Downregulation of ERK signaling impairs U2OS osteosarcoma cell migration in collagen matrix by suppressing MMP9 production

POUDEL, BARUN,KIM, DO-KUK,KI, HYEON-HUI,KWON, YOUNG-BAE,LEE, YOUNG-MI,KIM, DAE-KI D.A. Spandidos 2014 Oncology letters Vol.7 No.1

<P>The present study investigated the role of extracellular signal-regulated kinase (ERK) activation in the migratory phenotype of human U2OS osteosarcoma (OS) cells in a collagen matrix. The activation of ERK was inhibited by PD98059, a specific inhibitor of ERK kinase. Additionally, no significant differences were observed in the adhesion and proliferation of the cells with or without PD98059 treatment in collagen-coated dishes. The migratory capacity of the U2OS cells was then examined in non-coated and collagen-coated dishes, and the results depicted that collagen I enhanced the migration of the U2OS cells, the effect of which was significantly blocked by the treatment of the cells with PD98059. Furthermore, enhanced gene and protein expression of matrix metalloproteinase 9 (MMP9), but not MMP2, was observed to be involved in the enhanced migratory phenotype of the U20S cells in the collagen-coated plates. This effect was partially abolished by the treatment of the cells in the collagen-coated dishes with ERK inhibitor. Collectively, the data demonstrate that ERK signaling is important for the migration of U2OS cells through the extracellular matrix (ECM), which is comprised mostly of collagen, by enhancing MMP9 production. These results may contribute to the regulation of MMP9 production in metastatic OS.</P>

Collagen I-induced dendritic cells activation is regulated by TNF-alpha production through down-regulation of IRF4.

Poudel, Barun,Ki, Hyeon-Hui,Lee, Young-Mi,Kim, Dae-Ki Indian Academy of Sciences 2015 Journal of biosciences Vol.40 No.1

<P>Previously we have shown that collagen I enhances the maturation and function of dendritic cells (DCs). Inflammatory mediators such as tumour necrosis factor (TNF)- alpha, interleukin (IL)-1 beta and lipopolysaccharide (LPS) are also known to activate DCs. Here we investigated the involvement of TNF-alpha on the collagen I-induced DCs activation. TNF-a neutralization inhibited collagen I-induced IL-12 secretions by DCs. Additionally, we observed suppression of collagen I-induced costimulatory molecules expression along with down-regulation of genes involved in DCs activation pathway. Furthermore, TNF- alpha inhibition upon collagen Istimulation up-regulated the expression of interferon regulatory transcription factor IRF4, when compared to collagen I only treated cells. Collectively, our data demonstrate that collagen I induce TNF- alpha production, which is crucial for the activation and function of DCs, through down-regulation of IRF4, and implicates the importance in development of anti- TNF-alpha therapeutics for several inflammatory diseases.</P>

DDR2 inhibition reduces migration and invasion of murine metastatic melanoma cells by suppressing MMP2/9 expression through ERK/NF-κB pathway

Poudel, Barun,Lee, Young-Mi,Kim, Dae-Ki Oxford University Press 2015 Acta biochimica et biophysica Sinica Vol.47 No.4

<P>Metastatic melanoma is one of the most deadly and evasive cancers. Collagen I in the extracellular matrix promotes the migration and invasion of tumor cells through the production of matrix metalloproteinase (MMP) 2 and 9. Discoidin domain receptor (DDR) 2 is a collagen receptor that is implicated in several cancer types including breast and prostate cancers. However, the role of DDR2 in the migration and invasion of murine melanoma cells is less studied. In the present study, we investigated the effects and underlying mechanisms of DDR2 in migration and invasion of B16BL6 melanoma cells in response to collagen I. Results demonstrated that DDR2 is expressed and is phosphorylated by collagen I in the cells. Upon down-regulation of DDR2 using small-interfering RNA (siRNA) approach, both of the cell migratory and invasive phenotypes were significantly attenuated when compared with the control cells. This effect was mediated via suppression of MMP2/9 upon DDR2 inhibition. Furthermore, inhibition of DDR2 by specific siRNA markedly reduced the activation of extracellular regulated kinase (ERK) 1 and 2 and nuclear factor of kappa B (NF-κB) in the cells when compared with the control cells. Overall, these data demonstrated that DDR2 siRNA-mediated suppression of ERK1/2 and NF-κB could down-regulate the expressions of MMP2/9 in response to collagen I to reduce the migratory and invasive phenotypes of the cells.</P>

Triticumoside induces apoptosis via caspase-dependent mitochondrial pathway and inhibits migration through downregulation of MMP2/9 in human lung cancer cells

Poudel, Barun,Ki, Hyeon-Hui,Luyen, Bui Thi Thuy,Lee, Young-Mi,Kim, Young-Ho,Kim, Dae-Ki Oxford University Press 2016 Acta biochimica et biophysica Sinica Vol.48 No.2

<P>Non-small cell lung cancer (NSCLC) is the major cancer-related death worldwide with only 14% five-year survival rate. Triticumoside, a phenolic compound present in Triticum aestivum sprout extract, has been recognized to have antiobesity and anti-inflammatory effects. However, the effect of triticumoside on cancer cell proliferation and migration has not been studied. In order to elucidate whether triticumoside exhibits an anticancer effect, cells were incubated with different doses of triticumoside, and apoptosis was assessed by observing cell viability, cellular morphological changes, and annexin-V-fluorescein isothiocyanate/propidium iodide staining. Cell cycle analysis, western blotting, wound healing assay, and quantitative-polymerase chain reaction were also performed. Triticumoside exhibited marked cytotoxicity in the cells in dose-and time-dependent manner. Triticumoside caused morphological changes, including cellular rounding, nuclear condensation, and shrinkage. Likewise, triticumoside enhanced the sub-G1 proportion of cells. Additionally, triticumoside regulated expression of apoptosis-associated proteins, such as B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X, and procaspase-3/9. Triticumoside also inhibited migration of the cells through downregulation of matrix metalloproteinase-2/9 (MMP2/9). Collectively, these results suggest that triticumoside induces apoptosis through caspase-dependent mitochondrial pathway and suppresses migration via inhibition of MMP2/9 in NSCLC A549 cells.</P>

