紫杉醇诱导三阴性乳腺癌细胞自噬相关蛋白LC3 的表达 及其作用
| 作者: |
1吴至佛,
1姚晓艺,
1汪灵,
1邓增艳,
1石静,
1黄俊辉
1 中南大学湘雅医院 肿瘤科，湖南 长沙 410008 |
| 通讯: |
黄俊辉
Email: 808003@csu.edu.com |
| DOI: | 10.3978/.2018.06.012 |
| 基金: | 湖南省自然科学基金资助项目（11jj3122）；中南大学研究生自主探索创新基金资助项目（2016zzts531）。 |
摘要
目的：探讨紫杉醇对三阴性乳腺癌（TNBC）细胞自噬相关蛋白 LC3 表达的影响及意义。
方法：用 CCK-8 法测定紫杉醇对 TNBC 细胞 MDA-MB-231 增殖的抑制作用及 25% 抑制浓度（IC25）；用 IC25 浓度的紫杉醇作用 MDA-MB-231 细胞后，分别用免疫荧光化学法、Western blot、流式细胞术检测细胞 LC3 与凋亡相关蛋白的表达及细胞的凋亡率。
结果：紫杉醇呈浓度依懒性抑制 MDA-MB-231 细胞的增殖（P<0.05），其 IC25 为 3.11 μg/mL。IC25 浓度的紫杉醇处理后，MDA-MB-231 细胞后 LC3 的表达量以及 LC3B/LC3A 比例明显升高、凋亡蛋白 Bax与 caspase-3 蛋白表达量明显降低、总凋亡率与早期调亡率均明降低（均 P<0.05）。
结论：紫杉醇可诱导 TNBC 细胞自噬相关蛋白 LC3 表达升高，该作用可能降低细胞凋亡，从而导致TNBC 细胞产生紫杉醇耐药。
关键词：
三阴性乳腺癌；抗药性，肿瘤；自噬；细胞凋亡
方法：用 CCK-8 法测定紫杉醇对 TNBC 细胞 MDA-MB-231 增殖的抑制作用及 25% 抑制浓度（IC25）；用 IC25 浓度的紫杉醇作用 MDA-MB-231 细胞后，分别用免疫荧光化学法、Western blot、流式细胞术检测细胞 LC3 与凋亡相关蛋白的表达及细胞的凋亡率。
结果：紫杉醇呈浓度依懒性抑制 MDA-MB-231 细胞的增殖（P<0.05），其 IC25 为 3.11 μg/mL。IC25 浓度的紫杉醇处理后，MDA-MB-231 细胞后 LC3 的表达量以及 LC3B/LC3A 比例明显升高、凋亡蛋白 Bax与 caspase-3 蛋白表达量明显降低、总凋亡率与早期调亡率均明降低（均 P<0.05）。
结论：紫杉醇可诱导 TNBC 细胞自噬相关蛋白 LC3 表达升高，该作用可能降低细胞凋亡，从而导致TNBC 细胞产生紫杉醇耐药。
Paclitaxel induced expression of autophagy-associated protein LC3 in triple negative breast cancer cells and its action
CorrespondingAuthor:HUANG Junhui Email: 808003@csu.edu.com
Abstract
Objective: To investigate the infl uence of paclitaxel on expression of autophagy-associated protein LC3 in triple negative breast cancer (TNBC) cells and the signifi cance.
Methods: Th e inhibitory eff ect of paclitaxel on proliferation of TNBC MDA-MB-231 cells was determined by CCK-8 assay and then the 25% inhibition concentration (IC25) value was calculated. In MDA-MB-231 cells aft er treatment with IC25 concentration of paclitaxel, the expressions of LC3 protein and apoptosis-associated proteins as well as the cell apoptosis rates were determined by immunofl uorescence histochemistry, Western blot analysis and fl ow cytometry, respectively.
Results: The proliferation effect of TNBC-MDA-MB-231 cells was significantly inhibited by paclitaxel in a concentration-dependent manner (P<0.05), with an IC25 value of 3.11 μg/mL. In MDA-MB-231 cells after treatment with 3.11 μg/mL paclitaxel, the expression level of LC3 protein as well as LC3B/LC3A ratio were significantly increased, the expression levels of the apoptosis-related protein Bax and caspase-3 were significantly decreased, and the total and early apoptosis rates were significantly decreased (all P<0.05).
Conclusion: Paclitaxel can induce the increased expression of the autophagy-related protein LC3, and this action may probably reduce the cell apoptosis and thereby cause paclitaxel resistance in TNBC cells.
Keywords：
Triple Negative Breast Neoplasms; Drug Resistance
Neoplasm; Autophagy; Apoptosis
Methods: Th e inhibitory eff ect of paclitaxel on proliferation of TNBC MDA-MB-231 cells was determined by CCK-8 assay and then the 25% inhibition concentration (IC25) value was calculated. In MDA-MB-231 cells aft er treatment with IC25 concentration of paclitaxel, the expressions of LC3 protein and apoptosis-associated proteins as well as the cell apoptosis rates were determined by immunofl uorescence histochemistry, Western blot analysis and fl ow cytometry, respectively.
Results: The proliferation effect of TNBC-MDA-MB-231 cells was significantly inhibited by paclitaxel in a concentration-dependent manner (P<0.05), with an IC25 value of 3.11 μg/mL. In MDA-MB-231 cells after treatment with 3.11 μg/mL paclitaxel, the expression level of LC3 protein as well as LC3B/LC3A ratio were significantly increased, the expression levels of the apoptosis-related protein Bax and caspase-3 were significantly decreased, and the total and early apoptosis rates were significantly decreased (all P<0.05).
Conclusion: Paclitaxel can induce the increased expression of the autophagy-related protein LC3, and this action may probably reduce the cell apoptosis and thereby cause paclitaxel resistance in TNBC cells.