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Kim AL, Back JH, Chaudhary SC, Zhu Y, Athar M, Bickers DR. SOX9 Transcriptionally Regulates mTOR-Induced Proliferation of Basal Cell Carcinomas. J Invest Dermatol 2018; 138:1716-1725. [PMID: 29550418 DOI: 10.1016/j.jid.2018.01.040] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/17/2018] [Accepted: 01/28/2018] [Indexed: 01/20/2023]
Abstract
Currently available smoothened targeted therapies in patients with basal cell nevus syndrome are associated with substantial tumor recurrence and clinical resistance. Strategies bypassing smoothened and/or identifying additional downstream components of the Hedgehog pathway could provide novel antitumor targets with a better therapeutic index. Sry-related high mobility group box 9 (SOX9) is a Hedgehog/glioma-associated oncogene homolog-regulated transcription factor known to be overexpressed in basal cell carcinomas (BCCs). A sequence motif search for SOX9-responsive elements identified three motifs in the promoter region of mammalian target of rapamycin (mTOR). In murine BCC cells, SOX9 occupies the mTOR promoter and induces its transcriptional activity. Short hairpin RNA (shRNA)-mediated knockdown of SOX9, as well as smoothened inhibition by itraconazole and vismodegib, reduces mTOR expression and the phosphorylation of known downstream mTOR targets. These effects culminate in diminishing the proliferative capacity of BCC cells, demonstrating a direct mechanistic link between the Hedgehog and mTOR pathways capable of driving BCC growth. Furthermore, rapamycin, a pharmacologic mTOR inhibitor, suppressed the growth of UV-induced BCCs in Ptch1+/-/SKH-1 mice, a model that closely mimics the accelerated BCC growth pattern of patients with basal cell nevus syndrome. Our data demonstrate that Hedgehog signaling converges on mTOR via SOX9, and highlight the SOX9-mTOR axis as a viable additional target downstream of smoothened that could enhance tumor elimination in patients with BCC.
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Affiliation(s)
- Arianna L Kim
- Department of Dermatology, Columbia University Medical Center, New York, New York, USA.
| | - Jung Ho Back
- Department of Dermatology, Columbia University Medical Center, New York, New York, USA
| | - Sandeep C Chaudhary
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yucui Zhu
- Department of Dermatology, Columbia University Medical Center, New York, New York, USA
| | - Mohammad Athar
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - David R Bickers
- Department of Dermatology, Columbia University Medical Center, New York, New York, USA
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2
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Liao Y, Feng J, Zhang Y, Tang L, Wu S. The mechanism of CIRP in inhibition of keratinocytes growth arrest and apoptosis following low dose UVB radiation. Mol Carcinog 2017; 56:1554-1569. [PMID: 27864909 DOI: 10.1002/mc.22597] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 10/31/2016] [Accepted: 11/17/2016] [Indexed: 01/08/2023]
Abstract
UV induces CIRP expression and subsequent Stat3 activation, but the biological function and mechanism of CIRP and Stat3 in mediating UVB-induced skin carcinogenesis have not been fully elucidated. In this study, we demonstrate that CIRP is elevated in all tested melanoma and non-melanoma skin cancer cell lines; and the expression of CIRP is upregulated in keratinocytes after being irradiated with relatively low dose (<5 mJ/cm2 ), but not high dose (50 mJ/cm2 ), UVB acutely and chronically. The increased expression of CIRP, either induced by UVB or through overexpression, leads to resistance of keratinocytes to UVB-induced growth arrest and death; and reduced expression of CIRP by RNA knockdown sensitizes keratinocyte cells to the low dose UVB radiation. We also demonstrated that CIRP expression is required for the low dose UVB-induced Tyr705-phosphorylation, but not total amount, of Stat3. The p-Stat3 level is correlated with the expression levels of cyclin D1 and VEGF, two known downstream cell growth regulators of Stat3, as well as Bag-1/S, an apoptosis regulator. Inhibition of Stat3 DNA-binding activity by S3I-201 leads to a reduction of the p-Stat3 and Bag-1/S along with growth and survival of keratinocytes post-UVB; and the effect of S3I-201 on the UVB-irradiated cells can be partially inhibited by overexpression of CIRP or Bag-1/S. Furthermore, the overexpression of Bag-1/S can totally inhibit UVB-induced PARP cleavage and caspase 3 activation. The results presented above led us to propose that CIRP-p(705)Stat3 cascade promotes cell proliferation and survival post-UVB via upregulating the expression of cyclin D1 and Bag-1/S, respectively. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Yi Liao
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China.,Department of Chemistry and Biochemistry, 101 Konneker Laboratories, Edison Biotechnology Institute, Athens, Ohio.,Department of Cardiothoracic Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Jianguo Feng
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China.,Department of Anesthesiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Yi Zhang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China
| | - Liling Tang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China
| | - Shiyong Wu
- Department of Chemistry and Biochemistry, 101 Konneker Laboratories, Edison Biotechnology Institute, Athens, Ohio
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3
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Kim AL, Back JH, Zhu Y, Tang X, Yardley NP, Kim KJ, Athar M, Bickers DR. AKT1 Activation is Obligatory for Spontaneous BCC Tumor Growth in a Murine Model that Mimics Some Features of Basal Cell Nevus Syndrome. Cancer Prev Res (Phila) 2016; 9:794-802. [PMID: 27388747 DOI: 10.1158/1940-6207.capr-16-0066] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/28/2016] [Indexed: 01/14/2023]
Abstract
Patients with basal cell nevus syndrome (BCNS), also known as Gorlin syndrome, develop numerous basal cell carcinomas (BCC) due to germline mutations in the tumor suppressor PTCH1 and aberrant activation of Hedgehog (Hh) signaling. Therapies targeted at components of the Hh pathway, including the smoothened (SMO) inhibitor vismodegib, can ablate these tumors clinically, but tumors recur upon drug discontinuation. Using SKH1-Ptch1+/- as a model that closely mimics the spontaneous and accelerated growth pattern of BCCs in patients with BCNS, we show that AKT1, a serine/threonine protein kinase, is intrinsically activated in keratinocytes derived from the skin of newborn Ptch1+/- mice in the absence of carcinogenic stimuli. Introducing Akt1 haplodeficiency in Ptch1+/- mice (Akt1+/- Ptch1+/-) significantly abrogated BCC growth. Similarly, pharmacological inhibition of AKT with perifosine, an alkyl phospholipid AKT inhibitor, diminished the growth of spontaneous and UV-induced BCCs. Our data demonstrate an obligatory role for AKT1 in BCC growth, and targeting AKT may help reduce BCC tumor burden in BCNS patients. Cancer Prev Res; 9(10); 794-802. ©2016 AACR.
