351
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Clinicopathological and cellular signature of PAK1 in human bladder cancer. Tumour Biol 2014; 36:2359-68. [PMID: 25412958 DOI: 10.1007/s13277-014-2843-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 11/12/2014] [Indexed: 02/08/2023] Open
Abstract
Bladder cancer (BC) is the ninth most common cancer and the 13th most common cause of cancer death. Although p21 protein-activated kinase (PAK) regulates cell growth, motility, and morphology, the expression and function of PAK1 associated with the clinicopathological and cellular signature of human BC are not clear. This study was to examine the expression of PAK1 in human BC, the association of PAK1 with clinicopathological features, and the effect of PAK1 on cell proliferation, migration, and invasion in BC cells. A total of 54 BC and 12 normal bladder tissue specimens were retrieved. Among 54 BC patients, 39 cases were superficial BC and 15 cases were invasive BC. Histological examination revealed 29 patients with low-grade and 25 patients with high-grade papillary urothelial carcinomas. Immunohistochemical staining showed that PAK1 was overexpressed in BC tissue compared with normal bladder tissue. The overexpression of PAK1 was significantly associated with tumor size, histological grade, and lymph node metastasis, but not with gender, age, clinical stage, tumor number, and recurrence. Furthermore, the cytoplasmic distribution of PAK1 was observed in BC cells. Knocking down of PAK1 using lentiviral transduction decreased BC cell proliferation, migration, and invasion. In conclusion, we demonstrated that the overexpression of PAK1 is closely associated with the clinicopathological features of BC, suggesting that PAK1 may play an important role in the development and progression of BC and may be a potential therapeutic target for the treatment of BC.
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352
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Hudson AM, Yates T, Li Y, Trotter EW, Fawdar S, Chapman P, Lorigan P, Biankin A, Miller CJ, Brognard J. Discrepancies in cancer genomic sequencing highlight opportunities for driver mutation discovery. Cancer Res 2014; 74:6390-6396. [PMID: 25256751 PMCID: PMC4247168 DOI: 10.1158/0008-5472.can-14-1020] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cancer genome sequencing is being used at an increasing rate to identify actionable driver mutations that can inform therapeutic intervention strategies. A comparison of two of the most prominent cancer genome sequencing databases from different institutes (Cancer Cell Line Encyclopedia and Catalogue of Somatic Mutations in Cancer) revealed marked discrepancies in the detection of missense mutations in identical cell lines (57.38% conformity). The main reason for this discrepancy is inadequate sequencing of GC-rich areas of the exome. We have therefore mapped over 400 regions of consistent inadequate sequencing (cold-spots) in known cancer-causing genes and kinases, in 368 of which neither institute finds mutations. We demonstrate, using a newly identified PAK4 mutation as proof of principle, that specific targeting and sequencing of these GC-rich cold-spot regions can lead to the identification of novel driver mutations in known tumor suppressors and oncogenes. We highlight that cross-referencing between genomic databases is required to comprehensively assess genomic alterations in commonly used cell lines and that there are still significant opportunities to identify novel drivers of tumorigenesis in poorly sequenced areas of the exome. Finally, we assess other reasons for the observed discrepancy, such as variations in dbSNP filtering and the acquisition/loss of mutations, to give explanations as to why there is a discrepancy in pharmacogenomic studies, given recent concerns with poor reproducibility of data.
