NAT10/CEBPB/vimentin signalling axis promotes adenoid cystic carcinoma malignant phenotypes in vitro.

OBJECTIVE: To explore the biological function and mechanisms of CEBPB and NAT10-mediated N4-acetylcytidine (ac4c) modification in salivary adenoid cystic carcinoma (SACC). MATERIALS AND METHODS: CEBPB and NAT10 were knocked down in SACC-LM cells by siRNA transfection and overexpressed in SACC-83 cells by plasmid transfection. Malignant phenotypes were evaluated using CCK-8, Transwell migration and colony formation assays. Real-time PCR, western blotting, ChIP and acRIP were used to investigate the molecular mechanisms involved. RESULTS: We found that CEBPB was highly expressed in SACC tissues and correlated with lung metastasis and unfavourable prognosis. Gain- and loss-of-function experiments revealed that CEBPB promoted SACC malignant phenotypes. Mechanistically, CEBPB exerted its oncogenic effect by binding to the vimentin gene promoter region to enhance its expression. Moreover, NAT10-mediated ac4c modification led to stabilization and overexpression of CEBPB in SACC cells. We also found that NAT10, the only known human enzyme responsible for ac4C modification, promoted SACC cell migration, proliferation and colony formation. Moreover, CEBPB overexpression restored the inhibitory effect of NAT10 knockdown on malignant phenotypes. CONCLUSIONS: Our study reveals the critical role of the newly identified NAT10/CEBPB/vimentin axis in SACC malignant progression, and the findings may be applied to improve treatment for SACC.

Long non-coding RNA MRPL23-AS1 suppresses anoikis in salivary adenoid cystic carcinoma in vitro.

Distant lung metastasis is the main factor that affects the survival rate of patients with salivary adenoid cystic carcinoma (SACC). Anoikis resistance is a feature of tumor cells that easily metastasize. The long non-coding RNA (lncRNA) MRPL23 antisense RNA 1 (MPRL23-AS1) is related to lung metastasis in SACC, but its role in anoikis resistance is unknown. After altering MPRL23-AS1 expression in SACC cells, anoikis resistance was detected by calcein AM/PI staining and annexin V/PI flow cytometry. The apoptosis marker activated caspase-3 and the bcl-2/bax ratio were detected by Western blotting. The relationship between MPRL23-AS1 and the promoter of the potential downstream target gene p19INK4D was identified by chromatin immunoprecipitation (ChIP)-PCR assay. p19INK4D expression in patient tissues was determined using qRT-PCR and immunohistochemistry. The functional experiments showed that MPRL23-AS1 could promote anoikis resistance in vitro. MRPL23-AS1 recruited the EZH2 to the promoter region of p19INK4D, inhibited p19INK4D expression, and promoted tumor cell anoikis resistance. p19INK4D overexpression did not affect anoikis in attached cells; however, it attenuated the anoikis resistance effect of MPRL23-AS1 in suspension cells. p19INK4D expression was significantly lower in SACC tissues than in normal tissues. The novel MRPL23-AS1/p19INK4D axis may be a potential SACC biomarker or therapeutic target.

A Location Privacy Attack Based on the Location Sharing Mechanism with Erroneous Distance in Geosocial Networks.

Geographical social networks (GSN) is an emerging research area. For example, Foursquare, Yelp, and WeChat are all well-known service providers in this field. These applications are also known as location-based services (LBS). Previous studies have suggested that these location-based services may expose user location information. In order to ensure the privacy of the user's location data, the service provider may provide corresponding protection mechanisms for its applications, including spatial cloaking, fuzzy location information, etc., so that the user's real location cannot be easily cracked. It has been shown that if the positioning data provided by the user is not accurate enough, it is still difficult for an attacker to obtain the user's true location. Taking this factor into consideration, our attack method is divided into two stages for the entire attack process: (1) Search stage: cover the area where the targeted user is located with unit discs, and then calculate the minimum dominating set. Use the triangle positioning method to find the minimum precision disc. (2) Inference phase: Considering the existence of errors, an Error-Adjusted Space Partition Attack Algorithm (EASPAA) was proposed during the inference phase. Improved the need for accurate distance information to be able to derive the user's true location. In this study, we focus on the Location Sharing Mechanism with Maximal Coverage Limit to implement the whole attack. Experimental results show that the proposed method still can accurately infer the user's real location even when there is an error in the user's location information.

