Expression and Localization of hnRNP A2/B1 during Differentiation of Human Osteosarcoma MG-63 Cells Induced by HMBA
- 生命科学－已发表论文 
背景与目的:核基质蛋白的差异表达与细胞癌变和增殖分化调控关系密切。本研究观察了hnRNP A2/B1在诱导分化处理前后人成骨肉瘤MG-63细胞核基质中的存在和分布,及其与Actin、Prohibitin的共定位关系。方法:选择性抽提经环六亚甲基双乙酰胺(hexamethylene bisacetamide,HMBA)诱导处理前后的MG-63细胞核基质,并运用双向电泳、质谱分析、蛋白质印记杂交、免疫荧光、激光共聚焦等技术检测hnRNP A2/B1在核基质中的表达与定位变化,及其与相关蛋白的共定位关系。结果:双向电泳及蛋白质印迹杂交结果证实了hnRNP A2/B1存在于MG-63细胞核基质蛋白组分中,并在HMBA处理后细胞核基质中表达下调;免疫荧光显微镜观察显示hnRNP A2/B1定位在核基质上,经HMBA处理后hnRNP A2/B1表达减弱。激光共聚焦显微镜观察结果显示,hnRNP A2/B1与细胞核基质蛋白组分Actin、细胞增殖相关调控因子Prohibitin具有共定位关系,但在诱导处理后细胞内的共定位关系减弱。结论:hnRNP A2/B1在MG-63细胞诱导分化过程中的表达分布,及其与Actin、Prohibitin的共定位关系的改变对MG-63细胞分化具有重要影响,值得进一步探索和研究。BACKGROUND & OBJECTIVE: The differentially expressed nuclear matrix proteins have great effects on canceration and regulation of cell differentiation. This study was to explore the existence and distribution of ribonucleoprotein hnRNP A2/B1 in nuclear matrix and its co-localization with Actin and Prohibitin in human osteosarcoma MG-63 cells before and after hexamethylene bisacetamide (HMBA) treatment. METHODS: The nuclear matrix of MG-63 cells before and after treatment of HMBA were selectively extracted. The expression and localization of hnRNP A2/B1 in nuclear matrix were detected by 2-D PAGE, MALDI-TOF-MS, Western blot, and immunofluorescent staining. The co-localization of hnRNP A2/B1 with Actin and Prohibitin was observed under laser scanning confocal microscope (LSCM). RESULTS: hnRNP A2/B1 was detected in the component of nuclear matrix proteins of MG-63 cells by Western blot and immunogold staining and its expression was decreased after treatment of HMBA. hnRNP A2/B1 was located in the nuclear matrix, and its expression was weakened after HMBA treatment. hnRNP A2/B1 was co-localized with Actin or Prohibitin in MG-63 cells, while the co-localization relationship was weakened during differentiation of MG-63 cells. CONCLUSIONS: hnRNP A2/B1 is a kind of nuclear matrix protein, and localizes in the nuclear matrix. The distribution and expression of hnRNP A2/B1 and its co-localization with Actin and Prohibitin play important roles during the differentiation of MG-63 cells.