Inhibiting Effect Of Intravesical Triptolide Against Bladder Cancer In Rats

Objective:To investigate the inhibiting effect of intravesical triptolide against bladder cancer in sprague dawley rats, and explore its possible molecular mechanisms.Methods:We establish the animal model of bladder cancer in SD rats by intravesical MNU. We compare the inhibiting effect against bladder tumor growth and poisonous side effect in rats by intravesical triptolide or mitomycin C or NS. Weight of rats’ body and bladder was compared in each group. The tissue and cell morphologic change were observed by HE stain after treatment, and pathological diagnosis and grade were scored respectively. We analyse the tissue samples using the TUNEL method to assess tumour cell apoptosis and calculate apoptotic index of each group. Western blot were performed to determine apoptosis flag matter Bax, Caspase3, Bcl-2 protein and autophagy flag matter Atg5, Beclinl, LC3 protein under drug treatment.Results:The success rate of intravesical MNU inducing bladder cancer in rats was 93.3%, and 13.3% of rats was died. Pathological examination showed characteristic changes about bladder cancer without distant metastasis in week 8. Weight of bladder of TP group (162.50±12.13 mg) was lower than NS group (177.00±13.82 mg, P<0.05) and MC group (164.50±8.45 mg, P>0.05). Relative weight of bladder of TP group (0.4910.05) was lower than NS group (0.56±0.06, P<0.05) and MC group (0.51±0.05, P>0.05). Body weight of each group had no significant difference. Compared to CL group, pathological examination of others showed characteristic changes about bladder cancer without distant metastasis in week 14. The pathological grade of TP group (2.13±0.95) was lower than NS group (4.00±1.19, P<0.05) and MC group (3.06±0.62, P<0.05). The TUNEL test showed that apoptotic index of TP group (32.30±8.16%) was significantly higher than other three groups (P<0.01). The expression level of Bax protein in TP group was (0.56±0.05), NS group was (0.24±0.01) and MC group was (0.36+0.03), the difference of each group was statistically significant. so did Caspase3 protein, Atg5 protein, Beclinl protein, LC3-Ⅱ protein and LC3-Ⅱ/LC3-1. On the contrary, the expression level of Bcl-2 protein in TP group was (0.38±0.05), NS group was (0.68±00.03) and MC group was (0.48±0.04), the difference of each group was statistically significant.Conclusion:Intravesical MNU is a simple, convenient and effective method to induce orthotopic bladder cancer in SD rats and it need a fairly short period of time and just acted on bladder. Intravesical triptolide could inhibit the growth and progress of bladder cancer by apoptotic and autophagic pathways.