The role of microRNAs in photodynamic therapy of cancer

Photodynamic therapy (PDT) is a non-invasive treatment modality used in the management of both benign and malignant conditions. It involves the administration of a photosensitizing agent followed by local light irradiation, which activates the photosensitizer, resulting in tissue damage. An in-depth understanding of the molecular mechanisms and mediators of PDT is important, not only for appreciating how this treatment modality is effective, but also as an avenue for understanding potential shortfalls and untoward effects that can be managed or improved. MicroRNAs are a group of endogenous small non-coding regulatory molecules that play important roles in regulating several physiological processes and have been implicated in several pathologies including cancer. They have been found to regulate key cellular pathways and their aberrant expression highlights not only disease onset or progression, but is associated with therapy resistance and disease outcome. In the present review, we evaluate the role of microRNAs in PDT and dissect their function as effectors of PDT including the molecules they regulate. We also look at how miRNA signatures can be used as predictors of therapy response to PDT and what implications this may have in the treatment of patients with PDT. (C) 2017 Elsevier Masson SAS. All rights reserved.