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van Blokland-Post K, Weber MF, van Wolferen ME, Penning LC, van Sluijs FJ, Kummeling A. Prediction of outcome after ligation or thin film banding of extrahepatic shunts, based on plasma albumin concentration and hematologic expression of 8 target genes in 85 dogs. J Vet Intern Med 2023; 37:537-549. [PMID: 36934445 DOI: 10.1111/jvim.16680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 02/22/2023] [Indexed: 03/20/2023] Open
Abstract
BACKGROUND In dogs with a congenital extrahepatic portosystemic shunt (EHPSS), outcome after surgical attenuation is difficult to predict. OBJECTIVES Develop a minimally invasive test to predict outcome after surgical EHPSS attenuation and establish risk factors for postattenuation seizures (PAS). ANIMALS Eighty-five client-owned dogs referred for surgical attenuation of a single EHPSS. METHODS mRNA expression of 8 genes was measured in preoperatively collected venous blood samples. Outcome was determined at a median of 92 days (range, 26-208) postoperatively by evaluating clinical performance, blood test results and abdominal ultrasonography. Multivariable logistic regression was used to construct models predicting clinical and complete recovery. The associations between putative predictors and PAS were studied using univariable analyses. RESULTS Five of 85 dogs developed PAS. Risk factors were age, white blood cell (WBC) count and expression of hepatocyte growth factor activator and LysM and putative peptidoglycan-binding domain-containing protein 2. Clinical recovery was observed in 72 of 85 dogs and complete recovery in 51 of 80 dogs (median follow-up, 92 days). The model predicting clinical recovery included albumin, WBC count, and methionine adenosyltransferase 2 alpha (MAT2α) expression, whereas the model predicting complete recovery included albumin, and connective tissue growth factor precursor and MAT2α expression. The areas under the receiver operating characteristic curves were 0.886 (95% confidence interval [CI]: 0.783, 0.990) and 0.794 (95% CI: 0.686, 0.902), respectively. CONCLUSIONS AND CLINICAL IMPORTANCE Two models were constructed for predicting outcome after EHPSS attenuation using venous blood samples. The model predicting clinical recovery showed the best diagnostic properties. Clinical application requires further validation.
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Affiliation(s)
- Krista van Blokland-Post
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Maarten F Weber
- Royal GD, P.O. Box 9, 7400 AA Deventer, The Netherlands.,Department of Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Monique E van Wolferen
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Louis C Penning
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Freek J van Sluijs
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Anne Kummeling
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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2
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Wang H, Wu Y, Tang W. Methionine cycle in nonalcoholic fatty liver disease and its potential applications. Biochem Pharmacol 2022; 200:115033. [PMID: 35395242 DOI: 10.1016/j.bcp.2022.115033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/31/2022] [Accepted: 03/31/2022] [Indexed: 11/25/2022]
Abstract
As a chronic metabolic disease affecting epidemic proportions worldwide, the pathogenesis of Nonalcoholic Fatty Liver Disease (NAFLD) is not clear yet. There is also a lack of precise biomarkers and specific medicine for the diagnosis and treatment of NAFLD. Methionine metabolic cycle, which is critical for the maintaining of cellular methylation and redox state, is involved in the pathophysiology of NAFLD. However, the molecular basis and mechanism of methionine metabolism in NAFLD are not completely understood. Here, we mainly focus on specific enzymes that participates in methionine cycle, to reveal their interconnections with NAFLD, in order to recognize the pathogenesis of NAFLD from a new angle and at the same time, explore the clinical characteristics and therapeutic strategies.
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Affiliation(s)
- Haoyu Wang
- University of Chinese Academy of Sciences, Beijing, 100049, PR China; Laboratory of Anti-inflammation, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, PR China
| | - Yanwei Wu
- Laboratory of Anti-inflammation, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, PR China
| | - Wei Tang
- University of Chinese Academy of Sciences, Beijing, 100049, PR China; Laboratory of Anti-inflammation, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, PR China.
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3
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Gade M, Tan LL, Damry AM, Sandhu M, Brock JS, Delaney A, Villar-Briones A, Jackson CJ, Laurino P. Substrate Dynamics Contribute to Enzymatic Specificity in Human and Bacterial Methionine Adenosyltransferases. JACS AU 2021; 1:2349-2360. [PMID: 34977903 PMCID: PMC8715544 DOI: 10.1021/jacsau.1c00464] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Indexed: 05/14/2023]
Abstract
Protein conformational changes can facilitate the binding of noncognate substrates and underlying promiscuous activities. However, the contribution of substrate conformational dynamics to this process is comparatively poorly understood. Here, we analyze human (hMAT2A) and Escherichia coli (eMAT) methionine adenosyltransferases that have identical active sites but different substrate specificity. In the promiscuous hMAT2A, noncognate substrates bind in a stable conformation to allow catalysis. In contrast, noncognate substrates sample stable productive binding modes less frequently in eMAT owing to altered mobility in the enzyme active site. Different cellular concentrations of substrates likely drove the evolutionary divergence of substrate specificity in these orthologues. The observation of catalytic promiscuity in hMAT2A led to the detection of a new human metabolite, methyl thioguanosine, that is produced at elevated levels in a cancer cell line. This work establishes that identical active sites can result in different substrate specificity owing to the effects of substrate and enzyme dynamics.
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Affiliation(s)
- Madhuri Gade
- Protein
Engineering and Evolution Unit, Okinawa
Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna 904-0495, Okinawa, Japan
| | - Li Lynn Tan
- Research
School of Chemistry, Australian National
University, Canberra, 2601, Australia
| | - Adam M. Damry
- Research
School of Chemistry, Australian National
University, Canberra, 2601, Australia
| | - Mahakaran Sandhu
- Research
School of Chemistry, Australian National
University, Canberra, 2601, Australia
| | - Joseph S. Brock
- Research
School of Biology, Australian National University, Canberra 2601, Australia
| | - Andie Delaney
- Research
School of Chemistry, Australian National
University, Canberra, 2601, Australia
| | - Alejandro Villar-Briones
- Protein
Engineering and Evolution Unit, Okinawa
Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna 904-0495, Okinawa, Japan
| | - Colin J. Jackson
- Research
School of Chemistry, Australian National
University, Canberra, 2601, Australia
- Australian
Research Council Centre of Excellence for Innovations in Peptide and
Protein Science, Research School of Chemistry, Australian National University, Canberra 2601, ACT, Australia
- Australian
Research Council Centre of Excellence in Synthetic Biology, Research
School of Chemistry, Australian National
University, Canberra 2601, ACT, Australia
| | - Paola Laurino
- Protein
Engineering and Evolution Unit, Okinawa
Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna 904-0495, Okinawa, Japan
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4
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Tie W, Ge F. MALAT1 Inhibits Proliferation of HPV16-Positive Cervical Cancer by Sponging miR-485-5p to Promote Expression of MAT2A. DNA Cell Biol 2021; 40:1407-1417. [PMID: 34610246 DOI: 10.1089/dna.2020.6205] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cervical cancer is the leading cause of morbidity and mortality in women throughout the world, human papillomavirus 16 (HPV16) is the main type of HPV causing invasive cervical cancer. However, the underlying mechanism of the high carcinogenicity of HPV16 remains unclear. In the current study, we documented that metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long noncoding RNA, is upregulated in HPV16-positive cervical cancer tissue and cell lines. The results of immunohistochemistry and immunofluorescence showed that MALAT1 was mainly localized in the cytoplasm. To clarify the biological functions of MALAT1 in cervical cancer cells, we performed gain- and loss-of-function experiments to explore the underlying molecular mechanism. Functionally, the proliferation of cervical cancer was detected by Cell Counting Kit-8 (CCK-8) and colony formation assay in MALAT1 overexpression or knockdown cells, our data showed that MALAT1 promotes the proliferation of cervical cancer cells. Mechanistically, our results suggested that MALAT1 upregulates Methionine adenosyltransferase 2A (MAT2A) by sponging miR-485-5p. Moreover, the gain-of-function assay validated the function of MAT2A in HPV16-positive cervical cancer proliferation. Taken together, our results demonstrated that MALAT1 acts as a competitive endogenous RNA (ceRNA) to regulate MAT2A by sponging miR-485-5p in HPV16-positive cervical cancer, suggesting that MALAT1 may act as a potential therapeutic target for HPV16-positive cervical cancer.
