Hereditary leiomyomatosis and renal cell cancer: a syndrome associated with an aggressive form of inherited renal cancer

Radical nephrectomy and regional lymph node dissection for locally advanced type 2 papillary renal cell carcinoma in an at-risk individual from a family with hereditary leiomyomatosis and renal cell cancer: a case report

Background

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an autosomal dominant tumor susceptibility syndrome, and the disease-related gene has been identified as fumarate hydratase (fumarase, FH). HLRCC-associated kidney cancer is an aggressive tumor characterized by early metastasis to regional lymph nodes and distant organs. Since early diagnosis and provision of definitive therapy is thought to be the best way to reduce the tumor burden, it is widely accepted that germline testing and active surveillance for an at-risk individual from a family with HLRCC is very important. However, it still remains controversial how we should treat HLRCC-associated kidney cancer. We successfully treated the patient with locally advanced HLRCC-associated kidney cancer, who has received active surveillance because of at-risk individual, by radical nephrectomy and extended retroperitoneal lymph node dissection, and examined surgically resected samples from a molecular point of view.

Case presentation

We recommended that 13 at-risk individuals from a family with HLRCC should receive active surveillance for early detection of renal cancer. A 48-year-old woman with a left renal tumor and involvement of multiple regional lymph nodes with high accumulation of fluorine-18-deoxyglucose on positron emission tomography was treated with axitinib as a neoadjuvant therapy. Preoperative axitinib induced the shrinkage of the tumor with decreased fluorine-18-deoxyglucose accumulation. Resected samples showed two thirds tumor tissue necrosis as well as high expression of serine/threonine kinase Akt and low expression of nuclear factor E2-related factor 2 (Nrf2) which activates anti-oxidant response and protects against oxidative stress in viable cancer cells. Targeted next-generation sequencing revealed that FH mutation and loss of the second allele were completely identical between blood and tumor samples, suggesting that FH mutation plays a direct role in FH-deficient RCC. She has remained well after radical operation for over 33 months.

Conclusions

FH mutation plays a role in tumorigenic feature, a metabolic shift to aerobic glycolysis, and increased an anti-oxidant response phenotype in HLRCC-associated kidney cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2272-7) contains supplementary material, which is available to authorized users.

Hereditary Renal Cell Carcinoma Syndromes: Clinical, Pathologic, and Genetic Features

Renal cell carcinomas associated with syndromes of a heritable nature account for about 4% of all renal cell carcinomas. They are characterized by an earlier age of onset, and are often multicentric and bilateral. Some of these patients may fit into well-characterized kidney cancer syndromes, while many more may have a genetic component that is not fully recognized or understood. The presence of extrarenal clinical features may suggest a specific renal tumor susceptibility syndrome. Moreover, each syndrome is associated with specific renal pathology findings. Recognition of individuals and families with a high risk of renal neoplasia is important so that surveillance for renal tumors may be initiated. This manuscript reviews the clinical, pathological, and molecular features of hereditary renal cell carcinoma syndromes with emphasis on the morphologic features of these tumors and the molecular mechanisms of hereditary renal tumorigenesis.

Cutaneous manifestations of genitourinary malignancy

Genitourinary cancers are associated with a range of cutaneous syndromes, which can reflect direct metastatic spread, non-metastatic manifestations of malignancy or the consequences of treatment. More than 220,000 new cases of prostate cancer occur each year in the United States, and thus the associations with cutaneous involvement are quite well documented-rare metastatic spread, vasculitic and hemorrhagic syndromes. Cancers of the bladder and kidney may be associated with direct cutaneous metastases, vasculitic syndromes, hereditary leiomyomatosis, and other familial syndromes. Testicular cancer occasionally metastasizes to the skin but more commonly is associated with the dysplastic nevus (multiple atypical nevus) syndrome. A structured approach to history-taking, examination, and investigation is essential for optimal management, especially when these syndromes precede the diagnosis of a known malignancy. A brief review of the more common iatrogenic cutaneous complications is provided, and includes Raynaud's phenomenon, purpura, rash, hand-foot syndrome, the consequences of marrow failure, and bleomycin-induced pigmentation.

Comprehensive Molecular Characterization of Papillary Renal-Cell Carcinoma

BACKGROUND

Papillary renal-cell carcinoma, which accounts for 15 to 20% of renal-cell carcinomas, is a heterogeneous disease that consists of various types of renal cancer, including tumors with indolent, multifocal presentation and solitary tumors with an aggressive, highly lethal phenotype. Little is known about the genetic basis of sporadic papillary renal-cell carcinoma, and no effective forms of therapy for advanced disease exist.

METHODS

We performed comprehensive molecular characterization of 161 primary papillary renal-cell carcinomas, using whole-exome sequencing, copy-number analysis, messenger RNA and microRNA sequencing, DNA-methylation analysis, and proteomic analysis.

RESULTS

Type 1 and type 2 papillary renal-cell carcinomas were shown to be different types of renal cancer characterized by specific genetic alterations, with type 2 further classified into three individual subgroups on the basis of molecular differences associated with patient survival. Type 1 tumors were associated with MET alterations, whereas type 2 tumors were characterized by CDKN2A silencing, SETD2 mutations, TFE3 fusions, and increased expression of the NRF2-antioxidant response element (ARE) pathway. A CpG island methylator phenotype (CIMP) was observed in a distinct subgroup of type 2 papillary renal-cell carcinomas that was characterized by poor survival and mutation of the gene encoding fumarate hydratase (FH).

CONCLUSIONS

Type 1 and type 2 papillary renal-cell carcinomas were shown to be clinically and biologically distinct. Alterations in the MET pathway were associated with type 1, and activation of the NRF2-ARE pathway was associated with type 2; CDKN2A loss and CIMP in type 2 conveyed a poor prognosis. Furthermore, type 2 papillary renal-cell carcinoma consisted of at least three subtypes based on molecular and phenotypic features. (Funded by the National Institutes of Health.).

