Figure 4.

H₂ treatment increases lung cancer cell apoptosis and autophagy by repressing the activation of the STAT3/Bcl2 signaling pathway. The protein expression levels of STAT3, p-STAT3 and Bcl2 were detected using western blot analysis in (A) A549 and (B) H1975 cells following treatment with different concentrations of H₂. (C) STAT3 expression was detected using western blot analysis following transfection with OE-STAT3 or OE-NC. The protein expression levels of STAT3, p-STAT3 and Bcl2 were detected using western blot analysis in (D) A549 and (E) H1975 cells following treatment with H₂ and/or transfected with OE-STAT3. Cell apoptosis was investigated using (F) flow cytometry and the results were subsequently (G) quantified. The protein expression levels of cleaved-caspase 3, cleaved-PARP, Beclin1, p62, LC3BII and LC3BI in (H) A549 and (I) H1975 cells were detected using western blot analysis following transfection with OE-STAT3 and/or treated with H₂. *P<0.05 and **P<0.01. STAT, signal transducer and activator of transcription; p-, phosphorylated; PARP, poly ADP-ribose polymerase; LC3, light chain 3; H₂, hydrogen gas; OE, overexpression; NC, negative control