Transcriptomic response of HepG2 cells exposed to three common anti-inflammatory drugs: Ketoprofen, mefenamic acid, and diclofenac in domestic wastewater effluents.

The biological impacts of residual pharmaceuticals in the complex wastewater effluents have not been fully understood. Here, we investigated changes in the transcriptomic responses of hepatobrastoma (HepG2) cells exposed to a single or partially combined three common non-steroidal anti-inflammatory drugs (NSAIDs); ketoprofen (KPF), mefenamic acid (MFA) and diclofenac (DCF), in domestic wastewater effluents. After 48 h sub-lethal exposure to single compounds, the DNA microarray analysis identified 57-184 differently expressed genes (DEGs). The hierarchical clustering analysis and GO enrichment of the DEGs showed that gene expression profiles of the NSAIDs were distinct from each other although they are classified into the same therapeutic category. Four maker genes (i.e., EGR1, AQP3, SQSTM1, and NAG1) were further selected from the common DEGs, and their expressions were quantified by qPCR assay in a dose-dependent manner (ranging from μg/L to mg/L). The results revealed the insignificant induction of the marker genes at 1 μg/L of KPF, MFA, and DCF, suggesting negligible biological impacts of the NSAIDs on gene expression (early cellular responses) of HepG2 at typical concentration levels found in the actual wastewater effluents. Based on the quantitative expression analysis of the selected marker genes, the present study indicated that the presence of wastewater effluent matrix may mitigate the potentially adverse cellular impacts of the NSAIDs.