• Title/Summary/Keyword: STAT3 phosphorylation

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Reversal of Cisplatin Resistance by Epigallocatechin Gallate Is Mediated by Downregulation of Axl and Tyro 3 Expression in Human Lung Cancer Cells

  • Kim, Kyung-Chan;Lee, ChuHee
    • The Korean Journal of Physiology and Pharmacology
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    • v.18 no.1
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    • pp.61-66
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    • 2014
  • Lung cancer is still the number one cause of death from cancer worldwide. The clinical effect of platinum-based chemotherapy for non-small cell lung cancer is constrained by the resistance to drug. To overcome chemo-resistance, various modified treatment including combination therapy has been used, but overall survival has not been improved yet. In this study, chemo-resistant lung cancer cells, A549/Cis and H460/Cis, were developed by long-term exposure of cells to cisplatin and the proliferative capability of these resistant cells was verified to be reduced. We found cytotoxic effect of epigallocatechin gallate (EGCG), a major catechin derived from green tea, on both the parental lung cancer cells, A549 and H460, and their cisplatin resistant cells, A549/Cis and H460/Cis. ELISA and Western blot analysis revealed that EGCG was able to increase interlukine-6 (IL-6) production per cell, whereas its downstream effector Signal transducers and activators of transcription 3 (STAT3) phosphorylation was not changed by EGCG, indicating that IL-6/STAT3 axis is not the critical signaling to be inhibited by EGCG. We next found that EGCG suppresses the expression of both Axl and Tyro 3 receptor tyrosine kinases at mRNA and protein level, explaining the cytotoxic effect of EGCG on lung cancer cells, especially, regardless of cisplatin resistance. Taken together, these data suggest that EGCG impedes proliferation of lung cancer cells including their chemo-resistant variants through downregulation of Axl and Tyro 3 expression.

The Tuber Extract of Pinellia ternata (Thunb.) Brei Suppresses Cancer Cell Migration by Regulating Tumor-associated Macrophages (반하 추출물의 종양연관대식세포 조절을 통한 암세포 이동능 저해 효과)

  • Park, Shin-Hyung
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.36 no.1
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    • pp.1-6
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    • 2022
  • The tuber of Pinellia ternata (Thunb.) Brei (TPT) used in traditional Oriental medicine for the treatment of cough, sputum, vomiting, and insomnia, possesses antioxidant, antibacterial, and anti-inflammatory effects. Although recent studies have reported the anticancer effects of TPT in several cancer cells, it is still unclear whether TPT regulates tumor-associated macrophage (TAM) characterized by the immunosuppressive M2 macrophage phenotype. Our results showed that the ethanol extract of TPT (ETPT) suppressed the migration of RAW264.7 mouse macrophage cells and THP-1 human monocytes differentiated into macrophages towards the conditioned media (CM) collected from lung cancer cells, suggesting that ETPT would attenuate the recruitment of macrophages into tumors. In addition, ETPT suppressed the interleukin (IL)-4 or IL-6-induced M2 macrophage polarization in RAW264.7 cells. ETPT treatment not only downregulated the mRNA expression of M2 macrophage markers including arginase-1, mannose receptor C type 1 (MRC-1), and IL-10, but also inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and STAT6, general regulators of M2 macrophage polarization. Finally, the transwell assay results showed that the CM from M2-polarized RAW264.7 cells increased the migration of mouse lewis lung carcinoma (LLC) cells, while those from RAW264.7 cells co-treated with ETPT and IL-6 significantly reduced the migration of LLC cells. Taken together, our observations clearly demonstrate that ETPT suppressed the cancer cell migration by regulating macrophage recruitment and M2 macrophage polarization.

Mouse neutrophils express functional umami taste receptor T1R1/T1R3

  • Lee, NaHye;Jung, Young Su;Lee, Ha Young;Kang, NaNa;Park, Yoo Jung;Hwang, Jae Sam;Bahk, Young Yil;Koo, JaeHyung;Bae, Yoe-Sik
    • BMB Reports
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    • v.47 no.11
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    • pp.649-654
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    • 2014
  • Neutrophils play an important role in the initiation of innate immunity against infection and injury. Although many different types of G-protein coupled receptors are functionally expressed in neutrophils, no reports have demonstrated functional expression of umami taste receptor in these cells. We observed that mouse neutrophils express the umami taste receptor T1R1/T1R3 through RNA sequencing and quantitative RT-PCR analysis. Stimulation of mouse neutrophils with L-alanine or L-serine, which are ligands for the umami taste receptor, elicited not only ERK or p38 MAPK phosphorylation but also chemotactic migration. Moreover, addition of L-alanine or L-serine markedly reduced the production of several cytokines including TNFα induced by lipopoly-saccharide (LPS) through inhibition of NFκB activity or STAT3 phosphorylation in neutrophils. Our findings demonstrate that neutrophils express the umami taste receptor, through which tastants stimulate neutrophils, resulting in chemotactic migration, and attenuation of LPS-induced inflammatory response.

