Assessment of DNA damage induced on tumor cells by Proton beam from Folded Tandem Ion Accelerator

Radiation plays an important role in life science and medicine. Much of radiobiology is done with photons because they are readily available and they can penetrate a fair amount of material before loosing their effectiveness, and thus are easily encapsulated. But the behavior of charged particles (protons, light and heavy ions) are different and they can be confined by magnetic and electric field and thus be accelerated and directed as needed. Potential use of protons and other charged particles in the improvement of cancer treatment has been known for some time to offer several advantages over low LET radiation cancer therapy. In the present study the effect of different doses of 3.2 MeV proton beams from the folded tandem ion accelerator (FOTIA) on human tumor adeno carcinoma (HT 29) cells has been analysed using alkaline comet assay. Several techniques with different sensitivity to single-strand breaks and/or double strand breaks were applied to detect DNA breaks generated by ionizing radiation. Tests that assess DNA damage in single cells might be the appropriate tool to estimate damage induced by particles, facilitating the assessment of heterogeneity of damage in a cell population. Single cell gel electrophoresis or the comet assay is a sensitive technique to quantify DNA damage at single cell level