Long non-coding RNAs(lnc RNAs) play important roles in cancer. They are involved in chromatin remodeling, as well as transcriptional and post-transcriptional regulation, through a variety of chromatin-based mechanisms and via cross-talk with other RNA species. lnc RNAs can function as decoys, scaffolds, and enhancer RNAs. This review summarizes the characteristics of lnc RNAs, including their roles, functions, and working mechanisms, describes methods for identifying and annotating lnc RNAs, and discusses future opportunities for lnc RNA-based therapies using antisense oligonucleotides. They are involved in chromatin remodeling, as well as transcriptional and post-transcriptional regulation, through a variety of chromatin-based mechanisms and via cross-talk with other RNA species. lnc RNAs can function as decoys, scaffolds, and enhancer RNAs. This review summarizes the characteristics of lnc RNAs, including their roles, functions, and working mechanisms, describes methods for identifying and annotating lnc RNAs, and discusses future opportunities for lnc RNA-based therapies using antisense oligonucleotides.