期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2018
卷号:115
期号:44
页码:E10505-E10514
DOI:10.1073/pnas.1804897115
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Human BCL-2–associated death promoter (hBAD) is an apoptosis-regulatory protein mediating survival signals to carcinoma cells upon phosphorylation of Ser99, among other residues. Herein, we screened multiple small-molecule databases queried in a Laplacian-modified naive Bayesian-based cheminformatics platform and identified a Petasis reaction product as a site-specific inhibitor for hBAD phosphorylation. Based on apoptotic efficacy against mammary carcinoma cells, N -cyclopentyl-3-((4-(2,3-dichlorophenyl) piperazin-1-yl) (2-hydroxyphenyl) methyl) benzamide (NPB) was identified as a potential lead compound. In vitro biochemical analyses demonstrated that NPB inhibited the phosphorylation of hBAD specifically on Ser99. NPB was observed to exert this effect independently of AKT and other kinase activities despite the demonstration of AKT-mediated BAD-Ser99 phosphorylation. Using a structure-based bioinformatics platform, we observed that NPB exhibited predicted interactions with hBAD in silico and verified the same by direct binding kinetics. NPB reduced phosphorylation of BAD-Ser99 and enhanced caspase 3/7 activity with associated loss of cell viability in various human cancer cell lines derived from mammary, endometrial, ovarian, hepatocellular, colon, prostatic, and pancreatic carcinoma. Furthermore, by use of a xenograft model, it was observed that NPB, as a single agent, markedly diminished BAD phosphorylation in tumor tissue and significantly inhibited tumor growth. Similar doses of NPB utilized in acute toxicity studies in mice did not exhibit significant effects. Hence, we report a site-specific inhibitor of BAD phosphorylation with efficacy in tumor models.