Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined whether fibroblasts from subcutaneous, colon or lung tissues of nude mice influence the invasive potential of highly metastatic human colon carcinoma KM12SM cells. Primary cultures of nude mouse fibroblasts from skin, lung and colon were established. Invasive and metastatic KM12SM cells were cultured alone or with fibroblasts. Growth and invasive properties of the KM12SM cells were evaluated as well as their production of gelatinase activity. KM12SM cells were able to grow on monolayers of all three fibroblast cultures but did not invade through skin fibroblasts. The conditioned media of KM12SM cells cocultured with skin, colon or lung fibroblasts were examined for the presence of type IV collagenase (gelatinase). KM12SM growing on plastic and on colon or lung fibroblasts produced significant levels of latent and active forms of 64 kDa type IV collagenase, whereas KM12SM cells cocultivated with nude mouse skin fibroblasts did not. In contrast, human squamous cell carcinoma A431 cells produced significant levels of collagenase type IV when cocultured with nude mouse skin fibroblasts, a tissue they invaded and completely penetrated. Incubation of KM12SM cells in serum-free medium containing recombinant human interferon-beta (fibroblast interferon) was associated with significant reduction in gelatinase activity. Since the production of type IV collagenase by human colon cancer cells is specifically inhibited by mouse skin fibroblasts but not by colon or lung fibroblasts the data suggest that organ-specific fibroblasts can influence the invasive and metastatic properties of KM12SM cells.
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PMID:Modulation of the invasive phenotype of human colon carcinoma cells by organ specific fibroblasts of nude mice. 128 73

A detailed understanding of the pathogenesis of colon cancer metastasis has been hindered by the lack of appropriate animal models which accurately reflect events in this complex process. An animal model for colon cancer metastasis is described in which spontaneously metastasizing colonic tumors are formed after injection of murine colon cancer cells into the cecal wall of BALB/c mice. Using this model, tumor cells with different liver-metastasizing potential were selected and shown to possess several properties known to be associated with other metastatic cell lines. The ability of tumor cells to invade a reconstituted basement membrane and to secrete type IV collagenase was directly proportional to their metastatic ability. In addition, liver-metastasizing cells preferentially migrated toward liver extracts in a Boyden chamber assay, as compared to extracts of brain or lung, and adhered rapidly to highly purified hepatic sinusoidal endothelial cells versus hepatic parenchymal cells in vitro. This model may thus be useful for studying many aspects of the pathogenesis of colon cancer metastasis.
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PMID:An animal model for colon cancer metastasis: establishment and characterization of murine cell lines with enhanced liver-metastasizing ability. 302 9

Gelatinase A (MMP-2) and cathepsin B are proteinases which have been proposed to participate in human tumor invasion and metastasis. Precise quantitation of the activity of these enzymes in invading tumors has not been previously described. We utilized a novel tissue microdissection technique to determine levels of enzyme activity in specific microscopic areas of invasive human colon cancer. Tissue specimens smaller than one high power field can be extracted from the samples and analyzed. Increased levels of pro-enzyme and active enzyme forms of gelatinase A (MMP-2) and increased cathepsin B activity were localized in regions of tumor invasion as compared with a matched number of normal epithelial cells from the same patient. Levels of progelatinase B (MMP-9) were also increased in the tumors; however, we did not observe activation of this enzyme. To investigate the mechanism of gelatinase A activation, we amplified DNA of specific microdissected tumor cell populations using polymerase chain reaction. We did not detect a mutation in the activation locus of the enzyme in any of the tumors studied, which suggests that activation may be due to up-regulation of a tumor-associated gelatinase A activating species. Microdissection of frozen tissue sections may prove valuable in the study of proteinases in human tumor invasion as well as in the detection of genetic alterations in human cancers.
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PMID:Increased gelatinase A (MMP-2) and cathepsin B activity in invasive tumor regions of human colon cancer samples. 799 33

Overproduction of matrix metalloproteinases (MMPs) is a common characteristic of metastatic cancer cells. Since MMPs can be identified in plasma, we proposed that enhanced MMP-9 secretion by invasive cancer cells may be detected by plasma assay. To this end, we developed a specific sandwich enzyme-linked immunosorbent assay which uses two mouse monoclonal antibodies to human M(r) 92,000 type IV collagenase (MMP-9). The plasma concentration of MMP-9 (mean +/- SD) in 60 healthy subjects (9 +/- 11 ng/ml), 136 patients without cancer, and 179 patients with cancer of the lung, genitourinary tract, or lymphomas-leukemias did not differ significantly. In contrast, plasma MMP-9 was significantly increased (P < 0.01) in 122 patients with gastrointestinal tract cancer and breast cancer (18 +/- 23 and 21 +/- 22 ng/ml, respectively). Whereas carcinoembryonic antigen levels were significantly increased in patients with stage IV gastrointestinal cancer, MMP-9 concentrations were not significantly increased in patients with metastatic disease as compared to those with nonmetastatic cancer. Combining both assays improves sensitivity of detection of colon cancer. MMP-9 was also significantly increased during pregnancy which is consistent with the extensive ongoing tissue remodeling and the leaching of the tissue proteinase into plasma.
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PMID:M(r) 92,000 type IV collagenase is increased in plasma of patients with colon cancer and breast cancer. 841 38

