title: Low-intensity pulsed ultrasound enhances cell killing induced by X-irradiation.
abstract: To determine the effect of pulsed ultrasound (US) on radiation-induced cell killing, U937 and Molt-4 cell lines were exposed to 1.0 MHz US with 50% of duty factor at 0.3 W/cm(2) and pulsed at 1 Hz immediately after exposure to X-rays at 0, 0.5, 2.5 and 5 Gy. The cells were assayed 24 h after the treatments. The result showed significant enhancement of cell killing in the combined treatments. However, the ratio of apoptotic cells induced either by X-rays or US alone did not significantly change. These findings suggest that pulsed US can enhance the anticancer effect of X-irradiation due to US streaming under non-inertial cavitational condition. This combined treatment can potentially enhance the therapeutic effect of radiation therapy.
authors.affiliation: Cancer Research Institute of Tomsk Scientific Center of Siberian Branch of Russian Academy of Medical Science, Tomsk, Russia; Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
authors.forename: Mikhail A
authors.initials: MA
authors.lastname: Buldakov
authors.forename: Loreto B
authors.initials: LB
authors.lastname: Feril
authors.forename: Katsuro
authors.initials: K
authors.lastname: Tachibana
authors.forename: Nadejda V
authors.initials: NV
authors.lastname: Cherdyntseva
authors.forename: Takashi
authors.initials: T
authors.lastname: Kondo
mesh_terms: D017209:Apoptosis / Q000528:radiation effects*; D045744:Cell Line, Tumor; D006801:Humans; D014465:Ultrasonics; D014965:X-Rays
keywords: Apoptosis; Cell killing; Ultrasound; X-rays