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Salih AI, Al-Sudani BT, Mshimesh BAR. Targeting POLD1 to suppress the proliferation and migration of breast cancer MDA-MB-231 cell lines by downregulation of SIRT1. Toxicol Res (Camb) 2024; 13:tfae111. [PMID: 39036524 PMCID: PMC11256954 DOI: 10.1093/toxres/tfae111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Revised: 07/04/2024] [Accepted: 07/12/2024] [Indexed: 07/23/2024] Open
Abstract
Background The resistant and aggressive nature of triple-negative breast cancer (TNBC) renders it mostly incurable even following extensive multimodal treatment. Therefore, more studies are required to understand the underlying molecular mechanisms of its pathogenesis. SIRT1 is a class III histone deacetylase NAD + -dependent enzyme that is interlinked in tumor progression, apoptosis, metastasis, and other mechanisms of tumorigenesis, while DNA polymerase delta 1 (POLD1) functions as a gene coding for p125, which plays an important role in genome stability and DNA replication. Objective We aimed to investigate the downstream signaling pathway of EX-527, a potent and selective SIRT1 inhibitor, in MDA-MB-231 breast cancer cell lines, and the crosstalk between SIRT1 and POLD1, which is essential for the activities of polymerase δ. Methods The antiproliferative and apoptotic effects of EX-527 on MDA-MB-231 cells were assessed by MTT and annexin V/PI double staining assays. Migration and invasion activity of MDA-MB-231 cells were assessed by wound-healing scratch and transwell assays. Protein expressions were examined using Western Blot analysis. Results MDA-MB-231 cells treatment with IC50 values of 45.3 μM EX-527 significantly suppressed cell proliferation and induced apoptosis by down-regulating SIRT1. Also, it significantly repressed migration and invasion of MDA-MB-231 cells as evaluated by wound healing and transwell invasion assays. Western blot results showed that decreased expression of SIRT1 is positively correlated with expression of p53 along with down-regulating POLD1. Conclusion SIRT1 could have an oncogenic role in breast cancer development and progression via activating POLD1. These conclusions present new insights into the underlying mechanisms of TNBC.
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Affiliation(s)
- Areege Ibrahim Salih
- Department of Pharmacology and Toxicology, College of Pharmacy, Mustansiriyah University, Baghdad 10052, Iraq
| | - Basma Talib Al-Sudani
- Department of Pharmacology and Toxicology, College of Pharmacy, Mustansiriyah University, Baghdad 10052, Iraq
| | - Bahir Abdul-Razzaq Mshimesh
- Department of Pharmacology and Toxicology, College of Pharmacy, Mustansiriyah University, Baghdad 10052, Iraq
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Xiong J, Ma F, Ding N, Xu L, Ma S, Yang A, Hao Y, Zhang H, Jiang Y. miR-195-3p alleviates homocysteine-mediated atherosclerosis by targeting IL-31 through its epigenetics modifications. Aging Cell 2021; 20:e13485. [PMID: 34592792 PMCID: PMC8520716 DOI: 10.1111/acel.13485] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 08/25/2021] [Accepted: 09/12/2021] [Indexed: 12/13/2022] Open
Abstract
Atherosclerosis is a serious age-related disease, which has a tremendous impact on health care globally. Macrophage inflammation is crucial for the initiation and progression of atherosclerosis, and microRNAs (miRNAs) recently have emerged as potent modulators of inflammation, while the underlying mechanisms of its involvement in homocysteine (Hcy)-mediated macrophage inflammation of atherosclerosis remain largely unknown. Here, we demonstrated that elevated Hcy inhibits the expression of miR-195-3p, which in turn enhances IL-31 expression and thereby causes the secretion of macrophages pro-inflammatory factors IL-1β, IL-6 and TNF-α and accelerate atherosclerosis. Furthermore, we identified that Hcy can induce DNA hypermethylation and H3K9 deacetylation of miR-195-3p promoter due to the increased the binding of DNMT3a and HDAC11 at its promoter. More importantly, Sp1 interacts with DNMT3a suppressed the binding of HDAC11 at miR-195-3p promoter and promoted its transcription. In summary, our results revealed a novel mechanism that transcriptional and epigenetic regulation of miR-195-3p inhibits macrophage inflammation through targeting IL-31, which provides a candidate diagnostic marker and novel therapeutic target in cardiovascular diseases induced by Hcy.
