WISP-1 is a Wnt-1- and β-catenin-responsive oncogene

WISP-1 (Wnt-1 induced secreted protein 1) is a member of the CCN family of growth factors. This study identifies WISP-1 as a β-catenin-regulated gene that can contribute to tumorigenesis. The promoter of WISP-1 was cloned and shown to be activated by both Wnt-1 and β-catenin expression. TCF/LEF sites played a minor role, whereas the CREB site played an important role in this transcriptional activation. WISP-1 demonstrated oncogenic activities; overexpression of WISP-1 in normal rat kidney fibroblast cells (NRK-49F) induced morphological transformation, accelerated cell growth, and enhanced saturation density. Although these cells did not acquire anchorage- independent growth in soft agar, they readily formed tumors in nude mice, suggesting that appropriate cellular attachment is important for signaling oncogenic events downstream of WISP-1.