Fig. 2.

CircCSPP1 knockdown enhanced DOX sensitivity, inhibited cell proliferation, migration, invasion, and promoted apoptosis in DOX-resistant CRC cells. a–j LoVo/DOX and HCT116/DOX cells were transfected with si-NC or si-circCSPP1, respectively. a CircCSPP1 expression was determined by qRT-PCR in LoVo/DOX and HCT116/DOX cells after transfection. b The transfected LoVo/DOX and HCT116/DOX cells were analyzed by MTT assay. IC50 of 24 h was shown. c, d Cell proliferation was measured by MTT assay in LoVo/DOX (c) and HCT116/DOX (d) cells after transfection for 0 h, 24 h, 48 h, and 72 h respectively. e Cell proliferation was detected by colony formation assay. f, g Transwell assay was performed to assess cell migration (e) and invasion (f). h Cell apoptosis rate was determined by flow cytometry analysis. i, j Western blot assay was carried out to detect the protein levels of MRP1, P-gp and LRP. *P < 0.05