5-Azacytidine regulates matrix metalloproteinase-9 expression, and the migration and invasion of human fibrosarcoma HT1080 cells via PI3-kinase and ERK1/2 pathways

  • Authors:
    • Seon-Mi Yu
    • Song Ja Kim
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  • Published online on: July 6, 2016     https://doi.org/10.3892/ijo.2016.3612
  • Pages: 1241-1247
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Abstract

Abnormal methylation of promoter CpG islands is one of the hallmarks of cancer cells, and is catalyzed by DNA methyltransferases. 5-azacytidine (5-aza C), a methyltransferase inhibitor, can cause demethylation of promoter regions of diverse genes. Epigenetic processes contribute to the regulation of matrix metalloproteinase (MMP) expression. However, little is known about the mechanisms and effects of 5-aza C on the invasive and migratory capacities of human fibrosarcoma HT1080 cells. In the present study, we found that 5-aza C induces MMP-9 activity, as determined by zymography. HT1080 cell proliferation was determined following 5-aza C administration by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell cycle was examined by flow cytometry. 5-aza C treatment inhibited cell proliferation without affecting cell viability. Furthermore, 5-aza C significantly promoted migration and invasion of HT1080 cells. 5-aza C treatment enhanced phosphorylation of extracellular signal-regulated kinase (ERK) and phosphoinositide (PI)3-kinase/Akt, and their inhibitors blocked MMP-9 activity induction, and cellular invasion and migration. Together, these findings suggest that promoter methylation may be one of the mechanisms modulating MMP-9 levels in HT1080 cells, and that 5-aza C-induced MMP-9 production is associated with the activation of ERK and PI3-kinase/Akt signaling pathways.

Introduction

Although biochemical and clinical studies have resulted in significant advance of our knowledge of cancer, we have not been able to find a cure for the disease. High invasive and metastatic capacities are critical characteristics of fibrosarcoma, a malignant mesenchymal tumor, that partially account for rapid disease progression and poor prognosis. However, the molecular mechanisms leading to the invasion and metastasis of fibrosarcoma are still poorly understood.

Recently, the crucial role of DNA methylation alterations in human carcinogenesis was emphasized (1). The development and progression of cancer is caused by both, genetic mutations and epigenetic changes, including DNA methylation and histone modifications (2). In mammals, DNA methylation primarily involves a covalent modification of cytosine residues of CpG dinucleotides (3). DNA methylation changes include locus-targeted hypermethylation and global hypomethylation (4). Covalent methylation of DNA CpG islands is catalyzed by methyltransferases that methylate C-5 of cytosine nucleotides. Global cytosine methylation patterns in the mammalian genome appear to be established by a complex interplay of at least three independently encoded DNA methyltransferases (DNMTs): DNMT1, DNMT3A and DNMT3B.

5-aza C is a methyltransferase inhibitor. It is incorporated into the DNA of rapidly growing tumor cells during replication and blocks DNA methylation by trapping DNA methyltransferases on DNA, leading to their intracellular depletion (5). 5-Aza C exerts diverse effects on gene expression (6) and cellular survival (7).

Matrix metalloproteinases (MMPs) are a class of proteolytic enzymes that degrade all extracellular matrix (ECM) components (8). These enzymes regulate the migration of various cancer cells across the ECM, cell growth, angiogenesis and apoptosis. All these processes are essential for the dissemination of neoplastic cells. The MMP family member MMP-9, can degrade collagen, the main component of vascular basement membrane (9). MMP-9 activity is modulated on several levels, including gene transcription (10), mRNA stability (11), secretion (12) and enzymatic activity. MMP-9 gene expression can be regulated by a variety of stimuli, such as interleukin (IL)-1β, tumor necrosis factor α, epidermal growth factor and phorbol esters (13,14). However, the effects of 5-aza C on MMP-9 expression and activity in HT1080 cells have not been completely elucidated.

Therefore, we have studied the effects of 5-aza C on MMP-9 activity, migration and invasion. We demonstrated that 5-aza C enhances migration and invasion of HT1080 cells by activating MMP-9 via phosphoinositide (PI)3-kinase/Akt and extracellular signal-regulated kinase (ERK)1/2 signaling pathways.

