Magnetic Hyperthermia and Oxidative Damage to DNA of Human Hepatocarcinoma Cells

Abstract

Nanotechnology is addressing major urgent needs for cancer treatment. We conducted a study to compare the frequency of 3-(2-deoxy-β-d-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3H)-one deoxyguanosine (M1dG) and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) adducts, biomarkers of oxidative stress and/or lipid peroxidation, on human hepatocarcinoma HepG2 cells exposed to increasing levels of Fe3O4-nanoparticles (NPs) versus untreated cells at different lengths of incubations, and in the presence of increasing exposures to an alternating magnetic field (AMF) of 186 kHz using 32P-postlabeling. The levels of oxidative damage tended to increase significantly after ≥24 h of incubations compared to controls. The oxidative DNA damage tended to reach a steady-state after treatment with 60 μg/mL of Fe3O4-NPs. Significant dose–response relationships were observed. A greater adduct production was observed after magnetic hyperthermia, with the highest amounts of oxidative lesions after 40 min exposure to AMF. The effects of magnetic hyperthermia were significantly increased with exposure and incubation times. Most important, the levels of oxidative lesions in AMF exposed NP treated cells were up to 20-fold greater relative to those observed in nonexposed NP treated cells. Generation of oxidative lesions may be a mechanism by which magnetic hyperthermia induces cancer cell death.

Ligation-Mediated Polymerase Chain Reaction Detection of 8-Oxo-7,8-Dihydro-2′-Deoxyguanosine and 5-Hydroxycytosine at the Codon 176 of the p53 Gene of Hepatitis C-Associated Hepatocellular Carcinoma Patients

“…Furthermore, our in vitro results are in line with previous investigations [19,35], which examined the generation of oxidative base lesions along the sequence of the p53 gene, after ROS treatment in human adenocarcinoma, epithelial lung, and MDA-MB23 estrogen receptor negative (ER−) breast cells. The complete correspondence between the site of preferential adduct binding detected in HCV-HCC cases with those observed hepatocytes in vitro treated with a ROS-generating system, e.g., the xanthine plus xanthine oxidase system [20], as well as with an over-represented mutational profile, e.g., the codon 176, in HCV-HCC tumors [24], strongly indicates that oxidative stress and ROS potentially produced during viral infection and inflammatory processes can be behind the high rates of G:C to T:A transversions and G:C to A:T transitions in HCV-HCC tumors [24]. Furthermore, multivariate regression analysis demonstrated that the frequency of M 1 dG was significantly enhanced in HCV-HCC patients compared to controls, with a Mean Ratio (MR) value of 1.87 (95% C.I.…”

“…Calf-thymus DNA (Sigma, St Louis, MO, USA) was exposed to 10 mM MDA (ICN Biomedicals, Costa Mesa, CA, USA), as previously described [20]. MDA-treated calf-thymus DNA was diluted with untreated DNA to obtain lower amounts of the reference adduct standard to generate a calibration curve.…”

“…Therefore, we conducted an hospital-based study aimed at comparing the presence of 8-oxodG and other base lesions at codon 176 of the exon 5 of the p53 gene and the levels of M 1 dG in the genomic DNA in the hepatocytes of HCV-HCC patients in respect to controls in Italy, a country with a high HCC incidence [3]. The generation of oxidative DNA lesions was also examined in liver hepatocellular (HepG2) cells, which were exposed to a ROS-generating system [20]. The analysis of 8-oxodG and 5-hydroxycytosine (5-OHC) at the sequence level of the p53 gene was performed by LM-PCR [19], whereas the detection of M 1 dG by chromatography and mass spectrometry [16,21].…”

Utilizing Iron for Targeted Lipid Peroxidation as Anticancer Option of Integrative Biomedicine: A Short Review of Nanosystems Containing Iron

“…Exposure of human hepatocarcinoma cells to IONPs leads to the formation of 8-oxo-2'-deoxyguanosine (8-oxo-dG), and oxidative DNA damage markers. The administration of alternating magnetic field (AMF) induced magnetic hyperthermia and further contributed to an elevated 8-oxo-dG level and malignant destruction [41].…”

Chemically-Induced DNA Damage, Mutagenesis, and Cancer

“…The factors that dictate aberrant repair processes, including intracellular signaling, spatial interactions, and ENM-specific responses, were discussed. In another nanoparticle work, Cellai et al studied Fe 3 O 4 nanoparticles in the presence or absence of an alternating magnetic field (AMF) of 186 kHz [ 7 ]. The levels of oxidative damage (measured by the levels of M 1 dG (3-(2-deoxy- β - d -erythro-pentofuranosyl)pyrimido[1,2- α ]purin-10(3 H )-one) and 8-oxodGuo, the biomarkers for lipid peroxidation and/or oxidative damage) increased considerably after 24 h incubations relative to controls.…”