酸性核糖体蛋白P2在紫外线诱导的肿瘤细胞快速凋亡中的功能

目的研究酸性核糖体蛋白P2在紫外线（UV）诱导的细胞快速凋亡中的分子信号功能。方法选取小鼠淋巴瘤细胞3SB、人白血病细胞Jurkat、人宫颈癌细胞HeLa S3和人乳腺癌细胞MCF-7来研究其对UV诱导细胞凋亡的差异性。UV照射后,荧光显微镜活细胞染色计数分别观察细胞的凋亡形态学变化和凋亡率;Western blot分析凋亡相关的标志性蛋白的表达。并分别提取细胞质蛋白和细胞总蛋白,利用小型二维电泳、Western blot技术分析细胞质中游离的酸性核糖体蛋白P2的变化和总的P2的表达。结果 3SB和Jurkat细胞在UV照射后,24 h的凋亡率达100%,并观察到PARP和P21的激活;而HeLa S3和MCF-7细胞出现延迟性细胞凋亡。在快速凋亡的Jurkat细胞中,发现酸性核糖体蛋白P2去磷酸化。总的P2表达降低,存在剂量效应,并伴随着凋亡蛋白PARP的激活。结论酸性核糖体蛋白P2的去磷酸化及其在细胞内总量降低与UV诱导的细胞快速凋亡相关。

Acidic Ribosomal Proteins P2 and Its Function During the Process of Ultraviolet-induced Fast Apoptosis

Objective To investigate the role of acidic ribosomal protein P2 in ultraviolet（UV） induced fast cell apoptosis.Methods Murine thymoma cell line 3SB,human leukemia cell line Jurkat,human cervical cancer cell line HeLaS3,and human breast cancer cell line MCF-7 were confirmed their sensitivities to UV induced cell apoptosis.After UV irradiation,fluorescence microscope was applied to observe the cell apoptotic morphology,and erythrosine-staining cell was counted to calculate the cell death rate.The apoptotic mark protein expression in fast died cell was detected by Western blot.The cytosolic extracts were resolved with mini two dimensional gel electrophoresis and with P2 antibody using the Wes-tern blot to analyze the acidic ribosomal protein P2.Moreover,total acidic ribosomal protein P2 expression was assayed by Western blot.Results After UV irradiation,3SB and Jurkat cells demonstrated fast apoptosis,with 100% apoptotic rate reached within 24 h,and PARP and P21 were activated in those cells.However,HeLa S3 and MCF-7 showed delayed cell death.Dephosphorylated acidic ribosomal protein P2 was confirmed in fast apoptotic Jurkat cells,and total of P2 expression was reduced,accompanied with PARP activation.Conclusion Dephosphorylation and reduced expression of acidic ribosomal protein P2 is associated with the activation of UV-induced fast apoptosis.