DNA methylation change involved in doxorubicin-induced testicular toxicity in mice

Testicular toxicity is one of the frequent adverse effects of cancer chemotherapy and the problem is that there is no effective biomarker. To find effective biomarkers, we focused on epigenetic mechanisms of male germline. Therefore, our study investigated the DNA methylation status of male germline under the testicular toxicity induced by doxorubicin(DXR), a widely used anticancer agent. We established mouse models of initial stage of testicular toxicity and testicular pre-toxicity by administrating 0.2 mg/kg and 0.02 mg/kg of DXR twice a week for 5 weeks. Western blotting analysis revealed the protein expression levels of DNA methyltransferases DNMT3a and DNMT3b were decreased in both the DXR administration groups. Consistently, comprehensive DNA methylation analysis of sperm DNA using MBD-seq revealed that the majority of methylation changes induced by DXR administration were hypomethylation. This study showed the possibility of early diagnosis of testicular toxicity by examining DNA methylation status of sperm. DNA methylation profiles of sperms obtained from Control and doxorubicin(DXR) treated mice were analyzed using MBD2 mediated methylated DNA enrichment followed by next generation sequencing (MBD-seq) with Illumina MiSeq.