Unravelling the heterogeneity of oral squamous cell carcinoma by integrative analysis of single-cell and bulk transcriptome data.

Oral squamous cell carcinoma (OSCC) is a prevalent malignancy of the head and neck with rising global incidence. Despite advances in treatment modalities, OSCC prognosis remains diverse due to the complex molecular and cellular heterogeneity within tumours, as well as the heterogeneity in tumour microenvironment (TME). In this study, we utilized single-cell RNA sequencing (scRNA-seq) analysis to explore distinct subpopulations of tumour cells in OSCC tissues and their interaction with components in TME. We identified four major tumour cell subpopulations (C0, C1, C2 and C3) with unique molecular characteristics and functional features. Pathway enrichment analysis revealed that C0 primarily expressed genes involved in extracellular matrix interactions and C1 showed higher proliferation levels, suggesting that the two cell subpopulations exhibited tumour aggressiveness. Conversely, C2 and C3 displayed features associated with keratinization and cornified envelope formation. Accordingly, C0 and C1 subpopulations were associated with shorter overall and disease-free survival times, while C2 and C3 were weakly correlated with longer survival. Genomic analysis showed that C1 demonstrated a positive correlation with tumour mutation burden. Furthermore, C0 exhibited resistant to cisplatin treatment, while C1 showed more sensitive to cisplatin treatment, indicating that C0 might exhibit more aggressive compared to C1. Additionally, C0 had a higher level of communication with fibroblasts and endothelial cells in TME via integrin-MAPK signalling, suggesting that the function of C0 was maintained by that pathway. In summary, this study provided critical insights into the molecular and cellular heterogeneity of OSCC, with potential implications for prognosis prediction and personalized therapeutic approaches.

lncRNA MALAT1 mediates osteogenic differentiation of bone mesenchymal stem cells by sponging miR-129-5p.

Background: Bone mesenchymal stem cells (BMSCs) have good osteogenic differentiation potential and have become ideal seed cells in bone tissue engineering. However, the osteogenic differentiation ability of BMSCs gradually weakens with age, and the regulatory mechanism is unclear. Method: We conducted a bioinformatics analysis, dual-luciferase reporter (DLR) experiment, and RNA binding protein immunoprecipitation (RIP) to explore the hub genes that may affect BMSC functions. Results: The expression level of long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (Malat1) was significantly higher in the BMSCs from elderly than younger mice, while miR-129-5p showed the opposite trend. The results of alkaline phosphatase staining, quantitative reverse transcription PCR and western blot experiments indicated that inhibiting the expression of Malat1 inhibits the osteogenic differentiation of BMSCs. This effect can be reversed by reducing the expression of miR-129-5p. Additionally, DLR and RIP experiments confirmed that Malat1 acts as a sponge for miR-129-5p. Conclusion: Overall, our study findings indicated that lncRNA Malat1 may play a critical role in maintaining the osteoblast differentiation potential of BMSCs by sponging miR-129-5p.

[Shanghai municipal expert consensus on standardized prevention and control of COVID-19 during procedures of oral radiology].

The announcement of National Health Commission on January 20, 2020 (No.1 of 2020) has included novel coronavirus pneumonia into the B class infectious diseases according to the law of the People's Republic of China on the prevention and control of infectious diseases, and has been managed as A class infectious diseases. People's governments at all levels and health administration departments have been paying high attention to it. With the alleviation of COVID-19 nationwide, dental clinics gradually resume to work. The main transmission routes of COVID-19 are respiratory droplets and contact transmission, hence oral radiological examination is kind of a high-risk operation. Standardized radiologic process is of great significance to reduce the risk of COVID-19 transmission. In accordance with the national and Shanghai epidemic prevention requirements, and in combination with the actual situation of various medical institutions, Oral and Maxillofacial Radiology Committee of Shanghai Stomatological Association formulated the expert consensus on standardized prevention and control of COVID-19 for clinical reference. This recommendation will be updated according to the situation of epidemic prevention and control in China and the new relevant diagnosis and treatment plans.

