Estrone sulfatase activity in human uterine leiomyoma

Human uterine leiomyoma is a benign tumor and its development is closely related to estrogen. In this study, estrone sulfatase (E1SF) activity and concentrations of estrone (E1) and estrone sulfate (E1S) were measured in endometrial, leiomyoma, and myometrial tissues of the same human uterus (n = 11) with a leiomyoma. E1SF activity in endometrial tissue overlying a leiomyoma was 2.62 +/- 0.29 nmole/hr/mg protein (mean +/- SD), this activity being significantly higher (P less than 0.01) compared with that in normal endometrial tissue (2.0 +/- 0.24 nmole/hr/mg protein). E1SF activity in normal endometrial tissue was significantly higher (P less than 0.001) compared with that in leiomyoma tissue (0.49 +/- 0.82 nmole/hr/mg protein) or myometrial tissue (0.76 +/- 0.10 nmole/hr/mg protein). We also found a significant difference (P less than 0.05) in E1SF activity between leiomyoma tissue and myometrial tissue. On the other hand, the E1 concentration in endometrial tissue overlying a leiomyoma (10.9 +/- 8.9 pg/mg protein) proved to be higher than that in endometrial tissue overlying normal myometrium (1.23 +/- 1.97 pg/mg protein). E1S concentrations in these tissues, however, were 631 +/- 339 and 902 +/- 482 pg/mg protein, respectively, these values showing a trend opposite that of the E1 concentration data. Thus, these results suggest that high E1SF activity and high E1 concentration in the endometrium overlying a leiomyoma may be related to estrogen supply to a uterine leiomyoma node.