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Figiel M, Górka AK, Górecki A. Zinc Ions Modulate YY1 Activity: Relevance in Carcinogenesis. Cancers (Basel) 2023; 15:4338. [PMID: 37686614 PMCID: PMC10487186 DOI: 10.3390/cancers15174338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
YY1 is widely recognized as an intrinsically disordered transcription factor that plays a role in development of many cancers. In most cases, its overexpression is correlated with tumor progression and unfavorable patient outcomes. Our latest research focusing on the role of zinc ions in modulating YY1's interaction with DNA demonstrated that zinc enhances the protein's multimeric state and affinity to its operator. In light of these findings, changes in protein concentration appear to be just one element relevant to modulating YY1-dependent processes. Thus, alterations in zinc ion concentration can directly and specifically impact the regulation of gene expression by YY1, in line with reports indicating a correlation between zinc ion levels and advancement of certain tumors. This review concentrates on other potential consequences of YY1 interaction with zinc ions that may act by altering charge distribution, conformational state distribution, or oligomerization to influence its interactions with molecular partners that can disrupt gene expression patterns.
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Affiliation(s)
| | | | - Andrzej Górecki
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Physical Biochemistry, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland; (M.F.); (A.K.G.)
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2
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Jung M, Bui I, Bonavida B. Role of YY1 in the Regulation of Anti-Apoptotic Gene Products in Drug-Resistant Cancer Cells. Cancers (Basel) 2023; 15:4267. [PMID: 37686541 PMCID: PMC10486809 DOI: 10.3390/cancers15174267] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/21/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
Cancer is a leading cause of death among the various diseases encountered in humans. Cancer is not a single entity and consists of numerous different types and subtypes that require various treatment regimens. In the last decade, several milestones in cancer treatments were accomplished, such as specific targeting agents or revitalizing the dormant anti-tumor immune response. These milestones have resulted in significant positive clinical responses as well as tumor regression and the prolongation of survival in subsets of cancer patients. Hence, in non-responding patients and non-responding relapsed patients, cancers develop intrinsic mechanisms of resistance to cell death via the overexpression of anti-apoptotic gene products. In parallel, the majority of resistant cancers have been reported to overexpress a transcription factor, Yin Yang 1 (YY1), which regulates the chemo-immuno-resistance of cancer cells to therapeutic anticancer cytotoxic agents. The relationship between the overexpression of YY1 and several anti-apoptotic gene products, such as B-cell lymphoma 2 protein (Bcl-2), B-cell lymphoma extra-large (Bcl-xL), myeloid cell leukemia 1 (Mcl-1) and survivin, is investigated in this paper. The findings demonstrate that these anti-apoptotic gene products are regulated, in part, by YY1 at the transcriptional, epigenetic, post-transcriptional and translational levels. While targeting each of the anti-apoptotic gene products individually has been examined and clinically tested for some, this targeting strategy is not effective due to compensation by other overexpressed anti-apoptotic gene products. In contrast, targeting YY1 directly, through small interfering RNAs (siRNAs), gene editing or small molecule inhibitors, can be therapeutically more effective and generalized in YY1-overexpressed resistant cancers.
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Affiliation(s)
| | | | - Benjamin Bonavida
- Department of Microbiology, Immunology & Molecular Genetics, David Geffen School of Medicine, Jonsson Comprehensive Cancer Center, University of California, Los Angeles, CA 90095, USA
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Sarvagalla S, Kolapalli SP, Vallabhapurapu S. The Two Sides of YY1 in Cancer: A Friend and a Foe. Front Oncol 2019; 9:1230. [PMID: 31824839 PMCID: PMC6879672 DOI: 10.3389/fonc.2019.01230] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 10/28/2019] [Indexed: 12/12/2022] Open
Abstract
Yin Yang 1 (YY1), a dual function transcription factor, is known to regulate transcriptional activation and repression of many genes associated with multiple cellular processes including cellular differentiation, DNA repair, autophagy, cell survival vs. apoptosis, and cell division. Owing to its role in processes that upon deregulation are linked to malignant transformation, YY1 has been implicated as a major driver of many cancers. While a large body of evidence supports the role of YY1 as a tumor promoter, recent reports indicated that YY1 also functions as a tumor suppressor. The mechanism by which YY1 brings out opposing outcome in tumor growth vs. suppression is not completely clear and some of the recent reports have provided significant insight into this. Likewise, the mechanism by which YY1 functions both as a transcriptional activator and repressor is not completely clear. It is likely that the proteins with which YY1 interacts might determine its function as an activator or repressor of transcription as well as its role as a tumor suppressor or promoter. Hence, a collection of YY1-protein interactions in the context of different cancers would help us gain an insight into how YY1 promotes or suppresses cancers. This review focuses on the YY1 interacting partners and its target genes in different cancer models. Finally, we discuss the possibility of therapeutically targeting the YY1 in cancers where it functions as a tumor promoter.
