Using quantitative reverse transcriptase PCR analysis, we first selected and identified three aberrant plasma expression miRNAs (miR-21, miR-145, and miR-155) in a training set of 62 patients and 60 healthy smokers to define a panel that had high diagnostic efficiency for lung cancer.
Besides, the pooled PLR was 3.75 (95% CI: 2.76-5.10), NLR was 0.23 (95% CI: 0.15-0.37), DOR was 15.99 (95% CI: 8.11-31.52) and AUC was 0.87 (95% CI: 0.84-0.90), indicating a significant value of miR-155 in the lung cancer detection.
The results showed that expression of miR-155 was significantly higher in lung cancer tissues than in paracancerous and normal tissues; whereas Apaf-1 expression was lower in the lung cancerous tissues.
The aim of this study was to evaluate for the first time in lung cancer the use of liquid-based cytology both for EGFR and KRAS mutational testing and for the expression trend of some miRNAs involved in lung cancer pathogenesis: miR-21, miR-155, miR-7, and let7a.
However, the levels of miR10b (p = 0.002), miR141 (p = 0.0001) and miR155 (p = 0.007) were significantly higher in lung cancer patients than those in patients with benign disease.
The study indicated that transfection of miR-155-5p mimic significantly suppressed cell proliferation, migration and invasion of A549 cells, whereas its inhibition significantly promoted cell proliferation, migration and invasion of A549 cells, suggesting a potential therapeutic application of miR-155-5p in controlling lung cancer metastasis.
Additionally, in Asian and America subgroups, greater expression levels of miR-155 were related to poor prognoses for lung cancer (HR 1.71 95% CI: 1.22-2.40, P = 0.002, HR 2.35 95% CI: 1.42-3.89 P = 0.001), while no significant relationship was present in a Europe subgroup (HR 0.75 95%CI: 0.27-2.10, P = 0.587).
The octreotide-conjugated chitosan-molecular beacon nanoparticles (CS-MB-OCT) can specifically bind to SSTR2 expressed by the lung cancer cells to achieve the goal of identification of lung cancer cells and imaging miR-155 in vivo and in vitro.
Our findings indicate that FOXO3a is a significant factor in EGFR mutation-independent gefitinib resistance and the stemness of lung cancer, and suggest that targeting the NF-κB/miR-155/FOXO3a pathway has potential therapeutic value in lung cancer with the acquisition of resistance to EGFR-TKIs.
These results indicate that microRNAs show promising associations with prognosis in lung cancer; moreover, specific microRNAs such as miR-21 and miR-155 can predict recurrence and poor survival in NSCLC.
In addition, 4 microRNAs were investigated (miRNA 21, miRNA 155, miRNA 200c, and miRNA 34a) because their relation to lung cancer has been documented recently.
The rs767649 polymorphism, locating in the promoter of miR-155, was recently reported to be able to alter transcriptional activity of miR-155 and relate to lung cancer risk.