Flavonoids from Triticum aestivum inhibit adipogenesis in 3T3-L1 cells by upregulating the insig pathway

POUDEL, BARUN,NEPALI, SARMILA,XIN, MINGJIE,KI, HYEON-HUI,KIM, YOUNG-HO,KIM, DAE-KI,LEE, YOUNG-MI SPANDIDOS PUBLICATIONS 2015 MOLECULAR MEDICINE REPORTS Vol.12 No.2

<P>The present study aimed to compare the potential anti-adipogenic effects and underlying mechanisms of the luteolin, isoscoparin and isoorientin flavonoids, purified from Triticum aestivum sprout (TA) in 3T3-L1 cells. The cells were treated with different concentrations of flavonoids for 8 days and the lipid accumulation was assessed using Oil-Red-O staining. The expression levels of the transcription factors and the genes involved in adipogenesis in the cells were assessed by reverse transcription-quantitative polymerase chain reaction and western blotting. The results demonstrated that 10 μM luteolin, isoscoparin or isoorientin inhibited lipid deposition in the cells by 74, 63 and 65%, respectively. The flavonoids also significantly inhibited the transcriptional regulators of adipogenesis, including peroxisome proliferator-activated receptor-γ, CAAT/enhancer binding protein-α and sterol regulatory element binding protein (SREBP)-1c, compared with the control cells. Similarly, there was a significant downregulation of the adipocyte specific markers associated with lipid metabolism, including activating protein-2, fatty acid synthase, hormone-sensitive lipase and lipoprotein lipase, in the flavonoid treated cells. Notably, the cells treated with the flavonoids demonstrated increased expression levels of the insulin-induced genes, insig-1 and insig-2, which may have inhibited the activation of the adipogenic transcription factor, SREBP, eventually leading to the inhibition of adipogenesis. Taken together, these results revealed that the flavonoids from TA possessed an inhibitory effect on adipogenesis through downregulation of adipogenic transcription factors and genes associated with lipid metabolism, and the upregulation of insig 1 and 2, suggesting that the flavonoids from TA may be potential therapeutic agents for the prevention and treatment of obesity.</P>

Tools to Detect Influenza Virus

김대기,Barun Poudel 연세대학교의과대학 2013 Yonsei medical journal Vol.54 No.3

In 2009, pandemic influenza A (H1N1) virus (H1N1 09) started to spread quickly in many countries. It causes respiratory infection with signs and symptoms of common infectious agents. Thus, clinicians sometimes may miss the H1N1 patient. Clinical laboratory tests are important for the diagnosis of the H1N1 infection. There are several tests available, however, the rapid test and direct fluorescence antigen test are unable to rule out the influenza virus infection and viral culture test is time consuming. Therefore, nucleic acid amplification techniques based on reverse transcription polymerase chain reaction assays are regarded as a specific diagnosis to confirm the influenza virus infection. Although the nucleic acid-based techniques are highly sensitive and specific, the high mutation rate of the influenza RNA-dependent RNA polymerase could limit the utility of the techniques. In addition, their use depends on the availability, cost and throughput of the diagnostic techniques. To overcome these drawbacks, evaluation and development of the techniques should be continued. This review provides an overview of various techniques for specific diagnosis of influenza infection.

<i>In vitro</i> and <i>in vivo</i> anti-cancer activity of dichloromethane fraction of <i>Triticum aestivum</i> sprouts

Ki, Hyeon-Hui,Poudel, Barun,Lee, Ji-Hyun,Lee, Young-Mi,Kim, Dae-Ki Elsevier 2017 BIOMEDICINE AND PHARMACOTHERAPY Vol.96 No.-

<P><B>Abstract</B></P> <P> <I>Triticum aestivum</I> sprouts (TA) contain significant amounts of chlorophyll, minerals, enzymes, and other functional entities. Furthermore, TA extracts have been shown to possess anti-obesity, anti-diabetic and hepatoprotective effects and are believed to help blood flow, digestion, and general detoxification of the body. In this study, the mechanism underlying the anti-cancer effects of a dichloromethane fraction of TA (TDF) was investigated <I>in vitro</I> and <I>in vivo</I>. <I>In vitro</I> study was done by examining cancer cells growth, morphological changes, cell cycles, expressions of death receptors and apoptosis-linked proteins in wide range of human cancer cell lines. To investigate the effect of TDF <I>in vivo</I>, C57BL/6 mice were injected with B16 melanoma cells and orally administered TDF. TDF markedly inhibited cancer cell growth and induced cellular morphological alterations, cell cycle arrest and apoptosis, and enhanced the expressions of death receptors (DR)-4, 5, and 6 in cell lines. In addition, TDF regulated the expressions mitochondrial apoptosis-linked proteins and induced caspase-dependent cell death. It also significantly enhanced phosphorylation of ERK1/2 and JNK, but not p38, whereas inhibited the activation of NF-κB in cancer cells. In our mouse model, TDF significantly suppressed B16 melanoma growth, to an extent similar to cisplatin (reference control) and augmented immunomodulatory cytokines. In brief, this study presents the mechanism responsible for the anti-cancer effects of TDF <I>in vitro</I> and <I>in vivo</I>.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>