Stem cells  from exfoliated  deciduous  teeth alleviate hyposalivation caused by Sjögren syndrome.

OBJECTIVES: To evaluate the effect of stem cells  from  exfoliated  deciduous  teeth on the hyposalivation caused by Sjögren syndrome (SS) and investigate the mechanism. METHODS: Stem cells were injected into the tail veins of non-obese diabetic mice, the animal model of SS. The saliva flow was measured after pilocarpine intraperitoneal injection. Apoptosis and autophagy were evaluated by TUNEL and Western blot. Lymphocyte proportions were detected by flow cytometer. RESULTS: Fluid secretion was decreased in 21-week-old mice. Stem cell treatment increased fluid secretion, alleviated inflammation in the submandibular glands and reduced inflammatory cytokine levels in the serum, submandibular glands and saliva. Stem cells decreased the apoptotic cell number and the expressions of ATG5 and Beclin-1 in the submandibular glands. Stem cells have no effect on other organs. Furthermore, the infused stem cells migrated to the spleen and liver, not the submandibular gland. Stem cells directed T cells towards Treg cells and suppressed Th1 and Tfh cells in spleen lymphocytes. CONCLUSION: Stem cells  from  exfoliated  deciduous  teeth alleviate the hyposalivation caused by SS via decreasing the inflammatory cytokines, regulating the inflammatory microenvironment and decreasing the apoptosis and autophagy. The stem cells regulated in T-cell differentiation are involved in the immunomodulatory effects.

Hsa_circRNA_0059655 plays a role in salivary adenoid cystic carcinoma by functioning as a sponge of miR-338-3p.

Circular RNAs(circRNA) are recently demonstrated to have a close relationship with tumors.To investigate the role of circular RNA in the pathogenesis of salivary adenoid cystic carcinoma(SACC), ten SACC tissues and paired normal submandibular gland(SMG) tissues were collected as the tumor group and the control group. Total RNA was extracted and then measured using ceRNA microarray (including mRNA, lncRNA, and circRNA) and miRNA microarray. Gene Ontology(GO) analysis and Kyoto Encyclopedia of Gene and Genomes (KEGG) pathway analysis were performed in order to investigate the function of the differential expressing genes. The ceRNA regulatory network was constructed to find the core circRNAs. Then the role of circRNA on proliferation was examined in the SACC cell line SACC-83 using CCK-8,qRT-PCR and western blotting, and its roles on migration and invasion were examined using wound healing assay and transwell assay. The results of the microarrays showed that 3792 mRNAs, 7649 lncRNAs, 11553 circRNAs, and 132 miRNAs expressed differentially. The ceRNA regulatory network analysis showed that hsa_circ_0059655 and other 14circRNAs derived from PYGB target on several similar genes by miR-338-3p.Among the 15 circRNAs derived from PYGB, hsa_circ_0059655has the most relationships in the ceRNA network. Furthermore, after hsa_circ_0059655 was knocked down in SACC-83 cells, the expression of hsa-miR-338-3p was up-regulated while CCND1was down-regulated. The proliferation, migration, and invasion of SACC-83 cells also decreased after hsa_circ_0059655 knock-downed.Taken together, the circRNAs derived from PYGB may regulate the tumorigenesis and development of SACC through competing with miR-338-3p.

[Development of human embryonic stem cell platforms for human health-safety evaluation].

