyclin D1 was identified in 10 (91%) of 11 biopsy specimens from 10 patients with parathyroid carcinomas and in 11 (39%) of 28 parathyroid adenomas. In addition, 11 (61%) of 18 cases of parathyroid hyperplasia also expressed cyclin D1 protein, an observation not reported previously. These results confirm the high frequency of cyclin D1 expression in parathyroid carcinomas and adenomas. In addition, the results of this study indicate that overexpression of cyclin D1 protein is not limited to neoplastic proliferations of parathyroid tissue but is also seen in non-neoplastic proliferations of parathyroid gland. Cyclin D1 protein expression was rarely (<6%) present in normal parathyroid tissue.

Topics: Adenoma; Adult; Aged; Aged, 80 and over; Biopsy; Cyclin D1; Female; Humans; Hyperplasia; Immunohistochemistry; Male; Middle Aged; Parathyroid Glands; Parathyroid Neoplasms

Cyclin D1 is a cell cycle regulator which is overexpressed in a variety of human cancers. We examined overexpression of cyclin D1 in several stages of rat colorectal carcinogenesis induced by azoxymethane (AOM) treatment. The level of cyclin D1 in 13 aberrant crypt foci (ACF) (atypical hyperplasias), 22 colorectal tumors (14 non-invasive adenocarcinomas and eight invasive adenocarcinomas) was assessed by immunostaining using a polyclonal antibody. Cell proliferation of these samples was investigated by measurement of 5-bromo-2'-deoxyuridine-labeling index. Indices of cyclin D1-positive cells in adenocarcinomas and atypical hyperplasias were significantly higher than that in normal crypts (P < 0.05). Moreover, cyclin D1-positive rates in the two types of adenocarcinomas were significantly higher than that in atypical hyperplasias (P < 0.05). Staining of nuclear cyclin D1 was very strong in almost all adenocarcinomas and four ACF. Comparisons of BrdU-positive indices in colorectal lesions showed similar results to the cyclin D1-positive indices. These results suggested that overexpession of cyclin D1 occurs early in the multistep carcinogenesis, and plays an important role in rat colorectal carcinogenesis.

Topics: Adenocarcinoma; Animals; Azoxymethane; Bromodeoxyuridine; Cell Division; Cell Nucleus; Colorectal Neoplasms; Cyclin D1; Cytoplasm; Gene Expression; Hyperplasia; Intestinal Mucosa; Male; Rats; Rats, Inbred F344; Time Factors

To clarify the events leading to the disruption of cell growth control that occurs during the development of pulmonary adenocarcinoma (AC), we used immunohistochemistry to evaluate the expression of G1 cycle regulators, cyclin D1, Rb protein (pRb), and p16 MTS1 protein and the tumour proliferation marker, Ki 67, both in AC of the lung and in its precursor lesion, atypical adenomatous hyperplasia (AAH). The frequency of lesions with cyclin D1 overexpression was relatively high in AAH (47-89%), but was decreased in early AC (28%) and overt AC (35%). The loss of pRb expression was rare in both AAH (0-18%) and early AC (0%), and was infrequent even in overt AC (13%). The loss of p16 expression was also relatively infrequent in both the premalignant and the malignant lesions (11-25%). Our results suggest that overexpression of cyclin D1 is an early event and plays an important part in tumorigenesis in the case of lung AC. However, cyclin D1 overexpression is not required for the development and maintenance of a malignant phenotype. It is likely that some cyclin D1-independent pathways other than Rb and p16 abnormalities have an important role in the malignant transformation from AAH to early AC.

Topics: Adenocarcinoma; Adenoma; Adult; Aged; Aged, 80 and over; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Female; Humans; Hyperplasia; Immunohistochemistry; Ki-67 Antigen; Lung; Lung Neoplasms; Male; Middle Aged; Retinoblastoma Protein

