Induction of M(r) 92,000 type IV collagenase expression in a squamous cell carcinoma cell line by fibroblasts.
A previous investigation (Matsumoto et al., J. Oral Pathol. Med., 18: 498-501, 1989) has shown that the in vitro invasion of a collagen gel by squamous cell carcinoma can be substantially augmented in the presence of fibroblasts. Therefore, we undertook a study to determine if the production of collagenase(s) by a squamous cell carcinoma cell line, UM-SCC-1, was up-regulated by fibroblasts. Cocultivation of UM-SCC-1 cells with MDA-TU-138 fibroblasts, both established from the oral cavity, resulted in a dose-dependent increase in the activity of a M(r) 92,000 gelatinase as shown by zymography. Augmented M(r) 92,000 gelatinase activity was a consequence of the stimulation of the UM-SCC-1 cells by a soluble, fibroblast-derived factor since this effect could be reproduced with fibroblast-conditioned medium but not with glutaraldehyde-fixed fibroblasts. The increased M(r) 92,000 gelatinolytic activity could be accounted for by an increase in M(r) 92,000 type IV collagenase (MMP-9) protein, as demonstrated by Western blotting for this metalloproteinase. Trypsin treatment of the fibroblast-conditioned medium abolished its ability to increase MMP-9 secretion by UM-SCC-1 cells. Furthermore, fractionation of the fibroblast-conditioned medium revealed a M(r) 3,000-10,000 soluble factor(s) which was responsible for the augmented production of MMP-9 by UM-SCC-1 cells. To determine if the increased production of MMP-9, in response to the fibroblasts, was a consequence of increased promoter activity, UM-SCC-1 cells were transiently transfected with a chloramphenicol acetyltransferase reporter driven by the MMP-9 promoter and plated on plastic or on a monolayer of MDA-TU-138 fibroblasts. A 4-5-fold stimulation of MMP-9 promoter activity was observed with UM-SCC-1 cells plated with the MDA-TU-138 fibroblasts, when compared with similarly transfected cells recultured on plastic. In conclusion, we have demonstrated that MMP-9 expression in a squamous cell carcinoma cell line is augmented by a fibroblast-derived protein(s). This finding indicates a role for stromal cells in the regulation of MMP-9 expression in squamous cell carcinoma. The ability of fibroblasts to regulate MMP-9 expression in tumor cells in vitro may explain the observation that the amount of M(r) 92,000 type IV collagenase mRNA in tumor cells is highest at the tumor:stromal interface of resected squamous cell carcinoma.
Department of Tumor Biology, Anderson Cancer Center, Houston, Texas 77030.
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E
Lengyel
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Gum
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J
Juarez
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G
Clayman
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Seiki
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H
Sato
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D
Boyd
D002294:Carcinoma, Squamous Cell / Q000201:enzymology*; D017364:Collagenases / Q000096:biosynthesis* / Q000378:metabolism; D004790:Enzyme Induction; D005347:Fibroblasts / Q000502:physiology*; D006801:Humans; D020780:Matrix Metalloproteinase 9; D008970:Molecular Weight; D012680:Sensitivity and Specificity; D012995:Solubility; D014357:Trypsin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D014357:Trypsin; D017364:Collagenases; D020780:Matrix Metalloproteinase 9