New strategies in renal cell carcinoma: targeting the genetic and metabolic basis of disease

The development of new forms of treatment of advanced renal cell carcinoma over the past two decades has been primarily focused on targeting the VHL/HIF pathway. The recent identification of mutations of chromatin-remodeling genes in clear-cell renal carcinoma (ccRCC), of genomic heterogeneity, and of a Warburg-like metabolic phenotype in advanced disease has had a profound effect on our understanding of the evolution of ccRCC and on potential approaches to personalized therapy. Early approaches to therapy for patients with advanced type I papillary RCC that have centered around the MET/HGF pathway will expand as more genomic information becomes available. Sporadic and familial type II papillary renal cell carcinoma are characterized by enhanced aerobic glycolysis and share an antioxidant response phenotype. In fumarate hydratase-deficient RCC, fumarate-induced succination of KEAP1 activates Nrf2 signaling. CUL3 and Nrf2 mutations as well as an Nrf2 activation phenotype are found in sporadic type II papillary RCC. Therapeutic approaches designed to target the Nrf2 pathway as well as to impair blood flow and glucose delivery in these cancers that are highly dependent on a robust tumor vasculature and on ready availability of glucose for energy production and glycolysis are in development.

Genetic and Chromosomal Aberrations and Their Clinical Significance in Renal Neoplasms

The most common form of malignant renal neoplasms is renal cell carcinoma (RCC), which is classified into several different subtypes based on the histomorphological features. However, overlaps in these characteristics may present difficulties in the accurate diagnosis of these subtypes, which have different clinical outcomes. Genomic and molecular studies have revealed unique genetic aberrations in each subtype. Knowledge of these genetic changes in hereditary and sporadic renal neoplasms has given an insight into the various proteins and signalling pathways involved in tumour formation and progression. In this review, the genetic aberrations characteristic to each renal neoplasm subtype are evaluated along with the associated protein products and affected pathways. The potential applications of these genetic aberrations and proteins as diagnostic tools, prognostic markers, or therapeutic targets are also assessed.

Case 221: Hereditary Leiomyomatosis and Renal Cell Cancer Syndrome

History A 24-year-old woman presented to the emergency department with a history of acute urinary retention, gross hematuria, and left flank pain for 2 days. Past history was unrevealing. Her last menstrual period occurred 2 weeks prior to presentation. At physical examination, she had a temperature of 38.4°C. A palpable mass was noted in the suprapubic region, and a second mass was palpated in the left upper quadrant. Blood work revealed a hemoglobin level of 4.7 g/dL (normal range, 11.5-15.5 g/dL). Her coagulation profile and white blood cell count were within normal limits. Ultrasonography (US) of the abdomen and pelvis was performed and was followed by contrast material-enhanced (80 mL of iopamidol) computed tomography (CT) of the chest, abdomen, and pelvis. Magnetic resonance (MR) imaging of the abdomen and pelvis also was performed.

Nephron-sparing surgery for multifocal and hereditary renal tumors

PURPOSE OF REVIEW

Despite the controversy surrounding the benefits of nephron-sparing surgery, multiple absolute indications for nephron-sparing surgery still exist, including the classic indications of hereditary and bilateral kidney tumors.

RECENT FINDINGS

Multiple genetic mutations have been identified which lead to hereditary kidney cancer conditions. These are briefly reviewed because the surgical management of hereditary kidney tumors depends on the genetic and histologic subtypes involved. Clear understanding of these hereditary conditions is crucial for proper surgical management of these tumors.

SUMMARY

Complex partial nephrectomy for multiple renal tumors, or multiplex partial nephrectomy, requires not only exceptional surgical skills but expertise of numerous nonsurgical methodologies, such as hands-on intraoperative ultrasonography and interpretation of multiple imaging modalities. In addition, multidisciplinary management is crucial for optimal outcomes in patient care. This review evaluates the most advanced surgical techniques and perioperative management required to successfully care for these challenging cases.

Metastatic non-clear cell renal cell carcinoma: an evidence based review of current treatment strategies

Much progress has been made in the treatment of metastatic renal cell carcinoma (RCC) over the last decade, with the development of agents that block the vascular endothelial growth factor (VEGF) pathway or the mammalian target of rapamycin (mTOR) pathway. The incorporation of these agents into treatment algorithms has been the result of carefully conducted clinical trials leading to Food and Drug Administration (FDA) approval and subsequent adoption as the current standard of care. These trials, however, were dominated by patients with clear cell renal cell carcinoma (ccRCC), and little data are currently available on the treatment of non-clear cell renal cell carcinoma (nccRCC). nccRCC encompasses a biologically heterogeneous group of kidney tumors that portend very diverse prognoses and responses to therapy. This review is a pathway based approach that highlights the current systemic treatment strategies for metastatic nccRCC.

Potential genetic anticipation in hereditary leiomyomatosis-renal cell cancer (HLRCC)

Hereditary leiomyomatosis-renal cell cancer (HLRCC) is an autosomal dominant disorder characterised by cutaneous leiomyomas, symptomatic uterine leiomyomas and aggressive type II papillary renal cell carcinoma. It is caused by heterozygous mutations in the fumarate hydratase (FH) gene on chromosome 1q43. We present evidence of genetic anticipation in HLRCC syndrome. A comprehensive literature review was performed to determine the potential for genetic anticipation in HLRCC syndrome. The normal random effects model was used to evaluate for genetic anticipation to ensure reduction in bias. A total of 11 FH kindreds with available multi-generational data were identified for analysis. The mean difference in age at diagnosis of RCC between the first and second generation was -18.6 years (95 % CI -26.6 to -10.6, p < 0.001). The mean difference in age at diagnosis of RCC between the first and third generation was -36.2 years (95 % CI -47.0 to -25.4, p < 0.001). No evidence of anticipation for uterine leiomyomas was observed (p = 0.349). We report preliminary evidence of genetic anticipation of RCC in HLRCC syndrome. Additional clinical validation is important to confirm this observation, which may have practical implications on counseling and timing of surveillance initiation. Exploration of the underlying mechanisms of anticipation in HLRCC would be of considerable biological interest.

Concurrent renal-cell carcinoma and cutaneous leiomyomas: A case of HLRCC

A 51-year-old Caucasian female presenting with renal-cell cancer and cutaneous leiomyomas was later diagnosed with Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC) Syndrome. HLRCC is an autosomal dominant condition caused by a mutation in the fumarate hydratase gene, which encodes for an enzyme in the citric acid cycle. This syndrome has been reported in over 100 families throughout the world, the majority of whom are of Eastern European descent. Those with this syndrome have a significantly increased risk of developing renal-cell carcinoma, cutaneous leiomyomas, and uterine leiomyomas, and a smaller chance of developing uterine leiomyosarcomas. This syndrome has a relatively poor prognosis, with tumor metastasis occurring in approximately 50% of patients. However, more aggressive prophylactic measures and recent studies have shown potential to improve patient prognosis.

