What Are Cancer Cells?

How Do Cancer Cells Form

Cancer cells are formed by an error in the reproduction of a normal cell. When a normal cell divides itself to produce two identical descendant cells, there are a lot of accurate processes that occur. To simplify the explanation, let’s say that a certain component of the cell (RNA) ‘tells’ to another component (DNA) how to duplicate itself. Now, the elements that form the DNA (Citosin, Guanine, Timine and Adenine, or C, G, T, and A, respectively) must combine in exactly a certain sequence, with no errors. Under some circumstances (effects of radiation or certain chemicals, for instance) errors do occur. This causes a defective cell that most times is unable to survive, and is subsequently destroyed. But sometimes the defective cell is actually very capable of living and reproducing on its own. This cancer cell then begins reproducing without control or limit.

Characteristics Of Cancer Cells

Cancer cells grow in a disorganized and uncontrolled way. They are incapable of differentiating tissues, so for cancer cells it is exactly the same to reproduce in muscular tissue, blood or any other tissue. They have a mutated cell surface that doesn’t tell them to stop the division process when in contact with each other, so they can grow in multiple layers.
In addition, cancer cells can produce enzymes that cause or ease their movement, so basically they can travel from one place to another. They also have special receptors that allow them to stick to basement membranes and release an enzyme that degrades and destroys it, making it possible for the cell to get into the blood stream or lymphatic system.

How Are Cancer Cells Different From Normal Cells

There are many differences between a normal, healthy cell and a cancer cell. For instance, a normal cell can divide itself about 48-50 times before it dies, which means that every cell has a certain growth limit, an ‘age’ at which it will die. Cancer cells don’t have this limitation, which means that a single cancer cell can divide itself unlimited times without dying.
Normal cells also have what is called ‘contact inhibition’: they stop reproducing when they come in contact with each other, or with other type of tissue. This ensures that, for instance, muscle cells will not grow in the skin, or vice versa. Cancer cells are unable of this distinction, and they continue growing regardless of the tissue they are in contact with. Their reproduction eventually disrupts the normal cycle of the surrounding healthy cells and causes them to stop reproducing and die.

Another very important difference between a normal cell and a cancer cell is that healthy cells stay in place, but cancer cells have the ability to detach themselves from a group of cells and travel to other areas, where it can continue growing.

How Do Cancer Cells Develop Into Tumors And Cancers

When cells group together abnormally, a tumor is formed. If those cells are cancer cells, then the tumor is called a malignant tumor, or cancer.  As cancer cell reproduction continues the tumor growths bigger and bigger. It usually causes surrounding blood vessels to branch into the tumor due to the action of a growth enzyme released by the bad cells. This is known as ‘vascularization’.

As said above, a cancer cell is able to detach itself from the tumor and travel to other areas, where they can start other tumors. This is called ‘metastasis’, and when it happens the patient can no longer be cured by surgery, as new tumors will reappear in very different areas of the body.

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