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Deng W, Li J, Dorrah K, Jimenez-Tapia D, Arriaga B, Hao Q, Cao W, Gao Z, Vadgama J, Wu Y. The role of PPM1D in cancer and advances in studies of its inhibitors. Biomed Pharmacother 2020; 125:109956. [PMID: 32006900 DOI: 10.1016/j.biopha.2020.109956] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/08/2020] [Accepted: 01/23/2020] [Indexed: 12/16/2022] Open
Abstract
A greater understanding of factors causing cancer initiation, progression and evolution is of paramount importance. Among them, the serine/threonine phosphatase PPM1D, also referred to as wild-type p53-induced phosphatase 1 (Wip1) or protein phosphatase 2C delta (PP2Cδ), is emerging as an important oncoprotein due to its negative regulation on a number of crucial cancer suppressor pathways. Initially identified as a p53-regulated gene, PPM1D has been afterwards found amplified and more recently mutated in many human cancers such as breast cancer. The latest progress in this field further reveals that selective inhibition of PPM1D to delay tumor onset or reduce tumor burden represents a promising anti-cancer strategy. Here, we review the advances in the studies of the PPM1D activity and its relevance to various cancers, and recent progress in development of PPM1D inhibitors and discuss their potential application in cancer therapy. Consecutive research on PPM1D and its relationship with cancer is essential, as it ultimately contributes to the etiology and treatment of cancer.
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Affiliation(s)
- Wenhong Deng
- Department of General Surgery, Renmin Hospital of Wuhan University, Wuhan, 430060, China; Division of Cancer Research and Training, Department of Internal Medicine, Charles Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | - Jieqing Li
- Division of Cancer Research and Training, Department of Internal Medicine, Charles Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | - Kimberly Dorrah
- Division of Cancer Research and Training, Department of Internal Medicine, Charles Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | - Denise Jimenez-Tapia
- Division of Cancer Research and Training, Department of Internal Medicine, Charles Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | - Brando Arriaga
- Division of Cancer Research and Training, Department of Internal Medicine, Charles Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | - Qiongyu Hao
- Division of Cancer Research and Training, Department of Internal Medicine, Charles Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | - Wei Cao
- Division of Cancer Research and Training, Department of Internal Medicine, Charles Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
| | - Zhaoxia Gao
- Department of General Surgery, 5th Hospital of Wuhan, Wuhan, 430050, China; Department of Surgery, Johns Hopkins Hospital Bayview Campus, Baltimore, MD, USA
| | - Jay Vadgama
- Division of Cancer Research and Training, Department of Internal Medicine, Charles Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA.
| | - Yong Wu
- Division of Cancer Research and Training, Department of Internal Medicine, Charles Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA.
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Li K, Liu Y, Xu S, Wang J. PPM1D Functions as Oncogene and is Associated with Poor Prognosis in Esophageal Squamous Cell Carcinoma. Pathol Oncol Res 2018; 26:387-395. [PMID: 30374621 DOI: 10.1007/s12253-018-0518-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 10/25/2018] [Indexed: 12/13/2022]
Abstract
Mounting evidence has demonstrated that PPM1D participates in the development and progression of a wide variety of tumors. However, its precise roles in esophageal squamous cell carcinoma (ESCC) remain under investigation. Here, UALCAN, an interactive web-portal to perform the expression analyses of PPM1D using TCGA gene expression data, and PPM1D high expression was exhibited in primary esophageal cancer. Further investigation revealed that PPM1D expression was obviously higher in ESCC tissues than in normal tissues (P < 0.01), which was consistent with the results from real-time qPCR and Western blotting in ESCC tissues and paired normal esophageal tissues. Besides, PPM1D expression was closely correlated with TNM staging, tumor differentiation and lymph node metastasis (P < 0.01), but not related to the patients' gender and age (P > 0.05). Notably, PPM1D expression in metastatic ESCC patients was markedly higher than that in non-metastatic ESCC patients (P < 0.01), and the ESCC patients with high PPM1D expression predicted poor prognosis. Multivariate assay demonstrated that PPM1D and lymph node metastasis were considered as independent prognostic factors for the ESCC patients. These findings suggest PPM1D plays a pivotal important role in onset and progression of ESCC, and may be a new biomarker for metastasis and prognosis of the ESCC patients.