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Affiliation(s)
- Weiwei Tie
- Department of Gynaecology, Ningbo Medical Center Lihuili Hospital, Ningbo, China
| | - Fenfen Ge
- Department of Gynaecology, Ningbo Medical Center Lihuili Hospital, Ningbo, China
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5
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Murray B, Barbier-Torres L, Fan W, Mato JM, Lu SC. Methionine adenosyltransferases in liver cancer. World J Gastroenterol 2019; 25:4300-4319. [PMID: 31496615 PMCID: PMC6710175 DOI: 10.3748/wjg.v25.i31.4300] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 05/31/2019] [Accepted: 07/19/2019] [Indexed: 02/06/2023] Open
Abstract
Methionine adenosyltransferases (MATs) are essential enzymes for life as they produce S-adenosylmethionine (SAMe), the biological methyl donor required for a plethora of reactions within the cell. Mammalian systems express two genes, MAT1A and MAT2A, which encode for MATα1 and MATα2, the catalytic subunits of the MAT isoenzymes, respectively. A third gene MAT2B, encodes a regulatory subunit known as MATβ which controls the activity of MATα2. MAT1A, which is mainly expressed in hepatocytes, maintains the differentiated state of these cells, whilst MAT2A and MAT2B are expressed in extrahepatic tissues as well as non-parenchymal cells of the liver (e.g., hepatic stellate and Kupffer cells). The biosynthesis of SAMe is impaired in patients with chronic liver disease and liver cancer due to decreased expression and inactivation of MATα1. A switch from MAT1A to MAT2A/MAT2B occurs in multiple liver diseases and during liver growth and dedifferentiation, but this change in the expression pattern of MATs results in reduced hepatic SAMe level. Decades of study have utilized the Mat1a-knockout (KO) mouse that spontaneously develops non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC) to elucidate a variety of mechanisms by which MAT proteins dysregulation contributes to liver carcinogenesis. An increasing volume of work indicates that MATs have SAMe-independent functions, distinct interactomes and multiple subcellular localizations. Here we aim to provide an overview of MAT biology including genes, isoenzymes and their regulation to provide the context for understanding consequences of their dysregulation. We will highlight recent breakthroughs in the field and underscore the importance of MAT’s in liver tumorigenesis as well as their potential as targets for cancer therapy.
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Affiliation(s)
- Ben Murray
- Division of Digestive and Liver diseases, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, United States
| | - Lucia Barbier-Torres
- Division of Digestive and Liver diseases, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, United States
| | - Wei Fan
- Division of Digestive and Liver diseases, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, United States
| | - José M Mato
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Technology, Park of Bizkaia, Derio 48160, Bizkaia, Spain
| | - Shelly C Lu
- Division of Digestive and Liver diseases, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, United States
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6
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Wang K, Fang S, Liu Q, Gao J, Wang X, Zhu H, Zhu Z, Ji F, Wu J, Ma Y, Hu L, Shen X, Gao D, Zhu J, Liu P, Zhou H. TGF-β1/p65/MAT2A pathway regulates liver fibrogenesis via intracellular SAM. EBioMedicine 2019; 42:458-469. [PMID: 30926424 PMCID: PMC6491716 DOI: 10.1016/j.ebiom.2019.03.058] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/13/2019] [Accepted: 03/19/2019] [Indexed: 12/15/2022] Open
Abstract
Background Hepatic stellate cell (HSC) activation induced by transforming growth factor β1 (TGF-β1) plays a pivotal role in fibrogenesis, while the complex downstream mediators of TGF-β1 in such process are largely unknown. Methods We performed pharmacoproteomic profiling of the mice liver tissues from control, carbon tetrachloride (CCl4)-induced fibrosis and NPLC0393 administrated groups. The target gene MAT2A was overexpressed or knocked down in vivo by tail vein injection of AAV vectors. We examined NF-κB transcriptional activity on MAT2A promoter via luciferase assay. Intracellular SAM contents were analyzed by LC-MS method. Findings We found that methionine adenosyltransferase 2A (MAT2A) is significantly upregulated in the CCl4-induced fibrosis mice, and application of NPLC0393, a known small molecule inhibitor of TGF-β1 signaling pathway, inhibits the upregulation of MAT2A. Mechanistically, TGF-β1 induces phosphorylation of p65, i.e., activation of NF-κB, thereby promoting mRNA transcription and protein expression of MAT2A and reduces S-adenosylmethionine (SAM) concentration in HSCs. Consistently, in vivo and in vitro knockdown of MAT2A alleviates CCl4- and TGF-β1-induced HSC activation, whereas in vivo overexpression of MAT2A facilitates hepatic fibrosis and abolishes therapeutic effect of NPLC0393. Interpretation This study identifies TGF-β1/p65/MAT2A pathway that is involved in the regulation of intracellular SAM concentration and liver fibrogenesis, suggesting that this pathway is a potential therapeutic target for hepatic fibrosis. Fund This work was supported by National Natural Science Foundation of China (No. 81500469, 81573873, 81774196 and 31800693), Zhejiang Provincial Natural Science Foundation of China (No. Y15H030004), the National Key Research and Development Program from the Ministry of Science and Technology of China (No. 2017YFC1700200) and the Key Program of National Natural Science Foundation of China (No. 8153000502).
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Affiliation(s)
- Kuifeng Wang
- Department of Infectious Diseases, Affiliated Taizhou Hospital of Wenzhou Medical University, 150 Ximen Road of Linhai City, Taizhou 317000, China; Suzhou GenHouse Pharmaceutical Co., Ltd., 388 Ruoshui Road, Suzhou, Jiangsu 215123, China
| | - Shanhua Fang
- Department of Analytical Chemistry, CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China; E-Institute of Shanghai Municipal Education Committee, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China
| | - Qian Liu
- Department of Analytical Chemistry, CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China
| | - Jing Gao
- Department of Analytical Chemistry, CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China
| | - Xiaoning Wang
- E-Institute of Shanghai Municipal Education Committee, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China; Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shuguang Hospital, Department of Pharmacology, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai 201203, China
| | - Hongwen Zhu
- Department of Analytical Chemistry, CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China
| | - Zhenyun Zhu
- Department of Analytical Chemistry, CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China
| | - Feihong Ji
- Department of Infectious Diseases, Affiliated Taizhou Hospital of Wenzhou Medical University, 150 Ximen Road of Linhai City, Taizhou 317000, China; Suzhou GenHouse Pharmaceutical Co., Ltd., 388 Ruoshui Road, Suzhou, Jiangsu 215123, China
| | - Jiasheng Wu
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shuguang Hospital, Department of Pharmacology, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai 201203, China
| | - Yueming Ma
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shuguang Hospital, Department of Pharmacology, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai 201203, China
| | - Lihong Hu
- Department of Analytical Chemistry, CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China; State Key Laboratory Cultivation Base for TCM Quality and Efficacy, School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing 210023, China
| | - Xu Shen
- Department of Analytical Chemistry, CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China; State Key Laboratory Cultivation Base for TCM Quality and Efficacy, School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing 210023, China
| | - Daming Gao
- CAS Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Innovation Center for Cell Signaling Network, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Jiansheng Zhu
- Department of Infectious Diseases, Affiliated Taizhou Hospital of Wenzhou Medical University, 150 Ximen Road of Linhai City, Taizhou 317000, China.
| | - Ping Liu
- E-Institute of Shanghai Municipal Education Committee, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China; Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shuguang Hospital, Department of Pharmacology, Shanghai University of Traditional Chinese Medicine, 528 Zhangheng Road, Shanghai 201203, China.
| | - Hu Zhou
- Department of Analytical Chemistry, CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China; E-Institute of Shanghai Municipal Education Committee, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China.
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7
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Wang R, Jin Y, Yao XH, Fan W, Zhang J, Cao Y, Li J. A novel mechanism of the M1-M2 methionine adenosyltransferase switch-mediated hepatocellular carcinoma metastasis. Mol Carcinog 2018; 57:1201-1212. [PMID: 29749642 DOI: 10.1002/mc.22836] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 04/13/2018] [Accepted: 05/04/2018] [Indexed: 12/14/2022]
Abstract
Hepatocellular carcinoma (HCC) manifests as a highly metastatic cancer with extremely poor prognosis. However, mechanisms underlying metastasis of HCC are not fully understood. Here, we showed that switching gene expression from MAT1A to MAT2A (M1-M2 switch) promoted cancer invasion and metastasis. Reversion of the M1-M2 switch repressed, whereas enhancing the M1-M2 switch promoted the ability of HCC cells to metastasize. Moreover, we provided clinical data showing that tipping the balance between MAT1A and MAT2A expression correlated with increased metastasis and inferior recurrence-free survival in HCC patients. Molecular pathways analysis showed that downregulation of MAT1A, which augmented osteopontin (OPN) expression through decreasing methylation of the OPN promoter, and MAT2A upregulation, which induced integrin β3 (ITGB3) expression by binding to ITGB3 promoter, collaboratively triggered ERK signaling and thereby promoted metastasis. Thus, the simultaneous downregulation of MAT1A and upregulation of MAT2A are necessary and sufficient for HCC metastasis in the process of M1-M2 switch. Our findings provide novel mechanistic insights into cancer metastasis. Inhibition and prevention of the M1-M2 switch would offer a novel therapeutic option for treatment of HCC.
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Affiliation(s)
- Ruizhi Wang
- Department of Interventional Oncology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, P.R. China.,Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, P.R. China
| | - Yi Jin
- Department of Pathology, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, P.R. China
| | - Xue-Hua Yao
- Department of Interventional Oncology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, P.R. China
| | - Wenzhe Fan
- Department of Interventional Oncology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, P.R. China
| | - Jiang Zhang
- Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, P.R. China
| | - Yihai Cao
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
| | - Jiaping Li
- Department of Interventional Oncology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, P.R. China
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8
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Transcriptome Analysis Uncovers a Growth-Promoting Activity of Orosomucoid-1 on Hepatocytes. EBioMedicine 2017; 24:257-266. [PMID: 28927749 PMCID: PMC5652006 DOI: 10.1016/j.ebiom.2017.09.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 09/06/2017] [Accepted: 09/08/2017] [Indexed: 02/08/2023] Open
Abstract
The acute phase protein orosomucoid-1 (Orm1) is mainly expressed by hepatocytes (HPCs) under stress conditions. However, its specific function is not fully understood. Here, we report a role of Orm1 as an executer of HPC proliferation. Increases in serum levels of Orm1 were observed in patients after surgical resection for liver cancer and in mice undergone partial hepatectomy (PH). Transcriptome study showed that Orm1 became the most abundant in HPCs isolated from regenerating mouse liver tissues after PH. Both in vitro and in vivo siRNA-induced knockdown of Orm1 suppressed proliferation of mouse regenerating HPCs and human hepatic cells. Microarray analysis in regenerating mouse livers revealed that the signaling pathways controlling chromatin replication, especially the minichromosome maintenance protein complex genes were uniformly down-regulated following Orm1 knockdown. These data suggest that Orm1 is induced in response to hepatic injury and executes liver regeneration by activating cell cycle progression in HPCs. Serum Orm1 levels increased approximately 1.3- to 2.5-folds in both humans and mice after partial hepatectomy. Transcriptome analysis revealed that Orm1 mostly induced in hepatocytes as a regulator of mouse liver regeneration. Orm1 knockdown in mice impaired liver regeneration with poor hepatocyte growth and suppressed cell cycle signaling.
