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Zhang Z, Fu J, Rack JGM, Li C, Voorneveld J, Filippov DV, Ahel I, Luo ZQ, Das C. Legionella metaeffector MavL reverses ubiquitin ADP-ribosylation via a conserved arginine-specific macrodomain. Nat Commun 2024; 15:2452. [PMID: 38503748 PMCID: PMC10951314 DOI: 10.1038/s41467-024-46649-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 02/26/2024] [Indexed: 03/21/2024] Open
Abstract
ADP-ribosylation is a reversible post-translational modification involved in various cellular activities. Removal of ADP-ribosylation requires (ADP-ribosyl)hydrolases, with macrodomain enzymes being a major family in this category. The pathogen Legionella pneumophila mediates atypical ubiquitination of host targets using the SidE effector family in a process that involves ubiquitin ADP-ribosylation on arginine 42 as an obligatory step. Here, we show that the Legionella macrodomain effector MavL regulates this pathway by reversing the arginine ADP-ribosylation, likely to minimize potential detrimental effects caused by the modified ubiquitin. We determine the crystal structure of ADP-ribose-bound MavL, providing structural insights into recognition of the ADP-ribosyl group and catalytic mechanism of its removal. Further analyses reveal DUF4804 as a class of MavL-like macrodomain enzymes whose representative members show unique selectivity for mono-ADP-ribosylated arginine residue in synthetic substrates. We find such enzymes are also present in eukaryotes, as exemplified by two previously uncharacterized (ADP-ribosyl)hydrolases in Drosophila melanogaster. Crystal structures of several proteins in this class provide insights into arginine specificity and a shared mode of ADP-ribose interaction distinct from previously characterized macrodomains. Collectively, our study reveals a new regulatory layer of SidE-catalyzed ubiquitination and expands the current understanding of macrodomain enzymes.
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Affiliation(s)
- Zhengrui Zhang
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Jiaqi Fu
- Department of Biological Sciences, Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN, 47907, USA
| | - Johannes Gregor Matthias Rack
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, OX1 3RE, Oxford, UK
- MRC Centre for Medical Mycology, University of Exeter, Geoffrey Pope Building, Stocker Road, EX4 4QD, Exeter, UK
| | - Chuang Li
- Department of Biological Sciences, Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN, 47907, USA
| | - Jim Voorneveld
- Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, 2300 RA, Leiden, The Netherlands
| | - Dmitri V Filippov
- Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, 2300 RA, Leiden, The Netherlands
| | - Ivan Ahel
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, OX1 3RE, Oxford, UK
| | - Zhao-Qing Luo
- Department of Biological Sciences, Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN, 47907, USA
| | - Chittaranjan Das
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA.
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Hormaechea-Agulla D, Kim Y, Song MS, Song SJ. New Insights into the Role of E2s in the Pathogenesis of Diseases: Lessons Learned from UBE2O. Mol Cells 2018; 41:168-178. [PMID: 29562734 PMCID: PMC5881090 DOI: 10.14348/molcells.2018.0008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 03/08/2018] [Accepted: 03/13/2018] [Indexed: 12/23/2022] Open
Abstract
Intracellular communication via ubiquitin (Ub) signaling impacts all aspects of cell biology and regulates pathways critical to human development and viability; therefore aberrations or defects in Ub signaling can contribute to the pathogenesis of human diseases. Ubiquitination consists of the addition of Ub to a substrate protein via coordinated action of E1-activating, E2-conjugating and E3-ligating enzymes. Approximately 40 E2s have been identified in humans, and most are thought to be involved in Ub transfer; although little information is available regarding the majority of them, emerging evidence has highlighted their importance to human health and disease. In this review, we focus on recent insights into the pathogenetic roles of E2s (particularly the ubiquitin-conjugating enzyme E2O [UBE2O]) in debilitating diseases and cancer, and discuss the tantalizing prospect that E2s may someday serve as potential therapeutic targets for human diseases.
