pap, reg I? andreg I? mRNAs are concomitantly up-regulated during human colorectal carcinogenesis

We have established the phenotype of a colorectal tumor by partial sequencing of 2166 transcripts that were eventually arrayed on high-density filters. These filters were used for differential screening with mRNAs of colorectal cancer and normal adjacent mucosa to characterize genes whose expression is altered in colorectal carcinoma. Three genes encoding related proteins, PAP, reg Iα and reg Iβ, were over-expressed in cancer. Northern-blot analysis confirmed that their expression was very low in normal colonic epithelial cells, but elevated in 75% of tumors. Western blotting with specific antibodies to pap and reg Iα revealed in tumors a single band of the expected size (15–16 kDa), demons…