Transfected endometrial cultured cells: a system to study gene-regulation by estrogens

Gene transfer to cultured human endometrial stromal cells: a model to study cyclooxygenase-2 gene regulation

OBJECTIVE

To compare and optimize conditions for gene transfer to human endometrial stromal cells derived from primary culture and to determine the effect of interleukin-1beta (IL-1beta) and phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator. on the promoter activity of the human cyclooxygenase-2 (COX-2) gene.

DESIGN

Prospective controlled study.

SETTING

Academic research laboratory.

PATIENT(S)

Women undergoing benign gynecologic surgery for indications other than endometrial diseases.

INTERVENTION(S)

Endometrial stromal cells were used for transient transfection study.

MAIN OUTCOME MEASURE(S)

Luciferase activity in transfected endometrial stromal cells.

RESULT(S)

Gene transfer mediated by cationic lipid was more efficient and more consistent. Lipofectamine, a polycationic lipid, yielded the highest efficiency. Phorbol 12-myristate 13-acetate (30 nM) and IL-1beta (100 ng/mL) increased COX-2 promoter activity by 2.6-fold and 2.2-fold, respectively.

CONCLUSION(S)

Induction of COX-2 by IL-1beta and PMA suggests that COX-2 and prostaglandin have important roles in the growth and differentiation of endometrial stromal cells. This model can be used to explore the roles of different promoter regulatory elements in COX-2 gene activation.

ERE environment- and cell type-specific transcriptional effects of estrogen in normal endometrial cells

Our previous results have suggested a repression of E2 (17beta-estradiol) effect on the c-fos gene of cultured guinea-pig endometrial cells. To investigate this repression, the expression of three human c-fos gene recombinants, pFC1-BL (-2250/+41), pFC2-BL (-1400/+41) and pFC2E (-1300/-1050 and -230/+41), known to be E2-responsive in Hela cells, was studied in stromal (SC) and glandular epithelial cells (GEC). In both cellular types, pFC1-BL was not induced by E2, even in the presence of growth factors or co-transfected estrogen receptor. The pattern of pFC2-BL and pFC2E expression was strikingly different and depended on the cellular type: pFC2-BL and pFC2E induction was restricted to the glandular epithelial cells and did not occur in the SCs. We argue for a repression of E2 action which is dependent on the estrogen-responsive cis-acting element (ERE) environment and also cell type-specific involving DNA/protein and/or protein/protein interactions with cellular type-specific factors.

Androgens regulate expression of the gene coding for a mouse vas deferens protein related to the aldo-keto reductase superfamily in epithelial cell subcultures

Mouse vas deferens protein (MVDP), a member of the aldo-keto reductase superfamily, is exclusively produced in the vas deferens. To better understand androgen-regulated MVDP gene expression we have used RNA hybridization to study the effects of androgens on the steady-state levels of MVDP mRNA in vas deferens epithelial cell subcultures. Northern blot analysis revealed that these cells only express MVDP mRNA in the presence of androgens. There was a close relationship between MVDP mRNA levels and dihydrotestosterone concentrations. MVDP mRNA is induced over a period of 24h and maximal induction is about 25-fold. Treatment of cells with cycloheximide completely abolished the observed androgen effect suggesting that the induction of the MVDP gene by androgens depends on continuous protein synthesis. Transient transfection of vas deferens epithelial cells with MMTV-CAT vector showed that these cells contained functional androgen receptors and that they are a suitable system to study androgen effect on MVDP gene regulatory elements.