Correlation between miR-564, TGF-β1, and radiation-induced lung injury

Our study aimed to analyze the expression of miR-564 and TGF- β1 in cancer tissues and the serum of patients with radiation-induced lung injury, and to investigate the relationship between them and radiation-induced lung injury. Methods? In situ hybridization and real-time fluorescence quantitative method were used to detect the expression of miR-564. Additionally, immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) were performed to detect the expression of TGF- β1. Results? The overall incidence of acute radiation pneumonia was 55.9% (100/179). The incidence of≥ grade 2 radioactive pneumonia was 24.0% (43/179) and that of grade 1 was 31.8% (57/179). The expression of miR-564 in grade ≥ 2 was slightly higher than that in patients without or with grade 1, but there was no statistical difference (P = 0.86). The serum level and ratio of miR-564 in patients with grade≥ 2 were significantly higher than those without or with grade 1 (P = 0.005, P = 0.025, respectively). The expression of TGF- β1 in grade ≥ 2 was significantly higher than that of patients without or with grade 1 (P =0.017). The serum levels of TGF- β1 in grade ≥ 2 were significantly higher than those in patients without or with grade 1 (P = 0.038). Although the ratio of TGF- β1 in radiation pneumonia of grade ≥ 2 was significantly higher than that of without or with grade 1, there was no significant difference (P = 0.24). Moreover, patients with higher expression of miR-564 and lower expression of TGF-β1 had better prognosis. Conclusion? MiR-564 and TGF-β1 are predictors of radiation-induced lung injury. Monitoring its changing trend can improve the accuracy of predicting radiation-induced lung injury. The levels and ratio of serum miR-564 and TGF- β1 in patients with radiation-induced lung injury are related to the severity of radiation-induced lung injury.