Correlating two-photon excited fluorescence imaging of breast cancer cellular redox state with seahorse flux analysis of normalized cellular oxygen consumption.
Two-photon excited fluorescence (TPEF) imaging of the cellular cofactors nicotinamide adenine dinucleotide and oxidized flavin adenine dinucleotide is widely used to measure cellular metabolism, both in normal and pathological cells and tissues. When dual-wavelength excitation is used, ratiometric TPEF imaging of the intrinsic cofactor fluorescence provides a metabolic index of cells—the “optical redox ratio” (ORR). With increased interest in understanding and controlling cellular metabolism in cancer, there is a need to evaluate the performance of ORR in malignant cells. We compare TPEF metabolic imaging with seahorse flux analysis of cellular oxygen consumption in two different breast cancer cell lines (MCF-7 and MDA-MB-231). We monitor metabolic index in living cells under both normal culture conditions and, for MCF-7, in response to cell respiration inhibitors and uncouplers. We observe a significant correlation between the TPEF-derived ORR and the flux analyzer measurements (R=0.7901, p<0.001). Our results confirm that the ORR is a valid dynamic index of cell metabolism under a range of oxygen consumption conditions relevant for cancer imaging.
University of California, Laser Microbeam and Medical Program, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92612, United States.
Jue
J
Hou
University of California, Department of Molecular Biology and Biochemistry, 3205 McGaugh Hall, Irvine, California 92697-3900, United States.
Heather J
HJ
Wright
University of California, Laser Microbeam and Medical Program, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92612, United States.
Nicole
N
Chan
University of California, Laser Microbeam and Medical Program, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92612, United States.
Richard
R
Tran
University of California, Department of Molecular Biology and Biochemistry, 3205 McGaugh Hall, Irvine, California 92697-3900, United States.
Olga V
OV
Razorenova
University of California, Laser Microbeam and Medical Program, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92612, United States.
Eric O
EO
Potma
University of California, Laser Microbeam and Medical Program, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road, Irvine, California 92612, United States.
Bruce J
BJ
Tromberg
D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D061986:MCF-7 Cells; D061848:Optical Imaging; D010084:Oxidation-Reduction; D010101:Oxygen Consumption