MEK/ERK和PI3K/AKT信号通路抑制剂在诱导恶性黑色素瘤细胞凋亡中的协同作用

目的 通过联合抑制MEK和 AKT 信号通路关键靶点分子，探讨克服细胞耐药性的靶向治疗方法。 方法 体外培养和新鲜分离恶性黑色素瘤细胞株，分别在0.5%和5%血清浓度下单独或同时抑制靶点MEK（U0126, 20 μmol/L）和AKT（LY294002, 20 μmol/L），MTT法检测细胞增殖，PI染色流式细胞术检测细胞凋亡情况。 结果 当培养液血清浓度从0.5%提高到5%时，U0126和LY294002对肿瘤细胞增殖的抑制效应明显降低。LY294002以抑制细胞增殖为主，U0126主要诱导细胞凋亡，二者作用效果与细胞是否具备该通路关键靶点活化变异无关。联合用药时诱导细胞凋亡普遍增强，LY294002和U0126具有协同效应。 结论 联合抑制MEK/ERK和PI3K/AKT信号通路可较好地克服恶性黑色素瘤细胞的耐药性。

Synergistic Effect of Targeted Inhibition of MEK/ERK and PI3K/AKT Survival Signaling Pathways onInduction of Apoptosis in Melanoma

Objective The treatment of metastatic melanoma by conventional chemotherapeutic agents remains unsatisfactory. The present study was undertaken to reveal the role of co-inhibition of survival signaling pathways in apoptosis of melanoma cells. Methods A panel of human melanoma cell lines and fresh melanoma isolates was assessed for their sensitivity to the MEK inhibitor U0126 and/or AKT inhibitor LY294002. The proliferation and apoptosis of the cells were examined after treatment with the inhibitors. Results Constitutive activation of ERK1/2 and AKT was closely related to concentrations of serum in the culture medium (extracellular signals). The sensitivity of melanoma cells to apoptosis induced by inhibition of MEK/ERK was not correlated with the active BRAF mutation (BRAF^V600E. Inhibition of MEK/ERK predominantly induced apoptosis; whereas inhibition of PI3K/AKT primarily inhibited proliferation. Co-inhibition of MEK/ERK1/2 and PI3K/AKT synergistically induced apoptosis. Conclusion Co-targeting MEK/ERK and PI3K/AKT pathways may further improve treatment for melanoma.