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Koral K, Haynes M, Bowen WC, Orr A, Mars W, Michalopoulos GK. Lymphocyte-Specific Protein-1 Controls Sorafenib Sensitivity and Hepatocellular Proliferation through Extracellular Signal-Regulated Kinase 1/2 Activation. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:2074-2086. [PMID: 30126548 DOI: 10.1016/j.ajpath.2018.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 05/21/2018] [Accepted: 06/11/2018] [Indexed: 02/07/2023] [Imported: 08/29/2023]
Abstract
The gene leukocyte-specific protein-1 (LSP1), encodes an F-actin binding protein that directly interacts with the mitogen-activated protein kinase pathway. LSP1 has copy number variations in 52% of human hepatocellular carcinoma (HCC). LSP1 suppresses proliferation and migration in hepatocytes. LSP1 binds to the rapidly accelerated fibrosarcoma (RAF)/mitogen-activated protein/extracellular signal-regulated kinase (ERK)/ERK signaling cassette, the target for sorafenib, a crucial chemotherapeutic agent for HCC. This study addresses the role of LSP1 in liver regeneration and sensitivity to sorafenib in normal and neoplastic hepatocytes. Two mouse models, an Lsp1 global knockout (LSP1KO) and a hepatocyte-specific Lsp1 transgenic (LSP1TG) mouse, were used. After two-thirds hepatectomy (PHx), LSP1KO mice displayed increased proliferation and ERK activation, whereas LSP1TG mice displayed suppressed proliferation and decreased ERK activation. LSP1KO hepatocytes cultured without growth factors exhibited increased proliferation, whereas LSP1TG hepatocytes showed decreased proliferation. Rat and human hepatoma cells expressing Lsp1 shRNA displayed increased sensitivity to sorafenib, as evidenced by decreased cell numbers and phosphorylated ERK expression compared with control. LSP1 KO mice treated with sorafenib before PHx displayed decreased hepatocyte proliferation. Our data show that loss of LSP1 function, observed in HCC, leads to increased sensitivity to sorafenib treatment and enhanced hepatocellular proliferation after PHx in vivo and in cultured cells.
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Yokota S, Ono Y, Nakao T, Zhang P, Michalopoulos GK, Khan Z. Partial Bile Duct Ligation in the Mouse: A Controlled Model of Localized Obstructive Cholestasis. J Vis Exp 2018. [PMID: 29658929 DOI: 10.3791/56930] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] [Imported: 10/07/2023] Open
Abstract
In rodents, complete bile duct ligation (cBDL) of the common bile duct is an established surgical technique for studying obstructive cholestasis and bile duct proliferation. However, long-term experiments can lead to increased morbidity and mortality. In select mouse strains with underlying liver disease, meaningful comparisons can be made even with ligation of a single lobe of the liver, which can reduce animal losses and expenses. Here, we describe partial bile duct ligation (pBDL) in the mouse, in which only the left hepatic bile duct is ligated, causing biliary obstruction in the left lobe but not the remaining lobes. With careful microsurgical technique, pBDL experiments can be cost-effective, since the unligated lobe serves as an internal control to the ligated lobes, when subjected to the same conditions in the same animal. Unlike cBDL, a separate sham-operated control group is not necessary. pBDL is highly useful to directly compare localized versus systemic effects of cholestasis and other retained bile components. pBDL can also be repurposed as a novel method to investigate mechanisms related to medications and cell migration.
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Xue Y, Mars WM, Bowen W, Singhi AD, Stoops J, Michalopoulos GK. Hepatitis C Virus Mimics Effects of Glypican-3 on CD81 and Promotes Development of Hepatocellular Carcinomas via Activation of Hippo Pathway in Hepatocytes. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:1469-1477. [PMID: 29577937 DOI: 10.1016/j.ajpath.2018.02.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 01/23/2018] [Accepted: 02/13/2018] [Indexed: 02/08/2023] [Imported: 08/29/2023]
Abstract
Glypican (GPC)-3 is overexpressed in hepatocellular carcinomas (HCCs). GPC3 binds to CD81. Forced expression of CD81 in a GPC3-expressing HCC cell line caused activation of Hippo, a decrease in ezrin phosphorylation, and a decrease in yes-associated protein (YAP). CD81 is also associated with hepatitis C virus (HCV) entry into hepatocytes. Activation of CD81 by agonistic antibody causes activation of tyrosine-protein kinase SYK (SYK) and phosphorylation of ezrin, a regulator of the Hippo pathway. In cultures of normal hepatocytes, CD81 agonistic antibody led to enhanced phosphorylation of ezrin and an increase in nuclear YAP. HCV E2 protein mimicked GPC3 and led to enhanced Hippo activity and decreased YAP in cultured normal human hepatocytes. HCC tissue microarray revealed a lack of expression of CD81 in most HCCs, rendering them insusceptible to HCV infection. Activation of CD81 by agonistic antibody suppressed the Hippo pathway and increased nuclear YAP. HCV mimicked GPC3, causing Hippo activation and a decrease in YAP. HCV is thus likely to enhance hepatic neoplasia by acting as a promoter of growth of early CD81-negative neoplastic hepatocytes, which are resistant to HCV infection, and thus have a proliferative advantage to clonally expand as they participate in compensatory regeneration for the required maintenance of 100% of liver weight (hepatostat).
