MicroRNA-330-3p as a putative promoter of brain metastasis in non-small cell lung cancer.

e14007Background: Brain metastasis (BM) is the leading cause of poor prognosis, recurrence, and death in non-small-cell lung cancer (NSCLC) patients. The median overall survival (OS) of NSCLC patients with BM is only 4-6 months. Thus it is important to identify risk factors of BM in patients with NSCLC. MicroRNAs (miRNAs) are a class of conserved small non-coding RNAs of 18-25 nucleotides. Studies reported that some miRNAs were associated with BM of NSCLC. Methods: Study subjects were 122 patients with histologically confirmed NSCLC using AJCC criteria, blood and tissue samples were collected prior to any treatment. Patients without BM upon diagnosis (n = 60) received whole brain CT scan after every two cycles of chemotherapy to identify potential development of BM. The expression of candidate miRNAs (miR-325, miR-328, miR-330-3p, miR-500-3p, miR-326, and miR-370), which were reported high expression in NSCLC BM samples, were examined in a cohort of 122 NSCLC patients, 60 without BM and the remaining 62 w...