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Eliason O, Malitsky S, Panizel I, Feldmesser E, Porat Z, Sperfeld M, Segev E. The photo-protective role of vitamin D in the microalga Emiliania huxleyi. iScience 2024; 27:109884. [PMID: 38799580 PMCID: PMC11126961 DOI: 10.1016/j.isci.2024.109884] [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: 03/27/2024] [Revised: 04/16/2024] [Accepted: 04/30/2024] [Indexed: 05/29/2024] Open
Abstract
An essential interaction between sunlight and eukaryotes involves vitamin D production through exposure to ultraviolet (UV) radiation. While extensively studied in vertebrates, the role of vitamin D in non-animal eukaryotes like microalgae remains unclear. Here, we investigate the potential involvement of vitamin D in the UV-triggered response of Emiliania huxleyi, a microalga inhabiting shallow ocean depths that are exposed to UV. Our results show that E. huxleyi produces vitamin D2 and D3 in response to UV. We further demonstrate that E. huxleyi responds to external administration of vitamin D at the transcriptional level, regulating protective mechanisms that are also responsive to UV. Our data reveal that vitamin D addition enhances algal photosynthetic performance while reducing harmful reactive oxygen species buildup. This study contributes to understanding the function of vitamin D in E. huxleyi and its role in non-animal eukaryotes, as well as its potential importance in marine ecosystems.
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Affiliation(s)
- Or Eliason
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sergey Malitsky
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Irina Panizel
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ester Feldmesser
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ziv Porat
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Martin Sperfeld
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Einat Segev
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
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2
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Mintie CA, Musarra AK, Singh CK, Ndiaye MA, Sullivan R, Eickhoff JC, Ahmad N. Protective Effects of Dietary Grape on UVB-Mediated Cutaneous Damages and Skin Tumorigenesis in SKH-1 Mice. Cancers (Basel) 2020; 12:cancers12071751. [PMID: 32630288 PMCID: PMC7409354 DOI: 10.3390/cancers12071751] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 06/23/2020] [Accepted: 06/28/2020] [Indexed: 12/12/2022] Open
Abstract
Non-melanoma skin cancers (NMSCs) are the most diagnosed cancers in the US and occur more frequently in males. We previously demonstrated chemoprotective effects of dietary grape powder (GP) against UVB-mediated skin tumorigenesis in female SKH-1 mice. To expand on this, here, we determined the effects of GP in a short-term UVB exposure protocol (0 or 5% GP, followed by UVB every other day for 2 weeks) in male and female SKH-1 mice, as well as explored any sex-related differences in UVB carcinogenesis via male SKH-1 mice (0, 3, or 5% GP; UVB twice weekly for 28 weeks). In the short-term study, we found that GP protects against early-stage epithelial hyperplasia and mast cell infiltration in both sexes. In the long term, GP markedly reduced tumor counts and malignant conversion, along with significant decreases in mast cell infiltration, serum IgE and Eotaxin. We also found inhibition of P38 phosphorylation and reduced PCNA, Ki67 and BCL2 levels, suggesting that the anti-inflammatory effects of GP inhibits P38, acting as an upstream regulator to inhibit proliferation and reduce tumor cell survival. Together, GP appears to protect against UVB-mediated skin damage and carcinogenesis in SKH-1 mice and should be explored further as a supplement for NMSC prevention.
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Affiliation(s)
- Charlotte A. Mintie
- Department of Dermatology, University of Wisconsin, 1300 University Avenue, Madison, WI 53706, USA; (C.A.M.); (A.K.M.); (C.K.S.); (M.A.N.)
| | - Anna K. Musarra
- Department of Dermatology, University of Wisconsin, 1300 University Avenue, Madison, WI 53706, USA; (C.A.M.); (A.K.M.); (C.K.S.); (M.A.N.)
| | - Chandra K. Singh
- Department of Dermatology, University of Wisconsin, 1300 University Avenue, Madison, WI 53706, USA; (C.A.M.); (A.K.M.); (C.K.S.); (M.A.N.)
| | - Mary A. Ndiaye
- Department of Dermatology, University of Wisconsin, 1300 University Avenue, Madison, WI 53706, USA; (C.A.M.); (A.K.M.); (C.K.S.); (M.A.N.)
| | - Ruth Sullivan
- Department of Comparative Biosciences, University of Wisconsin, Madison, WI 53706, USA;
| | - Jens C. Eickhoff
- Department of Biostatistics & Medical Informatics, University of Wisconsin, Madison, WI 53705, USA;
| | - Nihal Ahmad
- Department of Dermatology, University of Wisconsin, 1300 University Avenue, Madison, WI 53706, USA; (C.A.M.); (A.K.M.); (C.K.S.); (M.A.N.)
- William S. Middleton VA Medical Center, Madison, WI 53705, USA
- Correspondence: ; Tel.: +1-608-263-2532
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3
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Khandelwal AR, Kent B, Hillary S, Alam MM, Ma X, Gu X, DiGiovanni J, Nathan CAO. Fibroblast growth factor receptor promotes progression of cutaneous squamous cell carcinoma. Mol Carcinog 2019; 58:1715-1725. [PMID: 31254372 DOI: 10.1002/mc.23012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/15/2019] [Accepted: 03/19/2019] [Indexed: 12/14/2022]
Abstract
Cutaneous squamous cell carcinoma (cSCC) is a keratinocyte-derived invasive and metastatic tumor of the skin. It is the second-most commonly diagnosed form of skin cancer striking 200 000 Americans annually. Further, in organ transplant patients, there is a 65- to 100-fold increased incidence of cSCC compared to the general population. Excision of cSCC of the head and neck results in significant facial disfigurement. Therefore, increased understanding of the mechanisms involved in the pathogeneses of cSCC could identify means to prevent, inhibit, and reverse this process. In our previous studies, inhibition of fibroblast growth factor receptor (FGFR) significantly decreased ultraviolet B-induced epidermal hyperplasia and hyperproliferation in SKH-1 mice, suggesting an important role for FGFR signaling in skin cancer development. However, the role of FGFR signaling in the progression of cSCC is not yet elucidated. Analysis of the expression of FGFR in cSCC cells and normal epidermal keratinocytes revealed protein overexpression and increased FGFR2 activation in cSCC cells compared to normal keratinocytes. Further, tumor cell-specific overexpression of FGFR2 was detected in human cSCCs, whereas the expression of FGFR2 was low in premalignant lesions and normal skin. Pretreatment with the pan-FGFR inhibitor; AZD4547 significantly decreased cSCC cell-cycle traverse, proliferation, migration, and motility. Interestingly, AZD4547 also significantly downregulated mammalian target of rapamycin complex 1 and AKT activation in cSCC cells, suggesting an important role of these signaling pathways in FGFR-mediated effects. To further bolster the in vitro studies, NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ mice with SCC12A tumor xenografts treated with AZD4547 (15 mg/kg/bw, twice weekly oral gavage) exhibited significantly decreased tumor volume compared to the vehicle-only treatment group. The current studies provide mechanistic evidence for the role of FGFR and selectively FGFR2 in the early progression of cSCC and identifies FGFR as a putative therapeutic target in the treatment of skin cancer.
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Affiliation(s)
- Alok R Khandelwal
- Department of Otolaryngology, Head and Neck Surgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana.,Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, Shreveport, Louisiana
| | - Burton Kent
- Department of Otolaryngology, Head and Neck Surgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana
| | - Savage Hillary
- Department of Otolaryngology, Head and Neck Surgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana
| | - Md Maksudul Alam
- Department of Otolaryngology, Head and Neck Surgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana
| | - Xiaohua Ma
- Department of Otolaryngology, Head and Neck Surgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana
| | - Xin Gu
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, Louisiana
| | - John DiGiovanni
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, Texas
| | - Cherie-Ann O Nathan
- Department of Otolaryngology, Head and Neck Surgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana.,Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, Shreveport, Louisiana.,Department of Surgery, Overton Brooks Veterans Affairs Hospital, Shreveport, Louisiana
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4
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Feehan RP, Nelson AM, Shantz LM. Inhibition of mTORC2 enhances UVB-induced apoptosis in keratinocytes through a mechanism dependent on the FOXO3a transcriptional target NOXA but independent of TRAIL. Cell Signal 2018; 52:35-47. [PMID: 30172026 DOI: 10.1016/j.cellsig.2018.08.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/22/2018] [Accepted: 08/28/2018] [Indexed: 01/06/2023]
Abstract
The primary cause of non-melanoma skin cancer (NMSC) is ultraviolet B (UVB) radiation. We have shown previously that mTORC2 inhibition sensitizes keratinocytes to UVB-induced apoptosis mediated by the transcription factor FOXO3a. FOXO3a is a key regulator of apoptosis and a tumor suppressor in several cancer types. Activation of FOXO3a promotes apoptosis through the coordinated expression of a variety of target genes, including TRAIL and NOXA. We hypothesized that in the setting of mTORC2 inhibition, the UVB-induced expression of these factors would lead to apoptosis in a FOXO3a-dependent manner. Using spontaneously immortalized human keratinocytes (HaCaT cells), we observed that both TRAIL and NOXA expression increased in cells exposed to UVB and the TOR kinase inhibitor Torin 2. Similar to knockdown of FOXO3a, NOXA knockdown reversed the sensitization to UVB-induced apoptosis caused by mTORC2 inhibition. In contrast, loss of TRAIL by either knockdown or knockout actually enhanced expression of nuclear FOXO3a, which maintained apoptosis. These surprising results are not due to faulty death receptor signaling in HaCaT cells, as we found that the cells undergo extrinsic apoptosis in response to treatment with recombinant TRAIL. Even more striking, TRAIL knockout cells were sensitized to recombinant TRAIL-induced apoptosis compared to wild-type HaCaT cells, with the largest increase occurring in the presence of mTORC2 inhibition. Taken together, these studies provide strong evidence that mTORC2 controls UVB-induced apoptosis by regulating NOXA expression downstream of FOXO3a. Moreover, FOXO3a transcriptional activation by mTORC2 inhibitors may be a valuable target for prevention or therapy of NMSC, especially in cases with low endogenous TRAIL.
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Affiliation(s)
- Robert P Feehan
- Department of Cellular & Molecular Physiology, Penn State College of Medicine, Hershey, PA 17033, United States.
| | - Amanda M Nelson
- Department of Dermatology, Penn State College of Medicine, Hershey, PA 17033, United States.
| | - Lisa M Shantz
- Department of Cellular & Molecular Physiology, Penn State College of Medicine, Hershey, PA 17033, United States.
