en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;"><span style="font-size:10pt"><span style="text-justify:newspaper"><span style="text-kashida-space:50%"><span style="line-height:119%"><span style="font-family:Calibri"><span style="color:black"><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Background</span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-weight:bold"><span style="language:en-US">:</span></span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">Bystander (B.s) effect can influence non-irradiated cells and affect the desired effect in cancer treatment. This study was conducted to assess this effect on simultaneous administration of ultrasound (US) and Gold nanoparticles as a sonodynamic therapy (SDT) which is an important newly stimuli-responsive method in cancer treatment. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Materials and Methods</span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-weight:bold"><span style="language:en-US">:</span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US"> Firstly, the appropriate concentration of Gold nanoparticles (GNPs) and US intensity for SDT on melanoma cancer cells (A375) were evaluated. After treatments, the target cell culture was transferred to the bystander cells and the induced bystander effects including cell viability, apoptosis, expression of P53 (a promoter of apoptosis gene) and HO-1 (an inhibitor of apoptosis gene) were examined. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Results</span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-weight:bold"><span style="language:en-US">:</span></span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">According to the MTT results, 50 &micro;g/ml concentration of GNPs and 1.5 W/cm2 intensity of US wave were selected. Our results revealed that SDT induced B.s effect can alter the cell viability and apoptosis up to 20% and 51.61%, respectively. Moreover, a 2.9-fold increase in p53 gene expression and a decrease in OH-1 gene expression to 0.181-fold in comparison to the control groups were observed. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Conclusions</span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-weight:bold"><span style="language:en-US">:</span></span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">These results confirmed that B.s effect of sonodynamic can reduce the cancerous cell viability. Our finding showed that this treatment can potentially be an alternative to traditional treatment modalities.</span></span></span></span></span></span></span></span></span></div> Bystander effect, sonodynamic therapy, gold nanoparticles, apoptosis, p53 & HO-1 genes. 391 398 http://ijrr.com/browse.php?a_code=A-10-1-1057&slc_lang=en&sid=1 A. Shanei 7900319475328460024089 7900319475328460024089 No Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran R. Kamran Samani 7900319475328460024090 7900319475328460024090 No Department of Medical Physics and Radiology, School of Allied Medical Sciences, Shahrekord University of Medical Sciences, Shahrekord, Iran H. Akbari-Zadeh 7900319475328460024091 7900319475328460024091 No Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran M. Rezaei masumrezaei@yahoo.com 7900319475328460024092 7900319475328460024092 Yes Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran M. Kazemi 7900319475328460024093 7900319475328460024093 No Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran