lncRNA HCG22 regulated cell growth and metastasis of papillary thyroid cancer via negatively modulating miR-425-5p.

INTRODUCTION: Papillary thyroid cancer (PTC) is a common malignant tumour in the endocrine system with increasing incidence. LncRNA HCG22 (HCG22) was noticed to be dysregulated in PTC, but its specific function and mechanism remain unknown. The function of HCG22 and its underlying molecular mechanism was investigated to evaluate its potential as a biomarker for PTC. MATERIAL AND METHODS: The expression of HCG22 was detected in PTC cells (TPC-1, SNU790, GLAG-66, and BCPAP) and normal thyroid cells (Nthy-ori) using real time quantative polymerase chain reaction (RT-qPCR). HCG22 and miR-425-5p were regulated by cell transfection. The cell proliferation and metastasis were assessed by CCK8 and Transwell assay. RESULTS: HCG22 was upregulated in PTC cells, of which the knockdown suppressed the proliferation, migration, and invasion of PTC cells. miR-425-5p was downregulated in PTC cells, which was negatively regulated by HCG22. Silencing miR-425-5p could reverse the inhibitory effect of HCG22 knockdown on the cellular processes of PTC. CONCLUSIONS: HCG22 served as a tumour promoter in PTC cells, which regulated cell proliferation and metastasis via negatively regulating miR-425-5p.

Evaluation of antimicrobial peptide LL-37 for treatment of Staphylococcus aureus biofilm on titanium plate.

ABSTRACT: The antimicrobial peptide LL-37 belongs to the cathelicidin family and is one of the few human bactericidal peptides with potent antistaphylococcal activity. Staphylococcus aureus is one of the main infection bacteria in orthopedic implant therapy. Biofilm formation after bacterial infection brings more and more severe test for clinical antiinfection treatment.However, there are few studies on LL-37 in S. aureus infection of prosthesis. In this work, addition to research the antibacterial activity and the inhibitory effect on bacterial adhesion of LL-37, an in vitro model of S. aureus biofilm formation on titanium alloy surface was established to observe the inhibitory effect of LL-37.The results showed that LL-37 has a strong antibacterial effect on S. aureus in vitro, and the minimum inhibitory concentration (MIC) is about 0.62 µΜ. Moreover, LL-37 has significant impact on the adhesion of S. aureus when the concentration ≥0.16 µM and significant anti-staphylococcal biofilm effects on static biofilm models at the concentration of 0.31 to 10 µM. Additionally, LL-37 at 5 µM had a significant destructive effect on S. aureus biofilm (P < .05) that formed on the titanium alloy surface.This study further confirmed the role of LL-37 in the process of S. aureus infection, including antimicrobial activities, inhibition of bacterial adhesion, and inhibition of mature biofilm. LL-37 can significantly destroy the stable biofilm structure on the titanium alloy surface in vitro, which may provide a new way for refractory infection caused by S. aureus in titanium alloy prosthesis infection.