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Doffou M, Adams G, Bowen WC, Paranjpe S, Parihar HS, Nguyen H, Michalopoulos GK, Bhave VS. Oct4 Is Crucial for Transdifferentiation of Hepatocytes to Biliary Epithelial Cells in an In Vitro Organoid Culture Model. Gene Expr 2018; 18:51-62. [PMID: 29212575 PMCID: PMC5885146 DOI: 10.3727/105221617x15124876321401] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] [Imported: 10/07/2023]
Abstract
Hepatocyte to biliary transdifferentiation has been documented in various models of bile duct injury. In this process, mature hepatocytes transform into mature biliary epithelial cells by acquiring biliary phenotypic markers. Several signaling pathways including PI3 kinase, Notch, Hes1, Sox9, and Hippo are shown to be involved in the process. However, whether Oct4 is involved in hepatocyte to biliary transdifferentiation is unknown. We investigated the role of Oct4 in hepatocyte to biliary transdifferentiation utilizing an in vitro organoid culture system as a model of transdifferentiation. Oct4 was inhibited using adenovirus containing Oct4 shRNA. Hepatocyte-specific HNF-4α and biliary-specific HNF-1β and CK19 expression were assessed to gauge the extent of transdifferentiation. Oct4 was induced during hepatocyte to biliary transdifferentiation. Oct4 inhibition significantly downregulated the appearance of biliary cells from hepatocytes. This was accompanied by a significant downregulation of signaling pathways including Notch, Sox9, and Hippo. Our findings suggest that Oct4 is crucial for hepatocyte to biliary transdifferentiation and maturation and that it acts upstream of Notch, Sox9, and Hippo signaling in this model. This finding identifies new signaling through Oct4 in plasticity between hepatocytes and biliary epithelial cells, which can be potentially utilized to identify new strategies in chronic biliary diseases.
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Chartoumpekis DV, Yagishita Y, Fazzari M, Palliyaguru DL, Rao UN, Zaravinos A, Khoo NK, Schopfer FJ, Weiss KR, Michalopoulos GK, Sipula I, O'Doherty RM, Kensler TW, Wakabayashi N. Nrf2 prevents Notch-induced insulin resistance and tumorigenesis in mice. JCI Insight 2018. [PMID: 29515034 DOI: 10.1172/jci.insight.97735] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] [Imported: 10/07/2023] Open
Abstract
Insulin resistance is associated with increased incidence and enhanced progression of cancers. However, little is known about strategies that can effectively ameliorate insulin resistance and consequently halt cancer progression. Herein, we propose that the transcription factor Nrf2 (also known as Nfe2l2) may be such a target, given its central role in disease prevention. To this end, we developed a mouse that overexpresses the Notch intracellular domain in adipocytes (AdNICD), leading to lipodystrophy-induced severe insulin resistance and subsequent development of sarcomas, as a model reflecting that Notch signaling is deregulated in cancers and shows positive associations with insulin resistance and fatty liver disease in humans. Nrf2 pathway activation was achieved by knocking down Keap1, a repressor of Nrf2, in the AdNICD background. Constitutively enhanced Nrf2 signaling in this setting led to prevention of hepatic steatosis, dyslipidemia, and insulin resistance by repressing hepatic lipogenic pathways and restoration of the hepatic fatty acid profile to control levels. This protective effect of Nrf2 against diabetes extended to significant reduction and delay in sarcoma incidence and latency. Our study highlights that the Nrf2 pathway, which has been induced by small molecules in clinical trials, is a potential therapeutic target against insulin resistance and subsequent risk of cancer.
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Kader M, Alaoui-EL-Azher M, Vorhauer J, Kode BB, Wells JZ, Stolz D, Michalopoulos G, Wells A, Scott M, Ismail N. MyD88-dependent inflammasome activation and autophagy inhibition contributes to Ehrlichia-induced liver injury and toxic shock. PLoS Pathog 2017; 13:e1006644. [PMID: 29049365 PMCID: PMC5663626 DOI: 10.1371/journal.ppat.1006644] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 10/31/2017] [Accepted: 09/11/2017] [Indexed: 01/19/2023] [Imported: 10/07/2023] Open
Abstract
Severe hepatic inflammation is a common cause of acute liver injury following systemic infection with Ehrlichia, obligate Gram-negative intracellular bacteria that lack lipopolysaccharide (LPS). We have previously shown that type I IFN (IFN-I) and inflammasome activation are key host-pathogenic mediators that promote excessive inflammation and liver damage following fatal Ehrlichia infection. However, the underlying signals and mechanisms that regulate protective immunity and immunopathology during Ehrlichia infection are not well understood. To address this issue, we compared susceptibility to lethal Ixodes ovatus Ehrlichia (IOE) infection between wild type (WT) and MyD88-deficient (MyD88-/-) mice. We show here that MyD88-/- mice exhibited decreased inflammasome activation, attenuated liver injury, and were more resistant to lethal infection than WT mice, despite suppressed protective immunity and increased bacterial burden in the liver. MyD88-dependent inflammasome activation was also dependent on activation of the metabolic checkpoint kinase mammalian target of rapamycin complex 1 (mTORC1), inhibition of autophagic flux, and defective mitophagy in macrophages. Blocking mTORC1 signaling in infected WT mice and primary macrophages enhanced bacterial replication and attenuated inflammasome activation, suggesting autophagy promotes bacterial replication while inhibiting inflammasome activation. Finally, our data suggest TLR9 and IFN-I are upstream signaling mechanisms triggering MyD88-mediated mTORC1 and inflammasome activation in macrophages following Ehrlichia infection. This study reveals that Ehrlichia-induced liver injury and toxic shock are mediated by MyD88-dependent inflammasome activation and autophagy inhibition. Human monocytic ehrlichiosis (HME) is the most prevalent emerging infectious disease in the United States. Ehrlichia chaffeensis, etiologic agent of HME, is a Gram negative obligate intracellular bacterium transmitted by infected tick bites and can infect different cell type. Although Ehrlichia lack lipopolysaccharide (LPS), they induce potentially life threatening HME that mimic sepsis or toxic shock associated with multi-organ failure. The clinical diagnosis of HME is difficult, and definitive diagnosis is most often retrospective. Late antibiotic treatment is frequently ineffective in preventing disease progression to fatal multi-organ failure. Liver failure is one of the most serious complications and the most frequent cause of death in patients with HME, however we only have a limited understanding of how this liver failure is caused during fatal Ehrlichia infection. The objective of this study is to determine how LPS-negative Ehrlichia activates inflammatory responses in macrophages during Ehrlichia infection to promote liver damage. We show here that MyD88-signaling causes detrimental derangement of the immune system and subsequent liver damage by regulating two key innate immune events in macrophages: autophagy and inflammasome activation. Targeting host-pathogenic pathways in ehrlichiosis can be incorporated into future design of novel therapeutic approaches for HME.
