OBJECTIVETo investigate the influence of fluorosis on nicotinic acetylcholine receptors (nAChRs) in protein and gene levels in SH-SY5Y cells and the mechanism of the receptor modification.

METHODSSH-SY5Y cells, a human neuroblastoma cell line, were incubated with different concentrations of fluoride or with antioxidant for 48 hours. The functions of cells were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) method, and protein oxidation detected by carbonyl content; the alpha3 and alpha7 nAChR subunits in protein level were measured by Western blotting and in mRNA level by RT-polymerase chain reaction (RT-PCR).

RESULTSIn high-dose group as compared to the control, the decreased MTT (49%), increased protein oxidation (72%), and lower expression of alpha3 (51%) and alpha7 (47%) nAChR subunit proteins were obviously observed in SH-SY5Y cells. There were no changes in expression of nAChR subunit mRNAs between the cells treated with fluoride and those un-treated in controls. Prior treatment with antioxidant resulted in preventing the decrease of nAChR protein in cells exposed to the high doses of fluoride.

CONCLUSIONFluorosis should result in damage of cells and the declined expression of nAChRs in protein levels, but no influences on gene expression of the receptors in human neuroblastoma neurons. The decreased nAChR proteins might be involved in the mechanism of oxidative stress induced by fluorosis.

Cell Line, Tumor ; Fluoride Poisoning ; metabolism ; Fluorides ; toxicity ; Humans ; Neuroblastoma ; metabolism ; pathology ; Protein Processing, Post-Translational ; drug effects ; Proteins ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Receptors, Nicotinic ; biosynthesis ; genetics

OBJECTIVETo investigate whether short interfering RNAs(siRNAs) of beta-site APP cleaving enzyme (BACE) can inhibit the expression of BACE in mammalian cells.

METHODSThe gene of EGFP, U6 promoter and beta-secretase targeting siRNA were cloned by PCR, respectively. The PCR products were inserted into plasmid pLXSN. The interfering vector pLXSN/EGFP-U6-siBACE was transferred into SK-N-SH cells to express BACE. The inhibition effect of BACE siRNA on BACE expression was investigated by fluoroscopy and immunohistochemistry method.

RESULTThe interfering vector pLXSN/EGFP-U6-siBACE was constructed successfully. The BACE siRNA inhibited the expression of BACE in the SK-N-SH cells specifically and effectively, and the production of A beta was reduced.

CONCLUSIONBACE siRNA can inhibit the expression of BACE gene of mammalian cells.

Amyloid Precursor Protein Secretases ; genetics ; metabolism ; Animals ; Green Fluorescent Proteins ; genetics ; metabolism ; Humans ; Immunohistochemistry ; Mice ; Microscopy, Fluorescence ; NIH 3T3 Cells ; Neuroblastoma ; genetics ; metabolism ; pathology ; Plasmids ; genetics ; RNA Interference ; RNA, Small Interfering ; genetics ; Recombinant Fusion Proteins ; genetics ; metabolism ; Tumor Cells, Cultured

OBJECTIVE: To explore the effects of nuclear protein-like transcription factor nuclear receptor subfamily 2 group E member 1 (NR2E1) on the growth, division, and proliferation of neuroblastoma cell line IMR32. METHODS: A NR2E1 shiRNA plasmid vector was constructed and transfected into neuroblastoma cell line IMR32 using lipofedamine™2000. Subsequent cell growth was measured by cell counting and the protein expression of somatic nuclear division was examined by immunofluorescent staining. RESULTS: At 48 h after the neuroblastoma cells IMR32 were transfected with NR2E1-shiRNA vector, the related nuclear division protein and the proliferation of the transfected cells IMR32 were remarkably depressed. CONCLUSION Cells division and proliferation of neuroblastoma cell line IMR32 is inhibited through transfection with the NR2E1-shiRNA plasmid vector.
Cell Division ; genetics ; physiology ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Neuroblastoma ; pathology ; RNA, Small Interfering ; genetics ; Receptors, Cytoplasmic and Nuclear ; genetics ; metabolism ; Transfection

OBJECTIVETo study the expression of E-cadherin and beta-catenin in neuroblastomas of various degrees of differentiation, and to investigate their molecular mechanisms in correlation with clinicopathologic parameters.