[Experimental study on the feasibility of low-dose cone beam computed tomography scanning].

OBJECTIVE: The effects of different tube currents and voltages on image quality and radiation dose were studied to provide a theoretical basis for low-dose cone beam computed tomography (CBCT) scanning in children. METHODS: Different tube currents and voltages were used to scan the incisor area of fresh Bama pig heads by CBCT. The radiation dose was recorded, and image quality was evaluated. RESULTS: As the tube current or voltage decreased, the radiation dose and image quality gradually decreased. The computed tomographic dose index (CTDIvol) of 90 kV, 2.5 mA and 60 kV, 7.0 mA were all 1.7 mGy. The image quality score of the former was higher than that of the latter, and the difference between them was statistically significant (P<0.05). CONCLUSIONS: Low-dose CBCT scanning appears to be able to reduce the necessary tube current during imaging by improving image quality.

Theaflavin-3, 3'-Digallate Suppresses RANKL-Induced Osteoclastogenesis and Attenuates Ovariectomy-Induced Bone Loss in Mice.

Theaflavin-3, 3'-digallate (TF3) is extracted from black tea and has strong antioxidant capabilities. The aim of this study was to assess the influences of TF3 on osteoclastogenesis and explore the underlying mechanisms. TF3 efficiently decreased receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoclast formation and reactive oxygen species (ROS) generation in a dose-dependent manner. Mechanistically, TF3 reduced ROS generation by activating nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream heme oxygenase-1 (HO-1) and also inhibited the mitogen-activated protein kinases (MAPK) pathway. Moreover, micro-computed tomography (CT) analysis, hematoxylin and eosin (H&E) staining, and TRAP staining of the femurs of C57BL/6J female mice showed that TF3 markedly attenuated bone loss and osteoclastogenesis in mice. Immunofluorescence staining, 2',7'-dichlorofluorescein diacetate (DCFH-DA) staining, and measurement of the levels of malonaldehyde (MDA) and superoxide dismutase (SOD) revealed that TF3 increased the expression of Nrf2 and decreased the intracellular ROS level in vivo. These findings indicated that TF3 may have the potential to treat osteoporosis and bone diseases related to excessive osteoclastogenesis via inhibiting the intracellular ROS level.

Construction and analysis of a lncRNA-miRNA-mRNA network based on competitive endogenous RNA reveal functional lncRNAs in oral cancer.

BACKGROUND: A growing evidence suggests that long non-coding RNAs (lncRNAs) can function as a microRNA (miRNA) sponge in various diseases including oral cancer. However, the pathophysiological function of lncRNAs remains unclear. METHODS: Based on the competitive endogenous RNA (ceRNA) theory, we constructed a lncRNA-miRNA-mRNA network in oral cancer with the human expression profiles GSE74530 from the Gene Expression Omnibus (GEO) database. We used topological analysis to determine the hub lncRNAs in the regulatory ceRNA network. Then, function enrichment analysis was performed using the clusterProfiler R package. Clinical information was downloaded from The Cancer Genome Atlas (TCGA) database and survival analysis was performed with Kaplan-Meier analysis. RESULTS: A total of 238 potential co-dysregulated competing triples were obtained in the lncRNA-associated ceRNA network in oral cancer, which consisted of 10 lncRNA nodes, 41 miRNA nodes and 122 mRNA nodes. Additionally, we found lncRNA HCG22 exhibiting superior potential as a diagnostic and prognostic marker of oral cancer. CONCLUSIONS: Our findings provide novel insights to understand the ceRNA regulation in oral cancer and identify a novel lncRNA as a potential molecular biomarker.

Identification of key genes and transcription factors in aging mesenchymal stem cells by DNA microarray data.

