Review
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World J Gastroenterol. Sep 7, 2014; 20(33): 11727-11735
Published online Sep 7, 2014. doi: 10.3748/wjg.v20.i33.11727
MicroRNAs as novel predictive biomarkers and therapeutic targets in colorectal cancer
Verena Stiegelbauer, Samantha Perakis, Alexander Deutsch, Hui Ling, Armin Gerger, Martin Pichler
Verena Stiegelbauer, Samantha Perakis, Armin Gerger, Division of Clinical Oncology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria
Alexander Deutsch, Division of Hematology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria
Hui Ling, Martin Pichler, Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, United States
Author contributions: Stiegelbauer V designed research and wrote the paper; Perakis S designed research and wrote the paper; Deutsch A designed research and wrote the paper; Ling H designed research and wrote the paper; Gerger A designed research and wrote the paper; Pichler M designed research and wrote the paper.
Supported by Erwin Schroedinger Scholarship of the Austrian Science Funds, No. J3389-B23 (all to Pichler M)
Correspondence to: Martin Pichler, MD, Division of Clinical Oncology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria. MPichler@mdanderson.org
Telephone: +43-316-3853115 Fax: +43-316-3853115
Received: January 17, 2014
Revised: April 4, 2014
Accepted: June 2, 2014
Published online: September 7, 2014
Abstract

Colorectal cancer (CRC) is the third most common cancer in western countries. Despite significant improvement in available treatment options, CRC still remains the second leading cause of cancer-related death. Traditionally, 5-fluorouracil has been used as the main chemotherapy drug for treatment of metastatic CRC (mCRC). However, during the last two decades more effective chemotherapeutic agents such as oxaliplatin, irinotecan and the monoclonal antibodies cetuximab, panitumumab and bevacizumab have been used in clinical practice. More recently, the therapeutic armamentarium has been supplemented by the monoclonal antibodies bevacizumab, cetuximab and panitumumab as well as the protein-trap aflibercept and the small molecule multi-kinase inhibitor regorafenib. One of the major problems for the management of CRC is the inherent or acquired resistance to therapeutic approaches. The discovery of microRNAs (miRNAs), a class of small, endogenous, non-coding, single-stranded RNAs that play a role as post-transcriptional regulators, has added new dimensions to the diagnosis and treatment of cancer. Because miRNAs are important regulators of carcinogenesis, progression, invasion, angiogenesis and metastases in CRC, they might serve as potential predictive and prognostic factors and even as therapeutic targets themselves. Several miRNAs are already known to be dysregulated in CRCs and have been linked to biological processes involved in tumor progression and response to anti-cancer therapies. This review summarizes current therapeutic approaches for treating CRC and highlights the role of miRNAs as novel predictive biomarkers and potential drug targets in CRC patients.

Keywords: Colorectal cancer, MicroRNAs, 5-fluorouracil, Epidermal growth factor receptor, Targeted therapy

Core tip: In this review article, we summarize the status quo of the current literature regarding microRNAs and their role in resistance against anti-cancer drugs in colorectal cancer. This Review Article explains how microRNAs influence colorectal cancer, and how these small molecules might be useful as predictive factors and drug targets by themselves.