1
|
Skelin J, Luk HY, Butorac D, Boon SS, Tomaić V. The effects of HPV oncoproteins on host communication networks: Therapeutic connotations. J Med Virol 2023; 95:e29315. [PMID: 38115222 DOI: 10.1002/jmv.29315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 11/13/2023] [Accepted: 11/29/2023] [Indexed: 12/21/2023]
Abstract
Human papillomavirus (HPV) infections are a leading cause of viral-induced malignancies worldwide, with a prominent association with cervical and head and neck cancers. The pivotal role of HPV oncoproteins, E5, E6, and E7, in manipulating cellular events, which contribute to viral pathogenesis in various ways, has been extensively documented. This article reviews the influence of HPV oncoproteins on cellular signaling pathways within the host cell, shedding light on the underlying molecular mechanisms. A comprehensive understanding of these molecular alterations is essential for the development of targeted therapies and strategies to combat HPV-induced premalignancies and prevent their progress to cancer. Furthermore, this review underscores the intricate interplay between HPV oncoproteins and some of the most important cellular signaling pathways: Notch, Wnt/β-catenin, MAPK, JAK/STAT, and PI3K AKT/mTOR. The treatment efficacies of the currently available inhibitors on these pathways in an HPV-positive context are also discussed. This review also highlights the importance of continued research to advance our knowledge and enhance therapeutic interventions for HPV-associated diseases.
Collapse
Affiliation(s)
- Josipa Skelin
- Division of Molecular Medicine, Ruđer Bošković Institute, Zagreb, Croatia
| | - Ho Yin Luk
- Department of Microbiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR
| | - Dražan Butorac
- Department of Gynecology and Obstetrics, Sestre Milosrdnice University Hospital Center, Zagreb, Croatia
| | - Siaw Shi Boon
- Department of Microbiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR
| | - Vjekoslav Tomaić
- Division of Molecular Medicine, Ruđer Bošković Institute, Zagreb, Croatia
| |
Collapse
|
2
|
Stavrou A, Ortiz A, Costa M. Cadmium Activates EGFR/STAT5 Signaling to Overcome Calcium Chelation and Promote Epithelial to Mesenchymal Transition. Biomolecules 2023; 13:116. [PMID: 36671501 PMCID: PMC9855692 DOI: 10.3390/biom13010116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 12/31/2022] [Accepted: 01/04/2023] [Indexed: 01/10/2023] Open
Abstract
Cadmium (Cd) is a heavy metal found in cigarette smoke, as well as in air and drinking water due to agricultural and industrial activities, and it poses a health risk to the general population. Prolonged low-dose Cd exposure via inhalation or ingestion causes lung and kidney cancers in humans and in animal models. While high doses of Cd exposure are correlated with the occupational setting and are cytotoxic, low doses of Cd are mainly correlated with exposure in the general population and induce carcinogenesis. The mechanism by which Cd-exposed cells overcome calcium chelation and induce malignant transformation remains unclear. This study examines how cells exposed to low doses of Cd survive loss of E-cadherin cell-cell adhesion via activation of the epidermal growth factor receptor (EGFR) and signal transducer and activator of transcription 5 (STAT5), which work to upregulate genes associated with survival and proliferation. To demonstrate the role of Cd in EGFR/STAT5 activation, we exposed two epithelial cell lines, BEAS-2B and HEK293, to two different doses (0.4 µM and 1.6 µM) of Cadmium chloride hemipentahydrate (CdCl2·2.5H2O) that are environmentally relevant to levels of Cd found in food and cigarettes for 24 h (hours) and 9 weeks (wks). When comparing cells treated with Cd with control cells, the Cd treated cells exhibited faster proliferation; therefore, we studied activation of EGFR via the STAT5 pathway using immunofluorescence (IF) for protein expression and localization and, in addition, RT-qPCR to examine changes in EGFR/STAT5 inducible genes. Our results showed an increase in EGFR and phosphorylated EGFR (p-EGFR) protein, with 1.6 µM of Cadmium having the highest expression at both 24-hour (hr) and 9-week (wk) exposures. Moreover, the IF analysis also demonstrated an increase of STAT5 and phosphorylated STAT5 (pSTAT5) in both short-term and long-term exposure, with 0.4 µM having the highest expression at 24 h. Finally, via Western blot analysis, we showed that there was a dose-dependent decrease in E-cadherin protein expression and increased N-cadherin in cells treated with low doses of Cd. These data demonstrate that epithelial cells can overcome Cd-mediated toxicity via activation of EGFR pathway to induce cell proliferation and survival and promote epithelial to mesenchymal transition.
Collapse
Affiliation(s)
| | | | - Max Costa
- Department of Medicine, Division of Environmental Medicine, New York University Grossman School of Medicine, New York, NY 10010, USA
| |
Collapse
|
3
|
Eckhardt KS, Münzel T, Gräb J, Berg T. Stafiba: A STAT5-Selective Small-Molecule Inhibitor. Chembiochem 2023; 24:e202200553. [PMID: 36300584 PMCID: PMC10099813 DOI: 10.1002/cbic.202200553] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/26/2022] [Indexed: 01/05/2023]
Abstract
The transcription factors STAT5a and STAT5b are constitutively active in many human tumors. Combined inhibition of both STAT5 proteins is a valuable approach with promising applications in tumor biology. We recently reported resorcinol bisphosphate as a moderately active inhibitor of the protein-protein interaction domains, the SH2 domains, of both STAT5a and STAT5b. Here, we describe the development of resorcinol bisphosphate to Stafiba, a phosphatase-stable inhibitor of STAT5a and STAT5b with activity in the low micromolar concentration range. Our data provide insights into the structure-activity relationships of resorcinol bisphosphates and the corresponding bisphosphonates for use as inhibitors of both STAT5a and STAT5b.
Collapse
Affiliation(s)
- Katrin S Eckhardt
- Leipzig University, Institute of Organic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Theresa Münzel
- Leipzig University, Institute of Organic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Julian Gräb
- Leipzig University, Institute of Organic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Thorsten Berg
- Leipzig University, Institute of Organic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| |
Collapse
|
4
|
Ni Y, Low JT, Silke J, O'Reilly LA. Digesting the Role of JAK-STAT and Cytokine Signaling in Oral and Gastric Cancers. Front Immunol 2022; 13:835997. [PMID: 35844493 PMCID: PMC9277720 DOI: 10.3389/fimmu.2022.835997] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 05/16/2022] [Indexed: 12/12/2022] Open
Abstract
When small proteins such as cytokines bind to their associated receptors on the plasma membrane, they can activate multiple internal signaling cascades allowing information from one cell to affect another. Frequently the signaling cascade leads to a change in gene expression that can affect cell functions such as proliferation, differentiation and homeostasis. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) and the tumor necrosis factor receptor (TNFR) are the pivotal mechanisms employed for such communication. When deregulated, the JAK-STAT and the TNF receptor signaling pathways can induce chronic inflammatory phenotypes by promoting more cytokine production. Furthermore, these signaling pathways can promote replication, survival and metastasis of cancer cells. This review will summarize the essentials of the JAK/STAT and TNF signaling pathways and their regulation and the molecular mechanisms that lead to the dysregulation of the JAK-STAT pathway. The consequences of dysregulation, as ascertained from founding work in haematopoietic malignancies to more recent research in solid oral-gastrointestinal cancers, will also be discussed. Finally, this review will highlight the development and future of therapeutic applications which modulate the JAK-STAT or the TNF signaling pathways in cancers.
Collapse
Affiliation(s)
- Yanhong Ni
- Central Laboratory, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Jun T Low
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - John Silke
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Lorraine A O'Reilly
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
5
|
Müller-Klieser D, Berg T. Asymmetrically Substituted m-Terphenyl Phosphates Inhibit the Transcription Factor STAT5a. Chembiochem 2021; 23:e202100603. [PMID: 34905258 PMCID: PMC9303812 DOI: 10.1002/cbic.202100603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/13/2021] [Indexed: 11/15/2022]
Abstract
We recently presented Stafia‐1 as the first chemical entity that inhibits the transcription factor STAT5a with selectivity over the highly homologous STAT5b. Stafia‐1, which was identified from a series of symmetrically substituted m‐terphenyl phosphates, binds to the interface between the SH2 domain and the linker domain of STAT5a. Here, we outline a synthetic strategy for the synthesis of asymmetrically substituted m‐terphenyl phosphates, which can be tailored to address their asymmetric STAT5a binding site in a more specific manner. The asymmetrically substituted m‐terphenyl phosphate with the highest activity against STAT5a was converted to a phosphatase‐stable monofluoromethylene phosphonate. The synthetic methodology and activity analysis described here provide first insights into the structure‐activity relationships of m‐terphenyl phosphates for use as selective STAT5a inhibitors.
Collapse
Affiliation(s)
- Daniel Müller-Klieser
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103, Leipzig, Germany
| | - Thorsten Berg
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103, Leipzig, Germany
| |
Collapse
|
6
|
Kordbacheh F, Farah CS. Molecular Pathways and Druggable Targets in Head and Neck Squamous Cell Carcinoma. Cancers (Basel) 2021; 13:3453. [PMID: 34298667 PMCID: PMC8307423 DOI: 10.3390/cancers13143453] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/02/2021] [Accepted: 07/08/2021] [Indexed: 12/30/2022] Open
Abstract
Head and neck cancers are a heterogeneous group of neoplasms, affecting an ever increasing global population. Despite advances in diagnostic technology and surgical approaches to manage these conditions, survival rates have only marginally improved and this has occurred mainly in developed countries. Some improvements in survival, however, have been a result of new management and treatment approaches made possible because of our ever-increasing understanding of the molecular pathways triggered in head and neck oncogenesis, and the growing understanding of the abundant heterogeneity of this group of cancers. Some important pathways are common to other solid tumours, but their impact on reducing the burden of head and neck disease has been less than impressive. Other less known and little-explored pathways may hold the key to the development of potential druggable targets. The extensive work carried out over the last decade, mostly utilising next generation sequencing has opened up the development of many novel approaches to head and neck cancer treatment. This paper explores our current understanding of the molecular pathways of this group of tumours and outlines associated druggable targets which are deployed as therapeutic approaches in head and neck oncology with the ultimate aim of improving patient outcomes and controlling the personal and economic burden of head and neck cancer.
