1
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Shen J, He Y, Li S, Chen H. Crosstalk of methylation and tamoxifen in breast cancer (Review). Mol Med Rep 2024; 30:180. [PMID: 39129315 PMCID: PMC11338244 DOI: 10.3892/mmr.2024.13304] [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: 06/02/2024] [Accepted: 07/23/2024] [Indexed: 08/13/2024] Open
Abstract
Tamoxifen is a widely used anti‑estrogen drug in the endocrine therapy of breast cancer (BC). It blocks estrogen signaling by competitively binding to estrogen receptor α (ERα), thereby inhibiting the growth of BC cells. However, with the long‑term application of tamoxifen, a subset of patients with BC have shown resistance to tamoxifen, which leads to low overall survival and progression‑free survival. The molecular mechanism of resistance is mainly due to downregulation of ERα expression and abnormal activation of the PI3K/AKT/mTOR signaling pathway. Moreover, the downregulation of targeted gene expression mediated by DNA methylation is an important regulatory mode to control protein expression. In the present review, methylation and tamoxifen are briefly introduced, followed by a focus on the effect of methylation on tamoxifen resistance and sensitivity. Finally, the clinical application of methylation for tamoxifen is described, including its use as a prognostic indicator. Finally, it is hypothesized that when methylation is used in combination with tamoxifen, it could recover the resistance of tamoxifen.
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Affiliation(s)
- Jin Shen
- Department of Rehabilitation, The Affiliated Zhuzhou Hospital of Xiangya Medical College, Central South University, Zhuzhou, Hunan 412000, P.R. China
| | - Yan He
- Department of Neurology, The Affiliated Zhuzhou Hospital of Xiangya Medical College, Central South University, Zhuzhou, Hunan 412000, P.R. China
| | - Shengpeng Li
- Department of Rehabilitation, The Affiliated Zhuzhou Hospital of Xiangya Medical College, Central South University, Zhuzhou, Hunan 412000, P.R. China
| | - Huimin Chen
- Department of Rehabilitation, The Affiliated Zhuzhou Hospital of Xiangya Medical College, Central South University, Zhuzhou, Hunan 412000, P.R. China
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2
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Zhou Y, Yao Z, Lin Y, Zhang H. From Tyrosine Kinases to Tyrosine Phosphatases: New Therapeutic Targets in Cancers and Beyond. Pharmaceutics 2024; 16:888. [PMID: 39065585 PMCID: PMC11279542 DOI: 10.3390/pharmaceutics16070888] [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: 04/25/2024] [Revised: 06/20/2024] [Accepted: 06/27/2024] [Indexed: 07/28/2024] Open
Abstract
Protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs) regulate the level of tyrosine phosphorylation in proteins. PTKs are key enzymes that catalyze the transfer of an ATP phosphoric acid to a tyrosine residue on target protein substrates. Protein tyrosine phosphatases (PTPs) are responsible for the dephosphorylation of tyrosine residues and play a role in countering PTK overactivity. As widespread oncogenes, PTKs were once considered to be promising targets for therapy. However, tyrosine kinase inhibitors (TKIs) now face a number of challenges, including drug resistance and toxic side effects. Treatment strategies now need to be developed from a new perspective. In this review, we assess the current state of TKIs and highlight the role of PTPs in cancer and other diseases. With the advances of allosteric inhibition and the development of multiple alternative proprietary drug strategies, the reputation of PTPs as "undruggable" targets has been overturned, and they are now considered viable therapeutic targets. We also discuss the strategies and prospects of PTP-targeted therapy, as well as its future development.
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Affiliation(s)
- Yu Zhou
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, MOE Key Laboratory of Tumor Molecular Biology, and Institute of Precision Cancer Medicine and Pathology, School of Medicine, Jinan University, Guangzhou 510632, China; (Y.Z.); (Z.Y.); (Y.L.)
| | - Zhimeng Yao
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, MOE Key Laboratory of Tumor Molecular Biology, and Institute of Precision Cancer Medicine and Pathology, School of Medicine, Jinan University, Guangzhou 510632, China; (Y.Z.); (Z.Y.); (Y.L.)
- Department of Urology Surgery, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou 510660, China
| | - Yusheng Lin
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, MOE Key Laboratory of Tumor Molecular Biology, and Institute of Precision Cancer Medicine and Pathology, School of Medicine, Jinan University, Guangzhou 510632, China; (Y.Z.); (Z.Y.); (Y.L.)
- Department of Thoracic Surgery, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou 510660, China
| | - Hao Zhang
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, MOE Key Laboratory of Tumor Molecular Biology, and Institute of Precision Cancer Medicine and Pathology, School of Medicine, Jinan University, Guangzhou 510632, China; (Y.Z.); (Z.Y.); (Y.L.)
- Department of Pathology, Gongli Hospital of Shanghai Pudong New Area, Shanghai 200135, China
- Zhuhai Institute of Jinan University, Zhuhai 511436, China
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3
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Dai W, Xiang W, Han L, Yuan Z, Wang R, Ma Y, Yang Y, Cai S, Xu Y, Mo S, Li Q, Cai G. PTPRO represses colorectal cancer tumorigenesis and progression by reprogramming fatty acid metabolism. CANCER COMMUNICATIONS (LONDON, ENGLAND) 2022; 42:848-867. [PMID: 35904817 PMCID: PMC9456702 DOI: 10.1002/cac2.12341] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 03/22/2022] [Accepted: 07/11/2022] [Indexed: 01/17/2023]
Abstract
BACKGROUND Abnormal expression of protein tyrosine phosphatases (PTPs) has been reported to be a crucial cause of cancer. As a member of PTPs, protein tyrosine phosphatase receptor type O (PTPRO) has been revealed to play tumor suppressive roles in several cancers, while its roles in colorectal cancer (CRC) remains to be elucidated. Hence, we aimed to explore the roles and mechanisms of PTPRO in CRC initiation and progression. METHODS The influences of PTPRO on the growth and liver metastasis of CRC cells and the expression patterns of different lipid metabolism enzymes were evaluated in vitro and in vivo. Molecular and biological experiments were conducted to uncover the underpinning mechanisms of dysregulated de novo lipogenesis and fatty acid β-oxidation. RESULTS PTPRO expression was notably downregulated in CRC liver metastasis compared to the primary cancer, and such a downregulation was associated with poor prognosis of patients with CRC. PTPRO silencing significantly promoted cell growth and liver metastasis. Compared with PTPRO wild-type mice, PTPRO-knockout mice developed more tumors and harbored larger tumor loads under treatment with azoxymethane and dextran sulfate sodium. Gene set enrichment analysis revealed that PTPRO downregulation was significantly associated with the fatty acid metabolism pathways. Blockage of fatty acid synthesis abrogated the effects of PTPRO silencing on cell growth and liver metastasis. Further experiments indicated that PTPRO silencing induced the activation of the AKT serine/threonine kinase (AKT)/mammalian target of rapamycin (mTOR) signaling axis, thus promoting de novo lipogenesis by enhancing the expression of sterol regulatory element-binding protein 1 (SREBP1) and its target lipogenic enzyme acetyl-CoA carboxylase alpha (ACC1) by activating the AKT/mTOR signaling pathway. Furthermore, PTPRO attenuation decreased the fatty acid oxidation rate by repressing the expression of peroxisome proliferator-activated receptor alpha (PPARα) and its downstream enzyme peroxisomal acyl-coenzyme A oxidase 1 (ACOX1) via activating the p38/extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) signaling pathway. CONCLUSIONS PTPRO could suppress CRC development and metastasis via modulating the AKT/mTOR/SREBP1/ACC1 and MAPK/PPARα/ACOX1 pathways and reprogramming lipid metabolism.
