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Purpose: To provide a comprehensive, thorough analysis of somatic mutation and promoter hypermethylation of the von Hippel-Lindau (VHL) gene in the cancer genome, unique to clear cell renal cancer (ccRCC). Identify relationships between the prevalence of VHL gene alterations and alteration subtypes with patient and tumor characteristics.Experimental Design: As part of a large kidney cancer case-control study conducted in Central Europe, we analyzed VHL mutations and promoter methylation in 205 well-characterized, histologically confirmed patient tumor biopsies using a combination of sensitive, high-throughput methods (endonuclease scanning and Sanger sequencing) and analysis of 11 CpG sites in the VHL promoter.Results: We identified mutations in 82.4% of cases, the highest VHL gene mutation prevalence reported to date. Analysis of 11 VHL promoter CpG sites revealed that 8.3% of tumors were hypermethylated and all were mutation negative. In total, 91% of ccRCCs exhibited alteration of the gene through genetic or epigenetic mechanisms. Analysis of patient and tumor characteristics revealed that certain mutation subtypes were significantly associated with Fuhrman nuclear grade, metastasis, node positivity, and self-reported family history of RCC.Conclusion: Detection of VHL gene alterations using these accurate, sensitive, and practical methods provides evidence that the vast majority of histologically confirmed ccRCC tumors possess genetic or epigenetic alteration of the VHL gene and support the hypothesis that VHL alteration is an early event in ccRCC carcinogenesis. These findings also indicate that VHL molecular subtypes can provide a sensitive marker of tumor heterogeneity among histologically similar ccRCC cases for etiologic, prognostic, and translational studies.

Von Hippel‐Lindau (VHL) is a hereditary multisystem disorder caused by germline alterations in the VHL gene. VHL patients are at risk for benign as well as malignant lesions in multiple organs including kidney, adrenal, pancreas, the central nervous system, retina, endolymphatic sac of the ear, epididymis, and broad ligament. An estimated 30%–35% of all families with VHL inherit a germline deletion of one, two, or all three exons. In this study, we have extensively characterized germline deletions identified in patients from 71 VHL families managed at the National Cancer Institute, including 59 partial (PD) and 12 complete VHL deletions (CD). Deletions that ranged in size from 1.09 to 355 kb. Fifty‐eight deletions (55 PD and 3 CD) have been mapped to the exact breakpoints. Ninety‐five percent (55 of 58) of mapped deletions involve Alu repeats at both breakpoints. Several novel classes of deletions were identified in this cohort, including two cases that have complex rearrangements involving both deletion and inversion, two cases with inserted extra Alu‐like sequences, six cases that involve breakpoints in Alu repeats situated in opposite orientations, and a “hotspot” PD of Exon 3 observed in 12 families that involves the same pair of Alu repeats., Von Hippel‐Lindau (VHL) is a hereditary multisystem disorder caused by germline alterations in the VHL gene. This study characterized 59 partial and 12 complete VHL germline deletions in 71 VHL families ranging in size from 1.09 to 355 kb. Exact breakpoints were mapped for 55 partial and 3 complete germline deletions and 95% involved Alu repeats at both breakpoints, with a common “hotspot” pair of Alu repeats observed in 12 families.

SummaryIndividuals with hemizygous germline fumarate hydratase (FH) mutations are predisposed to renal cancer. These tumors predominantly exhibit functional inactivation of the remaining wild-type allele, implicating FH inactivation as a tumor-promoting event. Hypoxia-inducible factors are expressed in many cancers and are increased in clear cell renal carcinomas. Under normoxia, the HIFs are labile due to VHL-dependent proteasomal degradation, but stabilization occurs under hypoxia due to inactivation of HIF prolyl hydroxylase (HPH), which prevents HIF hydroxylation and VHL recognition. We demonstrate that FH inhibition, together with elevated intracellular fumarate, coincides with HIF upregulation. Further, we show that fumarate acts as a competitive inhibitor of HPH. These data delineate a novel fumarate-dependent pathway for regulating HPH activity and HIF protein levels.

Hereditary leiomyomatosis and renal cell cancer is a recently described hereditary cancer syndrome in which affected individuals are at risk for cutaneous and uterine leiomyomas, and kidney cancer. Our initial experience revealed the aggressive behavior of these renal tumors, often with early metastasis, despite small primary tumor size. We report the clinical characteristics and urological treatment of patients with hereditary leiomyomatosis and renal cell cancer associated renal tumors.A total of 19 patients with hereditary leiomyomatosis and renal cell cancer associated renal tumors were evaluated. The 11 women and 8 men had a median age at diagnosis of 39 years (range 22 to 67), and a median clinical and radiological followup of 34 months (range 6 to 141). Hereditary leiomyomatosis and renal cell cancer manifestations in patients with renal tumors included cutaneous leiomyomas in 11 of 17 evaluable patients (65%) and uterine leiomyomas in 7 of 7 evaluable females (100%).Median pathological tumor size was 7.8 cm (range 1.5 to 20). Histological subtypes were consistent with hereditary leiomyomatosis and renal cell cancer renal carcinoma. Four of 7 patients with 2.0 to 6.7 cm T1 tumors had spread to regional lymph nodes or metastases at nephrectomy. Overall 9 of 19 patients (47%) presented with nodal or distant metastases.Renal tumors in patients with hereditary leiomyomatosis and renal cell cancer syndrome are significantly more aggressive than those in patients with other hereditary renal tumor syndromes. In contrast to other familial renal cancer syndromes, the observation of 3 cm or less renal tumors associated with hereditary leiomyomatosis and renal cell cancer is not recommended. Careful followup of affected and at risk individuals in families is necessary.

