Resistance to targeted therapies: a role for microRNAs?

• Resistance represents the major limit to targeted therapy efficacy.
• miRNAs can sustain resistance by targeting critical signal transducers.
• Selected miRNAs can be exploited as biomarkers of resistance.

The discovery of oncogene addiction dramatically changed the therapeutic approach for cancer treatment, and many drugs targeting specific molecular alterations are now in clinics. Despite the big success of these new compounds, the main limit to their efficacy is represented by resistance to therapy. The alteration of the activity or of the expression of many proteins has already been linked to the onset of resistance, but recent evidence indicates a role of microRNAs (miRNAs) as well. In this context, the idea of exploiting miRNAs as predictors of response or resistance to cancer therapy represents an intriguing possibility. The purpose of this review is to address the relationship between miRNAs and targeted therapies response and resistance.