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Li J, Yuan H, Xu H, Zhao H, Xiong N. Hypoxic Cancer-Secreted Exosomal miR-182-5p Promotes Glioblastoma Angiogenesis by Targeting Kruppel-like Factor 2 and 4. Mol Cancer Res 2020; 18:1218-1231. [PMID: 32366676 DOI: 10.1158/1541-7786.mcr-19-0725] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/22/2019] [Accepted: 04/30/2020] [Indexed: 11/16/2022]
Abstract
Glioblastoma (GBM) is the most lethal primary brain tumor and has a complex molecular profile. Hypoxia plays a critical role during tumor progression and in the tumor microenvironment (TME). Exosomes released by tumor cells contain informative nucleic acids, proteins, and lipids involved in the interaction between cancer and stromal cells, thus leading to TME remodeling. Accumulating evidence indicates that exosomes play a pivotal role in cell-to-cell communication. However, the mechanism by which hypoxia affects tumor angiogenesis via exosomes derived from tumor cells remains largely unknown. In our study, we found that, compared with the parental cells under normoxic conditions, the GBM cells produced more exosomes, and miR-182-5p was significantly upregulated in the exosomes from GBM cells under hypoxic conditions. Exosomal miR-182-5p directly suppressed its targets Kruppel-like factor 2 and 4, leading to the accumulation of VEGFR, thus promoting tumor angiogenesis. Furthermore, exosome-mediated miR-182-5p also inhibited tight junction-related proteins (such as ZO-1, occludin, and claudin-5), thus enhancing vascular permeability and tumor transendothelial migration. Knockdown of miR-182-5p reduced angiogenesis and tumor proliferation. Interestingly, we found elevated levels circulating miR-182-5p in patient blood serum and cerebrospinal fluid samples, and its expression level was inversely related to the prognosis. IMPLICATIONS: Overall, our data clarify the diagnostic and prognostic value of tumor-derived exosome-mediated miR-182-5p and reveal the distinctive cross-talk between tumor cells and human umbilical vein endothelial cells mediated by tumor-derived exosomes that modulate tumor vasculature.
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Affiliation(s)
- Junjun Li
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Hongliang Yuan
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Hao Xu
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Hongyang Zhao
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Nanxiang Xiong
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China.
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Tiwari A, Swamynathan S, Alexander N, Gnalian J, Tian S, Kinchington PR, Swamynathan SK. KLF4 Regulates Corneal Epithelial Cell Cycle Progression by Suppressing Canonical TGF-β Signaling and Upregulating CDK Inhibitors P16 and P27. Invest Ophthalmol Vis Sci 2019; 60:731-740. [PMID: 30786277 PMCID: PMC6383833 DOI: 10.1167/iovs.18-26423] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose Krüppel-like factor 4 (KLF4) promotes corneal epithelial (CE) cell fate while suppressing mesenchymal properties. TGF-β plays a crucial role in cell differentiation and development, and if dysregulated, it induces epithelial-mesenchymal transition (EMT). As KLF4 and TGF-β regulate each other in a context-dependent manner, we evaluated the role of the crosstalk between KLF4 and TGF-β-signaling in CE homeostasis. Methods We used spatiotemporally regulated ablation of Klf4 within the adult mouse CE in ternary transgenic Klf4Δ/ΔCE (Klf4LoxP/LoxP/ Krt12rtTA/rtTA/ Tet-O-Cre) mice and short hairpin RNA (shRNA)-mediated knockdown or lentiviral vector-mediated overexpression of KLF4 in human corneal limbal epithelial (HCLE) cells to evaluate the crosstalk between KLF4 and TGF-β-signaling components. Expression of TGF-β signaling components and cyclin-dependent kinase (CDK) inhibitors was quantified by quantitative PCR, immunoblots, and/or immunofluorescent staining. Results CE-specific ablation of Klf4 resulted in (1) upregulation of TGF-β1, -β2, -βR1, and -βR2; (2) downregulation of inhibitory Smad7; (3) hyperphosphorylation of Smad2/3; (4) elevated nuclear localization of phospho-Smad2/3 and Smad4; and (5) downregulation of CDK inhibitors p16 and p27. Consistently, shRNA-mediated knockdown of KLF4 in HCLE cells resulted in upregulation of TGF-β1 and -β2, hyperphosphorylation and nuclear localization of SMAD2/3, downregulation of SMAD7, and elevated SMAD4 nuclear localization. Furthermore, overexpression of KLF4 in HCLE cells resulted in downregulation of TGF-β1, -βR1, and -βR2 and upregulation of SMAD7, p16, and p27. Conclusions Collectively, these results demonstrate that KLF4 regulates CE cell cycle progression by suppressing canonical TGF-β signaling and overcomes the undesirable concomitant decrease in TGF-β–dependent CDK inhibitors p16 and p27 expression by directly upregulating them.
