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Question: How can you tell the difference between a cancer cell and a regular cell?
Answer: This is a great question that I actually discussed with the students in my Cancer Biology class and got their feedback in how to answer it.
Regular (or normal) cells are under specific control for growth in our bodies. Most normal cells don't divide except early in development. Some still do, like those making hair and lining your stomach and intestines.
When normal cells are old, are not needed anymore or are damaged, these cells die as part of a normal process in our bodies. Cancer cells are different from normal cells because they have lost some of this control. There are many types of cancer cells, but there are some generalizations that can be made about them all.
First, most normal cells once they make contact with other cells will stop growing (we call this contact inhibition). Most cancer cells do not stop growing when they contact another cell and keep growing and dividing indefinitely. This makes a benign tumor at this site that can cause a blockage in the normal tissue.
Second, there are two major types of genes that are different in cancer cells. There are genes that promote cell growth and others that promote cell death. Cancer cells often turn on (or make more of) the genes that promote cell growth while turning down (or making less of) the ones that promote cell death. In that way, they can get around the controls that our normal cells have when they grow in a tissue.
The final important difference between normal and cancer cells that I will discuss is that the cancer cells can move from their original location and make tumors in other places of your body. This is called metastasis and is one of the most life threatening aspects of getting cancer. Metastasis is a complicated process that involves the cancer cells generally coming off from their original tumor, getting into the blood stream, getting out of the bloodstream in another place in the body, and starting a tumor at that new location.
During the steps in metastasis, the cancer cells have to 'let go' of their normal hold on the surrounding tissue and be able to live in a free floating environment like the blood for some time. Most cells die if that were to happen to them so there are other differences between normal and cancer cells that must allow the latter cells to grow under those conditions.
When the cancer cells start to invade other tissues, most doctors call the condition cancer, although in biological research we call the cells growing without control in their original location cancer cells. Thus, there are very many differences between cancer and normal cells, some of which we understand and use to control the disease. But, there are many other differences that we don't understand, so much research to combat cancer is progressing on all fronts, including in my laboratory at Binghamton University.
Other institutions such as the American Cancer Society (ACS) are devoted to cancer research, contributing to many important discoveries that have led to a better understanding of cancer and cancer treatment.
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