Inhibition of autophagic flux by the curcumin analog EF‐24 and its antiproliferative effect on MCF‐7 cancer cells

Abstract

Abstract5‐Bis[(2‐fluorophenyl)methylene]‐4‐piperidinone (EF‐24) is a curcumin analog, which was identified for its physiochemical stability and diverse pharmacological functions. In the present study, EF‐24 was added to the breast cancer cell line MCF‐7 and its cellular effects were characterized. The results indicated that EF‐24 possessed antiproliferative and antimigratory activities on MCF‐7 cells as determined by MTT assay, wound healing, and transwell assay, respectively. In addition, the autophagosomal vesicles could be detected by acridine orange staining and electron microscope analysis in EF‐24‐treated cells. Conversion of LC3‐I to LC3‐II was also investigated following EF‐24 treatment of the cells. However, the expression analysis of p62 and LC3 revealed that EF‐24 could inhibit autophagic flux in MCF‐7 cells. Confocal microscopy suggested that EF‐24 could inhibit the degradation of autophagic vesicles by blocking the fusion of autophagosomes with lysosomes. EF‐24 could also induce apoptosis of MCF‐7 cells as determined by Hoechst 33342 staining, flow cytometry analysis, and western blot analysis. Moreover, treatment of the cells with the autophagy inhibitor 3‐MA enhanced the PARP1 cleavage of EF‐24‐treated MCF‐7 cells, which indicated the crosstalk between autophagy and apoptosis in breast cancer cells. Additional investigation of EF‐24 should be performed in future studies to assess its antiproliferation and antimigratory effects on MCF‐7 cells. However, the current results provide a solid foundation for the potential in vivo anticancer activity of this compound.