Potent in vitro and in vivo antitumor effects of MDM2 inhibitor nutlin-3 in gastric cancer cells
Potent in vitro and in vivo antitumor effects of MDM2 inhibitor nutlin-3 in gastric cancer cells
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DOI：
10.1111/j.1349-7006.2010.01821.x
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发表时间：
2011-03-01
期刊：
影响因子：
5.7
通讯作者：
Hyodo, Ichinosuke
中科院分区：
文献类型：
--
作者：
Endo, Shinji;Yamato, Kenji;Hyodo, Ichinosuke
肿瘤抑制基因p53是人类癌症中最常见的突变基因。但与其他癌症相比，其在胃癌中的突变率相对较低。在这项研究中，我们研究了nutlin-3抗肿瘤作用的机制，nutlin-3是一种人类同源的小鼠双分钟2 （MDM2）抑制剂。MDM2是p53的负调节因子。采用免疫印迹法分析4株野生型p53细胞株（wt p53）和3株突变型p53细胞株（mt p53）的MDM2和MDM4表达情况，并采用实时荧光定量PCR法进行基因扩增。WST-8法检测nutlin-3作用下细胞的活力，免疫印迹法检测p53及其下游基因的表达。Nutlin-3稳定p53，增加p21（WAF1）、Noxa和cleaved poly (ADP)-核糖聚合酶的表达，而不影响MDM2和MDM4在胃癌细胞中表达前的水平。流式细胞术显示，nutlin-3在G(1)期阻滞细胞周期，诱导细胞凋亡。这些坚果素-3效应在mt p53细胞系中未被观察到。Nutlin-3与5-氟尿嘧啶或顺铂联用对大多数wt p53细胞系具有加性或增效的细胞毒性。在MDM2过表达的异种移植瘤模型中证实了单独使用坚果素-3及其加用5-氟尿嘧啶增强的体内抗肿瘤作用。Nutlin-3对携带wt - p53的人胃癌细胞具有较强的抗肿瘤活性，在单用和与常规抗癌药物联用方面具有较好的应用前景。（癌症科学2011；102:605-613）
The tumor suppressor gene p53 is the most frequently mutated gene in human cancers. However, its mutation rate is relatively low in gastric cancer compared with other cancers. In this study, we investigated the mechanisms underlying the antitumor effects of nutlin-3, an inhibitor of human homolog of murine double minute 2 (MDM2). MDM2 is a negative regulator of p53. Four gastric cancer cell lines with wild-type p53 (wt p53) and three with mutant-type p53 (mt p53) were analyzed for MDM2 and MDM4 expression by immunoblotting, and for their gene amplification by quantitative real-time PCR. Moreover, the viability of cells exposed to nutlin-3 was examined by WST-8 assay, and the expression of p53 and its downstream genes was analyzed by immunoblotting. Nutlin-3 stabilized p53 and increased the expression of p21(WAF1) and Noxa, and cleaved poly (ADP)-ribose polymerase regardless of the pre-expression levels of MDM2 and MDM4 in gastric cancer cells with wt p53. Flow cytometry revealed that nutlin-3 arrested the cell cycle in G(1) phase and induced apoptosis in the cell lines. These nutlin-3 effects were not observed in the cell lines with mt p53. Nutlin-3 exerted additive or synergistic cytotoxicity in combination with 5-fluorouracil or cisplatin in most cell lines with wt p53. An in vivo antitumor effect of nutlin-3 alone and its additive augmentation by 5-fluorouracil were confirmed in an MDM2 overexpressed xenograft tumor model. Nutlin-3 showed potent antitumor activity against human gastric cancer cells with wt p53 and shows promise as a single agent and in combination with conventional anticancer drugs. (Cancer Sci 2011; 102: 605-613)