Orosomucoid-1 (Orm1) is an acute phase protein mainly expressed by hepatocytes under stress conditions. Beginning from the finding that Orm1 was induced after partial hepatectomy in humans and mice, we showed enrichment of Orm1 in regenerating hepatocytes of hepatectomized mice by transcriptome analysis and following culture and animal experiments. Knockdown of Orm1 in mice resulted in decreases in hepatocyte growth accompanying suppressed signaling in controlling chromatin replication. Therefore, Orm1 would be a potential therapeutic and prognostic biomarker for liver diseases, especially after surgical resection of cancer-bearing liver, through its newly found ability to stimulate the cell cycle in regenerating hepatocytes.
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9
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Liu M, Chen P. Proliferation‑inhibiting pathways in liver regeneration (Review). Mol Med Rep 2017; 16:23-35. [PMID: 28534998 DOI: 10.3892/mmr.2017.6613] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 03/13/2017] [Indexed: 12/14/2022] Open
Abstract
Liver regeneration, an orchestrated process, is the primary compensatory mechanism following liver injury caused by various factors. The process of liver regeneration consists of three stages: Initiation, proliferation and termination. Proliferation‑promoting factors, which stimulate the recovery of mitosis in quiescent hepatocytes, are essential in the initiation and proliferation steps of liver regeneration. Proliferation‑promoting factors act as the 'motor' of liver regeneration, whereas proliferation inhibitors arrest cell proliferation when the remnant liver reaches a suitable size. Certain proliferation inhibitors are also expressed and activated in the first two steps of liver regeneration. Anti‑proliferation factors, acting as a 'brake', control the speed of proliferation and determine the terminal point of liver regeneration. Furthermore, anti‑proliferation factors function as a 'steering‑wheel', ensuring that the regeneration process proceeds in the right direction by preventing proliferation in the wrong direction, as occurs in oncogenesis. Therefore, proliferation inhibitors to ensure safe and stable liver regeneration are as important as proliferation‑promoting factors. Cytokines, including transforming growth factor‑β and interleukin‑1, and tumor suppressor genes, including p53 and p21, are important members of the proliferation inhibitor family in liver regeneration. Certain anti‑proliferation factors are involved in the process of gene expression and protein modification. The suppression of liver regeneration led by metabolism, hormone activity and pathological performance have been reviewed previously. However, less is known regarding the proliferation inhibitors of liver regeneration and further investigations are required. Detailed information regarding the majority of known anti‑proliferation signaling pathways also remains fragmented. The present review aimed to understand the signalling pathways that inhbit proliferation in the process of liver regeneration.
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Affiliation(s)
- Menggang Liu
- Department of Hepatobiliary Surgery, Daping Hospital, The Third Military Medical University, Chongqing 400042, P.R. China
| | - Ping Chen
- Department of Hepatobiliary Surgery, Daping Hospital, The Third Military Medical University, Chongqing 400042, P.R. China
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10
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Hao X, Zhou M, Li H, Angres IA. Novel immunoassays to detect methionine adenosyltransferase activity and quantify S-adenosylmethionine. FEBS Lett 2017; 591:1114-1125. [PMID: 28337758 DOI: 10.1002/1873-3468.12631] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 03/12/2017] [Accepted: 03/16/2017] [Indexed: 12/15/2022]
Abstract
We present a novel real-time immunoassay to measure methionine adenosyltransferase (MAT) activity that integrates the MAT-catalyzed reaction of Met and adenosine triphosphate to produce S-adenosylmethionine (SAM) and a highly sensitive immunoassay to specifically quantify SAM simultaneously. The cellular localization of SAM and S-adenosylhomocysteine varies with cell proliferation status: in normal cells, they are found mostly in the cytoplasm, but localize to the nucleus in proliferating cells. MAT-I/III activity is stimulated by Met, but inhibited by S-nitrosoglutathione, and the methylation index (MI) increases after Met stimulation of L02 cells. Met and S-nitrosoglutathione inhibit MAT-II activity, and the MI decreases after Met stimulation of HepG2 cells. The method described provides a significant advancement in the field for the measurement of MAT activity under various conditions.
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Affiliation(s)
| | - Min Zhou
- Hunan SkyWorld Biotechnologies Co. Ltd., Hunan, China
| | - Huijun Li
- Hunan SkyWorld Biotechnologies Co. Ltd., Hunan, China
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11
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Frau M, Feo CF, Feo F, Pascale RM. New insights on the role of epigenetic alterations in hepatocellular carcinoma. J Hepatocell Carcinoma 2014; 1:65-83. [PMID: 27508177 PMCID: PMC4918272 DOI: 10.2147/jhc.s44506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Emerging evidence assigns to epigenetic mechanisms heritable differences in gene function that come into being during cell development or via the effect of environmental factors. Epigenetic deregulation is strongly involved in the development of hepatocellular carcinoma (HCC). It includes changes in methionine metabolism, promoter hypermethylation, or increased proteasomal degradation of oncosuppressors, as well as posttranscriptional deregulation by microRNA or messenger RNA (mRNA) binding proteins. Alterations in the methylation of the promoter of methyl adenosyltransferase MAT1A and MAT2A genes in HCC result in decreased S-adenosylmethionine levels, global DNA hypomethylation, and deregulation of signal transduction pathways linked to methionine metabolism and methyl adenosyltransferases activity. Changes in S-adenosylmethionine levels may also depend on MAT1A mRNA destabilization associated with MAT2A mRNA stabilization by specific proteins. Decrease in MAT1A expression has also been attributed to miRNA upregulation in HCC. A complex deregulation of miRNAs is also strongly involved in hepatocarcinogenesis, with up-regulation of different miRNAs targeting oncosuppressor genes and down-regulation of miRNAs targeting genes involved in cell-cycle and signal transduction control. Oncosuppressor gene down-regulation in HCC is also induced by promoter hypermethylation or posttranslational deregulation, leading to proteasomal degradation. The role of epigenetic changes in hepatocarcinogenesis has recently suggested new promising therapeutic approaches for HCC on the basis of the administration of methylating agents, inhibition of methyl adenosyltransferases, and restoration of the expression of tumor-suppressor miRNAs.
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Affiliation(s)
- Maddalena Frau
- Department of Clinical and Experimental Medicine, Division of Experimental Pathology and Oncology, University of Sassari, Sassari, Italy
| | - Claudio F Feo
- Department of Clinical and Experimental Medicine, Division of Surgery, University of Sassari, Sassari, Italy
| | - Francesco Feo
- Department of Clinical and Experimental Medicine, Division of Experimental Pathology and Oncology, University of Sassari, Sassari, Italy
| | - Rosa M Pascale
- Department of Clinical and Experimental Medicine, Division of Experimental Pathology and Oncology, University of Sassari, Sassari, Italy
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Frau M, Feo F, Pascale RM. Pleiotropic effects of methionine adenosyltransferases deregulation as determinants of liver cancer progression and prognosis. J Hepatol 2013; 59:830-41. [PMID: 23665184 DOI: 10.1016/j.jhep.2013.04.031] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/15/2013] [Accepted: 04/23/2013] [Indexed: 12/13/2022]
Abstract
Downregulation of liver-specific MAT1A gene, encoding S-adenosylmethionine (SAM) synthesizing isozymes MATI/III, and upregulation of widely expressed MAT2A, encoding MATII isozyme, known as MAT1A:MAT2A switch, occurs in hepatocellular carcinoma (HCC). Being inhibited by its reaction product, MATII isoform upregulation cannot compensate for MATI/III decrease. Therefore, MAT1A:MAT2A switch contributes to decrease in SAM level in rodent and human hepatocarcinogenesis. SAM administration to carcinogen-treated rats prevents hepatocarcinogenesis, whereas MAT1A-KO mice, characterized by chronic SAM deficiency, exhibit macrovesicular steatosis, mononuclear cell infiltration in periportal areas, and HCC development. This review focuses upon the pleiotropic changes, induced by MAT1A/MAT2A switch, associated with HCC development. Epigenetic control of MATs expression occurs at transcriptional and post-transcriptional levels. In HCC cells, MAT1A/MAT2A switch is associated with global DNA hypomethylation, decrease in DNA repair, genomic instability, and signaling deregulation including c-MYC overexpression, rise in polyamine synthesis, upregulation of RAS/ERK, IKK/NF-kB, PI3K/AKT, and LKB1/AMPK axis. Furthermore, decrease in MAT1A expression and SAM levels results in increased HCC cell proliferation, cell survival, and microvascularization. All of these changes are reversed by SAM treatment in vivo or forced MAT1A overexpression or MAT2A inhibition in cultured HCC cells. In human HCC, MAT1A:MAT2A and MATI/III:MATII ratios correlate negatively with cell proliferation and genomic instability, and positively with apoptosis and global DNA methylation. This suggests that SAM decrease and MATs deregulation represent potential therapeutic targets for HCC. Finally, MATI/III:MATII ratio strongly predicts patients' survival length suggesting that MAT1A:MAT2A expression ratio is a putative prognostic marker for human HCC.