The human embryonic stem cells (hESCs) serve as a self-renewable, genetically-healthy, pluripotent and single source of all body cells, tissues and organs. Therefore, it is considered as the good standard for all human stem cells by US, Europe and international authorities. In this study, the standard and healthy human mesenchymal progenitors, ligament tissues, cardiomyocytes, keratinocytes, primary neurons, fibroblasts, and salivary serous cells were differentiated from hESCs. The human cellular health-safety of NaF, retinoic acid, 5-fluorouracil, dexamethasone, penicillin G, adriamycin, lead acetate PbAc, bisphenol A-biglycidyl methacrylate (Bis-GMA) were evaluated selectively on the standardized platforms of hESCs, hESCs-derived cardiomyocytes, keratinocytes, primary neurons, and fibroblasts. The evaluations were compared with those on the currently most adopted cellular platforms. Particularly, the sensitivity difference of PM2.5 toxicity on standardized and healthy hESCs derived fibroblasts, currently adopted immortalized human bronchial epithelial cells Beas-2B and human umbilical vein endothelial cells (HUVECs) were evaluated. The RESULTS showed that the standardized hESCs cellular platforms provided more sensitivity and accuracy for human cellular health-safety evaluation.

Nimotuzumab suppresses epithelial-mesenchymal transition and enhances apoptosis in low-dose UV-C treated salivary adenoid cystic carcinoma cell lines in vitro.

Salivary adenoid cystic carcinoma (SACC), which is one of the most common malignant tumors of the salivary glands, is associated with a poor long-term outcome. There are currently few therapeutic options for patients with SACC. Recent studies have shown the potential of the application of ultraviolet-C (UV-C) irradiation for the treatment of human cancer. In the present study, we investigated the effects of UV-C in the SACC cell lines SACC-83 and SACC-LM. High-dose UV-C (200 J/m) induced apoptosis and inhibited colony formation significantly. However, low-dose UV-C (10 J/m), which had little effect on apoptosis and colony formation, increased the ability of migration in SACC cells accompanied by a decrease in E-cadherin and an increase in vimentin, suggesting the occurrence of epithelial-mesenchymal transition (EMT). Low-dose UV-C (10 J/m) also resulted in upregulation of the phosphorylated forms of epidermal growth factor receptor (EGFR) and Akt (p-EGFR and p-Akt, respectively). Pretreatment with Nimotuzumab, an anti-EGFR monoclonal antibody, reversed the EMT as well as upregulation of p-EGFR/p-Akt induced by UV-C. Moreover, Nimotuzumab enhanced UV-C induced apoptosis and inhibition of colony formation. Our results indicate that EMT exerts a protective effect against apoptosis induced by low-dose UV-C. Thus, the combined application of Nimotuzumab and low-dose UV-C in vitro has an advantageous antitumor effect in SACC compared with the application of UV-C alone.

ALMS1-IT1: A Key Player in the Novel Disulfidptosis-Related LncRNA Prognostic Signature for Head and Neck Squamous Cell Carcinoma.

Disulfidptosis is a newly discovered form of programmed cell death that is induced by disulfide stress. It is closely associated with various cancers, including head and neck squamous cell carcinoma (HNSCC). However, the factors involved in the modulation of disulfidptosis-related genes (DRGs) still remain unknown. In this study, we established and validated a novel risk score model composed of 11 disulfidptosis-related lncRNAs (DRLs) based on 24 DRGs in HNSCC. The results revealed strong correlations between the 11-DRL prognostic signature and clinicopathological features, immune cell infiltration, immune-related functions, and disulfidptosis-associated pathways, including NADPH and disulfide oxidoreductase activities. Furthermore, we studied and verified the involvement of ALMS1-IT1, one of the 11 model DRLs, in the disulfidptosis of HNSCC cell lines. A series of assays demonstrated that ALMS1-IT1 modulated cell death under starvation conditions in a pentose phosphate pathway (PPP)-dependent manner. Knockdown of ALMS1-IT1 inhibited the PPP, contributing to a decline in NADPH levels, which resulted in the formation of multiple intermolecular disulfide bonds between actin cytoskeleton proteins and the collapse of F-actin in the cytoplasm. Therefore, ALMS1-IT1, which is highly expressed in SLC7A11high cells, can be considered a promising therapeutic target for disulfidptosis-focused treatment strategies for cancer and other diseases.

