Statistical assessment of depth normalization for small RNA sequencing Journal Article


Authors: Qin, L. X.; Zou, J.; Shi, J.; Lee, A.; Mihailovic, A.; Farazi, T. A.; Tuschl, T.; Singer, S.
Article Title: Statistical assessment of depth normalization for small RNA sequencing
Abstract: PURPOSE: Methods for depth normalization have been assessed primarily with simulated data or cell-line-mixture data. There is a pressing need for benchmark data enabling a more realistic and objective assessment, especially in the context of small RNA sequencing. METHODS: We collected a unique pair of microRNA sequencing data sets for the same set of tumor samples; one data set was collected with and the other without uniform handling and balanced design. The former provided a benchmark for evaluating evidence of differential expression and the latter served as a test bed for normalization. Next, we developed a data perturbation algorithm to simulate additional data set pairs. Last, we assembled a set of computational tools to visualize and quantify the assessment. RESULTS: We validated the quality of the benchmark data and showed the need for normalization of the test data. For illustration, we applied the data and tools to assess the performance of 9 existing normalization methods. Among them, trimmed mean of M-values was a better scaling method, whereas the median and the upper quartiles were consistently the worst performers; one variation of remove unwanted variation had the best chance of capturing true positives but at the cost of increased false positives. In general, these methods were, at best, moderately helpful when the level of differential expression was extensive and asymmetric. CONCLUSION: Our study (1) provides the much-needed benchmark data and computational tools for assessing depth normalization, (2) shows the dependence of normalization performance on the underlying pattern of differential expression, and (3) calls for continued research efforts to develop more effective normalization methods.
Journal Title: JCO Clinical Cancer Informatics
Volume: 4
ISSN: 2473-4276
Publisher: American Society of Clinical Oncology  
Date Published: 2020-01-01
Start Page: 567
End Page: 582
Language: English
DOI: 10.1200/cci.19.00118
PUBMED: 32598180
PROVIDER: scopus
PMCID: PMC7330947
DOI/URL:
Notes: Article -- Export Date: 3 August 2020 -- Source: Scopus
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MSK Authors
  1. Li-Xuan Qin
    193 Qin
  2. Samuel Singer
    337 Singer
  3. Jiejun Shi
    2 Shi
  4. Ann Yeelin Lee
    12 Lee
  5. Jian Zou
    1 Zou