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Affiliation(s)
- Daniel Hormaechea-Agulla
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030,
USA
| | - Youngjo Kim
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Cheonan 31151,
Korea
| | - Min Sup Song
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030,
USA
- Cancer Biology Program, The University of Texas Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX 77030,
USA
| | - Su Jung Song
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Cheonan 31151,
Korea
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3
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Fahmidehkar MA, Shafiee SM, Eftekhar E, Mahbudi L, Seghatoleslam A. Induction of cell proliferation, clonogenicity and cell accumulation in S phase as a consequence of human UBE2Q1 overexpression. Oncol Lett 2016; 12:2169-2174. [PMID: 27602158 DOI: 10.3892/ol.2016.4860] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 06/17/2016] [Indexed: 02/07/2023] Open
Abstract
Ubiquitination is an important cellular mechanism with a pivotal role in the degradation of abnormal or short-lived proteins and the regulation of cell cycle and cell growth. The ubiquitin-proteasome pathway is altered in multiple types of human malignancies, including colorectal cancer (CRC). The alteration in the expression of the novel human gene ubiquitin-conjugating enzyme E2 Q1 (UBE2Q1), as a putative member of the E2 ubiquitin-conjugating enzyme family, has been reported in several malignancies, including carcinoma of the breast, hepatocellular and colorectal cancer, and pediatric acute lymphoblastic leukemia. In the present study, the effect of UBE2Q1 overexpression on cell growth, clonogenicity, motility and cell cycle was investigated in a CRC cell line. The UBE2Q1 gene was cloned in the pCMV6-AN-GFP expression vector. A series of stable transfectants of SW1116 cells overexpressing UBE2Q1 protein were established and confirmed by fluorescence microscopy and western blotting. Using these cells, MTT assay was performed to evaluate cell growth and proliferation, while crystal violet staining was used for clonogenicity assay. Cell cycle analysis was also performed to survey the ratio of cells accumulated in different phases of the cell cycle upon transfection. The motility of these cells was also studied using wound healing assay. UBE2Q1 transfectants exhibited a faster growth in cell culture, increased colony formation capacity and enhanced motility compared with control non-transfected cells and cells transfected with empty vector (mock-transfected cells). UBE2Q1 overexpression also resulted in a significant decrease in the number of cells accumulated in the G0/G1 phase of the cell cycle. The present findings suggest that UBE2Q1 may function as an oncogene that induces proliferation of cancer cells, and could be a novel diagnostic tool and a potential therapeutic target for CRC.
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Affiliation(s)
- Mohammad Ali Fahmidehkar
- Department of Biochemistry, School of Medicine, Shiraz University of Medical Sciences, Shiraz 71348-45794, Iran
| | - Sayed Mohammad Shafiee
- Department of Biochemistry, School of Medicine, Shiraz University of Medical Sciences, Shiraz 71348-45794, Iran
| | - Ebrahim Eftekhar
- Food and Cosmetic Health Research Center, Hormozgan University of Medical Sciences, Bandar Abbas 79158-73665, Iran
| | - Laleh Mahbudi
- Department of Biochemistry, School of Medicine, Shiraz University of Medical Sciences, Shiraz 71348-45794, Iran
| | - Atefeh Seghatoleslam
- Department of Biochemistry, School of Medicine, Shiraz University of Medical Sciences, Shiraz 71348-45794, Iran; Histomorphometry and Stereology Research Center, Shiraz University of Medical Sciences, Shiraz 71439-14693, Iran
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4
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Chang R, Wei L, Lu Y, Cui X, Lu C, Liu L, Jiang D, Xiong Y, Wang G, Wan C, Qian H. Upregulated expression of ubiquitin-conjugating enzyme E2Q1 (UBE2Q1) is associated with enhanced cell proliferation and poor prognosis in human hapatocellular carcinoma. J Mol Histol 2014; 46:45-56. [PMID: 25311764 DOI: 10.1007/s10735-014-9596-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 09/30/2014] [Indexed: 02/07/2023]
Abstract
Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. Ubiquitin-proteasome system has been shown to play a pivotal role in the pathophysiology of HCC and other malignancies. UBE2Q1 is a putative E2 ubiquitin conjugating enzyme, and may be involved in the regulation of cancer-related proteins. In this study, we investigated the expression pattern of UBE2Q1 in HCC cell lines and human HCC specimens, and its potential clinical and biological significance in HCC. Western blot and immunohistochemical analyses revealed that UBE2Q1 was significantly upregulated in HCC tumorous tissues compared with the adjacent noncancerous ones. Next, univariate and multivariate survival analyses were performed to determine the prognostic significance of UBE2Q1 in HCC. The results showed that upregulated expression of UBE2Q1 was positively correlated with high histological grades of HCC and predicted poor prognosis. In addition, the expression of UBE2Q1 was progressively increased in serum-refed HCC cells. UBE2Q1 depletion by small interfering RNA inhibited cell proliferation and led to G1 phase arrest in HepG2 and BEL-7404 cells. Furthermore, we showed that cells transfected with UBE2Q1-targeting siRNA resulted in significant increase in the levels of p53, p21 in HepG2 and BEL-7404 cells. These data imply that UBE2Q1 is upregulated in liver cancer cell lines and tumorous samples and may play a role in the development of HCC.
