Search results
Results from the WOW.Com Content Network
This is a step toward tumor progression. [2] [3] In order for a tumor cell to survive, it must decrease its expression of tumor suppressor genes such as p53, BRCA1, BRCA2, RB1, or the fas receptor. [4] [5] A tumor suppressor would trigger an apoptotic pathway in a cancer cell if there were DNA damage, polyploidy, or uncontrolled cell growth.
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]
Under this model, cancer arises as the result of a single, isolated event, rather than the slow accumulation of multiple mutations. [4] The exact function of some tumor suppressor genes is not currently known (e.g. MEN1, WT1), [5] but based on these genes following the Knudson "two-hit" hypothesis, they are strongly presumed to be suppressor genes.
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]
A mutation to only one tumor suppressor gene would not cause cancer either, due to the presence of many "backup" genes that duplicate its functions. It is only when enough proto-oncogenes have mutated into oncogenes, and enough tumor suppressor genes deactivated or damaged, that the signals for cell growth overwhelm the signals to regulate it ...
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.”
Since cancer is a genetic disease, two genomic events underlie acquired drug resistance: Genome alterations (e.g. gene amplification and deletion) and epigenetic modifications. Cancer cells are constantly using a variety of tools, involving genes, proteins, and altered pathways, to ensure their survival against antineoplastic drugs.
A tumor suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell during cell division and replication. [1] If the cell grows uncontrollably, it will result in cancer . When a tumor suppressor gene is mutated, it results in a loss or reduction in its function.