Transcriptional activity of the promoter region of rat frizzled-related protein gene

Frizzled-related protein (Frp) is a new family of secreted proteins involve d in tumorigenesis and Wnt-signaling pathway. Previous study has shown that rat Frp (rFrp) gene was found to be differentially expressed in Rat 6 fibr oblast cell line overexpressing p53(val135) (R6#13-8). The rFrp gene was ot herwise silent in normal parental Rat 6 cells. To elucidate the molecular b asis of the transcriptional activation of rFrp, we have isolated and analyz ed a 2-kilobase pair promoter region of the rFrp gene. Mapping of transcrip tion initiation sites of rFrp showed the existence of multiple initiation s ites. Transfection studies of serial deletion constructs in both Rat 6 and CHOK1 cell lines revealed that the region from -202 to -144 contains cis-ac ting elements essential for the efficient transcription of rFrp. This work provides a transcriptional regulation basis for Frp and gives insight into its implication in tumorigenesis. (C) 2001 Academic Press.