目的：探讨 miR-1207-5p 对乳腺癌 T47D 干细胞增殖、迁移和侵袭的影响及其可能的机制。方法: 以 IGF-1、EGF、 bFGF诱导、富集乳腺癌T47D干细胞并进行成球培养，流式细胞术分离干细胞，采用WB法检测干细胞分子标志物。采用qPCR 检测干细胞中miR-1207-5p的表达水平，双荧光素酶报告基因实验分析miR-1207-5p和LIMD1的靶向关系。CCK-8、Transwell和 划痕实验检测T47D干细胞的增殖、迁移和侵袭能力。WB法检测干细胞中LIMD1蛋白的表达水平。结果: 分离的T47D干细胞 能够形成细胞球，细胞球体积随培养天数的增加而增加；干细胞分子标志物 ALDH1、ESA 和 OCT4 的表达水平较亲本 T47D细 胞显著升高（P<0.05或P<0.01），miR-1207-5p在干细胞中高表达（P<0.01），敲降miR-1207-5p显著抑制T47D干细胞的增殖、迁移和侵袭（均 P<0.01）。miR-1207-5p靶向下调LIMD1 的表达（PP<0.01），miR-1207-5p通过靶向下调LIMD1 促进乳腺癌 T47D 干细胞的增殖、迁 移 和 侵袭能力（P<0.05或 P<0.01）。结论：miR-1207-5p通过靶向下调LIMD1的表达来促进乳腺癌T47D干细胞的增殖、迁移和侵袭能力。

Objective: To explore the effect of miR-1207-5p on the proliferation, migration and invasion of breast cancer T47D stem cells and its possible mechanism. Methods: Breast cancer T47D stem cells were induced and enriched with IGF-1, EGF and bFGF and cultured into spheroids. The stem cells were separated by Flow cytometry, and molecular markers of stem cells were detected by WB. qPCR was used to detect the expression level of miR-1207-5p in stem cells, and Dual luciferase reporter gene assay was used to analyze the targeting relationship between miR-1207-5p and LIMD1. CCK-8, Transwell and Cell scratch test were used to detect the proliferation, migration and invasion ability of T47D stem cells. WB was used to detect the expression level of LIMD1 protein in stem cells. Results: The isolated stem cells could form cell spheres, and the volume of the cell spheres increased with the increase of culture days. The expressions of stem cell molecular markers ALDH1, ESA and OCT4 were significantly higher than those of the parental T47D cells (P<0.05 or P<0.01 ), and miR-1207-5p was highly expressed in stem cells (P<0.01). Overexpression of miR-1207-5p significantly promoted the proliferation, migration and invasion of T47D stem cells (all P<0.01), and knockdown of miR-1207-5p significantly inhibited the proliferation, migration and invasion of T47D stem cell (all P<0.01). miR-1207-5p targetedly downregulated the expression of LIMD1 (P<0.01), by which it promoted the proliferation, migration and invasion of breast cancer T47D stem cells (P<0.05 or P<0.01). Conclusion: miR-1207-5p promotes the proliferation, migration and invasion of breast cancer T47D stem cells by targeted downregulation of the expression of LIMD1.

陈孝平科技发展基金项目（No. CXPJJH11900002-038）