Downregulation Of Matrix Metalloproteinase Expression Research Articles

Naturally occurring anti-cancer agents targeting EZH2

Natural products are considered as promising tools for the prevention and treatment of cancer. The enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase unit of polycomb repressor complexes such as PRC2 complex that has oncogenic roles through interference with growth and metastatic potential. Several agents targeting EZH2 has been discovered but they often induce side effects in clinical trials. Recently, EZH2 has emerged as a potential target of natural products with documented anti-cancer effects and this discloses a new scenario for the development of EZH2 inhibitory strategies with agents with low cytotoxic detrimental effects. In fact, several natural products such as curcumin, triptolide, ursolic acid, sulforaphane, davidiin, tanshindiols, gambogic acid, berberine and Alcea rosea have been shown to serve as EZH2 modulators. Mechanisms like inhibition of histone H3K4, H3K27 and H3K36 trimethylation, down-regulation of matrix metalloproteinase expression, competitive binding to the S-adenosylmethionine binding site of EZH2 and modulation of tumor-suppressive microRNAs have been demonstrated to mediate the EZH2-inhibitory activity of the mentioned natural products. This review summarizes the pathways that are regulated by various natural products resulting in the suppression of EZH2, and provides a plausible molecular mechanism for the putative anti-cancer effects of these compounds.

Raf kinase inhibitor protein inhibits esophageal cancer cell invasion through downregulation of matrix metalloproteinase expression

Esophageal cancer is the eighth most common malignant tumor in the world and is a common cause of tumor-related death. The development of esophageal cancer is a complex process involving many pathogenetic factors, multiple stages and accumulation of multiple gene mutations and interactions. This study aimed to investigate the effects of Raf kinase inhibitor protein (RKIP) on the proliferation, apoptosis and invasion of TE-1 esophageal cancer cells. Surgical specimens from esophageal cancer patients were classified into esophageal cancer tissues, tumor-adjacent tissues and normal esophageal tissues. The tissues were fixed in 4% paraformaldehyde solution for hematoxylin and eosin and immunohistochemical staining. RKIP expression in esophageal tissues was detected by immunohistochemical staining. The esophageal cancer cell line TE-1 was exposed to four different viruses: RKIP-RNAi-AD, NC-RNAi-GFP-AD, RKIP-AD and GFP-AD. Cell proliferation was detected by MTT assay and cell apoptosis was detected by flow cytometry. Cell invasion was determined by a Transwell coated with Matrigel. RKIP, phospho-RKIP, Raf-1, phospho-Raf-1, ERK1/2, phospho-ERK1/2, GRK-2 and GAPDH expression was assayed by western blotting. LIN28 and MMP-14 mRNA was assayed by qPCR. The results showed that RKIP expression was reduced in esophageal cancer tissues in comparison with expression in normal esophageal epithelium tissues and tumor-adjacent tissues. Reduced RKIP expression was associated with lymph node or distant metastasis in esophageal cancer. RKIP inhibited the invasive and metastatic abilities of esophageal cancer cell line TE-1 by downregulating mRNA expression of LIN28 and MMP-14. RKIP had no effect on the MAPK signaling pathway in the esophageal cancer cell line TE-1, but was involved in the G protein-coupled signaling pathway. Our findings clearly demonstrate that RKIP inhibits esophageal cancer cell invasion by downregulating the expression of GRK-2, LIN28 and MMP-14.

A novel splice variant of occludin deleted in exon 9 and its role in cell apoptosis and invasion

The tight junction protein occludin participates in cell adhesion and migration and has been shown to possess antitumorigenic properties; however, the exact mechanism underlying these effects is poorly understood. In liver cell lines, we identified an occludin splice variant deleted in exon 9 (Occ(DeltaE9)). Furthermore, comparison analysis of wild-type occludin (Occ(WT)) and Occ(DeltaE9) revealed that exon 9 played important roles in the induction of mitochondria-mediated apoptosis and the inhibition of invasion, along with the downregulation of matrix metalloproteinase expression. In addition, by using the calcium indicator X-rhod-1, and the inositol trisphosphate receptor inhibitor 2-aminoethoxydiphenyl borate, we found that Occ(WT) but not Occ(DeltaE9) increased calcium release from the endoplasmic reticulum. In conclusion, our results showed that occludin mediates apoptosis and invasion by elevating the cytoplasmic calcium concentration and that exon 9 of occludin is an important region that mediates these effects.