The cell cycle regulatory gene cyclin D1 is a candidate oncogene in breast cancer. It is overexpressed in 30-50% of invasive primary breast cancers and plays a key role in mediating mitogenic responses to steroids and growth factors in breast cancer cells in vitro. Because the role of cyclin D1 in the proliferative and early noninvasive stages of breast cancer is largely unknown, we examined normal breast epithelium (NBE), proliferative disease (PD), ductal carcinoma in situ (DCIS), and invasive carcinoma (IC) to evaluate the timing and possible importance of cyclin D1 expression in the development of breast cancer. Using immunohistochemistry, we examined cyclin D1 protein expression in 471 breast tissue samples. A quantitative scoring system for immunohistochemistry based on percentage of positive cells was developed that correlated with Western blot analysis of antigen concentration in paired samples (r2 = 0.91, P = 0.003). A sample was considered positive if >5% of relevant epithelial cells demonstrated nuclear staining. Cyclin D1 positivity was observed in 11.7% (7 of 60) samples of NBE, 25% (11 of 44) of PD without atypia, 39.4% (13 of 33) of atypical ductal hyperplasia, 43.6% (17 of 39) of low-grade DCIS, 47.9% (23 of 48) of high-grade DCIS, and 48.3% (99 of 205) of IC. Cyclin D1 expression was significantly higher in PD than NBE (P = 0.006) and in DCIS than PD (P = 0.038). There was no significant increase from DCIS to IC (P = 0.52). The increase in cyclin D1 expression in the overall progression from NBE to IC was also highly significant (P = 0.0001). Therefore, cyclin D1 expression was detected at levels significantly greater than in NBE in the earliest proliferative epithelial lesions of the breast with a further significant increase accompanying the progression to any form of cancer. This suggests that overexpression of cyclin D1 protein is important at the earliest stages of breast oncogenesis and continues to have a crucial role throughout the development of malignancy.

Topics: Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Cyclin D1; Female; Humans; Hyperplasia; Neoplasm Proteins; Tumor Cells, Cultured

Experimental studies suggest that cyclin D1 is a potential oncogene but in clinical studies of invasive breast cancer, overexpression of cyclin D1 is found to be associated with oestrogen receptor (ER) expression and low histological grade, both markers of good prognosis. Immunohistochemistry has been used to examine the relationship between cyclin D1 expression and differentiation in 36 cases of ductal carcinoma in situ (DCIS) and the interrelationship between expression of cyclin D1, its associated protein product of the retinoblastoma gene (pRb), and ER, in this group of cases. The expression of these markers has also been examined in nine cases of atypical ductal hyperplasia (ADH) and these results have been compared with the levels of expression seen in DCIS. Cyclin D1 overexpression was found in 23/36 (64 per cent) cases of DCIS and, in contrast to invasive carcinoma, there was no relationship with either differentiation or ER expression. The level of pRb expression was significantly associated with cyclin D1 expression (rS = 0.49, P = 0.001) and only two cases (6 per cent) were pRb-negative. There was no association between pRb and differentiation of DCIS or ER status. In contrast to DCIS, only one case of ADH showed overexpression of cyclin D1 (Mann-Whitney U-test, P = 0.02). All cases of ADH were ER-positive and showed moderate pRb staining, similar to that seen in well-differentiated DCIS. These results provide further evidence that overexpression of cyclin D1 plays a role early in carcinogenesis.

Topics: Adult; Aged; Aged, 80 and over; Breast; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Cyclin D1; Female; Humans; Hyperplasia; Immunoenzyme Techniques; Middle Aged; Neoplasm Proteins; Precancerous Conditions; Receptors, Estrogen; Retinoblastoma Protein

Expression of proliferation- and apoptosis-related proteins was studied by immunohistochemistry in 130 usual ductal hyperplasias of the breast, of which 39 cases (30%) had adjacent invasive cancer. Overexpression of cyclin D1 and Ki-67 was found in 6% and 29% of the cases, respectively. Only two mild ductal hyperplasias were Her-2/neu positive. Overexpression of p21 and reduced expression of p27, both cdk-inhibitors, was seen in 16% and 27% of the lesions, respectively. Reduced expression of bcl-2 was found in 16% of the cases, and p53 accumulation was present in 8%. Expression of six of the seven studied proteins showed no significant difference between mild, moderate, or florid ductal hyperplasias, indicating that there are no important cell biological differences with regard to the studied proteins between the lesions within this morphologically continuous spectrum. In addition, there were no differences between lesions with and without an invasive component. Cyclin D1 positivity was exclusively seen in lesions with 75% or more p27-positive nuclei. No significant correlations were found between other proteins. Twenty-three of 91 lesions (25%) had multiple events, of which five showed altered expressions of three or four proteins. In conclusion, altered protein expression of several proliferation- and apoptosis-related genes that are known to be involved in invasive breast cancer also may be found in usual ductal hyperplastic lesions, including several lesions with multiple events. This implies that usual ductal hyperplastic lesions may be among the earliest lesions within the breast oncogenetic spectrum.