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Affiliation(s)
- Arianna L Kim
- Department of Dermatology, Columbia University Medical Center, New York, New York.
| | - Jung Ho Back
- Department of Dermatology, Columbia University Medical Center, New York, New York
| | - Yucui Zhu
- Department of Dermatology, Columbia University Medical Center, New York, New York
| | - Xiuwei Tang
- Department of Dermatology, Columbia University Medical Center, New York, New York
| | - Nathan P Yardley
- Department of Dermatology, Columbia University Medical Center, New York, New York
| | - Katherine J Kim
- Department of Dermatology, Columbia University Medical Center, New York, New York
| | - Mohammad Athar
- University of Alabama at Birmingham, Birmingham, Alabama.
| | - David R Bickers
- Department of Dermatology, Columbia University Medical Center, New York, New York.
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4
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Lee H, Morales LD, Slaga TJ, Kim DJ. Activation of T-cell protein-tyrosine phosphatase suppresses keratinocyte survival and proliferation following UVB irradiation. J Biol Chem 2014; 290:13-24. [PMID: 25406309 DOI: 10.1074/jbc.m114.611681] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chronic exposure to UV radiation can contribute to the development of skin cancer by promoting protein-tyrosine kinase (PTK) signaling. Studies show that exposure to UV radiation increases the ligand-independent activation of PTKs and induces protein-tyrosine phosphatase (PTP) inactivation. In the present work, we report that T-cell PTP (TC-PTP) activity is stimulated during the initial response to UVB irradiation, which leads to suppression of keratinocyte cell survival and proliferation via the down-regulation of STAT3 signaling. Our results show that TC-PTP-deficient keratinocyte cell lines expressed a significantly increased level of phosphorylated STAT3 after exposure to low dose UVB. This increase corresponded with increased cell proliferation in TC-PTP-deficient keratinocytes following UVB irradiation. Loss of TC-PTP also reduced UVB-induced apoptosis. Corroborating with these results, overexpression of TC-PTP in keratinocyte cell lines yielded a decrease in phosphorylated STAT3 levels, which corresponded with a significant decrease in cell proliferation in response to low dose UVB. We demonstrate that TC-PTP activity was increased upon UVB exposure, and overexpression of TC-PTP in keratinocyte cell lines further increased its activity in the presence of UVB. Treatment of TC-PTP-deficient keratinocytes with the STAT3 inhibitor STA21 significantly reduced cell viability following UVB exposure in comparison with untreated TC-PTP-deficient keratinocytes, confirming that the effect of TC-PTP on cell viability is mediated by STAT3 dephosphorylation. Combined, our results indicate that UVB-mediated activation of TC-PTP plays an important role in the STAT3-dependent regulation of keratinocyte cell proliferation and survival. Furthermore, these results suggest that TC-PTP may be a novel potential target for the prevention of UVB-induced skin cancer.
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Affiliation(s)
- Hyunseung Lee
- From the Edinburg Regional Academic Health Center, Medical Research Division, University of Texas Health Science Center at San Antonio, Edinburg, Texas 78541 and the Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Liza D Morales
- From the Edinburg Regional Academic Health Center, Medical Research Division, University of Texas Health Science Center at San Antonio, Edinburg, Texas 78541 and
| | - Thomas J Slaga
- the Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Dae Joon Kim
- From the Edinburg Regional Academic Health Center, Medical Research Division, University of Texas Health Science Center at San Antonio, Edinburg, Texas 78541 and the Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
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5
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Liu L, Rezvani HR, Back JH, Hosseini M, Tang X, Zhu Y, Mahfouf W, Raad H, Raji G, Athar M, Kim AL, Bickers DR. Inhibition of p38 MAPK signaling augments skin tumorigenesis via NOX2 driven ROS generation. PLoS One 2014; 9:e97245. [PMID: 24824222 PMCID: PMC4019556 DOI: 10.1371/journal.pone.0097245] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 04/16/2014] [Indexed: 11/19/2022] Open
Abstract
p38 mitogen-activated protein kinases (MAPKs) respond to a wide range of extracellular stimuli. While the inhibition of p38 signaling is implicated in the impaired capacity to repair ultraviolet (UV)-induced DNA damage—a primary risk factor for human skin cancers—its mechanism of action in skin carcinogenesis remains unclear, as both anti-proliferative and survival functions have been previously described. In this study, we utilized cultured keratinocytes, murine tumorigenesis models, and human cutaneous squamous cell carcinoma (SCC) specimens to assess the effect of p38 in this regard. UV irradiation of normal human keratinocytes increased the expression of all four p38 isoforms (α/β/γ/δ); whereas irradiation of p53-deficient A431 keratinocytes derived from a human SCC selectively decreased p38α, without affecting other isoforms. p38α levels are decreased in the majority of human cutaneous SCCs assessed by tissue microarray, suggesting a tumor-suppressive effect of p38α in SCC pathogenesis. Genetic and pharmacological inhibition of p38α and in A431 cells increased cell proliferation, which was in turn associated with increases in NAPDH oxidase (NOX2) activity as well as intracellular reactive oxygen species (ROS). These changes led to enhanced invasiveness of A431 cells as assessed by the matrigel invasion assay. Chronic treatment of p53-/-/SKH-1 mice with the p38 inhibitor SB203580 accelerated UV-induced SCC carcinogenesis and increased the expression of NOX2. NOX2 knockdown suppressed the augmented growth of A431 xenografts treated with SB203580. These findings indicate that in the absence of p53, p38α deficiency drives SCC growth and progression that is associated with enhanced NOX2 expression and ROS formation.
