Wednesday, May 09, 2007

Autophagy and cancer

This is a new cellular mechanism I did not know about: autophagy. Nature's issue of April 12th (I am bit behind I know) has an interesting article in the section Q&A on autophagy and its role in cancer.

Autophagy is the process by which cells degrade faulty or redundant components. It is used by cells when they need to reuse molecules for other uses and also it plays an important role in complementing apoptosis. Both apoptosis and autophagy are connected to cell death but in the case of autophagy cell death is not always the outcome although it can be a substitute when the apoptotic mechanism is crippled. In that case the cell literally eats itself to death.

The image bellow comes from the article. Autophagy has the potential of being useful for cancer supression but also for cancer promotion. The balance is important, too little and you get cell death when the cell cannot produce things it needs by reusing parts of itself. Too much of it and you also get cell death since the cell can eat itself. Altering this balance in a tumour cell could be the source of a new therapy although as usual it is important to remember that cells might evolve mechanisms to avoid the trouble of autophagy, maybe by inactivating the atophagy mechanism all together. Even in that case the tumour cell would be less capable of surviving in situations of stress since it would not be able to recycle material.

Autophagy seems to be a mechanism whose precise role in cancer has not been fully studied yet but could be a promising extra target for a multi target therapy that could hinder cancer evolution and growth.

Monday, May 07, 2007

Evolution and medicine

Catriona MacCallum, an editor at PLoS Biology has posted the following essay (being PLoS, it is available to everybody) about medicine and evolution.

According to the article, physicians do not get much of a training in evolution as a method to study the origin of diseases. That is because most of the training of physicists is not to make them good scientists but to make them good at treating patients. Quoting the article: "does a mechanic need to understand the origins, history and technological advances that have gone into the modern motor vehicle in order to fix it?".

This approach is not entirely wrong and once can treat things that are the result of an evolutionary process without having to spend too much time studying evolution. A different thing is when the disease is not a result of evolution but they are evolution itself. They never mention cancer in the article but cancer and infectious diseases are clear cases of diseases in which evolution should be dealt with if the disease is to be cured or even contained. Without an understanding of evolution a physician will be unable to understand how the bacteria or cancer cells will react and evolve when a treatment is used or what phenotypical traits are more likely to be evolved and thus cause problems to or be exploited by the medical community.