An increasing body of evidence suggests that long noncoding RNAs play critical roles in human cancer. Breast cancer is a heterogeneous disease and the potential involvement of long noncoding RNAs in breast cancer remains poorly understood. Herein, the study identified a long noncoding RNA, DANCR, which promotes cisplatin chemoresistance in triple-negative breast cancer (TNBC) cells. Mechanistically, binding of DANCRto Krüppel-like factor 5 (KLF5) induced acetylation of KLF5 at lysine 369 (K369), and DANCRknockdown resulted in down-regulation of KLF5 protein levels. Furthermore, DANCR/KLF5signaling pathway induced hypersensitivity to cisplatin in chemoresistant patients by inhibiting p27transcription. In summary, this study reinforced the potential presence of a growth regulatory network in TNBC cells, and documented a DANCR/KLF5/p27signaling pathway mediating cisplatin chemoresistance in TNBC.