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Lee HC, Lai WL, Lin CY, Zeng CW, Sheu JC, Chou TB, Tsai HJ. Anp32a Promotes Neuronal Regeneration after Spinal Cord Injury of Zebrafish Embryos. Int J Mol Sci 2022; 23:ijms232415921. [PMID: 36555564 PMCID: PMC9786895 DOI: 10.3390/ijms232415921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
After spinal cord injury (SCI) in mammals, neuronal regeneration is limited; in contrast, such regeneration occurs quickly in zebrafish. Member A of the acidic nuclear phosphoprotein 32 (ANP32a) family is involved in neuronal development, but its function is controversial, and its involvement in zebrafish SCI remains unknown. To determine the role of zebrafish ANP32a in the neuronal regeneration of SCI embryos, we microinjected ANP32a mRNA into embryos from zebrafish transgenic line Tg(mnx1:GFP) prior to SCI. Compared to control SCI embryos, the results showed that the regeneration of spinal cord and resumption of swimming capability were promoted by the overexpression of ANP32a mRNA but reduced by its knockdown. We next combined fluorescence-activated cell sorting with immunochemical staining of anti-GFAP and immunofluorescence staining against anti-PH3 on Tg(gfap:GFP) SCI embryos. The results showed that ANP32a promoted the proliferation and cell number of radial glial cells at the injury epicenter at 24 h post-injury (hpi). Moreover, when we applied BrdU labeling to SCI embryos derived from crossing the Tg(gfap:GFP) and Tg(mnx1:TagRFP) lines, we found that both radial glial cells and motor neurons had proliferated, along with their increased cell numbers in Anp32a-overexpression SCI-embryos. On this basis, we conclude that ANP32a plays a positive role in the regeneration of zebrafish SCI embryos.
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Affiliation(s)
- Hung-Chieh Lee
- Department of Life Science, Fu Jen Catholic University, New Taipei City 242062, Taiwan
| | - Wei-Lin Lai
- Institute of Molecular and Cellular Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Cheng-Yung Lin
- Institute of Biomedical Science, Mackay Medical College, New Taipei City 25245, Taiwan
| | - Chih-Wei Zeng
- Liver Disease Prevention and Treatment Research Foundation, Taipei 100008, Taiwan
| | - Jin-Chuan Sheu
- Liver Disease Prevention and Treatment Research Foundation, Taipei 100008, Taiwan
| | - Tze-Bin Chou
- Institute of Molecular and Cellular Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Huai-Jen Tsai
- Department of Life Science, Fu Jen Catholic University, New Taipei City 242062, Taiwan
- Institute of Molecular and Cellular Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
- School of Medicine, Fu-Jen Catholic University, New Taipei City 242062, Taiwan
- Correspondence:
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Tian Z, Liu Z, Fang X, Cao K, Zhang B, Wu R, Wen X, Wen Q, Shi H, Wang R. ANP32A promotes the proliferation, migration and invasion of hepatocellular carcinoma by modulating the HMGA1/STAT3 pathway. Carcinogenesis 2021; 42:493-506. [PMID: 33332531 DOI: 10.1093/carcin/bgaa138] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 12/16/2022] Open
Abstract
Acidic leucine-rich nuclear phosphoprotein-32A (ANP32A) has been reported to play an essential role in the development and progression of various human cancers. However, its expression pattern and possible mechanism in human hepatocellular carcinoma (HCC) remain to be elucidated. In this study, we used western blot and immunohistochemical staining to detect protein expression. The effects of ANP32A on the proliferation, migration and invasion of HCC cells were examined using 5-ethynyl-20-deoxyuridine (EdU), colony formation, CCK-8, and transwell assays. RT-qPCR was performed to detect mRNA expression. The interaction between ANP32A and the high mobility group A1 (HMGA1) mRNA was assessed using RNA immunoprecipitation (RIP). The tumorigenicity of ANP32A was assessed by establishing a xenograft tumor model in Balb/c nude mice. We found that the ANP32A protein was expressed at high levels in patients with HCC, which was associated with a poor prognosis. Functional experiments revealed that the silencing of ANP32A inhibited the proliferation, migration, and invasion of HCC cells, whereas overexpression of ANP32A promoted these processes. Further investigations indicated that ANP32A bound the HMGA1 mRNA and maintained its stability to promote the expression of HMGA1, thereby increasing the expression and activation of STAT3. Finally, a xenograft tumor model of Balb/c nude mice confirmed the tumorigenicity of ANP32A. This study found that ANP32A is up-regulated in patients with HCC and may accelerate the proliferation, migration and invasion of HCC cells by modulating the HMGA1/STAT3 pathway.
