Fig. 7

circCDYL2 serves as a scaffold to promote EIF3D protein binding to RAD51 mRNA. A. The binding site of circCDYL2 to EIF3D protein was determined by RNA pull down in HNE2 and CNE2 cells after overexpression of circCDYL2 or its deletion mutants (DEL1 and DEL2). B. The binding site of circCDYL2 to EIF3D protein was determined by RIP assay in HNE2 and CNE2 cells after overexpression of circCDYL2 or its deletion mutants (DEL1 and DEL2). C. The binding site of circCDYL2 to RAD51 mRNA was determined by circRIP in HNE2 and CNE2 cells after overexpression of circCDYL2 or its deletion mutants (DEL1 and DEL2). D. The binding between EIF3D and RAD51 mRNA was determined by RIP in HNE2 and CNE2 cells after overexpression of circCDYL2 or its deletion mutants (DEL1 and DEL2). E. The expression of RAD51 was detected by western blotting in HNE2 and CNE2 cells after overexpression of circCDYL2 or its deletion mutants (DEL1 and DEL2). F. Schematic diagram of circCDYL2 promoting radiotherapy resistance in nasopharyngeal carcinoma via the EIF3D/RAD51 axis. circCDYL2 is generated by reverse splicing of exon 2 of CDYL2 pre-mRNA. It interacts with EIF3D protein and RAD51 5′-UTR and acts as a scaffold to recruit EIF3D protein to bind with RAD51 mRNA, facilitating the translation of RAD51 and accelerating homologous recombination repair, which ultimately leads to radiotherapy resistance in nasopharyngeal carcinoma. Data were represented as mean ± SD. ns, not significant; *, p < 0.05; **, p < 0.01; ***, p < 0.001