OBJECTIVETo investigate the function of POLH(polymerase eta) through establishment of the POLH gene-blocked cell line FL-POLH(-).

METHODSA mammalian expression vector expressing antisense POLH gene fragment pMAMneo-amp-POLHA (-) was constructed by cloning the 1473 - 2131 fragment of POLH gene into the mammalian expression vector pMAMneo-amp(-) in antisense orientation. The FL cells were transfected with this antisense RNA expressing vector and selected by G418. The mutation assay was conducted using the shuttle plasmid pZ189.

RESULTThe spontaneous mutation frequency of SupF tRNA gene in the plasmid replicated in the FL-POLH(-) was 13.5 x 10(-4), while it was 4.9x10(-4) and 3.7x10(-4) in the control cells FL and FL-M, respectively. The nontargeted mutation frequency of SupF tRNA gene decreased in the plasmid replicated in these cell lines pretreated with MNNG.

CONCLUSIONPOLH plays an important role in maintenance of genetic stability and genesis of nontargeted mutation.

Antisense Elements (Genetics) ; pharmacology ; Cell Line ; DNA-Directed DNA Polymerase ; genetics ; physiology ; Methylnitronitrosoguanidine ; toxicity ; Mutagenesis

Mammals have 3 pairs of major salivary glands i.e., the parotid, submandibular, and sublingual glands. Saliva secretion of these glands is modulated by taste perception. Salivary glands are composed mainly of acinar and ductal cells. Primary saliva is secreted by acinar cells and modified during ductal flow. Recently, of the murine 35 bitter taste receptors, Tas2r108 was expressed at highest levels in the submandibular gland by qPCR. Further, Tas2r108-transfected cells respond to a range of bitter compounds, such as denatonium, quinine, colchicine, diphenidol, caffeine and dapson. The objective of the present study was to characterize the expression of Tas2r108 mRNA in acinar and/or ductal cells of the submandibular gland using in situ hybridization (ISH). Male 42-60 days old DBA2 mice were used in the study. Messenger RNAs were extracted from the submandibular gland for generating digoxigenin (DIG) labeled-cRNA probes. These probes were transcribed in anti-sense and sense orientation using T7 RNA polymerase. Dot blot hybridization was performed using DIG labeled-cRNA probes, in order to estimate integrity and optimal diluting concentration of these probes. Subsequently, ISH was performed on murine submandibular gland to detect Tas2r108 mRNA. Dot blot hybridization data demonstrated that Tas2r108 DIG labeled-cRNA anti-sense probes specifically detected Tas2r108 cDNA. ISH results showed that the anti-sense probes labeled acinar and ductal cells in the submandibular gland, whereas no staining was visible in sense controls. Interestingly, the Tas2r108 expression levels were higher in acinar than ductal cells. These results suggested that Tas2r108 might be more associated with primary saliva secretion than with ductal modification of saliva composition.
Acinar Cells ; Animals ; Antisense Elements (Genetics) ; Caffeine ; Colchicine ; Digoxigenin ; DNA, Complementary ; DNA-Directed RNA Polymerases ; Humans ; In Situ Hybridization* ; Male ; Mammals ; Mice ; Quinine ; RNA, Messenger ; Saliva ; Salivary Glands ; Sublingual Gland ; Submandibular Gland* ; Taste Perception

OBJECTIVETo study the specific expression of the antisense RNA against hepatitis B virus X (HBX) gene in hepatoblastoma cell line and its anti -HBV activity.

METHODSHBX gene (nt.1370-1827) was amplified by PCR, then cloned into EB virus vector pEBAF which contained human alpha-fetoprotein promoter and enhancer. After transfected into 2.2.15 hepatoma cells and ECV304 human endothelial cells by lipofectin, northern blot, ELISA and real-time qualitative PCR were carried out to assay the expression of HBX mRNA, HBV antigens and HBV DNA level, respectively.