BACKGROUND: Mesenchymal stem cells (MSCs) are multipotent cells that can be widely used in stem cell therapy. However, few studies have revealed the potential mechanisms of the changes in aging MSC. MATERIALS AND METHODS: In this study, microarray data GSE35955 was downloaded from the Gene Expression Omnibus database. Then limma package in R was used to filtrate differentially expressed genes (DEGs), Transcription factors (TFs) were predicted by DCGL package. After predicting TFs, protein-protein interaction (PPI) network and TF-mediated transcriptional regulation network were constructed. The functional and pathway enrichment analysis of screened DEGs, hub genes and TFs were conducted by the DAVID. RESULTS: Totally 156 up-regulated DEGs and 343 down-regulated DEGs were obtained. 6 hub genes (CTNNB1, PPP2R1A, FYN, MAPK1, PIK3C2A and EP300) were obtained from PPI network. 11 TFs (CREB1, CUX1, EGR1, EP300, FOXC1, HSF2, MEF2A, PLAU, SP1, STAT1 and USF1) for DEGs were predicted and 2 highly scored co-expression relationships (EP300-PPP2R1A and STAT1-FOXC1) were acquired from the TF-mediated transcriptional regulation network. CONCLUSIONS: The discovery of the hub genes, TFs and pathways might contribute to the understanding of genetic and molecular functions of aging-related changes in MSC. Further validation studies on genes and TFs such as CTNNB1, FYN, PPP2R1A, MAPK1, EP300 and related biological processes and pathways, including adherens junction, DNA damage caused from oxidative stress, attribution of telomere, MSC differentiation and epigenetic regulation, are urgent for clinical prevention and treatment.

Phthalates in soft glass (a soft transparent PVC plastic sheet used extensively in household and public place in developing countries in recent years): Implication for oral exposure to young children.

It has been several years that a soft transparent polyvinyl chloride (PVC) plastic sheet, commonly known as "soft glass", or "crystal plate" in China and other developing countries, has quietly and gradually found extensive applications. This material has widely replaced cloth and glass as table cover in household and office, and replaced cloth as door drape in public place in China. In this study, the concentration of plasticizer used in soft glass and the migration of the plasticizer from soft glass to olive oil and porcine skin during contact were determined. The oral exposure of young children to the plasticizer from soft glass was estimated for the first time. Two exposure routes, one via ingestion of contaminated food, the other via mouthing of contaminated hand, were considered. It is found that Di(2-ethylhexyl) phthalate (DEHP) is the major plasticizer used in soft glass, which could leach out of the material and migrate easily to the olive oil and porcine skin during contact. A rough estimation of oral exposure for young children to DEHP from soft glass was 126 µg/person/d, which would be converted to 12.6 µg/kg bw/d and 7.9 µg/kg bw/d, for body weight of 10 kg and 16 kg, respectively. The estimated exposure dosages would not pose immediate health hazard to the children. The implications of these dosages were also discussed.

CerS6 regulates cisplatin resistance in oral squamous cell carcinoma by altering mitochondrial fission and autophagy.

Chemoresistance remains a challenge in the effective treatment of solid tumors, including oral squamous cell carcinoma (OSCC). Mitochondrial dynamics and autophagy have recently been implicated in the chemoresistance of cancer cells. The neutralization of ceramide is also associated with multidrug resistance, and ceramide synthase 6 (CerS6) is known to induce apoptosis. However, whether CerS6 regulates chemoresistance in OSCC is not clearly understood. Therefore, we investigated the role of CerS6 in the susceptibility of OSCC cells to cisplatin. In this study, we observed that cisplatin-resistant OSCC cells process lower levels of fission-state mitochondria and cell apoptosis than cisplatin-sensitive cells, and autophagy was activated in cisplatin-resistant OSCC cells. We found lower CerS6 expression in cisplatin-resistant OSCC cells. Overexpression of CerS6 with lentivirus-encoded CerS6 complementary DNA in cisplatin-resistant OSCC cells increased cisplatin sensitivity. Overexpression of CerS6 enhanced mitochondrial fission and apoptosis and attenuated cisplatin-induced autophagy in cisplatin-resistant OSCC cells. Further investigation indicated that CerS6 might function through altering calpain expression to enhance cisplatin sensitivity. Cisplatin-resistant OSCC cells xenografted onto a nude mouse model confirmed that CerS6 enhanced cisplatin chemotherapy sensitivity to reduce tumor volume. These data indicate that CerS6 could mediate an effective response to cisplatin in chemoresistant OSCC.

