TRPP2 Enhances Metastasis by Regulating Epithelial-Mesenchymal Transition in Laryngeal Squamous Cell Carcinoma.

BACKGROUND/AIM: Surgery and chemotherapy treatments of human laryngeal squamous cell carcinoma (HLSCC) may fail due to metastasis, in which epithelial-mesenchymal transition (EMT) plays an important role. TRPP2, a nonselective cation channel, is expressed in various cell types and participates in many biological processes. Here, we show that TRPP2 enhanced metastasis by regulating EMT. METHODS: We used immunohistochemistry, western blotting, Ca2+ imaging, transwell and wound healing assays to investigate TRPP2 expression levels in HLSCC tissue, and the role of TRPP2 in invasion and metastasis of a human laryngocarcinoma cell line (Hep2 cell). RESULTS: We found that TRPP2 protein expression levels were significantly increased in HLSCC tissue; higher TRPP2 levels were associated with decreased patient survival time and degree of differentiation and advanced clinical stage. Knockdown of TRPP2 by transfection with TRPP2 siRNA markedly suppressed ATP-induced Ca2+ release, wound healing, and cell invasion in Hep2 cells. Moreover, TRPP2 siRNA significantly decreased vimentin expression but increased E-cadherin expression in Hep2 cells. In the EMT signalling pathway, TRPP2 siRNA significantly decreased Smad4, STAT3, SNAIL, SLUG and TWIST expression in Hep2 cells. CONCLUSION: We revealed a previously unknown function of TRPP2 in cancer development and a TRPP2-dependent mechanism underlying laryngocarcinoma cell invasion and metastasis. Our results suggest that TRPP2 may be used as a biomarker for evaluating patient prognosis and as a novel therapeutic target in HLSCC.

Expression of Dbn1 during mouse brain development and neural stem cell differentiation.

Dbn1 is a newly discovered gene in the drebrin gene family of mice. Previous studies have reported that Dbn1 is specifically expressed in the mouse brain suggesting its potential role in brain development. However, a detailed analysis of Dbn1 expression during mouse brain development has not been demonstrated. Here, we describe the expression pattern of Dbn1 and the coexpression of Dbn1 and actin during the development of the mouse brain from embryonic day 14 (E14) to adulthood and during the differentiation of neural stem cells (NSCs), as determined using immunohistochemistry, double-labeling immunofluorescence, and quantitative real-time polymerase chain reaction. During mouse brain development, Dbn1 expression level was high at E14, attenuated postnatally, reached its highest point at postnatal day 7 (P7), and showed a very low level at adulthood. Imaging data showed that Dbn1 was mainly expressed in the hippocampus, ventricular zone, and cortex, where NSCs are densely distributed, and that the intracellular distribution of Dbn1 was predominantly located in the cytoplasm edges and neurites. Moreover, the signal for colocalization of Dbn1 with actin was intense at E14, P0, and P7, but it was weak at adulthood. During NSC differentiation, Dbn1 mRNA expression increased after the onset of differentiation and reached its highest point at 3days, followed by a decrease in expression. The imaging data showed that Dbn1 was increasingly expressed in the extending neurites in accordance with the cell morphological changes that occur during differentiation. Furthermore, obvious colocalization signals of Dbn1 with actin were found in the neurites and dendritic spines. Collectively, these results suggest that Dbn1 may play a key role in mouse brain development and may regulate NSC differentiation by filamentous actin.

Virtual microscopy system at Chinese medical university: an assisted teaching platform for promoting active learning and problem-solving skills.

BACKGROUND: Chinese medical universities typically have a high number of students, a shortage of teachers and limited equipment, and as such histology courses have been taught using traditional lecture-based formats, with textbooks and conventional microscopy. This method, however, has reduced creativity and problem-solving skills training in the curriculum. The virtual microscope (VM) system has been shown to be an effective and efficient educational strategy. The present study aims to describe a VM system for undergraduates and to evaluate the effects of promoting active learning and problem-solving skills. METHODS: Two hundred and twenty-nine second-year undergraduate students in the Third Military Medical University were divided into two groups. The VM group contained 115 students and was taught using the VM system. The light microscope (LM) group consisted of 114 students and was taught using the LM system. Post-teaching performances were assessed by multiple-choice questions, short essay questions, case analysis questions and the identification of structure of tissue. Students' teaching preferences and satisfaction were assessed using questionnaires. RESULTS: Test scores in the VM group showed a significant improvement compared with those in the LM group (p < 0.05). There were no substantial differences between the two groups in the mean score rate of multiple-choice questions and the short essay category (p > 0.05); however, there were notable differences in the mean score rate of case analysis questions and identification of structure of tissue (p < 0.05). The questionnaire results indicate that the VM system improves students' productivity and promotes learning efficiency. Furthermore, students reported other positive effects of the VM system in terms of additional learning resources, critical thinking, ease of communication and confidence. CONCLUSIONS: The VM system is an effective tool at Chinese medical university to promote undergraduates' active learning and problem-solving skills as an assisted teaching platform.