Topics: Apoptosis; Biomarkers, Tumor; Breast; Carcinoma, Ductal, Breast; Cell Cycle Proteins; Cell Division; Cyclin D1; Epithelial Cells; Female; Gene Products, rex; Humans; Hyperplasia; Immunoenzyme Techniques; Ki-67 Antigen; Oncogene Protein p21(ras); Proto-Oncogene Proteins c-bcl-2; Receptor, ErbB-2; Tumor Suppressor Protein p53

Previous studies showed that intratracheal instillation of endotoxin induces transient type II cell hyperplasia in the rat lung and described some of the mechanisms involved in the proliferative response of type II cells. The purpose of the present study was to investigate how long the type II cell hyperplasia persists and how it is resolved. The portion of epithelial cells in hyperplastic lesions of the rat lung expressing cyclin D1, an indicator for cells in the G1 phase of the cell cycle, was greatest at 3 d post instillation and decreased after 4 and 6 d. The fate of the proliferating epithelial cells was traced by injecting the rats with 5-bromo-2' deoxy uridine (BrdU) 2 d post instillation, the peak time point for maximum incorporation of BrdU. Exfoliated BrdU-positive epithelial cells were detected in the alveolar spaces in tissue sections from rats 4, 5, and 6 d post instillation. BrdU-positive epithelial cells showed flattened nuclei at 6 and 10 d post instillation. Expression of the 116 kD poly(ADP-ribose) polymerase (PARP) was low in type II cells from control rats, and was increased at 3, 4, and 6 d post instillation. In cells obtained by lavage, only a 35 kD cleavage product of PARP was detected, which is an indicator of necrotic cell death. In isolated type II cells from rats 3, 4, and 6 d post endotoxin instillation, progressive cleavage of the PARP to its 89 kD residual fragment was detected, which is a direct evidence for the activation of caspases. Furthermore, apoptotic epithelial cells with condensed nuclei were identified by electron microscopy in rats 4 d post instillation. These results indicate that apoptosis is an additional mechanism for the resolution of endotoxin-induced lung epithelial hyperplasias.

Topics: Animals; Apoptosis; Blotting, Western; Cell Division; Cyclin D1; Epithelium; Hyperplasia; Lipopolysaccharides; Male; Pulmonary Alveoli; Rats; Rats, Inbred F344

Tumours develop through the accumulation of genetic alterations associated with a progressive increase of the malignant phenotype. In lung cancer, chronic exposure of bronchial epithelium to carcinogens in cigarette smoke may lead to multiple dysplastic and hyperplastic lesions scattered throughout the tracheobronchial tree. Little is known about the genetic alterations in such lesions. This study was carried out to examine cyclin D1 (CCND1) and retinoblastoma (RB1) gene expression in the bronchial epithelium of patients with lung cancer. Lung tumours and their corresponding tumour-free resection margins from 33 patients who underwent resection of non-small-cell lung cancer (NSCLC) were examined by immunostaining with monoclonal antibodies against cyclin D1 (DCS-6; Novocastra) and pRb (NCL Rb-1; Novocastra). Examination of the resection margins revealed four carcinomas in situ, 19 hyperplasias and ten sections showing apparently normal bronchial epithelium. A control group of patients, without lung tumours and who had never smoked, revealed no or weak cyclin D1 and positive pRb staining within bronchial epithelia. Increased cyclin D1 and diminished pRb expression were found in 76% (n = 25) and 27% (n = 9) of the resection margins respectively, and in 12% (n = 4) both cyclin D1 and pRb expression were altered. In the corresponding tumours, 48% (n = 16) were normal, while altered expression was found for cyclin D1 in 33% (n = 11), pRb in 27% (n = 9) and both in 9% (n = 3) of cases. It appears that altered expression of cyclin D1 and pRb is an early event in NSCLC development in almost half of cases analysed. Further investigations are needed to determine the significance of immunostaining of bronchial specimens in individuals at risk of lung cancer, with the possibility that the observations are of importance in the early diagnosis of NSCLC.

