Introduction
Cancer is a genetic disease initiated by alterations in genes, such as oncogenes and tumor suppressors, that regulate cell proliferation, survival, and other homeostatic functions. In cancer cells, genes are either modified by mutations, which alter the function of the proteins they encode, or through epigenetics -- modifications to chromosomes that alter gene-expression patterns. This can occur through DNA methylation, and methylation, acetylation, or phosphorylation of histones and other proteins around which DNA is wound to form chromatin. Little is known about how these chemical modifications occur in the DNA of cancer cells, but they can affect the expression patterns of oncogenes or of tumor suppressor genes. For example, DNA methylation induces "epigenetic silencing" or the loss of expression of tumor suppressor genes, causing normal cells to be transformed into cancer cells.[1]
The conference recently held by the American Association for Cancer Research on Chromatin, Chromosomes, and Cancer Epigenetics in Waikoloa, Hawaii, brought together almost 300 of the world's leading researchers in this field. They discussed the chromosome regions and genes that most commonly undergo epigenetic alterations in cancer cells, ways of identifying epigenetic modifications in cancer cells, and possible therapies to reverse this process.
© 2004 Medscape
Comments