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Oscier D, Stamatopoulos K, Mirandari A, Strefford J. The Genomics of Hairy Cell Leukaemia and Splenic Diffuse Red Pulp Lymphoma. Cancers (Basel) 2022; 14:697. [PMID: 35158965 PMCID: PMC8833447 DOI: 10.3390/cancers14030697] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 12/12/2022] Open
Abstract
Classical hairy cell leukaemia (HCLc), its variant form (HCLv), and splenic diffuse red pulp lymphoma (SDRPL) constitute a subset of relatively indolent B cell tumours, with low incidence rates of high-grade transformations, which primarily involve the spleen and bone marrow and are usually associated with circulating tumour cells characterised by villous or irregular cytoplasmic borders. The primary aim of this review is to summarise their cytogenetic, genomic, immunogenetic, and epigenetic features, with a particular focus on the clonal BRAFV600E mutation, present in most cases currently diagnosed with HCLc. We then reflect on their cell of origin and pathogenesis as well as present the clinical implications of improved biological understanding, extending from diagnosis to prognosis assessment and therapy response.
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Affiliation(s)
- David Oscier
- Department of Haematology, Royal Bournemouth and Christchurch NHS Trust, Bournemouth BH7 7DW, UK
| | - Kostas Stamatopoulos
- Institute of Applied Biosciences, Centre for Research and Technology-Hellas, 57001 Thessaloniki, Greece;
| | - Amatta Mirandari
- Cancer Genomics Group, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK; (A.M.); (J.S.)
| | - Jonathan Strefford
- Cancer Genomics Group, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK; (A.M.); (J.S.)
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Zhao Z, Liao N. Bergamottin Induces DNA Damage and Inhibits Malignant Progression in Melanoma by Modulating miR-145/Cyclin D1 Axis. Onco Targets Ther 2021; 14:3769-3781. [PMID: 34168462 PMCID: PMC8216741 DOI: 10.2147/ott.s275322] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 05/19/2021] [Indexed: 02/06/2023] Open
Abstract
Background Melanoma is a prevalent skin cancer with the high rate of metastasis and mortality, affecting the increasing number of people worldwide. Bergamottin (BGM) is a natural furanocoumarin derived from grapefruits and presents the potential anti-cancer activity in several tumor models. However, the role of BGM in the development of melanoma remains unclear. Here, we aimed to explore the effect of BGM on the DNA damage and progression of melanoma. Methods The effect of BGM on the melanoma progression was analyzed by CCK-8 assays, colony formation assays, transwell assays, Annexin V-FITC Apoptosis Detection Kit, cell-cycle analysis, in vivo tumorigenicity analysis. The mechanism investigation was performed using luciferase reporter gene assays, qPCR assays, and Western blot analysis. Results We identified that BGM repressed cell proliferation, migration, and invasion of melanoma cells. BGM induced cell cycle arrest at the G0/G1 phase and enhanced apoptosis of melanoma cells. The DNA damage in the melanoma cells was stimulated by the BGM treatment. Meanwhile, BGM was able to up-regulate the expression of miR-145 and miR-145 targeted Cyclin D1 in the melanoma cells. Furthermore, BGM inhibited the progression of melanoma by targeting miR-145/Cyclin D1 axis in vitro. BGM attenuated the tumor growth of melanoma in vivo. Conclusion Thus, we conclude that BGM induces DNA damage and inhibits tumor progression in melanoma by modulating the miR-145/Cyclin D1 axis. Our finding provides new insights into the mechanism by which BGM modulates the development of melanoma. BGM may be applied as a potential anti-tumor candidate for the clinical treatment of melanoma.
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Affiliation(s)
- Zhongfang Zhao
- Department of Plastic and Cosmetic Surgery, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou City, Guangdong Province, 510150, People's Republic of China
| | - Nong Liao
- Department of Plastic and Cosmetic Surgery, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou City, Guangdong Province, 510150, People's Republic of China
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Comprehensive Investigation into the Role of Ubiquitin-Conjugating Enzyme E2S in Melanoma Development. J Invest Dermatol 2020; 141:374-384. [PMID: 32603752 DOI: 10.1016/j.jid.2020.05.113] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/27/2020] [Accepted: 05/03/2020] [Indexed: 12/21/2022]
Abstract
Ubiquitin-conjugating enzyme E2S (UBE2S) is involved in protein degradation and signal transduction, but its function in the development of melanoma is unclear. We focused on the role of UBE2S in melanoma development both in vitro and in vivo. UBE2S was overexpressed in malignant melanoma cells and tissues, and UBE2S expression was significantly different between tumor node metastasis staging T4 and T1/T2/T3. We designed UBE2S short hairpin RNA (shUBE2S) and transfected it into A375, SK-MEL-28, and MUM-2B cells using lentivirus. By whole-genome filtering, 247 genes and 265 genes were upregulated and downregulated, respectively, in shUBE2S-treated melanoma; these genes were mainly involved in immune reactions, apoptosis, DNA damage repair, and cell movement. The proliferation of melanoma cells was inhibited, apoptosis was increased, and cell cycle was arrested in G1/S in shUBE2S-treated melanoma. Expression of epithelial to mesenchymal transition-related proteins was significantly suppressed, and tumor growth was also suppressed in shUBE2S BALB/C nude mice. shUBE2S treatment may cause cell cycle arrest in G1/S phase, inhibit proliferation, induce apoptosis, and suppress tumor growth through DNA damage repair, epithelial to mesenchymal transition inhibition, protein kinase B-mTOR pathway, NF-κB signaling, and immune reactions, which provides a comprehensive understanding of the role of UBE2S in melanoma development and the need for advanced clinical research into UBE2S.
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Targeting CDC7 sensitizes resistance melanoma cells to BRAF V600E-specific inhibitor by blocking the CDC7/MCM2-7 pathway. Sci Rep 2019; 9:14197. [PMID: 31578454 PMCID: PMC6775054 DOI: 10.1038/s41598-019-50732-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 09/17/2019] [Indexed: 12/19/2022] Open
Abstract
Although the utilization of selective BRAFV600E inhibitors is associated with improved overall survival in patients with metastatic melanoma, a growing challenge of drug resistance has emerged. CDC7 has been shown to be overexpressed and associated with poor prognosis in various cancers including melanoma. Thus, we aimed to elucidate the biological role of CDC7 in promoting Vemurafenib resistance and the anticipated benefits of dual targeting of BRAFV600E and CDC7 in melanoma cells. We performed exosomes-associated microRNA profiling and functional assays to determine the role of CDC7 in drug resistance using Vemurafenib-sensitive and resistant melanoma cells. Our results demonstrated that Vemurafenib-resistant cells exhibited a persistent expression of CDC7 in addition to prolonged activity of MCM2 compared to drug-sensitive cells. Reconstitution of miR-3613-3p in resistant cells downregulated CDC7 expression and reduced the number of colonies. Treatment of cells with low concentrations of CDC7 inhibitor TAK-931 sensitized resistant cells to Vemurafenib and reduced the number of cell colonies. Taken together, CDC7 overexpression and downregulation of miR-3613-3p were associated with Vemurafenib resistance in BRAFV600E- bearing melanoma cells. Dual targeting of CDC7 and BRAFV600E reduced the development of resistance against Vemurafenib. Further studies are warranted to investigate the clinical effect of targeting CDC7 in metastatic melanoma.
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Fisk HA, Thomas JL, Nguyen TB. Breaking Bad: Uncoupling of Modularity in Centriole Biogenesis and the Generation of Excess Centrioles in Cancer. Results Probl Cell Differ 2019; 67:391-411. [PMID: 31435805 DOI: 10.1007/978-3-030-23173-6_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Centrosomes are tiny yet complex cytoplasmic structures that perform a variety of roles related to their ability to act as microtubule-organizing centers. Like the genome, centrosomes are single copy structures that undergo a precise semi-conservative replication once each cell cycle. Precise replication of the centrosome is essential for genome integrity, because the duplicated centrosomes will serve as the poles of a bipolar mitotic spindle, and any number of centrosomes other than two will lead to an aberrant spindle that mis-segregates chromosomes. Indeed, excess centrosomes are observed in a variety of human tumors where they generate abnormal spindles in situ that are thought to participate in tumorigenesis by driving genomic instability. At the heart of the centrosome is a pair of centrioles, and at the heart of centrosome duplication is the replication of this centriole pair. Centriole replication proceeds through a complex macromolecular assembly process. However, while centrosomes may contain as many as 500 proteins, only a handful of proteins have been shown to be essential for centriole replication. Our observations suggest that centriole replication is a modular, bottom-up process that we envision akin to building a house; the proper site of assembly is identified, a foundation is assembled at that site, and subsequent modules are added on top of the foundation. Here, we discuss the data underlying our view of modularity in the centriole assembly process, and suggest that non-essential centriole assembly factors take on greater importance in cancer cells due to their function in coordination between centriole modules, using the Monopolar spindles 1 protein kinase and its substrate Centrin 2 to illustrate our model.
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Affiliation(s)
- Harold A Fisk
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, USA.
| | - Jennifer L Thomas
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, USA
| | - Tan B Nguyen
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, USA
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Abstract
CDK4/6 inhibitors have emerged as a powerful class of agents with clinical activity in a number of malignancies. Targeting the cell cycle represents a core attack on a defining feature of cancer. However, the mechanisms through which selective CDK4/6 targeted agents act has few parallels in the current pharmaceutical armamentarium against cancer. Notably, CDK4/6 inhibitors act downstream of most mitogenic signaling cascades, which have implications both related to clinical efficacy and resistance. Core knowledge of cell cycle processes has provided insights into mechanisms of intrinsic resistance to CDK4/6 inhibitors; however, the basis of acquired resistance versus durable response is only beginning to emerge. This review focuses on the mechanism of action and biomarkers to direct the precision use of CDK4/6 inhibitors and rationally-developed combination therapies.
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Brożyna AA, Aplin A, Cohen C, Carlson G, Page AJ, Murphy M, Slominski AT, Carlson JA. CKS1 expression in melanocytic nevi and melanoma. Oncotarget 2018; 9:4173-4187. [PMID: 29423113 PMCID: PMC5790530 DOI: 10.18632/oncotarget.23648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/16/2017] [Indexed: 12/22/2022] Open
Abstract
Cyclin-dependent kinase subunit 1 (Cks1) regulates the degradation of p27, an important G1-S inhibitor, which is up regulated by MAPK pathway activation. In this study, we sought to determine whether Cks1 expression is increased in melanocytic tumors and correlates with outcome and/or other clinicopathologic prognostic markers. Cks1 expression was assessed by immunohistochemistry in 298 melanocytic lesions. The frequency and intensity of cytoplasmic and nuclear expression was scored as a labeling index and correlated with clinico-pathological data. Nuclear Cks1 protein was found in 63% of melanocytic nevi, 89% primary and 90% metastatic melanomas with mean labeling index of 7 ± 16, 19 ± 20, and 30 ± 29, respectively. While cytoplasmic Cks1 was found in 41% of melanocytic nevi, 84% primary and 95% metastatic melanomas with mean labeling index of 18 ± 34, 35 ± 34, and 52 ± 34, accordingly. Histologic stepwise model of tumor progression, defined as progression from benign nevi to primary melanomas, to melanoma metastases, revealed a significant increase in nuclear and cytoplasmic Cks1 expression with tumor progression. Nuclear and cytoplasmic Cks1 expression correlated with the presence of ulceration, increased mitotic rate, Breslow depth, Clark level, tumor infiltrating lymphocytes and gender. However, other well-known prognostic factors (age, anatomic site, and regression) did not correlate with any type of Cks1 expression. Similarly, increasing nuclear expression of Cks1 significantly correlated with worse overall survival. Thus, Cks1 expression appears to play a role in the progression of melanoma, where high levels of expression are associated with poor outcome. Cytoplasmic expression of Cks1 might represent high turnover of protein via the ubiquination/proteosome pathway.
