1
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Somanath PR, Chernoff J, Cummings BS, Prasad SM, Homan HD. Targeting P21-Activated Kinase-1 for Metastatic Prostate Cancer. Cancers (Basel) 2023; 15:2236. [PMID: 37190165 PMCID: PMC10137274 DOI: 10.3390/cancers15082236] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/06/2023] [Accepted: 04/09/2023] [Indexed: 05/17/2023] Open
Abstract
Metastatic prostate cancer (mPCa) has limited therapeutic options and a high mortality rate. The p21-activated kinase (PAK) family of proteins is important in cell survival, proliferation, and motility in physiology, and pathologies such as infectious, inflammatory, vascular, and neurological diseases as well as cancers. Group-I PAKs (PAK1, PAK2, and PAK3) are involved in the regulation of actin dynamics and thus are integral for cell morphology, adhesion to the extracellular matrix, and cell motility. They also play prominent roles in cell survival and proliferation. These properties make group-I PAKs a potentially important target for cancer therapy. In contrast to normal prostate and prostatic epithelial cells, group-I PAKs are highly expressed in mPCA and PCa tissue. Importantly, the expression of group-I PAKs is proportional to the Gleason score of the patients. While several compounds have been identified that target group-I PAKs and these are active in cells and mice, and while some inhibitors have entered human trials, as of yet, none have been FDA-approved. Probable reasons for this lack of translation include issues related to selectivity, specificity, stability, and efficacy resulting in side effects and/or lack of efficacy. In the current review, we describe the pathophysiology and current treatment guidelines of PCa, present group-I PAKs as a potential druggable target to treat mPCa patients, and discuss the various ATP-competitive and allosteric inhibitors of PAKs. We also discuss the development and testing of a nanotechnology-based therapeutic formulation of group-I PAK inhibitors and its significant potential advantages as a novel, selective, stable, and efficacious mPCa therapeutic over other PCa therapeutics in the pipeline.
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Affiliation(s)
- Payaningal R. Somanath
- Department of Clinical & Administrative Pharmacy, College of Pharmacy, University of Georgia, Augusta, GA 30912, USA
- MetasTx LLC, Basking Ridge, NJ 07920, USA
| | - Jonathan Chernoff
- MetasTx LLC, Basking Ridge, NJ 07920, USA
- Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Brian S. Cummings
- MetasTx LLC, Basking Ridge, NJ 07920, USA
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Sandip M. Prasad
- Morristown Medical Center, Atlantic Health System, Morristown, NJ 07960, USA
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2
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Manzar N, Ganguly P, Khan UK, Ateeq B. Transcription networks rewire gene repertoire to coordinate cellular reprograming in prostate cancer. Semin Cancer Biol 2023; 89:76-91. [PMID: 36702449 DOI: 10.1016/j.semcancer.2023.01.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 01/04/2023] [Accepted: 01/18/2023] [Indexed: 01/24/2023]
Abstract
Transcription factors (TFs) represent the most commonly deregulated DNA-binding class of proteins associated with multiple human cancers. They can act as transcriptional activators or repressors that rewire the cistrome, resulting in cellular reprogramming during cancer progression. Deregulation of TFs is associated with the onset and maintenance of various cancer types including prostate cancer. An emerging subset of TFs has been implicated in the regulation of multiple cancer hallmarks during tumorigenesis. Here, we discuss the role of key TFs which modulate transcriptional cicuitries involved in the development and progression of prostate cancer. We further highlight the role of TFs associated with key cancer hallmarks, including, chromatin remodeling, genome instability, DNA repair, invasion, and metastasis. We also discuss the pluripotent function of TFs in conferring lineage plasticity, that aids in disease progression to neuroendocrine prostate cancer. At the end, we summarize the current understanding and approaches employed for the therapeutic targeting of TFs and their cofactors in the clinical setups to prevent disease progression.
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Affiliation(s)
- Nishat Manzar
- Molecular Oncology Laboratory, Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016, UP, India
| | - Promit Ganguly
- Molecular Oncology Laboratory, Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016, UP, India
| | - Umar Khalid Khan
- Molecular Oncology Laboratory, Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016, UP, India
| | - Bushra Ateeq
- Molecular Oncology Laboratory, Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016, UP, India; Mehta Family Center for Engineering in Medicine, Indian Institute of Technology Kanpur, Kanpur 208016, India.
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3
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Chetty AK, Ha BH, Boggon TJ. Rho family GTPase signaling through type II p21-activated kinases. Cell Mol Life Sci 2022; 79:598. [PMID: 36401658 PMCID: PMC10105373 DOI: 10.1007/s00018-022-04618-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/07/2022] [Accepted: 10/28/2022] [Indexed: 11/21/2022]
Abstract
Signaling from the Rho family small GTPases controls a wide range of signaling outcomes. Key among the downstream effectors for many of the Rho GTPases are the p21-activated kinases, or PAK group. The PAK family comprises two types, the type I PAKs (PAK1, 2 and 3) and the type II PAKs (PAK4, 5 and 6), which have distinct structures and mechanisms of regulation. In this review, we discuss signal transduction from Rho GTPases with a focus on the type II PAKs. We discuss the role of PAKs in signal transduction pathways and selectivity of Rho GTPases for PAK family members. We consider the less well studied of the Rho GTPases and their PAK-related signaling. We then discuss the molecular basis for kinase domain recognition of substrates and for regulation of signaling. We conclude with a discussion of the role of PAKs in cross talk between Rho family small GTPases and the roles of PAKs in disease.
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Affiliation(s)
- Ashwin K Chetty
- Yale College, New Haven, CT, 06520, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, 333 Cedar Street, New Haven, CT, 06520, USA
| | - Byung Hak Ha
- Department of Pharmacology, Yale University, 333 Cedar Street, New Haven, CT, 06520, USA
| | - Titus J Boggon
- Department of Molecular Biophysics and Biochemistry, Yale University, 333 Cedar Street, New Haven, CT, 06520, USA.
- Department of Pharmacology, Yale University, 333 Cedar Street, New Haven, CT, 06520, USA.
- Yale Cancer Center, Yale University, 333 Cedar Street, New Haven, CT, 06520, USA.
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4
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Yang Q, Zhao Y, Chen Y, Chang Y, Huang A, Xu T, Li G, Wu G. PAK6 promotes cervical cancer progression through activation of the Wnt/β-catenin signaling pathway. Oncol Lett 2020; 20:2387-2395. [PMID: 32782556 PMCID: PMC7400107 DOI: 10.3892/ol.2020.11797] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 05/27/2020] [Indexed: 12/13/2022] Open
Abstract
p21-activated kinase 6 (PAK6), a member of the serine/threonine kinase family, has been reported to be involved in numerous types of cancers. The present study aimed to investigate the role of PAK6 in cervical cancer. In the present study, PAK6 expression was evaluated in tissue microarrays and cell lines by using immunohistochemistry and western blotting. The mRNA level of PAK6 was evaluated by reverse transcription quantitative PCR. The Wnt/β-catenin signaling-related protein expression was detected by western blotting following short hairpin (sh)RNA-mediated PAK6 knockdown or PAK6 overexpression. Cell proliferation was determined using Cell Countink Kit-8. Migration, invasion and colony formation were further assessed following PAK6 knockdown or overexpression. Co-immunoprecipitation (Co-IP) and fluorescence colocalization microscopy were used to detect the interaction between PAK6 and GSK3β. The results from tissue microarray revealed that the expression levels of PAK6 in cervical cancer tissues were upregulated. The downregulation of PAK6 expression levels using shRNA not only decreased cell growth and proliferation, but it also inhibited the migration and invasion of HeLa cells. Conversely, the overexpression of PAK6 promoted the proliferation, migration and invasion of HeLa cells. In addition, the expression levels of proteins involved in the Wnt/β-catenin signaling pathway were modified in the PAK6 knockdown group, including downregulation of GSK3β phosphorylation and Cyclin D1 protein, and upregulation of β-catenin phosphorylation and E-cadherin. In contrast, following the overexpression of PAK6, the Wnt/β-catenin signaling pathway was activated. Further investigation using fluorescence microscopy and Co-IP assays indicated that PAK6 may interact with GSK3β. In conclusion, the findings of the present study suggested that PAK6 may serve a role in promoting cervical cancer through activating the Wnt/β-catenin signaling pathway.
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Affiliation(s)
- Qin Yang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Yingchao Zhao
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Yeshan Chen
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Yu Chang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Ai Huang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Tie Xu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Guiling Li
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Gang Wu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
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5
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Venkadakrishnan VB, Ben-Salem S, Heemers HV. AR-dependent phosphorylation and phospho-proteome targets in prostate cancer. Endocr Relat Cancer 2020; 27:R193-R210. [PMID: 32276264 PMCID: PMC7583603 DOI: 10.1530/erc-20-0048] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 04/06/2020] [Indexed: 12/17/2022]
Abstract
Prostate cancer (CaP) is the second leading cause of cancer-related deaths in Western men. Because androgens drive CaP by activating the androgen receptor (AR), blocking AR's ligand activation, known as androgen deprivation therapy (ADT), is the default treatment for metastatic CaP. Despite an initial remission, CaP eventually develops resistance to ADT and progresses to castration-recurrent CaP (CRPC). CRPC continues to rely on aberrantly activated AR that is no longer inhibited effectively by available therapeutics. Interference with signaling pathways downstream of activated AR that mediate aggressive CRPC behavior may lead to alternative CaP treatments. Developing such therapeutic strategies requires a thorough mechanistic understanding of the most clinically relevant and druggable AR-dependent signaling events. Recent proteomics analyses of CRPC clinical specimens indicate a shift in the phosphoproteome during CaP progression. Kinases and phosphatases represent druggable entities, for which clinically tested inhibitors are available, some of which are incorporated already in treatment plans for other human malignancies. Here, we reviewed the AR-associated transcriptome and translational regulon, and AR interactome involved in CaP phosphorylation events. Novel and for the most part mutually exclusive AR-dependent transcriptional and post-transcriptional control over kinase and phosphatase expression was found, with yet other phospho-regulators interacting with AR. The multiple mechanisms by which AR can shape and fine-tune the CaP phosphoproteome were reflected in diverse aspects of CaP biology such as cell cycle progression and cell migration. Furthermore, we examined the potential, limitations and challenges of interfering with AR-mediated phosphorylation events as alternative strategy to block AR function during CaP progression.
