Validation of cyclin D1/CDK4 as an anticancer drug target in MCF-7 breast cancer cells: Effect of regulated overexpression of cyclin D1 and siRNA-mediated inhibition of endogenous cyclin D1 and CDK4 expression
Validation of cyclin D1/CDK4 as an anticancer drug target in MCF-7 breast cancer cells: Effect of regulated overexpression of cyclin D1 and siRNA-mediated inhibition of endogenous cyclin D1 and CDK4 expression
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DOI：
10.1007/s10549-005-9066-y
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发表时间：
2006-01-01
影响因子：
3.8
通讯作者：
Rabindran, SK
中科院分区：
文献类型：
--
作者：
Grillo, M;Bott, MJ;Rabindran, SK
我们研究了细胞周期蛋白D1和细胞周期蛋白依赖性激酶-4(CDK4)在MCF-7乳腺癌细胞周期进展和增殖中的作用。用四环素调控的表达系统强制表达细胞周期蛋白D1，用小干扰RNA(SiRNA)抑制内源性细胞周期蛋白D1和CDK4的表达，以验证该蛋白复合体作为抗癌药物发现的药物靶点。细胞周期蛋白D1的过表达增加了视网膜母细胞瘤基因产物(Rb)的磷酸化，促进了细胞通过GI-S相变，从而促进了细胞的增殖。当细胞周期蛋白D1的表达被关闭时，生长速度下降到低于对照细胞系中的水平，这表明细胞对这种蛋白的增殖依赖增加。通过RNA干扰抑制内源性细胞周期蛋白D1或CDK4的表达，导致Rb的低磷酸化和细胞在G1期的积聚。这些结果支持了流行的观点，即药物抑制细胞周期蛋白D1/CDK4复合体是抑制肿瘤生长的有效策略。此外，由于MCF-7细胞似乎依赖于这一途径来持续增殖，因此它是一种适合测试新的细胞周期蛋白D1/CDK4抑制剂的细胞系。
We have examined the role of cyclin D1 and cyclin-dependent kinase-4 (CDK4) in the cell cycle progression and proliferation of MCF-7 breast cancer cells. Forced expression of cyclin D1 using a tetracycline-regulated expression system, and suppression of endogenous cyclin D1 and CDK4 using small interfering RNA (siRNA) were used to validate this protein complex as a drug target in cancer drug discovery. Overexpression of cyclin D1 increased both phosphorylation of the retinoblastoma gene product (RB) and passage through the G I-S phase transition, resulting in increased proliferation of cells. When cyclin D1 expression was shut off, growth rates fell below those seen in control cell lines transfected with the vector, indicating an increased dependence on this protein for proliferation. Inhibition of endogenous cyclin D1 or CDK4 expression by RNA interference resulted in hypophosphorylation of RB and accumulation of cells in G1. These results support the prevailing view that pharmacological inhibition of cyclin D1/CDK4 complexes is a useful strategy to inhibit the growth of tumors. Furthermore, since MCF-7 cells appear to be dependent on this pathway for their continued proliferation, it is a suitable cell line to test novel cyclin D1/CDK4 inhibitors.