cyclin-d1 and von-Hippel-Lindau-Disease

A diagnosis of clear cell chondrosarcoma of the ulna was made in a patient with Von Hippel-Lindau disease (VHL). After surgery, genetic analysis of the tumor tissue showed loss of heterozygosity at the VHL gene locus. Immunohistochemical analysis confirmed loss of expression of the VHL protein in the tumor cells. In addition, abundant Cyclin D1 expression in the tumor was observed. Chondrosarcoma has been described before in a VHL patient and VHL protein expression has been correlated to tumor grade in a series of sporadic chondrosarcomas. In this report, we show that clear cell chondrosarcoma may be a rare but canonical VHL manifestation through a cell-autonomous mechanism involving somatic loss-of-heterozygosity of the VHL tumor suppressor gene. We discuss the relevance of this observation with regard to the pathogenesis of clear cell chondrosarcoma in the context of VHL.

Topics: Bone Neoplasms; Chondrosarcoma, Clear Cell; Cyclin D1; Female; Humans; Loss of Heterozygosity; Middle Aged; Ulna; von Hippel-Lindau Disease; Von Hippel-Lindau Tumor Suppressor Protein

Topics: Cyclin D1; Genetic Testing; Genotype; Humans; Phenotype; von Hippel-Lindau Disease; Von Hippel-Lindau Tumor Suppressor Protein

Von Hippel-Lindau (VHL) disease is an inherited syndrome caused by germline mutation in the VHL tumor suppressor gene predisposing to pancreatic endocrine tumors (PET). Whether these tumors derive from preexisting endocrine microadenomatosis as in multiple endocrine neoplasia type 1 (MEN1) is yet unknown. pVHL regulates hypoxia-inducible factor (HIF) that causes transcription activity of target genes like carbonic anhydrase 9 (CA9), vascular endothelial growth factor (VEGF), and cyclin D1. Our aim was to look for overexpression of these molecules to identify precursor endocrine lesions in the pancreas of VHL patients.. Nontumoral pancreas of 18 VHL patients operated on for PET, was examined for microadenomatosis (70% of VHL patients operated on for PET. These results demonstrate that the pVHL/HIF pathway is involved very early in pancreatic endocrine tumorigenesis in this disease.

Topics: Adenoma; Adult; Antigens, CD34; Antigens, Neoplasm; Basic Helix-Loop-Helix Transcription Factors; Biomarkers, Tumor; Carbonic Anhydrase IX; Carbonic Anhydrases; Chromogranin A; Cyclin D1; Female; Glucagon; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Immunohistochemistry; Insulin; Male; Middle Aged; Multiple Endocrine Neoplasia Type 1; Mutation; Pancreas; Pancreatectomy; Pancreatic Neoplasms; Precancerous Conditions; Vascular Endothelial Growth Factor A; von Hippel-Lindau Disease; Von Hippel-Lindau Tumor Suppressor Protein

Central nervous system (CNS) hemangioblastomas are highly-vascularized tumors occurring in sporadic form or as a manifestation of von Hippel-Lindau disease (VHL). The VHL protein (pVHL) regulates various target genes, one of which is the CCND1 gene, encoding cyclin D1, a protein that plays a critical role in the control of the cell cycle. Overexpression of cyclin D1 is found in many cancers. The CCND1 gene contains a common G --> A polymorphism (870G > A) that enhances alternative splicing of the gene. CCND1 genotype is associated with clinical outcome in a number of cancers although prognostic significance varies with tumor type. In VHL disease, CCND1 genotype has been suggested as a genetic modifier that influences susceptibility to hemangioblastomas. In order to analyze whether CCND1 genotype plays a role in sporadic CNS hemangioblastomas, we investigated CCND1 genotype in tumor tissue of 17 sporadic and also in five VHL-related CNS hemangioblastomas. In addition, in these tumors the extent and localization of cyclin D1 expression was investigated by immunohistochemistry. We found no deviation in CCND1 genotype distribution and allele frequencies from expected values. Also, there was no correlation between age at onset and CCND1 genotype. The expression of cyclin D1 as detected by immunohistochemistry was highly variable within and between tumors, without a clear correlation with CCND1 genotype. We conclude that, whereas variable but sometimes high cyclin D1 expression is a feature of sporadic hemangioblastomas, CCND1 genotype is unlikely to be an important genetic modifier in the oncogenesis of these tumors.

