• Title/Summary/Keyword: Signalling Pathway

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Equol Induces Mitochondria-Dependent Apoptosis in Human Gastric Cancer Cells via the Sustained Activation of ERK1/2 Pathway

  • Yang, Zhiping;Zhao, Yan;Yao, Yahong;Li, Jun;Wang, Wangshi;Wu, Xiaonan
    • Molecules and Cells
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    • v.39 no.10
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    • pp.742-749
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    • 2016
  • The cancer chemo-preventive effects of equol have been demonstrated for a wide variety of experimental tumours. In a previous study, we found that equol inhibited proliferation and induced apoptotic death of human gastric cancer MGC-803 cells. However, the mechanisms underlying equol-mediated apoptosis have not been well understood. In the present study, the dual AO (acridine orange)/EB (ethidium bromide) fluorescent assay, the comet assay, MTS, western blotting and flow cytometric assays were performed to further investigate the pro-apoptotic effect of equol and its associated mechanisms in MGC-803 cells. The results demonstrated that equol induced an apoptotic nuclear morphology revealed by AO/EB staining, the presence of a comet tail, the cleavage of caspase-3 and PARP and the depletion of cIAP1, indicating its pro-apoptotic effect. In addition, equol-induced apoptosis involves the mitochondria-dependent cell-death pathway, evidenced by the depolarization of the mitochondrial membrane potential, the cleavage of caspase-9 and the depletion of Bcl-xL and full-length Bid. Moreover, treating MGC-803 cells with equol induced the sustained activation of extracellular signal-regulated kinase (ERK), and inhibiting ERK by U0126, a MEK/ERK pathway inhibitor, significantly attenuated the equol-induced cell apoptosis. These results suggest that equol induces mitochondria-dependent apoptosis in human gastric cancer MGC-803 cells via the sustained activation of the ERK1/2 pathway. Therefore, equol may be a novel candidate for the chemoprevention and therapy of gastric cancer.

Effects of Thujae Orientalis Folium (TOF) on Gene Expression of Human melanoma cells (SK-MEL-2) (측백엽(側柏葉)이 인간 유래 악성 흑색종 세포의 유전자 발현에 미치는 영향)

  • Jung, Min-Young;Kim, Jong-Han;Park, Su-Yeon;Choi, Jeong-Hwa
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.23 no.2
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    • pp.81-108
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    • 2010
  • Objective : Thujae Orientalis Folium (TOF) can cool the blood and stop bleeding, eliminate phlegm and relieve cough in Oriental medicine. In addition, the fresh is used alone externally. Recently, TOF is known to have anti-tumor component. And also known to have tyrosinase inhibitory effect. Method : For these reasons, this study was designed to investigate anti-cancer and whitening activities of TOF. In this experiment, effects of TOF on proliferation rates of melanoma cells and on changes in genetic profiles were investigated. The genetic profile for the effect on human derived melanoma cell, SK-MEL-2, was measured using microarray technique, and the functional analysis on these genes was conducted. Results : Total 541 genes were up-regulated and 1,079 genes down-regulated in cells treated with TOF. Genes induced by TOF were mainly concerned with anti-cancer effects and apoptosis. Genes suppresed by TOF were related in extracellular signalling pathway. The network of total protein interactions was measured using cytoscape program, and some key molecules, such as THAP1, MAX1, STAM2, SMAD6, CYCS, PEX5, PSEN1, NONO, MAP2K7 and CREB1 that can be used for elucidation of therapeutical mechanism of medicine in future were identified. Conculusion : These results suggest possibility of TOF as anti-cancer drug for human melanoma. In addition, the present author also suggest that related mechanisms are involved in inhibition of several cancer pathway, activation of apoptosis pathway and suppression of general metabolic pathway.