The effects of three modified Hank's balanced salt solutions on root resorption of late replanted teeth: A pilot study.

PURPOSE: The purpose of this study was to evaluate the effects of replanted rats' teeth that had been soaked in one of three modified Hank's balanced salt solutions (HBSSs) before replantation and after extended extra-oral dry time. MATERIALS AND METHODS: Maxillary right incisors were extracted from 55 Wistar rats and kept dry for 30 or 60 min (n = 5 each). Afterwards, the pulp was extirpated and both the papilla and enamel organ were removed with a scalpel. Each group of teeth was soaked in one of three modified HBSSs or HBSS alone. After 30 min of immersion in solutions, the root canals were dried and filled with calcium hydroxide paste, and the teeth were replanted. After 8 weeks, animals were euthanized; then, specimens were processed as 5 µm-thick serial sections for histological examination and morphometric assessments. RESULTS: The percentages of root resorption for the groups were found to be in the following order: HBSS3 (the bFGF group) > the HBSS only group > HBSS2 (the GSH group) > no soaking (the positive control group) > HBSS1 (the ALN group) for 30 min and the positive control group > the HBSS only group > HBSS2 > HBSS3 > HBSS1 for 60 min. The lowest incidence of resorption was observed in immediately replanted teeth (negative control). CONCLUSIONS: The findings of this study suggest that soaking for 30 min in HBSS containing 1 mM alendronate can significantly inhibit root resorption for avulsed teeth that have been dried for 60 min.

Antitumor effects of WNT2B silencing in GLUT1 overexpressing cisplatin resistant head and neck squamous cell carcinoma.

OBJECTIVES: The increased rate of glucose uptake necessary to support the growth of tumor cells is mediated by glucose transporters, and glucose transporter 1 (GLUT1) is overexpressed in several types of cancer in correlation with poor prognosis. And WNT2B overexpression is thought to be involved in tumor progression. Here, we investigated the effects of WNT2B in GLUT1 overexpressing cisplatin resistant head and neck squamous cell carcinoma (HNSCC) in vitro and in vivo. MATERIALS AND METHODS: We generated GLUT1 overexpressing cisplatin resistant CAL27 and SCC25 oral cancer cells. Lentiviral mediated knock-down of WNT2B was performed in CAL27 and SCC25. QRT-PCR and Western blot analysis were used to detect the mRNA and protein expression of GLUT1, WNT2B, Cyclin D1 and ß-catenin. Cell viability was assessed by MTT analysis. Colony formation assay was performed by staining with 0.5% crystal violet. The role of WNT2B in HNSCC was examined in vivo through the generation of a CAL27 (or cisplatin resistant CAL27 or cisplatin resistant CAL27 with WNT2B knock-down) nude mice xenograft model of HNSCC. RESULTS: Knock-down of WNT2B in decreased cell viability and colony formation in cisplatin resistant CAL27 and SCC25 in association with the downregulation of GLUT1, cyclin D1 and ß-catenin. In a cisplatin resistant CAL27 mouse xenograft model, shRNA mediated silencing of WNT2B increased survival and decreased tumor growth in correlation with the downregulation of GLUT1, cyclin D1 and ß-catenin. CONCLUSION: WNT2B plays a role in tumorigenesis and chemotherapy resistance in oral cancer and provide a potential therapeutic target for the treatment of patients with HNSCC.

