Most of the time in most cells of the body, the great majority of genes are silenced, locked away within the compacted but orderly material that makes up chromosomes. Estimates are that only about 10 percent of the roughly 25,000 genes in the human genome are activated, or "on," at any given time in a particular cell - the default setting for most genes is "off," or repressed.
Reliable gene silencing is vital to the health of an organism. Improperly activated genes can and do lead to cancer, for example. Gene silencing is also thought to protect the genome from viruses and other potentially damaging entities, thus preserving genetic integrity.
For the complete article click here. from medicalnewstoday.com
There is a lot of drug research going on in this area.
Nutrients can also effect gene expressison. The following comes from a talk I heard by Jeane Wallace Phd CNC. There is excellent information on this site. I have added the hot links.
Promoting Gene Stability
GOAL: Control chronic excessive oxidation, which may promote genetic instability and
aggressive tumor behavior.
TESTING: Assessments of Redox balance. Functional Liver Detoxification (Phase I:
Methylation status (homocysteine). For an explanation of the relationship of homcysteine, methylation and cancer click here. For a 45 minute audio powerpoint explanation of of functional testting with Organic acids click here.
DIET: Diet goal target ≥ 5,000-7,500 ORAC/day
• Antioxidant nutrients (carotenoids, tocopherols/tocotrienols)
• Anti-inflammatory agents
• Methylating agents (further explanation of methylation to cancer click here.)
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Louw DF, Bose R, Sima A, Sutherland GR: Evidence for a high free radical state in low-
astrocytomas. Neurosurgery, Nov 1997;41(5):1146-51.
Maley CC, Galipeau PC, Li X, et al: The combination of genetic instability and clonal expansion
progression to esophageal adenocarcinoma. Cancer Res, Oct 15, 2004;64:7629-33.