Targeting ABL1-mediated oxidative stress adaptation in fumarate hydratase-deficient cancer

Patients with germline fumarate hydratase (FH) mutation are predisposed to develop aggressive kidney cancer with few treatment options and poor therapeutic outcomes. Activity of the proto-oncogene ABL1 is upregulated in FH-deficient kidney tumors and drives a metabolic and survival signaling network necessary to cope with impaired mitochondrial function and abnormal accumulation of intracellular fumarate. Excess fumarate indirectly stimulates ABL1 activity, while restoration of wild-type FH abrogates both ABL1 activation and the cytotoxicity caused by ABL1 inhibition or knockdown. ABL1 upregulates aerobic glycolysis via the mTOR/HIF1α pathway and neutralizes fumarate-induced proteotoxic stress by promoting nuclear localization of the antioxidant response transcription factor NRF2. Our findings identify ABL1 as a pharmacologically tractable therapeutic target in glycolytically dependent, oxidatively stressed tumors.

Hereditary leiomyomatosis and renal cell cancer (HLRCC): renal cancer risk, surveillance and treatment

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant condition in which susceptible individuals are at risk for the development of cutaneous leiomyomas, early onset multiple uterine leiomyomas and an aggressive form of type 2 papillary renal cell cancer. HLRCC is caused by germline mutations in the fumarate hydratase (FH) gene which inactivate the enzyme and alters the function of the tricarboxylic acid (Krebs) cycle. Issues surrounding surveillance and treatment for HLRCC-associated renal cell cancer were considered as part of a recent international symposium on HLRCC. The management protocol proposed in this article is based on a literature review and a consensus meeting. The lifetime renal cancer risk for FH mutation carriers is estimated to be 15 %. In view of the potential for early onset of RCC in HLRCC, periodic renal imaging and, when available, predictive testing for a FH mutation is recommended from 8 to 10 years of age. However, the small risk of renal cell cancer in the 10-20 years age range and the potential drawbacks of screening should be carefully discussed on an individual basis. Surveillance preferably consists of annual abdominal MRI. Treatment of renal tumours should be prompt and generally consist of wide-margin surgical excision and consideration of retroperitoneal lymph node dissection. The choice for systemic treatment in metastatic disease should, if possible, be part of a clinical trial. Screening procedures in HLRCC families should preferably be evaluated in large cohorts of families.

Diagnostic approach to eosinophilic renal neoplasms

CONTEXT

Eosinophilic renal neoplasms include a spectrum of solid and papillary tumors ranging from indolent benign oncocytoma to highly aggressive malignancies. Recognition of the correct nature of the tumor, especially in biopsy specimens, is paramount for patient management.

OBJECTIVE

To review the diagnostic approach to eosinophilic renal neoplasms with light microscopy and ancillary techniques.

DATA SOURCES

Review of the published literature and personal experience.

CONCLUSIONS

The following tumors are in the differential diagnosis of oncocytic renal cell neoplasm: oncocytoma, chromophobe renal cell carcinoma (RCC), hybrid tumor, tubulocystic carcinoma, papillary RCC, clear cell RCC with predominant eosinophilic cell morphology, follicular thyroid-like RCC, hereditary leiomyomatosis-associated RCC, acquired cystic disease-associated RCC, rhabdoid RCC, microphthalmia transcription factor translocation RCC, epithelioid angiomyolipoma, and unclassified RCC. In low-grade nonpapillary eosinophilic neoplasms, distinction between oncocytoma and low-grade RCC mostly rests on histomorphology; however, cytokeratin 7 immunostain may be helpful. In high-grade nonpapillary lesions, there is more of a role for ancillary techniques, including immunohistochemistry for cytokeratin 7, CA9, CD10, racemase, HMB45, and Melan-A. In papillary eosinophilic neoplasms, it is important to distinguish sporadic type 2 papillary RCC from microphthalmia transcription factor translocation and hereditary leiomyomatosis-associated RCC. Histologic and cytologic features along with immunohistochemistry and fluorescence in situ hybridization tests for TFE3 (Xp11.2) and TFEB [t(6;11)] are reliable confirmatory tests. Eosinophilic epithelial neoplasms with architecture, cytology, and/or immunoprofile not qualifying for either of the established types of RCC should be classified as unclassified eosinophilic RCC and arbitrarily assigned a grade (low or high).

The oncometabolite fumarate promotes pseudohypoxia through noncanonical activation of NF-κB signaling

Inactivating mutations of the gene encoding the tricarboxylic acid cycle enzyme fumarate hydratase (FH) have been linked to an aggressive variant of hereditary kidney cancer (hereditary leiomyomatosis and renal cell cancer). These tumors accumulate markedly elevated levels of fumarate. Fumarate is among a growing list of oncometabolites identified in cancers with mutations of genes involved in intermediary metabolism. FH-deficient tumors are notable for their pronounced accumulation of the transcription factor hypoxia inducible factor-1α (HIF-1α) and aggressive behavior. To date, HIF-1α accumulation in hereditary leiomyomatosis and renal cell cancer tumors is thought to result from fumarate-dependent inhibition of prolyl hydroxylases and subsequent evasion from von Hippel-Lindau-dependent degradation. Here, we demonstrate a novel mechanism by which fumarate promotes HIF-1α mRNA and protein accumulation independent of the von Hippel-Lindau pathway. Here we demonstrate that fumarate promotes p65 phosphorylation and p65 accumulation at the HIF-1α promoter through non-canonical signaling via the upstream Tank binding kinase 1 (TBK1). Consistent with these data, inhibition of the TBK1/p65 axis blocks HIF-1α accumulation in cellular models of FH loss and markedly reduces cell invasion of FH-deficient RCC cancer cells. Collectively, our data demonstrate a novel mechanism by which pseudohypoxia is promoted in FH-deficient tumors and identifies TBK1 as a novel putative therapeutic target for the treatment of aggressive fumarate-driven tumors.

