Department of Medical Immunology and Genetics, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
Early diagnosis of cancer is still the key to effective treatment of cancer in patients with low clinical stages. Many developments of molecular techniques with new, related markers have been identified in tumors. Current approaches to the detection of cancer and to prediction of its outcome are invasive and unable to detect the early stages. Less invasive techniques for example blood or urine are opened of screening. Studies based on microsatellite instability, loss of heterozygosity are frequently demonstrated in tumor tissue. Furthermore, nucleic acids are released in body fluids provides a good way to monitor disease progression, staging and to predict outcomes. Mutation in DNA mitochondria genome is present in the plasma in cancer patients. Using Real time PCR the level of circulating nucleic acids in cancer patients are different compared with healthy subjects. It is noteworthy that alterations of mRNA, microRNA and lncRNA profiles could be useful marker for the clinicopathological parameter and for follow up after treatment or clinical intervention. Moreover, circulating exosomal miRNA have been correlated with tumor miRNA levels in cancer. Circulating exosomal miRNA could potentially be used for screening in asymptomatic patients. Up/down regulation of these miRNA are involved in carcinogenesis. Evaluations of miRNA or DNA in urine, tissue, blood and serum as a new biomarker for the diagnosis and chemoresistance or chemosensitivity. A panel of tumor specific genetic markers in fluid body with sensitivity and specifity are needed.
Keywords:Cancer, Cell-free nucleic acids, Body fluids.