2050

EPHB4

EPH receptor B4;EPHB4;EPH receptor B4

ephrin receptor EphB4|ephrin type-B receptor 4|hepatoma transmembrane kinase|soluble EPHB4 variant 1|soluble EPHB4 variant 2|soluble EPHB4 variant 3|tyrosine-protein kinase TYRO11|tyrosine-protein kinase receptor HTK

7q22

protein-coding

OBJECTIVE: To investigate the role of the expression of ephrinB2 and EphB4 in non-small cell lung cancer (NSCLC), and their relationship with multi-slice spiral CT pulmonary perfusion imaging. METHODS: Thirty-one nodules with pathologically proven NSCLC underwent CT perfusion scan. The perfusion parameters including blood flow (BF), blood volume (BV), peak enhancement image (PEI) were collected. The expression of ephrinB2 and EphB4 in tumor cells and interstitial vasculature were detected by immunohistochemistry. Correlation analysis and trend test were used to assess the relationship between ephrinB2/EphB4 expression and clinicopathological features, and between ephrinB2/EphB4 expression and perfusion parameters. RESULTS: Positive expression of ephrinB2 and EphB4 in the NSCLC group was 83.9% and 71.0%, respectively, significantly higher than that in the internal control group (P < 0.01). The expression of ephrinB2 and EphB4 was consistently in tumor parenchyma but differently in tumor vessels. The expressions of ephrinB2 and EphB4 were positively correlated with lymphatic metastasis (P < 0.05). The expression of EphB4 was negatively correlated with blood flow (BF) and blood volume (BV), respectively (P < 0.05). There was a significant positive correlation between ephrinB2 expression and BF (r = 0.516, P = 0.003), and a positive correlation between ephrinB2 expression and BV (r = 0.448, P = 0.013). The expressions of ephrinB2 and EphB4 were not correlated with PEI (P > 0.05). The values of BF and BV in the high and moderate EphB4 expression groups were significantly decreased compared with that in the negative group (P < 0.01). The value of BF in the high ephrinB2 expression group was significantly increased compared with that in the moderately positive group and negative group (P < 0.01). The value of BV in the high ephrinB2 expression group was significantly increased compared with that in the negative group (P < 0.01). CONCLUSION: The CT pulmonary perfusion imaging reflects the density difference of blood vessels with functional lumen, and such difference also depends on the quantity and quality of vasculature with functional lumen.

Prostate cancer is the most common cancer in men. Advanced prostate cancer spreading beyond the gland is incurable. Identifying factors that regulate the spread of tumor into the regional nodes and distant sites would guide the development of novel diagnostic, prognostic, and therapeutic targets. The aim of our study was to examine the expression and biological role of EphB4 in prostate cancer. EphB4 mRNA is expressed in 64 of 72 (89%) prostate tumor tissues assessed. EphB4 protein expression is found in the majority (41 of 62, 66%) of tumors, and 3 of 20 (15%) normal prostate tissues. Little or no expression was observed in benign prostate epithelial cell line, but EphB4 was expressed in all prostate cancer cell lines to varying degrees. EphB4 protein levels are high in the PC3 prostate cancer cell line and several folds higher in a metastatic clone of PC3 (PC3M) where overexpression was accompanied by EphB4 gene amplification. EphB4 expression is induced by loss of PTEN, p53, and induced by epidermal growth factor/epidermal growth factor receptor and insulin-like growth factor-I/insulin-like growth factor-IR. Knockdown of the EphB4 protein using EphB4 short interfering RNA or antisense oligodeoxynucleotide significantly inhibits cell growth/viability, migration, and invasion, and induces apoptosis in prostate cancer cell lines. Antisense oligodeoxynucleotide targeting EphB4 in vivo showed antitumor activity in murine human tumor xenograft model. These data show a role for EphB4 in prostate cancer and provide a rationale to study EphB4 for diagnostic, prognostic, and therapeutic applications.