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Affiliation(s)
- Anna A Brożyna
- Department of Tumor Pathology and Pathomorphology, Faculty of Health Sciences, Nicolaus Copernicus University Collegium Medicum in Bydgoszcz, Oncology Centre - Prof. Franciszek Łukaszczyk Memorial Hospital, Bydgoszcz 85-796, Poland
| | - Andrew Aplin
- Department of Cancer Biology, BLSB 524, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Cynthia Cohen
- Winship Cancer Institute, Emory University Hospital, Atlanta, GA 30322, USA
| | - Grant Carlson
- Winship Cancer Institute, Emory University Hospital, Atlanta, GA 30322, USA
| | - Andrew Joseph Page
- Pancreas, Liver, and Cancer Surgery, Piedmont Healthcare, Atlanta, GA 30309, USA
| | - Michael Murphy
- Department of Dermatology, UConn Health, Farmington, CT 06030, USA
| | - Andrzej T Slominski
- Department of Dermatology, Comprehensive Cancer Center, Cancer Chemoprevention Program, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - J Andrew Carlson
- Department of Pathology and Laboratory Medicine, Albany Medical College MC-81, Albany, NY 12208, USA
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Grey W, Ivey A, Milne TA, Haferlach T, Grimwade D, Uhlmann F, Voisset E, Yu V. The Cks1/Cks2 axis fine-tunes Mll1 expression and is crucial for MLL-rearranged leukaemia cell viability. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2018; 1865:105-116. [PMID: 28939057 PMCID: PMC5701546 DOI: 10.1016/j.bbamcr.2017.09.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 09/09/2017] [Accepted: 09/17/2017] [Indexed: 12/25/2022]
Abstract
The Cdc28 protein kinase subunits, Cks1 and Cks2, play dual roles in Cdk-substrate specificity and Cdk-independent protein degradation, in concert with the E3 ubiquitin ligase complexes SCFSkp2 and APCCdc20. Notable targets controlled by Cks include p27 and Cyclin A. Here, we demonstrate that Cks1 and Cks2 proteins interact with both the MllN and MllC subunits of Mll1 (Mixed-lineage leukaemia 1), and together, the Cks proteins define Mll1 levels throughout the cell cycle. Overexpression of CKS1B and CKS2 is observed in multiple human cancers, including various MLL-rearranged (MLLr) AML subtypes. To explore the importance of MLL-Fusion Protein regulation by CKS1/2, we used small molecule inhibitors (MLN4924 and C1) to modulate their protein degradation functions. These inhibitors specifically reduced the proliferation of MLLr cell lines compared to primary controls. Altogether, this study uncovers a novel regulatory pathway for MLL1, which may open a new therapeutic approach to MLLr leukaemia.
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Affiliation(s)
- William Grey
- Department of Medical and Molecular Genetics, King's College London, Faculty of Life Sciences and Medicine, London, UK.
| | - Adam Ivey
- Department of Medical and Molecular Genetics, King's College London, Faculty of Life Sciences and Medicine, London, UK
| | - Thomas A Milne
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, NIHR Oxford Biomedical Research Centre Programme, University of Oxford, UK
| | | | - David Grimwade
- Department of Medical and Molecular Genetics, King's College London, Faculty of Life Sciences and Medicine, London, UK
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK
| | - Edwige Voisset
- Department of Medical and Molecular Genetics, King's College London, Faculty of Life Sciences and Medicine, London, UK.
| | - Veronica Yu
- Department of Medical and Molecular Genetics, King's College London, Faculty of Life Sciences and Medicine, London, UK
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CKS protein overexpression renders tumors susceptible to a chemotherapeutic strategy that protects normal tissues. Oncotarget 2017; 8:114911-114923. [PMID: 29383129 PMCID: PMC5777741 DOI: 10.18632/oncotarget.22931] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 11/10/2017] [Indexed: 11/25/2022] Open
Abstract
The cyclin-dependent kinase-interacting proteins Cyclin-dependent Kinase Subunit 1 and 2 (CKS1 and 2) are frequently overexpressed in cancer and linked to increased aggressiveness and poor prognoses. We previously showed that CKS protein overexpression overrides the replication stress checkpoint activated by oncoproteins. Since CKS overexpression and oncoprotein activation/overexpression are often observed in the same tumors, we have hypothesized that CKS-mediated checkpoint override could enhance the ability of premalignant cells experiencing oncoprotein-induced replication stress to expand. This tumor advantage, however, could represent a vulnerability to exploit therapeutically. Here, we first show in vitro that CKS protein overexpression selectively sensitizes tumor-derived cell lines to nucleoside analog-mediated toxicity under replication stress conditions. A treatment combination of the nucleoside analog gemcitabine and an agent that induces replication stress (thymidine or methotrexate) resulted in selective targeting of CKS protein-overexpressing tumor-derived cells while protecting proliferative cells with low CKS protein levels from gemcitabine toxicity. We validated this strategy in vivo and observed that Cks2-overexpressing mammary tumors in nude mice were selectively sensitized to gemcitabine under conditions of methotrexate-induced replication stress. These results suggest that high CKS expression might be useful as a biomarker to identify subgroups of cancer patients who might benefit from the described therapeutic approach.
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Treatment of melanoma with selected inhibitors of signaling kinases effectively reduces proliferation and induces expression of cell cycle inhibitors. Med Oncol 2017; 35:7. [PMID: 29214525 PMCID: PMC5719123 DOI: 10.1007/s12032-017-1069-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 11/30/2017] [Indexed: 01/01/2023]
Abstract
Cancer treatment often tends to involve direct targeting enzymes essential for the growth and proliferation of cancer cells. The aim of this study was the recognition of the possible role of selected protein kinases: PI3K, ERK1/2, and mTOR in cell proliferation and cell cycle in malignant melanoma. We investigated the role of protein kinase inhibitors: U0126 (ERK1/2), LY294002 (PI3K), rapamycin (mTOR), everolimus (mTOR), GDC-0879 (B-RAF), and CHIR-99021 (GSK3beta) in cell proliferation and expression of crucial regulatory cell cycle proteins in human melanoma cells: WM793 (VGP) and Lu1205 (metastatic). They were used either individually or in various combinations. The study on the effect of signaling kinases inhibitors on proliferation—BrdU ELISA test after 48–72 h. Their effect on the expression of cell cycle regulatory proteins: cyclin D1 and D3, cyclin-dependent kinase CDK4 and CDK6, and cell cycle inhibitors: p16, p21, and p27, was studied at the protein level (western blot). Treatment of melanoma cells with protein kinase inhibitors led to significantly decreased cell proliferation except the use of a GSK-3β kinase inhibitors—CHIR-99021. The significant decrease in the expression of selected cyclins and cyclin-dependent kinases (CDKs) with parallel increase in the expression of some of cyclin-dependent kinases inhibitors and in consequence meaningful reduction in melanoma cell proliferation by the combinations of inhibitors of signaling kinases clearly showed the crucial role of AKT, ERK 1/2, and mTOR signal transduction in melanoma progression. The results unanimously indicate those pathways as an important target for treatment of melanoma.
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Diniz MG, Guimarães BVA, Pereira NB, de Menezes GHF, Gomes CC, Gomez RS. DNA damage response activation and cell cycle dysregulation in infiltrative ameloblastomas: A proposed model for ameloblastoma tumor evolution. Exp Mol Pathol 2017; 102:391-395. [DOI: 10.1016/j.yexmp.2017.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 04/24/2017] [Indexed: 10/19/2022]
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Takahashi M, Li Y, Dillon TJ, Stork PJS. Phosphorylation of Rap1 by cAMP-dependent Protein Kinase (PKA) Creates a Binding Site for KSR to Sustain ERK Activation by cAMP. J Biol Chem 2016; 292:1449-1461. [PMID: 28003362 DOI: 10.1074/jbc.m116.768986] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 12/16/2016] [Indexed: 12/31/2022] Open
Abstract
Cyclic adenosine monophosphate (cAMP) is an important mediator of hormonal stimulation of cell growth and differentiation through its activation of the extracellular signal-regulated kinase (ERK) cascade. Two small G proteins, Ras and Rap1 have been proposed to mediate this activation. Using HEK293 cells as a model system, we have recently shown that both Ras and Rap1 are required for cAMP signaling to ERKs. However, cAMP-dependent Ras signaling to ERKs is transient and rapidly terminated by PKA phosphorylation of the Raf isoforms C-Raf and B-Raf. In contrast, cAMP-dependent Rap1 signaling to ERKs and Rap1 is potentiated by PKA. We show that this is due to sustained binding of B-Raf to Rap1. One of the targets of PKA is Rap1 itself, directly phosphorylating Rap1a on serine 180 and Rap1b on serine 179. We show that these phosphorylations create potential binding sites for the adaptor protein 14-3-3 that links Rap1 to the scaffold protein KSR. These results suggest that Rap1 activation of ERKs requires PKA phosphorylation and KSR binding. Because KSR and B-Raf exist as heterodimers within the cell, this binding also brings B-Raf to Rap1, allowing Rap1 to couple to ERKs through B-Raf binding to Rap1 independently of its Ras-binding domain.
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Affiliation(s)
- Maho Takahashi
- From the Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239-3098
| | - Yanping Li
- From the Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239-3098
| | - Tara J Dillon
- From the Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239-3098
| | - Philip J S Stork
- From the Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239-3098
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Lu W, Liu S, Li B, Xie Y, Izban MG, Ballard BR, Sathyanarayana SA, Adunyah SE, Matusik RJ, Chen Z. SKP2 loss destabilizes EZH2 by promoting TRAF6-mediated ubiquitination to suppress prostate cancer. Oncogene 2016; 36:1364-1373. [PMID: 27869166 DOI: 10.1038/onc.2016.300] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 06/24/2016] [Accepted: 07/17/2016] [Indexed: 02/06/2023]
Abstract
EZH2 is crucial for the progression of prostate cancer (PCa) and castration-resistant prostate cancer (CRPC) through upregulation and activation of progenitor genes, as well as androgen receptor (AR)-target genes. However, the mechanisms by which EZH2 is regulated in PCa and CRPC remain elusive. Here we report that EZH2 is post-transcriptionally regulated by SKP2 in vitro in cultured cells and in vivo in mouse models. We observed aberrant upregulation of Skp2, Ezh2 and histone H3 lysine 27 trimethylation (H3K27me3) in both Pten null mouse embryonic fibroblasts (MEFs) and Pten null mouse prostate tissues. Loss of Skp2 resulted in a striking decrease of Ezh2 levels in Pten/Trp53 double-null MEFs and in prostate tumors of Pten/Trp53 double-null mutant mice. SKP2 knockdown decreased EZH2 levels in human PCa cells through upregulation of TRAF6-mediated and lysine(K) 63-linked ubiquitination of EZH2 for degradation. Ectopic expression of TRAF6 promoted the K63-linked ubiquitination of EZH2 to decrease EZH2 and H3K27me3 levels in PCa cells. In contrast, TRAF6 knockdown resulted in a reduced EZH2 ubiquitination with an increase of EZH2 and H3K27me3 levels in PCa cells. Furthermore, the catalytically dead mutant TRAF6 C70A abolished the TRAF6-mediated polyubiquitination of recombinant human EZH2 in vitro. Most importantly, a concurrent elevation of Skp2 and Ezh2 was found in CRPC tumors of Pten/Trp53 mutant mice, and expression levels of SKP2 and EZH2 were positively correlated in human PCa specimens. Taken together, our findings revealed a novel mechanism on EZH2 ubiquitination and an important signaling network of SKP2-TRAF6-EZH2/H3K27me3, and targeting SKP2-EZH2 pathway may be a promising therapeutic strategy for CRPC treatment.
