Aberrant crypt foci
Encyclopedia
Aberrant crypt foci are clusters of abnormal tube-like glands in the lining of the colon
and rectum
. Aberrant crypt foci form before colorectal polyps and are one of the earliest changes seen in the colon that may lead to cancer
. ACF are, as opposed to normal epithelial cells, apoptosis
resistant. When looking for aberrant crypt foci with microscopy, methylene blue
is used as a staining agent .
The resulting figure is fairly easy to detect under the microscope at low magnification (x40) .
Chemically induced ACF in rodents have been used extensively to test chemicals and diets that might prevent colorectal cancer, and reported in more than 400 scientific articles . The "chemoprevention database" shows the results of all published scientific studies of chemopreventive agents, in people and in animals.
The relevance of ACF as a surrogate endpoint biomarker for cancer is controversial. Recently, several alternative precancerous lesions have been described (namely MDF, BCAC, and flat ACF), which might be better biomarkers than ACF
Colon (anatomy)
The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
and rectum
Rectum
The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...
. Aberrant crypt foci form before colorectal polyps and are one of the earliest changes seen in the colon that may lead to cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
. ACF are, as opposed to normal epithelial cells, apoptosis
Apoptosis
Apoptosis is the process of programmed cell death that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation...
resistant. When looking for aberrant crypt foci with microscopy, methylene blue
Methylene blue
Methylene blue is a heterocyclic aromatic chemical compound with the molecular formula C16H18N3SCl. It has many uses in a range of different fields, such as biology and chemistry. At room temperature it appears as a solid, odorless, dark green powder, that yields a blue solution when dissolved in...
is used as a staining agent .
The resulting figure is fairly easy to detect under the microscope at low magnification (x40) .
Chemically induced ACF in rodents have been used extensively to test chemicals and diets that might prevent colorectal cancer, and reported in more than 400 scientific articles . The "chemoprevention database" shows the results of all published scientific studies of chemopreventive agents, in people and in animals.
The relevance of ACF as a surrogate endpoint biomarker for cancer is controversial. Recently, several alternative precancerous lesions have been described (namely MDF, BCAC, and flat ACF), which might be better biomarkers than ACF