Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fructose 2,6-bisphosphate (Fru-2, 6-P2) represents the most powerful activator of 6-phosphofructo-1-kinase, rate-limiting enzyme of glycolysis. Fru-2,6-P2 content is tightly regulated and appears to be under the control of different hormones and growth factors, acting either through covalent modification of isoenzymatic forms of 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase (PFK-2/FBPase-2), the bifunctional enzyme responsible for the synthesis and the degradation of the compound, or through changes in transcription rate and/or in the expression of different isoforms of the enzyme. In the present study the metabolism of Fru-2,6-P2 was investigated during the differentiation toward megakaryocytes induced by phorbol 12-myristate 13-acetate (PMA) treatment of human leukemia K562 and MEG-01 cell lines. Fru-2,6-P2 content as well as PFK-2 activity were increased in a dose-dependent manner after 4 days of incubation with PMA. MEG-01 cells resulted more sensitive to the effect of the inducer, anyway in both cell types cytostatic concentrations of the phorbol ester were able to affect Fru-2,6-P2 metabolism. The effect of PMA was maximal at 4 days of incubation in both examined cell lines. Interestingly, the effect induced by the phorbol ester at 4 days was still appreciable subculturing K562 and MEG-01 cells for 3 days in the absence of the inducer and was associated with relevant changes in the molecular properties of PFK-2: namely increased Vmax and K(m). This latter finding suggests that the rise in Fru-2,6-P2 content during the differentiation process toward megakaryocytes might result from the expression of a novel PFK-2 isoform.
 ...
PMID:Fructose 2,6-bisphosphate metabolism during megakaryocytic differentiation of K562 and MEG-01 cells. 909 68

A homodimeric, fructose-binding lectin was isolated from Del Monte bananas by using a protocol that involved ion-exchange chromatography on DEAE-cellulose and SP-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. Not only fructose, but also glucose, mannose, rhamnose and glucosamine could inhibit the lectin. The N-terminal amino acid sequence of its identical 15-kDa subunits was similar to lectins from other Musa species except for the deletion of the N-terminal glycine residue in Del Monte banana lectin. The hemagglutinating activity was stable up to 80 degrees C and also stable in the range pH 1-13. However, the hemagglutinating activity dwindled to an undetectable level at 90 degrees C. The lectin was capable of eliciting a mitogenic response in murine splenocytes and inducing the expression of the cytokines interferon-gamma, tumor necrosis factor-alpha, and interleukin-2 in splenocytes. The lectin also inhibited proliferation of leukemia (L1210) cells and hepatoma (HepG2) cells and the activity of HIV-1 reverse transcriptase. The additional information obtained in the present study includes demonstration of fructose-binding activity and cytokine-inducing activity of Del Monte banana lectin. Fructose binding is an unusual characteristic of plant lectins. It is possible that the banana lectin can be developed into a useful anti-HIV, immunopotentiating and antitumor agent in view of its trypsin stability and thermostability.
 ...
PMID:Musa acuminata (Del Monte banana) lectin is a fructose-binding lectin with cytokine-inducing activity. 1919 58