1
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The importance of batch sensitization in missing value imputation. Sci Rep 2023; 13:3003. [PMID: 36810890 PMCID: PMC9944322 DOI: 10.1038/s41598-023-30084-2] [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: 02/05/2022] [Accepted: 02/15/2023] [Indexed: 02/23/2023] Open
Abstract
Data analysis is complex due to a myriad of technical problems. Amongst these, missing values and batch effects are endemic. Although many methods have been developed for missing value imputation (MVI) and batch correction respectively, no study has directly considered the confounding impact of MVI on downstream batch correction. This is surprising as missing values are imputed during early pre-processing while batch effects are mitigated during late pre-processing, prior to functional analysis. Unless actively managed, MVI approaches generally ignore the batch covariate, with unknown consequences. We examine this problem by modelling three simple imputation strategies: global (M1), self-batch (M2) and cross-batch (M3) first via simulations, and then corroborated on real proteomics and genomics data. We report that explicit consideration of batch covariates (M2) is important for good outcomes, resulting in enhanced batch correction and lower statistical errors. However, M1 and M3 are error-generating: global and cross-batch averaging may result in batch-effect dilution, with concomitant and irreversible increase in intra-sample noise. This noise is unremovable via batch correction algorithms and produces false positives and negatives. Hence, careless imputation in the presence of non-negligible covariates such as batch effects should be avoided.
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2
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Association between XRCC3 rs861539 Polymorphism and the Risk of Ovarian Cancer: Meta-Analysis and Trial Sequential Analysis. BIOMED RESEARCH INTERNATIONAL 2022; 2022:3915402. [PMID: 35978646 PMCID: PMC9377891 DOI: 10.1155/2022/3915402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 07/21/2022] [Indexed: 11/17/2022]
Abstract
Background Current studies on the relationship between XRCC3 rs861539 polymorphism and ovarian cancer risk have been inconsistent. Therefore, we performed a meta-analysis to explore their association. Methods Six electronic databases (PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, and China Wanfang Database) were searched for relevant studies published before December 2021. Meta-analysis, subgroup analysis, sensitivity analysis, and publication bias analysis were performed using Stata software 16.0. Trial sequential analysis (TSA) was performed using TSA 0.9.5.10 Beta software. Results A total of 12 studies were included in 9 literatures, comprising 4,634 cases of ovarian cancer and 7,381 controls. After Bonferroni correction, the meta-analysis showed an association between XRCC3 rs861539 polymorphism and ovarian cancer risk in the heterozygote model and the dominant model (GA vs. GG: OR = 0.88, 95%CI = 0.81-0.96, P = 0.003; GG vs. GA+AA: OR = 0.89, 95%CI = 0.82-0.96, P = 0.004). In an ethnically stratified subgroup analysis, XRCC3 rs861539 was shown to reduce the risk of ovarian cancer in Caucasian in the heterozygote model and the dominant model (GA vs. GG: OR = 0.88, 95%CI = 0.81-0.96, P = 0.004; GG vs. GA+AA: OR = 0.88, 95%CI = 0.81-0.96, P = 0.004). In the control source and detection method stratified subgroup analysis, hospital-based studies and PCR-RFLP-based studies were found to increase ovarian cancer risk (GG vs. AA: OR = 1.30, 95%CI = 1.05-1.62, P = 0.016; GG vs. AA: OR = 1.31, 95%CI = 1.06-1.62, P = 0.013). Conclusion This meta-analysis showed a significant association between XRCC3 rs861539 polymorphism and ovarian cancer risk, especially in Caucasians. Large-scale multicenter case-control studies in more different regions will be needed in the future.
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Rae S, Spillane C, Blackshields G, Madden SF, Keenan J, Stordal B. The EMT-activator ZEB1 is unrelated to platinum drug resistance in ovarian cancer but is predictive of survival. Hum Cell 2022; 35:1547-1559. [PMID: 35794446 PMCID: PMC9374625 DOI: 10.1007/s13577-022-00744-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 06/24/2022] [Indexed: 11/30/2022]
Abstract
The IGROVCDDP cisplatin-resistant ovarian cancer cell line is an unusual model, as it is also cross-resistant to paclitaxel. IGROVCDDP, therefore, models the resistance phenotype of serous ovarian cancer patients who have failed frontline platinum/taxane chemotherapy. IGROVCDDP has also undergone epithelial-mesenchymal transition (EMT). We aim to determine if alterations in EMT-related genes are related to or independent from the drug-resistance phenotypes. EMT gene and protein markers, invasion, motility and morphology were investigated in IGROVCDDP and its parent drug-sensitive cell line IGROV-1. ZEB1 was investigated by qPCR, Western blotting and siRNA knockdown. ZEB1 was also investigated in publicly available ovarian cancer gene-expression datasets. IGROVCDDP cells have decreased protein levels of epithelial marker E-cadherin (6.18-fold, p = 1.58e-04) and higher levels of mesenchymal markers vimentin (2.47-fold, p = 4.43e-03), N-cadherin (4.35-fold, p = 4.76e-03) and ZEB1 (3.43-fold, p = 0.04). IGROVCDDP have a spindle-like morphology consistent with EMT. Knockdown of ZEB1 in IGROVCDDP does not lead to cisplatin sensitivity but shows a reversal of EMT-gene signalling and an increase in cell circularity. High ZEB1 gene expression (HR = 1.31, n = 2051, p = 1.31e-05) is a marker of poor overall survival in high-grade serous ovarian-cancer patients. In contrast, ZEB1 is not predictive of overall survival in high-grade serous ovarian-cancer patients known to be treated with platinum chemotherapy. The increased expression of ZEB1 in IGROVCDDP appears to be independent of the drug-resistance phenotypes. ZEB1 has the potential to be used as biomarker of overall prognosis in ovarian-cancer patients but not of platinum/taxane chemoresistance.
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Affiliation(s)
- Sophie Rae
- Department of Natural Sciences, Middlesex University London, London, UK
| | - Cathy Spillane
- Department of Histopathology, St James' Hospital and Trinity College Dublin, Dublin, Ireland
| | - Gordon Blackshields
- Department of Histopathology, St James' Hospital and Trinity College Dublin, Dublin, Ireland
| | - Stephen F Madden
- Data Science Centre, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Joanne Keenan
- National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Britta Stordal
- Department of Natural Sciences, Middlesex University London, London, UK.
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OSov: An Interactive Web Server to Evaluate Prognostic Biomarkers for Ovarian Cancer. BIOLOGY 2021; 11:biology11010023. [PMID: 35053021 PMCID: PMC8773055 DOI: 10.3390/biology11010023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/17/2021] [Accepted: 12/21/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary The OSov web server incorporates gene expression profiles with clinical risk factors to estimate the ovarian cancers patients’ survival, and provides a tool for multiple analysis, such as forest-plot, uni/multi-variate survival analysis, Kaplan-Meier plot and nomogram construction. Abstract Ovarian cancer is one of the most aggressive and highly lethal gynecological cancers. The purpose of our study is to build a free prognostic web server to help researchers discover potential prognostic biomarkers by integrating gene expression profiling data and clinical follow-up information of ovarian cancer. We construct a prognostic web server OSov (Online consensus Survival analysis for Ovarian cancer) based on RNA expression profiles. OSov is a user-friendly web server which could present a Kaplan–Meier plot, forest plot, nomogram and survival summary table of queried genes in each individual cohort to evaluate the prognostic potency of each queried gene. To assess the performance of OSov web server, 163 previously published prognostic biomarkers of ovarian cancer were tested and 72% of them had their prognostic values confirmed in OSov. It is a free and valuable prognostic web server to screen and assess survival-associated biomarkers for ovarian cancer.