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Affiliation(s)
- W Lu
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN, USA
| | - S Liu
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN, USA
| | - B Li
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN, USA
| | - Y Xie
- Department of Biology, School of Science and Technology, Nazarbayev University, Astana, Republic of Kazakhstan
| | - M G Izban
- Department of Pathology, Anatomy and Cell Biology, Meharry Medical College, Nashville, TN, USA
| | - B R Ballard
- Department of Pathology, Anatomy and Cell Biology, Meharry Medical College, Nashville, TN, USA
| | | | - S E Adunyah
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN, USA
| | - R J Matusik
- Department of Urologic Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Z Chen
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN, USA
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BRAF V600E mutation in hairy cell leukemia: from bench to bedside. Blood 2016; 128:1918-1927. [DOI: 10.1182/blood-2016-07-418434] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 08/15/2016] [Indexed: 12/13/2022] Open
Abstract
AbstractHairy cell leukemia (HCL) is a distinct clinicopathological entity whose underlying genetic lesion has remained a mystery for over half a century. The BRAF V600E mutation is now recognized as the causal genetic event of HCL because it is somatic, present in the entire tumor clone, detectable in almost all cases at diagnosis (encompassing the whole disease spectrum), and stable at relapse. BRAF V600E leads to the constitutive activation of the RAF-MEK-extracellular signal-regulated kinase (ERK) signaling pathway which represents the key event in the molecular pathogenesis of HCL. KLF2 and CDNK1B (p27) mutations may cooperate with BRAF V600E in promoting leukemic transformation. Sensitive molecular assays for detecting BRAF V600E allow HCL (highly responsive to purine analogs) to be better distinguished from HCL-like disorders, which are treated differently. In vitro preclinical studies on purified HCL cells proved that BRAF and MEK inhibitors can induce marked dephosphorylation of MEK/ERK, silencing of RAF-MEK-ERK pathway transcriptional output, loss of the HCL-specific gene expression profile signature, change of morphology from “hairy” to “smooth,” and eventually apoptosis. The overall response rate of refractory/relapsed HCL patients to the BRAF inhibitor vemurafenib approached 100%, with 35% to 40% complete remissions (CRs). The median relapse free-survival was about 19 months in patients who had achieved CR and 6 months in those who had obtained a partial response. Future therapeutic perspectives include: (1) combining BRAF inhibitors with MEK inhibitors or immunotherapy (anti-CD20 monoclonal antibody) to increase the percentage of CRs and (2) better understanding of the molecular mechanisms underlying resistance of HCL cells to BRAF inhibitors.
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Li Y, Dillon TJ, Takahashi M, Earley KT, Stork PJS. Protein Kinase A-independent Ras Protein Activation Cooperates with Rap1 Protein to Mediate Activation of the Extracellular Signal-regulated Kinases (ERK) by cAMP. J Biol Chem 2016; 291:21584-21595. [PMID: 27531745 DOI: 10.1074/jbc.m116.730978] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 08/03/2016] [Indexed: 11/06/2022] Open
Abstract
Cyclic adenosine monophosphate (cAMP) is an important mediator of hormonal stimulation of cell growth and differentiation through its activation of the extracellular signal-regulated kinase (ERK) cascade. Two small G proteins, Ras and Rap1, have been proposed to mediate this activation, with either Ras or Rap1 acting in distinct cell types. Using Hek293 cells, we show that both Ras and Rap1 are required for cAMP signaling to ERKs. The roles of Ras and Rap1 were distinguished by their mechanism of activation, dependence on the cAMP-dependent protein kinase (PKA), and the magnitude and kinetics of their effects on ERKs. Ras was required for the early portion of ERK activation by cAMP and was activated independently of PKA. Ras activation required the Ras/Rap guanine nucleotide exchange factor (GEF) PDZ-GEF1. Importantly, this action of PDZ-GEF1 was disrupted by mutation within its putative cyclic nucleotide-binding domain within PDZ-GEF1. Compared with Ras, Rap1 activation of ERKs was of longer duration. Rap1 activation was dependent on PKA and required Src family kinases and the Rap1 exchanger C3G. This is the first report of a mechanism for the cooperative actions of Ras and Rap1 in cAMP activation of ERKs. One physiological role for the sustained activation of ERKs is the transcription and stabilization of a range of transcription factors, including c-FOS. We show that the induction of c-FOS by cAMP required both the early and sustained phases of ERK activation, requiring Ras and Rap1, as well as for each of the Raf isoforms, B-Raf and C-Raf.
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Affiliation(s)
- Yanping Li
- From the Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239-3098
| | - Tara J Dillon
- From the Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239-3098
| | - Maho Takahashi
- From the Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239-3098
| | - Keith T Earley
- From the Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239-3098
| | - Philip J S Stork
- From the Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239-3098
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16
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Pal HC, Baxter RD, Hunt KM, Agarwal J, Elmets CA, Athar M, Afaq F. Fisetin, a phytochemical, potentiates sorafenib-induced apoptosis and abrogates tumor growth in athymic nude mice implanted with BRAF-mutated melanoma cells. Oncotarget 2016; 6:28296-311. [PMID: 26299806 PMCID: PMC4695061 DOI: 10.18632/oncotarget.5064] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 07/03/2015] [Indexed: 12/21/2022] Open
Abstract
Melanoma is the most deadly form of cutaneous malignancy, and its incidence rates are rising worldwide. In melanoma, constitutive activation of the BRAF/MEK/ERK (MAPK) and PI3K/AKT/mTOR (PI3K) signaling pathways plays a pivotal role in cell proliferation, survival and tumorigenesis. A combination of compounds that lead to an optimal blockade of these critical signaling pathways may provide an effective strategy for prevention and treatment of melanoma. The phytochemical fisetin is known to possess anti-proliferative and pro-apoptotic activities. We found that fisetin treatment inhibited PI3K signaling pathway in melanoma cells. Therefore, we investigated the effect of fisetin and sorafenib (an RAF inhibitor) alone and in combination on cell proliferation, apoptosis and tumor growth. Combination treatment (fisetin + sorafenib) more effectively reduced the growth of BRAF-mutated human melanoma cells at lower doses when compared to individual agents. In addition, combination treatment resulted in enhanced (i) apoptosis, (ii) cleavage of caspase-3 and PARP, (iii) expression of Bax and Bak, (iv) inhibition of Bcl2 and Mcl-1, and (v) inhibition of expression of PI3K, phosphorylation of MEK1/2, ERK1/2, AKT and mTOR. In athymic nude mice subcutaneously implanted with melanoma cells (A375 and SK-MEL-28), we found that combination therapy resulted in greater reduction of tumor growth when compared to individual agents. Furthermore, combination therapy was more effective than monotherapy in: (i) inhibition of proliferation and angiogenesis, (ii) induction of apoptosis, and (iii) inhibition of the MAPK and PI3K pathways in xenograft tumors. These data suggest that simultaneous inhibition of both these signaling pathways using combination of fisetin and sorafenib may serve as a therapeutic option for the management of melanoma.
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Affiliation(s)
- Harish Chandra Pal
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ronald D Baxter
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Katherine M Hunt
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jyoti Agarwal
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Craig A Elmets
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, USA.,Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mohammad Athar
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, USA.,Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Farrukh Afaq
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, USA.,Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
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17
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Zhang P, Feng S, Liu G, Wang H, Zhu H, Ren Q, Bai H, Fu C, Dong C. Mutant B-Raf(V600E) Promotes Melanoma Paracellular Transmigration by Inducing Thrombin-mediated Endothelial Junction Breakdown. J Biol Chem 2015; 291:2087-106. [PMID: 26504080 DOI: 10.1074/jbc.m115.696419] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Indexed: 01/04/2023] Open
Abstract
Tumor invasiveness depends on the ability of tumor cells to breach endothelial barriers. In this study, we investigated the mechanism by which the adhesion of melanoma cells to endothelium regulates adherens junction integrity and modulates tumor transendothelial migration (TEM) by initiating thrombin generation. We found that the B-Raf(V600E) mutation in metastatic melanoma cells up-regulated tissue factor (TF) expression on cell membranes and promoted thrombin production. Co-culture of endothelial monolayers with metastatic melanoma cells mediated the opening of inter-endothelial spaces near melanoma cell contact sites in the presence of platelet-free plasma (PFP). By using small interfering RNA (siRNA), we demonstrated that B-Raf(V600E) and TF silencing attenuated the focal disassembly of adherens junction induced by tumor contact. Vascular endothelial-cadherin (VE-cadherin) disassembly was dependent on phosphorylation of p120-catenin on Ser-879 and VE-cadherin on Tyr-658, Tyr-685, and Tyr-731, which can be prevented by treatment with the thrombin inhibitor, hirudin, or by silencing the thrombin receptor, protease-activated receptor-1, in endothelial cells. We also provided strong evidence that tumor-derived thrombin enhanced melanoma TEM by inducing ubiquitination-coupled VE-cadherin internalization, focal adhesion formation, and actin assembly in endothelium. Confocal microscopic analysis of tumor TEM revealed that junctions transiently opened and resealed as tumor cells accomplished TEM. In addition, in the presence of PFP, tumor cells preferentially transmigrated via paracellular routes. PFP supported melanoma transmigration under shear conditions via a B-Raf(V600E)-thrombin-dependent mechanism. We concluded that the activation of thrombin generation by cancer cells in plasma is an important process regulating melanoma extravasation by disrupting endothelial junction integrity.
