Evaluation of Serum MicroRNAs (miR-9-5p, miR-17-5p, and miR-148a-3p) as Potential Biomarkers of Breast Cancer.

BACKGROUND: MicroRNAs (miRNAs) play important roles in the initiation and progression of cancers. The purpose of the present study was to evaluate the use of serum miRNA biomarkers in the early diagnosis of breast cancer. METHODS: The expression levels of miR-9-5p, miR-17-5p, and miR-148a-3p were analyzed by quantitative reverse transcription-polymerase chain reaction in 49 patients with newly diagnosed breast cancer and 49 healthy controls. The associations between miR-9-5p, miR-17-5p, and miR-148a-3p levels and clinicopathological parameters were also analyzed. Regression analysis and sensitivity and specificity analyses were used to determine the diagnostic efficacy of the miRNAs. RESULTS: Serum levels of miR-9-5p and miR-148a-3p were significantly higher in breast cancer patients than in healthy controls (both P < 0.05), but miR-17-5p levels were not different between the two groups (P = 0.996). Serum miR-9-5p levels were markedly higher in patients with human epidermal growth factor receptor 2- (HER2-) positive breast cancer than in those with HER2-negative breast cancer (P = 0.049). Serum levels of miR-9-5p and miR-148a-3p were positively correlated with the presence of breast cancer, and both miRNAs had high sensitivity and specificity for the diagnosis of breast cancer. CONCLUSIONS: These findings provide evidence that serum miR-9-5p and miR-148a-3p levels may be used as noninvasive biological markers for the clinical diagnosis of breast cancer.

Downregulated microRNA-140-5p expression regulates apoptosis, migration and invasion of lung cancer cells by targeting zinc finger protein 800.

Despite advances in the diagnosis and treatment in recent years, lung cancer is still one of the primary causes of cancer-associated morbidity and mortality in globally. Abnormally expressed microRNAs (miRNAs/miRs) in tumor tissues serve vital roles in the pathological mechanism of tumors and have become prospective biomarkers for cancer diagnosis. The present study aimed to investigate the effects of the miR-140-5p/zinc finger protein 800 (ZNF800) axis in lung carcinoma, and determine its potential underlying molecular mechanisms. The degree of cell proliferation was assessed via the MTT assay, while the migratory and invasive abilities of lung cancer cells were determined via the Transwell and Matrigel assays. The expression levels of miR-140-5p and ZNF800 were detected via reverse transcription-quantitative PCR and western blot analyses. The results demonstrated that miR-140-5p expression was notably higher in normal human bronchial epithelial cells compared with the respective lung cancer cell lines, H292, PC-9, CL1-5 and H460. Furthermore, miR-140-5p expression increased in the lung cancer cells compared with the control cells following transfection with miR-140-5p mimic. Overexpressing miR-140-5p significantly suppressed the proliferative, invasive and migratory abilities of H460 and PC-9 cells, and stimulated cell apoptosis by upregulating the expression of cleaved-caspase-3. Notably, these effects were reversed following transfection with miR-140-5p inhibitor. miR-140-5p was predicted as a negative regulator of ZNF800, and ZNF800 knockdown significantly suppressed the proliferative and metastatic abilities of lung adenocarcinoma (LUAD) cells, which was comparable to the effects of miR-140-5p mimic. Taken together, these results suggest that miR-140-5p may block the malignant phenotype of LUAD by negatively regulating ZNF800 expression. Thus, the miR-140-5p/ZNF800 axis may be used as an alternative therapeutic target for lung carcinoma in general, and LUAD in particular.