Synthesis And Biological Evaluation Of Inhibitors Of Topoisomerases And Histone Deacetylase For In Vitro Anticancer Activity

Abstract

iv newlineABSTRACT newline Synthesis and Biological Evaluation of Inhibitors of Topoisomerases and newlineHistone Deacetylase for In Vitro Anticancer Activity newlineName of student : Gaurav Joshi newlineRegistration Number : 15phdphm01 newlineDegree for which submitted: Ph. D. (Pharmaceutical Sciences) newlineSupervisor : Dr. Raj Kumar newlineCo-Supervisor : Dr. Sandeep Singh newlineDepartment : Pharmaceutical Sciences and Natural Products newlineSchool of Studies : Basic and Applied Sciences newlineKeywords : Cancer, Topoisomerases, Histone deacetylase, newlineTopoisomerases (Topos) and histone deacetylases (HDACs) are validated newlineoncotherapeutic targets due to their involvement in most of the cellular events such as newlineinitiation, proliferation, and survival of cancer cells. Widespread research has newlineundergone to design and discover small molecule inhibitors of each protein which has newlineled to the development of several drugs that are making their presence felt in clinic. newlineConsidering the issues of stability, toxicity, reported crosstalk(s) and resitance of newlineexisting pharmacophores, we herein report the discovery of target-based molecules newlinepertaining to pyrazolo[1,5-c]quinazolines, 2-aryl quinolines and imidazo[1,2- newlinea]quinoxaline scaffolds as inhibitors of TopoI or dual TopoI and II designed rationally newlinevia in silico tools. The chemical space of scaffolds was further exploited to design and newlinesynthesise dual/multi inhibitors of Topo-HDAC by connecting pharmacophoric features newlineof HDAC inhibitors via a linker. newlineDetailed biological evaluation of synthetics was performed using multiple cancer cell newlinelines as well as normal cells/cell lines. Utilizing MTT, dye exclusion, redox potential, cell newlinecycle and annexin V vs PI assays in 2D as well as 3D cultures, we established their newlinepreferential cytotoxic potential. Signaling responsible for anticancer mechanism was newlinedelineated using western immunoblotting and qPCR assays. Further, in vitro assays newlinev newlinefor topoisomerases (DNA relaxation and catenation), and/or HDAC1 revealed target newlinespecificity of synthetics. newlineIn addition, we also demonstrated a novel bioreductive methodology, sp