MiR-421 Is Overexpressed and Promotes Cell Proliferation in Non-Small Cell Lung Cancer.

BACKGROUND: Lung cancer is the main cause of cancer--related deaths worldwide, and the overall 5-year survival rate of non-small cell lung cancer (NSCLC) remained low. -MicroRNAs had been confirmed to be an important regulator in tumor progression, and they could serve as either tumor promoters or suppressors in NSCLC. OBJECTIVES: To identify the novel cancer-specific biomarkers for NSCLC patients, which may be useful to monitor tumor progression and improve NSCLC patients' survival. METHOD: The expression profile of miR-421 was analyzed in NSCLC samples using public datasets, including The Cancer Genome Atlas and GSE102286. The expression level of miR-421 was detected by reverse transcription-polymerase chain reaction. Cell proliferation and cell cycle were detected by Cell Counting Kit assay, flow cytometry assay, respectively. Kyoto Encyclopedia of Genes and Genomes analysis were applied to determine the biological roles of miR-421, based on the online DAVID system. Statistical comparisons between groups of normalized data were performed using t test or Mann-Whitney U test according to the test condition. RESULTS: In this study, we focused on exploring the roles of miR-421 in NSCLC prognosis and growth. The present study for the first time showed that miR-421 was overexpressed in NSCLC and associated with a shorter overall survival time of patients with NSCLC. Bioinformatics analysis revealed miR-421 was involved in transcription, cell cycle, and insulin signaling pathway regulation. Furthermore, a gain of function assay showed that overexpression of miR-421 could promote NSCLC cell proliferation and cell cycle progression. CONCLUSIONS: Our findings suggest that miR-421 might be a promising prognostic and therapeutic target for NSCLC.

Pax5 Re-expression in H460 Cells Treated with the Combination of Demethylating Agent and Histone Deacetylase Inhibitor is Associated with the Enhancement of P53 Binding to Pax5 Promoter Region.

BACKGROUND: The epigenetic combinations of DNA demethylating agents and histone deacetylase (HDAC) inhibitors have demonstrated clinical benefits for non-small cell lung cancer (NSCLC) treatment, however, there are few studies uncovering the underlying molecular mechanism of the combinations. Our previous study showed that DNA demethylating agent Azacitidine (Aza) demethylated CpG sites in paired box gene 5 (pax5) promoter region, but did not induce pax5 mRNA or protein expression. METHODS: In this study we used epigenetic combination of Aza and HDAC inhibitor Vorinostat (SAHA) to treat NSCLC cells and to elucidate the underlying molecular mechanism. We treated pax5- silenced NSCLC H460 cells with Aza+SAHA combination at sub-toxic concentration and detected the re-expression of pax5 mNRA and protein. RESULTS: The results showed demethylation of CpG sites in pax5 promoter region by Aza treatment and increased DNA accessibility for protein binding by SAHA treatment. The combination of Aza+SAHA significantly increased p53 protein binding to DNA in pax5 promoter region (p<0.01). More efficient binding of the transcription factor p53 to pax5 promoter region is likely because SAHA increased accessibility of the chromatin conformation and Aza-demethylated DNA was more permissive, allowing transcription factors to bind. CONCLUSION: Our study not only explained an underlying mechanism, that pax5 re-expression was induced by Aza+SAHA combination in H460 cells via p53, but also demonstrated a pattern showing that the combination of demethylating agent and HDAC inhibitor can re-activate tumor suppressor gene (TSG) which is associated with the enhancement of transcription factors binding to the promoter region of the TSG.

Diaphragmatic motion studied by M-mode ultrasonography in combined pulmonary fibrosis and emphysema.

BACKGROUND: The coexistence of emphysema and pulmonary fibrosis is known as combined pulmonary fibrosis and emphysema (CPFE). The aim of this study was to compare diaphragmatic motion measured by M-mode ultrasonography of patients with CPFE, idiopathic pulmonary fibrosis (IPF), and chronic obstructive pulmonary disease (COPD). METHODS: Pulmonary function, high-resolution computed tomography (HRCT), and diaphragmatic motion were examined in patients with CPFE (n = 25), IPF (n = 18), and COPD (n = 60), and in healthy controls (n = 21). Diaphragmatic motions were measured on M-mode ultrasonographic images during quiet breathing and deep breathing. RESULTS: There were no significant differences in right or left diaphragmatic motion during quiet breathing among the four groups, whereas differences were significant in right and left motion during deep breathing. Diaphragmatic motion in CPFE patients was the lowest among the four groups. COPD patients, especially those with severe COPD, showed significantly lower diaphragmatic motion than IPF patients or healthy controls. There were no differences in diaphragmatic motion between IPF patients and healthy controls. Right diaphragmatic motions during deep breathing were negatively correlated with emphysema scores (r = -0.606, p < 0.001), but were not correlated with fibrosis scores on HRCT. CONCLUSIONS: Diaphragmatic weakness was found in CPFE patients. Emphysema but not fibrosis may be one cause of limited diaphragmatic motion in patients with CPFE. M-mode ultrasonographic evaluation of diaphragmatic motion during deep breathing may be a useful tool in diagnosing CPFE and in discriminating CPFE patients from IPF or COPD patients.