EphB4 gene polymorphism and protein expression in non-small-cell lung cancer.

The objective of this study was to identify new diagnostic, prognostic or therapeutic molecules for non-small- cell lung cancer (NSCLC). We investigated the expression of EphB4, a tyrosine kinase receptor which has been shown to act as a tumor promoter in other cancers. Using immunohistochemistry, we visualized EphB4 expression in 28 samples of NSCLC and 12 samples of adjacent normal tissues. Additionally, we assessed a single-nucleotide polymorphism in EphB4 to determine its effect on protein expression. The correlation of both genotype and protein expression with disease severity was determined. EphB4 was expressed in 53.6% of patients with lung cancer, a significant increase compared to control lung samples (0.0%, P<0.05). Furthermore, EphB4 expression was correlated with differentiation, lymph node metastasis and TNM stage of tumors (P<0.05). Additionally, the polymorphism in EphB4 at rs314310 appeared to correspond to protein expression and disease susceptibility. While the frequencies of CC, CA and AA genotypes were not different between lung cancer patients and healthy controls, the frequencies of C and A alleles were significantly different between these groups (P<0.05). Further analysis showed that the positive rate of EphB4 expression in patients with the AA genotype was significantly higher compared to that in patients with other genotypes (P<0.05). Overexpression of EphB4 plays a role in the occurrence and development of NSCLC, and the polymorphism at rs314310 may predispose individuals to this disease.