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.