Cancer Cell Biology & Genetics
The cell is the structural and functional unit of life. It is the smallest structure of the body capable of performing all of the processes that define life. Each of the organs in the body, such as the lung, breast, colon, and brain, consists of specialized cells that carry out the organ's functions such as the transportation of oxygen, digestion of nutrients, excretion of waste materials, locomotion, reproduction, thinking, etc.
Cancer is basically a disease of uncontrolled cell division. Its development and progression are usually linked to a series of changes in the activity of cell cycle regulators. For example, inhibitors of the cell cycle keep cells from dividing when conditions aren’t right, so too little activity of these inhibitors can promote cancer. Similarly, positive regulators of cell division can lead to cancer if they are too active. In most cases, these changes in activity are due to mutations in the genes that encode cell cycle regulator proteins.Cancer cells behave contrtary to normal cells in the body. Many of these differences are related to cell division behavior. For example, cancer cells can multiply in culture (IN VITRO) without any growth factors, or growth-stimulating protein signals, being added. This is different from normal cells, which need growth factors to grow in culture.
Cancer cells also ignore signals that cause them to stop dividing. For instance, when normal cells grown in a dish are crowded by neighbors on all sides, they will no longer divide. Cancer cells, in contrast, keep dividing and pile up on the top of each other in many layers.