Radiation And Nasopharyngeal Carcinoma Cell Apoptosis And Related Gene Expression Study Of The Relationship

Apoptosis is a type of cell death with specific morphological and biochemical features and is the result of chain of reactions modulated by many genes. Now it has become a hot point of tumor research becouse it relates to tumorgenesis, growth, treatment and prognosis. Apoptosis in two cell lines of nasopharyngeal carcinoma induced by radiation and its relationship between apoptotic index and gene expression were studied.1:It was found in single dose irradiation apoptotic index (AI) was time and dose dependent in CNE cell line. AI increased and reached a plateau at about 48 hours after a single doses irradiation(?) single dose was 0,2,4,8,12, 20Gy, their AIs was 2%, 10.2%, 17.8%, 21.4%, 24% and 27 % respectively. In fractionated-irradiation study, the doses were divided into three groups: 2Gy/5f/5d , 5Gy/2f/5d and 10Gy/1f/1d, AI was 37.8%, 34.5%(72h spared between two frationated irradiation) and 22.8% respectively. It was found that 24 hours for 2Gy and 72 hours for 5Gy were needed for AIs to recover to the initial level.2: Different apoptotic responses were observed between two cell lines, AI was 3.5%, 15% , 20%, 31%, 38% and 48 % respectively in CNE-2 cell line irradiated at doses of 2, 4, 8, 12 and 20Gy,in contrast ,AIs was 2%, 10.2%, 17.