Design,Synthesis And Antitumor Evaluation Of Acyclic Nucleosides In Vitro And In Vivo

Malignant tumors seriously threaten human life health and are one of the main causes of human death.The development of antitumor drugs has always been one of the important direction in drug development.The synthetic nucleoside compounds are similar in structure to natural nucleoside compounds.After entering the human body,they can inhibit the replication of viruses or tumor cells and achieve the purpose of antiviral or anti-tumor.People pay more and more attention to the development of nucleoside antitumor and antiviral drugs.Acyclic nucleoside compound is an unique kind of nucleoside compounds.Because of their unique physical and chemical properties,they have become the focus of nucleoside drug development.At present,acyclic nucleoside compound is an important kind of antiviral drugs on the market.There are few studies on the antitumor activity of non-cyclic nucleoside compounds.More and more evidence showed that viral diseases have closely related to the occurrence of tumors.The innovative research on non-cyclic nucleoside antitumor drugs can not only break the international monopoly on nucleoside drugs,but also has important scientific significance and potential application prospect.In order to study the anti-tumor activity of acyclic nucleoside compounds,based on previous research,our research group synthesized 80 acyclic nucleoside compounds with different substituents at the2,6,8,9 position of purines and 1’position of purines side chain and 11 chiral acyclic nucleoside compounds with different configurations through reactions such as Aza-Michael addition reaction and allyl amination reaction.The MTT assay was used to conduct preliminary antitumor activity studies of these compounds,helping us to analyze and summarize the structure-activity relationship of these compounds.The experimental results showed that compound 9b had the strongest ability to inhibit proliferation of two colon cancer cell lines（HCT-116 and SW480）in vitro,with IC₅₀ of 0.89μM and 1.15μM,the control drug5-fluorouracil（5-FU）with the IC₅₀ of the two cells are 10.81μM and 9.70μM,respectively.And the chiral acyclic nucleoside compounds in the S-configuration exhibited stronger antitumor activity than the R-configuration.Next,we performed a series of evaluation studies on compound 9b in vivo and in vitro antitumor.Flow cytometry experiment result showed that compound 9b inhibited tumor proliferation mainly by inducing apoptosis.Western Blot experiment result showed that compound 9b promoted the expression of three apoptosis-related proteins,Bax,P53,and Cleaved-PARP at least,and inhibited the expression of Bcl-xl protein induced apoptosis.Mitochondrial membrane potential（MMP）experiment result showed that dissipation of MMP may be involved in apoptosis induced by compound 9b.Cell colony experiment result showed that compound 9b could inhibit the formation of cell colonies.Nude mouse xenograft experiment result showed that compound 9b had the same efficacy as the control drug 5-FU in a nude mouse model of SW480 cell transplantation and was less toxic than the control drug 5-FU.H&E staining experiment result of nude mice’s tumors showed that after administration of compound 9b,tumors in the mice had apparent necrosis.Through the evaluation of acyclic nucleoside in vivo and in vitro antitumor activity,it can obtain better anti-tumor lead compounds or candidate drug molecules,and can provide reasonable synthesis strategies and methods for chiral acyclic nucleoside drugs.To lay the foundation for the development of chiral anti-tumor acyclic nucleoside drugs with independent intellectual property rights.