| IntroductionHuman ovarian cancer is the hightest death - rate disease in Gynecologic cancer , drug - treat is the important therapy. Telomerase can be dective in most of gynecologic cancer cells . Maintenance of te-lomere length is crucial for survival of cells. Telomerase, an enzyme that is responsible for elongation of shortened telomeres, is active in human ovarian cancer cells as well as most tumor tissues and experimentally immortalized cells. In contrast, most mature somatic cells in human tissues express undetectable or low telomerase activity, implying the existence of a stringent and negative regulatory mechanism. In this study, we report the effects of cisplatin on telomerase activity in human ovarian cancer cells. The special relationship between activity and cancer has a important application value. Vitamin C can remission the symptom of cancer patien and lengthen life span, but the relationship of it and telomerase was not reported. Cisplatin is widely administrated in cancer therapy, it is cell cycle non - specific agent and is combined with other drugs. The caov3 cells were cultured in medium containing different concentrations vitamin C and for different time. Cisplatin and vitamin C colture caov3 cells, then the telomerase activity was observed in this text.In this study, we investigated the telomerase activity of vitamin C with or without cisplatin on cultured human ovarian cancer. At thesame time , investigated whether inhibitory effects induced by cispln tin resulted in tumor growth inhibition.Material and Methodsmaterial . caov3 cells (human ovarian cancer cell) Reagent and equipment . Rnase,MTT,TEMED,Acrylamide,Bi-sacrylamide,CHAPS,AEBSFB,Tag DNA polymerase,dNTP,Ts and Cxprimer,cispiatin,pBR322 DNA/Hae III Markers, all other chemicals were of resgent grade.752 Cultraviolet - visible spectrophotometer, phase contrast microscope,SCR-4 Hyperbaric electrophresis apparatus, THZ-95set homoiothermyshake box; ELX-800 enzyme-labelled equipment, HRSP0520 PCR instrument, SORVALL centrifugal machine,CO2 incubation equipmen, super clean benchMethods2. 1 Cultivation the caov3 cells.2. 2 Induction of the cisplatin and vitamin C.2. 3 The MTT assay.2.4 Protion determination . Pritein was determined by the method of lowry et al.2. 5 Purify the telomerase in human ovarian cancer cells2. 6 The telomerase activity in cells was detected by telomeric repeat amplification protocol ( TRAP) - silver straining and was analyzed by the specific software.ResultsBoth 50mol/L and 10mol/L vitamin C were not due to thechange of telomerase activity , however they can enhance the inhibition of telomerase activity by cisplatin . The suppressing effect was enhanced with the concentration increasing of vitamin C .In 200mol/L cisplatin, no telomerase inhibition was found when cells were collected only after 4 hours of drugs treatment, but the telomerase activity of cells was completely inhibited by cisplatin when removed the drug and recultured for 20 hours. However, vitamin C had no effect. In 8mol/L cisplatin , it was similar with 200mol/L cisplatin to uppress the telomerase acting of caov3.DiscussionTelomeres, which are important for maintaining chromosome integrity and functions, shorten with each cell division. Telomerase,responsible for telomere synthesis, is expressed in most of human tumor cells but seldom in normal somatic cells. Telomerase inhibition has, therefore, been proposed as a novel and potentially selective target for therapeutic intervention . A down - regulation of telomerase activity was found when cells of a human ovarian cancer cell line, caov3 , were treated with cisplatin. The present results may indicate a positive relationship between anticancer effects and down - regulation of telomerase activity by anticancer drugs. DDP reduced telomerase activity in the cells in a concentration - dependent manner as measured by using the telomere repeat amplification protocol (TRAP) assay. The effect on the telomerase activity of the type of an...
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