Ultrasound-induced DNA damage and repair

Abstract

Ultrasound (US) has been shown to induce cancer cell death. Here, we report on the potential of US to DNA damage and substantial repair signaling. We were able to observe gammaH2AX foci formation indicative the presence of DNA double strand breaks, in leukemia cells with observed radiation (IR) as well as US exposure. US-induced DNA damage was directly indicated by neutral comet assay. Nuclear localization of DNA repair proteins was also observed with immunohistochemistry and following repair of the damage was confirmed in decreased gammaH2AX signals and comet tail. The involvement of cavitational effects in gammaH2AX induction was supported by using dissolved gases which diminished inertial cavitation. Treatment with the specific inhibitors revealed that gammaH2AX induced by US were dependent on ATM and particularly on DNA-PK in contrast with that induced by IR. The data shown here revealed, for the first time, that US induced DNA double strand brakes via its cavitational effects.