Difference in responsiveness of human esophageal squamous cell carcinoma lines to epidermal growth factor for MMP-7 expression

Expression of MMP-7 in human esophageal squamous cell carcinoma lines (TE-9 and -10) was investigated. Under normal culture conditions, immunocytochemical staining and enzymography demonstrated the production of MMP-7 in their cytoplasm and its gelatinolytic activity in the medium of TE-9 and -10 cell cultures. When EGF was added to the cultures, Western blotting and RT-PCR analysis showed a dose-dependent increase in the amount of MMP-7 synthesized in the TE-9 cells, whereas in TE-10 cells, EGF failed to stimulate MMP-7 production. For luciferase reporter analysis of MMP-7 transcription, pMMP7LucWI (1132-bp) and pMMP7LucWII (334-bp) were cloned in the luciferase pGL3-basic vector. The promoter activity was enhanced from 1.5- to 2-fold by the addition of EGF to TE-9 cells transfected with pMMP7LucWI or WII, even though the response was low as compared with that of 12-O-tetra-decanoyl-phorbol-13-acetate (TPA); and in TE-10 cells, only TPA enhanced the promoter activity of MMP-7. Luciferase promoter analysis using a pMMP7WII mutant series revealed that the AP-1 site was essential for transcription of the MMP-7 gene in TE-9 cells, and Tcf-I was also an important site, and that to a lesser degree, Tcf-II and PEA3s participated in the transcription of the MMP-7 gene in these cells. Unlike the results with TE-9 cells, in TE-10 cells, EGF failed to stimulate transcription of the MMP-7 gene; and up-regulation of the promoter activity by TPA was dependent on the AP-1 site and to lesser degree, on Tcf-I and Tcf-II. These results suggest that EGF plays also an important role in MMP-7 production of TE-9 cells and that there is a difference not only in EGF-intracellular signaling system but also in regulation mechanisms of MMP-7 transcription by β-catenin-Tcf and/or PEA3 system between these 2 carcinoma lines.