Materials and methods

Reagents

5-aza C was purchased from Sigma-Aldrich (St. Louis, MO, USA). PD 98059 (PD) was purchased from Calbiochem (San Diego, CA, USA) and LY 294002 (LY) was purchased from Tocris Bioscience (Bristol, UK).

Cell culture

Human fibrosarcoma HT1080 cells (KCLB no. 10121; Korean Cell Line Bank, Seoul, Korea) were grown in RPMI-1640 medium (Gibco/Invitrogen, Carlsbad, CA, USA) supplemented with 10% fetal bovine serum (FBS; Gibco-Invitrogen), penicillin (50 U/ml; Sigma-Aldrich) and streptomycin (50 μg/ml; Sigma-Aldrich), in a humid atmosphere, 5% CO2 and 95% air at 37°C.

MTT assay

Proliferation of HT1080 cells was determined using colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cells were seeded into 96-well plates (0.5×105 cells/well in 100 μl medium) and cultured for 24 h. After an overnight incubation, the cells were treated with 5-aza C concentration gradient (0, 5, 10, or 20 μM) for 24 h, or with 10 μM 5-aza C for the indicated time periods, and then washed with phosphate-buffered saline (PBS). Thereafter, the medium was replaced by fresh medium (200 μl) containing 0.5 mg/ml MTT, and the mixture was incubated for 4 h at 37°C. Following the incubation, 100 μl solubilization buffer (10% SDS, 0.01 N HCl) was added to each well to terminate the MTT reaction and dissolve formazan crystals. After agitation for 1 h at room temperature, optical density of the solution in each well was measured at 595 nm using a microplate reader (Molecular Devices, Sunnyvale, CA, USA). Proliferation inhibition rate was calculated as: [1-A595 (experimental well)/A595 (control well)] ×s 100%.

Wound-healing assay

HT1080 cell migration was determined by wound-healing assay (15). Briefly, HT1080 cells (5×105/well) were seeded into 35-mm culture dish and after reaching ~90% confluence, a scratch was made in the cells with a 10-μl pipette tip. The remaining cells were washed with medium and incubated with 5-aza C in the absence or presence of inhibitors for 24 h. The migration distance of cells was then captured and the images were quantitatively analyzed using ImageJ software (National Institutes of Health, Bethesda, MD, USA). Distances between scratch edges were measured and statistically analyzed (see below).

Invasion assay

HT1080 invasion was determined with Transwell Matrigel system (16). Cells (1×105 cells/well) were cultured in the top chambers of 24-well Transwell plates (8.0 mm-pore; Corning Costar, Corning, NY, USA) and complete RPMI-1640 medium was added to the bottom chambers. After 24 h, the cells on the surface of the top chamber membrane were removed with a cotton swab. Cells that had migrated to the bottom surface of the top chamber membranes were fixed with 95% methanol, stained with 1 mg/ml crystal violet and hematoxylin solution, and counted (20 random fields) under a microscope (magnification, x200). Each experiment was performed in triplicate and repeated at least twice.

Flow cytometry

Cells (5×105 cells) were grown in 35-mm culture dish to ~80% confluence and starved in serum-free medium at 37°C for 12 h. The cells were then treated with 5-aza C for 24 h and harvested in trypsin-EDTA (0.25%, pH 7.2) buffer. Cells were washed with PBS prior to suspension in cold propidium iodide (PI) solution (50 μg/ml) in PBS (pH 7.4) containing RNase A (0.1 mg/ml) for 30 min in the dark. After incubation, cell apoptosis and cell cycle distribution were analyzed with a flow cytometer (Partec GmbH, Munster, Germany).

