: A mediator of glycolytic flux in cancer progression," Critical Review in Oncology/Hematology, vol.
Its S-System model contains five dependent variables: glucose ([X.sub.1]), glucose-6-phosphate ([X.sub.2]), fructose-1,6- diphosphate ([X.sub.3]), phosphoenolpyruvate ([X.sub.4]), and ATP ([X.sub.5]) and eight independent variables with the following steady-state values: glucose uptake ([X.sub.6]; 47.5mM/min), hexokinase ([X.sub.7]; 24.1mM/min), phosphofructokinase
([X.sub.8]; 53.9 mM/min), glyceraldehyde 3-phosphate dehydrogenase ([X.sub.9]; 91.4mM/min), pyruvate kinase ([X.sub.10]; 18.1mM/min), polysaccharide storage ([X.sub.11];82.9 mM/min), glycerol production ([X.sub.12]; 92.4 mM/min), and ATPase ([X.sub.13]; 1.0 mM/min) .
One such study examined Phosphofructokinase
(PFK), a glycolytic enzyme that catalyzes the phosphorylation of fructose-6-phosphate to fructose 1,6-bisphosphate in the presence of ATP.
The inactivation of pyruvate dehydrogenase causes citrate concentration to increase, which leads to inhibition of phosphofructokinase
and accumulation of glucose-6-phosphate, thus inhibiting hexokinase II, thereby decreasing glucose uptake.
Antibodies against complex I~V, hexokinase 2 (HK2), phosphofructokinase
(PFKM), pyruvate kinase 2 (PKM2), and [beta]-actin were obtained from Proteintech Group (Chicago, IL, USA).
The effect of free fatty acid (FAA) on partitioning of intra-cellular glucose fluxes was originally describe by Randle et al  according to this hypothesis (the glucose/fatty acids cycle), oxidation of FFA initiate an up-stream, chain-reaction-like inhibition of glycolytic enzymes, which ultimately inhibits glucose uptake(GH enhance mobilization and catabolism of FFA, increase catabolism of FFA cause increase production of acetyl-CoA that in turn inhibit pyruvate dehydrogenase and cause increase pyruvate level which in turn inhibit phosphofructokinase
and cause increase in glucose-6-phosphate level that in turn inhibit hexokinase and glucose uptake).
At the same time, the increase of ATP and citrate leads to inhibition of phosphofructokinase
and glycolysis resulting in glucose 6-phosphate accumulation.
Histochemical stains showed normal myophosphorylase, phosphofructokinase
and myoadenylate deaminase, succinate dehydrogenase, nicotinamide adenine dinucleotide + hydrogen and cytochrome oxidase activity.
Specifically, NXN has been observed as partner of phosphofructokinase
(PFK) 1, a glycolytic enzyme, reported as contributor for systemic metabolic conditions and also cancerous processes (Mor et al.
Indeed, exogenous application of allelopathic water extracts at low concentration activate various enzymes like pyruvate kinase, isomerase, phosphoglucose, PPi-dependent phosphofructokinase
and glucokinase, which play important role in many important processes involved in grain filling (Pupponen-Pimia et al., 2001).
(52) The genes encoding key enzymes that regulate the glycolysis pathway--such as hexokinase 2 (HK2), phosphofructokinase
(PFKP), and pyruvate kinase M2 (PKM2)--are markedly upregulated before activation of A-HSC marker proteins, such as [alpha]-SMA.
Effect of pH on the kinetics of frog muscle phosphofructokinase
. Journal of Biological Chemistry.