摘要
目的 观察反义表皮生长因子受体（EGFR）对人肺腺癌细胞系放射敏感性的影响。方法 在脂质体介导下用质粒pcDNA3-反义EGFR（pcDNA3-antiEGFR）转染spc-a-1细胞，并以未转染（对照组）和空质粒pcDNA3转染（pcDNA3组）细胞作对照。用G418筛选稳定表达的细胞克隆，以RT-PCR和Western blot检测转染后EGFR的mRNA及蛋白表达抑制情况，流式细胞仪检测转染后细胞周期及单次照射8Gy后各组细胞凋亡比例。3组细胞分别给予6MVX射线照射0、2、4、6和8Gy，计算克隆形成率，拟合生长曲线。结果pcDNA3-antiEGFR组与对照组、pcDNA3组比较，EGFR mRNA和蛋白表达量明显减少，G2/M期比例分别为（29．53±1．91）％、（13．7±1．30）％和（12．40±1．34）％，单次照射8Gv后，3个组细胞的凋亡率分别为（39．24±1．57）％、（13．79±0．63）％和（15．02±0．85）％。与对照组相比较，pcDNA3-antiEGFR组细胞的阢、D0、Sq 、SF2值分别由2．11、2．49和0．84降至1．19、0．15和0．32，提示抑制EGFR表达，可降低spc-a-1细胞对射线所致亚致死性损伤的修复能力。结论 反义EGFR可以降低人肺癌spc-a-1细胞中EGFR的表达，改变细胞周期分布，促进凋亡，降低亚致死性损伤的修复能力，增加肺癌细胞系spc．a．1的放射敏感性。
Objective To explore whether antisense-EGFR could enhance the radiosensitivity of human lung cancer spc-a-1 cell line. Methods The spc-a-1 cells were transfected with antisense-EGFR-pcDNA3 by lipofectamine 2000（pcDNA3 antiEGFR group）. Two other groups were used for comparison： control group （spc- a-1 cell without transfection） and pcDNA3 group （spc-a-1 cell transfected with pcDNA3 which did not contain antisense EGFR）. Cell clones that stable expressing antisense-EGFR was selected with G418 and the suppression of the expression of EGFR mRNA and protein were detected by RT-PCR and Western blot. The influence of antisense-EGFR on cell cycle was testified by flow cytometry assay. The cell apoptosis was analyzed by flow cytometry after 8 Gy irradiation. Further, cells of each group were irradiated with X-rays at the dose of 0, 2, 4, 6 and 8 Gy. Dose-survival corve of each group was established by colony-fornling assay. Results The expression of EGFR mRNA and protein were significantly inhibited after antisense-EGFR- pcDNA3 transfection. The cells arrested at the GE/M phase in the pcDNA3 antiEGFR group, control group and pcDNA3 group were （29.53 ± 1.91 ）%, （13.7 ± 1.30）% and （12.40 ± 1.34）%, respectively. The apoptosis index of spc-a-1 cells in the antisense-EGFR combined with irradiation group was obviously higher than that of the comparable groups [（39.24± 1.57）%, （13.79± 0.63）% and （15.02 ±0.85%）]. The values of Do, Dq, SF2 of pcDNA5 antiEGFR group declined obviously compared with the control group（2.11, 2.49, 0.84 vs 1.19, 0.15, 0.32）. Conclusions Antisense-EGFR could induce the GE/M cell cycle arrest, promote cell apoptosis and inhibit the ability of sublethal cell damage repair induced by irradiation, so that it could significantly improve the radiosensitivity of spc-a-1 cell in vitro.
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2008年第4期361-364,共4页
Chinese Journal of Radiological Medicine and Protection
