B7-H6 expression in non-small cell lung cancers.

B7 family has been known to be a negative regulator of immunity response in patients with lung cancer. B7-H6 as a novel identified member of B7 family is found to trigger natural killer (NK) cell cytotoxicity and cytokine secretion by binding natural cytotoxicity receptor NKp30. Up until now, no investigations have been made about B7-H6 expression in lung cancer. We present the result of the B7-H6 prognostic value in 65 non-small cell lung cancer (NSCLC) tissues and 65 matched adjacent non-tumor tissues by Immunohistochemistry (IHC). Meanwhile, fluorescence activated cell sorter (FACS) analysis was used to detect B7-H6 receptor NKp30 expression in 7 non-small cell lung cancer tissues and 7 adjacent non-tumor tissues. Here, the result showed B7-H6 immunoreactivity in 6/65 (9.23%) lung cancer patients and 4/65 (6.15%) in adjacent non-tumor tissues. No relationship was found between B7-H6 expression and clinic pathological features. Similarly, no relevance was found for NKp30 expression in lung cancer tissues and non-tumor tissues. However, B7-H6 positive carcinomas were significantly correlated with degree of differentiation (P = 0.044). Three year survival rate after operation did not show the prognostic value for B7-H6 expression. Our study suggests that B7-H6 has a limited value as a prognostic marker in the patients of lung cancer.