Uterine smooth muscle tumors with features suggesting fumarate hydratase aberration: detailed morphologic analysis and correlation with S-(2-succino)-cysteine immunohistochemistry

Rare, sporadic uterine leiomyomas arise in the setting of severe metabolic aberration due to a somatic fumarate hydratase mutation. Germline mutations account for the hereditary leiomyomatosis and renal cell carcinoma syndrome, which predisposes for cutaneous and uterine leiomyomas and aggressive renal cell carcinomas. Altered fumarate hydratase leads to fumarate accumulation in affected cells with formation of S-(2-succino)-cysteine, which can be detected with the polyclonal antibody. High levels of these modified cysteine residues are found characteristically in fumarate hydratase-deficient cells but not in normal tissues or tumors unassociated with hereditary leiomyomatosis and renal cell carcinoma syndrome. We hypothesized that S-(2-succino)-cysteine-positive leiomyomas, indicating fumarate hydratase aberration, have morphologic features that differ from those without S-(2-succino)-cysteine positivity. Hematoxylin and eosin-stained slides of uterine smooth-muscle tumors were prospectively analyzed for features suggesting hereditary leiomyomatosis and renal cell carcinoma syndrome, such as prominent eosinophilic macronucleoli with perinucleolar halos, yielding nine cases. Germline genetic testing for fumarate hydratase mutations was performed in three cases. A detailed morphological analysis was undertaken, and S-(2-succino)-cysteine immunohistochemical analysis was performed with controls from a tissue microarray (leiomyomas (19), leiomyosarcomas (29), and endometrial stromal tumors (15)). Of the nine study cases, four had multiple uterine smooth muscle tumors. All cases had increased cellularity, staghorn vasculature, and fibrillary cytoplasm with pink globules. All cases had inclusion-like nucleoli with perinuclear halos (7 diffuse, 1 focal). All showed diffuse granular cytoplasmic labeling with the S-(2-succino)-cysteine antibody. Two of three tested patients had germline fumarate hydratase mutations. Only one leiomyoma from the tissue microarray controls was immunohistochemically positive, and it showed features similar to other immunohistochemically positive cases. Smooth-muscle tumors with fumarate hydratase aberration demonstrate morphological reproducibility across cases and S-(2-succino)-cysteine immuno-positivity. Although the features described are not specific for the germline fumarate hydratase mutation or the hereditary leiomyomatosis and renal cell carcinoma syndrome, their presence should suggest fumarate hydratase aberration. Identifying these cases is an important step in the diagnostic workup of patients with possible hereditary leiomyomatosis and renal cell carcinoma.

Hereditary leiomyomatosis and renal cell carcinoma

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an autosomal-dominant hereditary syndrome, which is caused by germline mutations in the FH gene that encodes the tricarboxylic acid cycle enzyme fumarate hydratase (FH). HLRCC patients are predisposed to develop cutaneous leiomyomas, multiple, symptomatic uterine fibroids in young women resulting in early hysterectomies, and early onset renal tumors with a type 2 papillary morphology that can progress and metastasize, even when small. Since HLRCC-associated renal tumors can be more aggressive than renal tumors in other hereditary renal cancer syndromes, caution is warranted, and surgical intervention is recommended rather than active surveillance. At-risk members of an HLRCC family who test positive for the familial germline FH mutation should undergo surveillance by annual magnetic resonance imaging from the age of 8 years. Biochemical studies have shown that FH-deficient kidney cancer is characterized by a metabolic shift to aerobic glycolysis. It is hoped that through ongoing clinical trials evaluating targeted molecular therapies, an effective form of treatment for HLRCC-associated kidney cancer will be developed that will offer an improved prognosis for individuals affected with HLRCC-associated kidney cancer.

Understanding pathologic variants of renal cell carcinoma: distilling therapeutic opportunities from biologic complexity

CONTEXT

Once believed to represent a uniform malignant phenotype, renal cell carcinoma (RCC) is now viewed as a diverse group of cancers that arise from the nephron.

OBJECTIVE

To review the pathologic characteristics, clinical behavior, molecular biology, and systemic therapy options of recognized RCC histologic subtypes.

EVIDENCE ACQUISITION

A systematic review of English-language articles was performed using the Medline and Web of Science databases. Manuscripts were selected with consensus of the coauthors and evaluated using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria.

EVIDENCE SYNTHESIS

The major findings of the evaluated manuscripts are discussed with an emphasis on the description of the pathologic features, clinical behavior, prognosis, and therapeutic strategies.

CONCLUSIONS

Classification schemes for kidney cancer have undergone dramatic changes over the past two decades. Improvements in these classification schemes are important, as pathologic variants differ not only in disease biology, but also in clinical behavior, prognosis, and response to systemic therapy. In the era of genomic medicine, further refinements in characterization of RCC subtypes will be critical to the progress of this burgeoning clinical space.

PATIENT SUMMARY

Kidney cancer can be subdivided into related but different cancers that arise from the kidney's tubules. In this article we review current classifications for kidney cancer, discuss their characteristics, and provide an overview of each subtype's clinical behavior and treatment. We stress that each subtype harbors unique biology and thus responds differently to available treatment strategies.

Hereditary renal cell carcinoma: genetics, clinical features, and surgical considerations

OBJECTIVES

Hereditary renal cancer syndromes have been described and have illuminated novel methods to treat sporadic renal cell carcinoma. In this work, we aimed to review the genetic basis, molecular pathology and clinical manifestations of hereditary syndromes, as well as outline principles of surgical management and use of targeted therapy.

METHODS

We performed a comprehensive review of selected peer-reviewed publications regarding hereditary renal cancer syndromes, their genetic basis, and recommendations for surgical management.

RESULTS

The major syndromes contributing to hereditary renal cell carcinoma are discussed along with relevant literature guiding their management. The evolving surgical and molecular treatments are discussed.

CONCLUSIONS

Identification of genetic basis of hereditary carcinomas provides opportunity for targeted therapy of metastatic sporadic renal cell carcinoma. Appropriate and timely surgical management of hereditary renal cancers decreases the possibility of development of metastatic disease, and allows for preservation of renal function despite the need for repeat surgical interventions.

Aerobic glycolysis: a novel target in kidney cancer

Renal cell carcinoma (RCC) is a heterogenous group of cancers that arise from the nephron. While there are distinct histologic subtypes associated with common genetic alterations, most forms of RCC are linked by a common pathway of dysregulated metabolism. Reliance on aerobic glycolysis, a feature of cancer first hypothesized by Warburg, is a common feature in sporadic and hereditary forms of kidney cancer. Two hereditary forms of RCC, succinate dehydrogenase (SDH) and hereditary leiomyomatosis and RCC (HLRCC), are characterized by mutations in Krebs cycle enzymes, rendering them dependent on glycolysis for energy requirements. The reliance on these pathways may make them vulnerable to novel metabolic strategies, including inhibition of glycolysis, glucose uptake and macromolecule biosynthesis.

