Long non-coding RNAs (IncRNAs) are defined as a class of RNA transcripts longer than 200 nucleotides encoded by mammalian genomes that lack protein-coding potential. LncRNA ASBEL has been identified as an anti-sense transcript of BTG3 (B cell translocation gene 3) gene, which encodes an anti-proliferation protein. Remarkable down-regulation of BTG3 has been reported in triple-negative breast cancer (TNBC). In the present study, a number of single-stranded modified anti-sense DNA oligonucleotides (antago) were designed, synthesized and screened for specific IncRNA ASBEL knockdown. We showed here that anti-ASBEL antago played a significant tumor suppressive role in TNBC by effective down-regulating IncRNA ASBEL, which in turn led to increased BTG3 expression. The obtained data suggest IncRNA ASBEL as a novel therapeutic target in TNBC. (C) 2017 Elsevier Inc. All rights reserved.