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Affiliation(s)
- Anil Tiwari
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Sudha Swamynathan
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Nicholas Alexander
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - John Gnalian
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.,School of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Shenghe Tian
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Paul R Kinchington
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.,Department of Molecular Microbiology and Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States.,Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Shivalingappa K Swamynathan
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.,Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States.,Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
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3
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Njoroge RN, Vatapalli RJ, Abdulkadir SA. Organoids Increase the Predictive Value of in vitro Cancer Chemoprevention Studies for in vivo Outcome. Front Oncol 2019; 9:77. [PMID: 30842936 PMCID: PMC6391333 DOI: 10.3389/fonc.2019.00077] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 01/29/2019] [Indexed: 12/25/2022] Open
Abstract
Epidemiological and preclinical data suggest that antioxidants are protective against prostate cancer whose pathogenesis has been linked to oxidative stress. However, the selenium and vitamin E Cancer Prevention Trial (SELECT), found no efficacy for selenium in reducing prostate cancer incidence while vitamin E was associated with an increased risk of the disease. These results have called in to question the models used in preclinical chemoprevention efficacy studies and their ability to predict in vivo outcomes. Chemoprevention agents have traditionally been tested on two dimensional monolayer cultures of cell lines derived from advanced prostate cancers. But as SELECT demonstrates, results from advanced disease models were not predictive of the outcome of a primary chemoprevention trial. Additionally, lack of cell-matrix interactions in two dimensional cultures results in loss of biochemical and mechanical cues relevant for native tissue architecture. We use recent findings in three dimensional organoid cultures that recapitulated the SELECT trial results to argue that the organoid model could increase the predictive value of in vitro studies for in vivo outcomes.
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Affiliation(s)
- Rose N Njoroge
- Department of Urology, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States.,Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Rajita J Vatapalli
- Department of Urology, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States.,Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Sarki A Abdulkadir
- Department of Urology, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States.,Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL, United States.,Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
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4
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Park CS, Shen Y, Lewis A, Lacorazza HD. Role of the reprogramming factor KLF4 in blood formation. J Leukoc Biol 2016; 99:673-85. [DOI: 10.1189/jlb.1ru1215-539r] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 01/22/2016] [Indexed: 12/31/2022] Open
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Hu C, Liu M, Zhang W, Xu Q, Ma K, Chen L, Wang Z, He S, Zhu H, Xu N. Upregulation of KLF4 by methylseleninic acid in human esophageal squamous cell carcinoma cells: Modification of histone H3 acetylation through HAT/HDAC interplay. Mol Carcinog 2015; 54:1051-9. [PMID: 24789055 DOI: 10.1002/mc.22174] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 04/04/2014] [Accepted: 04/07/2014] [Indexed: 01/01/2023]
Abstract
Esophageal squamous cell carcinoma (ESCC) occurs at a very high frequency in certain areas of China. Supplementation with selenium-containing compounds was associated with a significantly lower cancer mortality rate in a study conducted in Linxia, China. Thus, selenium could be a potential anti-esophageal cancer agent. In this study, methylseleninic acid (MSA) could inhibit cell growth of ESCC cells in vitro and in vivo. Upon treated with MSA, the activity of histone deacetylases (HDACs) was decreased and general control nonrepressed protein 5 (GCN5) was upregulated in ESCC cells. Meanwhile, a significant increase of H3K9 acetylation (H3K9ac) was detected. Upregulation of Krüppel-like factor 4 (KLF4) was also observed after MSA treatment. Additionally, the acetylated histone H3 located more at KLF4 promoter region after MSA treatment, shown by chromatin immunoprecipitation (ChIP) assay. Moreover, knockdown of GCN5 decreased the protein level of both H3K9ac and KLF4, along with less cell growth inhibition. Taken all, our results indicated that MSA could inhibit ESCC cell growth, at least in part, by MSA-HDAC/GCN5-H3K9ac-KLF4 axis. To our best knowledge, this is the first report that MSA induced acetylation of histone H3 at Lys9, which might depend on the activities and the balance between HDACs and HATs.
