There are a number of researchers who are searching for useful tumor markers to indicate cure. Antigens are being applied as an effective target in clinical therapy. Hb3 is an anti-colorectal cancer monoclonal antibody produced in the researchers laboratory, and whose sensitivity and specificity are superior to that of anti-CEA. Previous results have showed that CA-Hb3 may be useful in the clinical diagnosis of colorectal cancer.
This study, carried out by a team led by Professor G. C. Li, is described in a research article that will be published on March 14, 2008, in the World Journal of Gastroenterology.
To comprehensively identify the proteins of the tumor-associated antigen Ca-Hb3 which is recognized by colorectal carcinoma monoclonal antibody Hb3, Ca-Hb3 was isolated by SDS-PAGE followed by digestion with trypsin. The trypsin peptides were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Applying bioinformatics to analyze the proteins which were identified by mass spectrometry, Ca-Hb3 was identified as CKAP4-similar protein by nano-HPLC tandem mass spectrometry analysis. The molecular weight of CKAP4-similar protein is 62.02 kDa, including one hydrophobic region, one transmembrane domain, five coiled coils, four glycosylation sites and forty-nine phosphorylation sites. CKAP4-similar protein has high homogeneity with Np63, and the characteristic expression of agrNp63 alpha that is considered a potential oncogene in the isoforms of p63 is similar to Ca-Hb3.
Np63 is an isoform of the p63 family. A number of studies have highlighted the oncogenic potential of agrNp63 alpha.agrNp63 alpha is overexpressed in several epithelial cancers, often as a result of gene amplification. The overexpression of an Np63 isoform in Rat 1A cells increases colony growth in soft agar and xenograft tumor formation in nude mice. It is hypothesized that agrNp63 alpha promotes survival and the maintenance of proliferative capacity in both epithelial stem cells and cancer cells.
|Contact: Jing Zhu|
World Journal of Gastroenterology