The effects of GLUT1 on the survival of head and neck squamous cell carcinoma.

BACKGROUND/AIMS: Cancer cells require increased nutrient uptake to support a high rate of proliferation, and the overexpression of glucose transporters, in particular GLUT1, is a common characteristic of human malignancies. Here, we investigated the relationship between the expression of GLUT1 and cell viability, colony forming ability and apoptosis of head and neck squamous cell carcinoma (HNSCC) in vitro and in a xenograft mouse model in vivo. METHODS: Lentiviral mediated overexpression and knock-down of GLUT1 was performed in two oral cancer cell lines (CAL27 and SCC25). QRT-PCR and Western blot analysis were used to detect the mRNA and protein expression of GLUT1 and nuclear factor-kappa B (NFκB) p65 subunit. Cell viability and apoptosis were assessed by MTT and flow cytometry analyses, respectively. Colony formation assays were performed by staining with 0.5% crystal violet. The role of GLUT1 in HNSCC was examined in vivo through the generation of a CAL27 (or CAL27 with different transfections) nude mice xenograft model of HNSCC. RESULTS: GLUT1 overexpression promoted cell viability and colony formation whereas GLUT1 silencing had the opposite effect. GLUT1 knock-down significantly increased the number of Annexin V positive cells in both cell lines and GLUT1 overexpression had the opposite effect, indicating that GLUT1 modulates apoptosis. Xenograft mouse models of GLUT1 knockdown and overexpression showed that GLUT1 expression was associated with poor survival and increased tumor growth. GLUT1 overexpression significantly upregulated the expression of NFκB-p65, and this effect was reversed by inhibition of GLUT1 expression. CONCLUSIONS: GLUT1 expression plays an important role in the survival of HNSCC, and its effects may be associated with the activation of the NFκB pathway.

Inhibition of glucose transporter 1 (GLUT1) chemosensitized head and neck cancer cells to cisplatin.

Glucose transporter 1 (GLUT1) facilitates the cellular uptake of glucose and is overexpressed in most cancers. The altered expression of GLUT1 may influence the sensitivity of tumor cells to chemotherapy. This study investigated whether the knockdown of GLUT1 expression to sensitize head and neck cancer cells to the chemotherapy drug cisplatin in vitro. Anti-GLUT1 antibody was used to block activity of GLUT1 protein, and GLUT1-shRNA was used to knock down its mRNA expression in Cal27 cells. Immunocytochemistry, Western blot, and qRT-PCR were used to detect expression of GLUT1 mRNA and protein, respectively. Lentivirus was used to carrying GLUT1-shRNA to knockdown GLUT1 expression in Cal27 cells for MTT and flow cytometry analyses of cell viability and apoptosis, respectively. Glucose uptake assay was used to assess the changes in glucose levels in Cal27 cells. It showed that GLUT1 mRNA and protein were expressed in Cal27 cells, and GLUT1 protein was localized on the cell membrane. Both anti-GLUT1 antibody and GLUT1-shRNA sensitized Cal27 cells to cisplatin treatment under both normoxia and hypoxia conditions. Anti- GLUT1 antibody and GLUT1-shRNA inhibited tumor cell growth in vitro and induced them to undergo apoptosis. GLUT1-shRNA also suppressed tumor cell uptake of glucose into the cells. Our findings suggest that inhibition of GLUT1 activity and expression can sensitize Cal27 cells to cisplatin treatment in both normoxic and hypoxic conditions. These data could be further verified in animal xenografts before potential application as a clinical adjuvant or neoadjuvant therapy of head and neck cancer with cisplatin.

Establishment and characterization of a rabbit oral squamous cell carcinoma cell line as a model for in vivo studies.

