The apoptotic pathways in the curcumin analog MHMD-induced lung cancer cell death and the essential role of actin polymerization during apoptosis

As a mode of cell death, apoptosis could be triggered by the extrinsic, intrinsic mitochondrial and intrinsic endoplasmic reticulum pathways and actin rearrangement is needed during apoptosis. We previously found that one curcumin analog MHMD could induce A549 lung cancer cells apoptosis. But the apoptotic pathways and the actin dynamics during apoptosis are not known. Here, we detected the activation of caspase-3, -8, -9, -12, PARP and the increase ratio of Bax/Bcl-2 by western blotting in MHMD-exposed A549 cells. Alternatively, caspases inhibitors could lead to the disappearance of MHMD-eliciting nuclei fragmentation by Hoechst 33342 staining. Besides, JC-1 and DCFH-DA staining showed the fall of mitochondrial membrane potential and the release of ROS. Moreover, wound healing assay confirmed the MHMD anti-migration ability, which was much more effective than curcumin. Importantly, unlike other anticarcinogenic drugs, MHMD might induce the actin polymerization but not depolymerization in the process of A549 cell apoptosis by phalloidin-FITC staining, which is essential to MHMD-induced extrinsic, intrinsic mitochondrial and intrinsic ER pathways of cell apoptosis.