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Chen X, Han M, Li Y, Li X, Zhang J, Zhu Y. Identification of functional gene modules by integrating multi-omics data and known molecular interactions. Front Genet 2023; 14:1082032. [PMID: 36760999 PMCID: PMC9902936 DOI: 10.3389/fgene.2023.1082032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 01/11/2023] [Indexed: 01/25/2023] Open
Abstract
Multi-omics data integration has emerged as a promising approach to identify patient subgroups. However, in terms of grouping genes (or gene products) into co-expression modules, data integration methods suffer from two main drawbacks. First, most existing methods only consider genes or samples measured in all different datasets. Second, known molecular interactions (e.g., transcriptional regulatory interactions, protein-protein interactions and biological pathways) cannot be utilized to assist in module detection. Herein, we present a novel data integration framework, Correlation-based Local Approximation of Membership (CLAM), which provides two methodological innovations to address these limitations: 1) constructing a trans-omics neighborhood matrix by integrating multi-omics datasets and known molecular interactions, and 2) using a local approximation procedure to define gene modules from the matrix. Applying Correlation-based Local Approximation of Membership to human colorectal cancer (CRC) and mouse B-cell differentiation multi-omics data obtained from The Cancer Genome Atlas (TCGA), Clinical Proteomics Tumor Analysis Consortium (CPTAC), Gene Expression Omnibus (GEO) and ProteomeXchange database, we demonstrated its superior ability to recover biologically relevant modules and gene ontology (GO) terms. Further investigation of the colorectal cancer modules revealed numerous transcription factors and KEGG pathways that played crucial roles in colorectal cancer progression. Module-based survival analysis constructed four survival-related networks in which pairwise gene correlations were significantly correlated with colorectal cancer patient survival. Overall, the series of evaluations demonstrated the great potential of Correlation-based Local Approximation of Membership for identifying modular biomarkers for complex diseases. We implemented Correlation-based Local Approximation of Membership as a user-friendly application available at https://github.com/free1234hm/CLAM.
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Affiliation(s)
- Xiaoqing Chen
- Basic Medical School, Anhui Medical University, Hefei, China,National Center for Protein Sciences (Beijing), Beijing Proteome Research Center, Beijing Institute of Lifeomics, Beijing, China
| | - Mingfei Han
- National Center for Protein Sciences (Beijing), Beijing Proteome Research Center, Beijing Institute of Lifeomics, Beijing, China
| | - Yingxing Li
- Central Research Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiao Li
- National Center for Protein Sciences (Beijing), Beijing Proteome Research Center, Beijing Institute of Lifeomics, Beijing, China
| | - Jiaqi Zhang
- National Center for Protein Sciences (Beijing), Beijing Proteome Research Center, Beijing Institute of Lifeomics, Beijing, China
| | - Yunping Zhu
- Basic Medical School, Anhui Medical University, Hefei, China,National Center for Protein Sciences (Beijing), Beijing Proteome Research Center, Beijing Institute of Lifeomics, Beijing, China,*Correspondence: Yunping Zhu,
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Maghsoudloo M, Azimzadeh Jamalkandi S, Najafi A, Masoudi-Nejad A. An efficient hybrid feature selection method to identify potential biomarkers in common chronic lung inflammatory diseases. Genomics 2020; 112:3284-3293. [PMID: 32540493 DOI: 10.1016/j.ygeno.2020.06.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 05/21/2020] [Accepted: 06/04/2020] [Indexed: 12/13/2022]
Abstract
Asthma, chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF) are three serious lung inflammatory diseases. The understanding of the pathogenesis mechanism and the identification of potential prognostic biomarkers of these diseases can provide the patients with more efficient treatments. In this study, an efficient hybrid feature selection method was introduced in order to extract informative genes. We implemented an ontology-based ranking approach on differentially expressed genes following a wrapper method. The examination of the different gene ontologies and their combinations motivated us to propose a biological functional-based method to improve the performance of further wrapper methods. The results identified: TOM1L1, SRSF1, and GIT2 in asthma; CHCHD4, PAIP2, CRLF3, UBQLN4, TRAK1, PRELID1, VAMP4, CCM2, and APBB1IP in COPD; and TUFT1, GAB2, B4GALNT1, TNFRSF17, PRDM8, and SETDB2 in IPF as the potential biomarkers. The proposed method can be used to identify hub genes in other high-throughput datasets.