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Affiliation(s)
- Chenfei Hu
- Laboratory of Cell and Molecular Biology and State Key Laboratory of Molecular Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR, China
| | - Mei Liu
- Laboratory of Cell and Molecular Biology and State Key Laboratory of Molecular Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR, China
| | - Wei Zhang
- Laboratory of Cell and Molecular Biology and State Key Laboratory of Molecular Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR, China
| | - Qing Xu
- Laboratory of Cell and Molecular Biology and State Key Laboratory of Molecular Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR, China
| | - Kai Ma
- Laboratory of Cell and Molecular Biology and State Key Laboratory of Molecular Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR, China
| | - Lechuang Chen
- Laboratory of Cell and Molecular Biology and State Key Laboratory of Molecular Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR, China
| | - Zaozao Wang
- Laboratory of Cell and Molecular Biology and State Key Laboratory of Molecular Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR, China
| | - Shun He
- Laboratory of Cell and Molecular Biology and State Key Laboratory of Molecular Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR, China
| | - Hongxia Zhu
- Laboratory of Cell and Molecular Biology and State Key Laboratory of Molecular Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR, China
| | - Ningzhi Xu
- Laboratory of Cell and Molecular Biology and State Key Laboratory of Molecular Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR, China
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Methylseleninic acid activates Keap1/Nrf2 pathway via up-regulating miR-200a in human oesophageal squamous cell carcinoma cells. Biosci Rep 2015; 35:BSR20150092. [PMID: 26341629 PMCID: PMC4613709 DOI: 10.1042/bsr20150092] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 08/25/2015] [Indexed: 12/20/2022] Open
Abstract
Methylseleninic acid (MSA), as a potent second-generation selenium compound, could activate KLF4/miR-200a/Keap1/Nrf2 pathway in oesophageal squamous cell carcinoma cells. Oesophageal squamous cell carcinoma (ESCC) occurs at a very high rates in certain regions of China. There are increasing evidences demonstrating that selenium could act as a potential anti-oesophageal cancer agent, but the precise mechanisms involved are still not completely understood. Methylseleninic acid (MSA), as a potent second-generation selenium compound, is a promising chemopreventive agent. Previous studies demonstrated that the kelch-like ECH-associated protein 1 (Keap1)/nuclear factor E2-related factor 2 (Nrf2) system plays a critical role in cancer prevention, but little is known about its association with MSA in ESCC cells. In the present study, we observed that MSA treatment significantly down-regulated Keap1, induced nuclear accumulation of Nrf2 and enhance the antioxidant response element (ARE) promoter activity in ESCC cells. MSA could also significantly induce miR-200a expression and inhibit Keap1 directly. Antagomir-200a could attenuate MSA treatment-induced Keap1 down-regulation in ESCC cells. Moreover, MSA-induced miR-200a expression was dependent on the mediation of Krüpple-like factor 4 (KLF4). These results reaffirm the potential role of MSA as a chemopreventive agent via the regulation of KLF4/miR-200a/Keap1/Nrf2 axis in ESCC cells.
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Na XY, Liu ZY, Ren PP, Yu R, Shang XS. Long non-coding RNA UCA1 contributes to the progression of prostate cancer and regulates proliferation through KLF4-KRT6/13 signaling pathway. Int J Clin Exp Med 2015; 8:12609-12616. [PMID: 26550172 PMCID: PMC4612857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 08/10/2015] [Indexed: 06/05/2023]
Abstract
Long non-coding RNAs (lncRNAs) UCA1 have been shown to paly an important regulatory roles in cancer biology, and UCA1 dysfunction is related to TNM stage, metastasis and postoperative survival in several cancers. However, the biological role and clinical significance of UCA1 in the carcinogenesis of prostate cancer (PC) remain largely unclear. Herein, we found that UCA1 was abnormally upregulated in tumor tissues from PC patients, and patients with high UCA1 levels had a significantly poorer prognosis. Intriguingly, the mRNA and protein levels of KLF4 were significantly increased in tumor tissues, which was highly correlated to UCA1 levels. Moreover, UCA1 depletion inhibited the growth and induced apoptosis in PC3 and LNCaP cell lines. In addition, UCA1 loss-of-function could decrease KLF4 expression, subsequently, the downregulation of KRT6 and KRT13. Taken together, our study indicated that UCA1 had a crucial role in the tumorigenesis of PC. Moreover, UCA1 loss-of-function inhibited cell proliferation and induced cell apoptosis, at least partially, through inactivation KLF4-KRT6/13 cascade.
