Objective:The aim of this study was to discuss the effect of pre-low-dose X-ray radiation on P53,Bcl-2 and apoptosis of HepG2 cells in tumor-bearing nude mouse,and further explore the mechanism of low doses radiation....Objective:The aim of this study was to discuss the effect of pre-low-dose X-ray radiation on P53,Bcl-2 and apoptosis of HepG2 cells in tumor-bearing nude mouse,and further explore the mechanism of low doses radiation.Methods:HepG2 cells were implanted subcutaneously into nude mice.14 days after the implanting,these mice were divided into 6 groups randomly,S group (sham-irradiation 0 cGy),D1 group (7.5 cGy,dosage rate=7.5 cGy/min),D2 group,(200 cGy,dosage rate=100 cGy/min),D1 + 2 h + D2 group,D1 + 6 h + D2 group and D1 + 12 h + D2 group.Tumor-bearing mice in each experimental group were executed at 24 h after the last irradiation.P53 and Bcl-2 were detected by immunohistochemical staining,the tumor tissues apoptosis were detected in site (Tunel).Results:Each combined exposure groups (D1 + 2 h + D2 group,D1 + 6 h + D2 group and D1 + 12 h + D2 group) compared with the D2 group,the percentages of positive P53 and Bcl-2 were decreased obviously,and the apoptotic indexs were increased (P < 0.01).Conclusion:Pre-low-dose radiation combined with the conventional radiation can increase the apoptosis of tumor tissues by decreasing the expression of P53 and Bcl-2,it can enhance the anti-tumor effect of conventional radiation,and it can have actual clinical significance on supporting radiotherapy.展开更多
文摘Objective:The aim of this study was to discuss the effect of pre-low-dose X-ray radiation on P53,Bcl-2 and apoptosis of HepG2 cells in tumor-bearing nude mouse,and further explore the mechanism of low doses radiation.Methods:HepG2 cells were implanted subcutaneously into nude mice.14 days after the implanting,these mice were divided into 6 groups randomly,S group (sham-irradiation 0 cGy),D1 group (7.5 cGy,dosage rate=7.5 cGy/min),D2 group,(200 cGy,dosage rate=100 cGy/min),D1 + 2 h + D2 group,D1 + 6 h + D2 group and D1 + 12 h + D2 group.Tumor-bearing mice in each experimental group were executed at 24 h after the last irradiation.P53 and Bcl-2 were detected by immunohistochemical staining,the tumor tissues apoptosis were detected in site (Tunel).Results:Each combined exposure groups (D1 + 2 h + D2 group,D1 + 6 h + D2 group and D1 + 12 h + D2 group) compared with the D2 group,the percentages of positive P53 and Bcl-2 were decreased obviously,and the apoptotic indexs were increased (P < 0.01).Conclusion:Pre-low-dose radiation combined with the conventional radiation can increase the apoptosis of tumor tissues by decreasing the expression of P53 and Bcl-2,it can enhance the anti-tumor effect of conventional radiation,and it can have actual clinical significance on supporting radiotherapy.
