LncRNA TUG1 facilitates proliferation, invasion and stemness of ovarian cancer cell via miR-186-5p/ZEB1 axis.

LncRNA TUG1 has been rarely studied in ovarian cancer (OC), our objective was to explore the role of TUG1 in the regulation of malignant phenotypes of OC. Vectors of sh-TUG1, miR-186-5p and pcDNA-ZEB1 were, respectively, constructed and used to infect OC cells. MTT and transwell assays were applied for representing cell proliferation and invasion, respectively. Sphere formation experiment was used to detect the stemness of OC cells. Western blotting and qRT-PCR were employed for detecting the expression of multiple biomarkers on protein and RNA levels, respectively. The luciferase assay was performed to reveal the interactions between miR-186-5p and TUG1 or ZEB1. The silencing of TUG1 and upregulation of miR-186-5p both suppressed the cell proliferation, invasion and cancer stem cell (CSC) properties. Additionally, luciferase assay verified that miR-186-5p directly binds TUG1 and ZEB1. Moreover, overexpression of ZEB1 rescued the impact on the proliferation, invasion and stemness of TUG1 silencing in OC. TUG1 sponges miR-186-5p to release ZEB1 and promotes the proliferation, invasion and stemness of OC cells, suggesting that TUG1 could be a potential therapeutic target for OC therapy. SIGNIFICANCE OF THE STUDY: LncRNA TUG1 could promote proliferation, invasion and stemness of ovarian cancer cells. Our study first discovered that TUG1 play a tumourigenic role in ovarian cancer by regulating stemness of cancer cells. Mechanism research exhibited the regulation role of TUG1 in ovarian cancer cells was miR-186-5p/ZEB1 axis depended. These results provided a new perspective to understand the pathogenesis and development of ovarian cancer; it will offer new evidence for better diagnosis and treatment therapy of ovarian cancer.

[Application of micro-lecture in standardized training of endodontic residents].

PURPOSE: To apply micro-lecture in standardized training of endodontic residents, in order to improve training quality. METHODS: Twenty endodontic residents were randomly divided into 2 groups, 10 students in each group. One group were taught with micro-lecture while the other group with lecture-based learning (LBL). The teaching effect was measured with examination and questionnaire survey. The examination results were analyzed by Student's t test using SPSS 18.0 software package. RESULTS: Micro-lecture group was better than LBL group in practical test and total scores, there were significant differences between the two groups (P＜0.05). Micro-lecture group was better than LBL group in didactic test, but there was no significant difference between the two groups (P＞0.05). Questionnaire survey showed that micro-lecture was well accepted by residents for its novelty and flexibility, self-motivated learning ability was trained, communication between teachers and residents was enhanced, but the production level of micro-lecture video needs to be improved. CONCLUSIONS: Micro-lecture achieves satisfactory teaching effect, and can be applied in standardized training of endodontic residents.

The Role of MicroRNA-143-5p in the Differentiation of Dental Pulp Stem Cells into Odontoblasts by Targeting Runx2 via the OPG/RANKL Signaling Pathway.

This study aims to elucidate the mechanisms by which microRNA-143-5p (miR-143-5p) targets runt-related transcription factor 2 (Runx2) in the differentiation of dental pulp stem cells (DPSCs) into odontoblasts, through regulating the osteoprotegerin receptor activator of the nuclear factor-κB ligand (OPG/RANKL) signaling pathway. Following transfection, DPSCs were divided into blank, control, miR-143-5p mimics, miR-143-5p inhibitors, miR-143-5p inhibitors + siRunx2 and siRunx2 groups. Alkaline phosphatase (ALP) activity and mineralized nodules were detected using ALP kit and alizarin red staining. Quantitative reverse transcriptase real time PCR (qRT-PCR) was conducted to measure mRNA expressions of miR-143-5p, Runx2, OPG, and RANKL. Western blotting was used to assess protein expression of odontoblast differentiation-related proteins. Transwell assay and an extracellular matrix (ECM) adhesion cell assay were employed to examine cell migration and cell adhesion. Compared with the blank group, the miR-143-5p mimics and siRunx2 groups showed decreased ALP activity, decreased mineralized nodules and displays of calcium. Fewer migrated cells, weakened cell adhesion, decreased protein expression of dentin phosphoprotein (DPP), dentin sialoprotein (DSP), dentin matrix protein 1 (DMP1), osteopontin (OPN), bone sialoprotein (BSP), osteocalcin (OCN), OPG and Runx2, and increased RANKL protein expressions were observed. Additionally, opposite results were observed in the miR-143-5p inhibitors group, demonstrating that down-regulated miR-143-5p promotes the differentiation of DPSCs into odontoblasts by enhancing Runx2 expression via the OPG/RANKL signaling pathway. Based on findings in this study, it is postulated that the enhancement of Runx2 expression via the regulation of the OPG/RANKL signaling pathway could be a beneficial approach for dental pulp regeneration. J. Cell. Biochem. 119: 536-546, 2018. © 2017 Wiley Periodicals, Inc.

