Anti-cancer effect of Lactobacillus rhamnosus GG extract on human malignant melanoma cell lines

Abstract

Human malignant melanoma is one of the aggressive skin cancers of which the incidence has been rising at a greater rate than any other cancers. Although various new therapeutic methods have been developed, its properties of high proliferation and metastasis rate have still been obstacles leading to a poor prognosis. It has been reported that a specific Lactobacillus extract has anti-cancer and anti–metastasis effect in vitro and in vivo. However, it has not been reported what effect the extract has on human malignant melanomas. It was confirmed that Lactobacillus Rhamnosus GG (LGG) extract had anti-cancer and anti–metastasis effects on the human malignant melanoma cell lines, A375P and A375SM. At first, it was found that while the LGG extract affects neonatal human dermal fibroblast (HDFn) a little, it induced the dose-dependent anti-cancer effect on A375P and A375SM by a WST-1 proliferation assay. As a result of a real-time PCR analysis, expression patterns of several genes related to cell cycle, proliferation, and apoptosis was modulating towards inhibiting the growth of both malignant melanoma cell lines after the treatment of the LGG extract. Furthermore, genes related with epithelial-mesenchymal transition (EMT) were modulating towards down-regulating the EMT and migration rate was also decreased significantly by the LGG extract. Our study showed that the LGG extract could be used as potential therapeutic sources.