1
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Wang H, Zhou Z, Zhang J, Hao T, Wang P, Wu P, Su R, Yang H, Deng G, Chen S, Gu L, He Y, Zeng L, Zhang C, Yin S. Pumilio1 regulates NPM3/NPM1 axis to promote PD-L1-mediated immune escape in gastric cancer. Cancer Lett 2024; 581:216498. [PMID: 38029539 DOI: 10.1016/j.canlet.2023.216498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/08/2023] [Accepted: 11/16/2023] [Indexed: 12/01/2023]
Abstract
Abnormal regulation of RNA binding proteins (RBPs) plays an essential role in tumorigenesis and progression, but their functions and mechanisms remain largely elusive. Previously, we reported that Pumilio 1 (PUM1), a RBP, could regulate glycolysis metabolism and promote the progression of gastric cancer (GC). However, the role of PUM1 in tumor immune regulation remains largely elusive. In this study, we report that PUM1 induces immune escape through posttranscriptional regulation of PD-L1 in GC. We used multiplexed immunohistochemistry to analyze the correlation between PUM1 expression and immune microenvironment in GC. The effect of PUM1 deficiency on tumor killing of T cells was examined in vitro and in vivo. The molecular mechanism of PUM1 was evaluated via RNA immunoprecipitation, chromatin immunoprecipitation, Western blot, co-immunoprecipitation, and RNA stability assays. Clinically, elevated PUM1 expression is associated with high-expression of PD-L1, lack of CD8+ T cell infiltration and poor prognosis in GC patients. PUM1 positively regulates PD-L1 expression and PUM1 reduction enhances T cell killing of tumors. Mechanistically, PUM1 directly binds to nucleophosmin/nucleoplasmin 3 (NPM3) mRNA and stabilizes NPM3. NPM3 interacts with NPM1 to promote NPM1 translocation into the nucleus and increase the transcription of PD-L1. PUM1 inhibits the anti-tumor activity of T cells through the PUM1/NPM3/PD-L1 axis. In summary, this study reveals the critical post-transcriptional effect of PUM1 in the modulation of PD-L1-dependent GC immune escape, thus provides a novel indicator and potential therapeutic target for cancer immunotherapy.
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Affiliation(s)
- Han Wang
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China; Department of Gastrointestinal Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Zhijun Zhou
- Department of Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Junchang Zhang
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China; Department of Metabolic and Bariatric Surgery, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Tengfei Hao
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China
| | - Pengliang Wang
- Department of Gastrointestinal Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Pei Wu
- Department of Gastrointestinal Surgery, Yongchuan Hospital of Chongqing Medical university, Chongqing, China
| | - Rishun Su
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China
| | - Huan Yang
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China
| | - Guofei Deng
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China
| | - Songyao Chen
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China
| | - Liang Gu
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China
| | - Yulong He
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China; Department of Gastrointestinal Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China.
| | - Leli Zeng
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China.
| | - Changhua Zhang
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China.
| | - Songcheng Yin
- Digestive Diseases Center, Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China.
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2
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Chen L, Yang D, Huang F, Xu W, Luo X, Mei L, He Y. NPM3 as an Unfavorable Prognostic Biomarker Involved in Oncogenic Pathways of Lung Adenocarcinoma via MYC Translational Activation. Comb Chem High Throughput Screen 2024; 27:203-213. [PMID: 37114782 DOI: 10.2174/1386207326666230419080531] [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: 08/04/2022] [Revised: 02/01/2023] [Accepted: 02/23/2023] [Indexed: 04/29/2023]
Abstract
BACKGROUND The nucleoplasmin/nucleophosmin (NPM) family was previously regarded as a critical regulator during disease development, and its mediation in carcinogenesis has achieved intensive attention recently. However, the clinical importance and functional mechanism of NPM3 in lung adenocarcinoma (LUAD) have not been reported yet. OBJECTIVE This study aimed to investigate the role and clinical significance of NPM3 in the development and progression of LUAD, including the underlying mechanisms. METHODS The expression of NPM3 in pan-cancer was analyzed via GEPIA. The effect of NPM3 on prognosis was analyzed by the Kaplan-Meier plotter and the PrognoScan database. In vitro, cell transfection, RT-qPCR, CCK-8 assay, and wound healing assay were employed to examine the role of NPM3 in A549 and H1299 cells. Gene set enrichment analysis (GSEA) was performed using the R software package to analyze the tumor hallmark pathway and KEGG pathway of NPM3. The transcription factors of NPM3 were predicted based on the ChIP-Atlas database. Dual-luciferase reporter assay was applied to verify the transcriptional regulatory factor of the NPM3 promoter region. RESULTS The NPM3 expression was found to be markedly higher in the LUAD tumor group than the normal group and to be positively correlated with poor prognosis, tumor stages, and radiation therapy. In vitro, the knockdown of NPM3 greatly inhibited the proliferation and migration of A549 and H1299 cells. Mechanistically, GSEA predicted that NPM3 activated the oncogenic pathways. Further, the NPM3 expression was found to be positively correlated with cell cycle, DNA replication, G2M checkpoint, HYPOXIA, MTORC1 signaling, glycolysis, and MYC targets. Besides, MYC targeted the promoter region of NPM3 and contributed to the enhanced expression of NPM3 in LUAD. CONCLUSION The overexpression of NPM3 is an unfavorable prognostic biomarker participating in oncogenic pathways of LUAD via MYC translational activation and it contributes to tumor progression. Thus, NPM3 could be a novel target for LUAD therapy.
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Affiliation(s)
- Long Chen
- Center for Rehabilitation Medicine, Department of Anesthesiology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, 310014, China
| | - Demeng Yang
- Faculty of College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang, 315211, China
| | - Fen Huang
- Department of Operating Room, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, 310014, China
| | - Weicai Xu
- Center for Rehabilitation Medicine, Department of Anesthesiology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, 310014, China
| | - Xiaopan Luo
- Center for Rehabilitation Medicine, Department of Anesthesiology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, 310014, China
| | - Lili Mei
- Medical School, Kunming University of Science and Technology, Kunming, 6505041, China
| | - Ying He
- Center for Rehabilitation Medicine, Department of Anesthesiology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, 310014, China
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Gu R, Kim TD, Song H, Sui Y, Shin S, Oh S, Janknecht R. SET7/9-mediated methylation affects oncogenic functions of histone demethylase JMJD2A. JCI Insight 2023; 8:e164990. [PMID: 37870957 PMCID: PMC10619491 DOI: 10.1172/jci.insight.164990] [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: 08/30/2022] [Accepted: 09/05/2023] [Indexed: 10/25/2023] Open
Abstract
The histone demethylase JMJD2A/KDM4A facilitates prostate cancer development, yet how JMJD2A function is regulated has remained elusive. Here, we demonstrate that SET7/9-mediated methylation on 6 lysine residues modulated JMJD2A. Joint mutation of these lysine residues suppressed JMJD2A's ability to stimulate the MMP1 matrix metallopeptidase promoter upon recruitment by the ETV1 transcription factor. Mutation of just 3 methylation sites (K505, K506, and K507) to arginine residues (3xR mutation) was sufficient to maximally reduce JMJD2A transcriptional activity and also decreased its binding to ETV1. Introduction of the 3xR mutation into DU145 prostate cancer cells reduced in vitro growth and invasion and also severely compromised tumorigenesis. Consistently, the 3xR genotype caused transcriptome changes related to cell proliferation and invasion pathways, including downregulation of MMP1 and the NPM3 nucleophosmin/nucleoplasmin gene. NPM3 downregulation phenocopied and its overexpression rescued, to a large degree, the 3xR mutation in DU145 cells, suggesting that NPM3 was a seminal downstream effector of methylated JMJD2A. Moreover, we found that NPM3 was overexpressed in prostate cancer and might be indicative of disease aggressiveness. SET7/9-mediated lysine methylation of JMJD2A may aggravate prostate tumorigenesis in a manner dependent on NPM3, implying that the SET7/9→JMJD2A→NPM3 axis could be targeted for therapy.
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Affiliation(s)
| | | | | | | | - Sook Shin
- Department of Cell Biology
- Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Sangphil Oh
- Department of Cell Biology
- Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Ralf Janknecht
- Department of Cell Biology
- Department of Pathology, and
- Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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4
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Ding X, Zhu XL, Xu DH, Li S, Yang Q, Feng X, Wei YG, Li H, Yang L, Zhang YJ, Deng XL, Liu KC, Shi SL. NPM promotes hepatotoxin-induced fibrosis by inhibiting ROS-induced apoptosis of hepatic stellate cells and upregulating lncMIAT-induced TGF-β2. Cell Death Dis 2023; 14:575. [PMID: 37648688 PMCID: PMC10469196 DOI: 10.1038/s41419-023-06043-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 07/25/2023] [Accepted: 08/04/2023] [Indexed: 09/01/2023]
Abstract
Liver fibrosis is caused by a variety of chronic liver injuries and has caused significant morbidity and mortality in the world with increasing tendency. Elucidation of the molecular mechanism of liver fibrosis is the basis for intervention of this pathological process and drug development. Nucleophosmin (NPM) is a widely expressed nucleolar phosphorylated protein, which is particularly important for cell proliferation, differentiation and survival. The biological role of NPM in liver fibrosis remains unknown. Here we show that NPM promotes liver fibrosis through multiple pathways. Our study found that NPM was up-regulated in cirrhosis tissues and activated in hepatic stellate cells (HSCs). NPM inhibition reduced liver fibrosis markers expression in HSCs and inhibited the HSCs proliferation and migration. In mice model, NPM knockdown in HSCs or application of specific NPM inhibitor can remarkably attenuate hepatic fibrosis. Mechanistic analysis showed that NPM promotes hepatic fibrosis by inhibiting HSCs apoptosis through Akt/ROS pathway and by upregulating TGF-β2 through Akt-induced lncMIAT. LncMIAT up-regulated TGF-β2 mRNA by competitively sponging miR-16-5p. In response to liver injury, hepatocytes, Kupffer cells and HSCs up-regulated NPM to increase TGF-β2 secretion to activate HSCs in a paracrine or autocrine manner, leading to increased liver fibrosis. Our study demonstrated that NPM regulated hepatotoxin-induced fibrosis through Akt/ROS-induced apoptosis of HSCs and via the Akt/lncMIAT-up-regulated TGF-β2. Inhibition of NPM or application of NPM inhibitor CIGB300 remarkably attenuated liver fibrosis. NPM serves a potential new drug target for liver fibrosis.
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Affiliation(s)
- Xue Ding
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China
- Department of Basic Medical Sciences, School of Medicine, Xiamen University, Xiamen, China
| | - Xin-Le Zhu
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China
- Department of Basic Medical Sciences, School of Medicine, Xiamen University, Xiamen, China
| | - Dong-Hui Xu
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China
- Department of Hepatic Biliary Pancreatic Vascular Surgery, the First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | - Shuang Li
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China
| | - Qiong Yang
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China
| | - Xian Feng
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China
| | - Yong-Gui Wei
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China
| | - Huan Li
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China
| | - Ling Yang
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China
| | - Yu-Jun Zhang
- Department of Basic Medical Sciences, School of Medicine, Xiamen University, Xiamen, China
| | - Xiao-Ling Deng
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China
| | - Kuan-Can Liu
- Xiang'an Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China.
| | - Song-Lin Shi
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China.
- Department of Basic Medical Sciences, School of Medicine, Xiamen University, Xiamen, China.
