Discovery of a small-molecule inhibitor of specific serine residue BAD phosphorylation

Vijay Pandey, Baocheng Wang, Chakrabhavi Dhananjaya Mohan, Ainiah Rushdiana Raquib, Shobith Rangappa, Venkatachalaiah Srinivasa, Julian E. Fuchs, Kesturu S. Girish, Tao Zhu, Andreas Bender, Lan Ma, Zhinan Yin, Basappa, Kanchugarakoppal S. Rangappa, Peter E. Lobie

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

Human BCL-2-associated death promoter (hBAD) is an apoptosisregulatory protein mediating survival signals to carcinoma cells upon phosphorylation of Ser99, among other residues. Herein, we screened multiple small-molecule databases queried in a Laplacianmodified 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 AKTmediated 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.

Original languageEnglish (US)
Pages (from-to)E10505-E10514
JournalProceedings of the National Academy of Sciences of the United States of America
Volume115
Issue number44
DOIs
StatePublished - Oct 30 2018

Keywords

  • AKT-PKB
  • BAD phosphorylation
  • Carcinoma
  • Laplacian-modified naive Bayesian classifier
  • NPB

ASJC Scopus subject areas

  • General

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