Emerging Role and Therapeutic Potential of lncRNAs in Colorectal Cancer

SIMPLE SUMMARY: Homeostasis of the intestine is maintained by a delicate balance of signaling networks that regulate self-renewal and differentiation. In the past years, increasing evidence suggests that long non-coding RNAs (lncRNAs) are involved in the control of intestinal crypt turnover. Indeed, their deregulation can enable and drive malignant cell growth. Notably, lncRNAs have high tissue specificity, and therefore hold great potential for therapeutic intervention. Here, we address the function of lncRNAs in the intestine in physiological and pathological conditions and discuss promising interference systems to target oncogenic lncRNAs. ABSTRACT: Maintenance of the intestinal epithelium is dependent on the control of stem cell (SC) proliferation and differentiation. The fine regulation of these cellular processes requires a complex dynamic interplay between several signaling pathways, including Wnt, Notch, Hippo, EGF, Ephrin, and BMP/TGF-β. During the initiation and progression of colorectal cancer (CRC), key events, such as oncogenic mutations, influence these signaling pathways, and tilt the homeostatic balance towards proliferation and dedifferentiation. Therapeutic strategies to specifically target these deregulated signaling pathways are of particular interest. However, systemic blocking or activation of these pathways poses major risks for normal stem cell function and tissue homeostasis. Interestingly, long non-coding RNAs (lncRNAs) have recently emerged as potent regulators of key cellular processes often deregulated in cancer. Because of their exceptional tissue and tumor specificity, these regulatory RNAs represent attractive targets for cancer therapy. Here, we discuss how lncRNAs participate in the maintenance of intestinal homeostasis and how they can contribute to the deregulation of each signaling pathway in CRC. Finally, we describe currently available molecular tools to develop lncRNA-targeted cancer therapies.