HGF/SF activates glycolysis and oxidative phosphorylation in DA3 murine mammary cancer cells

Hepatocyte growth factor/scatter factor (HGF/SF) is a paracrine growth factor which increases cellular motility and has also been implicated in tumor development and progression and in angiogenesis. Little is known about the metabolic alteration induced in cells following Met-HGF/SF signal transduction. The hypothesis that HGF/SF alters the energy metabolism of cancer cells was investigated in perfused DA3 murine mammary cancer cells by nuclear magnetic resonance (NMR) spectroscopy, oxygen and glucose consumption assays and confocal laser scanning microscopy (CLSM). 31P NMR demonstrated that HGF/SF induced remarkable alterations in phospholipid metabolites, and enhanced the rate of glucose phosphorylation (P < .05). 13C NMR measurements, using [13C1]-glucose-enriched medium, showed that HGS/SF reduced the steady state levels of glucose and elevated those of lactate (P < .05). In addition, HGF/SF treatment increased oxygen consumption from 0.58+/-0.02 to 0.71+/-0.03 micromol/hour per milligram protein (P < .05). However, it decreased CO2 levels, and attenuated pH decrease. The mechanisms of these unexpected effects were delineated by CLSM, using NAD(P)H fluorescence measurements, which showed that HGF/SF increased the oxidation of the mitochondrial NAD system. We propose that concomitant with induction of ruffling, HGF/SF enhances both the glycolytic and oxidative phosphorylation pathways of energy production.