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Affiliation(s)
- Varadha Balaji Venkadakrishnan
- Department of Cancer Biology, Cleveland Clinic, Cleveland, Ohio, USA
- Department of Biological, Geological and Environmental Sciences, Cleveland State University, Cleveland, Ohio, USA
| | - Salma Ben-Salem
- Department of Cancer Biology, Cleveland Clinic, Cleveland, Ohio, USA
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6
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Gong CC, Li TT, Pei DS. PAK6: a potential anti-cancer target. BRAZ J PHARM SCI 2020. [DOI: 10.1590/s2175-97902019000318315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
| | | | - Dong-Sheng Pei
- Xuzhou Medical University, China; Xuzhou Medical University, China
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7
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Goyette SR, Schott E, Uwimana A, Nelson DW, Boganski J. Detection of the steroid receptor interacting protein, PAK6, in a neuronal cell line. Heliyon 2019; 5:e01294. [PMID: 30923762 PMCID: PMC6423815 DOI: 10.1016/j.heliyon.2019.e01294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 01/18/2019] [Accepted: 02/26/2019] [Indexed: 01/31/2023] Open
Abstract
PAK6 is a Group II p21 activated kinase that unlike traditional signal transduction proteins interacts with multiple binding partners including sex-steroid receptors. PAK6 acts as a nodal checkpoint integrating multiple cellular inputs to promote distinct cellular outcomes, some of which are associated with cytoskeletal remodeling. Despite the possibility that PAK6 may couple sex-specific neuronal function and therefore serve as a valuable research, diagnostic and therapeutic target, there is currently no standardized protocol for assessing PAK6 activity in a neuronal cell line. Here, we present a protocol for assessing PAK6 levels in a commonly used neuronal cell line, PC-12. In comparison with other methodology, this approach (1) does not require ex-planted tissue to identify PAK6 in neurons and (2) unlike other protocols which require steroid depleted media for detection of PAK6 in non-neuronal cell lines, such as prostate cancer cell lines, we were easily able to detect PAK6 in PC-12 cells grown in complete, steroid-containing media. Thus the present protocol allows for the efficient detection of native PAK6 in PC-12 cells to expedite targeted basic research of the emerging importance of PAK6 function in the brain as well as to accelerate the identification and isolation of potential therapeutic targets not only in cancerous but brain disease states as well.
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Affiliation(s)
| | - Eric Schott
- Shields Science Center, Stonehill College, Easton MA, 02357, USA
| | | | - David W Nelson
- Shields Science Center, Stonehill College, Easton MA, 02357, USA
| | - Jacob Boganski
- Shields Science Center, Stonehill College, Easton MA, 02357, USA
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8
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Prognostic significance of PAK family kinases in acute myeloid leukemia. Cancer Gene Ther 2019; 27:30-37. [PMID: 30890765 DOI: 10.1038/s41417-019-0090-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Accepted: 02/10/2019] [Indexed: 12/17/2022]
Abstract
Acute myeloid leukemia (AML) is a clonal and heterogeneous disease characterized by a myriad of genetic defects. Genetic abnormalities are powerful prognostic factors. P21-activated kinases (PAKs) are a kind of serine/threonine protein kinases, which is regulator of plenty of oncogenic signaling pathways. The clinical and prognostic value of PAKs in AML is unclear. A total of 155 AML patients with PAK expression data from The Cancer Genome Atlas database were enrolled in this study. Eighty-four patients underwent chemotherapy only, 71 also underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). In the chemotherapy-only group, high PAK3 and PAK7 expression were both bound up with poor EFS and OS (all P < 0.05). However, high PAK2 expressers had better EFS and OS (all P < 0.05). Multivariate analysis demonstrated that high PAK7 expression was an adverse independent prognostic factor in patients who received chemotherapy only. PAKs have no influence in EFS and OS in patients who underwent allo-HSCT. In conclusion, high PAK2 expression is a favorable prognostic factor, as to the high expression of PAK3 and PAK7, they are poor prognostic factors, and PAK7 has better prognostic value, but their prognostic effects can be offset by allo-HSCT.
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9
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Wang K, Baldwin GS, Nikfarjam M, He H. p21-activated kinase signalling in pancreatic cancer: New insights into tumour biology and immune modulation. World J Gastroenterol 2018; 24:3709-3723. [PMID: 30197477 PMCID: PMC6127653 DOI: 10.3748/wjg.v24.i33.3709] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/22/2018] [Accepted: 06/27/2018] [Indexed: 02/06/2023] Open
Abstract
Pancreatic cancer is one of the most aggressive and lethal malignancies worldwide, with a very poor prognosis and a five-year survival rate less than 8%. This dismal outcome is largely due to delayed diagnosis, early distant dissemination and resistance to conventional chemo-therapies. Kras mutation is a well-defined hallmark of pancreatic cancer, with over 95% of cases harbouring Kras mutations that give rise to constitutively active forms of Kras. As important down-stream effectors of Kras, p21-activated kinases (PAKs) are involved in regulating cell proliferation, apoptosis, invasion/migration and chemo-resistance. Immunotherapy is now emerging as a promising treatment modality in the era of personalized anti-cancer therapeutics. In this review, basic knowledge of PAK structure and regulation is briefly summarised and the pivotal role of PAKs in Kras-driven pancreatic cancer is highlighted in terms of tumour biology and chemo-resistance. Finally, the involvement of PAKs in immune modulation in the tumour microenvironment is discussed and the potential advantages of targeting PAKs are explored.
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Affiliation(s)
- Kai Wang
- Department of Surgery, University of Melbourne, Melbourne 3084, Australia
| | - Graham S Baldwin
- Department of Surgery, University of Melbourne, Melbourne 3084, Australia
| | - Mehrdad Nikfarjam
- Department of Surgery, University of Melbourne, Melbourne 3084, Australia
| | - Hong He
- Department of Surgery, University of Melbourne, Melbourne 3084, Australia
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10
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Li K, Xu X, He Y, Tian Y, Pan W, Xu L, Ma Y, Gao Y, Gao J, Qi Y, Wei L, Zhang J. P21-activated kinase 7 (PAK7) interacts with and activates Wnt/β-catenin signaling pathway in breast cancer. J Cancer 2018; 9:1821-1835. [PMID: 29805709 PMCID: PMC5968771 DOI: 10.7150/jca.24934] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 02/22/2018] [Indexed: 12/30/2022] Open
Abstract
Background: Breast cancer is the highest incidence of tumor in women, which seriously threaten women's health. The occurrence and progression of breast cancer is linked to inactivation or downregulation of tumor suppressors, and activation or upregulation of oncogenes. However, the mechanism of PAK7 involving in the occurrence and progression of breast cancer is not yet fully understood. Methods: PAK7 expression was analyzed by RT-qPCR and immunohistochemistry and correlated with clinicopatholgical parameters in breast cancer tissue microarray. The effects of PAK7 on breast cancer cells were detected by CCK-8 assay, colon formation assay, wound healing and transwell assays, and flow cytometry. The relationship between PAK7 and Wnt/β-catenin signaling pathway was determined by western blotting, TOP/FOP flash, co-Immunoprecipitation and co-localization assays. Results: PAK7 expression was significantly increased in breast cancer tissues and positively correlated with pathological differentiation and TNM stage of breast cancer. Overexpression of PAK7 could significantly promote proliferation and migration of breast cancer cells, and inhibit apoptosis. In contrast, PAK7 knockdown significantly inhibited the proliferation and migration of breast cancer cells and promoted apoptosis. In addition, PAK7 could activate Wnt/β-catenin signaling pathway in breast cancer cells. Further study found that PAK7 could directly bind to GSK3β and β-catenin, and regulate β-catenin degradation by phosphorylating GSK3β. Conclusions: Our study demonstrated that PAK7, as an oncogene, involved in breast cancer progression by activating the Wnt/β-catenin signaling pathway, suggesting that the potential applicability of PAK7 as a target for breast cancer treatment.
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Affiliation(s)
- Kai Li
- Department of Pathology and Pathophysiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, Hubei, China
| | - Xiaolong Xu
- Department of Pathology and Pathophysiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, Hubei, China
| | - Yanqi He
- Department of Pathology and Pathophysiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, Hubei, China
| | - Yihao Tian
- Department of Anatomy, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, Hubei, China
| | - Wenting Pan
- Department of Pathology and Pathophysiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, Hubei, China
| | - Liu Xu
- Department of Pathology and Pathophysiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, Hubei, China
| | - Yanbin Ma
- Department of Pathology and Pathophysiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, Hubei, China
| | - Yang Gao
- Department of Breast and Thyroid Surgery, Zhongnan Hospital, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan 430071, Hubei, China
| | - Jingbo Gao
- Department of Breast and Thyroid Surgery, Zhongnan Hospital, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan 430071, Hubei, China
| | - Yuwen Qi
- Department of Breast and Thyroid Surgery, Zhongnan Hospital, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan 430071, Hubei, China
| | - Lei Wei
- Department of Pathology and Pathophysiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, Hubei, China
| | - Jingwei Zhang
- Department of Breast and Thyroid Surgery, Zhongnan Hospital, Hubei Key Laboratory of Tumor Biological Behaviors, Hubei Cancer Clinical Study Center, Wuhan University, Wuhan 430071, Hubei, China
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11
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Pérez-Yépez EA, Saldívar-Cerón HI, Villamar-Cruz O, Pérez-Plasencia C, Arias-Romero LE. p21 Activated kinase 1: Nuclear activity and its role during DNA damage repair. DNA Repair (Amst) 2018; 65:42-46. [PMID: 29597073 DOI: 10.1016/j.dnarep.2018.03.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 03/20/2018] [Indexed: 01/30/2023]
Abstract
p21-activated kinase 1 (PAK1) is a serine/threonine kinase activated by the small GTPases Rac1 and Cdc42. It is located in the chromosome 11q13 and is amplified and/or overexpressed in several human cancer types including 25-30% of breast tumors. This enzyme plays a pivotal role in the control of a number of fundamental cellular processes by phosphorylating its downstream substrates. In addition to its role in the cytoplasm, it is well documented that PAK1 also plays crucial roles in the nucleus participating in mitotic events and gene expression through its association and/or phosphorylation of several transcription factors, transcriptional co-regulators and cell cycle-related proteins, including Aurora kinase A (AURKA), polo-like kinase 1 (PLK1), the forkhead transcription factor (FKHR), estrogen receptor α (ERα), and Snail. More recently, PAK signaling has emerged as a component of the DNA damage response (DDR) as PAK1 activity influences the cellular sensitivity to ionizing radiation and promotes the expression of several genes involved in the Fanconi Anemia/BRCA pathway. This review will focus on the nuclear functions of PAK1 and its role in the regulation of DNA damage repair.