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MESH Headings
- Animals
- Autophagy/immunology
- Blotting, Western
- Disease Models, Animal
- Ehrlichia/immunology
- Ehrlichiosis/immunology
- Ehrlichiosis/metabolism
- Enzyme-Linked Immunosorbent Assay
- Female
- Flow Cytometry
- Fluorescent Antibody Technique
- Image Processing, Computer-Assisted
- In Situ Nick-End Labeling
- Inflammasomes/immunology
- Inflammasomes/metabolism
- Liver Failure, Acute/immunology
- Liver Failure, Acute/metabolism
- Liver Failure, Acute/microbiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microscopy, Confocal
- Microscopy, Electron, Transmission
- Myeloid Differentiation Factor 88/immunology
- Myeloid Differentiation Factor 88/metabolism
- Real-Time Polymerase Chain Reaction
- Shock, Septic/immunology
- Shock, Septic/metabolism
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Chen ZH, Yu YP, Tao J, Liu S, Tseng G, Nalesnik M, Hamilton R, Bhargava R, Nelson JB, Pennathur A, Monga SP, Luketich JD, Michalopoulos GK, Luo JH. MAN2A1-FER Fusion Gene Is Expressed by Human Liver and Other Tumor Types and Has Oncogenic Activity in Mice. Gastroenterology 2017; 153:1120-1132.e15. [PMID: 28245430 PMCID: PMC5572118 DOI: 10.1053/j.gastro.2016.12.036] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/16/2016] [Accepted: 12/23/2016] [Indexed: 02/07/2023] [Imported: 10/07/2023]
Abstract
BACKGROUND & AIMS Human tumors and liver cancer cell lines express the product of a fusion between the first 13 exons in the mannosidase α class 2A member 1 gene (MAN2A1) and the last 6 exons in the FER tyrosine kinase gene (FER), called MAN2A1-FER. We investigated whether MAN2A1-FER is expressed by human liver tumors and its role in liver carcinogenesis. METHODS We performed reverse transcription polymerase chain reaction analyses of 102 non-small cell lung tumors, 61 ovarian tumors, 70 liver tumors, 156 glioblastoma multiform samples, 27 esophageal adenocarcinomas, and 269 prostate cancer samples, as well as 10 nontumor liver tissues and 20 nontumor prostate tissues, collected at the University of Pittsburgh. We also measured expression by 15 human cancer cell lines. We expressed a tagged form of MAN2A1-FER in NIH3T3 and HEP3B (liver cancer) cells; Golgi were isolated for analysis. MAN2A1-FER was also overexpressed in PC3 or DU145 (prostate cancer), NIH3T3 (fibroblast), H23 (lung cancer), and A-172 (glioblastoma multiforme) cell lines and knocked out in HUH7 (liver cancer) cells. Cells were analyzed for proliferation and in invasion assays, and/or injected into flanks of severe combined immunodeficient mice; xenograft tumor growth and metastasis were assessed. Mice with hepatic deletion of PTEN were given tail-vein injections of MAN2A1-FER. RESULTS We detected MAN2A1-FER messenger RNA and fusion protein (114 kD) in the hepatocellular carcinoma cell line HUH7, as well as in liver tumors, esophageal adenocarcinoma, glioblastoma multiforme, prostate tumors, non-small cell lung tumors, and ovarian tumors, but not nontumor prostate or liver tissues. MAN2A1-FER protein retained the signal peptide for Golgi localization from MAN2A1 and translocated from the cytoplasm to Golgi in cancer cell lines. MAN2A1-FER had tyrosine kinase activity almost 4-fold higher than that of wild-type FER, and phosphorylated the epidermal growth factor receptor at tyrosine 88 in its N-terminus. Expression of MAN2A1-FER in 4 cell lines led to epidermal growth factor receptor activation of BRAF, MEK, and AKT; HUH7 cells with MAN2A1-FER knockout had significant decreases in phosphorylation of these proteins. Cell lines that expressed MAN2A1-FER had increased proliferation, colony formation, and invasiveness and formed larger (>2-fold) xenograft tumors in mice, with more metastases, than cells not expressing the fusion protein. HUH7 cells with MAN2A1-FER knockout formed smaller xenograft tumors, with fewer metastases, than control HUH7 cells. HUH7, A-172, and PC3 cells that expressed MAN2A1-FER were about 2-fold more sensitive to the FER kinase inhibitor crizotinib and the epidermal growth factor receptor kinase inhibitor canertinib; these drugs slowed growth of xenograft tumors from MAN2A1-FER cells and prevented their metastasis in mice. Hydrodynamic tail-vein injection of MAN2A1-FER resulted in rapid development of liver cancer in mice with hepatic disruption of Pten. CONCLUSIONS Many human tumor types and cancer cell lines express the MAN2A1-FER fusion, which increases proliferation and invasiveness of cancer cell lines and has liver oncogenic activity in mice.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Cell Line, Tumor
- Cell Movement
- Cell Proliferation
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Crizotinib
- Dose-Response Relationship, Drug
- Enzyme Activation
- ErbB Receptors/genetics
- ErbB Receptors/metabolism
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Neoplastic
