The role and mechanism of collagen type VI alpha 6 (COL6A6) on tumor growth and metastasis in pituitary adenoma (PA) was determined. COL6A6 was downregulated in PA tissues and cell lines, which was negatively associated with the expression of prolyl-4-hydroxylase alpha polypeptide III (P4HA3) in the progression of PA. Overexpression of COL6A6 significantly suppressed tumor growth and metastasis capacity in PA. In addition, P4HA3 worked as the upstream of the PI3K-Akt pathway to alleviate the antitumor activity of COL6A6 on the growth and metastasis of both AtT-20 and HP75 cells. Furthermore, the inhibitory effect of COL6A6 on cell proliferation, migration and invasion, and epithelial-mesenchymal transition (EMT) was reversed by P4HA3 overexpression or activation of the PI3K-Akt pathway induced by IGF-1 addition, which provided a new biomarker for clinical PA treatment.

Matrix metalloproteinase (MMP)-9 is a key enzyme responsible for extracellular matrix degradation and contributes to the progressive histological changes observed in lower respiratory tract infections. Integrin β1 and α-tubulin are potential MMP-9-interacting proteins, and microRNA (miR)-29b-3p can regulate MMP-9 expression. MMP-9 is highly expressed in chronic rhinosinusitis with nasal polyps (cRSwNPs), regardless of its effects on miR-29b-3p, integrin β1 and α-tubulin expression. In the present study, samples from 100 patients with cRSwNPs were examined via reverse transcription-quantitative PcR to assess the mRNA expression of miR-29b-3p, and western blotting was performed to assess the protein expression of MMP-2, MMP-9, acetyl-α-tubulin, integrin β1 and tissue inhibitor of metalloproteinase 1 (TIMP-1). A dual-luciferase reporter assay was used to verify the direct binding of miR-29b-3p and MMP-2/MMP-9. co-immunoprecipitation (co-IP) and GST pull-down assays showed that integrin β1 and α-tubulin were MMP-9-interacting proteins. Cell viability, apoptosis and inflammatory cytokine levels were determined via a Cell Counting Kit-8 assay, flow cytometry and ELISA, respectively. miR-29b-3p expression was found to be positively correlated with MMP-2 and MMP-9 expression. Whereas, TIMP-1 expression was negatively correlated with MMP-2 and MMP-9 expression. The dual-luciferase assay revealed that miR-29b-3p targeted the 3' untranslated region of MMP-2/MMP-9. The co-IP and GST pull-down assays showed that MMP-9 could directly bind to integrin β1 and indirectly bind to α-tubulin. Finally, the overexpression of miR-29b-3p decreased the expression of MMP-9 and increased the levels of acetyl-α-tubulin. By contrast, the knockdown of miR-29b-3p increased the expression of MMP-9 and decreased the levels of acetyl-α-tubulin. Additionally, MMP-9 expression was found to be negatively correlated with acetyl-α-tubulin expression. Of note, the expression of integrin β1 did not change following the overexpression and knockdown of MMP-9. Finally, the overexpression of miR-29b-3p not only decreased MMP-9 expression, but also alleviated lipopolysaccharide-induced inflammation in NP69 cells. The results showed that the downregulation of miR-29b-3p promoted α-tubulin deacetylation by increasing the number of MMP-9-integrin β1 complexes in cRSwNPs, thus targeting miR-29b-3p/MMP-9 may be a potential novel strategy for the clinical treatment of cRSwNPs.

Background Vestibular schwannoma (VS) is a kind of benign tumor deriving from the acoustic nerve sheath. Substantial long non-coding RNAs (lncRNAs) were illustrated to have crucial roles in multiple cancers. However, few lncRNAs were elucidated in VS. Methods HCG11, miR-620 and ELK4 expression were tested by RT-qPCR. Gain-of-function experiments were conducted to confirm the effect of HCG11 on VS. Results HCG11 possessed a low expression in VS cell lines. Overexpression of HCG11 repressed cell proliferation but accelerated apoptosis of VS cells. Moreover, we identified ELK4 stimulated the transcription of HCG11 and their affinity was verified by ChIP assays. MiR-620 was chosen to be a target of HCG11 and it was tested to have a high expression in VS cell lines. Moreover, depletion of miR-620 could inhibit cell proliferative ability while fostering apoptosis rate of VS cells. ELK4 was low expressed in VS cell lines and knockdown of ELK4 could rescue the effects made by HCG11 overexpression on progression of VS. Conclusions HCG11 could inhibit the growth of VS by targeting miR-620/ELK4 in VS cells. HCG11 was a novel therapeutic target for VS treatment.

Acute otitis media (AOM) is a common infectious disease in children that is accompanied by signs and symptoms of middle ear inflammation and infection. Previous studies have shown that the long non-coding (lnc)RNA nuclear-enriched abundant transcript 1(NEAT1) participates in various inflammatory conditions and plays an important regulatory role. The focus of the present study was the biological function of NEAT1 and underlying molecular mechanism in lipopolysaccharide (LPS)-induced human middle ear epithelial cells (HMEECs). The expression of NEAT1, miR-301b-3p and toll-like receptor 4 (TLR4) protein were determined by reverse transcription-quantitative PCR and western blot assays, respectively. Dual-luciferase reporter assay was performed to investigate the combination of miR-301b-3p and NEAT1 or TLR4. In addition, cell viability, apoptosis and the levels of pro-inflammatory factors (IL-1β, TNF-α and IL-6) were measured by Cell Counting Kit-8 assay, flow cytometry and ELISA, respectively. Cell viability was significantly decreased, whereas apoptosis and inflammation were increased in LPS-stimulated HMEECs. Functional analyses demonstrated that NEAT1 was upregulated following LPS treatment, whereas knockdown of NEAT1 significantly increased cell viability and alleviated apoptosis and inflammation. Mechanistically, NEAT1 directly bound to and negatively regulated miR-301b-3p expression, whereas miR-301b-3p inhibitors abolished the inhibitory effect of NEAT1 knockdown on cell apoptosis and inflammation. As a target of miR-301b-3p, TLR4 was regulated by NEAT1 and miR-301b-3p. TLR4 overexpression alleviated NEAT1 silencing-induced inflammatory suppression. Rescue experiments demonstrated that NEAT1 promoted TLR4 expression by inhibiting miR-301b-3p. Collectively, the results of the present study suggested that NEAT1 may attenuate LPS-induced inflammation and apoptosis in HMEECs by modulating the miR-301b-3p/TLR4 axis, and may provide a new therapeutic target for the clinical treatment of AOM.