Collapse
Affiliation(s)
- Farzaneh Kordbacheh
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA;
- ACRF Department of Cancer Biology and Therapeutics, The John Curtin School of Medical Research, Australian National University, Canberra, ACT 0200, Australia
| | - Camile S. Farah
- The Australian Centre for Oral Oncology Research & Education, Perth, WA 6009, Australia
- Genomics for Life, Brisbane, QLD 4064, Australia
- Anatomical Pathology, Australian Clinical Labs, Subiaco, WA 6008, Australia
- Peter MacCallum Cancer Centre, Head and Neck Cancer Signalling Laboratory, Melbourne, VIC 3000, Australia
| |
Collapse
|
7
|
Morgan EL, Macdonald A. Manipulation of JAK/STAT Signalling by High-Risk HPVs: Potential Therapeutic Targets for HPV-Associated Malignancies. Viruses 2020; 12:E977. [PMID: 32899142 PMCID: PMC7552066 DOI: 10.3390/v12090977] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/28/2020] [Accepted: 08/30/2020] [Indexed: 12/14/2022] Open
Abstract
Human papillomaviruses (HPVs) are small, DNA viruses that cause around 5% of all cancers in humans, including almost all cervical cancer cases and a significant proportion of anogenital and oral cancers. The HPV oncoproteins E5, E6 and E7 manipulate cellular signalling pathways to evade the immune response and promote virus persistence. The Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) pathway has emerged as a key mediator in a wide range of important biological signalling pathways, including cell proliferation, cell survival and the immune response. While STAT1 and STAT2 primarily drive immune signalling initiated by interferons, STAT3 and STAT5 have widely been linked to the survival and proliferative potential of a number of cancers. As such, the inhibition of STAT3 and STAT5 may offer a therapeutic benefit in HPV-associated cancers. In this review, we will discuss how HPV manipulates JAK/STAT signalling to evade the immune system and promote cell proliferation, enabling viral persistence and driving cancer development. We also discuss approaches to inhibit the JAK/STAT pathway and how these could potentially be used in the treatment of HPV-associated disease.
Collapse
Affiliation(s)
- Ethan L. Morgan
- Tumour Biology Section, Head and Neck Surgery Branch, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD 20892, USA
| | - Andrew Macdonald
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, West Yorkshire, UK
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, West Yorkshire, UK
| |
Collapse
|
8
|
Gräb J, Berg T. The Selectivity of Fosfosal for STAT5b over STAT5a is Mediated by Arg566 in the Linker Domain. Chembiochem 2020; 21:2264-2267. [PMID: 32227557 PMCID: PMC7496286 DOI: 10.1002/cbic.202000111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 03/29/2020] [Indexed: 12/17/2022]
Abstract
Fosfosal is the O-phosphorylated derivative of salicylic acid, with documented clinical use as a prodrug for the treatment of inflammatory diseases. We recently discovered that fosfosal itself inhibits the protein-protein interaction domain, the SH2 domain, of the tumor-related transcription factor STAT5b. Here, we demonstrate that fosfosal is selective for STAT5b over its close homologue STAT5a. This selectivity is mediated by the STAT5b residue Arg566, located in the SH2 domain-adjacent linker domain. Our data provide further evidence for the role of the STAT linker domain in determining the activity of small molecules against the SH2 domain. We present a refined binding model for fosfosal and STAT5b, which can serve as the basis for the development of fosfosal-based STAT5b inhibitors.
Collapse
Affiliation(s)
- Julian Gräb
- Leipzig University, Institute of Organic ChemistryJohannisallee 2904103LeipzigGermany
| | - Thorsten Berg
- Leipzig University, Institute of Organic ChemistryJohannisallee 2904103LeipzigGermany
| |
Collapse
|
9
|
Morgan EL, Macdonald A. JAK2 Inhibition Impairs Proliferation and Sensitises Cervical Cancer Cells to Cisplatin-Induced Cell Death. Cancers (Basel) 2019; 11:cancers11121934. [PMID: 31817106 PMCID: PMC6966458 DOI: 10.3390/cancers11121934] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 12/19/2022] Open
Abstract
Persistent infection with high-risk human papillomavirus (HPV) is the underlying cause of ~5% of all human cancers, including the majority of cervical carcinomas and many other ano-genital and oral cancers. A major challenge remains to identify key host targets of HPV and to reveal how they contribute to virus-mediated malignancy. The HPV E6 oncoprotein aberrantly activates the signal transducer and activator of transcription 3 (STAT3) transcription factor and this is achieved by a virus-driven increase in the levels of the pro-inflammatory cytokine interleukin-6 (IL-6) in HPV positive cervical cancers cells. Crucially, STAT3 activity is essential for the proliferation and survival of cervical cancer cells, suggesting that targeting STAT3 may have therapeutic potential. Unfortunately, the development of direct STAT3 inhibitors has been problematic in the clinic due to toxicity issues identified in early stage trials. To overcome this issue, we focused on the protein Janus kinase 2 (JAK2), which phosphorylates STAT3 and is essential for STAT3 activation. Here, we demonstrate that inhibiting JAK2 reduces cell proliferation and induces apoptosis in HPV transformed cervical cancer cells. We further establish that this is due to inhibition of phosphorylation of the JAK2 substrates STAT3 and STAT5. Finally, we demonstrate that the clinically available JAK2 inhibitor Ruxolitinib synergises with cisplatin in inducing apoptosis, highlighting JAK2 as a promising therapeutic target in HPV-driven cancers.
Collapse
|
10
|
Polak KL, Chernosky NM, Smigiel JM, Tamagno I, Jackson MW. Balancing STAT Activity as a Therapeutic Strategy. Cancers (Basel) 2019; 11:cancers11111716. [PMID: 31684144 PMCID: PMC6895889 DOI: 10.3390/cancers11111716] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/23/2019] [Accepted: 10/31/2019] [Indexed: 12/13/2022] Open
Abstract
Driven by dysregulated IL-6 family member cytokine signaling in the tumor microenvironment (TME), aberrant signal transducer and activator of transcription (STAT3) and (STAT5) activation have been identified as key contributors to tumorigenesis. Following transformation, persistent STAT3 activation drives the emergence of mesenchymal/cancer-stem cell (CSC) properties, important determinants of metastatic potential and therapy failure. Moreover, STAT3 signaling within tumor-associated macrophages and neutrophils drives secretion of factors that facilitate metastasis and suppress immune cell function. Persistent STAT5 activation is responsible for cancer cell maintenance through suppression of apoptosis and tumor suppressor signaling. Furthermore, STAT5-mediated CD4+/CD25+ regulatory T cells (Tregs) have been implicated in suppression of immunosurveillance. We discuss these roles for STAT3 and STAT5, and weigh the attractiveness of different modes of targeting each cancer therapy. Moreover, we discuss how anti-tumorigenic STATs, including STAT1 and STAT2, may be leveraged to suppress the pro-tumorigenic functions of STAT3/STAT5 signaling.
Collapse
Affiliation(s)
- Kelsey L Polak
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
| | - Noah M Chernosky
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
| | - Jacob M Smigiel
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
| | - Ilaria Tamagno
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
| | - Mark W Jackson
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
- Case Comprehensive Cancer Center, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
| |
Collapse
|
11
|
Berg A, Sperl B, Berg T. ATP Inhibits the Transcription Factor STAT5b. Chembiochem 2019; 20:2227-2231. [PMID: 30985989 DOI: 10.1002/cbic.201900173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Indexed: 12/14/2022]
Abstract
Although naturally occurring low-molecular-weight compounds have many known roles within the cell, these do not usually involve the direct inhibition of protein-protein interactions. Based on the results of high-throughput screening of a library of bioactive compounds and neurotransmitters, we report here that the four nucleoside triphosphates ATP, GTP, CTP and UTP inhibit the SH2 domain of the tumor-related transcription factor STAT5b. ATP and GTP are the most active nucleoside triphosphates and show specificity for STAT5b over STAT5a, STAT3, STAT6 and the p53-binding protein HDM2. As the inhibition constant of ATP against STAT5b is significantly lower than published values for the intracellular ATP concentration, our data suggest that ATP might inhibit the protein-protein interactions of STAT5b in living cells.
Collapse
Affiliation(s)
- Angela Berg
- Institute of Organic Chemistry, University of Leipzig, Johannisallee 29, 04103, Leipzig, Germany
| | - Bianca Sperl
- Department of Molecular Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Germany
| | - Thorsten Berg
- Institute of Organic Chemistry, University of Leipzig, Johannisallee 29, 04103, Leipzig, Germany
| |
Collapse
|
12
|
Gräb J, Berg A, Blechschmidt L, Klüver B, Rubner S, Fu DY, Meiler J, Gräber M, Berg T. The STAT5b Linker Domain Mediates the Selectivity of Catechol Bisphosphates for STAT5b over STAT5a. ACS Chem Biol 2019; 14:796-805. [PMID: 30835430 DOI: 10.1021/acschembio.9b00137] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
STAT family proteins are important mediators of cell signaling and represent therapeutic targets for the treatment of human diseases. Most STAT inhibitors target the protein-protein interaction domain, the SH2 domain, but specificity for a single STAT protein is often limited. Recently, we developed catechol bisphosphates as the first inhibitors of STAT5b demonstrated to exhibit a high degree of selectivity over the close homologue STAT5a. Here, we show that the amino acid in position 566 of the linker domain, not the SH2 domain, is the main determinant of specificity. Arg566 in wild-type STAT5b favors tight binding of catechol bisphosphates, while Trp566 in wild-type STAT5a does not. Amino acid 566 also determines the affinity for a tyrosine-phosphorylated peptide derived from the EPO receptor for STAT5a and STAT5b, demonstrating the functional relevance of the STAT5 linker domain for the adjacent SH2 domain. These results provide the first demonstration that a residue in the linker domain can determine the affinity of nonpeptidic small-molecule inhibitors for the SH2 domain of STAT proteins. We propose targeting the interface between the SH2 domain and linker domain as a novel design approach for the development of potent and selective STAT inhibitors. In addition, our data suggest that the linker domain could contribute to the enigmatically divergent biological functions of the two STAT5 proteins.
Collapse
Affiliation(s)
- Julian Gräb
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103 Leipzig, Germany
| | - Angela Berg
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103 Leipzig, Germany
| | - Linda Blechschmidt
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103 Leipzig, Germany
| | - Barbara Klüver
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103 Leipzig, Germany
| | - Stefan Rubner
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103 Leipzig, Germany
| | - Darwin Y. Fu
- Center for Structural Biology, Vanderbilt University, 465 21st Avenue South, BIOSCI/MRBIII, Nashville, Tennessee 37221, United States
| | - Jens Meiler
- Center for Structural Biology, Vanderbilt University, 465 21st Avenue South, BIOSCI/MRBIII, Nashville, Tennessee 37221, United States
| | - Martin Gräber
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103 Leipzig, Germany
| | - Thorsten Berg
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103 Leipzig, Germany
| |
Collapse
|
13
|
Heppler LN, Frank DA. Targeting Oncogenic Transcription Factors: Therapeutic Implications of Endogenous STAT Inhibitors. Trends Cancer 2017; 3:816-827. [PMID: 29198438 DOI: 10.1016/j.trecan.2017.10.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/10/2017] [Accepted: 10/11/2017] [Indexed: 02/07/2023]
Abstract
Misregulation of transcription factors, including signal transducer and activator of transcription (STAT) proteins, leads to inappropriate gene expression patterns that can promote tumor initiation and progression. Under physiologic conditions, STAT signaling is stimulus dependent and tightly regulated by endogenous inhibitors, namely, suppressor of cytokine signaling (SOCS) proteins, phosphatases, and protein inhibitor of activated STAT (PIAS) proteins. However, in tumorigenesis, STAT proteins become constitutively active and promote the expression of progrowth and prosurvival genes. Although STAT activation has been widely implicated in cancer, therapeutic STAT inhibitors are still largely absent from the clinic. This review dissects the mechanisms of action of two families of endogenous STAT inhibitors, the SOCS and PIAS families, to potentially inform the development of novel therapeutic inhibitors.
