Long non-coding RNA nuclear enriched abundant transcript 1 (NEAT1) has been demonstrated to serve key roles in numerous human cancer types, but its function in oral squamous cell carcinoma (OSCC) and underlying regulatory mechanism have not been evaluated. The present study demonstrated that expression of NEAT1 was significantly higher in OSCC tissue and cell lines compared with adjacent non-tumour tissue and normal oral keratinocytes, respectively. Additionally, upregulation of NEAT1 was significantly associated with advanced clinical stage and shorter survival time in patients with OSCC. Bioinformatics analysis and luciferase reporter gene assay data confirmed the interaction between NEAT1 and miR-365, and it was revealed that NEAT1 may downregulate microRNA (miR)-365 expression in OSCC cells. Furthermore, inhibition of NEAT1 expression led to a significant reduction in OSCC cell migration and invasion, which was accompanied by reduced matrix metalloproteinase (MMP)-2 and MMP9 protein expression. By contrast, inhibition of miR-365 eliminated suppressive effects of NEAT1 knockdown on OSCC cell migration and invasion. miR-365 was significantly downregulated in OSCC tissue and cell lines and an inverse correlation between miR-365 and NEAT1 expression in OSCC tissue was observed. To conclude, the present study demonstrated that NEAT1 promoted migration and invasiveness of OSCC cells by sponging miR-365. The current study suggests that NEAT1 may serve as a novel therapeutic target for the treatment of OSCC.

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Delayed resorption of crown-covered bone is a critical cause of delayed tooth eruption. Traditional herbal medicines may be good auxiliary treatments to promote the resorption of crown-covered bone. This study was carried out to analyse the effect of isorhamnetin 3-O-neohesperidoside on receptor activator of nuclear factor-kB ligand (RANKL)-induced osteoclastogenesis in vitro and resorption of the crown-covered bone of the lower first molars in mice in vivo. Isorhamnetin 3-O-neohesperidoside promoted osteoclastogenesis and the bone resorption of mouse bone marrow macrophages (BMMs) and upregulated mRNA expression of the osteoclast-specific genes cathepsin K (CTSK), vacuolartype H +-ATPase d2(V-ATPase d2), tartrate resistant acid phosphatase (TRAP) and nuclear factor of activated T-cells cytoplasmic 1 (NFATc1). NFATc1, p38 and AKT signalling was obviously activated by isorhamnetin 3-O-neohesperidoside in osteoclastogenesis. Isorhamnetin 3-O-neohesperidoside aggravated resorption of crown-covered bone in vivo. In brief, isorhamnetin 3-O-neohesperidoside might be a candidate adjuvant therapy for delayed intraosseous eruption. The development of osseous eruption is an indispensable stage in the tooth eruption process 1,2. Osteoclast differentiation is stimulated, causing the resorption of crown-covered bone of an erupting tooth, which forms an intraosseous eruption canal 3. Osteoclastogenesis in the crown-covered bone is essential. Impaired osseous eruption, in which osteoclastogenesis is disturbed, is common in clinical practice 4 and can manifest as either delayed or the complete absence of eruption 5,6. Although unerupted teeth are usually asymptomatic, they may cause cosmetic and pathologic complications 4 Treatments include orthodontic uprighting, surgical-orthodontic uprighting, surgical uprighting, surgical repositioning, surgical exposure or the removal of pathologic conditions 7. However, these treatments are very complex and invasive. Research shows that osteoclastogenesis is regulated by a key factor termed receptor activator of NF-κB ligand (RANKL). RANKL agonists or osteoclastogenesis-related drugs can be used to treat delayed tooth eruption 8,9. Traditional Chinese medicine, which is without toxic side effects may also be a good auxiliary treatment for delayed tooth eruption. Isorhamnetin 3-O-neohesperidin, known as Pu huang in Chinese 10 , is the main active substance of T. angustifolia, can also be isolated from the leaves of Acacia salicina 11. Because of its antioxidant, antiatherogenic and anti-inflammatory activities, Pu Huang has been widely used for the treatment of haematuria, dysmenorrhea, uterine bleeding and trauma in China for a long time 12. Isorhamnetin 3-O-neohesperidin has been reported to protect cells against oxidative stress by inhibiting H 2 O 2-induced genotoxicity and DNA damage induced by hydroxyl radicals 13. Intestinal flora including Escherichia sp. 23 and sp. 30, can convert isorhamnetin 3-O-neohesperidin to three main metabolites, isorhamnetin-3-O-glucoside(I3OG), isorhamnet...

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