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Affiliation(s)
- Zilu Tian
- Institute of Digestive Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of General Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Zhiyi Liu
- Institute of Digestive Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of General Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Xiaokang Fang
- Institute of Digestive Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of General Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Kuan Cao
- Institute of Digestive Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of General Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Bin Zhang
- Institute of Digestive Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of General Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Rui Wu
- Institute of Digestive Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of General Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Xin Wen
- Institute of Digestive Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of General Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Quan Wen
- Institute of Digestive Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of General Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Hengliang Shi
- Institute of Digestive Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of General Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.,Central Laboratory, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Renhao Wang
- Institute of Digestive Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of General Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
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3
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ANP32A regulates histone H3 acetylation and promotes leukemogenesis. Leukemia 2018; 32:1587-1597. [DOI: 10.1038/s41375-018-0010-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 12/07/2017] [Accepted: 12/18/2017] [Indexed: 12/16/2022]
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Yan W, Bai Z, Wang J, Li X, Chi B, Chen X. ANP32A modulates cell growth by regulating p38 and Akt activity in colorectal cancer. Oncol Rep 2017; 38:1605-1612. [PMID: 28731192 DOI: 10.3892/or.2017.5845] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 07/03/2017] [Indexed: 11/06/2022] Open
Abstract
Acidic leucine-rich nuclear phosphoprotein-32A (ANP32A) possesses multiple biochemical activities, has been found to be decreased or absent in malignant tumors. However, new findings have shown that it is expressed in greater amounts in advanced cancers than in early-stage tumors. The role and clinical significance of ANP32A in colorectal cancer (CRC) is still unknown. In the present study, the expression of ANP32A was assessed in 68 CRC patients by IHC, and then the correlation of its expression with clinicopathological factors was investigated using the Allred, Klein and immune response scoring system analysis. Western blot and real-time PCR analyses were used to assess ANP32A expression and the activity of Akt and p38 in cancer and normal tissues. These data indicated a significant association between ANP32A expression and the activity of Akt and p38, besides the tumor differentiation status in CRC patients. IHC and western blotting data revealed that ANP32A was overexpressed in CRC patients, and ANP32A levels were higher in poorly differentiated tumors. Protein and mRNA analysis revealed that with a high expression of ANP32A, the activation of Akt was enhanced, while the p-38 phosphorylation level was decreased in CRC tissues. MTT assay and functional studies revealed that knockdown of ANP32A inhibited cell growth and induced p38 phosphorylation and Akt dephosphorylation. The present study indicated that ANP32A promoted CRC proliferation by inhibition of p38 and activation of Akt signaling pathways and suggested that ANP32A may play a potential role in CRC diagnosis and therapy.
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Affiliation(s)
- Wei Yan
- College of Pharmacy, Guilin Medical University, Guilin 541004, P.R. China
| | - Zhun Bai
- Intensive Care Unit, The Affiliated Zhuzhou Hospital XiangYa Medical College CSU, Zhuzhou, Hunan 412007, P.R. China
| | - Juan Wang
- College of Pharmacy, Guilin Medical University, Guilin 541004, P.R. China
| | - Xumei Li
- College of Pharmacy, Guilin Medical University, Guilin 541004, P.R. China
| | - Bixia Chi
- Department of Gastroenterology, The First People's Hospital of Yueyang, Yueyang, Hunan 414000, P.R. China
| | - Xu Chen
- College of Pharmacy, Guilin Medical University, Guilin 541004, P.R. China
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Prognostic impact of Bcl-2 depends on tumor histology and expression of MALAT-1 lncRNA in non-small-cell lung cancer. J Thorac Oncol 2015; 9:1294-304. [PMID: 25036876 DOI: 10.1097/jto.0000000000000243] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Apoptosis is a crucial pathway in tumor growth and metastatic development. Apoptotic proteins regulate the underlying molecular cascades and are thought to modulate the tumor response to chemotherapy and radiation. However, the prognostic value of the expression of apoptosis regulators in localized non-small-cell lung cancer (NSCLC) is still unclear. METHODS We investigated the protein expression of apoptosis regulators Bcl-2, Bcl-xl, Mcl-1, and pp32/PHAPI, and the expression of the lncRNA MALAT-1 in tumor samples from 383 NSCLC patients (median age: 65.6 years; 77.5% male; paraffin-embedded tissue microarrays). For statistical analysis correlation tests, Log rank tests and Cox proportional hazard models were applied. RESULTS Tumor histology was significantly associated with the expression of Bcl-2, Bcl-xl and Mcl-1 (all p < 0.001). Among the tested apoptotic markers only Bcl-2 demonstrated prognostic impact (hazard ratio = 0.64, p = 0.012). For NSCLC patients with non-adenocarcinoma histology, Bcl-2 expression was associated with increased overall survival (p = 0.036). Besides tumor histology, prognostic impact of Bcl-2 was also found to depend on MALAT-1 lncRNA expression. Gene expression analysis of A549 adenocarcinoma cells with differential MALAT-1 lncRNA expression demonstrated an influence on the expression of Bcl-2 and its interacting proteins. CONCLUSIONS Bcl-2 expression was specifically associated with superior prognosis in localized NSCLC. An interaction of Bcl-2 with MALAT-1 lncRNA expression was revealed, which merits further investigation for risk prediction in resectable NSCLC patients.