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Affiliation(s)
- Pu Zhang
- From the Key Laboratory of Luminescence and Real Time Analytical Chemistry, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China, the Department of Bioengineering, Pennsylvania State University, University Park, Pennsylvania 16801, and
| | - Shan Feng
- From the Key Laboratory of Luminescence and Real Time Analytical Chemistry, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Gentao Liu
- the Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507 Zhengmin Road, Shanghai 200433, China
| | - Heyong Wang
- the Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507 Zhengmin Road, Shanghai 200433, China
| | - Huifeng Zhu
- From the Key Laboratory of Luminescence and Real Time Analytical Chemistry, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Qiao Ren
- From the Key Laboratory of Luminescence and Real Time Analytical Chemistry, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Huiyuan Bai
- From the Key Laboratory of Luminescence and Real Time Analytical Chemistry, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Changliang Fu
- the Department of Bioengineering, Pennsylvania State University, University Park, Pennsylvania 16801, and
| | - Cheng Dong
- the Department of Bioengineering, Pennsylvania State University, University Park, Pennsylvania 16801, and
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18
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Abstract
Melanoma is increasing in incidence and represents an aggressive type of cancer. Efforts have focused on identifying genetic factors in melanoma carcinogenesis to guide prevention, screening, early detection, and targeted therapy. This article reviews the hereditary risk factors associated with melanoma and the known molecular pathways and genetic mutations associated with this disease. This article also explores the controversies associated with genetic testing and the latest advances in identifying genetic targets in melanoma, which offer promise for future application in the multidisciplinary management of melanoma.
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Affiliation(s)
- Omar M Rashid
- Department of Cutaneous Oncology, Moffitt Cancer Center, 12902 Magnolia Drive, SRB 4.24012, Tampa, FL 33612, USA; Bienes Comprehensive Cancer Center, Holy Cross Hospital, 4725 N Federal Highway, Fort Lauderdale, FL 33308, USA
| | - Jonathan S Zager
- Department of Cutaneous Oncology, Moffitt Cancer Center, 12902 Magnolia Drive, SRB 4.24012, Tampa, FL 33612, USA.
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19
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Scartozzi M, Giampieri R, Aprile G, Iacono D, Santini D, dell’Aquila E, Silvestris N, Gnoni A, Bonotto M, Puzzoni M, Demurtas L, Cascinu S. The distinctive molecular, pathological and clinical characteristics ofBRAF-mutant colorectal tumors. Expert Rev Mol Diagn 2015; 15:979-87. [DOI: 10.1586/14737159.2015.1047346] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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20
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del Rincón SV, Widschwendter M, Sun D, Ekholm-Reed S, Tat J, Teixeira LK, Ellederova Z, Grolieres E, Reed SI, Spruck C. Cks overexpression enhances chemotherapeutic efficacy by overriding DNA damage checkpoints. Oncogene 2015; 34:1961-7. [PMID: 24858038 PMCID: PMC4245389 DOI: 10.1038/onc.2014.137] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 03/27/2014] [Accepted: 03/28/2014] [Indexed: 12/12/2022]
Abstract
Cdc kinase subunit (Cks) proteins Cks1 and Cks2 are adaptor-like proteins that bind many cyclin-dependent kinases. A wealth of clinical data has shown that Cks proteins are overexpressed in many types of human cancers and this often correlates with increased tumor aggressiveness. Previously, we showed that Cks overexpression abrogates the intra-S-phase checkpoint, a major barrier to oncogene-mediated transformation. Interestingly, the intra-S-phase checkpoint is crucial for the cellular response to replication stress, a major pathway of apoptosis induction by many chemotherapeutic agents. Here, we demonstrate cancer cells that overexpress Cks1 or Cks2 override the intra-S-phase checkpoint in the presence of replication stress-inducing chemotherapies such as 5-Fluorouracil (5-FU) and methotrexate (MTX) leading to enhanced sensitivity in vitro and in vivo. Furthermore, enforced expression of Cks1 in an MTX-resistant breast cancer cell line was found to restore drug sensitivity. Our results suggest that Cks proteins are important determinants of apoptosis induction of replication stress-inducing chemotherapies such as 5-FU.
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Affiliation(s)
- Sonia V. del Rincón
- Tumor Initiation and Maintenance Program, Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, California, USA
| | | | - Dahui Sun
- Tumor Initiation and Maintenance Program, Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, California, USA
| | - Susanna Ekholm-Reed
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - John Tat
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Leonardo K. Teixeira
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Zdenka Ellederova
- Tumor Initiation and Maintenance Program, Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, California, USA
| | - Elise Grolieres
- Tumor Initiation and Maintenance Program, Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, California, USA
| | - Steven I. Reed
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Charles Spruck
- Tumor Initiation and Maintenance Program, Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, California, USA
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21
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Abstract
From 1976 to 2010, only 2 medications were approved for treating metastatic melanoma. Between 2011 and 2013, 4 agents were approved and other therapies have shown great promise in clinical trials. Fundamental discoveries, such as the identification of oncogenic mutations in most melanomas, the elucidation of the molecular signaling resulting from these mutations, and the revelation that several cell surface molecules serve as regulators of immune activation, have been instrumental in this progress. This article summarizes the molecular pathogenesis of melanoma, describes the current efforts to target oncogene-driven signaling, and presents the rationale for combining immune and molecular targeting.
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Affiliation(s)
- Ryan J Sullivan
- Center for Melanoma, Massachusetts General Hospital Cancer Center, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
| | - David E Fisher
- Department of Dermatology, Massachusetts General Hospital Cancer Center, Harvard Medical School, Bartlett 6, 55 Fruit Street, Boston, MA 02114, USA.
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22
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Hartman KG, Vitolo MI, Pierce AD, Fox JM, Shapiro P, Martin SS, Wilder PT, Weber DJ. Complex formation between S100B protein and the p90 ribosomal S6 kinase (RSK) in malignant melanoma is calcium-dependent and inhibits extracellular signal-regulated kinase (ERK)-mediated phosphorylation of RSK. J Biol Chem 2014; 289:12886-95. [PMID: 24627490 DOI: 10.1074/jbc.m114.561613] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
S100B is a prognostic marker for malignant melanoma. Increasing S100B levels are predictive of advancing disease stage, increased recurrence, and low overall survival in malignant melanoma patients. Using S100B overexpression and shRNA(S100B) knockdown studies in melanoma cell lines, elevated S100B was found to enhance cell viability and modulate MAPK signaling by binding directly to the p90 ribosomal S6 kinase (RSK). S100B-RSK complex formation was shown to be Ca(2+)-dependent and to block ERK-dependent phosphorylation of RSK, at Thr-573, in its C-terminal kinase domain. Additionally, the overexpression of S100B sequesters RSK into the cytosol and prevents it from acting on nuclear targets. Thus, elevated S100B contributes to abnormal ERK/RSK signaling and increased cell survival in malignant melanoma.
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Affiliation(s)
- Kira G Hartman
- From the Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201
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23
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Lopez-Bergami P. The role of mitogen- and stress-activated protein kinase pathways in melanoma. Pigment Cell Melanoma Res 2014; 24:902-21. [PMID: 21914141 DOI: 10.1111/j.1755-148x.2011.00908.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recent discoveries have increased our comprehension of the molecular signaling events critical for melanoma development and progression. Many oncogenes driving melanoma have been identified, and most of them exert their oncogenic effects through the activation of the RAF/MEK/ERK mitogen-activated protein kinase (MAPK) pathway. The c-Jun N-terminal kinase (JNK) and p38 MAPK pathways are also important in melanoma, but their precise role is not clear yet. This review summarizes our current knowledge on the role of the three main MAPK pathways, extracellular regulated kinase (ERK), JNK, and p38, and their impact on melanoma biology. Although the results obtained with BRAF inhibitors in melanoma patients are impressive, several mechanisms of acquired resistance have emerged. To overcome this obstacle constitutes the new challenge in melanoma therapy. Given the major role that MAPKs play in melanoma, understanding their functions and the interconnection among them and with other signaling pathways represents a step forward toward this goal.
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Affiliation(s)
- Pablo Lopez-Bergami
- Instituto de Medicina y Biología Experimental, CONICET, Buenos Aires, Argentina.
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24
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Lewis SR, Hedman CJ, Ziegler T, Ricke WA, Jorgensen JS. Steroidogenic factor 1 promotes aggressive growth of castration-resistant prostate cancer cells by stimulating steroid synthesis and cell proliferation. Endocrinology 2014; 155:358-69. [PMID: 24265454 PMCID: PMC3891934 DOI: 10.1210/en.2013-1583] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 11/09/2013] [Indexed: 11/19/2022]
Abstract
The dependence of prostate cancer on androgens provides a targeted means of treating advanced disease. Unfortunately, androgen deprivation therapies eventually become ineffective, leading to deadly castration-resistant prostate cancer (CRPC). One of many factors implicated in the transition to CRPC is the onset of de novo steroidogenesis. Although reactivation of steroid receptors likely plays a pivotal role in aggressive CRPC, little is understood regarding the mechanisms whereby prostate cancer cells initiate and maintain steroidogenesis. We hypothesize that steroidogenic factor 1 (SF1, NR5A1, AD4BP), a key regulator of steroidogenesis in normal endocrine tissues, is expressed in CRPC where it stimulates aberrant steroidogenesis and fuels aggressive growth. Notably, SF1 is not expressed in normal prostate tissue. Our results indicated that SF1 was absent in benign cells but present in aggressive prostate cancer cell lines. Introduction of ectopic SF1 expression in benign human prostate epithelial cells (BPH-1) stimulated increased steroidogenic enzyme expression, steroid synthesis, and cell proliferation. In contrast, data from an aggressive human prostate cancer cell line (BCaPT10) demonstrated that SF1 was required for steroid-mediated cell growth because BCaPT10 cell growth was diminished by abiraterone treatment and short hairpin RNA-mediated knockdown of SF1 (shSF1). SF1-depleted cells also exhibited defective centrosome homeostasis. Finally, whereas xenograft experiments in castrated hosts with BCaPT10 control transplants grew large, invasive tumors, BCaPT10-shSF1 knockdown transplants failed to grow. Therefore, we conclude that SF1 stimulates steroid accumulation and controls centrosome homeostasis to mediate aggressive prostate cancer cell growth within a castrate environment. These findings present a new molecular mechanism and therapeutic target for deadly CRPC.
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Affiliation(s)
- Samantha R Lewis
- Department of Comparative Biosciences (S.R.L., J.S.J.), University of Wisconsin, Madison, Wisconsin 53706; University of Wisconsin Carbone Cancer Center (J.S.J., W.A.R.), Madison, Wisconsin 53792, Environmental Health Division (C.J.H.), Wisconsin State Laboratory of Hygiene, Madison, Wisconsin 53706; Wisconsin National Primate Research Center (C.J.H., T.Z.) Madison, Wisconsin 53715; Institute of Clinical and Translational Research (J.S.J., C.J.H., T.Z., W.A.R.), University of Wisconsin, Madison, Wisconsin 53705; and Department of Urology (W.A.R.), University of Wisconsin, Madison, Wisconsin 53792
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25
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Abstract
The rapidly increasing incidence of melanoma, coupled with its highly aggressive metastatic nature, is of urgent concern. In order to design rational therapies, it is of critical importance to identify the genetic determinants that drive melanoma formation and progression. To date, signaling cascades emanating from the EGF receptor, c-MET and other receptors are known to be altered in melanoma. Important mutations in signaling molecules, such as BRAF and N-RAS, have been identified. In this review, some of the major genetic alterations and signaling pathways involved in melanoma will be discussed. Given the great deal of genetic heterogeneity observed in melanoma, it is likely that many more genetic determinants exist. Through the use of powerful genomic technologies, it is now possible to identify these additional genetic alterations in melanoma. A critical step in this analysis will be culling bystanders from functionally important drivers, as this will highlight genetic elements that will be promising therapeutic targets. Such technologies and the important points to consider in understanding the genetics of melanoma will be reviewed.
