The expression of cyclooxygenase-2, VEGF and PGs in CIN and cervical carcinoma

To study the expression of cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF) and prostaglandins (PGs) in cervical tissues of differential pathological types, especially in cervical intraepithelial neoplasia (CIN) and cervical carcinoma, and their possible relationships in carcinogenesis.

Tissue blocks and blood samples from 20 normal cervix women, 20 cervix inflammation patients, 20 CIN patients and 40 patients with cervical carcinoma, respectively, at our institutions from February 2000 to March 2002 were available for this study. COX-2 mRNA was examined by reverse transcription-polymerase chain reaction (RT-PCR). COX-2 and VEGF proteins were measured by immunohistochemistry using monoclonal antibodies to them. PGs (PGE2, TXB2, 6-k-PGF(1alpha)) were detected by radioimmunoassay (RIA).

The overall positive expression of COX-2 and the quantity of PGs, especially PGE2 in inflammation, CIN and cervical carcinoma was higher and much higher than that in normal cervix (P < 0.001), There was a close relationship between COX-2 and PGs. The positive expression rate of VEGF in cervical carcinoma was higher than that in normal, inflammatory and CIN cervix, respectively (P < 0.001). VEGF protein was occasionally expressed in CIN cervix (15%). There was no association among COX-2, VEGF and clinicopathological parameters in cervical carcinoma. The expression of COX-2 and VEGF in cases with tumor in diameter more than 4 cm (90.9%, 72.7%) was higher than those with smaller tumor (86.2%, 51.7%).

The COX-2 probably is a gene involved early in carcinogenesis of cervical carcinoma by increase of PGs, and accelerates the progress of tumor by increase of PGs and VEGF. Therefore testing the expression of PGs may be a prognosis marker for clinical diagnosis.