Potential mechanism of apoptosis induced by ultrasound in human hepatocarcinoma cells via comparative proteomic analysis.

Abstract

To analyze the potential molecular mechanism of ultrasound induced apoptosis in cancer cells, comparative proteomic methods were introduced in the study. After ultrasound exposure at the intensity of 1.2 W/cm2, the human SMMC-7721 hepatocarcinoma cells were stained by trypan blue to detect the morphologic changes, and then the flow cytometry was used to examine the percentage of early apoptosis via double staining of FITC-labelled Annexin V and Propidium iodide. The proteins were separated by two-dimensional (2D) SDS polyacrylamide gel electrophoresis (PAGE). Among them, the differently expressed proteins were identified by MALDI-TOF mass spectrometry to reveal the key proteins response to ultrasound exposure. It's proved early apoptosis of cells were induced by focused ultrasound. After ultrasound exposure, the expressing characteristics of several proteins changed, in which some proteins in HSP family are associated with apoptosis initiation. It is suggested that the focused ultrasound could be applied in the assistant cancer therapy. Moreover, it is proved the comparative proteomic methods could supply information about the protein expression to analyze the metabolic processes related to bio-effects of biomedical ultrasound.