MicroRNA in radiotherapy: miRage or miRador?

Abstract

At least half of all cancer patients will receive radiation therapy. Tumour radioresistance, or the failure to control certain tumours with this treatment, can result in locoregional recurrence; thus there is great interest in understanding the underlying biology and developing strategies to overcome this problem. The expanding investigation of microRNA in cancer suggests that these regulatory factors can influence the DNA damage response, the microenvironment and survival pathways, among other processes, and thereby may affect tumour radioresistance. As microRNA are readily detectable in tumours and biofluids, they hold promise as predictive biomarkers for therapy response and prognosis. This review highlights the current insights on the major ways that microRNA may contribute to tumour radiation response and whether their levels reflect treatment success. We conclude by applying the potential framework of future roles of miR in personalised radiotherapy using prostate cancer clinical management as an example.

Figure 1

The potential utility for miR-predictive signatures in personalising the management of cancer and radiotherapy treatment. Using prostate cancer as an example, validated miR signatures could assist in determining which patients undergoing active surveillance should proceed to definitive treatment. In addition, they could aid in identifying those patients who potentially require additional radiotherapy dose escalation due to a cancer radioresistant signature, or are at increased risk of developing significant normal tissue radiotoxicity.