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Affiliation(s)
- Sailu Sarvagalla
- Division of Biology, Indian Institute of Science Education and Research Tirupati, Tirupati, India
| | | | - Sivakumar Vallabhapurapu
- Division of Biology, Indian Institute of Science Education and Research Tirupati, Tirupati, India
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4
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Hays E, Bonavida B. YY1 regulates cancer cell immune resistance by modulating PD-L1 expression. Drug Resist Updat 2019; 43:10-28. [PMID: 31005030 DOI: 10.1016/j.drup.2019.04.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/03/2019] [Accepted: 04/05/2019] [Indexed: 02/08/2023]
Abstract
Recent advances in the treatment of various cancers have resulted in the adaptation of several novel immunotherapeutic strategies. Notably, the recent intervention through immune checkpoint inhibitors has resulted in significant clinical responses and prolongation of survival in patients with several therapy-resistant cancers (melanoma, lung, bladder, etc.). This intervention was mediated by various antibodies directed against inhibitory receptors expressed on cytotoxic T-cells or against corresponding ligands expressed on tumor cells and other cells in the tumor microenvironment (TME). However, the clinical responses were only observed in a subset of the treated patients; it was not clear why the remaining patients did not respond to checkpoint inhibitor therapies. One hypothesis stated that the levels of PD-L1 expression correlated with poor clinical responses to cell-mediated anti-tumor immunotherapy. Hence, exploring the underlying mechanisms that regulate PD-L1 expression on tumor cells is one approach to target such mechanisms to reduce PD-L1 expression and, therefore, sensitize the resistant tumor cells to respond to PD-1/PD-L1 antibody treatments. Various investigations revealed that the overexpression of the transcription factor Yin Yang 1 (YY1) in most cancers is involved in the regulation of tumor cells' resistance to cell-mediated immunotherapies. We, therefore, hypothesized that the role of YY1 in cancer immune resistance may be correlated with PD-L1 overexpression on cancer cells. This hypothesis was investigated and analysis of the reported literature revealed that several signaling crosstalk pathways exist between the regulations of both YY1 and PD-L1 expressions. Such pathways include p53, miR34a, STAT3, NF-kB, PI3K/AKT/mTOR, c-Myc, and COX-2. Noteworthy, many clinical and pre-clinical drugs have been utilized to target these above pathways in various cancers independent of their roles in the regulation of PD-L1 expression. Therefore, the direct inhibition of YY1 and/or the use of the above targeted drugs in combination with checkpoint inhibitors should result in enhancing the cell-mediated anti-tumor cell response and also reverse the resistance observed with the use of checkpoint inhibitors alone.
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Affiliation(s)
- Emily Hays
- Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, United States
| | - Benjamin Bonavida
- Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, United States.
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5
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Keilwagen J, Posch S, Grau J. Accurate prediction of cell type-specific transcription factor binding. Genome Biol 2019; 20:9. [PMID: 30630522 PMCID: PMC6327544 DOI: 10.1186/s13059-018-1614-y] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 12/18/2018] [Indexed: 01/11/2023] Open
Abstract
Prediction of cell type-specific, in vivo transcription factor binding sites is one of the central challenges in regulatory genomics. Here, we present our approach that earned a shared first rank in the "ENCODE-DREAM in vivo Transcription Factor Binding Site Prediction Challenge" in 2017. In post-challenge analyses, we benchmark the influence of different feature sets and find that chromatin accessibility and binding motifs are sufficient to yield state-of-the-art performance. Finally, we provide 682 lists of predicted peaks for a total of 31 transcription factors in 22 primary cell types and tissues and a user-friendly version of our approach, Catchitt, for download.
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Affiliation(s)
- Jens Keilwagen
- Institute for Biosafety in Plant Biotechnology, Julius Kühn-Institut (JKI) - Federal Research Centre for Cultivated Plants, Erwin-Baur-Straße 27, Quedlinburg, 06484 Germany
| | - Stefan Posch
- Institute of Computer Science, Martin Luther University Halle–Wittenberg, Von-Seckendorff-Platz 1, Halle (Saale), 06120 Germany
| | - Jan Grau
- Institute of Computer Science, Martin Luther University Halle–Wittenberg, Von-Seckendorff-Platz 1, Halle (Saale), 06120 Germany
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6
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Shenoda BB, Tian Y, Alexander GM, Aradillas-Lopez E, Schwartzman RJ, Ajit SK. miR-34a-mediated regulation of XIST in female cells under inflammation. J Pain Res 2018; 11:935-945. [PMID: 29773953 PMCID: PMC5947841 DOI: 10.2147/jpr.s159458] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background Evidence is overwhelming for sex differences in pain, with women representing the majority of the chronic pain patient population. There is a need to explore novel avenues to elucidate this sex bias in the development of chronic inflammatory pain conditions. Complex regional pain syndrome (CRPS) is a chronic neuropathic pain disorder, and the incidence of CRPS is greater in women than in men by ~4:1. Since neurogenic inflammation is a key feature of CRPS, dysregulation of inflammatory responses can be a factor in predisposing women to chronic pain. Methods Our studies investigating alterations in circulating microRNAs (miRNAs) in whole blood from female CRPS patients showed significant differential expression of miRNAs between responders and poor responders to ketamine treatment. Several of these miRNAs are predicted to target the long noncoding RNA, X-inactive-specific transcript (XIST). XIST mediates X-chromosome inactivation and is essential for equalizing the expression of X-linked genes between females and males. Based on the well-established role in inflammatory process, we focused on miR-34a, one of the miRNAs predicted to target XIST, and downregulated in CRPS patients responding poorly to ketamine. Results Our in vitro and in vivo models of acute inflammation and data from patients with CRPS showed that miR-34a can regulate XIST under inflammation directly, and through pro-inflammatory transcription factor Yin-Yang 1 (YY1). XIST was significantly upregulated in a subset of CRPS patients responding poorly to ketamine. Conclusion Since dysregulation of XIST can result in genes escaping inactivation or reactivation in female cells, further investigations on the role of XIST in the predominance of chronic inflammatory and pain disorders in women is warranted.
