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Shiau JP, Chuang YT, Tang JY, Yang KH, Chang FR, Hou MF, Yen CY, Chang HW. The Impact of Oxidative Stress and AKT Pathway on Cancer Cell Functions and Its Application to Natural Products. Antioxidants (Basel) 2022; 11:1845. [PMID: 36139919 PMCID: PMC9495789 DOI: 10.3390/antiox11091845] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/14/2022] [Accepted: 09/16/2022] [Indexed: 01/10/2023] Open
Abstract
Oxidative stress and AKT serine-threonine kinase (AKT) are responsible for regulating several cell functions of cancer cells. Several natural products modulate both oxidative stress and AKT for anticancer effects. However, the impact of natural product-modulating oxidative stress and AKT on cell functions lacks systemic understanding. Notably, the contribution of regulating cell functions by AKT downstream effectors is not yet well integrated. This review explores the role of oxidative stress and AKT pathway (AKT/AKT effectors) on ten cell functions, including apoptosis, autophagy, endoplasmic reticulum stress, mitochondrial morphogenesis, ferroptosis, necroptosis, DNA damage response, senescence, migration, and cell-cycle progression. The impact of oxidative stress and AKT are connected to these cell functions through cell function mediators. Moreover, the AKT effectors related to cell functions are integrated. Based on this rationale, natural products with the modulating abilities for oxidative stress and AKT pathway exhibit the potential to regulate these cell functions, but some were rarely reported, particularly for AKT effectors. This review sheds light on understanding the roles of oxidative stress and AKT pathway in regulating cell functions, providing future directions for natural products in cancer treatment.
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Affiliation(s)
- Jun-Ping Shiau
- Division of Breast Oncology and Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan or
| | - Ya-Ting Chuang
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Jen-Yang Tang
- School of Post-Baccalaureate Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Department of Radiation Oncology, Kaohsiung Medical University Hospital, Kaoshiung Medical University, Kaohsiung 80708, Taiwan
| | - Kun-Han Yang
- Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Fang-Rong Chang
- Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Ming-Feng Hou
- Division of Breast Oncology and Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan or
- Department of Biomedical Science and Environmental Biology, College of Life Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Ching-Yu Yen
- Department of Oral and Maxillofacial Surgery, Chi-Mei Medical Center, Tainan 71004, Taiwan
- School of Dentistry, Taipei Medical University, Taipei 11031, Taiwan
| | - Hsueh-Wei Chang
- Department of Biomedical Science and Environmental Biology, College of Life Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Center for Cancer Research, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
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Xeroderma Pigmentosum C: A Valuable Tool to Decipher the Signaling Pathways in Skin Cancers. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:6689403. [PMID: 34630850 PMCID: PMC8495593 DOI: 10.1155/2021/6689403] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 03/24/2021] [Accepted: 04/19/2021] [Indexed: 12/13/2022]
Abstract
Xeroderma pigmentosum (XP) is a rare autosomal genodermatosis that manifests clinically with pronounced sensitivity to ultraviolet (UV) radiation and the high probability of the occurrence of different skin cancer types in XP patients. XP is mainly caused by mutations in XP-genes that are involved in the nucleotide excision repair (NER) pathway that functions in the removal of bulky DNA adducts. Besides, the aggregation of DNA lesions is a life-threatening event that might be a key for developing various mutations facilitating cancer appearance. One of the key players of NER is XPC that senses helical distortions found in damaged DNA. The majority of XPC gene mutations are nonsense, and some are missense leading either to the loss of XPC protein or to the expression of a truncated nonfunctional version. Given that no cure is yet available, XPC patients should be completely protected and isolated from all types of UV radiations (UVR). Although it is still poorly understood, the characterization of the proteomic signature of an XPC mutant is essential to identify mediators that could be targeted to prevent cancer development in XPC patients. Unraveling this proteomic signature is fundamental to decipher the signaling pathways affected by the loss of XPC expression following exposure to UVB radiation. In this review, we will focus on the signaling pathways disrupted in skin cancer, pathways modulating NER's function, including XPC, to disclose signaling pathways associated with XPC loss and skin cancer occurrence.