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Affiliation(s)
- Andrew M. Hudson
- Signalling Networks in Cancer Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, M20 4BX, UK
| | - Tim Yates
- RNA Biology Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, M20 4BX, UK
| | - Yaoyong Li
- Computational Biology Support Team, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, M20 4BX, UK
| | - Eleanor W. Trotter
- Signalling Networks in Cancer Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, M20 4BX, UK
| | - Shameem Fawdar
- Signalling Networks in Cancer Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, M20 4BX, UK
| | - Phil Chapman
- Computational Biology Support Team, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, M20 4BX, UK
| | - Paul Lorigan
- University of Manchester and The Christie NHS Foundation Trust, Manchester, M20 4BX, UK
| | - Andrew Biankin
- Wolfson Wohl Translational Cancer Research Centre, University of Glasgow, G61 1QH, UK
| | - Crispin J. Miller
- RNA Biology Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, M20 4BX, UK
- Computational Biology Support Team, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, M20 4BX, UK
| | - John Brognard
- Signalling Networks in Cancer Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, M20 4BX, UK
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353
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Shagisultanova E, Dunbrack RL, Golemis EA. Issues in interpreting the in vivo activity of Aurora-A. Expert Opin Ther Targets 2014; 19:187-200. [PMID: 25384454 DOI: 10.1517/14728222.2014.981154] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Based on its role as a mitotic regulatory kinase, overexpressed and associated with aneuploidy in cancer, small-molecule inhibitors have been developed for Aurora-A (AURKA) kinase. In preclinical and clinical assessments, these agents have shown efficacy in inducing stable disease or therapeutic response. In optimizing the use of Aurora-A inhibitors, it is critical to have robust capacity to measure the kinase activity of Aurora-A in tumors. AREAS COVERED We provide an overview of molecular mechanisms of mitotic and non-mitotic activation of Aurora-A kinase, and interaction of Aurora-A with its regulatory partners. Typically, Aurora-A activity is measured by use of phospho-antibodies targeting an autophosphorylated T288 epitope. However, recent studies have identified alternative means of Aurora-A activation control, including allosteric regulation by partners, phosphorylation on alternative activating residues (S51, S98), dephosphorylation on inhibitory sites (S342) and T288 phosphorylation by alternative kinases such as Pak enzymes. Additional work has shown that the relative abundance of Aurora-A partners can affect the activity of Aurora-A inhibitors, and that Aurora-A activation also occurs in interphase cells. EXPERT OPINION Taken together, this work suggests the need for comprehensive analysis of Aurora-A activity and expression of Aurora-A partners in order to stratify patients for likely therapeutic response.
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Affiliation(s)
- Elena Shagisultanova
- Fox Chase Cancer Center, Department of Medical Oncology , Philadelphia, PA 19111 , USA
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354
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Dammann K, Khare V, Gasche C. Republished: tracing PAKs from GI inflammation to cancer. Postgrad Med J 2014; 90:657-68. [PMID: 25335797 PMCID: PMC4222351 DOI: 10.1136/postgradmedj-2014-306768rep] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 04/07/2014] [Accepted: 04/10/2014] [Indexed: 12/20/2022]
Abstract
P-21 activated kinases (PAKs) are effectors of Rac1/Cdc42 which coordinate signals from the cell membrane to the nucleus. Activation of PAKs drive important signalling pathways including mitogen activated protein kinase, phospoinositide 3-kinase (PI3K/AKT), NF-κB and Wnt/β-catenin. Intestinal PAK1 expression increases with inflammation and malignant transformation, although the biological relevance of PAKs in the development and progression of GI disease is only incompletely understood. This review highlights the importance of altered PAK activation within GI inflammation, emphasises its effect on oncogenic signalling and discusses PAKs as therapeutic targets of chemoprevention.
