The methylcytosine dioxygenases TET proteins (TET1, TET2, and TET3) play important regulatory roles in neural function. In this study, we investigated the role of TET proteins in neuronal differentiation using Neuro2a cells as a model. We observed that knockdown of TET1, TET2 or TET3 promoted neuronal differentiation of Neuro2a cells, and their overexpression inhibited VPA (valproic acid)-induced neuronal differentiation, suggesting all three TET proteins negatively regulate neuronal differentiation of Neuro2a cells. Interestingly, the inducing activity of TET protein is independent of its enzymatic activity. Our previous studies have demonstrated that srGAP3 can negatively regulate neuronal differentiation of Neuro2a cells. Furthermore, we revealed that TET1 could positively regulate srGAP3 expression independent of its catalytic activity, and srGAP3 is required for TET-mediated neuronal differentiation of Neuro2a cells. The results presented here may facilitate better understanding of the role of TET proteins in neuronal differentiation, and provide a possible therapy target for neuroblastoma.
Animals ; Catalytic Domain ; Cell Differentiation ; drug effects ; physiology ; Cell Line, Tumor ; DNA-Binding Proteins ; antagonists & inhibitors ; genetics ; metabolism ; Enzyme Inhibitors ; pharmacology ; GTPase-Activating Proteins ; genetics ; metabolism ; Immunohistochemistry ; Mice ; Microscopy, Fluorescence ; Neuroblastoma ; metabolism ; pathology ; Protein Isoforms ; antagonists & inhibitors ; genetics ; metabolism ; Proto-Oncogene Proteins ; antagonists & inhibitors ; genetics ; metabolism ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; metabolism ; Valproic Acid ; pharmacology

Although human telomerase catalytic subunit (TERT) has several cellular functions including telomere homeostasis, genomic stability, cell proliferation, and tumorigenesis, the molecular mechanism underlying anti-apoptosis regulated by TERT remains to be elucidated. Here, we show that ectopic expression of TERT in spontaneously immortalized human fetal fibroblast (HFFS) cells, which are a telomerase- and p53-positive, leads to increases of cell proliferation and transformation, as well as a resistance to DNA damage response and inactivation of p53 function. We found that TERT and a mutant TERT (no telomerase activity) induce expression of basic fibroblast growth factor (bFGF), and ectopic expression of bFGF also allows cells to be resistant to DNA-damaging response and to suppress activation of p53 function under DNA-damaging induction. Furthermore, loss of TERT or bFGF markedly increases a p53 activity and DNA-damage sensitivity in HFFS, HeLa and U87MG cells. Therefore, our findings indicate that a novel TERT-bFGF axis accelerates the inactivation of p53 and consequent increase of resistance to DNA-damage response.
*Apoptosis ; *Catalytic Domain ; Cell Line, Transformed ; Cell Proliferation ; DNA Damage ; Fetus/cytology ; Fibroblast Growth Factor 2/*genetics/metabolism ; Fibroblasts/cytology/metabolism ; Gene Expression Regulation, Neoplastic ; Hela Cells ; Humans ; RNA, Messenger/genetics/metabolism ; Telomerase/deficiency/*metabolism ; Tumor Suppressor Protein p53/*metabolism

Recent studies have unequivocally established the link between FTO and obesity. FTO was biochemically shown to belong to the AlkB-like family DNA/RNA demethylase. However, FTO differs from other AlkB members in that it has unique substrate specificity and contains an extended C-terminus with unknown functions. Insight into the substrate selection mechanism and a functional clue to the C-terminus of FTO were gained from recent structural and biochemical studies. These data would be valuable to design FTO-specific inhibitors that can be potentially translated into therapeutic agents for treatment of obesity or obesity-related diseases.
AlkB Homolog 1, Histone H2a Dioxygenase ; Alpha-Ketoglutarate-Dependent Dioxygenase FTO ; Amino Acid Motifs ; Animals ; Catalytic Domain ; DNA ; metabolism ; DNA Repair Enzymes ; metabolism ; Humans ; Methylation ; Obesity ; genetics ; Proteins ; chemical synthesis ; classification ; genetics ; RNA ; metabolism ; Substrate Specificity