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Affiliation(s)
- Botros B Shenoda
- Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Yuzhen Tian
- Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, USA
| | | | - Enrique Aradillas-Lopez
- Neurology, Drexel University College of Medicine, Philadelphia, PA, USA.,Vincera Institute, Philadelphia, PA, USA
| | | | - Seena K Ajit
- Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, USA
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7
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Ji X, Shen Y, Sun H, Gao X. A novel anti-alpha-fetoprotein single-chain variable fragment displays anti-tumor effects in HepG2 cells as a single agent or in combination with paclitaxel. Tumour Biol 2016; 37:10085-96. [DOI: 10.1007/s13277-016-4803-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/06/2016] [Indexed: 01/16/2023] Open
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8
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Hou W, Li H, Jiang W, Zhang C, McNutt MA, Li G. Simian Immunodeficiency Virus Impacts MicroRNA-16 Mediated Post-Transcriptional Regulation of mu Opioid Receptor in CEM ×174 Cells. J Cell Biochem 2015; 117:84-93. [DOI: 10.1002/jcb.25251] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 06/04/2015] [Indexed: 01/09/2023]
Affiliation(s)
- Wenting Hou
- Department of Biochemistry and Molecular Biology; Peking University Health Science Center; Peking University; Beijing 100191 China
| | - Hui Li
- Department of Biochemistry and Molecular Biology; Peking University Health Science Center; Peking University; Beijing 100191 China
| | - Wei Jiang
- Department of Biochemistry and Molecular Biology; Peking University Health Science Center; Peking University; Beijing 100191 China
| | - Chao Zhang
- Department of Biochemistry and Molecular Biology; Peking University Health Science Center; Peking University; Beijing 100191 China
| | - Michael A McNutt
- Department of Pathology; Peking University Health Science Center; Peking University; Beijing 100191 China
| | - Gang Li
- Department of Biochemistry and Molecular Biology; Peking University Health Science Center; Peking University; Beijing 100191 China
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9
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Beketaev I, Zhang Y, Weng KC, Rhee S, Yu W, Liu Y, Mager J, Wang J. cis-regulatory control of Mesp1 expression by YY1 and SP1 during mouse embryogenesis. Dev Dyn 2015; 245:379-87. [DOI: 10.1002/dvdy.24349] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 08/20/2015] [Accepted: 09/12/2015] [Indexed: 11/08/2022] Open
Affiliation(s)
- Ilimbek Beketaev
- Center for Stem Cell Engineering, Department of Basic Research Laboratories; Texas Heart Institute at St. Luke's Episcopal Hospital; Houston Texas USA
| | - Yi Zhang
- In Vitro Fertilization Center; Affiliated Hospital of Hainan Medical University; Haikou Hainan People's Republic of China
| | - Kuo-Chan Weng
- Department of Biology and Biochemistry; University of Houston; Houston Texas USA
| | - Siyeon Rhee
- Department of Veterinary & Animal Sciences; University of Massachusetts; Amherst Massachusetts USA
| | - Wei Yu
- Department of Biology and Biochemistry; University of Houston; Houston Texas USA
| | - Yu Liu
- Department of Biology and Biochemistry; University of Houston; Houston Texas USA
| | - Jesse Mager
- Department of Veterinary & Animal Sciences; University of Massachusetts; Amherst Massachusetts USA
| | - Jun Wang
- Center for Stem Cell Engineering, Department of Basic Research Laboratories; Texas Heart Institute at St. Luke's Episcopal Hospital; Houston Texas USA
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10
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Zhang C, Chen X, Liu H, Li H, Jiang W, Hou W, McNutt MA, Lu F, Li G. Alpha fetoprotein mediates HBx induced carcinogenesis in the hepatocyte cytoplasm. Int J Cancer 2015; 137:1818-29. [PMID: 25846475 DOI: 10.1002/ijc.29548] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 03/17/2015] [Accepted: 03/24/2015] [Indexed: 12/14/2022]
Abstract
Although tumor-associated fetal protein AFP has demonstrated utility as a clinical tumor marker, the significance of intracellular AFP is still unclear. The aim of this study was to explore the role of cytoplasmic AFP during HBx induced carcinogenesis, which had not previously been recognized; 614 HCC patients were analyzed for correlation of HBV infection with AFP level, and much higher AFP levels were found in HBsAg positive patients. Tumor tissue specimens from 20 HCC patients were used for analysis of AFP and GADD45α. Analysis of HCC specimens showed that upregulation of cytoplasmic AFP is associated with down-regulation of GADD45α in neoplastic tissue. Transfected HBx promotes transcription of AFP by acting on the elements in the AFP gene regulatory region. HBx itself did not directly impact transcription of GADD45α. However, the obstruction of RAR signaling by HBx induced elevation of AFP, which led to down-regulation of GADD45α. Cytoplasmic AFP was able to interact with RAR, disrupting its entrance into the nucleus and binding to the elements in the regulatory region of the GADD45α gene. Knockdown of AFP in siRNA-transfected AFP positive cell lines was synchronously associated with an incremental increase of RAR binding to DNA, as well as upregulation of GADD45α and it was contrary in AFP gene-transfected AFP negative cell lines. These results indicate cytoplasmic AFP is not only a histochemical tumor biomarker for human hepatoma but is also an intracellular signal molecule and potential participant in HBx induced hepatocarcinogenesis.
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Affiliation(s)
- Chao Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Xiangmei Chen
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Hui Liu
- Department of Pathology, Beijing You'an Hospital, Beijing, China
| | - Hui Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Wei Jiang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Wenting Hou
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Michael A McNutt
- Department of Pathology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Fengmin Lu
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Gang Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.,Shenzhen PKU-HKUST Medical Center, Shenzhen, Guangdong, China
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Sorge RE, LaCroix-Fralish ML, Tuttle AH, Khoutorsky A, Sotocinal SG, Austin JS, Melmed K, Labialle S, Schmidt JV, Wood JN, Naumova AK, Mogil JS. The Yin and Yang of pain: variability in formalin test nociception and morphine analgesia produced by the Yin Yang 1 transcription factor gene. GENES BRAIN AND BEHAVIOR 2013; 12:405-13. [DOI: 10.1111/gbb.12030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 02/17/2013] [Indexed: 12/20/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | - J. V. Schmidt
- Department of Obstetrics and Gynecology; McGill University; Montreal; Canada
| | - J. N. Wood
- Molecular Nociception Group; University College London; London; UK
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12
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Wagley Y, Hwang CK, Lin HY, Kam AFY, Law PY, Loh HH, Wei LN. Inhibition of c-Jun NH2-terminal kinase stimulates mu opioid receptor expression via p38 MAPK-mediated nuclear NF-κB activation in neuronal and non-neuronal cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1476-88. [PMID: 23485395 DOI: 10.1016/j.bbamcr.2013.02.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 02/02/2013] [Accepted: 02/18/2013] [Indexed: 12/20/2022]
Abstract
Despite its potential side effects of addiction, tolerance and withdrawal symptoms, morphine is widely used for reducing moderate and severe pain. Previous studies have shown that the analgesic effect of morphine depends on mu opioid receptor (MOR) expression levels, but the regulatory mechanism of MOR is not yet fully understood. Several in vivo and in vitro studies have shown that the c-Jun NH2-terminal kinase (JNK) pathway is closely associated with neuropathic hyperalgesia, which closely resembles the neuroplastic changes observed with morphine antinociceptive tolerance. In this study, we show that inhibition of JNK by SP600125, its inhibitory peptide, or JNK-1 siRNA induced MOR at both mRNA and protein levels in neuronal cells. This increase in MOR expression was reversed by inhibition of the p38 mitogen-activated protein kinase (MAPK) pathway, but not by inhibition of the mitogen-activated protein/extracellular signal-regulated kinase (MEK) pathway. Further experiments using cell signaling inhibitors showed that MOR upregulation by JNK inhibition involved nuclear factor-kappa B (NF-κB). The p38 MAPK dependent phosphorylation of p65 NF-κB subunit in the nucleus was increased by SP600125 treatment. We also observed by chromatin immunoprecipitation (ChIP) analysis that JNK inhibition led to increased bindings of CBP and histone-3 dimethyl K4, and decreased bindings of HDAC-2, MeCP2, and histone-3 trimethyl K9 to the MOR promoter indicating a transcriptional regulation of MOR by JNK inhibition. All these results suggest a regulatory role of the p38 MAPK and NF-κB pathways in MOR gene expression and aid to our better understanding of the MOR gene regulation.
