Unconjugated
The incidence and mortality rate of oral cancer continue to rise, partly due to the lack of effective early diagnosis and increasing environmental exposure to cancer-causing agents. To identify new markers for oral cancer, we used a sialylation probe to investigate the glycoproteins differentially expressed on oral cancer cells. Of the glycoproteins identified, B7 Homolog 3 (B7-H3) was significantly overexpressed in oral squamous cell carcinoma (OSCC), and its overexpression correlated with larger tumor size, advanced clinical stage, and low survival rate in OSCC patients. In addition, knockdown of B7-H3 suppressed tumor cell proliferation, and restoration of B7-H3 expression enhanced tumor growth. It was also found that the N-glycans of B7-H3 from Ca9-22 oral cancer cells contain the terminal a-galactose and are more diverse with higher fucosylation and better interaction with DC-SIGN [DC-specific intercellular adhesion molecule-3 (ICAM-3)-grabbing nonintegrin] and Langerin on immune cells than that from normal cells, suggesting that the glycans on B7-H3 may also play an important role in the disease.
Blood group antigen expression in human colon cancer was studied by means of two monoclonal antibodies of broad anti-A (HE-14) and anti-type 3 and type 4 chain-based A and H (HE-10) specificity. These antigens were proved to reappear in tumors of the distal colon, the HE-10 antibody reacting more frequently (9 out of 12 samples) than HE-14 (5 out of 12 samples) and frequently with supranuclear staining of the cytoplasm probably in those places of the Golgi apparatus where carbohydrate antigens are synthesized. This staining pattern is characteristic of HE-10 in normal colonic mucosa as well. With HE-14, staining was often absent in less differentiated tumors, while HE-10 did react in such tumors. In this connection, the possible expression of type 3 and type 4 chain H antigens in the tumor tissue is discussed. In some cases, these two antibodies gave different staining patterns in parallel sections from the same tissue sample, primarily at the cellular level. Three out of 12 cases showed blood group antigen expression in the mucosa of the distal colon adjacent to the tumor only when HE-10 antibody was used.