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Affiliation(s)
- Papia Ghosh
- Dana-Farber Cancer Institute, Department of Medical Oncology, 44 Binney Street, Boston, MA 02215, USA, Tel.: +1 617 258 8614, ,
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26
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Qu X, Shen L, Zheng Y, Cui Y, Feng Z, Liu F, Liu J. A signal transduction pathway from TGF-β1 to SKP2 via Akt1 and c-Myc and its correlation with progression in human melanoma. J Invest Dermatol 2014; 134:159-167. [PMID: 23792459 DOI: 10.1038/jid.2013.281] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 10/12/2012] [Accepted: 10/29/2012] [Indexed: 12/31/2022]
Abstract
Both SKP2 (S-phase kinase-associated protein 2) and transforming growth factor-β1 (TGF-β1) play important roles in cancer metastasis through different mechanisms: TGF-β1 via induction of epithelial-mesenchymal transition (EMT) and SKP2 via downregulating p27(kip1). Recent studies indicated that c-Myc and Akt1 were active players in metastasis. In this study we demonstrated a crosstalk between these pathways. Specifically, we found that TGF-β1 treatment increased SKP2 expression accompanied with increased phosphorylation of Akt1 and c-Myc protein accumulation during EMT. We demonstrated that Akt1 was required for TGF-β1-mediated SKP2 upregulation and that c-Myc transcription factor specifically bound to the promoter of SKP2 for its enhanced transcription. Analysis of 25 samples of normal human skin, nevi, and melanomas revealed a positive correlation between c-Myc and SKP2 accumulation. Furthermore, accumulation of SKP2 and c-Myc proteins was significantly higher in metastatic melanoma samples as compared with that in primary melanomas, which again was higher than that in normal skin or nevi. In summary, our results integrated TGF-β1 signals to SKP2 via Akt1 and c-Myc during EMT, and provided, to our knowledge, a previously unreported mechanistic molecular event for TGF-β1-induced metastasis in human melanoma.
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Affiliation(s)
- Xuan Qu
- Institute of Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Xi'an Jiaotong University School of Life Science and Technology, Xi'an, China
| | - Liangliang Shen
- Department of Biochemistry and Molecular Biology, The State Key Laboratory of Cancer Biology, The Fourth Military Medical University, Xi'an, China
| | - Yan Zheng
- Department of Dermatology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Yang Cui
- Institute of Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Xi'an Jiaotong University School of Life Science and Technology, Xi'an, China
| | - Zhihui Feng
- Center for Mitochondrial Biology and Medicine, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
| | - Feng Liu
- Department of Medicine, University of California Irvine Medical School, Irvine, California, USA; Chao Family Comprehensive Cancer Center, University of California Irvine Medical School, Irvine, California, USA.
| | - Jiankang Liu
- Institute of Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Xi'an Jiaotong University School of Life Science and Technology, Xi'an, China
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27
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Li Y, Takahashi M, Stork PJS. Ras-mutant cancer cells display B-Raf binding to Ras that activates extracellular signal-regulated kinase and is inhibited by protein kinase A phosphorylation. J Biol Chem 2013; 288:27646-27657. [PMID: 23893412 DOI: 10.1074/jbc.m113.463067] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The small G protein Ras regulates proliferation through activation of the mitogen-activated protein (MAP) kinase (ERK) cascade. The first step of Ras-dependent activation of ERK signaling is Ras binding to members of the Raf family of MAP kinase kinase kinases, C-Raf and B-Raf. Recently, it has been reported that in melanoma cells harboring oncogenic Ras mutations, B-Raf does not bind to Ras and does not contribute to basal ERK activation. For other types of Ras-mutant tumors, the relative contributions of C-Raf and B-Raf are not known. We examined non-melanoma cancer cell lines containing oncogenic Ras mutations and express both C-Raf and B-Raf isoforms, including the lung cancer cell line H1299 cells. Both B-Raf and C-Raf were constitutively bound to oncogenic Ras and contributed to Ras-dependent ERK activation. Ras binding to B-Raf and C-Raf were both subject to inhibition by the cAMP-dependent protein kinase PKA. cAMP inhibited the growth of H1299 cells and Ras-dependent ERK activation via PKA. PKA inhibited the binding of Ras to both C-Raf and B-Raf through phosphorylations of C-Raf at Ser-259 and B-Raf at Ser-365, respectively. These studies demonstrate that in non-melanocytic Ras-mutant cancer cells, Ras signaling to B-Raf is a significant contributor to ERK activation and that the B-Raf pathway, like that of C-Raf, is a target for inhibition by PKA. We suggest that cAMP and hormones coupled to cAMP may prove useful in dampening the effects of oncogenic Ras in non-melanocytic cancer cells through PKA-dependent actions on B-Raf as well as C-Raf.
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Affiliation(s)
- Yanping Li
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
| | - Maho Takahashi
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
| | - Philip J S Stork
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239.
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28
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Omolo B, Carson C, Chu H, Zhou Y, Simpson DA, Hesse JE, Paules RS, Nyhan KC, Ibrahim JG, Kaufmann WK. A prognostic signature of G(2) checkpoint function in melanoma cell lines. Cell Cycle 2013; 12:1071-82. [PMID: 23454897 PMCID: PMC3646863 DOI: 10.4161/cc.24067] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 02/21/2013] [Indexed: 12/31/2022] Open
Abstract
As DNA damage checkpoints are barriers to carcinogenesis, G(2) checkpoint function was quantified to test for override of this checkpoint during melanomagenesis. Primary melanocytes displayed an effective G(2) checkpoint response to ionizing radiation (IR)-induced DNA damage. Thirty-seven percent of melanoma cell lines displayed a significant defect in G(2) checkpoint function. Checkpoint function was melanoma subtype-specific with "epithelial-like" melanoma lines, with wild type NRAS and BRAF displaying an effective checkpoint, while lines with mutant NRAS and BRAF displayed defective checkpoint function. Expression of oncogenic B-Raf in a checkpoint-effective melanoma attenuated G(2) checkpoint function significantly but modestly. Other alterations must be needed to produce the severe attenuation of G(2) checkpoint function seen in some BRAF-mutant melanoma lines. Quantitative trait analysis tools identified mRNA species whose expression was correlated with G(2) checkpoint function in the melanoma lines. A 165 gene signature was identified with a high correlation with checkpoint function (p < 0.004) and low false discovery rate (≤ 0.077). The G(2) checkpoint gene signature predicted G(2) checkpoint function with 77-94% accuracy. The signature was enriched in lysosomal genes and contained numerous genes that are associated with regulation of chromatin structure and cell cycle progression. The core machinery of the cell cycle was not altered in checkpoint-defective lines but rather numerous mediators of core machinery function were. When applied to an independent series of primary melanomas, the predictive G(2) checkpoint signature was prognostic of distant metastasis-free survival. These results emphasize the value of expression profiling of primary melanomas for understanding melanoma biology and disease prognosis.
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Affiliation(s)
- Bernard Omolo
- Division of Mathematics and Computer Science; University of South Carolina Upstate; Spartanburg, SC USA
| | - Craig Carson
- Department of Dermatology; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Haitao Chu
- Division of Biostatistics; University of Minnesota, Minneapolis, MN USA
| | - Yingchun Zhou
- Pathology and Laboratory Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Dennis A. Simpson
- Pathology and Laboratory Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Jill E. Hesse
- Environmental Stress and Cancer Group; National Institute of Environmental Health Sciences; Research Triangle Park, NC USA
| | - Richard S. Paules
- Environmental Stress and Cancer Group; National Institute of Environmental Health Sciences; Research Triangle Park, NC USA
| | - Kristine C. Nyhan
- Department of Radiation Oncology; University of California-San Francisco; San Francisco, CA USA
| | - Joseph G. Ibrahim
- Departments of Biostatistics; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
- Center for Environmental Health and Susceptibility; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
- Lineberger Comprehensive Cancer Center; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - William K. Kaufmann
- Pathology and Laboratory Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
- Center for Environmental Health and Susceptibility; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
- Lineberger Comprehensive Cancer Center; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
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Khattar V, Thottassery JV. Cks1: Structure, Emerging Roles and Implications in Multiple Cancers. ACTA ACUST UNITED AC 2013; 4:1341-1354. [PMID: 24563807 PMCID: PMC3930463 DOI: 10.4236/jct.2013.48159] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Deregulation of the cell cycle results in loss of normal control mechanisms that prevent aberrant cell proliferation and cancer progression. Regulation of the cell cycle is a highly complex process with many layers of control. One of these mechanisms involves timely degradation of CDK inhibitors (CKIs) like p27Kip1 by the ubiquitin proteasomal system (UPS). Cks1 is a 9 kDa protein which is frequently overexpressed in different tumor subtypes, and has pleiotropic roles in cell cycle progression, many of which remain to be fully characterized. One well characterized molecular role of Cks1 is that of an essential adaptor that regulates p27Kip1 abundance by facilitating its interaction with the SCF-Skp2 E3 ligase which appends ubiquitin to p27Kip1 and targets it for degradation through the UPS. In addition, emerging research has uncovered p27Kip1-independent roles of Cks1 which have provided crucial insights into how it may be involved in cancer progression. We review here the structural features of Cks1 and their functional implications, and also some recently identified Cks1 roles and their involvement in breast and other cancers.
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Affiliation(s)
| | - Jaideep V Thottassery
- Southern Research Institute, Birmingham, USA ; University of Alabama Comprehensive Cancer Center, Birmingham, USA
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Wang JJ, Fang ZX, Ye HM, You P, Cai MJ, Duan HB, Wang F, Zhang ZY. Clinical significance of overexpressed cyclin-dependent kinase subunits 1 and 2 in esophageal carcinoma. Dis Esophagus 2013; 26:729-36. [PMID: 23301842 PMCID: PMC4797631 DOI: 10.1111/dote.12013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The mammalian cyclin-dependent kinase subunit (Cks) family has two members, Cks1 and Cks2. Overexpression of Cks1 and Cks2 has been reported to be associated with high aggressiveness and poor prognosis in several malignancies, including prostate and hepatocellular carcinomas. However, whether Cks1 and Cks2 are overexpressed in esophageal carcinoma remains uncharacterized. To investigate whether overexpression of the Cks family is clinically relevant in esophageal carcinoma, and whether expression patterns of Cks1 and Cks2 can serve as biomarkers for esophageal carcinoma. Real-time quantitative reverse transcription polymerase chain reaction, immunohistochemistry, and Western blot analyses were applied to detect the expression of Cks1 and Cks2 at the mRNA and protein levels, respectively. The associations between Cks1 or Cks2 expressions and clinical features and p27(kip1) expressions in esophageal carcinoma were analyzed. Comparing with the adjacent noncancerous tissues, esophageal carcinoma exhibited elevated expression of Cks1 in 58% cases at the mRNA level and 54% cases at the protein level, and elevated expression of Cks2 in 65% cases at the mRNA level and 61% cases at the protein level, respectively. The expressions of both Cks1 and Cks2 were negatively associated with the p27(kip1) protein level in the tumor tissues. Furthermore, overexpression of Cks1 and Cks2 in esophageal carcinoma was closely associated with poor pathological features of esophageal carcinoma, including higher histologic grade of tumor, regional lymph nodes invasion, and neoplastic embolus. Overexpression of Cks1 and Cks2 is associated with the aggressive tumor behaviors of esophageal carcinoma. Further efforts are needed to determine whether overexpression of Cks1 and Cks2 can serve as novel biomarkers for esophageal carcinoma.
