Chemoresistance represents a major challenge in breast cancer (BC) treatment. This study aimed to probe the roles of LINC00160 in paclitaxel- and doxorubicin-resistant BC cells. Three pairs of BC and adjacent normal tissue were used for lncRNA microarray analysis. Paclitaxel-resistant MCF-7 (MCF-7/Tax) and doxorubicin-resistant BT474 (BT474/Dox) cells were generated by exposure of parental drug-sensitive MCF-7 or BT474 cells to gradient concentrations of drugs. Correlation between LINC00160 expression and clinical response to paclitaxel in BC patients was examined. Short interfering RNAs specifically targeting LINC00160 or TFF3 were designed to construct LINC00160- and TFF3-depleted BC cells to discuss their effects on biological episodes of MCF-7/Tax and BT474/Dox cells. Interactions among LINC00160, transcription factor C/EBPβ and TFF3 were identified. MCF-7/Tax and BT474/Dox cells stable silencing of LINC00160 were transplanted into nude mice. Consequently, up-regulated LINC00160 led to poor clinical response to paclitaxel in BC patients. LINC00160 knockdown reduced drug resistance in MCF-7/Tax and BT474/Dox cells and reduced cell migration and invasion. LINC00160 recruited C/EBPβ into the promoter region of TFF3 and increased TFF3 expression. LINC00160-depleted MCF-7/Tax and BT474/Dox cells showed decreased tumour growth rates in nude mice. Overall, we identified a novel mechanism of LINC00160-mediated chemoresistance via the C/EBPβ/TFF3 axis, highlighting the potential of LINC00160 for treating BC with chemoresistance.
Keywords: C/EBPβ; TFF3; breast cancer; drug resistance; long non-coding RNA-00160.
© 2020 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.