Collapse
Affiliation(s)
- Lisa N Heppler
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA; Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - David A Frank
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA; Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
14
|
Siavash H, Nikitakis N, Sauk J. Signal Transducers and Activators of Transcription: Insights into the Molecular Basis of Oral Cancer. ACTA ACUST UNITED AC 2016; 15:298-307. [DOI: 10.1177/154411130401500505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recent efforts on developing more direct and effective targets for cancer therapy have revolved around a family of transcription factors known as STATs (signal transducers and activators of transcription). STAT proteins are latent cytoplasmic transcription factors that become activated in response to extracellular signaling proteins. STAT proteins have been convincingly reported to possess oncogenic properties in a plethora of human cancers, including oral and oropharyngeal cancer. Signal transduction pathways mediated by these oncogenic transcription factors and their regulation in oral cancer are the focus of this review.
Collapse
Affiliation(s)
- H. Siavash
- Department of Biomedical Sciences and
- Department of Diagnostic Sciences and Pathology, University of Maryland, Dental School, 666 West Baltimore Street, Room 4-C-02, Baltimore, MD 21201; and
- Greenebaum Cancer Center, University of Maryland, Baltimore, MD 21201
| | - N.G. Nikitakis
- Department of Biomedical Sciences and
- Department of Diagnostic Sciences and Pathology, University of Maryland, Dental School, 666 West Baltimore Street, Room 4-C-02, Baltimore, MD 21201; and
- Greenebaum Cancer Center, University of Maryland, Baltimore, MD 21201
| | - J.J. Sauk
- Department of Biomedical Sciences and
- Department of Diagnostic Sciences and Pathology, University of Maryland, Dental School, 666 West Baltimore Street, Room 4-C-02, Baltimore, MD 21201; and
- Greenebaum Cancer Center, University of Maryland, Baltimore, MD 21201
| |
Collapse
|
15
|
Peng HY, Jiang SS, Hsiao JR, Hsiao M, Hsu YM, Wu GH, Chang WM, Chang JY, Jin SLC, Shiah SG. IL-8 induces miR-424-5p expression and modulates SOCS2/STAT5 signaling pathway in oral squamous cell carcinoma. Mol Oncol 2016; 10:895-909. [PMID: 27038552 PMCID: PMC5423170 DOI: 10.1016/j.molonc.2016.03.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/15/2016] [Accepted: 03/15/2016] [Indexed: 11/18/2022] Open
Abstract
Suppressor of cytokine signaling (SOCS) proteins are negative feedback regulators of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. Dysregulation of SOCS protein expression in cancers can be one of the mechanisms that maintain STAT activation, but this mechanism is still poorly understood in oral squamous cell carcinoma (OSCC). Here, we report that SOCS2 protein is significantly downregulated in OSCC patients and its levels are inversely correlated with miR‐424‐5p expression. We identified the SOCS2 protein, which modulates STAT5 activity, as a direct target of miR‐424‐5p. The miR‐424‐5p‐induced STAT5 phosphorylation, matrix metalloproteinases (MMPs) expression, and cell migration and invasion were blocked by SOCS2 restoration, suggesting that miR‐424‐5p exhibits its oncogenic activity through negatively regulating SOCS2 levels. Furthermore, miR‐424‐5p expression could be induced by the cytokine IL‐8 primarily through enhancing STAT5 transcriptional activity rather than NF‐κB signaling. Antagomir‐mediated inactivation of miR‐424‐5p prevented the IL‐8‐induced cell migration and invasion, indicating that miR‐424‐5p is required for IL‐8‐induced cellular invasiveness. Taken together, these data indicate that STAT5‐dependent expression of miR‐424‐5p plays an important role in mediating IL‐8/STAT5/SOCS2 feedback loop, and scavenging miR‐424‐5p function using antagomir may have therapeutic potential for the treatment of OSCC. miR‐424‐5p is overexpressed in OSCC. miR‐424‐5p directly targets SOCS2, leading to increased cell migration and invasion. STAT5 activation is required for IL‐8‐mediated miR‐424‐5p transcription. miR‐424‐5p plays an important role in mediating IL‐8/STAT5/SOCS2 feedback loop.
Collapse
Affiliation(s)
- Hsuan-Yu Peng
- National Institute of Cancer Research, National Health Research Institutes, Miaoli, Taiwan; Department of Life Sciences, National Central University, Taoyuan, Taiwan
| | - Shih-Sheng Jiang
- National Institute of Cancer Research, National Health Research Institutes, Miaoli, Taiwan
| | - Jenn-Ren Hsiao
- Department of Otolaryngology, Head and Neck Collaborative Oncology Group, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Michael Hsiao
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Yuan-Ming Hsu
- National Institute of Cancer Research, National Health Research Institutes, Miaoli, Taiwan
| | - Guan-Hsun Wu
- National Institute of Cancer Research, National Health Research Institutes, Miaoli, Taiwan
| | - Wei-Min Chang
- National Institute of Cancer Research, National Health Research Institutes, Miaoli, Taiwan; Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Jang-Yang Chang
- National Institute of Cancer Research, National Health Research Institutes, Miaoli, Taiwan; Department of Internal Medicine, Division of Hematology and Oncology, National Cheng Kung University Hospital, College of Medical, National Cheng Kung University, Tainan, Taiwan
| | | | - Shine-Gwo Shiah
- National Institute of Cancer Research, National Health Research Institutes, Miaoli, Taiwan.
| |
Collapse
|
16
|
Role of ubiquitin-specific peptidase 22 in carcinogenesis of human pharyngeal squamous cell carcinoma. Mol Med Rep 2014; 10:2973-8. [PMID: 25241842 DOI: 10.3892/mmr.2014.2589] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 06/05/2014] [Indexed: 11/05/2022] Open
Abstract
Human pharyngeal squamous cell carcinoma (HNSCC) are highly invasive and proliferative and exhibit a poor five-year survival rate, mainly due to poor understanding of HNSCC pathogenesis mechanisms, preventing efficient treatment. Ubiquitin‑specific peptidase 22 (USP22) is an important component of cell cycle regulation, as it indirectly affects chromatin structure via histone ubiquitination and regulates activation of gene transcription. In previous studies, silencing of USP22 significantly inhibited tumor cell proliferation. To investigate the expression levels and the role of USP22 in the carcinogenesis of human pharyngeal squamous cell carcinoma, pharyngeal squamous cell carcinoma and adjacent normal tissue samples were collected from four patients. Six pharyngeal squamous cell carcinoma cell lines (SAS, CAL-33, FaDu, HSC-4, UTSCC-5 and UTSCC-8) were also included in this study. The USP22 mRNA and protein expression levels in the patient and cell‑line samples were evaluated using quantitative polymerase chain reaction and western blotting analyses. Subsequently, stable USP22 gene silencing in cells was achieved using lentiviral-delivered small interfering RNA (siRNA), and an MTT assay was used to evaluate tumor cell proliferation. Expression levels of cell cycle-associated proteins following USP22 knockdown were assessed using western blot analysis. The results revealed that USP22 was upregulated in pharyngeal squamous cell carcinoma. USP22 knockdown, using lentivirus‑delivered siRNA, increased the expression levels of cell cycle proteins P21 and P27, but reduced the levels of phosphorylated retinoblastoma protein, resulting in the inhibition of FaDu cell growth and proliferation. In conclusion, USP22 is involved in the carcinogenesis of human pharyngeal squamous cell carcinoma through regulating tumor cell growth and proliferation.
Collapse
|
17
|
Abstract
Silencing of abnormally activated genes can be accomplished in a highly specific manner using nucleic acid based approaches. The focus of this review includes the different nucleic acid based inhibition strategies such as antisense oligodeoxynucleotides, small interfering RNA (siRNA), dominant-negative constructs, G-quartet oligonucleotides and decoy oligonucleotides, their mechanism of action and the effectiveness of these approaches to targeting the STAT (signal transducer and activator of transcription) proteins in cancer. Among the STAT proteins, especially STAT3, followed by STAT5, are the most frequently activated oncogenic STATs, which have emerged as plausible therapeutic cancer targets. Both STAT3 and STAT5 have been shown to regulate numerous oncogenic signaling pathways including proliferation, survival, angiogenesis and migration/invasion.
Collapse
Affiliation(s)
- Malabika Sen
- Department of Otolaryngology; University of Pittsburgh School of Medicine; Pittsburgh, PA USA
| | | |
Collapse
|
18
|
Dou YL, Lin JP, Liu FE, Wang LY, Shu HH, Jiang N, Xie Y, Duan Q. Midazolam inhibits the proliferation of human head and neck squamous carcinoma cells by downregulating p300 expression. Tumour Biol 2014; 35:7499-504. [PMID: 24789432 DOI: 10.1007/s13277-014-1991-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 04/17/2014] [Indexed: 11/26/2022] Open
Affiliation(s)
- Yun-Ling Dou
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China,
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Constitutive activation of STAT5A and STAT5B regulates IgM secretion in Waldenstrom's macroglobulinemia. Blood 2013; 123:1055-8. [PMID: 24335105 DOI: 10.1182/blood-2013-08-521963] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Activation of the Janus kinase family/signal transducer and activator of transcription (JAK/STAT) signaling pathway has been associated with the pathogenesis and progression of both solid and hematologic malignancies. We have detected constitutive activation of STAT5 in malignant B cells derived from patients with Waldenström's macroglobulinemia (WM). Although short hairpin RNA-mediated knockdown of the STAT5A and STAT5B isoforms did not affect cellular proliferation, loss of STAT5 significantly decreased immunoglobulin M (IgM) secretion. A similar dose-dependent inhibition of IgM secretion was observed when WM cell lines were treated with a small molecule inhibitor of STAT5. These data suggest that STAT5 is involved in regulating IgM production in WM and that inhibition of STAT5 may represent a novel therapeutic strategy for lowering IgM levels in WM patients.
