Acetaldehyde induces similar cytotoxic and genotoxic risks in BEAS-2B cells and HHSteCs: involvement of differential regulation of MAPK/ERK and PI3K/AKT pathways

Long-term use of alcohol and cigarettes is associated with millions of deaths each year, directly or indirectly. The carcinogen acetaldehyde is both a metabolite of alcohol and the most abundant carbonyl compound in cigarette smoke, and co-exposure of them is usual and primarily leads to liver and lung injury, respectively. However, few studies have explored the synchronic risk of acetaldehyde on the liver and lung. Here, we investigated the toxic effects and related mechanisms of acetaldehyde based on normal hepatocytes and lung cells. The results showed that acetaldehyde caused significant dose-dependent increases of cytotoxicity, ROS level, DNA adduct level, DNA single/double-strand breakage, and chromosomal damage in BEAS-2B cells and HHSteCs, with similar effects at the same doses. The gene and protein expression and phosphorylation of p38MAPK, ERK, PI3K, and AKT, key proteins of MAPK/ERK and PI3K/AKT pathways regulating cell survival and tumorigenesis, were significantly upregulated on BEAS-2B cells, while only protein expression and phosphorylation of ERK were upregulated significantly, the other three decreased in HHSteCs. When either the inhibitor of the four key proteins was co-treated with acetaldehyde, cell viabilities were almost unchanged in BEAS-2B cells and HHSteCs. Thus, acetaldehyde could synchronically induce similar toxic effects in BEAS-2B cells and HHSteCs, and MAPK/ERK and PI3K/AKT pathways seem to be involved in different regulatory mechanisms.