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Da-ano R, Lucia F, Masson I, Abgral R, Alfieri J, Rousseau C, Mervoyer A, Reinhold C, Pradier O, Schick U, Visvikis D, Hatt M. A transfer learning approach to facilitate ComBat-based harmonization of multicentre radiomic features in new datasets. PLoS One 2021; 16:e0253653. [PMID: 34197503 PMCID: PMC8248970 DOI: 10.1371/journal.pone.0253653] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/09/2021] [Indexed: 12/15/2022] Open
Abstract
PURPOSE To facilitate the demonstration of the prognostic value of radiomics, multicenter radiomics studies are needed. Pooling radiomic features of such data in a statistical analysis is however challenging, as they are sensitive to the variability in scanner models, acquisition protocols and reconstruction settings, which is often unavoidable in a multicentre retrospective analysis. A statistical harmonization strategy called ComBat was utilized in radiomics studies to deal with the "center-effect". The goal of the present work was to integrate a transfer learning (TL) technique within ComBat-and recently developed alternate versions of ComBat with improved flexibility (M-ComBat) and robustness (B-ComBat)-to allow the use of a previously determined harmonization transform to the radiomic feature values of new patients from an already known center. MATERIAL AND METHODS The proposed TL approach were incorporated in the four versions of ComBat (standard, B, M, and B-M ComBat). The proposed approach was evaluated using a dataset of 189 locally advanced cervical cancer patients from 3 centers, with magnetic resonance imaging (MRI) and positron emission tomography (PET) images, with the clinical endpoint of predicting local failure. The impact performance of the TL approach was evaluated by comparing the harmonization achieved using only parts of the data to the reference (harmonization achieved using all the available data). It was performed through three different machine learning pipelines. RESULTS The proposed TL technique was successful in harmonizing features of new patients from a known center in all versions of ComBat, leading to predictive models reaching similar performance as the ones developed using the features harmonized with all the data available. CONCLUSION The proposed TL approach enables applying a previously determined ComBat transform to new, previously unseen data.
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Affiliation(s)
- Ronrick Da-ano
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
- * E-mail:
| | - François Lucia
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
- Radiation Oncology Department, University Hospital, Brest, France
| | - Ingrid Masson
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
- Department of Radiation Oncology, Institut de cancérologie de l’Ouest René-Gauducheau, Saint-Herblain, France
| | - Ronan Abgral
- Department of Nuclear Medicine, University of Brest, Brest, France
| | - Joanne Alfieri
- Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec
| | - Caroline Rousseau
- Department of Nuclear Medicine, Institut de cancérologie de l’Ouest René-Gauducheau, Saint-Herblain, France
| | - Augustin Mervoyer
- Department of Radiation Oncology, Institut de cancérologie de l’Ouest René-Gauducheau, Saint-Herblain, France
| | - Caroline Reinhold
- Department of Radiology, McGill University Health Centre, Montreal, Canada
- Augmented Intelligence & Precision Health Laboratory of the Research Institute of McGill University Health Centre, Montreal, Canada
| | - Olivier Pradier
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
- Radiation Oncology Department, University Hospital, Brest, France
| | - Ulrike Schick
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
- Radiation Oncology Department, University Hospital, Brest, France
| | | | - Mathieu Hatt
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
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6
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Tsimberidou AM, Fountzilas E, Bleris L, Kurzrock R. Transcriptomics and solid tumors: The next frontier in precision cancer medicine. Semin Cancer Biol 2020; 84:50-59. [PMID: 32950605 DOI: 10.1016/j.semcancer.2020.09.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 08/16/2020] [Accepted: 09/09/2020] [Indexed: 01/08/2023]
Abstract
Transcriptomics, which encompasses assessments of alternative splicing and alternative polyadenylation, identification of fusion transcripts, explorations of noncoding RNAs, transcript annotation, and discovery of novel transcripts, is a valuable tool for understanding cancer mechanisms and identifying biomarkers. Recent advances in high-throughput technologies have enabled large-scale gene expression profiling. Importantly, RNA expression profiling of tumor tissue has been successfully used to determine clinically actionable molecular alterations. The WINTHER precision medicine clinical trial was the first prospective trial in diverse solid malignancies that assessed both genomics and transcriptomics to match treatments to specific molecular alterations. The use of transcriptome analysis in WINTHER and other trials increased the number of targetable -omic changes compared to genomic profiling alone. Other applications of transcriptomics involve the evaluation of tumor and circulating noncoding RNAs as predictive and prognostic biomarkers, the improvement of risk stratification by the use of prognostic and predictive multigene assays, the identification of fusion transcripts that drive tumors, and an improved understanding of the impact of DNA changes as some genomic alterations are silenced at the RNA level. Finally, RNA sequencing and gene expression analysis have been incorporated into clinical trials to identify markers predicting response to immunotherapy. Many issues regarding the complexity of the analysis, its reproducibility and variability, and the interpretation of the results still need to be addressed. The integration of transcriptomics with genomics, proteomics, epigenetics, and tumor immune profiling will improve biomarker discovery and our understanding of disease mechanisms and, thereby, accelerate the implementation of precision oncology.
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Affiliation(s)
- Apostolia M Tsimberidou
- The University of Texas MD Anderson Cancer Center, Department of Investigational Cancer Therapeutics, Houston, TX, USA.