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Li CX, Shen SM, Wang LS, Yu Y. Caspase-3-resistant uncleavable form of acidic leucine-rich nuclear phosphoprotein 32B potentiates leukemic cell apoptosis. Mol Med Rep 2014; 11:2813-8. [PMID: 25483709 DOI: 10.3892/mmr.2014.3035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 11/14/2014] [Indexed: 11/05/2022] Open
Abstract
One member of the highly conserved acidic leucine‑rich nuclear phosphoprotein 32 kDa (ANP32) family of proteins, ANP32B, is critical for normal development, as demonstrated by a study in ANP32B‑deficient mice. Another study indicated that ANP32B was a direct substrate of caspase‑3, and was primarily cleaved at the sequence Ala‑Glu‑Val‑Asp, following Asp‑163. To investigate the significance of ANP32B cleavage in apoptosis, leukemic U937T cell lines were generated with inducible expression of ANP32B(wild type; WT), the uncleavable mutant ANP32B(D163A) and the N‑terminal fragment ANP32B(1‑163). Notably, overexpression of ANP32B(WT) and ANP32B(D163A) moderately increased and significantly enhanced etoposide‑induced apoptosis and caspase‑3 activation, whereas expression of ANP32B(1‑163) produced no effect. Two hypotheses have been generated, which may explain the distinct roles of the various ANP32B forms: i) ANP32B(WT) and ANP32B(D163A) localize in the nucleus while ANP32B(1‑163) mainly resides in the cytosol; or ii) ANP32B(WT) and ANP32B(D163A), but not ANP32B(1‑163), inhibit the expression of the anti‑apoptotic protein Bcl‑2. Based on these observations, caspase‑3‑resistant uncleavable ANP32B(D163A) is hypothesized to be pro‑apoptotic in leukemic cells.
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Affiliation(s)
- Cai-Xia Li
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Center of Molecular Medicine, Rui‑Jin Hospital, Shanghai Jiao‑Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Shao-Ming Shen
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Center of Molecular Medicine, Rui‑Jin Hospital, Shanghai Jiao‑Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Li-Shun Wang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Center of Molecular Medicine, Rui‑Jin Hospital, Shanghai Jiao‑Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Yun Yu
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Center of Molecular Medicine, Rui‑Jin Hospital, Shanghai Jiao‑Tong University School of Medicine, Shanghai 200025, P.R. China
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Reilly PT, Yu Y, Hamiche A, Wang L. Cracking the ANP32 whips: important functions, unequal requirement, and hints at disease implications. Bioessays 2014; 36:1062-71. [PMID: 25156960 PMCID: PMC4270211 DOI: 10.1002/bies.201400058] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The acidic (leucine-rich) nuclear phosphoprotein 32 kDa (ANP32) family is composed of small, evolutionarily conserved proteins characterized by an N-terminal leucine-rich repeat domain and a C-terminal low-complexity acidic region. The mammalian family members (ANP32A, ANP32B, and ANP32E) are ascribed physiologically diverse functions including chromatin modification and remodelling, apoptotic caspase modulation, protein phosphatase inhibition, as well as regulation of intracellular transport. In addition to reviewing the widespread literature on the topic, we present a concept of the ANP32s as having a whip-like structure. We also present hypotheses that ANP32C and other intronless sequences should not currently be considered bona fide family members, that their disparate necessity in development may be due to compensatory mechanisms, that their contrasting roles in cancer are likely context-dependent, along with an underlying hypothesis that ANP32s represent an important node of physiological regulation by virtue of their diverse biochemical activities.
