Mechanisms Of Interaction Of Aging And Carcinogenesis

Cancer is a common denomination given to a number of different diseases. Common features to all cancers include 23,68

potential immortality of cancer cells due to avoiding apoptosis ability to invade surrounding tissues due to reduced sensitivity to signals from neighboring cells aimed to offset proliferation • cell de-differentiation with re-appearance of some embryonal proteins (e.g. a-fetoprotein) in cytoplasm growth signals autonomy, which allows cancer cells to proliferate in absence of outside signals due to only inner growth signals release of growth factors and promotion of angiogenesis in tissue, which favor tumor growth and metastasis increase in metabolism and number of mitochondria in cancer cells

Gene mutations, as well as changes in regulation of gene expression, which can produce these typical features, were suggested to be

key genetic events leading to cancer development , , . Down regulation of apoptosis gene, p53, as well as upregulation of myc and ras genes, which may favor excessive proliferation, could be examples of such events 69,70.

Both carcinogenesis and aging are associated with genomic alterations, which may act synergistically in causing cancer 23,68-71. In particular, three age-related changes in DNA metabolism may favor cell transformation and cancer growth. These changes are genetic instability, DNA hypomethylation, and formation of DNA adducts.

Genetic instability involves activation of genes that are normally suppressed, such as the cellular proto-oncogenes, and/or inactivation of some tumor suppression genes (p53, Rb, etc.) 23'31. DNA hypomethylation is characteristic of aging, as well as of transformed cells. Hypomethylation, a potential mechanism of oncogene activation, may result in spontaneous deamination of cytosine and consequent base transition, i.e., substitution of the pair thymine:adenine. Accumulation of inappropriate base pairs may

10 Ways To Fight Off Cancer

10 Ways To Fight Off Cancer

Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.

Get My Free Ebook


Post a comment