Jang Ji Hoon, Cho Yoon Chul, Kim Ki Ho, Lee Kyung Seop, Lee Jinho, Kim Dong Eun, Park Jun-Soo, Jang Byeong-Churl, Kim Shin, Kwon Taeg Kyu, Park Jong-Wook
Department of Immunology, School of Medicine, Keimyung University, Daegu, Republic of Korea.
Department of Urology, Dongguk University, College of Medicine, Gyeongju, Republic of Korea.
Int J Oncol. 2014 Oct;45(4):1680-90. doi: 10.3892/ijo.2014.2534. Epub 2014 Jul 4.
Previously, we reported the potential of a novel Cdk inhibitor, 2-[1,1'-biphenyl]-4-yl-N-[5-(1,1-dioxo-1λ6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide (BAI) as a cancer chemotherapeutic agent. In this study, we investigated mechanisms by which BAI modulates FTI-mediated apoptosis in human renal carcinoma Caki cells. BAI synergizes with FTI to activate DEVDase, cleavage of poly ADP-ribose polymerase (PARP), and degradation of various anti-apoptotic proteins in Caki cells. BAI plus LB42708-induced apoptosis was inhibited by pretreatment with pan-caspase inhibitor, z-VAD-fmk, but not by overexpression of CrmA. The ROS scavenger, N-acetylcysteine (NAC) did not reduce BAI plus LB4270-induced apoptosis. Co-treatment of BAI and LB42708 reduced the mitochondrial membrane potential (MMP, ∆Ψm) in a time-dependent manner, and induced release of AIF and cytochrome c from mitochondria in Caki cells. Furthermore, BAL plus LB42708 induced downregulation of anti-apoptotic proteins [c-FLIP (L), c-FLIP (s), Bcl-2, XIAP, and Mcl-1 (L)]. Especially, we found that BAI plus LB42708-induced apoptosis was significantly attenuated by overexpression of Bcl-2 and partially blocked by overexpression of c-FLIP (L). Taken together, our results show that the activity of BAI plus LB42708 modulate multiple components in apoptotic response of human renal Caki cells, and indicate a potential as combinational therapeutic agents for preventing cancer such as renal carcinoma.
此前，我们报道了一种新型细胞周期蛋白依赖性激酶（Cdk）抑制剂2-[1,1'-联苯]-4-基-N-[5-(1,1-二氧代-1λ6-异噻唑烷-2-基)-1H-吲唑-3-基]乙酰胺（BAI）作为癌症化疗药物的潜力。在本研究中，我们探究了BAI调节法尼基转移酶抑制剂（FTI）介导的人肾癌Caki细胞凋亡的机制。BAI与FTI协同作用，激活天冬氨酸特异性半胱氨酸蛋白酶（DEVDase）、切割聚ADP-核糖聚合酶（PARP）并降解Caki细胞中的多种抗凋亡蛋白。用泛半胱天冬酶抑制剂z-VAD-fmk预处理可抑制BAI加LB42708诱导的凋亡，但CrmA的过表达则不能。活性氧清除剂N-乙酰半胱氨酸（NAC）并未降低BAI加LB4270诱导的凋亡。BAI与LB42708联合处理以时间依赖性方式降低线粒体膜电位（MMP，∆Ψm），并诱导Caki细胞中凋亡诱导因子（AIF）和细胞色素c从线粒体释放。此外，BAL加LB42708诱导抗凋亡蛋白[c-FLIP (L)、c-FLIP (s)、Bcl-2、X连锁凋亡抑制蛋白（XIAP）和髓细胞白血病-1（Mcl-1）(L)]的下调。特别是，我们发现Bcl-2的过表达可显著减弱BAI加LB42708诱导的凋亡，而c-FLIP (L)的过表达可部分阻断该凋亡。综上所述，我们的结果表明，BAI加LB42708的活性调节人肾Caki细胞凋亡反应中的多个成分，并表明其作为预防肾癌等癌症的联合治疗药物的潜力。