| | - Elena Fountzilas
- Department of Medical Oncology, Euromedica General Clinic, Thessaloniki, Greece
| | - Leonidas Bleris
- Bioengineering Department, The University of Texas at Dallas, Richardson, TX, USA
| | - Razelle Kurzrock
- Center for Personalized Cancer Therapy and Division of Hematology and Oncology, UC San Diego Moores Cancer Center, San Diego, CA, USA
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Da-Ano R, Masson I, Lucia F, Doré M, Robin P, Alfieri J, Rousseau C, Mervoyer A, Reinhold C, Castelli J, De Crevoisier R, Rameé JF, Pradier O, Schick U, Visvikis D, Hatt M. Performance comparison of modified ComBat for harmonization of radiomic features for multicenter studies. Sci Rep 2020; 10:10248. [PMID: 32581221 PMCID: PMC7314795 DOI: 10.1038/s41598-020-66110-w] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/04/2020] [Indexed: 11/08/2022] Open
Abstract
Multicenter studies are needed to demonstrate the clinical potential value of radiomics as a prognostic tool. However, variability in scanner models, acquisition protocols and reconstruction settings are unavoidable and radiomic features are notoriously sensitive to these factors, which hinders pooling them in a statistical analysis. A statistical harmonization method called ComBat was developed to deal with the "batch effect" in gene expression microarray data and was used in radiomics studies to deal with the "center-effect". Our goal was to evaluate modifications in ComBat allowing for more flexibility in choosing a reference and improving robustness of the estimation. Two modified ComBat versions were evaluated: M-ComBat allows to transform all features distributions to a chosen reference, instead of the overall mean, providing more flexibility. B-ComBat adds bootstrap and Monte Carlo for improved robustness in the estimation. BM-ComBat combines both modifications. The four versions were compared regarding their ability to harmonize features in a multicenter context in two different clinical datasets. The first contains 119 locally advanced cervical cancer patients from 3 centers, with magnetic resonance imaging and positron emission tomography imaging. In that case ComBat was applied with 3 labels corresponding to each center. The second one contains 98 locally advanced laryngeal cancer patients from 5 centers with contrast-enhanced computed tomography. In that specific case, because imaging settings were highly heterogeneous even within each of the five centers, unsupervised clustering was used to determine two labels for applying ComBat. The impact of each harmonization was evaluated through three different machine learning pipelines for the modelling step in predicting the clinical outcomes, across two performance metrics (balanced accuracy and Matthews correlation coefficient). Before harmonization, almost all radiomic features had significantly different distributions between labels. These differences were successfully removed with all ComBat versions. The predictive ability of the radiomic models was always improved with harmonization and the improved ComBat provided the best results. This was observed consistently in both datasets, through all machine learning pipelines and performance metrics. The proposed modifications allow for more flexibility and robustness in the estimation. They also slightly but consistently improve the predictive power of resulting radiomic models.
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Affiliation(s)
- R Da-Ano
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France.
| | - I Masson
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
- Department of Radiation Oncology, Institut de cancérologie de l'Ouest René-Gauducheau, Saint-Herblain, France
| | - F Lucia
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
- Radiation Oncology Department, University Hospital, Brest, France
| | - M Doré
- Department of Radiation Oncology, Institut de cancérologie de l'Ouest René-Gauducheau, Saint-Herblain, France
| | - P Robin
- Department of Nuclear Medicine, University of Brest, Brest, France
| | - J Alfieri
- Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec, Canada
| | - C Rousseau
- Department of Nuclear Medicine, Institut de cancerologie de l'Ouest René-Gauducheau, Saint-Herblain, France
- CRCINA, University of Nantes, INSERM UMR1232, CNRS-ERL6001, Nantes, France
| | - A Mervoyer
- Department of Radiation Oncology, Institut de cancérologie de l'Ouest René-Gauducheau, Saint-Herblain, France
| | - C Reinhold
- Department of Radiology, McGill University Health Centre, Montreal, Canada
| | - J Castelli
- Radiotherapy Department Cancer, Institute Eugene Marquis, Rennes, France
- University of Rennes 1, LTSI, Rennes, France
| | - R De Crevoisier
- Radiotherapy Department Cancer, Institute Eugene Marquis, Rennes, France
- University of Rennes 1, LTSI, Rennes, France
| | - J F Rameé
- Department of Medical Oncology, Centre Hospitalier de Vendee, La Roche sur Yon, France
| | - O Pradier
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
- Radiation Oncology Department, University Hospital, Brest, France
| | - U Schick
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
- Radiation Oncology Department, University Hospital, Brest, France
| | - D Visvikis
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
| | - M Hatt
- INSERM, UMR 1101, LaTIM, University of Brest, Brest, France
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Bing Z, Yao Y, Xiong J, Tian J, Guo X, Li X, Zhang J, Shi X, Zhang Y, Yang K. Novel Model for Comprehensive Assessment of Robust Prognostic Gene Signature in Ovarian Cancer Across Different Independent Datasets. Front Genet 2019; 10:931. [PMID: 31681404 PMCID: PMC6798149 DOI: 10.3389/fgene.2019.00931] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Accepted: 09/05/2019] [Indexed: 12/31/2022] Open
Abstract
Different analytical methods or models can often find completely different prognostic biomarkers for the same cancer. In the study of prognostic molecular biomarkers of ovarian cancer (OvCa), different studies have reported a variety of prognostic gene signatures. In the current study, based on geometric concepts, the linearity-clustering phase diagram with integrated P-value (LCP) method was used to comprehensively consider three indicators that are commonly employed to estimate the quality of a prognostic gene signature model. The three indicators, namely, concordance index, area under the curve, and level of the hazard ratio were determined via calculation of the prognostic index of various gene signatures from different datasets. As evaluation objects, we selected 13 gene signature models (Cox regression model) and 16 OvCa genomic datasets (including gene expression information and follow-up data) from published studies. The results of LCP showed that three models were universal and better than other models. In addition, combining the three models into one model showed the best performance in all datasets by LCP calculation. The combination gene signature model provides a more reliable model and could be validated in various datasets of OvCa. Thus, our method and findings can provide more accurate prognostic biomarkers and effective reference for the precise clinical treatment of OvCa.
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Affiliation(s)
- Zhitong Bing
- Evidence Based Medicine Center, School of Basic Medical Science of Lanzhou University, Lanzhou, China.,Key Laboratory of Evidence Based Medicine and Knowledge Translation of Gansu Province, Lanzhou, China.,Department of Computational Physics, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
| | - Yuxiang Yao
- School of Physical Science and Technology, Lanzhou University, Lanzhou, China
| | - Jie Xiong
- Department of Applied Mathematics, Changsha University, Changsha, China
| | - Jinhui Tian
- Evidence Based Medicine Center, School of Basic Medical Science of Lanzhou University, Lanzhou, China.,Key Laboratory of Evidence Based Medicine and Knowledge Translation of Gansu Province, Lanzhou, China
| | - Xiangqian Guo
- Medical Bioinformatics Institute, School of Basic Medicine, Henan University, Henan, China
| | - Xiuxia Li
- Evidence Based Medicine Center, School of Basic Medical Science of Lanzhou University, Lanzhou, China.,Key Laboratory of Evidence Based Medicine and Knowledge Translation of Gansu Province, Lanzhou, China.,School of Public Health, Lanzhou University, Lanzhou, China
| | - Jingyun Zhang
- Evidence Based Medicine Center, School of Basic Medical Science of Lanzhou University, Lanzhou, China.,Key Laboratory of Evidence Based Medicine and Knowledge Translation of Gansu Province, Lanzhou, China
| | - Xiue Shi
- Institute for Evidence Based Rehabilitation Medicine of Gansu Province, Lanzhou, China
| | - Yanying Zhang
- Department of Pharmacology and Toxicology of Traditional Chinese Medicine, Gansu University of Chinese Medicine, Lanzhou, China
| | - Kehu Yang
- Evidence Based Medicine Center, School of Basic Medical Science of Lanzhou University, Lanzhou, China.,Key Laboratory of Evidence Based Medicine and Knowledge Translation of Gansu Province, Lanzhou, China.,Institute for Evidence Based Rehabilitation Medicine of Gansu Province, Lanzhou, China.,Department of Pharmacology and Toxicology of Traditional Chinese Medicine, Gansu University of Chinese Medicine, Lanzhou, China
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9
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Pseudogenes of annexin A2, novel prognosis biomarkers for diffuse gliomas. Oncotarget 2017; 8:106962-106975. [PMID: 29291003 PMCID: PMC5739788 DOI: 10.18632/oncotarget.22197] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 09/20/2017] [Indexed: 12/22/2022] Open
Abstract
Diffuse gliomas is a kind of common malignant primary brain tumor. Pseudogenes have multilayered biological function in the progression of human cancers. In this study, Differentially Expressed Pseudogenes (DEPs) between glioblastomas and non-tumor controls were found by bioinformatics analysis, of which the annexin A2 pseudogenes (ANXA2P1, ANXA2P2 and ANXA2P3) were significantly up-regulated, along with the parent gene annexin A2 (ANXA2). Among four glioblastoma subtypes, ANXA2P1 and ANXA2P2 were preferentially expressed in mesenchymal subtype and less expressed in proneural subtype. Meanwhile, Pearson’s correlation analysis revealed that the expression level of ANXA2 was positively correlated with ANXA2 pseudogenes expression. Then, the expression patterns of ANXA2 and its pseudogenes were validated in diffuse glioma specimens (n=99) and non-tumor tissues (n=12) by quantitative real-time PCR (qRT-PCR). Additionally, Kaplan–Meier analysis revealed that highly expressed ANXA2 and annexin A2 pseudogenes were associated with the poor survival outcome of glioma patients. Cox regression analyses suggested that ANXA2, ANXA2P1 and ANXA2P2 were the independent prognosis factors for gliomas. Furthermore, down-regulation of ANXA2 and ANXA2 pseudogenes might contribute to the improvement of patients’ survival who received chemotherapy and radiotherapy. These results demonstrated that ANXA2 pseudogenes and ANXA2 could be used as the novel biomarkers for diagnosis, prognosis and target therapy of gliomas.
