STUDY OF POSSIBLE TOXIC EFFECTS OF IRON-CORE NANOPARTICLES ON THE CELL CYCLE IN NEUROBLASTOMA CELL LINES
Anisa Meleis1, Moushira Zoheir1, Gayle Woloschak2, Noha Zahran1, Walaa Omar1
1Department of Histology and Cell Biology, Faculty of medicine, Alexandria University, Alexandria, Egypt
2Department of Radiation Oncology, Northwestern University, Chicago, USA.
Background: The unique characteristics of engineered nanoparticles (NPs) make them highly desirable in a wide range of medical applications, and their use became specifically unique in nanomedicine. Nanoparticles targeting cancer cells is the main concept behind the use of NPs in cancer treatment. Neuroblastoma, being one of the most important childhood cancers, is of great importance, especially with the high mortality rate at an early age. Also iron NPs have been chosen due to their unique properties, and to prove their expected enhancing effect with radiotherapy. The exact mechanism behind this enhancing effect is still unclear. The science of nanotechnology, how NPs behave and what they can do with the cells is still a mystery. Objective: Our study aims to show the possible effect of iron nanoparticles on neuroblastoma cell lines after treatment with iron nanoparticles (0.1 µM) followed by radiotherapy (2 Gy for 5 minutes). Material & Methods: One 70-80% confluent T75 flask was used to prepare 4 slides having synchronized SK-N-AS cells by a shake off procedure. The slides were divided into four groups; Group A: SK-N-AS cells, Group B: SK-N-AS cells + NPs, Group C: SK-N-AS cells + 2 Gy radiation, Group D: SK-N-AS cells + NPs + 2 Gy radiation. Cells were maintained in Dulbecco's Modified Eagle’s Minimum Essential Medium (DMEM). 0.1 µM of iron NPs (198 µM) were added to each ml of cells in groups B and D. 2 Gy radiation follows to groups C & D. Fixation of all the slides, staining by propidium iodide and 53PB1 and examination using phase contrast, confocal microscope and flow cytometery for all the slides. Results: Using confocal microscopy, Group A with SK-N-AS cells only showed homogenous diffuse staining of the nuclei for 53PB1. Group B with SK-N-AS cells that had iron NPs and were not exposed to irradiation had a homogenous diffuse staining of the nuclei for 53PB1 with presence of solitary foci. Group C with no NPs and exposed to 2 Gy irradiation showed discrete foci. Group D with cells with added iron core NPs and exposed to 2 Gy irradiation showed the maxiumum number of foci per cell. On examining the cell cycle by flow cytometer the tumor cell line were arrested at G2 phase Conclusion: Iron core NPs have a direct lethal effect on neuroblastoma cell lines and they enhance the effect of irradiation causing more DNA damage.
December 2014