METHODSImmunohistochemistry EnVision method was used to detect E-cadherin and beta-catenin expression in 90 paraffin-embedded tissue samples of neuroblastomas. The methylation status of CpG islands of E-cadherin promoter was investigated by MSP in 7 fresh tissue and 24 paraffin-embedded tissue samples. The mutation status of exon 3 of beta-catenin gene was studied by PCR in 7 fresh tissue samples. Statistical analysis of the data was performed by SPSS software.

RESULTSE-cadherin and beta-catenin were abnormally expressed in neuroblastomas in general. The expression of beta-catenin in well-differentiated neuroblastoms was markedly higher (47/70, 67.1%) than that of the poorly differentiated tumors (8/20, 40.0%). There was a markedly decreased expression of both genes in tumors with lymph node metastasis than those without. Demethylation was seen in some regions of the promoter of E-cadherin in 31 cases of nuroblatomas. PCR of the exon 3 of beta-catenin followed by DNA sequencing demonstrated rearrangements and mutations in 7 cases, including 2 cases harboring identical point mutation at gene position 27184, leading to a T-->A alteration.

CONCLUSIONSThe abnormal over-expression of E-cadherin in neuroblastomas is independent of the methylation status of their promoter sequences. The abnormal expression of beta-catenin may be related to mutational changes at exon 3 of the gene.

Cadherins ; genetics ; metabolism ; Child ; Child, Preschool ; CpG Islands ; genetics ; DNA Methylation ; DNA, Neoplasm ; genetics ; Exons ; Female ; Ganglioneuroblastoma ; genetics ; metabolism ; pathology ; Gene Rearrangement ; Humans ; Infant ; Lymphatic Metastasis ; Male ; Mediastinal Neoplasms ; genetics ; metabolism ; pathology ; Neuroblastoma ; genetics ; metabolism ; pathology ; Point Mutation ; Promoter Regions, Genetic ; genetics ; Retroperitoneal Neoplasms ; genetics ; metabolism ; pathology ; Sequence Analysis, DNA ; beta Catenin ; genetics ; metabolism

OBJECTIVE: To construct dopamine D1 receptor (DRD1) expression interference vectors to study the role of DRD1 in nerve cells and lay a foundation for drug development in anti-convulsion. METHODS: Based on DRD1 gene sequence in GenBank, 10 interfere vectors of DRD1 were designed. Liposomal was used to transfect NG-108-15 and the transfect effect was assayed by GFP. With realtime PCR and Western blot, the DRD1 expression was detected. RESULTS: The 10 constructed interfere vectors transfected into NG-108-15 cells by liposomal method and inhibited DRD1 mRNA and protein expression. DRD1 mRNA expression in NG-108-15 cells transfected with pGPU6-GFP-Neo-si-DRD1-5 was the lowest whereas DRD1 protein expression in NG-108-15 cells transfected with pGPU6-GFP-Neo-si-DRD1-1, -2, -6, -7 was the lowest. CONCLUSION DRD1 expression interference vector is successfully constructed.
Animals ; Cell Line, Tumor ; Genetic Vectors ; Glioma ; pathology ; Hybrid Cells ; Liposomes ; metabolism ; Mice ; Neuroblastoma ; pathology ; RNA Interference ; RNA, Messenger ; genetics ; metabolism ; RNA, Small Interfering ; genetics ; Receptors, Dopamine D1 ; genetics ; metabolism ; Transfection

OBJECTIVETo study the possible mechanism of the intracellular aggregate formation of small heat shock protein HSPB8 (HSPB8)(K141N) mutation resulting in axonal Charcot-Marie-Tooth disease type 2L(CMT2L).

METHODSThe cell models which transiently expressed pEGFPN1-HSPB8 and pEGFPN1-(K141N)HSPB8 were established. The immunofluorescent co-location study of EGFP-(K141N)HSPB8 and HSPB1, EGFP-(K141N)HSPB8 and neurofilament light chain (NEFL) was carried out in the SHSY5Y cell models. The aggregate formation of EGFP-(K141N)HSPB8 in cell models was investigated and the possible mechanism of cellular aggregate formation was analyzed by t test and analysis of variance between group(ANOVA).