Hereditary kidney cancer syndromes

Inherited susceptibility to kidney cancer is a fascinating and complex topic. Our knowledge about types of genetic syndromes associated with an increased risk of disease is continually expanding. Currently, there are 10 syndromes associated with an increased risk of all types of kidney cancer, which are reviewed herein. Clear cell kidney cancer is associated with von Hippel Lindau disease, chromosome 3 translocations, PTEN hamartomatous syndrome, and mutations in the BAP1 gene as well as several of the genes encoding the proteins comprising the succinate dehydrogenase complex (SDHB/C/D). Type 1 papillary kidney cancers arise in conjunction with germline mutations in MET and type 2 as part of hereditary leiomyomatosis and kidney cell cancer (fumarate hydratase [FH] mutations). Chromophone and oncocytic kidney cancers are predominantly associated with Birt-Hogg-Dubé syndrome. Patients with Tuberous Sclerosis Complex (TSC) commonly have angiomyolipomas and rarely their malignant counterpart epithelioid angiomyolipomas. The targeted therapeutic options for the kidney cancer associated with these diseases are just starting to expand and are an area of active clinical research.

Defining early-onset kidney cancer: implications for germline and somatic mutation testing and clinical management

PURPOSE

Approximately 5% to 8% of renal cell carcinoma (RCC) is hereditary. No guidelines exist for patient selection for RCC germline mutation testing. We evaluate how age of onset could indicate the need for germline mutation testing for detection of inherited forms of kidney cancer.

PATIENTS AND METHODS

We analyzed the age distribution of RCC cases in the SEER-17 program and in our institutional hereditary kidney cancer population. The age distributions were compared by sex, race, histology, and hereditary cancer syndrome. Models were established to evaluate the specific age thresholds for genetic testing.

RESULTS

The median age of patients with RCC in SEER-17 was 64 years, with the distribution closely approaching normalcy. Statistical differences were observed by race, sex, and subtype (P < .05). The bottom decile cutoff was ≤ 46 years of age and slightly differed by sex, race, and histology. The mean and median ages at presentation of 608 patients with hereditary kidney cancer were 39.3 years and 37 years, respectively. Although age varied by specific syndrome, 70% of these cases were found to lie at or below the bottom age decile. Modeling age-based genetic testing thresholds demonstrated that the 10th percentile maximized sensitivity and specificity.

CONCLUSION

Early age of onset might be a sign of hereditary RCC. Even in the absence of clinical manifestations and personal/family history, an age of onset of 46 years or younger should trigger consideration for genetic counseling/germline mutation testing and may serve as a useful cutoff when establishing genetic testing guidelines.

Non-clear cell renal cancer: disease-based management and opportunities for targeted therapeutic approaches

A better understanding of the biology of renal cell carcinoma (RCC) has significantly changed the treatment paradigm of the disease. Several novel vascular endothelial growth factor (VEGF) and mammalian target of rapamycin (mTOR) inhibitors have been approved recently by the US Food and Drug Administration. Unfortunately, the vast majority of clinical trials conducted today have been aimed to include patients with clear cell RCC, which remains the most common histologic subtype of the disease. Non-clear cell RCC represents approximately 20%-25% of all RCC patients. Non-clear cell RCC is made up of multiple histologic subtypes, each with a different molecular printing profile. Although VEGF and TORC inhibitors are commonly used in the management of this cohort of patients, non-clear cell histologies do not appear to be related to the von Hippel-Lindau gene (VHL). As such, the clinical efficacy of the existing agents is quite limited. There is a need to develop more rational therapeutic approaches that specifically target the biology of each of the different subtypes of non-clear cell RCC. In this review, we discuss molecular and clinical characteristics of each of the non-clear cell RCC subtypes and describe ongoing efforts to develop novel agents for this subset of patients.

The role of angiogenic factors in fibroid pathogenesis: potential implications for future therapy

BACKGROUND

It is well established that tumors are dependent on angiogenesis for their growth and survival. Although uterine fibroids are known to be benign tumors with reduced vascularization, recent work demonstrates that the vasculature of fibroids is grossly and microscopically abnormal. Accumulating evidence suggests that angiogenic growth factor dysregulation may be implicated in these vascular and other features of fibroid pathophysiology.

METHODS

Literature searches were performed in PubMed and Google Scholar for articles with content related to angiogenic growth factors and myometrium/leiomyoma. The findings are hereby reviewed and discussed.

RESULTS

Multiple growth factors involved in angiogenesis are differentially expressed in leiomyoma compared with myometrium. These include epidermal growth factor (EGF), heparin-binding-EGF, vascular endothelial growth factor, basic fibroblast growth factor, platelet-derived growth factor, transforming growth factor-β and adrenomedullin. An important paradox is that although leiomyoma tissues are hypoxic, leiomyoma feature down-regulation of key molecular regulators of the hypoxia response. Furthermore, the hypoxic milieu of leiomyoma may contribute to fibroid development and growth. Notably, common treatments for fibroids such as GnRH agonists and uterine artery embolization (UAE) are shown to work at least partly via anti-angiogenic mechanisms.

CONCLUSIONS

Angiogenic growth factors play an important role in mechanisms of fibroid pathophysiology, including abnormal vasculature and fibroid growth and survival. Moreover, the fibroid's abnormal vasculature together with its aberrant hypoxic and angiogenic response may make it especially vulnerable to disruption of its vascular supply, a feature which could be exploited for treatment. Further experimental studies are required in order to gain a better understanding of the growth factors that are involved in normal and pathological myometrial angiogenesis, and to assess the potential of anti-angiogenic treatment strategies for uterine fibroids.