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5
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Yadav DK, Kumar S, Saloni, Misra S, Yadav L, Teli M, Sharma P, Chaudhary S, Kumar N, Choi EH, Kim HS, Kim MH. Molecular Insights into the Interaction of RONS and Thieno[3,2-c]pyran Analogs with SIRT6/COX-2: A Molecular Dynamics Study. Sci Rep 2018; 8:4777. [PMID: 29556059 PMCID: PMC5859274 DOI: 10.1038/s41598-018-22972-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 03/05/2018] [Indexed: 01/21/2023] Open
Abstract
SIRT6 and COX-2 are oncogenes target that promote the expression of proinflammatory and pro-survival proteins through a signaling pathway, which leads to increased survival and proliferation of tumor cells. However, COX-2 also suppresses skin tumorigenesis and their relationship with SIRT6, making it an interesting target for the discovery of drugs with anti-inflammatory and anti-cancer properties. Herein, we studied the interaction of thieno[3,2-c]pyran analogs and RONS species with SIRT6 and COX-2 through the use of molecular docking and molecular dynamic simulations. Molecular docking studies revealed the importance of hydrophobic and hydrophilic amino acid residues for the stability. The molecular dynamics study examined conformational changes in the enzymes caused by the binding of the substrates and how those changes affected the stability of the protein-drug complex. The average RMSD values of the backbone atoms in compounds 6 and 10 were calculated from 1000 ps to 10000 ps and were found to be 0.13 nm for both compounds. Similarly, the radius of gyration values for compounds 6 and 10 were found to be 1.87 ± 0.03 nm and 1.86 ± 0.02 nm, respectively. The work presented here, will be of great help in lead identification and optimization for early drug discovery.
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Affiliation(s)
- Dharmendra K Yadav
- College of Pharmacy, Gachon University of Medicine and Science, 191, Hambangmoe-ro, Yeonsu-gu, Incheon, 21936, Republic of Korea.
| | - Surendra Kumar
- College of Pharmacy, Gachon University of Medicine and Science, 191, Hambangmoe-ro, Yeonsu-gu, Incheon, 21936, Republic of Korea
| | - Saloni
- College of Pharmacy, Gachon University of Medicine and Science, 191, Hambangmoe-ro, Yeonsu-gu, Incheon, 21936, Republic of Korea
| | - Sanjeev Misra
- Department of Biochemistry, All India Institute of Medical Science, Jodhpur, Rajasthan, 342005, India
| | - Lalit Yadav
- Department of Chemistry, Malaviya National Institute of Technology, Jawaharlal Nehru Marg, Jaipur, 302017, India
| | - Mahesh Teli
- Faculty of Biochemistry and Molecular Medicine Aapistie, University of Oulu, 7A, Oulu, 90220, Finland
| | - Praveen Sharma
- Department of Biochemistry, All India Institute of Medical Science, Jodhpur, Rajasthan, 342005, India
| | - Sandeep Chaudhary
- Department of Chemistry, Malaviya National Institute of Technology, Jawaharlal Nehru Marg, Jaipur, 302017, India
| | - Naresh Kumar
- Plasma Bioscience Research Center/Department of Electrical and Biological Physics, Kwangwoon University, 20 Kwangwon-Ro, Nowon-Gu, Seoul, 139-701, Republic of Korea.,Department of Chemistry, Research group PLASMANT, University of Antwerp, BE-2610, Wilrijk-Antwerp, Belgium
| | - Eun Ha Choi
- Plasma Bioscience Research Center/Department of Electrical and Biological Physics, Kwangwoon University, 20 Kwangwon-Ro, Nowon-Gu, Seoul, 139-701, Republic of Korea
| | - Hyung Sik Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Mi-Hyun Kim
- College of Pharmacy, Gachon University of Medicine and Science, 191, Hambangmoe-ro, Yeonsu-gu, Incheon, 21936, Republic of Korea.
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6
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Kenny FN, Drymoussi Z, Delaine-Smith R, Kao AP, Laly AC, Knight MM, Philpott MP, Connelly JT. Tissue stiffening promotes keratinocyte proliferation via activation of epidermal growth factor signaling. J Cell Sci 2018; 131:jcs.215780. [DOI: 10.1242/jcs.215780] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 04/11/2018] [Indexed: 12/21/2022] Open
Abstract
Tissue biomechanics regulate a wide range of cellular functions, but the influences on epidermal homeostasis and repair remain unclear. Here, we examined the role of extracellular matrix stiffness on human keratinocyte behavior using elastomeric substrates with defined mechanical properties. Increased matrix stiffness beyond normal physiologic levels promoted keratinocyte proliferation but did not alter the ability to self-renew or terminally differentiate. Activation of epidermal growth factor (EGF) signaling mediated the proliferative response to matrix stiffness and depended on focal adhesion assembly and cytoskeletal tension. Comparison of normal skin with keloid scar tissue further revealed an up-regulation of EGF signaling within the epidermis of stiffened scar tissue. We conclude that matrix stiffness regulates keratinocyte proliferation independently of changes in cell fate and is mediated by EGF signaling. These findings provide mechanistic insights into how keratinocytes sense and respond to their mechanical environment and suggest that matrix biomechanics may play a role in the pathogenesis keloid scar formation.
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Affiliation(s)
- Fiona N. Kenny
- Centre for Cell Biology and Cutaneous Research, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Zoe Drymoussi
- Centre for Cell Biology and Cutaneous Research, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Robin Delaine-Smith
- School of Engineering and Materials Science, Queen Mary University of London, UK
- Institute of Bioengineering, Queen Mary University of London, UK
| | - Alexander P. Kao
- School of Engineering and Materials Science, Queen Mary University of London, UK
| | - Ana Catarina Laly
- Centre for Cell Biology and Cutaneous Research, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
- Institute of Bioengineering, Queen Mary University of London, UK
| | - Martin M. Knight
- School of Engineering and Materials Science, Queen Mary University of London, UK
- Institute of Bioengineering, Queen Mary University of London, UK
| | - Michael P. Philpott
- Centre for Cell Biology and Cutaneous Research, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - John T. Connelly
- Centre for Cell Biology and Cutaneous Research, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
- Institute of Bioengineering, Queen Mary University of London, UK
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7
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Taute S, Pfister HJ, Steger G. Induction of Tyrosine Phosphorylation of UV-Activated EGFR by the Beta-Human Papillomavirus Type 8 E6 Leads to Papillomatosis. Front Microbiol 2017; 8:2197. [PMID: 29176966 PMCID: PMC5686093 DOI: 10.3389/fmicb.2017.02197] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 10/26/2017] [Indexed: 11/13/2022] Open
Abstract
Epidemiological evidence is accumulating that beta-human papillomaviruses (HPV) synergize with UV-light in the development of precancerous actinic keratosis, and cutaneous squamous cell carcinomas (cSCC), one of the most common cancers in the Caucasian population. We previously demonstrated the tumorigenic activity of beta-HPV type 8 (HPV8) in the skin of transgenic mice and its cooperation with UV-light. Analysis of underlying mechanisms now showed that in keratinocytes expressing the HPV8E6 protein a transient increase of tyrosine phosphorylated epidermal growth factor receptor (EGFR) in response to UV-irradiation occurred, while EGFR tyrosine phosphorylation, i.e., receptor tyrosine kinase (RTK)-activity was hardly affected in empty vector control cells. FACS and immunofluorescences revealed that the EGFR was internalized into early endosomes in response to UV-exposure in both, HPV8E6 positive and in control cells, yet with a higher rate in the presence of HPV8E6. Moreover, only in HPV8E6 expressing keratinocytes the EGFR was further sorted into CD63+ intraluminal vesicles, indicative for trafficking to late endosomes. The latter requires the ubiquitination of the EGFR, and in correlation, we could show that only in HPV8E6 positive keratinocytes the EGFR was ubiquitinated upon UV-exposure. HPV8E6 and tyrosine phosphorylated EGFR directly interacted which was enhanced by UV-irradiation. The treatment of K14-HPV8E6 transgenic mice with Canertinib, an inhibitor of the RTK-activity of the EGFR, suppressed skin papilloma growth in response to UV-irradiation. This confirms the crucial role of the RTK-activity of the EGFR in HPV8E6 and UV-mediated papillomatosis in transgenic mice. Taken together, our results demonstrate that HPV8E6 alters the signaling of the UV-activated EGFR and this is a critical step in papilloma formation in response to UV-light in transgenic mice. Our results provide a molecular basis how a beta-HPV type may support early steps of skin tumor formation in cooperation with UV-light.
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Affiliation(s)
- Stefanie Taute
- Institute of Virology, University of Cologne, Cologne, Germany
| | | | - Gertrud Steger
- Institute of Virology, University of Cologne, Cologne, Germany
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8
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Molecular signaling cascades involved in nonmelanoma skin carcinogenesis. Biochem J 2017; 473:2973-94. [PMID: 27679857 DOI: 10.1042/bcj20160471] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/10/2016] [Indexed: 12/17/2022]
Abstract
Nonmelanoma skin cancer (NMSC) is the most common cancer worldwide and the incidence continues to rise, in part due to increasing numbers in high-risk groups such as organ transplant recipients and those taking photosensitizing medications. The most significant risk factor for NMSC is ultraviolet radiation (UVR) from sunlight, specifically UVB, which is the leading cause of DNA damage, photoaging, and malignant transformation in the skin. Activation of apoptosis following UVR exposure allows the elimination of irreversibly damaged cells that may harbor oncogenic mutations. However, UVR also activates signaling cascades that promote the survival of these potentially cancerous cells, resulting in tumor initiation. Thus, the UVR-induced stress response in the skin is multifaceted and requires coordinated activation of numerous pathways controlling DNA damage repair, inflammation, and kinase-mediated signal transduction that lead to either cell survival or cell death. This review focuses on the central signaling mechanisms that respond to UVR and the subsequent cellular changes. Given the prevalence of NMSC and the resulting health care burden, many of these pathways provide promising targets for continued study aimed at both chemoprevention and chemotherapy.
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9
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Yao M, Shang YY, Zhou ZW, Yang YX, Wu YS, Guan LF, Wang XY, Zhou SF, Wei X. The research on lapatinib in autophagy, cell cycle arrest and epithelial to mesenchymal transition via Wnt/ErK/PI3K-AKT signaling pathway in human cutaneous squamous cell carcinoma. J Cancer 2017; 8:220-226. [PMID: 28243326 PMCID: PMC5327371 DOI: 10.7150/jca.16850] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 11/10/2016] [Indexed: 01/09/2023] Open
Abstract
Cutaneous squamous cell carcinoma (cSCC) contributes to one of most common types of skin cancer. Epidermal growth factor receptor (EGFR) activation has been investigated to be associated with the development of cSCC. Lapatinib is an inhibitor targeting HER2/neu and EGFR pathway. We found that lapatinib can inhibit proliferation by enhancing apoptosis of human cSCC cell lines. The cSCC cell cycle distribution could be arrested in G2/M phase after lapatinib treatment. In the in vitro experiment, we found that lapatinib interrupted PI3K/AKT/mTOR signaling pathway in human cSCC cells. Furthermore, lapatinib could suppress epithelial to mesenchymal transition (EMT) via Wnt/ErK/PI3K-AKT signaling pathway to represent a promising anticancer drug for cSCC treatment.
