• Title/Summary/Keyword: Cdc42

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Knockdown of Pyruvate Kinase M Inhibits Cell Growth and Migration by Reducing NF-κB Activity in Triple-Negative Breast Cancer Cells

  • Ma, Chaobing;Zu, Xueyin;Liu, Kangdong;Bode, Ann M.;Dong, Zigang;Liu, Zhenzhen;Kim, Dong Joon
    • Molecules and Cells
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    • v.42 no.9
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    • pp.628-636
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    • 2019
  • Altered genetic features in cancer cells lead to a high rate of aerobic glycolysis and metabolic reprogramming that is essential for increased cancer cell viability and rapid proliferation. Pyruvate kinase muscle (PKM) is a rate-limiting enzyme in the final step of glycolysis. Herein, we report that PKM is a potential therapeutic target in triple-negative breast cancer (TNBC) cells. We found that PKM1 or PKM2 is highly expressed in TNBC tissues or cells. Knockdown of PKM significantly suppressed cell proliferation and migration, and strongly reduced S phase and induced G2 phase cell cycle arrest by reducing phosphorylation of the CDC2 protein in TNBC cells. Additionally, knockdown of PKM significantly suppressed $NF-{\kappa}B$ (nuclear factor kappa-light-chain-enhancer of activated B cells) activity by reducing the phosphorylation of p65 at serine 536, and also decreased the expression of $NF-{\kappa}B$ target genes. Taken together, PKM is a potential target that may have therapeutic implications for TNBC cells.

A convergence study on handwashing awareness and practices among middle school students (일개 중학교 학생들의 손씻기 인식 및 실천에 관한 융합적 연구)

  • Kapali, Mariyum;Jung, In-Sook
    • Journal of Convergence for Information Technology
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    • v.8 no.2
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    • pp.51-60
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    • 2018
  • This descriptive research aimed to get the effects of handwashing awareness and practices among 294 students in J middle school, using revised tool developed by Korean CDC(2005). As a result of analyzing data using SPSS/Win 23.0, 42.9% of the subjects experienced common cold within the last 6 months, the scores of handwashing awareness was 3.47 out of 4, and the scores of handwashing practices at home and school was 3.36 and 3.35 each. 39.1% wash hands for 4~6times a day, average handwashing time was 11~15 seconds and 47.0% of the subjects who did not wash their hands due to not having a habit of handwashing. The explanation rate of handwashing awareness on practice was 23.2%, handwashing awareness had a significant effect on practices(p=.001). This study suggests the necessity of strengthening handwashing practices by educating handwashing awareness in order to prevent infectious diseases.

MicroRNA-27a Inhibits Cell Migration and Invasion of Fibroblast-Like Synoviocytes by Targeting Follistatin-Like Protein 1 in Rheumatoid Arthritis

  • Shi, Dong-liang;Shi, Gui-rong;Xie, Jing;Du, Xu-zhao;Yang, Hao
    • Molecules and Cells
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    • v.39 no.8
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    • pp.611-618
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    • 2016
  • Fibroblast-like synoviocytes (FLS) with aberrant expression of microRNA (miRNA) are critical pathogenic regulators in rheumatoid arthritis (RA). Previous studies have found that overexpression or silencing of miRNA can contribute to the development of miRNA-based therapeutics in arthritis models. In this study, we explored the effects of miR-27a on cell migration and invasion in cultured FLS from RA patients. We found that miR-27a was markedly downregulated in the serum, synovial tissue, and FLS of RA patients. Meanwhile, the expression of follistatin-like protein 1 (FSTL1) was upregulated, which suggests that FSTL1 plays a key role in RA development. The results of a Transwell assay showed that miR-27a inhibited FLS migration and invasion. However, miR-27a inhibition promoted the migration and invasion of FLS. In addition, the down-regulated expression of matrix metalloproteinases (MMP2, MMP9, and MMP13) and Rho family proteins (Rac1, Cdc42, and RhoA) was detected after treatment with miR-27a in RA-FLS by quantitative reverse transcription-PCR and western blot analysis. Then, a luciferase reporter assay validated that miR-27a targeted the 3-untranslated region (3'-UTR) of FSTL1. Moreover, miR-27a caused a significant decrease of FSTL1. In addition, the expression of TLR4 and $NF{\kappa}B$ was inhibited by miR-27a but increased by FSTL1 overexpression. In conclusion, we found that miR-27a inhibited cell migration and invasion of RA-FLS by targeting FSTL1 and restraining the $TLR4/NF{\kappa}B$ pathway.

