Plasminogen activator inhibitor-1 gene is associated with radioactive lung injury in lung cancer patients

Although the application of radiotherapy techniques reduced normal lung tissue of exposure for patients with non-small cell lung cancer, Radioactive Pneumonia (RP) and Pulmonary Fibrosis (RF) are still frequently occurred in the processes of lung cancer radiotherapy. Plasminogen Activator Inhibitor-1 (PAI-1) plays a crucial role in the process of lung injury during RP in lung cancer patients. However, the relationships between PAI-1 and lung injury have not well understood, yet. In this study, we investigated the role of PAI-1 in the progression of RP and PF in patients with lung cancer, who have undergone radiotherapy. A total of 126 lung cancer patients and 62 healthy volunteers were recruited to analyse the changes of PAI-1 serum levels. We showed that PAI-1 serum levels were down-regulated in patients with lung cancer compared to healthy volunteers. Outcomes demonstrated that PAI-1 was up-regulated in lung cancer patients after radiotherapy. Patients with RP presented higher serum levels of PAI-1 were positively correlated with degree of RP and PF for patients who undergone radiotherapy. We also showed that serum levels of PAI-1 were down-regulated after recovery of radioactive lung injury in lung cancer patients. Outcomes indicated that PAI-1 gene expression levels were up-regulated in lung fibroblasts in patients with radioactive lung injury compared to healthy controls. In conclusion, these findings indicate that serum levels of PAI-1 were associated with radioactive lung injury-induced PR and PF in lung cancer patients, who undergone radiotherapy.