Design,Synthesis And Structure-activity Relationship Study Of Pregnenolone/Coumarin Derivatives With Antitumor Activity

Cancer is one of the leading causes of death affecting millions of people worldwide.Over the past few decades,a number of clinical anticancer drugs have been developed to treat a variety of cancer diseases,even though there is an arsenal of available drugs there is an urgent need to develop new agents to overcome the limitations of the current therapies（for example,cardiac toxicity,diarrhea and neutrophils reduction）.Here in this article we wish to emphasize NF-?B and apoptosis related to cancer pathways and factor can be used to search novel anticancer lead molecules.In recent years,a large number of studies have shown that inhibiting the activation of NF-?B pathway can inhibit the proliferation of tumor cells.Twenty-five novel pregnenolone/2-cyanoacryloyl conjugates（6–30）were designed and prepared,with the aim of developing novel anticancer drugs with dual NF-?B inhibitory and anti-proliferative activities.Compounds 22 and 27–30 showed inhibition against TNF-a-induced NF-?B activation in luciferase assay,which was confirmed by Western blot.Among them,compound 30 showed potent NF-?B inhibitory activity(IC₅₀=2.5?M)and anti-proliferative against MCF-7,A549,H157,and HL-60 cell lines(IC₅₀=6.5–36.2?M).The present study indicated that pregnenolone/2-cyanoacryloyl conjugate I can server as a novel scaffold for developing NF-?B inhibitors and anti-proliferative agents in cancer chemotherapy.A series of novel coumarin/2-cyanoacryloyl hybrids were prepared and evaluated for their in vitro anticancer activity.Among them,two analogs 5p and 5q showed promising antiproliferative activity against a panel of cancer cell lines,including A549,H157,HepG2,MCF-7,MG63,and U2OS.Particularly,5q showed the most potent activity towards MG63cells with an IC₅₀ value of 5.06?0.25μM.Morphological observation and4,6-diamidino-2-phenylindole（DAPI）staining assay showed that 5q-treated MG63 cells displayed significant apoptosis characteristics.Moreover,flow cytometric detection of phosphatidylserine externalization revealed that 5q induced MG63 apoptosis in a dose-dependent manner.Real-time PCR and western blot assay further confirmed that 5q had strong effects to induce MG63 cell apoptosis,suggesting that the action was associated with down-regulation of the anti-apoptotic protein Bcl-2,upregulation of pro-apoptotic protein Bax,and induced activation of caspase-3,8 and 9.The present results provide a new chemotype for anticancer drug development and continuing investigation into candidates with coumarin/2-cyanoacryloyl scaffold is warranted.