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10
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Goh J, Mohan GR, Ladwa R, Ananda S, Cohen PA, Baron-Hay S. Frontline treatment of epithelial ovarian cancer. Asia Pac J Clin Oncol 2016; 11 Suppl 6:1-16. [PMID: 26669253 DOI: 10.1111/ajco.12449] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2015] [Indexed: 11/29/2022]
Abstract
This is a contemporaneous review of the frontline treatment of epithelial ovarian cancer (EOC), specifically on the importance of optimal surgical cytoreductive surgery, the pivotal role of platinum-based adjuvant chemotherapy (which encompasses intraperitoneal and dose-dense regimens) and the emergence of neo-adjuvant chemotherapy. Additionally, the benefit of concurrent and maintenance bevacizumab in the suboptimally debullked stage III and stage IV EOC setting is also reviewed. The article also discusses the increasing importance of prognostic and predictive molecular biomarkers in the future management of EOC.
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Affiliation(s)
- Jeffrey Goh
- Royal Brisbane and Women's Hospital (RBWH), Herston.,University of Queensland, St Lucia.,Greenslopes Private Hospital, Greenslopes, Queensland
| | - G Raj Mohan
- King Edward Memorial Hospital, Subiaco.,St John of God Hospital, Subiaco.,School of Women's and Infants' Health, University of Western Australia, Crawley, Western Australia
| | - Rahul Ladwa
- Royal Brisbane and Women's Hospital (RBWH), Herston
| | | | - Paul A Cohen
- St John of God Hospital, Subiaco.,School of Women's and Infants' Health, University of Western Australia, Crawley, Western Australia
| | - Sally Baron-Hay
- Royal North Shore Hospital, St Leonards, New South Wales, Australia
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11
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Yasrebi H. Comparative study of joint analysis of microarray gene expression data in survival prediction and risk assessment of breast cancer patients. Brief Bioinform 2015; 17:771-85. [PMID: 26504096 PMCID: PMC5863785 DOI: 10.1093/bib/bbv092] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Indexed: 11/16/2022] Open
Abstract
Microarray gene expression data sets are jointly analyzed to increase statistical power.
They could either be merged together or analyzed by meta-analysis. For a given ensemble of
data sets, it cannot be foreseen which of these paradigms, merging or meta-analysis, works
better. In this article, three joint analysis methods, Z -score
normalization, ComBat and the inverse normal method (meta-analysis) were selected for
survival prognosis and risk assessment of breast cancer patients. The methods were applied
to eight microarray gene expression data sets, totaling 1324 patients with two clinical
endpoints, overall survival and relapse-free survival. The performance derived from the
joint analysis methods was evaluated using Cox regression for survival analysis and
independent validation used as bias estimation. Overall, Z -score
normalization had a better performance than ComBat and meta-analysis. Higher Area Under
the Receiver Operating Characteristic curve and hazard ratio were also obtained when
independent validation was used as bias estimation. With a lower time and memory
complexity, Z -score normalization is a simple method for joint analysis
of microarray gene expression data sets. The derived findings suggest further assessment
of this method in future survival prediction and cancer classification applications.
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12
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Microarray Meta-Analysis and Cross-Platform Normalization: Integrative Genomics for Robust Biomarker Discovery. MICROARRAYS 2015; 4:389-406. [PMID: 27600230 PMCID: PMC4996376 DOI: 10.3390/microarrays4030389] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/16/2015] [Accepted: 08/17/2015] [Indexed: 01/24/2023]
Abstract
The diagnostic and prognostic potential of the vast quantity of publicly-available microarray data has driven the development of methods for integrating the data from different microarray platforms. Cross-platform integration, when appropriately implemented, has been shown to improve reproducibility and robustness of gene signature biomarkers. Microarray platform integration can be conceptually divided into approaches that perform early stage integration (cross-platform normalization) versus late stage data integration (meta-analysis). A growing number of statistical methods and associated software for platform integration are available to the user, however an understanding of their comparative performance and potential pitfalls is critical for best implementation. In this review we provide evidence-based, practical guidance to researchers performing cross-platform integration, particularly with an objective to discover biomarkers.
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Häfner N, Steinbach D, Jansen L, Diebolder H, Dürst M, Runnebaum IB. RUNX3 and CAMK2N1 hypermethylation as prognostic marker for epithelial ovarian cancer. Int J Cancer 2015; 138:217-28. [DOI: 10.1002/ijc.29690] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 06/15/2015] [Accepted: 07/02/2015] [Indexed: 01/23/2023]
Affiliation(s)
- Norman Häfner
- Department of Gynecology; Jena University Hospital-Friedrich Schiller University; Jena Germany
| | - Daniel Steinbach
- Department of Gynecology; Jena University Hospital-Friedrich Schiller University; Jena Germany
| | - Lars Jansen
- Department of Gynecology; Jena University Hospital-Friedrich Schiller University; Jena Germany
| | - Herbert Diebolder
- Department of Gynecology; Jena University Hospital-Friedrich Schiller University; Jena Germany
| | - Matthias Dürst
- Department of Gynecology; Jena University Hospital-Friedrich Schiller University; Jena Germany
| | - Ingo B. Runnebaum
- Department of Gynecology; Jena University Hospital-Friedrich Schiller University; Jena Germany
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14
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Davidson B, Tropé CG. Ovarian cancer: diagnostic, biological and prognostic aspects. ACTA ACUST UNITED AC 2015; 10:519-33. [PMID: 25335543 DOI: 10.2217/whe.14.37] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ovarian cancer remains the most lethal gynecologic malignancy, owing to late detection, intrinsic and acquired chemoresistance and remarkable heterogeneity. Despite optimization of surgical and chemotherapy protocols and initiation of clinical trials incorporating targeted therapy, only modest gains have been achieved in prolonging survival in this cancer. This review provides an update of recent developments in our understanding of the etiology, origin, diagnosis, progression and treatment of this malignancy, with emphasis on clinically relevant genetic classification approaches. In the authors' opinion, focused effort directed at understanding the molecular make-up of recurrent and metastatic ovarian cancer, while keeping in mind the unique molecular character of each of its histological types, is central to our effort to improve patient outcome in this cancer.
