表没食子儿茶素没食子酸酯联合曲妥珠单抗对HER2过表达乳腺癌细胞增殖的影响及其机制

The effect and mechanism of epigallocatechol gallate combined with trastuzumab on the proliferation of HER2 overexpressing breast cancer cells

目的研究表没食子儿茶素没食子酸酯(EGCG)联合曲妥珠单抗对人表皮生长因子受体2(HER2)过表达乳腺癌细胞增殖的影响及其作用机制。方法表达纯化曲妥珠单抗;用CCK-8细胞增殖检测试剂盒(CCK8)检测不同浓度EGCG、曲妥珠单抗及两药联用对HER2过表达乳腺癌细胞BT474、SK-BR-3的增殖抑制作用;用Western blot法检测EGCG、曲妥珠单抗及两药联用对BT474乳腺癌细胞中HER2,表皮生长因子受体(EGFR),丝裂原激活的蛋白激酶(MAPK)和蛋白激酶B(Akt)及它们的磷酸化蛋白的表达水平的影响。结果细胞增殖试验结果显示,EGCG、曲妥珠单抗以及二者联用均能有效抑制BT474和SK-BR-3细胞的增殖,且在一定浓度范围内,EGCG与曲妥珠单抗联用显示出协同增殖抑制作用。Western blot结果显示EGCG、曲妥珠单抗以及二者联合均能抑制BT474细胞中Akt,MAPK,EGFR,HER2的磷酸化蛋白表达,与单药相比,二者联合抑制作用显著增强,其差异具有统计学意义(P<0.05)。结论EGCG联合曲妥珠单抗能协同抑制HER2过表达乳腺癌细胞的增殖,其机制可能与Akt、MAPK信号通路有关。

Objective To study the effect and mechanism of epigallocatechol gallate(EGCG)combined with trastuzu-mab on the proliferation of human epidermal growth factor receptor 2(HER2)overexpressing breast cancer cells.Methods Trastuzumab was expressed and purified.The cell proliferation of HER2 overexpressing breast cancer cells BT474 and SK-BR-3 treated with trastuzumab,EGCG,or trastuzumab plus EGCG was evaluated by CCK8 assay.The effects of EGCG and trastuzumab on the expression of HER2,epidermal growth factor receptor(EGFR),mitogen-activated protein kinase(MAPK),protein kinase B(Akt),and their phosphorylated proteins in BT474 breast cancer cells were detected by Western blot.Results The results of cell proliferation assay indicated that EGCG and trastuzumab,alone or in combination,effectively inhibited the proliferation of BT-474 and SK-BR-3 cells.And within a certain concentration range,EGCG and trastuzumab showed a synergistic proliferation inhibitory effect on HER2 overexpressing breast cancer cells.Consistent with these results,Western blot results showed that trastuzumab and EGCG,alone or in combination significantly reduced the phosphorylation levels of Akt,MAPK,EGFR,and HER2 in BT474 cells.Moreover,the inhibition effect of EGCG plus trastuzumab was significantly more potent than either EGCG or trastuzumab.Conclusion EGCG and trastuzumab could synergistically inhibit the proliferation of HER2 overexpressing breast cancer cells,which may be related to the regulation of Akt and MAPK signaling pathways.