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Affiliation(s)
- Xin-Yu Na
- Department of Urology Surgery, Longsai HospitalNingbo 315200, China
| | - Zong-Yuan Liu
- Department of Urology Surgery, Longsai HospitalNingbo 315200, China
| | - Peng-Peng Ren
- Department of Urology Surgery, Longsai HospitalNingbo 315200, China
| | - Rui Yu
- Medical College of Ningbo UniversityNingbo 315211, China
| | - Xiao-Song Shang
- Department of Urology Surgery, Longsai HospitalNingbo 315200, China
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Hayashi K, Sasamura H, Nakamura M, Sakamaki Y, Azegami T, Oguchi H, Tokuyama H, Wakino S, Hayashi K, Itoh H. Renin-angiotensin blockade resets podocyte epigenome through Kruppel-like Factor 4 and attenuates proteinuria. Kidney Int 2015; 88:745-53. [PMID: 26108068 DOI: 10.1038/ki.2015.178] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Revised: 03/21/2015] [Accepted: 04/16/2015] [Indexed: 02/07/2023]
Abstract
Proteinuria is a central component of chronic kidney disease and an independent risk factor for cardiovascular disease. Kidney podocytes have an essential role as a filtration barrier against proteinuria. Kruppel-like Factor 4 (KLF4) is expressed in podocytes and decreased in glomerular diseases leading to methylation of the nephrin promoter, decreased nephrin expression and proteinuria. Treatment with an angiotensin receptor blocker (ARB) reduced methylation of the nephrin promoter in murine glomeruli of an adriamycin nephropathy model with recovery of KLF4 expression and a decrease in albuminuria. In podocyte-specific KLF4 knockout mice, the effect of ARB on albuminuria and the nephrin promoter methylation was attenuated. In cultured human podocytes, angiotensin II reduced KLF4 expression and caused methylation of the nephrin promoter with decreased nephrin expression. In patients, nephrin promoter methylation was increased in proteinuric kidney diseases with decreased KLF4 and nephrin expression. KLF4 expression in ARB-treated patients was higher in patients with than without ARB treatment. Thus, angiotensin II can modulate epigenetic regulation in podocytes and ARB inhibits these actions in part via KLF4 in proteinuric kidney diseases. This study provides a new concept that renin-angiotensin system blockade can exert therapeutic effects through epigenetic modulation of the kidney gene expression.
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Affiliation(s)
- Kaori Hayashi
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Hiroyuki Sasamura
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Mari Nakamura
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Yusuke Sakamaki
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Tatsuhiko Azegami
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Hideyo Oguchi
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Hirobumi Tokuyama
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Shu Wakino
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Koichi Hayashi
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Hiroshi Itoh
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
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Hu D, Zhou Z, Davidson NE, Huang Y, Wan Y. Novel insight into KLF4 proteolytic regulation in estrogen receptor signaling and breast carcinogenesis. J Biol Chem 2012; 287:13584-97. [PMID: 22389506 DOI: 10.1074/jbc.m112.343566] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Krüppel-like factor 4 (KLF4), a zinc finger-containing transcriptional factor, is a pivotal regulator of cellular fate. KLF4 has attracted considerable attention for its opposing effect in carcinogenesis as tumor suppressor (e.g. colorectal cancer) or oncoprotein (e.g. breast cancer), depending on tissue context, with the underlying mechanism remaining largely unknown. Here we report that KLF4 mediates estrogen signaling in breast cancer formation. Accumulation of KLF4 by inhibiting its turnover triggers estrogen-induced transactivation. We identified Von Hippel-Lindau, pVHL, as the protein that governs KLF4 turnover in breast cancer cells and demonstrated that estrogen-induced down-regulation of pVHL facilitates accumulation of KLF4. We provide mechanistic insights into KLF4 steady-state degradation as well as its elevation in the presence of estrogen and show that elevated levels of pVHL or depletion of KLF4 attenuates the estrogen-induced transactivation and cell growth. Finally, immunohistochemical staining revealed reduced concentration of pVHL and accumulation of KLF4 in breast cancer tissues. We thus propose that suppression of pVHL in response to estrogen signaling results in elevation of KLF4, which mediates estrogen-induced mitogenic effect.