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Affiliation(s)
- Eloy Andrés Pérez-Yépez
- UBIMED, Facultad de Estudios Superiores-Iztacala, UNAM, Tlalnepantla, Estado de México 54090, Mexico; Department of Medicine, Division of Gastroenterology and Nutrition, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Héctor Iván Saldívar-Cerón
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado postal 14-740, 07360 México, D. F., México
| | - Olga Villamar-Cruz
- UBIMED, Facultad de Estudios Superiores-Iztacala, UNAM, Tlalnepantla, Estado de México 54090, Mexico
| | - Carlos Pérez-Plasencia
- UBIMED, Facultad de Estudios Superiores-Iztacala, UNAM, Tlalnepantla, Estado de México 54090, Mexico
| | - Luis Enrique Arias-Romero
- UBIMED, Facultad de Estudios Superiores-Iztacala, UNAM, Tlalnepantla, Estado de México 54090, Mexico.
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12
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Civiero L, Greggio E. PAKs in the brain: Function and dysfunction. Biochim Biophys Acta Mol Basis Dis 2017; 1864:444-453. [PMID: 29129728 DOI: 10.1016/j.bbadis.2017.11.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/31/2017] [Accepted: 11/06/2017] [Indexed: 12/17/2022]
Abstract
p21-Activated kinases (PAKs) comprise a family of proteins covering a central role in signal transduction. They are downstream effectors of Rho GTPases and can affect a variety of processes in different cell types and tissues by remodeling the cytoskeleton and by promoting gene transcription and cell survival. Given the relevance of cytoskeletal organization in neuronal development as well as synaptic function and the importance of pro-survival signals in controlling neuronal cell fate, accumulating studies investigated the role of PAKs in the nervous system. In this review, we provide a critical overview of the role of PAKs in the nervous system, both in neuronal and non-neuronal cells, and discuss their potential link with neurodegenerative diseases.
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13
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Kumar R, Sanawar R, Li X, Li F. Structure, biochemistry, and biology of PAK kinases. Gene 2016; 605:20-31. [PMID: 28007610 DOI: 10.1016/j.gene.2016.12.014] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 11/24/2016] [Accepted: 12/14/2016] [Indexed: 02/07/2023]
Abstract
PAKs, p21-activated kinases, play central roles and act as converging junctions for discrete signals elicited on the cell surface and for a number of intracellular signaling cascades. PAKs phosphorylate a vast number of substrates and act by remodeling cytoskeleton, employing scaffolding, and relocating to distinct subcellular compartments. PAKs affect wide range of processes that are crucial to the cell from regulation of cell motility, survival, redox, metabolism, cell cycle, proliferation, transformation, stress, inflammation, to gene expression. Understandably, their dysregulation disrupts cellular homeostasis and severely impacts key cell functions, and many of those are implicated in a number of human diseases including cancers, neurological disorders, and cardiac disorders. Here we provide an overview of the members of the PAK family and their current status. We give special emphasis to PAK1 and PAK4, the prototypes of groups I and II, for their profound roles in cancer, the nervous system, and the heart. We also highlight other family members. We provide our perspective on the current advancements, their growing importance as strategic therapeutic targets, and our vision on the future of PAKs.
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Affiliation(s)
- Rakesh Kumar
- Department of Biochemistry and Molecular Medicine, School of Medicine and Health Sciences, George Washington University, Washington, DC 20037, USA; Cancer Biology Program, Rajiv Gandhi Center of Biotechnology, Thiruvananthapuram 695014, India.
| | - Rahul Sanawar
- Cancer Biology Program, Rajiv Gandhi Center of Biotechnology, Thiruvananthapuram 695014, India
| | - Xiaodong Li
- Department of Cell Biology, Key Laboratory of Medical Cell Biology, Chinese Ministry of Education, China Medical University, Shenyang 110122, China
| | - Feng Li
- Department of Cell Biology, Key Laboratory of Medical Cell Biology, Chinese Ministry of Education, China Medical University, Shenyang 110122, China.
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14
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Xu HT, Lai WL, Liu HF, Wong LLY, Ng IOL, Ching YP. PAK4 Phosphorylates p53 at Serine 215 to Promote Liver Cancer Metastasis. Cancer Res 2016; 76:5732-5742. [DOI: 10.1158/0008-5472.can-15-3373] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 07/13/2016] [Indexed: 11/16/2022]
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15
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Li YC, Luo ML, Guo H, Wang TT, Lin SR, Chen JB, Ma Q, Gu YL, Jiang ZM, Gui YT. Identification of NR0B1 as a novel androgen receptor co-repressor in mouse Sertoli cells. Int J Mol Med 2016; 38:853-60. [PMID: 27431683 DOI: 10.3892/ijmm.2016.2672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 06/22/2016] [Indexed: 11/06/2022] Open
Abstract
Nuclear receptor subfamily 0 group B member 1 (Nr0b1) is an atypical member of the nuclear receptor family that is predominantly expressed in mouse Sertoli cells (SCs). Mutations of NR0B1 in humans cause adrenal failure and hypogonadotropic hypogonadism. The targeted mutagenesis of Nr0b1 in mice has revealed a primary gonadal defect characterized by the overexpression of aromatase and cellular obstruction of the seminiferous tubules and efferent ductules, leading to germ cell death and infertility. The transgenic expression of Nr0b1 under the control of the Müllerian-inhibiting substance promoter (MIS-Nr0b1), which is selectively expressed in SCs, improves fertility. Testicular androgen receptor (AR) was also expressed in SCs. Many genes are directly regulated by androgen and its AR, which are involved in spermatogenesis and male infertility. As the association between NR0B1 and AR remains unclear in mouse SCs, we decided to further explore the relationship between them. In the present study, we have identified NR0B1 as a novel AR co-repressor in mouse SCs. Using RT‑qPCR and immunofluorescence, we determined that NR0B1 was mainly expressed in mouse SCs in an age-dependent manner from 2-8 weeks of age postnatally. The inhibition of the effects of AR on AR target genes by NR0B1, in an androgen‑dependent manner, was further demonstrated by western blot analysis and RT-qPCR in TM4 cells, a mouse Sertoli cell line. Finally, in vitro luciferase and co-immunoprecipitation assays validated that NR0B1, as an AR co-repressor, significantly inhibited the transcriptional activation of its target genes. These results suggest that novel inhibitory mechanisms underlie the effects of NR0B1 in modulating androgen-dependent gene transcription in mouse SCs.
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Affiliation(s)
- Yu-Chi Li
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Man-Ling Luo
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Huan Guo
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Tian-Tian Wang
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Shou-Ren Lin
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Jian-Bo Chen
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Qian Ma
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Yan-Li Gu
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Zhi-Mao Jiang
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Yao-Ting Gui
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
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16
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Kumar R, Li DQ. PAKs in Human Cancer Progression: From Inception to Cancer Therapeutic to Future Oncobiology. Adv Cancer Res 2016; 130:137-209. [PMID: 27037753 DOI: 10.1016/bs.acr.2016.01.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Since the initial recognition of a mechanistic role of p21-activated kinase 1 (PAK1) in breast cancer invasion, PAK1 has emerged as one of the widely overexpressed or hyperactivated kinases in human cancer at-large, allowing the PAK family to make in-roads in cancer biology, tumorigenesis, and cancer therapeutics. Much of our current understanding of the PAK family in cancer progression relates to a central role of the PAK family in the integration of cancer-promoting signals from cell membrane receptors as well as function as a key nexus-modifier of complex, cytoplasmic signaling network. Another core aspect of PAK signaling that highlights its importance in cancer progression is through PAK's central role in the cross talk with signaling and interacting proteins, as well as PAK's position as a key player in the phosphorylation of effector substrates to engage downstream components that ultimately leads to the development cancerous phenotypes. Here we provide a comprehensive review of the recent advances in PAK cancer research and its downstream substrates in the context of invasion, nuclear signaling and localization, gene expression, and DNA damage response. We discuss how a deeper understanding of PAK1's pathobiology over the years has widened research interest to the PAK family and human cancer, and positioning the PAK family as a promising cancer therapeutic target either alone or in combination with other therapies. With many landmark findings and leaps in the progress of PAK cancer research since the infancy of this field nearly 20 years ago, we also discuss postulated advances in the coming decade as the PAK family continues to shape the future of oncobiology.
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Affiliation(s)
- R Kumar
- School of Medicine and Health Sciences, George Washington University, Washington, DC, United States; Rajiv Gandhi Center of Biotechnology, Thiruvananthapuram, India.
| | - D-Q Li
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China; Key Laboratory of Breast Cancer in Shanghai, Shanghai Medical College, Fudan University, Shanghai, China; Key Laboratory of Epigenetics in Shanghai, Shanghai Medical College, Fudan University, Shanghai, China.
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17
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Cai S, Chen R, Li X, Cai Y, Ye Z, Li S, Li J, Huang H, Peng S, Wang J, Tao Y, Huang H, Wen X, Mo J, Deng Z, Wang J, Zhang Y, Gao X, Wen X. Downregulation of microRNA-23a suppresses prostate cancer metastasis by targeting the PAK6-LIMK1 signaling pathway. Oncotarget 2016; 6:3904-17. [PMID: 25714010 PMCID: PMC4414162 DOI: 10.18632/oncotarget.2880] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 12/08/2014] [Indexed: 12/14/2022] Open
Abstract
Here we found that levels of miR-23a were decreased in prostate cancer cell lines and tumor tissues. These low levels were associated with poor patients' prognosis. MiR-23a inhibited migration and invasion of prostate cancer in vivo and in orthotopic prostate cancer mice model. MiR-23a decreased levels of p21-activated kinase 6 (PAK6). Expression of miR-23a inhibited phosphorylation of LIM kinase 1 (LIMK1) and cofilin, in turn suppressing formation of stress fibers and actin filaments, which was required for cell motility and invasion. PAK6 bound to LIMK1 and activated it via phosphorylation at Thr-508. Also, PAK6 and LIMK1 were colocalized in the cytoplasma. Thus, miR-23a regulated cytoskeleton by affecting LIMK1 and cofilin. In summary, we have identified the miR-23a-PAK6-LIMK1 pathway of prostate cancer metastasis. Potential therapeutic approach by targeting miR-23 is suggested.
