Objective To explore the structure and activity of SATB1 promoter in different cells, ATRA and CoCl2 effect on its activity. Methods Using luciferase system to assay the promoter activity of human SATB1 gene, three luciferase reporter vectors were constructed which driven by different regions of 5＇ untranslated sequence from human SATB1 gene , called pGL3-SP2946-luc , pGL3-SP1718-luc and pGL3-SP751-luc , and transfected into Jurkat T, K562, U937 and Hela cells transiently using lipofectinamine, the expression activity was detected at different dosage of A TRA and CoCl2treatment for different time course. Results The reporter gene expression from SATB1 promoter were high activity in U937 cell, moderate in Jurkat T cell, low activity in K562 cell and showed no obvious activity in Hela cell, the reporter gene expression from pGL3-SP751-1uc kept on the higher lever in Jurkat T, K562 and U937 cells than the other two vectors. We also found that the repressive effect of CoCI2 on SATBI＇s mRNA expression and the relative luciferase expression from pGL3-SP751-luc in U937 cell was down-regu- lated obviously by ATRA and CoCI2 in the concentration- and time-dependent manners. Conclusion SATB1 pro- rooter drives gene expression with cell-specificity and its core promoter region maybe exist in the - 751 - - 9bp of 5＇ untranslated region of human SATB1 gene. Combined with the experiment result we found before that SATB1 was down-regulated by ATRA in U937, the results imply that STAB1 maybe is down-regulated by ATRA and CoCl2 through its promoter in the differentiation of myeloid cell line-U937.
