Clancy Cillian, Joyce Myles R, Kerin Michael J
Discipline of Surgery, School of Medicine, National University of Ireland, Galway, Ireland.
Department of Colorectal Surgery, University College Hospital Galway, Galway, Ireland.
Cancer Biomark. 2015;15(2):103-13. doi: 10.3233/CBM-140456.
Abnormal levels of microRNAs (miRNAs) have been found in the blood or its components in a number of different cancers including colorectal cancer. In addition to being abundant in circulation, miRNAs show remarkable stability in both plasma and serum making miRNAs ideal markers for early detection in colorectal cancer. Several miRNAs have been identified as potential circulating biomarkers although none have been incorporated into clinical practice.
To identify the most consistently dysregulated circulating miRNAs in colorectal cancer patients according to current literature and postulate reasons for heterogeneity in results.
A literature review was performed using the electronic databases PubMed, Embase and the Cochrane Library.
The 6 circulating miRNAs most frequently found to be dysregulated in colorectal cancer are miR-18a-5p, miR-21-5p, miR-29a-5p, miR-92a-5p, miR-143-5p and miR-378-5p. There are, however, multiple studies with conflicting findings. Studies vary significantly in ethnicity of populations, use of endogenous controls, source of miRNAs (whole blood, serum and plasma) and methods of detection.
Circulating miRNAs are promising diagnostic biomarkers in colorectal cancer. Further studies identifying the source of tumour derived miRNAs in circulation, including identification of exosomal miRNA content, are required. Identifying pre-profiling factors affecting miRNA expression and determining stable endogenous controls will expedite the incorporation of miRNAs into clinical practice.
在包括结直肠癌在内的多种不同癌症的血液或其成分中，已发现微小RNA（miRNA）水平异常。miRNA不仅在循环系统中含量丰富，而且在血浆和血清中均表现出显著的稳定性，这使得miRNA成为结直肠癌早期检测的理想标志物。尽管尚未有miRNA被纳入临床实践，但已有几种miRNA被确定为潜在的循环生物标志物。
根据当前文献，确定结直肠癌患者中最一致失调的循环miRNA，并推测结果异质性的原因。
使用电子数据库PubMed、Embase和Cochrane图书馆进行文献综述。
在结直肠癌中最常发现失调的6种循环miRNA是miR-18a-5p、miR-21-5p、miR-29a-5p、miR-92a-5p、miR-143-5p和miR-378-5p。然而，有多项研究结果相互矛盾。这些研究在人群种族、内源性对照的使用、miRNA的来源（全血、血清和血浆）以及检测方法等方面存在显著差异。
循环miRNA是结直肠癌中有前景的诊断生物标志物。需要进一步开展研究，确定循环中肿瘤来源miRNA的来源，包括鉴定外泌体miRNA的含量。确定影响miRNA表达的预分析因素并确定稳定的内源性对照，将加速miRNA纳入临床实践。