Rationale: Birt-Hogg-Dubesyndrome (BHDS) is an autosomal, dominantly inherited genodermatosis that predisposes to fibro- folliculomas, kidney neoplasms, lung cysts, and spontaneous pneumothorax. Objectives: We evaluated 198 patients from 89 families with BHDS to characterize the risk factors for pneumothorax and genotype- pulmonary associations. Methods: Helical computed tomography scans of the chest were used to screen for pulmonary abnormalities. BHD mutation data were used for genotype-pulmonary associations. We examined the relationship of pneumothorax with categorical parameters (sex, smoking history, and lung cysts) and continuous parameters (num- ber of cysts, lung cyst volume, and largest cyst diameter and vol- ume). Logistic regression analyses were used to identify the risk factors associated with pneumothorax. Measurements and Main Results: Twenty-four percent (48/198) of patients with BHDS had a history of pneumothorax. The presence of lung cysts was significantly associated with pneumothorax (p 0.006). Total lung cyst volume, largest cyst diameter and volume, and every parameter related to the number of lung cysts were significantly associated (p 0.0001) with pneumothorax. A logistic regression analysis showed that only the total number of cysts in the right parenchymal lower lobe and the total number of cysts located on the pleural surface in the right middle lobe were needed to classify a patient as to whether or not he or she was likely to have a pneumothorax. Exon location of the BHD mutation was associated with the numbers of cysts (p 0.0002). Conclusions: This study indicates that patients with BHDS have a significant association between lung cysts and spontaneous pneumothorax.

Birt-Hogg-Dubé syndrome (BHD) is a rare, inherited genodermatosis characterized by hair follicle hamartomas, kidney tumors and spontaneous pneumothorax. The BHD locus was mapped to chromosome 17p11.2 by linkage analysis, and germline mutations in a novel gene (BHD) were identified in a panel of BHD families. Using RNA interference to decrease expression of the Drosophila BHD homolog (DBHD), we have demonstrated that DBHD is required for male germline stem cell (GSC) maintenance in the fly testis. Reduction of DBHD gene activity suppresses the GSC overproliferation phenotype associated with overexpression of either unpaired (upd) or decapentaplegic (dpp). Further genetic interaction experiments suggest that DBHD regulates GSC maintenance downstream or in parallel of the JAK/STAT and Dpp signal-transduction pathways. These findings suggest that the BHD protein may regulate tumorigenesis through modulating stem cells in human.

Background: Hereditary leiomyomatosis and renal cell cancer (HLRCC) is the autosomal dominant heritable syndrome with predisposition to development of renal cell carcinoma and smooth muscle tumours of the skin and uterus. Objective: To measure the fumarate hydratase (FH) enzyme activity in lymphoblastoid cell lines and fibroblast cell lines of individuals with HLRCC and other familial renal cancer syndromes. Methods: FH enzyme activity was determined in the whole cell, cytosolic, and mitochondrial fractions in 50 lymphoblastoid and 16 fibroblast cell lines including cell lines from individuals with HLRCC with 16 different mutations. Results: Lymphoblastoid cell lines (n = 20) and fibroblast cell lines (n = 11) from individuals with HLRCC had lower FH enzyme activity than cells from normal controls (p

The Birt-Hogg-Dubé (BHD) syndrome is an inherited genodermatosis characterized by a predisposition to hamartomatous skin lesions, pulmonary cysts, and renal carcinoma. Seventy-seven renal tumors from 12 patients with germline BHD mutations were examined by DNA sequencing to identify somatic mutations in the second copy of BHD. Sequence alterations were detected in the majority of renal tumors (41 of 77, 53%), with loss of heterozygosity at the BHD locus in a minority of additional tumors (14 of 77, 17%). The somatic mutations were distributed across the entire gene, and the majority resulted in frameshifts that are predicted to truncate the BHD protein. These results support a role for BHD as a tumor suppressor gene that predisposes to the development of renal tumors when both copies are inactivated.

Birt-Hogg-Dubé syndrome (BHD), a genodermatosis characterized by multiple hamartomas of the hair follicle (fibrofolliculoma), predisposes individuals to an increased risk of developing renal neoplasms and spontaneous pneumothorax. Previously, we localized the BHD locus (also known as FLCN) to chromosome 17p11.2 by linkage analysis and subsequently identified germline mutations in a novel gene in probands from eight of the nine families with BHD in our screening panel. Affected members of five of the families inherited an insertion/deletion of a cytosine in a C8 tract in exon 11. This mutation was also identified by exon 11 screening in probands from 22 of 52 additional families with BHD and therefore represents a hypermutable “hotspot” for mutation in BHD. Here, we screened the remaining 30 families from this large BHD cohort by direct sequence analysis and identified germline BHD mutations in 84% (51/61) of all families with BHD recruited to our study. Mutations were located along the entire length of the coding region, including 16 insertion/deletion, 3 nonsense, and 3 splice-site mutations. The majority of BHD mutations were predicted to truncate the BHD protein, folliculin. Among patients with a mutation in the exon 11 hotspot, significantly fewer renal tumors were observed in patients with the C-deletion than those with the C-insertion mutation. Coding-sequence mutations were not found, however, in probands from two large families with BHD whose affected members shared their family’s BHD-affected haplotype. Of the 53 families with BHD whose members inherited either a germline mutation or the affected haplotype, 24 (45%) had at least one member with renal neoplasms. Three families classified with familial renal oncocytoma were identified with BHD mutations, which represents the first disease gene associated with this rare form of renal neoplasm. This study expands the BHD-mutation spectrum and evaluates genotype-phenotype correlations among families with BHD.

