The Emerging Role of EMT-related lncRNAs in Therapy Resistance and their Applications as Biomarkers.

Cancer is the world's second-largest cause of death. The most common cancer treatments are surgery, radiation therapy, and chemotherapy. Drug resistance, epithelial-- to-mesenchymal transition (EMT), and metastasis are pressing issues in cancer therapy today. Increasing evidence showed that drug resistance and EMT are co-related with each other. Indeed, drug-resistant cancer cells possess enhanced EMT and invasive ability. Recent research has demonstrated that lncRNAs (long non-coding RNAs) are non-coding transcripts which play an important role in the regulation of EMT, metastasis, and drug resistance in different cancers. However, the relationships among lncRNAs, EMT, and drug resistance are still unclear. These effects could be exerted via several signaling pathways, such as TGF-β, PI3K-AKT, and Wnt/β-catenin. Identifying the crucial regulatory roles of lncRNAs in these pathways and processes leads to the development of novel targeted therapies. We review the key aspects of lncRNAs associated with EMT and therapy resistance. We focus on the crosstalk between lncRNAs and molecular signaling pathways affecting EMT and drug resistance. Moreover, each of the mentioned lncRNAs could be used as a potential diagnostic, prognostic, and therapeutic therapy resistancefor cancer. However, the investigation of lncRNAs for clinical applications still has several challenges.