Novel histone deacetylase 8-selective inhibitor 1,3,4-oxadiazole-alanine hybrid induces apoptosis in breast cancer cells
- 280 Downloads
Identification of isoform-specific histone deacetylase inhibitors (HDACi) is a significant advantage to overcome the adverse side effects of pan-HDACi for the treatment of various diseases, including cancer. We have designed, and synthesized novel 1,3,4 oxadiazole with glycine/alanine hybrids as HDAC8-specific inhibitors and preliminary evaluation has indicated that 1,3,4 oxadiazole with alanine hybrid [(R)-2-amino-N-((5-phenyl-1,3,4-oxadiazol-2-yl)methyl)propanamide (10b)] to be a potent HDAC8 inhibitor. In the present study, the in vitro efficacy of the molecule in inhibiting the cancer cell proliferation and the underlying molecular mechanism was studied. 10b inhibited the growth of MDA-MB-231 and MCF7 breast cancer cells, with a lower IC50 of 230 and 1000 nM, respectively, compared to K562, COLO-205 and HepG2 cells and was not cytotoxic to normal breast epithelial cells, MCF10A. 10b was specific to HDAC8 and did not affect the expression of other class I HDACs. Further, a dose-dependent increase in H3K9 acetylation levels demonstrated the HDAC-inhibitory activity of 10b in MDA-MB-231 cells. Flow cytometric analysis indicated a dose-dependent increase and decrease in the percent apoptotic cells and mitochondrial membrane potential, respectively, when treated with 10b. Immunoblot analysis showed a modulation of Bax/Bcl2 ratio with a decrease in Bcl2 expression and no change in Bax expression. 10b treatment resulted in induction of p21 and inhibition of CDK1 proteins along with cytochrome c release from mitochondria, activation of caspases-3 and -9 and cleavage of poly ADP-ribose polymerase leading to apoptotic death of MDA-MB-231 and MCF7 cells. In conclusion, our results clearly demonstrated the efficacy of 10b as an anticancer agent against breast cancer.
KeywordsHDAC8-selective inhibitor 1,3,4 Oxadiazole-alanine hybrid Apoptosis Breast cancer cells
The funding was provided by Department of Biotechnology, Ministry of Science and Technology (Grant No. BT/327/NE/TBP/2012) to AMK. NSY is thankful to Department of Science and Technology for financial support through N-PDF (SERB File Number: PDF/2016/003244).
- 9.Khan N, Jeffers M, Kumar S, Hackett C, Boldog F, Khramtsov N, Qian X, Mills E, Berghs SC, Carey N, Finn PW, Collins LS, Tumber A, Ritchie JW, Jensen PB, Lichenstein HS, Sehested M (2008) Determination of the class and isoform selectivity of small-molecule histone deacetylase inhibitors. Biochem J 409(2):581–589. doi: 10.1042/BJ20070779 CrossRefPubMedGoogle Scholar
- 10.Hu E, Chen Z, Fredrickson T, Zhu Y, Kirkpatrick R, Zhang GF, Johanson K, Sung CM, Liu R, Winkler J (2000) Cloning and characterization of a novel human class I histone deacetylase that functions as a transcription repressor. J Biol Chem 275(20):15254–15264. doi: 10.1074/jbc.M908988199 CrossRefPubMedGoogle Scholar
- 17.Vannini A, Volpari C, Filocamo G, Casavola EC, Brunetti M, Renzoni D, Chakravarty P, Paolini C, De Francesco R, Gallinari P, Steinkuhler C, Di Marco S (2004) Crystal structure of a eukaryotic zinc-dependent histone deacetylase, human HDAC8, complexed with a hydroxamic acid inhibitor. Proc Natl Acad Sci USA 101(42):15064–15069. doi: 10.1073/pnas.0404603101 CrossRefPubMedPubMedCentralGoogle Scholar
- 19.Pidugu VR, Yarla NS, Pedada SR, Kalle AM, Satya AK (2016) Design and synthesis of novel HDAC8 inhibitory 2,5-disubstituted-1,3,4-oxadiazoles containing glycine and alanine hybrids with anti cancer activity. Bioorg Med Chem 24(21):5611–5617. doi: 10.1016/j.bmc.2016.09.022 CrossRefPubMedGoogle Scholar
- 29.Rettig I, Koeneke E, Trippel F, Mueller WC, Burhenne J, Kopp-Schneider A, Fabian J, Schober A, Fernekorn U, von Deimling A, Deubzer HE, Milde T, Witt O, Oehme I (2015) Selective inhibition of HDAC8 decreases neuroblastoma growth in vitro and in vivo and enhances retinoic acid-mediated differentiation. Cell Death Dis 6:e1657. doi: 10.1038/cddis.2015.24 CrossRefPubMedPubMedCentralGoogle Scholar
- 30.Chaligne R, Popova T, Mendoza-Parra MA, Saleem MA, Gentien D, Ban K, Piolot T, Leroy O, Mariani O, Gronemeyer H, Vincent-Salomon A, Stern MH, Heard E (2015) The inactive X chromosome is epigenetically unstable and transcriptionally labile in breast cancer. Genome Res 25(4):488–503. doi: 10.1101/gr.185926.114 CrossRefPubMedPubMedCentralGoogle Scholar
- 38.Qi J, Singh S, Hua WK, Cai Q, Chao SW, Li L, Liu H, Ho Y, McDonald T, Lin A, Marcucci G, Bhatia R, Huang WJ, Chang CI, Kuo YH (2015) HDAC8 inhibition specifically targets inv(16) acute myeloid leukemic stem cells by restoring p53 acetylation. Cell Stem Cell 17(5):597–610. doi: 10.1016/j.stem.2015.08.004 CrossRefPubMedPubMedCentralGoogle Scholar
- 39.Sinha S, Malonia SK, Mittal SP, Singh K, Kadreppa S, Kamat R, Mukhopadhyaya R, Pal JK, Chattopadhyay S (2010) Coordinated regulation of p53 apoptotic targets BAX and PUMA by SMAR1 through an identical MAR element. EMBO J 29(4):830–842. doi: 10.1038/emboj.2009.395 CrossRefPubMedPubMedCentralGoogle Scholar