Inhibitory Effect of Artemisinic Acid Isolated from Artemisia Annua L on the MDC in HaCaT Keratinocytes (HaCaT 각질형성세포에서 개똥쑥(Artemisia annua L) 유래 성분인 Artemisinic acid의 Macrophage-derived Chemokine 억제 효과)

  • Kang, Gyeoung-Jin;Kang, Na-Jin;Han, Sang-Chul;Koo, Dong-Hwan;Kim, Young-Soo;Lee, Jin-Hyuck;Kim, Sang-Chul;Park, Deok-Hoon;Lee, Jong-Sung;Kang, Hee-Kyung;Yoo, Eun-Sook
    • Korean Journal of Pharmacognosy
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    • v.43 no.3
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    • pp.217-223
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    • 2012
  • In the present study, we investigated anti-inflammatory activity of artemisinic acid in HaCaT cells and RAW264.7 cells. Artemisinic acid showed inhibitory activity on macrophage-derived chemokines (MDC) expression, a factor related with atopic dermatitis (AD), in interferon (IFN)-γ and tumor necrosis factor (TNF)-α-stimulated HaCaT cells. In the study on action mechanism, pretreated artemisinic acid reduced the phosphorylation of STAT1 and p38 and the degradation of IκB by IFN-γ and TNF-α stimulations. However, artemisinic acid didn't show the inhibitory activity on LPS-induced inflammatory mediators (NO, PGE2, IL-6) in RAW264.7 cell. These results indicate that artemisinic acid inhibits IFN-γ and TNF-α-induced MDC expression through inhibition of signal factors, STAT1, NF-κB, and p38, in HaCaT keratinocytes.

Anticancer Activity of Novel Daphnane Diterpenoids from Daphne genkwa through Cell-Cycle Arrest and Suppression of Akt/STAT/Src Signalings in Human Lung Cancer Cells

  • Jo, Si-Kyoung;Hong, Ji-Young;Park, Hyen Joo;Lee, Sang Kook
    • Biomolecules & Therapeutics
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    • v.20 no.6
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    • pp.513-519
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    • 2012
  • Although the immense efforts have been made for cancer prevention, early diagnosis, and treatment, cancer morbidity and mortality has not been decreased during last forty years. Especially, lung cancer is top-ranked in cancer-associated human death. Therefore, effective strategy is strongly required for the management of lung cancer. In the present study, we found that novel daphnane diterpenoids, yuanhualine (YL), yuanhuahine (YH) and yuanhuagine (YG) isolated from the flower of Daphne genkwa (Thymelaeaceae), exhibited potent anti-proliferative activities against human lung A549 cells with the IC50 values of 7.0, 15.2 and 24.7 nM, respectively. Flow cytometric analysis revealed that the daphnane diterpenoids induced cell-cycle arrest in the G0/G1 as well as G2/M phase in A549 cells. The cell-cycle arrests were well correlated with the expression of checkpoint proteins including the up-regulation of cyclin-dependent kinase inhibitor p21 and p53 and down-regulation of cyclin A, cyclin B1, cyclin E, cyclin dependent kinase 4, cdc2, phosphorylation of Rb and cMyc expression. In the analysis of signal transduction molecules, the daphnane diterpenoids suppressed the activation of Akt, STAT3 and Src in human lung cancer cells. The daphnane diterpenoids also exerted the potent anti-proliferative activity against anticancer-drug resistant cancer cells including gemcitabine-resistant A549, gefitinib-, erlotinib-resistant H292 cells. Synergistic effects in the growth inhibition were also observed when yuanhualine was combined with gemcitabine, gefitinib or erlotinib in A549 cells. Taken together, these findings suggest that the novel daphnane diterpenoids might provide lead candidates for the development of therapeutic agents for human lung cancers.

