Search

Flavonoids have chemo-preventive and chemotherapeutic properties against different human cancers including chronic myeloid leukemia. Quercetin and curcumin are two polyphenols with potential anti-carcinogenic and pro-apoptotic properties. We have previously demonstrated the synergistic protective effect of quercetin and curcumin on chronic myeloid leukemia cells (K562) cells. Anti-proliferative and apoptotic effects of these polyphenols were examined by apoptosis and cell viability assays. Oxidative status of the cells was analyzed by determining the level of reactive oxygen species, mitochondrial permeability and intracellular glutathione. Obtained data showed that quercetin and curcumin had beneficial and synergistic effects on K562 cells. On the basis of the above-mentioned data, herein we aimed to clarify signaling pathways involved in synergistic combination of quercetin and curcumin on K562 cells. Normal peripheral blood mononuclear cell line was used as controls. The mRNA and protein expressions of the signaling pathways were detected by Human Signal Transduction Pathway Finder-RT2 PCR Array system and Western blotting, respectively. The results of PCR array were evaluated by DAVID v6.8 and database for KEGG pathways. Our data revealed that synergistic combination of curcumin quercetin was effective on genes that were particularly related to P53, NF and TGF. We believe that our findings will lead to new research in this area and will contribute to the chronic myeloid leukemia treatment protocols.

In both healthy cells and cancer cells a number of different cellular responses influence the progress of cancer. In this study, we have investigated the effect of stress conditions on human hepatocyte cancer cells. Different concentrations of hydrogen peroxide, quercetin and N-acetyl cysteine were used to induce the acute cell stress. We have detected apoptosis, measured proteasome activity and performed a cell death array in both treated and control cells. Treatment of human hepatocyte cancer cells with hydrogen peroxide and quercetin resulted in decreased cell viability and increased apoptosis. On the other hand, proteasome activity was increased with hydrogen peroxide treatment but decreased with quercetin. N-acetyl cysteine supported cell viability and increased proteasome activity. In conclusion, cell death related genes were affected in quite different manner following hydrogen peroxide, quercetin and N-acetyl cysteine treatments.