Extracellular Vesicles Containing circMYBL1 Induce CD44 in Adenoid Cystic Carcinoma Cells and Pulmonary Endothelial Cells to Promote Lung Metastasis.

Adenoid cystic carcinoma (ACC) is a rare malignant epithelial neoplasm that arises in secretory glands and commonly metastasizes to the lungs. MYBL1 is frequently overexpressed in ACC and has been suggested to be a driver of the disease. In this study, we identified a circular RNA (circRNA) derived from MYBL1 pre-mRNA that was accompanied by the overexpression of MYBL1 in ACC. Overexpression of circMYBL1 was correlated with increased lung metastasis and poor overall survival in patients with ACC. Ectopic circMYBL1 overexpression promoted malignant phenotypes and lung metastasis of ACC cells. Mechanistically, circMYBL1 formed a circRNA-protein complex with CCAAT enhancer-binding protein ß (CEBPB), which inhibited ubiquitin-mediated degradation and promoted nuclear translocation of CEBPB. In the nucleus, circMYBL1 increased the binding of CEBPB to the CD44 promoter region and enhanced its transcription. In addition, circMYBL1 was enriched in small extracellular vesicles (sEV) isolated from the plasma of patients with ACC. Treatment with sEVs containing circMYBL1 in sEVs enhanced prometastatic phenotypes of ACC cells, elevated the expression of CD44 in human pulmonary microvascular endothelial cells (HPMEC), and enhanced the adhesion between HPMECs and ACC cells. Moreover, circMYBL1 encapsulated in sEVs increased the arrest of circulating ACC cells in the lung and enhanced lung metastatic burden. These data suggest that circMYBL1 is a tumor-promoting circRNA that could serve as a potential biomarker and therapeutic target for ACC. Significance: circMYBL1 stabilizes CEBPB and upregulates CD44 to promote adhesion between cancer cells and endothelial cells and enables lung metastasis of adenoid cystic carcinoma, suggesting that inhibition of this axis could improve patient outcomes.

Decreased adiponectin level is associated with aggressive phenotype of tongue squamous cell carcinoma.

Circulating adiponectin levels are inversely associated with risk of various obesity-related cancers. However, the effect of adiponectin on carcinogenesis and progression of tongue squamous cell carcinoma (TSCC) remains unknown. We measured serum adiponectin levels in 59 patients with TSCC and 50 healthy controls. Expression of adiponectin and its receptors in paired tumor and paracancerous specimens were determined by immunohistochemical staining (n = 37) and western blot (n = 30), respectively. Serum adiponectin level was lower in patients than in controls (5.0 ± 2.4 vs 8.4 ± 3.5 µg/mL, P < 0.01), and was inversely associated with histological grade and lymph node metastasis but not tumor size. Local adiponectin levels in tumor tissue gradually decreased as tumor-node-metastasis stage increased, while the expression of adiponectin receptors was unchanged. In addition, serum adiponectin levels in the TSCC patients without metabolic and cardiovascular diseases, or without smoking and drinking habits, were still lower than in controls. Furthermore, adiponectin inhibited the migration, but not proliferation, of SCC15 cells in vitro. These results indicate that a decreased adiponectin level is associated with risk of TSCC. Hypoadiponectinemia might be used as a biomarker to predict an aggressive phenotype of TSCC.

[Effects of platelet-rich fibrin on canine dental pulp cells in vitro].