Topics: Adult; Aged; Antibodies, Monoclonal; Biomarkers, Tumor; Carcinoma in Situ; Carcinoma, Non-Small-Cell Lung; Cyclin D1; Cyclins; Data Interpretation, Statistical; Epithelium; Female; Genes, Retinoblastoma; Humans; Hyperplasia; Immunohistochemistry; Lung; Lung Neoplasms; Male; Middle Aged; Oncogene Proteins; Prognosis; Staining and Labeling

Squamous carcinoma of the larynx arises from pre-existing lesions, the so-called "preneoplastic lesions". Hyperplastic lesions represent a part of their spectrum, from both clinical and biological points of view. On morphologic grounds, the most characteristic feature with prognostic value in the evaluation of preneoplastic lesions is dysplasia. It is not only nuclear alterations that are seen in the process of malignant transformation, the cytoplasmic pattern of cytokeratins changes through neoplastic progression, with a progressive reduction of the molecular weight of the produced species. Dysplasia also associates with gross alterations of the DNA content. This is in agreement with our finding of alterations of genes participating in the control of the cell cycle, p53 and p21(WAF1/cip1). p53 overexpression is detected in non-invasive squamous lesions (even in the absence of obvious dysplasia) and p21(WAF1/cip1) shows a dramatic change in the pattern of expression in dysplastic epithelium compared with the normal. However, not all genes participating in the control of the cell cycle are altered in early lesions. Overexpression of cyclin D1, a common phenomenon in advanced carcinomas, is not likely to participate in the early phases of neoplastic development.

Topics: Biomarkers, Tumor; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Cyclin D1; Cyclin-Dependent Kinases; Cyclins; DNA, Neoplasm; Epithelium; Genes, p53; Humans; Hyperplasia; Keratins; Laryngeal Diseases; Laryngeal Mucosa; Laryngeal Neoplasms; Oncogene Proteins; Precancerous Conditions

Overexpression of cyclin D1 has been implicated in the malignant transformation of a variety of human cancers, including urinary bladder carcinomas. However, few reports have addressed the significance of cyclin D1 overexpression in chemical carcinogenesis in rodents. In the present study, we evaluated the oncogenic potential of cyclin D1 in experimental rat urinary bladder carcinogenesis and its relationships to the oncogenes cyclin E, K-ras, and H-ras as well as tumor suppressor genes p53 and p21WAF1/Cip1. In addition, proliferation status of preneoplastic lesions and tumors was assessed by proliferating cell nuclear antigen immunohistochemistry. Fisher 344 rats were initiated with 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine in the drinking water for 4 weeks and then administered 5% sodium L-ascorbate in diet. Animals were sacrificed at weeks 4, 8, 12, 18, and 24. Preneoplastic lesions such as papillary or nodular hyperplasia and neoplastic lesions of the urinary bladder were observed during carcinogenesis. By immunohistochemical examination, overexpression of cyclin D1 protein was observed in 17% of papillary or nodular hyperplasias, 66% of papillomas, and 69% of transitional cell carcinomas, whereas nuclear accumulation of p53 was observed in none of the preneoplastic lesions and in fewer than 2% of transitional cell carcinomas. Overexpression of cyclin D1 in preneoplastic lesions and tumors was not dependent on the size of the tumors or their proliferation status. Quantitation of mRNA in tumors by multiplex reverse transcription-PCR showed that average mRNA expression of cyclin D1 and cyclin E was increased, whereas average p21WAF1/Cip1 mRNA expression was decreased. More than 2-fold overexpression of cyclin D1 mRNA was observed in 50 and 60% of tumors at weeks 18 and 24, respectively. Localization of cyclin D1 mRNA expression was demonstrated by in situ hybridization, and the results were comparable to immunohistochemistry findings. None of the 25 tumors we examined by PCR-single-strand conformational polymorphism analysis harbored p53 mutations, H-ras mutations, or K-ras mutations. Thus, during the promotion phase of two-stage bladder carcinogenesis, overexpression of cyclin D1 in tumor cells may provide yet another mechanism by which tumors can gain a growth advantage. In contrast, tumors with mutated p53 may not have a growth advantage. Our results suggest that overexpression of cyclin D1 plays a critical role during urinary bladder carcinogenesi

Topics: Animals; Ascorbic Acid; Butylhydroxybutylnitrosamine; Carcinogens; Carcinoma, Transitional Cell; Cell Nucleus; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Hyperplasia; Male; Neoplasm Proteins; Papilloma; Precancerous Conditions; Proliferating Cell Nuclear Antigen; Rats; Rats, Inbred F344; RNA, Messenger; Tumor Suppressor Protein p53; Urinary Bladder; Urinary Bladder Neoplasms

