Leuprolide acetate-treated leiomyomas retain their relative overexpression of collagen type I and collagen type III messenger ribonucleic acid.

OBJECTIVE

To evaluate the levels of mRNA for the extracellular matrix proteins collagen type I, collagen type III, and fibronectin in leiomyomas and myometrium obtained from women treated with GnRH-agonist (GnRH-a) and to examine steroid hormone regulation of these proteins using an in vitro explant culture system.

METHODS

Northern blot analysis of mRNA was obtained from hysterectomy specimens at the time of surgery or after 48 hours of in vitro steroid treatment. A portion of the tissue was processed for RNA, and the remaining tissue was used to establish explant cultures. Extracellular matrix/alpha-tubulin ratio was computed for each band, and within each experiment the lowest ratio was standardized to a value of one densitometry unit to allow for comparison among experiments.

RESULTS

There is a relative overexpression of both collagen type I and collagen type III mRNAs but not fibronectin in leiomyomas compared to myometrium from the same uteri of women treated with GnRH-a.

CONCLUSION

Leiomyomas obtained from women treated with GnRH-a show an up-regulation of collagens type I and type III similar to that seen in leiomyomas obtained from women in the proliferative phase of their menstrual cycles.