Castration-induced reduction of vascular endothelial growth factor expression in benign human prostate tissue is lost in advanced prostate cancer

Objective To determine the role of vascular response in the castration-indu ced regression of benign and malignant human prostate tissue, as recent stu dies show that castration rapidly decreases blood now and induces endotheli al cell death, which may be important for subsequent epithelial cell death and involution of the glandular tissue of the prostate. Materials and methods The expression of vascular endothelial growth factor (VEGF) and its receptors was analysed using the quantitative reverse transc riptase-polymerase chain reaction, in benign and tumour areas of core biops ies taken before, and approximate to1 week after castration therapy. The ca stration-induced VEGF response was related to therapy-induced changes in tu mour cell apoptotic index and subsequent response in serum prostate-specifi c antigen (PSA). In another set of patients, serum VEGF was quantified by e nzyme-linked immunosorbent assay before, and at 3-6 months after castration therapy. Results VEGF mRNA was down-regulated after castration in benign prostate ti ssue (P less than or equal to0.05). whereas in tumour tissue, VEGF levels w ere reduced in some of the patients but unchanged or increased in others, I n most patients whose tumour tissue responded with VEGF reduction, there wa s a corresponding increase in tumour cell apaptosis. Serum VEGF levels were not significantly changed after castration. Almost all patients responded with a substantial reduction in serum PSA after castration. Conclusion Castration reduces VEGF mRNA expression in benign prostate tissu e and generally in those prostate tumours where castration also induces tum our cell apoptosis. This suggests that a therapy-induced down-regulation of VEGF could be important for tumour cell death.