Effect Of Vitamin K3 On Gemcitabine-induced Apoptosis Of Bladder Cancer Cell Line T24

Background: Gemcitabine (Gem) was a new anti-pyrimidine nucleotide meta- bolism of chemotherapy drug, which had a broad anti-tumor spectrum, a unique mechanism, and low-toxicity, without cross-resistance and non-overlapping toxicity characteristics when used with other chemotherapy drugs. A lot of research including in vitro studies, animal experiments and clinical trials all indicated that Gem had a good anti-tumor activity to a variety of solid tumors ,which had been substantial applied to chemotherapy for advanced bladder cancer in recent years. The clinical value of Gem had been fully affirmed and that would be a hot issue on the combination chemotherapy of Gem based on clinical research . Researches had showed that vitamin K3 could enhance the anti-tumor activities of a variety of chemotherapy drugs when combined. Currentlly it had became a hot issue on the combination of vitamin K3 and certain first-line chemotherapy drugs,however, the research of combination with Gem is still rare. In our preliminary study, we observed the cell apoptosis of vitamin K3 combined with Gem acting on human bladder cancer cell line T24.Objective: To investigate the effect of vitamin K3 (VK3) combined with Gem on the cell apoptosis and cell cycle of human bladder cancer cell line T24.Method:⑴MTT was used to select the minimum effective concentration of Gem with certain concentration gradient (0.01,0.1,1.0,10.0μg/ml) for inhibiting T24 cell growth after 72h culture.⑵Then MTT was used to select the minimum effective concentration of combination of Gem and VK3 with certain concentration gradient (2,5,10,20μmol/L) for inhibiting T24 cell growth after 72h culture.⑶There would be three groups and cultivate each group : control group, the minimum effective concentration of Gem group and the minimum effective concentration of combination group.⑷The apoptosis was detected by the flow cytometry with PI,and the cell cycle was analyzed by FACS streaming software.⑸Microscope was used to observe the changes of the cell morphology in each group.Results:⑴The MTT selected minimum effective concentration of Gem for inhibiting T24 cell growth after 72h culture was 1.0μg/ml.⑵The MTT selected minimum effective concentration of Gem and VK3 for inhibiting T24 cell growth after 72h culture was 1.0μg/ml Gem and 10μmol/L VK3 group.⑶The result of flow cytometry indicated that the apoptosis rate of the combination group(.0μg/ml Gem and 10μmol/L VK3) was higher than Gem group (1.0μg/ml Gem ), difference was statistical significance (P<0.05).⑷The result of flow cytometry indicated that the cell cycle arrest at S phase of the combination group(10μmol/L VK3 and 1.0μg/ml Gem) was higher than Gem group (1.0μg/ml Gem ), difference was statistical significance (P<0.05).⑸It was observed by Microscope that the number of cells decreeased and cell necrosis increased of the combination group (10μmol/L VK3 and 1.0μg/ml Gem) compared to the Gem group(1.0μg/ml Gem ).Conclusions: VK3 could enhance the effect of Gem-induced human bladder cancer cell line T24 apoptosis,and the possible mechanism might be related to that VK3 could enhance Gem-induced cell cycle arrest at S phase (DNA-synthesis phase).