Collapse
|
20
|
Novel multiplexed assay for identifying SH2 domain antagonists of STAT family proteins. PLoS One 2013; 8:e71646. [PMID: 23977103 PMCID: PMC3745430 DOI: 10.1371/journal.pone.0071646] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 07/01/2013] [Indexed: 11/19/2022] Open
Abstract
Some of the signal transducer and activator of transcription (STAT) family members are constitutively activated in a wide variety of human tumors. The activity of STAT depends on their Src homology 2 (SH2) domain-mediated binding to sequences containing phosphorylated tyrosine. Thus, antagonizing this binding is a feasible approach to inhibiting STAT activation. We have developed a novel multiplexed assay for STAT3- and STAT5b-SH2 binding, based on amplified luminescent proximity homogeneous assay (Alpha) technology. AlphaLISA and AlphaScreen beads were combined in a single-well assay, which allowed the binding of STAT3- and STAT5b-SH2 to phosphotyrosine peptides to be simultaneously monitored. Biotin-labeled recombinant human STAT proteins were obtained as N- and C-terminal deletion mutants. The spacer length of the DIG-labeled peptide, the reaction time, and the concentration of sodium chloride were optimized to establish a HTS system with Z' values of greater than 0.6 for both STAT3- and STAT5b-SH2 binding. We performed a HTS campaign for chemical libraries using this multiplexed assay and identified hit compounds. A 2-chloro-1,4-naphthalenedione derivative, Compound 1, preferentially inhibited STAT3-SH2 binding in vitro, and the nuclear translocation of STAT3 in HeLa cells. Initial structure activity relationship (SAR) studies using the multiplexed assay showed the 3-substituent effect on both the activity and selectivity of STAT3 and STAT5b inhibition. Therefore, this multiplexed assay is useful for not only searching for potential lead compounds but also obtaining SAR data for developing new STAT3/STAT5b inhibitors.
Collapse
|
21
|
Katsantoni E. Protein Complexes and Target Genes Identification by in Vivo Biotinylation: The STAT5 ParadigmA Presentation from the European Society for Paediatric Endocrinology (ESPE) New Inroads to Child Health (NICHe) Conference on Stress Response and Child Health in Heraklion, Crete, Greece, 18 to 20 May 2012. Sci Signal 2012; 5:pt13. [DOI: 10.1126/scisignal.2003622] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Eleni Katsantoni
- Hematology/Oncology Division, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
| |
Collapse
|
22
|
Sen B, Peng S, Woods DM, Wistuba I, Bell D, El-Naggar AK, Lai SY, Johnson FM. STAT5A-mediated SOCS2 expression regulates Jak2 and STAT3 activity following c-Src inhibition in head and neck squamous carcinoma. Clin Cancer Res 2011; 18:127-39. [PMID: 22090359 DOI: 10.1158/1078-0432.ccr-11-1889] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE The inhibition of c-Src results in a striking reduction in cancer cell invasion, but the effect on cell survival is modest. Defining mechanisms that limit apoptosis following c-Src inhibition could result in an ideal therapeutic approach that both inhibits invasion and leads to apoptosis. In this regard, we discovered a novel feedback loop that results in STAT3 reactivation following sustained c-Src inhibition. Here we define the mechanism underlying this feedback loop and examine the effect of inhibiting it in vivo. EXPERIMENTAL DESIGN We measured levels and activity of pathway components using PCR, Western blotting, and kinase assays following their manipulation using both molecular and pharmacologic approaches. We used a heterotransplant animal model in which human oral squamous cancer is maintained exclusively in vivo. RESULTS Following c-Src inhibition, STAT5 is durably inhibited. The inhibition of STAT5A, but not STAT5B, subsequently reduces the expression of suppressors of cytokine signaling 2 (SOCS2). SOCS2 inhibits Janus kinase 2 (Jak2) activity and Jak2-STAT3 binding. SOCS2 expression is necessary for STAT3 inhibition by c-Src inhibitors. Overexpression of SOCS2 is adequate to prevent STAT3 reactivation and to enhance the cytotoxic effects of c-Src inhibition. Likewise, the combination of Jak and c-Src inhibitors led to significantly more apoptosis than either agent alone in vivo. CONCLUSIONS To our knowledge, ours is the first study that fully defines the mechanism underlying this feedback loop, in which sustained c-Src inhibition leads to diminished SOCS2 expression via sustained inhibition of STAT5A, allowing activation of Jak2 and STAT3, Jak2-STAT3 binding, and survival signals.
Collapse
Affiliation(s)
- Banibrata Sen
- Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Bebek G, Orloff M, Eng C. Microenvironmental genomic alterations reveal signaling networks for head and neck squamous cell carcinoma. J Clin Bioinforma 2011; 1:21. [PMID: 21884569 PMCID: PMC3170587 DOI: 10.1186/2043-9113-1-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Accepted: 08/02/2011] [Indexed: 01/04/2023] Open
Abstract
Background Advanced stage head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer with low survival rates. Loss-of-heterozygosity/allelic imbalance (LOH/AI) analysis has been widely used to identify genomic alterations in solid tumors and the tumor microenvironment (stroma). We hypothesize that these identified alterations can point to signaling networks functioning in HNSCC epithelial-tumor and surrounding stroma (tumor microenvironment). Results Under the assumption that genes in proximity to identified LOH/AI regions are correlated with the tumorigenic phenotype, we mined publicly available biological information to identify pathway segments (signaling proteins connected to each other in a network) and identify the role of tumor microenvironment in HNSCC. Across both neoplastic epithelial cells and the surrounding stromal cells, genetic alterations in HNSCC were successfully identified, and 75 markers were observed to have significantly different LOH/AI frequencies in these compartments (p < 0.026). We applied a network identification approach to the genes in proximity to these 75 markers in cancer epithelium and stroma in order to identify biological networks that can describe functional associations amongst these marker-associated genes. Conclusions We verified the involvement of T-cell receptor signaling pathways in HNSCC as well as associated oncogenes such as LCK and PLCB1, and tumor suppressors such as STAT5A, PTPN6, PARK2. We identified expression levels of genes within significant LOH/AI regions specific to stroma networks that correlate with better outcome in radiation therapy. By integrating various levels of high-throughput data, we were able to precisely focus on specific proteins and genes that are germane to HNSCC.
Collapse
Affiliation(s)
- Gurkan Bebek
- Genomic Medicine Institute, Cleveland Clinic, 9500 Euclid Avenue, Mailstop NE-50 Cleveland, OH 44195, USA.
| | | | | |
Collapse
|
24
|
Bojovic B, Crowe DL. Telomere dysfunction promotes metastasis in a TERC null mouse model of head and neck cancer. Mol Cancer Res 2011; 9:901-13. [PMID: 21593138 DOI: 10.1158/1541-7786.mcr-10-0345] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Squamous cell carcinoma arises from highly proliferative basal layer epithelial cells, which normally divide for a short time before detaching from the basement membrane and undergoing terminal differentiation. Basal layer cells in stratified epithelia express the reverse transcriptase known as telomerase. Most human cells do not express telomerase and therefore are subject to loss of telomeric DNA with age due to the inability of lagging strand synthesis to completely replicate chromosomal ends. Late generation telomerase deficient mice exhibit signs of premature aging including reduced function of proliferating cellular compartments. We examined development of squamous cell carcinoma in a telomerase deficient murine background with long and short telomeres. G1 Terc-/- mice (long telomeres) had fewer lymph node metastases, which correlated with increased numbers of apoptotic cells in these tumors compared with wild-type mice. However, G5 Terc-/- mice with short telomeres had increased metastatic tumor burden similar to wild type mice. This increased metastasis correlated with genomic instability and aneuploidy in tumor cells from G5 Terc-/- mice. A number of similarities with human SCC were noted in the mouse model, and dramatic differences in global gene expression profiles were shown between primary and metastatic tumors. We concluded that telomere shortening promotes metastatic tumor development in a Terc null mouse model of head and neck cancer.
Collapse
Affiliation(s)
- Bojana Bojovic
- University of Illinois Cancer Center, University of Illinois at Chicago, Chicago, IL 60612, USA
| | | |
Collapse
|
25
|
STAT-Related Profiles Are Associated with Patient Response to Targeted Treatments in Locally Advanced SCCHN. Transl Oncol 2011; 4:47-58. [PMID: 21286377 DOI: 10.1593/tlo.10217] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 11/08/2010] [Accepted: 11/18/2010] [Indexed: 02/07/2023] Open
Abstract
The anti-epidermal growth factor receptor antibody cetuximab (Erbitux, CTX) is currently used for the treatment of locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN), as yet with modest effectiveness, prompting for the identification of response predictors to this treatment and for the targeting of additional pathways implicated in this disease. Within this scope, we investigated the effect of SRC/STAT pathway components on LA-SCCHN patient outcome. SRC, STAT1, STAT3, STAT5A, STAT5B, ANXA1, CAV1, IGFBP2, EPHA2, EPHB2, and MSN relative gene expression, as well as Stat protein activation, were assessed on LA-SCCHN tumor tissues from 35 patients treated with combined radiotherapy (RT) and CTX-based regimens. Stat1, Stat3, and Stat5 proteins were usually found activated in neoplastic nuclei (70.4%, 85.7%, and 70.8%, respectively). Activated Stat3 and Stat5 were associated with each other (P = .017) and with a CAV1(high)/MSN(high)/IGFBP2(low) profile. All patients with tumors expressing high STAT5A/EPHA2 experienced a complete response on RT-CTX-based treatments (12/15 complete responders, P < .0001) and a longer progression-free survival (P = .024). Few tumors expressed high ANXA1/CAV1/EPHA2 and low IGFBP2, a putative dasatinib response-related profile, whereas high ANXA1 was associated with shorter overall survival (P = .003). In conclusion, Stat activation is common in LA-SCCHN, where overexpression of STAT5A and EPHA2 may predict for response to RT-CTX treatments. The STAT5A/EPHA2 profile seems of particular interest for validation in larger cohorts and in multiple tumor types because markers for the positive selection of patients to benefit from CTX-containing treatments are currently lacking.