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Affiliation(s)
- Yadav Wagley
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
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13
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Wang S, Jiang W, Chen X, Zhang C, Li H, Hou W, Liu Z, McNutt MA, Lu F, Li G. Alpha-fetoprotein acts as a novel signal molecule and mediates transcription of Fn14 in human hepatocellular carcinoma. J Hepatol 2012; 57:322-9. [PMID: 22521346 DOI: 10.1016/j.jhep.2012.03.029] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2011] [Revised: 03/15/2012] [Accepted: 03/29/2012] [Indexed: 12/21/2022]
Abstract
BACKGROUND & AIMS The function of cytoplasmic AFP as a regulatory factor in the growth of tumor cells has been well defined. However, its precise mechanism of action and its clinical significance remain to be worked out. METHODS Specimens from HCC patients were analyzed by using immunohistochemistry, co-immunoprecipitation (CoIP), and chromatin immunoprecipitation (ChIP) assays to evaluate the role of AFP in RAR signaling-mediated carcinogenesis. Quantitative real-time reverse transcription PCR, Western blotting, confocal microscopy, CoIP, GST pull-down, siRNA, gene transfection, and ChIP assays were also used for analysis of cell lines. RESULTS RAR is able to interact with cytoplasmic AFP and binds to the element of the regulatory region of the Fn14 gene in the neoplastic tissue of HCC patients. An assay of hepatocyte cell lines of differing AFP expression showed that cytoplasmic AFP is able to block ATRA-induced nuclear translocation of RAR and expression of the Fn14 gene. Knockdown of AFP in siRNA-transfected HepG2 and Bel7402 cells led to greater binding of RAR to its response element. The expression of the Fn14 gene was therefore up regulated as reflected by increases in mRNA and protein levels. Conversely, transfection of HLE and L02 cells (AFP negative) with the afp gene resulted in apparent reduction of RAR binding to DNA and Fn14 protein. CONCLUSIONS Demonstration of the involvement of cytoplasmic AFP in RAR-mediated expression of the Fn14 gene strongly indicates AFP plays a signal molecule-like role in the regulation of hepatocellular carcinoma growth.
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Affiliation(s)
- Shanshan Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
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14
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Regan PM, Dave RS, Datta PK, Khalili K. Epigenetics of µ-opioid receptors: intersection with HIV-1 infection of the central nervous system. J Cell Physiol 2012; 227:2832-41. [PMID: 22034138 DOI: 10.1002/jcp.24004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The abuse of intravenous drugs, such as heroin, has become a major public health concern due to the increased risk of HIV-1 infection. Opioids such as heroin were originally identified and subsequently abused for their analgesic effects. However, many investigations have found additional effects of opioids, including regulation of the immune system. As such, chronic opioid abuse has been shown to promote HIV-1 pathogenesis and facilitate HIV-1-associated neurocognitive dysfunction. Clinical opioids, such as morphine and methadone, as well as illicit opioids, such as heroin, exert their effects primarily through interactions with the µ-opioid receptor (MOR). However, the mechanisms by which opioids enhance neurocognitive dysfunction through MOR-mediated signaling pathways are not completely understood. New findings in the regulation of MOR expression, particularly epigenetic and transcriptional regulation as well as alternative splicing, sheds new insights into possible mechanisms of HIV-1 and opiate synergy. In this review, we identify mechanisms regulating MOR expression and propose novel mechanisms by which opioids and HIV-1 may modulate this regulation. Additionally, we suggest that differential regulation of newly identified MOR isoforms by opioids and HIV-1 has functional consequence in enhancing HIV-1 neurocognitive dysfunction.
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Affiliation(s)
- Patrick M Regan
- Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, Philadelphia, PA, USA
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15
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Gong M, Yu W, Pei F, You J, Cui X, McNutt MA, Li G, Zheng J. KLF6/Sp1 initiates transcription of the tmsg-1 gene in human prostate carcinoma cells: an exon involved mechanism. J Cell Biochem 2012; 113:329-39. [PMID: 21928351 DOI: 10.1002/jcb.23359] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The tumor metastasis suppressor gene-1 (tmsg-1) was first cloned as a new tumor suppressor gene in our laboratory several years ago. Since then, however, despite the substantial progression that has been made in investigation of the biologic roles played by this gene, the manner in which it exerts its regulatory influence is still unknown. With transfection of various deletion or mutation constructs, we identified a potential enhancer and three potential silencers in the 5'-flanking region. However, it was particularly interesting to find that a region (+59 to +123 bp) of exon 1 exhibited a strong role in initiation of tmsg-1 gene transcription. Deletion of this region led to essentially complete loss of driving activity of exon-1 sequence on luciferase. Further analysis showed that transcription factors KLF6 and Sp1 are able to interact with each other and bind to their elements in this region. Co-transfection of pGL3-114/+123 with KLF6- and/or Sp1-expressing plasmids resulted in an elevation of luciferase activity and transcription level of tmsg-1, which was abolished by knockdown of KLF6 or Sp1. Analysis of metastatic capacity showed that cells with high metastatic capability exhibited a lower level of KLF6/TMSG-1 proteins with higher invasive capability and vice versa. Thus, we concluded that interaction of KLF6 and Sp1, together with their binding of elements in exon 1 are critical events in initiation of transcription of the tmsg-1 gene. These results reveal a hitherto unreported mechanism for initiation of transcription of the tmsg-1 gene.
