Radiotherapy and IFN? treatment effect on transcriptome in HT1080 cells

Immune checkpoint blockade is a powerful oncologic treatment modality for a wide variety of human malignancies. Randomized clinical trials are assessing how best to interdigitate this treatment modality with traditional therapies including radiotherapy. A challenge in oncology is to rationally and effectively integrate immunotherapy with traditional modalities including radiotherapy. Here, we demonstrate that radiotherapy induces tumor cell ferroptosis. Ferroptosis agonists augment and ferroptosis antagonists limit radiotherapy efficacy in tumor models. Immunotherapy sensitizes tumors to radiotherapy by promoting tumor cell ferroptosis. Mechanistically, IFN? derived from immunotherapy-activated CD8+ T cells and radiotherapy-activated ATM independently, yet synergistically repress SLC7A11, a unit of the glutamate-cystine antiporter xc-, resulting in reduced cystine uptake, enhanced tumor lipid oxidation and ferroptosis, and improved tumor control. Thus, ferroptosis is an unappreciated mechanism and focus for the development of effective combinatorial cancer therapy. Overall design: Following Illumina's TruSeq RNA protocol, mRNA profile was got from HT1080 cells, treated with IFN?, radiation or combination.