SRC激酶在人乳腺癌细胞对阿霉素耐药及侵袭转移中的作用

目的 探讨SRC激酶抑制剂PP2在乳腺癌细胞对阿霉素（adriamycin, ADM）耐药及侵袭转移过程中的作用。 方法 采用MTT法检测不同浓度ADM对乳腺癌细胞敏感株（MCF-7）和耐药株(MCF-7/ADM)细胞的增殖抑制作用，计算半数抑制浓度（50% inhibitory concentration, IC₅₀）及耐药指数(resistance index, RI)；Western blot检测MCF-7和MCF-7/ADM细胞内多药耐药蛋白MDR1、SRC及缝隙连接蛋白43（Cx43）蛋白表达；Transwell和细胞划痕实验检测MCF-7、MCF-7/ADM细胞、不同浓度PP2（1、2、4 μmol/L）预处理MCF-7/ADM 24 h细胞的侵袭和迁移能力；采用标准集落形成分析法观察4 μmol/L PP2预处理对ADM细胞毒性的影响。 结果 ADM对MCF-7的增殖抑制作用大于MCF-7/ADM细胞（P<0.01）；ADM对MCF-7细胞IC₅₀为24.55 μmol/L， 对MCF-7/ADM细胞IC₅₀为770.57 μmol/L，RI为31；与MCF-7细胞比较，MCF-7/ADM细胞MDR1、SRC蛋白表达增高（P<0.01），且MCF-7/ADM细胞具有更强的侵袭迁移能力（P<0.01），采用SRC抑制剂后，MCF-7/ADM细胞侵袭转移能力被抑制（P<0.01），细胞集落形成率下降，即对ADM的敏感性提高（P<0.01）。 结论 人乳腺癌细胞MCF-7在对ADM耐药的过程中伴随着SRC蛋白表达增多， SRC抑制剂可以降低细胞耐药性以及侵袭转移能力。

Effect of SRC Kinase on Adriamycin Resistance and Invasion and Metastasis in Human Breast Cancer Cells

Objective To investigate the role of SRC kinase inhibitor PP2 in drug resistance to adriamycin (ADM) in breast cancer cells and invasion, metastasis of cells. Methods MTT assay was used to detect the inhibitory effect of ADM on MCF-7 and MCF-7/ADM cells. The 50% inhibitory concentration (IC₅₀) and resistance index (RI) of cells were calculated. The expression of MDR1, connexin 43 (Cx43) and SRC proteins in breast cancer cells were detected by Western blot assay. Transwell experiment and cell scratch test were used to determine the invasion and migration of cells respectively 〔MCF-7, MCF-7/ADM, PP2 (1, 2, 4 μmol/L)〕. Standard colony formation assay was used to detect the cytotoxicity effect of 4 μmol/L PP2 pretreatment on ADM. Results ADM inhibited the proliferation of MCF-7 more than MCF-7/ADM cells (P<0.01). The IC₅₀ of MCF-7/ADM cells was 24.55 μmol/L, the IC₅₀ of MCF-7/ADM cells was 770.57 μmol/L, the RI was 31. Compared with MCF-7 cells, expressions of the multidrug resistance proteins MDR1 and SRC were significantly increased (P<0.01). The invasion and migration ability of the MCF-7/ADM cells was stronger than that of the sensitive cells (P<0.01). When MCF-7/ADM was exposed to SRC inhibitor PP2, the invasion and metastasis ability of cells were inhibited (P<0.01) and the rate of colony formation was decreased, that is, more sensitivity to ADM (P<0.01). Conclusion The resistance of MCF-7 to ADM is accompanied by increased expression of SRC. SRC inhibitor PP2 can reduce the cell resistance, ability of invasion and metastasis.