Topics: Adult; Age of Onset; Aged; Biomarkers, Tumor; Cerebellar Neoplasms; Cyclin D1; Genetic Predisposition to Disease; Genotype; Hemangioblastoma; Humans; Immunohistochemistry; Middle Aged; Polymorphism, Restriction Fragment Length; von Hippel-Lindau Disease

Loss of the von Hippel-Lindau gene (VHL) expression ca-uses deregulation of contact inhibition of cell growth, which might be one of the bases of the tumor suppressor function of VHL. Here we show that this function of the VHL gene product (pVHL) depends on cell autonomous events. To identify the target gene of pVHL, which is directly involved in the contact inhibition, we compared the gene expression profile between VHL-deficient renal carcinoma 786-O cells and those infected with an adenovirus vector encoding VHL. In addition to known pVHL-regulated genes, such as vascular endothelial growth factor and carbonic anhydrase, we found cyclinD1 as a new target of pVHL at a high cell density. In VHL-expressing cells (VHL (+) cells), the cyclinD1 mRNA expression level diminishes at a high cell density, while it remains at a relatively high level in VHL-deficient cells (VHL (-) cells). The cyclinD1 expression level was also abnormally high in VHL (-) cells at a high cell density. Consequently, the phosporylation level of the retinoblastoma (Rb) protein remained high in these cells, whereas there was no phosporylated Rb in VHL (+) cells under the contact inhibition. The abnormal expression of cyclinD1 at a high cell density was observed even in VHL (+) cells under the hypoxic state. Moreover, ectopic expression of a HIF mutant resistant to pVHL-mediated proteolysis causes the abnormal cyclinD1 expression in VHL (+) cells. Taken together, these observations indicate that VHL is required for the downregulation of cyclinD1 at a high cell density through HIF.

Topics: Carbonic Anhydrases; Carcinoma, Renal Cell; Cell Division; Cell Hypoxia; Coculture Techniques; Cyclin D1; DNA-Binding Proteins; Endothelial Growth Factors; Gene Deletion; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1; Hypoxia-Inducible Factor 1, alpha Subunit; Intercellular Signaling Peptides and Proteins; Kidney Neoplasms; Kinetics; Ligases; Lymphokines; Nuclear Proteins; Phosphorylation; Transcription Factors; Transfection; Tumor Cells, Cultured; Tumor Suppressor Proteins; Ubiquitin-Protein Ligases; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors; von Hippel-Lindau Disease; Von Hippel-Lindau Tumor Suppressor Protein

Germ-line mutations in the von Hippel-Lindau (VHL) tumor suppressor disease are associated with a high risk of retinal and cerebellar hemangioblastomas, renal cell carcinoma (RCC), and, in some cases, pheochromocytoma (PHE). In addition, somatic mutation or epigenetic inactivation of the VHL gene occurs in most clear cell RCCs. VHL protein (pVHL) has a critical role in regulating proteasomal degradation of the HIF transcription factor, and VHL inactivation results in overexpression of many hypoxia-inducible mRNAs including vascular endothelial growth factor (VEGF). To identify novel pVHL target genes we investigated the effect of wild-type (WT) pVHL on the expression of 588 cancer-related genes in two VHL-defective RCC cell lines. Expression array analysis identified nine genes that demonstrated a >2-fold decrease in expression in both RCC cell lines after restoration of WT pVHL. Three of the nine genes (VEGF, PAI-1, and LRP1) had been reported previously as pVHL targets and are known to be hypoxia-inducible. In addition, six novel targets were detected: cyclin D1 (CCND1), cell division protein kinase 6, collagen VIII alpha 1 subunit, CD59 glycoprotein precursor, integrin beta8, and interleukin 6 precursor IFN-beta2. We found no evidence that CCND1, cell division protein kinase 6, CD59, and integrin beta8 expression was influenced by hypoxia suggesting that pVHL down-regulates these targets by a HIF-independent mechanism. A type 2C pVHL mutant (V188L), which is associated with a PHE only phenotype (and had been shown previously to retain the ability to promote HIF ubiquitylation), retained the ability to suppress CCND1expression suggesting that loss of pVHL-mediated suppression of cyclin D1 is not necessary for PHE development in VHL disease. Other studies have suggested that: (a) genetic modifiers influence the phenotypic expression of VHL disease; and (b) polymorphic variation at a CCND1 codon 242 A/G single nucleotide polymorphism (SNP) may influence cancer susceptibility or prognosis in some situations. Therefore, we analyzed the relationship between CCND1 genotype and phenotypic expression of VHL disease. There was an association between the G allele and multiple retinal angiomas (P = 0.04), and risk of central nervous system hemangioblastomas (P = 0.05). These findings suggest that a variety of HIF-independent mechanisms may contribute to pVHL tumor suppressor activity and that polymorphic variation at one pVHL target influences the phenotypic expre

Topics: Blotting, Northern; Carcinoma, Renal Cell; Cyclin D1; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Genes, Tumor Suppressor; Humans; Kidney Neoplasms; Ligases; Oligonucleotide Array Sequence Analysis; Oxygen; Transfection; Tumor Cells, Cultured; Tumor Suppressor Proteins; Ubiquitin-Protein Ligases; von Hippel-Lindau Disease; Von Hippel-Lindau Tumor Suppressor Protein