RESULTSThe HBX antisense RNA expression vector pEBAF-as-HBX which could be expressed specifically in 2.2.15 hepatoblastoma cells was successfully constructed. Both HBV DNA level and the expressions of hepatitis B virus surface antigen (HBsAg) and e antigen (HBeAg) in 2.2.15 hepatoblastoma cells were inhibited by pEBAF-as-HBX. Compared with those in sense control (pEBAF-s-HBX), the inhibitory rates of HBsAg, HBeAg, and HBV DNA were 37.9%, 36.8%, and 25%, respectively.

CONCLUSIONSThe pEBAF-as-HBX expression vector may lead to targeted-expression of HBX antisense RNA in hepatoma cells and shows great inhibition effect on HBV.

Animals ; Carcinoma, Hepatocellular ; genetics ; pathology ; virology ; Cell Line, Tumor ; DNA Replication ; Enhancer Elements, Genetic ; genetics ; Gene Expression Regulation, Viral ; drug effects ; Genetic Therapy ; methods ; Hepatitis B virus ; genetics ; physiology ; Humans ; Liver Neoplasms ; genetics ; pathology ; virology ; Promoter Regions, Genetic ; genetics ; RNA, Antisense ; pharmacology ; Trans-Activators ; biosynthesis ; genetics ; Transcriptional Activation ; Transfection ; alpha-Fetoproteins ; genetics

Antisense Elements (Genetics) ; Cell Line ; Cell Proliferation ; Collagen Type I ; biosynthesis ; Genetic Therapy ; Hepatic Stellate Cells ; cytology ; metabolism ; Humans ; RNA, Messenger ; genetics ; Receptor, Angiotensin, Type 1 ; genetics ; Transfection

RNA therapeutics inhibit the expression of specific proteins/RNAs by targeting complementary sequences of corresponding genes or encode proteins for the synthesis desired genes to treat genetic diseases. RNA-based therapeutics are categorized as oligonucleotide drugs (antisense oligonucleotides, small interfering RNA, RNA aptamers), and mRNA drugs. The antisense oligonucleotides and small interfering RNA for treatment of genetic diseases have been approved by the FDA in the United States, while RNA aptamers and mRNA drugs are still in clinical trials. Chemical modifications can be applied to RNA drugs, such as pseudouridine modification of mRNA, to reduce immunogenicity and improve the efficacy. The secure and effective delivery systems such as lipid-based nanoparticles, extracellular vesicles, and virus-like particles are under development to address stability, specificity, and safety issues of RNA drugs. This article provides an overview of the specific molecular mechanisms of eleven RNA drugs currently used for treating genetic diseases, and discusses the research progress of chemical modifications and delivery systems of RNA drugs.
Aptamers, Nucleotide ; RNA, Small Interfering/therapeutic use* ; RNA, Messenger ; Oligonucleotides, Antisense/therapeutic use*

To explore the effect of antisense phosphorothioate oligodeoxynucleotide (ASODN) of human telomerase reverse transcriptase (hTERT) gene on telomerase activity in CEM cells, PCR enzyme-linked immunoassay was used to determine telomerase activity. The expression levels of hTERT mRNA and protein were assayed by RT-PCR and immunofluorescence assay using fluoresce isothiocyanate label respectively. The results showed that the expression levels of hTERT mRNA and protein in CEM cells decreased with time after hTERT ASODN treatment. There was no difference in hTERT mRNA and protein levels between control and sense oligodeoxynucleotide-treated cells. Telomerase activity decreased when CEM cells were treated with ASODN for 48 hours. Telomerase activity of CEM cells was significantly inhibited when treated with ASODN for 72 hours. There was no difference in telomerase activity levels between control and hTERT sense oligodeoxynucleotide-treated cells. These results suggested that hTERT ASODN inhibited telomerase activity of CEM cells.
Cell Division ; drug effects ; Cell Line ; DNA-Binding Proteins ; Flow Cytometry ; Humans ; Oligodeoxyribonucleotides, Antisense ; pharmacology ; RNA, Messenger ; analysis ; Telomerase ; analysis ; genetics ; metabolism

OBJECTIVETo test the hypothesis that the introduction of antisense transforming growth factor beta receptor I (TBRI) plasmid and antisense tissue inhibitor of matrix metalloproteinase (TIMP-1) eukaryotic expressing plasmid into a rat liver fibrosis model may influence the progression of liver fibrosis.

