Abnormal Cell Growth Leading to Cancer
Abnormal Cell Growth Leading to Cancer
Cancer is the second leading cause of death in the United States. Half of all men and one-third of all women in the U.S. will develop cancer during their lifetimes. Although it is common knowledge that cancer is generally inherited, this paper will further explore the causes and what happens on a cellular level when cancer develops in the human body.
Basics of signal transduction
Cell communication, or signal transduction, is simply the means by which cells in the body respond to signals coming from outside those cells. The purpose of this chemical communication is to coordinate functions inside the cell, between cells or between organs in the body, allowing us the means to respond to our external environment.
Normally, cell division is a very carefully regulated process that ensures the body has neither too few nor too many of a given cell type. Some cell types in the body wear out quickly and need to be continuously replaced as they die, such as most blood cells and cells lining the digestive tract. The production of these cells must be precisely regulated based on their rate of cell death so that the body has the exact number of cells it needs. (Kruh, 2000)
The relationship with cancer
Abnormal - or more specifically - uncontrolled, rapid cell growth is a central feature of cancer. Virtually every cancer is caused by mutations of DNA, the genetic material that controls how cells behave. Genes that regulate cell division are most susceptible to mutations, which may lead to abnormal cell growth.
Cancer is a disease of the genes - it arises from defects in certain genes, the genes that normally regulate cell growth and cell death. Some genes, known as oncogenes, promote normal cell growth. Other genes, known as tumor suppressor genes, have the opposite effect, to retard cell growth. The normal division of our cells is a delicate balance of positive and negative growth signals from these genes.
This balance may be upset by either the abnormal over activation of oncogenes or the abnormal inactivation of tumor suppressor genes. These genetic events may be caused by environmental toxins, random internal changes, and also may be inherited from a family who has a history of cancer where a defective growth-regulatory gene is passed down through generations.
Cell division can get out of control when damage to specific genes in the cell’s DNA results in abnormally...