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Affiliation(s)
- Dong Hu
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
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10
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Shi JH, Zheng B, Chen S, Ma GY, Wen JK. Retinoic acid receptor α mediates all-trans-retinoic acid-induced Klf4 gene expression by regulating Klf4 promoter activity in vascular smooth muscle cells. J Biol Chem 2012; 287:10799-811. [PMID: 22337869 DOI: 10.1074/jbc.m111.321836] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transcription factor Krüppel-like factor 4 (KLF4) plays a critical role in vascular smooth muscle cell (VSMC) differentiation induced by all-trans-retinoic acid (ATRA). Although it has been demonstrated that ATRA stimulation augments both KLF4 protein and mRNA levels in VSMCs, the molecular mechanisms by which ATRA regulates Klf4 transcription are unknown. In this study, we examined the roles of ATRA-selective nuclear retinoic acid receptors (RARs) in the transcriptional regulation of Klf4. The introduction of small interfering RNA and an RAR antagonist demonstrated that RARα, but not RARβ or RARγ, mediated ATRA-induced Klf4 expression. A luciferase assay for the Klf4 promoter showed that three GC boxes in the proximal Klf4 promoter were indispensible for ATRA-induced Klf4 transcription and that RARα enhanced Klf4 promoter activity in a GC box-dependent manner. Furthermore, chromatin immunoprecipitation and oligonucleotide pulldown assays demonstrated that the transcription factors KLF4, Sp1, and YB1 directly bound to the GC boxes of the proximal Klf4 promoter. Upon RARα agonist stimulation, RARα was recruited to the Klf4 promoter through its interaction with KLF4, Sp1, and YB1 to form a transcriptional activation complex on the three GC boxes of the Klf4 promoter. These results suggest that RARα serves as an essential co-activator for ATRA signaling and that the recruitment of RARα to the KLF4-Sp1-YB1 complex, which leads to Klf4 expression in VSMCs, is independent of a retinoic acid response element.
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Affiliation(s)
- Jian-hong Shi
- Department of Biochemistry and Molecular Biology, the Key Laboratory of Neurobiology and Vascular Biology, China
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11
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Qi Y, Fu X, Xiong Z, Zhang H, Hill SM, Rowan BG, Dong Y. Methylseleninic acid enhances paclitaxel efficacy for the treatment of triple-negative breast cancer. PLoS One 2012; 7:e31539. [PMID: 22348099 PMCID: PMC3279411 DOI: 10.1371/journal.pone.0031539] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 01/12/2012] [Indexed: 12/17/2022] Open
Abstract
A major challenge in breast cancer therapy is the lack of an effective therapeutic option for a particularly aggressive subtype of breast cancer, triple-negative breast cancer. Here we provide the first preclinical evidence that a second-generation selenium compound, methylseleninic acid, significantly enhances the anticancer efficacy of paclitaxel in triple-negative breast cancer. Through combination-index value calculation, we demonstrated that methylseleninic acid synergistically enhanced the growth inhibitory effect of paclitaxel in triple-negative breast cancer cells. The synergism was attributable to more pronounced induction of caspase-mediated apoptosis, arrest of cell cycle progression at the G2/M checkpoint, and inhibition of cell proliferation. Treatment of SCID mice bearing MDA-MB-231 triple-negative breast cancer xenografts for four weeks with methylseleninic acid (4.5 mg/kg/day, orally) and paclitaxel (10 mg/kg/week, through intraperitoneal injection) resulted in a more pronounced inhibition of tumor growth compared with either agent alone. The attenuated tumor growth correlated with a decrease in tumor cell proliferation and an induction of apoptosis. The in vivo study also indicated the safety of using methylseleninic acid in the combination regime. Our findings thus provide strong justification for the further development of methylseleninic acid and paclitaxel combination therapy for the treatment of triple-negative breast cancer.