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Affiliation(s)
- Ming Yao
- Department of Burns and Plastic Surgery, General Hospital, Ningxia Medical University, Yinchuan, People's Republic of China.; Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA
| | - Yuan-Yuan Shang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA.; Department of Dermatology, General Hospital, Ningxia Medical University
| | - Zhi-Wei Zhou
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA
| | - Yin-Xue Yang
- Department of Colorectal Surgery, General Hospital, Ningxia Medical University
| | - Yin-Sheng Wu
- Department of Burns and Plastic Surgery, General Hospital, Ningxia Medical University, Yinchuan, People's Republic of China
| | - Li-Feng Guan
- Department of Burns and Plastic Surgery, General Hospital, Ningxia Medical University, Yinchuan, People's Republic of China
| | - Xin-Yu Wang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA.; Department of Pharmacy, General Hospital, Ningxia Medical University, Yinchuan
| | - Shu-Feng Zhou
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA
| | - Xi Wei
- Department of Diagnostic and Therapeutic Ultrasonography, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
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10
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Chen SJ, Lin PW, Lin HP, Huang SS, Lai FJ, Sheu HM, Hsu LJ, Chang NS. UV irradiation/cold shock-mediated apoptosis is switched to bubbling cell death at low temperatures. Oncotarget 2016; 6:8007-18. [PMID: 25779665 PMCID: PMC4480731 DOI: 10.18632/oncotarget.3153] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Accepted: 01/16/2015] [Indexed: 02/06/2023] Open
Abstract
When COS7 fibroblasts and other cells were exposed to UVC irradiation and cold shock at 4°C for 5 min, rapid upregulation and nuclear accumulation of NOS2, p53, WWOX, and TRAF2 occurred in 10-30 min. By time-lapse microscopy, an enlarging gas bubble containing nitric oxide (NO) was formed in the nucleus in each cell that finally popped out to cause "bubbling death". Bubbling occurred effectively at 4 and 22°C, whereas DNA fragmentation was markedly blocked at 4°C. When temperature was increased to 37°C, bubbling was retarded and DNA fragmentation occurred in 1 hr, suggesting that bubbling death is switched to apoptosis with increasing temperatures. Bubbling occurred prior to nuclear uptake of propidium iodide and DAPI stains. Arginine analog Nω-LAME inhibited NO synthase NOS2 and significantly suppressed the bubbling death. Unlike apoptosis, there were no caspase activation and flip-over of membrane phosphatidylserine (PS) during bubbling death. Bubbling death was significantly retarded in Wwox knockout MEF cells, as well as in cells overexpressing TRAF2 and dominant-negative p53. Together, UV/cold shock induces bubbling death at 4°C and the event is switched to apoptosis at 37°C. Presumably, proapoptotic WWOX and p53 block the protective TRAF2 to execute the bubbling death.
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Affiliation(s)
- Szu-Jung Chen
- Institute of Molecular Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan, ROC
| | - Pei-Wen Lin
- Institute of Molecular Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan, ROC
| | - Hsin-Ping Lin
- Institute of Molecular Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan, ROC
| | - Shenq-Shyang Huang
- Institute of Molecular Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan, ROC
| | - Feng-Jie Lai
- Department of Dermatology, Chi-Mei Medical Center, Tainan, Taiwan, ROC
| | - Hamm-Ming Sheu
- Department of Dermatology, National Cheng Kung University College of Medicine, Tainan, Taiwan, ROC
| | - Li-Jin Hsu
- Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University Medical College, Tainan, Taiwan, ROC.,Center of Infectious Disease and Signaling Research, National Cheng Kung University Medical College, Tainan, Taiwan, ROC
| | - Nan-Shan Chang
- Institute of Molecular Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan, ROC.,Center of Infectious Disease and Signaling Research, National Cheng Kung University Medical College, Tainan, Taiwan, ROC.,Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, Taiwan, ROC.,Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, NY, USA.,Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY, USA
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11
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Gerber PA, Buhren BA, Schrumpf H, Hevezi P, Bölke E, Sohn D, Jänicke RU, Belum VR, Robert C, Lacouture ME, Homey B. Mechanisms of skin aging induced by EGFR inhibitors. Support Care Cancer 2016; 24:4241-8. [PMID: 27165055 DOI: 10.1007/s00520-016-3254-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/26/2016] [Indexed: 01/18/2023]
Abstract
BACKGROUND The mechanisms of skin aging have not been completely elucidated. Anecdotal data suggests that EGFR inhibition accelerates aging-like skin changes. OBJECTIVE The objective of the study was to evaluate the clinical characteristics and investigate the cellular and molecular mechanisms underlying skin changes associated with the use of EFGRIs. PATIENTS AND METHODS Patients during prolonged treatment with EGFRIs (>3 months) were analyzed for aging-like skin changes. Baseline EGFR expression was compared in young (<25 years old) vs. old (> 65 years old) skin. In addition, the regulation of extracellular matrix, senescence-associated genes, and cell cycle status was measured in primary human keratinocytes treated with erlotinib in vitro. RESULTS There were progressive signs of skin aging, including xerosis cutis, atrophy, rhytide formation, and/or actinic purpura in 12 patients. Keratinocytes treated with erlotinib in vitro showed a significant down-modulation of hyaluronan synthases (HAS2 and HAS3), whereas senescence-associated genes (p21, p53, IL-6, maspin) were upregulated, along with a G1 cell cycle arrest and stronger SA β-Gal activity. There was significantly decreased baseline expression in EGFR density in aged skin, when compared to young controls. CONCLUSIONS EGFR inhibition results in molecular alterations in keratinocytes that may contribute to the observed skin aging of patients treated with respective targeted agents.
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Affiliation(s)
- Peter Arne Gerber
- Department of Dermatology, Medical Faculty, University of Düsseldorf, Moorenstrasse 5, D-40225, Duesseldorf, Germany.
| | - Bettina Alexandra Buhren
- Department of Dermatology, Medical Faculty, University of Düsseldorf, Moorenstrasse 5, D-40225, Duesseldorf, Germany
| | - Holger Schrumpf
- Department of Dermatology, Medical Faculty, University of Düsseldorf, Moorenstrasse 5, D-40225, Duesseldorf, Germany
| | - Peter Hevezi
- Department of Dermatology, Medical Faculty, University of Düsseldorf, Moorenstrasse 5, D-40225, Duesseldorf, Germany
| | - Edwin Bölke
- Clinic and Polyclinic, Radiation Therapy and Radiooncology, Medical Faculty, University of Duesseldorf, Duesseldorf, Germany
| | - Dennis Sohn
- Laboratory of Molecular Radiooncology, Radiation Therapy and Radiooncology, Medical Faculty, University of Duesseldorf, Duesseldorf, Germany
| | - Reiner U Jänicke
- Laboratory of Molecular Radiooncology, Radiation Therapy and Radiooncology, Medical Faculty, University of Duesseldorf, Duesseldorf, Germany
| | - Viswanath Reddy Belum
- Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Caroline Robert
- Dermatology Service and Paris-Sud University, Gustave Roussy Cancer Campus, Villejuif-Paris Sud, Paris, France
| | - Mario E Lacouture
- Dermatology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Bernhard Homey
- Department of Dermatology, Medical Faculty, University of Düsseldorf, Moorenstrasse 5, D-40225, Duesseldorf, Germany
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12
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Negative regulation of the FOXO3a transcription factor by mTORC2 induces a pro-survival response following exposure to ultraviolet-B irradiation. Cell Signal 2016; 28:798-809. [PMID: 27058291 DOI: 10.1016/j.cellsig.2016.03.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 03/16/2016] [Accepted: 03/28/2016] [Indexed: 12/30/2022]
Abstract
Exposure to ultraviolet-B (UVB) irradiation, the principal cause of non-melanoma skin cancer (NMSC), activates both the rapamycin-sensitive mammalian target of rapamycin complex 1 (mTORC1) and the rapamycin-resistant mTORC2. We have previously reported that UVB-induced keratinocyte survival is dependent on mTORC2, though the specific mechanism is not well understood. FOXO3a is an important transcription factor involved in regulating cell survival. The activity of FOXO3a is reduced as a result of protein kinase B (AKT/PKB) activation, which is downstream of mTORC2; however, the specific function of FOXO3a during UVB-induced apoptosis is unclear. In this study, we establish that in cells with wild-type mTORC2 activity, FOXO3a is quickly phosphorylated in response to UVB and sequestered in the cytoplasm. In contrast, loss of mTORC2 causes FOXO3a to be localized to the nucleus and sensitizes cells to UVB-induced apoptosis. Furthermore, this sensitization is rescued by knockdown of FOXO3a. Taken together, these studies provide strong evidence that inhibition of mTORC2 enhances UVB-induced apoptosis in a FOXO3a-dependent manner, and suggest that FOXO3a activation by mTORC2 inhibitors may be a valuable chemopreventive target in NMSC.
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13
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Bermudez Y, Stratton SP, Curiel-Lewandrowski C, Warneke J, Hu C, Bowden GT, Dickinson SE, Dong Z, Bode AM, Saboda K, Brooks CA, Petricoin EF, Hurst CA, Alberts DS, Einspahr JG. Activation of the PI3K/Akt/mTOR and MAPK Signaling Pathways in Response to Acute Solar-Simulated Light Exposure of Human Skin. Cancer Prev Res (Phila) 2015; 8:720-8. [PMID: 26031292 DOI: 10.1158/1940-6207.capr-14-0407] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 05/06/2015] [Indexed: 12/14/2022]
Abstract
The incidence of skin cancer is higher than all other cancers and continues to increase, with an average annual cost over $8 billion in the United States. As a result, identifying molecular pathway alterations that occur with UV exposure to strategize more effective preventive and therapeutic approaches is essential. To that end, we evaluated phosphorylation of proteins within the PI3K/Akt and MAPK pathways by immunohistochemistry in sun-protected skin after acute doses of physiologically relevant solar-simulated ultraviolet light (SSL) in 24 volunteers. Biopsies were performed at baseline, 5 minutes, 1, 5, and 24 hours after SSL irradiation. Within the PI3K/Akt pathway, we found activation of Akt (serine 473) to be significantly increased at 5 hours while mTOR (serine 2448) was strongly activated early and was sustained over 24 hours after SSL. Downstream, we observed a marked and sustained increase in phospho-S6 (serine 235/S236), whereas phospho-4E-BP1 (threonines 37/46) was increased only at 24 hours. Within the MAPK pathway, SSL-induced expression of phospho-p38 (threonine 180/tyrosine 182) peaked at 1 to 5 hours. ERK 1/2 was observed to be immediate and sustained after SSL irradiation. Phosphorylation of histone H3 (serine 10), a core structural protein of the nucleosome, peaked at 5 hours after SSL irradiation. The expression of both p53 and COX-2 was increased at 5 hours and was maximal at 24 hours after SSL irradiation. Apoptosis was significantly increased at 24 hours as expected and indicative of a sunburn-type response to SSL. Understanding the timing of key protein expression changes in response to SSL will aid in development of mechanistic-based approaches for the prevention and control of skin cancers.
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Affiliation(s)
- Yira Bermudez
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona
| | - Steven P Stratton
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona
| | - Clara Curiel-Lewandrowski
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona
| | - James Warneke
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona. Department of Surgery, University of Arizona, Tucson, Arizona
| | - Chengcheng Hu
- The University of Arizona Cancer Center, Tucson, Arizona
| | | | | | - Zigang Dong
- The Hormel Institute, University of Minnesota, Austin, Minnesota
| | - Ann M Bode
- The Hormel Institute, University of Minnesota, Austin, Minnesota
| | | | | | | | - Craig A Hurst
- College of Medicine, University of Arizona, Tucson, Arizona. Department of Surgery, University of Arizona, Tucson, Arizona
| | - David S Alberts
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona
| | - Janine G Einspahr
- College of Medicine, University of Arizona, Tucson, Arizona. The University of Arizona Cancer Center, Tucson, Arizona.