Collapse
|
26
|
Ferbeyre G, Moriggl R. The role of Stat5 transcription factors as tumor suppressors or oncogenes. Biochim Biophys Acta Rev Cancer 2010; 1815:104-14. [PMID: 20969928 DOI: 10.1016/j.bbcan.2010.10.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 10/08/2010] [Accepted: 10/08/2010] [Indexed: 02/06/2023]
Abstract
Stat5 is constitutively activated in many human cancers affecting the expression of cell proliferation and cell survival controlling genes. These oncogenic functions of Stat5 have been elegantly reproduced in mouse models. Aberrant Stat5 activity induces also mitochondrial dysfunction and reactive oxygen species leading to DNA damage. Although DNA damage can stimulate tumorigenesis, it can also prevent it. Stat5 can inhibit tumor progression like in the liver and it is a tumor suppressor in fibroblasts. Stat5 proteins are able to regulate cell differentiation and senescence activating the tumor suppressors SOCS1, p53 and PML. Understanding the context dependent regulation of tumorigenesis through Stat5 function will be central to understand proliferation, survival, differentiation or senescence of cancer cells.
Collapse
Affiliation(s)
- G Ferbeyre
- Département de Biochimie, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
| | | |
Collapse
|
27
|
Jinawath N, Vasoontara C, Jinawath A, Fang X, Zhao K, Yap KL, Guo T, Lee CS, Wang W, Balgley BM, Davidson B, Wang TL, Shih IM. Oncoproteomic analysis reveals co-upregulation of RELA and STAT5 in carboplatin resistant ovarian carcinoma. PLoS One 2010; 5:e11198. [PMID: 20585448 PMCID: PMC2887843 DOI: 10.1371/journal.pone.0011198] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Accepted: 05/25/2010] [Indexed: 01/23/2023] Open
Abstract
Background Ovarian cancer is one of the most lethal types of female malignancy. Although most patients are initially responsive to platinum-based chemotherapy, almost all develop recurrent chemoresistant tumors and succumb to their diseases. Elucidating the pathogenesis underlying drug resistance is fundamental to the development of new therapeutics, leading to improved clinical outcomes in these patients. Methods and Findings We compared the proteomes of paired primary and recurrent post-chemotherapy ovarian high-grade serous carcinomas from nine ovarian cancer patients using CIEF/Nano-RPLC coupled with ESI-Tandem MS. As compared to their primary tumors, more than half of the recurrent tumors expressed higher levels of several proteins including CP, FN1, SYK, CD97, AIF1, WNK1, SERPINA3, APOD, URP2, STAT5B and RELA (NF-κB p65), which were also validated by quantitative RT-PCR. Based on shRNA screening for the upregulated genes in in vitro carboplatin-resistant cells, we found that simultaneous knockdown of RELA and STAT5B was most effective in sensitizing tumor cells for carboplatin treatment. Similarly, the NF-κB inhibitor, BMS-345541, and the STAT5 inhibitor, Dasatinib, significantly enhanced cell sensitivity to carboplatin. Moreover, both RELA and STAT5 are known to bind to the promoter region of Bcl-X, regulating its promoter activity. In this regard, augmented Bcl-xL expression was detected in carboplatin-resistant cells. Combined ectopic expression of RELA and STAT5B enhanced Bcl-xL promoter activity while treatment with BMS-345541 and Dasatinib decreased it. Chromatin immunoprecipitation of the Bcl-X promoter region using a STAT5 antibody showed induction of RELA and STAT5 DNA-binding segments both in naïve cells treated with a high concentration of carboplatin as well as in carboplatin-resistant cells. Conclusions Proteomic analysis identified RELA and STAT5 as two major proteins associated with carboplatin resistance in ovarian tumors. Our results further showed that NF-κB and STAT5 inhibitor could sensitize carboplatin-resistant cells and suggest that such inhibitors can be used to benefit patients with carboplatin-resistant recurrent ovarian cancer.
Collapse
Affiliation(s)
- Natini Jinawath
- Departments of Pathology, Oncology, and Gynecology and Obstetrics, Johns Hopkins Medical Institutions, Baltimore, Maryland, United States of America
- Research Center, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Chanont Vasoontara
- Departments of Pathology, Oncology, and Gynecology and Obstetrics, Johns Hopkins Medical Institutions, Baltimore, Maryland, United States of America
| | - Artit Jinawath
- Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Xueping Fang
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, United States of America
| | - Kejia Zhao
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, United States of America
| | - Kai-Lee Yap
- Departments of Pathology, Oncology, and Gynecology and Obstetrics, Johns Hopkins Medical Institutions, Baltimore, Maryland, United States of America
| | - Tong Guo
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, United States of America
| | - Cheng S. Lee
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, United States of America
| | - Weijie Wang
- Human Genome Sciences, Rockville, Maryland, United States of America
| | - Brian M. Balgley
- Calibrant Biosystems, Gaithersburg, Maryland, United States of America
| | - Ben Davidson
- Department of Pathology, Norwegian Radium Hospital, Oslo University Hospital, University of Oslo, Oslo, Norway
- Medical Faculty, University of Oslo, Oslo, Norway
| | - Tian-Li Wang
- Departments of Pathology, Oncology, and Gynecology and Obstetrics, Johns Hopkins Medical Institutions, Baltimore, Maryland, United States of America
| | - Ie-Ming Shih
- Departments of Pathology, Oncology, and Gynecology and Obstetrics, Johns Hopkins Medical Institutions, Baltimore, Maryland, United States of America
- * E-mail:
| |
Collapse
|
28
|
Lai SY, Johnson FM. Defining the role of the JAK-STAT pathway in head and neck and thoracic malignancies: implications for future therapeutic approaches. Drug Resist Updat 2010; 13:67-78. [PMID: 20471303 DOI: 10.1016/j.drup.2010.04.001] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Accepted: 04/06/2010] [Indexed: 12/17/2022]
Abstract
Although the role of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway has been most extensively studied in hematopoietic cells and hematologic malignancies, it is also activated in epithelial tumors, including those originating in the lungs and head and neck. The canonical pathway involves the activation of JAK following ligand binding to cytokine receptors. The activated JAKs then phosphorylate STAT proteins, leading to their dimerization and translocation into the nucleus. In the nucleus, STATs act as transcription factors with pleiotropic downstream effects. STATs can be activated independently of JAKs, most notably by c-Src kinases. In cancer cells, STAT3 and STAT5 activation leads to the increased expression of downstream target genes, leading to increased cell proliferation, cell survival, angiogenesis, and immune system evasion. STAT3 and STAT5 are expressed and activated in head and neck squamous cell carcinoma (HNSCC) where they contribute to cell survival and proliferation. In HNSCC, STATs can be activated by a number of signal transduction pathways, including the epidermal growth factor receptor (EGFR), alpha7 nicotinic receptor, interleukin (IL) receptor, and erythropoietin receptor pathways. Activated STATs are also expressed in lung cancer, but the biological effects of JAK/STAT inhibition in this cancer are variable. In lung cancer, STAT3 can be activated by multiple pathways, including EGFR. Several approaches have been used to inhibit STAT3 in the hopes of developing an antitumor agent. Although several STAT3-specific agents are promising, none are in clinical development, mostly because of drug delivery and stability issues. In contrast, several JAK inhibitors are in clinical development. These orally available, ATP-competitive, small-molecule kinase inhibitors are being tested in myeloproliferative disorders. Future studies will determine whether JAK inhibitors are useful in the treatment of HNSCC or lung cancer.
Collapse
Affiliation(s)
- Stephen Y Lai
- Department of Head and Neck Surgery, The University of Texas M.D. Anderson Cancer Center at Houston, Houston, TX 77030, USA
| | | |
Collapse
|
29
|
Sobti RC, Singh N, Hussain S, Suri V, Bharadwaj M, Das BC. Deregulation of STAT-5 isoforms in the development of HPV-mediated cervical carcinogenesis. J Recept Signal Transduct Res 2010; 30:178-88. [DOI: 10.3109/10799891003786218] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
30
|
Tang JZ, Zuo ZH, Kong XJ, Steiner M, Yin Z, Perry JK, Zhu T, Liu DX, Lobie PE. Signal transducer and activator of transcription (STAT)-5A and STAT5B differentially regulate human mammary carcinoma cell behavior. Endocrinology 2010; 151:43-55. [PMID: 19966185 DOI: 10.1210/en.2009-0651] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Increased activation of signal transducer and activator of transcription (STAT)-5 has been reported in various malignancies including mammary carcinoma. However, it is only recently that potentially distinct roles of STAT5A and STAT5B in neoplasia have begun to emerge. Herein we systematically delineate the functions of STAT5A and STAT5B in human mammary carcinoma cell lines MCF-7 and T47D. Forced expression of constitutively active (CA) STAT5A enhanced both survival and anchorage-independent growth of human mammary carcinoma cells but concordantly suppressed cell motility as revealed in colony scattering, cell migration, and invasion assays. In contrast, forced expression of CA STAT5B exhibited lower potency than CA STAT5A in enhancing survival and anchorage-independent growth of mammary carcinoma cells and exerted no effects on cell motility. Differential expression of genes that regulate cellular survival and motility was concomitantly observed on forced expression of CA STAT5A or CA STAT5B. Small interfering RNA-mediated depletion of STAT5A significantly impaired anchorage-independent growth of human mammary carcinoma cells, whereas a smaller reduction was observed upon small interfering RNA-mediated depletion of STAT5B. Depletion of endogenous STAT5A also significantly enhanced cell motility, whereas depletion of endogenous STAT5B exhibited no effect. Xenograft studies provided data concordant with the in vitro effects of the two STAT5 isoforms. We therefore demonstrate that STAT5A and STAT5B differentially regulate behavior of human mammary carcinoma cells.
Collapse
Affiliation(s)
- Jian-Zhong Tang
- The Liggins Institute, University of Auckland, 2-6 Park Avenue, Private Bag 92019, Auckland 1023, New Zealand
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Koppikar P, Lui VWY, Man D, Xi S, Chai RL, Nelson E, Tobey ABJ, Grandis JR. Constitutive activation of signal transducer and activator of transcription 5 contributes to tumor growth, epithelial-mesenchymal transition, and resistance to epidermal growth factor receptor targeting. Clin Cancer Res 2009; 14:7682-90. [PMID: 19047094 DOI: 10.1158/1078-0432.ccr-08-1328] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE Signal transducer and activator of transcription 5 (STAT5) is activated in squamous cell carcinoma of the head and neck (SCCHN), where targeting of STAT5 inhibits tumor growth in vitro and in vivo. The role of STAT5 activation in carcinogenesis, tumor progression, and response to therapy remains incompletely understood. In this study, we investigated the effects of STAT5 activation on squamous epithelial carcinogenesis and response to therapy. EXPERIMENTAL DESIGN The functional consequences of STAT5 activation in squamous epithelial carcinogenesis were examined using cells derived from normal (Het-1A) and transformed mucosal epithelial cells engineered to express constitutive-active mutants of STAT5. RESULTS The growth rate of stable clones derived from both normal and transformed squamous epithelial cells expressing the constitutive-active STAT5 was increased. In SCCHN xenografts, tumor volumes were increased in constitutive-active STAT5 mutant cells compared with vector-transfected controls. Constitutive activation of STAT5 significantly increased cell migration and invasion through Matrigel, as well as the transforming efficiency of SCCHN cells in vitro, as assessed by soft agar assays. The constitutive-active STAT5 clones derived from SCCHN cells showed changes consistent with an epithelial-mesenchymal transition including decreased expression of E-cadherin and increased vimentin in comparison with control transfectants. In these cells, STAT5 activation was associated with resistance to cisplatin-mediated apoptosis and growth inhibition induced by the epidermal growth factor receptor tyrosine kinase inhibitor, erlotinib. CONCLUSIONS These results suggest that constitutive STAT5 signaling enhances tumor growth, invasion, and epithelial-to-mesenchymal transition in squamous epithelial carcinogenesis and may contribute to resistance to epidermal growth factor receptor tyrosine kinase inhibitor and chemotherapy.