Correlation between hearing impairment and the Triglyceride Glucose Index: based on a national cross-sectional study.

Objective: Data from the National Health and Nutrition Examination Survey (NHANES) were used to assess the association between the triglyceride-glucose (TyG) index and hearing impairment (HI). Methods: We used eight survey cycles from NHANES 2001-2012 and 2015-2018 to conduct this cross-sectional study. HI was designed as an dependent variable, and the TyG index was selected as an exposure factor (independent variable). The correlation between the two variables was assessed using multiple logistic regression. In order to assess whether there was a non-linear relationship between the TyG index and HI, the TyG index was distributed and a test for trend was conducted (P for trend), followed by smooth curve fitting (penalized spline) and generalized additive model (GAM) regression. We also performed a subgroup analysis to identify sensitive groups whose responses were clearly associated with independent variables. Results: 10,906 participants were finally included in the study, and those with a higher TyG index had a higher frequency of hearing impairment. There was a linear positive correlation between the TyG index and HI. For the low-frequency HI, however, this positive correlation was not statistically significant (OR = 1.05, 95% CI: 0.98, 1.14); however, it was more stable for the high-frequency HI (OR = 1.12, 95% CI: 1.03, 1.22). Additionally, as the TyG index increased, this positive association increased as well (P for trend = 0.05). The HPTA test showed a positive association with more severe HI (simultaneous) as the independent variable increased (OR = 1.14, 95% CI: 1.05-1.24), and this association was even more significant with increasing severity (P for trend 0.05). According to the subgroup analysis, the positive association between TyG index and high-frequency HI was more significant in females, 40-69 years old, without hypertension or diabetes, and when strict high-frequency HI was significant in males, females, 40-69 years old, with hypertension and diabetes. Conclusion: Participants with a higher TyG index may have a higher risk of HI. TyG index and HI risk showed a linear relationship, which became even more significant when HPTA was included.

Screening genes related to development and injury of the mouse optic nerve by cDNA microarrays.

The aim of this study was to screen genes related to the development and injury of the mouse optic nerve so as to provide possible target genes for gene-engineering therapy of central nervous system (CNS) injury. Gene expression was profiled by cDNA microarrays in the mouse superior colliculus at 8-time points during the development or following injury of the optic nerve; consequently, 1,095 highly expressed genes (ratio > or =2) were identified. Then, these genes were categorized functionally; there were 561 genes (51.19%) with unidentified functions and 534 genes (48.81%) with identified or partially identified functions. After discounting the overlapping genes, 486 genes with identified or partially identified functions were categorized into 17 functional groups. The 17 functional groups were as follows: I transcription regulation, II signal transduction, III protein synthesis, IV materials transporting, V RNA processing, VI metabolism-related genes, VII cell cycle or apoptosis-related genes, VIII extracellular matrix, IX protein folding and degradation, X cytoskeleton, XI histone metabolism, XII nervous system specific functional genes, XIII tumor related genes, XIV DNA replication and repair, XV axon growth and guidance, XVI immune response, and XVII cell adhesion. These genes may play key roles in the development, injury, and repairment of the optic nerve.

In vitro cultivation of human fetal pancreatic ductal stem cells and their differentiation into insulin-producing cells.

