Anticancer Effect And Cellular Mechanisms Of Novel Manganese-pyridine Compound

Object:In this study,anticancer activity of the novel manganese-pyridine compound and its possible mechanism were investigated.Methods:In vitro,six human cancer cell lines including HeLa,LOVO,HepG-2,A549 and U251 cells were treated by four manganese-pyridine derivatives.Cancer cells proliferation were detected by MTT assay and the 50%inhibitory concentration(IC₅₀) were calculated;mitochondria swelling was used to find out its interaction with mitochondria.In vivo,human hepatoma carcinoma(Hepes) xenografts were used to evluated its anticancer activity and primary toxicity.Cell apoptosis and autophagy were detected as follows: nucleus morphological changes were observed by staining with hoechest 33342; expression of autophagy-related protein LC3 and Beclin-1were analysised by western blot; the formation of autophagic vacuoles was assessed by staining cells with MDC;formation of ROS were detected by DCFH-DA staining;mitochondrial membrane potential was observed by JC-1 staining;ATP content was detected by luciferase assay.Results:Manganese-pyridine compound 4(named Adpa-Mn(â…¡)) exhibited significant inhibition on cancer cell proliferation.The IC₅₀ are around 5-15μmol/L.Adpa-Mn(â…¡) exhibited dose- and time-dependent effect on HeLa and U251 proliferation.In vivo,the anticancer activity of Adpa-Mn(â…¡) against human hepatoma carcinoma(Hepes) xenografts was comparable to that of cyclophosphamide(CTX) and cause no significant adverse effects.In vivo,the anticancer activity of Adpa-Mn(â…¡) against human hepatoma carcinoma (Hepes) xenografts was comparable to that of cyclophosphamide(CTX)and cause no significant adverse effects.Fe²⁺/Fe³⁺ reduced inhibition rate of Adpa-Mn(â…¡) on HeLa and U251 cells and Adpa-Mn(â…¡) inhibit Ca²⁺-induced mitochondria swelling via does-dependent way.Adpa-Mn(â…¡) induced apoptosis and autophagy in HeLa cells indicated by chromatin condensation,caspase-3 activation,enhanced fluorescence intensity of monodansylcadervarine(MDC),as well as elevated expression of autophagy-related protein LC3 and Beclin-1.Moreover,Adpa-Mn(â…¡) elevated ROS,but caused no significant change in mitochondrial membrane potential.When autophay was blocked by 3-MA,cell survival rate was elevated which indicated that autophahy promoted cell death. Adpa-Mn(â…¡) can slso induced apoptosis and autophagy in U251 cells demonstrated by chromatin condensation,caspase-3 activation,MDC fluorescence intensityand lysosme activity enhanced,as well as elevated expression of LC3 and Beclin-1.But Adpa-Mn(â…¡) primary disrupted mitochondria membrane potential which caused MPTP open which is different with in HeLa cells.And when MPTP was blocked by CsA,mitochondria membrane potential was partly restored with decreased rate of apoptosis and autophagy. When autophay was blocked by 3-MA,U251 cell survival rate was reduced which indicated that autophahy promoted cell death.Conclusion:In summary,Adpa-Mn(â…¡) exerts anticancer activity both in vivo and in vitro and has low toxicity.Adpa-Mn(â…¡) may be transported by Fe uptake-system and has interaction with mitochondria.Adpa-Mn(â…¡) can induced cancer cell death which may by cooperation of the effect of Mn(â…¡) and Adpa.Both apoptosis and autophagy were invovled in cell death(HeLa and U251) induced by Adpa-Mn(â…¡) but via different mechaisms:And it has promising anticancer activity in vivo against a human hepatoma cancer xenograft. Together,these data suggest further development of Adpa-Mn(â…¡) be a lead compound as a novel anticancer metal-drug.