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

Transgene silencing is one of two major obstacles in both basic biomedical research for transgene and clinical practice of gene therapy. Based on the model of HT1080 cell clones, which transduced single copy of retroviral vector MGPN2, the mechanism of transgene silencing was explored in this investigation by a serial molecular techniques. In the HT1080 cell clone that absence of GFP protein synthesized, no significant aberration of epigenetic modification was detected, but the transcript size and the sequence changed that resulted in the reading frame shift. In addition to chromosomal position effect leading to transgene silencing, the transcript reading frame shift associated with retroviral vector rearrangements could induce complete silencing of transgene.
Cell Line, Tumor ; Gene Rearrangement ; Gene Silencing ; physiology ; Genetic Engineering ; Genetic Vectors ; genetics ; Humans ; Retroviridae ; genetics ; metabolism ; Transgenes ; genetics

OBJECTIVETo observe the effect of small interfering RNA (siRNA)-induced MAPK p42 silencing on the survival of HeLa cells.

METHODSTwo siRNAs targeting at the MAPK p42 gene and one random siRNA were synthesized respectively by Silencer siRNA Construction Kit and transfected into HeLa cells by Lipofectamin 2000. The expression of p42(MAPK) in the transfected HeLa cells was analyzed by Western blotting and immunohistochemistry, and the morphology of cells were observed with electron microscope. TUNEL assay and Annexin V/PI staining were employed for detecting the cell apoptosis.

RESULTSThe expression of p42(MAPK) in the HeLa cells was remarkably suppressed after transfection with the two siRNAs, reduced by about 2.5 and 3.2 folds respectively in comparison with the negative control. Chromatin margination in the cell nuclei were observed in the transfected cells, and TUNEL assay and Annexin V/PI staining further confirmed the occurrence of cell apoptosis.

CONCLUSIONIn vitro MAPK p42 siRNA-1 and siRNA-2 transfection can specifically silence the gene expression and induce apoptosis of HeLa cells.

Apoptosis ; physiology ; Gene Silencing ; physiology ; HeLa Cells ; Humans ; Mitogen-Activated Protein Kinase 1 ; biosynthesis ; genetics ; RNA, Small Interfering ; genetics ; Transfection

Two stable transformed lines containing antisense LeETR1 [corrected] or LeETR2 [corrected] sequences and their hybridized line were investigated to determine the effect of LeETR1 [corrected] and LeETR2 [corrected] specificity in the ethylene receptor family in tomato (Lycopersicon esculentum Mill.) on ethylene signaling. The transgenic line ale1 containing antisense LeETR1 [corrected] displayed shorter length of seedling grown in the dark and adult plant in the light, severe epinastic petiole, and accelerated abscission of petiole explant and senescence of flower explant, compared with its wild type B1. The transgenic line ale2 containing antisense LeETR2 [corrected] also exhibited shorter hypocotyls and slightly accelerated abscission. The phenotypes of cross line dale of LeETR1 [corrected] and LeETR2 [corrected] were close to ale1 in many aspects. These results suggested that LeETR1 [corrected] probably plays a relatively important role in ethylene signaling of tomato growth and development.
Ethylenes ; metabolism ; Gene Silencing ; physiology ; Lycopersicon esculentum ; physiology ; Plant Proteins ; genetics ; metabolism ; Plants, Genetically Modified ; physiology ; RNA, Antisense ; physiology ; Receptors, Cell Surface ; genetics ; metabolism

This study was aimed to examine the effect of TREK-1 silencing on the function of astrocytes. Three 21-nucleotide small interfering RNA (siRNA) duplexes (siT1, siT2, siT3) targeting TREK-1 were constructed. Cy3-labeled dsRNA oligmers were used to determine the transfection efficiency in cultured astrocytes. TREK-1-specific siRNA duplexes (siT1, siT2, siT3) at the optimal concentration were transfected into cultured astrocytes, and the most efficient siRNA was identified by the method of immunocytochemical staining and Western blotting. The proliferation of astrocytes tranfected with TREK-1-targeting siRNA under hypoxia condition was measured by fluorescence-activated cell sorting (FACS). The results showed that TREK-1 was expressed in cultured astrocytes. The dsRNA oligmers targeting TREK-1 could be transfected efficiently in cultured astrocytes and down-regulate the expression of TREK-1 in astrocytes. Moreover, the down-regulation of TREK-1 in astrocytes contributed to the proliferation of astrocytes under hypoxia condition as determined by cell cycle analysis. It was concluded that siRNA is a powerful technique that can be used to knockdown the expression of TREK-1 in astrocytes, which helps further investigate the function of TREK-1 channel in astrocytes under physicological and pathological condition.
Animals ; Astrocytes ; physiology ; Cells, Cultured ; Gene Silencing ; physiology ; Potassium Channels ; Potassium Channels, Tandem Pore Domain ; genetics ; RNA Interference ; physiology ; RNA, Small Interfering ; genetics ; Rats

Animals ; Gene Expression Profiling ; Gene Silencing ; Hematologic Neoplasms ; genetics ; metabolism ; Hematopoiesis ; genetics ; Humans ; MicroRNAs ; metabolism ; physiology ; Neoplasms ; genetics ; metabolism ; Oligonucleotide Array Sequence Analysis ; T-Lymphocytes ; metabolism

OBJECTIVESTo investigate the effect of short interfering RNA targeting MAT 2A on growth and apoptosis of hepatoma cells.

