BACKGROUNDB7-H3 has been widely studied in the context of tumor progression in recent years, and behaves as a tumor cell marker in a variety of tumors including colorectal carcinoma. The mechanism of B7-H3 in tumor progression is complicated and not clear yet. Studies have revealed that B7 family molecules are expressed on infiltrated lymphocytes as well as tumor cells in tumor microenvironment, which indicates that different expression pattern may lead to different clinical outcomes.

METHODSThe expression of B7-H3 was detected in tissues of 98 colorectal carcinoma patients by using immunohistochemistry. Then the expression of B7-H3 on CD3(+) T lymphocytes isolated from fresh cancer tissues of 12 colorectal carcinoma patients was analyzed by flow cytometry assay. The relationship between the expression of B7-H3 on CD3(+) T lymphocytes and patients' clinical pathological parameters was demonstrated with statistical analysis.

RESULTSPatients with more CD3(+) T cell infiltration survived much longer than patients with less CD3(+) T cell infiltration (P < 0.05); B7-H3 was highly expressed by infiltrating CD3(+) T lymphocytes in colorectal carcinoma tissues. The expression of B7-H3 was found to be significantly related with lymph node metastasis status (P < 0.05), but not with the patient's gender, age, tumor size, differentiation degree, depth of tumor invasion, Dukes' stage, distant metastasis and whether or not mucinous adenocarcinoma was present (P > 0.05). Moreover, the survival time of patients with low expression of B7-H3 was obviously longer than those of high B7-H3 expression patients, but the seven-year survival rate showed no difference between the high and low B7-H3 expression patients (P > 0.05).

CONCLUSIONThe negative costimulatory molecule B7-H3 on infiltrating CD3(+) T lymphocytes in colorectal carcinoma bears importance in the clinical pathological progress and prognosis of colorectal carcinoma.