Protein biomarkers in the plasma of workers occupationally exposed to polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) form a chemical family containing several hundred compounds, including benzo[a]pyrene and pyrene. They are usually produced by the incomplete burning of coal, oil, gas, garbage, or other organic substances like tobacco or char-broiled meat. Exposure to PAH causes tumors, primarily in the lung, the bladder, and the skin. To investigate the differentially expressed proteins resultant from PAH exposure, the protein expression in human plasma was analyzed using two-dimensional electrophoresis (2-DE). The plasma exposed to PAH was obtained from 48 waste gas pollution measurers working at an automobile emission inspection center. The 1-hydroxypryene (1-OHP) level, which is the urinary PAH metabolite used for evaluation of PAH exposure, was 0.28 μmol/mol creatinine in PAH exposure groups, and 0.078 μmol/mol creatinine in unexposed groups (control, n = 33). A protein upregulated by PAH (putative capacitative calcium entry channel) and five over-expressed proteins (two fibrinogen γ-A chain precursors, a hemopexin precursor, an albumin precursor, and T-cell receptor β chain C region) were identified with matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and confirmed with tandem MS (MS/MS) and Western blotting. The putative capacitative calcium entry channel was partially validated with a laboratory made antibody of a representative peptide fragment in PAH-exposed human plasma samples.