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Affiliation(s)
- Songwang Cai
- Department of Cardiothoracic Surgery, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Ruihan Chen
- Department of Emergency, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xiaojuan Li
- Department of Health Care, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yi Cai
- Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhiqiang Ye
- Department of Emergency, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Shigeng Li
- Department of Emergency, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jun Li
- Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Huaiqiu Huang
- Department of Dermatology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Shubin Peng
- Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jun Wang
- Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yiran Tao
- Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hongxing Huang
- Department of Urology, Zhongshan People's Hospital, Zhongshan City, Guangdong, China
| | - Xinglai Wen
- Department of Urology, Qingyuan People's Hospital, Qingyuan City, Guangdong, China
| | - Jianfeng Mo
- Department of Urology, Qingyuan People's Hospital, Qingyuan City, Guangdong, China
| | - Zhupeng Deng
- Department of Urology, Taishan People's Hospital, Taishan City, Guangdong, China
| | - Jian Wang
- Department of Urology, The First People's Hospital of Foshan City, Foshan City, Guangdong, China
| | - Yangfan Zhang
- Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xin Gao
- Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xingqiao Wen
- Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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18
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Morse EM, Sun X, Olberding JR, Ha BH, Boggon TJ, Calderwood DA. PAK6 targets to cell-cell adhesions through its N-terminus in a Cdc42-dependent manner to drive epithelial colony escape. J Cell Sci 2015; 129:380-93. [PMID: 26598554 DOI: 10.1242/jcs.177493] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 11/18/2015] [Indexed: 12/26/2022] Open
Abstract
The six serine/threonine kinases in the p21-activated kinase (PAK) family are important regulators of cell adhesion, motility and survival. PAK6, which is overexpressed in prostate cancer, was recently reported to localize to cell-cell adhesions and to drive epithelial cell colony escape. Here we report that PAK6 targeting to cell-cell adhesions occurs through its N-terminus, requiring both its Cdc42/Rac interactive binding (CRIB) domain and an adjacent polybasic region for maximal targeting efficiency. We find PAK6 localization to cell-cell adhesions is Cdc42-dependent, as Cdc42 knockdown inhibits PAK6 targeting to cell-cell adhesions. We further find the ability of PAK6 to drive epithelial cell colony escape requires kinase activity and is disrupted by mutations that perturb PAK6 cell-cell adhesion targeting. Finally, we demonstrate that all type II PAKs (PAK4, PAK5 and PAK6) target to cell-cell adhesions, albeit to differing extents, but PAK1 (a type I PAK) does not. Notably, the ability of a PAK isoform to drive epithelial colony escape correlates with its targeting to cell-cell adhesions. We conclude that PAKs have a broader role in the regulation of cell-cell adhesions than previously appreciated.
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Affiliation(s)
- Elizabeth M Morse
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Xiaowen Sun
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jordan R Olberding
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Byung Hak Ha
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Titus J Boggon
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA Yale Cancer Center, Yale University School of Medicine, New Haven, CT 06520, USA
| | - David A Calderwood
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA Yale Cancer Center, Yale University School of Medicine, New Haven, CT 06520, USA
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19
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Closing the translational gap between mutant mouse models and the clinical reality of psychotic illness. Neurosci Biobehav Rev 2015; 58:19-35. [DOI: 10.1016/j.neubiorev.2015.01.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Revised: 01/07/2015] [Accepted: 01/12/2015] [Indexed: 02/03/2023]
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20
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Liu W, Liu Y, Liu H, Zhang W, Fu Q, Xu J, Gu J. Tumor Suppressive Function of p21-activated Kinase 6 in Hepatocellular Carcinoma. J Biol Chem 2015; 290:28489-28501. [PMID: 26442588 DOI: 10.1074/jbc.m115.658237] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Indexed: 01/16/2023] Open
Abstract
Our previous studies identified the oncogenic role of p21-activated kinase 1 (PAK1) in hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC). Contrarily, PAK6 was found to predict a favorable prognosis in RCC patients. Nevertheless, the ambiguous tumor suppressive function of PAK6 in hepatocarcinogenesis remains obscure. Herein, decreased PAK6 expression was found to be associated with tumor node metastasis stage progression and unfavorable overall survival in HCC patients. Additionally, overexpression and silence of PAK6 experiments showed that PAK6 inhibited xenografted tumor growth in vivo, and restricted cell proliferation, colony formation, migration, and invasion and promoted cell apoptosis and anoikis in vitro. Moreover, overexpression of kinase dead and nuclear localization signal deletion mutants of PAK6 experiments indicated the tumor suppressive function of PAK6 was partially dependent on its kinase activity and nuclear translocation. Furthermore, gain or loss of function in polycomb repressive complex 2 (PRC2) components, including EZH2, SUZ12, and EED, elucidated epigenetic control of H3K27me3-arbitrated PAK6 down-regulation in hepatoma cells. More importantly, negative correlation between PAK6 and EZH2 expression was observed in hepatoma tissues from HCC patients. These data identified the tumor suppressive role and potential underlying mechanism of PAK6 in hepatocarcinogenesis.
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Affiliation(s)
- Weisi Liu
- Departments of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032
| | - Yidong Liu
- Departments of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032
| | - Haiou Liu
- Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Hospital of Obstetrics and Gynecology, Fudan University, Shanghai 200011, China
| | - Weijuan Zhang
- Departments of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai 200032
| | - Qiang Fu
- Departments of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032
| | - Jiejie Xu
- Departments of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032.
| | - Jianxin Gu
- Departments of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032
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21
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Liu C, Zhang L, Huang Y, Lu K, Tao T, Chen S, Zhang X, Guan H, Chen M, Xu B. MicroRNA‑328 directly targets p21‑activated protein kinase 6 inhibiting prostate cancer proliferation and enhancing docetaxel sensitivity. Mol Med Rep 2015; 12:7389-95. [PMID: 26459798 PMCID: PMC4626198 DOI: 10.3892/mmr.2015.4390] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 09/01/2015] [Indexed: 01/19/2023] Open
Abstract
Prostate cancer (Pca) has one of the highest mortality rates for malignant cancers worldwide. Previous research has demonstrated that numerous genes are aberrantly expressed during Pca onset and development. p21-activated protein kinase 6 (PAK6) is known to be overexpressed in primary and metastatic Pca, however the mechanism of this aberrant expression remains unknown. In the present study, immunohistochemistry demonstrated that PAK6 is overexpressed in castration-resistant Pca (CRPC). Furthermore, PAK6 overexpression was regulated by microRNA (miR)-328. Luciferase reporter assay and western blot analysis indicated that PAK6 was directly targeted by miR-328. Forced expression of miR-328 enhanced docetaxel sensitivity, inhibited cell proliferation and promoted cell apoptosis without affecting the cell cycle. This indicates that miR-328 performs important functions in CRPC progression via PAK6 regulation. This mechanism may be used to enhance the effect of docetaxel.
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Affiliation(s)
- Chunhui Liu
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Lei Zhang
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Yeqing Huang
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Kai Lu
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Tao Tao
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Shuqiu Chen
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Xiaowen Zhang
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Han Guan
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Ming Chen
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Bin Xu
- Department of Urology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu 210009, P.R. China
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22
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Tian X, Wei Z, Wang J, Liu P, Qin Y, Zhong M. MicroRNA-429 inhibits the migration and invasion of colon cancer cells by targeting PAK6/cofilin signaling. Oncol Rep 2015; 34:707-14. [PMID: 26058485 DOI: 10.3892/or.2015.4039] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 04/24/2015] [Indexed: 11/06/2022] Open
Abstract
MicroRNAs (miRs), a class of non-coding RNAs 18-25 nucleotides in length, can lead to mRNA degradation or inhibit protein translation by directly binding to the 3'-untranslational region (UTR) of their target mRNAs. The deregulation of miR-429 has been suggested to be involved in the development and progression of colon cancer. However, the detailed molecular mechanism involved remains to be determined. The aim of the present study was to investigate the role of miR-429 in the regulation of migration and invasion of colon cancer cells using RT-qPCR and western blotting. The results showed that the expression of miR-429 was reduced in colon cancer cell lines, when compared to a normal colon epithelial cell line. Treatment with DNA demethylation agent 5-aza-2'-deoxycytidine and histone deacetylase inhibitor phenylbutyrate (PBA), or transfection with the pre-miR-429 lentivirus plasmid led to the upregulation of miR-429 expression, as well as inhibition of migration and invasion in colon cancer cells. Investigation of the molecular mechanism showed that PAK6 was a novel target of miR-429, and the expression of PAK6 was upregulated in colon cancer tissues and cell lines, and was negatively regulated by miR-429 in colon cancer cells. Moreover, the cofilin signaling acted as a downstream effector of miR-429 in colon cancer cells. In conclusion, the results of the present study suggested that miR-429 inhibits the migration and invasion of colon cancer cells, partly at least, by mediating the expression of PAK6, as well as the activity of cofilin signaling. Therefore, miR-429 is as a potential molecular target for the treatment of colon cancer.
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Affiliation(s)
- Xiangyang Tian
- Department of Oncology, Xiangya Hospital of Central South University, Changsha, Hunan 410008, P.R. China
| | - Zibai Wei
- Department of Oncology, Peace Hospital of Changzhi Medical College, Changzhi, Shanxi 046000, P.R. China
| | - Jia Wang
- Department of Immunology, Peace Hospital of Changzhi Medical College, Changzhi, Shanxi 046000, P.R. China
| | - Ping Liu
- Department of Oncology, Peace Hospital of Changzhi Medical College, Changzhi, Shanxi 046000, P.R. China
| | - Yijun Qin
- Department of Pathology, Peace Hospital of Changzhi Medical College, Changzhi, Shanxi 046000, P.R. China
| | - Meizuo Zhong
- Department of Oncology, Xiangya Hospital of Central South University, Changsha, Hunan 410008, P.R. China
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23
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Ha BH, Morse EM, Turk BE, Boggon TJ. Signaling, Regulation, and Specificity of the Type II p21-activated Kinases. J Biol Chem 2015; 290:12975-83. [PMID: 25855792 DOI: 10.1074/jbc.r115.650416] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The p21-activated kinases (PAKs) are a family of six serine/threonine kinases that act as key effectors of RHO family GTPases in mammalian cells. PAKs are subdivided into two groups: type I PAKs (PAK1, PAK2, and PAK3) and type II PAKs (PAK4, PAK5, and PAK6). Although these groups are involved in common signaling pathways, recent work indicates that the two groups have distinct modes of regulation and have both unique and common substrates. Here, we review recent insights into the molecular level details that govern regulation of type II PAK signaling. We also consider mechanisms by which signal transduction is regulated at the level of substrate specificity. Finally, we discuss the implications of these studies for clinical targeting of these kinases.