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5
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Wei S, Xing J, Lu K, Wang K, Yu W. NPM3 as a novel oncogenic factor and poor prognostic marker contributes to cell proliferation and migration in lung adenocarcinoma. Hereditas 2023; 160:27. [PMID: 37254219 DOI: 10.1186/s41065-023-00289-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/21/2023] [Indexed: 06/01/2023] Open
Abstract
BACKGROUND Lung cancer is the leading cause of cancer-related deaths worldwide, and despite recent advances in targeted therapies and immunotherapies, the clinical benefit remains limited. Therefore, there is an urgent need to further investigate the molecular mechanisms underlying lung cancer. The aim of this study was to investigate the expression and function of NPM3 in the tumor microenvironment of lung adenocarcinoma (LUAD). METHODS We utilized bioinformatics tools and databases, including UALCAN, GEPIA2, HPA, and Sangerbox, to analyze NPM3 expression in LUAD samples and its association with prognosis and mutational landscape. NPM3 expression in various cell types was assessed at the single cell level using the TISCH database. We also used algorithms such as TIMER and EPIC to explore the crosstalk between NPM3 expression and immune features. KEGG enrichment analysis was performed to identify potential signaling pathways of NPM3. Finally, we employed siRNA knockdown strategy to investigate the effect of NPM3 on LUAD cell proliferation and migration in vitro. RESULTS NPM3 was significantly upregulated in LUAD tissues and was strongly associated with poor prognosis and TP53 gene mutations. Single-cell sequencing analysis revealed that NPM3 was expressed in immune cells (dendritic cells and monocytes/macrophages) in the tumor microenvironment. Moreover, NPM3 expression was negatively associated with immune B cell and CD4 T cell infiltration, as well as with several immune-related genes (including CCL22, CXCR2, CX3CR1, CCR6, HLA-DOA, HLA-DQA2). KEGG enrichment analysis indicated that NPM3 expression was associated with cell cycle, CAMs, and NSCLC pathway genes. Finally, in vitro experiments showed that NPM3 knockdown inhibited LUAD cell proliferation and migration in NCI-H1299 and SPC-A1 cells, and suppressed the expression of CCNA2 and MAD2L1. CONCLUSION Elevated NPM3 expression predicts poor clinical outcome and an immunosuppressive microenvironment in LUAD tissues. NPM3 promotes LUAD progression by promoting cell proliferation and migration, and targeting NPM3 may represent a novel therapeutic strategy for LUAD.
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Affiliation(s)
- Shan Wei
- Department of Respiratory and Critical Care Medicine, The Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, 322000, Zhejiang, People's Republic of China
- Department of Respiratory and Critical Care Medicine, The Affiliated People's Hospital of Ningbo University (Ningbo Yinzhou People's Hospital), No.251, Baizhang Road, Ningbo, 315040, Zhejiang, People's Republic of China
| | - Jing Xing
- Department of Respiratory and Critical Care Medicine, The Affiliated People's Hospital of Ningbo University (Ningbo Yinzhou People's Hospital), No.251, Baizhang Road, Ningbo, 315040, Zhejiang, People's Republic of China
- Ningbo University School of Medicine, Zhejiang Province, Ningbo, People's Republic of China
| | - Kaining Lu
- Department of Urology, The Affiliated First Hospital of Ningbo University (Ningbo First Hospital), No.59, Liuting Street, Ningbo, 315010, Zhejiang, People's Republic of China
| | - Kai Wang
- Department of Respiratory and Critical Care Medicine, The Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, 322000, Zhejiang, People's Republic of China
| | - Wanjun Yu
- Department of Respiratory and Critical Care Medicine, The Affiliated People's Hospital of Ningbo University (Ningbo Yinzhou People's Hospital), No.251, Baizhang Road, Ningbo, 315040, Zhejiang, People's Republic of China.
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6
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Kaya M, Eroz R, Kabakliogli M. Expression of nucleolin, nucleophosmin, upstream binding transcription factor genes and propolis in wound models. J Wound Care 2022; 31:S28-S40. [DOI: 10.12968/jowc.2022.31.sup10.s28] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Objective: Nucleolar proteins have important functions in the regulation of cell homeostasis and play a crucial role in sensing various types of stress, such as genotoxic stress. Propolis has epithelial, analgesic, antibacterial, antifungal and antiviral effects. This study aimed to evaluate the gene expression levels of nucleolar proteins: nucleolin (NCL); nucleophosmin (NPM1); and upstream binding transcription factor (UBTF), as well as the benefits of propolis in wound healing. Method: This experimental study was conducted by creating clean and clean–contaminated wounds according to the Surgical Site Infection Guidelines, 2016. A total of seven animal groups were included in the study: control; laparotomy; anastomosis; fucidic acid with/without anastomosis; propolis with/without anastomosis Results: Statistically significant differences of levels of gene expression among the groups were detected for NCL (p=0.004), NPM1 (p=0.011) and UBTF (p=0.000). When the expression levels of the related genes and blood parameters are considered, the relationship between NCL, NPM1 and UBTF expression levels and blood parameters (NE, EO, NE(%), LY, LY(%), EO, EO(%), MO, MO(%), RBC, HB, HCT, MCV, MCHC, RDW, RDW(%), PLT, PDW and PCT) were statistically significant. Conclusion: The nucleolar proteins such as NCL, NPM1 and UBTF have important functions in cell viability and its maintenance under various condition such as stress and injury. Additionally, propolis has positive benefits in wound healing and in the prevention of wound infection. Our findings provide the first insights into the putative role of those proteins in wound healing.
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Affiliation(s)
- Murat Kaya
- Department of Pediatric Surgery, Duzce University, Medical Faculty, Duzce/Turkey
| | - Recep Eroz
- Department of Medical Genetics, Aksaray University, Medical Faculty, Aksaray, Turkey
| | - Murat Kabakliogli
- Department of Pediatric Surgery, Duzce University, Medical Faculty, Duzce/Turkey
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7
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Lavering ED, Petros IN, Weeks DL. Component analysis of nucleolar protein compartments using Xenopus laevis oocytes. Dev Growth Differ 2022; 64:306-317. [PMID: 35607824 PMCID: PMC9474603 DOI: 10.1111/dgd.12794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 05/12/2022] [Accepted: 05/17/2022] [Indexed: 12/19/2022]
Abstract
The nucleolus is a multi‐compartment, non‐membrane‐bound organelle within the nucleus. Nucleolar assembly is influenced by proteins capable of phase separation. Xenopus laevis oocytes contain hundreds of large nucleoli that provide experimental access for nucleoli that is unavailable in other systems. Here we detail methods to streamline the in vivo analysis of the compartmentalization of nucleolar proteins that are suspected of phase separation. The nucleolus is the main hub of ribosome biogenesis and here we present data supporting the division of proteins into nucleolar domains based on their function in ribosome biogenesis. We also describe the use of vital dyes such as Hoechst 33342 and Thioflavin T in nucleolar staining. Additionally, we quantify nucleolar morphology changes induced by heat shock and actinomycin D treatments. We suggest these approaches will be valuable in a variety of studies that seek to better understand the nucleolus, particularly those regarding phase separation. These approaches may also be instructive for other studies on phase separation, especially in the nucleus.
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Affiliation(s)
- Emily D Lavering
- Department of Biochemistry and Molecular Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Irini N Petros
- Department of Biochemistry and Molecular Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Daniel L Weeks
- Department of Biochemistry and Molecular Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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8
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KLF16 enhances stress tolerance of colorectal carcinomas by modulating nucleolar homeostasis and translational reprogramming. Mol Ther 2022; 30:2828-2843. [PMID: 35524408 PMCID: PMC9372374 DOI: 10.1016/j.ymthe.2022.04.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 04/25/2022] [Accepted: 04/29/2022] [Indexed: 12/22/2022] Open
Abstract
Translational reprogramming is part of the unfolded protein response (UPR) during endoplasmic reticulum (ER) stress, which acts to the advantage of cancer growth and development in different stress conditions. But the mechanism of ER stress-related translational reprogramming in colorectal carcinoma (CRC) progression remains unclear. Here, we identified that Krüppel-Like Factor 16 (KLF16) can promote CRC progression and stress tolerance through translational reprogramming. The expression of KLF16 was upregulated in CRC tissues and associated with poor prognosis for CRC patients. We found that ER stress inducers can recruit KLF16 to the nucleolus and increase its interaction with two essential proteins for nucleolar homeostasis, nucleophosmin1 (NPM1) and fibrillarin (FBL). Moreover, knockdown of KLF16 can dysregulate nucleolar homeostasis in CRC cells. Translation-reporter system and polysome profiling assays further showed that KLF16 can effectively promote cap-independent translation of ATF4, which can enhance ER-phagy and proliferation of CRC cells. Overall, our study unveils a previously unrecognized role for KLF16 as an ER stress regulator through mediating translational reprogramming to enhance stress tolerance of CRC cells and provides a potential therapeutic vulnerability.
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9
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Xie SQ, Leeke BJ, Whilding C, Wagner RT, Garcia-Llagostera F, Low Y, Chammas P, Cheung NTF, Dormann D, McManus MT, Percharde M. Nucleolar-based Dux repression is essential for embryonic two-cell stage exit. Genes Dev 2022; 36:331-347. [PMID: 35273077 PMCID: PMC8973846 DOI: 10.1101/gad.349172.121] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/17/2022] [Indexed: 12/14/2022]
Abstract
Upon fertilization, the mammalian embryo must switch from dependence on maternal transcripts to transcribing its own genome, and in mice this involves the transient up-regulation of MERVL transposons and MERVL-driven genes at the two-cell stage. The mechanisms and requirement for MERVL and two-cell (2C) gene up-regulation are poorly understood. Moreover, this MERVL-driven transcriptional program must be rapidly shut off to allow two-cell exit and developmental progression. Here, we report that robust ribosomal RNA (rRNA) synthesis and nucleolar maturation are essential for exit from the 2C state. 2C-like cells and two-cell embryos show similar immature nucleoli with altered structure and reduced rRNA output. We reveal that nucleolar disruption via blocking RNA polymerase I activity or preventing nucleolar phase separation enhances conversion to a 2C-like state in embryonic stem cells (ESCs) by detachment of the MERVL activator Dux from the nucleolar surface. In embryos, nucleolar disruption prevents proper nucleolar maturation and Dux silencing and leads to two- to four-cell arrest. Our findings reveal an intriguing link between rRNA synthesis, nucleolar maturation, and gene repression during early development.
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Affiliation(s)
- Sheila Q Xie
- MRC London Institute of Medical Sciences, London W12 0NN, United Kingdom.,Institute of Clinical Sciences, Imperial College London, London W12 0NN, United Kingdom
| | - Bryony J Leeke
- MRC London Institute of Medical Sciences, London W12 0NN, United Kingdom.,Institute of Clinical Sciences, Imperial College London, London W12 0NN, United Kingdom
| | - Chad Whilding
- MRC London Institute of Medical Sciences, London W12 0NN, United Kingdom.,Institute of Clinical Sciences, Imperial College London, London W12 0NN, United Kingdom
| | - Ryan T Wagner
- University of California at San Francisco, San Francisco, California 91413, USA
| | - Ferran Garcia-Llagostera
- MRC London Institute of Medical Sciences, London W12 0NN, United Kingdom.,Institute of Clinical Sciences, Imperial College London, London W12 0NN, United Kingdom
| | - YiXuan Low
- MRC London Institute of Medical Sciences, London W12 0NN, United Kingdom.,Institute of Clinical Sciences, Imperial College London, London W12 0NN, United Kingdom
| | - Paul Chammas
- MRC London Institute of Medical Sciences, London W12 0NN, United Kingdom.,Institute of Clinical Sciences, Imperial College London, London W12 0NN, United Kingdom
| | - Nathan T-F Cheung
- MRC London Institute of Medical Sciences, London W12 0NN, United Kingdom.,Institute of Clinical Sciences, Imperial College London, London W12 0NN, United Kingdom
| | - Dirk Dormann
- MRC London Institute of Medical Sciences, London W12 0NN, United Kingdom.,Institute of Clinical Sciences, Imperial College London, London W12 0NN, United Kingdom
| | - Michael T McManus
- University of California at San Francisco, San Francisco, California 91413, USA
| | - Michelle Percharde
- MRC London Institute of Medical Sciences, London W12 0NN, United Kingdom.,Institute of Clinical Sciences, Imperial College London, London W12 0NN, United Kingdom
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10
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Mutual dependency between lncRNA LETN and protein NPM1 in controlling the nucleolar structure and functions sustaining cell proliferation. Cell Res 2021; 31:664-683. [PMID: 33432115 PMCID: PMC8169757 DOI: 10.1038/s41422-020-00458-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 11/30/2020] [Indexed: 02/06/2023] Open
Abstract
Fundamental processes such as ribosomal RNA synthesis and chromatin remodeling take place in the nucleolus, which is hyperactive in fast-proliferating cells. The sophisticated regulatory mechanism underlying the dynamic nucleolar structure and functions is yet to be fully explored. The present study uncovers the mutual functional dependency between a previously uncharacterized human long non-coding RNA, which we renamed LETN, and a key nucleolar protein, NPM1. Specifically, being upregulated in multiple types of cancer, LETN resides in the nucleolus via direct binding with NPM1. LETN plays a critical role in facilitating the formation of NPM1 pentamers, which are essential building blocks of the nucleolar granular component and control the nucleolar functions. Repression of LETN or NPM1 led to similar and profound changes of the nucleolar morphology and arrest of the nucleolar functions, which led to proliferation inhibition of human cancer cells and neural progenitor cells. Interestingly, this inter-dependency between LETN and NPM1 is associated with the evolutionarily new variations of NPM1 and the coincidental emergence of LETN in higher primates. We propose that this human-specific protein-lncRNA axis renders an additional yet critical layer of regulation with high physiological relevance in both cancerous and normal developmental processes that require hyperactive nucleoli.