Collapse
Affiliation(s)
- Priya Koppikar
- Department of Otolaryngology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Mees C, Nemunaitis J, Senzer N. Transcription factors: their potential as targets for an individualized therapeutic approach to cancer. Cancer Gene Ther 2008; 16:103-12. [PMID: 18846113 DOI: 10.1038/cgt.2008.73] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Pro-cancer signals are controlled by the expression and transcription of oncogenes. Transcription of DNA is dependent on the spatially and temporally coordinated interaction between transcriptional machinery (RNA polymerase II, transcription factors (TFs)) and transcriptional regulatory components (promoter elements, enhancers, silencers and locus control regions). Unique TFs have been identified in association with cancer. This review summarizes key oncogene-related TFs and organizes their pro-cancer activity according to the six hallmark functions (self sufficiency in growth signals, insensitivity to growth-inhibitory signals, evasion of programmed cell death, limitless replicative potential, sustained angiogenesis and metastatic spread) proposed as constituting the infrastructure of the malignant process.
Collapse
Affiliation(s)
- C Mees
- Mary Crowley Cancer Research Centers, Dallas, TX 75201, USA
| | | | | |
Collapse
|
33
|
Basham B, Sathe M, Grein J, McClanahan T, D'Andrea A, Lees E, Rascle A. In vivo identification of novel STAT5 target genes. Nucleic Acids Res 2008; 36:3802-18. [PMID: 18492722 PMCID: PMC2441806 DOI: 10.1093/nar/gkn271] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
STAT5A and STAT5B proteins belong to the family of signal transducers and activators of transcription. They are encoded by two separate genes with 91% identity in their amino acid sequences. Despite their high degree of conservation, STAT5A and STAT5B exert non-redundant functions, resulting at least in part from differences in target gene activation. To better characterize the differential contribution of STAT5A and STAT5B in gene regulation, we performed single or double knockdown of STAT5A and STAT5B using small interfering RNA. Subsequent gene expression profiling and RT-qPCR analyses of IL-3-stimulated Ba/F3-β cells led to the identification of putative novel STAT5 target genes. Chromatin immunoprecipitation assays analyzing the corresponding gene loci identified unusual STAT5 binding sites compared to conventional STAT5 responsive elements. Some of the STAT5 targets identified are upregulated in several human cancers, suggesting that they might represent potential oncogenes in STAT5-associated malignancies.
Collapse
Affiliation(s)
- Beth Basham
- Schering-Plough Biopharma, 901 California Avenue, Palo Alto, CA 94304, USA
| | | | | | | | | | | | | |
Collapse
|
34
|
Müller J, Schust J, Berg T. A high-throughput assay for signal transducer and activator of transcription 5b based on fluorescence polarization. Anal Biochem 2008; 375:249-54. [DOI: 10.1016/j.ab.2008.01.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Revised: 01/09/2008] [Accepted: 01/14/2008] [Indexed: 10/22/2022]
|
35
|
Transcription Factors STAT5 and STAT3. Prostate Cancer 2008. [DOI: 10.1007/978-1-60327-079-3_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
36
|
Ku TKS, Nguyen DC, Karaman M, Gill P, Hacia JG, Crowe DL. Loss of p53 expression correlates with metastatic phenotype and transcriptional profile in a new mouse model of head and neck cancer. Mol Cancer Res 2007; 5:351-62. [PMID: 17426250 DOI: 10.1158/1541-7786.mcr-06-0238] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Squamous cell carcinoma of the head and neck (HNSCC) is the sixth most frequent cancer worldwide. Because HNSCC is largely acquired by environmental carcinogen exposure rather than through germ line mutations, there are no known familial forms of the disease in humans nor are there inbred rodent strains prone to spontaneous head and neck tumors. Transgenic animals with inactivation of tumor suppressor genes commonly mutated in human cases of HNSCC provide attractive models for studying the pathogenesis of head and neck cancer. p53 is the most frequently inactivated tumor suppressor gene in HNSCC. We used a chemical induction protocol in mice heterozygous for the p53 gene to evaluate how p53 inactivation contributed to head and neck carcinogenesis the mouse model. Metastatic squamous cell carcinomas developed in 100% of animals. Histopathologically, the tumors ranged from well to poorly differentiated and showed many molecular features of human HNSCC. Mice carrying only one p53 allele developed tumors with significantly reduced latency compared with wild-type controls (average, 18 versus 22 weeks). Metastatic cancer cells showed complete loss of p53 expression when compared with primary tumors. Transcriptional profiling showed not only distinct genetic differences between primary and metastatic tumors, but also when cancers from heterozygous null and wild-type animals were compared. Our results provide novel insights into the molecular genetics of tumor progression in head and neck cancer.
Collapse
Affiliation(s)
- Tony K S Ku
- Center for Craniofacial Molecular Biology, Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | | | | | | | | | | |
Collapse
|
37
|
Shi M, Cooper JC, Yu CL. A constitutively active Lck kinase promotes cell proliferation and resistance to apoptosis through signal transducer and activator of transcription 5b activation. Mol Cancer Res 2006; 4:39-45. [PMID: 16446405 DOI: 10.1158/1541-7786.mcr-05-0202] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Lck is a Src family protein tyrosine kinase and is expressed predominantly in T cells. Aberrant expression or activation of Lck kinase has been reported in both lymphoid and nonlymphoid malignancies. However, the mechanisms underlying Lck-mediated oncogenesis remain largely unclear. In this report, we establish a tetracycline-inducible system to study the biochemical and biological effects of a constitutively active Lck mutant with a point mutation at the negative regulatory tyrosine. Expression of the active Lck kinase induces both tyrosine phosphorylation and DNA-binding activity of signal transducer and activator of transcription 5b (STAT5b), a STAT family member activated in a variety of tumor cells. The active Lck kinase interacts with STAT5b in cells, suggesting that Lck may directly phosphorylate STAT5b. Expression of the constitutively active Lck mutant in interleukin-3 (IL-3)-dependent BaF3 cells promotes cell proliferation. In addition, the active Lck kinase protects BaF3 cells from IL-3 withdrawal-induced apoptotic death and leads to IL-3-independent growth. These transforming properties of the oncogenic Lck kinase can be further augmented by expression of exogenous wild-type STAT5b but attenuated by a dominant-negative form of STAT5b. All together, our results suggest the potential involvement of STAT5b in Lck-mediated cellular transformation.
Collapse
Affiliation(s)
- Mingjian Shi
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232-0615, USA
| | | | | |
Collapse
|
38
|
Walker SR, Nelson EA, Frank DA. STAT5 represses BCL6 expression by binding to a regulatory region frequently mutated in lymphomas. Oncogene 2006; 26:224-33. [PMID: 16819511 DOI: 10.1038/sj.onc.1209775] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Deregulated expression of BCL6 is a pathogenic event in many lymphomas. BCL6 blocks cellular differentiation by repressing transcription of its target genes, and this may promote tumorigenesis. Conversely, the transcription factor signal transducers and activators of transcription (STAT)5 promotes differentiation in many systems. STAT5 upregulates a number of genes repressed by BCL6, raising the possibility that STAT5 and BCL6 have opposing roles in transcriptional regulation. Therefore, we sought to determine the effects of STAT5 activation on BCL6 expression and function. We found that activation of STAT5 downregulates BCL6 expression in B-lymphoma cells and other hematopoietic cell lines. We identified two potential STAT-binding regions in the first exon and first intron of BCL6 that fell within regions of high inter-species homology, suggesting conservation of regulatory function. STAT5 can bind inducibly and regulate transcription at one of these regions, identifying BCL6 as a STAT5 target gene. Additionally, STAT5-mediated downregulation of BCL6 results in loss of BCL6 repression of its target genes, confirming that STAT5 is a negative regulator of BCL6 function. The STAT5 responsive region of the BCL6 gene is mutated frequently in B-cell lymphomas, suggesting that loss of the repressive effects of STAT5 on BCL6 might contribute to the pathogenesis of these cancers.
Collapse
Affiliation(s)
- S R Walker
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA
| | | | | |
Collapse
|
39
|
Nakasato M, Shirakura Y, Ooga M, Iwatsuki M, Ito M, Kageyama SI, Sakai S, Nagata M, Aoki F. Involvement of the STAT5 signaling pathway in the regulation of mouse preimplantation development. Biol Reprod 2006; 75:508-17. [PMID: 16775227 DOI: 10.1095/biolreprod.105.047860] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The signal transducer and activator of transcription 5 (STAT5) is an essential factor in the signal transduction pathways for a number of cytokines that regulate the growth and differentiation of mammalian cells. In this study, we investigated the STAT5 signaling pathway in mouse embryos, to elucidate the mechanism of cytokine signal transduction that regulates preimplantation development. The results of the RT-PCR analysis showed that both STAT5A and B were expressed throughout preimplantation development. Immunocytochemistry revealed that the STAT5A/B proteins were located in the nucleus from the early 1-cell stage to the blastocyst stage. STAT5 activation appeared to be regulated by Janus kinases (JAKs) and SRC family kinases (SFKs), since inhibitors of these kinases inhibited the localization of STAT5 proteins to the nucleus. The JAK inhibitor Ag490 reduced both the developmental rate of the embryos and the expression levels of the downstream genes of the JAK-STAT5 signaling pathway. These findings suggest that STAT5 proteins function in preimplantation development by mediating the signals from cytokines.