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Affiliation(s)
- Yanfeng Qi
- Departments of Structural and Cellular Biology, Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Xueqi Fu
- College of Life Sciences, Jilin University, Changchun, Jilin, China
| | - Zhenggang Xiong
- Department of Pathology and Laboratory Medicine, Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Haitao Zhang
- Department of Pathology and Laboratory Medicine, Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
- National Engineering Laboratory for AIDS Vaccine, College of Life Sciences, Jilin University, Changchun, Jilin, China
| | - Steven M. Hill
- Departments of Structural and Cellular Biology, Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Brian G. Rowan
- Departments of Structural and Cellular Biology, Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Yan Dong
- Departments of Structural and Cellular Biology, Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
- National Engineering Laboratory for AIDS Vaccine, College of Life Sciences, Jilin University, Changchun, Jilin, China
- * E-mail:
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Abstract
PURPOSE To evaluate the effect of selenium supplementation on the progress of naphthalene cataract. MATERIALS AND METHODS Sprague-Dawley rats were randomly divided into five groups as follows: normal control, naphthalene control and selenium-supplemented groups (Selenium I, II and III, which were orally administrated with selenium at doses of 0.0104 mg/kg, 0.0208 mg/kg and 0.0416 mg/kg, respectively). All the intervention groups were orally administered with 10% naphthalene solution for 5 weeks. The lens density of each group was determined by photography. Moreover, glutathione peroxidase (GPx) activity in the lens, erythrocyte and plasma was investigated. In addition, lens glutathione (GSH), malondialdehyde (MDA) and hydroxyl radical levels were evaluated. Selenium level in aqueous humor was determined using atomic absorption spectrometry. RESULTS The maximum, mean and minimum densities of lens opacities were lower in Selenium group II and III than those in naphthalene group. The maximum density of the lens increased more slowly in Selenium group I than that in naphthalene controls. In selenium-supplemented groups, blood and lens GPx activities as well as aqueous humor selenium level increased significantly. Selenium supplementation also significantly ameliorated the decrease in GSH level and increase in MDA and hydroxyl radical levels in the lens of naphthalene-treated rats. CONCLUSIONS Selenium supplementation could slow the development of naphthalene cataract possibly by attenuating the oxidative stress in the lens.
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Affiliation(s)
- Xiangjia Zhu
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, China
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Bureau C, Hanoun N, Torrisani J, Vinel JP, Buscail L, Cordelier P. Expression and Function of Kruppel Like-Factors (KLF) in Carcinogenesis. Curr Genomics 2011; 10:353-60. [PMID: 20119532 PMCID: PMC2729999 DOI: 10.2174/138920209788921010] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 06/15/2009] [Accepted: 06/18/2009] [Indexed: 11/22/2022] Open
Abstract
Krüppel-like factor (KLF) family members share a three C2H2 zinc finger DNA binding domain, and are involved in cell proliferation and differentiation control in normal as in pathological situations. Studies over the past several years support a significant role for this family of transcription factors in carcinogenesis. KLFs can both activate and repress genes that participate in cell-cycle regulation. Among them, many up-regulated genes are inhibitors of proliferation, whereas genes that promote cell proliferation are repressed. However, several studies do present KLFs as positive regulator of cell proliferation. KLFs can be deregulated in multiple cancers either by loss of heterozygosity (LOH), somatic mutation or transcriptional silencing by promoter hypermethylation. Accordingly, KLF expression was shown to mediate growth inhibition when ectopically expressed in multiple cancer-derived cell lines through the inhibition of a number of key oncogenic signaling pathways, and to revert the tumorogenic phenotype in vivo. Taken together, these observations suggest that KLFs act as tumor suppressor. However, in some occasion, KLFs could act as tumor promoters, depending on “cellular context”. Thus, this review will discuss the roles and the functions of KLF family members in carcinogenesis, with a special focus on cancers from epithelial origin.
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Affiliation(s)
- Christophe Bureau
- Institut National de la Santé et de la Recherche Médicale Unité 858-I2MR, Institut de Médecine Moléculaire de Rangueil, Département Cancers Epithéliaux, Angiogénèse et Signalisation, 31432 Toulouse Cedex 4 France
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Hu D, Wan Y. Regulation of Krüppel-like factor 4 by the anaphase promoting complex pathway is involved in TGF-beta signaling. J Biol Chem 2010; 286:6890-901. [PMID: 21177849 DOI: 10.1074/jbc.m110.179952] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Krüppel-like factor 4 (KLF4), a zinc finger-containing transcriptional factor, regulates a variety of biological processes, including cell proliferation, differentiation, apoptosis, and stem cell reprogramming. Post-translational modifications of KLF4, including phosphorylation, acetylation, and sumoylation, regulate its transcriptional activity. Most recent studies also demonstrate that KLF4 is targeted for ubiquitin-dependent proteolysis during cell cycle progression. However, the underlying mechanism remains largely unknown. In this study, we demonstrated that KLF4 is profoundly degraded in response to TGF-β signaling. We have identified the Cdh1-anaphase promoting complex as a putative E3 ligase that governs TGF-β-induced KLF4 degradation. The TGF-β-induced KLF4 degradation is mediated by the destruction box on the KLF4. Either depletion of Cdh1 by RNA interference or stabilization of KLF4 by disruption of its destruction box significantly attenuates TGF-β-induced ubiquitylation and degradation. In addition, depletion of Cdh1 or stabilization of KLF4 antagonizes TGF-β-induced activation of transcription. Determining the role of KLF4 proteolysis in response to TGF-β signaling has opened a new perspective to understand the TGF-β signaling pathway.
