Alternative route of colorectal cancer
The hereditary colorectal cancer syndrome is commonly known as familial adenomatous polyposis coli (FAP), where hundreds of polyps are found. This is associated with APC mutation.
There is another kind of hereditary predisposition of colon cancer where there is any increase in the number of polyps. The patient with this condition is called hereditary nonplyposis colorectal cancer or HNPCC. In these cases the tumor cells exhibit a normal number and karyotypes of the chromosomes.
The DNA repairing mechanism is one of the important events in the cellular function. Because of the absence of proof reading proteins, spontaneous mutation of the remaining functional gene produces a clone of somatic cells that accumulate mutations unusually rapidly. Thus most cancers arise from cells deficient in mismatch proof reading, therefore, have a greatly enhanced chance of becoming cancerous. We are fortunate that most of us inherit two good copies of each gene that encodes a mismatch proof reading protein. Mutations in any one of this gene inevitable DNA replication error and immediately elevate the spontaneous mutation rate by a hundred fold or more. These genetically unstable cells allow a clone of cells to progress malignancy. This genetic instability produces changes in the chromosomes; because the changes occur in short mono or dinucleotide repeat. This type of mutation in mismatch repair genes are found in about 15% of colorectal cancer, with no inheritable mutation and the chromosome karyotype is also normal.
Related Posts
Genes and Cancer (0)
The genes whose mutation contribute to the causation of cancer are known as cancer critical genes. T...
When the most types of mammalian cells are cultured in a dish in presence of serum, they adhere to t...
Both primary tumors and metastases, for their growth, formation of new blood vessels i.e., angiogene...
The cells are separated by a physical barrier, called basal lamina, which underlies layers of epithe...
Carcinogenesis appears to be linked with autogenesis, because, the aberrations in the cancer cell is...
It is fact that one transformed cell is enough to produce a cancer, i.e., the cancerous cells are in...
The older animals and humans have some localized growth of tissue, having cells that are closely res...
1. Changes in glycosidation of lipids and proteins: The Golgi complex plays a central role in the bi...
1. Immortalization of cancer cell: Cancer cells are characterized by immortalization; they overcome ...
1. The tumor cells are much rounded in shape compared to normal cells. 2. Mitochondrial size is said...
