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Liu W, Tang J, Gao W, Sun J, Liu G, Zhou J. PPP2R1B abolishes colorectal cancer liver metastasis and sensitizes Oxaliplatin by inhibiting MAPK/ERK signaling pathway. Cancer Cell Int 2024; 24:90. [PMID: 38429738 PMCID: PMC10908207 DOI: 10.1186/s12935-024-03273-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 02/15/2024] [Indexed: 03/03/2024] Open
Abstract
BACKGROUND Patients with colorectal cancer (CRC) with liver metastasis or drug resistance have a poor prognosis. Previous research has demonstrated that PPP2R1B inactivation results in the development of CRC. However, the role of PPP2R1B in CRC metastasis and drug resistance is unclear. METHODS Venny 2.1 was used to determine the intersection between survival-related differentially expressed genes (DEGs) and liver metastasis-related DEGs according to RNA-seq data from The Cancer Genome Atlas (TCGA) and the GEO database (GSE179979). LC‒MS/MS and coimmunoprecipitation were performed to predict and verify the substrate protein of PPP2R1B. Gene Set Variation Analysis (GSVA) was subsequently utilized to assess pathway enrichment levels. The predictive performance of PPP2R1B was assessed by regression analysis, Kaplan-Meier (KM) survival analysis and drug sensitivity analysis. Immunohistochemistry (IHC), qRT-PCR and western blotting were performed to measure the expression levels of related mRNAs or proteins. Biological features were evaluated by wound healing, cell migration and invasion assays and CCK-8 assays. A mouse spleen infection liver metastasis model was generated to confirm the role of PPP2R1B in the progression of liver metastasis in vivo. RESULTS According to bioinformatics analysis, PPP2R1B is significantly associated with liver metastasis and survival in CRC patients, and these findings were further verified via immunohistochemistry (IHC), qPCR and Western blotting. Pathway enrichment and LC‒MS/MS analysis revealed that PPP2R1B is negatively associated with the MAPK/ERK signalling pathway. Additionally, PD98059, a MAPK/ERK pathway inhibitor, inhibited EMT in vitro by reversing the changes in key proteins involved in EMT signalling (ZEB1, E-cadherin and Snail) and ERK/MAPK signalling (p-ERK) mediated by PPP2R1B. Oxaliplatin sensitivity prediction and validation revealed that PPP2R1B silencing decreased Oxaliplatin chemosensitivity, and these effects were reversed by PD98059 treatment. Moreover, PPP2R1B was coimmunoprecipitated with p-ERK in vitro. A negative correlation between PPP2R1B and p-ERK expression was also observed in clinical CRC samples, and the low PPP2R1B/high p-ERK coexpression pattern indicated a poor prognosis in CRC patients. In vivo, PPP2R1B silencing significantly promoted liver metastasis. CONCLUSIONS This study revealed that PPP2R1B induces dephosphorylation of the p-ERK protein, inhibits liver metastasis and increases Oxaliplatin sensitivity in CRC patients and could be a potential candidate for therapeutic application in CRC.
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Affiliation(s)
- Wei Liu
- Department of Gastrointestinal Surgery, The First Hospital of China Medical University, Nanjing Street 155, Shenyang, 110001, China
- Department of General Surgery, Daqing Oilfield General Hospital, Daqing, 163000, China
| | - Jingtong Tang
- Department of Gastrointestinal Surgery, The First Hospital of China Medical University, Nanjing Street 155, Shenyang, 110001, China
- Shenyang Medical Nutrition Clinical Medical Research Center, Shenyang, China
| | - Wei Gao
- Department of Gastrointestinal Surgery, The First Hospital of China Medical University, Nanjing Street 155, Shenyang, 110001, China
- Shenyang Medical Nutrition Clinical Medical Research Center, Shenyang, China
| | - Jian Sun
- Department of Gastrointestinal Surgery, The First Hospital of China Medical University, Nanjing Street 155, Shenyang, 110001, China
- Shenyang Medical Nutrition Clinical Medical Research Center, Shenyang, China
| | - Gang Liu
- Department of Gastrointestinal Surgery, The First Hospital of China Medical University, Nanjing Street 155, Shenyang, 110001, China
- Shenyang Medical Nutrition Clinical Medical Research Center, Shenyang, China
| | - Jianping Zhou
- Department of Gastrointestinal Surgery, The First Hospital of China Medical University, Nanjing Street 155, Shenyang, 110001, China.
