ABSTRACT
Serum microRNAs (miRNAs) have been implicated as noninvasive biomarkers for lung cancer diagnosis. However, there are no sensitive and specific biomarkers for the detection of radiotherapy-related non-small cell lung cancer (NSCLC) metastasis. The present study aimed to investigate the role of three serum miRNAs, namely miRNA (miR)-130a, miR-25 and miR-191*, in diagnosing NSCLC, and their biological functions in radiation-mediated development of metastatic properties in A549 cells. To determine this, serum samples were collected from 84 patients with NSCLC and 42 age- and sex-matched healthy controls. Differential expression of serum miRNAs was analyzed by quantitative PCR. Significant associations between miRNA expression and overall survival of patients with NSCLC were identified using the Cox proportional regression model. A receiver operating characteristic curve was generated to evaluate diagnostic accuracy. The functions of miR-130a, miR-25 and miR-191* in lung cancer cells were studied by transfecting A549 cells with miRNA mimics and inhibitors. The results of the present study demonstrated that the expression levels of miR-130a, miR-25 and miR-191* in the serum of patients with NSCLC were increased compared with those in healthy controls, and these increases were associated with advanced age (≥60 years), radiotherapy, histological type (squamous carcinoma), low survival rate and low median survival time. Additionally, irradiation induced the upregulation of miR-130a, miR-25 and miR-191* expression in A549 cells in vitro and in a xenograft mouse model. Irradiation also promoted the invasiveness of A549 cells in vitro and metastasis in vivo. In conclusion, miR-130a, miR-25 and miR-191* may be potential biomarkers for the diagnosis of patients with NSCLC and may serve oncogenic roles in radiation-mediated metastasis of NSCLC.
ABSTRACT
To explore the correlation between epidermal growth factor receptor (EGFR) mutation status and the risk of brain metastasis (BM) in patients with lung adenocarcinoma, the clinical data of 100 patients with pathologically confirmed lung adenocarcinoma and known EGFR mutation status at exon 18, 19, 20, or 21 were analyzed retrospectively. The incidence of BM was similar between patients with wild-type EGFR and those with EGFR mutations (p = 0.48). However, among patients with EGFR mutations, the incidence of BM was significantly higher in patients with mutation at exon 19 than in patients with mutation at other sites (p = 0.007). Besides, among patients with heterochronous BM, 66.7 % had EGFR mutations. Regarding brain-metastasis-free survival (BMFS), patients with EGFR sensitive mutations (mutation at exon 19/21/and dual mutation) had significantly shorter BMFS compared with patients with wild-type EGFR (p = 0.018). For patients treated only with chemotherapy, BM was an unfavorable prognostic factor. Patients with BM had worse overall survival compared with those without BM (p = 0.035). However, in patients with BM and EGFR sensitive mutations, those treated with tyrosine kinase inhibitors (TKIs) had significantly longer overall survival compared with those treated with chemotherapy only (p = 0.0081). In conclusion, among patients with EGFR mutations, those mutated at exon 19 had the highest incidence of BM. Furthermore, patients with EGFR mutations are more likely to develop heterochronous BM. The BMFS was significantly shorter in patients with EGFR sensitive mutations. TKIs improved the survival of patients with lung adenocarcinoma and BM who harbored EGFR sensitive mutations.