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Affiliation(s)
- Renan Chang
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
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5
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Roy SH, Tobin DV, Memar N, Beltz E, Holmen J, Clayton JE, Chiu DJ, Young LD, Green TH, Lubin I, Liu Y, Conradt B, Saito RM. A complex regulatory network coordinating cell cycles during C. elegans development is revealed by a genome-wide RNAi screen. G3 (BETHESDA, MD.) 2014; 4:795-804. [PMID: 24584095 PMCID: PMC4025478 DOI: 10.1534/g3.114.010546] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 02/25/2014] [Indexed: 12/11/2022]
Abstract
The development and homeostasis of multicellular animals requires precise coordination of cell division and differentiation. We performed a genome-wide RNA interference screen in Caenorhabditis elegans to reveal the components of a regulatory network that promotes developmentally programmed cell-cycle quiescence. The 107 identified genes are predicted to constitute regulatory networks that are conserved among higher animals because almost half of the genes are represented by clear human orthologs. Using a series of mutant backgrounds to assess their genetic activities, the RNA interference clones displaying similar properties were clustered to establish potential regulatory relationships within the network. This approach uncovered four distinct genetic pathways controlling cell-cycle entry during intestinal organogenesis. The enhanced phenotypes observed for animals carrying compound mutations attest to the collaboration between distinct mechanisms to ensure strict developmental regulation of cell cycles. Moreover, we characterized ubc-25, a gene encoding an E2 ubiquitin-conjugating enzyme whose human ortholog, UBE2Q2, is deregulated in several cancers. Our genetic analyses suggested that ubc-25 acts in a linear pathway with cul-1/Cul1, in parallel to pathways employing cki-1/p27 and lin-35/pRb to promote cell-cycle quiescence. Further investigation of the potential regulatory mechanism demonstrated that ubc-25 activity negatively regulates CYE-1/cyclin E protein abundance in vivo. Together, our results show that the ubc-25-mediated pathway acts within a complex network that integrates the actions of multiple molecular mechanisms to control cell cycles during development.
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Affiliation(s)
- Sarah H Roy
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - David V Tobin
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - Nadin Memar
- Center for Integrated Protein Science Munich (CiPSM), Biocenter, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Eleanor Beltz
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - Jenna Holmen
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - Joseph E Clayton
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - Daniel J Chiu
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - Laura D Young
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - Travis H Green
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - Isabella Lubin
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - Yuying Liu
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - Barbara Conradt
- Center for Integrated Protein Science Munich (CiPSM), Biocenter, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - R Mako Saito
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755 Norris Cotton Cancer Center, Lebanon, New Hampshire 03756
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6
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Langenfeld E, Deen M, Zachariah E, Langenfeld J. Small molecule antagonist of the bone morphogenetic protein type I receptors suppresses growth and expression of Id1 and Id3 in lung cancer cells expressing Oct4 or nestin. Mol Cancer 2013; 12:129. [PMID: 24160469 PMCID: PMC4176118 DOI: 10.1186/1476-4598-12-129] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 10/17/2013] [Indexed: 01/06/2023] Open
Abstract
Background Bone morphogenetic proteins (BMP) are embryonic morphogens that are aberrantly expressed in lung cancer. BMPs mediate cell fate decisions and self-renewal of stem cells, through transcription regulation of inhibitor of differentiation protein/DNA binding proteins (Id1-3). Inhibition of BMP signaling decreases growth and induces cell death of lung cancer cells lines by downregulating the expression of Id proteins. It is not known whether the BMP signaling cascade regulates growth and the expression of Id proteins of lung cancer cells expressing the stem cell markers Oct4 and/or nestin. Methods Lung cancer cells expressing Oct4 or nestin were isolated from lung cancer cell lines by stably transfecting the Oct4 promoter or nestin promoter expression vectors that induce expression of the green fluorescent protein reporter. Results Our studies suggest that lung cancer cells expressing Oct4 or nestin are different