摘要
目的探讨蛋白激酶A(PKA)活性下降对膀胱移行细胞癌细胞株T24增殖和化疗敏感性的影响及其机制。方法用0、15、30μmol/L H-89(PKA活性抑制剂)诱导T24细胞后,用放射免疫法检测H-89作用下T24细胞中PKA活性的变化；用流式细胞仪检测H-89作用下细胞凋亡的变化；用噻唑蓝(MTT)比色法检测丝裂霉素和表阿霉素单独作用下以及与15μmol/L H-89共同作用下T24细胞活力的变化；用Western blot检测15μmol/L H-89作用下T24细胞中bcl-2表达的变化。结果H-89能够使T24细胞中的PKA活性下降；在15μmol/LH-89作用36h后,流式细胞仪检测可见T24细胞凋亡率为57．81%,显著高于对照组4．37%(F=311．35,P＜0．01)。丝裂霉素(MMC)和表阿霉素(Epirubicin)对T24细胞的半数致死量分别为120mg/L和100mg/L；加入15μmol/L H-89后,细胞的存活率分别降为(31．14±4．37)%和(24．91±3．59)%,两组间差异有统计学意义(丝裂霉素组：F=23．94,P＜0．01；表阿霉素组：F=50．64,P＜0．01)。用15μmol/L H-89诱导T24细胞后,bcl-2表达呈下降趋势,并显著低于对照组。结论抑制PKA活性能够使bcl-2的表达下降,从而诱导膀胱癌T24细胞株凋亡,并提高其对化疗药物的敏感性。
Objective To investigate whether downregulation of protein kinase A （PKA） can influence the proliferation of T24 cell line and find out the possible mechanism between downregulated PKA activity and the corresponding changes in T24 cell proliferation. Methods T24 ceils were cultured with PKA inhibitor-H-89 at different concentrations or in combination with other chemotherapy drugs, and the changes in PKA activity, cell viability, cell cycle distribution and the expression of Bcl-2 were measured at different time points. Results （1） H-89 could significantly downregulate PKA activity and cell viability in T24 cells;（2） After T24 ceils were treated with H-89 for 36 h,The apoptosis rate was 57.81% ,higher than that in control group （4.37 %, F = 311.35, P 〈 0.01 ） ; （3） H-89 could enhance the sensitivity of T24 cell line to chemotherapy drugs. LD50 of T24 cells to MMC and Epirubicin was 120 mg/L and 100 mg/L,and the survival rate was reduced to （31.14 ± 4.37） % and （24.91 ± 3.59） % respectively when cultured in combination with 15 μmol/L H-89, with the difference being significant （MMC group： F = 23.94,P〈0.01 ;Epirubicin group：F= 50.64,P〈0.01） ;（4） After being cultured with 15 μmol/L H- 89, the expression of bcl-2 was downregulated significantly. Conclusion Downregulation of PKA activity can lead to reduction of Bcl-2 expression, resulting in proliferation inhibition and cell apoptosis, and can enhance the sensitivity of T24 cell line to chemotherapy drugs.
出处
《中华实验外科杂志》
CAS
CSCD
北大核心
2006年第9期1124-1126,共3页
Chinese Journal of Experimental Surgery
