肿瘤干细胞标记物CD133与miR-429在大肠癌组织中的表达及其相关性研究

目的：检测CD133不同亚群大肠癌细胞HT-29的miR-429表达情况，探讨miR-429及CD133的表达与肿瘤的发生发展之间的关系。方法：采用荧光活化细胞分选法（FACS）分选出CD133不同亚群细胞，实时荧光定量PCR分别检测两组细胞miR-429的表达，合成miR-429寡核苷酸和阴性对照miRNA并分别转染CD133＋和CD133＋两个亚群细胞。再将细胞种植于非肥胖糖尿病／严重联合免疫缺陷（NOD／SCID）小鼠体内构建移植瘤模型，不同时间测量肿瘤体积和重量，RT—PCR及蛋白质印迹检测CD133＋和CD133＋两组肿瘤CD133mRNA和蛋白质表达。结果：血清检出CD133＋细胞为67．9％，miR-429的表达量是CD133＋细胞的（1．83±0．91）倍（P〈0．05），CD133＋比例与miR-429表达呈负相关（r=0．591，P〈0．05）；miR-429＋／CD133＋组的移植瘤体积及重量与对照组比较有统计学差异（P〈0．05），且miR-429＋/CD133＋组成瘤时间较对照组晚约2周，但miR-429＋/CD133＋组的移植瘤CD133表达量低，与阴性对照组比较无明显差异（P〉0．05）。结论：miR-429可能作为CD133的负性调控因子，具有抑制肿瘤生长的作用，但miR-429与CD133在肿瘤发生、发展过程中的作用机制有待进一步研究阐明。

Corelation and Expressions of CD133 and miR-429 in the Tissues of Colorectal Carcinoma

Objective： To detect the expressions of miR-429 in different CD133 subgroups on the HT-29 cells in the colorectal cancer tissues of which to explore the corelafion between the occurrence and progression of tumors. Methods： The different CD133 subgroup cells were sorted out by fluorescence activated cell sorting （FACS）; the expression ofmiR-429 was detected by Real-time PCR; synthetic oligonucleotides of miR-429 and the negative control of microRNA were transfected in CD133＋ and CD133＋ subgroups; the non-obese diabetic/severe combined immunodeficiency mice （NOD/SCID） were planted the transfected cells to construct the transplanted tumor model; the tumor volume and weight were measured in different time; the expression of CD133 mRNA and protein in these two groups were detected by RT-PCR and western blotting. Results： The proportion of CD133＋cells was 67.9%; the expression of miR-429 in CD133 cell was （1.83±0.91） times ofCD133＋s（P〈0.05）; the corelation offD133＋ ＇s ratio and the expression ofmiR-429 was negative（r=0. 591, P〈0.05）; there were statistically significant differences in the volume and weight of transplanted tumors in miR-429＋/CD133＋ between the two groups（P〈0.05）; the tumorigenicity of miR-429＋/CD133＋ group was two weeks later than that of the control group, while the CD133 expression was lower with no significant difference than the negative control group（P〉0.05）. Conclusion： It is suggested that the miR-429 might be a negative regulatory factor of CD133 which could inhibite the growth ofturnor. However, the mechanism of miR-429 and CD133 in process of tumor occurrence and development needs to be further studied and clarified.