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Affiliation(s)
- Liang Liu
- Department of Dermatology, Columbia University Medical Center, New York, New York, United States of America
| | - Hamid Reza Rezvani
- Biothérapies des maladies génétiques et cancers, Univ. de Bordeaux, Bordeaux, France
- INSERM, Biothérapies des maladies génétiques et cancers, Bordeaux, France
| | - Jung Ho Back
- Department of Dermatology, Columbia University Medical Center, New York, New York, United States of America
| | - Mohsen Hosseini
- Biothérapies des maladies génétiques et cancers, Univ. de Bordeaux, Bordeaux, France
- INSERM, Biothérapies des maladies génétiques et cancers, Bordeaux, France
| | - Xiuwei Tang
- Department of Dermatology, Columbia University Medical Center, New York, New York, United States of America
| | - Yucui Zhu
- Department of Dermatology, Columbia University Medical Center, New York, New York, United States of America
| | - Walid Mahfouf
- Biothérapies des maladies génétiques et cancers, Univ. de Bordeaux, Bordeaux, France
- INSERM, Biothérapies des maladies génétiques et cancers, Bordeaux, France
| | - Houssam Raad
- Biothérapies des maladies génétiques et cancers, Univ. de Bordeaux, Bordeaux, France
- INSERM, Biothérapies des maladies génétiques et cancers, Bordeaux, France
| | - Grace Raji
- Department of Dermatology, Columbia University Medical Center, New York, New York, United States of America
| | - Mohammad Athar
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Arianna L. Kim
- Department of Dermatology, Columbia University Medical Center, New York, New York, United States of America
- * E-mail: (AK); (DB)
| | - David R. Bickers
- Department of Dermatology, Columbia University Medical Center, New York, New York, United States of America
- * E-mail: (AK); (DB)
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Chaudhary SC, Singh T, Kapur P, Weng Z, Arumugam A, Elmets CA, Kopelovich L, Athar M. Nitric oxide-releasing sulindac is a novel skin cancer chemopreventive agent for UVB-induced photocarcinogenesis. Toxicol Appl Pharmacol 2013; 268:249-55. [PMID: 23274568 PMCID: PMC3780591 DOI: 10.1016/j.taap.2012.12.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Revised: 12/12/2012] [Accepted: 12/14/2012] [Indexed: 11/18/2022]
Abstract
Nitric oxide (NO)-releasing non-steroidal anti-inflammatory drugs (NO-NSAIDs) which have been synthesized to reduce gastro-intestinal and cardiovascular toxicities of NSAIDs, possess anti-proliferative, pro-apoptotic and anti-cancer activities. Here, we show that NO-sulindac inhibited UVB-induced skin tumorigenesis in SKH-1 hairless mice. Topical application of NO-sulindac reduced tumor incidence, number (p<0.05) and volume (p<0.005) as compared to UVB (alone)-irradiated vehicle-treated mice. An increase in TUNEL-positive cells in skin lesions was accompanied by the enhanced Bax:Bcl-2 ratio. The expression of pro-apoptotic Bax was increased whereas anti-apoptotic Bcl-2 reduced. However, proliferation was identified as the major target of NO-sulindac in this study. A reduced expression of PCNA and cyclin D1 associated with the dampening of cell cycle progression was observed. The mechanism of this inhibition was related to the reduction in UVB-induced Notch signaling pathway. UVB-induced inflammatory responses were diminished by NO-sulindac as observed by a remarkable reduction in the levels of phosphorylated MAP Kinases Erk1/2, p38 and JNK1/2. In this regard, NO-sulindac also inhibited NFκB by enhancing IκBα as evidenced by the reduced expression of iNOS and COX-2, the direct NFκB transcription target proteins. NO-sulindac significantly diminished the progression of benign lesions to invasive carcinomas by suppressing the tumor aggressiveness and retarding epithelial-mesenchymal transition. A marked decrease in the expression of mesenchymal markers such as Fibronectin, N-cadherin, SNAI, Slug and Twist and an increase in epithelial cell polarity marker E-cadherin were noted in NO-sulindac-treated tumors. Our data suggest that NO-sulindac is a potent inhibitor of UVB-induced skin carcinogenesis and acts by targeting proliferation-regulatory pathways.
