Department of Molecular Cancer Science, Yamagata University School of Medicine, Yamagata, Japan.
Department of Neurosurgery, Yamagata University School of Medicine, Yamagata, Japan.
Anticancer Res. 2022 Oct;42(10):4727-4733. doi: 10.21873/anticanres.15977.
BACKGROUND/AIM: The development of pharmacological inhibitors targeting negative regulators of p53, such as murine double minute (MDM) 2 and, more recently, MDM4, has been actively pursued as a potential strategy to treat cancers with wild-type p53. We previously showed that CEP-1347, a small molecule kinase inhibitor originally developed for the treatment of Parkinson's disease, suppressed MDM4 expression and activated wild-type p53 in retinoblastoma cells. However, it remains unknown whether CEP-1347 acts as an MDM4 inhibitor and as such activates p53 in other types of human cancer cells.
The effects of CEP-1347 and MDM4 knockdown on the mRNA and protein expression of components of the p53 pathway, including MDM4, in human glioma cell lines with and without p53 mutation were examined by RT-PCR and western blot analyses. Trypan blue dye exclusion was used to examine the effect of CEP-1347 on cell growth.
CEP-1347 decreased the expression of MDM4, increase that of p53, and activated the p53 pathway in glioma cells with wild-type p53. Knockdown-mediated inhibition of MDM4 expression in a glioma cell line with wild-type p53 that overexpresses MDM4 resulted in increased p53 expression and activation of the p53 pathway. CEP-1347 preferentially inhibited the growth of glioma cells with wild-type p53 without showing toxicity to normal cells at clinically relevant concentrations.
Our findings suggest CEP-1347 is a novel inhibitor of MDM4 protein expression and as such activates p53 to inhibit the growth of cancer cells with wild-type p53, including retinoblastoma and glioblastoma.
背景/目的：开发针对 p53 负调节剂的药理学抑制剂，如鼠双微体（MDM）2，以及最近的 MDM4，已被积极探索作为治疗野生型 p53 癌症的潜在策略。我们之前表明，CEP-1347 是一种最初开发用于治疗帕金森病的小分子激酶抑制剂，可抑制视网膜母细胞瘤细胞中的 MDM4 表达并激活野生型 p53。然而，CEP-1347 是否作为 MDM4 抑制剂并因此在其他类型的人类癌细胞中激活 p53 仍不清楚。
通过 RT-PCR 和 Western blot 分析，研究了 CEP-1347 和 MDM4 敲低对具有和不具有 p53 突变的人胶质瘤细胞系中 p53 途径成分（包括 MDM4）的 mRNA 和蛋白表达的影响。使用台盼蓝排斥试验来检查 CEP-1347 对细胞生长的影响。
CEP-1347 降低了具有野生型 p53 的胶质瘤细胞中 MDM4 的表达，增加了 p53 的表达，并激活了 p53 途径。在过表达 MDM4 的具有野生型 p53 的胶质瘤细胞系中，通过敲低介导的 MDM4 表达抑制导致 p53 表达增加和 p53 途径激活。CEP-1347 优先抑制具有野生型 p53 的胶质瘤细胞的生长，而在临床相关浓度下对正常细胞没有毒性。
我们的发现表明 CEP-1347 是 MDM4 蛋白表达的新型抑制剂，因此激活 p53 以抑制具有野生型 p53 的癌细胞的生长，包括视网膜母细胞瘤和神经胶质瘤。