Multiple Effects of a Novel Epothilone Analog on Cellular Processes and Signaling Pathways Regulated by Rac1 GTPase in the Human Breast Cancer Cells

  • Zhang, Hong;An, Fan;Tang, Li;Qiu, Rongguo
    • The Korean Journal of Physiology and Pharmacology
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    • v.18 no.2
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    • pp.109-120
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    • 2014
  • The epothilones are a class of microtubule inhibitors that exhibit a strong antitumor activity. UTD2 is a novel epothilone analog generated by genetic manipulation of the polyketide biosynthetic gene cluster. This study investigated the effects of UTD2 on the actin cytoskeleton and its critical regulators, and the signaling pathways which are essential for cell motility, growth and survival in MCF-7 breast cancer cells. Results showed that UTD2 inhibited the cellular functions of actin cytoskeleton, such as wound-closure, migration and invasion, as well as adhesion. Our study further demonstrated that UTD2 suppressed Rac1 GTPase activation and reduced the activity of PAK1, which is a downstream effector of Rac1, while the activity of Cdc42 was not affected. Additionally, the phosphorylation of p38 and ERK were significantly inhibited, but the phosphorylation of JNK remained the same after UTD2 treatment. Moreover, UTD2 inhibited the activity and mRNA expression of MMP-2, which plays a key role in cell motility. UTD2 also reduced the phosphorylation of Akt, which is an important signaling kinase regulating the cell survival through Rac1. Furthermore, UTD2 interrupted the synergy between Rac1 and Raf in focus formation assays. Taken together, these results indicated that UTD2 exerted multiple effects on the actin cytoskeleton and signaling pathways associated with Rac1. This study provided novel insights into the molecular mechanism of the antineoplastic and antimetastatic activities of epothilones. Our findings also suggest that the signaling pathways regulated by Rac1 may be evaluated as biomarkers for the response to therapy in clinical trials of epothilones.

5-Hydroxytryptamine 6 Receptor (5-HT6R)-Mediated Morphological Changes via RhoA-Dependent Pathways

  • Rahman, Md. Ataur;Kim, Hanna;Lee, Kang Ho;Yun, Hyung-Mun;Hong, Jung-Hwa;Kim, Youngjae;Choo, Hyunah;Park, Mikyoung;Rhim, Hyewhon
    • Molecules and Cells
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    • v.40 no.7
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    • pp.495-502
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    • 2017
  • The $5-HT_6R$ has been considered as an attractive therapeutic target in the brain due to its exclusive expression in the brain. However, the mechanistic linkage between $5-HT_6Rs$ and brain functions remains poorly understood. Here, we examined the effects of $5-HT_6R$-mediated cell morphological changes using immunocytochemistry, Western blot, and live-cell imaging assays. Our results showed that the activation of $5-HT_6Rs$ caused morphological changes and increased cell surface area in HEK293 cells expressing $5-HT_6Rs$. Treatment with 5-HT specifically increased RhoA-GTP activity without affecting other Rho family proteins, such as Rac1 and Cdc42. Furthermore, live-cell imaging in hippocampal neurons revealed that activation of $5-HT_6Rs$ using a selective agonist, ST1936, increased the density and size of dendritic protrusions along with the activation of RhoA-GTP activity and that both effects were blocked by pretreatment with a selective $5-HT_6R$ antagonist, SB258585. Taken together, our results show that $5-HT_6R$ plays an important role in the regulation of cell morphology via a RhoA-dependent pathway in mammalian cell lines and primary neurons.