- Shenyang Medical Nutrition Clinical Medical Research Center, Shenyang, China.
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Jiang SL, Wang ZB, Zhu T, Jiang T, Fei JF, Liu C, Luo C, Cheng Y, Liu ZQ. The Downregulation of eIF3a Contributes to Vemurafenib Resistance in Melanoma by Activating ERK via PPP2R1B. Front Pharmacol 2021; 12:720619. [PMID: 34512348 PMCID: PMC8430041 DOI: 10.3389/fphar.2021.720619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/12/2021] [Indexed: 12/25/2022] Open
Abstract
Vemurafenib, a BRAF V600E inhibitor, provides therapeutic benefits for patients with melanoma, but the frequent emergence of drug resistance remains a challenge. An understanding of the mechanisms underlying vemurafenib resistance may generate novel therapeutic strategies for patients with melanoma. Here, we showed that eIF3a, a translational regulatory protein, was an important mediator involved in vemurafenib resistance. eIF3a was expressed at significantly lower levels in vemurafenib-resistant A375 melanoma cells (A375R) than in parental A375 cells. Overexpression of eIF3a enhanced the sensitivity to BRAF inhibitors by reducing p-ERK levels. Furthermore, eIF3a controlled ERK activity by regulating the expression of the phosphatase PPP2R1B via a translation mechanism, thus determining the sensitivity of melanoma cells to vemurafenib. In addition, a positive correlation between eIF3a and PPP2R1B expression was also observed in tumor samples from the Human Protein Atlas and TCGA databases. In conclusion, our studies reveal a previously unknown molecular mechanism of BRAF inhibitor resistance, which may provide a new strategy for predicting vemurafenib responses in clinical treatment.
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Affiliation(s)
- Shi-Long Jiang
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Engineering Research Center for Applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha, China
| | - Zhi-Bin Wang
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Engineering Research Center for Applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha, China
| | - Tao Zhu
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Engineering Research Center for Applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha, China
| | - Ting Jiang
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China
| | | | - Chong Liu
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Engineering Research Center for Applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha, China
| | - Chao Luo
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Shanghai Mental Health Center, Shanghai JiaoTong University School of Medicine, Shanghai, China
| | - Yan Cheng
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Zhao-Qian Liu
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Engineering Research Center for Applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha, China
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3
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Remmerie M, Janssens V. PP2A: A Promising Biomarker and Therapeutic Target in Endometrial Cancer. Front Oncol 2019; 9:462. [PMID: 31214504 PMCID: PMC6558005 DOI: 10.3389/fonc.2019.00462] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 05/14/2019] [Indexed: 12/14/2022] Open
Abstract
Over the last decade, the use of targeted therapies has immensely increased in the treatment of cancer. However, treatment for endometrial carcinomas (ECs) has lagged behind, although potential molecular markers have been identified. This is particularly problematic for the type II ECs, since these aggressive tumors are usually not responsive toward the current standard therapies. Therefore, type II ECs are responsible for most EC-related deaths, indicating the need for new treatment options. Interestingly, molecular analyses of type II ECs have uncovered frequent genetic alterations (up to 40%) in PPP2R1A, encoding the Aα subunit of the tumor suppressive heterotrimeric protein phosphatase type 2A (PP2A). PPP2R1A mutations were also reported in type I ECs and other common gynecologic cancers, albeit at much lower frequencies (0-7%). Nevertheless, PP2A inactivation in the latter cancer types is common via other mechanisms, in particular by increased expression of Cancerous Inhibitor of PP2A (CIP2A) and PP2A Methylesterase-1 (PME-1) proteins. In this review, we discuss the therapeutic potential of direct and indirect PP2A targeting compounds, possibly in combination with other anti-cancer drugs, in EC. Furthermore, we investigate the potential of the PP2A status as a predictive and/or prognostic marker for type I and II ECs.