To study the involvement of cyclin D1 in epithelial growth and differentiation and its putative role as an oncogene in skin, transgenic mice were developed carrying the human cyclin D1 gene driven by a bovine keratin 5 promoter. As expected, all squamous epithelia including skin, oral mucosa, trachea, vaginal epithelium, and the epithelial compartment of the thymus expressed aberrant levels of cyclin D1. The rate of epidermal proliferation increased dramatically in transgenic mice, which also showed basal cell hyperplasia. However, epidermal differentiation was unaffected, as shown by normal growth arrest of newborn primary keratinocytes in response to high extracellular calcium. Moreover, an unexpected phenotype was observed in the thymus. Transgenic mice developed a severe thymic hyperplasia that caused premature death due to cardio-respiratory failure within 4 months of age. By 14 weeks, the thymi of transgenic mice increased in weight up to 40-fold, representing 10% of total body weight. The hyperplastic thymi had normal histology revealing a well-differentiated cortex and medulla, which supported an apparently normal T-cell developmental program based on the distribution of thymocyte subsets. These results suggest that proliferation and differentiation of epithelial cells are under independent genetic controls in these organs and that cyclin D1 can modulate epithelial proliferation without altering the initiation of differentiation programs. No spontaneous development of epithelial tumors or thymic lymphomas was perceived in transgenic mice during their first 8 months of life, although they continue under observation. This model provides in vivo evidence of the action of cyclin D1 as a pure mediator of proliferation in epithelial cells.

Topics: Aging; Animals; Base Sequence; Body Weight; Cattle; Cell Division; Crosses, Genetic; Cyclin D1; Cyclins; DNA Primers; Epidermis; Epithelium; Female; Humans; Hyperplasia; Immunohistochemistry; Keratins; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Inbred Strains; Mice, Transgenic; Molecular Sequence Data; Oncogene Proteins; Organ Size; Polymerase Chain Reaction; Promoter Regions, Genetic; Restriction Mapping; T-Lymphocyte Subsets; T-Lymphocytes; Thymus Gland; Vagina

Deregulated expression of G1 cyclins D1 and D2 is a feature of some neoplasias. This study examined the altered expression of D1 and D2 cyclins, both the total pool and as associated with cdk4 and cdk2, at different stages of mouse mammary tumorigenesis. Three different mammary hyperplastic outgrowth lines, TM2, TM10 and TM12, and their respective tumors were examined. Increasing levels of the cyclin D1 protein pool, D1 binding to cdk4 and cdk2 and cdk4 kinase activity were closely correlated with tumorigenesis. In constrast, cyclin D2 binding to cdk4 was predominant in hyperplasias and much less in tumors, where cyclin D1 became predominant. However, the cyclin D2 pool showed increases of 15-65 times in hyperplasias compared with normal gland and further increases of 11-15 times in two of three different tumors. The message level for cyclin D1 increased only 2-3 times in tumors compared with normal gland. Cyclin D2 mRNA was highest in normal tissue and decreased only marginally in tumors. These results suggest that cyclin D2 functions uniquely from cyclin D1 in the early stages of mouse mammary tumor development. Cyclin D2 bound to cdk4 may act to guarantee a low level of kinase activity in hyperplasias and may be an attempt to direct the mammary epithelial cells through differentiation rather than proliferation. This interaction may be one of the negative regulatory mechanisms in the early stages in mouse mammary tumor development, until cyclin D1 totally replaces cyclin D2 binding to cdk4, which would activate the high levels of cdk4 kinase activity observed in neoplasias.

Topics: Animals; Cell Cycle; Cell Transformation, Neoplastic; Cyclin D1; Cyclin D2; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinases; Cyclins; Female; Hyperplasia; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Oncogene Proteins; Precancerous Conditions; Pregnancy; Protein Binding; Proto-Oncogene Proteins

