Effects of sex steroids and growth factors on migration and invasion of endometrial adenocarcinoma SNG-M cells in vitro.

Biological effects of sex steroids (estradiol-17beta, E2; progesterone, P; medroxyprogesterone acetate, MPA; Danazol, DZ) and growth factors (epidermal growth factor, EGF; transforming growth factor, TGF-alpha,beta) on migration and invasion of endometrial adenocarcinoma SNG-M cells were investigated by haptotactic migration and haptoinvasion assay. The enzymatic degradation of the extracellular matrix by tumor cells was also examined. Tumor cell migration along a gradient of substratum-bound fibronectin was inhibited by 0.1-10 microM MPA and DZ, but promoted by 0.1-10 nM EGF and TGF-alpha in a concentration-dependent manner. E2, P and TGF-beta did not have any effect on the motility of tumor cells. These effects were also confirmed by wound assay. The invasive activity of SNG-M cells into reconstituted basement membrane (Matrigel) was inhibited by the presence of 0.1-10 microM MPA and DZ, but promoted by 0.1-10 nM EGF and TGF-alpha in a concentration-dependent manner. E2, P and TGF-beta did not have any effect on tumor cell invasion. The zymography of tumor-conditioned medium showed that the treatment of SNG-M cells with EGF and TGF-alpha resulted in the increase of the 68, 72 and 92 kDa type IV collagenases (matrix metalloproteinase, MMP-2 and 9). Sex steroids and TGF-beta did not have significant effects on MMP-2 and 9. Stromelysin (MMP-3), also secreted by SNG-M cells, was not affected by sex steroids and growth factors. These results suggest that EGF and TGF-alpha act as positive regulators on the invasion process of endometrial adenocarcinoma cells, which may partly be associated with the induction of type IV collagenase secretion by tumor cells. The inhibitory effects of MPA and DZ on tumor cell invasion may depend at least partly on their inhibitory action on the motility of tumor cells.