Abstract

BACKGROUND
Uterine leiomyomas are common benign smooth muscle tumors among the reproductive aged-women. The research has been aimed to identify the differentially expressed genes between normal myometrium and leiomyoma and to investigate the effects of E2 on their expression.
METHODS
Gene microarray analysis was performed to identify the differentially expressed genes between normal myomerium and leiomyoma. The data was confirmed at protein level by tissue microarray.
RESULTS
Gene microarray analysis revealed 792 upregulated genes in leiomyoma. Four genes (tropomyosin 4 [TPM4], collagen, type IV, alpha 2 [COL4alpha2], insulin-like growth factor binding protein 5 [IGFBP5], tripartite motif-containing 28 [TRIM28]) showed the most dramatic upregulation in all leiomyoma samples. Tissue microarray analyses of 262 sample pairs showed significantly elevated expression of TPM4, IGFBP5, estrogen receptor-alpha, and progesterone receptor (PR) protein in leiomyoma from the patients in their forties, COL4alpha2 in the forties and fifties age-groups, and TRIM28 in the thirties age-group. PR, insulin-like growth factor 1 (IGF-1), IGF-1 receptor (IGF-1R) and IGFBP5 were induced by E2 in in vitro culture of tissue explants from which cells migrated throughout the plate. Among these, PR, IGF-1, IGFBP5 genes showed higher expression in tissue compared to cells-derived from tissue in leiomyoma and IGF-1R in leiomyoma cell.
CONCLUSIONS
This observation implies the importance of the whole tissue context including the cells-derived from tissue in the research for the understanding of molecular mechanism of leiomyoma. Here, we report higher expression of TRIM28 in leiomyoma for the first time and identify E2-responsive genes that may have important roles in leiomyoma development.

• Keywords: Leiomyoma;17beta-estradiol;Uterus;Oligonucleotide array sequence analysis;Immunohistochemistry