Experimental Trial On The Brachytherapy Of ¹²⁵I Radioactive Seed To Esophageal Carcinoma

Objective:To determine the effects of ¹²⁵I radioactive seed on cloning efficiency of human esophageal carcinoma cell line Eca-109 in vitro;To determine the effects of ¹²⁵I seed on apoptosis and cell cycle in human esophageal carcinoma Eca-109 cells line in vitro;To investigate the lethal effect of interstitial implantation with ¹²⁵I seeds in nude mice with the human esophageal tumor Eca-109 cell.Material and Methods:Human esophageal carcinoma cell line Eca-109 in exponentially growing phase incubated in high-glucose DMEM was made into a single-cell suspension.The numbers of cells were counted and the cells were diluted.Be seeded on 35-mm cell culture dishes. Randomized into 4 groups:A:control group(the untreated cell).B: low-dose group(treated with 0.2mCi ¹²⁵I seed).C:Middle-dose group (treated with 0.4mCi ¹²⁵I seed).D:high-dose group(treated with 0.8mCi ¹²⁵I seed).All cultures were done at 37℃with 5%CO₂ in a humidified incubator.The cloning efficiency of the 4 groups was evaluated from the 1 to 7 day.Randomized into 4 groups:A:the untreated cell.B:treated with 0.2mCi ¹²⁵I seed.C:treated with 0.4mCi ¹²⁵I seed.D:treated with 0.8mCi ¹²⁵I seed.The animal models of the human esophageal poorly differentialed Eca-109 cell tumor were established first through the injection of the cells into nude mice subcutaneously,following by the implantation of the ¹²⁵I seeds into the tumor mass.The animal were devided into 5 groups randomly(4 experimental groups and 1 control group).In control group,the nude mice were subjected to the implantation with 0 Bq seeds.The animal models of the Eca-109 tumor were established first through the injection of the cells into nude mice subcutaneously,followed by the implant of the ¹²⁵I at different dosages into the tumor mass.The volume of the tumor was measured,the inhibitory rate was calculated and the histopathological changes were observed at the 30th day after operation.Results:After 7 days,the cloning efficiency of the 3 treated group statistically lowed than that of control group(P＜0.05).That of C and B, D and B groups showed statistically significant difference(P＜0.01).But the cloning efficiency of D and C groups did not demonstrate a statistical difference(P＞0.05).After 7 days,the apoptosis and cell cycle of Eca-109 cells was detected by flow cytometry.The AI of the 3 treated group statistically higher than that of control group(P＜0.01).That of C and B,D and B groups showed statistically significant difference (P=0.000).But the AI of D and C groups did not demonstrate a statistical difference(P=0.209).G₂/M phase cells were increase with the dose enhancing of the ¹²⁵I seed(P＜0.01).The growth curve of the tumor in experimental group showed the decreased tendency,while in the experimental groups,there was an increased tendency.The inhibitory rate in E group was higher than other groups and histopathological response was seen.There were no statistically significant differences in the inhibitory rate and histopathological response between A and B group. The inhibitory rate of the C,D,E groups statistically higher than that of control group.That of C,D groups showed statistically significant difference than that of E group.But the inhibitory rate of A groups did not demonstrate a statistical difference than that of control group.Conclusion:(1)¹²⁵I radioactive seed show a positively inhibiting effect to the cloning efficiency of esophageal carcinoma cells Eca- 109 in vitro; (2)¹²⁵I seed show a positively inducing effect to the apoptosis of esophageal carcinoma cells Eca-109 in vitro.The cell apoptosis may be induced in the cell cycle G₂ / M phase.This Study verifies the efficiency of the ¹²⁵I granules in inhibiting the growth of esophageal cancer;(3)The dosage range of ¹²⁵I is between 14.8×10⁶Bq and 29.6×10⁶Bq.¹²⁵I has the remarkable inhibitory effect on the human esophageal cancer Eca-109 cells.