cell populations. Microarray and quantitative RT-PCR demonstrated that the expression of specific stem cell markers were different between isolated Oct4 and nestin cells. Both the Oct4 and nestin populations were more tumorigenic than controls but histologically they were quite different. The isolated Oct4 and nestin cells also responded differently to inhibition of BMP signaling. Blockade of BMP signaling with the BMP receptor antagonist DMH2 caused significant growth inhibition of both the Oct4 and nestin cell populations but only increased cell death in the nestin population. DMH2 also induced the expression of nestin in the Oct4 population but not in the nestin cells. We also show that BMP signaling is an important regulator of Id1 and Id3 in both the Oct4 and nestin cell populations. Furthermore, we show that NeuN is frequently expressed in NSCLC and provide evidence suggesting that Oct4 cells give rise to cancer cells expressing nestin and/or NeuN. Conclusion These studies show that although biologically different, BMP signaling is growth promoting in cancer cells expressing Oct4 or nestin. Inhibition of BMP signaling decreases expression of Id proteins and suppresses growth of cancer cells expressing Oct4 or Nestin. Small molecule antagonists of the BMP type I receptors represent potential novel drugs to target the population of cancer cells expressing stem cell markers.
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Affiliation(s)
| | | | | | - John Langenfeld
- Division of Thoracic Surgery, Rutgers-Robert Wood Johnson Medical School, One Robert Wood Johnson Place, P,O, Box 19, New Brunswick, NJ 08903-0019, USA.
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7
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Roetzer KM, Schwarzbraun T, Obenauf AC, Hauser E, Speicher MR. Further evidence for the pathogenicity of 15q24 microduplications distal to the minimal critical regions. Am J Med Genet A 2011; 152A:3173-8. [PMID: 21108404 DOI: 10.1002/ajmg.a.33750] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
DNA copy number alterations in 15q24 have repeatedly been reported in patients exhibiting mild to moderate developmental delay and dysmorphic features. To date, mainly microdeletions have been described, and comparison of overlapping regions allowed the definition of minimal critical regions (MCRs) for microdeletions as well as microduplications. These MCRs are associated with distinct phenotypes. Recently, a family with a new microduplication distal to these MCRs was reported. However, for this alteration the typical phenotypical consequences could not yet be determined. Here we present another family with a nearly identical microduplication exhibiting a broad clinical spectrum including developmental delay, autistic traits and dysmorphic features. Our data suggest that microduplications adjacent and distal to the known MCRs are variable in expressivity and are associated with distinct features. They might represent a novel and recurrent microduplication syndrome.
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Nikseresht M, Seghatoleslam A, Monabati A, Talei A, Ghalati FB, Owji AA. Overexpression of the novel human gene, UBE2Q2, in breast cancer. ACTA ACUST UNITED AC 2010; 197:101-6. [PMID: 20193842 DOI: 10.1016/j.cancergencyto.2009.11.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2009] [Revised: 11/01/2009] [Accepted: 11/25/2009] [Indexed: 12/17/2022]
Abstract
The ubiquitin-proteasome pathway facilitates the degradation of damaged proteins and regulates growth and stress response. This pathway is activated in various cancers, including breast cancer. We have previously reported that the novel human gene, UBE2Q2, is a putative ubiquitin-conjugating enzyme that is located on chromosome 15 and is overexpressed in tumor mass and invasive epithelium in head and neck squamous-cell carcinoma. Here, real-time polymerase chain reaction was used to investigate the expression levels of UBE2Q2 gene in a collection of 21 breast cancer tissues matched with normal adjacent counterparts. Immunohistochemistry and Western blot testing were also performed on formalin-fixed, paraffin-embedded tissue sections by using a rabbit polyclonal antibody that we generated against an amino acid sequence predicted from the DNA sequence of UBE2Q2 gene. In the 21 cases investigated, a high increase in the expression of UBE2Q2 mRNA was found in 8 breast cancers (38.1%), a moderately increased UBE2Q2 expression was observed in 7 cases (33.3%), and no significant changes were detected in 6 cases (28.6%) of tumor samples when compared with corresponding normal tissues. Consistently, a higher level of immunoreactivity for UBE2Q2 protein was detected in invasive epithelium of cancerous tissues when compared with that in the normal epithelium. Our data suggest that the novel human gene UBE2Q2 may have implications for pathogenesis of breast cancer and could be used in molecular diagnosis purposes in the future.