- Gene Fusion
- Golgi Apparatus/enzymology
- Humans
- Liver Neoplasms/drug therapy
- Liver Neoplasms/enzymology
- Liver Neoplasms/genetics
- Liver Neoplasms/pathology
- Mice
- Mice, Knockout
- Mice, SCID
- Morpholines/pharmacology
- NIH 3T3 Cells
- Neoplasm Invasiveness
- Neoplasm Transplantation
- Oncogene Proteins, Fusion/antagonists & inhibitors
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/metabolism
- Oncogenes
- PTEN Phosphohydrolase/deficiency
- PTEN Phosphohydrolase/genetics
- Phosphorylation
- Protein Kinase Inhibitors/pharmacology
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Protein-Tyrosine Kinases/genetics
- Protein-Tyrosine Kinases/metabolism
- Pyrazoles/pharmacology
- Pyridines/pharmacology
- RNA Interference
- Time Factors
- Transfection
- Tumor Burden
- alpha-Mannosidase/antagonists & inhibitors
- alpha-Mannosidase/genetics
- alpha-Mannosidase/metabolism
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Michalopoulos GK. Flexible Lineage Specifications of Adult Hepatic Cells, Associated Molecular Pathways, and Their Relationship to Liver Cancer. Cell Transplant 2017; 15 Suppl 1:S67-8. [PMID: 16826797 DOI: 10.3727/000000006783982377] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] [Imported: 08/29/2023] Open
Abstract
The availability of new cell culture, cell transplantation, and gene expression technology has highlighted a role of hepatocytes as facultative stem cells for the biliary epithelium. In addition, hepatocytes can revert to primitive progenitor cell types and express gene profiles that appear as characteristic “signatures” in hepatocellular carcinomas.
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Targeting genomic rearrangements in tumor cells through Cas9-mediated insertion of a suicide gene. Nat Biotechnol 2017; 35:543-550. [PMID: 28459452 PMCID: PMC5462845 DOI: 10.1038/nbt.3843] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 03/08/2017] [Indexed: 11/08/2022] [Imported: 10/07/2023]
Abstract
Specifically targeting genomic rearrangements and mutations in tumor cells remains an elusive goal in cancer therapy. Here, we used Cas9-based genome editing to introduce the gene encoding the prodrug-converting enzyme herpes simplex virus type 1 thymidine kinase (HSV1-tk) into the genomes of cancer cells carrying unique sequences resulting from genome rearrangements. Specifically, we targeted the breakpoints of TMEM135-CCDC67 and MAN2A1-FER fusions in human prostate cancer or hepatocellular carcinoma cells in vitro and in mouse xenografts. We designed one adenovirus to deliver the nickase Cas9D10A and guide RNAs targeting the breakpoint sequences, and another to deliver an EGFP-HSV1-tk construct flanked by sequences homologous to those surrounding the breakpoint. Infection with both viruses resulted in breakpoint-dependent expression of EGFP-tk and ganciclovir-mediated apoptosis. When mouse xenografts were treated with adenoviruses and ganciclovir, all animals showed decreased tumor burden and no mortality during the study. Thus, Cas9-mediated suicide-gene insertion may be a viable genotype-specific cancer therapy.
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Michalopoulos GK. Hepatostat: Liver regeneration and normal liver tissue maintenance. Hepatology 2017; 65:1384-1392. [PMID: 27997988 DOI: 10.1002/hep.28988] [Citation(s) in RCA: 294] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 11/30/2016] [Accepted: 11/30/2016] [Indexed: 12/13/2022] [Imported: 08/29/2023]
Abstract
In contrast to all other organs, liver-to-body-weight ratio needs to be maintained always at 100% of what is required for body homeostasis. Adjustment of liver size to 100% of what is required for homeostasis has been called "hepatostat." Removal of a portion of any other organ is followed with local regeneration of a limited degree, but it never attempts to reach 100% of the original size. The complex mechanisms involved in this uniquely hepatic process encompass a variety of regenerative pathways that are specific to different types of injury. The most studied form of liver regeneration (LR) is that occurring after loss of hepatocytes in a single acute injury, such as rodent LR after two-thirds partial hepatectomy or administration of damaging chemicals (CCl4 , acetaminophen, etc.). Alternative regenerative pathways become activated when normal regeneration is thwarted and trigger the appearance of "progenitor" cells. Chronic loss of hepatocytes is associated with regenerative efforts characterized by continual hepatocyte proliferation and often has adverse consequences (development of cirrhosis or liver cancer). Even though a very few hepatocytes proliferate at any given time in normal liver, the mechanisms involved in the maintenance of liver weight by this slow process in the absence of liver injury are not as well understood. (Hepatology 2017;65:1384-1392).
