[Expression and localization of hnRNP A2/B1 during differentiation of human osteosarcoma MG-63 cells induced by HMBA].

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.