OBJECTIVE: To study the inhibitory effects of short hairpin RNA (pshLMP1) combined with DNAzyme or alone on latent membrane protein-1 (LMP1)expression in HNE1 cell lines. METHOD: The pshLMP1 and DNAzymes were co-transfected with pEGFP-N1-1158 (a expression vector encoding LMP1 and EGFP fusion protein) into HNE1 cells, divided into 4 groups as positive control, RNA interference, combining and DNAzyme groups. The green fluorescence were analyzed and then the mRNA and protein of LMP1 gene were detected. RESULT: The HNE1 cells expressing green fluorescence in combining group were significantly less than that in RNA interference group (P < 0.01); The inhibition efficiency of green fluorescence in combining group were 86. 31% Wp 88.88% ,which were higher than that in RNA interference group with 75.15%. The detection of LMP1 mRNA and proteins showed that combining group had a higher inhibition ability. CONCLUSION Combining gene therapy with pshLMP1 and DNAzyme is superior to pshLMP1 alone to inhibit LMP1 gene expression.
Cell Line, Tumor ; DNA, Catalytic ; therapeutic use ; Exons ; Gene Expression Regulation, Viral ; Genetic Therapy ; Humans ; Nasopharyngeal Neoplasms ; genetics ; metabolism ; pathology ; RNA, Small Interfering ; genetics ; therapeutic use ; Transfection ; Viral Matrix Proteins ; genetics

Adenoviridae ; genetics ; Cell Death ; Genetic Vectors ; HT29 Cells ; Humans ; Interleukins ; biosynthesis ; genetics ; RNA, Catalytic ; biosynthesis ; genetics ; RNA, Messenger ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Transfection ; Vascular Endothelial Growth Factor A ; metabolism

In this study, DNAzymes against cyclin D1 (cyclin D1-DRz) were designed according to the secondary structure of cyclin D1 mRNA which was computed with RNAdraw and Mfold. Cyclin D1-DRz were transfected into tumor cell line u251 and HeLa by oligofectamine. The expression of cyclin D1 was detected by RT-PCR. It was shown that the expression of cyclin D1 gene was suppressed obviously, and the expressions of other cell-cycle related genes such as cyclin E1, cyclin A1 and cyclin B1 were also declined. The cell cycle analysis of tumor cells tansfected with cyclin D1-DRz revealed an arrestment in the G0/G1 phase. In conclusion, the approach is effective and feasible for designing DNAzyme. Cyclin D1-DRz is useful for interfering with the cell cycle procession of tumor cells.
Base Sequence ; Cell Cycle ; drug effects ; Cyclin D1 ; antagonists & inhibitors ; genetics ; metabolism ; DNA, Catalytic ; genetics ; metabolism ; pharmacology ; HeLa Cells ; Humans ; Molecular Sequence Data ; RNA, Messenger ; genetics ; metabolism ; Transfection

With the rapid development of genetic engineering and metabolic regulation, antisense technology displays its fascination to the world as a mild regulation genetic tool. Compared with other loss-of-function research methods (e.g. gene knockout), antisense technologies have advantages such as low cost, short period, and easy operation. It has been increasingly used in bacterial metabolic regulation as a powerful genetic tool. This review briefly summarized the latest progress and problems in antisense technologies that are recently used in metabolic engineering of bacteria, and compares the advantages and disadvantages of these technologies.
Bacteria ; genetics ; metabolism ; Genes, Bacterial ; Genetic Engineering ; Metabolic Networks and Pathways ; genetics ; Oligonucleotides, Antisense ; genetics ; RNA, Antisense ; genetics ; RNA, Catalytic ; genetics

