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"5' AMP-activated protein kinase or AMPK or 5' adenosine monophosphate-activated protein kinase is an enzyme that plays a role in cellular energy homeostasis. It consists of three proteins (subunits) that together make a functional enzyme, conserved from yeast to humans. It is expressed in a number of tissues, including the liver, brain, and skeletal muscle. The net effect of AMPK activation is stimulation of hepatic fatty acid oxidation and ketogenesis, inhibition of cholesterol synthesis, lipogenesis, and triglyceride synthesis, inhibition of adipocyte lipolysis and lipogenesis, stimulation of skeletal muscle fatty acid oxidation and muscle glucose uptake, and modulation of insulin secretion by pancreatic beta-cells.[1] It should not be confused with cyclic AMP-activated protein kinase (protein kinase A), which, although being of similar nature, may have opposite effects.[2]"

A signalling pathway that influences how sensitive cancer cells are to the beneficial effects of dietary restriction is described in this week's Nature. Dietary restriction - eating less calories while maintaining essential vitamins and minerals - can extend lifespan, and reduce cancer incidence and growth. But some types of cancer cell are more sensitive to the anti-growth effects of dietary restriction than others, Nada Kalaany and David Sabatini report. The effect hinges on the activity of the phosphatidylinositol-3-kinase (PI3K) pathway. If the pathway is active, dietary restriction has no effect on cancer cells. However, if the pathway is inactive, tumours are sensitive to dietary restriction.

Wyeth Pharmaceuticals announced today that the U.S. Food and Drug Administration (FDA) has granted a new "fast track" designation for temsirolimus (CCI-779), an investigational mTOR kinase inhibitor, in the first-line treatment of poor-prognosis patients

A collaborative study led by UCL (University College London) shows that the compound - inositol pentakisphosphate - found in beans, nuts and cereals inhibits a key enzyme (phosphoinositide 3-kinase) involved in tumour growth. The findings, published in the latest issue of Cancer Research, suggest that a diet enriched in such foods could help prevent cancer, while the inhibitor offers a new tool for anti-cancer therapy.

Berberine inhibits metastasis of nasopharyngeal carcinoma 5-8F cells by targeting Rho kinase-mediated Ezrin phosphorylation at threonine 567. Tang F, Wang D, Duan C, Huang D, Wu Y, Chen Y, Wang W, Xie C, Meng J, Wang L, Wu B, Liu S, Tian D, Zhu F, He Z, Deng F, Cao Y. J Biol Chem. 2009 Oct 2;284(40):27456-66. Epub 2009 Aug 3. PMID: 19651779

It is well known that eating green vegetables, beans, nuts, cereals and fruits prevents cancer, now it is found that beans and wheat bran contains an enzyme inhibitor Inositol // pentakisphosphate which is found to have anti-cancer effects by blocking the action of enzyme Phosphoinositide 3 kinase.

Tofu and cognitive function: food for thought. Grodstein F, Mayeux R, Stampfer MJ. J Am Coll Nutr. 2000 Apr;19(2):207-9. Review. PMID: 10763901 In addition, a plausible biologic hypothesis is generally an important part of judging epidemiologic relations. While high tofu intake may lead to lower plasma estrogen levels [12], we do not know how tofu influences estrogen levels in the brain; we also know very little about estrogen effects in men. Furthermore, data have not even consistently indicated that low endogenous estrogen levels are directly related to cognitive function in non-demented subjects [13]. The authors also posit a non-estrogen mediated hypothesis for the effects of tofu, namely that soy inhibits hippocampal tyrosine kinase and may block long-term potentiation (the likely mechanism by which humans learn and remember). Still, considerably more work must be done to substantiate this hypothesis. Finally, the single measures of outcome used in this study may have limited value, as cognitive function and brain structure change over time. Factors which predict these measures at one point may or may not be the same as those which predict decline over time; fundamentally, the public health interest is in preventing cognitive decline, as the steepness of the decline trajectory likely provides an early marker for risk of the more clinically relevant result-dementia.

Tumours with PI3K activation are resistant to dietary restriction. Nada Y. Kalaany & David M. Sabatini Nature. Published online 11 March 2009 doi:10.1038/nature07782

Vitamin D metabolites as clinical markers in autoimmune and chronic disease. Blaney GP, Albert PJ, Proal AD. Ann N Y Acad Sci. 2009 Sep;1173:384-90. PMID: 19758177 DOI: 10.1111/j.1749-6632.2009.04875.x

Dr Marco Falasca and colleagues have discovered that a natural compound, called inositol pentakisphosphate, which is found in most legumes as well as in wheat bran and nuts, blocks the activity of the enzyme. When they tested its action in mice with ovarian and lung cancer they found it not only blocked tumour growth but also enhanced the effect of other cancer-killing drug