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Khan Z, Yokota S, Ono Y, Bell AW, Oertel M, Stolz DB, Michalopoulos GK. Bile Duct Ligation Induces ATZ Globule Clearance in a Mouse Model of α-1 Antitrypsin Deficiency. Gene Expr 2017; 17:115-127. [PMID: 27938510 PMCID: PMC5296240 DOI: 10.3727/105221616x692991] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] [Imported: 10/07/2023]
Abstract
α-1 Antitrypsin deficiency (A1ATD) can progress to cirrhosis and hepatocellular carcinoma; however, not all patients are susceptible to severe liver disease. In A1ATD, a toxic gain-of-function mutation generates insoluble ATZ "globules" in hepatocytes, overwhelming protein clearance mechanisms. The relationship between bile acids and hepatocytic autophagy is less clear but may involve altered gene expression pathways. Based on previous findings that bile duct ligation (BDL) induces autophagy, we hypothesized that retained bile acids may have hepatoprotective effects in PiZZ transgenic mice, which model A1ATD. We performed BDL and partial BDL (pBDL) in PiZZ mice, followed by analysis of liver tissues. PiZZ liver subjected to BDL showed up to 50% clearance of ATZ globules, with increased expression of autophagy proteins. Analysis of transcription factors revealed significant changes. Surprisingly nuclear TFEB, a master regulator of autophagy, remained unchanged. pBDL confirmed that ATZ globule clearance was induced by localized stimuli rather than diet or systemic effects. Several genes involved in bile metabolism were overexpressed in globule-devoid hepatocytes, compared to globule-containing cells. Retained bile acids led to a dramatic reduction of ATZ globules, with enhanced hepatocyte regeneration and autophagy. These findings support investigation of synthetic bile acids as potential autophagy-enhancing agents.
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Khan Z, Orr A, Michalopoulos GK, Ranganathan S. Immunohistochemical Analysis of the Stem Cell Marker LGR5 in Pediatric Liver Disease. Pediatr Dev Pathol 2017; 20:16-27. [PMID: 28276299 PMCID: PMC5040613 DOI: 10.1177/1093526616686244] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] [Imported: 10/07/2023]
Abstract
Aims In regenerating liver, hepatic progenitor cells (HPCs) are recruited in response to injury; however, few highly specific human HPC markers exist for the hepatocyte lineage. Leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5), a Wnt-associated stem cell marker, has been extensively studied in intestinal stem cells, but little is known about its expression in human liver. We hypothesized that LGR5+ HPCs are induced in the regenerative response to pediatric liver injury. Methods and results Immunohistochemistry was used to characterize LGR5 expression in pediatric liver explants (n = 36). We found cytoplasmic LGR5 expression in all cases; although, much less was observed in acute hepatic necrosis compared to chronic liver diseases. In the latter cases, >50% of hepatocytes were LGR5+, signifying a robust regenerative response mainly in the periphery of regenerative nodules. Only weak LGR5 staining was noted in bile ducts, suggesting hepatocyte-specific expression at the interface. Conclusions Although we observed some degree of regenerative response in all cases, LGR5 was highly expressed in chronic liver disease, possibly due to alternate regeneration and reprogramming pathways. LGR5 is predominant in peri-septal hepatocytes rather than epithelial cell adhesion molecule (EpCAM) positive ductular reactions in chronic pediatric liver diseases and may represent a transitional HPC phenotype for the hepatocyte lineage. These studies are the first to support a unique role for LGR5 in human hepatocyte regeneration and as a potential predictive biomarker for recovery of liver function in children. Future work will also investigate the molecular mechanisms behind LGR5 expression.
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Paranjpe S, Bowen WC, Mars WM, Orr A, Haynes MM, DeFrances MC, Liu S, Tseng GC, Tsagianni A, Michalopoulos GK. Combined systemic elimination of MET and epidermal growth factor receptor signaling completely abolishes liver regeneration and leads to liver decompensation. Hepatology 2016; 64:1711-1724. [PMID: 27397846 PMCID: PMC5074871 DOI: 10.1002/hep.28721] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 07/06/2016] [Indexed: 02/06/2023] [Imported: 08/29/2023]
Abstract
UNLABELLED Receptor tyrosine kinases MET and epidermal growth factor receptor (EGFR) are critically involved in initiation of liver regeneration. Other cytokines and signaling molecules also participate in the early part of the process. Regeneration employs effective redundancy schemes to compensate for the missing signals. Elimination of any single extracellular signaling pathway only delays but does not abolish the process. Our present study, however, shows that combined systemic elimination of MET and EGFR signaling (MET knockout + EGFR-inhibited mice) abolishes liver regeneration, prevents restoration of liver mass, and leads to liver decompensation. MET knockout or simply EGFR-inhibited mice had distinct and signaling-specific alterations in Ser/Thr phosphorylation of mammalian target of rapamycin, AKT, extracellular signal-regulated kinases 1/2, phosphatase and tensin homolog, adenosine monophosphate-activated protein kinase α, etc. In the combined MET and EGFR signaling elimination of MET knockout + EGFR-inhibited mice, however, alterations dependent on either MET or EGFR combined to create shutdown of many programs vital to hepatocytes. These included decrease in expression of enzymes related to fatty acid metabolism, urea cycle, cell replication, and mitochondrial functions and increase in expression of glycolysis enzymes. There was, however, increased expression of genes of plasma proteins. Hepatocyte average volume decreased to 35% of control, with a proportional decrease in the dimensions of the hepatic lobules. Mice died at 15-18 days after hepatectomy with ascites, increased plasma ammonia, and very small livers. CONCLUSION MET and EGFR separately control many nonoverlapping signaling endpoints, allowing for compensation when only one of the signals is blocked, though the combined elimination of the signals is not tolerated; the results provide critical new information on interactive MET and EGFR signaling and the contribution of their combined absence to regeneration arrest and liver decompensation. (Hepatology 2016;64:1711-1724).