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Affiliation(s)
- Weixing Dai
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China
| | - Wenqiang Xiang
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China
| | - Lingyu Han
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China
| | - Zixu Yuan
- Department of Surgery, Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 528406, P. R. China
| | - Renjie Wang
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China
| | - Yanlei Ma
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China
| | - Yongzhi Yang
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China
| | - Sanjun Cai
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China
| | - Ye Xu
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China
| | - Shaobo Mo
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China
| | - Qingguo Li
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China
| | - Guoxiang Cai
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China
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4
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Dong H, Du L, Cai S, Lin W, Chen C, Still M, Yao Z, Coppes RP, Pan Y, Zhang D, Gao S, Zhang H. Tyrosine Phosphatase PTPRO Deficiency in ERBB2-Positive Breast Cancer Contributes to Poor Prognosis and Lapatinib Resistance. Front Pharmacol 2022; 13:838171. [PMID: 35431974 PMCID: PMC9010868 DOI: 10.3389/fphar.2022.838171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 03/07/2022] [Indexed: 02/05/2023] Open
Abstract
Despite the initial benefit from treating ERBB2-positive breast cancer with tyrosine kinase inhibitor lapatinib, resistance develops inevitably. Since the expression of protein tyrosine phosphatase receptor-type O (PTPRO), a member of the R3 subfamily of receptor protein tyrosine phosphatases (PTPs), is inversely correlated with the aggressiveness of multiple malignancies, we decided to explore the correlation between PTPRO and lapatinib resistance in ERBB2-positive breast cancer. Results of immunohistochemical (IHC) staining and the correlation analysis between the expression levels of PTPRO and the clinicopathological parameters indicate that PTPRO is downregulated in cancer tissues as compared with normal tissues and negatively associated with differentiation, tumor size, tumor depth, as well as the expression of ERBB2 and Ki67. Results from Kaplan-Meier analyses indicate that lower expression of PTPRO is correlated with shorter relapse-free survival for patients with ERBB2-positive breast cancer, and multivariable Cox regression analysis found that PTPRO can potentially serve as an independent prognostic indicator for ERBB2-positive breast cancer. Results from both human breast cancer cells with PTPRO knockdown or overexpression and mouse embryonic fibroblasts (MEFs) which derived from Ptpro +/+ and Ptpro -/- mice with then stably transfected plasmid FUGW-Erbb2 consistently demonstrated the essentiality of PTPRO in the lapatinib-mediated anticancer process. Our findings suggest that PTPRO is not only able to serve as an independent prognostic indicator, but upregulating PTPRO can also reverse the lapatinib resistance of ERBB2-positive breast cancer.
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Affiliation(s)
- Hongmei Dong
- Institute of Precision Cancer Medicine and Pathology, School of Medicine, Department of General Surgery, The First Affiliated Hospital of Jinan University, Minister of Education Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, China
| | - Liang Du
- Institute of Precision Cancer Medicine and Pathology, School of Medicine, Department of General Surgery, The First Affiliated Hospital of Jinan University, Minister of Education Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, China
- Departments of Biomedical Sciences of Cells and Systems, Section Molecular Cell Biology and Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Graduate School, Shantou University Medical College, Shantou, China
| | - Songwang Cai
- Department of Thoracic Surgery, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Wan Lin
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - Chaoying Chen
- Graduate School, Shantou University Medical College, Shantou, China
- Department of Clinical Laboratory, The First Affiliated Hospital of Hunan Traditional Chinese Medical College (Hunan Province Directly Affiliated TCM Hospital), Zhuzhou, China
| | - Matthew Still
- Department of Bio-Medical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, United States
| | - Zhimeng Yao
- Institute of Precision Cancer Medicine and Pathology, School of Medicine, Department of General Surgery, The First Affiliated Hospital of Jinan University, Minister of Education Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, China
| | - Robert P. Coppes
- Departments of Biomedical Sciences of Cells and Systems, Section Molecular Cell Biology and Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Yunlong Pan
- Department of General Surgery, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Dianzheng Zhang
- Department of Bio-Medical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, United States
| | - Shegan Gao
- Henan Key Laboratory of Microbiome and Esophageal Cancer Prevention and Treatment, Henan Key Laboratory of Cancer Epigenetics, Cancer Hospital, The First Affiliated Hospital (College of Clinical Medicine) of Henan University of Science and Technology, Luoyang, China
- *Correspondence: Hao Zhang, ; Shegan Gao,
| | - Hao Zhang
- Department of General Surgery, The First Affiliated Hospital of Jinan University, Institute of Precision Cancer Medicine and Pathology, School of Medicine, Minister of Education Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, China
- *Correspondence: Hao Zhang, ; Shegan Gao,
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5
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Jin K, Liu Y, Shi Y, Zhang H, Sun Y, Zhangyuan G, Wang F, Yu W, Wang J, Tao X, Chen X, Zhang W, Sun B. PTPROt aggravates inflammation by enhancing NF-κB activation in liver macrophages during nonalcoholic steatohepatitis. Am J Cancer Res 2020; 10:5290-5304. [PMID: 32373213 PMCID: PMC7196286 DOI: 10.7150/thno.42658] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/16/2020] [Indexed: 01/02/2023] Open
Abstract
Rationale: Inflammation plays a crucial role in the progression of nonalcoholic steatohepatitis (NASH). Protein tyrosine phosphatase receptor type O truncated isoform (PTPROt) is an integral membrane protein that has been identified in osteoclasts, macrophages, and B lymphocytes. However, its relationship between inflammation and NASH is largely unknown. Herein, we aimed to study the function of PTPROt in NASH progression. Methods: We established a NASH mouse model in wild-type (WT), PTPRO knockout mice by western diet (WD) and methionine-choline-deficient diet (MCD). In addition, MCD-induced NASH model was established in BMT mice. Moreover, we determined the expression of PTPROt in liver macrophages in human subjects without steatosis, with simple steatosis, and with NASH to confirm the relationship between PTPROt and NASH. In vitro assays were also performed to study the molecular role of PTPROt in NASH progression. Results: Human samples and animal model results illustrated that PTPROt is increased in liver macrophages during NASH progression and is positively correlated with the degree of NASH. Our animal model also showed that PTPROt in liver macrophages can enhance the activation of the NF-κB signaling pathway, which induces the transcription of genes involved in the inflammatory response. Moreover, PTPROt promotes the transcription of pro-oxidant genes and inhibits antioxidant and protective genes via increased activation of the NF-κB signaling pathway, thereby causing an increased level of reactive oxygen species (ROS) and damaged mitochondria. This triggers the NLRP3-IL1β axis and causes a heightened inflammatory response. Notably, PTPROt partially limits inflammation and ROS production by promoting mitophagy, which participates in a negative feedback loop in this model. Conclusions: Our data strongly indicate that PTPROt plays a dual role in inflammation via the NF-κB signaling pathway in liver macrophages during NASH. Further studies are required to explore therapeutic strategies and prevention of this common liver disease through PTPROt.
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6
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Lee S, Liang X, Woods M, Reiner AS, Concannon P, Bernstein L, Lynch CF, Boice JD, Deasy JO, Bernstein JL, Oh JH. Machine learning on genome-wide association studies to predict the risk of radiation-associated contralateral breast cancer in the WECARE Study. PLoS One 2020; 15:e0226157. [PMID: 32106268 PMCID: PMC7046218 DOI: 10.1371/journal.pone.0226157] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 11/20/2019] [Indexed: 01/13/2023] Open
Abstract
The purpose of this study was to identify germline single nucleotide polymorphisms (SNPs) that optimally predict radiation-associated contralateral breast cancer (RCBC) and to provide new biological insights into the carcinogenic process. Fifty-two women with contralateral breast cancer and 153 women with unilateral breast cancer were identified within the Women’s Environmental Cancer and Radiation Epidemiology (WECARE) Study who were at increased risk of RCBC because they were ≤ 40 years of age at first diagnosis of breast cancer and received a scatter radiation dose > 1 Gy to the contralateral breast. A previously reported algorithm, preconditioned random forest regression, was applied to predict the risk of developing RCBC. The resulting model produced an area under the curve (AUC) of 0.62 (p = 0.04) on hold-out validation data. The biological analysis identified the cyclic AMP-mediated signaling and Ephrin-A as significant biological correlates, which were previously shown to influence cell survival after radiation in an ATM-dependent manner. The key connected genes and proteins that are identified in this analysis were previously identified as relevant to breast cancer, radiation response, or both. In summary, machine learning/bioinformatics methods applied to genome-wide genotyping data have great potential to reveal plausible biological correlates associated with the risk of RCBC.
