RESUMO
Non-small cell lung cancer (NSCLC) is one type of the most common cancers, which results in the major death worldwide. This study focuses on the understanding of the molecular mechanism of lncRNA NR2F2-AS1 and its regulation on epithelial-mesenchymal transition (EMT) in the development of NSCLC. Expressions of lncRNA NR2F2-AS1, miR-545-5p, c-Met, biliverdin reductase (BVR), ATF-2 and EMT-related markers in NSCLC tissues and cells were measured by western blotting and RT-qPCR assays. The impact of lncRNA NR2F2-AS1 and miR-545-5p on the cell proliferation, migration, invasion and EMT were analyzed by CCK-8, colony formation, wound healing and transwell assays. The interactions among lncRNA NR2F2-AS1, miR-545-5p and c-Met predicted by bioinformatic analysis were evaluated through dual luciferase reporter assay and fluorescence in situ hybridization (FISH). After generating tumor xenografts, immunohistochemistry was utilized to measure the expression of Ki-67 and EMT-related proteins in vivo. Our results showed that lncRNA NR2F2-AS1, c-Met, BVR and ATF-2 were overexpressed while miR-545-5p was silenced in NSCLC tissues and cells. Silencing of lncRNA NR2F2-AS1 or upregulating miR-545-5p significantly inhibited the cell proliferation, migration, invasion and EMT process. The EMT process could be inhibited by suppressing c-Met/BVR/ATF-2 axis. The tumor xenograft experiments demonstrated that the tumor growth and EMT process were significantly inhibited by silencing lncRNA NR2F2-AS1 or overexpression of miR-545-5p in vivo. LncRNA NR2F2-AS1 promoted the NSCLC development through suppressing miR-545-5p to activate EMT process through c-Met/BVR/ATF-2 axis. Our study indicated that lncRNA NR2F2-AS1 and miR-545-5p could be used as potential therapeutic targets to improve NSCLC treatment.
RESUMO
With the advancement of tumor subtype-specific treatments, precise histopathologic distinction between adenocarcinoma (ADC) and squamous cell carcinoma (SCC) is of significant clinical importance. Nevertheless, the current markers are insufficiently precise in poorly differentiated tissue. This study aimed to establish a histology-specific immunomarker combination to subclassify non-small cell lung cancer (NSCLC) specimens. Based on previous work, we assessed the differential expression of anterior gradient 2 (AGR2) and keratin 5 (KRT5) in ADC and SCC by analyzing public datasets and postoperative specimens. Subsequently, we established a train set (n = 188) and a validation set (n = 42) comprised of NSCLC surgical specimens for training and verifying the subtype-identification capabilities of the two biomarkers separately and in combination, and contrasted the diagnostic utility of AGR2-KRT5 with that of the classic immunomarker combination, TTF1-P40. Differential expression of the two genes was statistically significant in ADC and SCC samples, both at the mRNA and protein levels. The specificity and sensitivity of AGR2 to detect ADC in the training set were 97.0% and 94.4%, while the sensitivity and specificity of KRT5 to determine SCC were 93.9% and 98.9%, respectively. The accuracies of AGR2-KRT5 in ADC, SCC, and across all samples were 93.3%, 92.0% and 92.6% respectively. In the validation cohort, the predictive accuracy of AGR2-KRT5 was up to 100% for ADC and 86.7% for SCC. Compared with TTF1-P40 in ADC samples, AGR2-KRT5 had 8.4% higher accuracy. In summary, the AGR2-KRT5 immunomarker combination reliably distinguished SCC from ADC, and was more accurate than TTF1-P40 in ADC.
