摘要:
Objective To investigate the effects of chloroquine (CQ on the metastasis ability of cancer stem cells in colorectal caner.Methods LoVo and xhCRC cells were sorted into CD133 + and CD133-two subpopulations by flow cytometry.Colonspheres formation assay was conducted to testify the stemness.Transwell migration and invasion assays were performed to test the inhibition effects on metastasis ability of CD133 + LoVo cells of CQ.Annexin V/7-amino-actinomycin D (7-AAD) assays were applied to detect CQ-induced apoptosis in CD133 + LoVo cells and CD133 + xhCRC cells.Western blotting was conducted to analyze the expression of Cleaved cysteinyl aspartate-specific protease (Caspase)-3 and epithelial to mesenchymal transition (EMT)-related proteins.Results CSCs are highly enriched in CD133 + cell subpopulation (P =0.004).CQ inhibited the metastatic capacity of CD133 + LoVo cells and CD133 + xhCRC cells in a concentration-dependent manner.In Transwell invasion assays,compared with the control,the number of cells incubated with 10 and 50 μmol/L CQ through the artificial matrix membrane is 71 and 42 in CD133 + LoVo cells (P =0.008,0.001,Comparison betweent the 10 μmol/L and the 50 μmol/L,P =0.009),the number in CD133 + xhCRC cells is 41 and 22 (P =0.044,0.001,P =0.036).In Transwell migration assays,the number is 179 and 95 in CD133 + LoVo cells (P=0.001,0.000,P =0.000);in CD133 + xhCRC cells is 61 and 43 (P =0.017,0.002,P =0.096).The apopto sis rates in CD133 + LoVo cells incubated with 10 and 50 μmol/L CQ are (2.9 ±0.4)%,(17.7 ± 1.5)% respectively (P =0.001,0.000,Comparison betweent the 10 μmol/L and the 50 μmol/L,P =0.000);In CD133 + xhCRC cells,the apoptosis rates are (9.7 ± 0.4) %,(17.6 ± 2.3) % respectively (P =0.003,0.000,P =0.005).The apoptosis rate in Western blotting revealed that CQ induced the expression of Cleaved Caspase-3 and inhibited the expression of EMT-related proteins.Conclusion CQ inhibits the metastasis ability of cancer stem cell (CSC) in colorectal cancer,which was related with the induced apoptosis and negative regulation of EMT-related proteins.%目的 观察氯喹(CQ)对结直肠癌干细胞转移能力的影响,并探讨其机制.方法 利用流式细胞仪从LoVo细胞和人结直肠癌小鼠移植瘤模型(xhCRC)单细胞悬液中分选出CD133+细胞和CD133-细胞,利用体外细胞球体形成实验检测两群细胞自我更新能力.利用Transwell侵袭和迁移实验检测浓度为10μmol/L和50 μmol/L CQ对CD133+ LoVo细胞和CD133+ xhCRC细胞转移能力的影响.通过膜联蛋白V(Annexin V)-藻红蛋白(PE)/7-氨基放线菌素D(7-AAD)细胞凋亡检测试剂盒检测CQ对CD133+ LoVo细胞和CD133+ xhCRC细胞凋亡的影响;Western blot检测CQ对凋亡相关蛋白裂解半胱氨酰天冬氨酸特异性蛋白酶-3(Cleaved Caspase-3)和上皮-间充质转化(EMT)相关蛋白E-钙黏蛋白(E-cadherin)、波形蛋白(Vimentin)和Snail的表达的影响.结果 体外球体形成实验结果显示,CD133+细胞比CD133-细胞具有更强的体外形成球体的能力(P =0.004).Transwell侵袭实验结果显示,在CD133+ LoVo细胞中,浓度为10、50 μmol/L的CQ处理细胞24 h,穿过小室的细胞数分别为71、42个,与对照组(115个)比较,差异有统计学意义(P=0.008、0.001,实验组间比较,P=0.009);在CD133+ xhCRC细胞中穿过小室的细胞数分别为41、22个,与对照组(61个)比较,差异有统计学意义(P =0.044、0.001,实验组问比较,P=0.036);Transwell迁移实验结果显示,在CD133+ LoVo细胞中,浓度为10、50 μmol/L的CQ处理细胞24 h,穿过小室的细胞分别为179、95个,与对照组(290个)比较,差异有统计学意义(P=0.001、0.000,实验组间比较,P=0.000),在CD133+ xhCRC细胞中穿过小室的细胞分别为61、43个,与对照组(97个)比较,差异有统计学意义(P=0.017、0.002,实验组间比较,P=0.096).细胞凋亡实验结果显示,浓度为10 μmol/L和50 μmol/L的CQ处理CD133+ LoVo细胞,细胞凋亡率分别为(2.9±0.4)%、(17.7±1.5)%,与对照组[(0.1±0.6)%]比较,差异均有统计学意义(P=0.001、0.000),实验组间比较,P=0.000);处理CD133+ xhCRC细胞,细胞凋亡率分别为(9.7±0.4)%、(17.6±2.3)%,与对照组[(1.0±0.6)%]比较,差异有统计学意义(P=0.003、0.000,实验组间比较,P=0.005).Western blot证实CQ可促进凋亡相关蛋白Cleaved Caspase-3的表达并呈剂量依赖关系,E-cadherin的表达随CQ浓度的增加逐渐减少.结论 CQ可抑制结直肠癌癌干细胞(CSCs)的转移能力,下调EMT相关蛋白表达并诱导其凋亡.