Figure 2 illustrates the impact of DNA and histone methylation (addition of a methyl group which is one carbon and 3 hydrogen at- oms) on gene expression. Effectually, the expression of the gene is silenced because of epigenetic modifications that have taken place. DNA methylation and histone modification may occur independently of one another or concomitantly. In general, methylation or modification will prevent expression of the gene. This may be a good thing or a bad thing depending upon the function of the gene product.
Figure 2. DNA and histone methylation with resultant gene silencing.
Epigenetic events can control normal cellular processes and abnormal events. Epigenetic mechanisms are essential for embryonic devel- opment and cell differentiation among other things. If a breakdown of an epigenetic mechanism takes place that pertains to cell differentia- tion, a tumor cell may develop. Furthermore, some epigenetic modifications alter the expression of tumor suppressor genes which prevent some cancers from developing. Fortunately, we are beginning to understand the environmental influences that impact epigenetics and the development of cancer. These, in part, include diet/obesity, physical activity, and stress.
NaturalNutmeg.com 13
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52