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Affiliation(s)
- Maddalena Frau
- Department of Clinical and Experimental Medicine, Laboratory of Experimental Pathology and Oncology, University of Sassari, Sassari, Italy
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13
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Lo TF, Tsai WC, Chen ST. MicroRNA-21-3p, a berberine-induced miRNA, directly down-regulates human methionine adenosyltransferases 2A and 2B and inhibits hepatoma cell growth. PLoS One 2013; 8:e75628. [PMID: 24098708 PMCID: PMC3787033 DOI: 10.1371/journal.pone.0075628] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 08/18/2013] [Indexed: 02/07/2023] Open
Abstract
Methionine adenosyltransferase (MAT) is the cellular enzyme that catalyzes the synthesis of S-adenosylmethionine (SAM), the principal biological methyl donor and a key regulator of hepatocyte proliferation, death and differentiation. Two genes, MAT1A and MAT2A, encode 2 distinct catalytic MAT isoforms. A third gene, MAT2B, encodes a MAT2A regulatory subunit. In hepatocellular carcinoma (HCC), MAT1A downregulation and MAT2A upregulation occur, known as the MAT1A:MAT2A switch. The switch is accompanied with an increasing expression of MAT2B, which results in decreased SAM levels and facilitates cancer cell growth. Berberine, an isoquinoline alkaloid isolated from many medicinal herbs such as Coptis chinensis, has a wide range of pharmacological effects including anti-cancer effects. Because drug-induced microRNAs have recently emerged as key regulators in guiding their pharmacological effects, we examined whether microRNA expression is differentially altered by berberine treatment in HCC. In this study, we used microRNA microarrays to find that the expression level of miR-21-3p (previously named miR-21*) increased after berberine treatment in the HepG2 human hepatoma cell line. To predict the putative targets of miR-21-3p, we integrated the gene expression profiles of HepG2 cells after berberine treatment by comparing with a gene list generated from sequence-based microRNA target prediction software. We then confirmed these predictions through transfection of microRNA mimics and a 3' UTR reporter assay. Our findings provide the first evidence that miR-21-3p directly reduces the expression of MAT2A and MAT2B by targeting their 3' UTRs. In addition, an overexpression of miR-21-3p increased intracellular SAM contents, which have been proven to be a growth disadvantage for hepatoma cells. The overexpression of miR-21-3p suppresses growth and induces apoptosis in HepG2 cells. Overall, our results demonstrate that miR-21-3p functions as a tumor suppressor by directly targeting both MAT2A and MAT2B, indicating its therapeutic potential in HCC.
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Affiliation(s)
- Ting-Fang Lo
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
- Institute of Biological Chemistry and Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Wei-Chung Tsai
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
- Institute of Biological Chemistry and Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Shui-Tein Chen
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
- Institute of Biological Chemistry and Genomics Research Center, Academia Sinica, Taipei, Taiwan
- * E-mail:
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Upadhyay RD, Balasinor NH, Kumar AV, Sachdeva G, Parte P, Dumasia K. Proteomics in reproductive biology: beacon for unraveling the molecular complexities. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1834:8-15. [PMID: 23072795 DOI: 10.1016/j.bbapap.2012.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 09/10/2012] [Accepted: 10/04/2012] [Indexed: 12/21/2022]
Abstract
Proteomics, an interface of rapidly evolving advances in physics and biology, is rapidly developing and expanding its potential applications to molecular and cellular biology. Application of proteomics tools has contributed towards identification of relevant protein biomarkers that can potentially change the strategies for early diagnosis and treatment of several diseases. The emergence of powerful mass spectrometry-based proteomics technique has added a new dimension to the field of medical research in liver, heart diseases and certain forms of cancer. Most proteomics tools are also being used to study physiological and pathological events related to reproductive biology. There have been attempts to generate the proteomes of testes, sperm, seminal fluid, epididymis, oocyte, and endometrium from reproductive disease patients. Here, we have reviewed proteomics based investigations in humans over the last decade, which focus on delineating the mechanism underlying various reproductive events such as spermatogenesis, oogenesis, endometriosis, polycystic ovary syndrome, embryo development. The challenge is to harness new technologies like 2-DE, DIGE, MALDI-MS, SELDI-MS, MUDPIT, LC-MS etc., to a greater extent to develop widely applicable clinical tools in understanding molecular aspects of reproduction both in health and disease.
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Affiliation(s)
- Rahul D Upadhyay
- Department of Neuroendocrinology, National Institute for Research in Reproductive Health, J.M. Street, Parel, Mumbai-400012, India.
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Abstract
S-adenosylmethionine (AdoMet, also known as SAM and SAMe) is the principal biological methyl donor synthesized in all mammalian cells but most abundantly in the liver. Biosynthesis of AdoMet requires the enzyme methionine adenosyltransferase (MAT). In mammals, two genes, MAT1A that is largely expressed by normal liver and MAT2A that is expressed by all extrahepatic tissues, encode MAT. Patients with chronic liver disease have reduced MAT activity and AdoMet levels. Mice lacking Mat1a have reduced hepatic AdoMet levels and develop oxidative stress, steatohepatitis, and hepatocellular carcinoma (HCC). In these mice, several signaling pathways are abnormal that can contribute to HCC formation. However, injury and HCC also occur if hepatic AdoMet level is excessive chronically. This can result from inactive mutation of the enzyme glycine N-methyltransferase (GNMT). Children with GNMT mutation have elevated liver transaminases, and Gnmt knockout mice develop liver injury, fibrosis, and HCC. Thus a normal hepatic AdoMet level is necessary to maintain liver health and prevent injury and HCC. AdoMet is effective in cholestasis of pregnancy, and its role in other human liver diseases remains to be better defined. In experimental models, it is effective as a chemopreventive agent in HCC and perhaps other forms of cancer as well.
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Affiliation(s)
- Shelly C Lu
- Division of Gastroenterology and Liver Diseases, USC Research Center for Liver Diseases, Southern California Research Center for ALPD and Cirrhosis, Keck School of Medicine, Los Angeles, California 90033, USA.
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Kummeling A, Penning LC, Rothuizen J, Brinkhof B, Weber MF, van Sluijs FJ. Hepatic gene expression and plasma albumin concentration related to outcome after attenuation of a congenital portosystemic shunt in dogs. Vet J 2012; 191:383-8. [DOI: 10.1016/j.tvjl.2011.04.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 04/18/2011] [Accepted: 04/30/2011] [Indexed: 10/18/2022]
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Pajares MA, Markham GD. Methionine adenosyltransferase (s-adenosylmethionine synthetase). ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2011; 78:449-521. [PMID: 22220481 DOI: 10.1002/9781118105771.ch11] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- María A Pajares
- Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM), Madrid Spain
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18
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Liu Q, Liu L, Zhao Y, Zhang J, Wang D, Chen J, He Y, Wu J, Zhang Z, Liu Z. Hypoxia induces genomic DNA demethylation through the activation of HIF-1α and transcriptional upregulation of MAT2A in hepatoma cells. Mol Cancer Ther 2011; 10:1113-23. [PMID: 21460102 DOI: 10.1158/1535-7163.mct-10-1010] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Hypoxia-inducible factor 1 (HIF-1) emerges as a crucial player in tumor progression. However, its role in hepatocellular carcinoma (HCC), especially its relation with global DNA methylation patterns in HCC under hypoxic tumor microenvironment is not completely understood. Methionine adenosyltransferase 2A (MAT2A) maintains the homeostasis of S-adenosylmethionine (SAM), a critical marker of genomic methylation status. In this study, we investigated the link between HIF-1α and MAT2A as a mechanism responsible for the change in genomic DNA methylation patterns in liver cancer under hypoxia conditions. Our results showed that hypoxia induces genomic DNA demethylation in CpG islands by reducing the steady-state SAM level both in vitro and in vivo. In addition, HIF-1α and MAT2A expression is correlated with tumor size and TNM stage of liver cancer tissues. We further showed that hypoxia-induced MAT2A expression is HIF-1α dependent and requires the recruitment of p300 and HDAC1. We also identified an authentic consensus HIF-1α binding site in MAT2A promoter by site-directed mutagenesis, electrophoretic mobility shift assay, and chromatin immunoprecipitation assay. Taken together, we show for the first time that hypoxia induces genomic DNA demethylation through the activation of HIF-1α and transcriptional upregulation of MAT2A in hepatoma cells. These findings provide new insights into our understanding of the molecular link between genomic DNA methylation and tumor hypoxia in HCC.
