Novel FH mutations in families with hereditary leiomyomatosis and renal cell cancer (HLRCC) and patients with isolated type 2 papillary renal cell carcinoma.

BACKGROUND: Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant disorder predisposing humans to cutaneous and uterine leiomyomas; in 20% of affected families, type 2 papillary renal cell cancers (PRCCII) also occur with aggressive course and poor prognosis. HLRCC results from heterozygous germline mutations in the tumour suppressor fumarate hydratase (FH) gene. METHODS: As part of the French National Cancer Institute (INCa) 'Inherited predispositions to kidney cancer' network, sequence analysis and a functional study of FH were preformed in 56 families with clinically proven or suspected HLRCC and in 23 patients with isolated PRCCII (5 familial and 18 sporadic). RESULTS: The study identified 32 different germline FH mutations (15 missense, 6 frameshifts, 4 nonsense, 1 deletion/insertion, 5 splice site, and 1 complete deletion) in 40/56 (71.4%) families with proven or suspected HLRCC and in 4/23 (17.4%) probands with PRCCII alone, including 2 sporadic cases. 21 of these were novel and all were demonstrated as deleterious by significant reduction of FH enzymatic activity. In addition, 5 asymptomatic parents in 3 families were confirmed as carrying disease-causing mutations. CONCLUSIONS: This study identified and characterised 21 novel FH mutations and demonstrated that PRCCII can be the only one manifestation of HLRCC. Due to the incomplete penetrance of HLRCC, the authors propose to extend the FH mutation analysis to every patient with PRCCII occurring before 40 years of age or when renal tumour harbours characteristic histologic features, in order to discover previously ignored HLRCC affected families.

Fumarate Hydratase-deficient Cell Line NCCFH1 as a New In Vitro Model of Hereditary Papillary Renal Cell Carcinoma Type 2.

BACKGROUND/AIM: Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is a rare autosomal dominant disorder characterized by fumarate hydratase (FH) gene mutation. It is associated with the development of very aggressive kidney tumors, characterized by early onset and high metastatic potential, and has no effective therapy. The aim of the study was to establish a new preclinical platform for investigating morphogenetic and metabolic features, and alternative therapy of metastatic hereditary papillary renal cell carcinoma type 2 (PRCC2). MATERIALS AND METHODS: Fresh cells were collected from pleural fluid of a patient with metastatic hereditary PRCC2. Morphogenetic and functional characteristics were evaluated via microscopy, FH gene sequencing analysis, real-time polymerase chaine reaction and enzymatic activity measurement. We performed bioenergetic analysis, gene-expression profiling, and cell viability assay with 19 anti-neoplastic drugs. RESULTS: We established a new in vitro model of hereditary PRCC2 - the NCCFH1 cell line. The cell line possesses a c.1162 delA - p.Thr375fs frameshift mutation in the FH gene. Our findings indicate severe attenuation of oxidative phosphorylation and glucose-dependent growth of NCCFH1 cells that is consistent with the Warburg effect. Furthermore, gene-expression profiling identified that the most prominent molecular features reflected a high level of apoptosis, cell adhesion, and cell signaling. Drug screening revealed a marked sensitivity of FH(-/-) cells to mitoxantrone, epirubicin, topotecan and a high sensitivity to bortezomib. CONCLUSION: We demonstrated that the NCCFH1 cell line is a very interesting preclinical model for studying the metabolic features and testing new therapies for hereditary PRCC2, while bortezomib may be a potential efficient therapeutic option.

An antioxidant response phenotype shared between hereditary and sporadic type 2 papillary renal cell carcinoma.

Fumarate hydratase (FH) mutation causes hereditary type 2 papillary renal cell carcinoma (PRCC2). The main effect of FH mutation is fumarate accumulation. The current paradigm posits that the main consequence of fumarate accumulation is HIF-α stabilization. Paradoxically, FH mutation differs from other HIF-α stabilizing mutations, such as VHL and SDH mutations, in its associated tumor types. We identified that fumarate can directly up-regulate antioxidant response element (ARE)-controlled genes. We demonstrated that aldo-keto reductase family 1 member B10 (AKR1B10) is an ARE-controlled gene and is up-regulated upon FH knockdown as well as in FH null cell lines. AKR1B10 overexpression is also a prominent feature in both hereditary and sporadic PRCC2. This phenotype better explains the similarities between hereditary and sporadic PRCC2.