Galanopoulos M, Tsoukalas N, Papanikolaou IS, Tolia M, Gazouli M, Mantzaris GJ. Abnormal DNA methylation as a cell-free circulating DNA biomarker for colorectal cancer detection: A review of literature. World J Gastrointest Oncol 2017; 9(4): 142-152 [PMID: 28451061 DOI: 10.4251/wjgo.v9.i4.142]
Corresponding Author of This Article
Nikolaos Tsoukalas, MD, MSc, PhD, Medical Oncologist, MSc in Bioinformatics, Department of Medical Oncology, Veterans Hospital (417 NIMTS), Gennimata N. 10-12 Ampelokipi, GR 11524 Athens, Greece. tsoukn@yahoo.gr
Research Domain of This Article
Oncology
Article-Type of This Article
Review
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
World J Gastrointest Oncol. Apr 15, 2017; 9(4): 142-152 Published online Apr 15, 2017. doi: 10.4251/wjgo.v9.i4.142
Abnormal DNA methylation as a cell-free circulating DNA biomarker for colorectal cancer detection: A review of literature
Michail Galanopoulos, Nikolaos Tsoukalas, Ioannis S Papanikolaou, Maria Tolia, Maria Gazouli, Gerassimos J Mantzaris
Michail Galanopoulos, Gerassimos J Mantzaris, Department of Gastroenterology, “Evaggelismos-Ophthalmiatreion Athinon-Polycliniki”, GR 10676 Athens, Greece
Nikolaos Tsoukalas, Department of Medical Oncology, Veterans Hospital (417 NIMTS), GR 11524 Athens, Greece
Ioannis S Papanikolaou, Hepatogastroenterology Unit, Second Department of Internal Medicine and Research Institute, Attikon University General Hospital, Medical School, National and Kapodistrian University of Athens, GR 12461 Athens, Greece
Maria Tolia, Department of Radiotherapy/Radiation Oncology, Faculty of Medicine, School of Health Sciences, University of Thessaly, GR 41110 Larissa, Greece
Maria Gazouli, Department of Basic Medical Sciences, Laboratory of Biology Medical School, National and Kapodistrian University of Athens, GR 11527 Athens, Greece
Author contributions: Galanopoulos M and Tsoukalas N contributed equally to this work; all authors contributed to this paper with conception and design of the study, literature review and analysis, drafting and critical revision and editing, and final approval of the final version.
Conflict-of-interest statement: No potential conflicts of interest. No financial support. All the authors declare that they have no conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Nikolaos Tsoukalas, MD, MSc, PhD, Medical Oncologist, MSc in Bioinformatics, Department of Medical Oncology, Veterans Hospital (417 NIMTS), Gennimata N. 10-12 Ampelokipi, GR 11524 Athens, Greece. tsoukn@yahoo.gr
Telephone: +30-697-7366056 Fax: +30-210-7237578
Received: July 28, 2016 Peer-review started: August 1, 2016 First decision: December 1, 2016 Revised: December 28, 2016 Accepted: March 12, 2017 Article in press: March 14, 2017 Published online: April 15, 2017 Processing time: 133 Days and 7 Hours
Abstract
Colorectal cancer (CRC) is one of the most prevalent malignancies in the world. CRC-associated morbidity and mortality is continuously increasing, in part due to a lack of early detection. The existing screening tools such as colonoscopy, are invasive and yet high cost, affecting the willingness of patients to participate in screening programs. In recent years, evidence is accumulating that the interaction of aberrant genetic and epigenetic modifications is the cornerstone for the CRC development and progression by alternating the function of tumor suppressor genes, DNA repair genes and oncogenes of colonic cells. Apart from the understanding of the underlying mechanism(s) of carcinogenesis, the aforementioned interaction has also allowed identification of clinical biomarkers, especially epigenetic, for the early detection and prognosis of cancer patients. One of the ways to detect these epigenetic biomarkers is the cell-free circulating DNA (circDNA), a blood-based cancer diagnostic test, mainly focusing in the molecular alterations found in tumor cells, such as DNA mutations and DNA methylation. In this brief review, we epitomize the current knowledge on the research in circDNA biomarkers - mainly focusing on DNA methylation - as potential blood-based tests for early detection of colorectal cancer and the challenges for validation and globally implementation of this emergent technology.
Core tip: Colorectal cancer (CRC) is one of the most prevalent malignancies in the world. CRC-associated morbidity and mortality is continuously increasing, in part due to a lack of early detection. The main aim of this article is the brief description of the basic screening modalities and their efficacy for CRC detection, the process of colorectal carcinogenesis and how the molecular pathways of CRC (focusing on epigenetic modifications) influence the clinical application of new blood-based biomarkers such as circDNA. Then we will focus on the most recent findings concerning the studies on circDNA, mainly related to DNA methylation and the challenges for validation and globally implementation of this emergent technology.