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Affiliation(s)
- Kyle Dammann
- Department of Medicine III, Division of Gastroenterology and Hepatology and Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria
| | - Vineeta Khare
- Department of Medicine III, Division of Gastroenterology and Hepatology and Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria
| | - Christoph Gasche
- Department of Medicine III, Division of Gastroenterology and Hepatology and Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria
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355
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Glaucarubinone inhibits colorectal cancer growth by suppression of hypoxia-inducible factor 1α and β-catenin via a p-21 activated kinase 1-dependent pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:157-65. [PMID: 25409929 DOI: 10.1016/j.bbamcr.2014.10.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/17/2014] [Accepted: 10/15/2014] [Indexed: 01/22/2023]
Abstract
p-21-Activated kinase 1 (PAK1) enhances colorectal cancer (CRC) progression by stimulating Wnt/β-catenin, ERK and AKT pathways. PAK1 also promotes CRC survival via up-regulation of hypoxia-inducible factor 1α (HIF-1α), a key player in cancer survival. Glaucarubinone, a quassinoid natural product, inhibits pancreatic cancer growth by down-regulation of PAK1. The aim of this study was to investigate the effect of glaucarubinone on CRC growth and metastasis, and the mechanism involved. Cell proliferation was measured in vitro by [(3)H]-thymidine incorporation and in vivo by volume of tumor xenografts. Protein concentrations were measured by Western blotting of cell extracts. We report here that glaucarubinone inhibited CRC growth both in vitro and in vivo. The potency of glaucarubinone as an inhibitor of cell proliferation was negatively correlated to PAK1 expression in CRC cells. Glaucarubinone suppressed the expression of HIF-1α and β-catenin. Knockdown of PAK1 by shRNA enhanced inhibition by glaucarubinone while constitutively active PAK1 blocked the inhibitory effect. Our findings indicate that glaucarubinone inhibited CRC growth by down-regulation of HIF-1α and β-catenin via a PAK1-dependent pathway.
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356
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Prudnikova TY, Rawat SJ, Chernoff J. Molecular pathways: targeting the kinase effectors of RHO-family GTPases. Clin Cancer Res 2014; 21:24-9. [PMID: 25336694 DOI: 10.1158/1078-0432.ccr-14-0827] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
RHO GTPases, members of the RAS superfamily of small GTPases, are adhesion and growth factor-activated molecular switches that play important roles in tumor development and progression. When activated, RHO-family GTPases such as RAC1, CDC42, and RHOA, transmit signals by recruiting a variety of effector proteins, including the protein kinases PAK, ACK, MLK, MRCK, and ROCK. Genetically induced loss of RHO function impedes transformation by a number of oncogenic stimuli, leading to an interest in developing small-molecule inhibitors that either target RHO GTPases directly, or that target their downstream protein kinase effectors. Although inhibitors of RHO GTPases and their downstream signaling kinases have not yet been widely adopted for clinical use, their potential value as cancer therapeutics continues to facilitate pharmaceutical research and development and is a promising therapeutic strategy.
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Affiliation(s)
| | - Sonali J Rawat
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania. Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Jonathan Chernoff
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania.
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357
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Genetic dissection of the vav2-rac1 signaling axis in vascular smooth muscle cells. Mol Cell Biol 2014; 34:4404-19. [PMID: 25288640 DOI: 10.1128/mcb.01066-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vascular smooth muscle cells (vSMCs) are key in the regulation of blood pressure and the engagement of vascular pathologies, such as hypertension, arterial remodeling, and neointima formation. The role of the Rac1 GTPase in these cells remains poorly characterized. To clarify this issue, we have utilized genetically engineered mice to manipulate the signaling output of Rac1 in these cells at will using inducible, Cre-loxP-mediated DNA recombination techniques. Here, we show that the expression of an active version of the Rac1 activator Vav2 exclusively in vSMCs leads to hypotension as well as the elimination of the hypertension induced by the systemic loss of wild-type Vav2. Conversely, the specific depletion of Rac1 in vSMCs causes defective nitric oxide vasodilation responses and hypertension. Rac1, but not Vav2, also is important for neointima formation but not for hypertension-driven vascular remodeling. These animals also have allowed us to dismiss etiological connections between hypertension and metabolic disease and, most importantly, identify pathophysiological programs that cooperate in the development and consolidation of hypertensive states caused by local vascular tone dysfunctions. Finally, our results suggest that the therapeutic inhibition of Rac1 will be associated with extensive cardiovascular system-related side effects and identify pharmacological avenues to circumvent them.
