Sari Anissa Nofita, Elwakeel Ahmed, Dhanjal Jaspreet Kaur, Kumar Vipul, Sundar Durai, Kaul Sunil C, Wadhwa Renu
AIST-INDIA DAILAB, National Institute of Advanced Industrial Science & Technology (AIST), Central 5-41, Tsukuba 305-8565, Japan.
School of Integrative & Global Majors (SIGMA), University of Tsukuba, Tsukuba 305-8577, Japan.
Cancers (Basel). 2021 Feb 17;13(4):835. doi: 10.3390/cancers13040835.
p53 has an essential role in suppressing the carcinogenesis process by inducing cell cycle arrest/apoptosis/senescence. Mortalin/GRP75 is a member of the Hsp70 protein family that binds to p53 causing its sequestration in the cell cytoplasm. Hence, p53 cannot translocate to the nucleus to execute its canonical tumour suppression function as a transcription factor. Abrogation of mortalin-p53 interaction and subsequent reactivation of p53's tumour suppression function has been anticipated as a possible approach in developing a novel cancer therapeutic drug candidate. A chemical library was screened in a high-content screening system to identify potential mortalin-p53 interaction disruptors. By four rounds of visual assays for mortalin and p53, we identified a novel synthetic small-molecule triazole derivative (4-[(1E)-2-(2-phenylindol-3-yl)-1-azavinyl]-1,2,4-triazole, henceforth named Mortaparib). Its activities were validated using multiple bioinformatics and experimental approaches in colorectal cancer cells possessing either wild-type (HCT116) or mutant (DLD-1) p53. Bioinformatics and computational analyses predicted the ability of Mortaparib to competitively prevent the interaction of mortalin with p53 as it interacted with the p53 binding site of mortalin. Immunoprecipitation analyses demonstrated the abrogation of mortalin-p53 complex formation in Mortaparib-treated cells that showed growth arrest and apoptosis mediated by activation of p21, or BAX and PUMA signalling, respectively. Furthermore, we demonstrate that Mortaparib-induced cytotoxicity to cancer cells is mediated by multiple mechanisms that included the inhibition of PARP1, up-regulation of p73, and also the down-regulation of mortalin and CARF proteins that play critical roles in carcinogenesis. Mortaparib is a novel multimodal candidate anticancer drug that warrants further experimental and clinical attention.
p53通过诱导细胞周期停滞/凋亡/衰老在抑制致癌过程中发挥重要作用。Mortalin/GRP75是热休克蛋白70（Hsp70）蛋白家族的成员，它与p53结合，导致p53被隔离在细胞质中。因此，p53无法转运到细胞核中，以作为转录因子执行其经典的肿瘤抑制功能。消除Mortalin与p53的相互作用并随后重新激活p53的肿瘤抑制功能，已被预期为开发新型癌症治疗候选药物的一种可能方法。在高内涵筛选系统中筛选化学文库，以鉴定潜在的Mortalin-p53相互作用破坏剂。通过对Mortalin和p53进行四轮视觉分析，我们鉴定出一种新型合成小分子三唑衍生物（4-[(1E)-2-(2-苯基吲哚-3-基)-1-氮杂乙烯基]-1,2,4-三唑，此后命名为Mortaparib）。在具有野生型（HCT116）或突变型（DLD-1）p53的结肠癌细胞中，使用多种生物信息学和实验方法验证了其活性。生物信息学和计算分析预测，Mortaparib能够与Mortalin的p53结合位点相互作用，从而竞争性地阻止Mortalin与p53的相互作用。免疫沉淀分析表明，在Mortaparib处理的细胞中，Mortalin-p53复合物的形成被消除，这些细胞分别表现出由p21激活介导的生长停滞和由BAX和PUMA信号激活介导的凋亡。此外，我们证明，Mortaparib诱导的对癌细胞的细胞毒性是由多种机制介导的，这些机制包括对PARP1的抑制、p73的上调，以及对在致癌过程中起关键作用的Mortalin和CARF蛋白的下调。Mortaparib是一种新型的多模式候选抗癌药物，值得进一步的实验和临床关注。
