Insulin-like growth factor I promotes leiomyoma cell growth in vitro.

OBJECTIVE

Our purpose was to determine whether insulin-like growth factors I and II preferentially stimulate uterine leiomyoma cells versus myometrial cells in monolayer culture.

STUDY

DESIGN

Leiomyomas and normal myometrium were obtained at hysterectomy from five premenopausal women. Specimens were enzymatically digested for use in primary monolayer cell cultures. By use of serum-free media, insulin-like growth factor I or II was added in 1, 10, and 100 ng/ml concentrations to both cell types with the patient serving as her own control. Cell number, prolactin production, and proliferative index values were measured on day 15 of cell culture.

RESULTS

Significant increases in cell number were found in the leiomyoma cultures (p < 0.05) treated with 10 and 100 ng/ml insulin-like growth factors I but not with insulin-like growth factors II. Neither factor exerted a stimulatory effect on myometrial cells.

CONCLUSION

Insulin-like growth factors I preferentially stimulates leiomyoma cells in monolayer culture. These results suggest an autocrine-paracrine role in vivo for this factor in conjunction with gonadal steroids in promoting leiomyoma growth.