OBJECTIVE: To investigate the effect of platelet-rich fibrin (PRF) on the proliferation and chemotaxis capacity of autogenous canine dental pulp cells (cDPCs), and to evaluate the use of PRF as a pulp capping material in vital pulp therapy. METHODS: cDPCs were isolated and cultured from permanent anterior teeth of Beagle dogs by enzymatic methods. PRF was attained by Choukroun's protocols and the exudates of PRF were collected at the time point of the 7th day. Cell counting kit-8 (CCK-8) was applied to analyze cell proliferation. The medium of the control group was minimum essential medium alpha medium (α-MEM) containing 2% (volume fraction) fetal bovine serum (FBS). The experiment group was the exudates of PRF containing 2% FBS, and was divided into 5 groups (20%, 40%, 60%, 80%, 100%) by the volume fraction of the exudates of PRF. The 5 groups were named as PRF1, PRF2, PRF3, PRF4 and PRF5 respectively. Transwell model was used to evaluate cell chemotaxis capacity. The exudates of PRF which was most effectively in promoting cDPCs proliferation was added in the lower chamber of the experimental group; The positive control group was α-MEM containing 30% FBS and the negative control group was fresh α-MEM; The upper chamber of each group was added with 1 × 105 cells. RESULTS: The optical density of group PRF2 (1.45 ± 0.06) was significantly higher than that of the control group(1.21 ± 0.11, P<0.001). The optical density of groups PRF1, PRF3, PRF4, and PRF5 were 1.20 ± 0.02, 1.28 ± 0.04, 1.19 ± 0.02, 1.22 ± 0.02, respectively, and there was no significant difference between these groups and the control group (PRF1: P=0.902; PRF3: P=0.084; PRF4: P=0.726; PRF5: P=0.779). Therefore, the volume fraction which was most effective in promoting cell proliferation was 40%. At these concentrations the number of migrated cells was higher in PRF group(55.89 ± 18.42) than in the negative group(6.52 ± 1.97, P<0.001), but there was no significant difference between PRF group and the positive group(59.25 ± 29.17, P=0.970). CONCLUSION: PRF was a biocompatible material with cDPCs. Appropriate concentration of the exudates of PRF accelerated the proliferation and migration of cDPCs, which contributes to pulp repair in vital pulp therapy.

[Development of human embryonic stem cell model for toxicity evaluation].

The current international standard for toxicity screening of biomedical devices and materials recommend the use of immortalized cell lines because of their homogeneous morphologies and infinite proliferation which provide good reproducibility for in vitro cytotoxicity screening. However, most of the widely used immortalized cell lines are derived from animals and may not be representative of normal human cell behavior in vivo, in particular in terms of the cytotoxic and genotoxic response. Therefore, It is vital to develop a model for toxicity evaluation. In our studies, two Chinese human embryonic stem cell (hESC) lines as toxicity model were established. hESC derived tissue/organ cell model for tissue/organ specific toxicity evaluation were developed. The efficiency and accuracy of using hESC model for cytoxicity, embryotoxicity and genotoxicity evaluation were confirmed. The results indicated that hESCs might be good tools for toxicity testing and biosafety evaluation in vitro.

[Cytotoxicity of two dental materials on fibroblasts derived from human embryonic stem cells].

OBJECTIVE: To investigate the cytotoxicity of calcium hydroxide (CH) and composite resin on fibroblasts derived from human embryo body fibroblasts-H9 (EBf-H9), human dental pulp cells (hDPCs) and immortalized fibroblasts L929; and to evaluate the use of EBf-H9 as a cellular model for cytotoxicity screening of dental materials. METHODS: The EBf-H9 cells were derived from human embryonic stem cells (H9) via outgrowth of embryonic body (EB); hDPCs were isolated from healthy dental pulp, and identified by immunochemical staining. Cell Counting Kit-8 (CCK-8) assay was applied to analyze the cytotoxicity of CH and composite resin with serial concentrations on the 3 kinds of cells. RESULTS: Following 24 h and 48 h (or 72 h) post-treatment of CH and composite resin, the viability of L929 cells was significantly lower than that of EBf-H9 and hDPCs (P<0.05), and there was no significant difference between the last two groups (P>0.05). CONCLUSION: Immortalized fibroblasts L929 cells exhibited different response to CH and composite resin compared with EBf-H9 and hDPCs, and the last two cell types were similar to each other. This study indicated that fibroblasts derived from human embryonic stem cells were a potential cellular model instead of traditional immortalized murine cell line for cytotoxicity screening assay.

