Colorectal cancer-associated nuclear antigen

By using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immu noblotting assays in the presence of polyclonal antiserum raised against el ectrophoretically specific polypeptides of colorectal cancer nuclear polype ptides with M-r of 35-40 kDa, we have identified p36 protein whose expressi on accompanies tumorigenesis of large intestine. Immunological analysis of 35 nuclear protein preparations has indicated expression of p36 antigen in nine of 11 right-sided (81.8%) and 21 of 24 (87.5%) left-sided colorectal t umor cases, but not in any control tissue samples. In this study, we have i dentified p36 antigen in two colon tumor cell lines, i.e., SW620 and HT29 a s well. Fractionation experiments based on selective extraction of nuclei i solated from cancerous specimens, which enables their separation into chrom atin, nuclear matrix and its subfraction, i.e., internal and peripheral mat rix have revealed the concentration of this particular antigen in the inter nal matrix. (C) 2000 Elsevier Science B.V. All rights reserved.