基于肿瘤干细胞学说探究天花粉蛋白干预乳腺癌耐药株SP细胞的实验研究

Research of TCS Intervening Drug-Resistant Breast Cancer SP Cells Based on Tumor Stem Cell Theory

目的:研究天花粉蛋白(TCS)对乳腺癌紫杉醇耐药株侧群细胞(MCF-7/PTX-SP细胞)的诱导凋亡作用,从干细胞角度探讨其作用机理。方法:FACS分选MCF-7/PTX细胞中的SP细胞,流式细胞仪检测SP细胞、非SP细胞中CD44^+CD24^-细胞比例、软琼脂克隆形成实验对其进行鉴定;流式细胞仪检测不同浓度TCS对SP细胞的促凋亡作用;RT-PCR法检测不同浓度TCS对SP细胞内Bcl-2和Bax基因表达的影响。结果:非SP细胞及SP细胞中CD44^+/CD24^细胞的比例分别为0.47%和59.14%;与非SP细胞相比,SP细胞具有更高的体外克隆形成能力;TCS对SP细胞具有凋亡诱导作用,随着药物浓度的增高,SP细胞的凋亡率也随之升高,差异有统计学意义(t1=-13.751,P<0.01;t2=-10.892,P<0.01;t3=-6.999,P<0.01);不同浓度TCS处理后SP细胞内BaxmRNA的表达量呈明显的剂量依赖性上升趋势(P<0.01),而Bcl-2mRNA的表达变化无统计学差异(P>0.05)。各浓度组Bcl-2/Bax值呈减少趋势(P<0.01)。结论:天花粉蛋白对乳腺癌耐药株侧群细胞具有凋亡诱导作用,其机制可能与上调Bax基因的表达有关。

Objective :To study the apoptosis induction of TCS on MCF -7/PTX -SP cells and explore its action mechanism from the perspective of stem cell.Methods :SP cells were selected by FACS from MCF -7/PTX cells.The proportion of CD44^+CD24^- cells in SP cells and nonsp cells was detected by flow cytometry and the experiment of soft AGAR cloning was conducted to identify it.Flow cytometry detected the apoptosis of TCS on SP cells.RT -PCR detected the influence of TCS on Bcl -2 and Bax of SP cells.Results :The proportions of CD44^+/CD24^- cells on NON - SP and SP cells were 0.47%and 59.14%.In vitro cloning of SP cells was significantly higher than that of non -sp cells.TCS had apoptotic induction effect on SP cells,and as the drug concentration increased,the apoptosis rate of SP cells increased,and the difference was statistically significant (t1 =-13.751,P <0.01;t2=-10.892,P <0.01;t3=-6.999,P <0.01). The expression of Bax mRNA in SP cells was significantly increased in the TCS treated with different concentrations(P < 0.01),while the expression changes of bcl -2 mRNA were not statistically significant(P >0.05).The bcl -2 /Bax value of each concentration group decreased (P <0.01).Conclusion :TCS has apoptosis induction in the tumor resistant strain cells.The mechanism may be related to the increase of Bax gene expression.