Interleukin 7 inhibit autophagy via P53 regulated AMPK/mTOR signaling pathway in non-small cell lung cancer

Abstract

Interleukin 7 (IL-7) has been demonstrated regulating lymphangiogenesis, apoptosis, and proliferation. Whether IL-7 induce or inhibit autophagy in non-small cell lung cancer (NSCLC) are unknown. In this study, Western blot was used to detect cytoplasmic and nuclear protein of p53, total protein of AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR) and Light chain 3 (LC3). Quantitative Real-Time PCR (qRT-PCR) was used to detect p53 mRNA level after treated with IL-7. Then using transmission electron microscopy to observe the morphological change of autophagosome. 123 cases of NSCLC were collected for survival analysis, immunohistochemistry staining and cox regression multivariate analysis. We find that IL-7 induce the p53 translocation from nucleus to cytoplasm, then IL-7 down-regulate phosphorylation of AMPK and up-regulate phosphorylation of mTOR. The expression of AMPK and p53 were associated with IL-7/IL-7R and mTOR expression. Clinically, AMPK and p53 were well correlated with stage and survival of lung cancer patients. IL-7R, mTOR and tumor stage were the strongest predictors of survival. In conclusion, IL-7 inhibit autophagy in NSCLC via P53 regulated AMPK/mTOR signaling pathway. AMPK and p53 are correlated with patients’ survival. IL-7R, mTOR and tumor stage are the strongest predictor of survival.