[Application of Flipped classroom combined with case-based learning in resident training of endodontics].

PURPOSE: To apply Flipped classroom combined with case-based learning(CBL) in resident training of endodontics, in order to improve training efficiency. METHODS: Fifty-one residents from China Medical University, School of Stomatology were randomly divided into 2 groups, twenty-six students in the experimental group were trained with Flipped classroom combined with CBL, the other twenty-five students in the control group were trained with traditional teaching method. At the end of the course, exams and questionnaires were conducted to evaluate the training quality of two different methods. The exams consisted of didactic and operational assessment. The data were analyzed with SPSS 13.0 software package. RESULTS: The results of didactic exam and comprehensive evaluation indicated that experimental group was significantly higher than the control group(P<0.05). The results of questionnaires indicated that residents showed much more satisfied with Flipped classroom combined with CBL (P<0.05).However, there was no significant difference in operational assessment(P>0.05). CONCLUSIONS: Compared with traditional teaching method, Flipped classroom combined with CBL can achieve better training effect, which is worthy of further application in dental resident training.

[Comparison of wear resistance and flexural strength of three kinds of bulk-fill composite resins].

PURPOSE: To compare the abrasion resistance and flexure strength of three bulk-fill resin composites with an universal nano-hybrid composite resins. METHODS: The specimens were prepared with three kinds of bulk fill composites (SDR , sonicfill, Tetric N-Ceram Bulk Fill) and an universal nano-hybrid composite resins(Herculite Precis). 10 mm in diameter × 2mm in height specimens were prepared for abrasion resistance, while 2 mm in width × 2 mm in depth×25 mm in length specimens were prepared for flexure strength. The specimens were mounted in a bal1-on-disc wear testing machine and abraded with the media artificial saliva(50 N loads, 10000 cycles).Flexural test was performed with an Universal Testing Machine at a cross-head speed of 1mm/min. One-way variance analysis was used to determine the statistical differences of volume loss and flexural strength among groups with SPSS 13.0 software package(P<0.05). RESULTS: The volume loss was as follows: SDR (1.2433±0.11) mm30.05). CONCLUSIONS: With regard to wear resistance and flexural strength, Tetric N-Ceram Bulk Fill is recommended as an alternative for posterior restorations.

[The effect of calcium hydroxide on IL-6 and TNF-α expression of osteoblast in periapical tissues].

PURPOSE: To compare the effect of calcium hydroxide in different position on pH and inflammation factor expression of periapical osteoblasts. METHODS: 140 sterilized single-rooted human teeth models were randomly divided into 6 experiment groups and one control group: Group 1-3:calcium hydroxide paste was placed in the apical half of root canal, the upper half of root canal and the pulp champer; Group 4-6:Apexcal was placed in the apical half of root canal, the upper half of root canal and the pulp champer; Group 7: the control group without medication. 10 teeth of each group were placed in P.e suspension, the IL-6 and TNF-α expression of MC3T3-E1 was tested at 3 d and 7 d. The other teeth of each group were placed in distilled water, and the pH in periapical region was tested at 3, 7, 14 and 21 d. SPSS 13.0 software package was used for statistical analysis. RESULTS: Calcium hydroxide placed in different position of the root canal increased periapical pH value and reached its peak at 14 d. The group in which calcium hydroxide paste was placed in pulp chamber gained lower pH level than other experimental groups. IL-6, TNF-α expression of MC3T3-E1 pretreated by P.e suspension of experimental groups was significantly reduced compared with control group, and there was no significant difference between the experimental groups. CONCLUSIONS: Calcium hydroxide placed in different position of the root canal could increase periapical pH value and reduce IL- 6, TNF-α expression of periapical osteoblasts.

