hsa-miR-485-5p reverses epithelial to mesenchymal transition and promotes cisplatin-induced cell death by targeting PAK1 in oral tongue squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is currently a highly prevalent disease worldwide. Cisplatin (CDDP) is widely used for the chemotherapy of OSCC. Yet, the molecular mechanisms responsible for cisplatin resistance have not been fully elucidated. In this study, we showed that overexpression of p21 (RAC1) activated kinase 1 (PAK1) induced epithelial to mesenchymal transition (EMT) and significantly promoted the invasion and migration of oral squamous cell carcinoma SCC25 cells. Emerging evidence indicates a strong link between resistance to therapy and the induction of EMT in cancer. We showed that overexpression of PAK1 induced cisplatin resistance in SCC25 cells. ERCC1 and YAP can promote cisplatin resistance in human OSCC. We showed that ERCC1 and YAP protein were upregulated by PAK1 in SCC25 cells. -We found that miR­485­5p inhibited PAK1 protein expression in the SCC25 cells. Contrary to PAK1, we demonstrated that overexpression of miR­485­5p reversed EMT and significantly inhibited invasion and migration. Moreover, its overexpression sensitized SCC25-CR cells (cisplatin-resistant cells) to cisplatin. Thus, we conclude that miR­485­5p reverses EMT and promotes cisplatin-induced cell death by targeting PAK1 in oral tongue squamous cell carcinoma. This study suggests that PAK1 plays an essential role in the progression of OSCC and it is a potential therapeutic target for OSCC.

Critical-size calvarial bone defects healing in a mouse model with silk scaffolds and SATB2-modified iPSCs.

Induced pluripotent stem cells (iPSCs) can differentiate into mineralizing cells and thus have a great potential in application in engineered bone substitutes with bioactive scaffolds in regeneration medicine. In the current study we characterized and demonstrated the pluripotency and osteogenic differentiation of mouse iPSCs. To enhance the osteogenic differentiation of iPSCs, we then transduced the iPSCs with the potent transcription factor, nuclear matrix protein SATB2. We observed that in SATB2-overexpressing iPSCs there were increased mineral nodule formation and elevated mRNA levels of key osteogenic genes, osterix (OSX), Runx2, bone sialoprotein (BSP) and osteocalcin (OCN). Moreover, the mRNA levels of HoxA2 was reduced after SATB2 overexpression in iPSCs. The SATB2-overexpressing iPSCs were then combined with silk scaffolds and transplanted into critical-size calvarial bone defects created in nude mice. Five weeks post-surgery, radiological and micro-CT analysis revealed enhanced new bone formation in calvarial defects in SATB2 group. Histological analysis also showed increased new bone formation and mineralization in the SATB2 group. In conclusion, the results demonstrate that SATB2 facilitates the differentiation of iPSCs towards osteoblast-lineage cells by repressing HoxA2 and augmenting the functions of the osteoblast determinants Runx2, BSP and OCN.

[Pulmonary pathology in fatal human influenza A (H1N1) infection].

OBJECTIVE: To study the pulmonary pathology in patients died of fatal human influenza A(H1N1) infection. METHODS: Eight cases of fatal human influenza A (H1N1) infection, including 2 autopsy cases and 6 paramortem needle puncture biopsies, were enrolled into the study. Histologic examination, immunohistochemitry, flow cytometry and Western blotting were carried out. RESULTS: The major pathologic changes included necrotizing bronchiolitis with surrounding inflammation, diffuse alveolar damage and pulmonary hemorrhage. Influenza viral antigen expression was detected in the lung tissue by Western blotting. Immunohistochemical study demonstrated the presence of nuclear protein and hemagglutinin virus antigens in parts of trachea, bronchial epithelium and glands, alveolar epithelium, macrophages and endothelium. Flow cytometry showed that the apoptotic rate of type II pneumocytes (32.15%, 78.15%) was significantly higher than that of the controls (1.93%, 3.77%). CONCLUSION: Necrotizing bronchiolitis, diffuse alveolar damage and pulmonary hemorrhage followed by pulmonary fibrosis in late stage are the major pathologic changes in fatal human influenza A (H1N1) infection.

[Immunohistochemical localization of leucine-rich proteoglycans in the developing periodontal tissues of mice].

OBJECTIVE: To study the distribution and expression of fibromodulin, decorin and biglycan in developing normal periodontal tissues, so as to understand its role in periodontal tissue formation. METHODS: Thirty six BALB/c mice in different developing stages were killed and their bilateral mandibular first molars with surrounding alveolar bones and gingival tissues were taken out, Power Vision two steps immunohistochemical method with anti-fibromodulin, anti-decorin and anti-biglycan was used to detect the tissue distribution and cellular localization of fibromodulin and related proteoglycans, decorin and biglycan. RESULTS: Fibromodulin was strongly expressed in the subcutaneous gingival connective tissue, periodontal ligament, mainly in gingival and periodontal fibroblasts as well as their matrices. Strong expression was also noted in the area close to the interfaces of periodontal ligament-alveolar bone and periodontal ligament-cementum. Decorin was strongly expressed in the area of gingival connective tissue, periodontal ligament and the surface of alveolar bone, while biglycan was stained evidently in gingival connective tissue throughout the period of investigation, but negative in the surface of alveolar bone and osteoblasts. CONCLUSIONS: Fibromodulin may interact with decorin and biglycan to regulate the network formation of gingival connective tissues and periodontal collagen fibers, and may be involved in mineralization of the alveolar bone and cementum.

[Histological location of DMP1, OPN and BSP in cementum formation of mouse].

PURPOSE: To study the distribution of dentin matrix protein 1, osteopontin and bone sialoprotein during cementum formation and cementoblasts differentiation in mouse. METHODS: Thirty six BALB/c postnatal mice were divided into four groups according to the developing stages, nine in each was subdivided into three parts randomly to examine the location of DMP1, OPN and BSP, a tooth developing study model was built and examined using histological methods correspondingly. PV two steps immunohistochemical assay was used to localize the distribution of the three regulatory factors timely and spatially. Repeated measures ANOVA and statistical analysis software of CMIAS were used to analyze the intensity of the dyed images. RESULTS: There was a series expression of the three regulatory proteins. DMP1 was expressed in the dental follicle cells in day 5 of postnatal stages and negatively expressed when the cell began to differentiate; meanwhile, since day 10 and on OPN was positively located in cementoblasts until the root developed completely; but BSP was expressed in the same cell in day 15 to 20, and then decreased to be negative. There were significant differences statistically among the three factors in each stage observed in the study except OPN between day 15 and 25. CONCLUSIONS: There are different locations timely and spatially among the three proteins, it hints that they play important different roles during the differentiation of cementoblasts and formation of cementum.