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Affiliation(s)
- Mazaher Maghsoudloo
- Laboratory of Systems Biology and Bioinformatics (LBB), Department of Bioinformatics, Kish International Campus, University of Tehran, Kish Island, Iran; Laboratory of Systems Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | | | - Ali Najafi
- Molecular Biology Research Center, Systems Biology and Poisonings Institute, Tehran, Iran
| | - Ali Masoudi-Nejad
- Laboratory of Systems Biology and Bioinformatics (LBB), Department of Bioinformatics, Kish International Campus, University of Tehran, Kish Island, Iran; Laboratory of Systems Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
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3
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Wang F, Ye BG, Liu JZ, Kong DL. miR-487b and TRAK2 that form an axis to regulate the aggressiveness of osteosarcoma, are potential therapeutic targets and prognostic biomarkers. J Biochem Mol Toxicol 2020; 34:e22511. [PMID: 32267991 DOI: 10.1002/jbt.22511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/24/2020] [Accepted: 03/26/2020] [Indexed: 12/21/2022]
Abstract
To investigate the effect of microRNA-487b (miR-487b) as well as the underlying mechanism in osteosarcoma (OS). Data downloaded from the Gene Expression Omnibus (GEO) database were used to analyze the expression and prognostic value of miR-487b/TRAK2. Cell counting kit-8, colony formation, and transwell assays were performed to investigate the biological functions of miR-487b and TRAK2. Luciferase reporter assay was applied to confirm the interactions between miR-487b and TRAK2. miR-487b was overexpressed in OS tissues and was inversely associated with the prognosis of OS patients. We discovered that miR-487b could contribute to the proliferative, clonogenic, invasive, and migratory capabilities of OS cells. Through target prediction using miRWalk and differential expression analysis based on the GEO data set, trafficking kinesin protein 2 (TRAK2) was recognized as a potential target of miR-487b, which was further verified by luciferase reporter assay. The expression of TRAK2 was decreased in OS tissues compared with normal tissues and was positively correlated with the prognosis of OS patients. A negative relevance was presented between the expression of miR-487b and TRAK2 in OS cells. Of note, further mechanistic analyses indicated that TRAK2 was implicated in the regulatory effect of miR-487b on the cell malignant behaviors in OS. To sum up, these results demonstrated that miR-487b played an oncogenic role in OS progression via directly targeting TRAK2, which could advance the development of cancer treatment.
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Affiliation(s)
- Fei Wang
- Department of Orthopedics, China-Japan Union Hospital Jilin University, Changchun, Jilin, China
| | - Bao-Guo Ye
- Department of Anesthesiology, China-Japan Union Hospital Jilin University, Changchun, Jilin, China
| | - Jun-Zhi Liu
- Department of Quality Control, China-Japan Union Hospital Jilin University, Changchun, Jilin, China
| | - Da-Liang Kong
- Department of Orthopedics, China-Japan Union Hospital Jilin University, Changchun, Jilin, China
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Furnish M, Caino MC. Altered mitochondrial trafficking as a novel mechanism of cancer metastasis. Cancer Rep (Hoboken) 2019; 3:e1157. [PMID: 32671955 DOI: 10.1002/cnr2.1157] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/07/2018] [Accepted: 01/07/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Mammalian cells must constantly reprogram the distribution of mitochondria in order to meet the local demands for energy, calcium, redox balance, and other mitochondrial functions. Mitochondrial localization inside the cell is a result of a combination of movement along the microtubule tracks plus anchoring to actin filaments. RECENT FINDINGS Recent advances show that subcellular distribution of mitochondria can regulate tumor cell growth, proliferation/motility plasticity, metastatic competence, and therapy responses in tumors. In this review, we discuss our current understanding of the mechanisms by which mitochondrial subcellular distribution is regulated in tumor cells. CONCLUSIONS Mitochondrial trafficking is dysregulated in tumors. Accumulation of mitochondria at the leading edge of the cell supports energy expensive processes of focal adhesion dynamics, cell membrane dynamics, migration, and invasion.