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Affiliation(s)
- Mohsen Nikseresht
- Department of Biochemistry, Shiraz University of Medical Sciences, Shiraz, Iran
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9
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Russo J, Snider K, Pereira JS, Russo IH. Estrogen induced breast cancer is the result in the disruption of the asymmetric cell division of the stem cell. Horm Mol Biol Clin Investig 2010; 1:53-65. [PMID: 21258630 DOI: 10.1515/hmbci.2010.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
There is evidence that in the human breast there is a stem cell population that can give rise to many different cell types and have the unique potential to divide asymmetrically. In this way stem cells maintain the stem cell pool and simultaneously generate committed cells that reconstitute the organ for example for preparing the breast for a new pregnancy after the involution from a previous pregnancy and lactation process. In addition to the in vivo models of mammary morphogenesis there are in vitro systems that are more amenable to study in critically determined conditions the ductulogenic pattern of growth of the breast epithelia. Primary mammary epithelial cells grown in collagen matrix are able to form tree-like structures resembling in vivo ductulogenesis. The human breast epithelial cells MCF-10F formed tubules when grown in type I collagen and we demonstrated that treatment of these cells with 17β-estradiol (E(2)) induces phonotypical changes indicative of neoplastic transformation. The transformation of MCF-10F by E(2) is associated with impaired ductal morphogenesis by altering the stem cells unique potential to divide asymmetrically inducing formation of solid masses mimicking intraductal carcinoma that progress to invasive and tumorigenic phenotype. In the present work we present evidence for the mechanism of cell asymmetry leading to normal ductulogenesis and how the normal stem cell is transformed to cancer stem cell by altering this process. Furthermore, we demonstrate that the carcinogenic agent, in this case E(2), induces a defect in the asymmetric cell division program of the normal mammary stem cell.
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Affiliation(s)
- Jose Russo
- Breast Cancer Research laboratory, Fox Chase Cancer Center, Philadelphia, PA, USA
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10
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Maeda H, Miyajima N, Kano S, Tsukiyama T, Okumura F, Fukuda S, Hatakeyama S. Ubiquitin-conjugating enzyme UBE2Q2 suppresses cell proliferation and is down-regulated in recurrent head and neck cancer. Mol Cancer Res 2009; 7:1553-62. [PMID: 19723876 DOI: 10.1158/1541-7786.mcr-08-0543] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The ubiquitin-proteasome system has a crucial role in maintaining and regulating cellular homeostasis including carcinogenesis. UBE2Q2, also designated Ubci, is one of the ubiquitin-conjugating enzymes (E2), and it has been reported that mRNA of UBE2Q2 is highly expressed in human head and neck squamous cell carcinoma, particularly hypopharyngeal carcinoma. However, the involvement of UBE2Q2 in carcinogenesis has not been fully elucidated. Most cases of head and neck carcinoma are treated with cis-diamminedichloroplatinum (II; CDDP) or docetaxel, which are the most effective chemotherapeutic agents against squamous cell carcinomas. Nevertheless, some head and neck cancers develop resistance to these drugs, although the causes and mechanisms remain unknown. In this study, we found high expression levels of UBE2Q2 in human head and neck carcinoma cell lines and cancer tissues by using an anti-UBE2Q2 antibody at the protein level. We also found that the expression level of UBE2Q2 is decreased in cell lines and cancer tissues that have resistance to CDDP or docetaxel and in cancer tissues treated with CDDP or docetaxel. Furthermore, we found that overexpression of UBE2Q2 affects cell proliferation and anchorage-independent cell growth. These findings suggest that UBE2Q2 is a novel oncosuppressor that inhibits tumor growth and is related to the resistance to anticarcinoma agents and that UBE2Q2 likely functions as a novel diagnostic tool and a potentially therapeutic target for head and neck squamous cell carcinoma.