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Affiliation(s)
| | - Elizabeth M Morse
- Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520
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24
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Al-Azayzih A, Gao F, Somanath PR. P21 activated kinase-1 mediates transforming growth factor β1-induced prostate cancer cell epithelial to mesenchymal transition. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1229-39. [PMID: 25746720 DOI: 10.1016/j.bbamcr.2015.02.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 02/25/2015] [Accepted: 02/28/2015] [Indexed: 12/11/2022]
Abstract
Transforming growth factor beta (TGFβ) is believed to play a dual role in prostate cancer. Molecular mechanism by which TGFβ1 suppresses early prostate tumor growth and induces epithelial-to-mesenchymal transition (EMT) in advanced stages is not known. We determined if P21-activated kinase1 (Pak1), which mediates cytoskeletal remodeling is necessary for the TGFβ1 induced prostate cancer EMT. Effects of TGFβ1 on control prostate cancer PC3 and DU145 cells and those with IPA 3 and siRNA mediated Pak1 inhibition were tested for prostate tumor xenograft in vivo and EMT in vitro. TGFβ1 inhibited PC3 tumor xenograft growth via activation of P38-MAPK and caspase-3, 9. Long-term stimulation with TGFβ1 induced PC3 and DU145 cell scattering and increased expression of EMT markers such as Snail and N-cadherin through tumor necrosis factor receptor-associated factor-6 (TRAF6)-mediated activation of Rac1/Pak1 pathway. Selective inhibition of Pak1 using IPA 3 or knockdown using siRNA both significantly inhibited TGFβ1-induced prostate cancer cell EMT and expression of mesenchymal markers. Our study demonstrated that TGFβ1 induces apoptosis and EMT in prostate cancer cells via activation of P38-MAPK and Rac1/Pak1 respectively. Our results reveal the potential therapeutic benefits of targeting TGFβ1-Pak1 pathway for advanced-stage prostate cancer.
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Affiliation(s)
- Ahmad Al-Azayzih
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA, United States; College of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Fei Gao
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA, United States
| | - Payaningal R Somanath
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA, United States; Department of Medicine, Vascular Biology Center and Cancer Center, Georgia Regents University, Augusta, GA, United States.
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25
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Jenardhanan P, Mathur PP. Kinases as targets for chemical modulators: Structural aspects and their role in spermatogenesis. SPERMATOGENESIS 2015; 4:e979113. [PMID: 26413395 DOI: 10.4161/21565562.2014.979113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 10/07/2014] [Accepted: 10/16/2014] [Indexed: 01/18/2023]
Abstract
Protein phosphorylation and de-phosphorylation events are crucial in deciding the fate of cells. They regulate cellular growth, differentiation and cell death, and kinases are the key players of these events. The members of ser/thr kinases and tyrosine kinases form the majority of protein kinase family, exerting their regulatory mechanism in almost all cells. In testis, they impact signal transduction events, regulate all stages of sperm development from mitosis through fertilization. Understanding the function of these kinases at the structural level and studying their interactions with inhibitors can help in understanding the machinery of spermatogenesis. In view of this, we have reviewed some of the prominent kinases that are known to play a role in spermatogenesis. A better understanding of the impacts of kinase inhibition on spermatogenesis should aid in the interpretation of lesions and hopefully further the development of more efficient and potent drug candidates.
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Affiliation(s)
- Pranitha Jenardhanan
- Centre for Bioinformatics; School of Life Sciences; Pondicherry University ; Puducherry, India
| | - Premendu P Mathur
- Centre for Bioinformatics; School of Life Sciences; Pondicherry University ; Puducherry, India ; Department of Biochemistry & Molecular Biology; School of Life Sciences; Pondicherry University ; Puducherry, India ; KIIT University ; Bhubaneshwar, Odisha, India
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26
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Cha E, Klinger M, Hou Y, Cummings C, Ribas A, Faham M, Fong L. Improved survival with T cell clonotype stability after anti-CTLA-4 treatment in cancer patients. Sci Transl Med 2015; 6:238ra70. [PMID: 24871131 DOI: 10.1126/scitranslmed.3008211] [Citation(s) in RCA: 306] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) blockade can promote antitumor T cell immunity and clinical responses. The mechanism by which anti-CTLA-4 antibodies induces antitumor responses is controversial. To determine the effects of CTLA-4 blockade on the T cell repertoire, we used next-generation deep sequencing to measure the frequency of individual rearranged T cell receptor β (TCRβ) genes, thereby characterizing the diversity of rearrangements, known as T cell clonotypes. CTLA-4 blockade in patients with metastatic castration-resistant prostate cancer and metastatic melanoma resulted in both expansion and loss of T cell clonotypes, consistent with a global turnover of the T cell repertoire. Overall, this treatment increased TCR diversity as reflected in the number of unique TCR clonotypes. The repertoire of clonotypes continued to evolve over subsequent months of treatment. Whereas the number of clonotypes that increased with treatment was not associated with clinical outcome, improved overall survival was associated with maintenance of high-frequency clones at baseline. In contrast, the highest-frequency clonotypes fell with treatment in patients with short overall survival. Stably maintained clonotypes included T cells having high-avidity TCR such as virus-reactive T cells. Together, these results suggest that CTLA-4 blockade induces T cell repertoire evolution and diversification. Moreover, improved clinical outcomes are associated with less clonotype loss, consistent with the maintenance of high-frequency TCR clonotypes during treatment. These clones may represent the presence of preexisting high-avidity T cells that may be relevant in the antitumor response.
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Affiliation(s)
- Edward Cha
- University of California, San Francisco, San Francisco, CA 94143, USA
| | | | - Yafei Hou
- University of California, San Francisco, San Francisco, CA 94143, USA
| | | | - Antoni Ribas
- University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Malek Faham
- Sequenta, South San Francisco, CA 94080, USA
| | - Lawrence Fong
- University of California, San Francisco, San Francisco, CA 94143, USA.
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Felgueiras J, Fardilha M. Phosphoprotein phosphatase 1-interacting proteins as therapeutic targets in prostate cancer. World J Pharmacol 2014; 3:120-139. [DOI: 10.5497/wjp.v3.i4.120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Revised: 09/01/2014] [Accepted: 09/24/2014] [Indexed: 02/06/2023] Open
Abstract
Prostate cancer is a major public health concern worldwide, being one of the most prevalent cancers in men. Great improvements have been made both in terms of early diagnosis and therapeutics. However, there is still an urgent need for reliable biomarkers that could overcome the lack of cancer-specificity of prostate-specific antigen, as well as alternative therapeutic targets for advanced metastatic cases. Reversible phosphorylation of proteins is a post-translational modification critical to the regulation of numerous cellular processes. Phosphoprotein phosphatase 1 (PPP1) is a major serine/threonine phosphatase, whose specificity is determined by its interacting proteins. These interactors can be PPP1 substrates, regulators, or even both. Deregulation of this protein-protein interaction network alters cell dynamics and underlies the development of several cancer hallmarks. Therefore, the identification of PPP1 interactome in specific cellular context is of crucial importance. The knowledge on PPP1 complexes in prostate cancer remains scarce, with only 4 holoenzymes characterized in human prostate cancer models. However, an increasing number of PPP1 interactors have been identified as expressed in human prostate tissue, including the tumor suppressors TP53 and RB1. Efforts should be made in order to identify the role of such proteins in prostate carcinogenesis, since only 26 have yet well-recognized roles. Here, we revise literature and human protein databases to provide an in-depth knowledge on the biological significance of PPP1 complexes in human prostate carcinogenesis and their potential use as therapeutic targets for the development of new therapies for prostate cancer.
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Abstract
PAKs 4, 5 and 6 are members of the group B family of p21-activated kinases. Among this group, PAK4 has been most extensively studied. While it has essential roles in embryonic development, in adults high levels of PAK4 are frequently associated with cancer. PAK4 is overexpressed in a variety of cancers, and the Pak4 gene is amplified in some cancers. PAK4 overexpression is sufficient to cause oncogenic transformation in cells and in mouse models. The tight connection between PAK4 and cancer make it a promising diagnostic tool as well as a potential drug target. The group B PAKs also have important developmental functions. PAK4 is important for many early developmental processes, while PAK5 and PAK6 play roles in learning and memory in mice. This chapter provides an overview of the roles of the group B PAKs in cancer as well as development, and includes a discussion of PAK mediated signaling pathways and cellular functions.
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Affiliation(s)
- Audrey Minden
- Susan Lehman Cullman Laboratory for Cancer Research; Department of Chemical Biology; Ernest Mario School of Pharmacy; Rutgers, The State University of New Jersey; Piscataway, NJ USA
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Zhao ZS, Manser E. PAK family kinases: Physiological roles and regulation. CELLULAR LOGISTICS 2014; 2:59-68. [PMID: 23162738 PMCID: PMC3490964 DOI: 10.4161/cl.21912] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The p21-activated kinases (PAKs) are a family of Ser/Thr protein kinases that are represented by six genes in humans (PAK 1-6), and are found in all eukaryotes sequenced to date. Genetic and knockdown experiments in frogs, fish and mice indicate group I PAKs are widely expressed, required for multiple tissue development, and particularly important for immune and nervous system function in the adult. The group II PAKs (human PAKs 4-6) are more enigmatic, but their restriction to metazoans and presence at cell-cell junctions suggests these kinases emerged to regulate junctional signaling. Studies of protozoa and fungal PAKs show that they regulate cell shape and polarity through phosphorylation of multiple cytoskeletal proteins, including microtubule binding proteins, myosins and septins. This chapter discusses what we know about the regulation of PAKs and their physiological role in different model organisms, based primarily on gene knockout studies.
