Effects Of Chemotherapy Medicine On The Length Of Telomere,Telomerase And HTERT In Heparto-carcinoma BEL-7404 And BEL-7404/ADM Cells

OBJECTIVE: To investigate the anticancer effect and the mechanism ofchemotherapy medicine DDP,MMC,ADM,VCR on telomere,telomerase andhuman telomerase reverse transcriptase (hTERT) on human hepatocellularcarcinoma cell line BEL-7404 and BEL-7404/ADM cells.METHODS: Reverse transcriptase polymerase chain reaction(RT-PCR) was usedto assay the effect of the expression levels of hTERT-mRNA in humanhepartocellular carcinamo BEL-7404 and BEL-7404/ADM cells treated withdifferent chemotherapy medicine and different concentration.The effect of differentchemotherapy medicine on the length of the telomere in hepartocellur carcinomaBEL-7404 and BEL-7404/ADM cells was determined by the Southen Blotting andgel electrophoresis. Telomerase Regulation-associated Protein-Polymerase ChainReaction-Enzyme Linked Immunoassay (TRAP-PCR-ELISA) was used todetermine the telomerse activitythe by different chemotherapy medicine inhepartocellur carcinoma BEL-7404 and BEL-7404/ADM cells.RESULTS: (1)After RT-PCR amplification, the expression levels of hTERT oftelomerase from BEL-7404 cells decreased with the the concentration ofchemotherapy medicine increasing.The hTERT expression was significantlyinhibited after treated with the high concentration DDP for 48h. And the hTERTexpression began to be inhibited for 48h and was totolly inhibited when treatedwith the low concentration DDP for 72h.The hTERT expression was also significantly inhibited treated with the highconcentration ADM (for 48h) and it began to be inhibited when treated with thelow concentration ADM for 72h.(2)The telomerase activity of BEL-7404/ADM cells was partly inhibited whentreated by the four kinds of medicines with high concentration (group C ) for 48h.The telomerase activity of BEL-7404/ADM cells was significantly inhibited whentreated by the DDP and MMC for 24h. There was significant difference betweenthe experimental groups and the normal controls (P <0. 01).There was significantdifference between the groups treated for 48h and 72h (P <0. 01). The inhibitingactivity was strengthened with the extension of the treated time. The telomeraseactivity were showed concentration and time dependent. While the telomeraseactivity was only partly inhibited by ADM and VCR. The telomerase activity ofBEL-7404/ADM cells was significantly inhibited when treated by the DDP andMMC with low concentration for 72h (Group A, B). There was significantdifference between the two groups (P <0. 01). While the ADM and VCR couldeffectively inhibit the telomerase activity after 72h. Four chemotherapy medicinecould reduce the telomerase activity of BEL-7404 cells and the inhibiting effectwere concentration and time dependent.(3)The average length of the telomere in the sensitive hepartocellular carcinomaBEL-7404 cells was longer than that in the drug-resistant BEL-7404/ADM cells.The length of the telomere shortened gradually with the increasing of theconcentration of chemotherapy medicine. Among these two kinds cells , there wereboth statistical significant difference in average length of the telomere between thehigh destiny groups treated with DDP, MMC, ADM, VCR and the normal controls.The significant inhibiting activity of DDP, MMC and ADM on BEL-7404 cellswas shown in low concentration group (group A , B ) with significant difference ofthe groups(P<0.01).They could also inhibit the BEL-7404/ADM cells and theeffect was concentration dependent.But VCR had no inhibiting activity on thetelomere length of the two kinds of cells.The average length of the telomere in thehepartocellular carcinoma cells treated with chemotherapy medicine and thedrug-resistant cells were significantly shorter than that in the control group. Theaverage length of the telomere in BEL-7404 cells was longer than that inBEL-7404/ADM cells. And the length in BEL-7404 cells would be shortened withthe denstiny of the chemotherapy medicine increasing.CONCLUSIONS: (1)Different chemotherapy medicine DDP , MMC , ADM ,VCR could inhibit hTERT of BEL-7404 cells with the remarkable effect ofconcentration and time dependent. DDP and MMC...