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Affiliation(s)
- Ke Li
- Department of Oncology, the Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, 127th Dongming Rd, Zhengzhou, Henan Province, 450008, People's Republic of China
| | - Ying Liu
- Department of Oncology, the Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, 127th Dongming Rd, Zhengzhou, Henan Province, 450008, People's Republic of China
| | - Shuning Xu
- Department of Oncology, the Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, 127th Dongming Rd, Zhengzhou, Henan Province, 450008, People's Republic of China
| | - Jufeng Wang
- Department of Oncology, the Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, 127th Dongming Rd, Zhengzhou, Henan Province, 450008, People's Republic of China.
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Dai L, Bai A, Smith CD, Rodriguez PC, Yu F, Qin Z. ABC294640, A Novel Sphingosine Kinase 2 Inhibitor, Induces Oncogenic Virus-Infected Cell Autophagic Death and Represses Tumor Growth. Mol Cancer Ther 2017; 16:2724-2734. [PMID: 28939554 DOI: 10.1158/1535-7163.mct-17-0485] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 07/13/2017] [Accepted: 09/11/2017] [Indexed: 01/07/2023]
Abstract
Kaposi sarcoma-associated herpes virus (KSHV) is the etiologic agent of several malignancies, including Kaposi sarcoma and primary effusion lymphoma (PEL), which preferentially arise in HIV+ patients and lack effective treatment. Sphingosine kinase 2 (SphK2) is a key factor within sphingolipid metabolism, responsible for the conversion of proapoptotic ceramides to antiapoptotic sphingosine-1-phosphate (S1P). We have previously demonstrated that targeting SphK2 using a novel selective inhibitor, ABC294640, leads to the accumulation of intracellular ceramides and induces apoptosis in KSHV-infected primary endothelial cells and PEL tumor cells but not in uninfected cells. In this study, we found that ABC294640 induces autophagic death instead of apoptosis in a KSHV long-term-infected immortalized endothelial cell-line, TIVE-LTC, but not in uninfected TIVE cells, through the upregulation of LC3B protein. Transcriptomic analysis indicates that many genes related to cellular stress responses, cell cycle/proliferation, and cellular metabolic process are altered in TIVE-LTC exposed to ABC294640. One of the candidates, Egr-1, was found to directly regulate LC3B expression and was required for the ABC294640-induced autophagic death. By using a Kaposi sarcoma-like nude mice model with TIVE-LTC, we found that ABC294640 treatment significantly suppressed KSHV-induced tumor growth in vivo, which indicates that targeting sphingolipid metabolism, especially SphK2, may represent a promising therapeutic strategy against KSHV-related malignancies. Mol Cancer Ther; 16(12); 2724-34. ©2017 AACR.
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Affiliation(s)
- Lu Dai
- Department of Pediatrics, Research Center for Translational Medicine and Key Laboratory of Arrhythmias, East Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Genetics, Louisiana State University Health Sciences Center, Louisiana Cancer Research Center, New Orleans, Louisiana
| | - Aiping Bai
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina
| | - Charles D Smith
- Apogee Biotechnology Corporation, Hershey Center for Applied Research, Hummelstown, Pennsylvania
| | | | - Fangyou Yu
- Department of Clinical Laboratory, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
| | - Zhiqiang Qin
- Department of Pediatrics, Research Center for Translational Medicine and Key Laboratory of Arrhythmias, East Hospital, Tongji University School of Medicine, Shanghai, China. .,Department of Genetics, Louisiana State University Health Sciences Center, Louisiana Cancer Research Center, New Orleans, Louisiana
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4
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Wang ZP, Tian Y, Lin J. Role of wild-type p53-induced phosphatase 1 in cancer. Oncol Lett 2017; 14:3893-3898. [PMID: 28959360 DOI: 10.3892/ol.2017.6685] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 12/16/2016] [Indexed: 12/23/2022] Open
Abstract
Wild-type p53-induced phosphatase (Wip1) is a member of the protein phosphatase type 2C family and is an established oncogene due to its dephosphorylation of several tumor suppressors and negative control of the DNA damage response system. It has been reported to dephosphorylate p53, ataxia telangiectasia mutated, checkpoint kinase 1 and p38 mitogen activated protein kinases, forming negative feedback loops to inhibit apoptosis and cell cycle arrest. Wip1 serves a major role in tumorigenesis, progression, invasion, distant metastasis and apoptosis in various types of human cancer. Therefore, it may be a potential biomarker and therapeutic target in the diagnosis and treatment of cancer. Furthermore, previous evidence has revealed a new role for Wip1 in the regulation of chemotherapy resistance. In the present review, the current knowledge on the role of Wip1 in cancer is discussed, as well as its potential as a novel target for cancer treatment and its function in chemotherapy resistance.
