Novel Ferrocene Derivatives Induce HT1080 Cell To Apoptosis

The organometallic compound ferrocene is a promising candidate for biological and medical applications due to its stability,electrochemical properties,and ease of use.In order to investigate the antitumor activity of three novel ferrocene derivatives (6-Ferrocenyl-3-phenyl-7H-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazine(FTF-H), 6-Ferrocenyl-3-p-tolyl-7H-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazine(FTF-CH₃)and 6-Ferrocenyl-3-(4-nitrophenyl)-7H-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazine (FTF-NO₂)),HT1080 and BJ cells were cultured in vitro,MTT assay showed that both FTF-CH₃ and FTF-NO₂ exert stronger inhibition of HT1080 cells proliferation than BJ cells.And in 24,48 and 72 hrs,the IC₅₀value of HT1080 treated with FTF-CH₃ is: 108.2μM,178.0μMå’Œ130.2μM,and that of BJ treated with FTF-CH₃ is:447.0μM,203.5μM and 209.5μM;The IC₅₀value of HT1080 treated with FTF-NO₂ is:202.8μM,23.0μM and 15.4μM,and that of BJ treated with FTF-NO₂ is:4479.0μM,572.5μM and 79.7μM,the IC₅₀value of HT1080 is lower than that of BJ.In soft agar assay, we found that FTF-CH₃ and FTF-NO₂ inhibited the anchorage-independent growth of HT1080 cells in a dose dependent manner.Apoptotic morphology of HT1080 cells treated with FTF-CH₃ and FTF-NO₂ was observed by phase contrast microscope,such as shrinkage and detachment;Flow cytometry analysis indicated that FTF-CH₃ and FTF-NO₂ inhibited HT1080 cell proliferation by arresting cell cycle at G1 phase and induced the appearance of sub-G1 peak.AO/EB assay showed early and late apoptotic morphology of HT1080 cells treated with FTF-CH₃ and FTF-NO₂,such as chromatin condensation,nucleosoma degradation and nucleared colored by jacinth or yellow,and the apoptosis rate increased gradually with the increase of drug concentration. Furthermore,FTF-NO₂-induced apoptosis was confirmed by observation of DNA fragementation of treated cells on 2%agarose gel electrophoresis.Rh123 label testing revealed that FTF-CH₃ and FTF-NO₂ significantly decreased the mitochondrial membrane potential of HT1080 cells.Taken together,our observations demonstrated that FTF-CH₃ and FTF-NO₂ exert stronger lethal effect on HT1080 cells than that on BJ cells,which is essential for cancer treatment.Moreover we also found that FTF-CH₃ and FTF-NO₂ induced HT1080 cell apoptosis by mitochondrial pathway.