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Affiliation(s)
- Ben Davidson
- Department of Pathology, Oslo University Hospital, Norwegian Radium Hospital, N-0310 Oslo, Norway
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15
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Stein CK, Qu P, Epstein J, Buros A, Rosenthal A, Crowley J, Morgan G, Barlogie B. Removing batch effects from purified plasma cell gene expression microarrays with modified ComBat. BMC Bioinformatics 2015; 16:63. [PMID: 25887219 PMCID: PMC4355992 DOI: 10.1186/s12859-015-0478-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 01/27/2015] [Indexed: 11/10/2022] Open
Abstract
Background Gene expression profiling (GEP) via microarray analysis is a widely used tool for assessing risk and other patient diagnostics in clinical settings. However, non-biological factors such as systematic changes in sample preparation, differences in scanners, and other potential batch effects are often unavoidable in long-term studies and meta-analysis. In order to reduce the impact of batch effects on microarray data, Johnson, Rabinovic, and Li developed ComBat for use when combining batches of gene expression microarray data. We propose a modification to ComBat that centers data to the location and scale of a pre-determined, ‘gold-standard’ batch. This modified ComBat (M-Combat) is designed specifically in the context of meta-analysis and batch effect adjustment for use with predictive models that are validated and fixed on historical data from a ‘gold-standard’ batch. Results We combined data from MIRT across two batches (‘Old’ and ‘New’ Kit sample preparation) as well as external data sets from the HOVON-65/GMMG-HD4 and MRC-IX trials into a combined set, first without transformation and then with both ComBat and M-ComBat transformations. Fixed and validated gene risk signatures developed at MIRT on the Old Kit standard (GEP5, GEP70, and GEP80 risk scores) were compared across these combined data sets. Both ComBat and M-ComBat eliminated all of the differences among probes caused by systematic batch effects (over 98% of all untransformed probes were significantly different by ANOVA with 0.01 q-value threshold reduced to zero significant probes with ComBat and M-ComBat). The agreement in mean and distribution of risk scores, as well as the proportion of high-risk subjects identified, coincided with the ‘gold-standard’ batch more with M-ComBat than with ComBat. The performance of risk scores improved overall using either ComBat or M-Combat; however, using M-ComBat and the original, optimal risk cutoffs allowed for greater ability in our study to identify smaller cohorts of high-risk subjects. Conclusion M-ComBat is a practical modification to an accepted method that offers greater power to control the location and scale of batch-effect adjusted data. M-ComBat allows for historical models to function as intended on future samples despite known, often unavoidable systematic changes to gene expression data.
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Affiliation(s)
- Caleb K Stein
- Myeloma Institute for Research and Therapy, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - Pingping Qu
- Cancer Research and Biostatistics, Seattle, WA, USA.
| | - Joshua Epstein
- Myeloma Institute for Research and Therapy, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - Amy Buros
- Myeloma Institute for Research and Therapy, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | | | - John Crowley
- Cancer Research and Biostatistics, Seattle, WA, USA.
| | - Gareth Morgan
- Myeloma Institute for Research and Therapy, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - Bart Barlogie
- Myeloma Institute for Research and Therapy, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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Abstract
Cytosine methylation in DNA constitutes an important epigenetic layer of transcriptional and regulatory control in many eukaryotes. Profiling DNA methylation across the genome is critical to understanding the influence of epigenetics in normal biology and disease, such as cancer. Genome-wide analyses such as arrays and next-generation sequencing (NGS) technologies have been used to assess large fractions of the methylome at a single-base-pair resolution. However, the range of DNA methylation profiling techniques can make selecting the appropriate protocol a challenge. This chapter discusses the advantages and disadvantages of various methylome detection approaches to assess which is appropriate for the question at hand. Here, we focus on four prominent genome-wide approaches: whole-genome bisulfite sequencing (WGBS); methyl-binding domain capture sequencing (MBDCap-Seq); reduced-representation-bisulfite-sequencing (RRBS); and Infinium Methylation450 BeadChips (450 K, Illumina). We discuss some of the requirements, merits, and challenges that should be considered when choosing a methylome technology to ensure that it will be informative. In addition, we show how genome-wide methylation detection arrays and high-throughput sequencing have provided immense insight into ovarian cancer-specific methylation signatures that may serve as diagnostic biomarkers or predict patient response to epigenetic therapy.
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17
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Madden SF, Clarke C, Stordal B, Carey MS, Broaddus R, Gallagher WM, Crown J, Mills GB, Hennessy BT. OvMark: a user-friendly system for the identification of prognostic biomarkers in publically available ovarian cancer gene expression datasets. Mol Cancer 2014; 13:241. [PMID: 25344116 PMCID: PMC4219121 DOI: 10.1186/1476-4598-13-241] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 09/26/2014] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Ovarian cancer has the lowest survival rate of all gynaecologic cancers and is characterised by a lack of early symptoms and frequent late stage diagnosis. There is a paucity of robust molecular markers that are independent of and complementary to clinical parameters such as disease stage and tumour grade. METHODS We have developed a user-friendly, web-based system to evaluate the association of genes/miRNAs with outcome in ovarian cancer. The OvMark algorithm combines data from multiple microarray platforms (including probesets targeting miRNAs) and correlates them with clinical parameters (e.g. tumour grade, stage) and outcomes (disease free survival (DFS), overall survival). In total, OvMark combines 14 datasets from 7 different array platforms measuring the expression of ~17,000 genes and 341 miRNAs across 2,129 ovarian cancer samples. RESULTS To demonstrate the utility of the system we confirmed the prognostic ability of 14 genes and 2 miRNAs known to play a role in ovarian cancer. Of these genes, CXCL12 was the most significant predictor of DFS (HR = 1.42, p-value = 2.42x10-6). Surprisingly, those genes found to have the greatest correlation with outcome have not been heavily studied in ovarian cancer, or in some cases in any cancer. For instance, the three genes with the greatest association with survival are SNAI3, VWA3A and DNAH12. CONCLUSIONS/IMPACT OvMark is a powerful tool for examining putative gene/miRNA prognostic biomarkers in ovarian cancer (available at http://glados.ucd.ie/OvMark/index.html). The impact of this tool will be in the preliminary assessment of putative biomarkers in ovarian cancer, particularly for research groups with limited bioinformatics facilities.
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Affiliation(s)
- Stephen F Madden
- Molecular Therapeutics for Cancer Ireland, National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland.