Western blot analysis

Preparation of cell lysates and western blot analyses were performed as previously described (17). Briefly, equal amounts of proteins from whole cell lysates (20–30 μg) were resolved by 8–12% SDS-polyacrylamide gel electrophoresis and transferred to a nitrocellulose membrane. The membrane was then incubated in blocking buffer comprising 5% skimmed milk in Tris-buffered saline with Tween-20 (TBST), at room temperature for 1 h. The blocked membrane was next incubated with primary antibodies, at 4°C, overnight. The following primary antibodies were used: rabbit anti-DNMT-1 polyclonal antibody (1:1,000 dilution; Santa Cruz Biotechnology Inc., Santa Cruz, CA, USA; sc-20701); mouse anti-phospho-Akt polyclonal antibody (1:1,000 dilution; Cell Signaling Technology Inc., Danvers, MA, USA; #9271); rabbit anti-Akt polyclonal antibody (1:1,000 dilution; Santa Cruz Biotechnology; #9272); rabbit anti-phospho-p44/42 MAP kinase (pERK1/2) polyclonal antibody (1:1,000 dilution; Cell Signaling Technology; #9101); rabbit anti-ERK-2 poly-clonal antibody (1:1,000 dilution; Santa Cruz Biotechnology; sc-154). The membrane was washed three times (10 min each) with TBST, and then incubated with secondary antibodies, at room temperature, for 2 h. The following secondary antibodies were used: anti-rabbit IgG antibody (1:3,000 dilution; Sigma-Aldrich; A0545); anti-mouse IgG antibody (1:3,000 dilution Enzo Life Sciences, Inc., Farmingdale, NY, USA; ADI-SAB-100). The antigen-antibody complex was detected with an enhanced chemiluminescence detection kit (Dogen, Seoul, Korea). Protein band intensities were quantified by the ImageJ and normalized to internal β-actin control. Normalized values were plotted and are presented.

Zymographic assay of MMP-9 gelatinase activity

MMP-9 gelatinase activity in conditioned media was performed using SDS-PAGE zymography, as previously described (18). Briefly, HT1080 cells were split into 35-mm culture dish. After 24 h, cells were serum-starved in RPMI-1640 medium (Gibco/Invitrogen) for additional 20 h, and then treated with increasing concentrations of 5-aza C (0, 5, 10 and 20 μM) for 24 h. Subsequently, 30 μl conditioned medium was mixed with reducing agent-devoid of 4X SDS sample buffer (62.5 mM Tris, 4% SDS, 25% glycerol, 0.01% bromophenol blue, pH 6.8) and subjected to electrophoresis in 7.5% SDS-PAGE gels containing 1 mg/ml gelatin (Sigma-Aldrich). After electrophoresis, gels were washed twice with 2.5% (v/v) Triton X-100 for 60 min at room temperature to remove SDS and subsequently incubated overnight at 37°C in a developing buffer containing 10 mM CaCl2, 150 mM NaCl, and 50 mM Tris-HCl, pH 8.0, for 24 h. The gels were stained with 0.5% Coomassie brilliant blue R-250 in 10% acetic acid (v/v) and 50% methanol, for ~1 h, and then destained in 50% methanol and 10% acetic acid solution at room temperature to clearly visualize the digested bands. MMP-9 proteolytic activities were visualized as clear bands against blue background of stained gelatin.

Statistical analysis

Data are presented as means ± SEM from three independent experiments and compared using one-way ANOVA. For P<0.05, differences were considered statistically significant and are indicated by an asterisk in the figures.

Results

5-Aza C inhibits the proliferation of HT1080 cells

To evaluate the effect of 5-aza C on cellular proliferation, cells were cultured with increasing 5-aza C concentrations (5, 10 and 20 μM), as described in Materials and methods, and their viability was assessed by MTT assay. 5-Aza C inhibited proliferation of cells in a dose-dependent manner (Fig. 1A). We next performed FACS analysis to investigate the effect of 5-aza C on the cell cycle (Fig. 1B). FACS analysis revealed that 5-aza C induced G2/M phase arrest (Fig. 1B). Only 32.2% untreated control HT1080 cells were in G2/M phase. However, 24 h of treatment with 5, 10 and 20 μM 5-aza C, the proportion of HT1080 cells arrested in the G2/M phase increased to 34.8, 42.9 and 62.8%, respectively (Fig. 1B). These results indicated that 5-aza C inhibits proliferation in a dose-dependent manner (Fig. 1).