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Han EJ, Kim SY, Han HJ, Kim HS, Kim KN, Fernando IPS, Madusanka DMD, Dias MKHM, Cheong SH, Park SR, Han YS, Lee K, Ahn G. UVB protective effects of Sargassum horneri through the regulation of Nrf2 mediated antioxidant mechanism. Sci Rep 2021; 11:9963. [PMID: 33976251 PMCID: PMC8113259 DOI: 10.1038/s41598-021-88949-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 04/06/2021] [Indexed: 12/30/2022] Open
Abstract
The present study aimed to evaluate the protective effect of a methanol extract of Sargassum horneri (SHM), which contains 6-hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydrobenzofuran-2(4H)-one (HTT) and apo-9'-fucoxanthinone, against ultraviolet B (UVB)-induced cellular damage in human keratinocytes and its underlying mechanism. SHM significantly improved cell viability of UVB-exposed human keratinocytes by reducing the generation of intracellular reactive oxygen species (ROS). Moreover, SHM inhibited UVB exposure-induced apoptosis by reducing the formation of apoptotic bodies and the populations of the sub-G1 hypodiploid cells and the early apoptotic cells by modulating the expression of the anti- and pro-apoptotic molecules, Bcl-2 and Bax, respectively. Furthermore, SHM inhibited NF-κB p65 activation by inducing the activation of Nrf2/HO-1 signaling. The cytoprotective and antiapoptotic activities of SHM are abolished by the inhibition of HO-1 signaling. In further study, SHM restored the skin dryness and skin barrier disruption in UVB-exposed human keratinocytes. Based to these results, our study suggests that SHM protects the cells against UVB-induced cellular damages through the Nrf2/HO-1/NF-κB p65 signaling pathway and may be potentially useful for the prevention of UVB-induced skin damage.
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Affiliation(s)
- Eui Jeong Han
- Research Center for Healthcare and Biomedical Engineering, Chonnam National University, Yeosu, 59626, Republic of Korea
- Department of Food Technology and Nutrition, Chonnam National University, Yeosu, 59626, Republic of Korea
| | - Seo-Young Kim
- Chuncheon Center, Korea Basic Science Institute, Chuncheon, 24341, Republic of Korea
| | - Hee-Jin Han
- Department of Food Technology and Nutrition, Chonnam National University, Yeosu, 59626, Republic of Korea
| | - Hyun-Soo Kim
- National Marine Biodiversity Institute of Korea, Janghang-eup, Seocheon, 33662, Republic of Korea
| | - Kil-Nam Kim
- Chuncheon Center, Korea Basic Science Institute, Chuncheon, 24341, Republic of Korea
| | - Ilekuttige Priyan Shanura Fernando
- Control Center for Aquatic Animal Diseases, Chonnam National University, Yeosu, 59626, Republic of Korea
- Department of Marine Bio-Food Sciences, Chonnam National University, Yeosu, 59626, Republic of Korea
| | | | | | - Sun Hee Cheong
- Department of Food Technology and Nutrition, Chonnam National University, Yeosu, 59626, Republic of Korea
- Department of Marine Bio-Food Sciences, Chonnam National University, Yeosu, 59626, Republic of Korea
| | - Sang Rul Park
- Estuarine and Coastal Ecology Laboratory, Department of Marine Life Sciences, Jeju National University, Jeju, 63243, Republic of Korea
| | - Young Seok Han
- Neo Environmental Business Co., Daewoo Technopark, Doyak-ro, Bucheon, 14523, Republic of Korea
| | - Kyounghoon Lee
- Division of Fisheries Science, Chonnam National University, Yeosu, 59626, Republic of Korea.
- Department of Marine Technology, Chonnam National University, Yeosu, 59626, Republic of Korea.
| | - Ginnae Ahn
- Department of Food Technology and Nutrition, Chonnam National University, Yeosu, 59626, Republic of Korea.
- Department of Marine Bio-Food Sciences, Chonnam National University, Yeosu, 59626, Republic of Korea.