Studies during the past two decades have shown that kidney cancer is not a single disease; it is made up of a number of different types of cancer that occur in this organ. Clear cell renal carcinoma is characterized by mutation of the VHL gene. The VHL gene product forms a heterotrimeric complex with elongin C, elongin B, and Cul-2 to target hypoxia-inducible factors 1 and 2α for ubiquitin-mediated degradation. VHL−/− clear cell renal carcinoma overexpresses epidermal growth factor receptor and transforming growth factor α. Both hypoxia-inducible factor 1α and the epidermal growth factor receptor are potential therapeutic targets in clear cell renal carcinoma. Studies of the hereditary form of renal cell carcinoma (RCC) associated with hereditary papillary renal carcinoma (HPRC) determined that the c-Met proto-oncogene on chromosome 7 is the gene for HPRC and for a number of sporadic papillary RCCs. The HPRC c-Met mutations are activating mutations in the tyrosine kinase domain of the gene. The gene for a new form of hereditary RCC (Birt Hogg Dubé syndrome) associated with cutaneous tumors, lung cysts, and colon polyps or cancer has recently been identified. Studies are currently under way to determine what type of gene BHD is and how damage to this gene leads to kidney cancer. Individuals affected with hereditary leiomyomatosis renal cell carcinoma are at risk for the development of cutaneous leiomyomas, uterine leiomyomas (fibroids), and type 2 papillary RCC. The HLRC gene has been found to be the Krebs cycle enzyme, fumarate hydratase. Studies are under way to understand the downstream pathway of this cancer gene.

The types of epithelial renal tumors are clear cell, types I and II papillary, chromophobe and oncocytoma. We identified the genetic basis of these different types of kidney cancer to provide better methods for early diagnosis of this disease as well as provide the foundation for the development of molecular therapeutic approaches.To identify the genetic basis of kidney cancer we studied families with an inherited predisposition to kidney cancer. Families in which 2 or more individuals had kidney cancer underwent a comprehensive evaluation to determine whether they were affected with a hereditary form of renal carcinoma. Genetic linkage analysis was performed to identify the gene for inherited forms of renal carcinoma.The gene for the inherited form of clear cell renal carcinoma associated with von Hippel-Lindau gene was identified. This gene has been found to be a tumor suppressor gene. A new form of inherited renal carcinoma, hereditary papillary renal carcinoma, was identified. The gene for this condition was identified and found to be the proto-oncogene c-Met. A previously unidentified form of familial renal oncocytoma was found. A familial form of chromophobe renal carcinoma and oncocytoma associated with Birt Hogg Dubé syndrome was found. The gene for this condition was localized on the short arm of chromosome 17 and it has been identified. We studied families with cutaneous leiomyomas, uterine leiomyomas and papillary renal carcinoma. We identified mutations in the fumarate hydratase gene in patients affected with this disorder, namely hereditary leiomyoma renal cell carcinoma.Kidney cancer used to be considered a single disease. It is now known that there are a number of different types of cancers of the kidney with different histological patterns and different clinical courses that appear to respond differently to therapy. These different types of kidney cancer are caused by different genes, ie they each have a distinct genetic basis. Understanding the molecular pathways of these cancer genes should provide insight into their varying clinical courses and responses to treatment as well as provide the foundation for the development of disease specific molecular therapeutic strategies.

We studied families with multiple members affected with renal cancer to delineate clinically distinct forms of inherited renal cancer, and to identify and characterize the genes responsible for these disorders. Today, cancer geneticists recognize seven clinically distinct, inherited forms of epithelial renal cancer; genes responsible for five inherited predispositions have been found. Positional cloning efforts for one kidney cancer gene are nearing completion. These discoveries will provide diagnostic tests for these diseases, a foundation for studies of the relationship between genotype and phenotype, and a basis for studies of the pathophysiology of the diverse types of epithelial renal cancer.

von Hippel Lindau disease (VHL) is an autosomal dominant familial cancer syndrome linked to alteration of the VHL tumor suppressor gene. Affected patients are predisposed to develop pheochromocytomas and cystic and solid tumors of the kidney, CNS, pancreas, retina, and epididymis. However, organ involvement varies considerably among families and has been shown to correlate with the underlying germline alteration. Clinically, we observed a paradoxically lower prevalence of renal cell carcinoma (RCC) in patients with complete germline deletion of VHL. To determine if a relationship existed between the type of VHL deletion and disease, we retrospectively evaluated 123 patients from 55 families with large germline VHL deletions, including 42 intragenic partial deletions and 13 complete VHL deletions, by history and radiographic imaging. Each individual and family was scored for cystic or solid involvement of CNS, pancreas, and kidney, and for pheochromocytoma. Germline deletions were mapped using a combination of fluorescent in situ hybridization (FISH) and quantitative Southern and Southern blot analysis. An age-adjusted comparison demonstrated a higher prevalence of RCC in patients with partial germline VHL deletions relative to complete deletions (48.9 vs. 22.6%, p=0.007). This striking phenotypic dichotomy was not seen for cystic renal lesions or for CNS (p=0.22), pancreas (p=0.72), or pheochromocytoma (p=0.34). Deletion mapping revealed that development of RCC had an even greater correlation with retention of HSPC300 (C3orf10), located within the 30-kb region of chromosome 3p, immediately telomeric to VHL (52.3 vs. 18.9%, p

CASE SUMMARY History A 68-year-old woman was referred for evaluation of multiple white to skin-colored papules distributed over her face, neck, and upper trunk. She had a history of right-sided spontaneous pneumothorax that occurred in 1990 and recurrent spontaneous pneumothorax in 1991, at which time she underwent pleurodesis. In 1992, a computed tomographic (CT) scan of abdomen and pelvis revealed a 34-cm tumor on her left kidney. She underwent left partial nephrectomy and pathologic examination revealed an oncocytic neoplasm. Her family history was significant for multiple relatives with “skin bumps” (Fig 1).

Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant genodermatosis characterized by the development of small dome-shaped papules on the face, neck, and upper trunk (fibrofolliculomas). In addition to these benign hair follicle tumors, BHD confers an increased risk of renal neoplasia and spontaneous pneumothorax. To date, there has been no systematic pathologic analysis of the renal tumors associated with this syndrome. We reviewed 130 solid renal tumors resected from 30 patients with BHD in 19 different families. Preoperative computed tomography scans demonstrated a mean of 5.3 tumors per patient (range 1-28 tumors), the largest tumors averaging 5.7 cm in diameter (+/- 3.4 cm, range 1.2-15 cm). Multiple and bilateral tumors were noted at an early age (mean 50.7 years). The resected tumors consisted predominantly of chromophobe renal cell carcinomas (44 of 130, 34%) or of hybrid oncocytic neoplasms that had areas reminiscent of chromophobe renal cell carcinoma and oncocytoma (65 of 130, 50%). Twelve clear cell (conventional) renal carcinomas (12 of 130, 9%) were diagnosed in nine patients. These tumors were on average larger (4.7 +/- 4.2 cm) than the chromophobe (3.0 +/- 2.5 cm) and hybrid tumors (2.2 +/- 2.4 cm). Microscopic oncocytosis was found in the renal parenchyma of most patients, including the parenchyma of five patients with evidence of clear cell renal cell carcinoma. Our findings suggest that microscopic oncocytic lesions may be precursors of hybrid oncocytic tumors, chromophobe renal cell carcinomas, and perhaps clear cell renal cell carcinomas in patients with BHD syndrome. Recognition by the pathologist of the unusual renal tumors associated with BHD may assist in the clinical diagnosis of the syndrome.

β-Galactosidase (β-Gal) staining is widely used to demonstrate specific gene expression during evaluation of gene targets in vivo. This technique is extremely sensitive to fixation. Optimal fixation conditions are necessary to obtain the maximal β-Gal activity. In this experiment, Carnoy's and three different aldehyde fixatives were used at different temperatures and over different time points. Kidneys from LacZ-stop-human alkaline phosphatase (ZA/P) double reporter mice were used to generate positive material for the experiment. The results show that glutaraldehyde combinative solution (LacZ) produced the most consistent and reliable results. Paraformaldehyde and formaldehyde were effective as fixatives only at 4C for a period of less than 4 hr, and Carnoy's solution destroyed β-Gal activity.

Birt-Hogg-Dube (BHD) syndrome is a rare inherited genodermatosis characterized by hair follicle hamartomas, kidney tumors, and spontaneous pneumothorax. Recombination mapping in BHD families delineated the susceptibility locus to 700 kb on chromosome 17p11.2. Protein-truncating mutations were identified in a novel candidate gene in a panel of BHD families, with a 44% frequency of insertion/deletion mutations within a hypermutable C 8 tract. Tissue expression of the 3.8 kb transcript was widespread, including kidney, lung, and skin. The full-length BHD sequence predicted a novel protein, folliculin, that was highly conserved across species. Discovery of disease-causing mutations in BHD , a novel kidney cancer gene associated with renal oncocytoma or chromophobe renal cancer, will contribute to understanding the role of folliculin in pathways common to skin, lung, and kidney development.

Missense mutations in the tyrosine kinase domain of the MET proto-oncogene occur in selected cases of papillary renal carcinoma. In biochemical and biological assays, these mutations produced constitutive activation of the MET kinase and led to tumor formation in nude mice. Some mutations caused transformation of NIH 3T3 cells. To elucidate the mechanism of ligand-independent MET kinase activation by point mutations, we constructed several 3D models of the wild-type and mutated MET catalytic core domains. Analysis of these structures showed that some mutations (e.g., V1110I, Y1248H/D/C, M1268T) directly alter contacts between residues from the activation loop in its inhibitory conformation and those from the main body of the catalytic domain; others (e.g., M1149T, L1213V) increase flexibility at the critical points of the tertiary structure and facilitate subdomain movements. Mutation D1246N plays a role in stabilizing the active form of the enzyme. Mutation M1268T affects the S+1 and S+3 substrate-binding pockets. Models implicate that although these changes do not compromise the affinity toward the C-terminal autophosphorylation site of the MET protein, they allow for binding of the substrate for the c-Abl tyrosine kinase. We provide biochemical data supporting this observation. Mutation L1213V affects the conformation of Tyr1212 in the active form of MET. Several somatic mutations are clustered at the surface of the catalytic domain in close vicinity of the probable location of the MET C-terminal docking site for cytoplasmic effectors.

This review summarizes information on inherited epithelial tumors of the kidney. Emphasis is placed on identifying clinically distinct inherited forms of renal cancer because each distinct clinical syndrome defines a different renal cancer susceptibility gene. So far, two genes that predispose to epithelial cancers of the kidney have been identified, VHL and the MET proto-oncogene. Available evidence suggests that several renal cancer genes remain to be identified.

Research tools which improve mutation detection, SNP discovery, and allele characterization will facilitate studies of cancer, inherited disease, and genomic evolution. Denaturing High-Performance Liquid Chromatography (DHPLC) is a recently developed methodology for detection of heteroduplexes formed in DNA samples containing mismatches between wild type and mutant strands. In an effort to develop a rapid, sensitive mutation detection method for studies of families with inherited kidney cancer, we evaluated DHPLC for detection and analysis of MET proto-oncogene mutations in papillary renal carcinomas (PRC). We found DHPLC to be 100% accurate in detecting 15 known disease-associated MET mutations. Significantly, each MET mutation and two novel SNPs generated a characteristic chromatographic profile or signature with reproducible distinguishing features. Standardization of DHPLC reagents and improved methods design were critical to the reliability and accuracy of mutation prediction. Improvements included addition of a 75% acetonitrile wash followed by a rejuvenating gradient, and detailed analysis of signature shape, retention time (RT), RT differences (DeltaRT), and temperature-dependent (melt) profiling. We used signatures to predict mutations in new PRC samples, mutation carriers in asymptomatic hereditary PRC family members, and in a blind study of previously characterized DNAs. Application to SNP discovery is discussed. Wiley-Liss, Inc.