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Affiliation(s)
- Jiantuan Xiong
- School of Basic Medical Sciences Ningxia Medical University Yinchuan China
- NHC Key Laboratory of Metabolic Cardiovascular Diseases Research Ningxia Medical University Yinchuan China
- Ningxia Key Laboratory of Vascular Injury and Repair Research Ningxia Medical University Yinchuan China
| | - Fang Ma
- School of Basic Medical Sciences Ningxia Medical University Yinchuan China
- NHC Key Laboratory of Metabolic Cardiovascular Diseases Research Ningxia Medical University Yinchuan China
- Ningxia Key Laboratory of Vascular Injury and Repair Research Ningxia Medical University Yinchuan China
| | - Ning Ding
- School of Basic Medical Sciences Ningxia Medical University Yinchuan China
- NHC Key Laboratory of Metabolic Cardiovascular Diseases Research Ningxia Medical University Yinchuan China
- Ningxia Key Laboratory of Vascular Injury and Repair Research Ningxia Medical University Yinchuan China
| | - Lingbo Xu
- School of Basic Medical Sciences Ningxia Medical University Yinchuan China
- NHC Key Laboratory of Metabolic Cardiovascular Diseases Research Ningxia Medical University Yinchuan China
- Ningxia Key Laboratory of Vascular Injury and Repair Research Ningxia Medical University Yinchuan China
| | - Shengchao Ma
- School of Basic Medical Sciences Ningxia Medical University Yinchuan China
- NHC Key Laboratory of Metabolic Cardiovascular Diseases Research Ningxia Medical University Yinchuan China
- Ningxia Key Laboratory of Vascular Injury and Repair Research Ningxia Medical University Yinchuan China
| | - Anning Yang
- School of Basic Medical Sciences Ningxia Medical University Yinchuan China
- NHC Key Laboratory of Metabolic Cardiovascular Diseases Research Ningxia Medical University Yinchuan China
- Ningxia Key Laboratory of Vascular Injury and Repair Research Ningxia Medical University Yinchuan China
| | - Yinju Hao
- School of Basic Medical Sciences Ningxia Medical University Yinchuan China
- NHC Key Laboratory of Metabolic Cardiovascular Diseases Research Ningxia Medical University Yinchuan China
- Ningxia Key Laboratory of Vascular Injury and Repair Research Ningxia Medical University Yinchuan China
| | - Huiping Zhang
- NHC Key Laboratory of Metabolic Cardiovascular Diseases Research Ningxia Medical University Yinchuan China
- Ningxia Key Laboratory of Vascular Injury and Repair Research Ningxia Medical University Yinchuan China
- Prenatal Diagnosis Center, General Hospital of Ningxia Medical University Yinchuan China
| | - Yideng Jiang
- School of Basic Medical Sciences Ningxia Medical University Yinchuan China
- NHC Key Laboratory of Metabolic Cardiovascular Diseases Research Ningxia Medical University Yinchuan China
- Ningxia Key Laboratory of Vascular Injury and Repair Research Ningxia Medical University Yinchuan China
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Hegde M, Joshi MB. Comprehensive analysis of regulation of DNA methyltransferase isoforms in human breast tumors. J Cancer Res Clin Oncol 2021; 147:937-971. [PMID: 33604794 PMCID: PMC7954751 DOI: 10.1007/s00432-021-03519-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 01/10/2021] [Indexed: 12/14/2022]
Abstract
Significant reprogramming of epigenome is widely described during pathogenesis of breast cancer. Transformation of normal cell to hyperplastic cell and to neoplastic phenotype is associated with aberrant DNA (de)methylation, which, through promoter and enhancer methylation changes, activates oncogenes and silence tumor suppressor genes in variety of tumors including breast. DNA methylation, one of the major epigenetic mechanisms is catalyzed by evolutionarily conserved isoforms namely, DNMT1, DNMT3A and DNMT3B in humans. Over the years, studies have demonstrated intricate and complex regulation of DNMT isoforms at transcriptional, translational and post-translational levels. The recent findings of allosteric regulation of DNMT isoforms and regulation by other interacting chromatin modifying proteins emphasizes functional integrity and their contribution for the development of breast cancer and progression. DNMT isoforms are regulated by several intrinsic and extrinsic parameters. In the present review, we have extensively performed bioinformatics analysis of expression of DNMT isoforms along with their transcriptional and post-transcriptional regulators such as transcription factors, interacting proteins, hormones, cytokines and dietary elements along with their significance during pathogenesis of breast tumors. Our review manuscript provides a comprehensive understanding of key factors regulating DNMT isoforms in breast tumor pathology and documents unsolved issues.
