Expression of miR-150 and miR-3940-5p is reduced in non-small cell lung carcinoma and correlates with clinicopathological features

The present study investigated the expression of miR-150 and miR-3940-5p in non-small cell lung carcinoma (NSCLC) and its relationship with clinicopathologic features. Samples included tumor, tumor-adjacent and normal lung parenchyma tissues from 90 NSCLC patients and 17 cases of embryonic lung cDNA. The expression levels of miR-150, miR-18b-5p, miR-643 and miR-3940-5p were detected by real-time PCR; p53, EGFR, Kras and Ki-67 expression in tumor tissues was determined by immunohistochemistry. p53 mRNA expression levels in NSCLC were examined by SYBR-Green real-time PCR. The relationship between the four miRNAs and clinicopathologic features of 90 cases was analyzed. The expression of miR-150 and miR-3940-5p was significantly downregulated in tumor tissues and embryonic lung tissues compared to normal lung tissues. The expression of miR-150 and miR-3940-5p in tumor tissues was also lower than that in the matched tumor-adjacent tissues. miR-150 was downregulated preferentially in subgroups of patients with a tumor diameter more than or equal to 3 cm, in smokers and in stage III and IV tumors. Specifically, miR-150 and miR-3940-5p expression was decreased in nuclear cell proliferation antigen Ki-67-positive NSCLC cases. miR-150 and miR-3940-5p were found to be significantly downregulated in p53 IHC-positive NSCLC cases and were negatively correlated with p53 mRNA. Reduced miR-150 and miR-3940-5p expression in tumor tissues and embryonic lung tissues suggests that these miRs may be involved in the tumorigenesis or de-differentiation of NSCLC. Due to this associaton with the Ki-67 proliferation index in NSCLC, downregulation of miR-150 and miR-3940-5p may contribute to tumor growth and proliferation. miR-150 and miR-3940-5p may affect p53 expression through a direct or indirect pathway.