The data showed that in fibroids compared to myometrium, 1) the relative abundance of IGF-I mRNA was not different, but there was an increase in the relative abundance of IGF-II mRNA (P < 0.001); 2) IGFBP-1 mRNA was undetectable in fibroids and detectable in only 1 specimen of myometrium; 3) there was no difference in the relative abundance of IGFBP-2 mRNA, but there was an increase in the relative abundance of IGFBP-3 mRNA in myometrium (P < 0.05).
The data showed that in fibroids compared to myometrium, 1) the relative abundance of IGF-I mRNA was not different, but there was an increase in the relative abundance of IGF-II mRNA (P < 0.001); 2) IGFBP-1 mRNA was undetectable in fibroids and detectable in only 1 specimen of myometrium; 3) there was no difference in the relative abundance of IGFBP-2 mRNA, but there was an increase in the relative abundance of IGFBP-3 mRNA in myometrium (P < 0.05).
Corresponding to increased progesterone receptor gene expression, the proliferation-associated antigen Ki-67 was also significantly elevated in the leiomyoma tissue.
Our results show for the first time that p53 mutations are frequent in leiomyosarcomas, and one distinguishing difference between benign leiomyomas and some malignant leiomyosarcomas is the acquisition of a p53 mutation.
In leiomyoma smooth muscle cells in culture (n = 4) and tissue explants (n = 4), aromatase activity was stimulated by dibutyryl cAMP, and this effect was potentiated by a phorbol ester.
We found that (1) ER binding was twice and PR binding was three times as great in fibroid as in myometrium and that there was no difference in binding for either receptor between fibroids from untreated and GnRHa pretreated women, (2) ER and PR mRNA abundances were similar in fibroids and myometrium from untreated women and in fibroids from untreated and GnRHa pretreated women, and (3) ER binding and ER mRNA abundance in both groups of fibroids and myometrium were independent of each other, but there was a positive correlation between PR binding and PR mRNA abundance in untreated fibroids and myometrium but not in GnRHa pretreated tumours.
As an initial step toward finding the gene or genes that are interrupted by the translocation breakpoint, a somatic cell hybrid carrying the derivative 14 as the single t(12;14) translocated chromosome was constructed from a leiomyoma cell line with this translocation.
We characterized the localization of three ECM proteins, collagen type I, collagen type III, and fibronectin, in leiomyomas and adjacent normal myometrium.
TBS increased by estrogen are downregulated when testosterone is given along with estrogen, while androgen receptor mRNA increased by estrogen was not significantly altered by testosterone with estrogen in endometrium and leiomyoma.
Analysis of androgen receptor DNA reveals the independent clonal origins of uterine leiomyomata and the secondary nature of cytogenetic aberrations in the development of leiomyomata.
Since the net biological action of ET-1 in a particular cell type presumably depends on the balance between the peptide itself, its receptors and degrading enzymes, these results suggest different roles for ET-1 action in uterine endometrium, myometrium and leiomyoma.
Western ligand blotting showed the presence of IGFBP-2 and -3 proteins, and when compared with a group of women with fibroids not treated with LHRHa (B.J.Vollenhoven et al., 1993, J. Clin.Endocrinol.
In contrast to ETA-R mRNA, which was more abundant in leiomyoma than in myometrium (p < 0.01), the ETB-R mRNA was less abundant in leiomyoma (p < 0.01).
These results suggest that there is a tissue difference in the expression of Ha-ras, c-myc, fos and jun among EM, MM and LM, under the influence of estrogen/progesterone.
TBS increased by estrogen are downregulated when testosterone is given along with estrogen, while androgen receptor mRNA increased by estrogen was not significantly altered by testosterone with estrogen in endometrium and leiomyoma.
Sixteen tumors were informative: four (leiomyosarcoma, liposarcoma, malignant Schwannoma, and a benign mesenchymal tumor, probably leiomyoma) had identical karyotypes in different samples, whereas the remaining 12 tumors (seven malignant fibrous histiocytomas [MFH], two leiomyosarcomas, two liposarcomas, and one synovial sarcoma) displayed intersample heterogeneity.
In contrast to ETA-R mRNA, which was more abundant in leiomyoma than in myometrium (p < 0.01), the ETB-R mRNA was less abundant in leiomyoma (p < 0.01).
We propose that increased expression of progesterone receptor in leiomyoma is most likely a consequence of overexpression of functional ER that results in increased end-organ sensitivity to estradiol.
It was suggested that P53 over-expression might be associated with the transformation of leiomyoma into leiomyosarcoma and could be used as an objective parameter in distinguishing the malignant from the benign and predicting the prognosis of patients with smooth muscle tumors of the gastrointestinal tract.
Our efforts have focused on cloning the t(12;14)(q14-q15;q23-q24) breakpoint in uterine leiomyoma to further our understanding of the biology of these tumors.