The Vitro Sensitivity Experiments Of Different Radiation Activity¹²⁵ I Seeds On The Human Moderately Differenriated Gastric Cancer Cell Line(AGS)

Objective:To discussed the sensititvity influence of different radiation activity 125I seeds on the human moderately differentiated gastric cancer cell line(AGS) and the influence of gastric cancer cell apoptosis, from the two aspects of the proliferation and apoptosis to discusse the effectiveness of 128I seeds in human moderately differentiated gastric cancer treatment.Methods:The irradiator consisted of nine Model BT-125-I seeds, Eight seeds were equally spaced around the circumference of a 3-cm diameter circle and the ninth seeds was confined to the center. The human moderately differentiated gastric cancer cells line (AGS) grown in diameter 35mm petri dishes, putting the grown well cells to accept radiotherapy activity of different radiation activity 125I seeds above and below the particle plane 5mm place. Divided into 4-groups:control groupA (no irradiation), experiment groupB(the radiation activity is 0.4mCi),experiment groupC(the radiation activity is 0.6mCi), experiment groupD(the radiation activity is 0.8mCi), each group cells cultured 24 hours,48 hours and 72 hours. Collecting and freezing-stored every group cells respectively. The stripping cancer used to detect cell cycle redistribution by the way of PI of FCM, to observe the changes of the cancer cells ultrastructural by TEM, to calculate the quantity of cancer cell apoptosis in situ and to detect the mRNA expression levels of Survivin and Bax t by RT—PCR at different time-poin.Results:With the accumulation of radiation time, the tumor cells cycle in experiment group was blocked in G0/G1, the proportion of S and G2/M was gradually reduced. we can observe the early-mid-late period cell apoptosis in the experiment group by TEM, rare cell apoptosis were found in the control group. Tunel was used to detect apoptosis in situ. Both the apoptosis rate between of each group at the same time points 24h,48h,72h and each group differences in different time points are statistically significant (P< 0.05), and the difference become remarkable start frome 48 hours between each experiment group. Through the detection of fluorescence detection quantitative RT-PCR, confirmed that expression of Survivin-mRNA gradually cut, expression of BaxmRNA gradually increase in the human moderately differentiated gastric cancer cell line(AGS) received different radiation activity 125I seeds. And each experimen group apoptosis rate increase, BaxmRNA over-active and SurvivinmRNA expression are exist the relationship of time-effect and dose-dependent.Conclusions:1. The different radiation activity 125I seeds can inhibit cell proliferation and promote cell apoptosis in the human moderately differentiated gastric cancer cells line(AGS).2. one of the important biological mechanism to restrain the human moderately differentiated gastric cancer cell line(AGS) of different radiation activity 125I seeds is block the cell cycle in G0/G1, increase the expression level of BaxmRNA, cut the expression level of SurvivinmRNA.3. Different radiation activity 125I seeds have different sensitivity for human moderately differentiated gastric cancer cell line(AGS) and exist the relationship of dose-dependent.