The gene expression of two type IV collagen-degrading enzymes (72-kd and 92-kd type IV collagenases) was investigated in human colon adenocarcinomas by in situ hybridization. In all cases (18 out of 18), messenger RNA for the 72-kd type IV collagenase was present and located in numerous fibroblasts in the stroma surrounding the invasive cancer tissue. In normal-appearing colonic mucosa distant from the cancer tissue, either no expression or only very weak expression of this enzyme was detected. Also the 92-kd type IV collagenase was found in all samples investigated (10 out of 10), exclusively expressed by tissue macrophages. A very strong hybridization signal for messenger RNA for the 92-kd enzyme was found in a subpopulation of tissue macrophages surrounding invading malignant epithelium. In normal-appearing colon tissue, a markedly weaker hybridization signal was observed in macrophages contained in Peyer's patches. No hybridization signals for either of the two type IV collagenases were detected in cancer cells. Together with previous findings on expression of components of the plasminogen activation system, these results indicate that several nonepithelial cell types in the tumor stroma are involved in production of factors involved in extracellular proteolysis during colon cancer invasion.
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PMID:Messenger RNA for two type IV collagenases is located in stromal cells in human colon cancer. 843 36

In this study, we describe the activity of CT1746, an orally-active synthetic MMP inhibitor that has a greater specificity for gelatinase A, gelatinase B and stromelysin than for interstitial collagenase and matrilysin, in a nude mouse model that better mimics the clinical development of human colon cancer. The model is constructed by surgical orthotopic implantation (SOI) of histologically-intact tissue of the metastatic human colon tumor cell line Co-3. Animals were gavaged with CT1746 twice a day at 100 mg/kg for 5 days after the SOI of Co-3 for 43 days. In this model CT1746 significantly prolonged the median survival time of the tumor-bearing animals from 51 to 78 days. Significant efficacy of CT1746 was observed on primary tumor growth (32% reduction in mean tumor area at day 36), total spread and metastasis (6/20 treated animals had no detectable spread and metastasis at autopsy compared to 100% incidence of secondaries in control groups). Efficacy of CT1746 could also be seen on reducing tumor spread and metastasis to individual organ sites such as the abdominal wall, cecum and lymph nodes compared to vehicle and untreated controls. We conclude that chronic administration of a peptidomimetic MMP inhibitor via the oral route is feasible and results in inhibition of solid tumor growth, spread and metastasis with increase in survival in this model of human cancer, thus converting aggressive cancer to a more controlled indolent disease.
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PMID:Conversion of highly malignant colon cancer from an aggressive to a controlled disease by oral administration of a metalloproteinase inhibitor. 906 95

Matrix metalloproteinase 2 (MMP-2) facilitates tumor growth and metastasis in colon cancer. Although tumor cells may produce MMP-2, stromal cells, such as macrophages and fibroblasts, contribute significantly to MMP-2 synthesis in human tumors. We characterized four human colon cancer cell lines with differing biological behavior for MMP-2 expression. While the parent tumors from which the cell lines were derived all expressed MMP-2 mRNA, MMP-2 transcripts were detected in only one cell line, TF-17C, which is nontumorigenic in a nude mouse tumor model. TF-43C, which is tumorigenic and metastatic in the same tumor model, did not produce MMP-2, yet the tumors which arose from it after injection into nude mice did contain MMP-2 mRNA, suggesting a contribution from stromal cells. Co-culturing TF-43C with fibroblasts resulted in an increase in MMP-2 protein, whereas co-culturing with the nontumorigenic cell line TF-13Cm did not alter constitutive fibroblast MMP-2 secretion. Conditioned medium from TF-43C cells also stimulated fibroblast MMP-2 production. These data suggest that a soluble factor from TF-43C cells can stimulate fibroblast MMP-2 production and support the hypothesis that colon cancer cell interactions with stromal fibroblasts may be important determinants of tumor behavior in vivo.
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PMID:Evidence for tumor-host cooperation in regulating MMP-2 expression in human colon cancer. 1043 5

The peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand-activated transcription factor belonging to the steroid receptor superfamily. It is a key regulator of adipogenic differentiation, the ligands of which have also been demonstrated to induce differentiation in human breast and colon cancer cell lines. This study examined PPARgamma, in non-small cell lung cancer (NSCLC). PPARgamma mRNA and protein were expressed in NSCLC cell lines, with highest levels in adenocarcinomas. PPARgamma protein was also expressed in 50% of primary lung cancers by immunohistochemistry. Treatment of multiple cell lines with two distinct PPARgamma ligands in the presence of serum resulted in growth arrest, irreversible loss of capacity for anchorage-independent growth, decreased activity and expression of matrix metalloproteinase 2, and modulation of multiple markers in a manner consistent with differentiation. Specifically, there was up-regulation of general markers of the differentiated state such as gelsolin, Mad, and p21. Down-regulation of specific markers of progenitor lineages for the peripheral lung, i.e., the type II pneumocyte lineage markers MUC1 and surfactant protein-A and the Clara cell lineage marker CC10, also occurred. In addition, HTI56, a marker of terminally differentiated type I pneumocytes, was also induced. Consistent with a more mature, less malignant phenotype, ligand treatment also inhibited the expression of cyclin D1 and led to hypophosphorylation of the retinoblastoma protein. In contrast, in the absence of serum, ligand treatment rapidly resulted in apoptosis and substantially earlier onset of differentiation. Taken together, these results show that depending on the growth milieu, ligands of PPARgamma induce differentiation and apoptosis in NSCLC, suggesting clinical utility for these agents.
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PMID:Induction of differentiation and apoptosis by ligands of peroxisome proliferator-activated receptor gamma in non-small cell lung cancer. 1070 35

The non-receptor tyrosine kinase c-Src has been implicated in the development of numerous human cancers. c-Src is activated in colon cancers, particularly in highly metastatic cells, and its overexpression strongly correlates with tumor progression. C-terminal Src kinase (Csk) has been demonstrated to negatively regulate Src family tyrosine kinases through tyrosine phosphorylation at the C-terminal regulatory site (Tyr-527). We report herein that down-regulation of Src kinase activity by adenovirus-mediated csk gene transfer abrogated the highly metastatic phenotype of colon cancer cells. Overexpression of Csk decreased Src tyrosine kinase activity in NL-17 cells, the highly metastatic clone of mouse colon adenocarcinoma 26. Importantly, Csk overexpression in NL-17 cells resulted in significant suppression of in vivo metastasis, without affecting its tumorgenicity. Csk overexpression decreased the invasiveness of NL-17 cells through Matrigel, in vitro reconstituted basement membrane. Gelatin zymography confirmed the decreased protein levels of MMP-2 (gelatinase A) in the supernatants of Csk-overexpressed NL- 17 cells. These results provide a therapeutic basis for interfering with metastasis of colon cancer by csk gene-mediated down-regulation of Src kinase activity.
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PMID:Overexpression of the csk gene suppresses tumor metastasis in vivo. 1105 67

Matrix metalloproteinase-2 (MMP-2) is overexpressed in human cancers and facilitates tumor growth and metastasis. It is synthesized as an inactive proenzyme that is activated by membrane-type matrix metalloproteinase-1 (MT1-MMP) and inhibited by tissue inhibitor of metalloproteinase-2 (TIMP-2). We hypothesized that there is an imbalance between the expression of TIMP-2 and the expression of MMP-2 and MT1-MMP that favors activation of MMP-2 in malignant colon tumors compared to normal colonic tissue. Specimens of colon tumors and of adjacent normal mucosa were obtained from 22 patients at the time of surgical resection. MMP-2, MT1-MMP, and TIMP-2 RNA transcripts were measured in each sample using a quantitative reverse transcriptase polymerase chain reaction assay. We observed that MMP-2 RNA levels were significantly elevated in tumors compared to normal tissue (P = 0.039). In addition, the TIMP-2:MMP-2 ratio was twofold lower (P = 0.001) and the TIMP-2:MT1-MMP ratio was 1.5-fold lower (P = 0.003) in tumors compared to normal mucosa. These results suggest that the balance between genes that activate and inhibit MMP-2 is shifted toward activation in colon tumors. The abnormal expression of gene products that regulate MMP-2 activity may be an important early step in the malignant transformation of colon cancer and may provide a useful target for new chemoprevention and adjuvant treatment strategies.
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PMID:Balance between activation and inhibition of matrix metalloproteinase-2 (MMP-2) is altered in colorectal tumors compared to normal colonic epithelium. 1218 36


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