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Dysregulation of microRNAs (miRNAs) is actively involved in the development and progression of glioma. miR-520c was previously found to inhibit glioblastoma cell migration. However, the clinical significance of miR-520c and its biological function in glioma remain largely unknown. In the present study, we found that miR-520c expression in glioma tissues was significantly decreased compared to adjacent non‑cancerous tissues. The low level of miR-520c was prominently correlated with advanced World Health Organization (WHO) grade and decreased overall survival of glioma patients. Overexpression of miR-520c in U251 cells significantly decreased the migration and invasion of the cancer cells, while miR-520c silencing promoted U87 cell migration and invasion in vitro. Mechanistically, miR-520c inversely regulated transforming growth factor-β receptor type 2 (TGFBRII) abundance in the glioma cells. Herein, TGFBRII was found to be a downstream target of miR-520c in glioma. Furthermore, an inverse correlation between TGFBRII and miR-520c expression was observed in the glioma cases. In constrast, restoration of TGFBRII expression abrogated the effects of miR-520c overexpression in U251 cells with increased cell migration and invasion. In addition, miR-520c overexpression blocked TGF-β1‑induced cell migration and invasion in U251 cells. Collectively, miR-520c may serve as a prognostic predictor and a therapeutic target for glioma patients.

Klebsiella pneumoniae is an opportunistic pathogen that mostly affects patients with weakened immune systems, but a few serotypes (especially K1 and K2) are highly invasive and result in systemic infection in healthy persons. The ability to evade and survive the components of the innate immune system is critical in infection. To investigate the role and mechanism of transcription regulator KP1_RS12260 (KbvR) in virulence and defense against the innate immune response, kbvR deletion mutant and complement strains were constructed. The in vivo animal infection assay and in vitro antiphagocytosis assay demonstrate K. pneumoniae KbvR is an important regulator that contributes to virulence and the defense against phagocytosis of macrophages. The transcriptome analysis and phenotype experiments demonstrated that deletion of kbvR decreased production of capsular polysaccharide (CPS) and biosynthesis of partly outer membrane proteins (OMPs). The findings suggest that KbvR is a global regulator that confers pathoadaptive phenotypes, which provide several implications for improving our understanding of the pathogenesis of K. pneumoniae.

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