Autophagy is a process of cytosol-to-lysosome vesicle trafficking of cellular constituents for degradation and recycling of their building blocks. Autophagy becomes very important for cell viability under different stress conditions, in particular under
amino acid limitation. In this report we demonstrate that single
amino acid arginine deprivation triggers profound prosurvival autophagic response in cultured human
ovarian cancer SKOV3 cells. In fact, a significant drop in viability of
arginine-starved SKOV3 cells was observed when autophagy was inhibited by either coadministration of
chloroquine or transcriptional silencing of the essential autophagy
protein BECLIN 1. Enzymatic
arginine deprivation is a novel anticancer
therapy undergoing clinical trials. This
therapy is considered nontoxic and selective, as it allows controlling the growth of malignant tumours deficient in
arginine biosynthesis. We propose that
arginine deprivation-based combinational treatments that include autophagy inhibitors (e.g.,
chloroquine) may produce a stronger anticancer effect as a second line
therapy for a subset of chemoresistant
ovarian cancers.