Oncolytic targeting of renal cell carcinoma via encephalomyocarditis virus

Abstract

Apoptosis is a fundamental host defence mechanism against invading microbes. Inactivation of NF-kB attenuates encephalomyocarditis virus (EMCV) virulence by triggering rapid apoptosis of infected cells, thereby pre-emptively limiting viral replication. Recent evidence has shown that hypoxia-inducible factor (HIF) increases NF-kB-mediated anti-apoptotic response in clear-cell renal cell carcinoma (CCRCC) that commonly exhibit hyperactivation of HIF due to the loss of its principal negative regulator, von Hippel-Lindau (VHL) tumour suppressor protein. Here, we show that EMCV challenge induces a strong NF-kB-dependent gene expression profile concomitant with a lack of interferon-mediated anti-viral response in VHL-null CCRCC, and thatmultiple established CCRCC cell lines, aswell as early-passage primary CCRCC cultured cells, are acutely susceptible to EMCV replication and virulence. Functional restoration of VHL or molecular suppression of HIF or NF-kB dramatically reverses CCRCC cellular susceptibility to EMCVinduced killing. Notably, intratumoural EMCV treatment of CCRCC in a murine xenograft model rapidly regresses tumour growth. These findings provide compelling pre-clinical evidence for the usage of EMCV in the treatment of CCRCC and potentially other tumours with elevated HIF/NF-kB-survival signature. © 2010 EMBO Molecular Medicine.