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Affiliation(s)
- Sangkyu Lee
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America
| | - Xiaolin Liang
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America
| | - Meghan Woods
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America
| | - Anne S. Reiner
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America
| | - Patrick Concannon
- Genetics Institute and Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, United States of America
| | - Leslie Bernstein
- Department of Population Sciences, Beckman Research Institute of the City of Hope, Duarte, CA, United States of America
| | - Charles F. Lynch
- Department of Epidemiology, The University of Iowa, Iowa City, IA, United States of America
| | - John D. Boice
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Joseph O. Deasy
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America
| | - Jonine L. Bernstein
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America
| | - Jung Hun Oh
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States of America
- * E-mail:
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7
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Ren W, Yi H, Bao Y, Liu Y, Gao X. Oestrogen inhibits PTPRO to prevent the apoptosis of renal podocytes. Exp Ther Med 2019; 17:2373-2380. [PMID: 30783489 DOI: 10.3892/etm.2019.7167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Accepted: 11/07/2018] [Indexed: 12/20/2022] Open
Abstract
Podocytes are a major component of the glomerular filtration membrane, and their apoptosis is involved in a variety of nephrotic syndromes. In the current study, the effects and molecular mechanisms of oestrogen on the proliferation and apoptosis of podocytes were investigated to elucidate the role of oestrogen in the pathogenesis of childhood nephrotic syndrome. The cell proliferation of mouse renal podocytes (MPC-5) and human primary renal podocytes was promoted by 17β-oestradiol (E2) in what appear to be a time-dependent manner. Apoptosis was inhibited by E2 and promoted by the E2 antagonist, tamoxifen. The expression of protein tyrosine phosphatase receptor type O (PTPRO) decreased with the increasing dosage of E2, but increased with the increasing dosage tamoxifen in MPC-5 and human podocytes. The protein, oestrogen receptor (ER)α, was not expressed in MPC-5 and human podocytes. E2 binding to ERβ completely eliminated PTPRO expression in MPC-5. In podocytes, PTPRO was phosphorylated by E2 at the Y1007 and associated with tyrosine-protein kinase JAK2 (JAK2) activation, rather than JAK1 activation. PTPRO was involved in the binding of E2 to signal transducer and activator of transcription (STAT)3 at the Y705 and S727 sites, resulting in the phosphorylation of STAT3 in podocytes. Through PTPRO, E2 also regulated the proliferation and apoptosis of podocytes. In conclusion, oestrogen binding to ERβ, rather than ERα, promoted the proliferation of podocytes and inhibited the apoptosis of podocytes by inhibiting the expression of PTPRO. The mechanism may be associated with the activation of the JAK2/STAT3 signalling pathway. The current study may provide a novel direction for the treatment of childhood nephrotic syndrome.
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Affiliation(s)
- Wei Ren
- Department of Internal Medicine, Xi'an Children's Hospital, Xi'an, Shaanxi 710003, P.R. China
| | - Huiru Yi
- Department of Internal Medicine, Xi'an Children's Hospital, Xi'an, Shaanxi 710003, P.R. China
| | - Ying Bao
- Department of Nephrology, Xi'an Children's Hospital, Xi'an, Shaanxi 710003, P.R. China
| | - Yingru Liu
- Department of Internal Medicine, Xi'an Children's Hospital, Xi'an, Shaanxi 710003, P.R. China
| | - Xinru Gao
- Department of Medical Ultrasound Center, The Northwest Women's and Children's Hospital, Xi'an, Shaanxi 710061, P.R. China
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8
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Huang Y, Zhang Y, Ge L, Lin Y, Kwok HF. The Roles of Protein Tyrosine Phosphatases in Hepatocellular Carcinoma. Cancers (Basel) 2018; 10:cancers10030082. [PMID: 29558404 PMCID: PMC5876657 DOI: 10.3390/cancers10030082] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/12/2018] [Accepted: 03/15/2018] [Indexed: 02/08/2023] Open
Abstract
The protein tyrosine phosphatase (PTP) family is involved in multiple cellular functions and plays an important role in various pathological and physiological processes. In many chronic diseases, for example cancer, PTP is a potential therapeutic target for cancer treatment. In the last two decades, dozens of PTP inhibitors which specifically target individual PTP molecules were developed as therapeutic agents. Hepatocellular carcinoma (HCC) is one of the most common malignant tumors and is the second most lethal cancer worldwide due to a lack of effective therapies. Recent studies have unveiled both oncogenic and tumor suppressive functions of PTP in HCC. Here, we review the current knowledge on the involvement of PTP in HCC and further discuss the possibility of targeting PTP in HCC.
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Affiliation(s)
- Yide Huang
- Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, College of Life Sciences, Fujian Normal University, Fuzhou 350117, China.
- Faculty of Health Sciences, University of Macau, Avenida de Universidade, Taipa, Macau, China.
| | - Yafei Zhang
- Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, College of Life Sciences, Fujian Normal University, Fuzhou 350117, China.
| | - Lilin Ge
- Faculty of Health Sciences, University of Macau, Avenida de Universidade, Taipa, Macau, China.
- Jiangsu Key Laboratory for Functional Substance of Chinese Medicine, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China.
| | - Yao Lin
- Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, College of Life Sciences, Fujian Normal University, Fuzhou 350117, China.
| | - Hang Fai Kwok
- Faculty of Health Sciences, University of Macau, Avenida de Universidade, Taipa, Macau, China.
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9
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Meeusen B, Janssens V. Tumor suppressive protein phosphatases in human cancer: Emerging targets for therapeutic intervention and tumor stratification. Int J Biochem Cell Biol 2017; 96:98-134. [PMID: 29031806 DOI: 10.1016/j.biocel.2017.10.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 02/06/2023]
Abstract
Aberrant protein phosphorylation is one of the hallmarks of cancer cells, and in many cases a prerequisite to sustain tumor development and progression. Like protein kinases, protein phosphatases are key regulators of cell signaling. However, their contribution to aberrant signaling in cancer cells is overall less well appreciated, and therefore, their clinical potential remains largely unexploited. In this review, we provide an overview of tumor suppressive protein phosphatases in human cancer. Along their mechanisms of inactivation in defined cancer contexts, we give an overview of their functional roles in diverse signaling pathways that contribute to their tumor suppressive abilities. Finally, we discuss their emerging roles as predictive or prognostic markers, their potential as synthetic lethality targets, and the current feasibility of their reactivation with pharmacologic compounds as promising new cancer therapies. We conclude that their inclusion in clinical practice has obvious potential to significantly improve therapeutic outcome in various ways, and should now definitely be pushed forward.
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Affiliation(s)
- Bob Meeusen
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium.
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10
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Dong H, Ma L, Gan J, Lin W, Chen C, Yao Z, Du L, Zheng L, Ke C, Huang X, Song H, Kumar R, Yeung SC, Zhang H. PTPRO represses ERBB2-driven breast oncogenesis by dephosphorylation and endosomal internalization of ERBB2. Oncogene 2017; 36:410-422. [PMID: 27345410 PMCID: PMC5269534 DOI: 10.1038/onc.2016.213] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 05/05/2016] [Accepted: 05/08/2016] [Indexed: 02/05/2023]
Abstract
The plasma membrane-associated tyrosine phosphatase PTPRO is frequently transcriptionally repressed in cancers and signifies poor prognosis of breast cancer patients. In this study, deletion of Ptpro in MMTV-Erbb2 transgenic mice dramatically shortened the mammary tumor latency and accelerated tumor growth due to loss of Ptpro within the breast cancer cells but not in surrounding tissue as confirmed by hetero-transplantation studies. Both in vitro and in vivo data demonstrated that the phosphatase activity was required for the inactivation of ERBB2 and its downstream signaling. PTPRO regulated the phosphorylation status of ERBB2 at Y1248. Co-immunoprecipitation and proximity ligation assay (Duolink) indicated that PTPRO directly physically interacted with ERBB2. Moreover, PTPRO phosphatase activity shortened the half-life of ERBB2 by increasing endocytotic degradation. PTPRO reexpression by demethylation treatment using 5-azacytidine reduced the proliferation and colony formation potential in ERBB2-positive breast cancer cells. Taken together, PTPRO inhibited ERBB2-driven breast cancer through dephosphorylation leading to dual effects of ERBB2 signaling suppression and endosomal internalization of ERBB2, Therefore, reexpression of PTPRO may be a potential therapy for ERBB2-overexpressing breast cancer.