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18
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Chemotherapy-induced dynamic gene expression changes in vivo are prognostic in ovarian cancer. Br J Cancer 2014; 110:2975-84. [PMID: 24867692 PMCID: PMC4056064 DOI: 10.1038/bjc.2014.258] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 03/13/2014] [Accepted: 04/17/2014] [Indexed: 12/18/2022] Open
Abstract
Background: The response of ovarian cancer patients to carboplatin and paclitaxel is variable, necessitating identification of biomarkers that can reliably predict drug sensitivity and resistance. In this study, we sought to identify dynamically controlled genes and pathways associated with drug response and its time dependence. Methods: Gene expression was assessed for 14 days post-treatment with carboplatin or carboplatin–paclitaxel in xenografts from two ovarian cancer models: platinum-sensitive serous adenocarcinoma-derived OV1002 and a mixed clear cell/endometrioid carcinoma-derived HOX424 with reduced sensitivity to platinum. Results: Tumour volume reduction was observed in both xenografts, but more dominantly in OV1002. Upregulated genes in OV1002 were involved in DNA repair, cell cycle and apoptosis, whereas downregulated genes were involved in oxygen-consuming metabolic processes and apoptosis control. Carboplatin–paclitaxel triggered a more comprehensive response than carboplatin only in both xenografts. In HOX424, apoptosis and cell cycle were upregulated, whereas Wnt signalling was inhibited. Genes downregulated after day 7 from both xenografts were predictive of overall survival. Overrepresented pathways were also predictive of outcome. Conclusions: Late expressed genes are prognostic in ovarian tumours in a dynamic manner. This longitudinal gene expression study further elucidates chemotherapy response in two models, stressing the importance of delayed biomarker detection and guiding optimal timing of biopsies.
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19
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De Cecco L, Bossi P, Locati L, Canevari S, Licitra L. Comprehensive gene expression meta-analysis of head and neck squamous cell carcinoma microarray data defines a robust survival predictor. Ann Oncol 2014; 25:1628-35. [PMID: 24827125 DOI: 10.1093/annonc/mdu173] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Head and neck squamous cell carcinoma refers to a heterogeneous disease frequently aggressive in its biologic behavior. Despite the improvements in the therapeutic modalities, the long-term survival rate remained unchanged over the past decade and patients with this type of cancer are at a high risk of developing recurrence. For this reason, there is a great need to find better ways to foresee outcome, to improve treatment choices, and to enable a more personalized approach. PATIENTS AND METHODS Nine microarray gene expression datasets, reporting survival data of a total of 841 samples, were retrieved from publicly repositories. Three datasets, profiled on the same version of microarray chips, were selected and merged following a meta-analysis approach to build a training set. The remaining six studies were used as independent validation sets. RESULTS The training set led us to identify a 172-gene signature able to stratify patients in low or high risk of relapse [log-rank, P = 2.44e-05; hazard ratio (HR) = 2.44, 95% confidence interval (CI) 1.58-3.76]. The model based on the 172 genes was validated on the six independent datasets. The performance of the model was challenged against other proposed prognostic signatures (radiosensitivity index, 13-gene oral squamous cell carcinoma signature, hypoxia metagene, 42-gene high-risk signature) and was compared with a human papillomavirus (HPV) signature: our model resulted independent and even better in prediction. CONCLUSIONS We have identified and validated a prognostic model based on the expression of 172 genes, independent from HPV status and able to improve assessment of patient's risk of relapse compared with other molecular signatures. In order to transpose our model into a useful clinical grade assay, additional work is needed following the framework established by the Institute of Medicine and REMARK guidelines.
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Affiliation(s)
- L De Cecco
- Functional Genomics and Informatics, Department of Experimental Oncology and Molecular Medicine
| | - P Bossi
- Head and Neck Medical Oncology Unit, Department of Molecular Oncology
| | - L Locati
- Head and Neck Medical Oncology Unit, Department of Molecular Oncology
| | - S Canevari
- Functional Genomics and Informatics, Department of Experimental Oncology and Molecular Medicine Molecular Therapies, Department of Experimental Oncology and Molecular Medicines, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - L Licitra
- Head and Neck Medical Oncology Unit, Department of Molecular Oncology
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20
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Zhang C, Han Y, Huang H, Min L, Qu L, Shou C. Integrated analysis of expression profiling data identifies three genes in correlation with poor prognosis of triple-negative breast cancer. Int J Oncol 2014; 44:2025-33. [PMID: 24676531 DOI: 10.3892/ijo.2014.2352] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 02/27/2014] [Indexed: 11/06/2022] Open
Abstract
Triple-negative breast cancer (TNBC) shows more aggressive clinical behavior and poorer outcome than non-triple-negative breast cancer (NTNBC), and cannot be treated either via endocrine therapy or by Trastuzumab. For TNBC, chemotherapy is currently the mainstay of systemic medical treatment, the lack of more efficient options of treatment has been a problem in breast cancer prevention. In this study, we aimed to find genes related to prognosis in TNBC by bioinformatic analysis and to provide therapeutic candidates for TNBC treatment. We compared the differences in gene expression levels between cancer patients and healthy individuals across five breast cancer microarray databases to generate a gene cohort specifically upregulated in the NTNBC subtype, whose expression levels are ≥2-fold higher in TNBC compared to NTNBC and healthy individuals. Another two databases with clinical information were applied for following Kaplan-Meier analysis, and high expression of BIRC5, CENPA and FAM64A in this cohort were found to be related to poor survival (OS, DMFS, DFS and RFS). This correlation was also seen in patients at early stages and grades. On the other hand, the outcome of patients with synchronous upregulation of these three genes was the worst, while those with synchronous low gene level was the best. In conclusion, BIRC5, CENPA and FAM64A are specifically upregulated in TNBC, and the high expression of these three genes is associated with poor breast cancer prognosis, suggesting their clinical implication as therapeutic targets in TNBC.
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Affiliation(s)
- Cheng Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, Peking University Cancer Hospital and Institute, Beijing 100142, P.R. China
| | - Yong Han
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, Peking University Cancer Hospital and Institute, Beijing 100142, P.R. China
| | - Hao Huang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, Peking University Cancer Hospital and Institute, Beijing 100142, P.R. China
| | - Li Min
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, Peking University Cancer Hospital and Institute, Beijing 100142, P.R. China
| | - Like Qu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, Peking University Cancer Hospital and Institute, Beijing 100142, P.R. China
| | - Chengchao Shou
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, Peking University Cancer Hospital and Institute, Beijing 100142, P.R. China
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21
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Kraiklang R, Pairojkul C, Khuntikeo N, Imtawil K, Wongkham S, Wongkham C. A novel predictive equation for potential diagnosis of cholangiocarcinoma. PLoS One 2014; 9:e89337. [PMID: 24586698 PMCID: PMC3938437 DOI: 10.1371/journal.pone.0089337] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 01/19/2014] [Indexed: 12/20/2022] Open
Abstract
Cholangiocarcinoma (CCA) is the second most common-primary liver cancer. The difficulties in diagnosis limit successful treatment of CCA. At present, histological investigation is the standard diagnosis for CCA. However, there are some poor-defined tumor tissues which cannot be definitively diagnosed by general histopathology. As molecular signatures can define molecular phenotypes related to diagnosis, prognosis, or treatment outcome, and CCA is the second most common cancer found after hepatocellularcarcinoma (HCC), the aim of this study was to develop a predictive model which differentiates CCA from HCC and normal liver tissues. An in-house PCR array containing 176 putative CCA marker genes was tested with the training set tissues of 20 CCA and 10 HCC cases. The molecular signature of CCA revealed the prominent expression of genes involved in cell adhesion and cell movement, whereas HCC showed elevated expression of genes related to cell proliferation/differentiation and metabolisms. A total of 69 genes differentially expressed in CCA and HCC were optimized statistically to formulate a diagnostic equation which distinguished CCA cases from HCC cases. Finally, a four-gene diagnostic equation (CLDN4, HOXB7, TMSB4 and TTR) was formulated and then successfully validated using real-time PCR in an independent testing set of 68 CCA samples and 77 non-CCA controls. Discrimination analysis showed that a combination of these genes could be used as a diagnostic marker for CCA with better diagnostic parameters with high sensitivity and specificity than using a single gene marker or the usual serum markers (CA19-9 and CEA). This new combination marker may help physicians to identify CCA in liver tissues when the histopathology is uncertain.