METHODSFragments of TBRI cDNA and TIMP-1 cDNA were obtained by reverse transcription polymerase chain reaction (RT-PCR) and then amplified by nest PCR. pcDNA3.1(+)-antisense TBRI eukaryotic expressing plasmid was constructed by directional and inverted joins with the purified linear pcDNA3.1(+) and the purified fragment of TBRI, as well as, pcDNA3.1(+)-antisense TIMP-1 eukaryotic expressing plasmid. The recombinant was identified by restriction endonuclease digestion and DNA sequence analysis. The recombinant plasmids were encapsulated with Lipofectmine 2000, and then they were injected intraperitoneally into the liver fibrosis model rats. The protein expression of type I collagen was evaluated by immunohistochemistry. VG staining of liver slides of the rats was used for histopathological examination.

RESULTSCompared with the empty plasmid control group and the disease control group, the deposition of type I collagen decreased in the three antisense treatment groups: antisense TBRI group (4.37+/-1.30) x 10(5), P less than 0.05; antisense TIMP-1 group (3.40+/-0.91) x 10(5), probability value less than 0.05; antisense TBRI + antisense TIMP-1 group (0.90+/-0.32) x 10(5), P less than 0.01; treatment control group (6.90+/-1.61) x 10(5); disease control group (7.34+/-1.68) x 10(5); and the normal control group (0.41+/-0.21) x 10(5)]. Significant differences in the pathological grades of fibrosis were found between the normal control group and the other five groups (P less than 0.05) and also between the disease control group and the three antisense treatment groups (antisense TBRI group P less than 0.05; antisense TIMP-1 group P less than 0.05; antisense TBRI + antisense TIMP-1 group P less than 0.01), but no difference was found between the empty plasmid control group and disease control group (P more than 0.05).

CONCLUSIONBoth antisense TBRI eukaryotic expressing plasmid and antisense TIMP-1 eukaryotic expressing plasmid can inhibit the progress of liver fibrosis. A combined action can inhibit the progress of liver fibrosis more.

Animals ; Antisense Elements (Genetics) ; Female ; Genetic Vectors ; Liver Cirrhosis ; pathology ; Protein-Serine-Threonine Kinases ; genetics ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Receptors, Transforming Growth Factor beta ; genetics ; Tissue Inhibitor of Metalloproteinase-1 ; genetics

This study was aimed to construct a recombinant adenovirus vector for antisense klf4 gene through AdEasy system. Human klf4 cDNA was reversely inserted into the multiple cloning sites (MCS)of the pShuttle-CMV by using the backbone plasmid AdEasy-l, the antisense klf4 gene was constructed through homologous recombination in E.coli BJ5183, then the adenoviruses were packaged and amplified in the HEK 293 ce1ls. The adenovirus vector for antisense klf4 gene confirmed by PCR, restriction analysis and DNA sequencing. After being transfected with the adenoviruses at 200 MOI for 48 hours, total RNA and protein were extracted from human umbilical vein endothelial cells (HUVEC). Klf4 mRNA and KLF4 protein expression levels were evaluated by Real-time PCR and Western-blot. The results showed that the recombinant adenovirus vector for antisense klf4 gene was successfully constructed, recombinant adenovirus could suppress the expression of klf4 mRNA and KLF4 protein in HUVECs. It is concluded that the adenovirus vector for antisense klf4 gene has been constructed successfully, which provides the material basis for further studying the biologic function and potential application of klf4.
Adenoviridae ; genetics ; Antisense Elements (Genetics) ; Genetic Vectors ; Humans ; Kruppel-Like Transcription Factors ; genetics ; Plasmids ; Transfection