Emodin Inhibits Breast Cancer Cell Proliferation through the ERα-MAPK/Akt-Cyclin D1/Bcl-2 Signaling Pathway

  • Sui, Jia-Qi;Xie, Kun-Peng;Zou, Wei;Xie, Ming-Jie
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6247-6251
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    • 2014
  • Background: The aim of the present study was to investigate the involvement of emodin on the growth of human breast cancer MCF-7 and MDA-MB-231 cells and the estrogen (E2) signal pathway in vitro. Materials and Methods: MTT assays were used to detect the effects of emodin on E2 induced proliferation of MCF-7 and MDA-MB-231 cells. Flow cytometry (FCM) was applied to determine the effect of emodin on E2-induced apoptosis of MCF-7 cells. Western blotting allowed detection of the effects of emodin on the expression of estrogen receptor ${\alpha}$, cyclin D1 and B-cell lymphoma-2 (Bcl-2), mitogen-activated protein kinases (MAPK) and phosphatidylinostiol 3-kinases (PI3K). Luciferase assays were emplyed to assess transcriptional activity of $ER{\alpha}$. Results: Emodin could inhibit E2-induced MCF-7 cell proliferation and anti-apoptosis effects, and arrest the cell cycle in G0/G1 phase, further blocking the effect of E2 on expression and transcriptional activity of $ER{\alpha}$. Moreover, Emodin influenced the ER ${\alpha}$ genomic pathway via downregulation of cyclin D1 and Bcl-2 protein expression, and influenced the non-genomic pathway via decreased PI3K/Akt protein expression. Conclusions: These findings indicate that emodin exerts inhibitory effects on MCF-7 cell proliferation via inhibiting both non-genomic and genomic pathways.

Apoptotic Pathway Induced by Dominant Negative ATM Gene in CT-26 Colon Cancer Cells (CT-26 대장암 세포에서 Dominant Negative ATM 유전자에 의하여 유도되는 세포자멸사의 경로)

  • Lee, Jung Chang;Yi, Ho Keun;Kim, Sun Young;Lee, Dae Yeol;Hwang, Pyoung Han;Park, Jin Woo
    • Clinical and Experimental Pediatrics
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    • v.46 no.7
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    • pp.679-686
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    • 2003
  • Purpose : Ataxia telangiectasia mutated(ATM) is involved in DNA damage responses at different cell cycle checkpoints, and signalling pathways associated with regulation of apoptosis in response to ionizing radiation(IR). However, the signaling pathway that underlies IR-induced apoptosis in ATM cells has remained unknown. The purpose of this study was, therefore, to investigate the apoptotic pathway that underlies IR-induced apoptosis in a CT-26 cells expressing dominant negative ATM (DN-ATM). Methods : We generated a replication-deficient recombinant adenovirus encoding the DN-ATM(Ad/DN-ATM) or control adenovirus encoding no transgene(Ad/GFP) and infected adenovirus to CT-26 cells. After infection, we examined apoptosis and apoptotic pathway by [$^3H$]-thymidine assay, DNA fragmentation, and Western immunoblot analysis. Results : DN-ATM gene served as the creation of AT phenotype in a CT-26 cells as revealed by decreased cell proliferations following IR. In addition, IR-induced apoptosis was regulated through the reduced levels of the anti-apoptotic protein Bcl-2, the increased levels of the apoptotic protein Bax, and the activation of caspase-9, caspase-3, and PARP. Conclusion : These results indicate that the pathway of IR-induced apoptosis in CT-26 cells expressing DN-ATM is mediated by mitochondrial signaling pathway involving the activation of caspase 9, caspase 3, and PARP.

$\beta$-catenin에 의한 신호전달과 그 역할 ($\beta$-catenin은 세포의 감초인가\ulcorner)

  • 정선주
    • The Zoological Society Korea : Newsletter
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    • v.18 no.1
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    • pp.16-25
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    • 2001
  • Wnt signaling의 주요 분자인 $\beta$-catenin의 기능과 조절에 관한 연구, 특히 TCF family 단백질과 함께 작용하는 신호전달에 관한 연구가 최근에 활발히 진행되고 있다. $\beta$-catenin 단백질은 Drosophila나 Xenopus의 발생초기에 중요한 역할을 한다는 것이 알려져 있고 Wnt (Wingless) 단백질에 의하여 활성화되는 신호전달 과정에 관여한다고 알려져 있으므로, TCF 단백질들이 Wnt signalling pathway에 작용한다는 것을 의미한다. 즉, $\beta$-catenin/TCF complex는 발생초기의 세포의 운명을 결정하는 세포의 분화에 중요하리라 생각된다. 또한 $\beta$-catenin/TCF complex는 세포의 암화에도 중요하다는 것이 보고되었다. 정상세포의 경우, $\beta$-catenin은 APC 라는 tumor suppressor에 의하여 결합하고 단백질의 분해가 유도되어 핵 안의 TCF와 결합하지 못하는데, 암세포의 경우 APC가 결실되었거나 $\beta$-catenin의 양이 과도하게 발현되어 암세포화 되는 것으로 보인다. 즉, $\beta$-catenin은 일종의 oncogene으로 작용하는 단백질이며, 그 작용에 필수적인 전사인자가 TCF라는 것이다. 특히, 대장암세포에서 이 $\beta$-catenin/TCF complex에 의해 활성화되는 유전자로서 c-myc과 cyclin Dl 등이 있는 것으로 보아, $\beta$-catenin/TCF 단백질은 세포의 증식 및 사멸에 관여하는 단백질들의 발현을 조절하는 매우 중요한 인자라고 생각된다.

