3-nitrofluoranthene (3-NF)-induced apoptosis and programmed necrosis.

Polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs are environmental pollutants formed during incomplete combustion of organic material.  Many possess mutagenic and carcinogenic properties, but their effects on cell death are less known. We have found that rather similar PAHs cause death by quite different mechanisms including apoptosis, necrosis as well as various mixtures of the two. In this addendum to our recent publication, Toxicology 2009 (255:140–50), we report that 3-nitrofluoranthene (3-NF) induces apoptosis as well as regulated necrosis with necroptotic features.  The typical necroptotic cell exhibited partial nuclear chromatin condensation combined with damaged plasma membrane. The cells were characterized by increased size as well as number of lysosomes and myelinosomes/autophagic vesicles, and also in expression of the autophagic marker, LC3B. However, the induced autophagy appears to be a parallel event rather than the cause of cell death.