The Relationship between Spontaneous Apoptosis and Radiation-induced Apoptosis of Nasopharyngeal Carcinoma

Objective To study the relationship between spontaneous apoptosis and radiation-induced apoptosis of nasopharyngeal carcinoma(NPC). Methods Exfoliated cells obtained from 30 cases of NPC before and during radiotherapy 10、30and 60GY were used in this study.Using terminal oxynucleotidyl transferase mediated dUTP biotin nick end labeling(TUNEL)，the spontaneous and radiation-iuduced apoptoic rate(AR)were examined. Results The AR of exfoliated cells of NPC before and during radiotherapy 10,30 and 60GY was 7.2%±2.4%，64.3%±21.4%，57.2%±17.3% and 16.2%±7.4% respectively,the radiation-induced apoptotic rate was significantly higher than that of spontaneous apoptotic rate(P＜0.01).In NPC，spontaneous apoptosis was positively correlated with the radiation-induced apoptosis. Conclusion Detecting the AR of exfoliated cells of NPC before and during radiotherapy may be helpful to predict the sensitivity to radiotherapy in NPC patients.