Mutant KRAS associated malic enzyme 1 expression is a predictive marker for radiation therapy response in non-small cell lung cancer

Background Advanced non-small cell lung cancer (NSCLC) is an aggressive tumor that is treated with a combination of chemotherapy and radiation if the patient is not a candidate for surgery. Predictive biomarkers for response to radiotherapy are lacking in this patient population, making it a non-tailored therapy regimen with unknown outcome. Twenty to 30 % of NSCLC harbor an activating mutation in KRASthat may confer radioresistance. We hypothesized that mutant KRAScan regulate glutamine metabolismgenes in NSCLC and maintain tumor redox balance through transaminationreactions that generate cytosolic NADPH via malic enzyme1 (ME1), which may contribute to radioresistance.