PDK-1 mediated Hippo-YAP-IRS2 signaling pathway and involved in the apoptosis of non-small cell lung cancer cells.

Pyruvate dehydrogenase kinase-1 (PDK-1), a gatekeeper enzyme, was involved in cancer progression, such as tumor angiogenesis, cell survival, and growth. Recent evidence indicated that PDK-1 may be involved in lung cancer, however, the function and underlying mechanism of PDK-1 is remaining unclear. In the present study, our aim was to investigate the role and mechanisms of PDK-1 in human non-small cell lung cancer (NSCLC) cells. We first observed that PDK-1 was highly expressed in NSCLC cell lines. PDK-1 silence resulted in the inhibition of NSCLC cell survival. Also, cell apoptosis and caspase-3 activity were increased by PDK-1 knockdown in H1299 and A549 cells. Attenuation of PDK-1 expression blocked YAP and insulin receptor substrate 2 (IRS2) expression, and PDK-1 silence suppressed IRS2 expression dependent on Hippo-YAP signaling pathway. Moreover, further studies confirmed that YAP or IRS2 overexpression reversed the action of PDK-1 in NSCLC cells. In conclusion, our findings indicate that PDK1/Hippo-YAP/IRS2 signaling pathway plays a critical role in NSCLC cell survival and apoptosis.