The incidence of oral squamous cell carcinoma (SCC) is increasing but the long-term survival rate remains low. An animal model would therefore be helpful for evaluation of new treatment modalities for oral SCC. Hamster is small animal, therefore, the cancer of hamster cheek pouch is not optimal for tumor imaging. The VX2 cell line has been used in many carcinoma-related studies, including oral SCC research, but it is derived from cutaneous tissue and not mucosa. We chemically induced tongue squamous cell carcinoma in rabbits and subsequently established a rabbit squamous cell line. The cells grew in multiple layers without contact inhibition for 60 passages over 2 years and were positive for cytokeratin (CK). Electron microscopy revealed that cells were polygonal with rich microvilli on the surface, and there were desmosomes between cells and bundles of tonofibril beside the cell membrane. The chromosome number ranged from 71 to 272, with a modal value of 145 (12.4%). The cells were transplantable into nude mice subcutaneously or rabbit submucosally and produced carcinomas in all the animals. The cell line should be a useful tool for the study of the biological characteristics of oral SCC, especially tongue SCC.

[Evaluation of fluorodeoxyglucose-position-emission tomography-computer tomography imaging on head and neck squamous cell carcinomas including primary tumors and lymph node metastases].

OBJECTIVE: To evaluate (18)F-fluorodeoxyglucose-position-emission tomography-computer tomography imaging ((18)F-FDG-PET-CT) on head and neck squamous cell carcinoma(HNSCCA) and lymph node metastasis. METHODS: (18)F-FDG-PET-CT imaging of 20 patients with HNSCCA was evaluated retrospectively. RESULTS: All the primary tumors were correctly diagnosed by (18)F-PET-CT imaging and SUV(avg) of the primary tumors was (6.22 +/- 2.20). All the sensitivity, specificity, positive predictive value and the negative predictive value were 100%. In detecting lymph node metastasis, the sensitivity was 51%, specificity 97.7%, false positive rate 2.3%, false negative rate 49%, positive predictive value 82%, and negative predictive value 91.2%. CONCLUSIONS: (18)F-FDG-PET-CT imaging was valuable in detecting HNSCCA and lymph node metastasis. SUV was helpful for differential diagnosis between benign or malignant tumors but it needs further study to determine the cutoff SUV for differentiating lymph node metastasis.

Expression of Glut-1 in primary and recurrent head and neck squamous cell carcinomas, and compared with 2-[18F]fluoro-2-deoxy-D-glucose accumulation in positron emission tomography.

The aim of the study was to investigate the pattern of glucose transporter-1 (Glut-1) expression in primary and recurrent head and neck squamous cell carcinomas (HNSCCAs) and the relation between Glut-1 expression and 2-[18F]fluoro-2-deoxy-D-glucose - positron emission tomography (FDG-PET). Standardised uptake values (SUVs) were used to evaluate FDG uptake by the tumour. Sections were stained immunohistochemically for Glut-1, which showed that high SUVs were seen in all HNSCCAs, and patients with higher T stage tumours or less well-differentiated tumours showed significantly higher SUVs than those with lower stage tumours or better-differentiated tumours (P=0.001 and 0.04, respectively). Glut-1 immunostaining was present in all cases. The Glut-1 staining index in primary HNSCCAs was significantly lower than that in recurrent HNSCCAs (P=0.03), and the index of better-differentiated tumours lower than that of poorly-differentiated tumours (P=0.02). However, there was no significant correlation between SUV(mean) and the Glut-1 staining index. In conclusion, our data suggest that high FDG uptakes were seen with overexpression of Glut-1 in primary and recurrent HNSCCAs. SUV(mean) was related to tumour T stage and grade of differentiation, which indicated that SUV was helpful in evaluating tumours. The expression of Glut-1 in recurrent HNSCCAs was higher than that in primary HNSCCAs, and in poorly-differentiated HNSCCAs higher than in better-differentiated HNSCCAs, which indicated that Glut-1 may have a useful role as a predictor for poor prognosis in HNSCCAs. However, there was no significant correlation between FDG accumulation and Glut-1 expression.