Calcium/Calmodulin-Dependent Protein Kinase is Involved in the Release of High Mobility Group Box 1 Via the Interferon-β Signaling Pathway

  • Ma, Lijuan;Kim, Seon-Ju;Oh, Kwon-Ik
    • IMMUNE NETWORK
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    • v.12 no.4
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    • pp.148-154
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    • 2012
  • Previously, we have reported that high mobility group box 1 (HMGB1), a proinflammatory mediator in sepsis, is released via the IFN-β-mediated JAK/STAT pathway. However, detailed mechanisms are still unclear. In this study, we dissected upstream signaling pathways of HMGB1 release using various molecular biology methods. Here, we found that calcium/calmodulin-dependent protein kinase (CaM kinase, CaMK) is involved in HMGB1 release by regulating IFN-β production. CaMK inhibitor, STO609, treatment inhibits LPS-induced IFN-β production, which is correlated with the phosphorylation of interferon regulatory factor 3 (IRF3). Additionally, we show that CaMK-I plays a major role in IFN-β production although other CaMK members also seem to contribute to this event. Furthermore, the CaMK inhibitor treatment reduced IFN-β production in a murine endotoxemia. Our results suggest CaMKs contribute to HMGB1 release by enhancing IFN-β production in sepsis.

Conditioning-induced cardioprotection: Aging as a confounding factor

  • Randhawa, Puneet Kaur;Bali, Anjana;Virdi, Jasleen Kaur;Jaggi, Amteshwar Singh
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.5
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    • pp.467-479
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    • 2018
  • The aging process induces a plethora of changes in the body including alterations in hormonal regulation and metabolism in various organs including the heart. Aging is associated with marked increase in the vulnerability of the heart to ischemia-reperfusion injury. Furthermore, it significantly hampers the development of adaptive response to various forms of conditioning stimuli (pre/post/remote conditioning). Aging significantly impairs the activation of signaling pathways that mediate preconditioning-induced cardioprotection. It possibly impairs the uptake and release of adenosine, decreases the number of adenosine transporter sites and down-regulates the transcription of adenosine receptors in the myocardium to attenuate adenosine-mediated cardioprotection. Furthermore, aging decreases the expression of peroxisome proliferator-activated receptor gamma co-activator 1-alpha (PGC1α) and subsequent transcription of catalase enzyme which subsequently increases the oxidative stress and decreases the responsiveness to preconditioning stimuli in the senescent diabetic hearts. In addition, in the aged rat hearts, the conditioning stimulus fails to phosphorylate Akt kinase that is required for mediating cardioprotective signaling in the heart. Moreover, aging increases the concentration of Na+ and K+, connexin expression and caveolin abundance in the myocardium and increases the susceptibility to ischemia-reperfusion injury. In addition, aging also reduces the responsiveness to conditioning stimuli possibly due to reduced kinase signaling and reduced STAT-3 phosphorylation. However, aging is associated with an increase in MKP-1 phosphorylation, which dephosphorylates (deactivates) mitogen activated protein kinase that is involved in cardioprotective signaling. The present review describes aging as one of the major confounding factors in attenuating remote ischemic preconditioning-induced cardioprotection along with the possible mechanisms.

5,8-Dimethoxy-2-Nonylamino-Naphthalene-1,4-Dione Inhibits Vascular Smooth Muscle Cell Proliferation by Blocking Autophosphorylation of PDGF-Receptor β

  • Kim, Yohan;Lee, Jung-Jin;Lee, Sang-Gil;Jung, Sang-Hyuk;Han, Joo-Hui;Yang, So Young;Yun, Eunju;Song, Gyu-Yong;Myung, Chang-Seon
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.3
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    • pp.203-208
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    • 2013
  • As the abnormal proliferation of vascular smooth muscle cells (VSMCs) plays a critical role in the development of atherosclerosis and vascular restenosis, a candidate drug with antiproliferative properties is needed. We investigated the antiproliferative action and underlying mechanism of a newly synthesized naphthoquinone derivative, 5,8-dimethoxy-2-nonylamino-naphthalene-1,4-dione (2-nonylamino-DMNQ), using VSMCs treated with platelet-derived growth factor (PDGF). 2-Nonylamino-DMNQ inhibited proliferation and cell number of VSMCs induced by PDGF, but not epidermal growth factor (EGF), in a concentration-dependent manner without any cytotoxicity. This derivative suppressed PDGF-induced [3H]-thymidine incorporation, cell cycle progression from G0/G1 to S phase, and the phosphorylation of phosphor-retinoblastoma protein (pRb) as well as the expression of cyclin E/D, cyclin-dependent kinase (CDK) 2/4, and proliferating cell nuclear antigen (PCNA). Importantly, 2-nonylamino-DMNQ inhibited the phosphorylation of PDGF receptorβ(PDGF-Rβ) enhanced by PDGF at Tyr579, Tyr716, Tyr751, and Tyr1021 residues. Subsequently, 2-nonylamino-DMNQ inhibited PDGF-induced phosphorylation of STAT3, ERK1/2, Akt, and PLCγ1. Therefore, our results indicate that 2-nonylamino-DMNQ inhibits PDGF-induced VSMC proliferation by blocking PDGF-Rβ autophosphorylation, and subsequently PDGF-Rβ-mediated downstream signaling pathways.