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Affiliation(s)
- Zhuo-Shen Zhao
- sGSK Group; Astar Neuroscience Research Partnership; Singapore
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Tanneeru K, Balla AR, Guruprasad L. In silico3D structure modeling and inhibitor binding studies of human male germ cell-associated kinase. J Biomol Struct Dyn 2014; 33:1710-9. [DOI: 10.1080/07391102.2014.968622] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Tse EYT, Ching YP. The role of p21-activated kinases in hepatocellular carcinoma metastasis. J Mol Signal 2014; 9:7. [PMID: 25093037 PMCID: PMC4121300 DOI: 10.1186/1750-2187-9-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 07/18/2014] [Indexed: 01/06/2023] Open
Abstract
The p21-activated kinases (PAKs) are downstream effectors of the Rho family small GTPases as well as a wide variety of mitogenic factors and have been implicated in cancer formation, development and metastasis. PAKs phosphorylate a wide spectrum of substrates to mediate extracellular signals and regulate cytoskeletal remodeling, cell motility and survival. In this review, we aim to summarize the findings regarding the oncogenic role and the underlying mechanisms of PAKs signaling in various cancers, and in particular highlight the prime importance of PAKs in hepatocellular carcinoma (HCC) progression and metastasis. Recent studies exploring the potential therapeutic application of PAK inhibitors will also be discussed.
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Affiliation(s)
- Edith Yuk Ting Tse
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Yick Pang Ching
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China ; State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong, China
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Abstract
INTRODUCTION Overexpression of p21-activated kinase 5 (PAK5) is discovered in many tumors, probably due to its regulation in cytoskeleton, antiapoptosis and proliferation. A better understanding of the modulation mechanisms of PAK5 is needed for the development of tumor treatment where current therapeutics is inadequate. AREAS COVERED This review discusses the current understanding of PAK5 functions as an oncogenic kinase in tumor cellular regulation. Mechanisms of action and molecular pathways involved in cytoskeleton regulation, antiapoptosis and proliferation of tumors are discussed. EXPERT OPINION PAKs are serine/threonine kinases and downstream effectors for Cdc42 and Rac, the subfamilies of Rho small GTPases. PAK5 shares sequence identities in p21-GTPase-binding domain and kinase domain and is completely different in other regions compared with other PAKs. Overexpression of PAK5 has been found in several tumors, probably due to its contribution to proliferation, cytoskeleton and anti-apoptosis. Additional regulation mechanisms which are independent of Rho GTPases also indicate that PAK5 functions as a special signal molecule in cellular signaling pathways of tumor progression.
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Affiliation(s)
- Yi-Yang Wen
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College , 84 West Huai-hai Road, Xuzhou, Jiangsu , China +86 0516 85582513 ; ;
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Liu W, Liu H, Liu Y, Xu L, Zhang W, Zhu Y, Xu J, Gu J. Prognostic Significance of p21-activated Kinase 6 Expression in Patients with Clear Cell Renal Cell Carcinoma. Ann Surg Oncol 2014; 21 Suppl 4:S575-83. [DOI: 10.1245/s10434-014-3680-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Indexed: 02/06/2023]
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Abstract
p21-Activated protein kinases (PAKs) are centrally involved in a plethora of cellular processes and functions. Their function as effectors of small GTPases Rac1 and Cdc42 has been extensively studied during the past two decades, particularly in the realms of cell proliferation, apoptosis, and hence tumorigenesis, as well as cytoskeletal remodeling and related cellular events in health and disease. In recent years, a large number of studies have shed light onto the fundamental role of group I PAKs, most notably PAK1, in metabolic homeostasis. In skeletal muscle, PAK1 was shown to mediate the function of insulin on stimulating GLUT4 translocation and glucose uptake, while in pancreatic β-cells, PAK1 participates in insulin granule localization and vesicle release. Furthermore, we demonstrated that PAK1 mediates the cross talk between insulin and Wnt/β-catenin signaling pathways and hence regulates gut proglucagon gene expression and the production of the incretin hormone glucagon-like peptide-1 (GLP-1). The utilization of chemical inhibitors of PAK and the characterization of Pak1(-/-) mice enabled us to gain mechanistic insights as well as to assess the overall contribution of PAKs in metabolic homeostasis. This review summarizes our current understanding of PAKs, with an emphasis on the emerging roles of PAK1 in glucose homeostasis.
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Abstract
The p21 activated kinases (Paks) are well known effector proteins for the Rho GTPases Cdc42 and Rac. The Paks contain 6 members, which fall into 2 families of proteins. The first family consists of Paks 1, 2, and 3, and the second consists of Paks 4, 5, and 6. While some of the Paks are ubiquitously expressed, others have more restrictive tissue specificity. All of them are found in the nervous system. Studies using cell culture, transgenic mice, and knockout mice, have revealed important roles for the Paks in cytoskeletal organization and in many aspects of cell growth and development. This review discusses the basic structures of the Paks, and their roles in cell growth, development, and in cancer.
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Affiliation(s)
- Chetan K Rane
- Susan Lehman Cullman Laboratory for Cancer Research; Department of Chemical Biology; Ernest Mario School of Pharmacy; Rutgers The State University of New Jersey; Piscataway, NJ USA
| | - Audrey Minden
- Susan Lehman Cullman Laboratory for Cancer Research; Department of Chemical Biology; Ernest Mario School of Pharmacy; Rutgers The State University of New Jersey; Piscataway, NJ USA
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Chen H, Miao J, Li H, Wang C, Li J, Zhu Y, Wang J, Wu X, Qiao H. Expression and prognostic significance of p21-activated kinase 6 in hepatocellular carcinoma. J Surg Res 2014; 189:81-8. [PMID: 24576777 DOI: 10.1016/j.jss.2014.01.049] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Revised: 01/15/2014] [Accepted: 01/24/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND p21-activated protein kinase (PAK) 6 is a serine-threonine kinase belonging to the PAK family. Previous studies have indicated that abnormal expressions of PAK1, PAK2, and PAK5 played critical roles in hepatocellular carcinoma (HCC). Recent studies suggested that deregulation of PAK6 expression played an important role in oncogenesis. To explore the potential roles of PAK6 in HCC, expression of PAK6 was detected in human HCC specimens. METHODS Immunohistochemistry and Western blot analysis were performed for PAK6 in 121 HCC samples. The data were correlated with clinicopathologic features. The univariate and multivariate survival analyses were also performed to determine their clinical prognostic significance. RESULTS PAK6 was overexpressed in HCC as compared with the adjacent noncancerous liver tissues. High expression of PAK6 was associated with Edmondson-Steiner grade (P = 0.006) and number of tumor nodules (P < 0.001), and PAK6 was positively correlated with proliferation marker Ki-67 (P < 0.01). Univariate analysis suggested that PAK6 expression was associated with poor prognosis (P < 0.001). Multivariate analysis indicated that PAK6 and Ki-67 protein expressions were independent prognostic markers for HCC (P = 0.0245 and 0.0331, respectively). CONCLUSIONS Our results suggest that PAK6 overexpression is involved in the pathogenesis of HCC; it may be an independent poor prognostic factor for HCC.
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Affiliation(s)
- Hongwei Chen
- Department of Clinical Laboratory, The First Hospital of Qinhuangdao, Qinhuangdao, China.
| | - Jinlin Miao
- Department of Magnetic Resonance Imaging, The Fourth People's Hospital of Taizhou, Taizhou, China
| | - Hongchen Li
- Department of Clinical Laboratory, The First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Chunhua Wang
- Department of Clinical Laboratory, The First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Junliang Li
- Department of Clinical Laboratory, The First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Yong Zhu
- Department of Clinical Laboratory, The First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Jianxin Wang
- Department of Clinical Laboratory, The First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Xia Wu
- Department of Clinical Laboratory, The First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Hongying Qiao
- Department of Clinical Laboratory, The First Hospital of Qinhuangdao, Qinhuangdao, China
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Role of p-21-activated kinases in cancer progression. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 309:347-87. [PMID: 24529727 DOI: 10.1016/b978-0-12-800255-1.00007-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The p-21-activated kinases (PAKs) are downstream effectors of Rho GTPases Rac and Cdc42. The PAK family consists of six members which are segregated into two subgroups (Group I and Group II) based on sequence homology. Group I PAKs (PAK1-3) are the most extensively studied but there is increasing interest in the functionality of Group II PAKs (PAK4-6). The PAK family proteins are thought to play an important role in many different cellular processes, some of which have particular significance in the context of cancer progression. This review explores established and more recent data, linking the PAK family kinases to cancer progression including expression profiles, evasion of apoptosis, promotion of cell survival, and regulation of cell invasion. Finally, we discuss attempts to therapeutically target the PAK family and outline the major obstacles that still need to be overcome.
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Abstract
Steroid hormones trigger a wide variety of biological responses through stage- and tissue-specific activation of target gene expression. The mechanisms that provide specificity to systemically released pulses of steroids, however, remain poorly understood. We previously completed a forward genetic screen for mutations that disrupt the destruction of larval salivary glands during metamorphosis in Drosophila melanogaster, a process triggered by the steroid hormone 20-hydroxyecdysone (ecdysone). Here, we characterize 10 complementation groups mapped to genes from this screen. Most of these mutations disrupt the ecdysone-induced expression of death activators, thereby failing to initiate tissue destruction. However, other responses to ecdysone, even within salivary glands, occur normally in mutant animals. Many of these newly identified regulators of ecdysone signaling, including brwd3, med12, med24, pak, and psg2, represent novel components of the ecdysone-triggered transcriptional hierarchy. These genes function combinatorially to provide specificity to ecdysone pulses, amplifying the hormonal cue in a stage-, tissue-, and target gene-specific manner. Most of the ecdysone response genes identified in this screen encode homologs of mammalian nuclear receptor coregulators, demonstrating an unexpected degree of functional conservation in the mechanisms that regulate steroid signaling between insects and mammals.
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Fram S, King H, Sacks DB, Wells CM. A PAK6-IQGAP1 complex promotes disassembly of cell-cell adhesions. Cell Mol Life Sci 2013; 71:2759-73. [PMID: 24352566 PMCID: PMC4059965 DOI: 10.1007/s00018-013-1528-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 10/30/2013] [Accepted: 11/18/2013] [Indexed: 12/04/2022]
Abstract
p-21 activated 6 (PAK6), first identified as interacting with the androgen receptor (AR), is over-expressed in multiple cancer tissues and has been linked to the progression of prostate cancer, however little is known about PAK6 function in the absence of AR signaling. We report here that PAK6 is specifically required for carcinoma cell–cell dissociation downstream of hepatocyte growth factor (HGF) for both DU145 prostate cancer and HT29 colon cancer cells. Moreover, PAK6 overexpression can drive cells to escape from adhesive colonies in the absence of stimulation. We have localized PAK6 to cell–cell junctions and have detected a direct interaction between the kinase domain of PAK6 and the junctional protein IQGAP1. Co-expression of IQGAP1 and PAK6 increases cell colony escape and leads to elevated PAK6 activation. Further studies have identified a PAK6/E-cadherin/IQGAP1 complex downstream of HGF. Moreover, we find that β-catenin is also localized with PAK6 in cell–cell junctions and is a novel PAK6 substrate. We propose a unique role for PAK6, independent of AR signaling, where PAK6 drives junction disassembly during HGF-driven cell–cell dissociation via an IQGAP1/E-cadherin complex that leads to the phosphorylation of β-catenin and the disruption of cell–cell adhesions.
