Oxidative and molecular interactions of multi-wall carbon nanotubes (MWCNT) in normal and malignant human mesothelial cells

Carbon nanotubes are new tools in industry and medicine with their potential applications in many uses. Multiwall carbon nanotubes (MWCNT) with their morphologic similarity to asbestos and wide commercial and biomedical applications necessitate these investigations. The present study investigated the biological reactivity of MWCNT in normal (NM) and malignant (MM) mesothelial cells. MWCNT containing low iron content generated only negligible amounts of reactive oxygen species with both cells. Exposure of both cell types to MWCNT caused cell death, cytotoxicity, DNA damage and apoptosis, which were greater in MM cells. Exposure of both cells to MWCNT caused a parallel activation of two important transcription factors, phosphorylation of H2AX, and PARP activation which were greater in NM cells. Phosphorylation of ERK1/2 and p38 was greater in MM cells than in NM cells. These findings demonstrate that MWCNT are biologically potent activators of molecular events in NM cells associated with mesothelioma development.