表皮生长因子受体在黑色素瘤紫杉醇耐药性中的机制研究

Mechanisms of epidermal growth factor receptor in paclitaxel resistance of melanoma

目的探究紫杉醇对黑色素瘤的作用机制及表皮生长因子受体(EGFR)信号通路在调节黑色素瘤侵袭与转移中的作用,揭示该信号通路与紫杉醇耐药的关系及相关机制。方法以EGFR高表达的恶性黑色素瘤A375细胞为研究对象,采用流式细胞术、细胞迁移实验、MTT法和蛋白质印迹法,研究紫杉醇及表皮生长因子(EGF)通过EGFR信号通路对A375细胞凋亡、增殖和迁移的影响。结果(1)细胞凋亡:紫杉醇诱导的A375细胞凋亡随浓度升高而增强(P<0.001),同时紫杉醇(0.1μmol/L)抑制Bcl-2并增加了Bax的表达(P<0.01);EGFR抑制剂AG1478可明显增加A375细胞凋亡并增强紫杉醇的诱导效果及对Bcl-2和Bax的影响(P<0.001);EGF单独处理对A375细胞凋亡无明显影响,但其可抑制紫杉醇诱导的细胞凋亡(P<0.05)及对Bcl-2和Bax的影响(P<0.001)。(2)细胞增殖:紫杉醇(0.1μmol/L)可显著抑制A375细胞增殖(P<0.001)且该作用可被AG1478进一步增强但被EGF减弱(P<0.001)。(3)细胞迁移:紫杉醇(0.1μmol/L)可显著抑制A375细胞的迁移(P<0.001),该抑制作用可被AG1478进一步增强但被EGF减弱(P<0.001)。结论紫杉醇能够降低Bcl-2并增加Bax表达,从而诱导黑色素瘤A375细胞的凋亡并抑制其增殖和迁移,而这些抑制作用可被EGF激活的EGFR通路减弱。

Objective To explore the mechanisms of paclitaxel on melanoma and the role of the epidermal growth factor receptor(EGFR)signaling pathway in regulating the invasion and metastasis of melanoma,and to reveal the relationship between the EGFR signaling pathway and paclitaxel resistance of melanoma cells.Methods Using malignant melanoma A375 cells with high EGFR expression,we utilized flow cytometry,Transwell assay,MTT,and Western blot to study the effects of paclitaxel and epidermal growth factor(EGF)on A375 cell apoptosis,proliferation,and migration.Results Paclitaxel induced apoptosis of A375 cells in a concentration-dependent manner(P<0.001).Meanwhile,paclitaxel(0.1μmol/L)inhibited Bcl-2 expression and increased the expression of Bax(P<0.01).EGFR inhibitor AG1478(20μmol/L)could significantly increase the apoptosis of A375 cells and enhance the apoptosis-inducing effect of paclitaxel(P<0.05)and its effect on Bcl-2 and Bax expression(P<0.001).EGF treatment alone had no significant effect on the apoptosis of A375 cells,but it could inhibit the apoptosis-inducing effect of paclitaxel(0.1μmol/L)as well as its effect on Bcl-2 and Bax(P<0.001).Paclitaxel(0.1μmol/L)inhibited the proliferation of A375 cells(P<0.001),which could be further enhanced by AG1478 but was inhibited by EGF(P<0.001).Paclitaxel(0.1μmol/L)inhibited the migration of A375 cells(P<0.001),which could be further enhanced by AG1478 but was decreased by EGF(P<0.001).Conclusion Paclitaxel can reduce Bcl-2 expression but increase the expression of Bax,thereby inducing the apoptosis of melanoma A375 cells and inhibiting their proliferation and migration.However,these inhibitory effects can be weakened by EGF via the EGFR pathway.