Effects of gold nanoparticles on normal hepatocytes in radiation therapy

BACKGROUND: Gold nanoparticles (GNP, AuNPs) have received much attention as a tool to improve the therapeutic index of radiation therapy. This study aimed to evaluate the normal in vitro toxicity of AuNPs at kilovoltage energies on hepatocytes to provide scientific support for using AuNPs with radiotherapy. METHODS: Using the same treatment protocol applied to tumor cell lines, hepatocytes were exposed to AuNPs and/or radiation at various time points. RESULTS: The combination of X-ray irradiation and AuNPs did not have any significant effect on cell survival and apoptosis in normal hepatocytes. Furthermore, the combination treatment resulted in no or little change in the level of gamma-H2A histone family member X (γ-H2AX), a marker for DNA double-strand breaks (DSB), nor on the proportion of cells in the G2/M phase. Additionally, interleukin-8 (IL-8) secretion was measured using an enzyme-linked immunosorbent assay (ELISA) to assess its role in tumor progression and angiogenesis. The combination of irradiation and AuNP treatment revealed no significant reduction in hepatocyte viability, proliferation, or secretory capacity compared to cells receiving either treatment alone. According to this study, AuNPs in combination with radiation do have potentially in the treatment of hepatocellular carcinoma (HCC) with no critical cytotoxicity on normal tissue. CONCLUSIONS: Therefore, it is postulated that radiation and AuNPs are an effective combination therapy against HCC with no little cytotoxic effects on normal tissue, a hypothesis which warrants further investigation in in vivo, as well as in in vitro.