Synthesis And Antitumor Activity Of G4 Targeted Alkyne-modified Ruthenium Complexes

Objective:To study the synthesis of alkynyl-modified PIP-type ruthenium complexes and DPPZ-type ruthenium complexes;To investigate the differences in the binding ability and antitumor activity of alkynyl-modified PIP-type ruthenium complexes with c-myc G-quadruplex DNA,and the regulation of c-Myc.The differences in antitumor activity of different alkynyl-modified DPPZ-type ruthenium complexes and the inhibitory effect of 3-aminophenylethynyl-modified ruthenium complexes on the invasion and metastasis of MDA-MB-231 were also studied.Methods:Using Sonogashira coupling reaction under microwave irradiation to synthesis the alkynyl-modified PIP-type ruthenium complexes and DPPZ-type ruthenium complexes.Using MTT,spectroscopic experiments,FRET,TEM,AFM,PCR-stop and Western-blot to investigate the differences in the binding ability and antitumor activity of alkynyl-modified PIP-type ruthenium complexes with c-myc G-quadruplex DNA.In addition,the antitumor activity of different alkynyl-modified DPPZ-type ruthenium complexes was investigated by MTT assay.Cellular localization,flow cytometry,comet assay,immunofluorescence,and luminal formation assays were used to investigate the inhibitory effects of 3-aminophenylethynyl-modified ruthenium complexes on the invasion and metastasis of MDA-MB-231.Results:2 PIP-type ruthenium complexes and 27 DPPZ-type complexes with alkynes have been successfully achieved by a Sonogashira coupling reaction under microwave irradiation.Besides,it was surprise that we found propargyl alcohol and ruthenium complexes containing bromine atoms can undergo coupling and isomerization to form aldehyde compounds and verified by ESI-MS,¹H-NMR,¹³C-NMR,spectroscopy,and silver mirror reaction.Then,observations revealed both PIP-type ruthenium complexes with alkynes could selectively bind to and stabilize c-myc G-quadruplex DNA,blocking its transcription and translation,down-regulating the expression of c-Myc and then promoting the apoptosis of cancer cells.In sum,these ruthenium（II）complexes can be developed as c-Myc inhibitor.Futhermore,observations revealed that the antitumor activity of dextrorotatory complexes is usually greater than that of levorotatory complexes.In addition,the introduction of an aromatic cycloalkynyl group usually enhances the antitumor activity of the complexes.The ruthenium complexes with 3-aminophenylacetylene show a ideal antitumor activity against MDA-MB-231 with IC₅₀0 is 25.51±1.42μM and inhibit the invasion and metastasis of MDA-MB-231 at a lower concentration,rather than kill the cells.In summary,the ruthenium complexes with alkynes are the most promising non-platinum anticancer drug candidates.