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Affiliation(s)
- Sandeep C. Chaudhary
- Department of Dermatology, University of Alabama at Birmingham, 1530 3 Avenue South, VH509, Birmingham, AL 35294-0019
| | - Tripti Singh
- Department of Dermatology, University of Alabama at Birmingham, 1530 3 Avenue South, VH509, Birmingham, AL 35294-0019
| | - Puneet Kapur
- Department of Dermatology, University of Alabama at Birmingham, 1530 3 Avenue South, VH509, Birmingham, AL 35294-0019
| | - Zhiping Weng
- Department of Dermatology, University of Alabama at Birmingham, 1530 3 Avenue South, VH509, Birmingham, AL 35294-0019
| | - Aadithya Arumugam
- Department of Dermatology, University of Alabama at Birmingham, 1530 3 Avenue South, VH509, Birmingham, AL 35294-0019
| | - Craig A. Elmets
- Department of Dermatology, University of Alabama at Birmingham, 1530 3 Avenue South, VH509, Birmingham, AL 35294-0019
| | - Levy Kopelovich
- Division of Cancer Prevention, National Cancer Institute, 6130 Executive Blvd, Suite 2114, Bethesda, MD 20892
| | - Mohammad Athar
- Department of Dermatology, University of Alabama at Birmingham, 1530 3 Avenue South, VH509, Birmingham, AL 35294-0019
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7
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Soluble E-cadherin: a critical oncogene modulating receptor tyrosine kinases, MAPK and PI3K/Akt/mTOR signaling. Oncogene 2013; 33:225-35. [PMID: 23318419 DOI: 10.1038/onc.2012.563] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 10/15/2012] [Accepted: 10/16/2012] [Indexed: 11/08/2022]
Abstract
E-cadherin, a cell-cell adhesion glycoprotein, is frequently downregulated with tumorigenic progression. The extracellular domain of E-cadherin is cleaved by proteases to generate a soluble ectodomain fragment, termed sEcad, which is elevated in the urine or serum of cancer patients. In this study, we explored the functional role of sEcad in the progression of skin squamous cell carcinomas (SCCs). We found that full-length E-cadherin expression was decreased and sEcad increased in human clinical tumor samples as well as in ultraviolet (UV)-induced SCCs in mice. Interestingly, sEcad associated with members of the human epidermal growth factor receptor (HER) and insulin-like growth factor-1 (IGF-1R) family of receptors in human and UV-induced mouse tumors. Moreover, in both E-cadherin-positive (E-cadherin(+)) and -negative (E-cadherin(-)) cells in vitro, sEcad activated downstream mitogen-activated protein (MAP) kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling and enhanced tumor growth, motility and invasion, the latter via activation of matrix metalloproteinase-2 (MMP-2) and MMP-9. To this end, HER, PI3K or MEK inhibitors suppressed sEcad's tumorigenic effects, including proliferation, migration and invasion. Taken together, our data suggest that sEcad contributes to skin carcinogenesis via association with the HER/IGF-1R-family of receptors and subsequent activation of the MAPK and PI3K/Akt/mTOR pathways, thereby implicating sEcad as a putative therapeutic target in cutaneous SCCs.
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8
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Kim H, Casta A, Tang X, Luke CT, Kim AL, Bickers DR, Athar M, Christiano AM. Loss of hairless confers susceptibility to UVB-induced tumorigenesis via disruption of NF-kappaB signaling. PLoS One 2012; 7:e39691. [PMID: 22761871 PMCID: PMC3382590 DOI: 10.1371/journal.pone.0039691] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 05/29/2012] [Indexed: 12/27/2022] Open
Abstract
In order to model squamous cell carcinoma development in vivo, researchers have long preferred hairless mouse models such as SKH-1 mice that have traditionally been classified as ‘wild-type’ mice irrespective of the genetic factors underlying their hairless phenotype. The work presented here shows that mutations in the Hairless (Hr) gene not only result in the hairless phenotype of the SKH-1 and Hr−/− mouse lines but also cause aberrant activation of NFκB and its downstream effectors. We show that in the epidermis, Hr is an early UVB response gene that regulates NFκB activation and thereby controls cellular responses to irradiation. Therefore, when Hr expression is decreased in Hr mutant animals there is a corresponding increase in NFκB activity that is augmented by UVB irradiation. This constitutive activation of NFκB in the Hr mutant epidermis leads to the stimulation a large variety of downstream effectors including the cell cycle regulators cyclin D1 and cyclin E, the anti-apoptosis protein Bcl-2, and the pro-inflammatory protein Cox-2. Therefore, Hr loss results in a state of uncontrolled epidermal proliferation that promotes tumor development, and Hr mutant mice should no longer be considered merely hairless 'wild-type' mice. Instead, Hr is a crucial UVB response gene and its loss creates a permissive environment that potentiates increased tumorigenesis.