Metabolic reprogramming for producing energy and reducing power in fumarate hydratase null cells from hereditary leiomyomatosis renal cell carcinoma

Fumarate hydratase (FH)-deficient kidney cancer undergoes metabolic remodeling, with changes in mitochondrial respiration, glucose, and glutamine metabolism. These changes represent multiple biochemical adaptations in glucose and fatty acid metabolism that supports malignant proliferation. However, the metabolic linkages between altered mitochondrial function, nucleotide biosynthesis and NADPH production required for proliferation and survival have not been elucidated. To characterize the alterations in glycolysis, the Krebs cycle and the pentose phosphate pathways (PPP) that either generate NADPH (oxidative) or do not (non-oxidative), we utilized [U-¹³C]-glucose, [U-¹³C,¹⁵N]-glutamine, and [1,2- ¹³C₂]-glucose tracers with mass spectrometry and NMR detection to track these pathways, and measured the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) of growing cell lines. This metabolic reprogramming in the FH null cells was compared to cells in which FH has been restored. The FH null cells showed a substantial metabolic reorganization of their intracellular metabolic fluxes to fulfill their high ATP demand, as observed by a high rate of glucose uptake, increased glucose turnover via glycolysis, high production of glucose-derived lactate, and low entry of glucose carbon into the Krebs cycle. Despite the truncation of the Krebs cycle associated with inactivation of fumarate hydratase, there was a small but persistent level of mitochondrial respiration, which was coupled to ATP production from oxidation of glutamine-derived α–ketoglutarate through to fumarate. [1,2- ¹³C₂]-glucose tracer experiments demonstrated that the oxidative branch of PPP initiated by glucose-6-phosphate dehydrogenase activity is preferentially utilized for ribose production (56-66%) that produces increased amounts of ribose necessary for growth and NADPH. Increased NADPH is required to drive reductive carboxylation of α-ketoglutarate and fatty acid synthesis for rapid proliferation and is essential for defense against increased oxidative stress. This increased NADPH producing PPP activity was shown to be a strong consistent feature in both fumarate hydratase deficient tumors and cell line models.

Renal cancer in von Hippel-Lindau disease and related syndromes

Sporadic and hereditary forms of renal cell carcinoma (RCC), von Hippel-Lindau (VHL) disease and the familial paraganglioma syndromes are closely related in terms of their clinical, molecular, and genetic aspects. Most RCCs occur sporadically and the heritable fraction of RCC is estimated to be just 2-4%. An understanding of the molecular genetic basis, the disease-specific and gene-specific biology and the clinical characteristics of these cancer syndromes is of utmost importance for effective genetic diagnosis and appropriate treatment. In addition, such insight will improve our understanding of sporadic RCCs. To date, 10 different heritable RCC syndromes have been described. VHL syndrome is the oldest known hereditary RCC syndrome. Similar to VHL disease, phaeochromocytoma is a major manifestation of the paraganglioma syndromes types 1, 3 and 4 in which RCCs have been reported. These syndromes are therefore regarded as VHL-related disorders and are included in this Review. Multifocal tumours, bilateral occurrence, a young age at diagnosis and/or family history are clinical red flags suggestive of hereditary disease and should trigger referral for genetic and molecular analysis. The identification of an underlying genetic alteration enables gene-specific risk assessment and opens up the possibility of a tailored follow-up strategy and specific surveillance protocols as the basis of effective preventive medicine. The important goals of preventive medicine are to increase the life expectancy of affected patients and to improve their quality of life. The study of seemingly rare hereditary syndromes and their susceptibility genes has consistently revealed clues regarding the aetiology and pathogenesis of these diseases, and can aid diagnosis and the development of therapeutics for patients affected by much more common sporadic counterparts.

Molecular pathways: Fumarate hydratase-deficient kidney cancer--targeting the Warburg effect in cancer

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is a hereditary cancer syndrome in which affected individuals are at risk for development of cutaneous and uterine leiomyomas and an aggressive form of type II papillary kidney cancer. HLRCC is characterized by germline mutation of the tricarboxylic acid (TCA) cycle enzyme, fumarate hydratase (FH). FH-deficient kidney cancer is characterized by impaired oxidative phosphorylation and a metabolic shift to aerobic glycolysis, a form of metabolic reprogramming referred to as the Warburg effect. Increased glycolysis generates ATP needed for increased cell proliferation. In FH-deficient kidney cancer, levels of AMP-activated protein kinase (AMPK), a cellular energy sensor, are decreased resulting in diminished p53 levels, decreased expression of the iron importer, DMT1, leading to low cellular iron levels, and to enhanced fatty acid synthesis by diminishing phosphorylation of acetyl CoA carboxylase, a rate-limiting step for fatty acid synthesis. Increased fumarate and decreased iron levels in FH-deficient kidney cancer cells inactivate prolyl hydroxylases, leading to stabilization of hypoxia-inducible factor (HIF)-1α and increased expression of genes such as VEGF and glucose transporter 1 (GLUT1) to provide fuel needed for rapid growth demands. Several therapeutic approaches for targeting the metabolic basis of FH-deficient kidney cancer are under development or are being evaluated in clinical trials, including the use of agents such as metformin, which would reverse the inactivation of AMPK, approaches to inhibit glucose transport, lactate dehydrogenase A (LDHA), the antioxidant response pathway, the heme oxygenase pathway, and approaches to target the tumor vasculature and glucose transport with agents such as bevacizumab and erlotinib. These same types of metabolic shifts, to aerobic glycolysis with decreased oxidative phosphorylation, have been found in a wide variety of other cancer types. Targeting the metabolic basis of a rare cancer such as FH-deficient kidney cancer will hopefully provide insights into the development of effective forms of therapies for other, more common forms of cancer.

Hereditary renal tumor syndromes: imaging findings and management strategies

OBJECTIVE

It is not rare for the radiologist to identify multiple renal masses and be the first to raise the possibility of a hereditary renal tumor syndrome. Characteristic renal and extrarenal imaging findings aid in making the correct diagnosis. The imaging findings, screening guidelines, and management techniques for the most common hereditary renal tumor syndromes are reviewed.

CONCLUSION

Hereditary renal tumor syndromes have specific screening guidelines and unique management techniques in which imaging plays a central role.

Morphologic and molecular characteristics of uterine leiomyomas in hereditary leiomyomatosis and renal cancer (HLRCC) syndrome