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Allicin reduces expression of Intercellular Adhesion Molecule-1 (ICAM-1) in gamma-irradiated endothelial cells: Involvement of p38 MAP kinase signalling pathway.

  • Son, Eun-Hwa;Mo, Sung-Ji;Cho, Seong-Jun;Yang, Kwang-Hee;Rhee, Dong-Kwon;Pyo, Suhk-Neung
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.307.1-307.1
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    • 2002
  • Inflammation is a frequent radiation-induced following therapeutic irradiation. Since the upregulation of adhesion molecules on endothelial cell surface has been known to be associated with inflammation. interfering with the expression of adhesion molecules is an important therapeutic target. We examined the effect of allicin. a major component of garlic. on the induction of intercellular adhesion molecule-1 (lCAM-1) by gamma-irradiation and the mechanisms of its effect in gamma-irradiated human umbilical vein endothelial cells (HUVECs). (omitted)

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Mutational Analysis of Key EGFR Pathway Genes in Chinese Breast Cancer Patients

  • Tong, Lin;Yang, Xue-Xi;Liu, Min-Feng;Yao, Guang-Yu;Dong, Jian-Yu;Ye, Chang-Sheng;Li, Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5599-5603
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    • 2012
  • Background: The epidermal growth factor receptor (EGFR) is a potential therapeutic target for breast cancer treatment; however, its use does not lead to a marked clinical response. Studies of non-small cell lung cancer and colorectal cancer showed that mutations of genes in the PIK3CA/AKT and RAS/RAF/MEK pathways, two major signalling cascades downstream of EGFR, might predict resistance to EGFR-targeted agents. Therefore, we examined the frequencies of mutations in these key EGFR pathway genes in Chinese breast cancer patients. Methods: We used a high-throughput mass-spectrometric based cancer gene mutation profiling platform to detect 22 mutations of the PIK3CA, AKT1, BRAF, EGFR, HRAS, and KRAS genes in 120 Chinese women with breast cancer. Results: Thirteen mutations were detected in 12 (10%) of the samples, all of which were invasive ductal carcinomas (two stage I, six stage II, three stage III, and one stage IV). These included one mutation (0.83%) in the EGFR gene (rs121913445-rs121913432), three (2.50%) in the KRAS gene (rs121913530, rs112445441), and nine (7.50%) in the PIK3CA gene (rs121913273, rs104886003, and rs121913279). No mutations were found in the AKT1, BRAF, and HRAS genes. Six (27.27%) of the 22 genotyping assays called mutations in at least one sample and three (50%) of the six assays queried were found to be mutated more than once. Conclusions: Mutations in the EGFR pathway occurred in a small fraction of Chinese breast cancers. However, therapeutics targeting these potential predictive markers should be investigated in depth, especially in Oriental populations.

