Bcl-xl反义寡核苷酸转染对肺腺癌A549细胞增殖及凋亡的影响

Effect of Bcl-xl antisense oligodeoxynucleotide on proliferation and apoptosis in lung adenocarcinoma A549 cells

目的研究Bcl-xl反义寡核苷酸(ASODN)对肺腺癌A549细胞增殖及凋亡的影响。方法将肺腺癌A549细胞分为细胞对照组(无脂质体及核酸)、脂质体(Lip)组(空脂质体,无核酸)、序列对照寡核苷酸(SCODN)组和ASODN组,设计合成特异性靶向Bcl-xl ASODN,用阳离子脂质体介导其转染肺腺癌A549细胞株。采用细胞计数试剂盒(CCK8)法检测A549细胞增殖抑制率;末端脱氧核苷酰基转移酶介导性d UTP切口末端标记(TUNEL)法检测A549细胞凋亡情况;反转录-聚合酶链反应(RT-PCR)和Western blot法检测A549细胞中Bcl-xlm RNA和蛋白表达水平。结果 ASODN和SCODN浓度为50 nmol·L^(-1)时,各组A549细胞增殖抑制率比较差异均无统计学意义(P>0.05);浓度为100、200、400 nmol·L^(-1)时,ASODN组A549细胞增殖抑制率均高于SCODN组和Lip组(P<0.05);ASODN对细胞增殖抑制作用随其浓度增加而增高,具有剂量依赖性(P<0.05)。细胞对照组、Lip组、SCODN组和ASODN组细胞凋亡率分别为(4.01±0.18)%、(5.23±0.22)%、(8.01±0.32)%和(41.50±1.91)%,ASODN组细胞凋亡率高于SCODN组、Lip组和细胞对照组(P<0.05)。ASODN和SCODN浓度为50 nmol·L^(-1)时,各组A549细胞中Bcl-xl mRNA表达量比较差异均无统计学意义(P>0.05);浓度为100、200、400 nmol·L^(-1)时,ASODN组A549细胞中Bcl-xl mRNA表达量均低于SCODN组、Lip组和细胞对照组(P<0.05);ASODN组A549细胞中Bcl-xl mRNA表达量随浓度增加相应地下降(P<0.05);SCODN组和Lip组Bcl-xl mRNA表达量较细胞对照组下降,但差异均无统计学意义(P>0.05)。细胞对照组、Lip组、SCODN组和ASODN组A549细胞中Bcl-xl蛋白表达量分别为0.62±0.17、0.67±0.27、0.62±0.21和0.23±0.10,ASODN组A549细胞中Bcl-xl蛋白表达量低于细胞对照组、Lip组和SCODN组(P<0.05)。结论转染Bcl-xl ASODN可下调Bcl-xl基因表达,能有效抑制A549细胞增殖,并显著促进A549细胞凋亡;Bcl-xl基因有望成为肺腺癌基因治疗的新靶点。

Objective To study the effect of Bcl-xl antisense oligodeoxynucleotide（ ASODN） on proliferation and apoptosis in lung adenocarcinoma A549 cell line. Methods Lung adenocarcinoma A549 cell was divided into cell control group（ without lipidosome and nucleic acid）,lipidosome（ Lip） group（ empty liposome,without nucleic acid）,SCODN group and ASODN group. The specifical target Bcl-xl ASODN were designed and transfected into A549 cell line by cationic liposome. The proliferation inhibitory rate of A549 cell was measured by cell counting kit-8（ CCK8）; the apoptosis was detected by terminal deoxynucleotidyl transferase-mediated d UTP nick end labeling（ TUNEL）; and the expression of Bcl-xl mRNA and protein was detected by reverse transcriptase polymerase chain reaction（ RT-PCR） and Western blot method. Results When the concentration was 50 nmol·L^-1,there was no statistic difference of inhibitory rate of A549 cell among the groups（ P 0. 05）. When the concentration was 100,200,400 nmol·L^-1,the inhibitory rate of A549 cell in ASODN group was significantly higher than that in SCODN group and Lip group（ P 0. 05）. The inhibitory action of ASODN on proliferation of A549 cell increased with the increasing of the concentration of ASODN（ P 0. 05）. The apoptosis rate in cell control group,Lip group,SCODN group and ASODN group was（ 4. 01 ± 0. 18） %,（ 5. 23 ± 0. 22） %,（ 8. 01 ± 0. 32） % and（ 41. 50 ± 1. 91） % respectively; the apoptosis rate in ASODN group was significantly higher than that in SCODN group,Lip group and cell control group（ P 0. 05）.When the concentration was 50 nmol·L^-1,there was no statistic difference of expression of Bcl-xl mRNA in A549 cell among the groups（ P 0. 05）. When the concentration was 100,200,400 nmol·L^-1,the expression of Bcl-xl mRNA in A549 cell in ASODN group was significantly lower than that in SCODN group,Lip group and cell control group（ P 0. 05）. The expression of Bcl-xl mRNA in A549 cell decreased with the increasing of the concentration of ASODN（ P 0. 05）. There was no statistic difference of the expression of Bcl-xl mRNA in A549 cell between the SCODN group,Lip group and cell control group（ P 0. 05）. The expression of Bcl-xl protein in cell control group,Lip group,SCODN group and ASODN group was 0. 62 ± 0. 17,0. 67 ± 0. 27,0. 62 ± 0. 21 and 0. 23 ± 0. 10 respectively; the expression of Bcl-xl protein in A549 cell in ASODN group was significantly lower than that in SCODN group,Lip group and cell control group（ P 0. 05）. Conclusion Transfection of Bcl-xl ASODN can down-regulate the expression of Bcl-xl gene,and can effectively inhibit the proliferation of A549 cell line and promote the apoptosis of A549 cell.