Modulation of protein expression and activity by radiation

Restenosis is a common complication of percutaneous transluminal coronary angioplasty. Recent studies have demonstrated a striking reduction in the neointimal hyperplasia characteristic of restenosis following intracoronary radiation (IR), but the mechanisms by which radiation reduces neointima formation following balloon overstretch injury are not elucidated fully. In addition to direct antimitotic effects mediated via oxygen free radicals, ionizing radiation can induce the expression of numerous genes and thereby mediate indirect effects. Additionally, IR prevents restenosis at the cost of decreased healing and increased thrombosis, and we suggest that these adverse reactions can be modulated by adjunct pharmacology or gene-based strategies. This review discusses several genes and proteins modulated by radiation in the context of arterial injury, and their possible therapeutic relevance.