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4
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Kirenol Inhibits B[a]P-Induced Oxidative Stress and Apoptosis in Endothelial Cells via Modulation of the Nrf2 Signaling Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:5585303. [PMID: 33981385 PMCID: PMC8088375 DOI: 10.1155/2021/5585303] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/18/2021] [Accepted: 04/15/2021] [Indexed: 12/20/2022]
Abstract
Atherosclerosis is a persistent inflammatory disorder specified by the dysfunction of the arteries, the world's leading cause of cardiovascular diseases. We sought to determine the effectiveness of KRL in B[a]P-induced oxidative stress and programmed cell death in endothelial cells. Western blotting, real-time PCR, DCFH2-DA, and TUNEL staining were performed to detect pPI3K, pAKT, Nrf2, HO-1, NQO-1, Bcl2, Bax, and caspase-3 on the HUVECs. Through the pretreatment of KRL, a drastic enhancement was observed in the cell viability of HUVECs, whereas DNA damage and generation of reactive oxygen species induced by B[a]P was suppressed. KRL's potential use as an antioxidant was observed to have a direct correlation with an antioxidant gene's augmented expression and the nuclear translocation activation of Nrf2, even during the event when B[a]P was found to be absent. In addition, this study proved that the signaling cascades of PI3K/AKT mediated Nrf2 translocation. Activation of suppressed nuclear Nrf2 and reduced antioxidant genes across cells interacting with an LY294002 confirmed this phenomenon. In addition, knockdown of Nrf2 by Nrf2-siRNA transfection abolished the protective effects of KRL on HUVECs cells against oxidative damage. Finally, the expression of apoptotic proteins also supported the hypothesis that KRL may inhibit endothelial dysfunction. This study showed that KRL potentially prevents B[a]P-induced redox imbalance in the vascular endothelium by inducing the Nrf2 signaling via the PI3K/AKT pathway.
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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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6
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Becatti M, Barygina V, Mannucci A, Emmi G, Prisco D, Lotti T, Fiorillo C, Taddei N. Sirt1 Protects against Oxidative Stress-Induced Apoptosis in Fibroblasts from Psoriatic Patients: A New Insight into the Pathogenetic Mechanisms of Psoriasis. Int J Mol Sci 2018; 19:ijms19061572. [PMID: 29799444 PMCID: PMC6032104 DOI: 10.3390/ijms19061572] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 01/17/2023] Open
Abstract
Psoriasis, a multisystem chronic disease characterized by abnormal keratinocyte proliferation, has an unclear pathogenesis where systemic inflammation and oxidative stress play mutual roles. Dermal fibroblasts, which are known to provide a crucial microenvironment for epidermal keratinocyte function, represented the selected experimental model in our study which aimed to clarify the potential role of SIRT1 in the pathogenetic mechanisms of the disease. We firstly detected the presence of oxidative stress (lipid peroxidation and total antioxidant capacity), significantly reduced SIRT1 expression level and activity, mitochondrial damage and apoptosis (caspase-3, -8 and -9 activities) in psoriatic fibroblasts. Upon SIRT1 activation, redox balance was re-established, mitochondrial function was restored and apoptosis was no longer evident. Furthermore, we examined p38, ERK and JNK activation, which was strongly altered in psoriatic fibroblasts, in response to SIRT1 activation and we measured caspase-3 activity in the presence of specific MAPK inhibitors demonstrating the key role of the SIRT1 pathway against apoptotic cell death via MAPK modulation. Our results clearly demonstrate the involvement of SIRT1 in the protective mechanisms related to fibroblast injury in psoriasis. SIRT1 activation exerts an active role in restoring both mitochondrial function and redox balance via modulation of MAPK signaling. Hence, SIRT1 can be proposed as a specific tool for the treatment of psoriasis.
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Affiliation(s)
- Matteo Becatti
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy.
| | - Victoria Barygina
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy.
| | - Amanda Mannucci
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy.
| | - Giacomo Emmi
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy.
| | - Domenico Prisco
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy.
| | - Torello Lotti
- Department of Dermatology, University of Rome "G. Marconi", 00146 Rome, Italy.
| | - Claudia Fiorillo
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy.
| | - Niccolò Taddei
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy.