[Application of PBL combined with SP method in during-course practice of endodontics for undergraduate dental students].

PURPOSE: To apply problem-based learning (PBL) combined with standardized patients(SP) in during-course practice of endodontics for undergraduate dental students, in order to improve the teaching quality. METHODS: One hundred and four undergraduate dental students of China Medical University School of Stomatology were randomly divided into 2 groups, 52 students in each group. One group were taught with PBL combined with SP while the other group with lecture-based learning (LBL) alone. The teaching effect was measured with examination and questionnaire survey. The data were analyzed by Student's t test using SPSS 11.5 software package. RESULTS: Students in PBL combined with SP group was better than LBL group in case analysis, didactic tests, practical tests and total scores, and there was significant difference between the two groups (P<0.05). LBL group was better than PBL combined with SP group in basic theoretical knowledge scores, and there was significant difference between the two groups (P<0.05). SP and PBL combined with SP method were welcomed by undergraduate dental students. CONCLUSIONS: The abilities of undergraduate dental students can be improved by PBL combined with SP in different aspects. PBL combined with SP achieves satisfactory teaching effect, and can be applied in during-course practice of endodontics to undergraduate dental students.

[Root canal treatment of mandibular first premolar with 4 root canals: a case report].

The mandibular first premolar can be considered one of the most challenging teeth to treat, due to the complexity of its root canal morphology and increased incidence of multiple canals. A case of endodontic treatment of a mandibular first premolar exhibiting a total of 4 distinct root canals and 4 apical foramina was described. Anatomic variation of root canal morphology should be considered in endodontic treatment to ensure a favorable healing outcome, and its identification could be enhanced by careful examination using a dental operating microscope. Obturation of root canals using a warm vertical compaction technique with a highly-radiopaque root canal sealer, such as AH Plus, after careful ultrasonic activated irrigation might allow the flow of sealer into the narrowed but unprepared part of the canal, thereby facilitating optimum chemo-mechanical debridement of the root canal system.

[Preliminary study on root canal morphology of maxillary second molars].

PURPOSE: To investigate the root canal morphology and anatomy of maxillary second molars using transparent tooth technique and cone-beam computed tomography (CBCT), and explore the consistency of 2 methods in identifying root canal configurations and morphology. METHODS: Fifty extracted maxillary second molars were scanned by CBCT and analyzed using assistant software. Root canal configurations of each root were identified based on Vertucci's classification and recorded. All transparent teeth samples were made with modified root canal staining technique, and the root canal configurations of each root were classified based on Vertucci's classification. The results were analyzed statistically with SPSS17.0 software package. RESULTS: According to transparent tooth technique, type I was the most common configuration in distobuccal root and palatal root. An additional configuration type 3-2-2 was found in the present study, which was not included in Vertucci's classification. The wide variety of canal systems was seen in the mesiobuccal root. Type I configuration was most prevalent(54.4%), followed by Type II, IV,V,VI. The prevalence of second canal in mesiobuccal root (MB2) was 41.3%. The results of canal morphology and configuration were consistent between transparent tooth technique and CBCT. CONCLUSIONS: Maxillary second molars have the most complex root and canal morphology, especially for the mesiobuccal root. For identifying root canal and root anatomy, CBCT can be used as an alternative to transparent tooth technique in clinical practice. The application of 3D reconstruction based on CBCT helps us to visualize the root canal anatomy.

[Application of problem-based learning in pre-job training of postgraduate students in department of endodontics].

