In vitro mutagenicity of the plasmacytomagenic agent pristane (2,6,10,14-tetramethylpentadecane)

Pristane is known to induce a distinct type of B-cell-derived malignant lymphoma, plasmacytoma, after administration into the peritoneal cavity of genetically susceptible BALB/cAnPt mice. Since the mechanism of pristane-induced plasmacytoma development is poorly understood, we chose to examine the possibility that pristane is mutagenic in rodent cells and decided to use bacteriophage λ-derived lacI/lacZ genes as target/reporter to quantitate mutagenesis. Here we show that in vitro exposure to micromolar amounts of pristane, delivered as an inclusion complex with β-cyclodextrin, resulted in 1.7-fold and 6.2-fold increases of mutant frequencies over controls in a cell line of rat fibroblasts and primary mouse B lymphocytes, respectively. We conclude that pristane can be mutagenic to mammalian cells, yet are currently unable to explain the mechanism of mutagenicity. It is suggested that B-cell mutagenesis contributes to the plasmacytomagenic activity of pristane in vivo.