Re:The language of cells (Score 3, Informative)

This post responds to the entire thread above.

The nature of genetic diseases is such that a even though there may be no survival benefits to a certain trait, it is propagated in the gene pool for multiple generations until it either mutates into a useful trait, or is finally selected out of the population. The genetics of cancer is such that cancers fall into two broad classes. Quick, very deadly cancers of the young, which come from usually a single serious mutation, and slower cancers of the old, which come from a lifelong accumulation of broken genes. In the young, like all inheritable diseases, are heavily selected against, evolutionarily speaking. In the old, mutations occur from all the various substances, stressors and random mutations that we collectively call carcinogens. The very process of living and interacting with one's environment can lead to mutations which lead to cancer. So it is not necessary that the specific mutations have any benefit, it is the very act of mutation that has a benefit.

In some cases the original cancerous cell may not be technically malfunctioning. That cell may be responding appropriately to surrounding tissue which has become numb and nonfunctional. This can be seen in bone cancers where the osteoblast count is at extreme low levels. The remaining osteoblasts are tired, overworked, stressed, and more than a little frightened by the absence of their comrades. Those cells begin exhibiting chemical signs of that stress meant to recruit the repropagation of other osteoblasts. If the situation isn't remedied, however, it's very easy to think that the osteoblast is evilly trying to metastasize. In tissues of high cell censity (kidney, pancreas, stomach, intestine, brain) it's most likely that the cancer is a result of a malfunctioning immune system. In a tissue of low cell density (bone) it's most likely that the cancer is a result of a deficiency in the tissue itself--maybe a logical sign of natural aging.

This statement is grossly erroneous. Cancer cells differ from neighbouring cells moreso than just dividing more. There are two key stages. The first is mutations that lead to the cell proliferating (dividing) uncontrollably. This leads to tumors (intitially benign). The second and truely cancerous stage is when the cell also loses the differentiation. This can progress until the cells begin to grow into nearby tissue (thus destroying it) or lossen from the extracellular matrix and begin to spread throughout the body. The researchers address that this last process is more complex than previously thought because the cancer cells secrete fibronectin and this prepares areas to downstream of the cancer. When the cells dislodge from the cancer and flow, they attach to areas that are ready to accept them. The most important thing is that cancer is is a disease caused by genetic mutations. The cells ARE malfunctioning.

Finally, the repair mechanisms of the body are limited. Our immune system DOES kill cancerous cells, when the present appropriate signs, but they are not killed outright because they dont have any foreigness to them. The immune system can only do so much to fight off cells that they recognize as part of the body without attacking the body in normal situations, as well. This is why cancer is so powerful. The cells have mutated to a point where they are grossly malfunctioning and are killing the body, but the immune system cant differentiate them sufficiently to stop them!