PURPOSE: To apply problem-based learning (PBL) in pre-job training of postgraduate students in department of endodontics. METHODS: Thirty master degree postgraduate students of China Medical University were randomly divided into 2 groups, there were 15 students in each group. One group were taught with PBL method while the other group with lecture-based learning (LBL) method. The teaching effect was measured with examination and questionnaire survey. The data were analyzed by student's t-test using SPSS 11.5 software package. RESULTS: There was no significant difference in basic knowledge, medical records writing, oral examination between the two groups (P>0.05). There were significant differences in case analysis, dental operation, theory examination, practical examination and total scores between the two groups (P<0.05). The PBL method was welcomed by master degree postgraduate students. CONCLUSIONS: The abilities of postgraduate students can be developed by PBL method in different aspects. PBL achieves satisfactory teaching effect, and can be applied in pre-job training of postgraduate students.

[The application of cone-beam computed tomography in diagnosing the lesions of apical periodontitis of posterior teeth].

PURPOSE: To evaluate the effect of periapical radiography in diagnosing the lesions of the apical periodontitis (AP) of posterior teeth, with CBCT imaging as a standard. METHODS: One hundred and six posterior teeth in 80 patients were examined by periapical radiography and CBCT, which consisted of healthy teeth (58 teeth), chronic pulpitis (11 teeth), chronic apical periodontitis (34 teeth), remnant teeth with normal apical images after root canal therapy (3 teeth). All images were measured and evaluated by two experienced dentists by using periapical index (PAI) to ensure the classifications. The results were analyzed statistically with SPSS 13.0 software package for χ2 test. RESULTS: AP was identified in 39.6% and 59.4% of 106 cases by radiography and CBCT, the difference was significant (χ2=8.32, P<0.01). The use of conventional radiography for detection of AP should be done with care because of the great possibility of artifacts which might lead to misdiagnosis. Because of its accuracy, CBCT is more useful for clinic diagnosis and therapy. Furthermore, the images of CBCT could show destruction of cortical bone that couldn't detect by periapical radiography. CONCLUSIONS: CBCT is more accurate than periapical radiography for AP diagnosis. CBCT can reveal the details of the lesions and adjacent structures and provide correct clinical diagnosis and scientific treatment planning with accurate evidence.

[Effect of Carisolv on endodontic microleakage].

PURPOSE: To evaluate the effect of Carisolv on endodontic microleakage by establishing a fluid transport model using sodium nitrite as tracer. METHODS: Seventy extracted teeth were randomly divided into 5 groups, all the root canals were prepared with different chemical reagents, including Carisolv,3% hydrogen peroxide+ 2%tosylchloramide sodium,2.5% sodium hypochlorite,5% sodium hypochlorite(negative control)and distilled water(positive control),post spaces were prepared after cold lateral condensation, the samples were put on the model, concentration of sodium nitrite which penetrated from the coronal to the apical end was measured by diazo reaction at 1,2,4,7,10,15,20,25,30,35,40,45,50,55 and 60 day. The data were analyzed by ANOVA using SPSS 11.5 software package. RESULTS: Sodium nitrite was not detected in negative control group from 1 day to 60 days. High concentration of sodium nitrite was detected in positive control group at first day, concentration of sodium nitrite was higher than that of other four groups from 1day to 60 days(P<0.01). Concentration of sodium nitrite in Carisolv group was significantly lower than that of 3%hydrogen peroxide+ 2% tosylchloramide sodium group(P<0.01), also lower than that of 2.5% sodium hypochlorite group(P<0.05),except at 25,30,35 and 40 days. CONCLUSIONS: Carisolv can remove the smear layer, decrease the endodontic microleakage, seal the root canal better. The fluid transport model using sodium nitrite as tracer can be used to evaluate the endodontic microleakage objectively,sensitively and exactly.

[Effect of root canal filling with warm vertical condensation under dental operating microscope].

