The molecular pathogenesis of renal cell carcinoma (RCC) is poorly understood. Whole-genome and exome sequencing followed by innovative tumorgraft analyses (to accurately determine mutant allele ratios) identified several putative two-hit tumor suppressor genes including BAP1. BAP1, a nuclear deubiquitinase, is inactivated in 15% of clear-cell RCCs. BAP1 cofractionates with and binds to HCF-1 in tumorgrafts. Mutations disrupting the HCF-1 binding motif impair BAP1-mediated suppression of cell proliferation, but not H2AK119ub1 deubiquitination. BAP1 loss sensitizes RCC cells in vitro to genotoxic stress. Interestingly, BAP1 and PBRM1 mutations anticorrelate in tumors (P=3×10−5), and combined loss of BAP1 and PBRM1 in a few RCCs was associated with rhabdoid features (q=0.0007). BAP1 and PBRM1 regulate seemingly different gene expression programs, and BAP1 loss was associated with high tumor grade (q=0.0005). Our results establish the foundation for an integrated pathological and molecular genetic classification of RCC, paving the way for subtype-specific treatments exploiting genetic vulnerabilities.

, and the Upper TractUrothelial Carcinoma Collaboration BACKGROUND: The literature on upper tract urothelial carcinoma (UTUC) has been limited to small, single center studies. A large series of patients treated with radical nephroureterectomy for UTUC were studied,

No abstract

To further understand the molecular distinctions between kidney cancer subtypes, we analyzed exome, transcriptome and copy number alteration data from 167 primary human tumors that included renal oncocytomas and non–clear cell renal cell carcinomas (nccRCCs), consisting of papillary (pRCC), chromophobe (chRCC) and translocation (tRCC) subtypes. We identified ten significantly mutated genes in pRCC, including MET, NF2, SLC5A3, PNKD and CPQ. MET mutations occurred in 15% (10/65) of pRCC samples and included previously unreported recurrent activating mutations. In chRCC, we found TP53, PTEN, FAAH2, PDHB, PDXDC1 and ZNF765 to be significantly mutated. Gene expression analysis identified a five-gene set that enabled the molecular classification of chRCC, renal oncocytoma and pRCC. Using RNA sequencing, we identified previously unreported gene fusions, including ACTG1-MITF fusion. Ectopic expression of the ACTG1-MITF fusion led to cellular transformation and induced the expression of downstream target genes. Finally, we observed upregulation of the anti-apoptotic factor BIRC7 in MiTF-high RCC tumors, suggesting a potential therapeutic role for BIRC7 inhibitors.

Clear cell renal cell carcinoma (ccRCC) is the most common form of human kidney cancer. Histological and molecular analyses suggest that ccRCCs have significantly altered metabolism. Recent human studies of lung cancer and intracranial malignancies demonstrated an unexpected preservation of carbohydrate oxidation in the tricarboxylic acid (TCA) cycle. To test the capacity of ccRCC to oxidize substrates in the TCA cycle, we infused C-labeled fuels in ccRCC patients and compared labeling patterns in tumors and adjacent kidney. After infusion with [U-C]glucose, ccRCCs displayed enhanced glycolytic intermediate labeling, suppressed pyruvate dehydrogenase flow, and reduced TCA cycle labeling, consistent with the Warburg effect. Comparing C labeling among ccRCC, brain, and lung tumors revealed striking differences. Primary ccRCC tumors demonstrated the highest enrichment in glycolytic intermediates and lowest enrichment in TCA cycle intermediates. Among human tumors analyzed by intraoperativeC infusions, ccRCC is the first to demonstrate a convincing shift toward glycolytic metabolism.

Most anticancer drugs entering clinical trials fail to achieve approval from the US FDA. Drug development is hampered by the lack of preclinical models with therapeutic predictive value. Herein, we report the development and validation of a tumorgraft model of renal cell carcinoma (RCC) and its application to the evaluation of an experimental drug. Tumor samples from 94 patients were implanted in the kidney of mice without additives or disaggregation. Tumors from 35 patients formed tumorgrafts, and 16 stable lines were established. Samples from metastatic sites engrafted at high frequency, and stable engraftment of primary tumors in mice correlated with decreased patient survival suggesting that tumor growth in mice may reveal the acquisition by the tumor of an ability to thrive at distant sites and metastasize. Tumorgrafts retained the histology, gene expression, DNA copy number alterations, and over 90% of the protein-coding gene mutations of the corresponding tumors. As determined by the induction of hypercalcemia in tumorgraft-bearing mice, tumorgrafts were able to act on the host causing paraneoplastic syndromes. In studies simulating drug exposures in patients, RCC tumorgraft growth was inhibited by sunitinib and sirolimus (into which temsirolimus is converted in humans), but not by erlotinib, which was used as a control. Dovitinib, a drug in clinical development, showed greater activity than sunitinib and sirolimus. The routine incorporation of models recapitulating the molecular genetics and drug sensitivities of human tumors into preclinical programs has the potential to improve oncology drug development.

Purpose To assess the association of lymphovascular invasion (LVI) with cancer recurrence and survival in a large international series of patients treated with radical nephroureterectomy (RNU) for upper urinary tract urothelial carcinoma (UTUC). Patients and Methods Data were collected on 1,453 patients treated with RNU at 13 academic centers and combined into a relational database. Pathologic slides were rereviewed by genitourinary pathologists according to strict criteria. LVI was defined as presence of tumor cells within an endothelium-lined space. Results LVI was observed in 349 patients (24%). Proportion of LVI increased with advancing tumor stage, high tumor grade, presence of tumor necrosis, sessile tumor architecture, and presence of lymph node metastasis (all P < .001). LVI was an independent predictor of disease recurrence and survival (P < .001 for both). Addition of LVI to the base model (comprising pathologic stage, grade, and lymph node status) marginally improved its predictive accuracy for both disease recurrence and survival (1.1%, P = .03; and 1.7%, P < .001, respectively). In patients with negative lymph nodes and those in whom a lymphadenectomy was not performed (n = 1,313), addition of LVI to the base model improved the predictive accuracy of the base model for both disease recurrence and survival by 3% (P < .001 for both). In contrast, LVI was not associated with disease recurrence or survival in node-positive patients (n = 140). Conclusion LVI was an independent predictor of clinical outcomes in nonmetastatic patients who underwent RNU for UTUC. Assessment of LVI may help identify patients who could benefit from multimodal therapy after RNU. After confirmation, LVI should be included in staging of UTUC.

No abstract