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358
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McCoull W, Hennessy EJ, Blades K, Box MR, Chuaqui C, Dowling JE, Davies CD, Ferguson AD, Goldberg FW, Howe NJ, Kemmitt PD, Lamont GM, Madden K, McWhirter C, Varnes JG, Ward RA, Williams JD, Yang B. Identification and optimisation of 7-azaindole PAK1 inhibitors with improved potency and kinase selectivity. MEDCHEMCOMM 2014. [DOI: 10.1039/c4md00280f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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359
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Abstract
P-21 activated kinases (PAKs) are effectors of Rac1/Cdc42 which coordinate signals from the cell membrane to the nucleus. Activation of PAKs drive important signalling pathways including mitogen activated protein kinase, phospoinositide 3-kinase (PI3K/AKT), NF-κB and Wnt/β-catenin. Intestinal PAK1 expression increases with inflammation and malignant transformation, although the biological relevance of PAKs in the development and progression of GI disease is only incompletely understood. This review highlights the importance of altered PAK activation within GI inflammation, emphasises its effect on oncogenic signalling and discusses PAKs as therapeutic targets of chemoprevention.
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Affiliation(s)
- Kyle Dammann
- Department of Medicine III, Division of Gastroenterology and Hepatology and Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria
| | - Vineeta Khare
- Department of Medicine III, Division of Gastroenterology and Hepatology and Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria
| | - Christoph Gasche
- Department of Medicine III, Division of Gastroenterology and Hepatology and Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria
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360
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Feng X, Degese MS, Iglesias-Bartolome R, Vaque JP, Molinolo AA, Rodrigues M, Zaidi MR, Ksander BR, Merlino G, Sodhi A, Chen Q, Gutkind JS. Hippo-independent activation of YAP by the GNAQ uveal melanoma oncogene through a trio-regulated rho GTPase signaling circuitry. Cancer Cell 2014; 25:831-45. [PMID: 24882515 PMCID: PMC4074519 DOI: 10.1016/j.ccr.2014.04.016] [Citation(s) in RCA: 413] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 03/06/2014] [Accepted: 04/24/2014] [Indexed: 02/05/2023]
Abstract
Mutually exclusive activating mutations in the GNAQ and GNA11 oncogenes, encoding heterotrimeric Gαq family members, have been identified in ∼ 83% and ∼ 6% of uveal and skin melanomas, respectively. However, the molecular events underlying these GNAQ-driven malignancies are not yet defined, thus limiting the ability to develop cancer-targeted therapies. Here, we focused on the transcriptional coactivator YAP, a critical component of the Hippo signaling pathway that controls organ size. We found that Gαq stimulates YAP through a Trio-Rho/Rac signaling circuitry promoting actin polymerization, independently of phospholipase Cβ and the canonical Hippo pathway. Furthermore, we show that Gαq promotes the YAP-dependent growth of uveal melanoma cells, thereby identifying YAP as a suitable therapeutic target in uveal melanoma, a GNAQ/GNA11-initiated human malignancy.
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Affiliation(s)
- Xiaodong Feng
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4340, USA; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
| | - Maria Sol Degese
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4340, USA
| | - Ramiro Iglesias-Bartolome
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4340, USA
| | - Jose P Vaque
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4340, USA
| | - Alfredo A Molinolo
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4340, USA
| | - Murilo Rodrigues
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | - M Raza Zaidi
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Bruce R Ksander
- Schepens Eye Research Institute, Harvard Medical School, Boston, MA 02114, USA
| | - Glenn Merlino
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, Bethesda, MD 20892, USA
| | - Akrit Sodhi
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | - Qianming Chen
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China.
| | - J Silvio Gutkind
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4340, USA.
