Aberrant crypt foci (ACF) are clusters of abnormal tube-like glands in the lining of the colon and

rectum The rectum is the final straight portion of the large intestine in humans and some other mammals, and the gut in others. The adult human rectum is about long, and begins at the rectosigmoid junction (the end of the sigmoid colon) at the l ...

. Aberrant crypt foci form before

colorectal polyps A colorectal polyp is a polyp (fleshy growth) occurring on the lining of the colon or rectum. Untreated colorectal polyps can develop into colorectal cancer. Colorectal polyps are often classified by their behaviour (i.e. benign vs. malignant) ...

and are one of the earliest changes seen in the colon that may lead to

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...

. ACF are, as opposed to normal epithelial cells, apoptosis resistant. When looking for aberrant crypt foci with microscopy,

methylene blue Methylthioninium chloride, commonly called methylene blue, is a salt used as a dye and as a medication. Methylene blue is a thiazine dye. As a medication, it is mainly used to treat methemoglobinemia by converting the ferric iron in hemoglob ...

is used as a

staining Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology (microscopic study of biological tissues), in cytology (microscopic study of cells), and in ...

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. Resveratrol glucoside from transgenic alfalfa has been used for the prevention of aberrant crypt foci in mice.Resveratrol From Transgenic Alfalfa for Prevention of Aberrant Crypt Foci in Mice. Brian D. Kineman, E. Charles Brummer, Nancy L. Paiva and Diane F. Birt, Nutrition and Cancer, 2010, Volume 62, Issue 3, pages 351-361,

References

Digestive system neoplasia Pathology {{Oncology-stub