Regulation of MMP-9 in Oral Squamous Carcinoma Cell Line-7

Production and activation of MMP-9 are implicated in tumor invasion and metastasis processes. Objective: to investigate the effect of tumour environment on the regulation of MMP-9 in oral human squamous carcinoma cell line-7 (HSC-7). Methods: Varied seeding densities of HSC-7 on cuture plate were performed. Cells were also seeded on collagen gel or co-cultured with primary human gingival fibroblasts (HGF). HGF-conditioned medium was used to stimulate HSC-7 cultured on collagen gel. Secreted MMP-9 was analysed from the cultured medium by zymography. MMP-9 mRNA was analysed by reverse transcriptase polymerase chain reaction. Cell number was analysed by MTT assay. Results: MMP-9 secretion was increased in HSC-7 with cell density and when cultured on collagen gel. Co-culture of HSC-7 and HGF reduced MMP-9 in the levels of mRNA and protein. Treatment by HGF-conditioned medium also reduced MMP-9 secretion in HSC-7. Conclusions: These results demonstrated the regulation of MMP-9 in HSC-7 by cell density, extracellular matrix and stromal cell interaction. This study was supported by Ratchadapisek Somphot endowment, Chulalongkorn University 2004.