Search results
Results from the WOW.Com Content Network
Peto's paradox is the observation that, at the species level, the incidence of cancer does not appear to correlate with the number of cells in an organism. [1] For example, the incidence of cancer in humans is much higher than the incidence of cancer in whales, [2] despite whales having more cells than humans.
Scientist Otto Warburg, whose research activities led to the formulation of the Warburg hypothesis for explaining the root cause of cancer.. The Warburg hypothesis (/ ˈ v ɑːr b ʊər ɡ /), sometimes known as the Warburg theory of cancer, postulates that the driver of carcinogenesis (cancer formation) is insufficient cellular respiration caused by insult (damage) to mitochondria. [1]
DNA damage in non-replicating cells, if not repaired and accumulated can lead to aging. DNA damage in replicating cells, if not repaired can lead to either apoptosis or to cancer. The schematic diagram indicates the roles of insufficient DNA repair in aging and cancer, and the role of apoptosis in cancer prevention.
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)).
Cells have developed complex and efficient repair mechanisms to fix the lesions. In the case of free radical attack on DNA, base-excision repair is the repair mechanism used. Hydroxyl radical reactions with the deoxyribose sugar backbone are initiated by hydrogen abstraction from a deoxyribose carbon, and the predominant consequence is eventual ...
Free radical damage within cells has been linked to a range of disorders including cancer, arthritis, atherosclerosis, Alzheimer's disease, and diabetes. [13] There has been some evidence to suggest that free radicals and some reactive nitrogen species trigger and increase cell death mechanisms within the body such as apoptosis and in extreme ...
In cancer cells, major changes in gene expression increase glucose uptake to support their rapid growth. Unlike normal cells, which produce lactate only when oxygen is low, cancer cells convert much of the glucose to lactate even in the presence of adequate oxygen. This is known as the “Warburg Effect.”
Cancer is caused by genetic changes leading to uncontrolled cell growth and tumor formation. The basic cause of sporadic (non-familial) cancers is DNA damage and genomic instability. [1] [2] A minority of cancers are due to inherited genetic mutations. [3] Most cancers are related to environmental, lifestyle, or behavioral exposures. [4]