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Affiliation(s)
- Madison Furnish
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - M Cecilia Caino
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado, USA
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Lee CA, Chin LS, Li L. Hypertonia-linked protein Trak1 functions with mitofusins to promote mitochondrial tethering and fusion. Protein Cell 2018; 9:693-716. [PMID: 28924745 PMCID: PMC6053349 DOI: 10.1007/s13238-017-0469-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 08/21/2017] [Indexed: 12/23/2022] Open
Abstract
Hypertonia is a neurological dysfunction associated with a number of central nervous system disorders, including cerebral palsy, Parkinson's disease, dystonia, and epilepsy. Genetic studies have identified a homozygous truncation mutation in Trak1 that causes hypertonia in mice. Moreover, elevated Trak1 protein expression is associated with several types of cancers and variants in Trak1 are linked to childhood absence epilepsy in humans. Despite the importance of Trak1 in health and disease, the mechanisms of Trak1 action remain unclear and the pathogenic effects of Trak1 mutation are unknown. Here we report that Trak1 has a crucial function in regulation of mitochondrial fusion. Depletion of Trak1 inhibits mitochondrial fusion, resulting in mitochondrial fragmentation, whereas overexpression of Trak1 elongates and enlarges mitochondria. Our analyses revealed that Trak1 interacts and colocalizes with mitofusins on the outer mitochondrial membrane and functions with mitofusins to promote mitochondrial tethering and fusion. Furthermore, Trak1 is required for stress-induced mitochondrial hyperfusion and pro-survival response. We found that hypertonia-associated mutation impairs Trak1 mitochondrial localization and its ability to facilitate mitochondrial tethering and fusion. Our findings uncover a novel function of Trak1 as a regulator of mitochondrial fusion and provide evidence linking dysregulated mitochondrial dynamics to hypertonia pathogenesis.
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Affiliation(s)
- Crystal A Lee
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Lih-Shen Chin
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Lian Li
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
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Xie JY, Chen PC, Zhang JL, Gao ZS, Neves H, Zhang SD, Wen Q, Chen WD, Kwok HF, Lin Y. The prognostic significance of DAPK1 in bladder cancer. PLoS One 2017; 12:e0175290. [PMID: 28388658 PMCID: PMC5384764 DOI: 10.1371/journal.pone.0175290] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 03/23/2017] [Indexed: 12/18/2022] Open
Abstract
Bladder cancer is one of the leading causes of cancer-related death in men, however, there was only limited effective treatment for invasive bladder cancer. DAPK1 has been shown to play important role in apoptosis and autophagy to suppress cancer progression. Previous results have shown that DAPK1 promoter was hypermethylated in the majority of bladder cancer specimens, however, the prognostic significance of DAPK1 in bladder cancer has yet to be demonstrated. In the present study, we found that DAPK1 expression was negatively associated with tumor stage and a low level expression of DAPK1 in bladder cancer specimens were associated with shorter survival in bladder cancer patients in 3 independent bladder cancer datasets (n = 462). Further investigation showed that FGFR3 knockdown resulted in downregulation of DAPK1 in bladder cancer cell line, suggesting that FGFR3 may be an upstream factor of DAPK1. Further analysis of the 3 independent bladder cancer datasets have identified ACOX1, UPK2, TRAK1, PLEKHG6 and MT1X genes had their expression significantly correlated with that of DAPK1. Knockdown of DAPK1 in bladder cancer T24 cells resulted in downregulation of ACOX1, UPK2 and TRAK1. Interestingly, TRAK1, by itself, was a favorable prognostic marker in the 3 independent bladder cancer datasets. Importantly, by using connectivity mapping with DAPK1-associated gene signature, we found that vemurafenib and trametinib could possibly reverse DAPK1-associated gene signature, suggesting that inhibition of Raf/MEK pathway may be a potential therapeutic approach for bladder cancer. Indeed, treatment of vemurafenib in T24 bladder cancer cells resulted in upregulation of DAPK1 confirming our connectivity mapping, while knockdown of DAPK1 resulted in reduced sensitivity towards inhibition of Braf signaling by vemurafenib. Together, our results suggest that DAPK1 is an important prognostic marker and therapeutic target for bladder cancer and have identified possible therapeutic agents for future testing in bladder cancer models with low DAPK1 expression.