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14
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A systems-biological study on the identification of safe and effective molecular targets for the reduction of ultraviolet B-induced skin pigmentation. Sci Rep 2015; 5:10305. [PMID: 25980672 PMCID: PMC4434836 DOI: 10.1038/srep10305] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 04/08/2015] [Indexed: 12/12/2022] Open
Abstract
Melanogenesis is the process of melanin synthesis through keratinocytes-melanocytes interaction, which is triggered by the damaging effect of ultraviolet-B (UVB) rays. It is known that melanogenesis influences diverse cellular responses, including cell survival and apoptosis, via complex mechanisms of feedback and crosstalk. Therefore, an attempt to suppress melanin production by modulating the melanogenesis pathway may induce perturbations in the apoptotic balance of the cells in response to UVB irradiation, which results in various skin diseases such as melasma, vitiligo, and skin cancer. To identify such appropriate target strategies for the reduction of UVB-induced melanin synthesis, we reconstructed the melanogenesis signaling network and developed a Boolean network model. Mathematical simulations of the melanogenesis network model revealed that the inhibition of beta-catenin in the melanocytes effectively reduce melanin production while having minimal influence on the apoptotic balance of the cells. Exposing cells to a beta-catenin inhibitor decreased pigmentation but did not significantly change the B-cell Chronic lymphocytic leukemia/lymphoma 2 expression, a potent regulator of apoptotic balance. Thus, our systems analysis suggests that the inhibition of beta-catenin may be the most appropriate target strategy for the reduction of UVB-induced skin pigmentation.
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15
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Modulating the structure of EGFR with UV light: new possibilities in cancer therapy. PLoS One 2014; 9:e111617. [PMID: 25386651 PMCID: PMC4227675 DOI: 10.1371/journal.pone.0111617] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Accepted: 10/06/2014] [Indexed: 02/06/2023] Open
Abstract
The epidermal growth factor receptor (EGFR) is a member of the ErbB family of receptor tyrosine kinases. EGFR is activated upon binding to e.g. epidermal growth factor (EGF), leading to cell survival, proliferation and migration. EGFR overactivation is associated with tumor progression. We have previously shown that low dose UVB illumination of cancer cells overexpressing EGFR prior to adding EGF halted the EGFR signaling pathway. We here show that UVB illumination of the extracellular domain of EGFR (sEGFR) induces protein conformational changes, disulphide bridge breakage and formation of tryptophan and tyrosine photoproducts such as dityrosine, N-formylkynurenine and kynurenine. Fluorescence spectroscopy, circular dichroism and thermal studies confirm the occurrence of conformational changes. An immunoassay has confirmed that UVB light induces structural changes in the EGF binding site. A monoclonal antibody which competes with EGF for binding sEGFR was used. We report clear evidence that UVB light induces structural changes in EGFR that impairs the correct binding of an EGFR specific antibody that competes with EGF for binding EGFR, confirming that the 3D structure of the EGFR binding domain suffered conformational changes upon UV illumination. The irradiance used is in the same order of magnitude as the integrated intensity in the solar UVB range. The new photonic technology disables a key receptor and is most likely applicable to the treatment of various types of cancer, alone or in combination with other therapies.
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16
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Yang G, Fu Y, Malakhova M, Kurinov I, Zhu F, Yao K, Li H, Chen H, Li W, Lim DY, Sheng Y, Bode AM, Dong Z, Dong Z. Caffeic acid directly targets ERK1/2 to attenuate solar UV-induced skin carcinogenesis. Cancer Prev Res (Phila) 2014; 7:1056-66. [PMID: 25104643 PMCID: PMC4185237 DOI: 10.1158/1940-6207.capr-14-0141] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Caffeic acid (3,4-dihydroxycinnamic acid) is a well-known phenolic phytochemical present in coffee and reportedly has anticancer activities. However, the underlying molecular mechanisms and targeted proteins involved in the suppression of carcinogenesis by caffeic acid are not fully understood. In this study, we report that caffeic acid significantly inhibits colony formation of human skin cancer cells and EGF-induced neoplastic transformation of HaCaT cells dose-dependently. Caffeic acid topically applied to dorsal mouse skin significantly suppressed tumor incidence and volume in a solar UV (SUV)-induced skin carcinogenesis mouse model. A substantial reduction of phosphorylation in mitogen-activated protein kinase signaling was observed in mice treated with caffeic acid either before or after SUV exposure. Caffeic acid directly interacted with ERK1/2 and inhibited ERK1/2 activities in vitro. Importantly, we resolved the cocrystal structure of ERK2 complexed with caffeic acid. Caffeic acid interacted directly with ERK2 at amino acid residues Q105, D106, and M108. Moreover, A431 cells expressing knockdown of ERK2 lost sensitivity to caffeic acid in a skin cancer xenograft mouse model. Taken together, our results suggest that caffeic acid exerts chemopreventive activity against SUV-induced skin carcinogenesis by targeting ERK1 and 2.
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Affiliation(s)
- Ge Yang
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
- Physiology and Pathophysiology, Basic Medical College, Zhengzhou University, ZhengZhou, 450001, China
- The First Affiliated Hospital of Zhengzhou University, ZhengZhou, 450001, China
| | - Yang Fu
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
- The First Affiliated Hospital of Zhengzhou University, ZhengZhou, 450001, China
| | - Margarita Malakhova
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
| | - Igor Kurinov
- Cornell University, NE-CAT, APS, Argonne, IL 60439, USA
| | - Feng Zhu
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
| | - Ke Yao
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
| | - Haitao Li
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
| | - Hanyong Chen
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
| | - Wei Li
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
| | - Do Young Lim
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
| | - Yuqiao Sheng
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
- Physiology and Pathophysiology, Basic Medical College, Zhengzhou University, ZhengZhou, 450001, China
- The First Affiliated Hospital of Zhengzhou University, ZhengZhou, 450001, China
| | - Ann M. Bode
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
| | - Ziming Dong
- Physiology and Pathophysiology, Basic Medical College, Zhengzhou University, ZhengZhou, 450001, China
| | - Zigang Dong
- The Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
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17
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Singh M, Suman S, Shukla Y. New Enlightenment of Skin Cancer Chemoprevention through Phytochemicals: In Vitro and In Vivo Studies and the Underlying Mechanisms. BIOMED RESEARCH INTERNATIONAL 2014; 2014:243452. [PMID: 24757666 PMCID: PMC3976810 DOI: 10.1155/2014/243452] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 12/05/2013] [Accepted: 12/05/2013] [Indexed: 02/08/2023]
Abstract
Skin cancer is still a major cause of morbidity and mortality worldwide. Skin overexposure to ultraviolet irradiations, chemicals, and several viruses has a capability to cause severe skin-related disorders including immunosuppression and skin cancer. These factors act in sequence at various steps of skin carcinogenesis via initiation, promotion, and/or progression. These days cancer chemoprevention is recognized as the most hopeful and novel approach to prevent, inhibit, or reverse the processes of carcinogenesis by intervention with natural products. Phytochemicals have antioxidant, antimutagenic, anticarcinogenic, and carcinogen detoxification capabilities thereby considered as efficient chemopreventive agents. Considerable efforts have been done to identify the phytochemicals which may possibly act on one or several molecular targets that modulate cellular processes such as inflammation, immunity, cell cycle progression, and apoptosis. Till date several phytochemicals in the light of chemoprevention have been studied by using suitable skin carcinogenic in vitro and in vivo models and proven as beneficial for prevention of skin cancer. This revision presents a comprehensive knowledge and the main molecular mechanisms of actions of various phytochemicals in the chemoprevention of skin cancer.
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Affiliation(s)
- Madhulika Singh
- Proteomics Laboratory, Council of Scientific & Industrial Research, Indian Institute of Toxicology Research, P.O. Box 80, M. G. Marg, Lucknow 226001, India
| | - Shankar Suman
- Proteomics Laboratory, Council of Scientific & Industrial Research, Indian Institute of Toxicology Research, P.O. Box 80, M. G. Marg, Lucknow 226001, India
| | - Yogeshwer Shukla
- Proteomics Laboratory, Council of Scientific & Industrial Research, Indian Institute of Toxicology Research, P.O. Box 80, M. G. Marg, Lucknow 226001, India
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18
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Becatti M, Fiorillo C, Barygina V, Cecchi C, Lotti T, Prignano F, Silvestro A, Nassi P, Taddei N. SIRT1 regulates MAPK pathways in vitiligo skin: insight into the molecular pathways of cell survival. J Cell Mol Med 2014; 18:514-29. [PMID: 24410795 PMCID: PMC3955157 DOI: 10.1111/jcmm.12206] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 11/04/2013] [Indexed: 12/15/2022] Open
Abstract
Vitiligo is an acquired and progressive hypomelanotic disease that manifests as circumscribed depigmented patches on the skin. The aetiology of vitiligo remains unclear, but recent experimental data underline the interactions between melanocytes and other typical skin cells, particularly keratinocytes. Our previous results indicate that keratinocytes from perilesional skin show the features of damaged cells. Sirtuins (silent mating type information regulation 2 homolog) 1, well-known modulators of lifespan in many species, have a role in gene repression, metabolic control, apoptosis and cell survival, DNA repair, development, inflammation, neuroprotection and healthy ageing. In the literature there is no evidence for SIRT1 signalling in vitiligo and its possible involvement in disease progression. Here, biopsies were taken from the perilesional skin of 16 patients suffering from non-segmental vitiligo and SIRT1 signalling was investigated in these cells. For the first time, a new SIRT1/Akt, also known as Protein Kinase B (PKB)/mitogen-activated protein kinase (MAPK) signalling has been revealed in vitiligo. SIRT1 regulates MAPK pathway via Akt-apoptosis signal-regulating kinase-1 and down-regulates pro-apoptotic molecules, leading to decreased oxidative stress and apoptotic cell death in perilesional vitiligo keratinocytes. We therefore propose SIRT1 activation as a novel way of protecting perilesional vitiligo keratinocytes from damage.