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Affiliation(s)
- H Dong
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - L Ma
- Department of Gastroenterology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - J Gan
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - W Lin
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - C Chen
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - Z Yao
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - L Du
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - L Zheng
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - C Ke
- Cancer Research Center, Shantou University Medical College, Shantou, China
| | - X Huang
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center of Nanjing University, Nanjing, China
| | - H Song
- Department of Cell Biology, Xi'an Jiaotong University Suzhou Academy, Suzhou, China
| | - R Kumar
- Department of Biochemistry and Molecular Medicine, School of Medicine and Health Sciences, George Washington University, Washington DC, USA
| | - S C Yeung
- Cancer Research Center, Shantou University Medical College, Shantou, China
- Department of Emergency Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA. E-mail:
| | - H Zhang
- Cancer Research Center, Shantou University Medical College, Shantou, China
- Department of Biotherapy, Affiliated Cancer Hospital of Shantou University Medical College, Shantou, China
- Cancer Research Center, Shantou University Medical College, Xinling Road No. 22, Shantou 515041, ChinaE-mail:
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Kang MM, Shan SL, Wen XY, Shan HS, Wang ZJ. Tumor-Suppression Mechanisms of Protein Tyrosine Phosphatase O and Clinical Applications. Asian Pac J Cancer Prev 2015; 16:6215-23. [PMID: 26434819 DOI: 10.7314/apjcp.2015.16.15.6215] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Tyrosine phosphorylation plays an important role in regulating human physiological and pathological processes. Functional stabilization of tyrosine phosphorylation largely contributes to the balanced, coordinated regulation of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Research has revealed PTPs play an important suppressive role in carcinogenesis and progression by reversing oncoprotein functions. Receptor-type protein tyrosine phosphatase O (PTPRO) as one member of the PTPs family has also been identified to have some roles in tumor development. Some reports have shown PTPRO over-expression in tumors can not only inhibit the frequency of tumor cell division and induce tumor cell death, but also suppress migration. However, the tumor-suppression mechanisms are very complex and understanding is incomplete, which in some degree blocks the further development of PTPRO. Hence, in order to resolve this problem, we here have summarized research findings to draw meaningful conclusions. We found tumor-suppression mechanisms of PTPRO to be diverse, such as controlling G0/G1 of the tumor cell proliferation cycle, inhibiting substrate phosphorylation, down-regulating transcription activators and other activities. In clinical anticancer efforts, expression level of PTPRO in tumors can not only serve as a biomarker to monitor the prognosis of patients, but act as an epigenetic biomarker for noninvasive diagnosis. In addition, the re-activation of PTPRO in tumor tissues, not only can induce tumor volume reduction, but also enhance the susceptibility to chemotherapy drugs. So, we can propose that these research findings of PTPRO will not only support new study ideas and directions for other tumor- suppressors, importantly, but also supply a theoretical basis for researching new molecular targeting agents in the future.
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Affiliation(s)
- Man-Man Kang
- The Center of Radiation Oncology, the 82th Hospital of People's Liberation Army of China, Huaian, Jiangsu, China E-mail : ,
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12
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Thummuri D, Kumar S, Surapaneni SK, Tikoo K. Epigenetic regulation of protein tyrosine phosphatase PTPN12 in triple-negative breast cancer. Life Sci 2015; 130:73-80. [DOI: 10.1016/j.lfs.2015.03.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 03/09/2015] [Accepted: 03/12/2015] [Indexed: 10/23/2022]
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You Y, Yang W, Qin X, Wang F, Li H, Lin C, Li W, Gu C, Zhang Y, Ran Y. ECRG4 acts as a tumor suppressor and as a determinant of chemotherapy resistance in human nasopharyngeal carcinoma. Cell Oncol (Dordr) 2015; 38:205-14. [PMID: 25707757 DOI: 10.1007/s13402-015-0223-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2015] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Human nasopharyngeal carcinoma (NPC) is a malignant type of cancer with an increasing incidence. As yet, however, molecular biomarkers with a strong diagnostic impact and a major therapeutic promise have remained elusive. Here, we identified the esophageal carcinoma related gene 4 (ECRG4) as a novel candidate tumor suppressor gene and a promising therapeutic target for NPC. METHODS RT-PCR, Western blotting, methylation-specific PCR and bisulfite sequencing were performed to assess the expression and methylation status of the ECRG4 gene in primary NPC samples, NPC-derived cell lines and patient-derived peripheral blood samples. The NPC-derived cell line CNE1 was selected for treatment with a methylation inhibitor to restore ECRG4 expression. In addition, cell proliferation, invasion and colony formation assays were performed to assess the inhibitory effects of exogenous ECRG4 expression in CNE1 cells. RESULTS Down-regulated ECRG4 expression was found to occur in 82.5% (33/40) of the primary NPC biopsies tested. This down-regulation was significantly correlated with its tumor-specific promoter methylation status (72.5%, 29/40) and was also observed in the matching peripheral blood samples from the NPC patients (57.5%, 23/40). Pharmacologic demethylation through 5-aza-dC treatment led to gene reactivation in ECRG4 methylated and silenced NPC cell lines. Moreover, exogenous expression of ECRG4 in the CNE1 cell line strongly inhibited its growth and invasive capacities, as well as its enhanced chemosensitivity to cisplatin through autophagy induction. CONCLUSION Our data suggest that methylation-mediated suppression of the ECRG4 gene occurs frequently in NPC and that restoration of its expression may have therapeutic benefits.
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Affiliation(s)
- Yanjie You
- Department of Pharmacy, Luohe Medical College, 148 Daxue-Road, Luohe, 462002, China,
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Azevedo Costa M, de Souza Rodrigues T, da Costa AGF, Natowicz R, Pádua Braga A. Sequential selection of variables using short permutation procedures and multiple adjustments: An application to genomic data. Stat Methods Med Res 2015; 26:997-1020. [PMID: 25575544 DOI: 10.1177/0962280214566262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This work proposes a sequential methodology for selecting variables in classification problems in which the number of predictors is much larger than the sample size. The methodology includes a Monte Carlo permutation procedure that conditionally tests the null hypothesis of no association among the outcomes and the available predictors. In order to improve computing aspects, we propose a new parametric distribution, the Truncated and Zero Inflated Gumbel Distribution. The final application is to find compact classification models with improved performance for genomic data. Results using real data sets show that the proposed methodology selects compact models with optimized classification performances.
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Affiliation(s)
- Marcelo Azevedo Costa
- 1 Department of Industrial Engineering, Universidade Federal de Minas Gerais, Belo Horizonte,Brazil
| | | | | | - René Natowicz
- 4 Computer Sciences Department, University of Paris-ESIEE/Paris, Paris, France
| | - Antônio Pádua Braga
- 5 Graduate Program in Electrical Engineering, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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15
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Motiwala T, Kutay H, Zanesi N, Frissora FW, Mo X, Muthusamy N, Jacob ST. PTPROt-mediated regulation of p53/Foxm1 suppresses leukemic phenotype in a CLL mouse model. Leukemia 2014; 29:1350-9. [PMID: 25482129 PMCID: PMC4456291 DOI: 10.1038/leu.2014.341] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 10/27/2014] [Accepted: 11/11/2014] [Indexed: 12/17/2022]
Abstract
The gene encoding PTPROt is methylated and suppressed in Chronic Lymphocytc Leukemia. PTPROt exhibits in vitro tumor suppressor characteristics through the regulation of B-cell receptor signaling. Here, we generated transgenic (Tg) mice with B-cell specific expression of PTPROt. While lymphocyte development is normal in these mice, crossing them with TCL1 Tg mouse model of CLL results in a survival advantage compared to the TCL1 Tg mice. Gene expression profiling of splenic B-lymphocytes before detectable signs of CLL followed by Ingenuity Pathway Analysis revealed that the most prominently regulated functions in TCL1 Tg vs non-transgenic (NTg) and TCL1 Tg vs PTPROt/TCL1 double Tg are the same and also biologically relevant to this study. Further, enhanced expression of the chemokine Ccl3, the oncogenic transcription factor Foxm1 and its targets in TCL1 Tg mice were significantly suppressed in the double Tg mice suggesting a protective function of PTPROt against leukemogenesis. This study also showed that PTPROt mediated regulation of Foxm1 involves activation of p53, a transcriptional repressor of Foxm1, which is facilitated through suppression of B-cell receptor signaling. These results establish the in vivo tumor suppressive function of PTPROt, and identify p53/Foxm1 axis as a key downstream effect of PTPROt-mediated suppression of BCR signaling.