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Affiliation(s)
- Jian-Yun Xie
- Department of Urology, The Affiliated People’s Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian Province, People’s Republic of China
| | - Peng-Chen Chen
- College of Life Sciences, Fujian Normal University, Fuzhou, Fujian Province, People’s Republic of China
| | - Jia-Li Zhang
- Department of Urology, The Affiliated People’s Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian Province, People’s Republic of China
| | - Ze-Shou Gao
- Department of Urology, The Affiliated People’s Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian Province, People’s Republic of China
| | - Henrique Neves
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau SAR
| | - Shu-Dong Zhang
- Northern Ireland Centre for Stratified Medicine, University of Ulster, C-TRIC Building, Altnagelvin Hospital Campus, Glenshane Road, Londonderry, United Kingdom
| | - Qing Wen
- Centre for Cancer Research & Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Wei-Dong Chen
- Department of Urology, The Affiliated People’s Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian Province, People’s Republic of China
- * E-mail: (YL); (HFK); (WDC)
| | - Hang Fai Kwok
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau SAR
- * E-mail: (YL); (HFK); (WDC)
| | - Yao Lin
- College of Life Sciences, Fujian Normal University, Fuzhou, Fujian Province, People’s Republic of China
- * E-mail: (YL); (HFK); (WDC)
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An Y, Zhang Z, Shang Y, Jiang X, Dong J, Yu P, Nie Y, Zhao Q. miR-23b-3p regulates the chemoresistance of gastric cancer cells by targeting ATG12 and HMGB2. Cell Death Dis 2015; 6:e1766. [PMID: 25996293 PMCID: PMC4669702 DOI: 10.1038/cddis.2015.123] [Citation(s) in RCA: 175] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 03/16/2015] [Accepted: 03/23/2015] [Indexed: 12/17/2022]
Abstract
Chemotherapy is an important treatment modality for gastric cancer (GC); however, it usually fails because of drug resistance, especially multidrug resistance (MDR). Previously, we found a novel subset of MDR-associated microRNAs (miRNAs) through high-throughput functional screening. In this report, we investigated the exact roles and mechanisms of miR-23b-3p in the MDR of GC. Using gain or loss-of-function in in vitro and in vivo experiments, we found that overexpression of miR-23b-3p reversed cancer cell resistance to multiple chemotherapeutics in vitro and sensitize tumors to chemotherapy in vivo. Reporter gene assay and western blot analysis showed that ATG12 and HMGB2 were the direct targets of miR-23b-3p. Meanwhile, ATG12 and HMGB2 were positively associated with the occurrence of autophagy. Reducing the expression of these target genes by siRNA or inhibition of autophagy both sensitized GC cells to chemotherapy. These findings suggest that a miR-23b-3p/ATG12/HMGB2/autophagy-regulatory loop has a critical role in MDR in GC. In addition, miR-23b-3p could be used as a prognostic factor for overall survival in GC. In conclusion, our data demonstrated that miR-23b-3p inhibited autophagy mediated by ATG12 and HMGB2 and sensitized GC cells to chemotherapy, and suggested the potential application of miR-23b-3p in drug resistance prediction and treatment.
