Effect of ionizing radiation on invasiveness of pulmonary adenocarcinoma cells A549 and its mechanism / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the effect of ionizing radiation on the invasion of the pulmonary adenocarcinoma cell line A549.Methods The invasiveness of A549 cells irradiated with 2 and 4 Gy doses of γ-rays was detected by using transwell invasion assay.The expression levels of matrix metalloproteinase (MMP)-2 mRNA and protein and phosphorylated signal transducers and activators of transcription 3 ( STAT3 ) protein were detected by reverse transcription PCR and Western blot.Results After irradiation with 2 or 4 Gy, the invasiveness of A549 cells increased by 200.0% ( F = 111.7, P ＜ 0.01 ) and 390.9% ( F = 593.7, P ＜ 0.01 ), respectively, compared with that in untreated A549 cells.Furthermore, the transcription and protein expression of MMP-2 24 h after irradiation and the phosphorylation of STAT3 12 h after irradiation were promoted.The irradiation-induced elevation of MMP-2 protein expression was suppressed using STAT3 phosphorylation specific inhibitor (AG490).Moreover,compared with 4 Gy of irradiation alone, treatment with 4 Gy of irradiation plus AG490 decreased the number of invasive cells by 76.1% ( F = 555.9, P ＜ 0.01 ), and the number of invasive cells in 4 Gy of irradiation plus AG490 group made up only 117.8% of that in untreated group ( F = 3.6, P ＞ 0.05 ).Conclusions Ionizing radiation could activate STAT3, which triggers the transcription of MMP-2, and then promote the invasiveness of A549 cells.