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Affiliation(s)
- T Motiwala
- Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH, USA
| | - H Kutay
- Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH, USA
| | - N Zanesi
- Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University, Columbus, OH, USA
| | - F W Frissora
- Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
| | - X Mo
- Center for Biostatistics, The Ohio State University, Columbus, OH, USA
| | - N Muthusamy
- Department of Internal Medicine, The Ohio State University, Wexner Medical Center, Columbus, OH, USA
| | - S T Jacob
- 1] Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH, USA [2] Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
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Li SY, Li R, Chen YL, Xiong LK, Wang HL, Rong L, Luo RC. Aberrant PTPRO methylation in tumor tissues as a potential biomarker that predicts clinical outcomes in breast cancer patients. BMC Genet 2014; 15:67. [PMID: 24919593 PMCID: PMC4062905 DOI: 10.1186/1471-2156-15-67] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 06/04/2014] [Indexed: 01/31/2023] Open
Abstract
Background Aberrant hypermethylation of gene promoter regions is a primary mechanism by which tumor suppressor genes become inactivated in breast cancer. Epigenetic inactivation of the protein tyrosine phosphatase receptor-type O gene (PTPRO) has been described in several types of cancer. Results We screened primary breast cancer tissues for PTPRO promoter hypermethylation and assessed potential associations with pathological features and patient outcome. We also evaluated its potential as a breast cancer biomarker. PTPRO methylation was observed in 53 of 98 (54%) breast cancer tissues but not in adjacent normal tissue. Among matched peripheral blood samples from breast cancer patients, 33 of 98 (34%) exhibited methylated PTPRO in plasma. In contrast, no methylated PTPRO was observed in normal peripheral blood from 30 healthy individuals. PTPRO methylation was positively associated with lymph node involvement (P = 0.014), poorly differentiated histology (P = 0.037), depth of invasion (P = 0.004), and HER2 amplification (P = 0.001). Multivariate analysis indicated that aberrant PTPRO methylation could serve as an independent predictor for overall survival hazard ratio (HR): 2.7; 95% CI: 1.1-6.2; P = 0.023), especially for patients with HER2-positive (hazard ratio (HR): 7.5; 95% CI: 1.8-31.3; P = 0.006), but not in ER + and PR + subpopulation. In addition, demethylation induced by 5-azacytidine led to gene reactivation in PTPRO-methylated and -silenced breast cancer cell lines. Conclusions Here, we report that tumor PTPRO methylation is a strong prognostic factor in breast cancer. Methylation of PTPRO silences its expression and plays an important role in breast carcinogenesis. The data we present here may provide insight into the development of novel therapies for breast cancer treatment. Additionally, detection of PTPRO methylation in peripheral blood of breast cancer patients may provide a noninvasive means to diagnose and monitor the disease.
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Affiliation(s)
- Shao-ying Li
- Department of Breast Surgery, Bao'an Maternal and Child Health Hospital, Shenzhen, People's Republic of China.
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PTPRO plays a dual role in hepatic ischemia reperfusion injury through feedback activation of NF-κB. J Hepatol 2014; 60:306-12. [PMID: 24128416 DOI: 10.1016/j.jhep.2013.09.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 09/15/2013] [Accepted: 09/30/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Nuclear factor-κB (NF-κB) activation in hepatocytes and macrophages appeared as a double-edged-sword in hepatic ischemia reperfusion (IR) injury. Protein tyrosine phosphatase receptor type O (PTPRO) was recently identified as a potential activator of c-Src, which can in turn activate the NF-κB pathway. In this study, we aimed to determine the change and function of PTPRO in hepatocytes and macrophages during IR. METHODS Clinical patients with benign liver condition undergoing liver surgery were recruited in our study. Wild type (WT) and ptpro(-/-) C57BL/6 mice were processed to construct hepatic IR models. Isolated mouse hepatocytes and macrophages were treated with peroxide or TNFα in vitro. RESULTS In human and mouse IR models, PTPRO level was decreased in the early phase but reversed in the late phase. In vitro studies demonstrated that NF-κB up-regulated PTPRO transcription. Using ptpro(-/-) mice and primary cells, we found that PTPRO deficiency resulted in reduction of NF-κB activation in both hepatocytes and macrophages and was correlated to c-Src phosphorylation; PTPRO in hepatocytes alleviated, but PTPROt in macrophages exacerbated IR injury. CONCLUSIONS PTPRO activates NF-κB in a positive feedback manner, and plays a dual role in hepatic IR injury.
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Hsu SH, Motiwala T, Roy S, Claus R, Mustafa M, Plass C, Freitas MA, Ghoshal K, Jacob ST. Methylation of the PTPRO gene in human hepatocellular carcinoma and identification of VCP as its substrate. J Cell Biochem 2013; 114:1810-8. [PMID: 23533167 DOI: 10.1002/jcb.24525] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 02/19/2013] [Indexed: 12/20/2022]
Abstract
We have previously reported that the gene encoding protein tyrosine phosphatase receptor type-O (PTPRO) is suppressed by promoter methylation in a rat model of hepatocellular carcinoma (HCC) and it functions as tumor suppressor in leukemia and lung cancer. Here, we explored the methylation and expression of PTPRO as well as its function in human HCC. MassARRAY analysis of primary human HCC and matching liver samples (n = 24) revealed significantly higher (P = 0.004) methylation density at the promoter CGI in tumors. Combined bisulfite restriction analysis (COBRA) of another set of human HCC samples (n = 17) demonstrated that the CGI was methylated in 29% of tumors where expression of PTPRO was lower than that in corresponding matching livers. A substrate-trapping mutant of PTPRO that stabilizes the bound substrates was used to identify its novel substrate(s). VCP/p97 was found to be a PTPRO substrate by mass spectrometry of the peptides pulled down by the substrate-trapping mutant of PTPRO. Tyrosyl dephosphorylation of VCP following ectopic expression of wild-type PTPRO in H293T and HepG2 cells confirmed that it is a bona fide substrate of PTPRO. Treatment of PTPRO overexpressing HepG2 cells with Doxorubicin, a DNA damaging drug commonly used in therapy of primary HCC, sensitized these cells to this potent anticancer drug that correlated with dephosphorylation of VCP. Taken together, these results demonstrate methylation and downregulation of PTPRO in a subset of primary human HCC and establish VCP as a novel functionally important substrate of this tyrosine phosphatase that could be a potential molecular target for HCC therapy.
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Affiliation(s)
- Shu-hao Hsu
- Department of Molecular & Cellular Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
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Kim TW, Kim B, Kim JH, Kang S, Park SB, Jeong G, Kang HS, Kim SJ. Nuclear-encoded mitochondrial MTO1 and MRPL41 are regulated in an opposite epigenetic mode based on estrogen receptor status in breast cancer. BMC Cancer 2013; 13:502. [PMID: 24160266 PMCID: PMC4015551 DOI: 10.1186/1471-2407-13-502] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 10/22/2013] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND MTO1 and MRPL41 are nuclear-encoded mitochondrial genes encoding a mitochondrial tRNA-modifying enzyme and a mitochondrial ribosomal protein, respectively. Although both genes have been known to have potential roles in cancer, little is known about their molecular regulatory mechanism, particularly from an epigenetic approach. In this study, we aimed to address their epigenetic regulation through the estrogen receptor (ER) in breast cancer. METHODS Digital differential display (DDD) was conducted to identify mammary gland-specific gene candidates including MTO1 and MRPL41. Promoter CpG methylation and expression in breast cancer cell lines and tissues were examined by methylation-specific PCR and real time RT-PCR. Effect of estradiol (E2), tamoxifen, and trichostatin A (TSA) on gene expression was examined in ER + and ER- breast cancer cell lines. Chromatin immunoprecipitation and luciferase reporter assay were performed to identify binding and influencing of the ER to the promoters. RESULTS Examination of both cancer tissues and cell lines revealed that the two genes showed an opposite expression pattern according to ER status; higher expression of MTO1 and MRPL41 in ER- and ER+ cancer types, respectively, and their expression levels were inversely correlated with promoter methylation. Tamoxifen, E2, and TSA upregulated MTO1 expression only in ER+ cells with no significant changes in ER- cells. However, these chemicals upregulated MRPL41 expression only in ER- cells without significant changes in ER+ cells, except for tamoxifen that induced downregulation. Chromatin immunoprecipitation and luciferase reporter assay identified binding and influencing of the ER to the promoters and the binding profiles were differentially regulated in ER+ and ER- cells. CONCLUSIONS These results indicate that different epigenetic status including promoter methylation and different responses through the ER are involved in the differential expression of MTO1 and MRPL41 in breast cancer.
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Affiliation(s)
| | | | | | | | | | | | - Han-Sung Kang
- Department of Life Science, Dongguk University-Seoul, Seoul 100-715, Korea.
