Optical detection of single cell lactate release for cancer metabolic analysis.
Sensitive detection of extracellular lactate concentrations at a single cell level is of importance for studying the metabolic alterations in tumor progression. A unique nanoscale optical fiber lactate sensor was developed to monitor the extracellular lactate concentrations of cancer cells by immobilizing its nanotip with lactate dehydrogenases, which could catalyze lactate conversion to generate NADH for sensitive fluorescence detection. The results demonstrate that the fabricated nanosensor can successfully detect the extracellular lactate concentrations for single HeLa, MCF-7, and human fetal osteoblast (hFOB) cells, showing that the cancer cells have distinctly higher extracellular lactate concentrations than normal cells as that predicted by Warburg effect. The nanosensor was also employed to investigate the effect of a monocarboxylate transporter inhibitor on the lactate efflux from cancer cells. Different lactate efflux inhibition profiles were obtained for HeLa and MCF-7 cell lines. This work demonstrates that the nanosensor has potential for evaluating the effect of metabolic agents on cancer metabolism and survival.
Zheng
Xin Ting
XT
School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457.
Yang
Hong Bin
HB
Li
Chang Ming
CM
D015374:Biosensing Techniques / Q000379:methods*; D002138:Calibration; D045744:Cell Line, Tumor; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D009369:Neoplasms / Q000378:metabolism*; D055100:Optical Fibers
D009243:NAD; D019344:Lactic Acid; D007770:L-Lactate Dehydrogenase