YAP manipulates proliferation via PTEN/AKT/mTOR-mediated autophagy in lung adenocarcinomas.

Background Autophagy is a double-edged sword during the initiation and progression of multiple tumors. The Hippo pathway effector YAP has been proved to be involved in autophagy processes. The present study aimed to investigate how YAP regulates cell proliferation via autophagy in lung adenocarcinomas (LUAD). Methods Data of LUAD chip GSE43458 was obtained from Gene Expression Omnibus (GEO). RT-qPCR and Western blot were performed to assess YAP expression in LUAD cell lines. CCK-8 assay, xenograft tumor model, immunochemistry and GFP-mRFP-LC3 fusion proteins were utilized to evaluate the effect of YAP on autophagy of LUAD cells in vitro and in vivo. Autophagy inhibitor treatment and rescue experiments were carried out to elucidate the mechanism by which YAP manipulates autophagy in LUAD cells. Results YAP was significantly overexpressed in samples of LUAD patients and its expression level is related to 5-year survival. YAP manipulated the proliferation and autophagy in A549 and H1299 LUAD cells. YAP could induce activation of Akt/mTOR signaling pathway via suppressing PTEN in a Hippo-pathway-dependent manner. 3-Methyladenine impeded autophagy flux and promoted the proliferation in vitro and in vivo. Conclusions Hippo pathway critical transcriptional coactivators YAP manipulates the proliferation of lung adenocarcinoma, which is regulated by PTEN/AKT/mTOR autophagic signaling.