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Huang YT, Li FF, Ke C, Li Z, Li ZT, Zou XF, Zheng XX, Chen YP, Zhang H. PTPRO promoter methylation is predictive of poorer outcome for HER2-positive breast cancer: indication for personalized therapy. J Transl Med 2013; 11:245. [PMID: 24090193 PMCID: PMC3852714 DOI: 10.1186/1479-5876-11-245] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 09/25/2013] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Protein Tyrosine Phosphatase Receptor-type O (PTPRO) has recently been in the spotlight as a tumor suppressor, whose encoding gene is frequently methylated in cancers. We examined the methylation status of the PTPRO gene promoter in breast cancer and evaluated the correlation between PTPRO promoter methylation and both clinicopathological parameters and prognosis of breast cancer patients. METHODS Two hundred twenty-one formalin-fixed, paraffin-embedded (FFPE) tumor tissues, 20 FFPE normal adjacent tissues and 24 matched plasma samples, collected from primary breast cancer patients, were assessed for PTPRO gene promoter methylation using methylation-specific PCR. Associations of promoter methylation with clinicopathological parameters were evaluated. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate the effect on survival. RESULTS 175 samples gave identifiable PCR products, of which 130 cases (74.3%) had PTPRO gene promoter methylation. PTPRO methylation correlated with higher histological grade (P = 0.028), but not other clinical parameters. Multivariate analysis indicated that overall survival (OS) was significantly poorer in HER2-positive, but not ER-positive patients with methylated-PTPRO. Methylated-PTPRO was detectable in matched plasma samples and only observed in plasma from patients whose corresponding primary tumors were also methylated. CONCLUSIONS PTPRO methylation is a common event in the primary breast cancer and can be reliably detected in peripheral blood samples. PTPRO methylation is associated with poor survival only in HER2-positive patients, suggesting use of PTPRO methylation as a prognostic factor for breast cancer and for optimizing individualized therapy for HER2-positive patients.
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Affiliation(s)
- Yi-Teng Huang
- Department of Integrative Oncology, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Fei-Fei Li
- Department of Integrative Oncology, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Chen Ke
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Zhou Li
- Department of Integrative Oncology, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Zong-Tai Li
- Department of Integrative Oncology, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Xiao-Fang Zou
- Department of Integrative Oncology, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Xiao-Xuan Zheng
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
| | - Yu-Ping Chen
- Department of Thoracic Surgery, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
| | - Hao Zhang
- Department of Integrative Oncology, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
- Tumor Tissue Bank, Affiliated Cancer Hospital of Shantou University Medical College, Shantou 515041, China
- Cancer Research Center, Shantou University Medical College, Shantou 515041, China
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Virag P, Fischer-Fodor E, Perde-Schrepler M, Brie I, Tatomir C, Balacescu L, Berindan-Neagoe I, Victor B, Balacescu O. Oxaliplatin induces different cellular and molecular chemoresistance patterns in colorectal cancer cell lines of identical origins. BMC Genomics 2013; 14:480. [PMID: 23865481 PMCID: PMC3776436 DOI: 10.1186/1471-2164-14-480] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 07/02/2013] [Indexed: 12/15/2022] Open
Abstract
Background Cancer cells frequently adopt cellular and molecular alterations and acquire resistance to cytostatic drugs. Chemotherapy with oxaliplatin is among the leading treatments for colorectal cancer with a response rate of 50%, inducing intrastrand cross-links on the DNA. Despite of this drug’s efficiency, resistance develops in nearly all metastatic patients. Chemoresistance being of crucial importance for the drug’s clinical efficiency this study aimed to contribute to the identification and description of some cellular and molecular alterations induced by prolonged oxaliplatin therapy. Resistance to oxaliplatin was induced in Colo320 (Colo320R) and HT-29 (HT-29R) colorectal adenocarcinoma cell lines by exposing the cells to increasing concentrations of the drug. Alterations in morphology, cytotoxicity, DNA cross-links formation and gene expression profiles were assessed in the parental and resistant variants with microscopy, MTT, alkaline comet and pangenomic microarray assays, respectively. Results Morphology analysis revealed epithelial-to-mesenchymal transition in the resistant vs parental cells suggesting alterations of the cells’ adhesion complexes, through which they acquire increased invasiveness and adherence. Cytotoxicity measurements demonstrated resistance to oxaliplatin in both cell lines; Colo320 being more sensitive than HT-29 to this drug (P < 0.001). The treatment with oxaliplatin caused major DNA cross-links in both parental cell lines; in Colo320R small amounts of DNA cross-links were still detectable, while in HT-29R not. We identified 441 differentially expressed genes in Colo320R and 613 in HT-29R as compared to their parental counterparts (at least 1.5 -fold up- or down- regulation, p < 0.05). More disrupted functions and pathways were detected in HT-29R cell line than in Colo320R, involving genes responsible for apoptosis inhibition, cellular proliferation and epithelial-to-mesenchymal transition. Several upstream regulators were detected as activated in HT-29R cell line, but not in Colo320R. Conclusions Our findings revealed a more resistant phenotype in HT-29R as compared to Colo320R and different cellular and molecular chemoresistance patterns induced by prolonged treatment with oxaliplatin in cell lines with identical origins (colorectal adenocarcinomas).
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Affiliation(s)
- Piroska Virag
- The Oncology Institute Prof.Dr.I. Chiricuta, 400015 Republicii Str,, nr, 34-36, Cluj-Napoca, Romania.
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Nunes-Xavier CE, Martín-Pérez J, Elson A, Pulido R. Protein tyrosine phosphatases as novel targets in breast cancer therapy. Biochim Biophys Acta Rev Cancer 2013; 1836:211-26. [PMID: 23756181 DOI: 10.1016/j.bbcan.2013.06.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Accepted: 06/01/2013] [Indexed: 02/07/2023]
Abstract
Breast cancer is linked to hyperactivation of protein tyrosine kinases (PTKs), and recent studies have unveiled that selective tyrosine dephosphorylation by protein tyrosine phosphatases (PTPs) of specific substrates, including PTKs, may activate or inactivate oncogenic pathways in human breast cancer cell growth-related processes. Here, we review the current knowledge on the involvement of PTPs in breast cancer, as major regulators of breast cancer therapy-targeted PTKs, such as HER1/EGFR, HER2/Neu, and Src. The functional interplay between PTKs and PTK-activating or -inactivating PTPs, and its implications in novel breast cancer therapies based on targeting of specific PTPs, are discussed.
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Affiliation(s)
- Caroline E Nunes-Xavier
- BioCruces Health Research Institute, Hospital de Cruces, Plaza Cruces s/n, 48903 Barakaldo, Spain
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Hou J, Xu J, Jiang R, Wang Y, Chen C, Deng L, Huang X, Wang X, Sun B. Estrogen-sensitive PTPRO expression represses hepatocellular carcinoma progression by control of STAT3. Hepatology 2013; 57:678-88. [PMID: 22821478 DOI: 10.1002/hep.25980] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 07/08/2012] [Indexed: 01/04/2023]
Abstract
UNLABELLED Protein tyrosine phosphatase receptor type O (PTPRO), one of the receptor types of phosphotyrosine phosphatases (PTP), was recently described as a tumor suppressor in various kinds of cancers. We aimed to clarify the role of PTPRO in hepatocellular carcinoma (HCC). It was demonstrated in 180 pairs (120 male and 60 female) of clinical HCC specimens that the PTPRO level was significantly reduced, as compared with adjacent tissue, and the PTPRO level in male adjacent tissue was lower than in female. We further found that estrogen receptor alpha (ERα) could up-regulate PTPRO expression as a transcription factor. Moreover, an in vitro study showed that cell proliferation was inhibited and apoptosis was promoted in PTPRO-transduced HCC cell lines, whereas an in vivo study represented that tumor number and size was increased in ptpro(-/-) mice. As a result of its tumor-suppressive position, PTPRO was proved to down-regulate signal transducers and activators of transcription (STAT3) activity dependent on Janus kinase 2 (JAK2) and phosphoinositide 3-kinase (PI3K) dephosphorylation. CONCLUSIONS PTPRO expression results in pathological deficiency and gender bias in HCC, which could be attributed to ERα regulation. The suppressive role of PTPRO in HCC could be ascribed to STAT3 inactivation.
