Transcription inhibition of heat shock proteins: a strategy for combination of 17-allylamino-17-demethoxygeldanamycin and actinomycin d.
Transcription inhibition of heat shock proteins: a strategy for combination of 17-allylamino-17-demethoxygeldanamycin and actinomycin d.
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DOI：
10.1158/0008-5472.can-08-4406
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发表时间：
2009-05-01
期刊：
影响因子：
11.2
通讯作者：
Gandhi V
中科院分区：
文献类型：
--
作者：
Cervantes-Gomez F;Nimmanapalli R;Gandhi V
热休克蛋白（HSP）90抑制剂17-烯丙基氨基-17-去甲氧基格尔德霉素（17-AAG）由于其独特的作用机制和抗肿瘤活性，目前正在进行临床试验。然而，17-AAG触发抗凋亡HSP 90、HSP 70和HSP 27的转录和升高，这导致肿瘤细胞的化学抗性。我们假设抑制HSP 90、HSP 70和HSP 27的转录可以增强多发性骨髓瘤（MM）细胞系中17-AAG诱导的细胞死亡。放线菌素D（ActD），一种临床上使用的药物和转录抑制剂，与17-AAG组合。根据治疗期间的靶向作用和血浆水平选择17-AAG和Act D的浓度。诱导型和组成型HSP 27，HSP 70，和HSP 90 mRNA和蛋白水平通过实时RT-PCR和免疫印迹测定。与未处理相比，单独的Act D降低了MM. 1 S和RPMI-8226细胞系中的HSP mRNA水平。Act D与17-AAG的组合没有减弱17-AAG介导的诱导型HSP 70转录水平的增加;然而，组成型HSP mRNA水平降低。与其对mRNA水平的影响相反，Act D能够消除17-AAG介导的所有HSP蛋白水平的增加。评估了Act D和17-AAG组合的细胞毒性。单独用Act D处理引起小于40%的细胞死亡，而17-AAG和Act D的组合导致两种MM细胞系中细胞死亡的增加。总之，这些结果表明，17-AAG介导的HSP 70和HSP 27表达的诱导可以被Act D减弱，因此可以潜在地改善MM的临床治疗。
The heat shock protein (HSP) 90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) is currently in clinical trials because of its unique mechanism of action and antitumor activity. However, 17-AAG triggers the transcription and elevation of antiapoptotic HSP90, HSP70, and HSP27, which lead to chemoresistance in tumor cells. We hypothesized that inhibiting HSP90, HSP70, and HSP27 transcription may enhance 17-AAG-induced cell death in multiple myeloma (MM) cell lines. Actinomycin D (Act D), a clinically used agent and transcription inhibitor, was combined with 17-AAG. The concentrations for 17-AAG and Act D were selected based on the target actions and plasma levels during therapy. Inducible and constitutive HSP27, HSP70, and HSP90 mRNA and protein levels were measured by real-time RT-PCR and immunoblot assays. Compared to no treatment, Act D alone decreased HSP mRNA levels in the MM.1S and RPMI-8226 cell lines. Combining of Act D with 17-AAG did not attenuate 17-AAG-mediated increases in transcript levels of inducible HSP70; however, constitutive HSP mRNA levels were decreased. In contrast to its effect on mRNA levels, Act D was able to abrogate 17-AAG-mediated increases in all HSP protein levels. The cytotoxicity of combined Act D and 17-AAG was assessed. Treatment with Act D alone caused less than 40% cell death, while the combination of 17-AAG and Act D resulted in an increase of cell death in both MM cell lines. In conclusion, these results indicate that 17-AAG-mediated induction of HSP70 and HSP27 expression can be attenuated by Act D and therefore can potentially improve the clinical treatment of MM.