Role of miRNA-21 in radiation-induced heart disease

Radiation-induced heart disease (RIHD) is a potentially fatal clinical complication of chest radiotherapy (RT). RIHD is detrimental to the long-term health of post-RT survivors and limits the dose and intensity of RT required to effectively kill tumor cells. However, the cellular and molecular mechanisms underlying these effects remain largely unknown. MicroRNAs (miRNAs) are highly conserved, non-coding, single-stranded, small molecular RNAs that regulate gene expression and participate in cellular proliferation, apoptosis, differentiation, and disease development. MicroRNA-21 (miRNA-21) has become one of the most intensively studied miRNAs in the fields of cancer and cardiovascular disease in recent years. miRNA-21 plays an important role in RIHD progression. This article reviews the origin and function of miRNA-21 in the cardiovascular system and its role in RIHD pathogenesis. In addition, the potential role of miRNA-21 as a new target for predicting and treating RIHD is also discussed.