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Affiliation(s)
- Patrick T Reilly
- Laboratory of Inflammation Biology, National Cancer Centre Singapore, Singapore, Singapore
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8
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Buddaseth S, Göttmann W, Blasczyk R, Huyton T. Dysregulation of cell cycle control caused by overexpression of the oncogene pp32r1 (ANP32C) and the Tyr>His mutant pp32r1Y140H. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1212-21. [PMID: 23403278 DOI: 10.1016/j.bbamcr.2013.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 01/22/2013] [Accepted: 02/01/2013] [Indexed: 11/25/2022]
Abstract
The pp32 (ANP32A) gene acts as a tumor suppressor while its closely related homologue pp32r1 (ANP32C) is oncogenic and is overexpressed in breast, prostate and pancreatic tumors. The transduction of p53wt cell lines (ACHN and HeLa) with pp32r1 or pp32r1Y140H lentivirus increased the proliferation of p53wt cell lines compared to the untransduced control cells while transduction of the p53(R248W) MiaPaCa2 cell line had no effect. Cell cycle analysis of transduced ACHN cells by PI staining and BrdU incorporation illustrated a pronounced shift toward the S-phase of the cell cycle in cells overexpressing the pp32r1 and pp32r1Y140H proteins. Confocal microscopy and western blotting demonstrated that pp32r1 and the pp32r1Y140H mutant protein reside predominantly in the cytoplasm in constrast to pp32 which is a nuclear/cytoplasmic shuttling protein. To determine the effects of pp32r1 or pp32r1Y140H overexpression at the proteomic level we performed a comprehensive proteome analysis on ACHN, ACHN-pp32r1 and ACHN-pp32r1Y140H cell lysates using the isotope-coded protein label (ICPL) method. Among those proteins with >40% regulation were Macrophage Capping protein (CAPG) and Chromodomain Helicase DNA binding protein 4 (CHD4) proteins which were significantly upregulated by pp32r1 and pp32r1Y140H overexpression. This increase in CHD4 also appears to influence a number of cell cycle regulator genes including; p53, p21 and cyclinD1 as judged by western blotting. Silencing of CHD4 in ACHN-pp32r1Y140H cells using specific shRNA reverted the cell cycle dysregulation caused by pp32r1Y140H expression to that of the untransduced ACHN cell line, suggesting that CHD4 is the prominent effector of the pp32r1/pp32r1Y140H phenotype.
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Affiliation(s)
- Salma Buddaseth
- Institute for Transfusion Medicine, Hannover Medical School, Hannover, Germany
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Yu Y, Shen SM, Zhang FF, Wu ZX, Han B, Wang LS. Acidic leucine-rich nuclear phosphoprotein 32 family member B (ANP32B) contributes to retinoic acid-induced differentiation of leukemic cells. Biochem Biophys Res Commun 2012; 423:721-5. [DOI: 10.1016/j.bbrc.2012.06.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 06/07/2012] [Indexed: 12/20/2022]
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Acidic nuclear phosphoprotein 32kDa (ANP32)B-deficient mouse reveals a hierarchy of ANP32 importance in mammalian development. Proc Natl Acad Sci U S A 2011; 108:10243-8. [PMID: 21636789 DOI: 10.1073/pnas.1106211108] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The highly conserved ANP32 proteins are proposed to function in a broad array of physiological activities through molecular mechanisms as diverse as phosphatase inhibition, chromatin regulation, caspase activation, and intracellular transport. On the basis of previous analyses of mice bearing targeted mutations of Anp32a or Anp32e, there has been speculation that all ANP32 proteins play redundant roles and are dispensable for normal development. However, more recent work has suggested that ANP32B may in fact have functions that are not shared by other ANP32 family members. Here we report that ANP32B expression is associated with a poor prognosis in human breast cancer, consistent with the increased levels of Anp32b mRNA present in proliferating wild-type (WT) murine embryonic fibroblasts and stimulated WT B and T lymphocytes. Moreover, we show that, contrary to previous assumptions, Anp32b is very important for murine embryogenesis. In a mixed genetic background, ANP32B-deficient mice displayed a partially penetrant perinatal lethality that became fully penetrant in a pure C57BL/6 background. Surviving ANP32B-deficient mice showed reduced viability due to variable defects in various organ systems. Study of compound mutants lacking ANP32A, ANP32B, and/or ANP32E revealed previously hidden roles for ANP32A in mouse development that became apparent only in the complete absence of ANP32B. Our data demonstrate a hierarchy of importance for the mammalian Anp32 genes, with Anp32b being the most critical for normal development.
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Brody JR, Gonye GE. HuR's role in gemcitabine efficacy: an exception or opportunity? WILEY INTERDISCIPLINARY REVIEWS-RNA 2010; 2:435-44. [PMID: 21957028 DOI: 10.1002/wrna.62] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Over the next few years, research teams will focus on, and millions of dollars will be spent on, sorting through cancer genomes. Undoubtedly, 'druggable' targets and events will be discovered that will improve our understanding and, hopefully, treatment of cancer. Highlighting an alternative to this 'genome-centric' approach, this review will further explore an underappreciated mechanism of gene expression regulation, posttranscription mRNA:protein interactions. A key molecule involved in this mode of gene regulation is HuR and we have shown that HuR levels and HuR cellular distribution can predict how pancreatic cancer patients responded to the standard of care chemotherapy (i.e., gemcitabine). HuR regulates post-transcriptional processes through: (1) association with specific mRNA cargos with ARE-rich sequences and (2) stress-induced increased cytoplasmic protein levels. Over multiple laboratories and diverse tumor types, it has been shown that HuR supports tumor survival through its regulation of tumor-promoting transcripts such as VEGF. In this article, we will highlight a recent discovery that this potent post-transcriptional gene regulatory mechanism has an impact on a common chemotherapeutic, gemcitabine. Specifically, we have identified the mechanism by which HuR can regulate a key gemcitabine metabolic enzyme, deoxycytidine kinase. We will use this example to explore and hypothesize the functional roles that HuR may have on anticancer drug therapies. We will survey novel high throughput global gene expression analysis tools to discover novel HuR targets. Future multidisciplinary approaches focused on HuR biology will provide critical events and 'druggable' targets in cancer that large-scale genomic sequencing efforts will miss.
