Role of Non-Coding RNAs in Colorectal Cancer: Focus on Long Non-Coding RNAs

SIMPLE SUMMARY: Non-coding RNAs are a type of RNA that is not translated into proteins. They play important roles in several cellular processes, mainly in the regulation of genetic information transfer from DNA to proteins. Mutations or imbalances in the non-coding RNA repertoire are involved in the development of many human diseases, including cancer. Here, we provide an overview of the role of long non-coding RNAs in the initiation and progression of colorectal cancer as well as in the development of drug resistance and demonstrate their relevance as predictive molecular biomarkers as well as novel potential therapeutic targets. ABSTRACT: Colorectal cancer is one of the most common causes of cancer-related deaths worldwide. Despite the advances in the knowledge of pathogenetic molecular mechanisms and the implementation of more effective drug treatments in recent years, the overall survival rate of patients remains unsatisfactory. The high death rate is mainly due to metastasis of cancer in about half of the cancer patients and the emergence of drug-resistant populations of cancer cells. Improved understanding of cancer molecular biology has highlighted the role of non-coding RNAs (ncRNAs) in colorectal cancer development and evolution. ncRNAs regulate gene expression through various mechanisms, including epigenetic modifications and interactions of long non-coding RNAs (lncRNAs) with both microRNAs (miRNAs) and proteins, and through the action of lncRNAs as miRNA precursors or pseudogenes. LncRNAs can also be detected in the blood and circulating ncRNAs have become a new source of non-invasive cancer biomarkers for the diagnosis and prognosis of colorectal cancer, as well as for predicting the response to drug therapy. In this review, we focus on the role of lncRNAs in colorectal cancer development, progression, and chemoresistance, and as possible therapeutic targets.