Genome-wide CRISPR screen reveals tumor-intrinsic responses to radiotherapy
Radiation therapy (RT) is one of the most commonly used anti-cancer therapies. However, the landscape of cellular response to irradiation, especially to a single high-dose irradiation, remains largely unknown. In this study, we performed a whole-genome CRISPR loss-of-function screen and revealed temporal inherent and acquired responses to RT. Specifically, we found that loss of the IL1R1 pathway led to cellular resistance to RT. This is in part due to the involvement of radiation-induced IL1R1-dependent transcriptional regulation, which relies on the NF-?B pathway. Moreover, the mitochondrial anti-apoptotic pathway, particularly the BCL2L1 gene, is crucially important for cell survival following radiation. BCL2L1 inhibition combined with RT dramatically impeded tumor growth in several breast cancer cell lines and syngeneic models. Taken together, our results suggest that the combination of an apoptosis inhibitor such as a BCL2L1 inhibitor with RT may represent a promising anti-cancer strategy for solid cancers including breast cancer. Overall design: MCF10A wild-type, IL1R1-KO, IL1RAP-KO cells (each with two biological replicates) with or without RT were collected. Total RNA was extracted (Qiagen), and an Illumina TruSeq Stranded Total RNA Library Prep Kit was used to prepare the library after rRNA depletion. mRNA sequencing was conducted at NextSeq 550 (Illumina) to generate 75-bp paired ends.