Quercetin, a wild distributed
bioflavonoid, exhibits antitumor effects on murine models by inducing apoptosis and inhibiting growth of many
cancer cell lines, while
proteins involved in antitumor effects at proteomic level are still unclear. In our study, we used a quantitative proteomic strategy termed stable
isotope labeling by
amino acids in cell culture (SILAC)-mass spectrometry (MS) to study the differential proteomic profiling of HepG2 cells treated by
quercetin. In all, there were 70 changed
proteins among those quantified
proteins in HepG2 cells treated by 50 microM
quercetin for 48 h, and 14
proteins showed significant upregulation, whereas 56
proteins were downregulated. The functional classification of changed
proteins includes signaling
protein,
protein synthesis, cytoskeleton, metabolism, etc. Of these,
Ras GTPase-activating-like
protein (IQGAP1) and
beta-tubulin were found to be reduced at a large degree. The migration inhibition of HepG2 cells can be induced by
quercetin, and the
RNA and
protein expression level of IQGAP1 and
beta-tubulin were respectively decreased obviously in HepG2 cells exposed to
quercetin for 48 h in the scratch migration assay. The downregulated expression of IQGAP1 and
beta-tubulin by
quercetin treatment correlated with cell migration ability, and
quercetin probably inhibits HepG2 proliferation and migration through IQGAP1 and
beta-tubulin expression changes and their interactions with other
proteins.