Patients with benign breast biopsies that exhibit atypical epithelial proliferation or fibroadenoma may be at increased risk for invasive breast cancer. We hypothesized that molecular markers might also be useful to evaluate the malignant potential of nonneoplastic breast tissue.. Study subjects belonged to a cohort of 6,805 women who underwent biopsy for nonmalignant breast disease at the Mayo Clinic and Rochester-affiliated hospitals between 1967 and 1981. As part of a nested case-control study that compared subjects who developed invasive breast cancer with those who did not, we analyzed a sample of 60 benign breast biopsies for the following markers: HER-2/neu and p53 over-expression by immunohistochemistry, HER-2/neu and PRAD-1 amplification using differential polymerase chain reaction (PCR), and p53 mutation using single-strand conformation analysis (SSCA) and direct DNA sequencing by asymmetric PCR.. None of 60 biopsies showed amplification of HER-2/neu or PRAD-1. Five samples exhibited low-level immunoreactivity to the HER-2/neu protein product. Fourteen samples exhibited focal or diffuse immunoreactivity to the p53 protein. Point mutations in the p53 gene were found in five samples: three of these samples exhibited mutations that altered the amino acid sequence. Only two of five samples with p53 mutation exhibited p53 overexpression. Histologic diagnoses on three samples with nonconservative p53 mutation were, respectively, nonproliferative fibrocystic change, papillomatous hyperplasia, and fibroadenoma.. The clinical significance of p53 mutation, p53 overexpression, and low-level HER-2/neu expression in benign breast tissue remains to be determined. Further research will be necessary to evaluate whether these markers could serve as useful adjuncts to histology in evaluation of the malignant potential of benign breast tissue.

Topics: Base Sequence; Biopsy; Breast Diseases; Breast Neoplasms; Case-Control Studies; Cyclin D1; Cyclins; DNA Mutational Analysis; Female; Fibroadenoma; Fibrocystic Breast Disease; Gene Amplification; Genes, p53; Humans; Hyperplasia; Immunohistochemistry; Molecular Sequence Data; Oncogene Proteins; Point Mutation; Polymerase Chain Reaction; Polymorphism, Single-Stranded Conformational; Receptor, ErbB-2; Tumor Suppressor Protein p53

Abnormal expression of cell-cycle regulatory proteins, particularly cyclin D1, has been described in human cancers. However, there are few reports of this kind in experimental carcinogenesis models, which provide a framework to analyze the importance of those alterations in early cancer development. Previous studies from our laboratory showed that cyclin D1 mRNA was overexpressed in skin tumors generated in SENCAR mice by a two-stage carcinogenesis protocol. In the study presented here, immunoprecipitation of fresh tumor samples confirmed the overexpression of cyclin D1 protein. We also developed an immunohistochemical technique to determine which cells in the lesions overexpressed the cyclin and the timing of deregulation during cancer development. Surprisingly, we found that all premalignant lesions, including small incipient papillomas, overexpressed cyclin D1, whereas normal and hyperproliferative skin were negative. Nuclear immunostaining was detected only in the proliferative compartments of the tumors and showed an apparent cell-cycle-related variation. These results provide evidence for a role of cyclin D1 overexpression in mouse skin carcinogenesis and support the use of this model as an alternative to in vitro studies to help understand the involvement of cyclin deregulation in cancer development.

Topics: Animals; Carcinoma, Squamous Cell; Cyclin D1; Cyclins; Female; Formaldehyde; Gene Expression; Hyperplasia; Immunohistochemistry; Mice; Oncogene Proteins; Papilloma; Paraffin Embedding; Precancerous Conditions; Precipitin Tests; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Tissue Fixation

Mantle cell (centrocytic) lymphoma (MCL) and occasional cases of B-cell small lymphocytic lymphoma/chronic lymphocytic leukemia (B-SLL/CLL) show a characteristic translocation, t(11:14)(q13;q32) involving rearrangement of the Bcl-1 region. Recently it was shown that the key Bcl-1 region oncogene is cyclin D1/PRAD1; cyclin D1 mRNA was shown to be overexpressed in cases of MCL. We examined cyclin D1 protein expression in low-grade B-cell lymphomas and reactive lymphoid hyperplasias using polyclonal and monoclonal antibodies to cyclin D1 protein. Definite nuclear staining was seen in 15 of 15 MCLs, 1 of 7 B-SLL/CLLs, 0 of 7 reactive hyperplasias, 0 of 10 follicular lymphomas, and 0 of 4 lymphomas of mucosa-associated lymphoid tissue using immunoperoxidase stains on paraffin-embedded sections. Best results were obtained with the affinity-purified polyclonal antibody on microwave-treated, formalin-fixed, paraffin-embedded tissue. MCLs showed diffuse nuclear staining, whereas the one positive B-SLL/CLL showed dot-like or globular nuclear staining. Nuclear cyclin D1 protein can be detected in all cases of MCL and in rare cases of B-SLL/CLL using an immunohistochemical technique on formalin-fixed, paraffin-embedded tissue, and it does not appear to be detectable in reactive hyperplasias and other low-grade B-cell lymphomas. This protein may be useful in subclassification of low-grade B-cell lymphomas.

