Effect of autophagy in curcumin enhancing chemosensitivity of LoVo cells to irinotecan

LUO Yong; CHEN Xiaowu; ZHU Dajian; WANG Guoxin; HUANG Yanfeng; YANG Yong

doi:10.3969/j.issn.1006-5725.2017.06.006

Abstract：Objective To study the role of autophagy in the curcumin (Cur) enhancing the chemosensitivity of the colorectal cancer LoVo cells to irinotecan (CPT-11). Methods The LoVo cells were separated into 4 groups:the control group,the Cur group,the CPT-11 group and the Mix group.Western blot assay was applied to determine the expression of autophagy-related protein LC3-Ⅱ and P62. LC3-Ⅱ was detected by immunofluorescence method. Transmission electron microscopy was used to detect the autophagosome. CCK-8 assay was applied to detect the cell growth inhibitory rate of LoVo cells ,which were pre-treated with autophagy inhibitor 3-MA before 24-h treatment of Cur and/or CPT-11. Western blot assay was applied to detect the expression of LC3- Ⅱ and P62. Results The mixed treatment significantly increased the expression of LC3-Ⅱwhile decreased P62 expression,compared with the Cur and CPT-11 treatments. The autophagosomes in cells of Mix group were significantly more than those in cells of the Cur and Cpt group. Pre-treatment of 3-MA significantly reduced cell growth rate in the Cur group,the Cpt group and the Mix group. Pre-treatment of 3-MA significantly decreased the expression of LC3-Ⅱ,while increased P62 expression,compared with the Mix group. Conclution Combinations of curcumin and CPT-11 could enhance the chemosensitivity of LoVo cells to CPT-11,which might be related to the activation of autophagy.