title: Inhibition of SIRT1 by a small molecule induces apoptosis in breast cancer cells.
abstract: Overexpression of SIRT1, a NAD+-dependent class III histone deacetylases (HDACs), is implicated in many cancers and therefore could become a promising antitumor target. Here we demonstrate a small molecule SIRT1 inhibitor, ILS-JGB-1741(JGB1741) with potent inhibitory effects on the proliferation of human metastatic breast cancer cells, MDA-MB 231. The molecule has been designed using medicinal chemistry approach based on known SIRT1 inhibitor, sirtinol. The molecule showed a significant inhibition of SIRT1 activity compared to sirtinol. Studies on the antitumor effects of JGB on three different cancer cell lines, K562, HepG2 and MDA-MB 231 showed an IC₅₀ of 1, 10 and 0.5 μM, respectively. Further studies on MDA-MB 231 cells showed a dose-dependent increase in K9 and K382 acetylation of H3 and p53, respectively. Results also demonstrated that JGB1741-induced apoptosis is associated with increase in cytochrome c release, modulation in Bax/Bcl2 ratio and cleavage of PARP. Flowcytometric analysis showed increased percentage of apoptotic cells, decrease in mitochondrial membrane potential and increase in multicaspase activation. In conclusion, the present study indicates the potent apoptotic effects of JGB1741 in MDA-MB 231 cells.
authors.affiliation: Institute of Life Sciences, University of Hyderabad Campus, Hyderabad, AP 500046, India. arunasreemk@ilsresearch.org
authors.forename: Arunasree M
authors.initials: AM
authors.lastname: Kalle
authors.forename: A
authors.initials: A
authors.lastname: Mallika
authors.forename: Jayasree
authors.initials: J
authors.lastname: Badiger
authors.lastname: Alinakhi
authors.forename: Pinaki
authors.initials: P
authors.lastname: Talukdar
authors.lastname: Sachchidanand
mesh_terms: D017209:Apoptosis; D001549:Benzamides / Q000494:pharmacology; D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D015195:Drug Design; D005260:Female; D056572:Histone Deacetylase Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D009284:Naphthols / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D056564:Sirtuin 1 / Q000037:antagonists & inhibitors*; D013876:Thiophenes / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D001549:Benzamides; D056572:Histone Deacetylase Inhibitors; C553745:JGB 1741; D009284:Naphthols; D013876:Thiophenes; C439060:sirtinol; C447939:SIRT1 protein, human; D056564:Sirtuin 1