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Affiliation(s)
- Dong Hu
- Department of Cell Biology and Physiology and University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
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Huang PH, Chen CH, Chou CC, Sargeant AM, Kulp SK, Teng CM, Byrd JC, Chen CS. Histone deacetylase inhibitors stimulate histone H3 lysine 4 methylation in part via transcriptional repression of histone H3 lysine 4 demethylases. Mol Pharmacol 2010; 79:197-206. [PMID: 20959362 DOI: 10.1124/mol.110.067702] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
This study investigates the mechanism by which histone deacetylase (HDAC) inhibitors up-regulate histone H3 lysine 4 (H3K4) methylation. Exposure of LNCaP prostate cancer cells and the prostate tissue of transgenic adenocarcinoma of the mouse prostate mice to the pan- and class I HDAC inhibitors (S)-(+)-N-hydroxy-4-(3-methyl-2-phenyl-butyrylamino)-benzamide (AR42), N-(2-aminophenyl)-4-[N-(pyridine-3-yl-methoxycarbonyl)-aminomethyl]-benzamide (MS-275), and vorinostat led to differential increases in H3K4 methylation. Chromatin immunoprecipitation shows that this accumulation of methylated H3K4 occurred in conjunction with decreases in the amount of the H3K4 demethylase RBP2 at the promoter of genes associated with tumor suppression and differentiation, including KLF4 and E-cadherin. This finding, together with the HDAC inhibitor-induced up-regulation of KLF4 and E-cadherin, suggests that HDAC inhibitors could activate the expression of these genes through changes in histone methylation status. Evidence indicates that this up-regulation of H3K4 methylation was attributable to the suppressive effect of these HDAC inhibitors on the expression of RBP2 and other JARID1 family histone demethylases, including PLU-1, SMCX, and LSD1, via the down-regulation of Sp1 expression. Moreover, shRNA-mediated silencing of the class I HDAC isozymes 1, 2, 3, and 8, but not that of the class II isozyme HDAC6, mimicked the drug effects on H3K4 methylation and H3K4 demethylases, which could be reversed by ectopic Sp1 expression. These data suggest a cross-talk mechanism between HDACs and H3K4 demethylases via Sp1-mediated transcriptional regulation, which underlies the complexity of the functional role of HDACs in the regulation of histone modifications.
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Affiliation(s)
- Po-Hsien Huang
- Division of Medicinal Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
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Liu S, Qi Y, Ge Y, Duplessis T, Rowan BG, Ip C, Cheng H, Rennie PS, Horikawa I, Lustig AJ, Yu Q, Zhang H, Dong Y. Telomerase as an important target of androgen signaling blockade for prostate cancer treatment. Mol Cancer Ther 2010; 9:2016-25. [PMID: 20571066 DOI: 10.1158/1535-7163.mct-09-0924] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
As the mainstay treatment for advanced prostate cancer, androgen deprivation therapy (ADT) targets the action of androgen receptor (AR) by reducing androgen level and/or by using anti-androgen to compete with androgens for binding to AR. Albeit effective in extending survival, ADT is associated with dose-limiting toxicity and the development of castration-resistant prostate cancer (CRPC) after prolonged use. Because CRPC is lethal and incurable, developing effective strategies to enhance the efficacy of ADT and circumvent resistance becomes an urgent task. Continuous AR signaling constitutes one major mechanism underlying the development of CRPC. The present study showed that methylseleninic acid (MSA), an agent that effectively reduces AR abundance, could enhance the cancer-killing efficacy of the anti-androgen bicalutamide in androgen-dependent and CRPC cells. We found that the combination of MSA and bicalutamide produced a robust downregulation of prostate-specific antigen and a recently identified AR target, telomerase, and its catalytic subunit, human telomerase reverse transcriptase. The downregulation of hTERT occurs mainly at the transcriptional level, and reduced AR occupancy of the promoter contributes to downregulation. Furthermore, apoptosis induction by the two agents is significantly mitigated by the restoration of hTERT. Our findings thus indicate that MSA in combination with anti-androgen could represent a viable approach to improve the therapeutic outcome of ADT. Given the critical role of hTERT/telomerase downregulation in mediating the combination effect and the fact that hTERT/telomerase could be measured in blood and urine, hTERT/telomerase could serve as an ideal tumor-specific biomarker to monitor the efficacy of the combination therapy noninvasively.