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Affiliation(s)
- Miaozi Gong
- Department of Pathology, Peking University Health Science Center, Beijing 100191, China
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16
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Zhao H, Zhao X, Cao X, Wu G. Age-Dependent Neuroimmune Modulation of IGF-1R in the Traumatic Mice. IMMUNITY & AGEING 2012; 9:12. [PMID: 22640633 PMCID: PMC3416715 DOI: 10.1186/1742-4933-9-12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 05/28/2012] [Indexed: 12/25/2022]
Abstract
Background Age-dependent neuroimmune modulation following traumatic stress is accompanied by discordant upregulation of Fyn signaling in the frontal cortex, but the mechanistic details of the potential cellular behavior regarding IGF-1R/Fyn have not been established. Methods Trans-synaptic IGF-1R signaling during the traumatic stress was comparably examined in wild type, Fyn (−/−) and MOR (−/−) mice. Techniques included primary neuron culture, in vitro kinase activity, immunoprecipitation, Western Blot, sucrose discontinuous centrifugation. Besides that, [3 H] incorporation was used to assay lymphocyte proliferation and NK cell activity. Results We demonstrate robust upregulation of synaptic Fyn activity following traumatic stress, with higher amplitude in 2-month mice than that in 1-year counterpart. We also established that the increased Fyn signaling is accompanied by its molecular connection with IGF-1R within the synaptic zone. Detained analysis using Fyn (−/−) and MOR (−/−) mice reveal that IGF-1R/Fyn signaling is governed to a large extent by mu opioid receptor (MOR), and with age-dependent manner; these signaling cascades played a central role in the modulation of lymphocyte proliferation and NK cell activity. Conclusions Our data argued for a pivotal role of synaptic IGF-1R/Fyn signaling controlled by MOR downstream signaling cascades were crucial for the age-dependent neuroimmune modulation following traumatic stress. The result here might present a new quality of synaptic cellular communication governing the stress like events and have significant potential for the development of therapeutic approaches designed to minimize the heightened vulnerability during aging.
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Affiliation(s)
- Hui Zhao
- Department of Integrative Medicine and Neurobiology, National Key lab of Medical Neurobiology, Institute of Brain Research Sciences, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China.
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17
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Abstract
Yin Yang 1 (YY1) is a transcription factor with diverse and complex biological functions. YY1 either activates or represses gene transcription, depending on the stimuli received by the cells and its association with other cellular factors. Since its discovery, a biological role for YY1 in tumor development and progression has been suggested because of its regulatory activities toward multiple cancer-related proteins and signaling pathways and its overexpression in most cancers. In this review, we primarily focus on YY1 studies in cancer research, including the regulation of YY1 as a transcription factor, its activities independent of its DNA binding ability, the functions of its associated proteins, and mechanisms regulating YY1 expression and activities. We also discuss the correlation of YY1 expression with clinical outcomes of cancer patients and its target potential in cancer therapy. Although there is not a complete consensus about the role of YY1 in cancers based on its activities of regulating oncogene and tumor suppressor expression, most of the currently available evidence supports a proliferative or oncogenic role of YY1 in tumorigenesis.
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Affiliation(s)
- Qiang Zhang
- Department of Cancer Biology and Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
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18
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Li C, Wang S, Jiang W, Li H, Liu Z, Zhang C, McNutt MA, Li G. Impact of intracellular alpha fetoprotein on retinoic acid receptors-mediated expression of GADD153 in human hepatoma cell lines. Int J Cancer 2011; 130:754-64. [PMID: 21365646 DOI: 10.1002/ijc.26025] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 02/17/2011] [Indexed: 12/13/2022]
Abstract
The aim of our study was to gain a better understanding of the molecular mechanism underlying the previously unrecognized role of cytoplasmic alpha fetoprotein (AFP) in retinoic acid receptors (RAR) mediated expression and biological effects of GADD153. Using microarray analysis, the expression of the GADD153 gene showed the greatest fold change among apoptosis/growth related genes in response to ATRA. AFP was able to interact with RAR in HepG2 cells, which was undetectable in HLE cells owing to absence of AFP. ATRA promoted nuclei entrance of RAR, expression of GADD153 and apoptosis, and these changes were reversed after transfection with the afp gene or addition of AGN193109. The level of GADD153 was gradually elevated as the effect of AFP was counteracted by increasing dose or prolonging treatment time with ATRA in HepG2 cells. Knockdown of AFP in siRNA-transfected HepG2 cells or over-expression of AFP in afp gene-transfected HLE cells was synchronously associated with up-regulation or down-regulation, respectively, of GADD153 expression. Both ATRA administration and AFP knockdown were each able to promote greater binding of RAR to its response element with consequent elevation of the proportion of apoptotic cells. Conversely, transfection of HLE cells with pcDNA3.1-afp resulted in apparent reduction of RAR binding to DNA and change of biological effect. These data taken together demonstrate the involvement of AFP in RAR-mediated expression and biological effects of GADD153. These findings provide a novel insight into the mechanism underlying the impact of AFP on the RAR signal network.
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Affiliation(s)
- Chaoying Li
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
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19
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Functional analysis of a promoter variant identified in the CFTR gene in cis of a frameshift mutation. Eur J Hum Genet 2011; 20:180-4. [PMID: 21847140 DOI: 10.1038/ejhg.2011.161] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
In monogenic diseases, the presence of several sequence variations in the same allele may complicate our understanding of genotype-phenotype relationships. We described new alterations identified in a cystic fibrosis (CF) patient harboring a 48C>G promoter sequence variation associated in cis of a 3532AC>GTA mutation and in trans with the F508del mutation. Functional analyses including in vitro experiments confirmed the deleterious effect of the 3532GTA frameshift mutation through the creation of a premature termination codon. The analyses also revealed that the 48G promoter variant has a negative effect on both transcription and mRNA level, thus demonstrating the importance of analyzing all mutations or sequence variations with potential impact on CF transmembrane conductance regulator processing, even when the two known disease-causing mutations have already been detected. Our results emphasize the need to perform, wherever possible, functional studies that may greatly assist the interpretation of the disease-causing potential of rare mutation-associated sequence variations.
