卡莫司汀对人脑肿瘤干细胞增殖及细胞周期的影响

目的:探讨卡莫司汀(BCNU)对人脑肿瘤干细胞在细胞增殖及细胞周期方面的影响。方法:取初发的室管膜瘤手术切除标本1例,取材后制备为单细胞,分别接种于无血清培养基获得肿瘤干细胞,接种于含血清培养基获得肿瘤细胞。不同浓度的BCNU作用于细胞72h后,MTT法检测细胞在体外对BCNU的敏感性,并用终浓度为0.01μg/mL的BCNU作用细胞不同的时间段,通过流式细胞仪检测BCNU对细胞周期的影响。结果:(1)MTT显示,BCNU能抑制肿瘤干细胞及肿瘤细胞的生长,其对肿瘤干细胞(IC50=0.157μg/mL)的抑制略低于对肿瘤细胞(IC50=0.072μg/mL)(P<0.05)。(2)细胞周期方面,与阴性对照比较,两类细胞均表现为随药物作用时间的延长,S期细胞比例增高,并伴有凋亡细胞的增多,但肿瘤干细胞的改变(24h)出现晚于肿瘤细胞(6h)。结论:BCNU对体外培养的脑肿瘤干细胞生长有明显的抑制作用,作用机制可能为通过干扰S期DNA的合成起作用;与脑肿瘤细胞相比,脑肿瘤干细胞在MTT及细胞周期的检测中,均表现出对BCNU有一定的耐药性。

Effects of BCNU on cell proliferation and cell cycle in human brain tumor stem cells

Objective To investigate the effects of BCNU on the proliferation and cell cycle of stem cells from human brain tumor. Methods Single cell suspensions generating from a specimen of primary ependymocytoma were cultured separately in serum-free and serum-supplemented medium to harvest BTSCs and BTCs. The cells were then treated with BCNU at different concentrations for 72 h and their sensitivity to BCNU in vitro was measured by MTT assay. They were also treated with BCNU at 0.01 μg/mL at different time points,then cell cycle was examined by flow cytometry. Results BCNU could inhibit the growth of both BTSCs and BTCs,with a slight lower level in BTSCs than in BTCs (0.157 μg/mL vs 0.072 μg/mL for IC50,P < 0.05). As compared with the negative controls,the proportion of the cells in S phase was increased with the prolonged treatment of BCNU,so was the amount of the apoptotic cells. However,the changes of BTSCs were behind that of BTCs (24 h vs 6 h). Conclusions BCNU has a marked inhibitory effect on the growth of BTSCs cultured in vitro,whose mechanism may be involved in interfering DNA synthesis in the S phase. BTSCs reveal some resistance to BCNU as compared with BTCs.