Normalization method for transcriptional studies of heterogeneous samples - Simultaneous array normalization and identification of equivalent expression Journal Article


Authors: Qin, L. X.; Satagopan, J. M.
Article Title: Normalization method for transcriptional studies of heterogeneous samples - Simultaneous array normalization and identification of equivalent expression
Abstract: Normalization is an important step in the analysis of microarray data of transcription profiles as systematic non-biological variations often arise from the multiple steps involved in any transcription profiling experiment. Existing methods for data normalization often assume that there are few or symmetric differential expression, but this assumption does not always hold. Alternatively, non-differentially expressed genes may be used for array normalization. However, it is unknown at the outset which genes are non-differentially expressed. In this paper we propose a hierarchical mixture model framework to simultaneously identify non-differentially expressed genes and normalize arrays using these genes. The Fisher's information matrix corresponding to array effects is derived, which provides useful intuition for guiding the choice of array normalization method. The operating characteristics of the proposed method are evaluated using simulated data. The simulations conducted under a wide range of parametric configurations suggest that the proposed method provides a useful alternative for array normalization. For example, the proposed method has better sensitivity than median normalization under modest prevalence of differentially expressed genes and when the magnitudes of over-expression and under-expression are not the same. Further, the proposed method has properties similar to median normalization when the prevalence of differentially expressed genes is very small. Empirical illustration of the proposed method is provided using a liposarcoma study from MSKCC to identify genes differentially expressed between normal fat tissue versus liposarcoma tissue samples. Copyright ©2009 The Berkeley Electronic Press. All rights reserved.
Keywords: genetics; gene expression; biological model; gene expression profiling; statistics; genetic transcription; transcription, genetic; oligonucleotide array sequence analysis; models, genetic; computer simulation; dna microarray; normal distribution; roc curve; liposarcoma; fisher's information; mixture models; normalization
Journal Title: Statistical Applications in Genetics and Molecular Biology
Volume: 8
Issue: 1
ISSN: 1544-6115
Publisher: The Berkeley Electronic Press  
Date Published: 2009-01-01
Start Page: epub
Language: English
DOI: 10.2202/1544-6115.1339
PUBMED: 19222377
PROVIDER: scopus
PMCID: PMC2861326
DOI/URL:
Notes: --- - "Export Date: 30 November 2010" - "Art. No.: 10" - "Source: Scopus"
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MSK Authors
  1. Jaya M Satagopan
    141 Satagopan
  2. Li-Xuan Qin
    190 Qin