Wild-type Renal Cell Carcinoma Research Articles

Molecular and Immune Landscape of Fumarate Hydratase-mutated Renal Cell Carcinoma

Fumarate hydratase-deficient renal cell carcinomas are an aggressive form of kidney cancer that often results in poor prognosis and high fatality rates. The implications of somatic mutations are not well described, and standard treatment has not been established for this renal cell carcinoma subtype. Further molecular characterization of fumarate hydratase-deficient renal cell carcinomas could potentially help to identify biomarkers that can be exploited with future targeted therapies. 2199 renal cell carcinomas were analyzed by DNA sequencing (592-gene panel) and whole- transcriptome sequencing and 40 tumors were identified with pathogenic FH mutations. Co-occurrence of mutation with other cancer-related genes were assessed along with immune profiles and immunotherapy biomarkers. Fumarate hydratase-deficient renal cell carcinomas had a lower prevalence of co-mutation with common renal cell carcinoma driver mutations such as VHL and chromatin remodeling genes when compared to wild type renal cell carcinoma. Conversely, prevalence of several cancer-related genes (MAX, BRCA1, PMS2, BRAF, NF2, and AKT1) was higher in fumarate hydratase-deficient renal cell carcinomas. Immunotherapy biomarkers (mismatch repair deficiency and tumor mutational burden) were detected at low frequency in mutant and wild type renal cell carcinomas, while PDL1 expression occurred at higher frequency in fumarate hydratase-deficient renal cell carcinomas. Fumarate hydratase-mutated kidney tumors may have a different mutational and immune landscape than wild type tumors. The absence of VHL mutations in a significant number of fumarate hydratase deficient renal cell carcinomas suggest that FH mutations may drive tumorigenesis using distinct angiogenic pathways. Our study highlights potential therapeutic implications that will require further study.

Abstract 50: HTI-1511, a novel anti-EGFR-ADC, overcomes mutation resistance and demonstrates significant activity against multiple tumor types in preclinical studies

Abstract Multiple solid tumor types over-express epidermal growth factor receptor (EGFR). Antibodies that target the receptor are often accompanied by adverse skin reactions due to interaction with receptors expressed in normal tissue. Additionally, downstream mutations (KRAS, BRAF) within tumors can result in EGFR-independent activation and resistance to treatment. We have previously described HTI-1511, an antibody-drug conjugate in pre-clinical development that targets EGFR. HTI-1511 carries the potent cytotoxin MMAE and a novel bis-alkylating linker, connected to a monoclonal antibody engineered to have improved specificity for EGFR in the tumor microenvironment (Huang et. al. AACR National Meeting, 2016, New Orleans, LA). Here we screened a panel of over 70 tumor cell lines derived from various solid tumor malignancies for both EGFR expression by flow cytometry and sensitivity to cell growth inhibition by HTI-1511 in vitro. Cell lines derived from head and neck squamous cell carcinoma (SCC15, CAL27, FaDu, CAL33, SCC25 [IC50 0.52 nM - 3.1 nM]), non-small cell lung cancer (HCC827, NCI-H1666, PC-9, NCI-H1650 [IC50 0.04 nM - 6.2 nM]), and pancreatic carcinoma (BxPC-3, PANC-1, AsPC-1 [IC50 0.99 nM - 4.44 nM]) showed particular sensitivity to HTI-1511. In conjunction, HTI-1511 efficacy was assessed in vivo for tumor growth inhibition (TGI) in several human tumor xenograft models. Evaluations in the human xenografts A431 (epidermoid, 93% TGI at 3.0 mg/kg, p<0.05), BxPC3 (pancreatic, >100% TGI at 3.0 mg/kg, p<0.05), AsPC-1 (pancreatic, >100% TGI at 3.0 mg/kg, p<0.05), and FaDu (HNSCC, >100% TGI at 3.0 mg/kg, p<0.05) indicated dose dependent tumor regressions in all cases, and no observed toxicity when administered weekly at dose levels up to 3 mg/kg for up to eight weeks. HTI-1511 anti-tumor activity was also investigated in a group of patient derived xenograft (PDX) models. An initial study evaluated weekly administration of a single dose level of 2.5 mg/kg HTI-1511 in three different PDX models. TGI of 83% (p<0.05) was observed in a BRAFmut colorectal cancer model and 57% (p<0.05) in a wildtype colorectal cancer model, as well as 46% (not significant) TGI seen in a wild type renal cell carcinoma model. A separate study in a NSCLC (KRASmut) PDX model demonstrated a dose dependent response with greater than 100% TGI at 1.0 and 3.0 mg/kg (both p<0.05, and also p<0.05 to a non-cognate antibody ADC control). The non-cognate antibody control yielded 67.4% (not significant) TGI by itself compared to the vehicle control group. These results support further development of HTI-1511 as a possible treatment for EGFR overexpressing tumors, including those with downstream activating mutations in the KRAS/BRAF pathway. Citation Format: Jesse D. Bahn, Feng Gao, Lei Huang, Barbara Blouw, Chunmei Zhao, Kelly Chen, Susan Zimmerman, Erin K. Wise, Maria L. Mancini, Matthew Bird, William McDowell, Curtis B. Thompson, Sanna Rosengren, Christopher D. Thanos. HTI-1511, a novel anti-EGFR-ADC, overcomes mutation resistance and demonstrates significant activity against multiple tumor types in preclinical studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 50. doi:10.1158/1538-7445.AM2017-50

