Chemotherapeutic targeting of etoposide to regions of the brain on the basis of polyamine level

Infusion of etoposide in the CA1 disrupts hippocampal immediate early gene expression and hippocampus-dependent learning

Tight regulation of immediate early gene (IEG) expression is important for synaptic plasticity, learning, and memory. Recent work has suggested that DNA double strand breaks (DSBs) may have an adaptive role in post-mitotic cells to induce IEG expression. Physiological activity in cultured neurons as well as behavioral training leads to increased DSBs and subsequent IEG expression. Additionally, infusion of etoposide-a common cancer treatment that induces DSBs-impairs trace fear memory. Here, we assessed the effects of hippocampal infusion of 60 ng of etoposide on IEG expression, learning, and memory in 3-4 month-old C57Bl/6J mice. Etoposide altered expression of the immediate early genes cFos and Arc in the hippocampus and impaired hippocampus-dependent contextual fear memory. These data add to the growing evidence that DSBs play an important role in IEG expression, learning, and memory, opening avenues for developing novel treatment strategies for memory-related disorders.

Chemotherapeutic targeting of etoposide to various tissues on the basis of polyamine level

The effects of etoposide on body weight, organ weights and the concentrations of putrescine, spermidine and spermine in 14 different tissues were examined in rats that had been given the drug for five consecutive days. Etoposide reduces all polyamines, which are associated with tumor cell growth, in the thymus and reduces polyamines of two kinds in the spleen, heart, small intestine, skeletal muscle and lung but it increases putrescine in the prostate and spleen, and spermine in the large intestine.