The role of suppression of small RNA molecules in the management of malignity and viral infection on human was studies and discussed. SiRNA (small interference RNA) suppressing gene expression was described. In the year 2001, Ribopharma AG researchers had first demontrated the function of RNAi in mammal cells. SIRPLEX is appropriate with target gene, for using in the treatment of suppression of pathological gene in various genera, including human.
RNA ; Genes ; Gene Silencing

RNA interference (RNAi) is a post-transcriptional gene silencing process by targeting mRNA for degradation in a sequence-specific manner. This powerful platform has enormous potential in functional genomics and medical research. As a tool to knock out expression of specific genes in a variety of organisms, RNAi was used to investigate gene function in a high throughput fashion. Highly conserved in evolution RNAi appears to have evolved as a cellular defense mechanism in plants and animals to suppress viral infection, transposon jumping and endogenous aberrant genes. Exploiting the natural mechanism, the researchers can shut down disease-causing genes and develop novel therapeutics against infection, tumor and other disease.
Gene Expression Regulation ; Gene Silencing ; Genomics ; RNA Interference ; RNA, Small Interfering ; RNA-Induced Silencing Complex

The purpose of this review is to confirm the reason resulted the gene silence and explore the countermeasure avoiding the gene silence in transgene plant. The method is to divide the gene silencing into transcriptional gene silencing(TGS) and posttranscriptional gene silencing(PTGS). Several models resulted PTGS were analyzed by RNA threshold model, ectopic pairing and aberrant RNA model and ds-RNA model. The results showed that it was important to decide the phenomena of restraining transgene silencing and the mechanism of PTGS. The strategies of identification of gene function and prevention of virus were presented by RNAi and gene silencing respectively, etc.
Animals ; Gene Silencing ; Models, Genetic ; RNA ; RNA Processing, Post-Transcriptional

OBJECTIVETo find some effective short interfering RNA's sites targeting HBV surface gene sequence using shRNA expression vectors.

METHODSFour shRNA expression vectors targeting HBV surface gene sequence were constructed based on pAVU6 + 27 vector, and cotransfected into AD293 cells with HBs-EGFP fusion gene plasmid. The changes of HBs-EGFP image were detected by FACS and microscopy. The HBs-EGFP mRNA expression was evaluated by RT-PCR.

RESULTSFour shRNA expression vectors and HBs-EGFP fusion gene plasmid were successfully constructed. pAVU6 + 4sh579 vector inhibited the HBs-EGFP expression by 69.8% in AD293 and suppressed the HBs-EGFP mRNA expression by 74.6%.

CONCLUSIONSThe results showed that the 579 site of HBV surface gene sequence was an effective target and pAVU6 + 4sh579 vector could suppress the HBs-EGFP expression in AD293 cells

Gene Expression Regulation, Viral ; Gene Silencing ; Gene Targeting ; methods ; Hepatitis B Surface Antigens ; genetics ; metabolism ; Humans ; RNA Interference ; RNA, Small Interfering ; genetics ; RNA-Induced Silencing Complex ; genetics

OBJECTIVETo explore the biological function and possible underlying mechanism of aldo-keto reductase family 1 member B10 (AKR1B10) gene during hepatocarcinogenesis.

METHODSA pair of chemically synthesized small interfering RNA (siRNA) targeting on AKR1B10 was transfected into liver cancer cell line MHCC97H by LipofectamineTM 2000. After confirming the interfering effects of AKR1B10-siRNAs through Quant SYBR Green polymerase chain reaction (Real-time PCR), Western blot and enzymatic activity assay, the capabilities of proliferation and apoptosis of the transfected cells were observed by CCK-8 assay and flow cytometry analysis, and the expressions of a group of tumor-related gene such as c-myc, c-fos, N-ras were observed through Real-time PCR.

RESULTSThe expressions of AKR1B10 and the enzymatic activity were down-regulated significantly in AKR1B10-siRNA-transfected cells. Compared with mock and blank control groups, cell growth in AKR1B10-siRNA-transfected group was inhibited by 26.6%+/-3.1% at 72h after transfection. The ratio of apoptotic cells was 37.3%+/-1.0% in AKR1B10-siRNA-transfected group, which was significantly higher than that in mock and blank control groups (P < 0.01). Real-time PCR showed that the expressions of oncogene c-myc, c-fos and N-ras, and the proliferation-associated gene ki-67 were down-regulated in AKR1B10-siRNA-transfected cells, while the expressions of apoptosis-promoting gene caspas-3 and bax were up-regulated.

CONCLUSIONSAKR1B10 might promote proliferation, inhibit apoptosis and then induce malignant transformation of hepatocytes by regulating the expression level of some tumor-related genes.

