Cordycepin inhibits proliferation and migration of gallbladder cancer cell SNU-308 by ERK1/2, Ezrin and Akt signaling pathways

AIM: To investigate the effects of cordycepin on the proliferation and migration abilities of gallbladder cancer cell line SNU-308 and its molecular mechanism. METHODS: The viability of SNU-308 cells treated with cordycepin at different concentrations was measured by MTT assay and the colony formation ability was also detected. The effect of cordycepin on apoptosis was analyzed by flow cytometry with Annexin V/PI double staining. The protein levels of apoptosis and autophagy markers, and the phosphorylation level of Akt, ERK1/2 and Ezrin were evaluated by Western blot. Immunofluorescence staining was also used to analyze the expression level of LC3 after cordycepin treatment. Wound healing assay and Transwell assay were performed to evaluate the migration ability of the SNU-308 cells after cordycepin treatment. Wound healing assay was also used to evaluate the effects of Akt inhibitor, ERK1/2 inhibitor and Ezrin knockdown on the changes of migration ability. RESULTS: Cordycepin significantly inhibited the viability and the ability of colony formation of gallbladder cancer cells (P<0.05). Induction of apoptosis by cordycepin were revealed by flow cytometry (P<0.05). The protein expression of Bcl-2 was down-regulated, while the protein levels of Bax, cytochrome C (Cyto C), Fas, FasL and cleaved caspase-3 were increased and the autophagy marker beclin 1 and the ratio of LC3-Ⅱ/I were upregulated by Western blot analysis (P<0.05). LC3 accumulation in the cytoplasm after cordycepin treatment was demonstrated by immunofluorescence staining. Cordycepin treatment resulted in the inhibition of cell migration were detected by Transwell assay and wound healing assay (P<0.05). The protein levels of p-Akt, p-ERK1/2 and p-Ezrin were down-regulated after cordycepin treatment (P<0.05). Besides, Ezrin knockdown, Akti-1/2 and GDC-0994 all resulted in the inhibition of migration ability (P<0.05). CONCLUSION: Cordycepin induces apoptosis and autophagy to inhibit gallbladder can-cer cell proliferation and migration by regulating ERK1/2, Ezrin and Akt signaling pathways.