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361
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Orgaz JL, Herraiz C, Sanz-Moreno V. Rho GTPases modulate malignant transformation of tumor cells. Small GTPases 2014; 5:e29019. [PMID: 25036871 DOI: 10.4161/sgtp.29019] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Rho GTPases are involved in the acquisition of all the hallmarks of cancer, which comprise 6 biological capabilities acquired during the development of human tumors. The hallmarks include proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, and activating invasion and metastasis programs, as defined by Hanahan and Weinberg. (1) Controlling these hallmarks are genome instability and inflammation. Emerging hallmarks are reprogramming of energy metabolism and evading immune destruction. To give a different view to the readers, we will not be focusing on invasion, metastasis, or cytoskeletal remodeling, but we will review here how Rho GTPases contribute to other hallmarks of cancer with a special emphasis on malignant transformation.
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Affiliation(s)
- Jose L Orgaz
- Randall Division of Cell and Molecular Biophysics; New Hunt's House; Guy's Campus; King's College London; London, UK
| | - Cecilia Herraiz
- Randall Division of Cell and Molecular Biophysics; New Hunt's House; Guy's Campus; King's College London; London, UK
| | - Victoria Sanz-Moreno
- Randall Division of Cell and Molecular Biophysics; New Hunt's House; Guy's Campus; King's College London; London, UK
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362
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Canonical and new generation anticancer drugs also target energy metabolism. Arch Toxicol 2014; 88:1327-50. [PMID: 24792321 DOI: 10.1007/s00204-014-1246-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 04/15/2014] [Indexed: 01/05/2023]
Abstract
Significant efforts have been made for the development of new anticancer drugs (protein kinase or proteasome inhibitors, monoclonal humanized antibodies) with presumably low or negligible side effects and high specificity. However, an in-depth analysis of the side effects of several currently used canonical (platin-based drugs, taxanes, anthracyclines, etoposides, antimetabolites) and new generation anticancer drugs as the first line of clinical treatment reveals significant perturbation of glycolysis and oxidative phosphorylation. Canonical and new generation drug side effects include decreased (1) intracellular ATP levels, (2) glycolytic/mitochondrial enzyme/transporter activities and/or (3) mitochondrial electrical membrane potentials. Furthermore, the anti-proliferative effects of these drugs are markedly attenuated in tumor rho (0) cells, in which functional mitochondria are absent; in addition, several anticancer drugs directly interact with isolated mitochondria affecting their functions. Therefore, several anticancer drugs also target the energy metabolism, and hence, the documented inhibitory effect of anticancer drugs on cancer growth should also be linked to the blocking of ATP supply pathways. These often overlooked effects of canonical and new generation anticancer drugs emphasize the role of energy metabolism in maintaining cancer cells viable and its targeting as a complementary and successful strategy for cancer treatment.
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363
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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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364
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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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365
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McCarty SK, Saji M, Zhang X, Knippler CM, Kirschner LS, Fernandez S, Ringel MD. BRAF activates and physically interacts with PAK to regulate cell motility. Endocr Relat Cancer 2014; 21:865-77. [PMID: 25228413 PMCID: PMC4487662 DOI: 10.1530/erc-14-0424] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Increased p21-activated kinase (PAK) signaling and expression have been identified in the invasive fronts of aggressive papillary thyroid cancers (PTCs), including those with RET/PTC, BRAFV600E, and mutant RAS expression. Functionally, thyroid cancer cell motility in vitro is dependent on group 1 PAKs, particularly PAK1. In this study, we hypothesize that BRAF, a central kinase in PTC tumorigenesis and invasion, regulates thyroid cancer cell motility in part through PAK activation. Using three well-characterized human thyroid cancer cell lines, we demonstrated in all cell lines that BRAF knockdown reduced PAK phosphorylation of direct downstream targets. In contrast, inhibition of MEK activity either pharmacologically or with siRNA did not reduce PAK activity, indicating MEK is dispensable for PAK activity. Inhibition of cell migration through BRAF loss is rescued by overexpression of either constitutive active MEK1 or PAK1, demonstrating that both signaling pathways are involved in BRAF-regulated cell motility. To further characterize BRAF-PAK signaling, immunofluorescence and immunoprecipitation demonstrated that both exogenously overexpressed and endogenous PAK1 and BRAF co-localize and physically interact, and that this interaction was enhanced in mitosis. Finally, we demonstrated that acute induction of BRAFV600E expression in vivo in murine thyroid glands results in increased PAK expression and activity confirming a positive signaling relationship in vivo. In conclusion, we have identified a signaling pathway in thyroid cancer cells which BRAF activates and physically interacts with PAK and regulates cell motility.