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Affiliation(s)
- Mangala Hegde
- Manipal School of Life Sciences, Manipal Academy of Higher Education, Planetarium Complex, Manipal, 576104, India
| | - Manjunath B Joshi
- Manipal School of Life Sciences, Manipal Academy of Higher Education, Planetarium Complex, Manipal, 576104, India.
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Construction of a Potential Breast Cancer-Related miRNA-mRNA Regulatory Network. BIOMED RESEARCH INTERNATIONAL 2020; 2020:6149174. [PMID: 33204705 PMCID: PMC7657683 DOI: 10.1155/2020/6149174] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/10/2020] [Accepted: 10/12/2020] [Indexed: 12/11/2022]
Abstract
Background Breast cancer is a malignant tumor that occurs in the epithelial tissue of the breast gland and has become the most common malignancy in women. The regulation of the expression of related genes by microRNA (miRNA) plays an important role in breast cancer. We constructed a comprehensive breast cancer-miRNA-gene interaction map. Methods Three miRNA microarray datasets (GSE26659, GSE45666, and GSE58210) were obtained from the GEO database. Then, the R software “LIMMA” package was used to identify differential expression analysis. Potential transcription factors and target genes of screened differentially expressed miRNAs (DE-miRNAs) were predicted. The BRCA GE-mRNA datasets (GSE109169 and GSE139038) were downloaded from the GEO database for identifying differentially expressed genes (DE-genes). Next, GO annotation and KEGG pathway enrichment analysis were conducted. A PPI network was then established, and hub genes were identified via Cytoscape software. The expression and prognostic roles of hub genes were further evaluated. Results We found 6 upregulated differentially expressed- (DE-) miRNAs and 18 downregulated DE-miRNAs by analyzing 3 Gene Expression Omnibus databases, and we predicted the upstream transcription factors and downstream target genes for these DE-miRNAs. Then, we used the GEO database to perform differential analysis on breast cancer mRNA and obtained differentially expressed mRNA. We found 10 hub genes of upregulated DE-miRNAs and 10 hub genes of downregulated DE-miRNAs through interaction analysis. Conclusions In this study, we have performed an integrated bioinformatics analysis to construct a more comprehensive BRCA-miRNA-gene network and provide new targets and research directions for the treatment and prognosis of BRCA.
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Development and validation of a novel metabolic signature for predicting prognosis in patients with laryngeal cancer. Eur Arch Otorhinolaryngol 2020; 278:1129-1138. [PMID: 33108563 DOI: 10.1007/s00405-020-06444-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE Despite advances in the development of treatments for laryngeal cancer (LC), including surgical treatments and radio-chemotherapy, the survival rate of LC remains low. Therefore, novel metabolic signatures are urgently needed to evaluate the prognosis of LC patients. METHODS Differentially expressed metabolic genes were extracted via bioinformatics analysis from the raw data of The Cancer Genome Atlas and Gene Expression Omnibus (GEO) databases. Univariate Cox regression and LASSO analyses were performed to identify metabolic genes that were significantly correlated with overall survival (OS). Using the Kaplan-Meier analysis and receiver operating characteristics, the prognostic power of candidate signatures was evaluated in the two databases. Gene Set Enrichment Analysis (GSEA) was performed to explore significant signaling pathways and underlying mechanisms in the high- and low-risk groups. RESULTS Thirteen metabolism genes showed superior ability to predict OS for LC when compared to clinical variables, and patients in the high-risk group showed significantly poorer OS than those in the low-risk group. The area under the curve of receiver operating curves for 5- and 3-year OS was 0.929 and 0.899, respectively, which were better than the OS obtained with clinicopathological variables. Similar results obtained in the GEO cohort indicated that this gene signature could differentiate between LC patients with and without recurrence. CONCLUSION To our knowledge, this study is the first to report that the 13 metabolic genes could serve as an independent biomarker for LC, which could provide vital prognostic information and prediction for personalized treatment of LC.
