J Cancer 2012; 3:432-448. doi:10.7150/jca.4919

Review

Cell-free Circulating miRNA Biomarkers in Cancer

Meng-Hsuan Mo1, Liang Chen1, Yebo Fu1, Wendy Wang2, Sidney W. Fu1✉

1. Department of Medicine, Division of Genomic Medicine, and Department of Microbiology, Immunology and Tropical Medicine, The George Washington University School of Medicine and Health Sciences, Washington, DC, USA;
2. Cancer Biomarkers Research Group, Division of Cancer Prevention, NIH/NCI, Bethesda, MD, USA.

Abstract

Considerable attention and an enormous amount of resources have been dedicated to cancer biomarker discovery and validation. However, there are still a limited number of useful biomarkers available for clinical use. An ideal biomarker should be easily assayed with minimally invasive medical procedures but possess high sensitivity and specificity. Commonly used circulating biomarkers are proteins in serum, most of which require labor-intensive analysis hindered by low sensitivity in early tumor detection. Since the deregulation of microRNA (miRNA) is associated with cancer development and progression, profiling of circulating miRNAs has been used in a number of studies to identify novel minimally invasive miRNA biomarkers. In this review, we discuss the origin of the circulating cell-free miRNAs and their carriers in blood. We summarize the clinical use and function of potentially promising miRNA biomarkers in a variety of different cancers, along with their downstream target genes in tumor initiation and development. Additionally, we analyze some technical challenges in applying miRNA biomarkers to clinical practice.

Keywords: serum, cancer, miRNA, biomarker.

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How to cite this article:
Mo MH, Chen L, Fu Y, Wang W, Fu SW. Cell-free Circulating miRNA Biomarkers in Cancer. J Cancer 2012; 3:432-448. doi:10.7150/jca.4919. Available from http://www.jcancer.org/v03p0432.htm