In-situ formed elastin-based hydrogels enhance wound healing via promoting innate immune cells recruitment and angiogenesis.

Harnessing the inflammation and angiogenesis is extremely important in wound healing. In this study, we developed bioactive elastin-based hydrogels which can recruit and modulate the innate immune cells and accelerate angiogenesis in the wound site and subsequently improve wound regeneration. These hydrogels were formed by visible-light cross-linking of acryloyl-(polyethylene glycol)-N-hydroxysuccinimide ester modified elastin with methacrylated gelatin, in order to mimic dermal microenvironment. These hydrogels showed highly tunable mechanical properties, swelling ratios and enzymatic degradation profiles, with moduli within the range of human skin. To mimic the in vivo degradation of the elastin by elastase from neutrophils, in vitro co-culture of the hydrogels and neutrophils was conducted. The derived conditioned medium containing elastin derived peptides (EDP-conditioned medium) promoted the expression of both M1 and M2 markers in M1 macrophages in vitro. Additionally, the EDP-conditioned medium induced superior tube formation of endothelia cells in Matrigel. In mice wound model, these elastin-based hydrogels attracted abundant neutrophils and predominant M2 macrophages to the wound and supported their infiltration into the hydrogels. The outstanding immunomodulatory effect of the elastin-based hydrogels resulted in superior angiogenesis, collagen deposition and dermal regeneration. Hence, these elastin-based hydrogels can be a promising regenerative platform to accelerate wound repair.

Activation of c-Jun N-terminal kinase is required for mevastatin-induced apoptosis of salivary adenoid cystic carcinoma cells.

Statins are inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, originally developed for lowering cholesterol. Statins also have pleiotropic effects, independent of cholesterol-lowering effects, including induction of apoptosis in various cell lines. However, the mechanism underlying statin-induced apoptosis is still not fully understood. This study aims to explore the proapoptotic effects and underlying mechanisms of statins on human salivary adenoid cystic carcinoma (SACC). Exposure of SACC cells to mevastatin resulted in cell growth inhibition and apoptosis in a dose-dependent manner, accompanied by the release of cytochrome c and cleavage of caspase-3. A remarkable decrease in phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and increase in phosphorylation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated kinase were observed. Furthermore, the JNK-specific inhibitor SP600125, but not the p38-specific inhibitor SB203580, abolished mevastatin-induced cell growth inhibition and apoptosis in SACC cells. This was supported by results in which the JNK inhibitor efficiently blocked mevastatin-induced JNK phosphorylation, but not p38 phosphorylation, and further decreased mevastatin-induced phosphorylation of ERK1/2. Taken together, the results suggest that the JNK pathway was required for mevastatin-induced cell growth inhibition and apoptosis in SACC cells. Statins could be potential anticancer agents for SACC chemotherapy.

[Combined application of non-specific activated immunocytes and cisplatin to treat hemangioendothelioma EOMA xenografts].