METHODSThe four siRNA against MAT 2A gene were transcript synthesized intracelluarly by expressed templates of plasmid vector pSilence-2.1-U6. We inserted the target sequence of MAT 2A gene into the upstream of the reporter gene in order to construct the recombinant plasmid vector plucA-MAT 2A. The recombinant plasmid and siRNA-producing plasmid were co-transfected into 293 T cells using this construct via lipofectamine methods. The inhibition effect was detected by measuring luciferase activity in the cell lysate to screen the effective siRNA, and then, the effective siRNA was transfected into Bel-7402 cells. The effect of siRNA treatment on the MAT 2A mRNA level and the MAT activity of hepatoma cells were measured. In order to study the effect of short interfering RNA targeting MAT 2A on growth and apoptosis of hepatoma cells, the tumor cell killing rate was analyzed by MTT method and the rate of apoptosis of hepatoma cells was evaluated by flow cytometry.

RESULTSThe two siRNA among the four siRNA displayed inhibitory effect on the lucifermase expression with the inhibitory rates of 81% and 89% respectively. The expression of MAT 2A mRNA in Bel-7402 cells was specifically inhibited and the MAT activity in Bel-7402 cells was decreased. Furthermore, silencing of the MAT 2A gene by RNAi significantly inhibited hepatoma cell growth and led to induction of apoptosis.

CONCLUSIONRNA interference-mediated silencing of MAT 2A gene attenuates growth and induces apoptosis of hepatoma cells; MAT 2A is an ideal target of gene-specific therapy for liver cancer.

Animals ; Apoptosis ; physiology ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Gene Silencing ; Genetic Therapy ; Liver Neoplasms ; pathology ; Methionine Adenosyltransferase ; genetics ; RNA Interference ; Rats

BACKGROUNDHuman epididymis secretory protein 4 (HE4) has been proved to be a promising novel biomarker for the detection of epithelial ovarian carcinomas. Compared with CA125, HE4 assay demonstrated an improved ability to discriminate between pelvic mass with malignant and benign disease. Though it is well known that HE4 is overexpressed in ovarian cancer, however, the role of HE4 in the carcinogenesis and progression of ovarian cancer remains unkown.

METHODSIn this study, we explored the role of HE4 in the carcinogenesis and progression of ovarian cancer. We screened nine ovarian cancer cell lines for HE4 expression, and using RNA interference (RNAi), we silenced HE4 gene expression in CaoV3 and SKOV3.ip1 ovarian cancer cell lines. We assessed the effect of HE4 gene silencing on the transformed phenotype by examining the cell cycle, apoptosis, proliferation and transwell migration/invasion in vitro.

RESULTSHE4 gene silencing induces G0/G1 arrest and blocks the progression from the G1 to S phase in CaoV3 and SKOV3.ip1 cells. HE4 knockdown also inhibited cell proliferation, migration and invasion in SKOV3.ip1 cells in vitro.

CONCLUSIONHE4 may be involved in the regulation of the cell cycle and promote ovarian cancer migration and invasion.

Biomarkers, Tumor ; analysis ; Cell Line, Tumor ; Disease Progression ; Epididymal Secretory Proteins ; analysis ; genetics ; physiology ; Female ; Gene Silencing ; physiology ; Humans ; Ovarian Neoplasms ; pathology ; RNA Interference

Animals ; Antineoplastic Agents ; therapeutic use ; Gene Silencing ; Genetic Therapy ; methods ; Humans ; MicroRNAs ; antagonists & inhibitors ; therapeutic use ; Neoplasms ; genetics ; therapy ; RNA Interference ; physiology ; RNA, Small Interfering ; antagonists & inhibitors ; therapeutic use ; RNA-Induced Silencing Complex ; metabolism

OBJECTIVETo investigate whether α-hemoglobin stabilizing protein (AHSP), the α-globin-specific molecular chaperone, is regulated by erythroid transcription factor NF-E2.

METHODSWe established the stable cell line with NF-E2p45 (the larger subunit of NF-E2) short hairpin RNA to silence its expression. Western blot, real-time polymerase chain reaction, and chromatin immunoprecipitation (ChIP) analysis were performed to detect the expression of AHSP, the histone modifications at AHSP gene locus, and the binding of GATA-1 at the AHSP promoter with NF-E2p45 deficiency. ChIP was also carried out in dimethyl sulfoxide (DMSO)-induced DS19 cells and estrogen-induced G1E-ER4 cells to examine NF-E2 binding to the AHSP gene locus and its changes during cell erythroid differentiation. Finally, luciferase assay was applied in HeLa cells transfected with AHSP promoter fragments to examine AHSP promoter activity in the presence of exogenous NF-E2p45.

RESULTSWe found that AHSP expression was highly dependent on NF-E2p45. NF-E2 bound to the regions across AHSP gene locus in vivo, and the transcription of AHSP was transactivated by exogenous NF-E2p45. In addition, we observed the decrease of H3K4 trimethylation and GATA-1 occupancy at the AHSP gene locus in NF-E2p45-deficient cells. Restoration of GATA-1 in G1E-ER4 cells in turn led to increased DNA binding of NF-E2p45.

CONCLUSIONNF-E2 may play an important role in AHSP gene regulation, providing new insights into the molecular mechanisms underlying the erythroid-specific expression of AHSP as well as new possibilities for β-thalassemia treatment.

Base Sequence ; Blood Proteins ; genetics ; DNA Primers ; GATA1 Transcription Factor ; physiology ; Gene Expression Regulation ; physiology ; Gene Silencing ; HeLa Cells ; Humans ; Methylation ; Molecular Chaperones ; genetics ; NF-E2 Transcription Factor, p45 Subunit ; physiology ; Promoter Regions, Genetic ; Reverse Transcriptase Polymerase Chain Reaction