RESULTSEGFP-(K141N)HSPB8 formed large aggregate which predominantly located around the nucleus in cell models. EGFP-(K141N)HSPB8 co-localized perfectly with HSPB1 and NEFL in the SHSY5Y cell models. The aggregate formation was different in different cell types, there were fewer aggregates formed in an sHSPs deficient milieu than in HEK293T cells.

CONCLUSION(K141N)HSPB8 formed aggregates predominantly locate around the nucleus in cells. (K141N)HSPB8 co-localizes perfectly with HSPB1 and NEFL. The aggregate formation may be due to (K141N)HSPB8 conformational change leading to self aggregation and its abnormal interaction with other sHSPs such as HSPB1.

Cell Line ; Cell Line, Tumor ; Cell Nucleus ; metabolism ; Charcot-Marie-Tooth Disease ; genetics ; metabolism ; Green Fluorescent Proteins ; genetics ; metabolism ; HSP27 Heat-Shock Proteins ; HeLa Cells ; Heat-Shock Proteins ; genetics ; metabolism ; Humans ; Kidney ; cytology ; metabolism ; Microscopy, Confocal ; Neoplasm Proteins ; genetics ; metabolism ; Neuroblastoma ; genetics ; metabolism ; pathology ; Neurofilament Proteins ; genetics ; metabolism ; Point Mutation ; Protein-Serine-Threonine Kinases ; genetics ; metabolism ; Recombinant Fusion Proteins ; genetics ; metabolism ; Transfection

OBJECTIVETo investigate the regulation of tissue factor (TF) on doxorubicin-induced apoptosis in human neuroblastoma.

METHODThe expression of TF was examined by Western blotting. TF siRNA-pSUPER plasmid was constructed by inserting a specific 19-nt silencing sequence targeting TF gene into pSUPER vector. Transfection of TF siRNA-pSUPER was performed using lipofectamine 2000. The activation of caspase-3 and PARP induced by doxorubicin was tested by Western blotting. The apoptotic cells were stained by Hochest 33342 and counted under fluorescence inverted microscope.

RESULTS(1) Human neuroblastoma cell line SK-N-MC expressed high level of TF. (2) Downregulation of TF expression was achieved by transfection of TF siRNA-pSUPER into SK-N-MC cells in a dose-dependent manner. (3) Cleavage of caspase-3 and PARP was increased in transfected SK-N-MC cell with down-regulation of TF. (4) TF siRNA treatment at 1 microg/ml for 8 h significantly increased apoptotic cell number in transfected SK-N-MC cells compared to that in non-transfected cells (P < 0.05) while exposing to 1 microg/ml doxorubicin for 8 h.

CONCLUSIONSDownregulation of TF expression by specific siRNA vector could increase the cytotoxicity of doxorubicin and enhance doxorubicin-induced apoptosis in human neuroblastoma cells.

Apoptosis ; drug effects ; genetics ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Doxorubicin ; pharmacology ; Genetic Vectors ; Humans ; Neuroblastoma ; metabolism ; pathology ; Poly(ADP-ribose) Polymerases ; metabolism ; RNA Interference ; RNA, Small Interfering ; genetics ; Thromboplastin ; genetics ; metabolism ; Transfection

OBJECTIVETo find the optimal design of small interfering RNA compounds, transfection concentration and transfection time to reduce the Al-induced apoptosis in SH-SY5Y cells.

METHODSThree siRNA sequences on bak gene were designed and transfected into SH-SY5Y cells, which were treated at various concentrations of aluminum. Cell viability was detected by CCK-8 kit on different siRNA sequences, various transfection concentrations, and diverse transfection courses. Transfection efficiency was determined by fluorescent staining of CY3, and interference efficiency was measured by QRT-PCR. Besides, immunohistochemical staining was used to express Bak protein content. Finally, apoptotic rate and necrotic rate in Al treated SH-SY5Y cells transfecting by the selected bak siRNA 1 were detected.

RESULTSBased on the viability of siRNA sequences, siRNA 1 was selected as the optimal siRNA sequences. The optimal transfection concentration was 10 nmol/L, and the optimal time course was 24 h after transfection. The transfection efficiency was above 90% and the interference efficiency with bak gene was 57.76%. Furthermore, there was significant transfection effect on Bak protein. The apoptotic rate in Al treated SH-SY5Y cells were significantly decreased by bak siRNA 1 transfection.