5-Aza C induces migration and invasion of HT1080 cells

Metastatic HT1080 cells possess high migration ability and therefore they are suitable for migration and invasion experiments verifying the effects of 5-aza C on tumor metastasis. HT1080 24-h exposure to 5-aza C resulted in significant increase in HT1080 cell migration area and induced the spread of HT1080 cells along wound edges, compared with the untreated control cells (Fig. 2A and B). Next, Matrigel invasion assays were performed with 5-aza C-treated HT1080 cells (Fig. 2C). HT1080 cell invasion capacity was significantly induced by 5-aza C, and the number of invasive cells increased when 5-aza C concentration was increased to 10 μM (Fig. 2C). Approximately 29 and 54% induction in invasion was observed after treatment with 5 and 10 μM 5-aza C, respectively, compared with the control (Fig. 2C). Both HT1080 migration and invasion were unaffected by 20 μM 5-aza C treatment (Fig. 2B and C), most possibly due to a cytotoxic, cell-cycle arresting effect of the compound (Fig. 1B).

5-Aza C induces MMP-9 activity in HT1080 cells

No cytotoxic effect was observed during HT1080 cell treatment with 5-aza C concentrations <10 μM and, therefore, 2–10 μM 5-aza C concentrations were used in subsequent experiments. To elucidate the potential mechanisms underlying the meta-static effects of 5-aza C on HT1080 cells, we assessed MMP-9 expression via zymography analysis. As shown in Fig. 3, 5-aza C treatment significantly induced MMP-9 expression in a dose- and time-dependent manner when compared with the control (Fig. 3). These findings suggested that induction of MMP-9 expression might be involved in the increased migration and invasion of HT1080 cells upon 5-aza C treatment.

PI3-kinase/Akt and ERK1/2 MAPK signaling pathways mediate 5-aza C-associated effects in HT1080 cells

To determine whether the MMP-9 activity and metastatic capacities of HT1080 cells induced by 5-aza C were associated with PI3-kinase and mitogen-activated protein kinase (MAPK) signaling pathways, we examined Akt, ERK1/2, p38 kinase and JNK1/2 phosphorylation. As shown in Fig. 4, 5-aza C caused a significant increase in phosphorylated Akt and ERK1/2 levels (Fig. 4). It also activated the p38 and JNK1/2 signaling pathways (data not shown). 5-aza C-induced MMP-9 activity and HT1080 cell metastatic capacities were significantly attenuated after blocking of ERK1/2 and PI3-kinase/Akt with PD and LY inhibitors, respectively (Fig. 5). In contrast, p38 kinase inhibition by SB203580 and JNK1/2 inhibition by SP600125 exerted no apparent effects (data not shown). Collectively, the data indicated that PI3-kinase/Akt and ERK1/2 may be the major pathways mediating 5-aza C-induced MMP-9 activity and metastatic capacities, migration and invasion, of HT1080 cells.

Discussion

MMPs, a family of zinc-dependent endopeptidases, participate in many physiological and pathological processes (19). Imbalance between MMP inhibition and activation is associated with various diseases, including osteoarthritis, rheumatoid arthritis, tumor metastasis, and cardiovascular disease (1921). Secretion of MMPs by structural and inflammatory cells is thought to take part in the processes of cancer metastasis to distant sites (22,23). MMPs are involved in this metastatic progression by initiating turnover of ECM components and modulating cancer cell migration (24). Previous studies have revealed that MMP-9 expression is the strongest in fibrosarcoma cells and has been implicated in tumor invasion and metastasis.

The cancer epigenome is characterized by global alterations in DNA methylation and histone modifications, as well as altered expression profiles of chromatin-modifying enzymes (25). Alteration of global DNA methylation plays a significant role in tumorigenesis and occurs at a variety of genome sequences, including repetitive elements, retrotransposons, CpG-poor promoters, introns and gene deserts (26).