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Affiliation(s)
- Y An
- 1] State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, 127 Changle Western Road, Xi'an, Shaanxi 710032, China [2] Department of General Surgery, General Hospital of Jinan Military Command, Jinan, China [3] Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo University School of Medicine, Ningbo, Zhejiang 315211, China
| | - Z Zhang
- 1] State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, 127 Changle Western Road, Xi'an, Shaanxi 710032, China [2] Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo University School of Medicine, Ningbo, Zhejiang 315211, China
| | - Y Shang
- 1] State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, 127 Changle Western Road, Xi'an, Shaanxi 710032, China [2] Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo University School of Medicine, Ningbo, Zhejiang 315211, China
| | - X Jiang
- 1] State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, 127 Changle Western Road, Xi'an, Shaanxi 710032, China [2] Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo University School of Medicine, Ningbo, Zhejiang 315211, China
| | - J Dong
- State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, 127 Changle Western Road, Xi'an, Shaanxi 710032, China
| | - P Yu
- State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, 127 Changle Western Road, Xi'an, Shaanxi 710032, China
| | - Y Nie
- State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, 127 Changle Western Road, Xi'an, Shaanxi 710032, China
| | - Q Zhao
- State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, 127 Changle Western Road, Xi'an, Shaanxi 710032, China
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Shi Y, Wang SH, Zhang FM. Role of γ-aminobutyric acid and its receptors in carcinogenesis. Shijie Huaren Xiaohua Zazhi 2012; 20:399-404. [DOI: 10.11569/wcjd.v20.i5.399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the adult mammalian brain and it is also expressed in the central nervous system, peripheral nerves and peripheral non-neural tissues. Recent studies have shown that GABA is involved in the proliferation and migration of tumor cells and other processes of tumor development. According to different sensitivity to agonists and antagonists, GABA receptors have been classified into three types: A, B and C. GABA receptors and their receptor subunits are involved in complicated regulation of tumor cells. Many studies have demonstrated that GABA binding to its receptors can activate or inhibit the cAMP signaling pathway and the MAPK/ERK pathway, and regulate cancer cell proliferation and migration. The potential value of GABA in cancer diagnosis, prognostic prediction and biotherapy has been gradually revealed. In the present article, we reviewed the recent progress in understanding the role of GABA and its receptors in carcinogenesis.
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Thorsen K, Schepeler T, Øster B, Rasmussen MH, Vang S, Wang K, Hansen KQ, Lamy P, Pedersen JS, Eller A, Mansilla F, Laurila K, Wiuf C, Laurberg S, Dyrskjøt L, Ørntoft TF, Andersen CL. Tumor-specific usage of alternative transcription start sites in colorectal cancer identified by genome-wide exon array analysis. BMC Genomics 2011; 12:505. [PMID: 21999571 PMCID: PMC3208247 DOI: 10.1186/1471-2164-12-505] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 10/14/2011] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Approximately half of all human genes use alternative transcription start sites (TSSs) to control mRNA levels and broaden the transcriptional output in healthy tissues. Aberrant expression patterns promoting carcinogenesis, however, may arise from alternative promoter usage. RESULTS By profiling 108 colorectal samples using exon arrays, we identified nine genes (TCF12, OSBPL1A, TRAK1, ANK3, CHEK1, UGP2, LMO7, ACSL5, and SCIN) showing tumor-specific alternative TSS usage in both adenoma and cancer samples relative to normal mucosa. Analysis of independent exon array data sets corroborated these findings. Additionally, we confirmed the observed patterns for selected mRNAs using quantitative real-time reverse-transcription PCR. Interestingly, for some of the genes, the tumor-specific TSS usage was not restricted to colorectal cancer. A comprehensive survey of the nine genes in lung, bladder, liver, prostate, gastric, and brain cancer revealed significantly altered mRNA isoform ratios for CHEK1, OSBPL1A, and TCF12 in a subset of these cancer types.To identify the mechanism responsible for the shift in alternative TSS usage, we antagonized the Wnt-signaling pathway in DLD1 and Ls174T colorectal cancer cell lines, which remarkably led to a shift in the preferred TSS for both OSBPL1A and TRAK1. This indicated a regulatory role of the Wnt pathway in selecting TSS, possibly also involving TP53 and SOX9, as their transcription binding sites were enriched in the promoters of the tumor preferred isoforms together with their mRNA levels being increased in tumor samples. Finally, to evaluate the prognostic impact of the altered TSS usage, immunohistochemistry was used to show deregulation of the total protein levels of both TCF12 and OSBPL1A, corresponding to the mRNA levels observed. Furthermore, the level of nuclear TCF12 had a significant correlation to progression free survival in a cohort of 248 stage II colorectal cancer samples. CONCLUSIONS Alternative TSS usage in colorectal adenoma and cancer samples has been shown for nine genes, and OSBPL1A and TRAK1 were found to be regulated in vitro by Wnt signaling. TCF12 protein expression was upregulated in cancer samples and correlated with progression free survival.
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Affiliation(s)
- Kasper Thorsen
- Department of Molecular Medicine, Aarhus University Hospital, Skejby, 8200 Aarhus N, Denmark
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