Summaryvon Hippel-Lindau disease (VHL [MIM 193300]) is a heritable autosomal dominant multiple-neoplastic disorder with high penetrance. It is characterized by brain and spinal-cord hemangioblastomas, retinal angiomas, clear-cell renal carcinoma, neuroendocrine tumors and cysts of the pancreas, pheochromocytomas, endolymphatic-sac tumors, and papillary cystadenomas of the epididymis and broad ligament. Although most index cases have a positive family history of VHL, some do not and may represent de novo cases. Cases without a family history of VHL may or may not have a germline mutation in their VHL tumor-suppressor gene. We present two cases of VHL mosaicism. In each of two families, standard testing methods (Southern blot analysis and direct sequencing) identified the germline mutation in the VHL gene of the offspring, but not in their clinically affected parent. Additional methods of analysis of the affected parents' blood detected the VHL-gene mutation in a portion of their peripheral blood lymphocytes. In one case, detection of the deleted allele was by FISH, and, in the second case, the 3-bp deletion was detected by conformational sensitive gel electrophoresis and DNA sequencing of cloned genomic DNA. Mosaicism in VHL is important to search for and recognize when an individual without a family history of VHL has VHL. Patients diagnosed without family histories of the disease have been reported in as many as 23% of kindreds with VHL. Identification of individuals potentially mosaic for VHL will affect counseling of families, and these individuals should themselves be included in clinical screening programs for occult disease.

To examine the localization of von Hippel–Lindau (VHL) protein in human tissues, we produced four novel monoclonal antibodies against human VHL protein. Western blot analysis revealed that two of these antibodies recognized the epitope in amino acid sequence 60–89 of the VHL protein and the others recognized sequences 54–60 and 189–213. In a wild-type VHL gene-transfected cell line, immunocytochemistry and immunoelectron microscopy demonstrated the intracytoplasmic localization of VHL protein, particularly in mitotic cells. In normal human tissues, VHL protein was detected immunohistochemically in epithelial cells covering the body surface and the alimentary, respiratory, and genitourinary tracts; in secretory epithelial cells of exocrine and endocrine organs; in parenchymal cells of visceral organs; in cardiomyocytes; in neurons in nervous tissue; in lymphocytes in lymphoid tissue; and in macrophages. In pathological specimens, VHL protein was expressed in VHL-related tumor, as well as in endothelial cells, fibroblasts, and pericytes, all of which are involved in active angiogenesis. These findings suggest that these monoclonal antibodies can be useful for various immunological assays and that the VHL protein plays fundamental roles in physiological and pathological situations, especially in neovascularization.

The von Hippel-Lindau gene product (pVHL) interacts with and inhibits the cellular transcription factor elongin. However, the subcellular localization of pVHL has remained uncertain. Naturally occurring pVHL mutants which fail to interact with elongin have been described in patients with VHL disease or sporadic renal cell carcinoma (RCC). Here, we have examined the cellular expression pattern of endogenous pVHL in different RCC cell lines by immunocytochemistry and confocal microscopy. Both anti-N-terminal and anti-C-terminal pVHL antibodies were able to recognize endogenous wild-type pVHL expressed by the RCC cells studied. A C-terminal truncated VHL mutant expressed by RCC cell line A498 was detected only by the N-terminal antibody but not by the C-terminal antibody as expected. The overall staining patterns of these cell lines are similar, with a predominant nuclear speckled pattern and a moderate cytoplasmic staining in subconfluent cell cultures. Interestingly, when cells reached confluency, more prominent nuclear staining with little or no cytoplasmic expression was observed. By using double labeling with anti-VHL and anti-bromodeoxyuridine (BrdU) antibodies and cell cycle analyses, we found that in the G1/G0-phase, pVHL was localized exclusively in the nucleus associated with distinctive large subnuclear structures, whereas the majority of the cells in S-phase of the cell cycle also showed a diffuse cytoplasmic staining. Our results indicate that subcellular localization of pVHL is regulated in a cell cycle-dependent manner.

Purpose: We analyzed familial renal oncocytoma to provide a foundation for studies aimed at defining genes involved in the pathogenesis of renal oncocytoma.Materials and Methods: We describe 5 families with multiple members affected with renal oncocytoma. Tumors were analyzed pathologically, and affected and nonaffected members were screened clinically and genetically.Results: We identified 12 affected male and 3 affected female (ratio 4:1) individuals in the 5 families. In affected family members renal oncocytomas were often multiple and bilateral. No metastatic disease was observed. Most renal oncocytomas were detected incidentally in asymptomatic individuals or during screening of asymptomatic members of renal oncocytoma families. One identical twin pair was affected with bilateral multiple renal oncocytomas.Conclusions: Renal oncocytoma may be inherited in some families.

von Hippel-Lindau disease (VHL) is an inherited neoplastic disorder characterized by the development of tumors in the eyes, brain, spinal cord, inner ear, adrenal gland, pancreas, kidney, and epididymis. The VHL tumor suppressor gene was identified in 1993. Initial studies reported the detection of germline mutations in the VHL gene in 39–75% of VHL families. We used tests that detect different types of mutations to improve the frequency of detection of germline mutations in VHL families. The methods included quantitative Southern blotting to detect deletions of the entire VHL gene, Southern blotting to detect gene rearrangements, fluorescence in situ hybridization (FISH) to confirm deletions, and complete sequencing of the gene. Here we report that we have detected germline mutations in the VHL gene in 100% (93/93) of VHL families tested. In addition, we describe 13 novel intragenic VHL germline mutations. With the methodology described in this article, it is now possible to identify germline mutations in virtually all families with VHL. Hum Mutat 12:417–423, 1998. © 1998 Wiley-Liss, Inc.