Relationship of the Signal Transduction-mediated Proteins and Enzymes to Contractility and Plasticity in Skeletal Muscles (골격근의 수축과 가소성에 대한 신호전달-매개 단백질 및 관련 효소의 상관성)

  • Kim, Jung-Hwan
    • The Journal of Korean Physical Therapy
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    • v.19 no.4
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    • pp.1-14
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    • 2007
  • Background: It is generally accepted that skeletal muscle contraction is triggered by nerve impulse and intracellular $Ca^{2+}\;([Ca^{2+}]_i)$ released from intracellular $Ca^{2+}$ stores such as sarcoplasmic reticulum (SR). Specifically, this process, called excitation-contraction (E-C) coupling, takes place at intracellular junctions between the plasma membrane, the transverse (T) tubule L-type $Ca^{2+}$ channel (dihydropyridine-sensitive L-rype $Ca^{2+}$ channel, DHPR, also called tetrads), and the SR $Ca^{2+}$ release channel (ryanodine-sensitive $Ca^{2+}$ release channel, RyR, also called feet) of internal $Ca^{2+}$ stores in skeletal muscle cells. Furthermore, it has been reported that the $Ca^{2+-}$ dependent and -independent contraction determine the expression of skeletal muscle genes, thus providing a mechanism for tightly coupling the extent of muscle contraction to regulation of muscle plasticity-related excitation-transcription (E-T) coupling. Purpose: Expression and activity of plasticity-associated enzymes in gastrocnemius muscle strips have not been well studied, however. Methods: Therefore, in this study the expression and phosphorylation of E-C and E-T coupling-related mediators such as protein kinases, ROS(reactive oxygen species)- and apoptosis-related substances, and others in gastrocnemius muscles from rats was examined. Results: I found that expression and activity of MAPKs (mitogen-activated protein kinases, ERK1/2, p38MAPK, and SAPK/JNK), apoptotic proteins (cleaved caspase-3, cytochrome c, Ref-1, Bad), small GTP-binding proteins (RhoA and Cdc42), actin-binding protein (cofilin), PKC (protein kinase C) and $Ca^{2+}$ channel (transient receptor potential channel 6, TRPC6) was observed in rat gastrocnemius muscle strips. Conclusion: These results suggest that MAPKs, ROS- and apoptosis-related enzymes, cytoskeleton-regulated proteins, and $Ca^{2+}$ channel may in part functionally import in E-C and E-T coupling from rat skeletal muscles.

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Activation of Small GTPases RhoA and Rac1 Is Required for Avian Reovirus p10-induced Syncytium Formation

  • Liu, Hung-Jen;Lin, Ping-Yuan;Wang, Ling-Rung;Hsu, Hsue-Yin;Liao, Ming-Huei;Shih, Wen-Ling
    • Molecules and Cells
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    • v.26 no.4
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    • pp.396-403
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    • 2008
  • The first ORF of the ARV S1133 S1 segment encodes the nonstructural protein p10, which is responsible for the induction of cell syncytium formation. However, p10-dependent signaling during syncytium formation is fully unknown. Here, we show that dominant negative RhoA, Rho inhibitor C3 exoenzyme, ROCK/Rho-kinase inhibitor Y-27632 and Rac1 inhibitor NSC23766 inhibit p10-mediated cell fusion. p10 over-expression is concomitant with activation and membrane translocation of RhoA and Rac1, but not cdc42. RhoA and Rac1 downstream events, including JNK phosphorylation and transcription factor AP-1 and $NF-{\kappa}B$ activation, as well as MLC expression and phosphorylation are simultaneously activated by p10. p10 point mutant T13M possessed 20% fusion-inducing ability and four p10 fusion-deficient mutants V15M, V19M, C21S and L32A reduced or lost their ability to activate RhoA and Rac1 signaling. We conclude that p10-mediated syncytium formation proceeds by utilizing RhoA and Rac1-dependent signaling.

Ginsenoside Rg3 reduces the adhesion, invasion, and intracellular survival of Salmonella enterica serovar Typhimurium

