Validation of syngeneic mouse models of melanoma and non-small cell lung cancer for investigating the anticancer effects of the soy-derived peptide Lunasin

Background: Lunasin is a naturally occurring peptide present in soybean that has both chemopreventive and therapeutic activities that can prevent cellular transformation and inhibit the growth of several human cancer types. Recent studies indicate that Lunasin has several distinct potential modes of action including suppressing integrin signaling and epigenetic effects driven by modulation of histone acetylation. In addition to direct effects on cancer cells, Lunasin also has effects on innate immunity that may contribute to its ability to inhibit tumor growth in vivo. Methods : Standard assays for cell proliferation and colony formation were used to assess Lunasin’s in vitro activity against murine Lewis lung carcinoma (LLC) and B16-F0 melanoma cells. Lunasin’s in vivo activity was assessed by comparing the growth of tumors initiated by subcutaneous implantation of LLC or B16-F0 cells in Lunasin-treated and untreated C57BL/6 mice. Results : Lunasin was found to inhibit growth of murine LLC cells and murine B16-F0 melanoma cells in vitro and in wild-type C57BL/6 mice. The effects of Lunasin in these two mouse models were very similar to those previously observed in studies of human non-small cell lung cancer and melanoma cell lines. Conclusions : We have now validated two established syngeneic mouse models as being responsive to Lunasin treatment. The validation of these two in vivo syngeneic models will allow detailed studies on the combined therapeutic and immune effects of Lunasin in a fully immunocompetent mouse model.