Vitamin D inhibits myometrial and leiomyoma cell proliferation in vitro.

OBJECTIVE

To determine the effect of 1,25(OH)(2)D(3) and 25(OH)D(3) vitamin D derivates on the growth of leiomyoma and myometrial cells in vitro.

DESIGN

In vitro study.

SETTING

Cell biology research laboratory.

PATIENT(S): Six premenopausal women with uterine leiomyomas undergoing hysterectomy.

INTERVENTION(S): Samples of leiomyomas and normal myometrial tissue were obtained, and paired cultures were established.

MAIN OUTCOME MEASURE(S): A colorimetric crystal violet assay to determine the effect of 1,25(OH)(2)D(3) and 25(OH)D(3) on cell growth.

RESULT(S): In both myometrial and leiomyoma cells, 0.1 nM physiologic level of 1,25(OH)(2)D(3) inhibited growth by 12% when compared with controls. The growth inhibition was concentration dependent; the highest concentration of 1,25(OH)(2)D(3) (100 nM) inhibited growth by 62% in both cell types. All the differences were statistically significant. A slight stimulation (<4%) of cell proliferation was observed with the lowest 25(OH)(2)D(3) concentrations. When treated with either a 500 nM or 1000 nM concentration of the compound, the growth of both cell types fell to approximately 50% of that of the control cultures, and the level of inhibition with the latter concentration was statistically significant.

CONCLUSION(S): Both myometrial and leiomyoma cell growth in vitro was effectively inhibited by 1,25(OH)(2)D(3). Vitamin D may play a role in the growth of uterine leiomyomas.