Submitted to: Cancer Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/1995
Publication Date: N/A
Interpretive Summary: One of the major challenges in human nutrition research is the question how certain nutrients may prevent the early onset of chronic diseases such as cancer and atherosclerosis. In order to answer this question, we are utilizing strategies developed by cell biologists. We are developing sensitive cellular indicators of disease risk, based upon the fact that there are specific cell surface markers (mostly proteins) that are predictors of disease risk. Using this method in this paper, we have studied several cancer cell lines (established in tissue culture) for specific surface markers. We have found that combinations of of two or more markers are reliable indicators of the malignant change characteristic of cancer. This is a significant contribution in that we can now follow changes in these markers in free-living subjects fed diets rich in chemopreventive factors such as the retinoids, vitamin E, selenium or carotenoids.
Technical Abstract: The objective of this research was to characterize the expression of tumor-associated cell surface antigens in cultured human colon adenocarcinoma cell (HCAC) lines under different states of differentiation and compare them with a normal colon fibroblast cell line. The monoclonal antibodies to tumor associated antigens used in this study were carcinoembryonic antibody (CEA) and carbohydrate antibody (CA)19-9. In addition, we examined the patterns of expression of CD44, a cell surface glycoprotein that is recognized as a cell adhesion marker. The extent of binding of each monoclonal antibody (mAb) to its respective antigen on the surface of the cells was measured by flow cytometry. LS-180 HCAC showed very strong binding with CEA (81%), CA 19-9 (87%), and CD44 (83%). LS-174t cells, a trypsinized variant of LS-180, showed binding less than LS-180 with CEA (66%) and CA 19-9 (49%), while they showed no binding with CD44. With cells from HCAC line HT-29, antigen expression was highly variable; CEA (13%+18), CD44 (31%+35). However, HT-29 was consistently positive with CA19-9 (33%+13). The expression of CEA in Caco-2 HCAC was weak (24%), while CA19-9 and CD44 were totally absent. Normal human colon fibroblast cells (CCD-18Co) did not recognize CEA and CA 19-9, but were very strongly positive with the CD44 antibody (97%). These data should be useful in establishing markers of proliferation potential for screening human cell samples.