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Affiliation(s)
- Shuang Liu
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, New Orleans, Louisiana 70112, USA
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Zhang W, Yan S, Liu M, Zhang G, Yang S, He S, Bai J, Quan L, Zhu H, Dong Y, Xu N. beta-Catenin/TCF pathway plays a vital role in selenium induced-growth inhibition and apoptosis in esophageal squamous cell carcinoma (ESCC) cells. Cancer Lett 2010; 296:113-22. [PMID: 20457486 DOI: 10.1016/j.canlet.2010.04.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 04/06/2010] [Accepted: 04/07/2010] [Indexed: 12/13/2022]
Abstract
Epidemiological and experimental studies have indicated selenium could reduce the risk of some cancers. In our present study, growth inhibition and apoptosis were detected upon methylseleninic acid (MSA) treatment in human esophageal squamous cell carcinoma cell lines EC9706 and KYSE150. MSA reduced beta-catenin protein levels, while there was no significant change observed on transcriptional levels. Moreover, we found MSA accelerated the degradation of beta-catenin and activated glycogen synthase kinase 3beta (GSK-3beta). Some targets of beta-catenin/TCF pathway and apoptosis-related genes altered after MSA treatment. Notably, utilizing the inducible 293-TR/beta-catenin cell line, we found the apoptotic phenotypes induced by MSA were partially reversed by the overexpression of beta-catenin. Overall, our data indicate the effects induced by MSA in ESCC cells may act on the inhibition of beta-catenin/TCF pathway.
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Affiliation(s)
- Wei Zhang
- Laboratory of Cell and Molecular Biology & State Key Laboratory of Molecular Oncology, Cancer Institute & Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, PR China
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Liuzzi JP, Guo L, Chang SM, Cousins RJ. Krüppel-like factor 4 regulates adaptive expression of the zinc transporter Zip4 in mouse small intestine. Am J Physiol Gastrointest Liver Physiol 2009; 296:G517-23. [PMID: 19147802 PMCID: PMC2660179 DOI: 10.1152/ajpgi.90568.2008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Epithelial cells of the small intestine are the site of zinc absorption. Intestinal uptake of zinc is inversely proportional to the dietary supply of this essential micronutrient. The mechanism responsible for this adaptive differential in apical zinc transport is not known. The zinc transporter Zip4 (Slc39a4) is essential for adequate enteric zinc uptake. In mice, Zip4 expression is upregulated at low zinc intakes with a concomitant ZIP4 localization to the apical enterocyte plasma membrane. With the present experiments, we show that the zinc finger transcription factor Krüppel-like factor 4 (KLF4), produced in high abundance in the intestine, is expressed at elevated levels in mice fed a low-zinc diet. In the murine intestinal epithelial cell (IEC) line MODE-K, zinc depletion of culture medium with cell-permeant and cell-impermeant chelators increased Zip4 and Klf4 mRNA and Zip4 heterogeneous nuclear RNA expression. Zinc depletion led to increased KLF4 in nuclear extracts. Knockdown of KLF4 using small interfering RNA transfection drastically limited ZIP4 induction upon zinc depletion and reduced 65Zn uptake by depleted IECs. EMSAs with nuclear extracts of IECs showed KLF4 binding to cis elements of the mouse Zip4 promoter, with increased binding under zinc-limited conditions. Reporter constructs with the Zip4 promoter and mutation studies further demonstrated that Zip4 is regulated through a KLF4 response element. These data from experiments with mice and murine IECs demonstrate that KLF4 is induced during zinc restriction and is a transcription factor involved in adaptive regulation of the zinc transporter ZIP4.
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Affiliation(s)
- Juan P. Liuzzi
- Center for Nutritional Sciences and Food Science and Human Nutrition Department, University of Florida, Gainesville, Florida
| | - Liang Guo
- Center for Nutritional Sciences and Food Science and Human Nutrition Department, University of Florida, Gainesville, Florida
| | - Shou-Mei Chang
- Center for Nutritional Sciences and Food Science and Human Nutrition Department, University of Florida, Gainesville, Florida
| | - Robert J. Cousins
- Center for Nutritional Sciences and Food Science and Human Nutrition Department, University of Florida, Gainesville, Florida
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