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Affiliation(s)
- Jia-Jia Wang
- Center for Clinical Laboratory, Zhongshan Hospital, Fujian Medical University, Xiamen University, Xiamen, China
| | - Zan-Xi Fang
- Center for Clinical Laboratory, Zhongshan Hospital, Xiamen University, Xiamen, China
| | - Hui-Ming Ye
- Center for Clinical Laboratory, Zhongshan Hospital, Xiamen University, Xiamen, China
| | - Pan You
- Center for Clinical Laboratory, Zhongshan Hospital, Xiamen University, Xiamen, China
| | - Min-Jing Cai
- Center for Clinical Laboratory, Zhongshan Hospital, Fujian Medical University, Xiamen University, Xiamen, China
| | - Hong-Bing Duan
- Department of Chest Surgery, Zhongshan Hospital, Xiamen University, Xiamen, China
| | - Fen Wang
- Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - Zhong-Ying Zhang
- Center for Clinical Laboratory, Zhongshan Hospital, Fujian Medical University, Xiamen University, Xiamen, China
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Park KS, Kim JB, Bae J, Park SY, Jee HG, Lee KE, Youn YK. Berberine inhibited the growth of thyroid cancer cell lines 8505C and TPC1. Yonsei Med J 2012; 53:346-51. [PMID: 22318822 PMCID: PMC3282951 DOI: 10.3349/ymj.2012.53.2.346] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
PURPOSE Thyroid cancer is the most common malignancy in Korean females and can be treated with good prognosis. However, drugs to treat aggressive types of thyroid cancer such as poorly differentiated or anaplastic thyroid cancer have not yet been established. To that end, we analyzed the effects of berberine on human thyroid cancer cell lines to determine whether this compound is useful in the treatment of aggressive thyroid cancer. MATERIALS AND METHODS The two thyroid cancer cell lines 8505C and TPC1, under adherent culture conditions, were treated with berberine and analyzed for changes in cell growth, cell cycle duration, and degree of apoptosis. RESULTS Following berberine treatment, both cell lines showed a dose-dependent reduction in growth rate. 8505C cells showed significantly increased levels of apoptosis following berberine treatment, whereas TPC1 cells showed cell cycle arrest at the G0/G1 phase. Immunobloting of p-27 expression following berberine treatment showed that berberine induced a little up-regulation of p-27 in 8505c cells but relatively high up-regulation of p-27 in TPC1 cells. CONCLUSION These results suggest that berberine treatment of thyroid cancer can inhibit proliferation through apoptosis and/or cell cycle arrest. Thus, berberine may be a novel anticancer drug for the treatment of poorly differentiated or anaplastic thyroid cancer.
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Affiliation(s)
- Kyoung Sik Park
- Department of Surgery, Konkuk University School of Medicine, Seoul, Korea
| | - Jong Bin Kim
- Department of Surgery, Konkuk University School of Medicine, Seoul, Korea
| | - Jaeman Bae
- Department of Obstetrics and Gynecology, Konkuk University School of Medicine, Seoul, Korea
| | - Seo-Young Park
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Hyeon-Gun Jee
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Kyu Eun Lee
- Department of Surgery, Konkuk University School of Medicine, Seoul, Korea
| | - Yeo-Kyu Youn
- Department of Surgery, Seoul National University College of Medicine, Seoul, Korea
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32
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Nicolaides TP, Li H, Solomon DA, Hariono S, Hashizume R, Barkovich K, Baker SJ, Paugh BS, Jones C, Forshew T, Hindley GF, Hodgson JG, Kim JS, Rowitch DH, Weiss WA, Waldman TA, James CD. Targeted therapy for BRAFV600E malignant astrocytoma. Clin Cancer Res 2011; 17:7595-604. [PMID: 22038996 DOI: 10.1158/1078-0432.ccr-11-1456] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE Malignant astrocytomas (MA) are aggressive central nervous system tumors with poor prognosis. Activating mutation of BRAF (BRAF(V600E)) has been reported in a subset of these tumors, especially in children. We have investigated the incidence of BRAF(V600E) in additional pediatric patient cohorts and examined the effects of BRAF blockade in preclinical models of BRAF(V600E) and wild-type BRAF MA. EXPERIMENTAL DESIGN BRAF(V600E) mutation status was examined in two pediatric MA patient cohorts. For functional studies, BRAF(V600E) MA cell lines were used to investigate the effects of BRAF shRNA knockdown in vitro, and to investigate BRAF pharmacologic inhibition in vitro and in vivo. RESULTS BRAF(V600E) mutations were identified in 11 and 10% of MAs from two distinct series of tumors (six of 58 cases total). BRAF was expressed in all MA cell lines examined, among which BRAF(V600E) was identified in four instances. Using the BRAF(V600E)-specific inhibitor PLX4720, pharmacologic blockade of BRAF revealed preferential antiproliferative activity against BRAF(V600E) mutant cells in vitro, in contrast to the use of shRNA-mediated knockdown of BRAF, which inhibited cell growth of glioma cell lines regardless of BRAF mutation status. Using orthotopic MA xenografts, we show that PLX4720 treatment decreases tumor growth and increases overall survival in mice-bearing BRAF(V600E) mutant xenografts, while being ineffective, and possibly tumor promoting, against xenografts with wild-type BRAF. CONCLUSIONS Our results indicate a 10% incidence of activating BRAF(V600E) among pediatric MAs. With regard to implications for therapy, our results support evaluation of BRAF(V600E)-specific inhibitors for treating BRAF(V600E) MA patients.
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Tiacci E, Trifonov V, Schiavoni G, Holmes A, Kern W, Martelli MP, Pucciarini A, Bigerna B, Pacini R, Wells VA, Sportoletti P, Pettirossi V, Mannucci R, Elliott O, Liso A, Ambrosetti A, Pulsoni A, Forconi F, Trentin L, Semenzato G, Inghirami G, Capponi M, Di Raimondo F, Patti C, Arcaini L, Musto P, Pileri S, Haferlach C, Schnittger S, Pizzolo G, Foà R, Farinelli L, Haferlach T, Pasqualucci L, Rabadan R, Falini B. BRAF mutations in hairy-cell leukemia. N Engl J Med 2011; 364:2305-15. [PMID: 21663470 PMCID: PMC3689585 DOI: 10.1056/nejmoa1014209] [Citation(s) in RCA: 781] [Impact Index Per Article: 55.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Hairy-cell leukemia (HCL) is a well-defined clinicopathological entity whose underlying genetic lesion is still obscure. METHODS We searched for HCL-associated mutations by performing massively parallel sequencing of the whole exome of leukemic and matched normal cells purified from the peripheral blood of an index patient with HCL. Findings were validated by Sanger sequencing in 47 additional patients with HCL. RESULTS Whole-exome sequencing identified five missense somatic clonal mutations that were confirmed on Sanger sequencing, including a heterozygous mutation in BRAF that results in the BRAF V600E variant protein. Since BRAF V600E is oncogenic in other tumors, further analyses were focused on this genetic lesion. The same BRAF mutation was noted in all the other 47 patients with HCL who were evaluated by means of Sanger sequencing. None of the 195 patients with other peripheral B-cell lymphomas or leukemias who were evaluated carried the BRAF V600E variant, including 38 patients with splenic marginal-zone lymphomas or unclassifiable splenic lymphomas or leukemias. In immunohistologic and Western blot studies, HCL cells expressed phosphorylated MEK and ERK (the downstream targets of the BRAF kinase), indicating a constitutive activation of the RAF-MEK-ERK mitogen-activated protein kinase pathway in HCL. In vitro incubation of BRAF-mutated primary leukemic hairy cells from 5 patients with PLX-4720, a specific inhibitor of active BRAF, led to a marked decrease in phosphorylated ERK and MEK. CONCLUSIONS; The BRAF V600E mutation was present in all patients with HCL who were evaluated. This finding may have implications for the pathogenesis, diagnosis, and targeted therapy of HCL. (Funded by Associazione Italiana per la Ricerca sul Cancro and others.).
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Affiliation(s)
- Enrico Tiacci
- Institute of Hematology, University of Perugia, Perugia, Italy
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Heterogeneous topographic profiles of kinetic and cell cycle regulator microsatellites in atypical (dysplastic) melanocytic nevi. Mod Pathol 2011; 24:471-86. [PMID: 21336261 DOI: 10.1038/modpathol.2010.143] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Atypical (dysplastic) melanocytic nevi are clinically heterogeneous malignant melanoma precursors, for which no topographic analysis of cell kinetic, cell cycle regulators and microsatellite profile is available. We selected low-grade atypical melanocytic nevi (92), high-grade atypical melanocytic nevi (41), melanocytic nevi (18 junctional, 25 compound) and malignant melanomas (16 radial growth phase and 27 vertical growth phase). TP53, CDKN2A, CDKN1A, and CDKN1B microsatellite patterns were topographically studied after microdissection; Ki-67, TP53, CDKN2A, CDKN1A, and CDKN1B expressions and DNA fragmentation by in situ end labeling for apoptosis were topographically scored. Results were statistically analyzed. A decreasing junctional-dermal marker expression gradient was observed, directly correlating with atypical melanocytic nevus grading. High-grade atypical melanocytic nevi revealed coexistent TP53-CDKN2A-CDKN1B microsatellite abnormalities, and significantly higher junctional Ki67-TP53 expression (inversely correlated with CDKN1A-CDKN1B expression and in situ end labeling). Malignant melanomas showed coexistent microsatellite abnormalities (CDKN2A-CDKN1B), no topographic gradient, and significantly decreased expression. Melanocytic nevi and low-grade atypical melanocytic nevi revealed sporadic junctional CDKN2A microsatellite abnormalities and no significant topographic kinetic differences. High-grade atypical melanocytic nevi accumulate junctional TP53-CDKN1A-CDKN1B microsatellite abnormalities, being progression TP53-independent and better assessed in the dermis. Melanocytic nevi and low-grade atypical melanocytic nevi show low incidence of microsatellite abnormalities, and kinetic features that make progression unlikely.
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Cytoplasmic Skp2 expression is increased in human melanoma and correlated with patient survival. PLoS One 2011; 6:e17578. [PMID: 21386910 PMCID: PMC3046256 DOI: 10.1371/journal.pone.0017578] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 02/09/2011] [Indexed: 12/05/2022] Open
Abstract
Background S-phase kinase protein 2 (Skp2), an F-box protein, targets cell cycle regulators via ubiquitin-mediated degradation. Skp2 is frequently overexpressed in a variety of cancers and associated with patient survival. In melanoma, however, the prognostic significance of subcellular Skp2 expression remains controversial. Methods To investigate the role of Skp2 in melanoma development, we constructed tissue microarrays and examined Skp2 expression in melanocytic lesions at different stages, including 30 normal nevi, 61 dysplastic nevi, 290 primary melanomas and 146 metastatic melanomas. The TMA was assessed for cytoplasmic and nuclear Skp2 expression by immunohistochemistry. The Kaplan-Meier method was used to evaluate the patient survival. The univariate and multivariate Cox regression models were performed to estimate the harzard ratios (HR) at five-year follow-up. Results Cytoplasmic but not nuclear Skp2 expression was gradually increased from normal nevi, dysplastic nevi, primary melanomas to metastatic melanomas. Cytoplasmic Skp2 expression correlated with AJCC stages (I vs II–IV, P<0.001), tumor thickness (≤2.00 vs >2.00 mm, P<0.001) and ulceration (P = 0.005). Increased cytoplasmic Skp2 expression was associated with a poor five-year disease-specific survival of patients with primary melanoma (P = 0.018) but not metastatic melanoma (P>0.05). Conclusion This study demonstrates that cytoplasmic Skp2 plays an important role in melanoma pathogenesis and its expression correlates with patient survival. Our data indicate that cytoplasmic Skp2 may serve as a potential biomarker for melanoma progression and a therapeutic target for this disease.
