Abstract: Abstract：Objective To explore the effect of obstructive sleep apnea syndrome (OSAS), OSAS- like intermittent hypoxia (IH）on the expression levels of P -YAP and YAP in A549 lung cancer cell lines. Methods A549 cells were treated with IH exposure ( exposed to 5% O2 for 300 seconds and 21% O2 for 300 seconds) for 1, 3 and 6 h (IH1, IH3, IH6) or normoxia exposure (N group). Quantificational real-time PCR was used to measure the mRNA expression levels of YAP. Western blot assay was used to detect the protein expression levels of YAP and P-YAP. Results The mRNA expression levels of YAP were significantly increased with the increase of IH exposure time points in IH1 (2.50±0.18), IH3 (4.07±0.25) and IH6 (9.18±0.58) groups than those in N group (1.00±0.01) (all P＜0.05). The protein expression levels of YAP were significantly increased with the increase of IH exposure time points in IH1, IH3 and IH6 groups than those in N group. The protein expression levels of P-YAP were significantly decreased with the increase of IH exposure time points in IH1, IH3 and IH6 groups than those in N group. Conclusion YAP cell signaling plays an important role in the process of OSAS-like IH induced tumor development.

Key words: sleep apnea, obstructive, cell hypoxia, A549 cell, YAP, P-YAP, qRT-PCR, Western blot