miR-300 inhibits epithelial to mesenchymal transition and metastasis by targeting Twist in human epithelial cancer.

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) is a key step of the progression of tumor cell metastasis. Recent work has demonstrated some miRNAs play critical roles in EMT. In this study, we focused on the roles of miR-300 in regulating EMT. METHODS: The expression levels of miR-300 were examined in epithelial carcinoma cells that underwent an EMT using quantitative reverse transcription-PCR. The role of miR-300 in EMT was investigated by transfection of the miR-300 mimic or inhibitor in natural epithelial-mesenchymal phenotype cell line pairs and in transforming growth factor (TGF) beta-induced EMT cell models. A luciferase reporter assay and a rescue experiment were conducted to confirm the target gene of miR-300. The efficacy of miR-300 against tumor invasion and metastasis was evaluated both in vitro and in vivo. Correlation analysis between miR-300 expression and the expression levels of its target gene, as well as tumor metastasis was performed in specimens from patients with head and neck squamous cell carcinoma (HNSCC). RESULTS: MiR-300 was found down-regulated in the HNSCC cells and breast cancer cells that underwent EMT. Ectopic expression of miR-300 effectively blocked TGF-beta-induced EMT and reversed the phenotype of EMT in HN-12 and MDA-MB-231 cells, but inhibition of miR-300 in the epithelial phenotype cells, HN-4 and MCF-7 cells, could induce EMT. The luciferase reporter assay and the rescue assay results showed that miR-300 directly targets the 3'UTR of Twist. Enforced miR-300 expression suppressed cell invasion in vitro and experimental metastasis in vivo. Clinically, miR-300 expression was found inversely correlated with Twist expression and reduced miR-300 was associated with metastasis in patient specimens. CONCLUSIONS: Down-regulation of miR-300 is required for EMT initiation and maintenance. MiR-300 may negatively regulate EMT by direct targeting Twist and therefore inhibit cancer cell invasion and metastasis, which implicates miR-300 as an attractive candidate for cancer therapy.

Downregulation of miR-153 contributes to epithelial-mesenchymal transition and tumor metastasis in human epithelial cancer.

The epithelial-mesenchymal transition (EMT) is a crucial step in epithelial cancer invasion and metastasis. The aims of this study were to investigate and validate unidentified micro RNAs (miRNAs) that regulate EMT and to reveal their clinical relevance in epithelial cancer patients. By applying miRNA array screening in a natural epithelial-mesenchymal phenotype cell line pair and in a transforming growth factor ß-induced EMT cell model, we found miR-153 was markedly downregulated in the cells that underwent an EMT. A close association was confirmed between inhibition of miR-153 and the EMT phenotype, as well as the invasive ability of epithelial cancer cells. Ectopic expression of miR-153 in mesenchymal-like cells resulted in an epithelial morphology change with decreased cellular invasive ability. On the contrary, transfection of a miR-153 inhibitor in epithelial-like cells led to a mesenchymal phenotype change. In vivo ectopic expression of miR-153 significantly inhibited tumor cell metastasis formation. Data from the dual-luciferase reporter gene assay showed, for the first time, that SNAI1 and ZEB2 were direct targets of miR-153. Inverse correlations were also observed between miR-153 and SNA1 and ZEB2 levels in oral cancer patients' samples. Furthermore, low expression level of miR-153 was found to be significantly related to metastasis and poor prognosis in oral cancer patients. These data demonstrate that miR-153 is a novel regulator of EMT by targeting SNAI1 and ZEB2 and indicate its potential therapeutic value for reducing cancer metastasis.

The performance tests of three-dimensional printing titanium alloy craniomaxillofacial bone plate: A preliminary preclinical study.

Background/purpose: Because of the complex anatomical structure of the maxillofacial skeleton, bending plates is necessary during surgery. The fast developing three-dimensional printing (3DP) technology has provided a new method for making personalized craniomaxillofacial bone plates. However, the properties of these bone plates remain unknown. This study evaluates the mechanical, fatigue, and morphological properties of these bone plates, which may provide data supporting future clinical applications. Materials and methods: The 3DP bone plate was fabricated by selective laser melting (SLM) and electron beam melting (EBM) technologies. Mechanical, surface, and defect analyses were performed to compare their properties with a standard machined sample. One-way analysis of variance was applied, with p < 0.05 considered significant. Results: The 3DP craniomaxillofacial bone plate had better bending strength than that of the standard machined plate (p < 0.01). Whereas the fatigue resistance of the 3DP bone plate needs to be improved in the future. Surface analysis indicated greater roughness of the 3DP bone plate (p < 0.01). However, the surface roughness could be significantly reduced by polishing the surface, which would meet the needs of clinical application after polishing. Further defect analysis revealed the internal defect inside the plate, which should be avoided to improve the mechanical strength of the printed sample in the future. Conclusion: The 3DP titanium craniomaxillofacial bone plate has good mechanical performance and surface morphology, meeting the requirements of clinical application. However, poorer fatigue resistance and a high number of internal defects should be modified in the future.

Histopathological features of condylar hyperplasia and condylar Osteochondroma: a comparison study.