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20
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Mains RE, Kiraly DD, Eipper-Mains JE, Ma XM, Eipper BA. Kalrn promoter usage and isoform expression respond to chronic cocaine exposure. BMC Neurosci 2011; 12:20. [PMID: 21329509 PMCID: PMC3048553 DOI: 10.1186/1471-2202-12-20] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 02/17/2011] [Indexed: 12/31/2022] Open
Abstract
Background The long-term effects of cocaine on behavior are accompanied by structural changes in excitatory glutamatergic synapses onto the medium spiny neurons of the striatum. The Kalrn gene encodes several functionally distinct isoforms; these multidomain guanine nucleotide exchange factors (GEFs) contain additional domains known to interact with phosphatidylinositides as well as with a number of different proteins. Through their activation of Rho proteins and their interactions with other proteins, the different Kalirin isoforms affect cytoskeletal organization. Chronic exposure of adult male rodents to cocaine increases levels of Kalirin 7 in the striatum. When exposed chronically to cocaine, mice lacking Kalirin 7, the major adult isoform, fail to show an increase in dendritic spine density in the nucleus accumbens, show diminished place preference for cocaine, and exhibit increased locomotor activity in response to cocaine. Results The use of alternate promoters and 3'-terminal exons of the mouse Kalrn gene were investigated using real-time quantitative polymerase chain reaction. While the two most distal full-length Kalrn promoters are used equally in the prefrontal cortex, the more proximal of these promoters accounts for most of the transcripts expressed in the nucleus accumbens. The 3'-terminal exon unique to the Kalirin 7 isoform accounts for a greater percentage of the Kalrn transcripts in prefrontal cortex than in nucleus accumbens. Western blot analyses confirmed these differences. Chronic cocaine treatment increases usage of the promoter encoding the Δ-Kalirin isoforms but does not alter full-length Kalirin promoter usage. Usage of the 3'-terminal exon unique to Kalirin 7 increases following chronic cocaine exposure. Conclusions Kalrn promoter and 3'-terminal exon utilization are region-specific. In the nucleus accumbens, cocaine-mediated alterations in promoter usage and 3'-terminal exon usage favor expression of Kalirin 7 and Δ-Kalirin 7. The Δ-isoform, which lacks a Sec14p domain and four of the nine spectrin-like repeats found in full-length Kalirin isoforms, increases spine headsize without increasing dendritic spine numbers. Thus cocaine-mediated changes in alternative splicing of the Kalrn gene may contribute importantly to the behavioral, morphological and biochemical responses observed.
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Affiliation(s)
- Richard E Mains
- Department of Neuroscience, University of Connecticut Health Center, 263 Farmington Ave, Farmington, CT 06030-3401, USA.
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21
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Li M, Li H, Li C, Wang S, Jiang W, Liu Z, Zhou S, Liu X, McNutt MA, Li G. Alpha-fetoprotein: a new member of intracellular signal molecules in regulation of the PI3K/AKT signaling in human hepatoma cell lines. Int J Cancer 2011; 128:524-32. [PMID: 20473866 DOI: 10.1002/ijc.25373] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Despite its well-defined role as a serum growth factor during fetal liver development and hepatic oncogenesis, the biological significance of cytoplasmic alpha-fetoprotein (AFP) remains incompletely understood. Here, we provide evidence to illustrate that cytoplasmic AFP may function as a regulator in the phosphatidylinositol 3-kinase (PI3K)/AKT pathway in human hepatocellular carcinoma cells. The results demonstrated colocalization and interaction of AFP and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) in the cytoplasm of AFP-producing Bel 7402 and HepG2 cells, with an interaction distance of 12.6 ± 2.7 Å as determined with the fluorescence resonance energy transfer technique. Knockdown of AFP mRNA or inhibition of AFP expression by all trans-retinoic acid resulted in enhancement of the PTEN level with a synchronous decrease in phosphorylated AKT. Transfection of the afp gene into HLE cells (originally AFP negative) led to a significant activation of AKT signaling. The inhibition of PI3K signaling by LY 294002 was simultaneously reversed by transfection, accompanied by diminution of all trans-retinoic acid-induced upregulation of PTEN and enhancement of cell growth. In conclusion, these results demonstrate that cytoplasmic AFP is involved in regulation of hepatocellular growth and tumorigenesis.
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Affiliation(s)
- Mengsen Li
- Key Laboratory of Molecular Biology, Hainan Medical College, Haikou, Hainan, China
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22
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Brown JL, Kassis JA. Spps, a Drosophila Sp1/KLF family member, binds to PREs and is required for PRE activity late in development. Development 2010; 137:2597-602. [PMID: 20627963 DOI: 10.1242/dev.047761] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The Polycomb group of proteins (PcG) is important for transcriptional repression and silencing in all higher eukaryotes. In Drosophila, PcG proteins are recruited to the DNA by Polycomb-group response elements (PREs), regulatory sequences whose activity depends on the binding of many different sequence-specific DNA-binding proteins. We previously showed that a binding site for the Sp1/KLF family of zinc-finger proteins is required for PRE activity. Here, we report that the Sp1/KLF family member Spps binds specifically to Ubx and engrailed PREs, and that Spps binds to polytene chromosomes in a pattern virtually identical to that of the PcG protein, Psc. A deletion of the Spps gene causes lethality late in development and a loss in pairing-sensitive silencing, an activity associated with PREs. Finally, the Spps mutation enhances the phenotype of pho mutants. We suggest that Spps may work with, or in parallel to, Pho to recruit PcG protein complexes to PREs.