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Affiliation(s)
- Sally Fram
- Division of Cancer Studies, King's College London, New Hunts House, Guys Campus, London, SE1 1UL, UK
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Shoni M, Nagymanyoki Z, Vitonis AF, Jimenez C, Ng SW, Quade BJ, Berkowitz RS. p-21-Activated kinase-1, -4 and -6 and estrogen receptor expression pattern in normal placenta and gestational trophoblastic diseases. Gynecol Oncol 2013; 131:759-63. [DOI: 10.1016/j.ygyno.2013.09.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 09/11/2013] [Accepted: 09/11/2013] [Indexed: 11/29/2022]
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Furnari MA, Jobes ML, Nekrasova T, Minden A, Wagner GC. Differential sensitivity of Pak5, Pak6, and Pak5/Pak6 double-knockout mice to the stimulant effects of amphetamine and exercise-induced alterations in body weight. Nutr Neurosci 2013; 17:109-15. [PMID: 23710594 DOI: 10.1179/1476830513y.0000000072] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVES PAK5 and PAK6 are protein kinases highly expressed in the brain. Previously, we observed that Pak6 knockout mice gained significantly more weight during development than Pak5 knockout mice as well as wild-type controls and double-knockout mice lacking both Pak5 and Pak6. In this study, we assessed the effects of exercise on food intake and weight gain of these mice as well as their sensitivity to the stimulant effects of amphetamine. METHODS Mice of each genotype were placed in cages with free access to run wheel exercise or in cages without run wheels for a total of 74 days. Food and fluid intake as well as body weight of each mouse were measured on a weekly basis. Finally, mice were given a high dose of amphetamine and activity levels were observed immediately thereafter for 90 minutes. Brains and testes of mice were assayed for protein levels of the estrogen alpha and progesterone receptors. RESULTS While run wheel mice consumed significantly more food, they weighed less than non-run wheel mice. In addition, although Pak6 knockout mice consumed the same amount of food as wild-type mice, they were significantly heavier regardless of run wheel condition. Pak5 knockout mice were found to be more active than other genotypes after amphetamine treatment. Finally, protein levels of the progesterone and estrogen alpha receptors were altered in brain and testes of the Pak6 knockout mice. DISCUSSION Collectively, these data suggest that PAK6 play a role in weight gain unrelated to exercise and caloric intake and that Pak5 knockout mice are more sensitive to the stimulant effects of amphetamine.
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Protein kinase D-mediated phosphorylation at Ser99 regulates localization of p21-activated kinase 4. Biochem J 2013; 455:251-60. [PMID: 23841590 DOI: 10.1042/bj20130281] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PAKs (p21-activated kinases) are effectors of RhoGTPases. PAK4 contributes to regulation of cofilin at the leading edge of migrating cells through activation of LIMK (Lin-11/Isl-1/Mec-3 kinase). PAK4 activity is regulated by an autoinhibitory domain that is released upon RhoGTPase binding as well as phosphorylation at Ser474 in the activation loop of the kinase domain. In the present study, we add another level of complexity to PAK4 regulation by showing that phosphorylation at Ser99 is required for its targeting to the leading edge. This phosphorylation is mediated by PKD1 (protein kinase D1). Phosphorylation of PAK4 at Ser99 also mediates binding to 14-3-3 protein, and is required for the formation of a PAK4-LIMK-PKD1 complex that regulates cofilin activity and directed cell migration.
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Gao J, Ha BH, Lou HJ, Morse EM, Zhang R, Calderwood DA, Turk BE, Boggon TJ. Substrate and inhibitor specificity of the type II p21-activated kinase, PAK6. PLoS One 2013; 8:e77818. [PMID: 24204982 PMCID: PMC3810134 DOI: 10.1371/journal.pone.0077818] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 09/04/2013] [Indexed: 01/07/2023] Open
Abstract
The p21-activated kinases (PAKs) are important effectors of Rho-family small GTPases. The PAK family consists of two groups, type I and type II, which have different modes of regulation and signaling. PAK6, a type II PAK, influences behavior and locomotor function in mice and has an ascribed role in androgen receptor signaling. Here we show that PAK6 has a peptide substrate specificity very similar to the other type II PAKs, PAK4 and PAK5 (PAK7). We find that PAK6 catalytic activity is inhibited by a peptide corresponding to its N-terminal pseudosubstrate. Introduction of a melanoma-associated mutation, P52L, into this peptide reduces pseudosubstrate autoinhibition of PAK6, and increases phosphorylation of its substrate PACSIN1 (Syndapin I) in cells. Finally we determine two co-crystal structures of PAK6 catalytic domain in complex with ATP-competitive inhibitors. We determined the 1.4 Å co-crystal structure of PAK6 with the type II PAK inhibitor PF-3758309, and the 1.95 Å co-crystal structure of PAK6 with sunitinib. These findings provide new insights into the structure-function relationships of PAK6 and may facilitate development of PAK6 targeted therapies.
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Affiliation(s)
- Jia Gao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-biosciences, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Byung Hak Ha
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Hua Jane Lou
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Elizabeth M. Morse
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Rong Zhang
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - David A. Calderwood
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Yale Cancer Center, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Benjamin E. Turk
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Yale Cancer Center, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Titus J. Boggon
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Yale Cancer Center, Yale University School of Medicine, New Haven, Connecticut, United States of America
- * E-mail:
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Liu X, Busby J, John C, Wei J, Yuan X, Lu ML. Direct interaction between AR and PAK6 in androgen-stimulated PAK6 activation. PLoS One 2013; 8:e77367. [PMID: 24130878 PMCID: PMC3795072 DOI: 10.1371/journal.pone.0077367] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Accepted: 09/02/2013] [Indexed: 01/14/2023] Open
Abstract
A p21-activated kinase 6 (PAK6) was previously identified to be an androgen receptor (AR) interacting protein through a yeast two-hybrid screening. We used hormone responsive prostate cancer LAPC4 and LNCap cell lines as models to study the signaling events associated with androgen stimulation and PAK6. An androgen-stimulated PAK6 kinase activation was observed in LAPC4 cells expressing endogenous PAK6 and in LNCap cells ectopically expressing a wild type PAK6. This activation was likely mediated through a direct interaction between AR and PAK6 since siRNA knock-down of AR in LAPC4 cells downregulated androgen-stimulated PAK6 activation. In addition, LNCap cells expressing a non-AR-interacting PAK6 mutant exhibited dampened androgen-stimulated kinase activation. As a consequence of androgen-stimulated activation, PAK6 was phosphorylated at multiple serine/threonine residues including the AR-interacting domain of PAK6. Furthermore, androgen-stimulation promoted prostate cancer cell motility and invasion were demonstrated in LNCap cells ectopically expressing PAK6-WT. In contrast, LNCap expressing non-AR-interacting mutant PAK6 did not respond to androgen stimulation with increased cell motility and invasion. Our results demonstrate that androgen-stimulated PAK6 activation is mediated through a direct interaction between AR and PAK6 and PAK6 activation promotes prostate cancer cells motility and invasion.
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Affiliation(s)
- Xia Liu
- Urologic Research, Brigham and Women's Hospital, Department of Surgery, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jennifer Busby
- Department of Molecular Therapeutics, Scripps South Florida, Jupiter, Florida, United States of America
| | - Ciny John
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, Florida, United States of America
| | - Jianning Wei
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, Florida, United States of America
| | - Xin Yuan
- Division of Hematology-Oncology, Beth Israel Deaconess Medical Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Michael L. Lu
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, Florida, United States of America
- * E-mail:
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Flajollet S, Rachez C, Ploton M, Schulz C, Gallais R, Métivier R, Pawlak M, Leray A, Issulahi AA, Héliot L, Staels B, Salbert G, Lefebvre P. The elongation complex components BRD4 and MLLT3/AF9 are transcriptional coactivators of nuclear retinoid receptors. PLoS One 2013; 8:e64880. [PMID: 23762261 PMCID: PMC3677938 DOI: 10.1371/journal.pone.0064880] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 04/18/2013] [Indexed: 12/20/2022] Open
Abstract
Nuclear all-trans retinoic acid receptors (RARs) initiate early transcriptional events which engage pluripotent cells to differentiate into specific lineages. RAR-controlled transactivation depends mostly on agonist-induced structural transitions in RAR C-terminus (AF-2), thus bridging coactivators or corepressors to chromatin, hence controlling preinitiation complex assembly. However, the contribution of other domains of RAR to its overall transcriptional activity remains poorly defined. A proteomic characterization of nuclear proteins interacting with RAR regions distinct from the AF-2 revealed unsuspected functional properties of the RAR N-terminus. Indeed, mass spectrometry fingerprinting identified the Bromodomain-containing protein 4 (BRD4) and ALL1-fused gene from chromosome 9 (AF9/MLLT3), known to associate with and regulates the activity of Positive Transcription Elongation Factor b (P-TEFb), as novel RAR coactivators. In addition to promoter sequences, RAR binds to genomic, transcribed regions of retinoid-regulated genes, in association with RNA polymerase II and as a function of P-TEFb activity. Knockdown of either AF9 or BRD4 expression affected differentially the neural differentiation of stem cell-like P19 cells. Clusters of retinoid-regulated genes were selectively dependent on BRD4 and/or AF9 expression, which correlated with RAR association to transcribed regions. Thus RAR establishes physical and functional links with components of the elongation complex, enabling the rapid retinoid-induced induction of genes required for neuronal differentiation. Our data thereby extends the previously known RAR interactome from classical transcriptional modulators to components of the elongation machinery, and unravel a functional role of RAR in transcriptional elongation.