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Affiliation(s)
- Hyunmi Kim
- Department of Genetics & Development, Columbia University, College of Physicians & Surgeons, New York, New York, United States of America
- Department of Dermatology, Columbia University, College of Physicians & Surgeons, New York, New York, United States of America
| | - Alexandre Casta
- Institute of Human Nutrition, Columbia University, College of Physicians & Surgeons, New York, New York, United States of America
| | - Xiuwei Tang
- Department of Dermatology, Columbia University, College of Physicians & Surgeons, New York, New York, United States of America
| | - Courtney T. Luke
- Department of Dermatology, Columbia University, College of Physicians & Surgeons, New York, New York, United States of America
| | - Arianna L. Kim
- Department of Dermatology, Columbia University, College of Physicians & Surgeons, New York, New York, United States of America
| | - David R. Bickers
- Department of Dermatology, Columbia University, College of Physicians & Surgeons, New York, New York, United States of America
| | - Mohammad Athar
- Department of Dermatology, Columbia University, College of Physicians & Surgeons, New York, New York, United States of America
| | - Angela M. Christiano
- Department of Genetics & Development, Columbia University, College of Physicians & Surgeons, New York, New York, United States of America
- Department of Dermatology, Columbia University, College of Physicians & Surgeons, New York, New York, United States of America
- * E-mail:
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9
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Perez C, Parker-Thornburg J, Mikulec C, Kusewitt DF, Fischer SM, Digiovanni J, Conti CJ, Benavides F. SKHIN/Sprd, a new genetically defined inbred hairless mouse strain for UV-induced skin carcinogenesis studies. Exp Dermatol 2012; 21:217-20. [PMID: 22379968 DOI: 10.1111/j.1600-0625.2011.01430.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Strains of mice vary in their susceptibility to ultra-violet (UV) radiation-induced skin tumors. Some strains of hairless mice (homozygous for the spontaneous Hr(hr) mutation) are particularly susceptible to these tumors. The skin tumors that develop in hairless mice resemble, both at the morphologic and molecular levels, UV-induced squamous cell carcinomas (SCC) and their precursors in human. The most commonly employed hairless mice belong to the SKH1 stock. However, these mice are outbred and their genetic background is not characterized, which makes them a poor model for genetic studies. We have developed a new inbred strain from outbred SKH1 mice that we named SKHIN/Sprd (now at generation F31). In order to characterize the genetic background of this new strain, we genotyped a cohort of mice at F30 with 92 microsatellites and 140 single nucleotide polymorphisms (SNP) evenly distributed throughout the mouse genome. We also exposed SKHIN/Sprd mice to chronic UV irradiation and showed that they are as susceptible to UV-induced skin carcinogenesis as outbred SKH1 mice. In addition, we proved that, albeit with low efficiency, inbred SKHIN/Sprd mice are suitable for transgenic production by classical pronuclear microinjection. This new inbred strain will be useful for the development of transgenic and congenic strains on a hairless inbred background as well as the establishment of syngeneic tumor cell lines. These new tools can potentially help elucidate a number of features of the cutaneous response to UV irradiation in humans, including the effect of genetic background and modifier genes.
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Affiliation(s)
- Carlos Perez
- Department of Molecular Carcinogenesis, The University of Texas M. D. Anderson Cancer Center, Smithville, TX 78957, USA
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Back JH, Zhu Y, Calabro A, Queenan C, Kim AS, Arbesman J, Kim AL. Resveratrol-mediated downregulation of Rictor attenuates autophagic process and suppresses UV-induced skin carcinogenesis. Photochem Photobiol 2012; 88:1165-72. [PMID: 22272775 DOI: 10.1111/j.1751-1097.2012.01097.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Macroautophagy is a cellular response to various environmental stresses that ensures lysosomal degradation of long-lived and damaged proteins and cellular organelles. It occurs through the formation of an autophagosome, which then fuses with a lysosome to form an autolysosome. Depending on the cellular context, autophagy may promote cancer cell survival or it may serve as a mechanism of tumor suppression. Herein, we show that resveratrol, a natural phytoalexin, induces premature senescence in human A431 SCC cells, and that resveratrol-induced premature senescence is associated with a blockade of autolysosome formation, as assessed by the absence of colocalization of LC3 and Lamp-2, markers for autophagosomes and lysosomes, respectively. Further, we show that resveratrol downregulates the level of Rictor, a component of mTORC2, leading to decreased RhoA-GTPase and altered actin cytoskeleton organization. Exogenous overexpression of Rictor restores RhoA-GTPase activity and actin cytoskeleton network, and decreases resveratrol-induced senescence-associated β-gal activity, indicating a direct role of Rictor in senescence induction. Rictor is overexpressed in UV-induced murine SCCs, whereas its expression is diminished by oral administration of resveratrol. These data indicate that resveratrol attenuates autophagic process via Rictor, and suggest that downregulation of Rictor may be a mechanism of tumor suppression associated with premature senescence.
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Affiliation(s)
- Jung H Back
- Department of Dermatology, Columbia University Medical Center, Russ Berrie Medical Science Pavilion, New York, NY, USA
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11
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Constitutive activation and targeted disruption of signal transducer and activator of transcription 3 (Stat3) in mouse epidermis reveal its critical role in UVB-induced skin carcinogenesis. Oncogene 2009; 28:950-60. [PMID: 19137019 PMCID: PMC2645481 DOI: 10.1038/onc.2008.453] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In this study, the potential role of Stat3 in UVB-induced skin carcinogenesis was examined using skin-specific gain and loss of function transgenic mice, i.e., K5.Stat3C and K5Cre.Stat3fl/fl mice, respectively. The epidermis of Stat3-deficient mice was highly sensitive to UVB-induced apoptosis, whereas the epidermis of K5.Stat3C mice was more resistant to UVB-induced apoptosis. In particular, the status of Stat3 influenced the survival of UV-photoproduct cells, including those located in the bulge region of hair follicles. K5.Stat3C mice exhibited significantly increased epidermal proliferation and hyperplasia in response to UVB irradiation, whereas Stat3-deficient mice showed reduced epidermal proliferation and hyperplasia. Expression of target genes regulated by Stat3, such as cyclin D1 and Bcl-xL, was increased in epidermis of both control and UVB-irradiated K5.Stat3C mice, and downregulated in epidermis of both control and UVB-irradiated K5Cre.Stat3fl/fl mice. Following UVB irradiation, the formation of skin tumors in K5.Stat3C mice was accelerated and both the incidence and multiplicity of skin tumors was significantly greater than wild-type controls. In contrast, Stat3-deficient mice were resistant to UVB skin carcinogenesis. These results demonstrate that Stat3 plays an important role in the development of UVB-induced skin tumors through its effects on both survival and proliferation of keratinocytes during carcinogenesis.