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Affiliation(s)
- Quanyan Liu
- Department of General Surgery, Zhongnan Hospital, Wuhan, China
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Role of methionine adenosyltransferase genes in hepatocarcinogenesis. Cancers (Basel) 2011; 3:1480-97. [PMID: 24212770 PMCID: PMC3757373 DOI: 10.3390/cancers3021480] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 01/27/2011] [Accepted: 01/30/2011] [Indexed: 12/19/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. Detection of HCC can be difficult, as most of the patients who develop this tumor have no symptoms other than those related to their longstanding liver disease. There is an urgent need to understand the molecular mechanisms that are responsible for the development of this disease so that appropriate therapies can be designed. Methionine adenosyltransferase (MAT) is an essential enzyme required for the biosynthesis of S-adenosylmethionine (AdoMet), an important methyl donor in the cell. Alterations in the expression of MAT genes and a decline in AdoMet biosynthesis are known to be associated with liver injury, cirrhosis and HCC. This review focuses on the role of MAT genes in HCC development and the scope for therapeutic strategies using these genes.
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20
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Liu Q, Chen J, Liu L, Zhang J, Wang D, Ma L, He Y, Liu Y, Liu Z, Wu J. The X protein of hepatitis B virus inhibits apoptosis in hepatoma cells through enhancing the methionine adenosyltransferase 2A gene expression and reducing S-adenosylmethionine production. J Biol Chem 2011; 286:17168-80. [PMID: 21247894 PMCID: PMC3089560 DOI: 10.1074/jbc.m110.167783] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The X protein (HBx) of hepatitis B virus (HBV) is involved in the development of hepatocellular carcinoma (HCC), and methionine adenosyltransferase 2A (MAT2A) promotes the growth of liver cancer cells through altering S-adenosylmethionine homeostasis. Thus, we speculated that a link between HBx and MAT2A may contribute to HCC development. In this study, the effects of HBx on MAT2A expression and cell apoptosis were investigated, and the molecular mechanism by which HBx and MAT2A regulate tumorigenesis was evaluated. Results from immunohistochemistry analyses of 37 pairs of HBV-associated liver cancer tissues/corresponding peritumor tissues showed that HBx and MAT2A are highly expressed in most liver tumor tissues. Our in vitro results revealed that HBx activates MAT2A expression in a dose-dependent manner in hepatoma cells, and such regulation requires the cis-regulatory elements NF-κB and CREB on the MAT2A gene promoter. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) further demonstrated that HBx facilitates the binding of NF-κB and CREB to MAT2A gene promoter. In addition, overexpression of HBx or MAT2A inhibits cell apoptosis, whereas knockdown of MAT2A expression stimulates apoptosis in hepatoma cells. Furthermore, we demonstrated that HBx reduces MAT1A expression and AdoMet production but enhances MAT2β expression. Thus, we proposed that HBx activates MAT2A expression through NF-κB and CREB signaling pathways to reduce AdoMet production, inhibit hepatoma cell apoptosis, and perhaps enhance HCC development. These findings should provide new insights into our understanding how the molecular mechanisms underline the effects of HBV infection on the production of MAT2A and the development of HCC.
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Affiliation(s)
- Quanyan Liu
- Department of General Surgery, Research Center of Digestive Diseases, Zhongnan Hospital, Wuhan 430071, China
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Brown JM, Ball JG, Hogsett A, Williams T, Valentovic M. Temporal study of acetaminophen (APAP) and S-adenosyl-L-methionine (SAMe) effects on subcellular hepatic SAMe levels and methionine adenosyltransferase (MAT) expression and activity. Toxicol Appl Pharmacol 2010; 247:1-9. [PMID: 20450926 PMCID: PMC2906679 DOI: 10.1016/j.taap.2010.04.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Revised: 03/19/2010] [Accepted: 04/08/2010] [Indexed: 01/19/2023]
Abstract
Acetaminophen (APAP) is the leading cause of drug induced liver failure in the United States. Previous studies in our laboratory have shown that S-adenosyl methionine (SAMe) is protective for APAP hepatic toxicity. SAMe is critical for glutathione synthesis and transmethylation of nucleic acids, proteins and phospholipids which would facilitate recovery from APAP toxicity. SAMe is synthesized in cells through the action of methionine adenosyltransferase (MAT). This study tested the hypothesis that total hepatic and subcellular SAMe levels are decreased by APAP toxicity. Studies further examined MAT expression and activity in response to APAP toxicity. Male C57BL/6 mice (16-22 g) were treated with vehicle (Veh; water 15 ml/kg ip injections), 250 mg/kg APAP (15 ml/kg, ip), SAMe (1.25 mmol/kg) or SAMe administered 1h after APAP injection (SAMe and SAMe+APAP). Hepatic tissue was collected 2, 4, and 6h after APAP administration. Levels of SAMe and its metabolite S-adenosylhomocysteine (SAH) were determined by HPLC analysis. MAT expression was examined by Western blot. MAT activity was determined by fluorescence assay. Total liver SAMe levels were depressed at 4h by APAP overdose, but not at 2 or 6h. APAP depressed mitochondrial SAMe levels at 4 and 6h relative to the Veh group. In the nucleus, levels of SAMe were depressed below detectable limits 4h following APAP administration. SAMe administration following APAP (SAMe+APAP) prevented APAP associated decline in mitochondrial and nuclear SAMe levels. In conclusion, the maintenance of SAMe may provide benefit in preventing damage associated with APAP toxicity.
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Affiliation(s)
- J. Michael Brown
- Department of Pharmacology, Physiology, and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV 25755
| | - John G. Ball
- Department of Pharmacology, Physiology, and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV 25755
| | - Amy Hogsett
- Department of Pharmacology, Physiology, and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV 25755
| | - Tierra Williams
- Department of Pharmacology, Physiology, and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV 25755
| | - Monica Valentovic
- Department of Pharmacology, Physiology, and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV 25755
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22
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Vázquez-Chantada M, Fernández-Ramos D, Embade N, Martínez-Lopez N, Varela-Rey M, Woodhoo A, Luka Z, Wagner C, Anglim PP, Finnell RH, Caballería J, Laird-Offringa IA, Gorospe M, Lu SC, Mato JM, Martínez-Chantar ML. HuR/methyl-HuR and AUF1 regulate the MAT expressed during liver proliferation, differentiation, and carcinogenesis. Gastroenterology 2010; 138:1943-53. [PMID: 20102719 PMCID: PMC2860011 DOI: 10.1053/j.gastro.2010.01.032] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Revised: 12/18/2009] [Accepted: 01/14/2010] [Indexed: 01/15/2023]
Abstract
BACKGROUND & AIMS Hepatic de-differentiation, liver development, and malignant transformation are processes in which the levels of hepatic S-adenosylmethionine are tightly regulated by 2 genes: methionine adenosyltransferase 1A (MAT1A) and methionine adenosyltransferase 2A (MAT2A). MAT1A is expressed in the adult liver, whereas MAT2A expression primarily is extrahepatic and is associated strongly with liver proliferation. The mechanisms that regulate these expression patterns are not completely understood. METHODS In silico analysis of the 3' untranslated region of MAT1A and MAT2A revealed putative binding sites for the RNA-binding proteins AU-rich RNA binding factor 1 (AUF1) and HuR, respectively. We investigated the posttranscriptional regulation of MAT1A and MAT2A by AUF1, HuR, and methyl-HuR in the aforementioned biological processes. RESULTS During hepatic de-differentiation, the switch between MAT1A and MAT2A coincided with an increase in HuR and AUF1 expression. S-adenosylmethionine treatment altered this homeostasis by shifting the balance of AUF1 and methyl-HuR/HuR, which was identified as an inhibitor of MAT2A messenger RNA (mRNA) stability. We also observed a similar temporal distribution and a functional link between HuR, methyl-HuR, AUF1, and MAT1A and MAT2A during fetal liver development. Immunofluorescent analysis revealed increased levels of HuR and AUF1, and a decrease in methyl-HuR levels in human livers with hepatocellular carcinoma (HCC). CONCLUSIONS Our data strongly support a role for AUF1 and HuR/methyl-HuR in liver de-differentiation, development, and human HCC progression through the posttranslational regulation of MAT1A and MAT2A mRNAs.
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Affiliation(s)
- Mercedes Vázquez-Chantada
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Technology Park of Bizkaia, 48160-Derio, Bizkaia, Spain
| | - David Fernández-Ramos
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Technology Park of Bizkaia, 48160-Derio, Bizkaia, Spain
| | - Nieves Embade
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Technology Park of Bizkaia, 48160-Derio, Bizkaia, Spain
| | - Nuria Martínez-Lopez
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Technology Park of Bizkaia, 48160-Derio, Bizkaia, Spain
| | - Marta Varela-Rey
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Technology Park of Bizkaia, 48160-Derio, Bizkaia, Spain
| | - Ashwin Woodhoo
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Technology Park of Bizkaia, 48160-Derio, Bizkaia, Spain
| | - Zigmund Luka
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232-0146, USA
| | - Conrad Wagner
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232-0146, USA, Tennessee Valley Department of Medical Affairs Medical Center, Nashville, TN, USA
| | - Paul P. Anglim
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9176, USA
| | - Richard H. Finnell
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, USA
| | | | - Ite A. Laird-Offringa
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9176, USA
| | - Myriam Gorospe
- Laboratory of Cellular and Molecular Biology, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Shelly C Lu
- Division of Gastrointestinal and Liver Diseases, Keck School of Medicine, University Southern California, Los Angeles, CA 90033, USA
| | - José M Mato
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Technology Park of Bizkaia, 48160-Derio, Bizkaia, Spain
| | - M Luz Martínez-Chantar
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Technology Park of Bizkaia, 48160-Derio, Bizkaia, Spain
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Wang Q, Liu QY, Liu ZS, Qian Q, Sun Q, Pan DY. Inhibition of hepatocelluar carcinoma MAT2A and MAT2beta gene expressions by single and dual small interfering RNA. J Exp Clin Cancer Res 2008; 27:72. [PMID: 19025580 PMCID: PMC2613873 DOI: 10.1186/1756-9966-27-72] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Accepted: 11/21/2008] [Indexed: 03/02/2023] Open
Abstract
RNA interference (RNAi) has been successfully applied in suppression of hepatic cancer genes. In hepatocelluar carcinoma cell, one methionine adenosyltransferase (MAT) isozyme, MATII was found to have two catalytic subunits which were encoded by MAT2A and MAT2β respectively. During tumorigeness of hepatocelluar carcinoma, expressions of the two genes were discovered to be increased combining with a switch of MAT (form MATI to MATII), To figure out the role played by MATII in hepatic cancer, In this study, for the first time we established a dual small interfering RNA (siRNA) expression system, which could simultaneously express two different siRNA molecules specifically targeting two genes. To test the effectiveness of this system, we applied this approach to express simultaneously two different siRNA duplexes that specifically target MAT2A and MAT2β genes of hepatocelluar carcinoma respectively in HepG2 cell. Results indicated that dual siRNA could simultaneously inhibit the expression of MAT2A and MAT2β gene by 89.5% and 97.8% respectively, In addition, dual siRNA molecules were able to significantly suppress growth of hepatocelluar carcinoma cell in vitro as well as induce apoptosis which was involved in arrest cell cycle at the G1/S checkpoint and the expressions of p21, p27 and Bax.