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Affiliation(s)
- J Lesley Brown
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 6 Center Drive, Bethesda, MD 20892, USA
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23
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Yu HT, Chan WWL, Chai KH, Lee CWC, Chang RCC, Yu MS, McLoughlin DM, Miller CCJ, Lau KF. Transcriptional regulation of human FE65, a ligand of Alzheimer's disease amyloid precursor protein, by Sp1. J Cell Biochem 2010; 109:782-93. [PMID: 20091743 DOI: 10.1002/jcb.22457] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
FE65 is a neuronal-enriched adaptor protein that binds to the Alzheimer's disease amyloid precursor protein (APP). FE65 forms a transcriptionally active complex with the APP intracellular domain (AICD). The precise gene targets for this complex are unclear but several Alzheimer's disease-linked genes have been proposed. Additionally, evidence suggests that FE65 influences APP metabolism. The mechanism by which FE65 expression is regulated is as yet unknown. To gain insight into the regulatory mechanism, we cloned a 1.6 kb fragment upstream of the human FE65 gene and found that it possesses particularly strong promoter activity in neurones. To delineate essential regions in the human FE65 promoter, a series of deletion mutants were generated. The minimal FE65 promoter was located between -100 and +5, which contains a functional Sp1 site. Overexpression of the transcription factor Sp1 potentiates the FE65 promoter activity. Conversely, suppression of the FE65 promoter was observed in cells either treated with an Sp1 inhibitor or in which Sp1 was knocked down. Furthermore, reduced levels of Sp1 resulted in downregulation of endogenous FE65 mRNA and protein. These findings reveal that Sp1 plays a crucial role in transcriptional control of the human FE65 gene.
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Affiliation(s)
- Hoi-Tin Yu
- Department of Biochemistry (Science), The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR
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Abstract
The development of multidrug resistance (MDR) to chemotherapy remains a major challenge in the treatment of cancer. Resistance exists against every effective anticancer drug and can develop by numerous mechanisms including decreased drug uptake, increased drug efflux, activation of detoxifying systems, activation of DNA repair mechanisms, evasion of drug-induced apoptosis, etc. In the first part of this chapter, we briefly summarize the current knowledge on individual cellular mechanisms responsible for MDR, with a special emphasis on ATP-binding cassette transporters, perhaps the main theme of this textbook. Although extensive work has been done to characterize MDR mechanisms in vitro, the translation of this knowledge to the clinic has not been crowned with success. Therefore, identifying genes and mechanisms critical to the development of MDR in vivo and establishing a reliable method for analyzing clinical samples could help to predict the development of resistance and lead to treatments designed to circumvent it. Our thoughts about translational research needed to achieve significant progress in the understanding of this complex phenomenon are therefore discussed in a third section. The pleotropic response of cancer cells to chemotherapy is summarized in a concluding diagram.
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A potent enhancer element in the 5′-UTR intron is crucial for transcriptional regulation of the human ubiquitin C gene. Gene 2009; 448:88-101. [DOI: 10.1016/j.gene.2009.08.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 08/26/2009] [Accepted: 08/28/2009] [Indexed: 02/01/2023]
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Abstract
This paper is the 31st consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2008 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, 65-30 Kissena Blvd, Flushing, NY 11367, United States.
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27
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Liu H, Li H, Guo L, Li M, Li C, Wang S, Jiang W, Liu X, McNutt MA, Li G. Mechanisms involved in phosphatidylinositol 3-kinase pathway mediated up-regulation of the mu opioid receptor in lymphocytes. Biochem Pharmacol 2009; 79:516-23. [PMID: 19765550 DOI: 10.1016/j.bcp.2009.09.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 09/08/2009] [Accepted: 09/10/2009] [Indexed: 01/12/2023]
Abstract
Despite the substantial progress made in understanding initiation expression of the MOR gene in lymphocytes, the signal pathway associated with MOR gene transcription remains to be better defined. As the phosphatidylinositol 3-kinase (PI3K)/AKT pathway can mediate diverse biological responses and is crucial for optimal immune responses and lymphocyte development, this study was undertaken to delineate the role of PI3K/AKT signaling in expression of the MOR gene in CEM x174 cells. The data show that morphine treatment enhanced the level of phosphorylated, rather than un-phosphorylated, PI3K and AKT, which were synchronously recruited to membrane. The levels of PTEN and p53 which are negative regulators of these signal molecules were reduced, and as a result, the interaction between PTEN and p53 was completely interrupted. With morphine treatment, the levels of both cytoplasmic and nuclear E2F1 which is the downstream effecter of AKT were elevated and the interaction of E2F1 with YY1, rather than Sp1, was also increased. Subsequently, E2F1 triggered the transcription of the MOR gene through its enhanced ability to bind the element in promoter region of the MOR gene. All responses to morphine were abolished by naloxone, which is an antagonist of MOR, or by LY294002, an inhibitor of PI3K, implying specific involvement of PI3K/AKT. These results strongly suggest that the PI3K/AKT pathway plays a critical role in the transfer of signal from morphine stimuli to the machinery by which MOR gene transcription is initiated.
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Affiliation(s)
- Han Liu
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Peking University, Beijing 100083, China
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Cytoplasmic alpha-fetoprotein functions as a co-repressor in RA-RAR signaling to promote the growth of human hepatoma Bel 7402 cells. Cancer Lett 2009; 285:190-9. [PMID: 19501957 DOI: 10.1016/j.canlet.2009.05.014] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 05/15/2009] [Accepted: 05/15/2009] [Indexed: 12/16/2022]
Abstract
The role of AFP in the retinoic acid-RAR signaling pathway was investigated in human hepatoma Bel 7402 cells. The results showed that AFP and RAR-beta were co-localized and interacted in cytoplasm. AFP may inhibit translocation of RAR-beta into the nucleus via competitive binding to RAR-beta with ATRA, which was reversed by AFP-siRNA transfection. Our data suggest that the ATRA resistance of Bel 7402 cells is at least in part attributable to their high level of cytoplasmic AFP. Thus, by counteracting the effect of AFP, it may be possible to increase the sensitivity of tumor cells to ATRA.
