Metabolomics analysis to investigate the effects of benzo[a]pyrene exposure in human bladder cells

Polycyclic aromatic hydrocarbons (PAHs) are among the most prevalent environmental pollutants known to be involved in carcinogenesis. The long half-life of PAHs in soil, water, air, and subsequently our food makes it a persistent contaminant that can be absorbed through different exposure routes. Among PAHs congeners, benzo[a]pyrene (B[a]P) is most toxic and classified as Group I carcinogens in humans by the International Agency for Research on Cancer (IARC). Epidemiological studies have suggested the potential association of PAHs with human bladder cancer. Nevertheless, the mechanism underlying the potential carcinogenicity of PAHs in bladder remains poorly understood. Dysregulated metabolism has recently been acknowledged as a key hallmark of cancer. Up to date, whether B[a]P, and of PAHs more generally, can trigger metabolic shift such as “Warburg effect” in the bladder has not been assessed. Metabolomics, which measures changes in endogenous metabolites, is a powerful tool for studying global cellular metabolic responses to toxicants. In this proposal, a comprehensive mass spectrometry-based metabolomics approach will be used for the first time to explore the metabolic responses of human bladder cells exposed to B[a]P- the prototype of PAHs. Both LC/MS and GC/MS will be utilized to enable a broad coverage of the metabolites. Chemometric analysis will be performed to identify the biomarkers that associated with B[a]P exposure. The metabolite set enrichment analysis and pathway analysis will be conducted to elucidate the disturbed metabolic pathways. Moreover, the identified metabolic pathways and intermediate metabolites related to“Warburg effect” will be further validated using targeted metabolomics approach. The metabolic enzymes involved in the perturbed metabolic pathways will be confirmed by RT-PCR and western blotting assays. The obtained results are expected to provide new clues concerning the toxicological mechanisms of B[a]P in human bladder from a metabolomics perspective