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Affiliation(s)
- Qun Wang
- Department of General Surgery, Zhongnan Hospital of Wuhan University, Hubei Province, PR China.
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Ramani K, Yang H, Xia M, Ara AI, Mato JM, Lu SC. Leptin's mitogenic effect in human liver cancer cells requires induction of both methionine adenosyltransferase 2A and 2beta. Hepatology 2008; 47:521-31. [PMID: 18041713 PMCID: PMC2387125 DOI: 10.1002/hep.22064] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
UNLABELLED Leptin is an adiopokine that plays a pivotal role in the progression of liver fibrogenesis and carcinogenesis. Recently, leptin was shown to be mitogenic in human liver cancer cell lines HepG2 and Huh7. Whether leptin can act as a mitogen in normal hepatocytes is unclear. Methionine adenosyltransferase (MAT) is an essential enzyme that catalyzes the formation of S-adenosylmethionine (SAMe), the principal methyl donor and precursor of polyamines. Two genes (MAT1A and MAT2A) encode for the catalytic subunit of MAT, whereas a third gene (MAT2beta) encodes for a regulatory subunit that modulates the activity of MAT2A-encoded isoenzyme. The aims of this study were to examine whether leptin's mitogenic activity involves MAT2A and MAT2beta and whether this can be modulated. We found that leptin is mitogenic in HepG2 cells but not in primary human or mouse hepatocytes. Leptin induced the expression of MAT2A and MAT2beta in HepG2 cells and normal human and mouse hepatocytes, but although it increased SAMe level in HepG2 cells, it had no effect on SAMe level in normal hepatocytes. Leptin-mediated induction of MAT genes and growth in HepG2 cells required activation of extracellular signal-regulated kinase and phosphatidylinositol-3-kinase signaling pathways. Treatment with SAMe or its metabolite methylthioadenosine (MTA) lowered expression of MAT2A and MAT2beta and blocked leptin-induced signaling, including an increase in MAT gene expression and growth. Increased expression of MAT2A and MAT2beta is required for leptin to be mitogenic, although by entirely different mechanisms. CONCLUSION Leptin induces MAT2A and MAT2beta expression in HepG2 cells and normal hepatocytes but is mitogenic only in HepG2 cells. Pharmacological doses of SAMe or MTA lower expression of both MAT2A and MAT2beta and interfere with leptin signaling.
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Affiliation(s)
- Komal Ramani
- Division of Gastroenterology and Liver Diseases, University of Southern California Research Center for Liver Diseases, University of Southern California–University of California at Los Angeles Research Center for Alcoholic Liver and Pancreatic Diseases, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Heping Yang
- Division of Gastroenterology and Liver Diseases, University of Southern California Research Center for Liver Diseases, University of Southern California–University of California at Los Angeles Research Center for Alcoholic Liver and Pancreatic Diseases, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Meng Xia
- Division of Gastroenterology and Liver Diseases, University of Southern California Research Center for Liver Diseases, University of Southern California–University of California at Los Angeles Research Center for Alcoholic Liver and Pancreatic Diseases, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Ainhoa Iglesias Ara
- Division of Gastroenterology and Liver Diseases, University of Southern California Research Center for Liver Diseases, University of Southern California–University of California at Los Angeles Research Center for Alcoholic Liver and Pancreatic Diseases, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - José M. Mato
- Centro de Investigación Cooperativa en Biociencias, CIBERehd, Technology Park of Bizkaia, Derio, Bizkaia, Spain
| | - Shelly C. Lu
- Division of Gastroenterology and Liver Diseases, University of Southern California Research Center for Liver Diseases, University of Southern California–University of California at Los Angeles Research Center for Alcoholic Liver and Pancreatic Diseases, Keck School of Medicine, University of Southern California, Los Angeles, CA
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Fang HL, Lin HY, Chan MC, Lin WL, Lin WC. Treatment of chronic liver injuries in mice by oral administration of ethanolic extract of the fruit of Hovenia dulcis. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2007; 35:693-703. [PMID: 17708635 DOI: 10.1142/s0192415x07005181] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The present study examined the effects of an ethanolic extract of the fruit of Hovenia dulcis (EHD) on chronic hepatitis induced by carbon tetrachloride (CCl(4)) in mice. CCl(4) (5%; 0.1 ml/10 g body weight) was given twice a week for 9 weeks, and mice received EHD throughout the entire experimental period. Plasma activities of GPT and GOT, and hepatic levels of malondialdehyde were significantly lowered in mice treated with EHD as compared to mice treated with CCl(4) only. Histological evaluation showed that EHD could attenuate the liver fibrosis and necrosis caused by CCl(4). RT-qPCR analysis also showed that EHD treatment decreased hepatic collagen (alpha1)(I) and collagen (alpha1)(III) mRNA expressions. Chronic CCl(4) treatment caused liver injuries in mice, characterized by an increase in hepatic methionine adenosyltransferase (MAT) 2A gene expression, and decreased MAT1A gene expression. EHD significantly reduced the changes in MAT gene expression due to the chronic CCl(4) treatment. These results clearly demonstrate that the EHD can reduce hepatic injuries in mice induced by CCl(4).
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Affiliation(s)
- Hsun-Lang Fang
- Graduate Institute of Chinese Pharmaceutical Science, China Medical University, Taichung 404, Taiwan
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26
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Ma X, Fan L, Meng Y, Hou Z, Mao YD, Wang W, Ding W, Liu JY. Proteomic analysis of human ovaries from normal and polycystic ovarian syndrome. Mol Hum Reprod 2007; 13:527-35. [PMID: 17557764 DOI: 10.1093/molehr/gam036] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility, affecting 5-10% of females of reproductive age. Currently, little is known about the changes in whole proteins between PCOS and normal ovaries. In the present study, a proteomic approach comprised two-dimensional gel electrophoresis (2DE) analysis and mass spectroscopy was used to identify proteins and examine expression patterns in three PCOS and normal ovaries. One hundred and ten protein spots were separated and showed different intensities between PCOS and normal ovaries. Sixty-nine proteins associated with cellular metabolism and physiological process were identified from 72 spots. Fifty-four proteins were up-regulated in PCOS ovaries and 15 other proteins were up-regulated in normal ovaries. These data demonstrate, for the first time, the complexity in the regulation of ovarian protein expression in human PCOS, and will provide important insight for a better understanding of the pathogenetic mechanisms underlying this clinical disorder.
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Affiliation(s)
- Xiang Ma
- Laboratory of Reproductive Medicine, Nanjing Medical University, and The Center of Clinical Reproductive Medicine, The First Affiliated Hospital of Nanjing Medical University, People's Republic of China
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Liu Q, Wu K, Zhu Y, He Y, Wu J, Liu Z. Silencing MAT2A gene by RNA interference inhibited cell growth and induced apoptosis in human hepatoma cells. Hepatol Res 2007; 37:376-88. [PMID: 17441811 DOI: 10.1111/j.1872-034x.2007.00041.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AIMS A switch in gene expression from MAT1A to MAT2A was found in liver cancer, suggesting that MAT2A plays an important role in facilitating cancer growth. MAT2A is an interesting target for antineoplastic therapy. The molecular mechanisms of silencing MAT2A by RNA interference inhibited cell growth and induced apoptosis in hepatoma cells was studied. METHODS We investigated the effects of MAT2A on S-adenosyl-methionine (SAM) production, cell growth and apoptotic cell death in hepatoma cell lines (Bel-7402, HepG2, and Hep3B) using an RNA interference approach. RESULTS The treatment of three hepatoma cell lines with small interfering RNA (siRNA) targeting to the MAT2A gene resulted in reducing the MAT II activity, facilitating SAM production, increasing SAM : SAH ratio, inhibiting cell growth and inducing cell apoptosis in hepatoma cells. In addition, silencing MAT2A gene resulted in the stimulation of MAT1A mRNA production, which was blocked by 3-deazaadenosine and l-ethionine, but not d-ethionine, suggesting that such effect was specific and mediated by upregulation of SAM level and SAM : S-adenosylethionine (SAH) ratio. CONCLUSION Silencing MAT2A by sequence-specific small interfering RNA caused a switch of MAT gene expression from MAT2A to MAT1A, which led the content of SAM to change to a higher steady-state level that resulted in the inhibition of cell growth and the induction of apoptotic cell death in human hepatoma cells. These results also suggested that MAT2A may hold potential as a new target for liver cancer gene therapy.
