Expression of the costimulatory molecule B7-H3 in human oral cancer

Objectives: B7-H3 is a member of B7 family, which is a group of immune costimulatory molecules responsible for the regulation of T cell-mediated immune response. Although elevated expressions of B7 family molecules in several human cancers and their positive correlation with a poor prognosis have been reported, there is no consensus about the physiological or pathophysiological roles of B7 family. There is no studies reported the role of B7-H3 in oral cancer either. In this study, we aimed to investigate the expression pattern and clinical significance of B7-H3 in oral cancer. Methods: Thirteen patients pathologically diagnosed as oral squamous cell carcinoma were recruited. Six female and seven male with an average age of 53.71 ± 20.43 years. Biopsied cancer tissues were subjected to immunohistochemical study of B7-H3 using a semi quantitative method, and normal oral mucosal tissues from the same patients were used as control. Results: B7-H3 molecule was positively expressed in all of the OSCC samples and the control samples. The expression of B7-H3 cell surface protein was generally present in the epithelial cells in both groups, and was much stronger in the cancer cells. The B7-H3 staining in the cancer tissues (47.76±11.90%) was more intensive and extensive than that in the normal tissues (22.89±16.59%). Conclusions:B7-H3 costimulatory molecule has a stronger expression in oral cancer tissues than in normal mucosal tissue. Further study with a larger sample size is necessary to explore correlation between the expression pattern of B7-H3 and the clinical as well as pathologic conditions, and prognosis of OSCC.