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Yu C, Yan S, Khambu B, Chen X, Dong Z, Luo J, Michalopoulos GK, Wu S, Yin XM. Gene Expression Analysis Indicates Divergent Mechanisms in DEN-Induced Carcinogenesis in Wild Type and Bid-Deficient Livers. PLoS One 2016; 11:e0155211. [PMID: 27196317 PMCID: PMC4873180 DOI: 10.1371/journal.pone.0155211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 04/26/2016] [Indexed: 12/27/2022] [Imported: 10/07/2023] Open
Abstract
Bid is a Bcl-2 family protein. In addition to its pro-apoptosis function, Bid can also promote cell proliferation, maintain S phase checkpoint, and facilitate inflammasome activation. Bid plays important roles in tissue injury and regeneration, hematopoietic homeostasis, and tumorigenesis. Bid participates in hepatic carcinogenesis but the mechanism is not fully understood. Deletion of Bid resulted in diminished tumor burden and delayed tumor progression in a liver cancer model. In order to better understand the Bid-regulated events during hepatic carcinogenesis we performed gene expression analysis in wild type and bid-deficient mice treated with a hepatic carcinogen, diethylnitrosamine. We found that deletion of Bid caused significantly fewer alterations in gene expression in terms of the number of genes affected and the number of pathways affected. In addition, the expression profiles were remarkably different. In the wild type mice, there was a significant increase in the expression of growth regulation-related and immune/inflammation response-related genes, and a significant decrease in the expression of metabolism-related genes, both of which were diminished in bid-deficient livers. These data suggest that Bid could promote hepatic carcinogenesis via growth control and inflammation-mediated events.
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Yu YP, Ding Y, Chen Z, Liu S, Michalopoulos A, Chen R, Gulzar ZG, Yang B, Cieply KM, Luvison A, Ren BG, Brooks JD, Jarrard D, Nelson JB, Michalopoulos GK, Tseng GC, Luo JH. Novel fusion transcripts associate with progressive prostate cancer. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 184:2840-9. [PMID: 25238935 DOI: 10.1016/j.ajpath.2014.06.025] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 06/25/2014] [Accepted: 06/30/2014] [Indexed: 12/21/2022] [Imported: 10/07/2023]
Abstract
The mechanisms underlying the potential for aggressive behavior of prostate cancer (PCa) remain elusive. In this study, whole genome and/or transcriptome sequencing was performed on 19 specimens of PCa, matched adjacent benign prostate tissues, matched blood specimens, and organ donor prostates. A set of novel fusion transcripts was discovered in PCa. Eight of these fusion transcripts were validated through multiple approaches. The occurrence of these fusion transcripts was then analyzed in 289 prostate samples from three institutes, with clinical follow-up ranging from 1 to 15 years. The analyses indicated that most patients [69 (91%) of 76] positive for any of these fusion transcripts (TRMT11-GRIK2, SLC45A2-AMACR, MTOR-TP53BP1, LRRC59-FLJ60017, TMEM135-CCDC67, KDM4-AC011523.2, MAN2A1-FER, and CCNH-C5orf30) experienced PCa recurrence, metastases, and/or PCa-specific death after radical prostatectomy. These outcomes occurred in only 37% (58/157) of patients without carrying those fusion transcripts. Three fusion transcripts occurred exclusively in PCa samples from patients who experienced recurrence or PCaerelated death. The formation of these fusion transcripts may be the result of genome recombination. A combination of these fusion transcripts in PCa with Gleason's grading or with nomogram significantly improves the prediction rate of PCa recurrence. Our analyses suggest that formation of these fusion transcripts may underlie the aggressive behavior of PCa.
