Artesunate induces G2/M cell cycle arrest through autophagy induction in breast cancer cells

Objective Autophagy is termed as type Ⅱ programmed cell death (PCD). Artesunate (ART) can inhibit the proliferation of various cancer cell lines. In the present study, we investigated the regulation on cell cycle by artesunate. Methods Cell cycle was tested by flow cytometry. Gene expression level was determined by fluorescent quantitative polymerase chain reaction (FQ-PCR) and Western blotting. Formation of autophagosome was determined by immunofluorescence. For cell signaling transduction investigation, autophagy-dependent pathway was blocked by 3-methyladenine (3-MA), a classical autophagy inhibitor. Results The G2/M cell population rate of artesunate group (16.67±3.29)% was higher than the control group (9.64±0.74)% (t=3.614, P=0.022). The expression of p21 mRNA and protein of artesunate group were (14.28±0.10, t=23.094, P=0.000), (1.58±0.80, t=7.330, P=0.018) higher than that of the control group. We showed that artesunate arrested the cell cycle in the G2/M phase, which was accompanied by upregulation of p21, a member of cyclin dependent kinases inhibitor (CKI). The expression of Beclin1 mRNA, protein of artesunate group were (1.71±0.14), (1.61±0.91) higher than that of the control group. The microtubule-associated protein 1 light chain 3(LC3) punctate of artesunate group was (2.79±0.42, t=7.342, P=0.018) higher than that of the control group. We found that artesunate could induce autophagy. Pretreated with 3-MA, artesunate could no longer increase p21 protein expression and G2/M cell population. Conclusion Artesunate arrested cell cycle in G2/M phase through autophagy pathway dependent manner. Key words: Artesunate; Autophagy; Breast cancer; Cell cycle