Knockdown of lncRNA BLACAT1 reverses the resistance of afatinib to non-small cell lung cancer via modulating STAT3 signalling.

Afatinib, a second-generation irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), has been approved as EGFR, HER2, HER3 and HER4 inhibitor for non-small cell lung cancer (NSCLC) treatment. However, acquired resistance to afatinib has been found in most EGFR mutant NSCLC patients. Bladder cancer associated transcript 1 (BLACAT1) is a novel long non-coding RNAs (lncRNA) that play a functional role as an oncogenic lncRNA and is associated with chemoresistance. We aimed to identify the role of BLACAT1 in afatinib-resistant NSCLC and underlying mechanisms. Afatinib-resistant NSCLC cells were established. MTT assay, colony formation assay, apoptosis analysis, qRT-PCR and western blot analysis, immunohistochemistry, and in vivo study were carried out. BLACAT1 was up-regulated in afatinib-resistant NSCLC cells. Knockdown of BLACAT1 reversed the resistance of afatinib to NSCLC cells by modulating STAT3 signalling. The results provided a potential strategy for afatinib-resistant NSCLC by targeting BLACAT1.