Adenomatosis Polyposis Coli Down Regulated 1 (APCDD1)

The APCDD1 gene encodes a membrane-bound glycoprotein that inhibits Wnt signaling. The deduced 514-amino acid protein has a calculated molecular mass of about 59 kD. Northern blot analysis detected a 2.6-kb transcript expressed ubiquitously, with abundant expression in heart, pancreas, prostate, and ovary.

Assays performed with functional mutations in each of the TCF4-binding sites indicated that both are required for maximum APCDD1 transcription. Transfection of APCDD1 into LoVo colon cancer cells increased their rate of growth. LoVo-APCDD1 cells transplanted into nude mice showed a tendency toward larger and faster tumor growth than LoVo-vector, but the difference was not statistically significant.