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Affiliation(s)
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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Grassi E, Santoro R, Umbach A, Grosso A, Oliviero S, Neri F, Conti L, Ala U, Provero P, DiCunto F, Merlo GR. Choice of Alternative Polyadenylation Sites, Mediated by the RNA-Binding Protein Elavl3, Plays a Role in Differentiation of Inhibitory Neuronal Progenitors. Front Cell Neurosci 2019; 12:518. [PMID: 30687010 PMCID: PMC6338052 DOI: 10.3389/fncel.2018.00518] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/12/2018] [Indexed: 01/09/2023] Open
Abstract
Alternative polyadenylation (APA) is a widespread mechanism involving about half of the expressed genes, resulting in varying lengths of the 3′ untranslated region (3′UTR). Variations in length and sequence of the 3′UTR may underlie changes of post-transcriptional processing, localization, miRNA targeting and stability of mRNAs. During embryonic development a large array of mRNAs exhibit APA, with a prevalence of the longer 3′UTR versions in differentiating cells. Little is known about polyA+ site usage during differentiation of mammalian neural progenitors. Here we exploit a model of adherent neural stem (ANS) cells, which homogeneously and efficiently differentiate into GABAergic neurons. RNAseq data shows a global trend towards lengthening of the 3′UTRs during differentiation. Enriched expression of the longer 3′UTR variants of Pes1 and Gng2 was detected in the mouse brain in areas of cortical and subcortical neuronal differentiation, respectively, by two-probes fluorescent in situ hybridization (FISH). Among the coding genes upregulated during differentiation of ANS cells we found Elavl3, a neural-specific RNA-binding protein homologous to Drosophila Elav. In the insect, Elav regulates polyA+ site choice while interacting with paused Pol-II promoters. We tested the role of Elavl3 in ANS cells, by silencing Elavl3 and observed consistent changes in 3′UTR length and delayed neuronal differentiation. These results indicate that choice of the polyA+ site and lengthening of 3′UTRs is a possible additional mechanism of posttranscriptional RNA modification involved in neuronal differentiation.
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Affiliation(s)
- Elena Grassi
- Department of Molecular Biotechnology, University of Turin, Turin, Italy
| | - Roberto Santoro
- Department of Molecular Biotechnology, University of Turin, Turin, Italy
| | - Alessandro Umbach
- Department of Molecular Biotechnology, University of Turin, Turin, Italy
| | - Anna Grosso
- Department of Neurosciences, University of Turin, Turin, Italy
| | - Salvatore Oliviero
- Italian Institute for Genomic Medicine, Turin, Italy.,Department of Life Science and System Biology, University of Turin, Turin, Italy
| | - Francesco Neri
- Italian Institute for Genomic Medicine, Turin, Italy.,Department of Life Science and System Biology, University of Turin, Turin, Italy
| | - Luciano Conti
- Centre for Integrative Biology-CIBIO, University of Trento, Povo, Italy
| | - Ugo Ala
- Department of Molecular Biotechnology, University of Turin, Turin, Italy
| | - Paolo Provero
- Department of Molecular Biotechnology, University of Turin, Turin, Italy
| | - Ferdinando DiCunto
- Department of Molecular Biotechnology, University of Turin, Turin, Italy.,Department of Neurosciences, University of Turin, Turin, Italy
| | - Giorgio R Merlo
- Department of Molecular Biotechnology, University of Turin, Turin, Italy
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Chen YC, Ke WC, Chiu HW. Risk classification of cancer survival using ANN with gene expression data from multiple laboratories. Comput Biol Med 2014; 48:1-7. [PMID: 24631783 DOI: 10.1016/j.compbiomed.2014.02.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 01/16/2014] [Accepted: 02/13/2014] [Indexed: 01/28/2023]
Abstract
Numerous cancer studies have combined gene expression experiments and clinical survival data to predict the prognosis of patients of specific gene types. However, most results of these studies were data dependent and were not suitable for other data sets. This study performed cross-laboratory validations for the cancer patient data from 4 hospitals. We investigated the feasibility of survival risk predictions using high-throughput gene expression data and clinical data. We analyzed multiple data sets for prognostic applications in lung cancer diagnosis. After building tens of thousands of various ANN architectures using the training data, five survival-time correlated genes were identified from 4 microarray gene expression data sets by examining the correlation between gene signatures and patient survival time. The experimental results showed that gene expression data can be used for valid predictions of cancer patient survival classification with an overall accuracy of 83.0% based on survival time trusted data. The results show the prediction model yielded excellent predictions given that patients in the high-risk group obtained a lower median overall survival compared with low-risk patients (log-rank test P-value<0.00001). This study provides a foundation for further clinical studies and research into other types of cancer. We hope these findings will improve the prognostic methods of cancer patients.