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Affiliation(s)
- Matteo Becatti
- Department of Biochemical Sciences, University of Florence, Florence, Italy
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19
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Tu Y, Ji C, Yang B, Yang Z, Gu H, Lu CC, Wang R, Su ZL, Chen B, Sun WL, Xia JP, Bi ZG, He L. DNA-dependent protein kinase catalytic subunit (DNA-PKcs)-SIN1 association mediates ultraviolet B (UVB)-induced Akt Ser-473 phosphorylation and skin cell survival. Mol Cancer 2013; 12:172. [PMID: 24365180 PMCID: PMC3922905 DOI: 10.1186/1476-4598-12-172] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 12/10/2013] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The exposure of skin keratinocytes to Ultraviolet (UV) irradiation leads to Akt phosphorylation at Ser-473, which is important for the carcinogenic effects of excessive sun exposure. The present study investigated the underlying mechanism of Akt Ser-473 phosphorylation by UVB radiation. RESULTS We found that DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and mammalian target of rapamycin (mTOR) complex 2 (mTORC2) were both required for UVB-induced Akt Ser-473 phosphorylation in keratinocytes. Inhibition of DNA-PKcs activity via its inhibitor NU7026, a dominant-negative kinase-dead mutation, RNA interference (RNAi) or gene depletion led to the attenuation of UVB-induced Akt Ser-473 phosphorylation. Meanwhile, siRNA silencing or gene depletion of SIN1, a key component of mTORC2, abolished Akt Ser-473 phosphorylation by UVB. Significantly, we discovered that DNA-PKcs was associated with SIN1 in cytosol upon UVB radiation, and this complexation appeared required for Akt Ser-473 phosphorylation. Meanwhile, this DNA-PKcs-SIN1 complexation by UVB was dependent on epidermal growth factor receptor (EGFR) activation, and was disrupted by an EGFR inhibitor (AG1478) or by EGFR depletion. UVB-induced complexation between DNA-PKcs and mTORC2 components was also abolished by NU7026 and DNA-PKcs mutation. Finally, we found that both DNA-PKcs and SIN1 were associated with apoptosis resistance of UVB radiation, and inhibition of them by NU7026 or genetic depletion significantly enhanced UVB-induced cell death and apoptosis. CONCLUSION Taken together, these results strongly suggest that DNA-PKcs-mTORC2 association is required for UVB-induced Akt Ser-473 phosphorylation and cell survival, and might be important for tumor cell transformation.
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Affiliation(s)
| | - Chao Ji
- Department of Dermatology, The First Affiliated Hospital of Kunming Medical University, Yunnan Provincial Institute of Dermatology, Kunming 650032, Yunnan, China.
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20
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Strozyk E, Kulms D. The role of AKT/mTOR pathway in stress response to UV-irradiation: implication in skin carcinogenesis by regulation of apoptosis, autophagy and senescence. Int J Mol Sci 2013; 14:15260-85. [PMID: 23887651 PMCID: PMC3759859 DOI: 10.3390/ijms140815260] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 06/27/2013] [Accepted: 07/01/2013] [Indexed: 02/06/2023] Open
Abstract
Induction of DNA damage by UVB and UVA radiation may generate mutations and genomic instability leading to carcinogenesis. Therefore, skin cells being repeatedly exposed to ultraviolet (UV) light have acquired multilayered protective mechanisms to avoid malignant transformation. Besides extensive DNA repair mechanisms, the damaged skin cells can be eliminated by induction of apoptosis, which is mediated through the action of tumor suppressor p53. In order to prevent the excessive loss of skin cells and to maintain the skin barrier function, apoptotic pathways are counteracted by anti-apoptotic signaling including the AKT/mTOR pathway. However, AKT/mTOR not only prevents cell death, but is also active in cell cycle transition and hyper-proliferation, thereby also counteracting p53. In turn, AKT/mTOR is tuned down by the negative regulators being controlled by the p53. This inhibition of AKT/mTOR, in combination with transactivation of damage-regulated autophagy modulators, guides the p53-mediated elimination of damaged cellular components by autophagic clearance. Alternatively, p53 irreversibly blocks cell cycle progression to prevent AKT/mTOR-driven proliferation, thereby inducing premature senescence. Conclusively, AKT/mTOR via an extensive cross talk with p53 influences the UV response in the skin with no black and white scenario deciding over death or survival.
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Affiliation(s)
- Elwira Strozyk
- Experimental Dermatology, Department of Dermatology, TU Dresden, 01307 Dresden, Germany; E-Mail:
| | - Dagmar Kulms
- Experimental Dermatology, Department of Dermatology, TU Dresden, 01307 Dresden, Germany; E-Mail:
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21
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Liu K, Yu D, Cho YY, Bode AM, Ma W, Yao K, Li S, Li J, Bowden GT, Dong Z, Dong Z. Sunlight UV-induced skin cancer relies upon activation of the p38α signaling pathway. Cancer Res 2013; 73:2181-8. [PMID: 23382047 DOI: 10.1158/0008-5472.can-12-3408] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The activation of cellular signal transduction pathways by solar ultraviolet (SUV) irradiation plays a vital role in skin tumorigenesis. Although many pathways have been studied using pure ultraviolet A (UVA) or ultraviolet B (UVB) irradiation, the signaling pathways induced by SUV (i.e., sunlight) are not understood well enough to permit improvements for prevention, prognosis, and treatment. Here, we report parallel protein kinase array studies aimed at determining the dominant signaling pathway involved in SUV irradiation. Our results indicated that the p38-related signal transduction pathway was dramatically affected by SUV irradiation. SUV (60 kJ UVA/m(2)/3.6 kJ UVB/m(2)) irradiation stimulates phosphorylation of p38α (MAPK14) by 5.78-fold, MSK2 (RPS6KA4) by 6.38-fold, and HSP27 (HSPB1) by 34.56-fold compared with untreated controls. By investigating the tumorigenic role of SUV-induced signal transduction in wild-type and p38 dominant-negative (p38 DN) mice, we found that p38 blockade yielded fewer and smaller tumors. These results establish that p38 signaling is critical for SUV-induced skin carcinogenesis.
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Affiliation(s)
- Kangdong Liu
- The Hormel Institute, University of Minnesota, Austin, MN 55912, USA
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22
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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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Carr TD, DiGiovanni J, Lynch CJ, Shantz LM. Inhibition of mTOR suppresses UVB-induced keratinocyte proliferation and survival. Cancer Prev Res (Phila) 2012; 5:1394-404. [PMID: 23129577 DOI: 10.1158/1940-6207.capr-12-0272-t] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
UV radiation is the major risk factor for developing skin cancer, the most prevalent cancer worldwide. Several studies indicate that mTOR signaling is activated by UVB and may play an important role in skin tumorigenesis. mTOR exists in two functionally and compositionally distinct protein complexes: the rapamycin-sensitive mTOR complex 1 (mTORC1) and the rapamycin-resistant mTOR complex 2 (mTORC2). The purpose of these studies was to investigate the roles of the two mTOR complexes in UVB-mediated proliferation and apoptosis in the skin. We used rapamycin, a pharmacologic inhibitor of mTORC1, and an inducible mTOR-deficient (K5-CreER(T2);mTOR(fl/fl)) mouse model that allows epidermal-specific disruption of mTOR following topical treatment with 4-hydroxytamoxifen (4OHT). Rapamycin blocked UVB-induced phosphorylation of S6K, the downstream target of mTORC1, and significantly reduced UVB-stimulated epidermal proliferation and cell-cycle progression, but had no effect on cell death. In contrast, mTOR deletion, which attenuated UVB-induced phosphorylation of both S6K and the mTORC2 target AKT(Ser473), significantly increased apoptosis both in vivo and in keratinocyte cultures, in addition to reducing hyperproliferation following UVB irradiation. The role of mTORC2 in UVB-induced prosurvival signaling was verified in Rictor(-/-) mouse embryo fibroblasts, which lack functional mTORC2 and were more sensitive to UVB-induced apoptosis than controls. These studies show that mTORC1 and mTORC2 play unique but complementary roles in controlling proliferation and apoptosis in the skin. Our findings underscore the importance of both mTOR complexes in mediating UVB-induced signaling in keratinocytes and provide new insight into the pathogenesis of skin cancer.
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Affiliation(s)
- Theresa D Carr
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA
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24
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Cho YY, Lee MH, Lee CJ, Yao K, Lee HS, Bode AM, Dong Z. RSK2 as a key regulator in human skin cancer. Carcinogenesis 2012; 33:2529-37. [PMID: 22918890 DOI: 10.1093/carcin/bgs271] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Our previous report demonstrated that RSK2 plays an important role in cell proliferation and transformation induced by tumor promoters such as epidermal growth factor mediated through the N-terminal kinase domain of RSK2 in JB6 Cl41 mouse skin epidermal cells in vitro. However, no direct evidence has been reported regarding the relationship of RSK2 activity and human skin cancer. To elucidate the relationship of RSK2 activity and human skin cancer, we examined the effect of knocking down RSK2 expression on epidermal growth factor-induced anchorage-independent transformation in the premalignant HaCaT human skin keratinocyte cell line and on soft agar colony growth of SK-MEL-28 malignant melanoma cells. We found that the phosphorylated protein levels of RSK2 were enhanced in cancer tissues compared with normal tissues in a human skin cancer tissue array. We found that UVB stimulation induced increased in not only the total and phosphorylated protein levels of ERKs and RSK2 but also the nuclear localization and gene expression of RSK2. RSK2 knockdown inhibited proliferation and anchorage-independent transformation of HaCaT cells and soft agar colony growth of malignant melanoma cells. Moreover, RSK2(-/-) mouse embryonic fibroblast (MEF) showed enhanced sub-G(1) accumulation induced by UVB stimulation compared with RSK2(+/+) MEFs, indicating that RSK2 might play an important role in tolerance against stress associated with ultraviolet. Importantly, activated RSK2 protein levels were highly abundant in human skin cancer tissues compared with matched skin normal tissues. Taken together, our results demonstrated that RSK2 plays a key role in neoplastic transformation of human skin cells and in skin cancer growth.
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Affiliation(s)
- Yong-Yeon Cho
- Integrated Research Institute of Pharmaceutical Sciences, College of Pharmacy, The Catholic University of Korea, 43, Jibong-ro, Wonmi-gu, Bucheon-si, Gyeonggi-do 420-743, Republic of Korea.
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25
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Oi N, Chen H, Ok Kim M, Lubet RA, Bode AM, Dong Z. Taxifolin suppresses UV-induced skin carcinogenesis by targeting EGFR and PI3K. Cancer Prev Res (Phila) 2012; 5:1103-14. [PMID: 22805054 DOI: 10.1158/1940-6207.capr-11-0397] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Skin cancer is one of the most commonly diagnosed cancers in the United States. Taxifolin reportedly exerts multiple biologic effects, but the molecular mechanisms and direct target(s) of taxifolin in skin cancer chemoprevention are still unknown. In silico computer screening and kinase profiling results suggest that the EGF receptor (EGFR), phosphoinositide 3-kinase (PI3K), and Src are potential targets for taxifolin. Pull-down assay results showed that EGFR, PI3K, and Src directly interacted with taxifolin in vitro, whereas taxifolin bound to EGFR and PI3K, but not to Src in cells. ATP competition and in vitro kinase assay data revealed that taxifolin interacted with EGFR and PI3K at the ATP-binding pocket and inhibited their kinase activities. Western blot analysis showed that taxifolin suppressed UVB-induced phosphorylation of EGFR and Akt, and subsequently suppressed their signaling pathways in JB6 P+ mouse skin epidermal cells. Expression levels and promoter activity of COX-2 and prostaglandin E(2) (PGE(2)) generation induced by UVB were also attenuated by taxifolin. The effect of taxifolin on UVB-induced signaling pathways and PGE(2) generation was reduced in EGFR knockout murine embryonic fibroblasts (MEF) compared with EGFR wild-type MEFs. Taxifolin also inhibited EGF-induced cell transformation. Importantly, topical treatment of taxifolin to the dorsal skin significantly suppressed tumor incidence, volume, and multiplicity in a solar UV (SUV)-induced skin carcinogenesis mouse model. Further analysis showed that the taxifolin-treated group had a substantial reduction in SUV-induced phosphorylation of EGFR and Akt in mouse skin. These results suggest that taxifolin exerts chemopreventive activity against UV-induced skin carcinogenesis by targeting EGFR and PI3K.
