Monday, February 11, 2013

Cancer #1: Not a bunch of dead cells

Cancer is a word that everyone has heard but not many people actually understand.

"How can they kill cells that are already dead?"

I have had multiple conversations with family members explaining that cancer cells are not dead cells, in fact that is the problem.

Every cell in your body has a purpose; "be bone" "pump the heart" "feel heat" "make enzymes" and so on.

Every cell in your body has the same DNA (deoxyribonucleic acid) that codes for your entire existence. What makes a bone cell a bone cell and heart muscle heart muscle are the genes it expresses. Simply put it can be thought of as light switches. All cells have each and every switch built in but only some get turned on, the ones that say "make this protein". Each gene codes for a specific protein, those proteins can be enzymes that break down other molecules or put other molecules together, receptors that sit in the cell membrane and wait for a signal, or proteins that make the cell do other things like move.

All cells have genes that tell them when to divide and when to die. Most cells divide rather slowly and stop when they touch other cells, a phenomenon called "contact inhibition". Cells will die when they are no longer useful or there are too many of the same kind.

When a cell divides it replicates its DNA to make an identical copy. Each and every time this happens there is the possibility for error. A simple typo can cause the wrong information to be passed from a parent cell to a daughter. Most of these errors are found and fixed before it can do any harm. And many errors that occur are in areas that code for nothing. However, occasionally an error will get by, and the new cell will be dysfunctional in some way.

"Your pigment is blue now" rather than green; relatively harmless. Often the consequences are imperceptible.

When this happens in certain parts of the genome, the ones that code for cell division and cell death, we see a different scenario, we get cancer. The gene that says "stop dividing" has been silenced, or the gene that says "time to die" is quiet. With cancer the cells lose the ability to stop dividing, they no longer die as they should. Thus they continue to replicate faster than they die and accumulate a large mass of cells. They lose their original function over time and stop resembling the cell they originally were.

These cells have a high metabolic rate since they are constantly dividing and require a large blood supply to fulfill their need for oxygen and nutrients. They are leeching the nutrients away from the rest of the body, and that is when you start to feel ill. The mass gets large enough to put pressure on other tissue causing pain; symptoms emerge.
With quick detection and quick diagnosis, treatments can be very effective in removing the cancer or at least returning the patient to a normal lifestyle. The best case scenario we all hope for after hearing the diagnosis.


In a future post we will discuss the difference between benign and malignant tumors, and what metastasis means. We will also explore what chemotherapy means and how it works.

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