MPPa-PDT induced apoptosis and autophagy through JNK and p38 MAPK signaling pathways in A549 cells.

Objectives: The antitumor effects of pyropheophorbide-α methyl ester-mediated photodynamic therapy (MPPa-PDT) were observed in several cancers. The objective of this investigation was to examine the antineoplastic efficacy of MPPa-PDT acting on lung carcinoma A549 cells and further elaborate mechanisms. Methods: The viability of A549 cells was examined with cell counting kit-8 after MPPa-PDT disposal. Hoechst 33342 staining, monodansylcadaverine (MDC) staining, and transmission electron microscopy were employed to observe apoptotic bodies and autophagic vesicles. Flow cytometry with Annexin V/propidium iodide (PI) labeling objectively assessed cell death. The expression of associated proteins, including Caspase-3, Beclin-1, LC-3II, and mitogen-activated protein kinase (MAPK) families concluding c-jun NH2-terminal kinase (JNK), p38 MAPK, and extracellular signal-regulated kinase 1/2 (ERK) were identified by Western blotting. Results: Prolonged exposure to MPPa-PDT gradually decreased lung cancer A549 cell viability. Apoptosis and autophagy activity were higher in the MPPa-PDT cohort in comparison to the control group. Meanwhile, autophagy inhibition enhanced cell-killing efficacy apparently. Besides, the JNK and p38 MAPK pathways were implicated in MPPa-PDT-triggered apoptosis and autophagy. Conclusions: This study demonstrated that JNK and p38 MAPK were engaged in MPPa-PDT-mediated apoptosis and autophagy in lung carcinoma A549 cells. [ABSTRACT FROM AUTHOR]