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Affiliation(s)
- Jonathan R Brody
- Department of Surgery, Thomas Jefferson University, Philadelphia, PA, USA.
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Williams TK, Costantino CL, Bildzukewicz NA, Richards NG, Rittenhouse DW, Einstein L, Cozzitorto JA, Keen JC, Dasgupta A, Gorospe M, Gonye GE, Yeo CJ, Witkiewicz AK, Brody JR. pp32 (ANP32A) expression inhibits pancreatic cancer cell growth and induces gemcitabine resistance by disrupting HuR binding to mRNAs. PLoS One 2010; 5:e15455. [PMID: 21152064 PMCID: PMC2994932 DOI: 10.1371/journal.pone.0015455] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 09/26/2010] [Indexed: 01/12/2023] Open
Abstract
The expression of protein phosphatase 32 (PP32, ANP32A) is low in poorly differentiated pancreatic cancers and is linked to the levels of HuR (ELAV1), a predictive marker for gemcitabine response. In pancreatic cancer cells, exogenous overexpression of pp32 inhibited cell growth, supporting its long-recognized role as a tumor suppressor in pancreatic cancer. In chemotherapeutic sensitivity screening assays, cells overexpressing pp32 were selectively resistant to the nucleoside analogs gemcitabine and cytarabine (ARA-C), but were sensitized to 5-fluorouracil; conversely, silencing pp32 in pancreatic cancer cells enhanced gemcitabine sensitivity. The cytoplasmic levels of pp32 increased after cancer cells are treated with certain stressors, including gemcitabine. pp32 overexpression reduced the association of HuR with the mRNA encoding the gemcitabine-metabolizing enzyme deoxycytidine kinase (dCK), causing a significant reduction in dCK protein levels. Similarly, ectopic pp32 expression caused a reduction in HuR binding of mRNAs encoding tumor-promoting proteins (e.g., VEGF and HuR), while silencing pp32 dramatically enhanced the binding of these mRNA targets. Low pp32 nuclear expression correlated with high-grade tumors and the presence of lymph node metastasis, as compared to patients' tumors with high nuclear pp32 expression. Although pp32 expression levels did not enhance the predictive power of cytoplasmic HuR status, nuclear pp32 levels and cytoplasmic HuR levels associated significantly in patient samples. Thus, we provide novel evidence that the tumor suppressor function of pp32 can be attributed to its ability to disrupt HuR binding to target mRNAs encoding key proteins for cancer cell survival and drug efficacy.
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Affiliation(s)
- Timothy K. Williams
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Christina L. Costantino
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Nikolai A. Bildzukewicz
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Nathan G. Richards
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - David W. Rittenhouse
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Lisa Einstein
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Joseph A. Cozzitorto
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Judith C. Keen
- Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Camden, New Jersey, United States of America
| | - Abhijit Dasgupta
- Department of Pathology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Myriam Gorospe
- Laboratory of Cellular and Molecular Biology, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Gregory E. Gonye
- Department of Pathology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Charles J. Yeo
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Agnieszka K. Witkiewicz
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Department of Pathology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Jonathan R. Brody
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Department of Pathology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Reilly PT, Afzal S, Wakeham A, Haight J, You-Ten A, Zaugg K, Dembowy J, Young A, Mak TW. Generation and characterization of the Anp32e-deficient mouse. PLoS One 2010; 5:e13597. [PMID: 21049064 PMCID: PMC2964292 DOI: 10.1371/journal.pone.0013597] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 10/01/2010] [Indexed: 01/17/2023] Open
Abstract
Background Accumulated literature suggests that the acidic nuclear phosphoprotein 32 kilodalton (Anp32) proteins control multiple cellular activities through different molecular mechanisms. Like other Anp32 family members, Anp32e (a.k.a. Cpd1, PhapIII) has been conserved throughout vertebrate evolution, suggesting that it has an important function in organismal survival. Principal Findings Here, we demonstrate that the Anp32e gene can be deleted in mice without any apparent effect on their wellbeing. No defects in thymocyte apoptosis in response to various stresses, fibroblast growth, gross behaviour, physical ability, or pathogenesis were defined. Furthermore, combined deletion of Anp32a and Anp32e also resulted in a viable and apparently healthy mouse. Significance These results provide evidence that significant functional redundancy exists among Anp32 family members.