Inhibition of Adrenergic Agonists-induced Metastatic Ability of Liver Cancer Cells by Ethanol Extract of Premature Citrus Unshiu Peel (청피 에탄올 추출물이 스트레스성 카테콜아민으로 유도한 간암세포의 전이를 억제하는 효과 및 기전 연구)

  • Shin-Hyung Park
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.38 no.1
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    • pp.10-15
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    • 2024
  • Previous studies have highlighted the pivotal role of the β-adrenergic receptor (β-AR) signaling pathway in stimulating cancer metastasis induced by chronic stress. According to the theory of traditional Korean medicine, chronic stress can induce Qi stagnation. Based on the traditional role of premature citrus unshiu peel in moving Qi, we hypothesized that an ethanol extract of premature citrus unshiu peel (EPCU) can attenuate chronic stress-induced cancer progression. In this study, we investigated the potential role of EPCU on modulating the adrenergic agonists-induced metastatic properties of liver cancer cells. Our findings revealed that adrenergic agonists, including norepinephrine (NE), epinephrine (E), and isoproterenol (ISO), augmented the migratory capacity of Hep3B human hepatocellular carcinoma cells, which was completely abrogated by EPCU treatment in a concentration-dependent manner. Consistently, EPCU inhibited the E-induced invasive property of Hep3B cells in a dose-dependent manner. These results suggest that EPCU efficiently attenuates adrenergic agonists-induced metastatic abilities of liver cancer cells. As a molecular mechanism, EPF suppressed the phosphorylation of major components of β-AR signaling pathway, including Src, signal transducer and activator of transcription 3 (STAT3) and ERK, induced by E treatment. Taken together, our results demonstrate that EPCU impedes the adrenergic agonists-driven metastatic potential of cancer cells by inhibiting β-AR signaling pathway. This study provides basic evidence supporting the probable use of premature citrus unshiu peel to prevent metastasis in liver cancer patients under chronic stress.

Anti-Inflammatory Effect of 3-Bromo-4,5-Dihydroxybenzaldehyde, a Component of Polysiphonia morrowii, In Vivo and In Vitro

  • Kang, Na-Jin;Han, Sang-Chul;Kang, Hyun-Jae;Ko, Geum;Yoon, Weon-Jong;Kang, Hee-Kyoung;Yoo, Eun-Sook
    • Toxicological Research
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    • v.33 no.4
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    • pp.325-332
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    • 2017
  • 3-Bromo-4,5-dihydroxybenzaldehyde (BDB) is a natural bromophenol compound that is most commonly isolated from red algae. The present study was designed to investigate the anti-inflammatory properties of BDB on atopic dermatitis (AD) in mice induced by 2,4-dinitrochlorobenzene (DNCB) and on lipopolysaccharide (LPS)-stimulated murine macrophages. BDB treatment (100 mg/kg) resulted in suppression of the development of AD symptoms compared with the control treatment (induction-only), as demonstrated by reduced immunoglobulin E levels in serum, smaller lymph nodes with reduced thickness and length, a decrease in ear edema, and reduced levels of inflammatory cell infiltration in the ears. In RAW 264.7 murine macrophages, BDB (12.5, 25, 50, and 100μM) suppressed the production of interleukin-6, a proinflammatory cytokine, in a dose-dependent manner. BDB also had an inhibitory effect on the phosphorylation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and signal transducer and activator of transcription 1 (STAT1; Tyr 701), two major signaling molecules involved in cellular inflammation. Taken together, the results show that BDB treatment alleviates inflammatory responses in an atopic dermatitis mouse model and RAW 264.7 macrophages. These results suggest that BDB may be a useful therapeutic strategy for treating conditions involving allergic inflammation such as atopic dermatitis.