Abstract
microRNA (miRNA) is involved in many life phenomena through gene expression regulation. We found that sonication changed miRNA expressions significantly. To examine if the phenomenon could be applied for ultrasound mediated gene regulation (UMGR), we prepared 16 DNA fragments by random ligation of target sequences of four miRNAs whose expressions decreased by sonication. The fragments were introduced into a 3'UTR of the luciferase gene, constructing a gene cassette library. When cells transfected with gene cassettes were sonicated, two cassettes increased luciferase activities over two fold. The target fragments of these gene cassettes were then introduce the luciferase gene under control of a sonication responsive promoter and introduced into cells. Without sonication, one of them decreased luciferase activity to 30% of that of identical cells without the target fragment while it didn't much decrease luciferase activity (〜90%) of that of identical cells without the target fragment at the peak after sonication. When the luciferase gene was replaced with a suicide gene, cell death was lowered without sonication (23% to 4%) while keeping high cell death rate after sonication (60% to 49%). These results indicate that sonication affected miRNA expressions and that target sequences could be useful for UMGR.