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Cooper SJ, Bowden GT. Ultraviolet B regulation of transcription factor families: roles of nuclear factor-kappa B (NF-kappaB) and activator protein-1 (AP-1) in UVB-induced skin carcinogenesis. Curr Cancer Drug Targets 2008; 7:325-34. [PMID: 17979627 DOI: 10.2174/156800907780809714] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Prolonged and repeated exposure of the skin to ultraviolet light (UV) leads not only to aging of the skin but also increases the incidence of non-melanoma skin cancer (NMSC). Damage of cells induced by ultraviolet B (UVB) light both at the DNA level and molecular level initiates the activation of transcription factor pathways, which in turn regulate the expression of a number of genes termed the "UV response genes". Two such transcription factor families that are activated in this way are those of the nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) families. These two transcription factor families have been identified to be involved in the processes of cell proliferation, cell differentiation and cell survival and therefore play important roles in tumorigenesis. The study of these two transcription factor pathways and the cross-talk between them in response to UVB exposure may help with the development of new chemopreventive strategies for the prevention of UVB-induced skin carcinogenesis.
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Affiliation(s)
- S J Cooper
- Arizona Cancer Center, Tucson, Arizona 85724, USA
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Tang X, Zhu Y, Han L, Kim AL, Kopelovich L, Bickers DR, Athar M. CP-31398 restores mutant p53 tumor suppressor function and inhibits UVB-induced skin carcinogenesis in mice. J Clin Invest 2007; 117:3753-64. [PMID: 18060030 PMCID: PMC2096455 DOI: 10.1172/jci32481] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 09/19/2007] [Indexed: 01/10/2023] Open
Abstract
Mutations in the tumor suppressor p53 are detectable in over 50% of all human malignancies. Mutant p53 protein is incapable of transactivating its downstream target genes that are required for DNA repair and apoptosis. Chronic exposure to UVB induces p53 mutations and is carcinogenic in both murine and human skin. CP-31398, a styrylquinazoline compound, restores the tumor suppressor functions of mutant forms of p53 in tumor cells. However, its effectiveness in vivo remains unclear. Here, we demonstrate that CP-31398 blocked UVB-induced skin carcinogenesis and was associated with increases in p53, p21, and BclXs. CP-31398 downregulated Bcl2, proliferating nuclear cell antigen, and cyclin D1. Activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase also occurred in both tumor and perilesional skin following treatment. CP-31398 induced the expression of p53-dependent target proteins, and this was followed by apoptosis in UVB-irradiated wild-type mice but not in their p53-deficient littermates. Similar effects were observed in human skin carcinoma A431 cells expressing mutant p53. In addition, CP-31398 induced mitochondrial translocation of p53, leading to changes in mitochondrial membrane permeability pore transition (MPT) and consequent cytochrome c release in these cells. Blocking MPT diminished p53 translocation and apoptosis. These studies indicate that reconstituting p53 tumor suppressor functions in vivo by small molecular weight compounds may block the pathogenesis and progression of skin cancer.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Apoptosis/genetics
- Apoptosis/radiation effects
- Caspase 3/genetics
- Caspase 3/metabolism
- Cell Line, Tumor
- Cell Transformation, Neoplastic/drug effects
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Cell Transformation, Neoplastic/radiation effects
- Cyclin D
- Cyclins/genetics
- Cyclins/metabolism
- Cytochromes c/genetics
- Cytochromes c/metabolism
- Environmental Exposure/adverse effects
- Female
- Humans
- Male
- Mice
- Mice, Hairless
- Mitochondria/genetics
- Mitochondria/metabolism
- Mitochondria/pathology
- Mitochondrial Membrane Transport Proteins/antagonists & inhibitors
- Mitochondrial Membrane Transport Proteins/genetics
- Mitochondrial Membrane Transport Proteins/metabolism
- Mitochondrial Permeability Transition Pore
- Mutation/drug effects
- Mutation/radiation effects
- Neoplasms, Radiation-Induced/drug therapy
- Neoplasms, Radiation-Induced/genetics
- Neoplasms, Radiation-Induced/metabolism
- Neoplasms, Radiation-Induced/pathology
- Poly(ADP-ribose) Polymerases/genetics
- Poly(ADP-ribose) Polymerases/metabolism
- Proliferating Cell Nuclear Antigen/genetics
- Proliferating Cell Nuclear Antigen/metabolism
- Protein Transport/drug effects
- Protein Transport/genetics
- Protein Transport/radiation effects
- Pyrimidines/pharmacology
- Pyrimidines/therapeutic use
- Skin Neoplasms/drug therapy
- Skin Neoplasms/genetics
- Skin Neoplasms/metabolism
- Tumor Suppressor Protein p53/genetics
- Tumor Suppressor Protein p53/metabolism
- Ultraviolet Rays/adverse effects
- bcl-X Protein/genetics
- bcl-X Protein/metabolism
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Affiliation(s)
- Xiuwei Tang
- Department of Dermatology, Columbia University College of Physicians and Surgeons, New York, New York, USA.
Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, USA
| | - Yucui Zhu
- Department of Dermatology, Columbia University College of Physicians and Surgeons, New York, New York, USA.
Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, USA
| | - Lydia Han
- Department of Dermatology, Columbia University College of Physicians and Surgeons, New York, New York, USA.
Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, USA
| | - Arianna L. Kim
- Department of Dermatology, Columbia University College of Physicians and Surgeons, New York, New York, USA.
Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, USA
| | - Levy Kopelovich
- Department of Dermatology, Columbia University College of Physicians and Surgeons, New York, New York, USA.
Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, USA
| | - David R. Bickers
- Department of Dermatology, Columbia University College of Physicians and Surgeons, New York, New York, USA.
Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, USA
| | - Mohammad Athar
- Department of Dermatology, Columbia University College of Physicians and Surgeons, New York, New York, USA.
Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, USA
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Kim AL, Zhu Y, Zhu H, Han L, Kopelovich L, Bickers DR, Athar M. Resveratrol inhibits proliferation of human epidermoid carcinoma A431 cells by modulating MEK1 and AP-1 signalling pathways. Exp Dermatol 2006; 15:538-46. [PMID: 16761963 DOI: 10.1111/j.1600-0625.2006.00445.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Resveratrol (trans-3,4',5-trihydroxystilbene) is a naturally occurring polyphenolic phytoalexin found in grapes, and has been shown to inhibit the growth of various types of cancer cells. We investigated the mechanism of the antiproliferative effect of resveratrol in A431-transformed keratinocytes harbouring mutant p53, and show that it is accompanied by G1 cell cycle arrest, which coincides with a marked inhibition of G1 cell cycle regulatory proteins, including cyclins A and D1 and cyclin-dependent kinase (CDK)6 and p53-independent induction of p21WAF1. Cell cycle arrest was also associated with the accumulation of hypophosphorylated Rb and p27KIP1. Resveratrol inhibited mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK)1 > extracellular signal-regulated protein kinase (ERK)1/2 signalling, downregulated c-Jun, and suppressed activating protein (AP)-1 DNA-binding and promoter activity. In addition, the inhibition of MEK1 > ERK1/2 signalling appears to be independent of retinoblastoma protein (pRb) hypophosphorylation in A431 cells, as PD098059 did not suppress pRb phosphorylation. Our results demonstrate that resveratrol affects multiple cellular targets in A431 cells, and that the downregulation of both AP-1 and pRb contributes to its antiproliferative activity in these cells.
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Affiliation(s)
- Arianna L Kim
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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15
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Kim AL, Labasi JM, Zhu Y, Tang X, McClure K, Gabel CA, Athar M, Bickers DR. Role of p38 MAPK in UVB-Induced Inflammatory Responses in the Skin of SKH-1 Hairless Mice. J Invest Dermatol 2005; 124:1318-25. [PMID: 15955110 DOI: 10.1111/j.0022-202x.2005.23747.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The p38 mitogen-activated protein kinase (MAPK) signaling pathway is activated by numerous inflammatory mediators and environmental stresses. We assessed the effects of ultraviolet B (UVB) on the p38 MAPK pathway and determined whether cyclooxygenase (COX)-2 expression is downstream of this kinase in the skin of UVB-irradiated SKH-1 mice. SKH-1 mice were irradiated with a single dose of UVB (360 mJ per cm2), and activation of the epidermal p38 MAPK pathway was assessed. UVB-induced phosphorylation of p38 MAPK occurred in a time-dependent manner. Phosphorylation of MAPK-activated protein kinase-2 (MAPKAPK-2) also was detected and correlated with an increase in its kinase activity. Phosphorylation of heat shock protein 27 (HSP27), a substrate for MAPKAPK-2, also was detected post-irradiation. Oral administration of the p38 inhibitor, SB242235, prior to UVB irradiation, blocked activation of the p38 MAPK cascade, and abolished MAPKAPK-2 kinase activity and phosphorylation of HSP27. Moreover, SB242235 inhibited expression of the pro-inflammatory cytokines interleukin (IL)-6 and KC (murine IL-8) and COX-2. Our data demonstrate that UVB irradiation of murine skin activates epidermal p38 MAPK signaling and induces a local pro-inflammatory response. Blockade of the p38 MAPK pathway may offer an effective approach to reducing or preventing skin damage resulting from acute solar radiation.
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Affiliation(s)
- Arianna L Kim
- Department of Dermatology, Columbia University College of Physicians & Surgeons, New York, New York 10032, USA.
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Reagan-Shaw S, Afaq F, Aziz MH, Ahmad N. Modulations of critical cell cycle regulatory events during chemoprevention of ultraviolet B-mediated responses by resveratrol in SKH-1 hairless mouse skin. Oncogene 2004; 23:5151-60. [PMID: 15122319 DOI: 10.1038/sj.onc.1207666] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Multiple exposures to solar ultraviolet (UV) radiation cause critical damages that may lead to the development of several cutaneous disorders including skin cancer, the most frequently diagnosed malignancy in the USA. Therefore, efforts are needed to: (i) study the mechanism(s) of UV-mediated cutaneous damages, and (ii) design novel approaches for the management of skin cancer. 'Chemoprevention' via plant-based agents may be a useful approach for the management of neoplasia. Here, we evaluated the involvement of cell cycle regulatory molecules during resveratrol-mediated protection from multiple exposures of UVB (180 mJ/cm(2); on alternate days x 7 exposures) radiations in the SKH-1 hairless mouse skin. Resveratrol was topically applied on the skin of SKH-1 hairless mice at a dose of 10 micromol/mouse (in 0.2 ml acetone; 30 min prior to each UVB exposure). Studies were performed at 24 h following the last UVB exposure. Topical application of resveratrol resulted in significant decrease in UVB-induced bi-fold skin thickness, hyperplasia, and infiltration of leukocytes. The data from immunoblot and/or immunohistochemical analyses revealed that multiple exposure to UVB radiations causes significant upregulation in: (i) proliferating cell nuclear antigen (PCNA), a marker of cellular proliferation, and (ii) cyclin-dependent kinase (cdk)-2, -4 and -6, cyclin-D1, and cyclin-D2. Resveratrol treatment resulted in significant downregulation in UV-mediated increases in these critical cell cycle regulatory proteins. An interesting observation of this study was that resveratrol treatment resulted in a further stimulation of UVB-mediated increases in cyclin kinase inhibitor WAF1/p21 and tumor suppressor p53. Further, resveratrol was also found to cause significant decreases in UVB-mediated upregulation of: (i) the mitogen-activated protein kinase kinase, and (ii) the 42 kDa isotype of mitogen-activated protein kinase (MAPK). Thus, our data suggested that the antiproliferative effects of resveratrol might be mediated via modulation in the expression and function of cell cycle regulatory proteins cyclin-D1 and -D2, cdk-2, -4 and -6, and WAF1/p21. Our data further suggest that the modulation of cki-cyclin-cdk network by resveratrol may be associated with inhibition of the MAPK pathway. We suggest that resveratrol may be useful for the prevention of UVB-mediated cutaneous damages including skin cancer.
