Mitotic kinesin inhibitors induce mitotic arrest and cell death in taxol-resistant and -sensitive cancer cells
Mitotic kinesin inhibitors induce mitotic arrest and cell death in taxol-resistant and -sensitive cancer cells
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DOI：
10.1074/jbc.m413471200
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发表时间：
2005-03-25
影响因子：
4.8
通讯作者：
Giannakakou, P
中科院分区：
文献类型：
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作者：
Marcus, AI;Peters, U;Giannakakou, P
紫杉烷类是一种靶向微管细胞骨架的强效化疗药物，可导致有丝分裂停滞和细胞死亡;然而，由于耐药性的发展，其临床疗效受到阻碍。因此，其他参与纺锤体组装的蛋白质正在被研究作为抗癌治疗的潜在靶点。有丝分裂驱动蛋白Eg5对于正确的纺锤体组装至关重要;因此，Eg5的抑制导致有丝分裂停滞，使其成为潜在的抗癌靶标。我们希望验证Eg5作为治疗靶点，并确定Eg5抑制剂是否在紫杉醇耐药细胞中保留活性。使用亲和层析，我们首先表明，化合物HR22C16是Eg5抑制剂，不与其他微管马达蛋白测试相互作用。此外，HR22 C16沿着其类似物，抑制紫杉醇敏感性和耐药性卵巢癌细胞中的细胞存活，其功效比第一代Eg5抑制剂monastrol高至少15倍。对最有效的HR22C16类似物HR22C16-A1的进一步分析表明，它在PgP过表达细胞中保留了功效，表明它不是PgP底物。我们进一步表明，HR22C16-A1诱导细胞死亡后，有丝分裂停滞通过内在的凋亡途径。有趣的是，HR22C16-A1与紫杉醇的组合导致拮抗性抗增殖和抗有丝分裂作用，这可能是由于HR22C16-A1废除了紫杉醇诱导的有丝分裂纺锤体。综上所述，我们的研究结果表明，Eg5抑制剂具有很好的抗癌活性，并可能用于克服紫杉醇耐药的临床设置。
Taxanes are powerful chemotherapy agents that target the microtubule cytoskeleton, leading to mitotic arrest and cell death; however, their clinical efficacy has been hampered due to the development of drug resistance. Therefore, other proteins involved in spindle assembly are being examined as potential targets for anticancer therapy. The mitotic kinesin, Eg5 is critical for proper spindle assembly; as such, inhibition of Eg5 leads to mitotic arrest making it a potential anticancer target. We wanted to validate Eg5 as a therapeutic target and determine if Eg5 inhibitors retain activity in Taxol-resistant cells. Using affinity chromatography we first show that the compound HR22C16 is an Eg5 inhibitor and does not interact with other microtubule motor proteins tested. Furthermore, HR22C16 along with its analogs, inhibit cell survival in both Taxol-sensitive and -resistant ovarian cancer cells with at least 15-fold greater efficacy than monastrol, the first generation Eg5 inhibitor. Further analysis with HR22C16-A1, the most potent HR22C16 analog, showed that it retains efficacy in PgP-overexpressing cells, suggesting that it is not a PgP substrate. We further show that HR22C16-A1 induces cell death following mitotic arrest via the intrinsic apoptotic pathway. Interestingly, the combination of HR22C16-A1 with Taxol results in an antagonistic antiproliferative and antimitotic effect, possibly due to the abrogation of Taxol-induced mitotic spindles by HR22C16-A1. Taken together, our results show that Eg5 inhibitors have promising anticancer activity and can be potentially used to overcome Taxol resistance in the clinical setting.