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Affiliation(s)
- Naomi Oi
- The Hormel Institute, University of Minnesota, 801 16 Ave NE, Austin, MN 55912, USA
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26
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Ji H, Ding Z, Hawke D, Xing D, Jiang BH, Mills GB, Lu Z. AKT-dependent phosphorylation of Niban regulates nucleophosmin- and MDM2-mediated p53 stability and cell apoptosis. EMBO Rep 2012; 13:554-60. [PMID: 22510990 DOI: 10.1038/embor.2012.53] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 03/06/2012] [Accepted: 03/22/2012] [Indexed: 02/06/2023] Open
Abstract
Although Niban is highly expressed in human cancer cells, the cellular functions of Niban remain largely unknown. We demonstrate here that ultraviolet irradiation induces phosphorylation of Niban at S602 by AKT, which increases the association of Niban with nucleophosmin and disassociation of nucleophosmin from the MDM2 complex. This leads to the promotion of MDM2-p53 interaction and subsequent p53 degradation, thereby providing an antiapoptotic effect. Conversely, depletion of or deficiency in Niban expression promotes stabilization of p53 with increased cell apoptosis. Our findings illustrate a pivotal role for AKT-mediated phosphorylation of Niban in protecting cells from genotoxic stress-induced cell apoptosis.
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Affiliation(s)
- Haitao Ji
- Brain Tumor Center and Department of Neuro-Oncology, Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
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27
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Einspahr JG, Calvert V, Alberts DS, Curiel-Lewandrowski C, Warneke J, Krouse R, Stratton SP, Liotta L, Longo C, Pellacani G, Pellicani G, Prasad A, Sagerman P, Bermudez Y, Deng J, Bowden GT, Petricoin EF. Functional protein pathway activation mapping of the progression of normal skin to squamous cell carcinoma. Cancer Prev Res (Phila) 2012; 5:403-13. [PMID: 22389437 PMCID: PMC3297971 DOI: 10.1158/1940-6207.capr-11-0427] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Reverse phase protein microarray analysis was used to identify cell signaling derangements in squamous cell carcinoma (SCC) compared with actinic keratosis (AK) and upper inner arm (UIA). We analyzed two independent tissue sets with isolation and enrichment of epithelial cells by laser capture microdissection. Set 1 served as a pilot and a means to identify protein pathway activation alterations that could be further validated in a second independent set. Set 1 was comprised of 4 AK, 13 SCC, and 20 UIA. Set 2 included 15 AK, 9 SCCs, and 20 UIAs. Activation of 51 signaling proteins, known to be involved in tumorigenesis, were assessed for set 1 and showed that the MEK-ERK [mitogen-activated protein (MAP)/extracellular signal-regulated (ERK; MEK)] pathway was activated in SCC compared with AK and UIA, and that epidermal growth factor receptor (EGFR) and mTOR pathways were aberrantly activated in SCC. Unsupervised two-way hierarchical clustering revealed that AK and UIA shared a common signaling network activation architecture while SCC was dramatically different. Statistical analysis found that prosurvival signaling through phosphorylation of ASK and 4EBP1 as well as increased Bax and Bak expression was higher in AK compared with UIA. We expanded pathway network activation mapping in set 2 to 101 key signaling proteins, which corroborated activation of MEK-ERK, EGFR, and mTOR pathways through discovery of a number of upstream and downstream signaling molecules within these pathways to conclude that SCC is indeed a pathway activation-driven disease. Pathway activation mapping of SCC compared with AK revealed several interconnected networks that could be targeted with drug therapy for potential chemoprevention and therapeutic applications.
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Affiliation(s)
- Janine G Einspahr
- University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, AZ 85724, USA.
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28
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Lin F, Xu W, Guan C, Zhou M, Hong W, Fu L, Liu D, Xu A. Niacin protects against UVB radiation-induced apoptosis in cultured human skin keratinocytes. Int J Mol Med 2012; 29:593-600. [PMID: 22246168 PMCID: PMC3577345 DOI: 10.3892/ijmm.2012.886] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 12/23/2011] [Indexed: 11/06/2022] Open
Abstract
Niacin and its related derivatives have been shown to have effects on cellular activities. However, the molecular mechanism of its reduced immunosuppressive effects and photoprotective effects remains unclear. In this study, we investigated the molecular mechanism of the photoprotective effect of niacin in ultraviolet (UV)-irradiated human skin keratinocytes (HaCaT cells). We found that niacin effectively suppressed the UV-induced cell death and cell apoptosis of HaCaT cells. Existing data have shown that AKT activation is involved in the cell survival process. Yet, the potential mechanism of niacin in protection against UV-induced skin damage has thus far not fully been eluvidated. We observed that niacin pretreatment enhances UV induced activation of AKT (Ser473 phosphorylation) as well as that of the downstream signal mTOR (S6 and 4E-BP1 phosphorylation). The PI3K/AKT inhibitor, LY294002, and the mTOR inhibitor, rapamycin, largely neutralized the protective effects of niacin, suggesting that AKT and downstream signaling mTOR/S6 activation are necessary for the niacin-induced protective effects against UV-induced cell death and cell apoptosis. Collectively, our data suggest that niacin may be utilized to prevent UV-induced skin damage and provide a novel mechanism of its photoprotective effects against the UV radiation of sunlight by modulating both AKT and downstream mTOR signaling pathways.
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Affiliation(s)
- Fuquan Lin
- Department of Dermatology, Third People's Hospital of Hangzhou, Hangzhou 310009, PR China
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29
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López-Camarillo C, Ocampo EA, Casamichana ML, Pérez-Plasencia C, Álvarez-Sánchez E, Marchat LA. Protein kinases and transcription factors activation in response to UV-radiation of skin: implications for carcinogenesis. Int J Mol Sci 2011; 13:142-72. [PMID: 22312244 PMCID: PMC3269678 DOI: 10.3390/ijms13010142] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 12/14/2011] [Accepted: 12/16/2011] [Indexed: 12/18/2022] Open
Abstract
Solar ultraviolet (UV) radiation is an important environmental factor that leads to immune suppression, inflammation, photoaging, and skin carcinogenesis. Here, we reviewed the specific signal transduction pathways and transcription factors involved in the cellular response to UV-irradiation. Increasing experimental data supporting a role for p38, MAPK, JNK, ERK1/2, and ATM kinases in the response network to UV exposure is discussed. We also reviewed the participation of NF-κB, AP-1, and NRF2 transcription factors in the control of gene expression after UV-irradiation. In addition, we discussed the promising chemotherapeutic intervention of transcription factors signaling by natural compounds. Finally, we focused on the review of data emerging from the use of DNA microarray technology to determine changes in global gene expression in keratinocytes and melanocytes in response to UV treatment. Efforts to obtain a comprehensive portrait of the transcriptional events regulating photodamage of intact human epidermis after UV exposure reveals the existence of novel factors participating in UV-induced cell death. Progress in understanding the multitude of mechanisms induced by UV-irradiation could lead to the potential use of protein kinases and novel proteins as specific targets for the prevention and control of skin cancer.
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Affiliation(s)
- César López-Camarillo
- Genomics Sciences Program, Oncogenomics and Cancer Proteomics Laboratory, University Autonomous of Mexico City, Av. San Lorenzo 290, 03100, Mexico; E-Mails: (M.L.-C.); (E.Á.-S.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +55-5488-6661 ext. 15307
| | - Elena Aréchaga Ocampo
- Carcinogenesis Laboratory, National Institute of Cancerology, Av. Saint Fernando 22, 14080, México; E-Mail:
| | - Mavil López Casamichana
- Genomics Sciences Program, Oncogenomics and Cancer Proteomics Laboratory, University Autonomous of Mexico City, Av. San Lorenzo 290, 03100, Mexico; E-Mails: (M.L.-C.); (E.Á.-S.)
| | - Carlos Pérez-Plasencia
- Massive Sequencing Unit, National Institute of Cancerology, Av. Saint Fernando 22, 14080, México; E-Mail:
- Genomics Laboratory, FES-I, UBIMED, National Autonomous University of Mexico, Av. De los Barrios 1, 54090, México
| | - Elizbeth Álvarez-Sánchez
- Genomics Sciences Program, Oncogenomics and Cancer Proteomics Laboratory, University Autonomous of Mexico City, Av. San Lorenzo 290, 03100, Mexico; E-Mails: (M.L.-C.); (E.Á.-S.)
| | - Laurence A. Marchat
- Biotechnology Program, Institutional Program of Molecular Biomedicine, National School of Medicine and Homeopathy of the National Polytechnic Institute, Guillermo Massieu Helguera 239, 07320, Mexico; E-Mail:
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30
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Kiguchi K, Kitamura T, Moore T, Rumi M, Chang HC, Treece D, Ruffino L, Connolly K, DiGiovanni J. Dual inhibition of both the epidermal growth factor receptor and erbB2 effectively inhibits the promotion of skin tumors during two-stage carcinogenesis. Cancer Prev Res (Phila) 2010; 3:940-52. [PMID: 20682802 PMCID: PMC2940063 DOI: 10.1158/1940-6207.capr-10-0010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The erbB family of receptor tyrosine kinases are known to play important roles in normal epithelial development and epithelial neoplasia. Considerable evidence also suggests that signaling through the epidermal growth factor receptor (EGFR) plays an important role in multistage skin carcinogenesis in mice; however, less is known about the role of erbB2. In this study, to further examine the role of both erbB2 and EGFR in epithelial carcinogenesis, we examined the effect of a dual erbB2/EGFR tyrosine kinase inhibitor, GW2974, given in the diet on skin tumor promotion during two-stage carcinogenesis in wild-type and BK5.erbB2 mice. In BK5.erbB2 mice, erbB2 is overexpressed in the basal layer of epidermis and leads to heightened sensitivity to skin tumor development. GW2974 effectively inhibited skin tumor promotion by 12-O-tetradecanoylphorbol-13-acetate in wild-type and BK5.erbB2 mice, although a more marked effect was seen in BK5.erbB2 mice. In addition, this inhibitory effect was reversible when GW2974 treatment was withdrawn. GW2974 inhibited 12-O-tetradecanoylphorbol-13-acetate-induced epidermal hyperproliferation, which correlated with reduced activation of both the EGFR and erbB2. These results support the hypothesis that both the EGFR and erbB2 play an important role in the development of skin tumors during two-stage skin carcinogenesis, especially during the tumor promotion stage. Furthermore, the marked sensitivity of BK5.erbB2 mice to the inhibitory effects of GW2974 during tumor promotion suggest greater efficacy for this compound when erbB2 is overexpressed or amplified as an early event in the carcinogenic process.