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MicroRNAs for Virus Pathogenicity and Host Responses, Identified in SARS-CoV-2 Genomes, May Play Roles in Viral-Host Co-Evolution in Putative Zoonotic Host Species. Viruses 2021; 13:v13010117. [PMID: 33467206 PMCID: PMC7830670 DOI: 10.3390/v13010117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/07/2021] [Accepted: 01/13/2021] [Indexed: 12/12/2022] Open
Abstract
Our recent study identified seven key microRNAs (miR-8066, 5197, 3611, 3934-3p, 1307-3p, 3691-3p, 1468-5p) similar between SARS-CoV-2 and the human genome, pointing at miR-related mechanisms in viral entry and the regulatory effects on host immunity. To identify the putative roles of these miRs in zoonosis, we assessed their conservation, compared with humans, in some key wild and domestic animal carriers of zoonotic viruses, including bat, pangolin, pig, cow, rat, and chicken. Out of the seven miRs under study, miR-3611 was the most strongly conserved across all species; miR-5197 was the most conserved in pangolin, pig, cow, bat, and rat; miR-1307 was most strongly conserved in pangolin, pig, cow, bat, and human; miR-3691-3p in pangolin, cow, and human; miR-3934-3p in pig and cow, followed by pangolin and bat; miR-1468 was most conserved in pangolin, pig, and bat; while miR-8066 was most conserved in pangolin and pig. In humans, miR-3611 and miR-1307 were most conserved, while miR-8066, miR-5197, miR-3334-3p and miR-1468 were least conserved, compared with pangolin, pig, cow, and bat. Furthermore, we identified that changes in the miR-5197 nucleotides between pangolin and human can generate three new miRs, with differing tissue distribution in the brain, lung, intestines, lymph nodes, and muscle, and with different downstream regulatory effects on KEGG pathways. This may be of considerable importance as miR-5197 is localized in the spike protein transcript area of the SARS-CoV-2 genome. Our findings may indicate roles for these miRs in viral–host co-evolution in zoonotic hosts, particularly highlighting pangolin, bat, cow, and pig as putative zoonotic carriers, while highlighting the miRs’ roles in KEGG pathways linked to viral pathogenicity and host responses in humans. This in silico study paves the way for investigations into the roles of miRs in zoonotic disease.
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12
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Akef A, McGraw K, Cappell SD, Larson DR. Ribosome biogenesis is a downstream effector of the oncogenic U2AF1-S34F mutation. PLoS Biol 2020; 18:e3000920. [PMID: 33137094 PMCID: PMC7660540 DOI: 10.1371/journal.pbio.3000920] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 11/12/2020] [Accepted: 09/22/2020] [Indexed: 01/05/2023] Open
Abstract
U2 Small Nuclear RNA Auxiliary Factor 1 (U2AF1) forms a heterodimeric complex with U2AF2 that is primarily responsible for 3' splice site selection. U2AF1 mutations have been identified in most cancers but are prevalent in Myelodysplastic Syndrome (MDS) and Acute Myeloid Leukemia (AML), and the most common mutation is a missense substitution of serine-34 to phenylalanine (S34F). The U2AF heterodimer also has a noncanonical function as a translational regulator. Here, we report that the U2AF1-S34F mutation results in specific misregulation of the translation initiation and ribosome biogenesis machinery. The net result is an increase in mRNA translation at the single-cell level. Among the translationally up-regulated targets of U2AF1-S34F is Nucleophosmin 1 (NPM1), which is a major driver of myeloid malignancy. Depletion of NPM1 impairs the viability of the U2AF1-S34F mutant cells and causes ribosomal RNA (rRNA) processing defects, thus indicating an unanticipated synthetic interaction between U2AF1, NPM1, and ribosome biogenesis. Our results establish a unique molecular phenotype for the U2AF1 mutation that recapitulates translational misregulation in myeloid disease.
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MESH Headings
- Amino Acid Substitution
- Animals
- Cell Cycle Checkpoints/genetics
- Cell Line
- Eukaryotic Initiation Factors/genetics
- Eukaryotic Initiation Factors/metabolism
- Gene Silencing
- Humans
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Mice
- Mice, Transgenic
- Mutation
- Myelodysplastic Syndromes/genetics
- Myelodysplastic Syndromes/metabolism
- Myeloid Progenitor Cells/metabolism
- Nuclear Proteins/antagonists & inhibitors
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Nucleophosmin
- RNA Processing, Post-Transcriptional
- RNA, Ribosomal, 28S/genetics
- RNA, Ribosomal, 28S/metabolism
- Ribosomes/genetics
- Ribosomes/metabolism
- Splicing Factor U2AF/genetics
- Splicing Factor U2AF/metabolism
- Tumor Suppressor Protein p53/genetics
- Tumor Suppressor Protein p53/metabolism
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Affiliation(s)
- Abdalla Akef
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kathy McGraw
- Department of Malignant Hematology, Moffitt Cancer Center, Tampa, Florida, United States of America
| | - Steven D. Cappell
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Daniel R. Larson
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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13
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Pang MYH, Sun X, Ausió J, Ishibashi T. Histone H4 variant, H4G, drives ribosomal RNA transcription and breast cancer cell proliferation by loosening nucleolar chromatin structure. J Cell Physiol 2020; 235:9601-9608. [PMID: 32385931 DOI: 10.1002/jcp.29770] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 04/09/2020] [Accepted: 04/25/2020] [Indexed: 02/06/2023]
Abstract
The hominidae-specific histone variant H4G is expressed in breast cancer patients in a stage-dependent manner. H4G localizes primarily in the nucleoli via its interaction with nucleophosmin (NPM1). H4G is involved in rDNA transcription and ribosome biogenesis, which facilitates breast cancer cell proliferation. However, the molecular mechanism underlying this process remains unknown. Here, we show that H4G is not stably incorporated into nucleolar chromatin, even with the chaperoning assistance of NPM1. H4G likely form transient nucleosome-like-structure that undergoes rapid dissociation. In addition, the nucleolar chromatin in H4GKO cells is more compact than WT cells. Altogether, our results suggest that H4G relaxes the nucleolar chromatin and enhances rRNA transcription by forming destabilized nucleosome in breast cancer cells.
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Affiliation(s)
- Matthew Y H Pang
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China
| | - Xulun Sun
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China
| | - Juan Ausió
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Toyotaka Ishibashi
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China
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14
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Kim D, Kim YH, Kang JH, Park CS. Increased expression of nucleophosmin is associated with the pathophysiology of chronic rhinosinusitis with nasal polyposis. Auris Nasus Larynx 2020; 47:807-813. [PMID: 32139285 DOI: 10.1016/j.anl.2020.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 01/31/2020] [Accepted: 02/17/2020] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Nucleophosmin (NPM1) has been suggested to be involved in the pathophysiologic mechanism of inflammatory disorders. We measured the expression level of NPM1 in nasal polyp (NP) tissues of patients with chronic rhinosinusitis with nasal polyposis (CRSwNP). We also assessed the correlation between NPM1 expression and other parameters such as eosinophilic infiltration, inflammatory cytokines, and clinical indicators such as Lund-Mackay computed tomography (CT) score. METHODS Thirty patients with CRSwNP were included. We performed pre-operative CT scan to determine Lund-Mackay CT scores. During endoscopic sinus surgery, we harvested NP tissues from patients with CRSwNP. We performed Sirius red staining to evaluate eosinophilia and conducted immunohistochemical staining for NPM1 and real-time PCR for cytokines including interleukin (IL)-5, IL-17A, and IL-32. RESULTS The mRNA expression of NPM1 was significantly up-regulated in eosinophilic NP tissues (RQ 0.58 ± 0.06), compared to non-eosinophilic NP tissues (RQ 0.38 ± 0.08, p < 0.05). In the epithelium of NP tissue, a significant positive correlation was observed between eosinophilic infiltration and NPM1 expression. The expression of NPM1 was significantly correlated with that of IL-5 (r = 0.6229, p = 0.0004), IL-17A (r = 0.5971, p = 0.001), and IL-32 (r = -0.5985, p = 0.0068). There was no significant correlation between the mRNA expression of NPM1 and the Lund-Mackay CT score (Spearman r = -0.2563, p = 0.1879). CONCLUSION Expression of NPM1 was significantly increased in eosinophilic NP tissues from patients with CRSwNP. We observed an association between NPM1 expression and various pro-inflammatory cytokines such as IL-5, IL-17, and IL-32 and eosinophilic infiltration, which is thought to contribute to the pathophysiology of NP.
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Affiliation(s)
- Dana Kim
- Department of Pharmacology and Medicinal Toxicology Research Center, Incheon, South Korea; Hypoxia-Related Diseases Research Center, Inha University School of Medicine, Incheon, South Korea
| | - Young Hyo Kim
- Department of Otorhinolaryngology, Head and Neck Surgery, Inha University School of Medicine, Incheon, Republic of Korea; Inha Institute of Aerospace Medicine, Inha University School of Medicine, Incheon, Republic of Korea.
| | - Ju-Hee Kang
- Department of Pharmacology and Medicinal Toxicology Research Center, Incheon, South Korea; Hypoxia-Related Diseases Research Center, Inha University School of Medicine, Incheon, South Korea
| | - Chang-Shin Park
- Department of Pharmacology and Medicinal Toxicology Research Center, Incheon, South Korea; Hypoxia-Related Diseases Research Center, Inha University School of Medicine, Incheon, South Korea.