Various epigenetic drugs have been recently identified that can successfully reverse DNA methylation and histone modification abnormalities that occur in cancer (27). DNA methylation inhibitors, such as 5-aza C and decitabine, promote decrease in DNA methylation, inducing gene expression and differentiation of cultured cells. This facilitates our understanding of the potential use of epigenetic drugs in cancer therapy (28). In addition, DNA methylation inhibitors are in clinical use, as part of anticancer strategy, restoring normal function to abnormally hypermethylated genes (29). In particular, 5-aza C inhibits tumor cell proliferation by demethylating and reactivating genes silenced by methylation in cervical cell lines CaSki, C-33A, HeLa and SiHa (30). In contrast, 5-aza C treatment of acute myeloid leukemia might result in enhanced invasiveness of tumor cells via a mechanism involving MMP-9 (31). Previous studies revealed that 5-aza C increased invasiveness of several pancreatic (32) and acute myeloid leukemia cells (31). Similarly, our results indicated that 5-aza C-associated global DNA hypomethylation was accompanied by an increased invasiveness of HT1080 cells.

Considering the above, it is important to understand epigenetic mechanisms used by cells to regulate MMP expression to modulate their invasive properties. In the present study, we focused on the role of DNA methylation alteration in the modulation of MMP-9 activity in human HT1080 fibrosarcoma cells. We demonstrated the biological properties of 5-aza C by showing that 5-aza C treatment increased migration and invasion of HT1080 cells and induced MMP-9 activity, possibly via PI3-kinase/Akt and ERK1/2 pathway activation. We observed a significant increase of migration with 5-aza C concentrations up to ~10 μM. This effect was abolished in the presence of 20 μM 5-aza C, probably because of the compound’s anti-proliferative effect (Fig. 2).

MAPKs regulate cellular responses, including gene expression, cell proliferation, metabolism and migration (33). Various lines of evidence suggest that MMP-9 expression in corneal epithelial cells (34), osteoblast-like MC3T3-E1 cells (35), tracheal smooth muscle cells (36), and breast epithelial cells (37) is increased via MAPKs, ERK1/2, p38 and JNK1/2 activation. The roles of individual MAPKs in MMP expression vary with cell types and stimuli. For example, activation of p38 kinase might play a crucial role in transforming growth factor β-induced corneal epithelial migration in C57BL/6J mice (38), while ERK1/2 and JNK1/2, rather than p38 kinase, have been associated with the regulation of IL-1β induction of MMP expression in corneal fibroblasts (39). PI3-kinase pathway plays a critical role in a variety of cellular processes by phosphorylating its downstream target Akt. These processes include mitogenic signaling, cytoskeletal remodeling, metabolic control and cell survival (40). In the present study, inhibiting PI3-kinase/Akt activity by LY, or ERK1/2 activity by PD, downregulated not only MMP-9 activity but also HT1080 cell migration (Fig. 5).

Collectively, our data suggest that 5-aza C may play an important role in tumor invasiveness through MMP-9 modulation. The potential adverse effects of 5-aza C treatment on tumors need to be evaluated before future clinical applications in therapy of other solid neoplasms.

Acknowledgements

The present was supported by the National Research Foundation of Korea (NRF) grants funded by the Korea government (MSIP) (nos. 2015R1C1A2A01055015 and 2014R1A1A3049653) and the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (A120960-1201-0000300).

Abbreviations:

MMPs

matrix metalloproteinases

5-aza C

5-azacytidine

ERK

extracellular signal-regulated kinase

PI3- kinase

phosphoinositide 3-kinase

ECM

extracellular matrix

DNMTs

DNA methyltransferases

PD

PD 98059

LY

LY 294002

References

1 

Avgustinova A and Benitah SA: The epigenetics of tumour initiation: Cancer stem cells and their chromatin. Curr Opin Genet Dev. 36:8–15. 2016. View Article : Google Scholar : PubMed/NCBI

2 

Miremadi A, Oestergaard MZ, Pharoah PD and Caldas C: Cancer genetics of epigenetic genes. Hum Mol Genet. 16(R1): R28–R49. 2007. View Article : Google Scholar : PubMed/NCBI

3 

Bird A: DNA methylation patterns and epigenetic memory. Genes Dev. 16:6–21. 2002. View Article : Google Scholar : PubMed/NCBI