PURPOSE: To evaluate the clinical effect of root canal filling with warm vertical condensation with or without dental operating microscope. METHODS: Fifty maxillary anterior teeth with single, straight canals were divided into two groups. Each tooth was instrumented by X-Smart rotary nickel-titanium files to a master file 0.06 taper F3, root canal in the group 1 was obturated with warm vertical condensation using system B for downpack and Obtura II for backfilling without dental operating microscope; root canal in the group 2 was obturated using the same methods under the dental operating microscope. The effect of quality of root canal filling was evaluated by X-ray radiograph post-operatively and after two years of treatment. SPSS10.0 software package was used for Chi-square test. RESULTS: Significant difference was found between the two groups on the quality of root canal filling post-operatively (P < 0.05),with better quality of root canal filling in the group using dental operating microscope, no significant difference was found between the two groups after two years (P > 0.05). CONCLUSIONS: Warm vertical condensation under the dental operating microscope is a good method for root canal filling. It may improve the quality of root canal filling effectively, and therefore, worthy of clinical application.

[Three dimensional finite element stress analysis on model of maxillary first premolar with different cavity designs and restorations].

PURPOSE: To investigate the influence of stress on three-dimentional finite element models of maxillary first premolar with multifactors:cavities designs,restored materials,basing materials and loading sites. METHODS: Three dimensional finite element models for maxillary first premolar with different types cavity which were filled with different basing materials and restoration were constructed and the maximum main stress was measured according to factorial design.ANSYS9.0 software were employed,and the data was statistically analyzed with SPSS 13.0 software package for multivariate ANOVA. RESULTS: Loading sites,cavity designs,restored materials and basing materials had effects on stress. Loading sites were the most important factors. Basing materials only had effect on occlusal stress. Cervix region was one of the stress concentration sites. CONCLUSIONS: Loading site has significant influence on stress,cavity designs,restored materials must be considered during restorations. Supported by Key Research Project of Science and Technology Commission of Liaoning Province (Grant No. 99225008).

[Effect of Carisolv on root canal cleanness in chemomechanical preparation].

PURPOSE: To evaluate the effect of Carisolv as chemical reagent on root canal cleanness in chemomechanical preparation. METHODS: Sixty extracted teeth which were dyed with methylene blue were randomly divided into 3 groups, different chemical reagents were applied in different groups. The optical density of methylene blue in irrigating solution were measured with UV-VIS spectrophotomer after preparation with each file, the root canal cleanness was evaluated under SEM. Two-way ANOVA and Kruskal-Wallis H test in SPSS 11.5 software package were used for statistical analysis. RESULTS: There were significant differences in the optical density between the root canals treated with Carisolv and those with 2% tosylchloramide sodium plus 3% hydrogen peroxide (P<0.05), no significant difference was found in optical density between the root canals treated with Carisolv and those with 2.5% sodium hypochlorite (P>0.05). The results of SEM were consistent with those of the optical density of methylene blue. CONCLUSIONS: As a chemical reagent, the cleaning ability of Carisolv was as effective as 2.5% sodium hypochlorite. Carisolv can remove the smear layer and debris, without causing excessive demineralization. Supported by Key Research Project of Science and Technology Committee of Liaoning Province(Grant No.00225001).

[Study of the relative factors of cure depths of light curing composite resin].

PURPOSE: To investigate the effect of different composite resin, different light curing units, different irradiation time, different irradiation distance on cure depths of light curing composite resin. METHODS: Designed by factorial experiment, 192 Cylindrical samples were made with 4mm internal diameter and 6mm high mold. The whole samples were scanned by Planmeca ProMax panoramic X-ray unit, cure depths were measured using a scoping method described in the ISO standard for resin-based composites. The data was statistically analyzed by SPSS11.5 software package for ANOVA. RESULTS: The differences of four factors-composite resin, light curing units, irradiation time, irradiation distance were significant (P<0.01), and the effects between-subjects were involved among four factors (P<0.01). CONCLUSIONS: From this study, we conclude that cure depths may be affected by two kinds of light curing units, two kinds of composite resin, four kinds of irradiation time and four kinds of irradiation distances, once each factor is strengthened, cure depths could reach a more ideal effect. Supported by Key Research Project of Science and Technology Committee of Liaoning Province (Grant No.00225001).