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Affiliation(s)
- Samantha K McCarty
- Division of EndocrinologyDiabetes and Metabolism, Department of Internal MedicineDepartment of Molecular VirologyImmunology, and Medical GeneticsCenter for BiostatisticsThe Ohio State University and Arthur G. James Comprehensive Cancer Center, 565 McCampbell Hall, 1581 Dodd Dr., Columbus, Ohio 43210, USA
| | - Motoyasu Saji
- Division of EndocrinologyDiabetes and Metabolism, Department of Internal MedicineDepartment of Molecular VirologyImmunology, and Medical GeneticsCenter for BiostatisticsThe Ohio State University and Arthur G. James Comprehensive Cancer Center, 565 McCampbell Hall, 1581 Dodd Dr., Columbus, Ohio 43210, USA
| | - Xiaoli Zhang
- Division of EndocrinologyDiabetes and Metabolism, Department of Internal MedicineDepartment of Molecular VirologyImmunology, and Medical GeneticsCenter for BiostatisticsThe Ohio State University and Arthur G. James Comprehensive Cancer Center, 565 McCampbell Hall, 1581 Dodd Dr., Columbus, Ohio 43210, USA
| | - Christina M Knippler
- Division of EndocrinologyDiabetes and Metabolism, Department of Internal MedicineDepartment of Molecular VirologyImmunology, and Medical GeneticsCenter for BiostatisticsThe Ohio State University and Arthur G. James Comprehensive Cancer Center, 565 McCampbell Hall, 1581 Dodd Dr., Columbus, Ohio 43210, USA
| | - Lawrence S Kirschner
- Division of EndocrinologyDiabetes and Metabolism, Department of Internal MedicineDepartment of Molecular VirologyImmunology, and Medical GeneticsCenter for BiostatisticsThe Ohio State University and Arthur G. James Comprehensive Cancer Center, 565 McCampbell Hall, 1581 Dodd Dr., Columbus, Ohio 43210, USA Division of EndocrinologyDiabetes and Metabolism, Department of Internal MedicineDepartment of Molecular VirologyImmunology, and Medical GeneticsCenter for BiostatisticsThe Ohio State University and Arthur G. James Comprehensive Cancer Center, 565 McCampbell Hall, 1581 Dodd Dr., Columbus, Ohio 43210, USA
| | - Soledad Fernandez
- Division of EndocrinologyDiabetes and Metabolism, Department of Internal MedicineDepartment of Molecular VirologyImmunology, and Medical GeneticsCenter for BiostatisticsThe Ohio State University and Arthur G. James Comprehensive Cancer Center, 565 McCampbell Hall, 1581 Dodd Dr., Columbus, Ohio 43210, USA
| | - Matthew D Ringel
- Division of EndocrinologyDiabetes and Metabolism, Department of Internal MedicineDepartment of Molecular VirologyImmunology, and Medical GeneticsCenter for BiostatisticsThe Ohio State University and Arthur G. James Comprehensive Cancer Center, 565 McCampbell Hall, 1581 Dodd Dr., Columbus, Ohio 43210, USA Division of EndocrinologyDiabetes and Metabolism, Department of Internal MedicineDepartment of Molecular VirologyImmunology, and Medical GeneticsCenter for BiostatisticsThe Ohio State University and Arthur G. James Comprehensive Cancer Center, 565 McCampbell Hall, 1581 Dodd Dr., Columbus, Ohio 43210, USA
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