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7
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Matic I, Revandkar A, Chen J, Bisio A, Dall'Acqua S, Cocetta V, Brun P, Mancino G, Milanese M, Mattei M, Montopoli M, Alimonti A. Identification of Salvia haenkei as gerosuppressant agent by using an integrated senescence-screening assay. Aging (Albany NY) 2017; 8:3223-3240. [PMID: 27922821 PMCID: PMC5270665 DOI: 10.18632/aging.101076] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/14/2016] [Indexed: 12/13/2022]
Abstract
Cellular senescence is a stable cell cycle arrest that is the causative process of aging. The PI3K/AKT/mTOR pathway is implicated in the control of cellular senescence and inhibitors of this pathway have been successfully used for life span prolongation experiments in mammals. PTEN is the major regulator of the PI3K/AKT/mTOR pathway and loss of PTEN promotes a senescence response termed PICS. Here we report a novel-screening assay, for the identification of compounds that block different types of senescence response. By testing a library of more than 3000 natural and chemical compounds in PTEN deficient cells we have found that an extract from Salvia haenkei (SH), a native plant of Bolivia is a potent inhibitor of PICS. SH also decreases replicative and UV-mediated senescence in human primary fibroblasts and in a model of in vitro reconstructed human epidermis. Mechanistically, SH treatment affects senescence driven by UV by interfering with IL1-α signalling. Pre-clinical and clinical testing of this extract by performing toxicity and irritability evaluation in vitro also demonstrate the safety of SH extract for clinical use as anti-aging skin treatment.
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Affiliation(s)
- Ivana Matic
- Laboratory for Research and Development in Aging, Atrahasis S.r.l., 00189 Rome, Italy.,Research Center, San Pietro "Fatebenefratelli", 00189 Rome, Italy
| | - Ajinkya Revandkar
- Institute of Oncology Research (IOR), Bellinzona CH 6500, Switzerland
| | - Jingjing Chen
- Institute of Oncology Research (IOR), Bellinzona CH 6500, Switzerland
| | - Angela Bisio
- Department of Chemistry and Pharmaceutical Technologies, University of Genova, 16126 Genova, Italy
| | - Stefano Dall'Acqua
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35121 Padova, Italy
| | - Veronica Cocetta
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35121 Padova, Italy
| | - Paola Brun
- Department of Molecular Medicine, University of Padova, 35121 Padova, Italy
| | - Giorgio Mancino
- Research Center, San Pietro "Fatebenefratelli", 00189 Rome, Italy
| | | | - Maurizio Mattei
- Animal Technology Facility of University Tor Vergata, 00173 Rome, Italy
| | - Monica Montopoli
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35121 Padova, Italy
| | - Andrea Alimonti
- Laboratory for Research and Development in Aging, Atrahasis S.r.l., 00189 Rome, Italy.,Institute of Oncology Research (IOR), Bellinzona CH 6500, Switzerland
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Li R, Li J, Sang D, Lan Q. Phosphorylation of AKT induced by phosphorylated Hsp27 confers the apoptosis-resistance in t-AUCB-treated glioblastoma cells in vitro. J Neurooncol 2014; 121:83-9. [PMID: 25200832 DOI: 10.1007/s11060-014-1610-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 08/30/2014] [Indexed: 11/26/2022]
Abstract
The aim of this study is to determine whether phosphorylation of AKT could be effected by t-AUCB-induced p-Hsp27 and whether p-AKT inhibition sensitizes glioblastoma cells to t-AUCB, and to evaluate the effects of simultaneous inhibition of p-Hsp27 and p-AKT on t-AUCB treated glioblastoma cells. Cell growth was detected using CCK-8 assay; Caspase-3 activity assay kits and flow cytometry were used in apoptosis analysis; Western blot analysis was used to detect p-Hsp27 and p-AKT levels; RNA interference using the siRNA oligos of Hsp27 was performed to knockdown gene expression of Hsp27. All data were analyzed by the Student-Newman-Keul's test. We demonstrated that t-AUCB treatment induces AKT phosphorylation by activating Hsp27 in U251 and LN443 cell lines. Inhibition of AKT phosphorylation by AKT inhibitor IV sensitizes glioblastoma cells to t-AUCB, strengthens t-AUCB suppressing cell growth and inducing cell apoptosis. We also found inhibiting both p-Hsp27 and p-AKT synergistically strengthen t-AUCB suppressing cell growth. Thus, p-AKT induced by p-Hsp27 confers the apoptosis-resistance in t-AUCB-treated glioblastoma cells. Targeting p-Hsp27 and/or p-AKT may be a potential effective strategy for the treatment of glioblastoma.