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Tang X, Kim AL, Feith DJ, Pegg AE, Russo J, Zhang H, Aszterbaum M, Kopelovich L, Epstein EH, Bickers DR, Athar M. Ornithine decarboxylase is a target for chemoprevention of basal and squamous cell carcinomas in Ptch1+/- mice. J Clin Invest 2004; 113:867-75. [PMID: 15067319 PMCID: PMC362123 DOI: 10.1172/jci20732] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2003] [Accepted: 01/12/2004] [Indexed: 11/17/2022] Open
Abstract
Solar ultraviolet B (UVB) radiation induces cutaneous ornithine decarboxylase (ODC), the first enzyme in the polyamine-biosynthesis pathway, which drives continued proliferation and clonal expansion of initiated (mutated) cells, leading to tumorigenesis. Therefore ODC is a potentially important target for chemoprevention of basal cell carcinomas (BCCs), the majority of which have mutations in the tumor-suppressor gene known as patched (PTCH). To assess this possibility, we first overexpressed ODC in the skin of Ptch1+/- mice using a keratin 6 (K6) promoter that directs constitutive ODC expression in the outer root sheath of the hair follicle. UVB irradiation of these mice accelerated induction of BCCs as compared with their Ptch1+/- littermates. To further verify the role of ODC in BCC tumorigenesis, we used an antizyme (AZ) approach to inhibit ODC activity in the Ptch1+/- mice. Ptch1+/- mice with AZ overexpression driven by the K6 promoter were resistant to the induction of BCCs by UVB. Furthermore, oral administration of the suicidal ODC inhibitor alpha-difluoromethylornithine reduced UVB-induced BCCs in Ptch1+/- mice. These results demonstrate the crucial importance of ODC for the induction of BCCs and indicate that chemopreventive strategies directed at inhibiting this enzyme may be useful in reducing BCCs in human populations.
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Affiliation(s)
- Xiuwei Tang
- Department of Dermatology, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA
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Richard-Parpaillon L, Cosgrove RA, Devine C, Vernon AE, Philpott A. G1/S phase cyclin-dependent kinase overexpression perturbs early development and delays tissue-specific differentiation in Xenopus. Development 2004; 131:2577-86. [PMID: 15115752 DOI: 10.1242/dev.01121] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cell division and differentiation are largely incompatible but the molecular links between the two processes are poorly understood. Here, we overexpress G1/S phase cyclins and cyclin-dependent kinases in Xenopus embryos to determine their effect on early development and differentiation. Overexpression of cyclin E prior to the midblastula transition (MBT), with or without cdk2, results in a loss of nuclear DNA and subsequent apoptosis at early gastrula stages. By contrast, overexpressed cyclin A2 protein does not affect early development and, when stabilised by binding to cdk2, persists to tailbud stages. Overexpression of cyclin A2/cdk2 in post-MBT embryos results in increased proliferation specifically in the epidermis with concomitant disruption of skin architecture and delay in differentiation. Moreover, ectopic cyclin A2/cdk2 also inhibits differentiation of primary neurons but does not affect muscle. Thus, overexpression of a single G1/S phase cyclin/cdk pair disrupts the balance between division and differentiation in the early vertebrate embryo in a tissue-specific manner.
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Affiliation(s)
- Laurent Richard-Parpaillon
- Department of Oncology, Cambridge University, Hutchison/MRC Research Centre, Addenbrookes Hospital, Hills Road, Cambridge CB2 2XZ, UK.
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Tang X, Kim AL, Feith DJ, Pegg AE, Russo J, Zhang H, Aszterbaum M, Kopelovich L, Epstein EH, Bickers DR, Athar M. Ornithine decarboxylase is a target for chemoprevention of basal and squamous cell carcinomas in Ptch1+/– mice. J Clin Invest 2004. [DOI: 10.1172/jci200420732] [Citation(s) in RCA: 305] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Kim AL, Gautier J, Bickers DR, Athar M. Reduced cyclin D1 ubiquitination in UVB-induced murine squamous cell carcinomas. Biochem Biophys Res Commun 2002; 298:377-82. [PMID: 12413951 DOI: 10.1016/s0006-291x(02)02435-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ubiquitination of cyclin D1 signals for its proteosomal degradation. To assess the possibility that reduced cyclin D1 proteolysis is a putative mechanism for its accumulation during UVB-induced skin tumorigenesis, ubiquitination activity of cyclin D1 was assessed in UVB-induced murine SCCs. Cyclin D1 was rapidly ubiquitinated by control skin extract, whereas ubiquitination of cyclin D1 was significantly reduced in SCCs. Mutant cyclin D1, in which residues important for GSK3beta-mediated degradation of cyclin D1 are altered to non-phosphorylatable alanine, was not ubiquitinated. We also observed phosphorylation-dependent inactivation of GSK3beta in SCCs. Our results indicate reduced ubiquitination of cyclin D1 in UVB-induced murine SCCs and suggest that inactivation of GSK3beta-dependent cyclin D1 degradation pathway contributes to the accumulation of cyclin D1 in UVB-induced murine SCCs.
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Affiliation(s)
- Arianna L Kim
- Department of Dermatology, Columbia University College of Physicians and Surgeons, 630 West 168th Street, New York, NY 10032, USA
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