The enhanced expression of transketolase
-like 1 (TLKL-1) protein--the only transketolase
that is overexpressed in cancer--was shown to correlate with a more malignant RCC phenotype in a study by Langbein and colleagues.
plays a role in a chain of reactions called the pentose phosphate pathway, whereas PDH and KGDH are involved in glycolysis and the citric acid cycle.
During periods of high metabolic demand and high glucose intake, thiamine is needed as a cofactor for several enzymes, including transketolase
, [alpha]-ketoglutarate dehydrogenase, and pyruvate dehydrogenase.
Vitamin B(1) status assessed by direct measurement of thiamin pyrophosphate in erythrocytes or whole blood by HPLC: comparison with erythrocyte transketolase
WE occurs as a result of thiamine deficiency, (40) which is an important cofactor for several enzymatic systems, such as transketolase
and pyruvate dehydrogenase, (41,42) that are responsible for cerebral glucose utilization and glutamate elimination.
These enzymes are called transketolase
, pyruvate dehydrogenase (PDH) and alphaketoglutarate dehydrogenase ([alpha]-KGDH); they all participate in the catabolism of sugar molecules (i.
Thiamin deficiency was diagnosed: serum thiamin 34 U (normal range 50 to 100 U) red cell transketolase
stimulation 17% (marginal deficiency 15 to 22%).
The use of erythrocyte transketolase
activity is an easy way of observing deficiency of thiamine pyrophosphate (TPP), and it has been found to be a frequently abnormal laboratory test that is guarantee of the biochemical lesion.
In the PPP, glu-6P is first converted into pentose 5-phosphates, which are subsequently recycled to glu-6P by two enzymes: transketolase
and transaldolase (TALDO; Fig.
Avemar makes this very difficult for cancer cells to do, because it inhibits the activity of the key enzyme in that pathway, transketolase
The TDP assay is more precise than the transketolase
activation (ETK) test, and the method described is an important advance for which I thank the authors.
One of the postulated mechanisms of action of Benfotiamine is that it blocks three major pathways (the hexosamine pathway, the advanced glycation end product formation pathway, and the diacylglycerol (DAG)-protein kinase C (PKC) pathway) by probable removal of glyceryl aldehyde 3-phosphate and fructose 6-phosphate through the activation of the pentos phosphate enzyme transketolase