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Affiliation(s)
- Rujun Li
- Department of Neurosurgery, Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou, 215004, Jiangsu, China
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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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10
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Rauhala L, Hämäläinen L, Salonen P, Bart G, Tammi M, Pasonen-Seppänen S, Tammi R. Low dose ultraviolet B irradiation increases hyaluronan synthesis in epidermal keratinocytes via sequential induction of hyaluronan synthases Has1-3 mediated by p38 and Ca2+/calmodulin-dependent protein kinase II (CaMKII) signaling. J Biol Chem 2013; 288:17999-8012. [PMID: 23645665 DOI: 10.1074/jbc.m113.472530] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hyaluronan, a major epidermal extracellular matrix component, responds strongly to different kinds of injuries. This also occurs by UV radiation, but the mechanisms involved are poorly understood. The effects of a single ultraviolet B (UVB) exposure on hyaluronan content and molecular mass, and expression of genes involved in hyaluronan metabolism were defined in monolayer and differentiated, organotypic three-dimensional cultures of rat epidermal keratinocytes. The signals regulating the response were characterized using specific inhibitors and Western blotting. In monolayer cultures, UVB increased hyaluronan synthase Has1 mRNA already 4 h postexposure, with a return to control level by 24 h. In contrast, Has2 and Has3 were persistently elevated from 8 h onward. Silencing of Has2 and especially Has3 decreased the UVB-induced accumulation of hyaluronan. p38 and Ca(2+)/calmodulin-dependent protein kinase II pathways were found to be involved in the UVB-induced up-regulation of Has2 and Has3 expression, respectively, and their inhibition reduced hyaluronan deposition. However, the expressions of the hyaluronan-degrading enzymes Hyal1 and Hyal2 and the hyaluronan receptor Cd44 were also up-regulated by UVB. In organotypic cultures, UVB treatment also resulted in increased expression of both Has and Hyal genes and shifted hyaluronan toward a smaller size range. Histochemical stainings indicated localized losses of hyaluronan in the epidermis. The data show that exposure of keratinocytes to acute, low dose UVB increases hyaluronan synthesis via up-regulation of Has2 and Has3. The simultaneously enhanced catabolism of hyaluronan demonstrates the complexity of the UVB-induced changes. Nevertheless, enhanced hyaluronan metabolism is an important part of the adaptation of keratinocytes to radiation injury.
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Affiliation(s)
- Leena Rauhala
- School of Medicine, Institute of Biomedicine/Anatomy, University of Eastern Finland, Kuopio Campus, Yliopistonranta 1 E, P.O. Box 1627, 70211 Kuopio, Finland.
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11
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Syed DN, Afaq F, Mukhtar H. Differential activation of signaling pathways by UVA and UVB radiation in normal human epidermal keratinocytes. Photochem Photobiol 2012; 88:1184-90. [PMID: 22335604 DOI: 10.1111/j.1751-1097.2012.01115.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ultraviolet (UV) radiation from the solar spectrum is a major etiological factor for many cutaneous pathologies including cancer. By understanding changes in cell signaling pathways induced by UVA and UVB, novel strategies for prevention and treatment of UV-related pathologies could be developed. However, much of the information in the literature from various laboratories cannot cross talk because of difficulties associated with the use of ill-defined light sources and physiologically irrelevant light dosimetry. Herein, we have assessed the effect of exposure of normal human epidermal keratinocytes (NHEK) to UVA (2 and 4 J cm(-2)) or UVB (20 and 40 mJ cm(-2)) radiation. Employing western blot analysis, we found that exposure of NHEK to UVB, but not UVA, phosphorylates JNK1/2 at Th(183)/Tyr(185), STAT3 at Ser(727) , AKT at Ser(473) and increases c-Fos expression, whereas exposure to UVA, but not UVB, phosphorylates AKT at Thr(308). UVB as well as UVA exposure leads to increased phosphorylation of (1) ERK1/2 at Th(202)/Tyr(204); (2) p38 at Th(180)/Tyr(204); (3) STAT3 at Tyr(705); (4) mTOR at Thr(2448); and (v) p70S6k at Thr(421) /Ser(424); enhanced expression of PI3K (p85) and c-jun; and nuclear translocation of NFκB proteins. These findings could be considered as a beginning for understanding the differential effects of UVA and UVB in the human skin and may have implications both with respect to risk assessment from exposure to solar UV radiation, and to target interventions against signaling events mediated by UVA and UVB.