OBJECTIVE: To investigate the possibility of combined non-specific activated splenocytes (aSplenocytes) and cisplatin in treating murine hemangioendothelioma EOMA cell line. METHODS: The effects of cisplatin, aSplenocytes or both on EOMA cells were measured by MTT assay and trypan blue exclusive method, respectively. EOMA-bearing mice were established by subcutaneous inoculation of 1.5x10(6) EOMA cells in 6-week old male BALB/c nu/nu mice, divided into untreated control, cisplatin group, aSplenocytes group, and combination group, 5 mice per group. Tumor was treated with 1.5x10(6) aSplenocytes per 100 microL via intratumoral injection, and 24 hours later, followed by cisplatin treatment via intraperitoneal injection. Cisplatin treatment was repeated once a week at the dose of 8 mg/kg of body weight. Tumor volume was measured at indicated time. RESULTS: Both cisplatin and aSplenocytes had inhibitory effects on EOMA cells. 47.7%+/-5.9% EOMA cells were found in 100 micromol/L cisplatin-treated EOMA cells for 24 hours. 42.8%+/-2.6% and 45.3%+/-2.2% EOMA cells were in survival in 1x10(5) /mL aSplenocytes-treated EOMA cells in cell-cell direct contact co-culture system and in transwell system for 48 hours, respectively. When EOMA cells were sensitized with 1x10(5) aSplenocytes in cell-cell direct contact system or in transwell system for 24 hours, followed with 100 micromol/L cisplatin for additional 24 hours, only 25.0%+/-2.7% and 27.5%+/-3.8% EOMA cells were in survival. Compared with single-agent alone treatments, aSplenocytes plus cisplatin significantly inhibited the growth of EOMA cells (P<0.05). There was no significant difference in EOMA cell survival between the two co-culture systems (P>0.05). In vivo assay showed the tumor volume was (680.3+/-68.0) mm3, (825.2+/-71.8) mm3, (535.3+/-74.5) mm3 and (351.5+/-79.5) mm3 in the control, aSplenocytes, cisplatin and aSplenocytes plus cisplatin group, respectively, on the 18 th day after treatment. aSplenocytes plus cisplatin markedly delayed EOMA tumor growth (P<0.05). CONCLUSION: aSplenocytes could enhance the cytotoxicity of cisplatin in EOMA cells in vitro and in vivo.

[Application of keratinocytes derived from human embryonic stem cells for toxicological evaluation of drugs].

PURPOSE: To preliminarily explore the cytotoxicological responses of keratinocytes derived from human embryonic stem cells(K-hESCs) to drugs, and to provide a basis for the establishment of a new biosafety evaluation model. METHODS: CCK-8 assay was used to detect cell viability and cytotoxicity. The detection of pharmacological response was observed and compared when K-hESCs directly derived from human embryonic stem cells, human gingival epithelial cells (HGECs), and human immortalized oral epithelial cells (HIOECs) were treated with retinoic acid (RA), 5-fluorouracil(5-FU), dexamethasone(DEX), and penicillin G(PG). Statistical analysis was performed using SPSS 16.0 software package. RESULTS: After drugs were applied to HGECs, HIOEC and K-hESCs, the half inhibitory concentrations (IC50) of RA was 6.1±0.03, 5.62±0.05 and 6.58±0.02, respectively. The IC50 of 5-FU was 1.65±0.02，3.00±0.02 and 1.72±0.04, respectively. The IC50 of DEX was 113.67±0.014，328±0.002 and 126.17±0.05, respectively. The IC50 of PG was 2200±1.34，3795±2.42 and 2880±1.5, respectively. The IC50 of the four drugs between HIOEC and HGECs had significant differences(P<0.05), but there was no significant difference in IC50 between K-hESCs and HGECs(P>0.05). The IC50 of K-hESCs and HIOEC also had significant differences(P<0.05). CONCLUSIONS: IC50 of K-hESCs was closer to HGECs than HIOEC. It was speculated that K-hESCs could simulate the response of normal human cells in cytotoxicity study.

Long Noncoding RNA MRPL23-AS1 Promotes Adenoid Cystic Carcinoma Lung Metastasis.