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Affiliation(s)
- Zhi-Peng Wang
- Department of Urology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Ye Tian
- Department of Urology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Jun Lin
- Department of Urology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
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Ahmad G, Amiji MM. Cancer stem cell-targeted therapeutics and delivery strategies. Expert Opin Drug Deliv 2016; 14:997-1008. [DOI: 10.1080/17425247.2017.1263615] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Gulzar Ahmad
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, MA, USA
| | - Mansoor M. Amiji
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, MA, USA
- Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
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Wang P, Cui J, Wen J, Guo Y, Zhang L, Chen X. Cisplatin induces HepG2 cell cycle arrest through targeting specific long noncoding RNAs and the p53 signaling pathway. Oncol Lett 2016; 12:4605-4612. [PMID: 28105167 PMCID: PMC5228559 DOI: 10.3892/ol.2016.5288] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 09/28/2016] [Indexed: 01/08/2023] Open
Abstract
Cisplatin has been used effectively in the treatment of hepatocellular carcinoma (HCC). Long noncoding RNAs (lncRNAs) were recently reported to contribute to the pathogenesis and progression of HCC. Their molecular mechanism related to cisplatin treatment remains unclear. The purpose of this study is to identify specific lncRNAs and to clarify their functions in HCC after cisplatin exposure. Reannotation and identification of differentially expressed lncRNAs were performed using the microarray data set GSE38122 in the Gene Expression Omnibus database. Four significantly differentially expressed lncRNAs (RP11-134G8.8, RP11-612B6.2, RP11-363E7.4 and RP1-193H18.2) were identified in HepG2 cells exposed to cisplatin by bioinformatics methods. The upregulated RP11-134G8.8 and RP11-363E7.4 and the downregulated RP1-193H18.2 were confirmed by reverse transcription-quantitative polymerase chain reaction. Furthermore, 57 significant co-expressing genes and their corresponding pathways were annotated and identified. The p53 signaling pathway showed the most significant difference among all pathways. Based on these results, the cell cycle and three key genes, cyclin-dependent kinase inhibitor 1A (CDKN1A, also known as p21), tumor protein p53 inducible protein 3 (TP53I3) and wild-type p53-induced phosphatase 1 (Wip1, also known as PPM1D), were examined. CDKN1A, TP53I3 and PPM1D were all downregulated by RP1-193H18.2 but upregulated by RP11-134G8.8 and RP11-363E7.4. And obvious S phase arrest was induced by cisplatin treatment for 24 h in HepG2 cells. Finally, the immunofluorescence results showed upregulation of TP53I3 and Wip1 and downregulation of p21 at the protein level. The results suggested that the lncRNAs RP11-134G8.8, RP11-363E7.4 and RP1-193H18.2, and their co-expression genes, which annotated into the p53 signaling pathway, could be potential targets for cisplatin treatment.
