The health impacts of the BP oil spill are yet to be further revealed as the toxicological effects of oil products and dispersants on human respiratory system may be latent and complex, and hence difficult to study and follow up. Here we performed
RNA-seq analyses of a system of human airway epithelial cells treated with the BP
crude oil and/or dispersants
Corexit 9500 and
Corexit 9527 that were used to help break up the oil spill. Based on the
RNA-seq data, we then systemically analyzed the transcriptomic perturbations of the cells at the KEGG pathway level using two pathway-based analysis tools, GAGE (generally applicable gene set enrichment) and GSNCA (Gene Sets Net Correlations Analysis). Our results suggested a pattern of change towards
carcinogenesis for the treated cells marked by upregulation of ribosomal biosynthesis (hsa03008) (p=1.97E-13),
protein processing (hsa04141) (p=4.09E-7), Wnt signaling (hsa04310) (p=6.76E-3),
neurotrophin signaling (hsa04722) (p=7.73E-3) and
insulin signaling (hsa04910) (p=1.16E-2) pathways under the dispersant
Corexit 9527 treatment, as identified by GAGE analysis. Furthermore, through GSNCA analysis, we identified gene co-expression changes for several KEGG
cancer pathways, including
small cell lung cancer pathway (hsa05222, p=9.99E-5), under various treatments of oil/dispersant, especially the mixture of oil and
Corexit 9527. Overall, our results suggested carcinogenic effects of dispersants (in particular
Corexit 9527) and their mixtures with the BP
crude oil, and provided further support for more stringent safety precautions and regulations for operations involving long-term respiratory exposure to oil and dispersants.