Figure 5. ESRP1 mediates chemoresistance of SCLC by regulating alternative splicing of CARM1. (A) Transfection of siRNA in H69AR cells and qRT-PCR assay to detect down-regulation efficiency. (B) Through CCK8 assay to detect IC50 value of cisplatin and etoposide after down-regulation of CARM1 in H69AR cells. (C) Transfected plasmids in H69AR and H446DDP cells to up-regulate the expression of CARM1FL and CARM1ΔE15, using qRT-PCR assay to detect down-regulation efficiency. (D) Through CCK8 assay to detect IC50 value of cisplatin and etoposide after up-regulation of CARM1 in H69AR cells. (E) Western blot assay was used to detect the expression of apoptosis-related proteins after H69AR cells were treated with cisplatin for 24 hours. (F) Cell apoptosis was analyzed by flow cytometry after H69AR cells were treated with cisplatin or etoposide for 24 hours. (G) Cell cycle arrest was analyzed by flow cytometry after H69AR cells were treated with cisplatin or etoposide for 24 hours. *, p<0.05; **, p <0.01; ***, p <0.001; ****, p <0.0001.