Caffeine Research Today is a free monthly online journal that collates and summarizes the latest research about Caffeine, including details on addiction, drugs, effects, coffee. | ||||||||
|
Inhibition of epidermal growth factor-induced cell transformation and Akt activation by caffeine.Nomura M, Ichimatsu D, Moritani S, Koyama I, Dong Z, Yokogawa K, Miyamoto K Department of Hospital Pharmacy, School of Medicine, Kanazawa University, Kanazawa, Japan. We found that caffeine significantly inhibited epidermal growth factor (EGF)- and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cell transformation in the JB6 mouse epidermal cell line. The tumor promoter-induced cell transformation was also blocked by treatment with an adenosine A1 receptor antagonist, 8-phenyltheophylline (8-PTH). Caffeine slightly attenuated activation of EGF-induced activator protein 1 (AP-1) activation, which play important roles in cell transformation, but only at the highest concentration examined (1 mM). Interestingly, pretreatment with caffeine suppressed EGF-induced phosphorylation and activation of Akt and ribosomal p 70 S6 protein kinase (p 70 S 6 K), a target of Akt, without inhibiting phosphatidylinositol 3-kinase (PI 3 K) activation. The inhibition of Akt activation of caffeine was not a result of its adenosine receptor antagonism. Because Akt plays a key role in signal transduction pathways leading to cell proliferation and apoptosis, our results provide novel insight into possible mechanisms of the chemotherapeutic effect of caffeine. Published 1 August 2005 in Mol Carcinog, 44(1): 67-76.
© 2004-2008 Caffeine Research Today. All Rights Reserved. |
| ||||||