Evaluation of the Synergistic Effect of Tamoxifen and HSP70 Inhibitor on Breast Cancer Cells Based on Optical Metabolic Imaging

Nicotinamide adenine dinucleotide (NADH) and Flavin adenine dinucleotide (FAD) are the endogenous fluorophores in cells. Optical redox ratio determined by the ratio of NADH and FAD was an important oxygenic indicator to reflect cell metabolism. Heat shock protein 70 (HSP70) has been recognized as a target for antitumor therapy. In this study, the optical redox ratio was used to evaluate the metabolic changes after the synergistic treatment of tamoxifen and HSP70 inhibitor in MCF-7 breast cancer cells based on optical metabolic imaging. In addition, the cell viability was also measured after the treatments of tamoxifen and HSP70 inhibitor by MTT assay. We observed that changes of the redox ratio and the cell viability with synergistic treatment of tamoxifen and HSP70 inhibitor were more obvious than the results of the sole treatment of tamoxifen or HSP70 inhibitor. These results indicated that the inhibition of HSP70 improve drug response of MCF-7 breast cancer cells.