BMC Cancer 2006, 6:132 http://www.biomedcentral.com/1471-2407/6/132 FPGS gene promoter activity in Bp- and T-ALL lineages The human FPGS minimal promoter has been character- ized in CCRF-CEM cells and encompassed a region start- ing -43 bp from the main transcriptional start site to +150 bp of exon 1 [17] (see Figure 2). To further investigate the mechanisms that control FPGS transcription in human hematopoietic cells, we analyzed and compared DNA fragments located upstream of exon A1b and in the 5'- flanking region of exon 1 (encompassing the previously described minimal promoter region) for promoter/ enhancer transcriptional activity in CCRF-CEM and NALM6 cells. FPGS-luciferase transcriptional gene fusions were constructed and assayed as described in Material and Methods. Under our experimental conditions, transfec- tion efficiencies were 38–50% and 42–50% in CCRF-CEM and NALM6 cells, respectively. As shown in Figure 3, DNA fragments located upstream of exon A1b (pGL2256 and pGL3588-2628) yielded no promoter or enhancer activity in both cell lines suggesting that the 5'-flanking region of exon A1b exerts no regulatory activity on human FPGS expression. The higher level of luciferase activity detected in pGL3588-2628 vs. pGL2256 is likely the result of the presence of the additional fragment of 2628 bp contained in pGL3588-2628 that included the FPGS minimal pro- moter region. When DNA fragments from the 5'-flanking region of exon 1 (pGL1374, pGL2628-ATGm/c, pGL4689) encompassing the described minimal pro- moter were analyzed, we found 4- to 12-fold higher level SFcigheumreat2ic representation of the human FPGS gene and promoter region Schematic representation of the human FPGS gene and promoter region. FPGS exon A1b, exons 1 to 15, and the nucleotide sequence of the FPGS gene promoter region (accession # AL162586) are depicted. Putative transcription factor recognition motifs were identified using the MatInspector program from Genomatix (Release 7.3.1) [34]. Sp1 (GGGCGG; +5, -10, -15, -65, -72, -77, -82, -102, -147), NFY-box (CCAAT; -20 and -57), and E-box (CANNTG; +61) transcription factor bind- ing sites are indicated. The protected DNase I footprint region, called H1 (+45 to +71) is shown underlined [17]. Page 6 of 12 (page number not for citation purposes)