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Affiliation(s)
- Deeba N Syed
- Department of Dermatology, University of Wisconsin, Madison, WI, USA
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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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Sustained expression of NADPH oxidase 4 by p38 MAPK-Akt signaling potentiates radiation-induced differentiation of lung fibroblasts. J Mol Med (Berl) 2010; 88:807-16. [PMID: 20396861 DOI: 10.1007/s00109-010-0622-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 02/26/2010] [Accepted: 03/16/2010] [Indexed: 01/10/2023]
Abstract
Radiation-induced fibrosis (RIF) is a long-term adverse effect of curative radiotherapy; however, the distinct molecular mechanisms of RIF in neighboring normal tissue are not fully understood. We investigated the mechanisms underlying radiation-induced fibroblast differentiation into myofibroblasts. Lung fibroblasts produced reactive oxygen species (ROS) immediately after irradiation, the level of which remained increased for 24 h. The NADPH oxidase inhibitor, diphenyleneiodonium (DPI), suppressed ROS production and significantly decreased the radiation-induced expression of alpha-smooth muscle actin (alpha-SMA) and fibronectin (FN). The mRNA and protein expression of Nox4 was increased by radiation, and siRNA knockdown of Nox4 reduced alpha-SMA and FN levels. Increased phosphorylation of p38MAPK, Erk, and PI3k/Akt was observed after irradiation. Inhibitors of p38 MAPK and Akt, but not of Erk, reduced radiation-induced fibroblast differentiation and Nox4 expression. Notably, DPI partially decreased phosphorylation of p38MAPK and Akt, suggesting that p38MAPK, Akt, and Nox4 may cooperate in a positive feedback loop. Nox4 expression was also increased during bleomycin-induced fibroblast differentiation, and downregulation of Nox4 reduced alpha-SMA levels and extracellular matrix (ECM) accumulation. These results demonstrate that interfering Nox4 activation can be a potential strategy to disrupt fibrotic process.
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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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Song L, Li J, Ye J, Yu G, Ding J, Zhang D, Ouyang W, Dong Z, Kim SO, Huang C. p85alpha acts as a novel signal transducer for mediation of cellular apoptotic response to UV radiation. Mol Cell Biol 2007; 27:2713-31. [PMID: 17242187 PMCID: PMC1899908 DOI: 10.1128/mcb.00657-06] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Apoptosis is an important cellular response to UV radiation (UVR), but the corresponding mechanisms remain largely unknown. Here we report that the p85alpha regulatory subunit of phosphatidylinositol 3-kinase (PI-3K) exerted a proapoptotic role in response to UVR through the induction of tumor necrosis factor alpha (TNF-alpha) gene expression. This special effect of p85alpha was unrelated to the PI-3K-dependent signaling pathway. Further evidence demonstrated that the inducible transcription factor NFAT3 was the major downstream target of p85alpha for the mediation of UVR-induced apoptosis and TNF-alpha gene transcription. p85alpha regulated UVR-induced NFAT3 activation by modulation of its nuclear translocation and DNA binding and the relevant transcriptional activities. Gel shift assays and site-directed mutagenesis allowed the identification of two regions in the TNF-alpha gene promoter that served as the NFAT3 recognition sequences. Chromatin immunoprecipitation assays further confirmed that the recruitment of NFAT3 to the endogenous TNF-alpha promoter was regulated by p85alpha upon UVR exposure. Finally, the knockdown of the NFAT3 level by its specific small interfering RNA decreased UVR-induced TNF-alpha gene transcription and cell apoptosis. The knockdown of endogenous p85alpha blocked NFAT activity and TNF-alpha gene transcription, as well as cell apoptosis. Thus, we demonstrated p85alpha-associated but PI-3K-independent cell death in response to UVR and identified a novel p85alpha/NFAT3/TNF-alpha signaling pathway for the mediation of cellular apoptotic responses under certain stress conditions such as UVR.
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Affiliation(s)
- Lun Song
- Nelson Institute of Environmental Medicine, New York University School of Medicine, 57 Old Forge Road, Tuxedo, NY 10987, USA
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