Abstract 2381: The effect of ERK5 inhibition in clear cell renal cell carcinoma

Abstract Introduction Clear-cell renal cell carcinoma (ccRCC) is the most prevalent kidney cancer and is characterized by von Hippel-Lindau tumor suppressor gene (VHL) mutation. VHL protein acts in a ubiquitin ligase complex, mediating the proteasomal degradation of ubiquitinized proteins, including hypoxia-inducible factor (HIF). Therefore, HIF accumulates in VHL-defective cell lines. A recent study revealed that extracellular signal-regulated kinase 5 (ERK5) is degraded through the ubiquitin-proteasome system, in a process mediated by VHL and HIF. Our objectives were to examine the effects of ERK5 in ccRCC and to investigate ERK5 as a potential therapeutic target. Methods ERK5 expression was investigated in surgically resected ccRCC specimens using immunohistochemistry. To confirm that ERK5 is degraded by the VHL pathway, ERK5 levels were examined by western blotting in Caki-1 VHL wildtype renal cell carcinoma (RCC) cells and in A498 and A704 VHL-mutant RCC cells with or without the MG132 proteasome inhibitor. Furthermore, VHL-mutant cell lines were examined, with or without siRNA and XMD8-92-mediated ERK5 inhibition, to investigate the role of ERK5 in RCC cells using flow cytometry, MTS assays, and western blotting . Results In surgical specimens, RCC cells showed higher levels of ERK5 expression than did normal cells. In addition, MG132 enhanced ERK5 expression in wildtype cell lines, but not in VHL-mutant cell lines. Therefore, ERK5 degradation involves the VHL pathway. Furthermore, ERK5 inhibition resulted in increase of the sub-G1 population as observed by flow cytometry and cleaved RARP expression as seen by western blotting, indicating an increase in apoptotic cells. ERK5 inhibition also suppressed cell viability and downregulated p16 and Bcl-2 expression. Conclusion Our results show that ERK5 inhibition contributes to the downregulation of anti-apoptotic and cell cycle proteins and suggest that ERK5 is a promising therapeutic target for ccRCC. Citation Format: Hidenori Kanno, Sei Naito, Osamu Ichiyanagi, Norihiko Tsuchiya. The effect of ERK5 inhibition in clear cell renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2381. doi:10.1158/1538-7445.AM2017-2381