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Qin Q, Tan Q, Li J, Yang W, Lian B, Mo Q, Wei C. Elevated expression of POLD1 is associated with poor prognosis in breast cancer. Oncol Lett 2018; 16:5591-5598. [PMID: 30344713 PMCID: PMC6176253 DOI: 10.3892/ol.2018.9392] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 04/16/2018] [Indexed: 01/02/2023] Open
Abstract
Polymerase δ catalytic subunit gene 1 (POLD1) may serve an important function in the development of tumors. However, its role in breast cancer remains unclear. The aim of the present study was to observe the expression and the function of POLD1 in breast cancer. A total of 84 patients with invasive breast carcinoma were recruited between 2011 and 2013. The expression of POLD1 was detected in paired tumor and adjacent normal tissues. Gene expression level of POLD1 was assessed using reverse transcription quantitative polymerase chain reaction. The protein expression of POLD1 was assessed using western blot analysis. The association between the clinicopathological features of patients with breast cancer and POLD1 expression was analyzed using a χ2 test. Disease-free survival (DFS) was analyzed using Kaplan-Meier method, and Cox regression analysis was performed to investigate clinicopathological significance of POLD1 expression. Additionally, the effects of POLD1 in regulating cell cycle and proliferation of MCF-7 cells were evaluated in vitro. The results demonstrated that gene and protein expression levels of POLD1 were significantly elevated in breast cancer tissues compared with those in adjacent normal tissues. Increased expression of POLD1 was significantly associated with positive lymph node status (P=0.028), histological grade (P=0.025), p53 status (P<0.001) and ki-67 index (P=0.020). Survival analysis demonstrated that increased expression of POLD1 was associated with poor DFS (P=0.033). Additionally, increased expression of POLD1 was associated with shorter DFS at early-stage (P=0.037), late-stage cases (P=0.023) and with the presence of triple-negative tumors (TNBC; P=0.049). Multivariate analysis revealed that POLD1 may be used as an independent prognostic factor in patients with breast cancer. In vitro studies revealed that downregulation of POLD1 suppressed cell cycle progression and proliferation in MCF-7 cells. In conclusion, POLD1 may be considered as a potential prognostic marker for invasive breast carcinoma.
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Affiliation(s)
- Qinghong Qin
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Qixing Tan
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Jinyuan Li
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Weiping Yang
- Department of Ultrasound Diagnosis, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Bin Lian
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Qinguo Mo
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Changyuan Wei
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
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The synthetic antihyperlipidemic drug potassium piperate selectively kills breast cancer cells through inhibiting G1-S-phase transition and inducing apoptosis. Oncotarget 2018; 8:47250-47268. [PMID: 28467790 PMCID: PMC5564562 DOI: 10.18632/oncotarget.16872] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 03/14/2017] [Indexed: 01/09/2023] Open
Abstract
Piper longum L. is a well-known traditional antihyperlipidemic medicine in China, containing medicinal constituents of piperine, pipernonaline and piperlonguminine in its fruit. However, the antitumor properties of these constituents have not yet been studied. We found that potassium piperate (GBK), a derivative of piperine, inhibited proliferation of cancer cells. GBK selectively inhibited the G1-S-phase transition in breast cancer cells and the G1 arrest was correlated with induction of p27 expression, which is an inhibitor for cyclin-dependent kinases, and inhibition of cyclin A, cyclin E and cyclin B expression. Moreover, GBK treatment led to a downregulation of the mini-chromosome maintenance protein expression and induction of mitochondrial-dependent cell apoptosis in breast cancer cells. Our results also suggested that GBK might also inhibit cancer cell proliferation through epigenetic signaling pathways. A synergistic effect in inhibition of cancer cell proliferation was found when GBK was combined with chemotherapy medicines etoposide phosphate or cisplatin at middle or low doses in vitro. These results show that GBK is a novel potential anti-breast cancer drug that inhibits cell proliferation and promotes cell apoptosis.
