Decreased expression of mac25 mRNA in uterine leiomyomata compared with adjacent myometrium

PROBLEM: The pathogenesis of uterine leiomyomata is still unclear. Recently it has been suggested that mac25 prays a tumor-suppressive role in various tumors. The aims of this study were to evaluate a possible involvement of mac25 in the growth of leiomyoma and in the mechanism of a gonadotropin-rel easing hormone agonist (GnRHa) inducing shrinkage of leiomyoma. METHODS OF STUDY: Mac25 mRNA transcript was measured by Northern blot in to tal RNA extracted from the paired specimens of leiomyoma and adjacent myome trium from untreated patients (n = 25) and from leiomyoma specimens from Gn RHa-pretreated patients (n = 10). RESULTS: Mac25 mRNA expression was significantly lower in large leiomyoma ( more than 150 cm(3) in volume) than in adjacent myometrium and small leiomy oma (less than 120 cm(3) in volume) from untreated patients. There was no d ifference in this expression between the proliferative and secretory phases of the menstrual cycle. Leiomyoma from GnRHa-pretreated patients had mac25 gene expression levels similar to myometrium and small leiomyoma from untr eated patients. CONCLUSIONS: Mac25 may be involved in the growth of uterine leiomyoma and t he action of GnRHa may, in part, be mediated by mac25.