维生素D对乳腺癌细胞及乳腺癌干细胞凋亡的影响

目的:探究维生素D对人乳腺癌细胞及乳腺癌干细胞凋亡的影响。方法:MTT法检测维生素D对乳腺癌SUM159细胞活力的影响；Hoechst33258染色检测维生素D对乳腺癌SUM159细胞凋亡的影响；实时定量PCR法检测维生素D对乳腺癌SUM159细胞凋亡相关分子Bax和Bcl-2 mRNA表达水平的影响；无血清悬浮培养法（serum-free medium,SFM）富集乳腺癌干细胞,显微镜下观察维生素D对乳腺癌干细胞球大小和数量的影响；实时定量PCR法检测维生素D对乳腺癌干细胞凋亡相关分子Bax、Bcl-2 mRNA表达水平的影响。结果:MTT法检测结果显示，维生素D可显著抑制乳腺癌细胞活力，且随着维生素D浓度升高，乳腺癌SUM159细胞活力的下降具有一定的剂量依赖效应，单因素方差分析显示，差异具有统计学意义(P＜0.01)；Hoechst33258染色结果显示，维生素D可诱导乳腺癌SUM159细胞发生细胞凋亡形态改变；进一步PCR法检测结果显示，维生素D可显著上调乳腺癌SUM159细胞促凋亡蛋白Bax mRNA的表达，下调抗凋亡蛋白Bcl-2 mRNA的表达，单因素方差分析显示，差异具有统计学意义(P＜0.01)。SFM培养可有效富集乳腺癌干细胞，维生素D干预可明显抑制SFM富集的乳腺癌干细胞球的大小和数量，且与对照组相比，维生素D可显著上调乳腺癌干细胞球Bax mRNA的表达水平，下调Bcl-2 mRNA的表达水平，单因素方差分析显示，差异具有统计学意义(P＜0.01)。结论:维生素D可抑制乳腺癌细胞及乳腺癌干细胞活力，诱导乳腺癌细胞凋亡。

Effect of vitamin D on the apoptosis of breast cancer cells and breast cancer stem cells

Objective:To investigate the effect of vitamin D on apoptosis of human breast cancer cells and breast cancer stem cells.Methods:MTT assay was used to detect the cell viability of vitamin D on SUM159 cells.The effects of vitamin D on the apoptosis of SUM159 cells were detected by Hoechst33258 staining.mRNA levels of Bax and Bcl-2 were detected by real-time quantitative PCR.Serum-free medium culture（SFM) was used to enrich breast cancer stem cell spheres.Effects of vitamin D on the size and number of breast cancer stem cells were observed under microscope.Real-time quantitative PCR was used to detect the effect of vitamin D on the mRNA levels of Bax and Bcl-2.Results:MTT assay showed that vitamin D significantly decreased the viability of SUM159 cells,and in a dose-dependent way.Hoechst33258 staining showed that vitamin D induced apoptosis of SUM159 cells.Real-time PCR showed that vitamin D significantly up-regulated the mRNA level of Bax and down-regulated the mRNA levels of Bcl-2 in SUM159 cells.Serum-free medium culture could effectively enrich breast cancer stem cell spheres.Vitamin D significantly inhibited the size and number of breast cancer stem cell spheres.In addition,compared with the control group,vitamin D could up-regulate the mRNA level of Bax,and down-regulate the mRNA level of Bcl-2.Conclusion:Vitamin D could inhibit the activity and induce apoptosis of breast cancer cells and breast cancer stem cells.