Identification of new targets involved in chemoresistance

Abstract

Tumor chemoresistance, is a major factor in the failure of many forms of chemotherapy. It affects patients with a variety of blood cancers and solid tumors, including breast, prostate, lung, and lower gastrointestinal tract cancers. Different cell pathways are involved in the mechanism of chemoresistance, and multiple mechanisms can be activated at different times of the cancer progression. This project aims to identify new targets involved in resistance against the main therapies used for colorectal cancer treatment (5-FU, Irinotecan, Oxaliplatin and Cetuximab) using a recent powerful approach: "synthetic lethality screening". We will perform synthetic lethality screening on three resistant cell lines HCT116-s and HCT116-G7 (irinotecan resistant) and HCT116-s and HCT116-R2 (oxaliplatin resistant), to identify drug-specific resistance mechanism as well as a possible common pathway involved in multiple chemoresistance. We will use genetic screens to identify genes whose inhibition confers sensitivity to resistant cell lines. The same sensitive and resistant colorectal cancer cells will be infected with pooled retroviral shRNA library expressing thousands of different ShRNAs. These transduced cells will then be cultured in absence or presence of the drug of interest. Cells expressing ShRNAs targeting genes involved in drug sensitivity will be depleted relative to the untreated cells. Then, the relative abundance of shRNA will be determined by sequencing (Next Generation Sequencing). (AU)