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15
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Evidence that melatonin downregulates Nedd4-1 E3 ligase and its role in cellular survival. Toxicol Appl Pharmacol 2019; 379:114686. [DOI: 10.1016/j.taap.2019.114686] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/14/2019] [Accepted: 07/16/2019] [Indexed: 01/06/2023]
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16
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Liu L, Xiao L, Chung HK, Kwon MS, Li XX, Wu N, Rao JN, Wang JY. RNA-Binding Protein HuR Regulates Rac1 Nucleocytoplasmic Shuttling Through Nucleophosmin in the Intestinal Epithelium. Cell Mol Gastroenterol Hepatol 2019; 8:475-486. [PMID: 31195150 PMCID: PMC6718926 DOI: 10.1016/j.jcmgh.2019.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 06/03/2019] [Accepted: 06/03/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS The mammalian intestinal epithelium is a rapidly self-renewing tissue in the body, and its homeostasis is tightly regulated via well-controlled mechanisms. The RNA-binding protein HuR is essential for maintaining gut epithelial integrity, and targeted deletion of HuR in intestinal epithelial cells (IECs) disrupts mucosal regeneration and delays repair after injury. Here, we defined the role of HuR in regulating subcellular distribution of small guanosine triphosphatase Rac1 and investigated the implication of nucleophosmin (NPM) as a molecular chaperone in this process. METHODS Studies were conducted in intestinal epithelial tissue-specific HuR knockout (IE-HuR-/-) mice and cultured IEC-6 cells, derived from rat small intestinal crypts. Functions of HuR and NPM in vitro were investigated via their gene silencing and overexpression. RESULTS The abundance of cytoplasmic Rac1 in the small intestinal mucosa increased significantly in IE-HuR-/- mice, although HuR deletion did not alter total Rac1 levels. HuR silencing in cultured IECs also increased the cytoplasmic Rac1 levels, without an effect on whole-cell Rac1 content. In addition, HuR deficiency in the intestinal epithelium decreased the levels of NPM in IE-HuR-/- mice and cultured IECs. NPM physically interacted with Rac1 and formed the NPM/Rac1 complex. NPM silencing decreased the NPM/Rac1 association and inhibited nuclear accumulation of Rac1, along with an increase in cytoplasmic abundances of Rac1. In contrast, ectopically expressed NPM enhanced Rac1 nuclear translocation and restored Rac1 subcellular localization to near normal in HuR-deficient cells. CONCLUSIONS These results indicate that HuR regulates Rac1 nucleocytoplasmic shuttling in the intestinal epithelium by altering NPM expression.
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Affiliation(s)
- Lan Liu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Hee K. Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Min S. Kwon
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Xiao-Xue Li
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Na Wu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jaladanki N. Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland,Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland,Correspondence Address correspondence to: Jian-Ying Wang, MD, PhD, Baltimore Veterans Affairs Medical Center (112), 10 North Greene Street, Baltimore, Maryland 21201. fax: (410) 706-1049.
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17
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Prohibitin 2 localizes in nucleolus to regulate ribosomal RNA transcription and facilitate cell proliferation in RD cells. Sci Rep 2018; 8:1479. [PMID: 29367618 PMCID: PMC5784149 DOI: 10.1038/s41598-018-19917-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 01/09/2018] [Indexed: 01/03/2023] Open
Abstract
Prohibitin 2 (PHB2), as a conserved multifunctional protein, is traditionally localized in the mitochondrial inner membrane and essential for maintenance of mitochondrial function. Here, we investigated the role of PHB2 in human rhabdomyosarcoma (RMS) RD cells and found substantial localization of PHB2 in the nucleolus. We demonstrated that PHB2 knockdown inhibited RD cell proliferation through inducing cell cycle arrest and suppressing DNA synthesis. Meanwhile, down-regulation of PHB2 also induced apoptosis and promoted differentiation in fractions of RD cells. In addition, PHB2 silencing led to altered nucleolar morphology, as observed by transmission electron microscopy, and impaired nucleolar function, as evidenced by down-regulation of 45S and 18S ribosomal RNA synthesis. Consistently, upon PHB2 knockdown, occupancy of c-Myc at the ribosomal DNA (rDNA) promoter was attenuated, while more myoblast determination protein 1 (MyoD) molecules bound to the rDNA promoter. In conclusion, our findings suggest that nucleolar PHB2 is involved in maintaining nucleolar morphology and function in RD cells by regulating a variety of transcription factors, which is likely to be one of the underlying mechanisms by which PHB2 promotes tumor proliferation and represses differentiation. Our study provides new insight into the pathogenesis of RMS and novel characterizations of the highly conserved PHB2 protein.
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18
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Luo F, Li H, Liang J, Jia H, Li X, Xiao H, He X, He J, Tian Y, Zhao H. Downregulation of NPM reverses multidrug resistance in human hepatoma cells via inhibition of P-glycoprotein expression. Mol Med Rep 2017; 15:2360-2368. [PMID: 28259962 DOI: 10.3892/mmr.2017.6246] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 12/19/2016] [Indexed: 11/05/2022] Open
Abstract
Multidrug resistance (MDR) is an important issue in current cancer treatments. In human cancer, drug resistance is primarily associated with the overexpression of multidrug resistance gene 1 (MDR1). Therefore, the human MDR1 gene promoter may be a target for anti‑MDR drug screening. Numerous methods to prevent MDR have been investigated. However, they have been proven to be clinically ineffective. Therefore, the aim of the present study was to investigate whether downregulation of nucleophosmin (NPM) demonstrates any effects on the reversal of MDR in hepatocellular carcinoma (HCC) cells. In the present study, two in vitro MDR HCC cell lines, HepG2/Adriamycin (ADM) and SMMC7721/ADM, were established and the level of MDR was measured. The results demonstrated that NPM downregulation markedly reversed the effects of MDR in the model used. In addition, NPM downregulation reduced P-glycoprotein expression, as well as MDR1 expression. These results suggested that downregulation of NPM may be a novel and effective method of reversing the effects of MDR, and may be a potential adjuvant for tumor chemotherapy.
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Affiliation(s)
- Fei Luo
- Department of Breast Surgery, Shanxi Cancer Hospital, Taiyuan, Shanxi 030013, P.R. China
| | - Huiyu Li
- Department of General Surgery, Shanxi Academy of Medical Sciences, Shanxi Dayi Hospital, Taiyuan, Shanxi 030032, P.R. China
| | - Jianfang Liang
- Department of Pathology, The First Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Hongyan Jia
- Department of General Surgery, The First Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Xiaoyu Li
- Department of Molecular Biology, Shanxi Cancer Hospital, Taiyuan, Shanxi 030013, P.R. China
| | - Hong Xiao
- Department of Pathology, The First Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Xuehua He
- Department of Blood Transfusion, Shanxi Academy of Medical Sciences Shanxi Dayi Hospital, Taiyuan, Shanxi 030032, P.R. China
| | - Jiefeng He
- Department of General Surgery, Shanxi Academy of Medical Sciences, Shanxi Dayi Hospital, Taiyuan, Shanxi 030032, P.R. China
| | - Yanzhang Tian
- Department of General Surgery, Shanxi Academy of Medical Sciences, Shanxi Dayi Hospital, Taiyuan, Shanxi 030032, P.R. China
| | - Haoliang Zhao
- Department of General Surgery, Shanxi Academy of Medical Sciences, Shanxi Dayi Hospital, Taiyuan, Shanxi 030032, P.R. China
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19
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Mai W, Huang F, Chen H, Zhou Y, Chen Y. Nervous necrosis virus capsid protein exploits nucleolar phosphoprotein Nucleophosmin (B23) function for viral replication. Virus Res 2016; 230:1-6. [PMID: 28034778 DOI: 10.1016/j.virusres.2016.12.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Revised: 12/01/2016] [Accepted: 12/16/2016] [Indexed: 01/15/2023]
Abstract
Nucleolar proteins facilitate the replication of certain human and animal viruses through interaction with viral proteins. In this study, an interaction between nervous necrosis virus capsid protein and nucleolar phosphoprotein B23 was identified using in vitro experimental approaches. The capsid protein binds to B23 early during the viral infection and accumulates in the nucleus, particularly in the nucleolus. However, over the course of the infection B23 is redistributed from the nucleoli to the nucleoplasm. siRNA-mediated knockdown of B23 reduced viral replication and cytopathic effect. Thus, B23 targets capsid protein to the nucleus and facilitates NNV replication. The results provide the first demonstration that nucleolar protein B23 has a direct role in the nodavirus replication process.
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Affiliation(s)
- Weijun Mai
- The Institute of Life Sciences, Jiangsu University, Zhenjiang, 212013, China.
| | - Fang Huang
- The Institute of Life Sciences, Jiangsu University, Zhenjiang, 212013, China
| | - Huiqing Chen
- The Institute of Life Sciences, Jiangsu University, Zhenjiang, 212013, China
| | - Yajing Zhou
- The Institute of Life Sciences, Jiangsu University, Zhenjiang, 212013, China
| | - Yan Chen
- The Institute of Life Sciences, Jiangsu University, Zhenjiang, 212013, China
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20
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Dai L, Li J, Xing M, Sanchez TW, Casiano CA, Zhang JY. Using Serological Proteome Analysis to Identify Serum Anti-Nucleophosmin 1 Autoantibody as a Potential Biomarker in European-American and African-American Patients With Prostate Cancer. Prostate 2016; 76:1375-86. [PMID: 27418398 DOI: 10.1002/pros.23217] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 05/25/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND The prostate-specific antigen (PSA) testing has been widely implemented for the early detection and management of prostate cancer (PCa). However, the lack of specificity has led to overdiagnosis, resulting in many possibly unnecessary biopsies and overtreatment. Therefore, novel serological biomarkers with high sensitivity and specificity are of vital importance needed to complement PSA testing in the early diagnosis and effective management of PCa. This is particularly critical in the context of PCa health disparities, where early detection and management could help reduce the disproportionately high PCa mortality observed in African-American men. Previous studies have demonstrated that sera from patients with PCa contain autoantibodies that react with tumor-associated antigens (TAAs). METHODS The serological proteome analysis (SERPA) approach was used to identify tumor-associated antigens (TAAs) of PCa. In evaluation study, the level of anti-NPM1 antibody was examined in sera from test cohort, validation cohort, as well as European-American (EA) and African-American (AA) men with PCa by using immunoassay. RESULTS Nucleophosmin 1 (NPM1) as a 33 kDa TAA in PCa was identified and characterized by SERPA approach. Anti-NPM1 antibody level in PCa was higher than in benign prostatic hyperplasia (BPH) patients and healthy individuals. Receiver operating characteristic (ROC) curve analysis showed similar high diagnostic value for PCa in the test cohort (area under the curve (AUC):0.860) and validation cohort (AUC: 0.822) to differentiate from normal individuals and BPH. Interestingly, AUC values were significantly higher for AA PCa patients. When considering concurrent serum measurements of anti-NPM1 antibody and PSA, 97.1% PCa patients at early stage were identified correctly, while 69.2% BPH patients who had elevated PSA levels were found to be anti-NPM1 negative. Additionally, anti-NPM1 antibody levels in PCa patients at early stage significantly increased after surgery treatment. CONCLUSION This intriguing data suggested that NPM1 can elicit autoantibody response in PCa and might be a potential biomarker for the immunodiagnosis and prognosis of PCa, and for supplementing PSA testing in distinguishing PCa from BPH. Prostate 76:1375-1386, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Liping Dai
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas
| | - Jitian Li
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas
| | - Mengtao Xing
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas
| | - Tino W Sanchez
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
| | - Carlos A Casiano
- Center for Health Disparities and Molecular Medicine, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
- Division of Rheumatology, Department of Medicine, Loma Linda University School of Medicine, Loma Linda, California
| | - Jian-Ying Zhang
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas.
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Scott DD, Oeffinger M. Nucleolin and nucleophosmin: nucleolar proteins with multiple functions in DNA repair. Biochem Cell Biol 2016; 94:419-432. [PMID: 27673355 DOI: 10.1139/bcb-2016-0068] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The nucleolus represents a highly multifunctional intranuclear organelle in which, in addition to the canonical ribosome assembly, numerous processes such as transcription, DNA repair and replication, the cell cycle, and apoptosis are coordinated. The nucleolus is further a key hub in the sensing of cellular stress and undergoes major structural and compositional changes in response to cellular perturbations. Numerous nucleolar proteins have been identified that, upon sensing nucleolar stress, deploy additional, non-ribosomal roles in the regulation of varied cell processes including cell cycle arrest, arrest of DNA replication, induction of DNA repair, and apoptosis, among others. The highly abundant proteins nucleophosmin (NPM1) and nucleolin (NCL) are two such factors that transit to the nucleoplasm in response to stress, and participate directly in the repair of numerous different DNA damages. This review discusses the contributions made by NCL and (or) NPM1 to the different DNA repair pathways employed by mammalian cells to repair DNA insults, and examines the implications of such activities for the regulation, pathogenesis, and therapeutic targeting of NPM1 and NCL.
