Fig. 5: Downregulation of CYLD contributes to cancer radioresistance.

a Immunoblot and b real-time PCR analysis of CYLD expression levels in radiation-resistant cells (CNE2-IR and HK1-IR) compared with radiation-responsive cells (CNE2 and HK1). β-Actin was used as a control. c–f Colony formation assay showing survival fractions of CYLD overexpression cells treated or not treated with 4 Gy irradiation, surviving fractions were calculated by comparing the colony number of each treatment group with untreated groups (0 Gy). (CYLD wt: full-length CYLD plasmid; CYLD-C601A: c601 mutant CYLD plasmid lacking enzyme function). The relative SF (survival fraction) is plotted below the results, Results are plotted as the mean surviving fraction ± SEM of 3 independent experiments.