Involvement of matrix metalloproteinase-7 in invasion-metastasis through induction of cell dissociation in pancreatic cancer.
ABSTRACT Epidermal growth factor receptor (EGFR) mediated mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway was isolated as invasion-metastasis related factor in pancreatic cancer in our previous studies. Matrix metalloproteinase-7 (MMP-7) and tight junction (TJ) proteins are indicated to be involved in cancer invasion-metastasis. To clarify the underlying mechanism of involvement of MMP-7 in cancer invasion, western blotting, invasion assay and immunohistochemistry were performed in dissociated (PC-1.0 and AsPC-1) and non-dissociated (PC-1 and Capan-2) pancreatic cancer cells, as well as pancreatic cancer tissues. Intracellular MMP-7 protein presented as pre-proenzyme and its expression was decreased by AG1478 (EGFR inhibitor) or U0126 (MEK inhibitor) treatment in pancreatic cancer cells. Activated MMP-7 protein was only detected in the medium of PC-1.0 and AsPC-1 cells, but not detected in the medium of PC-1 and Capan-2 cells. Moreover, MMP-7 treatment significant induced the dissociation of cell colonies in PC-1 and Capan-2 cells. Synchronously, TJ structure was apparently disrupted and translocation of TJ proteins to cytoplasm or extracellular medium was induced in PC-1 and Capan-2 cells. Furthermore, MMP-7 treatment markedly increased the in vitro invasion of PC-1 and Capan-2 cells. In addition, MMP-7 expression at the invasive front was obviously stronger than that at the center of pancreatic cancer tissues. Activation of MMP-7 protein is closely involved in disruption of TJ structure and consequent induction of cell dissociation as well as invasion in pancreatic cancer. EGFR mediated MEK/ERK signaling pathway is implied to be involved in regulation of MMP-7 expression in pancreatic cancer cells.
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ABSTRACT: Recent studies have shown that overexpression of regenerating gene family member 4 (REG4) is associated with the initiation and progression of pancreatic cancer. In our study, we explored the role of REG4 in the invasion of pancreatic cancer. Real-time reverse transcription-polymerase chain reaction (RT-PCR) and western blotting were used to determine REG4 expression in pancreatic cancer cell lines. A 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was conducted to test the effect of REG4 on the growth of pancreatic cancer cells. The involvement of REG4 in cancer cell invasion was examined by transwell invasion assay. Two MMPs (Matrix Metalloproteinase), MMP-7 and MMP-9, were identified from a pool of candidate genes to be related to REG4 induced cell invasion by RT-PCR and western blotting. Immunohistochemistry was used to confirm the correlation between REG4 and two MMPs. High expression of REG4 was found in BXPC-3 cells and its culture media. But in PANC-1 and ASPC-1, REG4 expression levels were very low, and no detectable protein was found in the culture medium. MTT and transwell invasion assay showed that recombination REG4 protein and BXPC-3 condition media significantly promoted the proliferation and invasiveness of pancreatic cancer cells. It was also shown that MMP-7 and MMP-9 are upregulated by REG4 induction using Real-time PCR and western blotting analysis. Immunohistochemical study further verified this result. In conclusion, REG4 promotes not only growth but also in vitro invasiveness of pancreatic cancer cells by upregulating MMP-7 and MMP-9.Cancer Science 09/2012; · 3.48 Impact Factor
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ABSTRACT: Mesothelin (MSLN) and cancer antigen125/mucin 16 (CA125/MUC16) are potential biomarkers for pancreatic cancer (PC) that are co-overexpressed at the invading edges of PC tissues, and their expression correlates with poor survival rates. However, the role of MSLN-MUC16 molecular interaction in PC cell motility and invasion has yet to be elucidated. Using sophisticated bioengineering and molecular biology tools, we report that the binding of MSLN to MUC16 markedly enhances PC cell motility and invasion via the selective induction of matrix metalloproteinase (MMP)-7. MSLN-mediated MMP-7 upregulation in MUC16-expressing PC cells occurs via a p38 MAPK-dependent pathway. Depletion of MMP-7 or inhibition of p38 activity abolishes MSLN-mediated PC motility and invasion. These findings provide a novel perspective on the enhanced invasive potential associated with MSLN and MUC16 co-overexpression, and the mechanism underlying MMP-7 activation in PC invasion and metastasis.Scientific Reports 05/2013; 3:1870. · 2.93 Impact Factor
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ABSTRACT: BACKGROUND: Treatment of solid tumors with vascular disrupting agent OXi4503 results in over 90% tumor destruction. However, a thin rim of viable cells persists in the tumor periphery following treatment, contributing to subsequent recurrence. This study investigates inherent differences in the microenvironment of the tumor periphery that contribute to treatment resistance. METHODS: Using a murine colorectal liver metastases model, spatial morphological and molecular differences within the periphery and the center of the tumor that may account for differences in resistance to OXi4503 treatment were investigated. H&E staining and immunostaining were used to examine vessel maturity and stability, hypoxia and HIF1alpha levels, accumulation of immune cells, expression of proangiogenic factors/receptors (VEGF, TGF-beta, b-FGF, and AT1R) and expression of EMT markers (ZEB1, vimentin, E-cadherin and beta-catenin) in the periphery and center of established tumors. The effects of OXi4503 on tumor vessels and cell kinetics were also investigated. RESULTS: Significant differences were found between tumor periphery and central regions, including association of the periphery with mature vessels, higher accumulation of immune cells, increased growth factor expression, minimal levels of hypoxia and increased evidence of EMT. OXi4503 treatment resulted in collapse of vessels in the tumor center; however vasculature in the periphery remained patent. Similarly, tumor apoptosis and proliferation were differentially modulated between centre and periphery after treatment. CONCLUSIONS: The molecular and morphological differences between tumor periphery and center may account for the observed differential resistance to OXi4503 treatment and could provide targets for drug development to totally eliminate metastases.BMC Cancer 11/2012; 12(1):522. · 3.33 Impact Factor