Aldehyde Reductase ; genetics ; Cell Line, Tumor ; Gene Expression ; Gene Silencing ; Humans ; RNA, Small Interfering ; genetics

Color is an important indicator for evaluating the ornamental traits of horticultural plants, and plant pigments is a key factor affecting the color phenotype of plants. Plant pigments and their metabolites play important roles in color formation of ornamental organs, regulation of plant growth and development, and response to adversity stress. It has therefore became a hot topic in the field of plant research. Virus-induced gene silencing (VIGS) is a vital genomics tool that specifically reduces host endogenous gene expression utilizing plant homology-dependent defense mechanisms. In addition, VIGS enables characterization of gene function by rapidly inducing the gene-silencing phenotypes in plants. It provides an efficient and feasible alternative for verifying gene function in plant species lacking genetic transformation systems. This paper reviews the current status of the application of VIGS technology in the biosynthesis, degradation and regulatory mechanisms of plant pigments. Moreover, this review discusses the potential and future prospects of VIGS technology in exploring the regulatory mechanisms of plant pigments, with the aim to further our understandings of the metabolic processes and regulatory mechanisms of different plant pigments as well as improving plant color traits.
Plant Viruses/genetics* ; Plants/genetics* ; Gene Silencing ; Plant Development ; Gene Expression Regulation, Plant ; Genetic Vectors

Animals ; Gene Silencing ; physiology ; Gene Targeting ; Genetic Therapy ; methods ; Genomics ; Humans ; RNA Interference ; RNA, Small Interfering ; genetics ; therapeutic use ; RNA-Induced Silencing Complex

OBJECTIVEThe aim of this review was to assess RNA interference (RNAi) and its possibility as a potential and powerful tool to develop highly specific double-stranded RNA (dsRNA) or small interfering RNA (siRNA) based gene-silencing therapeutics.

DATA SOURCESThe data used in this review were obtained from the current RNAi-related research reports.

STUDY SELECTIONdsRNA-mediated RNAi has recently emerged as a powerful reverse genetic tool to silence gene expression in multiple organisms. The discovery that synthetic duplexes of 21 nucleotides siRNAs trigger gene-specific silencing in mammalian cells has further expanded the utility of RNAi in to the mammalian system.

DATA EXTRACTIONThe currently published papers reporting the discovery and mechanism of RNAi phenomena and application of RNAi on gene function in mammalian cells were included.

DATA SYNTHESISSince the recent development of RNAi technology in the mammalian system, investigators have used RNAi to elucidate gene function, and to develop gene-based therapeutics by delivery exogenous siRNA or siRNA expressing vector. The general and sequence-specific inhibitory effects of RNAi that will be selective, long-term, and systemic to modulate gene targets mentioned in similar reports have caused much concern about its effectiveness in mammals and its eventual use as a therapeutic mordality.

CONCLUSIONSIt is certain that the ability of RNAi in mammals to silence specific genes, either when transfected directly as siRNAs or when generated from DNA vectors, will undoubtedly accelerate the study of gene function and might also be used as a potentially useful method to develop highly gene-specific therapeutic methods. It is also expected that RNAi might one day be used to treat human diseases.

Animals ; Antigens, Neoplasm ; Gene Silencing ; Genes, abl ; Genetic Therapy ; Humans ; Neoplasm Proteins ; genetics ; RNA Interference

OBJECTIVE: Hypermethylation of p16, a tumor suppressor gene, has been frequently detected in a variety of cancer cells and is known to represent the level of p16 transcription. In human meningiomas, genetic alterations of p16 have shown to be infrequent. The purpose of this study is to investigate the role of p16 associated with the progression of meningiomas. METHODS: Sixty-eight meningiomas(randomly sampled 29 benign, 16 atypical and 23 malignant formalin-fixed, paraffin-embedded tissues) were analyzed. We examined the molecular mechanism of inactivation of p16 in these benign, atypical and malignant meningiomas by detecting the methylation status of p16 using methylation-specific polymerase chain reaction. RESULTS: One out of 29(3.4%) revealed hypermethylation of p16 in benign meningiomas. Atypical and malignant meningiomas showed hypermethylation of p16 in 2 out of 16 cases(12.5%) and in 5 out of 23 cases(21.7%), respectively. Immunohistochemical analysis of methylation-positive tumors demonstrated that tumor cells had reduced immunoreactivity compared to normal lymphocytes. CONCLUSIONS: Our results suggest that inactivation of p16 gene plays a role in the pathogenesis of meningioma and hypermethylation is one of the processes for gene inactivation.
CpG Islands* ; Gene Silencing ; Genes, p16 ; Genes, Tumor Suppressor ; Humans ; Lymphocytes ; Meningioma* ; Methylation* ; Polymerase Chain Reaction

OBJECTIVETo study the mechanism of p16 gene inactivation in salivary adenoid cystic carcinoma.

METHODS53 cases of freshly excised salivary adenoid cystic carcinomas were studied. Polymerase chain reaction (PCR) and single-stranded conformation polymorphism analysis of polymerase chain reaction products (PCR-SSCP) were used to detect deletion and mutation of p16 gene in salivary adenoid cystic carcinomas. Methylation specific PCR (MSP) was used to detect the methylation status of p16 gene.

RESULTSThe homozygous deletion, mutation and hypermethylation of p16 gene were noted in 16 cases (30.2%), 4 cases (7.5%) and 26 cases (49.1%) respectively in 53 cases of salivary adenoid cystic carcinomas.

CONCLUSIONThe main inactivation mechanisms of p16 gene in salivary adenoid cystic carcinoma were hypermethylation and homozygous deletion. The mutation p16 gene was rare in salivary adenoid cystic carcinoma.

Carcinoma, Adenoid Cystic ; DNA Methylation ; Gene Silencing ; Humans ; Mutation ; Polymerase Chain Reaction