siRNA as a therapy for asthma.

RNAi is the process of sequence-specific, post-transcriptional/transcriptional gene silencing through siRNA. RNAi is a popular method of controlling gene expression and has potential in the development of drugs for several diseases, such as various types of cancer and viral infections. Gene therapy for asthma has already been developed and has demonstrated promising results in animal models. Recent progress in delivering siRNA to the respiratory system has also improved the therapeutic feasibility of RNAi for asthma. In this review, the mechanism, as well as the general strategies and problems associated with the application of RNAi in vivo, are discussed, focusing on the possibility of applying RNAi to alleviate airway inflammation in allergic asthma. Data from studies with siRNA against molecules involved in allergic responses are summarized, and the potential and limitations of RNAi as a novel therapeutic approach are discussed.