Von Hippel-Lindau (VHL) gene mutations occur throughout three exons including the exon-intron boundaries in human VHL disease–associated and sporadic renal cell carcinomas. To explore the possible role of the VHL gene in chemically induced rat kidney tumors originating from various cell types, more than 150 bp of Fischer 344 and Noble rat VHL intron sequences flanking the three exons was determined by dideoxy sequencing. Five primer sets were selected for polymerase chain reaction amplification of the coding regions of rat VHL exons 1–3 and the exon-intron boundaries. Tissues from 10 renal eosinophilic epithelial tumors induced by N-nitrosoethyl(2-hydroxyethyl)amine, 10 nephroblastomas induced by N-nitroso-N-ethylurea, and seven renal mesenchymal tumors induced by N-nitrosomethyl(methoxymethyl)amine were examined for VHL mutations by polymerase chain reaction–single-strand conformation polymorphism analysis. No mutation was detected in any tumor type, indicating that VHL mutations are not involved in the pathogenesis of rat kidney tumors arising from the distal region of the renal tubules, the metanephric blastema, or stromal tissues of the cortex. Mol. Carcinog. 19:230–235, 1997. © 1997 Wiley-Liss, Inc. This article is a US Government work and, as such, is the public domain in the United States of America.

Metastatic castration resistant prostate cancer (mCRPC) is a lethal disease and molecular markers that differentiate indolent from aggressive subtypes are needed. We sequenced the exomes of five metastatic tumors and healthy kidney tissue from an index case with mCRPC to identify lesions associated with disease progression and metastasis. An Ashkenazi Jewish (AJ) germline founder mutation, del185AG in BRCA1, was observed and AJ ancestry was confirmed. Sixty-two somatic variants altered proteins in tumors, including cancer-associated genes, TMPRSS2-ERG, PBRM1, and TET2. The majority (n=53) of somatic variants were present in all metastases and only a subset (n=31) was observed in the primary tumor. Integrating tumor next generation sequencing (NGS) and DNA copy number showed somatic loss of BRCA1 and TMPRSS2-ERG. We sequenced 19 genes with deleterious mutations in the index case in additional mCRPC samples and detected a frameshift, two somatic missense alterations, tumor loss of heterozygosity (LOH), and combinations of germline missense SNPs in TET2. In summary, genetic analysis of metastases from an index case permitted us to infer a chronology for the clonal spread of disease based on sequential accrual of somatic lesions. The role of TET2 in mCRPC deserves additional analysis and may define a subset of metastatic disease.

We have isolated the 3' untranslated region (3'UTR) of the human von Hippel-Lindau (VHL) tumor suppressor gene from a P1 phage containing the entire VHL genomic sequence. Several putative noncanonical (ATTAAA) poly(A) signals were identified, and the functional significance of these signals was examined by preparing VHL mammalian expression constructs with this DNA fragment and the previously isolated partial cDNA. Northern blot analysis from transfected renal carcinoma cells showed that both the endogenous and transgene VHL transcripts were the same length. Use of VHL transgene deletion mutants indicated that an ATTAAA sequence located between nucleotide (nt) +4237 and nt +4379 most likely serves as an active poly(A) signal in renal carcinoma cells, yielding a 3.6-kb 3'UTR. This work indicates that, together with the 5'UTR and the coding region, these sequences comprise the full-length human VHL cDNA. Sequence analysis revealed a 300- to 600-bp region conserved in human, murine, and rat VHL UTRs. In addition, the human 3'UTR was extremely rich in Alu repetitive elements.

von Hippel-Lindau (VHL) disease is a dominantly inherited familial cancer syndrome predisposing to retinal, cerebellar and spinal hemangioblastoma, renal cell carcinoma (RCC), pheochromocytoma and pancreatic tumors. Clinically two types of the disease can be distinguished: VHL type 1 (without pheochromocytoma) and VHL type 2 (with pheochromocytoma). We report VHL germline mutations and trends in phenotypic variation in families from central Europe. We identified 28 mutations in 53/65 (81.5%) families with 18 (64%) mutations being unique to this population. Whereas types and distribution of mutations as well as a strong correlation of missense mutations with the VHL 2 phenotype were similar to those identified in other populations, these families have provided new insights into the molecular basis for variability in the VHL 2 phenotype. Seven different missense mutations in exons 1 and 3 varied in their biological consequences from a minimal VHL 2 phenotype with pheochromocytoma only to a full VHL 2 phenotype with RCC and pancreatic lesion. These findings contribute to a better understanding of the fundamental mechanisms of VHL disease and its phenotypic variability. Further, we have provided rapid VHL screening for the families in central Europe, which has resulted in improved diagnosis and clinical management.

We used comparative genomic hybridization to analyze 17 tumor samples from 11 patients with papillary renal cell carcinoma (RCC), including three patients with hereditary papillary RCC. Whereas the most frequent aberrations confirmed data obtained by banding analyses, copy number increases on 5q, which previously were considered characteristic of nonpapillary RCC, were identified in two cases. In two complex cases belonging to the same family, a characteristic pattern of chromosomal aberrations was found: five of the six imbalances present in the less complex case were included in the karyotype of the other case, suggesting a genetically determined mechanism resulting in genomic instability of specific chromosomes or chromosomal subregions and/or selection of specific mutations.