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Affiliation(s)
- Daniel D Scott
- a Laboratory of RNP Biochemistry, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC H2W 1R7, Canada
- b Division of Experimental Medicine, Faculty of Medicine, McGill University, Montréal, QC H3A 2A3, Canada
| | - Marlene Oeffinger
- a Laboratory of RNP Biochemistry, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC H2W 1R7, Canada
- b Division of Experimental Medicine, Faculty of Medicine, McGill University, Montréal, QC H3A 2A3, Canada
- c Département de biochimie et médecine moléculaire, Faculté de Médecine, Université de Montréal, QC H3T 1J4, Canada
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22
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Box JK, Paquet N, Adams MN, Boucher D, Bolderson E, O'Byrne KJ, Richard DJ. Nucleophosmin: from structure and function to disease development. BMC Mol Biol 2016; 17:19. [PMID: 27553022 PMCID: PMC4995807 DOI: 10.1186/s12867-016-0073-9] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 08/16/2016] [Indexed: 12/11/2022] Open
Abstract
Nucleophosmin (NPM1) is a critical cellular protein that has been implicated in a number of pathways including mRNA transport, chromatin remodeling, apoptosis and genome stability. NPM1 function is a critical requirement for normal cellular biology as is underlined in cancer where NPM1 is commonly overexpressed, mutated, rearranged and sporadically deleted. Consistent with a multifunctional role within the cell, NPM1 can function not only as a proto-oncogene but also as a tumor suppressor. The aim of this review is to look at the less well-described role of NPM1 in the DNA repair pathways as well as the role of NPM1 in the regulation of apoptosis and its mutation in cancers.
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Affiliation(s)
- Joseph K Box
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Nicolas Paquet
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.
| | - Mark N Adams
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Didier Boucher
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Emma Bolderson
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kenneth J O'Byrne
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Derek J Richard
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.
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Frau-Méndez MA, Fernández-Vega I, Ansoleaga B, Blanco Tech R, Carmona Tech M, Antonio Del Rio J, Zerr I, Llorens F, José Zarranz J, Ferrer I. Fatal familial insomnia: mitochondrial and protein synthesis machinery decline in the mediodorsal thalamus. Brain Pathol 2016; 27:95-106. [PMID: 27338255 DOI: 10.1111/bpa.12408] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 05/16/2016] [Indexed: 11/29/2022] Open
Abstract
The expression of subunits of mitochondrial respiratory complexes and components of the protein synthesis machinery from the nucleolus to the ribosome was analyzed in the mediodorsal thalamus in seven cases of fatal familial insomnia (FFI) compared with age-matched controls. NDUFB8 (complex I subunit), SDHB (complex II subunit), UQCRC2 (complex III subunit), COX2 (complex IV subunit), and ATP50 (complex V subunit) expression levels, as revealed by western blotting, were reduced in FFI. Voltage-dependent anion channel (VDAC) and ATP5H were also reduced due to the marked depopulation of neurons. In contrast, a marked increase in superoxide dismutase 2 (SOD2) was found in reactive astrocytes thus suggesting that astrocytes are key factors in oxidative stress responses. The histone-binding chaperones nucleolin and nucleoplasmin 3, and histone H3 di-methylated K9 were markedly reduced together with a decrease in the expression of protein transcription elongation factor eEF1A. These findings show severe impairment in the expression of crucial components of mitochondrial function and protein synthesis in parallel with neuron loss in mediodorsal thalamus at terminal stages of FFI. Therapeutic measures must be taken long before the appearance of clinical symptoms to prevent the devastating effects of FFI.
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Affiliation(s)
- Margalida A Frau-Méndez
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Spain
| | - Iván Fernández-Vega
- Department of Neuropathology, Pathology Department, University Hospital Araba, Álava, Brain Bank Araba University Hospital, Basque Biobank for Research (O+eHun), Spain
| | - Belén Ansoleaga
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Spain
| | - Rosa Blanco Tech
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Spain.,Department of Neuropathology, Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Spain
| | - Margarita Carmona Tech
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Spain.,Department of Neuropathology, Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Spain
| | - Jose Antonio Del Rio
- Department of Neuropathology, Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Spain.,Department of Cell Biology, Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, University of Barcelona, Barcelona, Spain
| | - Inga Zerr
- Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Franc Llorens
- Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Juan José Zarranz
- Neurology Department, University Hospital Cruces, University of the Basque Country, Bizkaia, Spain
| | - Isidro Ferrer
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Spain.,Department of Neuropathology, Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Spain
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24
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Tasdemir S, Eroz R, Dogan H, Erdem HB, Sahin I, Kara M, Engin RI, Turkez H. Association Between Human Hair Loss and the Expression Levels of Nucleolin, Nucleophosmin, and UBTF Genes. Genet Test Mol Biomarkers 2016; 20:197-202. [PMID: 26866305 DOI: 10.1089/gtmb.2015.0246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Nucleolar organizer regions, also known as argyrophilic nucleolar organizer regions, are associated with ribosomal genes. The main function of the nucleolus is the rapid production of ribosomal subunits, a process that must be highly regulated to provide the appropriate levels for cellular proliferation and cell growth. There are no studies in the literature addressing the expression and function of nucleolar component proteins, including nucleophosmin, nucleolin and the upstream binding transcription factor (UBTF), in human follicular hair cells. METHODS Nineteen healthy males who had normal and sufficient hair follicles on the back of the head, but exhibited hair loss on the frontal/vertex portions of the head and 14 healthy males without hair loss were included in the current study. Gene expression levels were measured by relative quantitative real time polymerase chain reaction. RESULTS In the individuals suffering from alopecia, the total expression levels of nucleolin, nucleophosmin, and UBTF were lower in normal sites than in hair loss sites. Strong expression level correlations were detected between: nucleophosmin and nucleolin; nucleophosmin and UBTF, and nucleolin and UBTF for both groups. CONCLUSIONS There was an association between human hair loss and the expression levels of nucleolin, nucleophosmin, and UBTF genes.
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Affiliation(s)
- Sener Tasdemir
- 1 Department of Medical Genetics, Faculty of Medicine, Ataturk University , Erzurum, Turkey
| | - Recep Eroz
- 2 Department of Medical Genetics, Faculty of Medicine, Duzce University , Duzce, Turkey
| | - Hasan Dogan
- 3 Department of Medical Biology, Faculty of Medicine, Ataturk University , Erzurum, Turkey
| | - Haktan Bagis Erdem
- 1 Department of Medical Genetics, Faculty of Medicine, Ataturk University , Erzurum, Turkey
| | - Ibrahim Sahin
- 1 Department of Medical Genetics, Faculty of Medicine, Ataturk University , Erzurum, Turkey
| | - Murat Kara
- 4 Department of Medical Genetics, Faculty of Medicine, Mugla Sitki Kocaman University , Mugla, Turkey
| | - Ragip Ismail Engin
- 5 Department of Dermatology, Regional Training and Research Hospital , Erzurum, Turkey
| | - Hasan Turkez
- 6 Department of Molecular Biology and Genetics, Faculty of Science, Erzurum Technical University , Erzurum, Turkey
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25
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Hernández-Ortega K, Garcia-Esparcia P, Gil L, Lucas JJ, Ferrer I. Altered Machinery of Protein Synthesis in Alzheimer's: From the Nucleolus to the Ribosome. Brain Pathol 2015; 26:593-605. [PMID: 26512942 DOI: 10.1111/bpa.12335] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 10/22/2015] [Indexed: 12/17/2022] Open
Abstract
Ribosomes and protein synthesis have been reported to be altered in the cerebral cortex at advanced stages of Alzheimer's disease (AD). Modifications in the hippocampus with disease progression have not been assessed. Sixty-seven cases including middle-aged (MA) and AD stages I-VI were analyzed. Nucleolar chaperones nucleolin, nucleophosmin and nucleoplasmin 3, and upstream binding transcription factor RNA polymerase I gene (UBTF) mRNAs are abnormally regulated and their protein levels reduced in AD. Histone modifications dimethylated histone H3K9 (H3K9me2) and acetylated histone H3K12 (H3K12ac) are decreased in CA1. Nuclear tau declines in CA1 and dentate gyrus (DG), and practically disappears in neurons with neurofibrillary tangles. Subunit 28 ribosomal RNA (28S rRNA) expression is altered in CA1 and DG in AD. Several genes encoding ribosomal proteins are abnormally regulated and protein levels of translation initiation factors eIF2α, eIF3η and eIF5, and elongation factor eEF2, are altered in the CA1 region in AD. These findings show alterations in the protein synthesis machinery in AD involving the nucleolus, nucleus and ribosomes in the hippocampus in AD some of them starting at first stages (I-II) preceding neuron loss. These changes may lie behind reduced numbers of dendritic branches and reduced synapses of CA1 and DG neurons which cause hippocampal atrophy.
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Affiliation(s)
- Karina Hernández-Ortega
- Institute of Neuropathology, Service of Pathologic Anatomy, IDIBELL-Bellvitge University Hospital, University of Barcelona, Hospitalet de Llobregat, Spain.,Neuropathology, CIBERNED (Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas), Madrid, Spain
| | - Paula Garcia-Esparcia
- Institute of Neuropathology, Service of Pathologic Anatomy, IDIBELL-Bellvitge University Hospital, University of Barcelona, Hospitalet de Llobregat, Spain.,Neuropathology, CIBERNED (Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas), Madrid, Spain
| | - Laura Gil
- Department of Genetics, Medical School, Alfonso X el Sabio University (UAX), Villanueva de la Cañada; Centro de Investigaciones Biologicas (CIB), CSIC, Madrid, Spain
| | - José J Lucas
- Neuropathology, CIBERNED (Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas), Madrid, Spain.,Department of Molecular Biology, Center for Molecular Biology "Severo Ochoa" (CBMSO) CSIC/UAM, Madrid, 28049, Spain
| | - Isidre Ferrer
- Institute of Neuropathology, Service of Pathologic Anatomy, IDIBELL-Bellvitge University Hospital, University of Barcelona, Hospitalet de Llobregat, Spain.,Neuropathology, CIBERNED (Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas), Madrid, Spain
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26
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Garcia-Esparcia P, Hernández-Ortega K, Koneti A, Gil L, Delgado-Morales R, Castaño E, Carmona M, Ferrer I. Altered machinery of protein synthesis is region- and stage-dependent and is associated with α-synuclein oligomers in Parkinson's disease. Acta Neuropathol Commun 2015; 3:76. [PMID: 26621506 PMCID: PMC4666041 DOI: 10.1186/s40478-015-0257-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/14/2015] [Indexed: 01/17/2023] Open
Abstract
INTRODUCTION Parkinson's disease (PD) is characterized by the accumulation of abnormal α-synuclein in selected regions of the brain following a gradient of severity with disease progression. Whether this is accompanied by globally altered protein synthesis is poorly documented. The present study was carried out in PD stages 1-6 of Braak and middle-aged (MA) individuals without alterations in brain in the substantia nigra, frontal cortex area 8, angular gyrus, precuneus and putamen. RESULTS Reduced mRNA expression of nucleolar proteins nucleolin (NCL), nucleophosmin (NPM1), nucleoplasmin 3 (NPM3) and upstream binding transcription factor (UBF), decreased NPM1 but not NPM3 nucleolar protein immunostaining in remaining neurons; diminished 18S rRNA, 28S rRNA; reduced expression of several mRNAs encoding ribosomal protein (RP) subunits; and altered protein levels of initiation factor eIF3 and elongation factor eEF2 of protein synthesis was found in the substantia nigra in PD along with disease progression. Although many of these changes can be related to neuron loss in the substantia nigra, selective alteration of certain factors indicates variable degree of vulnerability of mRNAs, rRNAs and proteins in degenerating sustantia nigra. NPM1 mRNA and 18S rRNA was increased in the frontal cortex area 8 at stage 5-6; modifications were less marked and region-dependent in the angular gyrus and precuneus. Several RPs were abnormally regulated in the frontal cortex area 8 and precuneus, but only one RP in the angular gyrus, in PD. Altered levels of eIF3 and eIF1, and decrease eEF1A and eEF2 protein levels were observed in the frontal cortex in PD. No modifications were found in the putamen at any time of the study except transient modifications in 28S rRNA and only one RP mRNA at stages 5-6. These observations further indicate marked region-dependent and stage-dependent alterations in the cerebral cortex in PD. Altered solubility and α-synuclein oligomer formation, assessed in total homogenate fractions blotted with anti-α-synuclein oligomer-specific antibody, was demonstrated in the substantia nigra and frontal cortex, but not in the putamen, in PD. Dramatic increase in α-synuclein oligomers was also seen in fluorescent-activated cell sorter (FACS)-isolated nuclei in the frontal cortex in PD. CONCLUSIONS Altered machinery of protein synthesis is altered in the substantia nigra and cerebral cortex in PD being the frontal cortex area 8 more affected than the angular gyrus and precuneus; in contrast, pathways of protein synthesis are apparently preserved in the putamen. This is associated with the presence of α-synuclein oligomeric species in total homogenates; substantia nigra and frontal cortex are enriched, albeit with different band patterns, in α-synuclein oligomeric species, whereas α-synuclein oligomers are not detected in the putamen.
