IndraLab
Statements
"TNF-{alpha} reduces insulin-stimulated receptor tyrosine kinase activity at low concentrations and can also decrease the expression of the insulin receptor, IRS-1 and GLUT-4 at higher concentrations (22) as well as increase the phosphorylation of serine 307 of IRS-1, thus impairing its ability to bind to the insulin receptor and initiate downstream signaling."
"Accordingly, under the cellular context of the elevated expression of IL- 6Ra on myeloma cells, it is assumed that IL-6Ra molecules are located close to IGF-I receptors at lipid rafts, and IL-6 stimulation triggers the complex formation of IL-6Ra not only with gp130 but also with IGF-I receptors, leading to autophosphorylation of IGF-I receptor b and subsequent acti- vation of PI-3 kinase-Akt pathways (Fig. 4) 79 ."