To investigate the role of mutant hepatitis B virus (HBV) in the development of hepatocellular carcinoma (HCC), 20 patients with HCC were studied for precore and core promoter mutations in tumorous and nontumorous tissues. The precore and core promoter region was amplified and analyzed by direct sequencing. Among the 20 tumorous and nontumorous tissues, precore mutant HBV was found in 12 (60%) and 18 (90%), respectively. Of the 12 tumorous tissues with precore mutant, nine tissues had a single mutation (1896) and one tissue had another single mutation (1899). The remaining two tissues had a double mutation (1896 and 1899). A single mutation (1896) and a single mutation (1899) were found in 11 and two of the 18 nontumorous tissues with precore mutant, respectively. Among 20 tumorous and nontumorous tissues, HBV with a C to T mutation at nucleotide (nt) 1846 was detected in six and eight, respectively, and was associated with the virus carrying a mutation (1896 or 1899) except in two tumorous tissues. Mutations at nt 1762 and 1764 in core promoter were observed in 16 (80%) tumorous tissues and 18 (90%) nontumorous tissues. Mutations in the precore and core promoter region were found frequently in nontumorous tissue and in tumorous tissue (18/20 and 12/20 in precore region, 18/20 and 16/20 in core promoter respectively). The high prevalence of precore and core promoter mutations in liver tissue from patients with HCC suggests that these mutations may contribute to the development of HCC.
Adult ; Aged ; Antisense Elements (Genetics) ; Base Sequence ; Carcinoma, Hepatocellular/virology ; Carcinoma, Hepatocellular/genetics* ; Female ; Gene Expression Regulation, Neoplastic ; Gene Expression Regulation, Viral ; Hepatitis B/genetics ; Hepatitis B Virus/genetics ; Hepatitis B e Antigens/genetics* ; Human ; Korea ; Liver Neoplasms/virology ; Liver Neoplasms/genetics* ; Male ; Middle Age ; Molecular Sequence Data ; Point Mutation* ; Promoter Regions (Genetics)* ; Sequence Analysis, DNA

OBJECTIVETo study the effects of antisense transforming growth factor beta receptor-II (TGFbetaRII) expressing plasmid on experimental liver fibrosis.

METHODSRT-Nest-PCR and gene recombinant techniques were used to construct the rat antisense TGFbetaRII recombinant plasmid which can be expressed in eukaryotic cells. Thirty-six male SD rats were randomly distributed into five groups: 10 in experimental liver fibrosis model induced by pig-serum as disease control group; 10 in antisense TGFbetaRII transfection as treatment group; 10 in pCDNA3 transfection as treatment control group and 6 in normal control group. The recombinant plasmid and empty vector (pCDNA3) were encapsulated by glycosyl-poly-L-lysine and then transducted into rats of pig serum-induced liver fibrosis model respectively. Expression of exogenous transfected plasmid was assessed by Northern blot, RT-PCR and Western blot. We also tested ELISA of serum TGF-beta1, the contents of hepatic hydroxyproline, immunohistochemistry of type I and III collagen, and VG staining for pathological study.

RESULTSThe antisense TGFbetaRII expressing plasmid could be well expressed in vivo, and could block the mRNA and protein expression of TGFbetaRII in the fibrotic liver induced by pig serum. Its expression also reduced the level of TGF-beta1 [antisense treatment group (23.16+/-3.13) ng/ml, disease control group (32.96+/-3.79) ng/ml; F=36.73, 0.01]. Compared with the disease control group, the contents of hepatic hydroxyproline [antisense treatment group (0.17+/-0.01) mg/g liver, disease control group (0.30+/-0.03) mg/g liver; F=15.48, 0.01] and the deposition of collagens type I and type III decreased in the antisense group (antisense treatment group collagen type I 650.26+/-51.51, collagen type III 661.58+/-55.28; disease control group type I 1209.44+/-116.60, collagen type III 1175.14+/-121.44; F values are 69.87, 70.46, 0.01). And its expression also improved the pathologic classification of liver fibrosis models (0.01).

CONCLUSIONThe results demonstrate that TGF-beta plays a key role in liver fibrogenesis and the prevention of liver fibrosis by antisense TGFbetaRII recombinant plasmid intervention may be therapeutically useful.

Animals ; Antisense Elements (Genetics) ; therapeutic use ; Liver Cirrhosis, Experimental ; etiology ; therapy ; Male ; Plasmids ; therapeutic use ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Receptors, Transforming Growth Factor beta ; antagonists & inhibitors ; genetics ; Transforming Growth Factor beta ; physiology