BACKGROUND: Both mandibular condylar hyperplasia and condylar osteochondroma can lead to maxillofacial skeletal asymmetry and malocclusion, although they exhibit different biological behavior. This study attempted to compare the histological features of mandibular condylar hyperplasia and condylar osteochondroma using hematoxylin-and-eosin (H&E) staining, and immunohistochemistry staining of PCNA and EXT1 with quantitative analysis method. RESULTS: The H&E staining showed that condylar hyperplasia and condylar osteochondroma could be divided into four histological types and exhibited features of different endochondral ossification stages. There was evidence of a thicker cartilage cap in condylar osteochondroma as compared condylar hyperplasia (P = 0.018). The percentage of bone formation in condylar osteochondroma was larger than was found in condylar hyperplasia (P = 0.04). Immunohistochemical staining showed that PCNA was mainly located in the undifferentiated mesenchymal layer and the hypertrophic cartilage layer, and there were more PCNA positive cells in the condylar osteochondroma (P = 0.007). EXT1 was mainly expressed in the cartilage layer, and there was also a higher positive rate of EXT1 in condylar osteochondroma (P = 0.0366). The thicker cartilage cap, higher bone formation rate and higher PCNA positive rate indicated a higher rate of proliferative activity in condylar osteochondroma. The more significant positive rate of EXT1 in condylar osteochondroma implied differential biological characteristic as compared to condylar hyperplasia. CONCLUSIONS: These features might be useful in histopathologically distinguishing condylar hyperplasia and osteochondroma.

Proteolytic Release of the p75NTR Intracellular Domain by ADAM10 Promotes Metastasis and Resistance to Anoikis.

Resistance to anoikis allows cancer cells to survive during systemic circulation; however, the mechanism underlying anoikis resistance remains unclear. Here we show that A disintegrin and metalloprotease 10 (ADAM10)-mediated cleavage of p75 neurotrophin receptor (p75NTR) and subsequent generation of the p75NTR intracellular domain (ICD) endow cancer cells with resistance to anoikis. p75NTR ICD promoted expression of TNF receptor-associated factor 6 (TRAF6), a critical intermediary in p75NTR ICD-mediated signal transduction, at the translational level. Cell detachment-induced activation of EGFR triggered autoubiquitination of TRAF6 by facilitating its dimerization, subsequently activated NFκB, and eventually led to anoikis resistance. ADAM10 and p75NTR ICD also promoted tumor metastasis formation in vivo Together, our findings uncover a previously unknown function for the ADAM10-p75NTR ICD-TRAF6-NFκB axis in preventing anoikis and suggest ADAM10 and p75NTR ICD as potential cancer therapeutic targets.Significance: These findings identify the ADAM10-p75NTR ICD-TRAF6-NFκB signaling axis as a potential candidate for cancer therapy. Cancer Res; 78(9); 2262-76. ©2018 AACR.

Disruption and inactivation of the PP2A complex promotes the proliferation and angiogenesis of hemangioma endothelial cells through activating AKT and ERK.

Hemangioma is a benign vascular neoplasm of unknown etiology. In this study, we generated an endothelial-specific PyMT gene-expressing transgenic mouse model that spontaneously develops hemangioma. Based on this transgenic model, a specific binding between PyMT and the core AC dimer of protein phosphatase 2A (PP2A) was verified in hemangioma vascular endothelial cells. The binding between PyMT and the PP2A AC dimer resulted in dissociation of the B subunit from the PP2A complex and inactivation of PP2A phosphatases, which in turn activated AKT and ERK signaling and promoted cell proliferation, migration and angiogenesis in vitro and tumorigenesis in vivo. Consistent with the in vitro findings, decreased PP2A phosphatase activity and disruption of the PP2A heterotrimeric complex were also observed in both primary transgene-positive TG(+) mouse hemangioma endothelial cells (TG(+) HEC cells) and human proliferating phase hemangioma endothelial (human HEC-P) cells, but not in transgene-negative TG(-) mouse normal vascular endothelial cells (TG(-) NEC cells) and human involuting phase hemangioma endothelial (human HEC-I) cells. Further, it was observed that in human hemangioma cells, endoglin could compete with the PP2A/A, C subunits for binding to the PP2A/B subunit, thereby resulting in dissociation of the B subunit from the PP2A complex. Treatment of Tie2/PyMT transgenic mice with the PP2A activator FTY720 significantly delayed the occurrence of hemangioma. Our data provide evidence of a previously unreported anti-proliferation and anti-angiogenesis effect of PP2A in vascular endothelial cells, and show the therapeutic value of PP2A activators in hemangioma.

The potential of pH-responsive PEG-hyperbranched polyacylhydrazone micelles for cancer therapy.

pH-responsive hyperbranched polymers have attracted much attention due to their unique properties for tumor-targeted drug delivery. In this study, we describe a pH-responsive drug carrier, poly (ethylene glycol) (PEG)-hyperbranched polyacylhydrazone (HPAH), which can form nanoscale micelles to be used as anti cancer drug carriers with pH-controlled drug release. The molecular structure of PEG-HPAH was confirmed by nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR). The drug-loaded micelles with a diameter of approximately 190 nm, were prepared using a dialysis method against PBS with a pH of 8.0. The drug-loaded micelles showed the desired pH-dependent drug release properties. The drug release levels were low at neutral and alkaline pH, but increased significantly with a decrease in the pH of the medium. Intracellular uptake results indicated that the PEG-HPAH-drug micelles could efficiently deliver chemotherapeutic drugs into the cells. In addition, it was found that the subcellular localization of the drug-loaded micelles was different from that of free drugs, in which the drug-loaded micelles were mainly in the cytoplasm. The docetaxel (DTX)-loaded PEG-HPAH micelles presented a high cytotoxic activity against tumor cells in vitro. When combined with the administration of glucose, the PEG-HPAH-DTX micelles exhibited a superior anti-tumor efficacy and a lower systemic toxicity in vivo. The biodistribution profile showed increased accumulated drug levels in tumor tissue and plasma in micelles treated group. The results indicate that the nanoscale PEG-HPAH-DTX micelles may serve as a selective tumor-targeting drug delivery system.