Science and Reason: Cancer, metabolism, and oncogenes

I want to call attention (somewhat belatedly) to a series of three very good tutorial blog posts at The Daily Transcript. Although they are nominally about changing views regarding cancer and its causes, they actually provide a nice overview of a number of important topics in molecular biology. Reading these posts will be a big help in understanding a lot of things written about here, in particular topics such as:

cancer, and how it is "caused" by various factors like metabolism and genetic mutations, and indirectly affected by other biological systems like the immune system
metabolism in general, and how problems with metabolism lead to disease conditions like diabetes and metabolic syndrome, perhaps even Alzheimer's disease
calorie restriction, and how it seems to play a role in longevity
stem cells – what makes them special, how they function biologically and may play a role in the process of cancer
important processes in cell biology, such as apoptosis, autophagy, and (of course) the cell cycle itself
general topics in molecular biology, such as growth factors, transcription factors, signaling cascades, and cell surface receptors

So here are the links, with a brief summary of each:

From Metabolism to Oncogenes and Back - Part I (3/17/08): Historical introduction to the subject. Explains how Otto Warbug had the idea, 100 years ago, that the way to understand cancer was through metabolism. Somewhat later, the discovery of the Rous Sarcoma Virus (1916), and much later, after the revolutionary understanding of DNA and modern molecular biology came about, the focus shifted to the role of oncogenes, tumor suppressors, and genetic mutations in cancer.
From Metabolism to Oncogenes and Back - Part II (3/21/08): More detailed look at the molecular biology of cancer, protein signaling pathways in general, and TOR signaling in particular. This part includes a great diagram of some of the more important signaling pathways as far as metabolism and cancer are concerned. Besides TOR, it clearly emphasizes the importance of the MAP kinase Ras, and the phosphoinositide signaling proteins PI3K, PTEN, and AKT.
From Metabolism to Oncogenes and Back - Part III (4/2/08): An even more technical summary of recent discoveries about metabolism, and the peculiar kind of metabolic activity found in cancer cells. It appears that a type of enzyme called pyruvate kinase, which occurs in various forms, plays a big role in cell metabolism and whether a cell uses available energy for making sugars, fats, or DNA.