A trans-splicing ribozyme which can specifically reprogram human telomerase reverse transcriptase (hTERT) RNA was previously suggested as a useful agent for tumor-targeted gene therapy. In this study, we evaluated in vivo function of the hTERT-targeting trans-splicing ribozymes by employing the molecular analysis of expression level of genes affected by the ribozyme delivery into peritoneal carcinomatosis mice model. To this effect, we constructed adenoviral vector encoding the specific ribozyme. Noticeably, more than four-fold reduction in the level of hTERT RNA was observed in tumor nodules by the systemic infection of the ribozyme-encoding virus. Such hTERT RNA knockdown in vivo induced changes in the global gene expression profile, including the suppression of specific genes associated with anti-apoptosis including bcl2, and genes for angiogenesis and metastasis. In addition, specific trans-splicing reaction with the targeted hTERT RNA took place in the tumors established as peritoneal carcinomatosis in mice by systemic delivery of the ribozyme. In conclusion, this study demonstrates that an hTERT-specific RNA replacement approach using trans-splicing ribozyme represents a potential modality to treat cancer.
Animals ; Cell Line ; Gene Expression/*physiology ; Genetic Vectors ; Humans ; Mice ; Neoplasm Metastasis ; Neoplasms/genetics/pathology ; RNA, Catalytic/genetics/*metabolism ; RNA, Messenger/genetics/metabolism ; RNA, Neoplasm/genetics/metabolism ; Telomerase/antagonists & inhibitors/genetics/*metabolism ; Trans-Splicing/*genetics

OBJECTIVElo investigate the effects of anti-VEGF antibody and anti-VEGF hairpin ribozyme gene on the proliferation, apoptosis and related gene expression of the leukemia K562 cells and the possible molecular mechanisms.

METHODSK562 cells were cultured in different concentrations of anti-VEGF antibody. The recombinant eukaryotic expression plasmid (pcDNA3-RZ) containing anti-VEGF hairpin ribozyme gene and the vector-alone were introduced into K562 cells by lipofectamine mediation. Cell proliferative capacity was determined by MTT, colony formation assay and cells cycles analysis. Cell apoptosis was assayed by DNA ladder and Annexin V -FITC/PI flow cytometry.

RESULTSThe anti-VEGF antibody was able to inhibit growth and induce apoptosis of K562 cells in a dose-dependent manner. Exposure to anti-VEGF antibody at 0. 165 microg/ml for 72 hours, the cells exhibited typical DNA ladders. The apoptosis rate peaked at antibody concentration of 0. 825 microg/ml. RT-PCR showed a decrease of MRP and TOPO II expression but a relative constant expression of GST. The introduction of exogenous anti-VEGF ribozyme gene resulted in a decrease of the proliferative capacity and colony forming efficiency from (30.5 +/- 3.3) % in control group to (16.3 +/- 2.8) % in K562/RZ group, higher G1 and lower S ratio in cell cycle distribution in comparison with the control groups. Typical DNA fragmentation and higher Annexin V + ratio occurred in K562/RZ cells after treated with 0.5 micromot/L of As2O3 for 3 days, the apoptosis rate increased from 13.4% in control group to 31. 5% in As2O3 treated group.

CONCLUSIONAnti-VEGF antibody can inhibit growth, induce apoptosis and down-regulate the expression of MRP, TOPO II genes of K562 cells in vitro. Transfection with anti-VEGF ribozyme gene can inhibit the proliferation of the cells by delaying the progression G1 into S phase in cell cycles and induce cell apoptosis by down-regulating VEGF gene expression.

Antibodies ; pharmacology ; Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Gene Expression Regulation ; Genetic Vectors ; Humans ; K562 Cells ; Liposomes ; RNA, Catalytic ; genetics ; Transfection ; Vascular Endothelial Growth Factor A ; immunology ; metabolism

OBJECTIVE: To explore the possibility of 10-23DNAzyme becoming a new gene therapy for laryngeal carcinoma treatment at the cell level. METHOD: Thiosthorothioate 10-23DNAzyme specific to eIF4E gene mRNA 1059 was designed and synthesized, and its inhibition effects on the expression of eIF4E gene in Hep-2 cells were observed. RESULT: The expression of eIF4E gene was remarkable depressed after Hep-2 cells was transfected by DNAzyme. The level of inhibiting eIF4E in hep-2 cells transfected by DNAzyme was lower than that by only lipofectamine 2000 transfected and Hep-2. CONCLUSION The expression of eIF4E gene in Hep-2 cells 10-23DNAzyme can be highly blocked. It is a specific and effective gene therapeutic means.
Apoptosis ; Cell Line, Tumor ; DNA, Catalytic ; genetics ; DNA, Single-Stranded ; genetics ; Eukaryotic Initiation Factor-4E ; genetics ; metabolism ; Gene Expression ; Genetic Therapy ; Humans ; Laryngeal Neoplasms ; genetics ; RNA, Messenger ; genetics ; Transfection