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Affiliation(s)
- Paula Garcia-Esparcia
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat; Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Karina Hernández-Ortega
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat; Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Anusha Koneti
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat; Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Laura Gil
- Department of Genetics, Medical School, Alfonso X el Sabio University, Villanueva de la Cañada, Madrid, Spain
| | - Raul Delgado-Morales
- Cancer Epigenetics and Biology Program, IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | - Ester Castaño
- Biology-Bellvitge Unit, Scientific and Technological Centers-University of Barcelona (CCiTUB), Hospitalet de Llobregat, Barcelona, Spain
| | - Margarita Carmona
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat; Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Isidre Ferrer
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat; Biomedical Research Center of Neurodegenerative Diseases (CIBERNED), Barcelona, Spain.
- Institute of Neuropathology, Service of Pathologic Anatomy, Bellvitge University Hospital, carrer Feixa Llarga s/n, 08907, Hospitalet de Llobregat, Spain.
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Kim JY, Cho YE, Park JH. The Nucleolar Protein GLTSCR2 Is an Upstream Negative Regulator of the Oncogenic Nucleophosmin-MYC Axis. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:2061-8. [DOI: 10.1016/j.ajpath.2015.03.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 02/13/2015] [Accepted: 03/19/2015] [Indexed: 11/16/2022]
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Pfister JA, D'Mello SR. Insights into the regulation of neuronal viability by nucleophosmin/B23. Exp Biol Med (Maywood) 2015; 240:774-86. [PMID: 25908633 DOI: 10.1177/1535370215579168] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The vastness of the neuronal network that constitutes the human brain proves challenging when trying to understand its complexity. Furthermore, due to the senescent state they enter into upon maturation, neurons lack the ability to regenerate in the face of insult, injury or death. Consequently, their excessive death can be detrimental to the proper functioning of the brain. Therefore, elucidating the mechanisms regulating neuronal survival is, while challenging, of great importance as the incidence of neurological disease is becoming more prevalent in today's society. Nucleophosmin/B23 (NPM) is an abundant and ubiquitously expressed protein that regulates vital cellular processes such as ribosome biogenesis, cell proliferation and genomic stability. As a result, it is necessary for proper embryonic development, but has also been implicated in many cancers. While highly studied in the context of proliferative cells, there is a lack of understanding NPM's role in post-mitotic neurons. By exploring its role in healthy neurons as well as its function in the regulation of cell death and neurodegeneration, there can be a better understanding of how these diseases initiate and progress. Owing to what is thus far known about its function in the cell, NPM could be an attractive therapeutic target in the treatment of neurodegenerative diseases.
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Affiliation(s)
- Jason A Pfister
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275, USA
| | - Santosh R D'Mello
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275, USA
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29
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Liu M, Varela-Ramirez A, Li J, Dai L, Aguilera RJ, Zhang JY. Humoral autoimmune response to nucleophosmin in the immunodiagnosis of hepatocellular carcinoma. Oncol Rep 2015; 33:2245-52. [PMID: 25779011 PMCID: PMC4391589 DOI: 10.3892/or.2015.3854] [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: 12/10/2014] [Accepted: 01/26/2015] [Indexed: 02/07/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is a worldwide prevalent cancer with an exremely poor prognosis. Detection of serum α-fetoprotein (AFP) and liver imaging techniques are the conventional methods used clinically for the identification of this malignancy. However, these techniques are not reliable for early diagnosis, and particularly the sensitivity and specificity of AFP in HCC diagnosis are not optimal. Therefore, there is an urgent need for the development of more sensitive and specific methods that can improve AFP quantification in the early detection of HCC. In the present study, autoantibody responses to nucleophosmin (NPM1) in HCC patients were evaluated by enzyme-linked immunosorbent assay (ELISA), western blotting and indirect immunofluorescence. Immunohistochemistry (IHC) with tissue array slides was also performed to analyze protein expression of NPM1 in HCC and control tissues. The prevalence of autoantibodies against NPM1 was 22.4% (17/76) in HCC, which was significantly higher than that in sera from patients with liver cirrhosis (LC), chronic hepatitis (CH) and systemic lupus erythematosus (SLE) (P<0.01). The average titer of autoantibodies against NPM1 in HCC sera was higher compared to that in LC, CH, SLE and normal human sera (NHS) (P<0.01). In addition, anti-NMP1 autoantibodies were detected in sera from several HCC patients with serial bleeding samples. A stronger reactive band corresponding to NMP1 was visualized in the western blot analyses, utilizing sera from patients 3–6 months before the clinical diagnosis of HCC. Our data indicate that NPM1 and the anti-NPM1 system may have potential as an early-stage biomarker for HCC screening and diagnosis.
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Affiliation(s)
- Mei Liu
- Department of Biological Sciences and Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX 79968, USA
| | - Armando Varela-Ramirez
- Department of Biological Sciences and Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX 79968, USA
| | - Jitian Li
- Department of Biological Sciences and Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX 79968, USA
| | - Liping Dai
- Department of Biological Sciences and Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX 79968, USA
| | - Renato J Aguilera
- Department of Biological Sciences and Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX 79968, USA
| | - Jian-Ying Zhang
- Department of Biological Sciences and Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX 79968, USA
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30
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The nucleolar phosphoprotein B23 targets Newcastle disease virus matrix protein to the nucleoli and facilitates viral replication. Virology 2014; 452-453:212-22. [PMID: 24606698 DOI: 10.1016/j.virol.2014.01.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 11/28/2013] [Accepted: 01/17/2014] [Indexed: 01/14/2023]
Abstract
The cellular nucleolar proteins are reported to facilitate the replication cycles of some human and animal viruses by interaction with viral proteins. In this study, a nucleolar phosphoprotein B23 was identified to interact with Newcastle disease virus (NDV) matrix (M) protein. We found that NDV M protein accumulated in the nucleolus by binding B23 early in infection, but resulted in the redistribution of B23 from the nucleoli to the nucleoplasm later in infection. In vitro binding studies utilizing deletion mutants indicated that amino acids 30-60 of M and amino acids 188-245 of B23 were required for binding. Furthermore, knockdown of B23 by siRNA or overexpression of B23 or M-binding B23-derived polypeptides remarkably reduced cytopathic effect and inhibited NDV replication. Collectively, we show that B23 facilitates NDV replication by targeting M to the nucleolus, demonstrating for the first time a direct role for nucleolar protein B23 in a paramyxovirus replication process.
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31
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Iribarren C, Hermosilla V, Morin V, Puchi M. Functional studies of MP62 during male chromatin decondensation in sea urchins. J Cell Biochem 2013; 114:1779-88. [PMID: 23444173 DOI: 10.1002/jcb.24520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 02/12/2013] [Indexed: 11/10/2022]
Abstract
In amphibians, sperm histone transition post-fertilization during male pronucleus formation is commanded by histone chaperone Nucleoplasmin (NPM). Here, we report the first studies to analyze the participation of a Nucleoplasmin-like protein on male chromatin remodeling in sea urchins. In this report, we present the molecular characterization of a nucleoplasmin-like protein that is present in non fertilized eggs and early zygotes in sea urchin specie Tetrapygus niger. This protein, named MP62 can interact with sperm histones in vitro. By male chromatin decondensation assays and immunodepletion experiments in vitro, we have demonstrated that this protein is responsible for sperm nucleosome disorganization. Furthermore, as amphibian nucleoplasmin MP62 is phosphorylated in vivo immediately post-fertilization and this phosphorylation is dependent on CDK-cyclin activities found after fertilization. As we shown, olomoucine and roscovitine inhibits male nucleosome decondensation, sperm histone replacement in vitro and MP62 phosphorylation in vivo. This is the first report of a nucleoplasmin-like activity in sea urchins participating during male pronucleus formation post-fecundation.
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Affiliation(s)
- Claudio Iribarren
- Department of Biochemistry and Molecular Biology, Universidad de Concepción, Concepción, Chile
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32
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Kumari S, Swaminathan A, Chatterjee S, Senapati P, Boopathi R, Kundu TK. Chromatin organization, epigenetics and differentiation: an evolutionary perspective. Subcell Biochem 2013; 61:3-35. [PMID: 23150244 DOI: 10.1007/978-94-007-4525-4_1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Genome packaging is a universal phenomenon from prokaryotes to higher mammals. Genomic constituents and forces have however, travelled a long evolutionary route. Both DNA and protein elements constitute the genome and also aid in its dynamicity. With the evolution of organisms, these have experienced several structural and functional changes. These evolutionary changes were made to meet the challenging scenario of evolving organisms. This review discusses in detail the evolutionary perspective and functionality gain in the phenomena of genome organization and epigenetics.
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Affiliation(s)
- Sujata Kumari
- Transcription and Disease Laboratory, Molecular Biology and Genetics Unit (MBGU), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur Post, Bangalore, 560064, India
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Finn RM, Ellard K, Eirín-López JM, Ausió J. Vertebrate nucleoplasmin and NASP: egg histone storage proteins with multiple chaperone activities. FASEB J 2012; 26:4788-804. [PMID: 22968912 DOI: 10.1096/fj.12-216663] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Recent reviews have focused on the structure and function of histone chaperones involved in different aspects of somatic cell chromatin metabolism. One of the most dramatic chromatin remodeling processes takes place immediately after fertilization and is mediated by egg histone storage chaperones. These include members of the nucleoplasmin (NPM2/NPM3), which are preferentially associated with histones H2A-H2B in the egg and the nuclear autoantigenic sperm protein (NASP) families. Interestingly, in addition to binding and providing storage to H3/H4 in the egg and in somatic cells, NASP has been shown to be a unique genuine chaperone for histone H1. This review revolves around the structural and functional roles of these two families of chaperones whose activity is modulated by their own post-translational modifications (PTMs), particularly phosphorylation. Beyond their important role in the remodeling of paternal chromatin in the early stages of embryogenesis, NPM and NASP members can interact with a plethora of proteins in addition to histones in somatic cells and play a critical role in processes of functional cell alteration, such as in cancer. Despite their common presence in the egg, these two histone chaperones appear to be evolutionarily unrelated. In contrast to members of the NPM family, which share a common monophyletic evolutionary origin, the different types of NASP appear to have evolved recurrently within different taxa.
