Optimal Ratios of Biliary Glycoprotein Isoforms Required for Inhibition of Colonic Tumor Cell Growth

摘要: Abstract Rodent biliary glycoprotein (Bgp), also known as C-CAM, has recently been shown to function a tumor suppressor in colon, prostate, and bladder cancers. This is member of the carcinoembryonic antigen family one only proteins this encode either long (71–73 amino acids) or short (10 cytoplasmic domain. We others have that growth-inhibitory properties Bgp depend upon expression its However, two isoforms normally coexist most cell types surveyed; longer variant usually present lower amounts than shorter one. In study, we examined vitro vivo growth both mouse variants separately combination. To determine physiologically relevant levels ratios variants, quantified amount normal colonic epithelial cells showed it constitutes 15–20% total expressed tissue. mimic situation, generated double transfectant lines expressing coordinately tumorigenic CT51 carcinoma demonstrated isoform exhibits dominant inhibition phenotype over within physiological Bgp. Unexpectedly, significant overexpression alone led reversal phenotype. These results, therefore, suggest there may be limiting threshold Bgp-associating mediating