Nitric Oxide Donors Selectively Reduce the Expression of Matrix Metalloproteinases-8 and -9 by Human Diabetic Skin Fibroblasts

Chronic, nonhealing skin wounds are a common ailment in uncontrolled diabetes and are associated with significant morbidity. The nonhealing diabetic foot wound displays pathologically elevated matrix metalloproteinase (MMP) activity. In contrast, the concentration of nitric oxide (NO) is significantly reduced in these chronic ulcers. Addition of NO to diabetic wounds improves wound healing, but the mechanism for this effect is poorly understood. Diabetic and nondiabetic human skin fibroblasts were cultured to confluence and then treated with 0, 1, 10, and 100 nm concentrations of three NO donors (NOR-3, SNAP, and SNOG) with varying half-lives for 1, 3, and 7 days. At harvest, the cultures were analyzed for their production of NO and the effect of NO donor treatment on cell proliferation (cell number) and MMP expression (MMP-1, -2, -8, -9, and -13). The NO donor with the shortest half-life (NOR-3) produced a rise in NO on day 1 in both normal and diabetic fibroblasts at the highest concentration used; there was a corresponding decrease in both MMP-8 and MMP-9 expression in the diabetic fibroblasts and a decrease in only MMP-9 expression in the normal fibroblasts. After longer times in culture or at lower concentrations, NOR-3 was without effect on NO production or MMP expression. Further, NOR-3 had no effect on cell proliferation. In contrast to NOR-3, NO donors with longer half-lives (SNAP and SNOG) significantly (P < 0.05) increased NO production by both normal and diabetic fibroblasts during the entire course of the experiment and even after a media change lacking additional NO donor at day 3. SNAP and SNOG dose-dependently reduced MMP-8 and -9 mRNA expression in both normal and diabetic fibroblasts through day 7. The expression of MMP-1, -2, and -13 was not significantly affected by any of the NO donor treatments. These experiments show distinct deficits in NO production and elevations in MMP-8 and -9 expression in diabetic human skin fibroblasts compared to normal. In addition, treating these cultures with NO donor compounds with half-lives greater than 5 h selectively raised NO production by the cells, increased cell proliferation, and decreased MMP-8 and -9 expression in a dose-dependent manner. There was no effect of the NO donor compounds on MMP-1, -2, or -13 expression. One possible mechanism to account for NO's beneficial effect on wound healing may involve stimulation of cell proliferation and down-regulation of MMP expression.

Inhibitory effects of a benz[ f]indole-4,9-dione analog on cancer cell metastasis mediated by the down-regulation of matrix metalloproteinase expression in human HT1080 fibrosarcoma cells

In our previous study, a synthetic benz[ f]indole-4,9-dione analog, 2-amino-3-ethoxycarbonyl- N-methylbenz[ f]indole-4,9-dione (SME-6), exhibited a potential anti-tumor activity. We, in this study, further explored the anti-metastatic and anti-invasive effect of SME-6 by determining the regulation of matrix metalloproteinases (MMPs). MMPs, zinc-dependent proteolytic enzymes, play a pivotal role in tumor metastasis by cleavage of extracellular matrix as well as non-matrix substrates. On this line, we examined the influence of SME-6 on the expressions of MMP-2, -9, membrane type 1-MMP (MT1-MMP), tissue inhibitor of metalloproteinases (TIMP-1, -2), and in vitro invasiveness of human fibrosarcoma cells. Dose-dependent suppressions of MMPs and TIMP-2 mRNA levels were observed in SME-6-treated HT1080 human fibrosarcoma cells detected by reverse transcriptase–polymerase chain reaction. TIMP-1 mRNA level, however, was induced in a dose-dependent manner. Gelatin zymographic analysis also exhibited a significant down-regulation of MMP-2 and -9 expression in HT1080 cells treated with SME-6 compared to controls. Furthermore, SME-6 inhibited the invasion, motility, and migration of tumor cells. Taken together, these data provide a possible role of SME-6 as a potential antitumor agent with the markedly inhibition of the metastatic and invasive capacity of malignant cells.

Inhibitory effects of caffeic acid phenethyl ester on cancer cell metastasis mediated by the down-regulation of matrix metalloproteinase expression in human HT1080 fibrosarcoma cells

Caffeic acid phenethyl ester (CAPE) derived from honeybee propolis has been used as a folk medicine. Recent study also revealed that CAPE has several biological activities including antioxidation, anti-inflammation and inhibition of tumor growth. The present study investigated the effect of CAPE on tumor invasion and metastasis by determining the regulation of matrix metalloproteinases (MMPs). Matrix metalloproteinases, which are zinc-dependent proteolytic enzymes, play a pivotal role in tumor metastasis by cleavage of extracellular matrix (ECM) as well as nonmatrix substrates. On this line, we examined the influence of CAPE on the gene expression of MMPs (MMP-2, MMP-9, MT1-MMP), tissue inhibitor of metalloproteinase-2 (TIMP-2) and in vitro invasiveness of human fibrosarcoma cells. Dose-dependent decreases in MMP and TIMP-2 mRNA levels were observed in CAPE-treated HT1080 human fibrosarcoma cells as detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Gelatin zymography analysis also exhibited a significant down-regulation of MMP-2 and MMP-9 expression in HT1080 cells treated with CAPE compared to controls. In addition, CAPE inhibited the activated MMP-2 activity as well as invasion, motility, cell migration and colony formation of tumor cells. These data therefore provide direct evidence for the role of CAPE as a potent antimetastatic agent, which can markedly inhibit the metastatic and invasive capacity of malignant cells.