Tumor-stromal cell contact promotes invasion of human uterine cervical carcinoma cells by augmenting the expression and activation of stromal matrix metalloproteinases.
OBJECTIVE
The augmentation of the expression and activation of matrix metalloproteinases (MMPs) is associated with tumor invasion and metastasis. In addition, tumor-stromal cell contact provides a crucial signal for regulating the pericellular proteolysis for the progression of tumor invasiveness. The present study evaluates the regulation of the expression and activation of MMPs and tissue inhibitors of metalloproteinases (TIMPs) by tumor-stromal cell contact in an in vitro co-culture model of human uterine cervical carcinoma cells and human uterine cervical fibroblasts.


METHODS
When human uterine cervical carcinoma SKG-II cells were co-cultured with human uterine cervical fibroblasts (HUCFs), the invasive activity of SKG-II cells was analyzed using an in vitro invasion assay using Matrigel. The production, mRNA expression and activation of MMPs and TIMPs were monitored by Western blot and Northern blot analyses and gelatin zymography.


RESULTS
SKG-II cells, which constitutively produced membrane-type 1 MMP (MT1-MMP) and a trace of proMMP-2 but neither TIMP-1 nor TIMP-2, showed poor invasiveness in vitro. Upon co-culturing with HUCFs, SKG-II cells were found to transform to the invasive phenotype by enhancing the production and mRNA expression of tumoral MT1-MMP. In addition, a sequential increase in the activation of fibroblast proMMP-2 was observed along with the formation of an MT1-MMP-TIMP-2-proMMP-2 complex on the tumor cell surface. Furthermore, the production and gene expression of fibroblast proMMP-1 and proMMP-3 were augmented under co-culture conditions, whereas mRNA expression of proMMP-2, TIMP-1 and TIMP-2 was unchanged. Moreover, we demonstrated the partial involvement of tumor-cell-derived soluble factors in the augmentation of the production of proMMP-1 and proMMP-3 in HUCFs. However, anti-integrin beta1 and beta3 antibodies failed to abolish the augmentation of fibroblast proMMP-3 production and proMMP-2 activation in the co-culture.


CONCLUSIONS
Cell-cell contact between cervical carcinoma cells and peripheral stromal fibroblasts augments the production and activation of MMPs, and therefore the subsequent imbalance between MMPs and TIMPs may result in the progression of invasiveness of cervical carcinoma cells in vivo.
Sato
Takashi
T
Department of Biochemistry and Molecular Biology, School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo 192-0392, Japan. satotak@ps.toyaku.ac.jp
Sakai
Takeaki
T
Noguchi
Yutaka
Y
Takita
Morichika
M
Hirakawa
Shun
S
Ito
Akira
A
D002450:Cell Communication / Q000502:physiology*; D045744:Cell Line, Tumor; D002584:Cervix Uteri / Q000166:cytology / Q000201:enzymology; D018920:Coculture Techniques; D017364:Collagenases / Q000096:biosynthesis / Q000378:metabolism; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000201:enzymology; D018093:Gelatinases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D006801:Humans; D020781:Matrix Metalloproteinase 1; D020782:Matrix Metalloproteinases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D009361:Neoplasm Invasiveness; D012333:RNA, Messenger / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology / Q000201:enzymology; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D002583:Uterine Cervical Neoplasms / Q000201:enzymology / Q000473:pathology*
D004792:Enzyme Precursors; D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; D019716:Tissue Inhibitor of Metalloproteinase-2; D017364:Collagenases; D018093:Gelatinases; D020782:Matrix Metalloproteinases; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; C069860:progelatinase; C048047:prostromelysin; D020781:Matrix Metalloproteinase 1