4 

Jovanovic J, Rønneberg JA, Tost J and Kristensen V: The epigenetics of breast cancer. Mol Oncol. 4:242–254. 2010. View Article : Google Scholar : PubMed/NCBI

5 

Jones PA and Baylin SB: The fundamental role of epigenetic events in cancer. Nat Rev Genet. 3:415–428. 2002.PubMed/NCBI

6 

Qiu X, Hother C, Ralfkiær UM, Søgaard A, Lu Q, Workman CT, Liang G, Jones PA and Grønbæk K: Equitoxic doses of 5-azacytidine and 5-aza-2′deoxycytidine induce diverse immediate and overlapping heritable changes in the transcriptome. PLoS One. 5:e129942010. View Article : Google Scholar

7 

Snyder RD and Lachmann PJ: Differential effects of 5-azacyti-dine and 5-azadeoxycytidine on cytotoxicity, DNA-strand breaking and repair of X-ray-induced DNA damage in HeLa cells. Mutat Res. 226:185–190. 1989. View Article : Google Scholar : PubMed/NCBI

8 

Liu Z, Lu H, Liu R, Chen B, Wang S, Ma J and Fu J: The dineolignan from Saururus chinensis, manassantin B, inhibits tumor-induced angiogenesis via downregulation of matrix metalloproteinases 9 in human endothelial cells. Oncol Rep. 32:659–667. 2014.PubMed/NCBI

9 

Kumta SM, Huang L, Cheng YY, Chow LT, Lee KM and Zheng MH: Expression of VEGF and MMP-9 in giant cell tumor of bone and other osteolytic lesions. Life Sci. 73:1427–1436. 2003. View Article : Google Scholar : PubMed/NCBI

10 

Sato H and Seiki M: Regulatory mechanism of 92 kDa type IV collagenase gene expression which is associated with invasiveness of tumor cells. Oncogene. 8:395–405. 1993.PubMed/NCBI

11 

Iyer V, Pumiglia K and DiPersio CM: Alpha3beta1 integrin regulates MMP-9 mRNA stability in immortalized keratinocytes: A novel mechanism of integrin-mediated MMP gene expression. J Cell Sci. 118:1185–1195. 2005. View Article : Google Scholar : PubMed/NCBI

12 

Ramos-DeSimone N, Hahn-Dantona E, Sipley J, Nagase H, French DL and Quigley JP: Activation of matrix metalloproteinase-9 (MMP-9) via a converging plasmin/stromelysin-1 cascade enhances tumor cell invasion. J Biol Chem. 274:13066–13076. 1999. View Article : Google Scholar : PubMed/NCBI

13 

Watanabe H, Nakanishi I, Yamashita K, Hayakawa T and Okada Y: Matrix metalloproteinase-9 (92 kDa gelatinase/type IV collagenase) from U937 monoblastoid cells: Correlation with cellular invasion. J Cell Sci. 104:991–999. 1993.PubMed/NCBI

14 

Lyons JG, Birkedal-Hansen B, Pierson MC, Whitelock JM and Birkedal-Hansen H: Interleukin-1 beta and transforming growth factor-alpha/epidermal growth factor induce expression of M(r) 95,000 type IV collagenase/gelatinase and interstitial fibroblast-type collagenase by rat mucosal keratinocytes. J Biol Chem. 268:19143–19151. 1993.PubMed/NCBI

15 

Ito M, Hagiyama M, Mimae T, Inoue T, Kato T, Yoneshige A, Nakanishi J, Kondo T, Okada M and Ito A: α-Parvin, a pseudopodial constituent, promotes cell motility and is associated with lymph node metastasis of lobular breast carcinoma. Breast Cancer Res Treat. 144:59–69. 2014. View Article : Google Scholar : PubMed/NCBI

16 

Wang D, Lu P, Zhang H, Luo M, Zhang X, Wei X, Gao J, Zhao Z and Liu C: Oct-4 and Nanog promote the epithelial-mesenchymal transition of breast cancer stem cells and are associated with poor prognosis in breast cancer patients. Oncotarget. 5:10803–10815. 2014. View Article : Google Scholar : PubMed/NCBI

