LAUSR

Renal cell carcinoma (RCC) is characterized by an infrequent number of somatic mutations. By contrast, epigenetic aberrations are commonly found in RCC, indicating that epigenetic reprogramming is an important event in RCC development. Epigenetic alterations comprise several different aberrations, such as changes in histone modifications, DNA methylation, and microRNA levels, and occur in the most important signalling pathways in RCC, such as the von Hippel–Lindau disease tumour suppressor (VHL)–hypoxia-inducible factor (HIF) pathway, the WNT–β-catenin pathway, and pathways involved in epithelial–mesenchymal transition. Owing to their involvement in these pathways and frequent occurrence in RCC, epigenetic alterations are regarded as potential biomarkers for the early detection of disease and for prediction of prognosis and treatment response. In addition, most of these alterations are potentially reversible, so they also provide new targets for therapy. At the moment, epigenetic biomarkers for RCC are not being used in clinical practice, but targeted epigenetic therapies are under investigation. Understanding the extent of epigenetic changes occurring in RCC and the mechanisms by which they influence disease progression and treatment response, as well as knowledge of current research on biomarkers and treatments, is crucial to successful clinical translation of epigenetics in RCC.Joosten et al. review the main epigenetic alterations involved in renal carcinogenesis and their effects on key signalling pathways. The authors also discuss the utility of epigenetic aberrations as renal cancer biomarkers and their potential as treatment targets.Key pointsSomatic mutations occur infrequently in renal cell carcinoma (RCC) and, for a long time, mutations in VHL were the only commonly found genetic aberrations.Exome sequencing also revealed relatively frequent mutations in genes that encode histone-modifying and chromatin-modifying proteins, implicating epigenetic reprogramming as a key feature of renal carcinogenesis.Epigenetic modifications are frequent in RCC, and important signalling pathways are epigenetically deregulated by aberrant promoter methylation of pathway components or by abnormal expression of microRNAs.Epigenetic alterations might be promising biomarkers for RCC diagnosis, as well as for prognosis and prediction of therapy response in patients with RCC, and provide new targets for therapy.Despite great interest in epigenetic alterations in RCC, no epigenetic markers are currently used in the clinic, and the quality of research and reporting has to be improved to enable clinical translation.Therapeutic targeting of the epigenome might be attractive in RCC; in particular, the combination of epigenetic therapy and antiangiogenic or immune checkpoint treatments is a promising paradigm that could overcome frequent monotherapy resistance.