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Affiliation(s)
- Patrick T. Reilly
- Department of Cellular and Molecular Research, National Cancer Centre Singapore, Singapore, Singapore
- Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Samia Afzal
- Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, Canada
- Graduate Program in Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Wakeham
- Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Jillian Haight
- Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Annick You-Ten
- Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Kathrin Zaugg
- Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Joanna Dembowy
- Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Ashley Young
- Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Tak W. Mak
- Department of Cellular and Molecular Research, National Cancer Centre Singapore, Singapore, Singapore
- Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, Canada
- * E-mail:
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14
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Brody JR, Witkiewicz A, Williams TK, Kadkol SS, Cozzitorto J, Durkan B, Pasternack GR, Yeo CJ. Reduction of pp32 expression in poorly differentiated pancreatic ductal adenocarcinomas and intraductal papillary mucinous neoplasms with moderate dysplasia. Mod Pathol 2007; 20:1238-44. [PMID: 17906614 DOI: 10.1038/modpathol.3800974] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Nuclear phosphoprotein 32 (pp32) inhibits K-ras induced transformation in experimental models. pp32 mRNA expression correlates with differentiation status in breast and prostate cancers. In this study, we evaluated pp32 protein expression in relation to the differentiation status of pancreatic ductal adenocarcinomas and precursor lesions of the pancreatic cancers. pp32 expression showed strong nuclear staining in normal pancreatic acini and ducts. The intensity of this staining was maintained in pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasms with mild dysplasia, well-differentiated adenocarcinomas, and in a subset of moderately differentiated adenocarcinomas. pp32 staining was absent or reduced in poorly differentiated tumors and in intraductal papillary mucinous neoplasms with moderate dysplasia. We validated pp32 expression by a second technique, immunoblot analysis of lysates from resected pancreatic ductal adenocarcinomas and pancreatic cancer cell lines. The well-differentiated pancreatic cancer cell line HPAC expressed high amounts of pp32, as compared to the poorly differentiated pancreatic cancer cell lines MiaPaCa2, Pl19, and Pl21 cells. Artificial introduction of pp32 expression into a poorly differentiated cell line, MiaPaCa2, caused an increase in G1 arrest compared to control cells. On the basis of this study and previous functional work that shows pp32 can inhibit K-ras transformation, we propose that reduction in pp32 expression levels may be a critical event in the progression of pancreatic tumorigenesis in an aggressive subset of pancreatic ductal adenocarcinomas.
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Affiliation(s)
- Jonathan R Brody
- Department of Surgery, Thomas Jefferson University, 1015 Walnut Street, Philadelphia, PA 19107, USA.
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15
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Ouellet V, Le Page C, Guyot MC, Lussier C, Tonin PN, Provencher DM, Mes-Masson AM. SET complex in serous epithelial ovarian cancer. Int J Cancer 2006; 119:2119-26. [PMID: 16823850 DOI: 10.1002/ijc.22054] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
With low cure rates but increasing diverse treatment options that provide variable remission times, ovarian cancer is increasingly being recognized as a chronic disease. This reality indicates the need for a better understanding of factors influencing disease progression. In a previous global analysis of gene expression, we identified genes differentially expressed when comparing serous epithelial ovarian tumors of low and high malignant potential (grade 0 vs grade 3). In this analysis, 4 out of 5 members of the SET complex, SET, APE1, NM23 and HMGB2, were highly expressed in invasive grade 3 tumors. To further investigate the expression of these genes and the fifth member of the SET complex (pp32), we performed immunohistochemistry, on a tissue array composed of 235 serous tumors of different grades and disease stages. A significant correlation between expression of all SET complex proteins and the tumor differentiation was observed (p < 0.05). When combining all tumors, overexpression of Nm23 (p = 0.04), Set (p = 0.004) and Ape1 (p = 0.004) was associated with the clinical stage of the disease. No marker by itself was associated with prognosis. The combination of a high level of Nm23 in the context of a low level of Set compared to all other combinations of these markers did confer a better prognosis (p = 0.03). When combined, high expression of Hmgb2 and low expression of Ape1 was also associated with patient prognosis (p = 0.05). These findings suggest that a strategy that sums the activities of different partners within a pathway may be more appropriate in designing nomograms for patient stratification.