Germline mutation analysis was performed in 469 VHL families from North America, Europe, and Japan. Germline mutations were identified in 300/469 (63%) of the families tested; 137 distinct intragenic germline mutations were detected. Most of the germline VHL mutations (124/137) occurred in 1–2 families; a few occured in four or more families. The common germline VHL mutations were: delPhe76, Asn78Ser, Arg161Stop, Arg167Gln, Arg167Trp, and Leu178Pro. In this large series, it was possible to compare the effects of identical germline mutations in different populations. Germline VHL mutations produced similar cancer phenotypes in Caucasian and Japanese VHL families. Germline VHL mutations were identified that produced three distinct cancer phenotypes: (1) renal carcinoma without pheochromocytoma, (2) renal carcinoma with pheochromocytoma, and (3) pheochromocytoma alone. The catalog of VHL germline mutations with phenotype information should be useful for diagnostic and prognostic studies of VHL and for studies of genotype-phenotype correlations in VHL. © 1996 Wiley-Liss, Inc.

Papillary cystadenoma of the epididymis is an uncommon benign lesion that may occur sporadically or as a manifestation of von Hippel-Lindau (VHL) disease. Neither immunohistochemical studies nor molecular genetic analyses of the VHL gene have been reported previously for this lesion. The authors describe two cases of clear cell papillary cystadenoma of the epididymis, both of which were initially confused with metastatic renal cell carcinoma. Both lesions showed positive immunohistochemical staining for low and intermediate molecular weight keratins (Cam 5.2 and AE1/AE3), EMA, vimentin, alpha 1-antitrypsin, and alpha 1-antichymotrypsin. Each was negative for CEA. Because clear cell papillary cystadenoma is similar to renal cell carcinoma histologically, and because both occur as components of the von Hippel-Lindau disease complex, the authors analyzed both cases for the presence of mutations in the VHL gene. A somatic VHL gene mutation was detected in one of the two tumors by polymerase chain reaction followed by single-strand conformation polymorphism analysis. Direct sequencing revealed a cytosine to thymine transition at nucleotide 694, resulting in the replacement of an arginine with a stop codon after the sixth amino acid of exon 3. As the VHL gene is believed to function as a tumor suppressor gene, VHL gene mutations may play a role in the initiation of tumorigenesis in sporadic cystadenomas of the epididymis.

Germline H255Y and K508R missense mutations in the folliculin (FLCN) gene have been identified in patients with bilateral multifocal (BMF) kidney tumours and clinical manifestations of Birt-Hogg-Dubé (BHD) syndrome, or with BMF kidney tumours as the only manifestation; however, their impact on FLCN function remains to be determined. In order to determine if FLCN H255Y and K508R missense mutations promote aberrant kidney cell proliferation leading to pathogenicity, we generated mouse models expressing these mutants using BAC recombineering technology and investigated their ability to rescue the multi-cystic phenotype of Flcn-deficient mouse kidneys. Flcn H255Y mutant transgene expression in kidney-targeted Flcn knockout mice did not rescue the multi-cystic kidney phenotype. However, expression of the Flcn K508R mutant transgene partially, but not completely, abrogated the phenotype. Notably, expression of the Flcn K508R mutant transgene in heterozygous Flcn knockout mice resulted in development of multi-cystic kidneys and cardiac hypertrophy in some mice. These results demonstrate that both FLCN H255Y and K508R missense mutations promote aberrant kidney cell proliferation, but to different degrees. Based on the phenotypes of our preclinical models, the FLCN H255Y mutant protein has lost it tumour suppressive function leading to the clinical manifestations of BHD, whereas the FLCN K508R mutant protein may have a dominant negative effect on the function of wild-type FLCN in regulating kidney cell proliferation and, therefore, act as an oncoprotein. These findings may provide mechanistic insight into the role of FLCN in regulating kidney cell proliferation and facilitate the development of novel therapeutics for FLCN-deficient kidney cancer.

Von Hippel-Lindau (VHL) disease is a familial cancer syndrome that has a dominant inherited pattern which predisposes affected individuals to a variety of tumors. The most frequent tumors are hemangioblastomas of the central nervous system and retina, renal cell carcinoma (RCC), and pheochromocytoma. The recent identification and characterization of the VHL gene on human chromosome 3p and mutational analyses confirms the VHL gene functions as a classical tumor suppressor. Not only are mutations in this gene responsible for the VHL syndrome, but mutations are also very frequent in sporadic RCC. VHL expression in human kidney and during embryogenesis, was analyzed by in situ mRNA hybridization with 35S-labeled antisense VHL probes, derived from human and mouse cDNAs, on cryosections of human fetal kidney and paraffin sections of murine embryos. In human fetal kidney, there was enhanced expression of VHL within the epithelial lining of the proximal tubules. During embryogenesis, VHL expression was ubiquitous in all three germ cell layers and their derivatives. Expression occurred in the cerebral cortex, midbrain, cerebellum, retina, spinal cord, and postganglionic cell bodies. All organs of the thoracic and abdominal cavities expressed VHL, but enhanced expression was most apparent in the epithelial components of the lung, kidney, and eye. In human fetal kidney, the enhanced epithelial expression of the VHL gene is consistent with the role of this gene in RCC. There is widespread expression of the VHL gene during embryogenesis, but this is pronounced in areas associated with VHL phenotypes. These findings provide a histological framework for investigating the physiological role of the VHL gene and as basis for further mutational analysis.

The combined efforts of a number of investigators have led to the identification of the VHL gene, which appears to function as a tumor suppressor gene and is implicated in both sporadic and familial forms of RCC. These findings should increase our understanding of the molecular biology of this malignancy; however, there is much work to be done. Identification of the mechanism of inactivation of the VHL gene, as well as the structure and function of the VHL gene product, ultimately may provide clinicians with greater understanding of this malignancy as well as with methods for earlier diagnosis. The role of other tumor suppressor genes, such as p53, is incompletely understood. It is hoped that the techniques that have been applied to the study of RCC also will result in advances in our knowledge of other urologic malignancies.

