Up-regulation of histidine decarboxylase expression and histamine content in B16F10 murine melanoma cells

Objective and design This study was conducted to determine if differences in histidine decarboxylase expression and histamine levels exist between B16F10 melanoma cells and non-cancerous Melan-A melanocytes. Methods Immunofluorescence and western blot analysis were used to detect and compare histidine decarboxylase protein levels. Enzyme-linked immunoassay was used to detect, measure, and compare histamine levels. Results Histidine decarboxylase expression was found to be elevated in the B16F10 cells. Western blot analysis demonstrated levels of histidine decarboxylase protein expression more than twofold higher (p < 0.001) in B16F10 than in Melan-A cells. Histamine levels were 280-fold higher (p < 0.001) in B16F10 (229 ± 15 pg/mg protein) than in Melan-A (0.83 ± 0.03 pg/mg protein) cells. Conclusion Results indicate an up-regulated histaminergic system in the B16F10 melanoma cells when compared to non-cancerous melanocytes. This supports the use of B16F10 cells as a model in which to investigate a potential role of the endogenous histaminergic system in regulating malignant cell function.