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Rose AE, Wang G, Hanniford D, Monni S, Tu T, Shapiro RL, Berman RS, Pavlick AC, Pagano M, Darvishian F, Mazumdar M, Hernando E, Osman I. Clinical relevance of SKP2 alterations in metastatic melanoma. Pigment Cell Melanoma Res 2010; 24:197-206. [PMID: 20883453 DOI: 10.1111/j.1755-148x.2010.00784.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In this study, we investigated the mechanism(s) of altered expression of protooncogene SKP2 in metastatic melanoma and its clinical relevance in patients with metastatic melanoma. The genomic status of SKP2 was assessed in cell lines by sequencing, single nucleotide polymorphism array, and genomic PCR. Copy number status was then evaluated for concordance with SKP2 mRNA and protein expression. SKP2 protein was further evaluated by immunohistochemistry in 93 human metastatic tissues. No mutations were identified in SKP2. Increased copy number at the SKP2 locus was observed in 6/14 (43%) metastatic cell lines and in 9/22 (41%) human metastatic tissues which was associated with overexpression of SKP2 protein. Overexpression of SKP2 protein in human tissues was associated with worse survival in a multivariate model controlling for the site of metastasis. Copy number gain is a major contributing mechanism of SKP2 overexpression in metastatic melanoma. Results may have implications for the development of therapeutics that target SKP2.
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Affiliation(s)
- Amy E Rose
- Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY, USA
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Karim RZ, Gerega SK, Yang YH, Spillane A, Carmalt H, Scolyer RA, Lee CS. p16 and pRb immunohistochemical expression increases with increasing tumour grade in mammary phyllodes tumours. Histopathology 2010; 56:868-75. [DOI: 10.1111/j.1365-2559.2010.03562.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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BRAF mutations, microsatellite instability status and cyclin D1 expression predict metastatic colorectal patients' outcome. Br J Cancer 2010; 102:1762-8. [PMID: 20485284 PMCID: PMC2883698 DOI: 10.1038/sj.bjc.6605694] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background: The significance of BRAF mutations, microsatelite instability (MSI) status and cyclin D1 expression in patients with metastatic colorectal cancer (mCRC) was evaluated. Methods: Primary tumours from 144 patients treated for mCRC were assessed for BRAF (V600E) mutation, MSI status and cyclin D1. The data were correlated with progression-free survival (PFS) and overall survival (OS). Results: BRAF mutations were detected in 10 (out of 22, 45%) patients with MSI-H tumours compared with 2 (out of 122, 1.6%) in those with microsatellite stable tumours (P<0.001). The presence of BRAF mutations was correlated with cyclin D1 overexpression (7 out of 26 patients, 58% vs 5 out of 118 patients, 14% P=0.001). Patients with BRAF-mutated primary tumours had a significantly decreased PFS (2.7 vs 9.8 months; P<0.001) and median OS (14 vs 30 months; P<0.001) than patients with wild-type (wt) tumours. Patients with MSI-H and BRAF-mutated tumours experienced significantly lower PFS (3.1 vs 11.4 months; P=0.008) and OS (14.5 vs 35.5 months; P=0.004) than patients with MSI-H and BRAF wt tumours. Similarly, BRAF mutations and cyclin D1 overexpression were correlated with decreased PFS (3.1 vs 8.6 months; P=0.03) and OS (17.8 vs 39.2 months; P=0.01). Conclusion: BRAF V600E mutations are associated with MSI-H status and cyclin D1 overexpression and characterize a subgroup of patients with poor prognosis.
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Hu R, Aplin AE. alphaB-crystallin is mutant B-RAF regulated and contributes to cyclin D1 turnover in melanocytic cells. Pigment Cell Melanoma Res 2010; 23:201-9. [PMID: 20067552 PMCID: PMC2855751 DOI: 10.1111/j.1755-148x.2010.00668.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The serine/threonine kinase, B-RAF, is frequently mutated in melanoma and is required for cell proliferation. Proteasomal turnover of cyclins and cyclin-dependent kinase inhibitors via E3 ubiquitin ligases regulates cell cycle progression. We previously showed that B-RAF regulates Cks1, a co-factor for the F-box protein Skp2. Recently, a second F-box protein cofactor was identified, alphaB-crystallin, that binds Fbx4 and promotes cyclin D1 degradation. Here, we demonstrate that alphaB-crystallin is down-regulated in mutant B-RAF melanoma cells compared to melanocytes in a B-RAF and MEK-dependent manner. In a subset of lines, MEK inhibition was sufficient to up-regulate alphaB-crystallin protein levels; whereas in other lines combined MEK and proteasome inhibition was required. alphaB-crystallin knockdown partially stabilized cyclin D1 in melanocytes. Expression of alphaB-crystallin in mutant B-RAF melanoma cells did not promote cyclin D1 turnover under normal conditions, but did enhance turnover following etoposide-induced DNA damage. Together, these data show that alphaB-crystallin is highly expressed in melanocytes contributing, in part, to cyclin D1 turnover. Furthermore, alphaB-crystallin is down-regulated in a B-RAF-dependent manner in melanoma cells and its re-expression regulates cyclin D1 turnover after DNA damage.
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Affiliation(s)
- Rong Hu
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107
- Center for Cell Biology and Cancer Research, Albany Medical College, Albany, NY 12208
| | - Andrew E. Aplin
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107
- Center for Cell Biology and Cancer Research, Albany Medical College, Albany, NY 12208
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Abel EV, Aplin AE. FOXD3 is a mutant B-RAF-regulated inhibitor of G(1)-S progression in melanoma cells. Cancer Res 2010; 70:2891-900. [PMID: 20332228 DOI: 10.1158/0008-5472.can-09-3139] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The forkhead box transcription factor FOXD3 is a stemness factor that prevents the production of melanocyte progenitors from the developing neural crest; however, its role in human cancers is not known. Transformation of melanocytes gives rise to melanoma. In two thirds of melanomas, the serine/threonine kinase B-RAF is mutated to a constitutively active form. Here, we show that FOXD3 levels are upregulated following attenuation of B-RAF and mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK) signaling in mutant B-RAF harboring human melanoma cells. This effect was selective because FOXD3 was not upregulated following MEK inhibition in wild-type B-RAF melanoma cells and mutant B-RAF thyroid carcinoma cells. Ectopic FOXD3 expression potently inhibited melanoma cell growth without altering mutant B-RAF activation of ERK1/2. Inhibition of cell growth was due to a potent G(1) cell cycle arrest and was associated with p53-dependent upregulation of p21(Cip1). FOXD3-induced cell cycle arrest was prevented by p53 depletion and, to a lesser extent, p21(Cip1) depletion. These studies show that FOXD3 is suppressed by B-RAF, uncover a novel role and mechanism for FOXD3 as a negative cell cycle regulator, and have implications for the repression of melanocytic lineage cells.
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Affiliation(s)
- Ethan V Abel
- Department of Cancer Biology and Kimmel Cancer Center, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA 19107, USA
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Nakayama K. Growth and progression of melanoma and non-melanoma skin cancers regulated by ubiquitination. Pigment Cell Melanoma Res 2010; 23:338-51. [DOI: 10.1111/j.1755-148x.2010.00692.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Huang CW, Lin CY, Huang HY, Liu HW, Chen YJ, Shih DF, Chen HY, Juan CC, Ker CG, Huang CYF, Li CF, Shiue YL. CKS1B overexpression implicates clinical aggressiveness of hepatocellular carcinomas but not p27(Kip1) protein turnover: an independent prognosticator with potential p27 (Kip1)-independent oncogenic attributes? Ann Surg Oncol 2010; 17:907-922. [PMID: 19866239 DOI: 10.1245/s10434-009-0779-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Indexed: 12/25/2022]
Abstract
BACKGROUND Through data mining the Stanford Microarray Database, the CKS1B transcript was found to be frequently upregulated in hepatocellular carcinomas (HCCs) with low alpha-fetal protein (AFP) expression. Together with SKP2, CKS1B is known to implicate p27(Kip1) protein turnover promoting cell-cycle progression. METHODS CKS1B, p27(Kip1), and SKP2 were immunostained in 75 HCCs and correlated with clinicopathological features, local recurrence-free survival (LRFS), and overall survival (OS). Silencing of CKS1B and SKP2 with interference short-hairpin RNA (shRNA) was performed in SK-Hep1 and Hep-3B cell lines. RESULTS Immunohistochemically, increased CKS1B and SKP2, and attenuated p27(Kip1) were all associated with tumor multiplicity (P < 0.05) and increasing American Joint Committee on Cancer (AJCC) stage (P < 0.05). Overexpression of CKS1B significantly correlated with advanced Okuda stages (P = 0.048) and SKP2 overexpression (P = 0.047). Neither CKS1B nor SKP2 was inversely related to p27(Kip1), which was reinforced by no alteration in p27(Kip1) abundance in HCC-derived cells with CKS1B or SKP2 silencing. Both CKS1B overexpression (P = 0.0011 and P = 0.0017) and p27(Kip1) attenuation (P = 0.0079 and P = 0.0085) were predictive of OS and LRFS, respectively, while SKP2 overexpression was associated with worse OS alone (P = 0.0043). Combined assessment of CKS1B and p27(Kip1) was able to robustly distinguish three prognostically different groups (P < 0.0001). In multivariate comparison, CKS1B overexpression represented the strongest independent adverse prognosticator [OS, P = 0.0235, hazard ratio (HR): 4.193; LRFS, P = 0.0204, HR: 4.262], followed by p27(Kip1) attenuation (OS, P = 0.0320, HR: 2.553; LRFS, P = 0.0262, HR: 2.533). CONCLUSIONS CKS1B protein overexpression in HCCs is implicated in clinical aggressiveness but not in p27(Kip1) turnover, implying presence of p27(Kip1)-independent oncogenic attributes. The combined assessment of CKS1B and p27(Kip1) immunoexpressions effectively risk-stratifies HCCs with different prognoses, which may aid in the management of this deadly malignancy.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Blotting, Western
- CDC2-CDC28 Kinases
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/metabolism
- Carcinoma, Hepatocellular/pathology
- Carrier Proteins/antagonists & inhibitors
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cyclin-Dependent Kinase Inhibitor p27/genetics
- Cyclin-Dependent Kinase Inhibitor p27/metabolism
- Cyclin-Dependent Kinases/antagonists & inhibitors
- Cyclin-Dependent Kinases/genetics
- Cyclin-Dependent Kinases/metabolism
- Female
- Humans
- Immunoenzyme Techniques
- Liver Neoplasms/genetics
- Liver Neoplasms/metabolism
- Liver Neoplasms/pathology
- Male
- Middle Aged
- Neoplasm Staging
- Prognosis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Small Interfering/pharmacology
- Reverse Transcriptase Polymerase Chain Reaction
- S-Phase Kinase-Associated Proteins/antagonists & inhibitors
- S-Phase Kinase-Associated Proteins/genetics
- S-Phase Kinase-Associated Proteins/metabolism
- Tumor Cells, Cultured
- alpha-Fetoproteins/genetics
- alpha-Fetoproteins/metabolism
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Affiliation(s)
- Ching-Wen Huang
- Department of Surgery, Yuan's General Hospital, Kaohsiung, Taiwan
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Cui Y, Borysova MK, Johnson JO, Guadagno TM. Oncogenic B-RafV600E Induces Spindle Abnormalities, Supernumerary Centrosomes, and Aneuploidy in Human Melanocytic Cells. Cancer Res 2010; 70:675-84. [DOI: 10.1158/0008-5472.can-09-1491] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Shen DY, Fang ZX, You P, Liu PG, Wang F, Huang CL, Yao XB, Chen ZX, Zhang ZY. Clinical significance and expression of cyclin kinase subunits 1 and 2 in hepatocellular carcinoma. Liver Int 2010; 30:119-25. [PMID: 19845855 DOI: 10.1111/j.1478-3231.2009.02106.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND The mammalian cyclin kinase subunit (Cks) family has two members, Cks1 and Cks2, which were identified based on the protein sequence homology to yeast Cks. Overexpression of Cks1 and Cks2 has been reported to be associated with high aggressiveness and a poor prognosis in various malignancies, including gastric, breast and prostate carcinomas. Yet, whether Cks1 and Cks2 are overexpressed in hepatocellular carcinoma (HCC) remains uncharacterized. AIMS To investigate whether overexpression of the Cks family is clinically relevant to HCC, and whether expression patterns of Cks1 and Cks2 in HCC have diagnostic and prognostic value. METHODS Real-time quantitative reverse transcriptase polymerase chain reaction, immunostaining and Western blot analyses were used to detect the expression of Cks1 and Cks2 at the mRNA and protein levels respectively. The associations between Cks1 and Cks2 expressions and clinical features, as well as the association between Cks1 or Cks2 and p27(kip1) expressions in HCC, were analysed. RESULTS Expressions of Cks1 and Cks2 at both mRNA and protein levels were significantly higher in HCC than those in the adjacent noncancerous tissues (including chronic hepatitis and cirrhosis) and normal liver tissues. Overexpressions of Cks1 and Cks2 in HCC were closely associated with poor differentiation features. The expressions of both Cks1 and Cks2 were negatively associated with p27(kip1) at the protein level. CONCLUSIONS Overexpression of Cks1 and Cks2 is associated with the aggressive tumour behaviours of HCC, and thus has diagnostic and prognostic value. Further efforts are needed to develop novel biomarkers for HCC based on CKs1 and Cks2 expressions.
