EphrinB2 expression in prostate adenocarcinoma: Implications for targeted therapy

Background: Prostate cancer is managed by surgery, androgen deprivation and cytotoxic chemotherapy. Targeted therapy is emerging as an important pillar in cancer therapeutics, however, efficacy in prostate cancer has been limited. Eph-ephrin is a novel pathway that is upregulated in prostate cancer and promotes the initiation and progression of cancer. The aim of this study was to determine the immunohistochemical expression of ephrinB2 in prostate adenocarcinoma.

Methods: A tissue microarray comprising of prostate adenocarcinoma of different grade groups was stained with a monoclonal anti-ephrinB2 antibody (Abcam, AB201512). The tumor and endothelial cells expressing the ephrinB2 positivity were noted. The statistical analysis was performed to determine the difference in expression based on grade groups and the TNM stage.

Results: EphrinB2 was expressed in 40 out of 72 cases (55.5 %) of prostate adenocarcinoma and was predominantly negative in the normal prostatic tissue. There was no significant difference in the expression of ephrinB2 in various grade groups (p = 0.7) or stages (p = 0.6).

Conclusions: EphrinB2 is expressed in a significant number of prostate adenocarcinoma regardless of grade and stage. Hence, there is a potential to target this molecule in the low-grade tumors with localized disease as well as high grade, high volume tumors with metastatic disease.