Antidiabetic Effect of Standardized Chrysanthemum rubellum Hydroethanolic Extract by Targeting α-Glucosidase and the PTP-1B Signaling Pathway for Alleviating Diabetes in Experimental Model

  • Bichitrananda Tripathy;Nityananda Sahoo;Sudhir Kumar Sahoo
    • Journal of Pharmacopuncture
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    • v.26 no.4
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    • pp.319-326
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    • 2023
  • Objectives: The study's goal was to find out whether Chrysanthemum rubellum extract has anti-diabetic properties by concentrating on α-glucosidase and the PTP-1B signaling pathway. C. rubellum flowers were used for extraction using Methanol/water (80/20) as solvent. Methods: LC-MS techniques was used to check the presence of phytoconstituents present in C. rubellum extract. In vitro antidiabetic activity was evaluated using α-glucosidase inhibitory activity and PTP-1B signaling pathway. On Streptozotocin (STZ)-induced rats with diabetes, the in vivo antidiabetic efficacy was assessed using a test for oral glucose tolerance. Results: The phytoconstituents identified in the extract of C. rubellum were apigenin, diosmin, myricetin, luteolin, luteolin-7-glucoside, and Quercitrin as compound 1-6, respectively. Results showed that diosmin exhibited highest α-glucosidase inhibitory activity i.e. 90.39%. The protein level of PTP-1B was lowered and the insulin signalling activity was directly increased by compounds 1-6. The maximum blood glucose levels were seen in all groups' OGTT findings at 30 minutes following glucose delivery, followed by gradual drops. In comparison to the control group, the extract's glucose levels were 141 mg/dL at 30 minutes before falling to 104 mg/dL after 120 minutes. The current study has demonstrated, in summary, that extract with phytoconstituents reduce blood sugar levels in rats. Conclusion: This finding suggests that extract may reduce the chance of insulin resistance and shield against disorders like hyperglycemia.

Profiling of Gene Expression in Human Keratinocyte Cell Line Exposed to Quantum Dot Nanoparticles

  • Kim, In-Kyoung;Lee, Seung-Ho;Kim, Yu-Ri;Seo, Sang-Hui;Jeong, Sang-Hoon;Son, Sang-Wook;Kim, Meyoung-Kon
    • Molecular & Cellular Toxicology
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    • v.5 no.1
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    • pp.51-57
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    • 2009
  • Quantum Dot (QD) nanoparticles are used in various industrial applications, such as diagnostic, drug delivery, and imaging agents of biomedicine. Although QDs are extensively used in many medical science, several studies have been demonstrated the potential toxicity of nanoparticles. The first objective of this study was to investigate the nanotoxicity of QDs in the HaCaT human keratinocyte cell line by focusing on gene expression pattern. In order to evaluate the effect of QDs on gene expression profile in HaCaT cells, we analyzed the differential genes which related to oxidative stress and antioxidant defense mechanisms by using human cDNA microarray and PCR array. A human cDNA microarray was clone set, which was sorted for a list of genes correlated with cell mechanisms. We tried to confirm results of cDNA microarray by using PCR array, which is pathway-focused gene expression profiling technology using Real-Time PCR. Although we could not find the exactly same genes in both methods, we have screened the effects of QDs on global gene expression profiles in human skin cells. In addition, our results show that QD treatment somehow regulates cellular pathways of oxidative stress and antioxidant defense mechanisms. Therefore, we suggest that this study can enlarge our knowledge of the transcriptional profile and identify new candidate biomarker genes to evaluate the toxicity of nanotoxicology.

A review of the immunomodulatory activities of polysaccharides isolated from Panax species

  • Hu, Yeye;He, Yang;Niu, Zhiqiang;Shen, Ting;Zhang, Ji;Wang, Xinfeng;Hu, Weicheng;Cho, Jae Youl
    • Journal of Ginseng Research
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    • v.46 no.1
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    • pp.23-32
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    • 2022
  • Panax polysaccharides are biopolymers that are isolated and purified from the roots, stems, leaves, flowers, and fruits of Panax L. plants, which have attracted considerable attention because of their immunomodulatory activities. In this paper, the composition and structural characteristics of purified polysaccharides are reviewed. Moreover, the immunomodulatory activities of polysaccharides are described both in vivo and in vitro. In vitro, Panax polysaccharides exert immunomodulatory functions mainly by activating macrophages, dendritic cells, and the complement system. In vivo, Panax polysaccharides can increase the immune organ indices and stimulate lymphocytes. In addition, this paper also discusses the membrane receptors and various signalling pathways of immune cells. Panax polysaccharides have many beneficial therapeutic effects, including enhancing or activating the immune response, and may be helpful in treating cancer, sepsis, osteoporosis, and other conditions. Panax polysaccharides have the potential for use in the development of novel therapeutic agents or adjuvants with beneficial immunomodulatory properties.