Finding Cancer Quick Facts is defining how carcinogens affect DNA and the best way to do that is try to understand how cigarette smoke influences DNA. Therefore we must understand the sequences of events that leads from smoke inhalation to formation of a tumor many year or decades later. One of the initial and most crucial events is damage of the genetic materials (DNA) by a cigarette smoke carcinogen.
This damage can under certain circumstances be corrected… by DNA repair mechanisms. However, if not repaired, these cells will attempt to duplicate their DNA during normal cell division; but are than impeded by the damage and will carry out an error – prone duplication process leading to gene mutations (changes on the gene.)
Such gene mutations are found many years later in the DNA of lung tumors. Gene mutations are particularly harmful “if” they occur in genes that controll cell division rates or genetic stability. According to current thinking, a number of genes need be mutated or functionally disabled before a normal cell loses all normal growth control mechanisms and is brought into a path of uncontrolled cell division and eventually leading to tumor growth.
Gene mutations have been found in genes such as p53, ras and p16 at a relatively high frequency in human lung cancer. One of these cigarette smoke carcinogens implicated in the development of lung cancer that also is implicated in the development of lung cancer is benzo[a]pyrene. Since benzo[a]pyrene is not the only carcinogen found in cigarette smoke and p53 is not the omly gene that gets damaged by these compounds.
The theme of DNA damage is caused by a number of cigarette smoke carcinogens, which genes and which positions within genes are targeted is anybodys guess. However, what is known is that cigarette smoking is the number one cause of death in the United States yearly. Not only, does smoking cause 30% of all cancers; but also, responsible for diseases and other illness (Emphysema, COPD and heart disease.)