CONCLUSIONApoptosis is one of the major cell death pathways in SH-SY5Y cells induced by aluminum. When chemically synthesized siRNA is inducted to neural cells, it can significantly reduce bak gene level, decrease Bak protein expression and apoptotic rate, which may serve as the basis for preventing neural cells apoptosis and inhibiting the development of neurodegenerative diseases.

Aluminum ; pharmacology ; Apoptosis ; drug effects ; genetics ; Cell Line, Tumor ; Cell Survival ; drug effects ; genetics ; Humans ; Neuroblastoma ; genetics ; metabolism ; pathology ; RNA, Small Interfering ; genetics ; Transfection ; bcl-2 Homologous Antagonist-Killer Protein ; genetics ; metabolism

OBJECTIVETo establish a tumor-bearing nude mouse model of human neuroblastoma in order to study the mechanisms of neuroblastoma invasion and metastasis, and to investigate potential therapeutic modalities in the experimental animal models.

METHODSA human neuroblastoma cell line was cultured in vitro. 1 x 10(7) cells undergoing exponential growth were collected in 0.1 ml of suspension and subcutaneously inoculated into the right flank next to the forelimb in nude mice. The biological characteristics of the developed tumors were observed, and histopathological and DNA microarray analyses were performed. The expressions of NSE in the subcutaneous tumor, metastatic tumor and the primary neuroblastoma tumor tissues from a pediatric patient were analyzed by immunohistochemistry.

RESULTSTumors successfully grew in 36 out of 48 injected mice, with a total tumor-formation rate of 75.0%. Metastasis occurred in 10 cases, and the metastatic rate was 20.8%. Tumors in five injected mice grew locally without metastasis. These tumors had large volume and the tumor weight reached up to half of the body weight of the host animal. Four mice exhibited systemic metastasis without tumor growth at the primary inoculation site. There were six mice with locally growing tumor accompanied by metastasis.

CONCLUSIONWe have successfully established a human neuroblastoma xenograft model in nude mice with high tumor growth and metastatic rates. This model depicting the natural cell growth, local infiltration and distant metastasis characteristics of human neuroblastoma, providing an ideal animal model for in vivo studies of neuroblastoma. In addition, the results of this study indicate the heterogeneous nature of neuroblastoma, it may play an important role in metastasis of this tumor.

Animals ; Cell Line, Tumor ; Child, Preschool ; Disease Models, Animal ; Female ; Gene Expression Profiling ; Humans ; Liver Neoplasms ; genetics ; metabolism ; pathology ; secondary ; Male ; Mice ; Mice, Nude ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Neoplasm Transplantation ; Neuroblastoma ; genetics ; metabolism ; pathology ; secondary ; Phosphopyruvate Hydratase ; metabolism ; Tumor Burden

OBJECTIVETo examine the feasibility and practicability of quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) with SYBR GREEN I fluorescence for detecting the MYCN mRNA expression in neuroblastoma cell line LA-N-5.

METHODSMYCN mRNA expression in LA-N-5 cells was measured using real time RT-PCR with SYBR GREEN I. Glyceraldehyde phosphate dehydrogenase (GAPDH) was used as internal control. The level of the MYCN mRNA was calculated as MYCN copies/GAPDH copies.

RESULTSStandard curves were linear and showed high correlations (R2>0.99). The ratio of MYCN mRNA copies to GAPDH mRNA copies was calculated based on specific PCR products. The MYCN mRNA level in LA-N-5 cells was obtained (17.4 +/- 1.2).

CONCLUSIONSQuantitative RT-PCR with SYBR GREEN I fluorescence may be a sensitive and reliable method for detecting the MYCN mRNA expression. It may also be potential applicable for detecting the MYCN mRNA expression in the small amount neuroblastoma tissues.

Cell Line, Tumor ; Humans ; Neuroblastoma ; metabolism ; pathology ; Proto-Oncogene Proteins c-myc ; genetics ; RNA, Messenger ; analysis ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Sensitivity and Specificity