Purpose: The activation of T lymphocytes needs theT cell receptor(signal 1) and the costimulatory molecules (signal 2). In the past years, we have found two new molecules -B7-H3 and B7-H4 in the costimulatory family. Both of them can influence the activation and function of T cells response. While we have few experiments about the role that they act on the cancer cells. So we investigate the expression of B7-H3 and B7-H4 in tumor specimens of breast cancer and colorectal cancer.Experimental design: The expression of B7-H3 and B7-H4 in 52 surgically resected specimens of breast cancer and 40 specimens of carcinoma of colon was evaluated immunohistochemically; Furthermore, we examined the correlation between the expression of them and the clinicopathological variables.Result:1.In these tumor specimens, expression of B7-H3 and B7-H4 was observed in the cell membrane, cytoplasm, or both.2.1n the 52 breast cancer tissues, 88.5%(46/52) specimens was positive for B7-H3 and 88.2%(45/51) for B7-H4. And there was a significant correlation between the expression of B7-H3 and B7-H4. The expression of B7-H3 was significantly related to the tumor size and stage, furthermore, it was related to the Her-2/neu status too. The expression of B7-H3 in the Her-2/neu-positive group was much higher than that in the corresponding Her-2/neu-negtive group. The expression of B7-H4 was only... |