The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Introduction of Sd(a) carbohydrate antigen in gastrointestinal cancer cells eliminates selectin ligands and inhibits metastasis.

The Sd(a) blood group carbohydrate structure is expressed in the normal gastrointestinal mucosa. We reported previously that the expression of Sd(a) carbohydrate structures and beta1,4-N-acetylgalactosaminyltransferase (beta1,4GalNAcT) activity responsible for Sd(a) synthesis were remarkably decreased in cancer lesions of the gastrointestinal tract. In this study, we found that Sd(a) antigen was expressed mainly in chief cells of normal stomach but not in cancer tissue by immunohistologic staining. In separated gastric mucosal cells, the Sd(a) glycolipids and beta1,4GalNAcT activity were concentrated in a fraction that contained chief cells as a major population. We cloned the cDNA encoding the glycosyltransferase that catalyzes the synthesis of Sd(a) (Sd(a)-beta1,4GalNAcT). Introduction of this cloned cDNA into KATO III gastric or HT29 colonic cancer cell lines, which originally expressed the E-selectin ligands, sialyl Lewis(x) and sialyl Lewis(a), resulted in a marked increase in cell-surface expression of Sd(a) along with the concomitant total loss of both sialyl Lewis(x) and sialyl Lewis(a). Both KATO III and HT29 cells transfected with the Sd(a)-beta1,4GalNAcT gene showed significantly decreased adhesion to activated human umbilical vein endothelial cells when compared with mock-transfected cells. Sd(a) determinants showed no direct binding to Siglec-3, -5, -7, and -9. These Sd(a)-beta1,4GalNAcT-transfected cells showed strikingly reduced metastatic potential in vivo when compared with mock-transfected cells. In summary, forced expression of Sd(a) carbohydrate determinant caused remarkable elimination of carbohydrate ligands for selectin and reduced metastasis of human gastrointestinal tract cancer cells.[1]


  1. Introduction of Sd(a) carbohydrate antigen in gastrointestinal cancer cells eliminates selectin ligands and inhibits metastasis. Kawamura, Y.I., Kawashima, R., Fukunaga, R., Hirai, K., Toyama-Sorimachi, N., Tokuhara, M., Shimizu, T., Dohi, T. Cancer Res. (2005) [Pubmed]
WikiGenes - Universities