الفهرس 
AcknowledgmentsOnly 14 pages are availabe for public view
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Abstract
Cancer treatment has undergone evolutionary changes as understanding of the biological processes has increased. Complete removal of the cancer without damage to the rest of the body is the ideal goal of treatment. Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth by either damaging DNA directly or create charged particles (free radicals) within the cells that can in turn damage the DNA and lead to cell death. However, tumor responses to radiation vary with repair capacity, oxygenation, and other factors, and side effects in normal tissues increase with the higher doses used to kill radioresistant tumor cells.
In the present work, we studied the combination therapy of fractionated X-ray irradiation along with a natural product MGN-3/Biobran (a rice bran derivative) aiming to increase the radiosensitivity of Ehrlich solid tumor to fractionated X-irradiation and to evaluate the molecular mechanism of radiosensitization potential of MGN-3/Biobran.
In the current study (60) female Swiss albino mice weighing 22±2g were inoculated intramuscularly with 0.2mL EAC cells (2.5×〖10〗^6) in the right thigh of the lower limb with Ehrlich ascites carcinoma (EAC) cells. Mice with solid tumor mass (~300 mm3) that developed within 9 days post-inoculation were used in the study. In conclusion, this study demonstrated that treatment with MGN-3/Biobran increased the susceptibility of tumor cells to radiation therapy. When MGN-3 was combined with X-irradiation to treat solid tumor bearing mice, a profound tumor growth inhibition was observed, whereas treatment with X-irradiation alone was less effective. This result suggests that MGN-3/Biobran, which is a natural product and extracted from rice bran, has a radiosensitization potential by activating radiotherapy induced tumor apoptotic cell death through enhancing the expression of p53, bax and caspase-3, reducing the expression of Bcl2, increasing Bax/Bcl2 ratio and DNA fragmentation. Therefore, MGN-3 is a safe product and may be used as radiosensitizer to potentiate the therapeutic effect of ionizing radiation in the treatment of solid tumors and to minimize its side effects on normal cells.