In order to elucidate the mechanisms of multidrug resistance (MDR) in bladder cancer, the expression of glutathione S-transferase-π (GST-π) and multidrug resistance associated protein (MRP) in tissue samples resec...In order to elucidate the mechanisms of multidrug resistance (MDR) in bladder cancer, the expression of glutathione S-transferase-π (GST-π) and multidrug resistance associated protein (MRP) in tissue samples resected from 44 patients and 6 normal bladder mucosa as control was de- tected by using immunohistochemical method, and the results were analyzed by computer-assisted im- age analyzing system (IAS) to achieve semi-quantitative data. In addition, correlation between the expression of both factors was studied. The results showed that the positive expression rate of GST- π and MRP in bladder cancer was 72. 7 % (32/44) and 68. 2 % (30/44) respectively, significantly higher than those in normal bladder mucosa, being 16. 7% and 33. 3% respectively. The rate of GST-πpositive staining was increased correspondingly with tumor grade and stage elevated, being higher in recurrent tumors treated by chemotherapy, but not significantly (P>0. 05). There was no significant differences between the expression of MRP and tumors' behaviors and clinical characters. However, the results demonstrated that the correlation between the expression of both resistant fac- tors was very evident (r=0. 695, P<0. 0025). It was suggested that the activation of GST-π and MRP might occur during malignant transformation of normal mucosa, but tumors' differentiation and progression could not be the unique factors that influenced both overexpression. Chemotherapy might be another important reason. The correlation of both indicated that there was a common mech- anism regulating their expression probably, which made them play a pivotal role in chemotherapy drug resistance of bladder cancers.展开更多
目的研究右旋美托咪啶(dexmedetomidine,Dex)对异氟醚所致新生大鼠海马细胞凋亡的保护作用及与Akt/Bad信号通路的关系。方法出生7 d SD大鼠随机分为空气组(Air+NS)、二甲基亚砜组(Air+DMSO)、LY294002组(Air+LY)、异氟醚组(Iso+NS)、异...目的研究右旋美托咪啶(dexmedetomidine,Dex)对异氟醚所致新生大鼠海马细胞凋亡的保护作用及与Akt/Bad信号通路的关系。方法出生7 d SD大鼠随机分为空气组(Air+NS)、二甲基亚砜组(Air+DMSO)、LY294002组(Air+LY)、异氟醚组(Iso+NS)、异氟醚+Dex组(Iso+Dex)、异氟醚+Dex+LY294002组(Iso+Dex+LY)。前3组吸入空气6h,后3组吸入体积分数为0.0075异氟醚6h。吸入异氟醚前40min,Air+DMSO组、Air+LY组和Iso+Dex+LY组分别经侧脑室注射5μl体积分数为0.1的DMSO或25μg LY294002;Iso+Dex组和Iso+Dex+LY组分别在麻醉0、2、4 h腹腔内注射Dex 25μg·kg-1;Air+NS组和Iso+NS组在同时间点腹腔内注射等体积生理盐水。Western blot法检测海马激活型caspase-3、Akt、磷酸化Akt(p-Akt)、Bad、磷酸化Bad(p-Bad)、Bcl-xl蛋白表达变化(n=5),TUNEL法检测海马CA1区细胞凋亡(n=5)。结果 Dex可明显减少异氟醚引起的海马CA1区TUNEL阳性细胞表达(P<0.01),减低激活型caspase-3(P<0.01)和Bad蛋白表达(P<0.01),上调p-Akt/Akt、p-Bad/Bad和Bcl-xl/Bad比值(P<0.01)。LY294002逆转了Dex对上述蛋白表达的影响。结论Dex通过激活Akt/Bad信号通路减少异氟醚诱导的新生大鼠海马细胞凋亡。展开更多
基金This project was supported by a grant from the fund of science of Hubei Province (No. 99J124 ).
文摘In order to elucidate the mechanisms of multidrug resistance (MDR) in bladder cancer, the expression of glutathione S-transferase-π (GST-π) and multidrug resistance associated protein (MRP) in tissue samples resected from 44 patients and 6 normal bladder mucosa as control was de- tected by using immunohistochemical method, and the results were analyzed by computer-assisted im- age analyzing system (IAS) to achieve semi-quantitative data. In addition, correlation between the expression of both factors was studied. The results showed that the positive expression rate of GST- π and MRP in bladder cancer was 72. 7 % (32/44) and 68. 2 % (30/44) respectively, significantly higher than those in normal bladder mucosa, being 16. 7% and 33. 3% respectively. The rate of GST-πpositive staining was increased correspondingly with tumor grade and stage elevated, being higher in recurrent tumors treated by chemotherapy, but not significantly (P>0. 05). There was no significant differences between the expression of MRP and tumors' behaviors and clinical characters. However, the results demonstrated that the correlation between the expression of both resistant fac- tors was very evident (r=0. 695, P<0. 0025). It was suggested that the activation of GST-π and MRP might occur during malignant transformation of normal mucosa, but tumors' differentiation and progression could not be the unique factors that influenced both overexpression. Chemotherapy might be another important reason. The correlation of both indicated that there was a common mech- anism regulating their expression probably, which made them play a pivotal role in chemotherapy drug resistance of bladder cancers.