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GenePANDA-a novel network-based gene prioritizing tool for complex diseases. Sci Rep 2017; 7:43258. [PMID: 28252032 PMCID: PMC5333103 DOI: 10.1038/srep43258] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 01/23/2017] [Indexed: 02/08/2023] Open
Abstract
Here we describe GenePANDA, a novel network-based tool for prioritizing candidate disease genes. GenePANDA assesses whether a gene is likely a candidate disease gene based on its relative distance to known disease genes in a functional association network. A unique feature of GenePANDA is the introduction of adjusted network distance derived by normalizing the raw network distance between two genes with their respective mean raw network distance to all other genes in the network. The use of adjusted network distance significantly improves GenePANDA’s performance on prioritizing complex disease genes. GenePANDA achieves superior performance over five previously published algorithms for prioritizing disease genes. Finally, GenePANDA can assist in prioritizing functionally important SNPs identified by GWAS.
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Yang F, He K, Huang L, Zhang L, Liu A, Zhang J. Casticin inhibits the activity of transcription factor Sp1 and the methylation of RECK in MGC803 gastric cancer cells. Exp Ther Med 2016; 13:745-750. [PMID: 28352361 DOI: 10.3892/etm.2016.4003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 09/27/2016] [Indexed: 02/06/2023] Open
Abstract
The present study investigated the effect of casticin on reversion-inducing-cysteine-rich protein with kazal motifs (RECK) gene expression and intracellular methylation levels in MGC803 gastric cancer cells. Cells were treated with 1, 10 and 30 µmol/l casticin. Western blotting and reverse transcription-quantitative polymerase chain reaction assays were performed to determine the protein expression and mRNA levels of RECK and DNA methyltransferase 1 (DNMT1), respectively. High-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry was used to detect RECK methylation. In addition, MGC803 cell proliferation was measured by an MTT assay and the DNA-binding activity of transcription factor Sp1 was determined using an enzyme-linked immunosorbent assay. The results demonstrated that treatment with 1, 10 and 30 µmol/l casticin significantly increased RECK protein expression and mRNA levels. In addition, casticin (30 µmol/l) decreased RECK promoter methylation levels by 31%, global DNA methylation levels by 39% and nuclear methylation activity by 71.6%. Furthermore, casticin downregulated the mRNA levels and protein expression of DNMT1. The MTT assay demonstrated that MGC803 cell proliferation was inhibited by casticin treatment and DNA binding assays indicated that casticin reduced the DNA-binding activity of Sp1. The present study therefore indicated that casticin inhibits the proliferation of gastric cancer MGC803 cells by upregulating RECK gene expression and reducing intracellular methylation levels.
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Affiliation(s)
- Fan Yang
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China; Department of Basic Medicine, Xiangnan University, Chenzhou, Hunan 423000, P.R. China
| | - Kefei He
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China
| | - Li Huang
- Department of Oncology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi 341000, P.R. China
| | - Lingyan Zhang
- Medical Department of Chongqing Bishan People's Hospital, Chongqing 402760, P.R. China
| | - Aixue Liu
- Department of Oncology, The Second People's Hospital of Shenzhen, Shenzhen, Guangdong 518000, P.R. China
| | - Jiren Zhang
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China
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Chen Y, Tang Q, Xiao Q, Yang L, Hann SS. Targeting EP4 downstream c-Jun through ERK1/2-mediated reduction of DNMT1 reveals novel mechanism of solamargine-inhibited growth of lung cancer cells. J Cell Mol Med 2016; 21:222-233. [PMID: 27620163 PMCID: PMC5264151 DOI: 10.1111/jcmm.12958] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/19/2016] [Indexed: 12/15/2022] Open
Abstract
Lung cancer is the most common cancer and the leading cause of cancer deaths worldwide. We previously showed that solamargine, one natural phytochemicals from traditional plants, inhibited the growth of lung cancer cells through inhibition of prostaglandin E2 (PGE2 ) receptor EP4. However, the potential downstream effectors of EP4 involving in the anti-lung cancer effects of solamargine still remained to be determined. In this study, we further verified that solamargine inhibited growth of non-small-cell lung cancer (NSCLC) cells in multiple cell lines. Mechanistically, solamargine increased phosphorylation of ERK1/2. Moreover, solamargine inhibited the protein expression of DNA methyltransferase 1 (DNMT1) and c-Jun, which were abrogated in cells treated with MEK/ERK1/2 inhibitor (PD98059) and transfected with exogenously expressed DNMT1 gene, respectively. Interestingly, overexpressed DNMT1 gene antagonized the effect of solamargine on c-Jun protein expression. Intriguingly, overexpressed c-Jun blocked solamargine-inhibited lung cancer cell growth, and feedback resisted the solamargine-induced phosphorylation of ERK1/2. A nude mouse xenograft model implanted with lung cancer cells in vivo confirmed the results in vitro. Collectively, our results show that solamargine inhibits the growth of human lung cancer cells through reduction of EP4 protein expression, followed by increasing ERK1/2 phosphorylation. This results in decrease in DNMT1 and c-Jun protein expressions. The inter-correlations between EP4, DNMT1 and c-Jun and feedback regulation of ERK1/2 by c-Jun contribute to the overall responses of solamargine in this process. This study uncovers an additional novel mechanism by which solamargine inhibits growth of human lung cancer cells.