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MESH Headings
- Algorithms
- Animals
- Antineoplastic Agents/therapeutic use
- Cell Line, Tumor
- Cell Transformation, Neoplastic/drug effects
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/pathology
- Disease Progression
- Drug Evaluation, Preclinical
- ErbB Receptors/antagonists & inhibitors
- ErbB Receptors/genetics
- Gene Expression Regulation, Neoplastic/drug effects
- Mice
- Mice, Transgenic
- Neoplasms, Glandular and Epithelial/drug therapy
- Neoplasms, Glandular and Epithelial/genetics
- Neoplasms, Glandular and Epithelial/pathology
- Protein Kinase Inhibitors/therapeutic use
- Quinazolines/therapeutic use
- Receptor, ErbB-2/antagonists & inhibitors
- Receptor, ErbB-2/genetics
- Skin Neoplasms/drug therapy
- Skin Neoplasms/genetics
- Skin Neoplasms/pathology
- Treatment Outcome
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Affiliation(s)
- Kaoru Kiguchi
- Department of Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Smithville, Texas, USA
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31
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Palmieri G, Capone M, Ascierto ML, Gentilcore G, Stroncek DF, Casula M, Sini MC, Palla M, Mozzillo N, Ascierto PA. Main roads to melanoma. J Transl Med 2009; 7:86. [PMID: 19828018 PMCID: PMC2770476 DOI: 10.1186/1479-5876-7-86] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 10/14/2009] [Indexed: 12/12/2022] Open
Abstract
The characterization of the molecular mechanisms involved in development and progression of melanoma could be helpful to identify the molecular profiles underlying aggressiveness, clinical behavior, and response to therapy as well as to better classify the subsets of melanoma patients with different prognosis and/or clinical outcome. Actually, some aspects regarding the main molecular changes responsible for the onset as well as the progression of melanoma toward a more aggressive phenotype have been described. Genes and molecules which control either cell proliferation, apoptosis, or cell senescence have been implicated. Here we provided an overview of the main molecular changes underlying the pathogenesis of melanoma. All evidence clearly indicates the existence of a complex molecular machinery that provides checks and balances in normal melanocytes. Progression from normal melanocytes to malignant metastatic cells in melanoma patients is the result of a combination of down- or up-regulation of various effectors acting on different molecular pathways.
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Affiliation(s)
- Giuseppe Palmieri
- Istituto di Chimica Biomolecolare, Consiglio Nazionale delle Ricerche (CNR), Sassari, Italy.
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32
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Madson JG, Lynch DT, Svoboda J, Ophardt R, Yanagida J, Putta SK, Bowles A, Trempus CS, Tennant RW, Hansen LA. Erbb2 suppresses DNA damage-induced checkpoint activation and UV-induced mouse skin tumorigenesis. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 174:2357-66. [PMID: 19406993 DOI: 10.2353/ajpath.2009.080638] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The Erbb2 receptor is activated by UV irradiation, the primary cause of non-melanoma skin cancer. We hypothesized that Erbb2 activation contributes to UV-induced skin tumorigenesis by suppressing cell cycle arrest. Consistent with this hypothesis, inhibition of Erbb2 in v-ras(Ha) transgenic mice before UV exposure resulted in both 56% fewer skin tumors and tumors that were 70% smaller. Inhibition of the UV-induced activation of Erbb2 also resulted in milder epidermal hyperplasia, S-phase accumulation, and decreased levels of the cell cycle regulator Cdc25a, suggesting altered cell cycle regulation on inhibition of Erbb2. Further investigation using inhibition or genetic deletion of Erbb2 in vitro revealed reduced Cdc25a levels and increased S-phase arrest in UV-irradiated cells lacking Erbb2 activity. Ectopic expression of Cdc25a prevented UV-induced S-phase arrest in keratinocytes lacking Erbb2 activity, demonstrating that maintenance of Cdc25a by Erbb2 suppresses cell cycle arrest. Examination of checkpoint pathway activation upstream of Cdc25a revealed Erbb2 activation did not alter Ataxia Telangiectasia and Rad3-related/Ataxia Telangiectasia Mutated activity but increased inhibitory phosphorylation of Chk1-Ser(280). Since Akt phosphorylates Chk1-Ser(280), the effect of Erbb2 on phosphatidyl inositol-3-kinase (PI3K)/Akt signaling during UV-induced cell cycle arrest was determined. Erbb2 ablation reduced the UV-induced activation of PI3K while inhibition of PI3K/Akt increased UV-induced S-phase arrest. Thus, UV-induced Erbb2 activation increases skin tumorigenesis through inhibitory phosphorylation of Chk1, Cdc25a maintenance, and suppression of S-phase arrest via a PI3K/Akt-dependent mechanism.
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Affiliation(s)
- Justin G Madson
- Department of Biomedical Sciences, School of Medicine, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
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33
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Cao C, Lu S, Kivlin R, Wallin B, Card E, Bagdasarian A, Tamakloe T, Chu WM, Guan KL, Wan Y. AMP-activated protein kinase contributes to UV- and H2O2-induced apoptosis in human skin keratinocytes. J Biol Chem 2008; 283:28897-908. [PMID: 18715874 DOI: 10.1074/jbc.m804144200] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
AMP-activated protein kinase or AMPK is an evolutionarily conserved sensor of cellular energy status, activated by a variety of cellular stresses that deplete ATP. However, the possible involvement of AMPK in UV- and H(2)O(2)-induced oxidative stresses that lead to skin aging or skin cancer has not been fully studied. We demonstrated for the first time that UV and H(2)O(2) induce AMPK activation (Thr(172) phosphorylation) in cultured human skin keratinocytes. UV and H(2)O(2) also phosphorylate LKB1, an upstream signal of AMPK, in an epidermal growth factor receptor-dependent manner. Using compound C, a specific inhibitor of AMPK and AMPK-specific small interfering RNA knockdown as well as AMPK activator, we found that AMPK serves as a positive regulator for p38 and p53 (Ser(15)) phosphorylation induced by UV radiation and H(2)O(2) treatment. We also observed that AMPK serves as a negative feedback signal against UV-induced mTOR (mammalian target of rapamycin) activation in a TSC2-dependent manner. Inhibiting mTOR and positively regulating p53 and p38 might contribute to the pro-apoptotic effect of AMPK on UV- or H(2)O(2)-treated cells. Furthermore, activation of AMPK also phosphorylates acetyl-CoA carboxylase or ACC, the pivotal enzyme of fatty acid synthesis, and PFK2, the key protein of glycolysis in UV-radiated cells. Collectively, we conclude that AMPK contributes to UV- and H(2)O(2)-induced apoptosis via multiple mechanisms in human skin keratinocytes and AMPK plays important roles in UV-induced signal transduction ultimately leading to skin photoaging and even skin cancer.
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Affiliation(s)
- Cong Cao
- Department of Biology, Providence College, Providence, Rhode Island 02918-0001, USA
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34
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Cao C, Lu S, Kivlin R, Wallin B, Card E, Bagdasarian A, Tamakloe T, Wang WJ, Song X, Chu WM, Kouttab N, Xu A, Wan Y. SIRT1 confers protection against UVB- and H2O2-induced cell death via modulation of p53 and JNK in cultured skin keratinocytes. J Cell Mol Med 2008; 13:3632-43. [PMID: 18681908 PMCID: PMC4516512 DOI: 10.1111/j.1582-4934.2008.00453.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
SIRT1 is a member of a highly conserved gene family (sirtuins) encoding nicotinamide adenine dinucleotide (NAD)(+)-dependent deacetylases, originally found to deacetylate histones leading to increased DNA stability and prolonged survival in yeast and higher organisms, including mammals. SIRT1 has been found to function as a deacetylase for numerous protein targets involved in various cellular pathways, including stress responses, apoptosis and axonal degeneration. However, the role of SIRT1 in ultraviolet (UV) signalling pathways remains unknown. Using cell culture and Western blot analysis in this study we found that SIRT1 is expressed in cultured human skin keratinocytes. Both UV radiation and H(2)O(2), two major inducers of skin cell damage, down-regulate SIRT1 in a time- and dose-dependent manner. We observed that reactive oxygen species-mediated JNK activation is involved in this SIRT1 down-regulation. SIRT1 activator, resveratrol, which has been considered as an important antioxidant, protects against UV- and H(2)O(2)-induced cell death, whereas SIRT inhibitors such as sirtinol and nicotinamide enhance cell death. Activation of SIRT1 negatively regulates UV- and H(2)O(2)-induced p53 acetylation, because nicotinamide and sirtinol as well as SIRT1 siRNA enhance UV- and H(2)O(2)-induced p53 acetylation, whereas SIRT1 activator resveratrol inhibits it. We also found that SIRT1 is involved in UV-induced AMP-activated protein kinase (AMPK) and downstream acetyl-CoA carboxylase (ACC), phosphofructose kinase-2 (PFK-2) phosphorylation. Collectively, our data provide new insights into understanding of the molecular mechanisms of UV-induced skin aging, suggesting that SIRT1 activators such as resveratrol could serve as new anti-skin aging agents.
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Affiliation(s)
- Cong Cao
- Department of Biology, Providence College, Providence, RI 02918-0001, USA
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35
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Cao C, Lu S, Jiang Q, Wang WJ, Song X, Kivlin R, Wallin B, Bagdasarian A, Tamakloe T, Chu WM, Marshall J, Kouttab N, Xu A, Wan Y. EGFR activation confers protections against UV-induced apoptosis in cultured mouse skin dendritic cells. Cell Signal 2008; 20:1830-8. [PMID: 18644433 DOI: 10.1016/j.cellsig.2008.06.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Accepted: 06/19/2008] [Indexed: 01/31/2023]
Abstract
Ultraviolet radiation (UV) induces apoptosis and functional maturation in skin dendritic cells (DCs). However, the molecular mechanisms through which UV activates DCs have not been thoroughly investigated. In this study, we examined the mechanisms of activation and apoptosis of DCs after UV irradiation by focusing on epidermal growth factor receptor (EGFR). Our previous studies have demonstrated that in addition to cognate ligands, EGFR is also activated by UVB irradiation in cultured human skin keratinocytes in vitro and in human skin in vivo. We found for the first time in this study that UV also induces EGFR activation in cultured mouse skin DCs (XS 106 cell line) as well as mouse monocyte-derived dendritic cells (MoDCs). Pharmacological inhibition of EGFR tyrosine kinase significantly inhibits UV-induced ERK, p38, and JNK MAP kinases, and their effectors, transcription factors c-Fos and c-Jun. Inhibition of EGFR also suppresses UV-induced activation of PI3K/AKT/mTOR/S6K and NF-kappaB signal transduction pathways. Our data demonstrated that UV induces LKB1/AMPK pathway, also dependent on EGFR trans-activation. We further observed that MAPK, LKB1/AMPK, PI3K/AKT/mTOR/S6K as well as NF-kappaB activation are impaired in EGFR-/- cells compared to wide type MEF cells after UV radiation. Taken together, we conclude that UV induces multiple signaling pathways mediated by EGFR trans-activation leading to possible maturation, apoptosis and survival, and EGFR activation protects against UV-induced apoptosis in cultured mouse dendritic cells.