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Affiliation(s)
- Sébastien Flajollet
- European Genomic Institute for Diabetes (EGID), FR 3508, Lille, France
- INSERM UMR1011, Lille, France
- Univ Lille 2, Lille, France
- Institut Pasteur de Lille, Lille, France
| | - Christophe Rachez
- Unité de Régulation Epigénétique, URA 2578 du CNRS, Département de Biologie du Développement, Institut Pasteur, Paris, France
| | - Maheul Ploton
- European Genomic Institute for Diabetes (EGID), FR 3508, Lille, France
- INSERM UMR1011, Lille, France
- Univ Lille 2, Lille, France
- Institut Pasteur de Lille, Lille, France
| | - Céline Schulz
- Interdisciplinary Research Institute, Univ Lille 1, USR 3078 CNRS, Biophotonique Cellulaire Fonctionnelle, Villeneuve d’Ascq, France
| | - Rozenn Gallais
- Equipe SPARTE, UMR CNRS 6026-Université Rennes 1, Rennes, France
| | - Raphaël Métivier
- Equipe SPARTE, UMR CNRS 6026-Université Rennes 1, Rennes, France
| | - Michal Pawlak
- European Genomic Institute for Diabetes (EGID), FR 3508, Lille, France
- INSERM UMR1011, Lille, France
- Univ Lille 2, Lille, France
- Institut Pasteur de Lille, Lille, France
| | - Aymeric Leray
- Interdisciplinary Research Institute, Univ Lille 1, USR 3078 CNRS, Biophotonique Cellulaire Fonctionnelle, Villeneuve d’Ascq, France
| | - Al Amine Issulahi
- Interdisciplinary Research Institute, Univ Lille 1, USR 3078 CNRS, Biophotonique Cellulaire Fonctionnelle, Villeneuve d’Ascq, France
| | - Laurent Héliot
- Interdisciplinary Research Institute, Univ Lille 1, USR 3078 CNRS, Biophotonique Cellulaire Fonctionnelle, Villeneuve d’Ascq, France
| | - Bart Staels
- European Genomic Institute for Diabetes (EGID), FR 3508, Lille, France
- INSERM UMR1011, Lille, France
- Univ Lille 2, Lille, France
- Institut Pasteur de Lille, Lille, France
| | - Gilles Salbert
- Equipe SPARTE, UMR CNRS 6026-Université Rennes 1, Rennes, France
| | - Philippe Lefebvre
- European Genomic Institute for Diabetes (EGID), FR 3508, Lille, France
- INSERM UMR1011, Lille, France
- Univ Lille 2, Lille, France
- Institut Pasteur de Lille, Lille, France
- * E-mail:
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Wang XX, Cheng Q, Zhang SN, Qian HY, Wu JX, Tian H, Pei DS, Zheng JN. PAK5-Egr1-MMP2 signaling controls the migration and invasion in breast cancer cell. Tumour Biol 2013; 34:2721-9. [PMID: 23696025 DOI: 10.1007/s13277-013-0824-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 04/26/2013] [Indexed: 12/19/2022] Open
Abstract
p21-activated kinases (PAKs) are activated by various extracellular stimuli and, in turn, activate other kinases by phosphorylating them at specific serine/threonine residues or through protein-protein interaction. As a recently identified member of the group B PAK family, the role of PAK5 in cancer is poorly understood. In this study, we investigated the effect of PAK5 on the malignant phenotype, such as proliferation, cell cycle, apoptosis, migration, and invasion. Cell growth assay and cell cycle analysis consistently showed that knockdown of PAK5 could significantly inhibit the proliferation of breast cancer cells. Wound healing assay. migration assay, and invasion assay showed that PAK5 promoted cell migration. Furthermore, in order to elucidate the underlying mechanism of PAK5 on cellular growth and migration, we examined the protein expressions of cyclin D1, p21, early growth response protein 1 (Egr1), and matrix metalloproteinase 2 (MMP2). Our work further reveals the PAK5-Egr1-MMP2 signaling pathway to be a critical regulator of cell migration and invasion. These results suggest that PAK5 may be a potential therapeutic target for breast cancer.
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Affiliation(s)
- Xiao-Xia Wang
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou, Jiangsu, 221002, China
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Functional deficits in PAK5, PAK6 and PAK5/PAK6 knockout mice. PLoS One 2013; 8:e61321. [PMID: 23593460 PMCID: PMC3620390 DOI: 10.1371/journal.pone.0061321] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 03/07/2013] [Indexed: 11/19/2022] Open
Abstract
The p21-activated kinases are effector proteins for Rho-family GTPases. PAK4, PAK5, and PAK6 are the group II PAKs associated with neurite outgrowth, filopodia formation, and cell survival. Pak4 knockout mice are embryonic lethal, while Pak5, Pak6, and Pak5/Pak6 double knockout mice are viable and fertile. Our previous work found that the double knockout mice exhibit locomotor changes and learning and memory deficits. We also found some differences with Pak5 and Pak6 single knockout mice and the present work further explores the potential differences of the Pak5 knockout and Pak6 knockout mice in comparison with wild type mice. The Pak6 knockout mice were found to weigh significantly more than the other genotypes. The double knockout mice were found to be less active than the other genotypes. The Pak5 knockout mice and the double knockout mice performed worse on the rotorod test. All the knockout genotypes were found to be less aggressive in the resident intruder paradigm. The double knockout mice were, once again, found to perform worse in the active avoidance assay. These results indicate, that although some behavioral differences are seen in the Pak5 and Pak6 single knockout mice, the double knockout mice exhibit the greatest changes in locomotion and learning and memory.
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48
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Dart AE, Wells CM. P21-activated kinase 4--not just one of the PAK. Eur J Cell Biol 2013; 92:129-38. [PMID: 23642861 DOI: 10.1016/j.ejcb.2013.03.002] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/24/2013] [Accepted: 03/25/2013] [Indexed: 12/18/2022] Open
Abstract
P21-activated kinase 4 (PAK4) is a member of the p21-activated kinase (PAK) family. Historically much of the attention has been directed towards founding family member PAK1 but the focus is now shifting towards PAK4. It is a pluripotent serine/threonine kinase traditionally recognised as a downstream effector of the Rho-family GTPases. However, emerging research over the last few years has revealed that this kinase is much more than that. New findings have shed light on the molecular mechanism of PAK4 activation and how this kinase is critical for early development. Moreover, the number of PAK4 substrates and binding partners is rapidly expanding highlighting the increasing amount of cellular functions controlled by PAK4. We propose that PAK4 should be considered a signalling integrator regulating numerous fundamental cellular processes, including actin cytoskeletal dynamics, cell morphology and motility, cell survival, embryonic development, immune defence and oncogenic transformation. This review will outline our current understanding of PAK4 biology.
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Affiliation(s)
- Anna E Dart
- Division of Cancer Studies, New Hunts House, Guy's Campus, King's College London, London SE1 1UL, UK
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Goc A, Al-Azayzih A, Abdalla M, Al-Husein B, Kavuri S, Lee J, Moses K, Somanath PR. P21 activated kinase-1 (Pak1) promotes prostate tumor growth and microinvasion via inhibition of transforming growth factor β expression and enhanced matrix metalloproteinase 9 secretion. J Biol Chem 2012; 288:3025-35. [PMID: 23258534 DOI: 10.1074/jbc.m112.424770] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
P21-activated kinases (Paks) are major effectors downstream of the small Rho family of GTPases. Among the six isoforms, Pak1 is the most ubiquitous and the best characterized member. Previous studies have shown that inhibition of Pak6, which is predominantly present in the prostate compared with other tissues, inhibits prostate tumor growth in vivo. Even though Pak1 has been identified in normal prostatic epithelial cells and cancer cells, its specific role in the development of prostate cancer remains unclear. We report here that highly invasive prostate cancer cells express significantly higher levels of Pak1 protein compared with non-invasive prostate cancer cells. Furthermore, prostate tumor tissues and prostate cancer metastasized to lungs showed a higher expression of Pak1 compared with normal tissues. Interestingly, Pak6 protein expression levels did not change with the invasive/metastatic potential of the cancer cells or tumors. Although inhibition of Pak1, and not Pak6, resulted in impaired PC3 cell migration, the effects of Pak1 knockdown on transendothelial migration (microinvasion), tumor growth, and tumor angiogenesis was higher compared with Pak6 knockdown. Finally, gene array data revealed reduced expression of matrix metalloproteinase 9 with the ablation of either Pak1 or Pak6 gene expression in PC3 cells, whereas protein levels of TGFβ was elevated significantly with specific modulation of Pak1 activity or ablation of the Pak1 gene. Our observations suggest that although some level of functional redundancy exists between Pak1 and Pak6 in prostate cancer cells, targeting Pak1 is a potential option for the management of prostate tumor growth, microinvasion, and metastasis.
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Affiliation(s)
- Anna Goc
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, Georgia
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Liu T, Li Y, Gu H, Zhu G, Li J, Cao L, Li F. p21-Activated kinase 6 (PAK6) inhibits prostate cancer growth via phosphorylation of androgen receptor and tumorigenic E3 ligase murine double minute-2 (Mdm2). J Biol Chem 2012; 288:3359-69. [PMID: 23132866 DOI: 10.1074/jbc.m112.384289] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The androgen receptor (AR) signaling pathway plays a crucial role in the development and growth of prostate malignancies. Regulation of AR homeostasis in prostate tumorigenesis has not yet been fully characterized. In this study, we demonstrate that p21-activated kinase 6 (PAK6) inhibits prostate tumorigenesis by regulating AR homeostasis. First, we demonstrated that in normal prostate epithelium, AR co-localizes with PAK6 in the cytoplasm and translocates into the nucleus in malignant prostate. Furthermore, AR phosphorylation at Ser-578 by PAK6 promotes AR-E3 ligase murine double minute-2 (Mdm2) association, causing AR degradation upon androgen stimuli. We also showed that PAK6 phosphorylates Mdm2 on Thr-158 and Ser-186, which is critical for AR ubiquitin-mediated degradation. Moreover, we found that Thr-158 collaborates with Ser-186 for AR-Mdm2 association and AR ubiquitin-mediated degradation as it facilitates PAK6-mediated AR homeostasis. PAK6 knockdown promotes prostate tumor growth in vivo. Interestingly, we found a strong inverse correlation between PAK6 and AR expression in the cytoplasm of prostate cancer cells. These observations indicate that PAK6 may be important for the maintenance of androgen-induced AR signaling homeostasis and in prostate malignancy, as well as being a possible new therapeutic target for AR-positive and hormone-sensitive prostate cancer.
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Affiliation(s)
- Tong Liu
- Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health, Ministry of Education, China Medical University, Shenyang 110001, China
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