Topics: Blotting, Western; Cyclin D1; Cyclins; Humans; Hyperplasia; Immunohistochemistry; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma, B-Cell; Lymphoma, Follicular; Lymphoma, Non-Hodgkin; Neoplasms, Multiple Primary; Oncogene Proteins; Staining and Labeling

The objective of this study was to quantify the changes in p53 and cyclin D1 protein levels in different stages of human esophageal and gastric cardia carcinogenesis in a high-risk population in Henan, China. Immunoreactivity of p53, cyclin D1 and proliferating-cell nuclear antigen (PCNA) was observed in the cell nuclei of esophageal and gastric cardia biopsies. The number of p53-immunostaining-positive cells was low in normal epithelia, slightly increased in basal-cell hyperplasia (BCH), markedly increased in dysplasia (DYS) (10-fold), and further increased in squamous-cell carcinoma (SCC) (40-fold). This pattern of change was similar to that of cell proliferation as indicated by PCNA immunostaining. On the other hand, the number of cyclin D1-immunostaining-positive cells did not increase from BCH to DYS, although a slight increase from DYS to SCC was noted. In the gastric cardia, again, the pattern of change of p53-positive cells in different stages of lesions paralleled the pattern of cell proliferation. The number of p53-positive cells was very low, much lower than that of PCNA-positive cells, in normal, chronic superficial gastritis (CSG) and chronic atrophic gastritis (CAG); therefore, the increase of p53-positive cells from CAG to DYS was more dramatic (100-fold). From DYS to adenocarcinoma (AC), the p53-positive and the PCNA-positive cells increased 4-fold. On the other hand, the number of cyclin D1-positive cells did not increase in pre-cancerous lesions, but increased slightly in AC. This study demonstrates that p53 protein accumulation increased with the progression of pre-cancerous lesions, especially in the genesis of dysplasia, both in the esophagus and in the gastric cardia. Our approach of quantitative immunohistochemistry sheds light on the mechanisms of genesis of esophageal and gastric-cardia cancers, which frequently occur together in many high-incidence areas.

Topics: Adenocarcinoma; Adult; Aged; Biomarkers, Tumor; Carcinoma, Squamous Cell; Cardia; Cell Division; Cell Transformation, Neoplastic; Chi-Square Distribution; Cyclin D1; Cyclins; Esophageal Neoplasms; Female; Humans; Hyperplasia; Immunoenzyme Techniques; Male; Middle Aged; Neoplasm Proteins; Neoplasm Staging; Oncogene Proteins; Precancerous Conditions; Proliferating Cell Nuclear Antigen; Stomach Neoplasms; Tumor Suppressor Protein p53

Physical associations between cyclins, viral oncogenes and tumour suppressor genes imply a central role for cyclins in growth control. Cyclin D1 was identified as a candidate oncogene (PRAD1) in tumour-specific DNA rearrangements and is suspected to be a contributor to several types of neoplasms including breast cancer. Cyclin D1 also rescues G1 cyclin-defective Saccharomyces cerevisiae, and is a growth-regulated gene. Despite evidence suggesting that cyclin D1 is an oncogene, its ability to transform cells directly in culture remains controversial. To evaluate its potential to deregulate growth in vivo in a physiologically relevant tissue we overexpressed cyclin D1 in mammary cells in transgenic mice. We report here that overexpression of cyclin D1 resulted in abnormal mammary cell proliferation including the development of mammary adenocarcinomas. We conclude that overexpression of cyclin D1 deregulates cell proliferation and can induce tumorigenic changes in mammary tissues, suggesting that cyclin D1 indeed plays an important oncogenic role in breast cancer.

Topics: Adenocarcinoma; Animals; Cyclin D1; Cyclins; Female; Humans; Hyperplasia; Male; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mammary Tumor Virus, Mouse; Mice; Mice, Inbred BALB C; Mice, Transgenic; Oncogene Proteins; Oncogenes; Tumor Cells, Cultured