Human prolyl hydroxylase expression in uterine leiomyoma during the menstrual cycle

BACKGROUND: To investigate the role of prolyl hydroxylase (PH), a key enzyme of collagen synthesis, in human uterine leiomyoma, PH expression was determined in the normal uterine myometrium and the leiomyoma tissues during the menstrual cycle. METHODS: The tissues were obtained from 40 regularly cycling women (aged 29 to 53 yr) who were undergoing abdominal hysterectomy for symptomatic uterine leiomyoma. Immunohistochemistry for human PH with specific monoclonal antibody was used for analysis. RESULTS: Immunohistochemical staining for PH revealed intense staining of leiomyoma cells in the uterine leiomyoma throughout the menstrual cycle, as compared with the adjacent normal myometrium. In the secretory phase, weak or no immunostaining for PH was detected in the normal myometrial tissues. CONCLUSIONS: These results suggest that increased expression of PH might play an role in the physiology of uterine leiomyoma during the menstrual cycle.