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a hereditary cancer syndrome in which affected individuals are predisposed to the development of multiple leiomyomas of the skin and uterus and aggressive forms of kidney cancer. Affected individuals harbor a germline heterozygous loss-of-function mutation of the fumarate hydratase (FH) gene. Uterine leiomyomas are present in up to 77% of women with this syndrome. Previous studies have shown that inactivation of the FH gene is unusual for nonsyndromic leiomyomas. Therefore, it might be possible to distinguish 2 genetic groups of smooth muscle tumors: the most common group of sporadic uterine leiomyomas without FH gene inactivation and the more unusual group of HLRCC leiomyomas in patients who harbor a germline mutation of FH, although the exact prevalence of hereditary HLRCC is unknown. We reviewed the clinical, morphologic, and genotypic features of uterine leiomyomas in 19 HLRCC patients with FH germline mutations. Patients with HLRCC syndrome were younger in age compared with those with regular leiomyomata. DNA was extracted by microdissection, and analysis of loss of heterozygosity (LOH) at 1q43 was performed. Uterine leiomyomas in HLRCC have young age of onset and are multiple, with size ranging from 1 to 8 cm. Histopathologically, HLRCC leiomyomas frequently had increased cellularity, multinucleated cells, and atypia. All cases showed tumor nuclei with large orangeophilic nucleoli surrounded by a perinucleolar halo similar to the changes found in HLRCC. Occasional mitoses were found in 3 cases; however, the tumors did not fulfill the criteria for malignancy. Our study also showed that LOH at 1q43 was frequent in HLRCC leiomyomas (8/10 cases), similarly to what has been previously found in renal cell carcinomas from HLRCC patients. LOH is considered to be the second hit that inactivates the FH gene. We conclude that uterine leiomyomas associated with HLRCC syndrome have characteristic morphologic features. Both, uterine leiomyomas and renal cell carcinoma share some morphologic nuclear changes and genotypic features in HLRCC patients. The specific morphologic features of the uterine leiomyomas that we describe may help in the identification of patients who may be part of the hereditary syndrome.

The metabolic basis of kidney cancer

Kidney cancer is not a single disease; it is made up of a number of different types of cancer that occur in the kidney. Each of these different types of kidney cancer can have a different histology, have a different clinical course, can respond differently to therapy and is caused by a different gene. Kidney cancer is essentially a metabolic disease; each of the known genes for kidney cancer, VHL, MET, FLCN, TSC1, TSC2, TFE3, TFEB, MITF, fumarate hydratase (FH), succinate dehydrogenase B (SDHB), succinate dehydrogenase D (SDHD), and PTEN genes is involved in the cells ability to sense oxygen, iron, nutrients or energy. Understanding the metabolic basis of kidney cancer will hopefully provide the foundation for the development of effective forms of therapy for this disease.

Downregulation of fumarate hydratase is related to tumorigenesis in sporadic renal cell cancer

OBJECTIVE

Although germline mutations of fumarate hydratase (FH) are a useful molecular marker of hereditary leiomyomatosis and renal cell cancer (RCC) syndrome, their clinical significance in sporadic RCC has not been studied in detail. The aim of the present study was to investigate possible correlations between the expression of FH and the clinical implications of sporadic RCC.

MATERIALS AND METHODS

FH mRNA levels were evaluated in 140 tumor specimens from patients with primary RCC and in 62 specimens of corresponding normal-appearing kidney tissue using real-time quantitative polymerase chain reaction. Immunohistochemical staining was performed on 6 normal surrounding tissues and 71 RCC tissues.

RESULTS

FH mRNA levels were significantly lower in tumor tissues than in matched normal-appearing kidney tissues (p = 0.031). In all normal tissues, FH staining intensity was strong. However, the expression of FH showed no significant correlation with the pathological and clinical characteristics of patients with sporadic RCC.

CONCLUSIONS

Our results showed that FH mRNA expression decreased significantly in correlation with the transition from normal renal parenchyma to RCC. FH may be an indicator or tumorigenesis in sporadic RCC and could be a potential target for therapies against RCC in the future.

Succinate dehydrogenase kidney cancer: an aggressive example of the Warburg effect in cancer

PURPOSE

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Protein profiling of blood samples from patients with hereditary leiomyomatosis and renal cell cancer by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an extremely rare syndrome with autosomal dominant inheritance. HLRCC is characterized by a predisposition to leiomyomas of the skin and the uterus as well as renal cell carcinoma. The disease-related gene has been identified as fumarate hydratase (fumarase, FH), which encodes an enzyme involved in the mitochondrial tricarboxylic acid cycle. Protein profiling may give some insight into the molecular pathways of HLRCC. Therefore, we performed protein profiling of blood samples from HLRCC patients, their family members, and healthy volunteers, using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) coupled with IMAC-Cu chips. For hierarchical clustering analysis, we used the 45 peaks that revealed significant differences in single-marker analysis over the range from 1500 to 15,000 m/z. Heat map analysis based on the results of clustering distinguished the HLRCC kindred from non-HLRCC subjects with a sensitivity of 94% and a specificity of 90%. SELDI-TOF MS profiling of blood samples can be applied to identify patients with HLRCC and to assess specific molecular mechanisms involved in this condition.

Genetic basis of kidney cancer: role of genomics for the development of disease-based therapeutics

Kidney cancer is not a single disease; it is made up of a number of different types of cancer, including clear cell, type 1 papillary, type 2 papillary, chromophobe, TFE3, TFEB, and oncocytoma. Sporadic, nonfamilial kidney cancer includes clear cell kidney cancer (75%), type 1 papillary kidney cancer (10%), papillary type 2 kidney cancer (including collecting duct and medullary RCC) (5%), the microphalmia-associated transcription (MiT) family translocation kidney cancers (TFE3, TFEB, and MITF), chromophobe kidney cancer (5%), and oncocytoma (5%). Each has a distinct histology, a different clinical course, responds differently to therapy, and is caused by mutation in a different gene. Genomic studies identifying the genes for kidney cancer, including the VHL, MET, FLCN, fumarate hydratase, succinate dehydrogenase, TSC1, TSC2, and TFE3 genes, have significantly altered the ways in which patients with kidney cancer are managed. While seven FDA-approved agents that target the VHL pathway have been approved for the treatment of patients with advanced kidney cancer, further genomic studies, such as whole genome sequencing, gene expression patterns, and gene copy number, will be required to gain a complete understanding of the genetic basis of kidney cancer and of the kidney cancer gene pathways and, most importantly, to provide the foundation for the development of effective forms of therapy for patients with this disease.

Adrenal nodular hyperplasia in hereditary leiomyomatosis and renal cell cancer

PURPOSE

The condition hereditary leiomyomatosis and renal cell carcinoma is characterized by cutaneous leiomyomas, uterine fibroids and aggressive papillary renal cell carcinoma. A number of our patients with hereditary leiomyomatosis and renal cell carcinoma had atypical adrenal nodules, which were further evaluated to determine whether these nodules were associated with hereditary leiomyomatosis and renal cell carcinoma.

MATERIALS AND METHODS

Patients with hereditary leiomyomatosis and renal cell carcinoma underwent a comprehensive clinical and genetic evaluation. We reviewed the clinical presentation, anatomical and functional imaging, endocrine evaluation, pathological examination and germline mutation testing results.