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Affiliation(s)
- Véronique Ouellet
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CHUM), Institut du cancer de Montréal, Montreal, Canada
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16
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Fan Z, Zhang H, Zhang Q. Tumor suppressor pp32 represses cell growth through inhibition of transcription by blocking acetylation and phosphorylation of histone H3 and initiating its proapoptotic activity. Cell Death Differ 2005; 13:1485-94. [PMID: 16341127 DOI: 10.1038/sj.cdd.4401825] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
pp32 belongs to a family of leucine-rich acidic nuclear proteins, which play important roles in many cellular processes including regulation of chromatin remodeling, transcription, RNA transport, transformation and apoptosis. pp32 is described as a new tumor suppressor. It is unknown as to how pp32 works in tumor suppression. We found that overexpression of pp32 in human Jurkat T cells inhibits cell growth, and silenced pp32 promotes growth. We first showed that hyperacetylation and hyperphosphorylation of histone H3 are required for T-cell activation. Phosphorylation of histone H3 precedes acetylation during T-cell activation. pp32 specifically binds to histone H3 and blocks its acetylation and phosphorylation. pp32 directly initiates caspase activity and also promotes granzyme A-mediated caspase-independent cell death. Taken together, pp32 plays a repressive role by inhibiting transcription and triggering apoptosis.
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Affiliation(s)
- Z Fan
- National Laboratory of Biomacromolecules and Center for Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
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17
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Kandilci A, Grosveld GC. SET-induced calcium signaling and MAPK/ERK pathway activation mediate dendritic cell-like differentiation of U937 cells. Leukemia 2005; 19:1439-45. [PMID: 15931263 DOI: 10.1038/sj.leu.2403826] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Human SET, a target of chromosomal translocation in human leukemia encodes a highly conserved, ubiquitously expressed, nuclear phosphoprotein. SET mediates many functions including chromatin remodeling, transcription, apoptosis and cell cycle control. We report that overexpression of SET directs differentiation of the human promonocytic cell line U937 along the dendritic cell (DC) pathway, as cells display typical morphologic changes associated with DC fate and express the DC surface markers CD11b and CD86. Differentiation occurs via a calcium-dependent mechanism involving the CaMKII and MAPK/ERK pathways. Similar responses are elicited by interferon-gamma (IFN-gamma) treatment with the distinction that IFN-gamma signaling activates the DNA-binding activity of STAT1 whereas SET overexpression does not. In addition, unlike IFN-gamma signaling, SET generated stress-induced p38/MAPK activity. Interestingly, IFN-gamma treatment transiently upregulated endogenous SET in a dose-dependent manner. These results suggest that SET is part of both IFN-gamma-mediated and stress-mediated cellular responses and that SET induces cell differentiation via calcium and MAPK/ERK pathways.
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Affiliation(s)
- A Kandilci
- Department of Genetics and Tumor Cell Biology, St Jude Children's Research Hospital, 332 N. Lauderdale, Memphis, TN 38105, USA
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18
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Xia Q, Wang HX, Wang J, Zhang JY, Liu BY, Li AL, Lv M, Hu MR, Yu M, Feng JN, Yang SC, Zhang XM, Shen BF. Proteomic analysis of interleukin 6-induced differentiation in mouse myeloid leukemia cells. Int J Biochem Cell Biol 2005; 37:1197-207. [PMID: 15778084 DOI: 10.1016/j.biocel.2004.11.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Revised: 11/01/2004] [Accepted: 11/16/2004] [Indexed: 11/24/2022]
Abstract
Cytokine-induced differentiation of myeloid leukemia cells has important therapeutic implications, but the mechanism remains to be clarified. M1 cell, a mouse acute myeloid leukemia cell line, which underwent growth inhibition, terminal differentiation and apoptosis in response to IL-6, was selected as an experimental model to study on the molecular mechanisms of myeloid cell differentiation on a proteome-wide scale. Cell differentiation was evaluated by cell morphology and CD11b expression. With two-dimensional (2D) gel analyses, 17 protein spots showed obvious changes in quantity during the process of differentiation were found. With matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF-MS) or/and nano-electrospray ionization MS/MS (ESI-MS/MS) analysis, 15 protein spots were identified. The mRNA levels of these 15 proteins during differentiation were also examined using a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis. Except two proteins, the mRNA levels demonstrated similar expression patterns to what the proteomic analysis revealed. The identified proteins were known to be involved in different cellular functions, including protein synthesis, transcription, signal transduction, cell cycle control, cell rescue and defense, cellular organization, and metabolism. Notably, seven proteins were not described before to be involved in differentiation. Our data provide novel information for a better understanding of the mechanisms by which terminal differentiation of acute myeloid leukemia cells induced by IL-6.
