An Introspective Update on the Influence of miRNAs in Breast Carcinoma and Neuroblastoma Chemoresistance.

Chemoresistance to conventional cytotoxic drugs may occur in any type of cancer and this can either be inherent or develop through time. Studies have linked this acquired resistance to the abnormal expression of microRNAs (miRNAs) that normally silence genes. At abnormal levels, miRNAs can either gain ability to silence tumour suppressor genes or else lose ability to silence oncogenes. miRNAs can also affect pathways that are involved in drug metabolism, such as drug efflux pumps, resulting in a resistant phenotype. The scope of this review is to provide an introspective analysis on the specific niches of breast carcinoma and neuroblastoma research.