Collapse
Affiliation(s)
- Makoto Nakasato
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Chiba 277-8562, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Baśkiewicz-Masiuk M, Walczak M, Grzegrzółka R, Rogowska D, Machaliński B. The influence of STAT5 antisense oligodeoxynucleotides on the proliferation and apoptosis of selected human cutaneous T-cell lymphoma cell lines. Arch Dermatol Res 2006; 297:450-8. [PMID: 16502315 DOI: 10.1007/s00403-006-0647-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Revised: 01/12/2006] [Accepted: 01/24/2006] [Indexed: 10/25/2022]
Abstract
STAT5 (signal transducers and activators of transcription) are suggested to play a role in the pathogenesis of leukaemia and lymphoma; however, their influence on the growth of cutaneous T-cell lymphoma cells is not clear enough. The aim of our study was to analyse the function of STAT5 proteins in the proliferation and apoptosis of selected cutaneous T-cell lymphoma cell lines (HUT 78; PB-1; HUT 102B), using antisense oligodeoxynucleotide (ODN) strategy. RT-PCR and Western blot were applied to analyse the expression of STAT5 after incubation with antisense ODN (AS ODN). The effect of ODN pretreatment on the cell clonogenecity was analysed in methylcellulose cultures. The process of apoptosis was estimated using two different flow cytometry (FACScan) methods: (1) combined Annexin V/propidium iodide staining, (2) the TUNEL method. Perturbation of STAT5 expression reduced the proliferation of the PB-1 cells after a 24-h exposure to antisense ODNs. Prolonged exposure (72 h) decreased the growth of each examined cell line, especially after antisense STAT5A (AS STAT5A) treatment. Incubation with AS STAT5 induced apoptosis in the population of HUT 78 and PB-1 cells. STAT5s may play a significant role in the growth and the process of apoptosis of selected human cutaneous T-cell lymphoma cells.
Collapse
Affiliation(s)
- Magdalena Baśkiewicz-Masiuk
- Department of General Pathology, Pomeranian Medical University, Al. Powstańców Wlkp. 72, 70-111, Szczecin, Poland.
| | | | | | | | | |
Collapse
|
41
|
Corvinus FM, Orth C, Moriggl R, Tsareva SA, Wagner S, Pfitzner EB, Baus D, Kaufmann R, Huberb LA, Zatloukal K, Beug H, Öhlschläger P, Schütz A, Halbhuber KJ, Friedrich K. Persistent STAT3 activation in colon cancer is associated with enhanced cell proliferation and tumor growth. Neoplasia 2005; 7:545-55. [PMID: 16036105 PMCID: PMC1501283 DOI: 10.1593/neo.04571] [Citation(s) in RCA: 322] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Revised: 01/20/2005] [Accepted: 01/21/2005] [Indexed: 02/07/2023] Open
Abstract
Colorectal carcinoma (CRC) is a major cause of morbidity and mortality in Western countries. It has so far been molecularly defined mainly by alterations of the Wnt pathway. We show here for the first time that aberrant activities of the signal transducer and activator of transcription STAT3 actively contribute to this malignancy and, thus, are a potential therapeutic target for CRC. Constitutive STAT3 activity was found to be abundant in dedifferentiated cancer cells and infiltrating lymphocytes of CRC samples, but not in non-neoplastic colon epithelium. Cell lines derived from malignant colorectal tumors lost persistent STAT3 activity in culture. However, implantation of colon carcinoma cells into nude mice resulted in restoration of STAT3 activity, suggesting a role of an extracellular stimulus within the tumor microenvironment as a trigger for STAT activation. STAT3 activity in CRC cells triggered through interleukin-6 or through a constitutively active STAT3 mutant promoted cancer cell multiplication, whereas STAT3 inhibition through a dominant-negative variant impaired IL-6-driven proliferation. Blockade of STAT3 activation in CRC-derived xenograft tumors slowed down their development, arguing for a contribution of STAT3 to colorectal tumor growth.
Collapse
Affiliation(s)
- Florian M Corvinus
- Institute of Biochemistry I, Friedrich-Schiller University Jena Medical School, Jena, Germany
| | - Carina Orth
- Institute of Biochemistry I, Friedrich-Schiller University Jena Medical School, Jena, Germany
| | | | - Svetlana A Tsareva
- Institute of Biochemistry I, Friedrich-Schiller University Jena Medical School, Jena, Germany
| | - Stefan Wagner
- Institute of Biochemistry I, Friedrich-Schiller University Jena Medical School, Jena, Germany
| | - Edith B Pfitzner
- Institute for Biomedical Research, Georg-Speyer-Haus, Frankfurt/Main, Germany
| | - Daniela Baus
- Institute for Biomedical Research, Georg-Speyer-Haus, Frankfurt/Main, Germany
| | - Roland Kaufmann
- Clinic for General and Visceral Surgery, Friedrich-Schiller University Medical School, Jena, Germany
| | - Lukas A Huberb
- Department of Histology and Molecular Cell Biology, University of Innsbruck, Innsbruck, Austria
| | - Kurt Zatloukal
- Institute of Pathology, University of Graz, Graz, Austria
| | - Hartmut Beug
- Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Peter Öhlschläger
- Department of Gynaecology, Friedrich-Schiller University Medical School, Jena, Germany
| | | | - Karl-Jürgen Halbhuber
- Institute of Anatomy II, Friedrich-Schiller University Medical School, Jena, Germany
| | - Karlheinz Friedrich
- Institute of Biochemistry I, Friedrich-Schiller University Jena Medical School, Jena, Germany
| |
Collapse
|
42
|
Abstract
Signal transducer and activator of transcription (STAT) proteins are latent cytoplasmic transcription factors that were discovered in the context of cytokine and growth factor signalling. Normal STAT signalling is tightly controlled with finite kinetics, which is in keeping with standard cellular responses. However, persistent STAT activation has also been observed and is frequently associated with malignant transformation. Constitutive activation of STAT proteins, notably of Stat3 and Stat5, is detected in many human tumour cells and cells transformed by oncoproteins that activate tyrosine kinase signalling pathways. It is well-established that constitutively active Stat3 is one of the molecular abnormalities that has a causal role in oncogenesis. Aberrant Stat3 promotes uncontrolled growth and survival through dysregulation of gene expression, including cyclin D1, c-Myc, Bcl-xL, Mcl-1 and survivin genes, and thereby contributes to oncogenesis. Moreover, recent studies reveal that persistently active Stat3 induces tumour angiogenesis by upregulation of vascular endothelial growth factor induction, and modulates immune functions in favour of tumour immune evasion. Overall, studies have validated Stat3 as a novel target for cancer therapy, and hence provided the rationale for developing small-molecule Stat3 inhibitors. This review will discuss current evidence for the critical role of aberrant STAT signalling in malignant transformation, and examine the validity as well as the therapeutic potential of Stat3 as a cancer target. An update on the efforts to develop novel Stat3 inhibitors for therapeutic application will also be provided.
Collapse
Affiliation(s)
- James Turkson
- Molecular Oncology Program, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, SRB 22214, Tampa, FL 33612, USA.
| |
Collapse
|
43
|
Lai SY, Childs EE, Xi S, Coppelli FM, Gooding WE, Wells A, Ferris RL, Grandis JR. Erythropoietin-mediated activation of JAK-STAT signaling contributes to cellular invasion in head and neck squamous cell carcinoma. Oncogene 2005; 24:4442-9. [PMID: 15856028 DOI: 10.1038/sj.onc.1208635] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Originally characterized as a growth factor for erythrocytes, erythropoietin (EPO) is used to treat anemia and fatigue in cancer patients receiving radiation therapy and chemotherapy. EPO and the EPO receptor (EPOR) are expressed in nonhematopoietic cells and cancers. However, the role of EPO and EPOR within nonhematopoietic cancer cells remains incompletely understood. Although a recent clinical trial demonstrated worse tumor control and survival in head and neck cancer patients treated with EPO, the role of EPO and EPOR in head and neck squamous cell carcinoma (HNSCC) has not been examined. In the present study, we demonstrate the previously unrecognized EPO-mediated invasion by HNSCC cells through the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway. Furthermore, we confirmed the expression of EPO and EPOR in a panel of human HNSCC cell lines and tissue specimens. Pharmacological doses of EPO also had a limited proliferation effect in these cell lines. These results define a novel role for EPO in mediating tumor cell invasion. Increased levels of EPO and EPOR in lymph node metastases as compared to primary tumors from HNSCC patients further support the role of EPO/EPOR in HNSCC disease progression and metastasis.
Collapse
Affiliation(s)
- Stephen Y Lai
- Department of Otolaryngology--Head and Neck Surgery, The Eye & Ear Institute, University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213, USA.
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Pomerantz RG, Grandis JR. The epidermal growth factor receptor signaling network in head and neck carcinogenesis and implications for targeted therapy. Semin Oncol 2005; 31:734-43. [PMID: 15599851 DOI: 10.1053/j.seminoncol.2004.09.015] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Improved understanding of the molecular signaling pathways that mediate cellular transformation has led to the development of novel strategies for the treatment of cancer. The epidermal growth factor receptor (EGFR), a transmembrane protein with intrinsic tyrosine kinase activity, transduces important signals from the surface of epithelial cells to the intracellular domain. Aberrant signaling through EGFR plays a key role in the carcinogenesis of squamous cell carcinomas of the head and neck (SCCHN). SCCHN tend to express high levels of EGFR, and the degree of expression correlates with poor clinical outcome. Since EGFR is present at much higher levels in cancerous lesions than in normal epithelial tissue, the receptor has been implicated as a highly specific therapeutic target for the treatment of SCCHN. EGFR can be abrogated at the extracellular level using either monoclonal antibodies or toxin conjugates that compete with the natural ligand at the binding site of the receptor, and targeting of the EGFR intracellular domain has been achieved by specific inhibitors of tyrosine kinase activity. Antisense strategies use synthesized DNA or RNA oligonucleotides to block the translation of the mRNA sequences that code for the production of the EGFR or other proteins with a role in EGFR-mediated cell signaling. Clinical evaluation of EGFR-specific monoclonal antibodies and tyrosine kinase inhibitors has demonstrated limited toxicity in SCCHN patients, and concurrent administration with standard cytotoxic therapies has produced additive or synergistic antitumor effects.
