1. Digestive Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran; Molecular Medicine Department, Pasteur Institute of Iran, Tehran, Iran. Electronic address: email@example.com 2. Department of bilology,centeral tehran branch,Islamic Azad University,Tehran,Islamic Republic of Iran
Colorectal cancer is the third most prevalent cancer in the world. globally it has been estimated that about 1.4 million new cases of colorectal cancer are diagnosed every year. colorectal cancer is a multifactorial disease that arise due to genetics as well as epigenetic alternation in a number of oncogenes, tumor suppressor genes, mismatch repair genes, as well as cycle regulating genes in signaling pathway. these genes regulate the proliferation of cells in mucosa. small amounts of free dna circulate in the body fluids of healthy and diseased people while increased concentrations of dna can be detected in the body fluids of cancerous patients
It is review article
These genetic changes in cell free dnas are seen as mutations in tumor suppressor genes or oncogenes or chromosomal abreactions. also epigenetic changes can be seen in dna as methylation, histone modification or rna changes. alterations in the rna profile can be seen as different profile of mirna, exososomes or long non coding rnas. these changes in patients are different from normal healthy people.
These changes in patients are different from normal healthy people. they can be considered as biomarkers for diagnosing different types of cancer or choosing the best plan of therapies.