Correlation Of Telomere Length,Telomerase Activity With Radiosensitivity In Human Breast Cancer Cell Lines

Object To investigate telomere length ,telomerase activity and its changes ,radiosensitivity index survival fraction at 2Gy (SF2) in different human breast cancer cell lines and its association with radiosensitivity.Methods Five human breast cancer cells were irradiated with 2Gy60Co Y ray.Before irradiation telomere length(TRF) was detected by southern blot.At different times after irradiation,telomerase activity (TA) was detected by PCR-based telomeric repeat amplification coupled with ELISA.Radiosensitivity index survival fraction (SF) was measured by colonogenic assay.Results Telomerase activity and its changes,telomere length and SFa of different breast cancer cell lines is different(P<0.01),telomerase activity of ZR-75-30 is nagetive,and the rests are positive.Telomere length is not correlation with telomerase ativity (P>0.05).And there is no correlation in telomerase activity and its changes with SF2 (P>0.05).There is liner correlation between telomere length and SF2 (P<0.01,r=0.984).Conclution Telomere length,telomerase activity,its change and radiosensitivity of different breast cancer cell lines is different.but telomerase activity and its changes could not reflect radiosensitivity.But telomere length is correlation with radiosensitivity,and it may be a detector of radiosensitivity.