Genome wide analysis of cisplatin resistance associated genes in A549 Lung Cancer cells using a CRISPR/Cas9 library

Abstract

Currently available treatment options for Cancer include surgery, radiotherapy, endocrine therapy, immunotherapy and chemotherapy, being the last one the first line of treatment for several types of Cancers. Chemotherapy treatments often fail because of drug resistance and most chemotherapy drugs are cytotoxic and unspecific, leading to a wide-range of side-effects. Therefore, understanding the molecular mechanisms of Cancer drug resistance and optimizing Cancer therapy may not only avoid Cancer resistance but also minimize side-effects due to usage of lower drug doses. Platinum-based drugs, as cisplatin, are employed for the treatment of a wide variety of solid tumors, including testicular, ovarian, head and neck, colorectal, bladder and lung Cancers. Several molecular pathways have been associated with cisplatin resistance, showing complexity and importance to further studies approaching this matter. Amongst the alterations in Cancer cells associated with drug resistance, metabolic changes are currently under investigation and several studies point that targeting metabolism in Cancer cells may be an important adjuvant therapy to counter drug resistance. For example, metformin is able to diminish cisplatin resistance in lung and gastric Cancer, enhancing the drug effectiveness, and rapamycin presents adjuvant effects against cisplatin resistance in gastric Cancer. The understanding of how Cancer cells become resistant to therapies is an important demand for more precise directed therapeutic approaches, reducing dosage of often aggressive chemotherapeutic drugs and thus side effects, increasing the efficiency of the therapy and wellness of patients. Here we propose to perform a genome-wide analysis of A549 lung Cancer cells after treatment with cisplatin using a CRISPR/Cas9 library, identifying new genes related to cisplatin resistance. Our main focus will be metabolism-related genes, including those related to mTOR signaling. After identification, validation of some of those genes will be performed for a better understanding of the molecular mechanism that trigger or maintain lung Cancer cells resistance to cisplatin. Analysis of patient's samples from ICESP-USP will be performed to validate our in vitro results. (AU)