Search results
Results from the WOW.Com Content Network
A cancer syndrome or family cancer syndrome is a genetic disorder in which inherited genetic mutations in one or more genes predisposes the affected individuals to the development of cancers and may also cause the early onset of these cancers. Although cancer syndromes exhibit an increased risk of cancer, the risk varies.
Inflammation-induced ROS that cause DNA damage can trigger apoptosis, [52] [53] but may also cause cancer if repair and apoptotic processes are insufficiently protective. [45] Bile acids, stored in the gall bladder, are released into the small intestine in response to fat in the diet. Higher levels of fat cause greater release. [54]
The central role of DNA damage and epigenetic defects in DNA repair genes in carcinogenesis. DNA damage is considered to be the primary cause of cancer. [17] More than 60,000 new naturally-occurring instances of DNA damage arise, on average, per human cell, per day, due to endogenous cellular processes (see article DNA damage (naturally occurring)).
The likely major underlying cause of mutations in cancer is DNA damage. [citation needed] For example, in the case of lung cancer, DNA damage is caused by agents in exogenous genotoxic tobacco smoke (e.g. acrolein, formaldehyde, acrylonitrile, 1,3-butadiene, acetaldehyde, ethylene oxide and isoprene). [25]
This advantage to the cell is disadvantageous to the whole organism because such mutant cells can give rise to cancer. Thus, DNA damage in frequently dividing cells, because it gives rise to mutations, is a prominent cause of cancer. In contrast, DNA damage in infrequently-dividing cells is likely a prominent cause of aging. [17]
A metabolite of benzopyrene forms an intercalated DNA adduct, at center. In molecular genetics, a DNA adduct is a segment of DNA bound to a cancer-causing chemical. This process could lead to the development of cancerous cells, or carcinogenesis. DNA adducts in scientific experiments are used as biomarkers of exposure.
As examples, DNA damaging effects have been reported for acrolein, [14] formaldehyde, [15] and acrylonitrile. [16] Breast cancer is the second most frequent cancer worldwide on a yearly basis [(1.38 million cases, 10.9% of all cancer cases), and ranks 5th as cause of death (458,000, 6.1% of all cancer deaths)]. [12]
Although silencing of some genes in cancers occurs by mutation, a large proportion of carcinogenic gene silencing is a result of altered DNA methylation (see DNA methylation in cancer). DNA methylation causing silencing in cancer typically occurs at multiple CpG sites in the CpG islands that are present in the promoters of protein coding genes.