Study On The Mechanism Of Anti-tumor Effect In Human Bladder Cancer By ?-elemene

1.Background and Purpose:Bladder cancer is one of the most common malignant tumors in the urinary system,and superficial bladder cancers account for about 75%.The recurrence rate of superficial bladder tumors is high and about half of the patients relapsed.Transurethral resection combined with postoperative intravesical drug perfusion are the most commom treatments in the world rightnow.The commonly used drugs include mitomycin,doxorubicin,BCG,and ?-elemene et al.As a Chinese original research and patented drug,?-elemene has anti-tumor effects on various tumors,and famous of the characteristics of small toxic and side effects,but the mechanism of anti-tumor effect is still unclear.The main purpose of this study is to analyze its anti-tumor effect and further explore its anti-tumor mechanism,which may provides a new theoretical basis for clinical bladder cancer chemotherapy.2.Methods:The primary bladder tumor cells(PBC)were extracted from fresh bladder tumor tissue,and the survival ability and IC50 of PBC,T24,5367 bladder tumor cell lines and SV-HUC-1 normal cell lines were observed after treatment with ?-elemene,and the toxicity was evaluated too.To observe the apoptosis-inducing effect of elemene on bladder tumor cells,the apoptosis of PBC,T24,5367 and SV-HUC-1 cells treated with elemene was detected by flow cytometry in vitro.To further evaluate the effect of elemene on the migration and invasion of bladder tumor cells by scratch and Transwell assays.Western-blot was used to detect the changes of apoptosis-related proteins in bladder cacer cells after treatment with ?-elemene.Tumor-bearing nude mouse model was constructed,after intraperitoneal perfusion,the changes in tumor volume and weight were observed,and the proliferation and apoptosis were detected too.Western-blot was also used to detect the expression of PTEN-AKT protein in human bladder tissue and the bladder cancer cells which treated with ?-elemene,then anylysised the significance in the anti-tumor effect of?-elemene and verified it in vivo.Lentivirus was used to scilence the expression of PTEN,the detection of proliferation,apoptosis and protein expression was used to further verify the feasibility of PTEN-AKT signaling pathway as the anti-tumor mechanism of ?-elemene.3.Results:The results of MTT assay showed that 0-elemene significantly inhibited the growth of PBC,T24 and 5367 bladder tumor cells,and the inhibitory force increased with the the?-elemene concentration as a dose-dependent manner.While the toxicity of normal SV-HUC-1 normal cell was lower,and its IC50 is significantly higher than that of the three bladder cancer cells.Flow cytometry showed that ?-elemene can significantly induce more apoptosis in PBC,T24,5367 bladder tumor cells compared with SV-HUC-1.The results of Scratch and Transwell test showed that 0-elemene can significantly reduce the ability of migration and invasion in T24 and 5367 bladder cancer cells.Moreover,Western-blot assay showed the expression of Caspase-3,Bax and Bad after elemene treatment was increased,but the expression of Bcl-2 was significantly decreased.The results of tumor-bearing nude mice showed that ?-elemene can significantly inhibit tumor growth and promote tumor cell apoptosis in vivo.Compared with normal tissues,PTEN protein expression was significantly decreased in bladder cancer tissue,p-AKT protein expression was significantly increased,but the AKT protein expression was not significantly changed.The results of treatment with ?-elemene in vitro and in vivo showed that the expression of PTEN in bladder cancer was increased,and the expression of p-AKT was decreased significantly,while the expression of AKT did not change significantly.After the scilence of PTEN by lentivirus,the growth inhibition and apoptosis induction of?-elemene on bladder tumor cells was weakened Significantly,but it still has a certain anti-tumor effect.4.Conclusions:?-elemene has a certain anti-tumor effct which can inhibit the growth and promote apoptosis in bladder cancer,and it has few effect on normal cells.PTEN-AKT signaling pathway plays an important role in the anti-tumor mechanism of ?-elemene.However,there are other mechanisms involved in the anti-tumor effect of ?-elemene,which deserves further study.