The expression of cyclooxygenase-2 in cervical cancers and Hela cells was regulated by estrogen/progestogen

Summary To investigate the relationship between the expression of cyclooxygenase-2 (COX-2) and menstrual cycle, the regulatory effects of 17-β-estradiol (E 2 ) and medroxyprogesterone acetate (MPA) on the expression of COX-2 in cervical cancer Hela cells were examined. Cervical cancer specimens were obtained from 47 pre-menopausal patients. The phase of menstrual cycle was determined by case history and HE staining of uterine endometrium. COX-2 was immunohistochemically stained by SABC staining and the staining intensity was determined with computerized image analysis system. Hela cells were incubated with alcohol, E 2 , E 2 +MPA, MPA for 12, 24 and 48 h respectively. The expression of COX-2 in Hela cells was detected by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). Our results showed that the expression of COX-2 was significantly higher during proliferative phase than secretory phase ( P <0.05), but there was no difference in the positive rate between proliferative phase and secretory phase ( P >0.05). Incubation with E 2 could significantly enhance the expression of COX-2 continually. On the contrary, E 2 +MPA and MPA alone could decrease the expression of COX-2 as compared with the control and E 2 group ( P <0.05 and P <0.01 respectively). It is concluded that the expression of COX-2 in cervical cancer of pre-menopausal patients and Hela cells was regulated by estrogen/progestogen.