RESULTS

Of 255 patients with hereditary leiomyomatosis and renal cell carcinoma 20 (7.8%) had primary adrenal lesions, including 4 with bilateral adrenal lesions and 4 with multiple nodules. Two patients had adrenocorticotropic hormone independent hypercortisolism. A total of 27 adrenal lesions were evaluated. The imaging characteristics of 5 of these lesions (18.5%) were not consistent with adenoma by noncontrast computerized tomography criteria. Positron emission tomography was positive in 7 of 10 cases (70%). A total of 12 nodules were surgically resected from 10 adrenal glands. Pathological examination revealed macronodular adrenal hyperplasia in all specimens.

CONCLUSIONS

Unilateral and bilateral adrenal nodular hyperplasia was detected in a subset of patients with hereditary leiomyomatosis and renal cell carcinoma. A functional endocrine evaluation is recommended when an adrenal lesion is discovered. Imaging frequently reveals lesions that are not typical of adenomas and positron emission tomography may be positive. To date no patient has had adrenal malignancy, and active surveillance of hereditary leiomyomatosis and renal cell carcinoma adrenal nodules appears justified.

Hereditary leiomyomatosis and renal cell cancer presenting as metastatic kidney cancer at 18 years of age: implications for surveillance

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant syndrome characterized by skin piloleiomyomas, uterine leiomyomas and papillary type 2 renal cancer caused by germline mutations in the fumarate hydratase (FH) gene. Previously, we proposed renal imaging for FH mutation carriers starting at the age of 20 years. However, recently an 18-year-old woman from a Dutch family with HLRCC presented with metastatic renal cancer. We describe the patient and family data, evaluate current evidence on renal cancer risk and surveillance in HLRCC and consider the advantages and disadvantages of starting surveillance for renal cancer in childhood. We also discuss the targeted therapies administered to our patient.

State of the science: an update on renal cell carcinoma

Renal cell carcinomas (RCC) are emerging as a complex set of diseases that are having a major socioeconomic impact and showing a continued rise in incidence throughout the world. As the field of urologic oncology faces these trends, several major genomic and mechanistic discoveries are altering our core understanding of this multitude of cancers, including several new rare subtypes of renal cancers. In this review, these new findings are examined and placed in the context of the well-established association of clear cell RCC (ccRCC) with mutations in the von Hippel-Lindau (VHL) gene and resultant aberrant hypoxia inducible factor (HIF) signaling. The impact of novel ccRCC-associated genetic lesions on chromatin remodeling and epigenetic regulation is explored. The effects of VHL mutation on primary ciliary function, extracellular matrix homeostasis, and tumor metabolism are discussed. Studies of VHL proteostasis, with the goal of harnessing the proteostatic machinery to refunctionalize mutant VHL, are reviewed. Translational efforts using molecular tools to elucidate discriminating features of ccRCC tumors and develop improved prognostic and predictive algorithms are presented, and new therapeutics arising from the earliest molecular discoveries in ccRCC are summarized. By creating an integrated review of the key genomic and molecular biological disease characteristics of ccRCC and placing these data in the context of the evolving therapeutic landscape, we intend to facilitate interaction among basic, translational, and clinical researchers involved in the treatment of this devastating disease, and accelerate progress toward its ultimate eradication.

A novel fumarate hydratase-deficient HLRCC kidney cancer cell line, UOK268: a model of the Warburg effect in cancer

The role of energy deregulation and altered/adapted metabolism in tumor cells is an increasingly important issue in understanding cancer. Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an aggressive form of RCC characterized by germline mutation of fumarate hydratase (FH), followed by somatic loss of the remaining wild-type allele and known to be a highly metastatic and lethal malignancy compared to other RCCs. The intrinsic loss of normal tricarboxylic acid (TCA) cycle presumably aids tumorigenesis due to the necessary metabolic alterations required and the enforced dependence on glycolysis derived energy, mimicking the Warburg effect. Thus, there is considerable utility in establishing a preclinical cell model from these tumors to study energy metabolism deregulation, as well as developing new targeted therapeutic approaches for TCA cycle enzyme-deficient cancers. Here, we describe a new immortalized cell line, UOK268, derived from a patient's primary HLRCC-associated kidney cancer. This represents the first primary renal cell line to model TCA cycle gene loss and provides a perfect partner cell line to our previously described metastasis-derived HLRCC-associated cell line, UOK262. We identified a novel germline FH missense mutation, p.His192Asp, and the subsequent loss of heterozygosity in UOK268. The UOK268 cell line expressed mutant FH protein, which localized to the mitochondria, but with loss of almost all catalytic activity. The UOK268 cells had severely compromised oxidative phosphorylation and increased glycolytic flux. Ingenuity pathways analysis of human mitochondria-focused cDNA microarray (hMitChip3) gene chip data confirmed the altered mRNA expression patterns of genes involved in several important pathways, such as lipid metabolism, apoptosis, and energy production/glycolysis. UOK268 provides a unique model of a primary cell line demonstrating an enforced, irreversible Warburg effect and, combined with UOK262, provides a unique in vitro preclinical model for studying the bioenergetics of the Warburg effect in human cancer.

Genetic syndromes associated with renal cell carcinoma: a review

AIMS

A review of recent knowledge on heredital syndromes related to renal cell carcinoma.

METHODS

Aim of this review was to summarize the recent knowledge of genetic syndromes associated with renal cell carcinoma.

RESULTS

Summary of incidence and factors modulating risk of hereditary renal cell carcinoma development.

CONCLUSIONS

Hereditary forms of RCC are relatively rare. Their study is beneficial in many ways. In individuals at a higher risk of a hereditary syndrome, the knowledge of hereditary forms may help to significantly decrease the impact of the hereditary disease. In the general population, knowledge acquired by the study of hereditary forms of RCC may in the future contribute to both diagnosis and treatment of sporadic tumours.

Detection of a novel FH whole gene deletion in the propositus leading to subsequent prenatal diagnosis in a sibship with fumarase deficiency

Fumarase deficiency is a rare autosomal recessive metabolic condition. We report on a sibship with molecularly confirmed fumarase deficiency. Prenatal findings included agenesis of the corpus callosum, ventriculomegaly, and ventriculoseptal defect. The postnatal course was significant for metabolic acidosis ultimately leading to death around 3 weeks of age. Postmortem findings were noted including swollen mitochondria with abnormal cristae on electron microscopy within the liver. Molecular testing revealed a novel whole gene deletion in conjunction with a point mutation. While the point mutation has been previously reported, the detection of a whole gene deletion has not been described to date in an individual with fumarase deficiency.