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Affiliation(s)
- Yen-Chen Chen
- Graduate Institute of Biomedical Informatics, Taipei Medical University, 250 Wu-Hsing Street, Taipei City, Taiwan
| | - Wan-Chi Ke
- Graduate Institute of Biomedical Informatics, Taipei Medical University, 250 Wu-Hsing Street, Taipei City, Taiwan
| | - Hung-Wen Chiu
- Graduate Institute of Biomedical Informatics, Taipei Medical University, 250 Wu-Hsing Street, Taipei City, Taiwan.
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Stebbing J, Lit LC, Zhang H, Darrington RS, Melaiu O, Rudraraju B, Giamas G. The regulatory roles of phosphatases in cancer. Oncogene 2014; 33:939-53. [PMID: 23503460 DOI: 10.1038/onc.2013.80] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 02/01/2013] [Indexed: 02/06/2023]
Abstract
The relevance of potentially reversible post-translational modifications required for controlling cellular processes in cancer is one of the most thriving arenas of cellular and molecular biology. Any alteration in the balanced equilibrium between kinases and phosphatases may result in development and progression of various diseases, including different types of cancer, though phosphatases are relatively under-studied. Loss of phosphatases such as PTEN (phosphatase and tensin homologue deleted on chromosome 10), a known tumour suppressor, across tumour types lends credence to the development of phosphatidylinositol 3-kinase inhibitors alongside the use of phosphatase expression as a biomarker, though phase 3 trial data are lacking. In this review, we give an updated report on phosphatase dysregulation linked to organ-specific malignancies.
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Affiliation(s)
- J Stebbing
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
| | - L C Lit
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
| | - H Zhang
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
| | - R S Darrington
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
| | - O Melaiu
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
| | - B Rudraraju
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
| | - G Giamas
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
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WANG FENG, ZOU YANG, LIU FAYING, YU XIAOHONG, HUANG HUANG, ZHANG NAN, QI YINGYING, LIU RONGFANG, LIU XIAOYAN, CHEN JIA, HUANG OUPING, HE MING. Infrequent mutations of the PPP2R1A and PPP2R1B genes in patients with ovarian cancer. Mol Med Rep 2013; 7:1826-30. [DOI: 10.3892/mmr.2013.1416] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 03/27/2013] [Indexed: 11/06/2022] Open
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8
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Arnold HK, Sears RC. A tumor suppressor role for PP2A-B56alpha through negative regulation of c-Myc and other key oncoproteins. Cancer Metastasis Rev 2008; 27:147-58. [PMID: 18246411 DOI: 10.1007/s10555-008-9128-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Loss or inhibition of the serine/threonine protein phosphatase 2A (PP2A) has revealed a critical tumor suppressor function for PP2A. However, PP2A has also been shown to have important roles in cell cycle progression and survival. Therefore, PP2A is not a typical tumor suppressor. This is most likely due to the fact that PP2A represents a large number of different holoenzymes. Further understanding of PP2A function(s), and especially its tumor suppressor activity, will depend largely on our ability to determine specific targets for these different PP2A holoenzymes and to gain an understanding of how these targets confer tumor suppressor activity or contribute to cell cycle progression and cell survival. Recent work has identified c-Myc as a target of the PP2A holoenzyme, PP2A-B56alpha. This holoenzyme also negatively regulates beta-catenin expression and modulates the anti-apoptotic activity of Bcl2, thus characterizing PP2A-B56alpha as a tumor suppressor PP2A holoenzyme. This review will focus on the role of PP2A-B56alpha in regulating c-Myc and will place this tumor suppressor activity of PP2A within the context of its other tumor suppressor functions. Finally, the mechanism(s) through which PP2A-B56alpha tumor suppressor activity may be lost in cancer will be discussed.
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Affiliation(s)
- Hugh K Arnold
- Department of Molecular and Medical Genetics, Oregon Health & Sciences University, Portland, OR 97239, USA
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