17 

Yu SM and Kim SJ: Production of reactive oxygen species by withaferin A causes loss of type collagen expression and COX-2 expression through the PI3K/Akt, p38, and JNK pathways in rabbit articular chondrocytes. Exp Cell Res. 319:2822–2834. 2013. View Article : Google Scholar : PubMed/NCBI

18 

Yu SM and Kim SJ: DNA-hypomethylating agent, 5′-azacytidine, induces cyclooxygenase-2 expression via the PI3-kinase/Akt and extracellular signal-regulated kinase-1/2 pathways in human HT1080 fibrosarcoma cells. Int J Oncol. 47:1469–1475. 2015.PubMed/NCBI

19 

Yoshihara Y, Nakamura H, Obata K, Yamada H, Hayakawa T, Fujikawa K and Okada Y: Matrix metalloproteinases and tissue inhibitors of metalloproteinases in synovial fluids from patients with rheumatoid arthritis or osteoarthritis. Ann Rheum Dis. 59:455–461. 2000. View Article : Google Scholar : PubMed/NCBI

20 

Spinale FG, Coker ML, Krombach SR, Mukherjee R, Hallak H, Houck WV, Clair MJ, Kribbs SB, Johnson LL, Peterson JT, et al: Matrix metalloproteinase inhibition during the development of congestive heart failure: Effects on left ventricular dimensions and function. Circ Res. 85:364–376. 1999. View Article : Google Scholar : PubMed/NCBI

21 

Stricklin GP and Welgus HG: Human skin fibroblast collagenase inhibitor. Purification and biochemical characterization. J Biol Chem. 258:12252–12258. 1983.PubMed/NCBI

22 

Gueders MM, Foidart JM, Noel A and Cataldo DD: Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs in the respiratory tract: Potential implications in asthma and other lung diseases. Eur J Pharmacol. 533:133–144. 2006. View Article : Google Scholar : PubMed/NCBI

23 

Offersen BV, Pfeiffer P, Andreasen P and Overgaard J: Urokinase plasminogen activator and plasminogen activator inhibitor type-1 in non small-cell lung cancer: Relation to prognosis and angiogenesis. Lung Cancer. 56:43–50. 2007. View Article : Google Scholar : PubMed/NCBI

24 

Kessenbrock K, Plaks V and Werb Z: Matrix metalloproteinases: Regulators of the tumor microenvironment. Cell. 141:52–67. 2010. View Article : Google Scholar : PubMed/NCBI

25 

Zhang Z and Zhang R: Epigenetics in autoimmune diseases: Pathogenesis and prospects for therapy. Autoimmun Rev. 14:854–863. 2015. View Article : Google Scholar : PubMed/NCBI

26 

Rodriguez J, Frigola J, Vendrell E, Risques RA, Fraga MF, Morales C, Moreno V, Esteller M, Capellà G, Ribas M, et al: Chromosomal instability correlates with genome-wide DNA demethylation in human primary colorectal cancers. Cancer Res. 66:8462–9468. 2006. View Article : Google Scholar : PubMed/NCBI

27 

Yoo CB and Jones PA: Epigenetic therapy of cancer: Past, present and future. Nat Rev Drug Discov. 5:37–50. 2006. View Article : Google Scholar : PubMed/NCBI

28 

Constantinides PG, Jones PA and Gevers W: Functional striated muscle cells from non-myoblast precursors following 5-azacytidine treatment. Nature. 267:364–366. 1977. View Article : Google Scholar : PubMed/NCBI

29 

Alexander VM, Roy M, Steffens KA, Kunnimalaiyaan M and Chen H: Azacytidine induces cell cycle arrest and suppression of neuroendocrine markers in carcinoids. Int J Clin Exp Med. 3:95–102. 2010.PubMed/NCBI

30 

Wu Y, Meng L, Wang H, Xu Q, Wang S, Wu S, Xi L, Zhao Y, Zhou J, Xu G, et al: Regulation of DNA methylation on the expression of the FHIT gene contributes to cervical carcinoma cell tumorigenesis. Oncol Rep. 16:625–629. 2006.PubMed/NCBI