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MESH Headings
- Animals
- Apoptosis/drug effects
- CD11b Antigen/biosynthesis
- Cell Differentiation/drug effects
- Cell Line, Tumor
- Cystatin B
- Cystatins/biosynthesis
- Electrophoresis, Gel, Two-Dimensional
- Fructose-Bisphosphate Aldolase/biosynthesis
- Interleukin-6/pharmacology
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Membrane Proteins/biosynthesis
- Mice
- Peroxidases/biosynthesis
- Peroxiredoxins
- Proteomics
- Recombinant Proteins/pharmacology
- Reverse Transcriptase Polymerase Chain Reaction
- Spectrometry, Mass, Electrospray Ionization
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
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Affiliation(s)
- Qing Xia
- Department of Molecular Immunology, Beijing Institute of Basic Medical Science, TaiPing Road 27, Beijing 100850, PR China
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19
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Song E, Zhu P, Lee SK, Chowdhury D, Kussman S, Dykxhoorn DM, Feng Y, Palliser D, Weiner DB, Shankar P, Marasco WA, Lieberman J. Antibody mediated in vivo delivery of small interfering RNAs via cell-surface receptors. Nat Biotechnol 2005; 23:709-17. [PMID: 15908939 DOI: 10.1038/nbt1101] [Citation(s) in RCA: 764] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2005] [Accepted: 04/27/2005] [Indexed: 02/07/2023]
Abstract
Delivery of small interfering RNAs (siRNAs) into cells is a key obstacle to their therapeutic application. We designed a protamine-antibody fusion protein to deliver siRNA to HIV-infected or envelope-transfected cells. The fusion protein (F105-P) was designed with the protamine coding sequence linked to the C terminus of the heavy chain Fab fragment of an HIV-1 envelope antibody. siRNAs bound to F105-P induced silencing only in cells expressing HIV-1 envelope. Additionally, siRNAs targeted against the HIV-1 capsid gene gag, inhibited HIV replication in hard-to-transfect, HIV-infected primary T cells. Intratumoral or intravenous injection of F105-P-complexed siRNAs into mice targeted HIV envelope-expressing B16 melanoma cells, but not normal tissue or envelope-negative B16 cells; injection of F105-P with siRNAs targeting c-myc, MDM2 and VEGF inhibited envelope-expressing subcutaneous B16 tumors. Furthermore, an ErbB2 single-chain antibody fused with protamine delivered siRNAs specifically into ErbB2-expressing cancer cells. This study demonstrates the potential for systemic, cell-type specific, antibody-mediated siRNA delivery.
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Affiliation(s)
- Erwei Song
- CBR Institute for Biomedical Research and Department of Pediatrics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
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20
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Adegbola O, Pasternack GR. Phosphorylated retinoblastoma protein complexes with pp32 and inhibits pp32-mediated apoptosis. J Biol Chem 2005; 280:15497-502. [PMID: 15716273 DOI: 10.1074/jbc.m411382200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The retinoblastoma gene product (Rb) is a tumor suppressor that affects apoptosis paradoxically. Most sporadic cancers inactivate Rb by preferentially targeting the pathway that regulates Rb phosphorylation, resulting in resistance to apoptosis; this contrasts with Rb inactivation by mutation, which is associated with high rates of apoptosis. How phosphorylated Rb protects cells from apoptosis is not well understood, but there is evidence that Rb may sequester a pro-apoptotic nuclear factor. pp32 (ANP32A) is a pro-apoptotic nuclear phosphoprotein, the expression of which is commonly increased in cancer. We report that hyperphosphorylated Rb interacts with pp32 but not with the closely related proteins pp32r1 and pp32r2. We further demonstrate that pp32-Rb interaction inhibits the apoptotic activity of pp32 and stimulates proliferation. These results suggest a mechanism whereby cancer cells gain both a proliferative and survival advantage when Rb is inactivated by hyperphosphorylation.
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Affiliation(s)
- Onikepe Adegbola
- Division of Molecular Pathology, Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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21
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Kutney SN, Hong R, Macfarlan T, Chakravarti D. A signaling role of histone-binding proteins and INHAT subunits pp32 and Set/TAF-Ibeta in integrating chromatin hypoacetylation and transcriptional repression. J Biol Chem 2004; 279:30850-5. [PMID: 15136563 DOI: 10.1074/jbc.m404969200] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Various post-translational modifications of histones significantly influence gene transcription. Although un- or hypoacetylated histones are tightly linked to transcriptional repression, the mechanisms and identities of chromatin signal transducer proteins integrating histone hypoacetylation into repression in humans have remained largely unknown. Here we show that the mammalian histone-binding proteins and inhibitor of acetyltransferases (INHAT) complex subunits, Set/template-activating factor-Ibeta (TAF-Ibeta) and pp32, specifically bind to unacetylated, hypoacetylated, and repressively marked histones but not to hyperacetylated histones. Additionally, Set/TAF-Ibeta and pp32 associate with histone deacetylases in vitro and in vivo and repress transcription from a chromatin-integrated template in vivo. Finally, Set/TAF-Ibeta and pp32 associate with an endogenous estrogen receptor-regulated gene, EB1, in the hypoacetylated transcriptionally inactive state but not with the hyperacetylated transcriptionally active form. Together, these data define a novel in vivo mechanistic role for the mammalian Set/TAF-Ibeta and pp32 proteins as transducers of chromatin signaling by integrating chromatin hypoacetylation and transcriptional repression.
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Affiliation(s)
- Sara N Kutney
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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