RODENT MODEL OF REPRODUCTIVE-TRACT LEIOMYOMATA - ESTABLISHMENT AND CHARACTERIZATION OF TUMOR-DERIVED CELL-LINES

Uterine myometrial tumors are the most commonly found gynecological ne oplasm ill women. The underlying causes of uterine leiomyomata are poo rly understood, a result in part of the absence of a good animal model system in which to study these tumors. This report describes a novell rat model (Eker rat) in which spontaneous gynecological smooth muscle tumors arise with a high frequency. Leiomyomas are the predominant re productive tract tumor that arise in these animals, although leiomyosa rcomas have also been observed Cell lines have been established front both the benign and malignant lesions. All of the lines express smooth muscle-specific actin, and leiomyoma-derived cell lines express desmi n. Two of the cell lines are tumorigenic in nude mice, and the lines a re variable for expression of estrogen and progesterone receptors. The se lines are the first rodent tumor-derived lines to be established fr om leiomyomata and are the only lilies available from a hereditary for m of these tumors. Together with Eker rats that spontaneously develop leiomyomata, they constitute an in vitro/in vivo model system for gain ing insights into the mechanism of transformation of uterine smooth mu scle cells and the role of steroid hormones and hormone receptors in m yometrial tumorigenesis.