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Affiliation(s)
- Ping Wang
- Department of Otolaryngology-Head and Neck Surgery, First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jiayue Cui
- Department of Histology and Embryology, College of Basic Medical Sciences Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jihong Wen
- Department of Gynaecology and Obstetrics, First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yunhui Guo
- Department of Pharmacology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Liangzi Zhang
- Department of Pharmacology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Xia Chen
- Department of Pharmacology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
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Igawa T. Role of protein phosphatases in genitourinary cancers. Int J Urol 2016; 24:16-24. [DOI: 10.1111/iju.13197] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 07/22/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Tsukasa Igawa
- Department of Urology; Kurume University School of Medicine; Kurume Fukuoka Japan
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Xu Z, Cao C, Xia H, Shi S, Hong L, Wei X, Gu D, Bian J, Liu Z, Huang W, Zhang Y, He S, Lee NPY, Chen J. Protein phosphatase magnesium-dependent 1δ is a novel tumor marker and target in hepatocellular carcinoma. Front Med 2016; 10:52-60. [PMID: 26809466 DOI: 10.1007/s11684-016-0433-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 12/10/2015] [Indexed: 12/19/2022]
Abstract
Hepatocellular carcinoma (HCC) is a lethal liver malignancy worldwide. In this study, we reported that protein phosphatase magnesium-dependent 1δ (PPM1D) was highly expressed in the majority of HCC cases (approximately 59%) and significantly associated with high serum α-fetoprotein (AFP) level (P = 0.044). Kaplan- Meier and Cox regression data indicated that PPM1D overexpression was an independent predictor of HCCspecific overall survival (HR, 2.799; 95% CI, 1.346-5.818, P = 0.006). Overexpressing PPM1D promoted cell viability and invasion, whereas RNA interference-mediated knockdown of PPM1D inhibited proliferation, invasion, and migration of cultured HCC cells. In addition, PPM1D suppression by small interfering RNA decreased the tumorigenicity of HCC cells in vivo. Overall, results suggest that PPM1D is a potential prognostic marker and therapeutic target for HCC.
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Affiliation(s)
- Zhi Xu
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China.
| | - Chunxiang Cao
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China
| | - Haiyan Xia
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China
| | - Shujing Shi
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China
| | - Lingzhi Hong
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China
| | - Xiaowei Wei
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China
| | - Dongying Gu
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China
| | - Jianmin Bian
- Department of General Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China
| | - Zijun Liu
- Department of General Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China
| | - Wenbin Huang
- Department of Pathology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China
| | - Yixin Zhang
- Department of General Surgery, Nantong Tumor Hospital, Nantong, 226361, China
| | - Song He
- Department of Pathology, Nantong Tumor Hospital, Nantong, 226361, China
| | - Nikki Pui-Yue Lee
- Department of Surgery, Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Jinfei Chen
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China.
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Wu B, Guo BM, Kang J, Deng XZ, Fan YB, Zhang XP, Ai KX. PPM1D exerts its oncogenic properties in human pancreatic cancer through multiple mechanisms. Apoptosis 2015; 21:365-78. [DOI: 10.1007/s10495-015-1211-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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10
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Tao Z, Zhu C, Song C, Song W, Ji G, Shan Y, Xu W, Li H. Lentivirus-mediated RNA interference of myostatin gene affects MyoD and Myf5 gene expression in duck embryonic myoblasts. Br Poult Sci 2015; 56:551-8. [PMID: 26301941 DOI: 10.1080/00071668.2015.1085958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The aim of this study was to construct lentivirus-mediated short hairpin RNA (shRNA) vectors targeting the duck MSTN gene and investigate whether these vectors can affect the development of duck primary cultured embryonic myoblasts. MSTN mRNA levels in the myoblasts were detected using quantitative real-time polymerase chain reaction (PCR), cell proliferation was assessed by MTT assays and cell differentiation was assayed by photography. MSTN mRNA levels in PLL3.7-MSTN-shRNA1, PLL3.7-MSTN-shRNA2 and PLL3.7-MSTN-shRNA3 lentivirus-mediated shRNA groups were reduced by 61.6%, 76.9% and 79.1%, respectively, compared to control cells. Down-regulation of MSTN in duck embryonic myoblasts stimulated cell proliferation and inhibited differentiation, accompanied by a greater than twofold down-regulation of MyoD expression and up-regulation of Myf5 expression. These results revealed that silencing of MSTN changes the development of duck embryonic myoblasts by regulating the expression level of MyoD and Myf5 genes.
