Effect of Lithium and Chloroquine on Neuronal Ultrastructure in a Melanoma Mice Model

The incidence of the most malignant form of skin cancer, melanoma, is increasing. Tumor cells and tumor microenvironment cells produce proinflammatory cytokines, which can contribute to damage to the blood-brain barrier and, as a result, impairment of neuronal function. Lithium and chloroquine drugs are recognized as antitumor therapy agents. Lithium carbonate is used in the treatment of psychoemotional disorders and exhibits neuroprotective properties. The antitumor effect of chloroquine is manifested in the inhibition of autophagy in tumor cells. The purpose of the study was to evaluate the effects of lithium carbonate and chloroquine on the structural organization of prefrontal cortex pyramidal neurons in the melanoma mice model. Experiments were performed on male C57BL/6 mice, injected with Melanoma B16 tumor cells, and treated with lithium carbonate and chloroquine for 7 days. Using morphometric analysis, we calculated the quantitative and volume density of organelles of prefrontal cortex pyramidal neurons. Lithium carbonate has been shown to exhibit neuroprotective properties in melanoma: reduced signs of ER stress and oxidative stress, reduced autophagy. Chloroquine has been noted to block autophagic activity also leads to the accumulation of lipofuscin bodies, which may be one of the factors leading to neurodegeneration.