增殖细胞核抗原短发夹状RNA对人骨肉瘤细胞生长的影响

Inhibition of osteosarcoma cell proliferation by a short hairpin RNA targeting proliferation cell nuclear antigen

目的构建增殖细胞核抗原(PCNA)短发夹状RNA表达载体,检测其对人骨肉瘤细胞PCNA表达、细胞增殖及细胞凋亡的影响。方法体外构建PCNAshRNA表达载体pSilence2.1neo-PCNA,转染人骨肉瘤细胞系MG63,逆转录聚合酶链反应(RT-PCR)法检测转染前后PCNAmRNA表达,免疫组织化学(SP)法检测转染前后PCNA蛋白的表达,四甲基偶氮唑盐(MTT)比色法及克隆形成试验检测细胞增殖活性,3H胸腺嘧啶核苷(3H-TdR)细胞掺入试验检测细胞DNA合成,流式细胞仪检测细胞周期分布,吖啶橙染色法检测细胞凋亡情况。结果pSilence2.1neo-PCNA载体转染能显著抑制PCNAmRNA及蛋白的表达,转染后mRNA表达抑制率为80.51%、增殖指数值为空白组的25.68%。转染组48h细胞增殖抑制率为61.78%,转染组3H-TdR掺入率明显低于空白组(P<0.01)。细胞周期分析显示,siRNA转染组G0G1期细胞含量显著增加,而S期细胞含量显著减低。转染组凋亡率为16.54%。结论pSilence2.1neo-PCNA可显著抑制MG63细胞PCNA的表达及细胞增殖活性,促进细胞凋亡。

Objective To construct a plasmid vector expressing the short hairpin RNA (shRNA) targeting proliferation cell nuclear antigen (PCNA), and to investigate its effect in vitro on the expression of PCNA, proliferation and apoptosis of human osteosarcoma cells. Methods A plasmid vector expressing the short hairpin RNA targeting at PCNA was constructed and transfected into human osteosarcoma cell line MG-63 by dosper liposomal method. PCNA mRNA and protein expressions were examined using RT-PCR and immunohistochemical staining, respectively. Inhibition of the cell proliferation was studied by MTT method and colony forming assay. DNA synthesis was analyzed by ~3H-TdR incorporation and the cell cycle was determined by flow cytometry. The apoptotic cells were stained with acridine orange. Results Expression of PCNA mRNA after the transfection was markedly inhibited by 80.51% with a PI value of 25.68% of that of the control group. PCNA shRNA inhibited MG-63 cell growth detected by using MTT method, with an inhibition rate of 61.78% at 48 h. DNA synthesis rate also decreased in the ~3H-TdR incorporation test. Flow cytometry analysis showed an increase of the percentage of G 0/G 1 phase cells, along with a decrease of cell population in the S phase. The apoptosis rate of cells transfected with the plasmid vector was 16.54%. Conclusions PCNA shRNA significantly suppresses the expression of PCNA at both mRNA and protein levels, corresponding to an inhibition of the proliferation of MG-63 cell and an increase of the cellular apoptosis.