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Affiliation(s)
- Ratthaphol Kraiklang
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Chawalit Pairojkul
- Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Narong Khuntikeo
- Department of Surgery, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Kanokwan Imtawil
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Sopit Wongkham
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Chaisiri Wongkham
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
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22
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Matias-Guiu X, Davidson B. Prognostic biomarkers in endometrial and ovarian carcinoma. Virchows Arch 2014; 464:315-31. [PMID: 24504546 DOI: 10.1007/s00428-013-1509-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 11/05/2013] [Accepted: 11/07/2013] [Indexed: 02/06/2023]
Abstract
This article reviews the main prognostic and predictive biomarkers of endometrial (EC) and ovarian carcinoma (OC). In EC, prognosis still relies on conventional pathological features such as histological type and grade, as well as myometrial or lymphovascular space invasion. Estrogen receptor, p53, Ki-67, and ploidy analysis are the most promising biomarkers among a long list of molecules that have been proposed. Also, a number of putative predictive biomarkers have been proposed in molecular targeted therapy. In OC, prognosis is predominantly dependent on disease stage at diagnosis and the extent of residual disease at primary operation. Diagnostic markers which aid in establishing histological type in OC are available. However, not a single universally accepted predictive or prognostic marker exists to date. Targeted therapy has been growingly focused at in recent years, in view of the frequent development of chemoresistance at recurrent disease. The present review emphasizes the crucial role of correct pathological classification and stringent selection criteria of the material studied as basis for any evaluation of biological markers. It further emphasizes the promise of targeted therapy in EC and OC, while simultaneously highlighting the difficulties remaining before this can become standard of care.
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Affiliation(s)
- Xavier Matias-Guiu
- Department of Pathology and Molecular Genetics and Research Laboratory, Hospital Universitari Arnau de Vilanova, IRBLLEIDA, University of Lleida, Av. Alcalde Rovira Roure 80, 25198, Lleida, Spain,
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23
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Reese SE, Archer KJ, Therneau TM, Atkinson EJ, Vachon CM, de Andrade M, Kocher JPA, Eckel-Passow JE. A new statistic for identifying batch effects in high-throughput genomic data that uses guided principal component analysis. Bioinformatics 2013; 29:2877-83. [PMID: 23958724 PMCID: PMC3810845 DOI: 10.1093/bioinformatics/btt480] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 07/03/2013] [Accepted: 08/14/2013] [Indexed: 12/31/2022] Open
Abstract
MOTIVATION Batch effects are due to probe-specific systematic variation between groups of samples (batches) resulting from experimental features that are not of biological interest. Principal component analysis (PCA) is commonly used as a visual tool to determine whether batch effects exist after applying a global normalization method. However, PCA yields linear combinations of the variables that contribute maximum variance and thus will not necessarily detect batch effects if they are not the largest source of variability in the data. RESULTS We present an extension of PCA to quantify the existence of batch effects, called guided PCA (gPCA). We describe a test statistic that uses gPCA to test whether a batch effect exists. We apply our proposed test statistic derived using gPCA to simulated data and to two copy number variation case studies: the first study consisted of 614 samples from a breast cancer family study using Illumina Human 660 bead-chip arrays, whereas the second case study consisted of 703 samples from a family blood pressure study that used Affymetrix SNP Array 6.0. We demonstrate that our statistic has good statistical properties and is able to identify significant batch effects in two copy number variation case studies. CONCLUSION We developed a new statistic that uses gPCA to identify whether batch effects exist in high-throughput genomic data. Although our examples pertain to copy number data, gPCA is general and can be used on other data types as well. AVAILABILITY AND IMPLEMENTATION The gPCA R package (Available via CRAN) provides functionality and data to perform the methods in this article. CONTACT reesese@vcu.edu
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Affiliation(s)
- Sarah E Reese
- Department of Biostatistics, Biostatistics Shared Resource Core, VCU Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23284, USA, Division of Biomedical Statistics and Informatics and Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, Rochester, MN 55905, USA
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Individuality in FGF1 expression significantly influences platinum resistance and progression-free survival in ovarian cancer. Br J Cancer 2012; 107:1327-36. [PMID: 22990650 PMCID: PMC3494420 DOI: 10.1038/bjc.2012.410] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: Ovarian cancer is frequently advanced at presentation when treatment is rarely curative. Response to first-line platinum-based chemotherapy significantly influences survival, but clinical response is unpredictable and is frequently limited by the development of drug-resistant disease. Methods: We used qRT–PCR analysis to assess intertumour differences in the expression of fibroblast growth factor 1 (FGF1) and additional candidate genes in human ovarian tumours (n=187), and correlated individuality in gene expression with tumour histology, chemotherapy response and survival. We used MTT assays to assess platinum chemosensitivity in drug-sensitive and drug-resistant ovarian cell lines. Results: Marked intertumour differences in gene expression were observed, with each tumour having a unique gene expression profile. Nine genes, including FGF1 (P=1.7 × 10−5) and FGFR2 (P=0.003), were differentially expressed in serous and nonserous tumours. MDM2 (P=0.032) and ERBB2 (P=0.064) expression was increased in platinum-sensitive patients, and FGF1 (adjusted log-rank test P=0.006), FGFR2 (P=0.04) and PDRFRB expression (P=0.037) significantly inversely influenced progression-free survival. Stable FGF1 gene knockdown in platinum-resistant A2780DPP cells re-sensitised cells to both cisplatin and carboplatin. Conclusion: We show for the first time that FGF1 is differentially expressed in high-grade serous ovarian tumours, and that individuality in FGF1 expression significantly influences progression-free survival and response to platinum-based chemotherapy.
