电离辐射对人肺腺癌A549细胞中STAT3靶基因表达的影响

Effect of ionizing radiation on the expressions of STAT3 target genes in A549 cells

目的探讨1射线照射对人肺腺癌A549细胞中促血管生成基因VEGF以及抗凋亡基因bcl-2和存活素（survivin）表达的影响及其与转录因子STAT3的关系。方法利用RT．PCR和Westernblot检测2和4Gy1射线照射后24hA549细胞中VEGF、Bel-2和Survivin表达水平以及STAT3抑制后VEGF和Survivin的表达变化。结果2和4Gy1射线照射后，VEGF和Survivin的表达均显著升高，而Bel-2的表达不受1射线照射的影响。利用抑制剂AG490阻断Y射线照射诱导的STAT3激活后，辐射诱导的VEGF和Survivin的表达升高被抑制。结论y射线照射可通过激活STAT3上调A549细胞中Survivin和VEGF的表达，Survivin蛋白的上调在一定程度上抑制了辐射诱导的肿瘤细胞凋亡，而VEGF的表达升高则有助于肿瘤血管生成。

Objective To investigate the effect of ionizing radiation on the expression of transcription factor STAT3 target genes in the pulmonary adenoearcinoma cell line A549. Methods The expressions of VEGF, Bel-2 and Survivin in A549 cells with or without STAT3 inhibition were detected by RT-PCR and/or Western blot 24 h after 2 or 4 Gy of T-ray irradiation. Results After T-ray irradiation with 2 or 4 Gy, the expression of VEGF and Survivin increased significantly. However, the expression of Bcl-2 was not affected by T-ray irradiation. Furthermore, the increased expression of VEGF and Survivin induced by radiation was found to be inhibited after radiation-induced activation of STAT3 was blocked by AG490 inhibiter. Conclusions Y-ray irradiation could up-regulate the expression of Survivin and VEGF via activating STAT3. The increase of Survivin might partly inhibit the radiation-induced apoptosis of A549 cells, and the up-regulation of VEGF might contribute to the tumor angiogenesis.