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Affiliation(s)
- Quanyan Liu
- Department of General Surgery, Research Center of Digestive Diseases, ZhongNan Hospital, Wuhan University, Wuhan, China
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28
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Yang H, Magilnick N, Noureddin M, Mato JM, Lu SC. Effect of hepatocyte growth factor on methionine adenosyltransferase genes and growth is cell density-dependent in HepG2 cells. J Cell Physiol 2007; 210:766-73. [PMID: 17154373 DOI: 10.1002/jcp.20891] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hepatocyte growth factor (HGF) is a potent hepatocyte mitogen but its effect in liver cancer is conflicting. Methionine adenosyltransferase (MAT) is an essential enzyme encoded by two genes (MAT1A and MAT2A), while a third gene (MAT2beta) encodes for a subunit that regulates the MAT2A-encoded isoenzyme. MAT1A is silenced while MAT2A and MAT2beta are induced in hepatocellular carcinoma (HCC). The current work examined expression of HGF/c-met in HCC and whether HGF regulates MAT genes and growth in HepG2 cells. We found the mRNA levels of HGF and c-met are markedly increased in HCC. To study the influence of cell density, HepG2 cells were plated under high-density (HD) or low-density (LD) and treated with HGF (10 ng/ml). Cell density had a dramatic effect on MAT1A expression, being nearly undetectable at LD to a ninefold induction under HD. Cell density also determined the effect of HGF. At HD, HGF increased the mRNA levels of p21 and p27, while lowering the levels of MAT genes, cyclin A, and c-met. At LD, HGF increased the mRNA levels of cyclin A, MAT2A, MAT2beta, and c-met. Consistently, HGF inhibits growth under HD but stimulates growth under LD. HGF induced sustained high ERK activation under HD as compared to LD. In summary, HGF induces genes favoring growth and is mitogenic when HepG2 cells are plated under LD; however, the opposite occurs under HD. This involves cell density-dependent differences in HGF-induced ERK activation. This may explain why HGF is mitogenic only when there is loss of cell-cell contact in vivo.
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Affiliation(s)
- Heping Yang
- Division of Gastroenterology and Liver Diseases, USC Research Center for Liver Diseases, USC-UCLA Research Center for Alcoholic Liver and Pancreatic Diseases, Keck School of Medicine USC, Los Angeles, California 90033, USA
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29
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Rodríguez JL, Boukaba A, Sandoval J, Georgieva EI, Latasa MU, García-Trevijano ER, Serviddio G, Nakamura T, Avila MA, Sastre J, Torres L, Mato JM, López-Rodas G. Transcription of the MAT2A gene, coding for methionine adenosyltransferase, is up-regulated by E2F and Sp1 at a chromatin level during proliferation of liver cells. Int J Biochem Cell Biol 2007; 39:842-50. [PMID: 17317269 DOI: 10.1016/j.biocel.2007.01.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2006] [Revised: 12/28/2006] [Accepted: 01/08/2007] [Indexed: 12/15/2022]
Abstract
Methionine adenosyltransferase (MAT) is an essential enzyme because it catalyzes the formation of S-adenosylmethionine, the main methyl donor. Two MAT-encoding genes (MAT1A, MAT2A) are found in mammals. The latter is expressed in proliferating liver, dedifferentiation and cancer, whereas MAT1A is expressed in adult quiescent hepatocytes. Here, we report studies on the molecular mechanisms controlling the induction of MAT2A in regenerating rat liver and in proliferating hepatocytes. The MAT2A is up-regulated at two discrete moments during liver regeneration, as confirmed by RNApol-ChIP analysis. The first one coincides with hepatocyte priming (i.e. G0-G1 transition), while the second one takes place at the G1-S interface. Electrophoretic mobility shift assays showed that a putative E2F sequence present in MAT2A promoter binds this factor and ChIP assays confirmed that E2F1, E2F3 and E2F4, as well as the pocket protein p130, are bound to the promoter in quiescent liver. MAT2A activation is accompanied by changes in the binding of histone-modifying enzymes to the promoter. Interestingly, p130 is not displaced from MAT2A promoter during hepatocyte priming, but it is in the late expression of the gene at the G1-S transition. Finally, the transcription factor Sp1 seems to play a decisive role in MAT2A induction, as it binds the promoter when the gene is being actively transcribed. In summary, the present work shows that the molecular mechanism of MAT2A expression is different during G0-G1 or G1-S transition and this may be related to the distinct requirements of S-adenosylmethionine during liver regeneration.
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Affiliation(s)
- José L Rodríguez
- Department of Biochemistry and Molecular Biology, University of Valencia, Spain
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30
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Floyd RA, Kotake Y, Towner RA, Guo WX, Nakae D, Konishi Y. Nitric Oxide and Cancer Development. J Toxicol Pathol 2007. [DOI: 10.1293/tox.20.77] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Robert A. Floyd
- Oklahoma Medical Research Foundation
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center
| | | | | | | | - Dai Nakae
- Tokyo Metropolitan Institute of Public Health
- Tokyo University of Agriculture
| | - Yoichi Konishi
- International Federation of Societies of Toxicologic Pathologists
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31
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Nie AY, McMillian M, Parker JB, Leone A, Bryant S, Yieh L, Bittner A, Nelson J, Carmen A, Wan J, Lord PG. Predictive toxicogenomics approaches reveal underlying molecular mechanisms of nongenotoxic carcinogenicity. Mol Carcinog 2006; 45:914-33. [PMID: 16921489 DOI: 10.1002/mc.20205] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Toxicogenomics technology defines toxicity gene expression signatures for early predictions and hypotheses generation for mechanistic studies, which are important approaches for evaluating toxicity of drug candidate compounds. A large gene expression database built using cDNA microarrays and liver samples treated with over one hundred paradigm compounds was mined to determine gene expression signatures for nongenotoxic carcinogens (NGTCs). Data were obtained from male rats treated for 24 h. Training/testing sets of 24 NGTCs and 28 noncarcinogens were used to select genes. A semiexhaustive, nonredundant gene selection algorithm yielded six genes (nuclear transport factor 2, NUTF2; progesterone receptor membrane component 1, Pgrmc1; liver uridine diphosphate glucuronyltransferase, phenobarbital-inducible form, UDPGTr2; metallothionein 1A, MT1A; suppressor of lin-12 homolog, Sel1h; and methionine adenosyltransferase 1, alpha, Mat1a), which identified NGTCs with 88.5% prediction accuracy estimated by cross-validation. This six genes signature set also predicted NGTCs with 84% accuracy when samples were hybridized to commercially available CodeLink oligo-based microarrays. To unveil molecular mechanisms of nongenotoxic carcinogenesis, 125 differentially expressed genes (P<0.01) were selected by Student's t-test. These genes appear biologically relevant, of 71 well-annotated genes from these 125 genes, 62 were overrepresented in five biochemical pathway networks (most linked to cancer), and all of these networks were linked by one gene, c-myc. Gene expression profiling at early time points accurately predicts NGTC potential of compounds, and the same data can be mined effectively for other toxicity signatures. Predictive genes confirm prior work and suggest pathways critical for early stages of carcinogenesis.
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Affiliation(s)
- Alex Y Nie
- Johnson & Johnson Pharmaceutical Research & Development, LLC, Raritan, New Jersey, USA
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32
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Olivero M, Ruggiero T, Saviozzi S, Rasola A, Coltella N, Crispi S, Di Cunto F, Calogero R, Di Renzo MF. Genes regulated by hepatocyte growth factor as targets to sensitize ovarian cancer cells to cisplatin. Mol Cancer Ther 2006; 5:1126-35. [PMID: 16731744 DOI: 10.1158/1535-7163.mct-06-0013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Advanced ovarian cancers are initially responsive to chemotherapy with platinum drugs but develop drug resistance in most cases. We showed recently that hepatocyte growth factor (HGF) enhances death of human ovarian cancer cell lines treated with cisplatin (CDDP) and that this effect is mediated by the p38 mitogen-activated protein kinase. In this work, we integrated genome-wide expression profiling, in silico data survey, and functional assays to identify transcripts regulated in SK-OV-3 ovarian cancer cells made more responsive to CDDP by HGF. Using oligonucleotide microarrays, we found that HGF pretreatment changes the transcriptional response to CDDP. Quantitative reverse transcription-PCR not only validated all the 15 most differentially expressed genes but also confirmed that they were primarily modulated by the combined treatment with HGF and CDDP and reversed by suppressing p38 mitogen-activated protein kinase activity. Among the differentially expressed genes, we focused functional analysis on two regulatory subunits of the protein phosphatase 2A, which were down-modulated by HGF plus CDDP. Decrease of each subunit by RNA interference made ovarian cancer cells more responsive to CDDP, mimicking the effect of HGF. In conclusion, we show that HGF and CDDP modulate transcription in ovarian cancer cells and that this transcriptional response is involved in apoptosis regulation. We also provide the proof-of-concept that the identified genes might be targeted to either increase the efficacy of chemotherapeutics or revert chemotherapy resistance.
