The Potential Role of MicroRNA-Based Therapy for Lung Cancer Stem Cells

Abstract

Lung cancer is the leading cause of cancer death and has a poor prognosis. A better understanding of lung cancer biology and improvements in treatment are strongly needed. Increasing evidence indicates that lung cancer stem cells (CSCs) are a therapeutic target for lung cancer. The CSC hypothesis is based on the simple concept that cancers contain a similar hierarchy with respect to self-renewal, differentiation and innate therapy resistance. Investigating putative lung CSCs will greatly improve our understanding of the origins of lung cancer and may lead to novel therapeutic approaches for selectively targeting these cells. During the last decade, a novel class of molecules, small non-protein-coding RNAs, was found to be involved in carcinogenesis. MicroRNAs (miRNAs) are a group of these RNAs that are now established as important regulators of gene expression. They are key players in various critical cellular processes such as proliferation, cell cycle progression, apoptosis and differentiation. Recent studies have shown that several miRNAs with critical roles in normal stem cell functions during development are important regulators of CSCs. Emerging evidence also illustrates that miRNAs control many signaling pathways that regulate CSCs. Targeting miRNAs involved in CSC regulation has the potential to provide novel miRNA-based therapeutic strategies in oncology. This chapter highlights recent findings on the crucial role of miRNAs in the maintenance, growth and behavior of lung CSCs, thus indicating the powerful potential for novel prognostic and therapeutic miRNA-based strategies.