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Affiliation(s)
- Cong Cao
- Department of Biology, Providence College, Providence, RI 02918, USA
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Rittié L, Kansra S, Stoll SW, Li Y, Gudjonsson JE, Shao Y, Michael LE, Fisher GJ, Johnson TM, Elder JT. Differential ErbB1 signaling in squamous cell versus basal cell carcinoma of the skin. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 170:2089-99. [PMID: 17525275 PMCID: PMC1899432 DOI: 10.2353/ajpath.2007.060537] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/22/2007] [Indexed: 11/20/2022]
Abstract
In this study, we examined ErbB1 signaling in human basal and squamous cell carcinomas (BCC and SCC) of the skin in vivo. We used enzyme-linked immunosorbent assay, laser capture microdissection-coupled real-time reverse transcriptase-polymerase chain reaction, and immunohistochemistry to assess expression and activation levels of ErbB1 protein, ligands, and potential downstream effectors, in BCC and SCC tumors, stroma, and adjacent epidermis. Although total ErbB1 protein and mRNA were similar in cancerous and normal skin, we found that ErbB1 activation (phospho-Tyr(1068)) was greater in bulk SCC versus BCC or normal skin. In addition, three ErbB1 ligand transcripts (amphiregulin, heparin-binding epidermal growth factor-like growth factor, and transforming growth factor-alpha) were up-regulated in tumor cells of SCC but not BCC. Expression of these ligands was also increased in asymptomatic epidermis adjacent to both SCC and BCC, relative to normal skin. Interestingly, betacellulin transcript levels were inversely regulated compared with the other ligands. Consistently, downstream ErbB1 effectors (Erk1/2 and Akt) were activated in tumor cells of SCC but not of BCC and in adjacent epidermis of both BCC and SCC. These results demonstrate that ErbB1 signaling is hyperactive in tumor cells of SCC but not of BCC and in nearby asymptomatic epidermis of both tumor types. Our results suggest that targeting ErbB1 signaling might be of benefit in the treatment of SCC.
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Affiliation(s)
- Laure Rittié
- Department of Dermatology, University of Michigan Medical Center, 1500 East Medical Center Drive, Ann Arbor, MI 48109-0932, USA
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El-Abaseri TB, Hansen LA. EGFR activation and ultraviolet light-induced skin carcinogenesis. J Biomed Biotechnol 2007; 2007:97939. [PMID: 17541473 PMCID: PMC1874677 DOI: 10.1155/2007/97939] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Accepted: 02/14/2007] [Indexed: 01/08/2023] Open
Abstract
The epidermal growth factor receptor (EGFR) regulates the proliferation of keratinocytes through multiple mechanisms that differ depending on the localization of the cell within the skin. Ultraviolet (UV) irradiation, the main etiologic factor in the development of skin cancer, also activates the receptor. In this review, we discuss how the UV-induced activation of EGFR regulates the response of the skin to UV. UV-induced EGFR activation increases keratinocyte proliferation, suppresses apoptosis, and augments and accelerates epidermal hyperplasia in response to UV. Pharmacological inhibition of the UV-induced activation of EGFR in a genetically initiated mouse skin tumorigenesis model suppresses tumorigenesis and the activation of mitogen-activated protein (MAP) kinases and phosphatidyl inositol-3-kinase (PI3K)/AKT signaling pathways. EGFR has pleiotropic, complex, and cell-type-specific functions in cutaneous keratinocytes; suggesting that the receptor is an appropriate target for the development of molecularly targeted therapies for skin cancer and other pathologies.
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Affiliation(s)
| | - Laura A. Hansen
- Department of Biomedical Sciences, School of Medicine, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
- *Laura A. Hansen:
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El-Abaseri TB, Putta S, Hansen LA. Ultraviolet irradiation induces keratinocyte proliferation and epidermal hyperplasia through the activation of the epidermal growth factor receptor. Carcinogenesis 2005; 27:225-31. [PMID: 16123117 DOI: 10.1093/carcin/bgi220] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Chronic exposure to ultraviolet (UV) irradiation induces skin cancer, in part, through epigenetic mechanisms that result in the deregulation of cell proliferation. UV irradiation also rapidly activates the epidermal growth factor receptor (EGFR). Since EGFR activation is strongly mitogenic in many cell types including keratinocytes of the skin, we hypothesized that UV-induced cutaneous proliferation results from EGFR activation. The role of EGFR activation in the response of the skin to UV was determined using Egfr-null and Egfr-wild-type skin grafted onto athymic nude mouse hosts, because Egfr-null mice survive only a few days after birth. EGFR was rapidly activated in mouse epidermis following exposure to UV, as detected by the phosphorylation of EGFR on tyrosine residues 992, 1045, 1068 and 1173. UV induced epidermal hyperplasia in Egfr-wild-type skin between 48 and 72 h post-UV. However, no epidermal hyperplasia occurred in Egfr-null skin. Baseline cell proliferation was similar in skin grafts of both genotypes. However, UV exposure increased cell proliferation, as measured by Ki67 immunohistochemistry and proliferating cell nuclear antigen immunoblotting, maximally at 48 h to a level more than three times higher in wild-type compared with Egfr-null skin. Apoptotic cell death, as measured by terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling (TUNEL) analysis, was also increased in UV-exposed Egfr-null skin when compared with wild-type 1-2 days post-UV. These changes in cellular homeostasis after UV were accompanied by increased cyclin D expression in wild-type but not Egfr-null skin and increased expression of p53 and the cyclin-dependent kinase (CDK) inhibitor p21waf1 in Egfr-null skin when compared with wild-type. Collectively, these results demonstrate that the UV-induced activation of EGFR augments keratinocyte proliferation and suppresses apoptosis, leading to epidermal hyperplasia, associated with increased G1 cyclin expression and suppression of CDK inhibitor expression.
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Affiliation(s)
- Taghrid B El-Abaseri
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE 68178, USA
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Bachelor MA, Cooper SJ, Sikorski ET, Bowden GT. Inhibition of p38 mitogen-activated protein kinase and phosphatidylinositol 3-kinase decreases UVB-induced activator protein-1 and cyclooxygenase-2 in a SKH-1 hairless mouse model. Mol Cancer Res 2005; 3:90-9. [PMID: 15755875 DOI: 10.1158/1541-7786.mcr-04-0065] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Activation of activator protein-1 (AP-1) and increased expression of cyclooxygenase-2 (COX-2) have been clearly shown to play a functional role in UVB-induced skin tumor promotion. In this study, we examined UVB-induced signal transduction pathways in SKH-1 mouse epidermis leading to increases in COX-2 expression and AP-1 activity. We observed rapid increases in p38 mitogen-activated protein kinase (MAPK) signaling through activation of p38 MAPK and its downstream target, MAPK activated protein kinase-2. UVB also increased phosphatidylinositol 3-kinase (PI3K) signaling as observed through increases in AKT and GSK-3beta phosphorylation. Activation of the p38 MAPK and PI3K pathways results in the phosphorylation of cyclic AMP-responsive element binding protein, which was also observed in UVB-irradiated SKH-1 mice. Topical treatment with SB202190 (a specific inhibitor of p38 MAPK) or LY294002 (a specific inhibitor of PI3K) significantly decreased UVB-induced AP-1 activation by 84% and 68%, respectively, as well as COX-2 expression. Our data show that in mouse epidermis, UVB activation of the p38 MAPK and PI3K pathways leads to AP-1 activation and COX-2 expression.
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Affiliation(s)
- Michael A Bachelor
- Department of Cell Biology and Anatomy, Arizona Cancer Center, University of Arizona, 1515 North Campbell Avenue, Room 4999, Tucson, AZ 85724, USA
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Kadekaro AL, Kavanagh R, Kanto H, Terzieva S, Hauser J, Kobayashi N, Schwemberger S, Cornelius J, Babcock G, Shertzer HG, Scott G, Abdel-Malek ZA. alpha-Melanocortin and endothelin-1 activate antiapoptotic pathways and reduce DNA damage in human melanocytes. Cancer Res 2005; 65:4292-9. [PMID: 15899821 DOI: 10.1158/0008-5472.can-04-4535] [Citation(s) in RCA: 200] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
UV radiation is an important etiologic factor for skin cancer, including melanoma. Constitutive pigmentation and the ability to tan are considered the main photoprotective mechanism against sun-induced carcinogenesis. Pigmentation in the skin is conferred by epidermal melanocytes that synthesize and transfer melanin to keratinocytes. Therefore, insuring the survival and genomic stability of epidermal melanocytes is critical for inhibiting photocarcinogenesis, particularly melanoma, the most deadly form of skin cancer. The paracrine factors alpha-melanocortin and endothelin-1 are critical for the melanogenic response of cultured human melanocytes to UV radiation. We report that alpha-melanocortin and endothelin-1 rescued human melanocytes from UV radiation-induced apoptosis and reduced DNA photoproducts and oxidative stress. The survival effects of alpha-melanocortin and endothelin-1 were mediated by activation of the melanocortin 1 and endothelin receptors, respectively. Treatment of melanocytes with alpha-melanocortin and/or endothelin-1 before exposure to UV radiation activated the inositol triphosphate kinase-Akt pathway and increased the phosphorylation and expression of the microphthalmia-related transcription factor. Treatment with alpha-melanocortin and/or endothelin-1 enhanced the repair of cyclobutane pyrimidine dimers and reduced the levels of hydrogen peroxide induced by UV radiation. These effects are expected to reduce genomic instability and mutagenesis.
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Affiliation(s)
- Ana Luisa Kadekaro
- Department of Dermatology, University of Cincinnati College of Medicine and Shriners' Burns Institute, Cincinnati, Ohio 45267-0592, USA
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El-Abaseri TB, Fuhrman J, Trempus C, Shendrik I, Tennant RW, Hansen LA. Chemoprevention of UV light-induced skin tumorigenesis by inhibition of the epidermal growth factor receptor. Cancer Res 2005; 65:3958-65. [PMID: 15867397 DOI: 10.1158/0008-5472.can-04-2204] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The epidermal growth factor receptor (EGFR) is activated in skin cells following UV irradiation, the primary cause of nonmelanoma skin cancer. The EGFR inhibitor AG1478 prevented the UV-induced activation of EGFR and of downstream signaling pathways through c-Jun NH2-terminal kinases, extracellular signal-regulated kinases, p38 kinase, and phosphatidylinositol 3-kinase in the skin. The extent to which the UV-induced activation of EGFR influences skin tumorigenesis was determined in genetically initiated v-ras(Ha) transgenic Tg.AC mice, which have enhanced susceptibility to skin carcinogenesis. Topical treatment or i.p. injection of AG1478 before UV exposure blocked the UV-induced activation of EGFR in the skin and decreased skin tumorigenesis in Tg.AC mice. AG1478 treatment before each of several UV exposures decreased the number of papillomas arising and the growth of these tumors by approximately 50% and 80%, respectively. Inhibition of EGFR suppressed proliferation, increased apoptotic cell death, and delayed the onset of epidermal hyperplasia following UV irradiation. Genetic ablation of Egfr similarly delayed epidermal hyperplasia in response to UV exposure. Thus, the UV-induced activation of EGFR promotes skin tumorigenesis by suppressing cell death, augmenting cell proliferation, and accelerating epidermal hyperplasia in response to UV. These results suggest that EGFR may be an appropriate target for the chemoprevention of UV-induced skin cancer.
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Affiliation(s)
- Taghrid B El-Abaseri
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, Nebraska 68178, USA
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