MAPK8 and breast carcinoma: To determine whether miR-25-3p and JNK1 are involved in CBR3-AS1-mediated chemotherapy resistance in breast cancer cells, a CCK-8 assay was conducted with MCF-7 cells, and the results showed that overexpression of miR-25-3p or inhibition of JNK1 reversed the decrease in ADR sensitivity caused by overexpression of CBR3-AS1 (Fig. 4a).