中电导钙激动钾离子通道在多种乳腺癌细胞中的表达差异及作用

Expression and function of KCa3.1 in various mammary carcinoma cells

目的 观察中电导钙激动钾离子通道（KCa3.1）在乳腺癌细胞中的表达,在体外及体内探讨KCa3.1在乳腺癌增殖和细胞凋亡的作用.方法 Western blot技术检测KCa3.1在多种乳腺癌细胞株中的表达;免疫荧光技术检测KCa3.1在细胞中的表达定位;使用噻唑蓝（MTT）法研究KCa3.1对乳腺癌增殖的影响;流式细胞术研究KCa3.1对乳腺癌凋亡的影响;检测体内干预KCa3.1对乳腺癌细胞体内成瘤增殖及凋亡的影响.结果 KCa3.1在MDA-MB-231及MCF7细胞中存在表达,而在T-47D细胞中无明显表达;KCa3.1在乳腺癌中的表达定位于细胞膜上;体外干预KCa3.1可影响乳腺癌细胞的增殖,促进乳腺癌细胞的凋亡,MDA-MB-231细胞各组凋亡率分别为48 h：四乙铵-34（TRAm34）组（17.29 ±2.14）％,1-EBIO组（35.32±3.74）％,对照组（8.41±1.31）％;72 hTRAm34组（27.47±5.74）％,1-EBIO组（57.62±5.94）％,对照组（9.43±2.12）％;使用1-EBIO体内激活KCa3.1通道,可降低成瘤组织的增殖,促进成瘤组织的凋亡,各组凋亡率：对照组为（11.34±4.75）％,实验组为（23.92±5.96）％.结论 KCa3.1参与调控乳腺癌细胞的增殖及凋亡,成功在体内成瘤模型中验证了干预KCa3.1对肿瘤形成的抑制作用.

Objective To study the expression of KCa3.1 in mammary carcinoma,and its function on cell proliferation and apoptosis in vitro and in vivo.Methods Western blotting was used to detect the expression level of KCa3.1 in various mammary carcinoma cell lines.Immunofluorescence was used to detect the expression and localization of KCa3.1 in cells.Methyl thiazol tetrazolium （MTT） assay was used to research regulation function of KCa3.1 on cell proliferation of mammary carcinoma.Flow cytometry was used to study the function of KCa3.1 on apoptosis of mammary carcinoma.Immunohistochemistry and TdT-mediated dUTP nick end labeling （TUNEL） were used to detect the effect of KCa3.1 on proliferation and apoptosis of mammary carcinoma.Results The expression of KCa3.1 was confirmed in MDA-MB-231 and MCF7,but not in T-47D.The KCa3.1 protein was localized in the plasma membrane of mammary carcinoma cells.Proliferation and apoptosis of mammary carcinoma cells were induced by intervening KCa3.1 in vitro [MDA-MB-231 apoptosis rate：at 48 h tetraethylammonium-34 （TRAM-34）,（17.29 ± 2.14） %,1-EBIO （35.32 ± 3.74） %,Control （8.41 ± 1.31） %;at 72 h TRAM-34 （27.47 ± 5.74） %,1-EBIO （57.62 ± 5.94） %,Control （9.43 ± 2.12） %].The activation of KCa3.1 induced by channel opener 1-EBIO could reduce the proliferation and activate the apoptosis of mammary tumor tissues in vivo [apoptosis rate：1-EBIO （11.34 ± 4.75） %,Control （23.92 ± 5.96） %].Conclusion KCa3.1 was involved in the regulation of proliferation and apoptosis in mammary carcinoma cells.The verification of the inhibition on tumor formation induced by intervening KCa3.1 was accomplished in vivo.