MnSOD过量表达与BSO对食管癌细胞系的增敏效应

Radiosensitization effect of MnSOD and BSO on esophageal cancer cells by overexpression of MnSOD and BSO

目的研究过量表达锰超氧化物歧化酶(MnSOD)在丁胱磺酰亚胺(BSO)作用下对食管癌TE-1细胞放射敏感性的影响。方法采用慢病毒转染法建立MnSOD过量表达的稳定转染细胞(TE-1 Mm)及空载体细胞(TE-1Mn)。RT-PCR、Western blot及流式细胞术等方法检测MnSOD过量表达对细胞增殖、凋亡、放射增敏、活性氧荧光强度及蛋白表达变化的影响。结果 RT-PCR及Western blot证实建立了稳定过量表达MnSOD的TE-1细胞系。TE-1 Mm细胞平皿克隆集落形成能力、活性氧荧光强度降低,细胞凋亡率、细胞生长抑制率、放射增敏比及MnSOD蛋白表达相对量明显增加,与TE-1细胞相比差异均具有统计学意义(P<0.05)。结论 MnSOD过量表达与BSO通过抑制增殖、诱导凋亡、下调细胞内活性氧浓度提高食管癌细胞放射敏感性。

Objective To explore effect of manganese superoxide dismutase （MnSOD） overexpression on rediosen- sitivity in the esophageal cancer cell line in the presence of buthionine sulfoximine （BSO）. Methods Overexpres- sion of MnSOD eDNA by lentivirus to get stable transfected TE-1 cell lines of MnSOD overexpression （TE-1 Mm）. Reverse transcription polymerase chine reaction （ RT-PCR）, Western blot and flow eytometry were then used to de- tect MnSOD overexpression that might be found on cell proliferation, cell apoptosis, cell radiosensitivity, eaetive oxygen species （ROS） fluorescence index. Results RT-PCR and Western blot showed that TE-1 cells transfected with MnSOD contained the target genes in overexpression. Plating efficiency was reduced in the MnSOD overexpres- sion transfected cell line and decreased the plating efficiency. While the TE-1 cell had a higher plating efficiency. Furthermore, apparent apoptosis of TE-1 Mm cell induced by transfected MnSOD overexpression was demonstratedby Annexin V-FITC/PI staining compared to TE-1 cell. Moreover, in multitarget single-hit model-fitting survival curves, the values of DO, Dq, N, and SER in TE-1 Mm cell lines were less than in TE-1 cell. FCM results indica- ted that TE-1 Mm of reactive oxygen species （ROS） fluorescence index was less than that in TE-1 cell. Western blot demonstrated that TE-1 Mm had a higher MnSOD protein expression than those of TE-1 treated with BSO and radiation. Conclusions MnSOD overexpression can increase the radiosensitivity of esophageal cancer cells by in- hibiting cell proliferation, inducing cell apoptosis and decreasing ROS concention in combination with BSO.