The Diagnostic and Prognostic Role of microRNA in Colorectal Cancer - a Comprehensive review

Abstract

The discovery of microRNA, a group of regulatory short RNA fragments, has added a new dimension to the diagnosis and management of neoplastic diseases. Differential expression of microRNA in a unique pattern in a wide range of tumor types enables researches to develop a microRNA-based assay for source identification of metastatic disease of unknown origin. This is just one example of many microRNA-based cancer diagnostic and prognostic assays in various phases of clinical research.Since colorectal cancer (CRC) is a phenotypic expression of multiple molecular pathways including chromosomal instability (CIN), micro-satellite instability (MIS) and CpG islands promoter hypermethylation (CIMP), there is no one-unique pattern of microRNA expression expected in this disease and indeed, there are multiple reports published, describing different patterns of microRNA expression in CRC.The scope of this manuscript is to provide a comprehensive review of the scientific literature describing the dysregulation of and the potential role for microRNA in the management of CRC. A Pubmed search was conducted using the following MeSH terms, "microRNA" and "colorectal cancer". Of the 493 publications screened, there were 57 papers describing dysregulation of microRNA in CRC.

Papel de los micro-RNA en el cribado del cáncer colorrectal

“…En general, se ha objetivado que casi 300 micro-RNA se encuentran alterados en las muestras de tejido coló nico tumoral respecto a la mucosa normal, con una variabilidad importante respecto a los micro-RNA evaluados, nú mero de muestras empleadas y nú mero de micro-RNA alterados 16 .…”

miR-142-3p inhibits LPS-induced activation of NF-κB by targeting IRAK1 in colorectal cancer

“…Evidence suggests that miRNAs are involved in the development and progression of CRC [12][13][14]. miRNAs can function as tumor suppressors or oncogenes, thereby regulating the carcinogenesis of CRC [12].…”

Other Body Fluids as Non-invasive Sources of Cell-Free DNA/RNA

“…These include saliva, urine, amniotic fluid and bronchial lavage/ aspirates. Breast milk, tears, seminal fluid, peritoneal fluid and colostrums have all been mentioned as possible sources [1] together with fresh stools [2,3]. Some examples will be given concerning amniotic fluid, saliva, urine, cerebrospinal fluid and bronchial lavage/aspirates in order to show how these alternative sources of DNA/RNA have been exploited and for what purposes.…”