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Affiliation(s)
- Z Tao
- a Jiangsu Provincial Key Laboratory of Poultry Genetics & Breeding , Jiangsu Institute of Poultry Sciences , Yangzhou , P.R. China
| | - C Zhu
- a Jiangsu Provincial Key Laboratory of Poultry Genetics & Breeding , Jiangsu Institute of Poultry Sciences , Yangzhou , P.R. China
| | - C Song
- a Jiangsu Provincial Key Laboratory of Poultry Genetics & Breeding , Jiangsu Institute of Poultry Sciences , Yangzhou , P.R. China
| | - W Song
- a Jiangsu Provincial Key Laboratory of Poultry Genetics & Breeding , Jiangsu Institute of Poultry Sciences , Yangzhou , P.R. China
| | - G Ji
- a Jiangsu Provincial Key Laboratory of Poultry Genetics & Breeding , Jiangsu Institute of Poultry Sciences , Yangzhou , P.R. China
| | - Y Shan
- a Jiangsu Provincial Key Laboratory of Poultry Genetics & Breeding , Jiangsu Institute of Poultry Sciences , Yangzhou , P.R. China
| | - W Xu
- a Jiangsu Provincial Key Laboratory of Poultry Genetics & Breeding , Jiangsu Institute of Poultry Sciences , Yangzhou , P.R. China
| | - H Li
- a Jiangsu Provincial Key Laboratory of Poultry Genetics & Breeding , Jiangsu Institute of Poultry Sciences , Yangzhou , P.R. China
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11
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Novel delivery approaches for cancer therapeutics. J Control Release 2015; 219:248-268. [PMID: 26456750 DOI: 10.1016/j.jconrel.2015.09.067] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/09/2015] [Accepted: 09/30/2015] [Indexed: 02/07/2023]
Abstract
Currently, a majority of cancer treatment strategies are based on the removal of tumor mass mainly by surgery. Chemical and physical treatments such as chemo- and radiotherapies have also made a major contribution in inhibiting rapid growth of malignant cells. Furthermore, these approaches are often combined to enhance therapeutic indices. It is widely known that surgery, chemo- and radiotherapy also inhibit normal cells growth. In addition, these treatment modalities are associated with severe side effects and high toxicity which in turn lead to low quality of life. This review encompasses novel strategies for more effective chemotherapeutic delivery aiming to generate better prognosis. Currently, cancer treatment is a highly dynamic field and significant advances are being made in the development of novel cancer treatment strategies. In contrast to conventional cancer therapeutics, novel approaches such as ligand or receptor based targeting, triggered release, intracellular drug targeting, gene delivery, cancer stem cell therapy, magnetic drug targeting and ultrasound-mediated drug delivery, have added new modalities for cancer treatment. These approaches have led to selective detection of malignant cells leading to their eradication with minimal side effects. Lowering multi-drug resistance and involving influx transportation in targeted drug delivery to cancer cells can also contribute significantly in the therapeutic interventions in cancer.
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Zhang M, Xu E, Zhang J, Chen X. PPM1D phosphatase, a target of p53 and RBM38 RNA-binding protein, inhibits p53 mRNA translation via dephosphorylation of RBM38. Oncogene 2015; 34:5900-11. [PMID: 25823026 PMCID: PMC4589422 DOI: 10.1038/onc.2015.31] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 01/04/2015] [Accepted: 01/25/2015] [Indexed: 12/14/2022]
Abstract
PPM1D phosphatase, also called wild-type p53-induced phosphatase 1 (Wip1), promotes tumor development by inactivating the p53 tumor suppressor pathway. RBM38 RNA-binding protein, also called RNPC1 and a target of p53, inhibits p53 mRNA translation, which can be reversed by GSK3 protein kinase via phosphorylation of RBM38 at serine 195. Here we showed that ectopic expression of RBM38 increases, whereas knockdown of RBM38 inhibits, PPM1D mRNA translation. Consistent with this, we found that RBM38 directly binds to PPM1D 3' untranslated region (3’UTR) and promotes expression of a heterologous reporter gene that carries PPM1D 3’UTR in a dose-dependent manner. Interestingly, we showed that PPM1D directly interacts with and dephosphorylates RBM38 at serine 195. Furthermore, we showed that PPM1D modulates p53 mRNA translation and p53-dependent growth suppression through dephosphorylation of RBM38. These findings provide evidence that the crosstalk between PPM1D and RBM38, both of which are targets and modulators of p53, plays a critical role in p53 expression and activity.
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Affiliation(s)
- M Zhang
- Comparative Oncology Laboratory, Department of Surgical & Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - E Xu
- Comparative Oncology Laboratory, Department of Surgical & Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - J Zhang
- Comparative Oncology Laboratory, Department of Surgical & Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - X Chen
- Comparative Oncology Laboratory, Department of Surgical & Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
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