Elevated RTP801 promotes cell proliferation in non-small cell lung cancer.

Lung cancer, particularly non-small cell lung cancer (NSCLC), is one of main causes of mortality in cancer patients worldwide. It is necessary to seek effective biomarkers to improve diagnostic and therapeutic efficacies in human NSCLC. RTP801 is a stress-response protein that can be induced by many types of cellular stress such as hypoxia and DNA damage, produces different biological effects depending on cell type and context. Up to now, there is no direct evidence showing the expression and involvement of RTP801 in human NSCLC. Here, we found that the expression of RTP801 significantly increased in NSCLC tissues compared with that in normal lung and the level of RTP801 in peripheral blood of NSCLC patients was higher than that of healthy persons. Further study showed that knockdown of RTP801 induced by lentivirus encoded RTP801-shRNA markedly inhibited the proliferation of A549 and SW900 cells. Moreover, the inhibitor of PI3K significantly decreased the expression of RTP801 mRNA and protein and, at the same time, inhibited the proliferation of A549 and SW900 cells. Taken together, our study provides the novel and direct evidence that there is a close relationship between RTP801 and human NSCLC, and RTP801 can promote the proliferation of NSCLC cells which is regulated by PI3K signaling pathway, suggesting that RTP801 could be a potential biomarker for diagnosis and therapeutic target of human NSCLC. © 2018 IUBMB Life, 70(4):310-319, 2018.