Meta-analysis of microarray datasets for the risk assessment of coplanar polychlorinated biphenyl 77 (PCB77) on human health

Polychlorinated biphenyls (PCBs) are persistent organic compounds that have been banned since 1970s, but continue to contaminate the environment. PCBs are categorized into two structural groups: coplanar and non-coplanar PCBs. The coplanar PCBs are dioxin-like potent toxic compounds. To evaluate their effects on humans, we chose a coplanar PCB77 for data analysis. We performed meta- analysis by integrating datasets via the Rank Product method, and identified 375 up- and 66 down- regulated differentially expressed genes (DEGs). Notably, up-regulated genes were significantly associated with liver and kidney diseases. Using gene ontology enrichment, we found that the up-regulated DEGs were significantly enriched in the apoptotic process (false discovery rate, FDR=1.62e-10) and response to unfolded protein (FDR=7.65e-10). Protein-protein interaction networks identified the hub proteins containing HSP90AB1 and HSPA5. These findings suggest that our DEGs may provide a robust set of genetic markers for PCB77.