Experimental study of antisense epidermal growth factor receptor enhancing the radiosensitivity of human lung cancer cell line spc-a-1 / 中华放射医学与防护杂志

ABSTRACT

Objective To explore whether antisense-EGFR could enhance the radiosonsitivity of human lung cancer spc-a-1 cell line.Methods The spc-a-1 cells were transfected with antisenso.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 transfeeted with pcDNA3 which did not contain antisense EGFR).Cell clones that stable expressing antisense-EGFR wa8 selected with G41 8 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 curve of each group was established by colony-forming assay.Results The expression of EGFR mRNA and protein were significantly inhibited after antisense-EGFR-pcDNA3 transfection.The cells arrested at the G2/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 antisonse-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 D0,Dq,SF2 of pcDNA3 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 G2/M cell cycle arrest,promote cell apoptosis and inhibit the ability of sublethal cell damage repair induced by irradiation,80 that it could significantly improve the radiosensitivity of spc-a-1 cell in vitro.