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Affiliation(s)
- Dong-Yan Shen
- Center for Clinical Laboratory, Xiamen University Affiliated Zhongshan Hospital, Xiamen, China
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Preto A, Gonçalves J, Rebocho AP, Figueiredo J, Meireles AM, Rocha AS, Vasconcelos HM, Seca H, Seruca R, Soares P, Sobrinho-Simões M. Proliferation and survival molecules implicated in the inhibition of BRAF pathway in thyroid cancer cells harbouring different genetic mutations. BMC Cancer 2009; 9:387. [PMID: 19878585 PMCID: PMC2776025 DOI: 10.1186/1471-2407-9-387] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Accepted: 10/31/2009] [Indexed: 01/07/2023] Open
Abstract
Background Thyroid carcinomas show a high prevalence of mutations in the oncogene BRAF which are inversely associated with RAS or RET/PTC oncogenic activation. The possibility of using inhibitors on the BRAF pathway as became an interesting therapeutic approach. In thyroid cancer cells the target molecules, implicated on the cellular effects, mediated by inhibition of BRAF are not well established. In order to fill this lack of knowledge we studied the proliferation and survival pathways and associated molecules induced by BRAF inhibition in thyroid carcinoma cell lines harbouring distinct genetic backgrounds. Methods Suppression of BRAF pathway in thyroid cancer cell lines (8505C, TPC1 and C643) was achieved using RNA interference (RNAi) for BRAF and the kinase inhibitor, sorafenib. Proliferation analysis was performed by BrdU incorporation and apoptosis was accessed by TUNEL assay. Levels of protein expression were analysed by western-blot. Results Both BRAF RNAi and sorafenib inhibited proliferation in all the cell lines independently of the genetic background, mostly in cells with BRAFV600E mutation. In BRAFV600E mutated cells inhibition of BRAF pathway lead to a decrease in ERK1/2 phosphorylation and cyclin D1 levels and an increase in p27Kip1. Specific inhibition of BRAF by RNAi in cells with BRAFV600E mutation had no effect on apoptosis. In the case of sorafenib treatment, cells harbouring BRAFV600E mutation showed increase levels of apoptosis due to a balance of the anti-apoptotic proteins Mcl-1 and Bcl-2. Conclusion Our results in thyroid cancer cells, namely those harbouring BRAFV600Emutation showed that BRAF signalling pathway provides important proliferation signals. We have shown that in thyroid cancer cells sorafenib induces apoptosis by affecting Mcl-1 and Bcl-2 in BRAFV600E mutated cells which was independent of BRAF. These results suggest that sorafenib may prove useful in the treatment of thyroid carcinomas, particularly those refractory to conventional treatment and harbouring BRAF mutations.
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Affiliation(s)
- Ana Preto
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-465, Porto, Portugal.
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Fecher LA, Amaravadi RK, Schuchter LM, Flaherty KT. Drug targeting of oncogenic pathways in melanoma. Hematol Oncol Clin North Am 2009; 23:599-618, x. [PMID: 19464605 DOI: 10.1016/j.hoc.2009.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Melanoma continues to be one of the most aggressive and morbid malignancies once metastatic. Overall survival for advanced unresectable melanoma has not changed over the past several decades. However, the presence of some long-term survivors of metastatic melanoma highlights the heterogeneity of this disease and the potential for improved outcomes. Current research is uncovering the molecular and genetic scaffolding of normal and aberrant cell function. The known oncogenic pathways in melanoma and the attempts to develop therapy for them are discussed. The targeting of certain cellular processes, downstream of the common genetic alterations, for which the issues of target and drug validation are somewhat distinct, are also highlighted.
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Affiliation(s)
- Leslie A Fecher
- Department of Medicine, Division of Hematology and Oncology, Abramson Cancer Center, University of Pennsylvania, 3400 Spruce Street, 16 Penn Tower, Philadelphia, PA 19104, USA.
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Karim RZ, Li W, Sanki A, Colman MH, Yang YH, Thompson JF, Scolyer RA. Reduced p16 and increased cyclin D1 and pRb expression are correlated with progression in cutaneous melanocytic tumors. Int J Surg Pathol 2009; 17:361-7. [PMID: 19666944 DOI: 10.1177/1066896909336177] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The immunohistochemical expression of cell cycle proteins p16, cyclin D1, and pRb was assessed in 112 benign and malignant melanocytic tumors and correlated with tumor progression, prognosis, and outcome. Comparing benign and malignant tumors, there were significant differences in the median score for all 3 proteins, with decreased p16 (P = .000001), increased cyclin D1 (P = .01), and increased pRb in melanomas (P = .01). There was a progressive loss of expression of p16 with progression from benign naevi to primary melanomas and to metastases. p16 was significantly decreased in primary tumors from melanoma patients who developed recurrent disease (P = .0000013). Cyclin D1 and pRb showed a progressive increase in expression from benign to malignant tumors but with relative decreases in the more advanced tumors (thick primaries and metastatic melanomas). Alterations in cell cycle proteins involved in G1/S transition are implicated in melanocytic tumor progression and have a potential role in diagnosis and prognostication.
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Affiliation(s)
- Rooshdiya Z Karim
- Discipline of Pathology, The University of Sydney, Sydney Melanoma Unit, Sydney Cancer Centre, Royal Prince Alfred Hospital and Melanoma Institute Australia
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Knauf JA, Fagin JA. Role of MAPK pathway oncoproteins in thyroid cancer pathogenesis and as drug targets. Curr Opin Cell Biol 2009; 21:296-303. [PMID: 19231149 DOI: 10.1016/j.ceb.2009.01.013] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 01/16/2009] [Indexed: 12/24/2022]
Abstract
Constitutive activation of MAPK in cancer occurs through activating mutations or overexpression of upstream effectors in the pathway, primarily of genes encoding receptor tyrosine kinases, RAS and BRAF. Arguably, the evidence for MAPK activation is most compelling in thyroid cancers and in melanomas. In this review we discuss the mechanisms of tumor development by oncogenic BRAF in these two cancer cell lineages, since this kinase signals preferentially through this pathway. We describe recent information on the mediators of BRAF-induced tumor initiation and escape from senescence. In addition, we review the biochemical events implicated in cellular growth triggered by oncogenic BRAF and the determinants of oncogene addiction. The biology of thyroid cancers induced by oncogenic BRAF is quite distinct, both in humans and in mice. There is great interest in using these insights to design rational new therapies, for which it will become crucial to understand the determinants of sensitivity and resistance to compounds designed to block the pathway. In thyroid cancer, this interest is further heightened by new information on the role of activated BRAF and MAPK pathway activation in disrupting iodine transport and thyroid hormonogenesis.
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Affiliation(s)
- Jeffrey A Knauf
- Department of Medicine and Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
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Abstract
Genetic and biochemical studies have provided considerable insight into the multiple functions of cyclin-dependent kinase subunit (cks)1 in cell division cycle. In addition to enhanced substrate targeting by specific ubiquitin ligases SCF(skp2) and APC/C, its direct interaction with proteasome components normalizes multiple cell cycle regulators. Importantly, it also acts as a transcriptional regulator. cks1 overexpression reflects poor prognosis in malignancy thus indicating its possible role in tumour diagnosis and management. The present review compiles the multiple functional roles of cks1 in cell division with specific emphasis on its molecular mechanisms. Its docking functions and the possible downstream proteolytic and transcriptional targets are described. The spatial configuration of cks1-cdk2 complex and the structural organization of cks1-p27-skp2 assembly required for p27 ubiquitination are discussed in detail. In addition to enhanced p27 degradation, the possible other mechanisms which underlie its pathological functions in human cancer progression are also discussed. Though there are apparent gaps in information, the turnover mechanism of cks1 is well addressed and presents opportunity to exploit the target for disease management.
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Affiliation(s)
- Anand Krishnan
- Translational Cancer Research Laboratory, Department of Molecular Medicine, Rajiv Gandhi Centre for Biotechnology, Kerala, India
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Karim RZ, Scolyer RA, Tse GM, Tan PH, Putti TC, Lee CS. Pathogenic mechanisms in the initiation and progression of mammary phyllodes tumours. Pathology 2009; 41:105-17. [DOI: 10.1080/00313020802579342] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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