Effects Of Antimicrobial Peptide Cecropin B On Human Bladder Cancer T24 Cell Line

Objective: To study the antitumor effects and mechanism of antimicrobial peptide Cecropin B on human bladder cancer T24 cell line in vitro.Methods: (1) Human bladder cancer T24 cell line and human umbilical vein endothelial cell(HUVEC) were educated in vitro. (2) Three groups involved in the study: antimicrobial peptide Cecropin B group, Mitomycin C group and Cecropin B combine with Mitomycin C group. The different densities (15, 30, 60, 120, 240 ug/ml) of the three groups of medicines were added in to the human bladder cancer T24 cell and incubated ,and the antiproliferative and cytotoxic potential of the three groups of medicines were quantified by MTT assay in human bladder cancer T24 cell line. (3) When the above-mentioned five densities of antimicrobial peptide Cecropin B were added into the HUVEC, the antiproliferative and cytotoxic potential of Cecropin B were also quantified by MTT assay. (4) When different densities (0, 5, 20, 140 ug/ml) of antimicrobial peptide Cecropin B were added in to T24 cell and HUVEC, cell cycle was measured by flow cytometry. (5) Scanning electron microscopy was performed to visualize the morphological changes induced by antimicrobial peptide Cecropin B in human bladder cancer T24 cells.Results: (1) Antimicrobial peptide Cecropin B group, Mitomycin C group and Cecropin B associate with mitomycin C group inhibit human bladder T24 cell proliferation and viability in a dose dependent fashion. The inhibition ratio was gradually increased along with the densities of the three groups medicines increasing. Both antimicrobial peptide Cecropin B and Mitomycin C inhibited the human bladder T24 cell line significantly (P<0.05), but both inhibition ratios had no statistical difference (P>0.05). And the inhibition ratio of the human bladder cancer T24 cell was increased significantly by Cecropin B combine with Mitomycin C (P<0.05). (2) In contrast, HUVEC was significantly less or not at all susceptible to antimicrobial peptide Cecropin B. (3) The ratio of G0/G1 phase T24 cell was increased and the ratio of G2/M phase T24 cell was decreased,whereas the ratio of G0/G1 phase and the ratio of G2/M phase HUVEC were not significantly affected. (4) Scanning electron microscopy demonstrated lethal membrane disruption in human bladder cancer T24 cells.Conclusions: (1) Both antimicrobial peptide Cecropin B and Mitomycin C can inhibited the human bladder T24 cell significantly, with no statistical difference. The combine therapy of CB and MMC shows significant inhibite effect (2) Antimicrobial peptide Cecropin B exert selective cytotoxic and antiproliferative efficacy in human bladder cancer cells while sparing targets of HUVEC. (3) Cecropin B could inhibit the growth of human bladder cancer T24 cell by inducing cell cycle arrest at G0/G1 phase, and the mechanism of antimicrobial peptide Cecropin B killing human bladder cancer T24 cell could be drilling the membrane. (4) Cecropin B may offer novel therapeutic strategies for the treatment of bladder cancer with limited cytotoxic effects on normal cells. Cecropin B is a potential candidate for further preclinical evaluation as one of the intravesical treatment potent in non-muscle invasive bladder cancer.