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29
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Li M, Li H, Li C, Zhou S, Guo L, Liu H, Jiang W, Liu X, Li P, McNutt MA, Li G. Alpha fetoprotein is a novel protein-binding partner for caspase-3 and blocks the apoptotic signaling pathway in human hepatoma cells. Int J Cancer 2009; 124:2845-54. [PMID: 19267404 DOI: 10.1002/ijc.24272] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Although there is increasing evidence that alpha fetoprotein (AFP) may function as regulatory factor in the growth of tumor cells, the precise mechanism is still unclear. In the current study, we investigated the role of the cytoplasmic AFP in caspase-3-mediated signaling of apoptosis. Our results showed that low doses of TNF-related apoptosis-inducing ligand (TRAIL) elevated the activity of caspase-8, but not caspase-3. Caspase-3 colocalized and interacted with AFP in the cytoplasm of Bel 7402 cells, and translocated into nuclei in association with the occurrence of apoptosis while cells were under cotreatment with all-trans retinoic acid (ATRA) or TRAIL. AFP was able to form complexes with caspase-3 and block onward transmission of signaling from caspase-8. Knockdown of AFP increased the sensitivity of Bel 7402 cells to TRAIL, and thereby, triggered caspase-3 signaling. No intermolecule interaction occurred between AFP and caspase-8, nor was caspase-8 activity altered after AFP knockdown, demonstrating the selectivity of AFP in interfering with the apoptotic signaling pathway. The effect of AFP on caspase-3 was further confirmed by transfection of the AFP gene into HLE cells (AFP negative). We conclude that ATRA or TRAIL resistance in AFP producing hepatoma is at least, in part, attributable to the high level of the cytoplasmic AFP. Therefore, it is possible that the combination of AFP gene silencing together with ATRA/TRAIL cotreatment will benefit the enhancement of the chemotherapeutic efficiency of these agents on tumors.
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Affiliation(s)
- Mengsen Li
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, China
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30
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Guo L, Li H, Liu H, Li C, Li M, Jiang W, He P, Wang S, McNutt MA, Li G. Involvement of STAT5a signaling in morphine-induced up-regulation of the cyclin D1. Biochem Pharmacol 2009; 77:1553-60. [DOI: 10.1016/j.bcp.2009.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2008] [Revised: 02/11/2009] [Accepted: 02/12/2009] [Indexed: 01/24/2023]
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31
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Liu H, Li H, Guo L, Li C, Li M, Jiang W, Liu X, McNutt MA, Li G. The mechanism involved in the repression of the μ opioid receptor gene expression in CEM ×174 cells infected by simian immunodeficiency virus. J Leukoc Biol 2009; 85:684-691. [DOI: 10.1189/jlb.0908543] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2023] Open
Abstract
AbstractMorphine can promote the pathogenesis of human acquired immunodeficiency syndrome through binding to the μ opioid receptor (MOR) in immune cells. Previous investigation has suggested that expression of the MOR gene in lymphocytes is triggered by cooperative interaction between transcription factors, specificity protein 1 (Sp1) and Ying Yang 1 (YY1), in the promoter region. However, the specific molecular mechanism by which immunodeficiency virus infection impacts regulation of the MOR gene expression in lymphocytes is still unclear. In this study, it was demonstrated that SIV (SIVmac239) infection may result in gradual reduction of the MOR gene expression and Sp1 during a period of 48 h postinfection by analysis of quantitative real-time RT-PCR and Western blotting. The results of methylation-specific PCR showed that two of 14 CpG islands adjacent to the Sp1 and YY1 elements in the promoter region were methylated, which together with reduced Sp1, contributed to the failure of interaction of Sp1 with YY1 and their binding to the elements, as determined by coimmunoprecipitation, chromatin immunoprecipitation-real-time PCR, and EMSAs. The repression of the MOR gene secondary to SIVmac239 infection could be abolished by the demethylating agent 5-aza-2′-deoxycytidine. Transfection with Sp1-expressing vector (PN3-Sp1) was also able to enhance the activity of the promoter in SIVmac239-infected cells. We therefore concluded that aberrant methylation of the promoter and reduction of Sp1 resulting from SIVmac239 infection led to the silencing of the MOR gene. This finding will be helpful in understanding the synergistic mechanism of HIV infection and morphine addiction in the pathogenesis of AIDS.
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Affiliation(s)
- Han Liu
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Peking University , Beijing , China
| | - Hui Li
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Peking University , Beijing , China
| | - Liyuan Guo
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Peking University , Beijing , China
| | - Chaoying Li
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Peking University , Beijing , China
| | - Mengsen Li
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Peking University , Beijing , China
| | - Wei Jiang
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Peking University , Beijing , China
| | - Xinhua Liu
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Peking University , Beijing , China
| | - Michael A McNutt
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Peking University , Beijing , China
| | - Gang Li
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Peking University , Beijing , China
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Glenn DJ, Wang F, Chen S, Nishimoto M, Gardner DG. Endothelin-stimulated human B-type natriuretic peptide gene expression is mediated by Yin Yang 1 in association with histone deacetylase 2. Hypertension 2009; 53:549-55. [PMID: 19139378 DOI: 10.1161/hypertensionaha.108.125088] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Increased B-type natriuretic peptide (BNP) gene expression is regarded as one of the hallmarks of cardiac myocyte hypertrophy. Here we demonstrate that both basal- and endothelin-1-dependent stimulation of human (h) BNP gene transcription requires the presence of an intact Yin Yang 1 (YY1) binding site positioned at -62 bp relative to the transcription start site. Mutation of this site reduced both basal and stimulated hBNP promoter activity. This site was shown to bind YY1 both in vitro and within the context of the intact cell. The latter interaction increased after endothelin-1 treatment. Exposure to endothelin-1 also resulted in increased nuclear localization of YY1 and a reduction in acetylation of the YY1 protein. Overexpression of wild-type YY1 increased both basal and endothelin-stimulated hBNP promoter activity, whereas a carboxy-terminal deletion mutant of YY1 was devoid of activity. Treatment with the histone deacetylase inhibitor trichostatin A resulted in decreased hBNP reporter activity. YY1 was shown to associate with histone deacetylase 2, and histone deacetylase 2 was shown to associate directly with the hBNP promoter in the intact cell. Collectively these findings demonstrate that YY1 plays an important role in regulating the transcriptional activity of the hBNP gene promoter. These data suggest a model in which YY1 activates hBNP transcription through interaction with histone deacetylase 2.
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Affiliation(s)
- Denis J Glenn
- Department of Medicine and Diabetes Center, University of California at San Francisco, USA
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