Enhanced Radiosensitivity Of H22 Ascitic Tumor To Heavy Ion Radiation In Ultra-filtration Extract Mixture From Astragalus Mongholicus-treated Mice

Objective:The study was conducted to investigate the effect of the ultra-filtration extract mixture from Astragalus Mongholicus on heavy ions radio-sensitivity of hepatoma-22 malignant ascites mice and explore the mechanism,which may provide theoretical basis for UEMAM plus heavy ion beam radiotherapy on the malignant ascites.Methods:1: Established mice model of ascites and divided into 4 groups randomly, the model mice were treated with 50mg/kg、100mg/kg、150mg/kg dose of UEMAM and normal saline, statisticed the body weights、abdomen circumference、ascites volume and survival time,calculated the ascites inhibition rate and prolongation of life span to determine the most effective dose of UEMAM.2: Established mice model of ascites and divided into 4 groups randomly, treated with normal saline, UEMAM, heavy ion beam radiotherapy and UEMAM plus heavy ion beam radiotherapy. Their behavior were observed every day,The body weights, abdomen circumference、ascites volume and ascites inhibition rate of the mice were measured,besides,statisticed the survival time and prolongation of life span through the remaining mice.And then through the following experimrnts to explore the mechanism: flow cytometry technique was used to assess H22 ascites tumor cell apoptosis;the single cell gel electrophoresis was used to detect the level of deoxyribo nucleic acid damage(DNA damage);and the gene and protein levels of P53、Bax、Bcl-2 and Cleaved Caspase-3 were analyzed by PCR and western blot.Results:1:Compared with the control mice,UEMAM middle and high dose groups could inhibit the formation of malignant ascites, improve the survival quality of malignant ascites mice, extend the lifetime of malignant ascites mice, and the differences were statistically significant( P < 0.05),but the UEMAM low dose group was not statistically significant(P>0.05),and there was nodifference between UEMAM middle and high dose group either(P>0.05).So we chose the UEMAM middle dose as the most effective dose.2:The body weights、abdomen circumference and ascites volume of UEMAM plus radiotherapy group was lower than other groups(P<0.05), and the mean survival time of mice in UEMAM plus radiotherapy group was the longest, and the prolonged survival rate was the highest. Compared with other groups,the differences were statistically significant(P<0.05).3:The rate of apoptosis increased with the extension of time in each treatment proup,and compared with other groups,the combination group was the highest at various time points(P<0.01).4:The comet images showed that the DNA damage in UEMAM plus radiotherapy group was the most serious. Compared with other groups,the differences were statistically significance(P<0.05).5:The gene and protein levels of P53 、 Bax and Cleaved Caspase-3 were increased obviously in UEMAM plus radiotherapy group,and the gene and protein levels of Bcl-2 was decreased in combination group. Compared with other groups,the differences were statistically significant(P<0.05).Conclusions: UEMAM can enhance the radiosensitivity of H22 ascitic tumor mice, the mechanisms of its enhancing the radiosensitivity is relation to cell apoptosis signal pathway by activing P53. which are related to damage cell DNA, increase the gene and protein levels of P53、Bax, decrease the gene and protein levels of Bcl-2, active the expression of Cleaved Caspase-3,and then induce the apoptosis of H22 ascitic tumor cell.