  • Mechesso, Abraham F.;Quah, Yixian;Park, Seung-Chun
    • Journal of Ginseng Research
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    • v.45 no.1
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    • pp.75-85
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    • 2021
  • Background: Invasive infections due to foodborne pathogens, including Salmonella enterica serovar Typhimurium, are prevalent and life-threatening. This study aimed to evaluate the effects of ginsenoside Rg3 (Rg3) on the adhesion, invasion, and intracellular survival of S. Typhimurium. Methods: The impacts of Rg3 on bacterial growth and host cell viability were determined using the time kill and the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays, respectively. Gentamicin assay and confocal microscopic examination were undertaken to determine the effects of Rg3 on the adhesive and invasive abilities of S. Typhimurium to Caco-2 and RAW 264.7 cells. Quantitative reverse transcription polymerase chain reaction was performed to assess the expression of genes correlated with the adhesion, invasion, and virulence of S. Typhimurium. Results: Subinhibitory concentrations of Rg3 significantly reduced (p < 0.05) the adhesion, invasion, and intracellular survival of S. Typhimurium. Rg3 considerably reduced (p < 0.05) the bacterial motility as well as the release of nitrite from infected macrophages in a concentration-dependent manner. The expression of genes related to the adhesion, invasion, quorum sensing, and virulence of S. Typhimurium including cheY, hilA, OmpD, PrgK, rsgE, SdiA, and SipB was significantly reduced after Rg3 treatment. Besides, the compound downregulated rac-1 and Cdc-42 that are essential for actin remodeling and membrane ruffling, thereby facilitating Salmonella entry into host cells. This report is the first to describe the effects of Rg3 on "trigger" entry mechanism and intracellular survival S. Typhimurium. Conclusion: Rg3 could be considered as a supplement agent to prevent S. Typhimurium infection.

Effect of Banhahoobak-tang (Banxiahoupo-tang) Extract (BHTe) on Psychological Stress (반하후박탕(半夏厚朴湯)이 생쥐의 심리적 스트레스에 미치는 영향과 유전자 분석)

  • Choi, Geum-Ae;Cho, Su-In;Kim, Kyeong-Su;Choi, Chang-Won;Wei, Tung-Shuen;Yang, Seung-Joung;Park, Soo-Yeon;Kim, Kyeong-Ok
    • Journal of Oriental Neuropsychiatry
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    • v.26 no.2
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    • pp.117-130
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    • 2015
  • Objectives: Banhahoobak-tang has been used to treat plum-pit qi, chest and hypochondriac distension, moist or greasy tongue coat, and wiry slow or wiry slippery pulse. It might be used to control coughing and vomiting. We observed that Banhahoobak-tang extract (BHTe) had anti-psychological stress effect. The objective of this study was to determine the effect of BHTe on restoring the transcriptional regulation of genes related to psychological stress. Methods: After giving psychological stress to mice, BHTe was orally administered at 100 mg/kg/day for five days. After extracting whole brain tissue from the mice, the gene expression changes were determined by microarray. Transcription factor binding site (TFBS) analysis showed up- and down-regulated genes related to psychological stress were protected by BHTe and segregated according to the structure of TFBS. We performed text based Pubmed search to select significant target genes involved in psychological stress affected by BHTe. Results: 1. Serum corticosterone level was decreased in the BHTe administered group, although the psychological stress was increased. 2. The BHTe administered group had no significant change in noradrenaline content in brain tissue, but the psychological stress group had decreased level. 3. The BHTe administered group had increased time of staying at open-arm than the psychological stress group. 4. Microarray revealed that TANK and RARA genes were up-regulated genes while AES, CDC42, FOS, NCL, and PVR were down-regulated genes by psychological stress but restored by BHTe.

The effects of drinking motives, refusal self-efficacy, and outcome expectancy on high risk drinking (남자대학생의 음주 동기, 음주거절효능감, 음주결과기대가 고위험음주에 미치는 영향)

  • Lee, Eun Kyung;Park, Jin-Hwa
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.4
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    • pp.1047-1057
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    • 2016
  • The purpose of this study was to examine if high risk drinkers are different from normal drinkers in terms of drinking motives, drinking refusal self-efficacy, and alcohol outcome expectancy. A total of 139 university male students in D area completed a self-reporting questionnaires to assess general characteristics, drinking motives, drinking refusal self-efficacy, alcohol outcome expectancy, and amount of drinking. The subjects were divided into high risk drinking and normal drinking based on a CDC guideline. The results of study show that high risk drinking group has higher odds for current smoking (adjusted OR=2.95, 95% CI [1.08, 8.05]), psychology major (adjusted OR=3.79, 95% CI [1.05, 13.71]), and enhancement motives (adjusted OR=2.64, 95% CI [1.15, 6.09]), whereas lower odds for junior grade (adjusted OR=0.21, 95% CI [0.05, 0.96]) and drinking refusal self-efficacy in social pressure (adjusted OR=0.42, 95% CI [0.24, 0.73]). The results suggest that drinking educational nursing intervention and smoking cessation program for university students are necessary to prevent high risk drinking effects.