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Affiliation(s)
- Martina Olivero
- Laboratory of Cancer Genetics, Institute for Cancer Research and Treatment, University of Torino School of Medicine, SP 142, KM 3.95, 10060, Candiolo (Torino), Italy.
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Abstract
AIM: To investigate the effects of Reishi mushroom, Ganoderma lucidum extract (GLE), on liver fibrosis induced by carbon tetrachloride (CCl4) in rats.
METHODS: Rat hepatic fibrosis was induced by CCl4. Forty Wistar rats were divided randomly into 4 groups: control, CCl4, and two GLE groups. Except for rats in control group, all rats were administered orally with CCl4 (20%, 0.2 mL/100 g body weight) twice a week for 8 weeks. Rats in GLE groups were treated daily with GLE (1 600 or 600 mg/kg) via gastrogavage throughout the whole experimental period. Liver function parameters, such as ALT, AST, albumin, and albumin/globulin (A/G) ratio, spleen weight and hepatic amounts of protein, malondiladehyde (MDA) and hydroxyproline (HP) were determined. Histochemical staining of Sirius red was performed. Expression of transforming growth factor β1 (TGF-β1), methionine adenosyltransferase (MAT1) 1A and MAT2A mRNA were detected by using RT-PCR.
RESULTS: CCl4 caused liver fibrosis, featuring increase in plasma transaminases, hepatic MDA and HP contents, and spleen weight; and decrease in plasma albumin, A/G ratio and hepatic protein level. Compared with CCl4 group, GLE (600, 1 600 mg/kg) treatment significantly increased plasma albumin level and A/G ratio (P < 0.05) and reduced the hepatic HP content (P < 0.01). GLE (1 600 mg/kg) treatment markedly decreased the activities of transaminases (P < 0.05), spleen weight (P < 0.05) and hepatic MDA content (P < 0.05); but increased hepatic protein level (P < 0.05). Liver histology in the GLE (1 600 mg/kg)-treated rats was also improved (P < 0.01). RT-PCR analysis showed that GLE treatment decreased the expression of TGF-β1 (P < 0.05-0.001) and changed the expression of MAT1A (P < 0.05-0.01) and MAT2A (P < 0.05-0.001).
CONCLUSION: Oral administration of GLE significantly reduces CCl4-induced hepatic fibrosis in rats, probably by exerting a protective effect against hepatocellular necrosis by its free-radical scavenging ability.
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Affiliation(s)
- Wen-Chuan Lin
- Department of Pharmacology, China Medical University, 91 Hsueh Shih Road, Taichung 404, Taiwan, China.
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Pozuelo Rubio M, Geraghty KM, Wong BHC, Wood NT, Campbell DG, Morrice N, Mackintosh C. 14-3-3-affinity purification of over 200 human phosphoproteins reveals new links to regulation of cellular metabolism, proliferation and trafficking. Biochem J 2004; 379:395-408. [PMID: 14744259 PMCID: PMC1224091 DOI: 10.1042/bj20031797] [Citation(s) in RCA: 366] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2003] [Revised: 01/26/2004] [Accepted: 01/27/2004] [Indexed: 01/14/2023]
Abstract
14-3-3-interacting proteins were isolated from extracts of proliferating HeLa cells using 14-3-3 affinity chromatography, eluting with a phosphopeptide that competes with targets for 14-3-3 binding. The isolated proteins did not bind to 14-3-3 proteins (14-3-3s) after dephosphorylation with protein phosphatase 2A (PP2A), indicating that binding to 14-3-3s requires their phosphorylation. The binding proteins identified by tryptic mass fingerprinting and Western blotting include many enzymes involved in generating precursors such as purines (AMP, GMP and ATP), FAD, NADPH, cysteine and S-adenosylmethionine, which are needed for cell growth, regulators of cell proliferation, including enzymes of DNA replication, proteins of anti-oxidative metabolism, regulators of actin dynamics and cellular trafficking, and proteins whose deregulation has been implicated in cancers, diabetes, Parkinsonism and other neurological diseases. Several proteins bound to 14-3-3-Sepharose in extracts of proliferating cells, but not in non-proliferating, serum-starved cells, including a novel microtubule-interacting protein ELP95 (EMAP-like protein of 95 kDa) and a small HVA22/Yop1p-related protein. In contrast, the interactions of 14-3-3s with the N-methyl-D-aspartate receptor 2A subunit and NuMA (nuclear mitotic apparatus protein) were not regulated by serum. Overall, our findings suggest that 14-3-3s may be central to integrating the regulation of biosynthetic metabolism, cell proliferation, survival, and other processes in human cells.
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Affiliation(s)
- Mercedes Pozuelo Rubio
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
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Chen L, Zeng Y, Yang H, Lee TD, French SW, Corrales FJ, García-Trevijano ER, Avila MA, Mato JM, Lu SC. Impaired liver regeneration in mice lacking methionine adenosyltransferase 1A. FASEB J 2004; 18:914-6. [PMID: 15033934 DOI: 10.1096/fj.03-1204fje] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Methionine adenosyltransferase (MAT) is an essential enzyme because it catalyzes the formation of S-adenosylmethionine (SAMe), the principal biological methyl donor. Of the two genes that encode MAT, MAT1A is mainly expressed in adult liver and MAT2A is expressed in all extrahepatic tissues. Mice lacking MAT1A have reduced hepatic SAMe content and spontaneously develop hepatocellular carcinoma. The current study examined the influence of chronic hepatic SAMe deficiency on liver regeneration. Despite having higher baseline hepatic staining for proliferating cell nuclear antigen, MAT1A knockout mice had impaired liver regeneration after partial hepatectomy (PH) as determined by bromodeoxyuridine incorporation. This can be explained by an inability to up-regulate cyclin D1 after PH in the knockout mice. Upstream signaling pathways involved in cyclin D1 activation include nuclear factor kappaB (NFkappaB), the c-Jun-N-terminal kinase (JNK), extracellular signal-regulated kinases (ERKs), and signal transducer and activator of transcription-3 (STAT-3). At baseline, JNK and ERK are more activated in the knockouts whereas NFkappaB and STAT-3 are similar to wild-type mice. Following PH, early activation of these pathways occurred, but although they remained increased in wild-type mice, c-jun and ERK phosphorylation fell progressively in the knockouts. Hepatic SAMe levels fell progressively following PH in wild-type mice but remained unchanged in the knockouts. In culture, MAT1A knockout hepatocytes have higher baseline DNA synthesis but failed to respond to the mitogenic effect of hepatocyte growth factor. Taken together, our findings define a critical role for SAMe in ERK signaling and cyclin D1 regulation during regeneration and suggest chronic hepatic SAMe depletion results in loss of responsiveness to mitogenic signals.
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Affiliation(s)
- Lixin Chen
- Division of Gastroenterology and Liver Diseases, USC-UCLA Research Center for Alcoholic Liver and Pancreatic Diseases, USC Liver Disease Research Center, USC School of Medicine, Los Angeles, California 90033, USA
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Liu SL, Lin X, Shi DY, Cheng J, Wu CQ, Zhang YD. Reactive oxygen species stimulated human hepatoma cell proliferation via cross-talk between PI3-K/PKB and JNK signaling pathways. Arch Biochem Biophys 2002; 406:173-82. [PMID: 12361705 DOI: 10.1016/s0003-9861(02)00430-7] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reactive oxygen species (ROS) are important for intracellular signaling mechanisms regulating many cellular processes. Manganese superoxide dismutase (MnSOD) may regulate cell growth by changing the level of intracellular ROS. In our study, we investigated the effect of ROS on 7721 human hepatoma cell proliferation. Treatment with H2O2 (1-10 microM) or transfection with antisense MnSOD cDNA constructs significantly increased the cell proliferation. Recently, the mitogen-activated protein kinases (MAPK) and the protein kinase B (PKB) were proposed to be involved in cell growth. Accordingly, we assessed the ability of ROS to activate MAPK and PKB. PKB and extracellular signal-regulated kinase (ERK) were both rapidly and transiently activated by 10 microM H2O2, but the activities of p38 MAPK and JNK were not changed. ROS-induced PKB activation was abrogated by the phosphatidylinositol 3-kinase (PI3-K) inhibitor LY294002, suggesting that PI3-K is an upstream mediator of PKB activation in 7721 cells. Transfection with sense PKB cDNA promoted c-fos and c-jun expression in 7721 cells, suggesting that ROS may regulate c-fos and c-jun expression via the PKB pathway. Furthermore we found that exogenous H2O2 could stimulate the proliferation of PKB-AS7721 cells transfected with antisense PKB cDNA, which was partly dependent on JNK activation, suggesting that H2O2 stimulated hepatoma cell proliferation via cross-talk between the PI3-K/PKB and the JNK signaling pathways. However, insulin could stimulate 7721 cell proliferation, which is independent of cross-talk between PI3-K/PKB and JNK pathways. In addition, H2O2 did not induce the cross-talk between the PI3-K/PKB and the JNK pathways in normal liver cells. Taken together, we found that ROS regulate hepatoma cell growth via specific signaling pathways (cross-talk between PI3-K/PKB and JNK pathway) which may provide a novel clue to elucidate the mechanism of hepatoma carcinogenesis.
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Affiliation(s)
- Shan-Lin Liu
- Department of Biochemistry, Shanghai Medical College of Fudan University, Free Radical Regulation Research Center of Fudan University, Shanghai, People's Republic of China.
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