TGF-β1/Smad7信号通路在乳腺癌组织中的表达及与细胞增殖和转移的关系

Expressions of TGF-β1/Smad7 signaling pathway in breast cancer and its relationship with cell proliferation and metastasis

目的 :探讨TGF-β1/Smad7信号通路在乳腺癌组织中的表达及与细胞增殖、转移的关系。方法:留取67例乳腺癌患者肿瘤及癌旁组织,利用实时荧光定量PCR检测乳腺癌及癌旁组织中TGF-β1和Smad7基因表达,培养人乳腺癌Luminal A型细胞株MCF-7,根据转染处理不同分为TGF-β1 si RNA转染组、阴性对照组和空白对照组,MTT法检测不同转染组细胞增殖能力,Transwell细胞侵袭、迁移实验检测不同转染组细胞侵袭和迁移能力,利用实时荧光定量PCR检测不同转染组细胞中TGF-β1、Smad7和EMT相关基因表达。结果:乳腺癌组织中TGF-β1 m RNA相对表达量高于癌旁组织,而Smad7 m RNA相对表达量则低于癌旁组织,差异有统计学意义(P<0.05);MTT检测结果显示,TGF-β1 si RNA转染组细胞48、72和96 h时吸光度值均低于阴性对照组和空白对照组,差异有统计学意义(P<0.05);细胞侵袭实验结果显示,TGF-β1 si RNA转染组每高倍视野细胞数均低于阴性对照组和空白对照组(P<0.05);细胞迁移实验结果显示,TGF-β1 si RNA转染组每高倍视野细胞数均低于阴性对照组和空白对照组(P<0.05);TGF-β1 si RNA转染组细胞中TGF-β1 m RNA、Vimentin m RNA、Snail-2 m RNA和MMP-9 m RNA相对表达量均低于阴性对照组和空白对照组,而Smad7m RNA和E-cadherin m RNA相对表达量均高于阴性对照组和空白对照组,差异有统计学意义(P<0.05)。结论:乳腺癌发生与TGF-β1/Smad7信号通路激活有关,特异性抑制TGF-β1可促进Smad7表达而抑制乳腺癌细胞EMT发生,从而抑制肿瘤细胞增殖、侵袭和转移过程。

Objectiw,： To investigate the expressions of TGF- β 1/Smad7 Signaling Pathway in breast cancer and its relationship with cell proliferation and metastasis. Methods： The specimens of cancerous and adjacent tissues of 67 cases of breast cancer were selected. The expressions of TGF- β1 and Smad7 genes in in breast cancer and adjacent cancer tissues were detected by using re- al-time quantitative PCR. The Luminal A type of human breast cancer cells line MCF-7 were cultured. According to the difference of transfection process, the cells were divided into TGF-β1 siRNA transfection group, negative control group and blank control group. The cell proliferations of different transfected groups were tested by using MTT assay. The cell invasion and migration of different transfected groups were tested by using Transwell cell invasion and migration assay. The expressions of TGF- β1, Smad7 and EMT related genes in different transfected groups were detected by using real-time PCR. Results： The relative expression levels of TGF- β1 mRNA in breast cancer tissues were higher than the adjacent tissues, while the relative expression levels of Smad7 mRNA were lower than the adjacent tissues, the differences were statistically significant（P〈0.05）. MTT assay showed, the absorbance values in the TGF-β 1 siRNA transfection group at 48 h, 72 h and 96 h were lower than the negative control group and blank control group, the difference was statistically significant （P〈0.05）. Cell invasion assay showed that, per high power field cells in TGF- β 1 siRNA transfection group were lower than the negative control group and blank control group （P〈0.05）, cell migration assay showed that, per high power field cells in TGF- β 1 siRNA transfection group were lower than the negative control group and blank control group （P〈0.05）. The relative expression levels of TGF-β1 mRNA, Vimentin mRNA, Snail-2 mRNA and MMP-9 mRNA were lower than the negative control group and blank controt group, while the relative expression levels of Smad7 mRNA and E-cadherin mRNA were higher than the negative control group and the blank control group, the differences were statistically significant （P〈0.05）. Conclusion： TGF-β 1/Smad7 signaling pathway activated in Breast cancer. Specific inhi- bition of TGF- β 1 could promote the expression of Smad7 and inhibit breast cancer cell EMT occurrence, thereby inhibit tumor cell proliferation, invasion and metastasis.