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Affiliation(s)
- Jiajie Hou
- Liver Transplantation Center of First Affiliated Hospital and State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
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Putnik M, Zhao C, Gustafsson JÅ, Dahlman-Wright K. Global identification of genes regulated by estrogen signaling and demethylation in MCF-7 breast cancer cells. Biochem Biophys Res Commun 2012; 426:26-32. [PMID: 22902638 DOI: 10.1016/j.bbrc.2012.08.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 08/02/2012] [Indexed: 01/16/2023]
Abstract
Estrogen signaling and epigenetic modifications, in particular DNA methylation, are involved in regulation of gene expression in breast cancers. Here we investigated a potential regulatory cross-talk between these two pathways by identifying their common target genes and exploring underlying molecular mechanisms in human MCF-7 breast cancer cells. Gene expression profiling revealed that the expression of approximately 140 genes was influenced by both 17β-estradiol (E2) and a demethylating agent 5-aza-2'-deoxycytidine (DAC). Gene ontology (GO) analysis suggests that these genes are involved in intracellular signaling cascades, regulation of cell proliferation and apoptosis. Based on previously reported association with breast cancer, estrogen signaling and/or DNA methylation, CpG island prediction and GO analysis, we selected six genes (BTG3, FHL2, PMAIP1, BTG2, CDKN1A and TGFB2) for further analysis. Tamoxifen reverses the effect of E2 on the expression of all selected genes, suggesting that they are direct targets of estrogen receptor. Furthermore, DAC treatment reactivates the expression of all selected genes in a dose-dependent manner. Promoter CpG island methylation status analysis revealed that only the promoters of BTG3 and FHL2 genes are methylated, with DAC inducing demethylation, suggesting DNA methylation directs repression of these genes in MCF-7 cells. In a further analysis of the potential interplay between estrogen signaling and DNA methylation, E2 treatment showed no effect on the methylation status of these promoters. Additionally, we show that the ERα recruitment occurs at the FHL2 promoter in an E2- and DAC-independent fashion. In conclusion, we identified a set of genes regulated by both estrogen signaling and DNA methylation. However, our data does not support a direct molecular interplay of mediators of estrogen and epigenetic signaling at promoters of regulated genes.
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Affiliation(s)
- Milica Putnik
- Department of Biosciences and Nutrition, Novum, Karolinska Institutet, Huddinge S-14183, Sweden.
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25
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Expression profiling during mammary epithelial cell three-dimensional morphogenesis identifies PTPRO as a novel regulator of morphogenesis and ErbB2-mediated transformation. Mol Cell Biol 2012; 32:3913-24. [PMID: 22851698 DOI: 10.1128/mcb.00068-12] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Identification of genes that are upregulated during mammary epithelial cell morphogenesis may reveal novel regulators of tumorigenesis. We have demonstrated that gene expression programs in mammary epithelial cells grown in monolayer cultures differ significantly from those in three-dimensional (3D) cultures. We identify a protein tyrosine phosphate, PTPRO, that was upregulated in mature MCF-10A mammary epithelial 3D structures but had low to undetectable levels in monolayer cultures. Downregulation of PTPRO by RNA interference inhibited proliferation arrest during morphogenesis. Low levels of PTPRO expression correlated with reduced survival for breast cancer patients, suggesting a tumor suppressor function. Furthermore, we showed that the receptor tyrosine kinase ErbB2/HER2 is a direct substrate of PTPRO and that loss of PTPRO increased ErbB2-induced cell proliferation and transformation, together with tyrosine phosphorylation of ErbB2. Moreover, in patients with ErbB2-positive breast tumors, low PTPRO expression correlated with poor clinical prognosis compared to ErbB2-positive patients with high levels of PTPRO. Thus, PTPRO is a novel regulator of ErbB2 signaling, a potential tumor suppressor, and a novel prognostic marker for patients with ErbB2-positive breast cancers. We have identified the protein tyrosine phosphatase PTPRO as a regulator of three-dimensional epithelial morphogenesis of mammary epithelial cells and as a regulator of ErbB2-mediated transformation. In addition, we demonstrated that ErbB2 is a direct substrate of PTPRO and that decreased expression of PTPRO predicts poor prognosis for ErbB2-positive breast cancer patients. Thus, our results identify PTPRO as a novel regulator of mammary epithelial transformation, a potential tumor suppressor, and a predictive biomarker for breast cancer.
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26
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Labbé DP, Hardy S, Tremblay ML. Protein tyrosine phosphatases in cancer: friends and foes! PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 106:253-306. [PMID: 22340721 DOI: 10.1016/b978-0-12-396456-4.00009-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Tyrosine phosphorylation of proteins serves as an exquisite switch in controlling several key oncogenic signaling pathways involved in cell proliferation, apoptosis, migration, and invasion. Since protein tyrosine phosphatases (PTPs) counteract protein kinases by removing phosphate moieties on target proteins, one may intuitively think that PTPs would act as tumor suppressors. Indeed, one of the most described PTPs, namely, the phosphatase and tensin homolog (PTEN), is a tumor suppressor. However, a growing body of evidence suggests that PTPs can also function as potent oncoproteins. In this chapter, we provide a broad historical overview of the PTPs, their mechanism of action, and posttranslational modifications. Then, we focus on the dual properties of classical PTPs (receptor and nonreceptor) and dual-specificity phosphatases in cancer and summarize the current knowledge of the signaling pathways regulated by key PTPs in human cancer. In conclusion, we present our perspective on the potential of these PTPs to serve as therapeutic targets in cancer.
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Affiliation(s)
- David P Labbé
- Goodman Cancer Research Centre, McGill University, Montréal, Québec, Canada
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27
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Leung YK, Lee MT, Lam HM, Tarapore P, Ho SM. Estrogen receptor-beta and breast cancer: translating biology into clinical practice. Steroids 2012; 77:727-37. [PMID: 22465878 PMCID: PMC3356459 DOI: 10.1016/j.steroids.2012.03.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 03/15/2012] [Accepted: 03/16/2012] [Indexed: 02/07/2023]
Abstract
Estrogen receptor (ER) β was discovered over a decade ago. The design of most studies on this receptor was based on knowledge of its predecessor, ERα. Although breast cancer (BCa) has been a main focus of ERβ research, its precise roles in breast carcinogenesis remain elusive. Data from in vitro models have not always matched those from observational or clinical studies. Several inherent factors may contribute to these discrepancies: (a) several ERβ spliced variants are expressed at the protein level, and isoform-specific antibodies are unavailable for some variants; (b) post-translational modifications of the receptor regulate receptor functions; (c) the role of the receptor differs significantly depending on the type of ligands, cis-elements, and co-regulators that interact with the receptor; and (d) the diversity of distribution of the receptor among intracellular organelles of BCa cells. This review addresses the gaps in knowledge in ERβ research as it pertains to BCa regarding the following questions: (1) is ERβ a tumor suppressor in BCa?; (2) do ERβ isoforms play differential roles in breast carcinogenesis?; (3) do nuclear signaling and extranuclear ERβ signaling differ in BCa?; (4) what are the consequences of post-translational modifications of ERβ in BCa?; (5) how do co-regulators and interacting proteins increase functional diversity of ERβ?; and (6) how do the types of ligand and regulatory cis-elements affect the action of ERβ in BCa?. Insights gained from these key questions in ERβ research should help in prevention, diagnosis/prognosis, and treatment of BCa.
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Affiliation(s)
- Yuet-Kin Leung
- Division of Environmental Genetics and Molecular Toxicology, Department of Environmental Health, University of Cincinnati Medical Center, Cincinnati, OH 45267, USA.
