Abstract
The rare sugar D-allose, the C-3 epimer of D-glucose, was shown to have a novel inhibitory effect on production of reactive oxygen species (ROS). We also found that D-allose has a novel inhibitory effect on cell proliferation of various human cancer cells. To identify the proteins that may play an important physiological role in apoptosis of cancer cells, we analyzed cancer cells treated with D-allose using a proteomic approach. First, we examined the change of protein phosphorylation after D-allose treatment by Western blotting with anti-phosphotyrosine antibody. Since the various growth factor receptors as well as other intracellular proteins are controlled by phosphorylation, elucidation of tyrosine-phosphorylated proteins may give us clues to understand the mechanism of D-allose-mediated growth inhibition of cancer cells. To analyze the effect of these phosphorylation changes in cancer cells, we compared the global protein expression profile in human cancer cell lines in the presence and absence of D-allose treatment using the stable isotope labeling with amino acids in cell culture (SILAC) method and tandem mass spectrometry (MS/MS). SILAC has recently gained popularity for its ability to compare the expression levels of proteins in a single experiment. Using this method we identified more than two hundred proteins and found some highly up- and down-regulated proteins. On the basis of these findings, we will discuss the possible mechanism of action of D-allose. [Jpn J Physiol 55 Suppl:S81 (2005)]
