Normal Cells To Cancer Cells

5. Normal Cells To Cancer Cells

Cancer is a fundamental derangement of the normal mechanisms controlling the division, placement and function of cells. Whereas normal cells divide and stop dividing after a certain fixed time, cancer cells do not. They do not “know” when their division is to be stopped and they proliferate in a disorderly fashion.

As soon as cells become cancerous they are no longer controlled by body mechanisms. Cancer cells proliferate and form a mass of cells. Cancer cells have different degrees of affinity for each other, which accounts partly for their propensity to metastasize. An invasive cancer cell is a cancer cell that has a great predilection for spreading rapidly and uncontrollably.

Even though our knowledge about the division of normal cells is limited, we do know that they stop growing when they touch each other if placed on a solid surface such as that of a glass slide. This mechanism of growth control is called contact inhibition. Cancer cells, however, growing in the same conditions, do not stop proliferating; they have lost contact inhibition. While normal cells grow on solid surfaces in single layers, cancer cells show less affinity for the solid surface and grow in irregular masses several layers deep.

Normal cells reside with one another and have a ”home” of their own. A kidney cell stays in the kidney and lung cell in the lung. Cancer cells may be said to belong nowhere, to have no proper residence, no “home.” We may compare the chemical composition of both normal and cancer cells, for they have the same components, although in slightly different amounts and relationships.

Cancer can be induced experimentally in animals by external agents called carcinogens. Once a cell has changed from normal to cancerous, its succeeding generations are cancerous too; this is true at the cellular level only. A cancer cell is a normal cell deranged by toxic substances and loses contact with the organism. It has been rendered “crazy” by poisoning.