[Genetic linkage analysis and mutation detection in Chinese families with basal cell nevus syndrome].

OBJECTIVE: To study the molecular genetic etiology of a Chinese pedigree with basal cell nevus syndrome. METHODS: The proband and his affected mother and a unaffected individual in the pedigree were chosen and peripheral blood was collected from them for DNA. Direct sequencing was performed to detect the mutations of PTCH gene. In order to further confirm the results of sequence analysis, all available family members were analyzed with genetic linkage analysis using 3 highly polymorphic microsatellite DNA markers in the region of 9q22.3-q31. RESULTS: No mutations of PTCH gene was detected in the proband's mother, one synonymous mutation was detected in the proband. Linkage analysis showed that the Lod scores of the 3 markers were: D9S283, Z = -2.11 (theta = 0.00); D9S1690, Z = -2.95 (theta = 0.00); D9S1677, Z = -5.94 (theta = 0.00). CONCLUSIONS: In this pedigree, mutation of PTCH gene is not related to the underlying pathogenesis of the syndrome.

[A study on the mechanism of inducing apoptosis of Tca8113 cells by means of ultrasound hyperthermia].

PURPOSE: To investigate the mechanism of apoptosis in Tca8113 cells induced by ultrasound hyperthermia by detecting changes in related index. METHODS: Tca8113 cells were treated in vitro by ultrasound hyperthermia in different heating temperatures (38 degrees C to 44 degrees C,10 minutes) and heating times (42 degrees C,10 to 60 minutes), and then the dynamic changes of early apoptosis and secondary necrosis treated by 42 degrees C for 10 minutes were assayed to detect deltapsim and Caspase-3 levels of different groups by flow cytometry (FCM). The means of each group were compared by ANOVA with SAS6.12 software package. RESULTS: After heated by ultrasound in 42 degrees C for 10 minutes, the early apoptosis of Tca8113 was detected. The apoptosis index reached its highest level at the 6th to 8th hour, then decreased rapidly and maintained in a lower level after 12 hours. The level of secondary necrosis increased with the level of early apoptosis, but kept in a higher level until the 10th hour, the level of secondary necrosis correlated with that of the early apoptosis (r = 0.7909, P = 0.0064). The fraction of cells with low mitochondria membrane potential and increased activity of Caspase-3 were detected either in the heating-temperature grads group or in the heating-time grads group, which showed significant relationship between thetwo apoptosis related index (r = 0.89189, P = 0.0029 in the heating-temperature grads group; r = 0.9679, P = 0.0003 in the heating-time grads group). CONCLUSIONS: Tca8113 cells developed apoptosis after heated by ultrasound hyperthermia along with deltapsim level decreasing and Caspase-3 activity increasing. Ultrasound hyperthermia induces apoptosis of Tca8113 cells by the mitochondrum-Caspase pathway.

[Induction of mouse embryonic stem cells forming odontoblast-like cells by co-culture with pulp fibroblast].

PURPOSE: To investigate the methods of induction of mouse embryonic stem cells to differentiate into odontoblast-like cells by co-culture with pulp fibroblast. METHODS: By suspension culture, embryonic stem cells were induced to form embryoid bodies. Then the cells from embryoid bodies were co-cultured with pulp fibroblast in Transwell system for differentiation toward odontoblast-like cells. RESULTS: By RT-PCR analysis, embryoid body cells gave rise to the cell population expressing DSPP, a specific odontoblast cell marker, after 10 days of co-culture with pulp fibroblast and the expression of DSPP was enhanced after 15 days of co-culture. On the other hand, the expression of DSPP was not detected in the isolately cultured embryoid body cells. CONCLUSIONS: Embryonic stem cells can be induced into odontoblast-like cells by co-culture with pulp fibroblast. Supported by Science and Technology Development Fund of Shanghai Municipality (Grant No. 03ZR14027).