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Bhushan B, Edwards G, Desai A, Michalopoulos GK, Apte U. Liver-Specific Deletion of Integrin-Linked Kinase in Mice Attenuates Hepatotoxicity and Improves Liver Regeneration After Acetaminophen Overdose. Gene Expr 2016; 17:35-45. [PMID: 27125733 PMCID: PMC5341619 DOI: 10.3727/105221616x691578] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] [Imported: 10/07/2023]
Abstract
Acetaminophen (APAP) overdose is the major cause of acute liver failure in the US. Prompt liver regeneration is critical for recovery after APAP hepatotoxicity, but mechanisms remain elusive. Extracellular matrix (ECM)-mediated signaling via integrin-linked kinase (ILK) regulates liver regeneration after surgical resection. However, the role of ECM signaling via ILK in APAP toxicity and compensatory regeneration is unknown, which was investigated in this study using liver-specific ILK knockout (KO) mice. ILK KO and wild-type (WT) mice were treated with 300 mg/kg APAP, and injury and regeneration were studied at 6 and 24 h after APAP treatment. ILK KO mice developed lower liver injury after APAP overdose, which was associated with decreased JNK activation (a key mediator of APAP toxicity). Further, higher glutathione levels after APAP treatment and lower APAP protein adducts levels, along with lower levels of CYP2E1, suggest decreased metabolic activation of APAP in ILK KO mice. Interestingly, despite lower injury, ILK KO mice had rapid and higher liver regeneration after APAP overdose accompanied with increased β-catenin signaling. In conclusion, liver-specific deletion of ILK improved regeneration, attenuated toxicity after APAP overdose, and decreased metabolic activation of APAP. Our study also indicates that ILK-mediated ECM signaling plays a role in the regulation of CYP2E1 and may affect toxicity of several centrilobular hepatotoxicants including APAP.
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Monga S, Jacob S. Editorial. Gene Expr 2016; 17:1-5. [PMID: 26789721 PMCID: PMC8749946 DOI: 10.3727/105221616x692595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] [Imported: 10/07/2023]
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Kang LI, Isse K, Koral K, Bowen WC, Muratoglu S, Strickland DK, Michalopoulos GK, Mars WM. Tissue-type plasminogen activator suppresses activated stellate cells through low-density lipoprotein receptor-related protein 1. J Transl Med 2015; 95:1117-29. [PMID: 26237273 PMCID: PMC4586397 DOI: 10.1038/labinvest.2015.94] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 05/28/2015] [Accepted: 06/20/2015] [Indexed: 12/21/2022] [Imported: 10/07/2023] Open
Abstract
Hepatic stellate cell (HSC) activation and trans-differentiation into myofibroblast (MFB)-like cells is key for fibrogenesis after liver injury and a potential therapeutic target. Recent studies demonstrated that low-density lipoprotein receptor-related protein 1 (LRP1)-dependent signaling by tissue-type plasminogen activator (t-PA) is a pro-fibrotic regulator of the MFB phenotype in kidney. This study investigated whether LRP1 signaling by t-PA is also relevant to HSC activation following injury. Primary and immortalized rat HSCs were treated with t-PA and assayed by western blot, MTT, and TUNEL. In vitro results were then verified using an in vivo, acute carbon tetrachloride (CCl4) injury model that examined the phenotype and recovery kinetics of MFBs from wild-type animals vs mice with a global (t-PA) or HSC-targeted (LRP1) deletion. In vitro, in contrast to kidney MFBs, exogenous, proteolytically inactive t-PA suppressed, rather than induced, activation markers in HSCs following phosphorylation of LRP1. This process was mediated by LRP1 as inhibition of t-PA binding to LRP1 blocked the effects of t-PA. In vivo, following acute injury, phosphorylation of LRP1 on activated HSCs occurred immediately prior to their disappearance. Mice lacking t-PA or LRP1 retained higher densities of activated HSCs for a longer time period compared with control mice after injury cessation. Hence, t-PA, an FDA-approved drug, contributes to the suppression of activated HSCs following injury repair via signaling through LRP1. This renders t-PA a potential target for exploitation in treating patients with fibrosis.
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Michalopoulos GK, Khan Z. Liver Stem Cells: Experimental Findings and Implications for Human Liver Disease. Gastroenterology 2015; 149:876-882. [PMID: 26278502 PMCID: PMC4584191 DOI: 10.1053/j.gastro.2015.08.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 08/08/2015] [Accepted: 08/10/2015] [Indexed: 02/07/2023] [Imported: 08/29/2023]
Abstract
Evidence from human histopathology and experimental studies with rodents and zebrafish has shown that hepatocytes and cholangiocytes may function as facultative stem cells for each other in conditions of impaired regeneration. The interpretation of the findings derived from these studies has generated considerable discussion and some controversies. This review examines the evidence obtained from the different experimental models and considers implications that these studies may have for human liver disease.