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Affiliation(s)
- Ron M Finn
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada V8W 3P6
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34
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Liu X, Liu D, Qian D, Dai J, An Y, Jiang S, Stanley B, Yang J, Wang B, Liu X, Liu DX. Nucleophosmin (NPM1/B23) interacts with activating transcription factor 5 (ATF5) protein and promotes proteasome- and caspase-dependent ATF5 degradation in hepatocellular carcinoma cells. J Biol Chem 2012; 287:19599-609. [PMID: 22528486 DOI: 10.1074/jbc.m112.363622] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Nucleophosmin (NPM1/B23) and the activating transcription factor 5 (ATF5) are both known to subject to cell type-dependent regulation. NPM1 is expressed weakly in hepatocytes and highly expressed in hepatocellular carcinomas (HCC) with a clear correlation between enhanced NPM1 expression and increased tumor grading and poor prognosis, whereas in contrast, ATF5 is expressed abundantly in hepatocytes and down-regulated in HCC. Re-expression of ATF5 in HCC inhibits cell proliferation. We report here that using an unbiased approach, tandem affinity purification (TAP) followed with mass spectrometry (MS), we identified NPM1 as a novel ATF5-interacting protein. Unlike many other NPM1-interacting proteins that interact with the N-terminal oligomerization domain of NPM1, ATF5 binds via its basic leucine zipper to the C-terminal region of NPM1 where its nucleolar localization signal is located. NPM1 association with ATF5, whose staining patterns partially overlap in the nucleoli, promotes ATF5 protein degradation through proteasome-dependent and caspase-dependent pathways. NPM1-c, a mutant NPM1 that is defective in nucleolar localization, failed to stimulate ATF5 polyubiquitination and was unable to down-regulate ATF5. NPM1 interaction with ATF5 displaces HSP70, a known ATF5-interacting protein, from ATF5 protein complexes and antagonizes its role in stabilization of ATF5 protein. NPM1-promoted ATF5 down-regulation diminished ATF5-mediated repression of cAMP-responsive element-dependent gene transcription and abrogates ATF5-induced G(2)/M cell cycle blockade and inhibition of cell proliferation in HCC cells. Our study establishes a mechanistic link between elevated NPM1 expression and depressed ATF5 in HCC and suggests that regulation of ATF5 by NPM1 plays an important role in the proliferation and survival of HCC.
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Affiliation(s)
- Xijun Liu
- Penn State College of Medicine, Hershey, Pennsylvania 17033, USA
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35
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Okuwaki M, Sumi A, Hisaoka M, Saotome-Nakamura A, Akashi S, Nishimura Y, Nagata K. Function of homo- and hetero-oligomers of human nucleoplasmin/nucleophosmin family proteins NPM1, NPM2 and NPM3 during sperm chromatin remodeling. Nucleic Acids Res 2012; 40:4861-78. [PMID: 22362753 PMCID: PMC3367197 DOI: 10.1093/nar/gks162] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Sperm chromatin remodeling after oocyte entry is the essential step that initiates embryogenesis. This reaction involves the removal of sperm-specific basic proteins and chromatin assembly with histones. In mammals, three nucleoplasmin/nucleophosmin (NPM) family proteins-NPM1, NPM2 and NPM3-expressed in oocytes are presumed to cooperatively regulate sperm chromatin remodeling. We characterized the sperm chromatin decondensation and nucleosome assembly activities of three human NPM proteins. NPM1 and NPM2 mediated nucleosome assembly independently of other NPM proteins, whereas the function of NPM3 was largely dependent on formation of a complex with NPM1. Maximal sperm chromatin remodeling activity of NPM2 required the inhibition of its non-specific nucleic acid-binding activity by phosphorylation. Furthermore, the oligomer formation with NPM1 elicited NPM3 nucleosome assembly and sperm chromatin decondensation activity. NPM3 also suppressed the RNA-binding activity of NPM1, which enhanced the nucleoplasm-nucleolus shuttling of NPM1 in somatic cell nuclei. Our results proposed a novel mechanism whereby three NPM proteins cooperatively regulate chromatin disassembly and assembly in the early embryo and in somatic cells.
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Affiliation(s)
- Mitsuru Okuwaki
- Faculty of Medicine and Graduate School of Comprehensive Human Sciences, Initiative for Promotion of Young Scientists' Independent Research, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan.
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36
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Castle CD, Cassimere EK, Denicourt C. LAS1L interacts with the mammalian Rix1 complex to regulate ribosome biogenesis. Mol Biol Cell 2012; 23:716-28. [PMID: 22190735 PMCID: PMC3279398 DOI: 10.1091/mbc.e11-06-0530] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 11/14/2011] [Accepted: 12/13/2011] [Indexed: 01/02/2023] Open
Abstract
The coordination of RNA polymerase I transcription with pre-rRNA processing, preribosomal particle assembly, and nuclear export is a finely tuned process requiring the concerted actions of a number of accessory factors. However, the exact functions of some of these proteins and how they assemble in subcomplexes remain poorly defined. LAS1L was first described as a nucleolar protein required for maturation of the 60S preribosomal subunit. In this paper, we demonstrate that LAS1L interacts with PELP1, TEX10, and WDR18, the mammalian homologues of the budding yeast Rix1 complex, along with NOL9 and SENP3, to form a novel nucleolar complex that cofractionates with the 60S preribosomal subunit. Depletion of LAS1L-associated proteins results in a p53-dependent G1 arrest and leads to defects in processing of the pre-rRNA internal transcribed spacer 2 region. We further show that the nucleolar localization of this complex requires active RNA polymerase I transcription and the small ubiquitin-like modifier-specific protease SENP3. Taken together, our data identify a novel mammalian complex required for 60S ribosomal subunit synthesis, providing further insight into the intricate, yet poorly described, process of ribosome biogenesis in higher eukaryotes.
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Affiliation(s)
- Christopher D. Castle
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030
| | - Erica K. Cassimere
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030
| | - Catherine Denicourt
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030
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Marquez-Lona EM, Tan Z, Schreiber SS. Nucleolar stress characterized by downregulation of nucleophosmin: a novel cause of neuronal degeneration. Biochem Biophys Res Commun 2011; 417:514-20. [PMID: 22166220 DOI: 10.1016/j.bbrc.2011.11.152] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 11/30/2011] [Indexed: 11/30/2022]
Abstract
Nucleophosmin (NPM) is a multifunctional nucleolar protein that has been linked with nucleolar stress. In non-neuronal cell lines, NPM may enhance or inhibit the activity of tumor suppressor p53, a major apoptotic protein. The relationship between NPM and p53 in the central nervous system (CNS) remains unknown. Here, we assessed the role of NPM in the CNS using a model of seizure-induced neurodegeneration. We show that NPM overexpression is neuroprotective against kainic acid-induced excitotoxicity, and that downregulation of NPM is pro-apoptotic in a p53-independent manner. These results suggest a key role for NPM in promoting neuronal survival and a novel mechanism of neuronal degeneration triggered by nucleolar stress.
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Wang QQ, Zhang ZY, Xiao JY, Yi C, Li LZ, Huang Y, Yun JP. Knockdown of nucleophosmin induces S-phase arrest in HepG2 cells. CHINESE JOURNAL OF CANCER 2011; 30:853-60. [PMID: 22098949 PMCID: PMC4013333 DOI: 10.5732/cjc.011.10362] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Nucleophosmin/B23 (NPM) is a universally expressed nucleolar phosphoprotein that participates in proliferation, apoptosis, ribosome assembly, and centrosome duplication; however, the role of NPM in cell cycle regulation is not well characterized. We investigated the mechanism by which NPM is involved in cell cycle regulation. NPM was knocked down using siRNA in HepG2 hepatoblastoma cells. NPM translocation following actinomycin D (ActD) treatment was investigated using immunofluorescent staining. Expression of NPM and other factors involved in cell cycle regulation was examined by Western blotting. Cell cycle distribution was measured using flow cytometry to detect 5-ethynyl-2'-deoxyuridine (EdU) incorporation. Cell proliferation was quantified by the MTT assay. Knockdown of NPM increased the percentage of HepG2 cells in S phase and led to decreased expression of P53 and P21Cip1/WAF1. S-phase arrest in HepG2 cells was significantly enhanced by ActD treatment. Furthermore, knockdown of NPM abrogated ActD-induced G2/M phase cell cycle arrest. Taken together, these data demonstrate that inhibition of NPM has a significant effect on the cell cycle.
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Affiliation(s)
- Qing-Qing Wang
- Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, People's Republic of China
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39
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Rimsza LM, Unger JM, Tome ME, Leblanc ML. A strategy for full interrogation of prognostic gene expression patterns: exploring the biology of diffuse large B cell lymphoma. PLoS One 2011; 6:e22267. [PMID: 21829609 PMCID: PMC3150354 DOI: 10.1371/journal.pone.0022267] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 06/21/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Gene expression profiling yields quantitative data on gene expression used to create prognostic models that accurately predict patient outcome in diffuse large B cell lymphoma (DLBCL). Often, data are analyzed with genes classified by whether they fall above or below the median expression level. We sought to determine whether examining multiple cut-points might be a more powerful technique to investigate the association of gene expression with outcome. METHODOLOGY/PRINCIPAL FINDINGS We explored gene expression profiling data using variable cut-point analysis for 36 genes with reported prognostic value in DLBCL. We plotted two-group survival logrank test statistics against corresponding cut-points of the gene expression levels and smooth estimates of the hazard ratio of death versus gene expression levels. To facilitate comparisons we also standardized the expression of each of the genes by the fraction of patients that would be identified by any cut-point. A multiple comparison adjusted permutation p-value identified 3 different patterns of significance: 1) genes with significant cut-point points below the median, whose loss is associated with poor outcome (e.g. HLA-DR); 2) genes with significant cut-points above the median, whose over-expression is associated with poor outcome (e.g. CCND2); and 3) genes with significant cut-points on either side of the median, (e.g. extracellular molecules such as FN1). CONCLUSIONS/SIGNIFICANCE Variable cut-point analysis with permutation p-value calculation can be used to identify significant genes that would not otherwise be identified with median cut-points and may suggest biological patterns of gene effects.
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Affiliation(s)
- Lisa M Rimsza
- Department of Pathology, University of Arizona, Tucson, Arizona, United States of America.
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40
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Motoi N, Hasebe T, Suzuki KIT, Ishizuya-Oka A. Spatiotemporal expression profile of no29/nucleophosmin3 in the intestine of Xenopus laevis during metamorphosis. Cell Tissue Res 2011; 344:445-53. [PMID: 21519897 DOI: 10.1007/s00441-011-1163-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 03/04/2011] [Indexed: 01/30/2023]
Abstract
A Xenopus laevis homolog of nucleophosmin/nucleoplasmin3 (NPM3), no29, has been previously identified as a thyroid hormone (TH)-response gene during TH-induced metamorphosis. X. laevis has another NPM3 homolog (npm3) in the pseudo-tetraploid genome, whereas X. tropicalis possesses one ortholog in the diploid genome. To assess the possible roles of these NPM3 homologs in amphibian metamorphosis, we have analyzed their expression profiles in X. laevis tadpoles. Levels of no29 and npm3 mRNA are rapidly up-regulated by exogenous TH in various organs of the premetamorphic tadpoles. Notably, in the small intestine, no29 and npm3 mRNA levels are transiently up-regulated during metamorphic climax, when progenitor/stem cells of the adult epithelium appear and actively proliferate. In situ hybridization analysis has revealed that the no29 transcript is specifically localized in adult epithelial progenitor/stem cells of the intestine during natural and TH-induced metamorphosis. Double-staining for in situ hybridization and immunohistochemistry has shown co-expression of no29 mRNA and no38 protein (an ortholog of NPM1), which is known to interact with NPM3 and to regulate cell proliferation in mammals. Thus, no29/npm3 might serve as a stem cell marker in the intestine during metamorphosis.
