Mucin 12, Cell Surface Associated (MUC12)

MUC12 protein contains a predicted transmembrane domain, 2 extracellular cysteine-rich EGF-like domains, a coiled-coil region, and a domain consisting of serine-, threonine-, and proline-rich degenerate tandem repeats of 28 amino acids, a structural feature typical of mucins. Human MUC12 shares high sequence homology with MUC3 and MUC4. MUC12 expression was not detected in any of 6 colorectal cancer cell lines examined. MUC11 expression was detected in colon, small intestine, pancreas, liver, kidney, prostate, uterus, appendix, lung, and thymus, with highest expression in colon. Expression of MUC11 was downregulated in 12 of 15 (80%) colorectal tumors, as compared with matched normal colonic tissues. MUC11 was expressed at low levels in 4 colorectal cancer cell lines, and at relatively high levels in 2 other colorectal cancer cell lines.