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28
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Whitmore TE, Peterson A, Holzman T, Eastham A, Amon L, McIntosh M, Ozinsky A, Nelson PS, Martin DB. Integrative Analysis of N-Linked Human Glycoproteomic Data Sets Reveals PTPRF Ectodomain as a Novel Plasma Biomarker Candidate for Prostate Cancer. J Proteome Res 2012; 11:2653-65. [DOI: 10.1021/pr201200n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Theodore E. Whitmore
- Institute for Systems Biology, 1441 N. 34th St., Seattle, Washington 98103,
United States
| | - Amelia Peterson
- Department
of Chemistry, University of Wisconsin,
Madison, Wisconsin, United States
| | | | - Ashley Eastham
- Analytical & Formulation Sciences, Amgen Inc., Seattle, Washington 98119, United States
| | | | | | - Adrian Ozinsky
- Institute for Systems Biology, 1441 N. 34th St., Seattle, Washington 98103,
United States
| | | | - Daniel B. Martin
- Seattle Cancer Care Alliance,
825 Eastlake Avenue East, P.O. Box 19023, Seattle, Washington 98109,
United States
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29
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You YJ, Chen YP, Zheng X, Meltzer SJ, Zhang H. Aberrant methylation of the PTPRO gene in peripheral blood as a potential biomarker in esophageal squamous cell carcinoma patients. Cancer Lett 2012; 315:138-44. [PMID: 22099875 PMCID: PMC3248961 DOI: 10.1016/j.canlet.2011.08.032] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 08/30/2011] [Accepted: 08/31/2011] [Indexed: 02/05/2023]
Abstract
Epigenetic inactivation of protein tyrosine phosphatase receptor-type O (PTPRO), a new member of the PTP family, has been described in several forms of cancer. We evaluated PTPRO promoter hypermethylation as a potential biomarker in esophageal squamous cell carcinoma (ESCC). This alteration was observed in 27 (75%) of 36 primary tumors and correlated significantly with depth of invasion (T-stage, P = 0.013). Among matched peripheral blood samples from ESCC patients, 13 (36.1%) of 36 exhibited detectable methylated PTPRO in plasma, while 15 (41.7%) of 36 had this abnormality in buffy coat. No methylated PTPRO was observed in normal peripheral blood samples from 10 healthy individuals. In addition, demethylation by 5-aza-dC treatment led to gene reactivation in PTPRO-methylated and -silenced ESCC cell lines. To our knowledge, this is the first report of methylated PTPRO as a noninvasive tumor biomarker in peripheral blood. These findings suggest that hypermethylated PTPRO occurs frequently in ESCC. Further, detection in peripheral blood of ESCC patients suggests potential clinical application for noninvasive diagnosis and disease monitoring.
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Affiliation(s)
- Yan-Jie You
- Department of Integrative Chinese and Western Medicine, Cancer Hospital of Shantou University Medical College, Shantou, People’s Republic of China
- Oncological Research Lab, Cancer Hospital of Shantou University Medical College, Shantou, People’s Republic of China
- Cancer Research Center, Medical College of Shantou University, Shantou, People’s Republic of China
| | - Yu-Ping Chen
- Department of Surgery, Cancer Hospital of Shantou University Medical College, Shantou, People’s Republic of China
| | - Xiaoxuan Zheng
- Cancer Research Center, Medical College of Shantou University, Shantou, People’s Republic of China
| | - Stephen J. Meltzer
- Division of Gastroenterology, Departments of Medicine and Oncology, the Johns Hopkins University School of Medicine, Baltimore, Maryland
- Sidney Kimmel Comprehensive Cancer Center, the Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Hao Zhang
- Department of Integrative Chinese and Western Medicine, Cancer Hospital of Shantou University Medical College, Shantou, People’s Republic of China
- Tumor Tissue Bank, Cancer Hospital of Shantou University Medical College, Shantou, People’s Republic of China
- Oncological Research Lab, Cancer Hospital of Shantou University Medical College, Shantou, People’s Republic of China
- Cancer Research Center, Medical College of Shantou University, Shantou, People’s Republic of China
- Corresponding author address: Hao Zhang, Cancer Research Center, Medical College of Shantou University, 22 Xinling-Road, Shantou 515041, People’s Republic of China. Tel.: 86-754-8900406; Fax: 86-754-8900406; (H Zhang)
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30
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Mbita Z, Meyer M, Skepu A, Hosie M, Rees J, Dlamini Z. De-regulation of the RBBP6 isoform 3/DWNN in human cancers. Mol Cell Biochem 2011; 362:249-62. [PMID: 22139301 DOI: 10.1007/s11010-011-1150-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 11/03/2011] [Indexed: 01/30/2023]
Abstract
Retinoblastoma binding protein 6 (RBBP6) is a nuclear protein, previously implicated in the regulation of cell cycle and apoptosis. The human RBBP6 gene codes for three protein isoforms and isoform 3 consists of the domain with no name domain only whilst the other two isoforms, 1 and 2 comprise of additional zinc, RING, retinoblastoma and p53 binding domains. In this study, the localization of RBBP6 using RBBP6 variant 3 mRNA-specific probe was performed to investigate the expression levels of the gene in different tumours and find a link between RBBP6 and human carcinogenesis. Using FISH, real-time PCR and Western blotting analysis our results show that RBBP6 isoform 3 is down-regulated in human cancers. RBBP6 isoform 3 knock-down resulted in reduced G2/M cell cycle arrest whilst its over-expression resulted in increased G2/M cell cycle arrest using propidium iodide DNA staining. The results further demonstrate that the RBBP6 isoform 3 may be the cell cycle regulator and involved in mitotic apoptosis not the isoform 1 as previously reported for mice. In conclusion, these findings suggest that RBBP6 isoform 3 is a cell cycle regulator and may be de-regulated in carcinogenesis.
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Affiliation(s)
- Zukile Mbita
- College of Agriculture and Environmental Science, University of South Africa, Florida Campus, Johannesburg, South Africa
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31
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Hill VK, Ricketts C, Bieche I, Vacher S, Gentle D, Lewis C, Maher ER, Latif F. Genome-Wide DNA Methylation Profiling of CpG Islands in Breast Cancer Identifies Novel Genes Associated with Tumorigenicity. Cancer Res 2011; 71:2988-99. [DOI: 10.1158/0008-5472.can-10-4026] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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32
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Abstract
Members of the protein tyrosine phosphatase (Ptp) family dephosphorylate target proteins and counter the activities of protein tyrosine kinases that are involved in cellular phosphorylation and signalling. As such, certain PTPs might be tumour suppressors. Indeed, PTPs play an important part in the inhibition or control of growth, but accumulating evidence indicates that some PTPs may exert oncogenic functions. Recent large-scale genetic analyses of various human tumours have highlighted the relevance of PTPs either as putative tumour suppressors or as candidate oncoproteins. Progress in understanding the regulation and function of PTPs has provided insights into which PTPs might be potential therapeutic targets in human cancer.
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Affiliation(s)
- Sofi G Julien
- Goodman Cancer Research Centre, Department of Biochemistry, McGill University, Montreal, Quebec, Canada
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33
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Lustberg MB, Ramaswamy B. Epigenetic targeting in breast cancer: therapeutic impact and future direction. ACTA ACUST UNITED AC 2010; 22:369-81. [PMID: 19890494 DOI: 10.1358/dnp.2009.22.7.1405072] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Breast carcinogenesis is a multistep process involving both genetic and epigenetic changes. Epigenetics is defined as a reversible and heritable change in gene expression that is not accompanied by alteration in gene sequence. DNA methylation and histone modifications are the two major epigenetic changes that influence gene expression in cancer. The interaction between methylation and histone modification is intricately orchestrated by the formation of repressor complexes. Several genes involved in proliferation, antiapoptosis, invasion and metastasis have been shown to be methylated in various malignant and premalignant breast neoplasms. The histone deacetylase inhibitors (HDi) have emerged as an important class of drugs to be used synergistically with other systemic therapies in the treatment of breast cancer. Since epigenetic changes are potentially reversible processes, much effort has been directed toward understanding this mechanism with the goal of finding novel therapies as well as more refined diagnostic and prognostic tools in breast cancer.
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Affiliation(s)
- M B Lustberg
- Division of Hematology and Oncology, Comprehensive Cancer Center, The Ohio State University Medical Center, USA
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34
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Repression of ESR1 through actions of estrogen receptor alpha and Sin3A at the proximal promoter. Mol Cell Biol 2009; 29:4949-58. [PMID: 19620290 DOI: 10.1128/mcb.00383-09] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Gene expression results from the coordinated actions of transcription factor proteins and coregulators. Estrogen receptor alpha (ERalpha) is a ligand-activated transcription factor that can both activate and repress the expression of genes. Activation of transcription by estrogen-bound ERalpha has been studied in detail, as has antagonist-induced repression, such as that which occurs by tamoxifen. How estrogen-bound ERalpha represses gene transcription remains unclear. In this report, we identify a new mechanism of estrogen-induced transcriptional repression by using the ERalpha gene, ESR1. Upon estrogen treatment, ERalpha is recruited to two sites on ESR1, one distal (ENH1) and the other at the proximal (A) promoter. Coactivator proteins, namely, p300 and AIB1, are found at both ERalpha-binding sites. However, recruitment of the Sin3A repressor, loss of RNA polymerase II, and changes in histone modifications occur only at the A promoter. Reduction of Sin3A expression by RNA interference specifically inhibits estrogen-induced repression of ESR1. Furthermore, an estrogen-responsive interaction between Sin3A and ERalpha is identified. These data support a model of repression wherein actions of ERalpha and Sin3A at the proximal promoter can overcome activating signals at distal or proximal sites and ultimately decrease gene expression.
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