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Affiliation(s)
- Natsuki Motoi
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima, Hiroshima, 939-8526, Japan
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The Multifunctional Nucleolar Protein Nucleophosmin/NPM/B23 and the Nucleoplasmin Family of Proteins. THE NUCLEOLUS 2011. [PMCID: PMC7121557 DOI: 10.1007/978-1-4614-0514-6_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nucleophosmin (NPM)/nucleoplasmin family of nuclear chaperones has three members: NPM1, NPM2, and NPM3. Nuclear chaperones serve to ensure proper assembly of nucleosomes and proper formation of higher order structures of chromatin. In fact, this family of proteins has such diverse functions in cellular processes such as chromatin remodeling, ribosome biogenesis, genome stability, centrosome replication, cell cycle, transcriptional regulation, apoptosis, and tumor suppression. Of the members of this family, NPM1 is the most studied and is the main focus of this review. NPM2 and NPM3 are less well characterized, and are also discussed wherever appropriate. The structure–function relationship of NPM proteins has largely been worked out. Other than the many processes in which NPM1 takes part, the major interest comes from its involvement in human cancers, particularly acute myeloid leukemia (AML). Its significance stems from the fact that AML with mutated NPM1 accounts for ∼30% of all AML cases and usually has good prognosis. Its clinical importance also comes from its involvement in virus replication, particularly in the era of outbreaks of infectious diseases.
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NPM1/B23: A Multifunctional Chaperone in Ribosome Biogenesis and Chromatin Remodeling. Biochem Res Int 2010; 2011:195209. [PMID: 21152184 PMCID: PMC2989734 DOI: 10.1155/2011/195209] [Citation(s) in RCA: 226] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Accepted: 08/29/2010] [Indexed: 12/21/2022] Open
Abstract
At a first glance, ribosome biogenesis and chromatin remodeling are quite different processes, but they share a common problem involving interactions between charged nucleic acids and small basic proteins that may result in unwanted intracellular aggregations. The multifunctional nuclear acidic chaperone NPM1 (B23/nucleophosmin) is active in several stages of ribosome biogenesis, chromatin remodeling, and mitosis as well as in DNA repair, replication and transcription. In addition, NPM1 plays an important role in the Myc-ARF-p53 pathway as well as in SUMO regulation. However, the relative importance of NPM1 in these processes remains unclear. Provided herein is an update on the expanding list of the diverse activities and interacting partners of NPM1. Mechanisms of NPM1 nuclear export functions of NPM1 in the nucleolus and at the mitotic spindle are discussed in relation to tumor development. It is argued that the suggested function of NPM1 as a histone chaperone could explain several, but not all, of the effects observed in cells following changes in NPM1 expression. A future challenge is to understand how NPM1 is activated, recruited, and controlled to carry out its functions.
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Lessard F, Morin F, Ivanchuk S, Langlois F, Stefanovsky V, Rutka J, Moss T. The ARF Tumor Suppressor Controls Ribosome Biogenesis by Regulating the RNA Polymerase I Transcription Factor TTF-I. Mol Cell 2010; 38:539-50. [DOI: 10.1016/j.molcel.2010.03.015] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 02/24/2010] [Accepted: 03/25/2010] [Indexed: 11/29/2022]
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Gadad SS, Shandilya J, Kishore AH, Kundu TK. NPM3, a member of the nucleophosmin/nucleoplasmin family, enhances activator-dependent transcription. Biochemistry 2010; 49:1355-7. [PMID: 20073534 DOI: 10.1021/bi9021632] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The chromatin is comprised of repeating subunits that make up the nucleosome which is composed of an octamer of histones: H3, H4, H2A, and H2B. The replication-dependent and -independent nucleosome assembly occurs in an ordered fashion and is aided by cellular proteins such as histone chaperones and chromatin remodelers. Previously, we found that the histone chaperone NPM1 activates transcription from the chromatin template. Here we report that NPM3, a member of the nucleophosmin/nucleoplasmin family, lacks intrinsic histone chaperone activity, inhibits histone assembly activity of NPM1 in vitro, and dramatically enhances transcription in a cellular system.
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Affiliation(s)
- Shrikanth S Gadad
- Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
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45
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Falini B. Acute myeloid leukemia with mutated nucleophosmin (NPM1): molecular, pathological, and clinical features. Cancer Treat Res 2010; 145:149-168. [PMID: 20306250 DOI: 10.1007/978-0-387-69259-3_9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The NPM1 gene encodes for nucleophosmin, a nucleolus-located shuttling protein that is involved in multiple cell functions, including regulation of ribosome biogenesis, control of centrosome duplication and preservation of ARF tumor suppressor integrity. The NPM1 gene is specifically mutated in about 30% acute myeloid leukemia (AML) but not in other human neoplasms. Mutations cause crucial changes at the C-terminus of the NPM1 protein that are responsible for the aberrant nuclear export and accumulation of NPM1 mutants in the cytoplasm of leukemic cells. Diagnosis of AML with mutated NPM1 can be done using molecular techniques, immunohistochemistry (looking at cytoplasmic dislocation of nucleophosmin that is predictive of NPM1 mutations) and Western blotting with antibodies specifically directed against NPM1 mutants. Because of its distinctive molecular, pathological, immunophenotypic and prognostic features, AML with mutated NPM1 (synonym: NPMc+ AML) has been included, as a new provisional entity, in the 2008 World Health Organization (WHO) classification of myeloid neoplasms.
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46
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Meani N, Alcalay M. Role of nucleophosmin in acute myeloid leukemia. Expert Rev Anticancer Ther 2009; 9:1283-94. [PMID: 19761432 DOI: 10.1586/era.09.84] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nucleophosmin (NPM) is a nucleolar phosphoprotein implicated in the regulation of multiple cellular functions, which possesses both oncogenic and tumor-suppressor properties. Mutations of the NPM1 gene leading to the expression of a cytoplasmic mutant protein, NPMc+, are the most frequent genetic abnormalities found in acute myeloid leukemias. Acute myeloid leukemias with mutated NPM1 have distinct characteristics, including a significant association with a normal karyotype, involvement of different hematopoietic lineages, a specific gene-expression profile and clinically, a better response to induction therapy and a favorable prognosis. NPMc+ maintains the capacity of wild-type NPM to interact with a variety of cellular proteins, and impairs their activity by delocalizing them to the cytoplasm. In this review we summarize recent discoveries concerning NPM function, and discuss their possible impact on the pathogenesis of acute myeloid leukemias with mutated NPM1.
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Affiliation(s)
- Natalia Meani
- Istituto Europeo di Oncologia, IFOM-IEO Campus, Via Adamello 16, 20139 Milan, Italy.
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47
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Pradeepa MM, Nikhil G, Hari Kishore A, Bharath GN, Kundu TK, Rao MRS. Acetylation of transition protein 2 (TP2) by KAT3B (p300) alters its DNA condensation property and interaction with putative histone chaperone NPM3. J Biol Chem 2009; 284:29956-67. [PMID: 19710011 PMCID: PMC2785624 DOI: 10.1074/jbc.m109.052043] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 08/25/2009] [Indexed: 01/17/2023] Open
Abstract
The hallmark of mammalian spermiogenesis is the dramatic chromatin remodeling process wherein the nucleosomal histones are replaced by the transition proteins TP1, TP2, and TP4. Subsequently these transition proteins are replaced by the protamines P1 and P2. Hyperacetylation of histone H4 is linked to their replacement by transition proteins. Here we report that TP2 is acetylated in vivo as detected by anti-acetylated lysine antibody and mass spectrometric analysis. Further, recombinant TP2 is acetylated in vitro by acetyltransferase KAT3B (p300) more efficiently than by KAT2B (PCAF). In vivo p300 was demonstrated to acetylate TP2. p300 acetylates TP2 in its C-terminal domain, which is highly basic in nature and possesses chromatin-condensing properties. Mass spectrometric analysis showed that p300 acetylates four lysine residues in the C-terminal domain of TP2. Acetylation of TP2 by p300 leads to significant reduction in its DNA condensation property as studied by circular dichroism and atomic force microscopy analysis. TP2 also interacts with a putative histone chaperone, NPM3, wherein expression is elevated in haploid spermatids. Interestingly, acetylation of TP2 impedes its interaction with NPM3. Thus, acetylation of TP2 adds a new dimension to its role in the dynamic reorganization of chromatin during mammalian spermiogenesis.
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Affiliation(s)
- Madapura M. Pradeepa
- From the Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P. O., Bangalore 560064, India and
| | - Gupta Nikhil
- From the Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P. O., Bangalore 560064, India and
| | - Annavarapu Hari Kishore
- From the Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P. O., Bangalore 560064, India and
| | - Giriyapura N. Bharath
- From the Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P. O., Bangalore 560064, India and
| | - Tapas K. Kundu
- From the Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P. O., Bangalore 560064, India and
| | - Manchanahalli R. Satyanarayana Rao
- From the Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P. O., Bangalore 560064, India and
- the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
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Inoue A, Aoki F. Role of the nucleoplasmin 2 C-terminal domain in the formation of nucleolus-like bodies in mouse oocytes. FASEB J 2009; 24:485-94. [PMID: 19805576 DOI: 10.1096/fj.09-143370] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nucleolus-like bodies (NLBs) are characteristic structures found in the germinal vesicles of mammalian oocytes. Although these structures are essential for embryonic development, their composition, precise function, and mechanism of formation have not been elucidated. Here, we used immunoblotting and EGFP fusion protein fluorescence to demonstrate that murine nucleoplasmin 2 (NPM2) is a component of mouse NLBs and that the targeting of NPM2 to NLBs is regulated by a lysine-rich, 16-aa C-terminal motif (K-rich motif). When the K-rich motif was fused to another nuclear protein, MafG, the resultant fusion protein accumulated in NLBs but not in the nucleoli of somatic cells, suggesting that the K-rich motif functions to target NPM2 specifically to NLBs. To investigate the role of the K-rich motif in NLB formation, we replaced the endogenous NPM2 in growing oocytes with a mutant NPM2 protein lacking the K-rich motif (NPM2(C16del)). Growing oocytes surrounded by granulosa layers were coinjected with NPM2(C16del) mRNA and with small-interfering RNA targeting NPM2 (siNpm2), which was used to degrade the endogenous NPM2 mRNA. After culture in vitro, the NLBs in the resulting full-grown oocytes were significantly smaller than those in control oocytes that had been coinjected with siNpm2 and NPM2 mRNA, indicating that the K-rich motif is necessary for NLB development. Together, these results suggest that NPM2 targeting of NLBs is regulated by the K-rich motif and is essential for the formation of NLBs.
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Affiliation(s)
- Azusa Inoue
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8562, Japan
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Sheval EV, Dudnik OA, Abramchuk SS, Polyakov VY. Perichromosomal layer proteins associate with chromosome scaffold and nuclear matrix throughout the cell cycle. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2009. [DOI: 10.1134/s199074780902010x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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50
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Stepiński D. Immunodetection of nucleolar proteins and ultrastructure of nucleoli of soybean root meristematic cells treated with chilling stress and after recovery. PROTOPLASMA 2009; 235:77-89. [PMID: 19241118 DOI: 10.1007/s00709-009-0033-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Accepted: 01/19/2009] [Indexed: 05/03/2023]
Abstract
The nucleolar proteins, fibrillarin and nucleophosmin, have been identified immunofluorescently in the root meristematic cells of soybean seedlings under varying experimental conditions: at 25 degrees C (control), chilling at 10 degrees C for 3 h and 4 days and recovery from the chilling stress at 25 degrees C. In each experimental variant, the immunofluorescence signals were present solely at the nucleolar territories. Fluorescent staining for both proteins was mainly in the shape of circular domains that are assumed to correspond to the dense fibrillar component of the nucleoli. The fewest fluorescent domains were observed in the nucleoli of chilled plants, and the highest number was observed in the plants recovered after chilling. This difference in the number of circular domains in the nucleoli of each variant may indicate various levels of these proteins in each variant. Both the number of circular domains and the level of these nucleolar proteins changed with changes in the transcriptional activity of the nucleoli, with the more metabolically active cell having higher numbers of active areas in the nucleolus and higher levels of nucleolar proteins, and conversely. Electron microscopic studies revealed differences in the ultrastructure of the nucleoli in all experimental variants and confirmed that the number of fibrillar centres surrounded by dense fibrillar component was the lowest in the nucleoli of chilled plants, and the highest in the nucleoli of recovered seedlings.
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Affiliation(s)
- Dariusz Stepiński
- Department of Cytophysiology, University of Łódź, Pilarskiego 14, 90-231, Łódź, Poland.
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