AIM: To isolate, culture and identify the human fetal pancreatic ductal stem cells in vitro, and to observe the potency of these multipotential cells differentiation into insulin-producing cells. METHODS: The human fetal pancreas was digested by 1 g/L collagease type IV and then 2.5 g/L trypsin was used to isolate the pancreatic ductal stem cells, followed by culture in serum-free, glucose-free DMEM media with some additional chemical substrates in vitro (according to the different stage). The cells were induced by glucose-free (control), 5 mmol/L, 17.8 mmol/L and 25 mmol/L glucose, respectively. The cell types of differentiated cells were identified using immunocytochemical staining. RESULTS: The shape of human fetal pancreatic ductal stem cells cultured in vitro was firstly fusiform in the first 2 wk, and became monolayer and cobblestone pattern after another 3 to 4 wk. After induced and differentiated by the glucose of different concentrations for another 1 to 2 wk, the cells formed the pancreatic islet-like structures. The identification and potency of these cells were then identified by using the pancreatic ductal stem cell marker, cytokeratin-19 (CK-19), pancreatic beta cell marker, insulin and pancreatic alpha cell marker, glucagons with immunocytochemical staining. At the end of the second week, 95.2% of the cells were positive for CK-19 immunoreactivity. Up to 22.7% of the cells induced by glucose were positive for insulin immunoreactivity, and less than 3.8% of the cells were positive for glucagon immunoreactivity in pancreatic islet-like structures. The positive ratio of immunoreactive staining was dependent on the concentration of glucose, and it was observed that the 17.8 mmol/L glucose stimulated effectively to produce insulin- and glucagons-producing cells. CONCLUSION: The human fetal pancreatic ductal stem cells are capable of proliferation in vitro. These cells have multidifferentiation potential and can be induced by glucose and differentiated into insulin-producing cells in vitro.

Hierarchically clustering to 1,033 genes differentially expressed in mouse superior colliculus in the courses of optic nerve development and injury.

Tempo spatially specific expression of many development-related genes is the molecular basis for the formation of the central nervous system (CNS), especially those genes regulating the proliferation, differentiation, migration, axon growth, and orientation of nerve cells. The development-related genes are usually prominent during the embryonic and newborn stages, but rarely express during the adulthood. These genes are believed to be suitable target genes for promoting CNS regeneration, despite majority of which remains unknown. Hence, the aim of this study was to screen development-related genes which might contribute to CNS regeneration. In this study, 1,033 differentially-expressed genes of superior colliculus in the courses of mouse optic nerve development and injury, as previously identified by cDNA microarrays, were hierarchically clustered to display expression pattern of each gene and reveal the relationships among these genes, and infer the functions of some unknown genes based on function-identified genes with the similar expression patterns. Consequently, the expression patterns of 1,033 candidate genes were revealed at eight time points during optic nerve development or injury. According to the similarity among gene expression patterns, 1,033 genes were divided into seven groups. The potential function of genes in each group was inferred on the basis of the dynamic trend for mean gene expression values. Moreover, the expression patterns of six function-unidentified genes were extremely similar to that of the ptn gene which could promote and guide axonal extension. Therefore, these six genes are temporally regarded as candidate genes related to axon growth and guidance. The results may help to better understand the roles of function-identified genes in the stages of CNS development and injury, and offer useful clues to evaluate the functions of hundreds of unidentified genes.

In nonfunctional pituitary adenomas, estrogen receptors and slug contribute to development of invasiveness.

CONTEXT: Clinical studies suggest that an imbalance in the actions of estrogen receptor (ER)-α and ERß is associated with invasion of tumors of epithelial origin. Both ER have been detected in the pituitary adenomas (PA). Our previous study together with other reports suggests that an imbalance between ERα and ERß contributes to the pathogenesis and biological behavior of PA including invasion. However, the roles of the two ER in invasiveness of PA have not been clarified. OBJECTIVE: The expression of ER, Slug, and E-cadherin in 41 cases of nonfunctional PA (NFPA) were determined to evaluate whether ER were related to the invasiveness of NFPA. Furthermore, we aimed by analysis of the correlation between ER and E-cadherin or Slug to understand molecular mechanisms related to invasiveness. METHODS: Immunohistochemistry, RT-PCR, and Western blot were performed. RESULTS: Nuclear ERα staining was significantly stronger in invasive NFPA than noninvasive ones (P < 0.01). In contrast, nuclear ERß staining was significantly weaker in invasive NFPA than in noninvasive ones (P < 0.01). Both E-cadherin mRNA and protein were decreased in invasive NFPA compared with noninvasive ones. Moreover, Slug, a repressor of E-cadherin, was significantly increased in invasive over noninvasive NFPA (P < 0.01). There were significant correlations between ER and Slug or E-cadherin in NFPA, in which Slug was positively correlated with ERα and inversely correlated with ERß, whereas E-cadherin was positively correlated with ERß and inversely correlated with ERα. CONCLUSIONS: ERα and ERß may act in opposite directions to regulate the Slug-E-cadherin pathway and to affect invasiveness of NFPA.