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Xue Y, Michalopoulos G. Tregs: A Therapeutic Target for the Treatment of Portal Fibrosis? Dig Dis Sci 2015; 60:1878-80. [PMID: 25972149 DOI: 10.1007/s10620-015-3687-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 04/23/2015] [Indexed: 12/22/2022] [Imported: 08/29/2023]
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Prostaglandin E2Receptor EP1Transactivates EGFR/MET Receptor Tyrosine Kinases and Enhances Invasiveness in Human Hepatocellular Carcinoma Cells. J Cell Physiol 2015. [DOI: 10.1002/jcp.24869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] [Imported: 10/07/2023]
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Fontes P, Lopez R, van der Plaats A, Vodovotz Y, Minervini M, Scott V, Soltys K, Shiva S, Paranjpe S, Sadowsky D, Barclay D, Zamora R, Stolz D, Demetris A, Michalopoulos G, Marsh JW. Liver preservation with machine perfusion and a newly developed cell-free oxygen carrier solution under subnormothermic conditions. Am J Transplant 2015; 15:381-94. [PMID: 25612645 PMCID: PMC5024042 DOI: 10.1111/ajt.12991] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 07/28/2014] [Accepted: 08/23/2014] [Indexed: 01/25/2023] [Imported: 10/07/2023]
Abstract
We describe a new preservation modality combining machine perfusion (MP) at subnormothermic conditions(21 °C) with a new hemoglobin-based oxygen carrier (HBOC) solution. MP (n=6) was compared to cold static preservation (CSP; n=6) in porcine orthotopic liver transplants after 9 h of cold ischemia and 5-day follow-up. Recipients' peripheral blood, serial liver biopsies, preservation solutions and bile specimens were collected before, during and after liver preservation. Clinical laboratorial and histological analyses were performed in addition to mitochondrial functional assays, transcriptomic, metabolomic and inflammatory inflammatory mediator analyses. Compared with CSP, MP animals had: (1) significantly higher survival (100%vs. 33%; p<0.05); (2) superior graft function (p<0.05);(3) eight times higher hepatic O2 delivery than O2 consumption (0.78 mL O2/g/h vs. 0.096 mL O2/g/h) during MP; and (4) significantly greater bile production (MP=378.5 ± 179.7; CS=151.6 ± 116.85). MP downregulated interferon (IFN)-α and IFN-γ in liver tissue. MP allografts cleared lactate, produced urea, sustained gluconeogenesis and produced hydrophilic bile after reperfusion. Enhanced oxygenation under subnormothermic conditions triggers regenerative and cell protective responses resulting in improved allograft function. MP at 21 °C with the HBOC solution significantly improves liver preservation compared to CSP.
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Koral K, Paranjpe S, Bowen WC, Mars W, Luo J, Michalopoulos GK. Leukocyte-specific protein 1: a novel regulator of hepatocellular proliferation and migration deleted in human hepatocellular carcinoma. Hepatology 2015; 61:537-47. [PMID: 25234543 PMCID: PMC4303494 DOI: 10.1002/hep.27444] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 09/14/2014] [Indexed: 01/18/2023] [Imported: 08/29/2023]
Abstract
UNLABELLED Hepatocellular carcinoma (HCC) is the most commonly diagnosed form of liver cancer with high morbidity and mortality. Copy number variation (CNV) analysis of human HCC revealed that leukocyte-specific protein 1 (LSP1) had the highest number of cases with CNV. LSP1, a F-actin-binding protein, is expressed in hematopoietic cells and interacts with kinase suppressor of Ras (KSR), a scaffold for the extracellular signal-related kinase/mitogen-activated protein kinase pathway. Expression of LSP1 in liver, and its role in normal hepatocellular function and carcinogenesis, remains unknown. Therefore, LSP1 messenger RNA and protein levels were analyzed in normal hepatocytes in culture, rat liver following partial hepatectomy (PHx), and hepatoma cell lines. In culture and after PHx, LSP1 increased after the termination of hepatocyte proliferation. To investigate LSP1 function in HCC, short hairpin RNA was utilized to stably knock down LSP1 expression in the JM1 rat hepatoma cell line. Loss of LSP1 in JM1 cells resulted in dramatic up-regulation of cyclin D1 and phosphorylated ERK2, increased cell proliferation, and migration. Coimmunoprecipitation and immunofluorescence analysis displayed an interaction and colocalization between LSP1, KSR, and F-actin in JM1 cells and liver during regeneration. Conversely, expression of LSP1 in the JM2 rat hepatoma cell line led to decreased proliferation. Enhanced expression of LSP1 in mouse hepatocytes during liver regeneration after injection of an LSP1 expression plasmid also led to decreased hepatocyte proliferation. CONCLUSION LSP1 is expressed in normal hepatocytes and liver after PHx after termination of proliferation. In rat hepatoma cell lines and mouse liver in vivo, LSP1 functions as a negative regulator of proliferation and migration. Given the high frequency of LSP1 CNV in human HCC, LSP1 may be a novel target for diagnosis and treatment of HCC.
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Chen ZH, Yu YP, Michalopoulos G, Nelson J, Luo JH. The DNA replication licensing factor miniature chromosome maintenance 7 is essential for RNA splicing of epidermal growth factor receptor, c-Met, and platelet-derived growth factor receptor. J Biol Chem 2014; 290:1404-11. [PMID: 25425645 DOI: 10.1074/jbc.m114.622761] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] [Imported: 10/07/2023] Open
Abstract
Miniature chromosome maintenance 7 (MCM7) is an essential component of DNA replication licensing complex. Recent studies indicate that MCM7 is amplified and overexpressed in a variety of human malignancies. In this report, we show that MCM7 binds SF3B3. The binding motif is located in the N terminus (amino acids 221-248) of MCM7. Knockdown of MCM7 or SF3B3 significantly increased unspliced RNA of epidermal growth factor receptor, platelet-derived growth factor receptor, and c-Met. A dramatic drop of reporter gene expression of the oxytocin exon 1-intron-exon 2-EGFP construct was also identified in SF3B3 and MCM7 knockdown PC3 and DU145 cells. The MCM7 or SF3B3 depleted cell extract failed to splice reporter RNA in in vitro RNA splicing analyses. Knockdown of SF3B3 and MCM7 leads to an increase of cell death of both PC3 and DU145 cells. Such cell death induction is partially rescued by expressing spliced c-Met. To our knowledge, this is the first report suggesting that MCM7 is a critical RNA splicing factor, thus giving significant new insight into the oncogenic activity of this protein.
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