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Affiliation(s)
- Yuqing Chen
- Laboratory of Tumor Biology, Department of Medical Oncology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, China
| | - Qing Tang
- Laboratory of Tumor Biology, Department of Medical Oncology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, China
| | - Qian Xiao
- Laboratory of Tumor Biology, Department of Medical Oncology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, China
| | - LiJun Yang
- Laboratory of Tumor Biology, Department of Medical Oncology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, China
| | - Swei S Hann
- Laboratory of Tumor Biology, Department of Medical Oncology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, China
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Sun L, Liang J, Wang Q, Li Z, Du Y, Xu X. MicroRNA-137 suppresses tongue squamous carcinoma cell proliferation, migration and invasion. Cell Prolif 2016; 49:628-35. [PMID: 27571935 DOI: 10.1111/cpr.12287] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 07/14/2016] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES Tongue squamous cell carcinoma (TSCC) is the most frequent type of oral malignancy. Increasing evidence has shown that miRNAs play key roles in many biological processes such as cell development, invasion, proliferation, differentiation, metabolism, apoptosis and migration. MATERIALS AND METHODS qRT-PCR analysis was performed to measure miR-137 expression. CCK-8 analysis, cell colony formation, wound-healing analysis and invasion were performed to detect resultant cell functions. The direct target of miR-137 was labelled and measured by luciferase assay and Western blotting. RESULTS We demonstrated that expression of miR-137 was downregulated in TSCC tissues compared to matched normal ones. miR-137 expression was downregulated in TSCC lines (SCC4, SCC1, UM1 and Cal27) compared to the immortalized NOK16B cell line and normal oral keratinocytes in culture (NHOK). In addition, we have shown that miR-137 expression was epigenetically regulated in TSCCs. Overexpression of miR-137 suppressed TSCC proliferation and colony formation. Ectopic expression of miR-137 promoted expression of the epithelial biomarker, E-cadherin, and inhibited the mesenchymal biomarker, N-cadherin, as well as vimentin and Snail expression, indicating that miR-137 suppressed TSCC epithelial-mesenchymal transition (EMT). We also showed that ectopic expression of miR-137 inhibited TSCC invasion and migration. In addition, we identified SP1 as a direct target gene of miR-137 in SCC1 cells. SP1 overexpression rescued inhibitory effects exerted by miR-137 on cell proliferation and EMT. CONCLUSIONS These results indicate that miR-137 acted as a tumour suppressor in TSCC by targeting SP1.
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Affiliation(s)
- Lanying Sun
- School of Stomatology, Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Shandong University, Jinan, 250012, China.,Oral Implantology Center, Stomatology Hospital of Jinan, Jinan, 250001, China
| | - Jin Liang
- School of Stomatology, Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Shandong University, Jinan, 250012, China
| | - Qibao Wang
- Department of Endodontics, Stomatology Hospital of Jinan, Jinan, 250001, China
| | - Zhaoyuan Li
- Oral Implantology Center, Stomatology Hospital of Jinan, Jinan, 250001, China
| | - Yi Du
- Department of Endodontics, Stomatology Hospital of Jinan, Jinan, 250001, China
| | - Xin Xu
- School of Stomatology, Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Shandong University, Jinan, 250012, China.
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