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Affiliation(s)
- Hiroyuki Maeda
- Department of Biochemistry, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan
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11
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Wickliffe K, Williamson A, Jin L, Rape M. The multiple layers of ubiquitin-dependent cell cycle control. Chem Rev 2009; 109:1537-48. [PMID: 19146381 PMCID: PMC3206288 DOI: 10.1021/cr800414e] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Katherine Wickliffe
- University of California at Berkeley, Department of Molecular and Cell Biology, Berkeley, CA 94720, USA
| | - Adam Williamson
- University of California at Berkeley, Department of Molecular and Cell Biology, Berkeley, CA 94720, USA
| | - Lingyan Jin
- University of California at Berkeley, Department of Molecular and Cell Biology, Berkeley, CA 94720, USA
| | - Michael Rape
- University of California at Berkeley, Department of Molecular and Cell Biology, Berkeley, CA 94720, USA
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Wassler MJ, Shur BD, Zhou W, Geng YJ. Characterization of a novel ubiquitin-conjugating enzyme that regulates beta1,4-galactosyltransferase-1 in embryonic stem cells. Stem Cells 2008; 26:2006-18. [PMID: 18511602 DOI: 10.1634/stemcells.2007-1080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this study we identified a novel galactosyltransferase 1-associating protein (GTAP) by cDNA cloning from a murine embryonic cDNA library using the two-hybrid yeast system. GTAP is expressed in early embryonic tissues, as well as in adult tissues with active cell turnover, and belongs to the class III ubiquitin-conjugating (E2) enzyme family. Its COOH-terminal domain contains a consensus sequence for ubiquitin binding shared by all the ubiquitin-conjugating enzymes, whereas its NH(2)-terminal domain appears critical for the binding and internalization of cell surface galactosyltransferase 1 (GalT1) in embryonic stem cells through a monensin- and MG132-dependent pathway. We have found that GTAP regulates GalT1-associated, laminin-dependent embryonic cell adhesion and the formation of embryoid bodies. Thus, GTAP functions as an evolutionarily conserved E2 enzyme, which may participate in intercellular adhesion and embryonic development. Disclosure of potential conflicts of interest is found at the end of this article.
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Affiliation(s)
- Michael J Wassler
- Center for Cardiovascular Biology and Atherosclerosis Research, Division of Cardiology, Department of Internal Medicine, The University of Texas Health Science Center at Houston, School of Medicine, Houston 77030, USA.
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Brooks WS, Helton ES, Banerjee S, Venable M, Johnson L, Schoeb TR, Kesterson RA, Crawford DF. G2E3 is a dual function ubiquitin ligase required for early embryonic development. J Biol Chem 2008; 283:22304-15. [PMID: 18511420 DOI: 10.1074/jbc.m803238200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
G2E3 is a putative ubiquitin ligase (E3) identified in a microarray screen for mitotic regulatory proteins. It shuttles between the cytoplasm and nucleus, concentrating in nucleoli and relocalizing to the nucleoplasm in response to DNA damage. In this study, we demonstrate that G2E3 is an unusual ubiquitin ligase that is essential in early embryonic development to prevent apoptotic death. This protein has a catalytically inactive HECT domain and two distinct RING-like ubiquitin ligase domains that catalyze lysine 48-linked polyubiquitination. To address in vivo function, we generated a knock-out mouse model of G2E3 deficiency that incorporates a beta-galactosidase reporter gene under control of the endogenous promoter. Animals heterozygous for G2E3 inactivation are phenotypically normal with no overt change in development, growth, longevity, or fertility, whereas G2E3 null embryos die prior to implantation. Although normal numbers of G2E3(-/-) blastocysts are present at embryonic day 3.5, these blastocysts involute in culture as a result of massive apoptosis. Using beta-galactosidase staining as a marker for protein expression, we demonstrate that G2E3 is predominantly expressed within the central nervous system and the early stages of limb bud formation of the developing embryo. In adult animals, the most intense staining is found in Purkinje cell bodies and cells lining the ductus deferens. In summary, G2E3 is a dual function ubiquitin ligase essential for prevention of apoptosis in early embryogenesis.
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Affiliation(s)
- William S Brooks
- Department of Cell Biology, University of Alabama, Birmingham, Alabama 35233, USA
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