Search results for "collage"

Cell-cell and cell-collagen interactions influence gelatinase production by human breast-carcinoma cell line 8701-BC

1995

We previously produced evidence that the human mammary-carcinoma cell line 8701-BC expresses several metalloproteinases (MMP-1, -2, -9, and -10) and their tissue inhibitors. In order to obtain a better understanding of the environmental control over gelatinolytic activities, we have tested the enzyme production of 8701-BC cells, at time intervals after plating on different collagen substrates, i.e., types I, III, IV, V and OF/LB, used as films in culture dishes. Proteinase activities, released in the conditioned culture media, were tested by zymography on SDS-PAGE, and by quantificative analyses, using 14C carboxy-methylated transferrin as substrate in a liquid incubation medium. Enzymatic …

Metalloproteinase and TIMP expression by the human breast carcinoma cell line 8701-BC.

1993

It is widely accepted that collagenolytic enzymes are required to facilitate the invasion and spread of tumour cells into host tissues. Immunohistochemical, zymographic and PCR analyses have produced evidence that the recently established human mammary carcinoma cell line, 8701-BC, expresses several metalloproteinases (MMP-1, -2, -9 and -10) and their tissue inhibitors (TIMP-1 and -2). Application of these different techniques has led to several observations, both complementary and dissimilar. Whereas PCR analysis showed that mRNA was detected for each of the proteins, the immunolocalization study demonstrated that MMP-1, MMP-2, MMP-9 and TIMP-1 production was restricted to only a proportio…

Absence of regular alpha2(I) collagen chains in colon carcinoma biopsy fragments.

1998

The extracellular matrix (ECM) is known to play an active role in numerous biological processes such as differentiation, apoptosis and cancer. Extensive alterations of epithelial basement membranes and of interstitial ECM are known to occur during the progression of most invasive carcinomas. Collagen, which represents the major component of the interstitial ECM, is primarily involved in the stromal changes at the site of tumor cell invasion. We have previously described the occurrence in breast and colon cancer ECM of an oncofetal form of collagen, characterized by an acidic chain distinct from those of type I and III collagen. In the present paper, we bring evidence that alpha2(I) collagen…

Temozolomide- and fotemustine-induced apoptosis in human malignant melanoma cells: response related to MGMT, MMR, DSBs, and p53

2009

Malignant melanomas are highly resistant to chemotherapy. First-line chemotherapeutics used in melanoma therapy are the methylating agents dacarbazine (DTIC) and temozolomide (TMZ) and the chloroethylating agents BCNU and fotemustine. Here, we determined the mode of cell death in 11 melanoma cell lines upon exposure to TMZ and fotemustine. We show for the first time that TMZ induces apoptosis in melanoma cells, using therapeutic doses. For both TMZ and fotemustine apoptosis is the dominant mode of cell death. The contribution of necrosis to total cell death varied between 10 and 40%. The O(6)-methylguanine-DNA methyltransferase (MGMT) activity in the cell lines was between 0 and 1100 fmol m…

The protease complex consisting of dipeptidyl peptidase IV and seprase plays a role in the migration and invasion of human endothelial cells in colla…

2006

Abstract Dipeptidyl peptidase IV (DPP4/CD26) and seprase/fibroblast activation protein α are homologous type II transmembrane, homodimeric glycoproteins that exhibit unique prolyl peptidase activities. Human DPP4 is ubiquitously expressed in epithelial and endothelial cells and serves multiple functions in cleaving the penultimate positioned prolyl bonds at the NH2 terminus of a variety of physiologically important peptides in the circulation. Recent studies showed a linkage between DPP4 and down-regulation of certain chemokines and mitogenic growth factors, and degradation of denatured collagens (gelatin), suggesting a role of DPP4 in the cell invasive phenotype. Here, we found the existen…

Ultrastructural evidence of collagenolytic activity in ductal infiltrating carcinoma of the human breast

1987

The stroma of ductal infiltrating carcinoma of the human breast shows characteristic and localized areas of collagen rarefaction and fragmentation. This finding has been correlated with a peculiar type of fibrillar damage, observed in a small percentage of collagen fibrils isolated in the native state from the tumour stroma. The same pattern of lesion has been reproduced in vitro by human collagenase digestion on reconstituted fibrils. No effect has been detected by other nonspecific proteases in the same system.

Type V collagen and protein kinase C η down-regulation in 8701-BC breast cancer cells

2011

We previously reported that ductal infiltrating carcinomas (d.i.c.) of the human breast display profound modifications of the stromal architecture, associated with anomalous collagen composition. Among the major alterations observed in the interstitial collagen, the relative increase of type V collagen content was detected. When type V collagen was used as an "in vitro" substrate for 8701-BC d.i.c. cells, it appeared able to restrain cell growth, inhibit cell motility and invasion "in vitro", and modify the expression levels of genes coding for apoptosis factors, caspases and stress response proteins. In the present paper we demonstrate that type V collagen induces the down-regulation of pr…

Partial restoration of pre-transformation levels of lysyl oxidase and transin mRNAs in phenotypic ras revertants.

1995

Neoplastic transformation mediated by ras oncogenes is associated with deregulated expression of genes encoding, for example, various proteases, lysyl oxidase, and smooth-muscle α-actin. To define the role of these genes in the initiation or maintenance of the ras-transformed state, we compared their steady-state mRNA levels in two different sets of preneoplastic fibroblast lines, ras-transformed clones, and phenotypic revertants derived from them. Compared with the preneoplastic fibroblasts, the ras-transformed derivatives exhibited elevated levels of cathepsin L (major excreted protein), transin (stromelysin I, matrix metalloproteinase–3), and collagenase I (matrix metalloproteinase–1) mR…

Use of recombinant collagenases class I and II in optimization of cell purification for tissue engineering applications

2014

Mammary-derived growth inhibitor (MDGI) interacts with integrin α-subunits and suppresses integrin activity and invasion

2010

The majority of mortality associated with cancer is due to formation of metastases from the primary tumor. Adhesion mediated by different integrin heterodimers has an important role during cell migration and invasion. Protein interactions with the β1-integrin cytoplasmic tail are known to influence integrin affinity for extracellular ligands, but regulating binding partners for the α-subunit cytoplasmic tails have remained elusive. In this study, we show that mammary-derived growth inhibitor (MDGI) (also known as FABP-3 or H-FABP) binds directly to the cytoplasmic tail of integrin α-subunits and its expression inhibits integrin activity. In breast cancer cell lines, MDGI expression correlat…