What two main genetic pathways are associated with the development of colon cancer?
The chromosomal instability pathway (CIN) and microsatellite instability pathway (MSI) are the two recognized pathways of carcinogenesis in CRC. In the 1980s researchers proposed a four-step progression of gene alterations in colonic epithelium.
What mutation causes colorectal cancer?
GREM1 gene mutations are most common in individuals of Ashkenazi Jewish ancestry and cause an increased risk for various types of colon polyps and colorectal cancer.
Why do genetic defects in the APC gene make colorectal cancer more likely to occur?
In many cases, the first mutation occurs in the APC gene. This leads to an increased growth of colorectal cells because of the loss of this “brake” on cell growth. Further mutations may then occur in other genes, which can lead the cells to grow and spread uncontrollably.
What does BRAF stand for?
BRAF is a human gene that encodes a protein called B-Raf. The gene is also referred to as proto-oncogene B-Raf and v-Raf murine sarcoma viral oncogene homolog B, while the protein is more formally known as serine/threonine-protein kinase B-Raf.
What happens if APC gene is mutated?
People with mutations in the APC gene have familial adenomatous polyposis (FAP) or attenuated FAP (AFAP). You have an increased chance to develop multiple gastrointestinal polyps, colorectal cancer, and possibly other cancers. There are risk management options to detect cancer early or lower the risk to develop cancer.
How is APC a tumor suppressor?
The APC protein acts as a tumor suppressor, which means that it keeps cells from growing and dividing too fast or in an uncontrolled way. It helps control how often a cell divides, how it attaches to other cells within a tissue, and whether a cell moves within or away from a tissue.
What is the most common BRAF mutation?
More than 97% of BRAF mutations are located in codon 600 of the BRAF gene. The most common mutation (in up to 90% of cases) is the result of a transversion of T to A at nucleotide 1799 (T1799A), which results in a substitution of valine (V) for glutamic acid (E) at position 600.
What is the major cause of colon cancer?
Diet—The risk is higher for those who eat a high-fat diet, a lot of processed meat or red meat. Aim for a diet rich in fruits, vegetables and fiber. Drinking—Moderate to heavy alcohol consumption, and even light to moderate drinking, may raise the risk of colorectal cancer.