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Zhang J, Lu K, Xiang Y, Islam M, Kotian S, Kais Z, Lee C, Arora M, Liu HW, Parvin JD, Huang K. Weighted frequent gene co-expression network mining to identify genes involved in genome stability. PLoS Comput Biol 2012; 8:e1002656. [PMID: 22956898 PMCID: PMC3431293 DOI: 10.1371/journal.pcbi.1002656] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 07/09/2012] [Indexed: 12/20/2022] Open
Abstract
Gene co-expression network analysis is an effective method for predicting gene functions and disease biomarkers. However, few studies have systematically identified co-expressed genes involved in the molecular origin and development of various types of tumors. In this study, we used a network mining algorithm to identify tightly connected gene co-expression networks that are frequently present in microarray datasets from 33 types of cancer which were derived from 16 organs/tissues. We compared the results with networks found in multiple normal tissue types and discovered 18 tightly connected frequent networks in cancers, with highly enriched functions on cancer-related activities. Most networks identified also formed physically interacting networks. In contrast, only 6 networks were found in normal tissues, which were highly enriched for housekeeping functions. The largest cancer network contained many genes with genome stability maintenance functions. We tested 13 selected genes from this network for their involvement in genome maintenance using two cell-based assays. Among them, 10 were shown to be involved in either homology-directed DNA repair or centrosome duplication control including the well-known cancer marker MKI67. Our results suggest that the commonly recognized characteristics of cancers are supported by highly coordinated transcriptomic activities. This study also demonstrated that the co-expression network directed approach provides a powerful tool for understanding cancer physiology, predicting new gene functions, as well as providing new target candidates for cancer therapeutics.
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Affiliation(s)
- Jie Zhang
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio, USA
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Zhang SN, Sun HH, Jin YM, Piao LZ, Jin DH, Lin ZH, Shen XH. Identification of differentially expressed genes in gastric cancer by high density cDNA microarray. Cancer Genet 2012; 205:147-55. [PMID: 22559975 DOI: 10.1016/j.cancergen.2012.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 12/24/2011] [Accepted: 01/09/2012] [Indexed: 11/25/2022]
Abstract
The identification of molecular markers for diagnosis, treatment, and prognosis is a significant issue in the management of patients with gastric cancer. We compared the expression profiles of 23 gastric cancers and 22 normal gastric tissues using cDNA microarrays. We divided the samples into two sets, 11 pairs as a training set and 12 unpaired gastric cancer and 11 unpaired normal gastric tissues as a test set. We selected significant genes in the training set and validated the significance of the genes in the test set. We obtained 238 classifier genes that showed a maximum cross-validation probability and clear hierarchical clustering pattern in the training set, and showed excellent class prediction probability in the independent test set. The classifier genes consisted of known genes related to the biological features of cancer and 28% unknown genes. We obtained genome-wide molecular signatures of gastric cancer, which provides preliminary exploration data for the pathophysiology of gastric cancer.
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Affiliation(s)
- Song-Nan Zhang
- Department of Oncology, Affiliated Hospital of Yanbian University, Yanji, China
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Zhang L, Ju X, Cheng Y, Guo X, Wen T. Identifying Tmem59 related gene regulatory network of mouse neural stem cell from a compendium of expression profiles. BMC SYSTEMS BIOLOGY 2011; 5:152. [PMID: 21955788 PMCID: PMC3191490 DOI: 10.1186/1752-0509-5-152] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 09/29/2011] [Indexed: 11/10/2022]
Abstract
Background Neural stem cells offer potential treatment for neurodegenerative disorders, such like Alzheimer's disease (AD). While much progress has been made in understanding neural stem cell function, a precise description of the molecular mechanisms regulating neural stem cells is not yet established. This lack of knowledge is a major barrier holding back the discovery of therapeutic uses of neural stem cells. In this paper, the regulatory mechanism of mouse neural stem cell (NSC) differentiation by tmem59 is explored on the genome-level. Results We identified regulators of tmem59 during the differentiation of mouse NSCs from a compendium of expression profiles. Based on the microarray experiment, we developed the parallelized SWNI algorithm to reconstruct gene regulatory networks of mouse neural stem cells. From the inferred tmem59 related gene network including 36 genes, pou6f1 was identified to regulate tmem59 significantly and might play an important role in the differentiation of NSCs in mouse brain. There are four pathways shown in the gene network, indicating that tmem59 locates in the downstream of the signalling pathway. The real-time RT-PCR results shown that the over-expression of pou6f1 could significantly up-regulate tmem59 expression in C17.2 NSC line. 16 out of 36 predicted genes in our constructed network have been reported to be AD-related, including Ace, aqp1, arrdc3, cd14, cd59a, cds1, cldn1, cox8b, defb11, folr1, gdi2, mmp3, mgp, myrip, Ripk4, rnd3, and sncg. The localization of tmem59 related genes and functional-related gene groups based on the Gene Ontology (GO) annotation was also identified. Conclusions Our findings suggest that the expression of tmem59 is an important factor contributing to AD. The parallelized SWNI algorithm increased the efficiency of network reconstruction significantly. This study enables us to highlight novel genes that may be involved in NSC differentiation and provides a shortcut to identifying genes for AD.
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Affiliation(s)
- Luwen Zhang
- Laboratory of Molecular Neurobiology, Institute of Systems Biology, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai 200433, China
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Marchion DC, Cottrill HM, Xiong Y, Chen N, Bicaku E, Fulp WJ, Bansal N, Chon HS, Stickles XB, Kamath SG, Hakam A, Li L, Su D, Moreno C, Judson PL, Berchuck A, Wenham RM, Apte SM, Gonzalez-Bosquet J, Bloom GC, Eschrich SA, Sebti S, Chen DT, Lancaster JM. BAD phosphorylation determines ovarian cancer chemosensitivity and patient survival. Clin Cancer Res 2011; 17:6356-66. [PMID: 21849418 DOI: 10.1158/1078-0432.ccr-11-0735] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE Despite initial sensitivity to chemotherapy, ovarian cancers (OVCA) often develop drug resistance, which limits patient survival. Using specimens and/or genomic data from 289 patients and a panel of cancer cell lines, we explored genome-wide expression changes that underlie the evolution of OVCA chemoresistance and characterized the BCL2 antagonist of cell death (BAD) apoptosis pathway as a determinant of chemosensitivity and patient survival. EXPERIMENTAL DESIGN Serial OVCA cell cisplatin treatments were performed in parallel with measurements of genome-wide expression changes. Pathway analysis was carried out on genes associated with increasing cisplatin resistance (EC(50)). BAD-pathway expression and BAD protein phosphorylation were evaluated in patient samples and cell lines as determinants of chemosensitivity and/or clinical outcome and as therapeutic targets. RESULTS Induced in vitro OVCA cisplatin resistance was associated with BAD-pathway expression (P < 0.001). In OVCA cell lines and primary specimens, BAD protein phosphorylation was associated with platinum resistance (n = 147, P < 0.0001) and also with overall patient survival (n = 134, P = 0.0007). Targeted modulation of BAD-phosphorylation levels influenced cisplatin sensitivity. A 47-gene BAD-pathway score was associated with in vitro phosphorylated BAD levels and with survival in 142 patients with advanced-stage (III/IV) serous OVCA. Integration of BAD-phosphorylation or BAD-pathway score with OVCA surgical cytoreductive status was significantly associated with overall survival by log-rank test (P = 0.004 and P < 0.0001, respectively). CONCLUSION The BAD apoptosis pathway influences OVCA chemosensitivity and overall survival, likely via modulation of BAD phosphorylation. The pathway has clinical relevance as a biomarker of therapeutic response, patient survival, and as a promising therapeutic target.
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Affiliation(s)
- Douglas C Marchion
- Department of Women's Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33647, USA
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