Collapse
Affiliation(s)
- Rebecca G Pomerantz
- Department of Otolaryngology, University of Pittsburgh School of Medicine and Cancer Institute, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | | |
Collapse
|
45
|
Siavash H, Nikitakis NG, Sauk JJ. Abrogation of IL-6-mediated JAK signalling by the cyclopentenone prostaglandin 15d-PGJ(2) in oral squamous carcinoma cells. Br J Cancer 2004; 91:1074-80. [PMID: 15316561 PMCID: PMC2747713 DOI: 10.1038/sj.bjc.6602055] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Cyclopentenone 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) exerts antineoplastic effects on various types of human cancer. We recently showed that treatment with 15d-PGJ(2) induces apoptosis accompanied by downregulation of the oncogenic signal transducer and activator of transcription 3 (Stat3) signalling in human oral squamous cell carcinoma (SCC) cells. The current study examines the effects of 15d-PGJ(2) on the epidermal growth factor receptor (EGFR) and Janus Kinase (JAK)-mediated signalling pathways. Inhibition of Stat3 by 15d-PGJ(2) was abolished by exogenous stimulation with transforming growth factor alpha (TGF-alpha), but not interleukin 6 (IL-6), supporting a selective effect of 15d-PGJ(2) on IL-6-mediated signalling. Importantly, 15d-PGJ(2) selectively abrogated constitutive and IL-6-mediated JAK phosphorylation without affecting EGFR-activated levels. Moreover, the inhibitory effect of 15d-PGJ(2) on JAK signalling required the reactive alpha,beta-unsaturated carbon within the cyclopentenone ring. Targeting of JAK signalling using a specific JAK inhibitor also abolished Stat3 phosphorylation and resulted in apoptosis in oral SCC cells. Our findings provide the first evidence for 15d-PGJ(2)-mediated downregulation of constitutive and IL-6-induced JAK signalling in cancer and support that JAK inhibition and suppression of EGFR-independent Stat3 activation by 15d-PGJ(2) represent a promising approach for induction of apoptosis in oral SCC cells.
Collapse
Affiliation(s)
- H Siavash
- Department of Biomedical Sciences, University of Maryland, Baltimore, MD 21201, USA.
| | | | | |
Collapse
|
46
|
Baśkiewicz-Masiuk M, Machaliński B. The role of the STAT5 proteins in the proliferation and apoptosis of the CML and AML cells. Eur J Haematol 2004; 72:420-9. [PMID: 15128421 DOI: 10.1111/j.1600-0609.2004.00242.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The STAT5 proteins are activated by many haematological cytokines and growth factors. They regulate cell cycle, apoptosis and proliferation of different cells via the influence on gene transcription. Because STAT5s are constitutively activated in certain haematooncologic diseases, they are suggested to play an important role in leukaemogenesis. However, the real function of these proteins in haematopoietic cell transformation and proliferation is not clear enough. The aim of this study was to evaluate the influence of suppression of STAT5A and STAT5B expression on the clonogenicity and apoptosis of the chronic myeloid leukaemia (CML) and acute myeloid leukaemia (AML) cells. MATERIAL AND METHODS Blast cells from 34 newly diagnosed patients with CML and AML were used in our experiments. Antisense oligodeoxynucleotides (ODNs) were applied to block STAT5A and STAT5B at the mRNA level and the RT-PCR method was used to study STAT5 mRNA expression in the cells after incubation with ODNs. Moreover, Western blot analysis of the STAT5 proteins was performed. The effect of ODN pretreatment on cell clonogenicity in methylocellulose cultures was examined according to the type of oligodeoxynucleotide and the time of exposure. The induction of apoptosis in cells was also estimated by the Annexin V/PI staining and the TUNEL method using flow cytometry. RESULTS Perturbation of STAT5 expression decreased proliferative potential of the CML and the AML blasts as well as enhanced their apoptosis (P < 0.05). CONCLUSIONS Our studies showed that the STAT5 proteins may be critical in the regulation of growth and apoptosis of the CML and AML leukaemic cells.
Collapse
|
47
|
Baśkiewicz-Masiuk M, Masiuk M, Machaliński B. The influence of STAT5 antisense oligonucleotides on the proliferation and apoptosis of selected human leukaemic cell lines. Cell Prolif 2003; 36:265-78. [PMID: 14521520 PMCID: PMC6495883 DOI: 10.1046/j.1365-2184.2003.00283.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The signal transducers and activators of transcription--STAT5A and STAT5B--take part in the regulation of many essential physiopathological processes. They influence the cell cycle, apoptosis and the proliferation of different types of cell lines. The STAT5 proteins are induced in response to multiple haematopoietic cytokines. Because they are constitutively active in certain haemato-oncologic diseases, it is also suggested that they play an important role in leukaemogenesis. However, function of these proteins in haematopoietic cell transformation and proliferation is not clear. The aim of this study was to evaluate the impact of perturbation of STAT5 expression [using oligodeoxynucleotide (ODN) against STAT5 mRNA], on the clonogenicity and survival of selected human leukaemic cell lines, HEL, HL-60, K562, TF-1. We analysed the effect of ODN pre-treatment on the cell clonogenicity in methylcellulose cultures according to the time and the temperature of exposure. Moreover, we attempted to estimate apoptosis induced in examined cells, by flow cytometry using combined Annexin V-PI staining and the TUNEL method. We also applied the RT-PCR method to analyse Bax and Bcl-xL gene expression. We found that the perturbation of STAT5 expression with antisense oligonucleotides caused a decrease in the proliferative potential of human K562 and TF-1 cell lines. Also, we observed higher induction of apoptotic cell death in the K562 and TF-1 cells incubated with the antisense STAT5A ODNs. We did not notice any impact of ODNs on the HL-60 and HEL cells. Our studies using STAT5 antisense oligonucleotides showed that these proteins may be critical in the regulation of growth and apoptosis of some types of leukaemic blasts.
Collapse
Affiliation(s)
- M Baśkiewicz-Masiuk
- Department of General Pathology, Pomeranian Medical University, Szczecin, Poland.
| | | | | |
Collapse
|
48
|
Xi S, Zhang Q, Dyer KF, Lerner EC, Smithgall TE, Gooding WE, Kamens J, Grandis JR. Src kinases mediate STAT growth pathways in squamous cell carcinoma of the head and neck. J Biol Chem 2003; 278:31574-83. [PMID: 12771142 DOI: 10.1074/jbc.m303499200] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Signal transducer and activator of transcription (STAT) proteins are constitutively activated in many malignancies, including squamous cell carcinoma of the head and neck (SCCHN). Previously, we reported that phosphorylation of the epidermal growth factor receptor (EGFR) is linked to activation of STATs 3 and 5 in SCCHN cells. The present study was undertaken to determine the role of Src family kinases in STAT activation and SCCHN growth. The Src family kinases c-Src, c-Yes, Fyn, and Lyn were expressed and activated by transforming growth factor-alpha stimulation in all four SCCHN cell lines examined but not in corresponding normal epithelial cells. In nine SCCHN cell lines tested, Src phosphotyrosine expression levels were highly correlated with activation levels of STATs 3 and 5. Co-immunoprecipitation analysis demonstrated interaction between c-Src and STATs 3 or 5 and EGFR in SCCHN cells, but no heterodimerization was detected between STAT3 and STAT5. SCCHN cells treated with either of two Src-specific inhibitors or transfected with a dominant-negative c-Src construct demonstrated decreased activation of STATs 3 and 5 and reduced growth rates in vitro. These results demonstrate a role for Src kinases in mediating activation of STATs 3 and 5 in concert with the EGFR in SCCHN cells. Strategies to target Src activation may contribute to the treatment of cancers that demonstrate increased levels of EGFR and STATs, including SCCHN.
Collapse
Affiliation(s)
- Sichuan Xi
- Department of Otolaryngology, University of Pittsburgh School of MedicinePennsylvania 15213, USA
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Hsiao JR, Jin YT, Tsai ST, Shiau AL, Wu CL, Su WC. Constitutive activation of STAT3 and STAT5 is present in the majority of nasopharyngeal carcinoma and correlates with better prognosis. Br J Cancer 2003; 89:344-9. [PMID: 12865928 PMCID: PMC2394270 DOI: 10.1038/sj.bjc.6601003] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Constitutively activated signal transducers and activators of transcription (STAT) factors, in particular STAT1, STAT3 and STAT5, have been demonstrated in a variety of human tumours and cancer cell lines. However, data on the expression of these STATs in nasopharyngeal carcinoma (NPC) are limited. In this study, the expression patterns of STAT1, STAT3 and STAT5 were immunohistochemically examined on the archival specimens from 61 patients with NPC. Staining results of each STATs were then correlated with the clinical parameters and prognosis of these patients. The results showed that constitutive activation of STAT3 and STAT5 was detected in the majority, 70.5 and 62.3%, respectively, of the 61 tumour specimens. Furthermore, coexpression of activated STAT3 and STAT5 was found in 54.1% of the specimens. In contrast, constitutive activated STAT1 could only be detected in 8 (13.1%) cases. Surprisingly, following radiotherapy, patients with constitutive STAT5 activation, or activation of both STAT3 and STAT5, had better disease-free survival and overall survival than those without activated STAT5. To our knowledge, this is the first report providing the overall expression patterns and prognostic significance of specific STATs in NPC.
Collapse
Affiliation(s)
- J-R Hsiao
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, 1 Doshiue Road, Tainan 701, Taiwan
| | | | | | | | | | | |
Collapse
|
50
|
McLaughlin PJ, Stack BC, Levin RJ, Fedok F, Zagon IS. Defects in the opioid growth factor receptor in human squamous cell carcinoma of the head and neck. Cancer 2003; 97:1701-10. [PMID: 12655527 DOI: 10.1002/cncr.11237] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND The endogenous opioid peptide, [Met(5)]-enkephalin, termed opioid growth factor (OGF), interacts with its receptor (OGFr) to play a role as a constitutively expressed inhibitory growth factor in the proliferation of epithelial cells. This study compared protein and gene expression of OGFr in surgical specimens of human squamous cell carcinoma of the head and neck (SCCHN) with normal epithelium. METHODS Tissues from 64 patients with SCCHN and from 49 patients undergoing uvulapalatoplasty or tonsillectomy were utilized. Binding affinity and capacity were assessed by receptor binding assays and the levels of OGFr protein were determined by quantitative Western blot analysis. Immunohistochemistry assessed the presence and distribution of OGFr. Levels of OGFr mRNA were quantitated by Northern blot analysis. Protein and gene expressions of OGFr also were evaluated in the margins of SCCHN. RESULTS Binding analyses indicated nearly ninefold fewer OGFr binding sites in tumor tissue in comparison with normal samples. The OGFr protein levels were reduced fivefold in tumor tissues relative to normal epithelium. Values of OGFr mRNA were comparable in tumors and normal epithelium. Tumor margins had intermediate levels of protein and binding, but OGFr mRNA values were similar to those of normal specimens. CONCLUSIONS These data demonstrate that OGFr is defective in SCCHN and that translation/posttranslation of OGFr protein, but not transcriptional levels of the OGFr gene, is involved. In addition, the attenuated levels of OGFr binding capacity may serve as a marker for SCCHN. These subnormal levels of OGFr may be responsible in part for tumor progression, diminishing the interaction of OGF with OGFr that aids in stabilizing cell replication by an inhibitory mechanism. Gene therapy to reinstate OGFr and/or function could provide a useful treatment for inhibiting tumor progression.
Collapse
Affiliation(s)
- Patricia J McLaughlin
- Department of Neuroscience and Anatomy, Division of Otolaryngology, The Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, Pennsylvania 17033, USA.
| | | | | | | | | |
Collapse
|