Control of APOBEC3B induction and cccDNA decay by NF-κB and miR-138-5p

•Impairment of NF-κB signalling prevents APOBEC3B induction and cccDNA decay.•APOBEC3B is post-transcriptionally regulated by the hsa-miR-138-5p.•Over-expression of the hsa-miR-138-5p inhibits APOBEC3B expression and cccDNA decay.•A3B timely induces cccDNA decay without damage to cancer-related genes.•APOBEC3B-mediated cccDNA decay is independent of cccDNA transcriptional activity.