31 

Bernal T, Moncada-Pazos A, Soria-Valles C and Gutiérrez-Fernández A: Effects of azacitidine on matrix metalloproteinase-9 in acute myeloid leukemia and myelodysplasia. Exp Hematol. 41:172–179. 2013. View Article : Google Scholar

32 

Sato N, Maehara N, Su GH and Goggins M: Effects of 5-aza-2′-deoxycytidine on matrix metalloproteinase expression and pancreatic cancer cell invasiveness. J Natl Cancer Inst. 95:327–330. 2003. View Article : Google Scholar : PubMed/NCBI

33 

Johnson GL and Lapadat R: Mitogen-activated protein kinase pathways mediated by ERK, JNK, and p38 protein kinases. Science. 298:1911–1912. 2002. View Article : Google Scholar : PubMed/NCBI

34 

Kim HS, Luo L, Pflugfelder SC and Li DQ: Doxycycline inhibits TGF-beta1-induced MMP-9 via Smad and MAPK pathways in human corneal epithelial cells. Invest Ophthalmol Vis Sci. 46:840–848. 2005. View Article : Google Scholar : PubMed/NCBI

35 

Chia-Lan T, Chen WC, Hsieh HL, Chi PL, Hsiao LD and Yang CM: Erratum to: TNF-alpha induces MMP-9 expression and soluble ICAM-1 release via TRAF2, c-src, MAPKs and NF-kappaB in osteoblast-like MC3T3-E1 cells. J Biomed Sci. 22:202015. View Article : Google Scholar

36 

Liang KC, Lee CW, Lin WN, Lin CC, Wu CB, Luo SF and Yang CM: Interleukin-1beta induces MMP-9 expression via p42/p44 MAPK, p38 MAPK, JNK, and nuclear factor-kappaB signaling pathways in human tracheal smooth muscle cells. J Cell Physiol. 211:759–770. 2007. View Article : Google Scholar : PubMed/NCBI

37 

Reddy KB, Krueger JS, Kondapaka SB and Diglio CA: Mitogen-activated protein kinase (MAPK) regulates the expression of progelatinase B (MMP-9) in breast epithelial cells. Int J Cancer. 82:268–273. 1999. View Article : Google Scholar : PubMed/NCBI

38 

Saika S, Okada Y, Miyamoto T, Yamanaka O, Ohnishi Y, Ooshima A, Liu CY, Weng D and Kao WW: Role of p38 MAP kinase in regulation of cell migration and proliferation in healing corneal epithelium. Invest Ophthalmol Vis Sci. 45:100–109. 2004. View Article : Google Scholar

39 

Lu Y, Fukuda K, Liu Y, Kumagai N and Nishida T: Dexamethasone inhibition of IL-1-induced collagen degradation by corneal fibro-blasts in three-dimensional culture. Invest Ophthalmol Vis Sci. 45:2998–3004. 2004. View Article : Google Scholar : PubMed/NCBI

40 

Wymann MP and Pirola L: Structure and function of phosphoinositide 3-kinases. Biochim Biophys Acta. 1436:127–150. 1998. View Article : Google Scholar : PubMed/NCBI

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APA
Yu, S., & Yu, S. (2016). 5-Azacytidine regulates matrix metalloproteinase-9 expression, and the migration and invasion of human fibrosarcoma HT1080 cells via PI3-kinase and ERK1/2 pathways. International Journal of Oncology, 49, 1241-1247. https://doi.org/10.3892/ijo.2016.3612
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Yu, S., Kim, S. J."5-Azacytidine regulates matrix metalloproteinase-9 expression, and the migration and invasion of human fibrosarcoma HT1080 cells via PI3-kinase and ERK1/2 pathways". International Journal of Oncology 49.3 (2016): 1241-1247.
Chicago
Yu, S., Kim, S. J."5-Azacytidine regulates matrix metalloproteinase-9 expression, and the migration and invasion of human fibrosarcoma HT1080 cells via PI3-kinase and ERK1/2 pathways". International Journal of Oncology 49, no. 3 (2016): 1241-1247. https://doi.org/10.3892/ijo.2016.3612