Lung metastasis is a major factor affecting long-term survival in patients with adenoid cystic carcinoma. Here, we showed that the long noncoding RNA (lncRNA) MRPL23 antisense RNA 1 (MRPL23-AS1) was highly expressed and correlated with lung metastasis and overall survival in patients with salivary adenoid cystic carcinoma (SACC). MRPL23-AS1 positively regulated epithelial-mesenchymal transition by forming an RNA-protein complex with enhancer of zeste homolog 2 (EZH2). MRPL23-AS1 increased the binding of EZH2 and H3K27me3 on the E-cadherin promoter region. Moreover, MRPL23-AS1 levels were higher in exosomes isolated from the blood plasma of patients with SACC, and exosomal MRPL23-AS1 affected pulmonary microvascular endothelial cells in an "exosomecrine" manner. MRPL23-AS1-enriched exosomes increased microvascular permeability and facilitated the metastasis of SACC in vivo. Collectively, these findings highlight a molecular mechanism of lung metastasis in SACC. MRPL23-AS1 may represent a biomarker and target for clinical intervention to control this intractable disease. SIGNIFICANCE: This study identifies a novel metastasis-promoting lncRNA MRPL23-AS1, which mediates the transcriptional silencing of E-cadherin through forming an RNA-protein complex with EZH2.

MicroRNA­103a­3p promotes metastasis by targeting TPD52 in salivary adenoid cystic carcinoma.

Salivary adenoid cystic carcinoma (SACC) exhibits slow continuous growth, frequent local recurrences and a high incidence of blood metastasis, with advanced lung metastasis frequently occurring and being among the primary causes of mortality. MicroRNAs (miR) serve a significant role in the initiation and development of cancer and may be tumour­specific molecular targets. However, the role of miR­103a­3p in SACC remains largely unknown. In the present study, the expression levels of miR­103a­3p and tumour protein D52 (TPD52) were detected by reverse transcription­quantitative PCR. In addition, wound­healing assays, Transwell assays and mouse models of lung metastasis were used to investigate the biological functions exerted by miR­103a­3p. The present results suggested that miR­103a­3p expression was significantly upregulated in SACC samples. Gain­of­function and loss­of­function studies in SACC cells demonstrated that miR­103a­3p acted as an oncogene by promoting tumour cell migration in vitro and lung metastasis in vivo. Dual­luciferase reporter gene assays indicated that miR­103a­3p exerted its regulatory functions by binding to the 3' untranslated region of TPD52 mRNA. TPD52 overexpression rescued the effect of miR­103a­3p on promoting SACC cell migration, suggesting that miR­103a­3p acted as an oncogene to promote cancer metastasis by directly targeting TPD52. Thus, the newly identified miR­103a­3p/TPD52 axis contributes to the understanding of SACC pathogenesis, providing insights into the identification of novel biomarkers or potential therapeutic targets in SACC.

Relationship of activated extracellular signal-regulated kinase 1/2 with lung metastasis in salivary adenoid cystic carcinoma.

Lung metastasis is one of the important characteristics of salivary adenoid cystic carcinoma (SACC). Although activation of extracellular signal-regulated kinase 1/2 (ERK1/2) pathway may be associated with cancer progression in some malignant tumors, its roles in lung metastasis of SACC remains unclear. We examined the expression of activated ERK1/2 in SACC-LM with high lung-metastatic rate and SACC-83 with low lung-metastatic rate, as well as in the tissues from lung-metastatic and non-metastatic groups of SACC patients. Western blot analysis indicated that SACC-LM exhibited higher expression of activated ERK1/2 than SACC-83. Similarly, immunohistochemistry showed that expression of activated ERK1/2 was detected in 73% (8/11) of the primary tissues from SACC patients with lung metastasis, while only 25% (3/12) of the primary tissues from SACC patients without lung metastasis (P<0.05). Furthermore, we examined the effects of U0126, a specific inhibitor of mitogen activated protein kinase kinase (MEK or MAPKK), on migration and invasion in SACC-LM cells, showing U0126 not only inactivated ERK1/2, but also inhibited migration and invasion of SACC-LM. The present findings suggested that the elevated expression of activated ERK1/2 may play a role in lung metastasis of salivary adenoid cystic carcinoma.