Large-scale labeling and assessment of sex bias in publicly available expression data

Background: Women are at more than 1.5-fold higher risk for clinically relevant adverse drug events. While this higher prevalence is partially due to gender-related effects, biological sex differences likely also impact drug response. Publicly available gene expression databases provide a unique opp...

Full description

Bibliographic Details
Main Authors: Altman, R.B (Author), Chang, A. (Author), Flynn, E. (Author)
Format: Article
Language:English
Published: BioMed Central Ltd 2021
Subjects:
Online Access:View Fulltext in Publisher
LEADER 03401nam a2200553Ia 4500
001 10.1186-s12859-021-04070-2
008 220427s2021 CNT 000 0 und d
020 |a 14712105 (ISSN) 
245 1 0 |a Large-scale labeling and assessment of sex bias in publicly available expression data 
260 0 |b BioMed Central Ltd  |c 2021 
856 |z View Fulltext in Publisher  |u https://doi.org/10.1186/s12859-021-04070-2 
520 3 |a Background: Women are at more than 1.5-fold higher risk for clinically relevant adverse drug events. While this higher prevalence is partially due to gender-related effects, biological sex differences likely also impact drug response. Publicly available gene expression databases provide a unique opportunity for examining drug response at a cellular level. However, missingness and heterogeneity of metadata prevent large-scale identification of drug exposure studies and limit assessments of sex bias. To address this, we trained organism-specific models to infer sample sex from gene expression data, and used entity normalization to map metadata cell line and drug mentions to existing ontologies. Using this method, we inferred sex labels for 450,371 human and 245,107 mouse microarray and RNA-seq samples from refine.bio. Results: Overall, we find slight female bias (52.1%) in human samples and (62.5%) male bias in mouse samples; this corresponds to a majority of mixed sex studies in humans and single sex studies in mice, split between female-only and male-only (25.8% vs. 18.9% in human and 21.6% vs. 31.1% in mouse, respectively). In drug studies, we find limited evidence for sex-sampling bias overall; however, specific categories of drugs, including human cancer and mouse nervous system drugs, are enriched in female-only and male-only studies, respectively. We leverage our expression-based sex labels to further examine the complexity of cell line sex and assess the frequency of metadata sex label misannotations (2–5%). Conclusions: Our results demonstrate limited overall sex bias, while highlighting high bias in specific subfields and underscoring the importance of including sex labels to better understand the underlying biology. We make our inferred and normalized labels, along with flags for misannotated samples, publicly available to catalyze the routine use of sex as a study variable in future analyses. © 2021, The Author(s). 
650 0 4 |a animal 
650 0 4 |a Animals 
650 0 4 |a Bias 
650 0 4 |a Cell culture 
650 0 4 |a Cell lines 
650 0 4 |a Cellular levels 
650 0 4 |a Databases, Factual 
650 0 4 |a Drug response 
650 0 4 |a Expression data 
650 0 4 |a factual database 
650 0 4 |a female 
650 0 4 |a Female 
650 0 4 |a gene expression 
650 0 4 |a Gene expression 
650 0 4 |a Gene Expression 
650 0 4 |a Gene Expression Data 
650 0 4 |a genetics 
650 0 4 |a Human cancer 
650 0 4 |a male 
650 0 4 |a Male 
650 0 4 |a Mammals 
650 0 4 |a metadata 
650 0 4 |a Metadata 
650 0 4 |a Metadata 
650 0 4 |a Mice 
650 0 4 |a mouse 
650 0 4 |a neoplasm 
650 0 4 |a Neoplasms 
650 0 4 |a Sampling bias 
650 0 4 |a Sex difference 
650 0 4 |a sex factor 
650 0 4 |a Sex Factors 
650 0 4 |a statistical bias 
700 1 |a Altman, R.B.  |e author 
700 1 |a Chang, A.  |e author 
700 1 |a Flynn, E.  |e author 
773 |t BMC Bioinformatics