We recently described a 3-generation family with members affected with papillary renal cell carcinoma, an uncommon histological type of renal cell carcinoma. Possibly family 150 is an isolated occurrence, a reflection of some as yet unknown environmental factor. Alternatively, family 150 may represent a distinct class of inherited cancer. To distinguish between these 2 possibilities we sought additional families with papillary renal cell carcinoma and we identified 9 with members affected with papillary renal cell carcinoma. There were 29 affected male and 12 affected female subjects (ratio 2.41:1), including affected members of family 150. Papillary renal cell carcinomas were often detected incidentally in asymptomatic individuals or during screening of asymptomatic members of renal cell carcinoma families. The penetrance, the proportion of obligate gene carriers that showed clinical evidence of the disease, was reduced. The median survival of affected individuals was 52 years. The results suppor...

Recently, a new renal cell cancer syndrome has been linked to germline mutation of multiple subunits (SDHB/C/D) of the Krebs cycle enzyme, succinate dehydrogenase. We report our experience with the diagnosis, evaluation and treatment of this novel form of hereditary kidney cancer.Patients with suspected hereditary kidney cancer were enrolled on a National Cancer Institute institutional review board approved protocol to study inherited forms of kidney cancer. Individuals from families with germline SDHB, SDHC and SDHD mutations, and kidney cancer underwent comprehensive clinical and genetic evaluation.A total of 14 patients from 12 SDHB mutation families were evaluated. Patients presented with renal cell cancer at an early age (33 years, range 15 to 62), metastatic kidney cancer developed in 4 and some families had no manifestation other than kidney tumors. An additional family with 6 individuals found to have clear cell renal cell cancer that presented at a young average age (47 years, range 40 to 53) was identified with a germline SDHC mutation (R133X) Metastatic disease developed in 2 of these family members. A patient with a history of carotid body paragangliomas and an aggressive form of kidney cancer was evaluated from a family with a germline SDHD mutation.SDH mutation associated renal cell carcinoma can be an aggressive type of kidney cancer, especially in younger individuals. Although detection and management of early tumors is most often associated with a good outcome, based on our initial experience with these patients and our long-term experience with hereditary leiomyomatosis and renal cell carcinoma, we recommend careful surveillance of patients at risk for SDH mutation associated renal cell carcinoma and wide surgical excision of renal tumors.

INTRODUCTION AND OBJECTIVES: In 1994 we described a novel hereditary cancer syndrome, Hereditary Papillary Renal Cell Carcinoma (HPRC). HPRC is an autosomal dominant hereditary cancer syndrome in which affected individuals are at risk for the development of bilateral, multifocal, type 1 papillary kidney cancer. In 1997 we identified the proto-oncogene MET as the HPRC gene. HPRC patients are characterized by germline activating missense mutation in tyrosine kinase domain of MET and have a lifelong risk for the development of bilateral multifocal kidney tumors. Here we present our near-20-year experience on management of these patients. METHODS: From May 1992 to October 2011, 12 families with known germline MET mutation were followed with careful, periodic screening for development, growth, recurrence and metastasis of their renal tumors. Surgical removal was recommended when the largest kidney tumor reached a 3-cm cutoff size, and preference was given to nephron-sparing surgery. Median follow up was 65 months (range 1 month to 20 years). RESULTS: A total of 56 patients underwent periodic surveillance. Of these patients, 34 developed renal tumors: bilateral in 17, unilateral multiple in 13 and single in 4 patients. The average age at onset was 42 years (range 19 to 66). Twenty-nine patients underwent 42 kidney surgeries, of which 23 were performed at the National Cancer Institute: 17 were partial nephrectomies, of which 1 was a simultaneous bilateral partial nephrectomy, 2 were radical nephrectomies and 4 were radiofrequency ablation of renal tumors. Up to 59 tumors were removed from each renal unit. None of the patients required renal replacement therapy, with 22/23 patients maintaining postoperative eGFR 60. Metastatic disease developed in 5 patients all of whom presented with large or very rapidly growing lesions. CONCLUSIONS: In the largest reported experience worldwide with HPRC, patients affected by hereditary papillary renal cancer can be safely managed by expectant management, with nephron-sparing surgery triggered by tumors reaching a 3 cm size threshold. This management optimizes the renal function of these patients without compromising their oncologic outcomes.

Multiple, bilateral renal carcinomas are a frequent occurrence in von Hippel-Lindau (VHL) disease. To elucidate the aetiological role of the VHL gene in human kidney tumorigenesis, localized and advanced tumours from 110 patients with sporadic renal carcinoma were analysed for VHL mutations and loss of heterozygosity (LOH). VHL mutations were identified in 57% of clear cell renal carcinomas analysed and LOH was observed in 98% of those samples. Moreover, VHL was mutated and lost in a renal tumour from a patient with familial renal carcinoma carrying the constitutional translocation, t(3;8)(p14;q24). The identification of VHL mutations in a majority of localized and advanced sporadic renal carcinomas and in a second form of hereditary renal carcinoma indicates that the VHL gene plays a critical part in the origin of this malignancy.

We describe a 3 generation family with members affected with papillary renal cell carcinoma, an uncommon histological type of renal cell carcinoma. Multiple tumors of varying size were present in both kidneys of affected family members. The disorder was not linked to polymorphic markers on chromosome 3p and there was no loss of heterozygosity at loci on 3p in renal tumors. The results suggest the presence of a renal cell carcinoma gene not located on 3p that predisposes to renal cell carcinoma with a distinct histological appearance. The inherited disorder in this family appears to be different from recognized hereditary cancer syndromes.