Antitumor Activity of Monasnicotinic Acid Isolated from the Fungus Aspergillus cavernicola

It has been found that monasnicotinic acid (MNA) isolated from the fungus Aspergillus cavernicola VKM F-906 reduces the proliferation and migration of human prostate cancer cells LnCaP and inhibits the AKT–mTORC1 and FAK–Src signaling pathways. However, MNA also increases the level of HSP60 and the phosphorylation of c-Jun, factors that stimulate the vital activity of cancer cells. MNA-induced cellular responses appear only after 48 h, which indicates the involvement of either the products of MNA metabolism or tautomers arising during the MNA protonation due to the growth of cell cultures and utilization of the compound by human cells. These results suggest that MNA is a promising compound for the production of various derivatives that would inhibit oncogenic signaling pathways without stimulating the factors providing the survival of tumor cells.