SELEX technology (Systematic Evolution of Ligand by Exponential Enrichment) is a new in vitro screening technology appeared and developed in the past 20 years. SELEX integrate library technology and screening techniques, screening a nucleic acid molecule from nucleic acid library by ligand-aptamer interaction. Similar to the antibodies, aptamers bind with the specific target substance. SELEX screening technology develops rapidly, and aptamer have been widely applied in biomedical field. This article briefly-overviewed the progress and its applications of SELEX technology in recent years.
Animals ; Gene Library ; Humans ; Oligonucleotides ; genetics ; SELEX Aptamer Technique ; methods

OBJECTIVETo test the efficiency of transfecting (99)Tc(m)-labeled anti-miR208b oligonucleotide into early hypertrophic cardiac myocytes in vitro.

METHODSThe anti-oligonucleotide targeting miR208b (AMO) was synthesized and modified with LNA followed by conjugation with N-hydroxysuccinimidyl S-acetyl-meraptoacetyl triglycine (NHS-MAG3) and radiolabeling with (99)Tc(m). NHS-MAG3-LNA-AMO and labeled AMO were purified with Sep-Pak C18 column chromatography, and the former was examined for UV absorption at the 260 nm using Gene Quant DNA/RNA calculator. The labeling efficiency, radiochemical purity, stability and molecular hybridization activity were analyzed. An angiotensin II-induced cell model of hypertrophic cardiac myocytes was transfected with (99)Tc(m)-NHS-MAG3-LNA-AMO via liposome, and the relative expression of miRNA208b and retention ratio of the labeled AMO in early hypertrophic cells were determined.

RESULTSThe labeling efficiency and radiochemical purity of the labeled AMO after purification exceeded 84% and 86%, respectively. The radio- chemical purities of the labeled AMO incubated in serum and normal saline for 12 h were both higher than 80%, and the labeled AMO showed a capacity to hybridize with the target gene. In the hypertrophic model of cardiac myocytes, the retention ratio of labeled AMO at 6 h was higher than 20%.

CONCLUSIONThe (99)Tc(m)-labeled antisense probe can be efficiently transfected into hypertrophic cardiac myocytes in vitro, which provides an experimental basis for subsequent radionuclide imaging studies.

Humans ; Isotope Labeling ; Liposomes ; MicroRNAs ; genetics ; Myocytes, Cardiac ; Oligonucleotides ; Oligonucleotides, Antisense ; Oligopeptides ; Radiopharmaceuticals ; Silicon Dioxide ; Succinimides ; Transfection

Duchenne muscular dystrophy (DMD) is a lethal muscular disorder caused by mutations in the dystrophin gene for which no mutation targeted therapy has been available so far. However, a new method named exon-skipping mediated by antisense oligonucleotides has considerable potential for DMD therapy. In this review, the principle, basic research and clinical research of exon-skipping are mainly summarized.
Animals ; Exons ; genetics ; Humans ; Muscular Dystrophy, Duchenne ; genetics ; therapy ; Oligonucleotides, Antisense ; genetics

The transfection efficiency of oligonucleotide and plasmid to the HL-60 cell line with lipofectaminePLUS was compared through observing the transfection rate and the expression duration of exogenous gene in the target cells. The results showed that the transfection rate of oligonucleotide to the HL-60 was about 90% - 95% and it had no obvious attenuation within 84 h. However, the plasmid transfection rate was only 5% -25% and it was decreased significantly within 60 h. It was suggested that the transfection of oligonucleotide with liposomes was better than that of plasmid.
Green Fluorescent Proteins/genetics ; HL-60 Cells ; Liposomes ; Oligonucleotides/*genetics ; Plasmids/*genetics ; 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

Base Sequence ; Hepacivirus ; drug effects ; genetics ; Hepatitis C ; drug therapy ; virology ; Humans ; Molecular Sequence Data ; Oligonucleotides ; therapeutic use ; Phosphorothioate Oligonucleotides ; therapeutic use

DNA, Viral ; genetics ; Hep G2 Cells ; Hepatitis B virus ; drug effects ; Humans ; Oligonucleotides, Antisense ; pharmacology

The study was supposed to investigate the inhibitory effect of antisense phosphorothioate oligodeoxynucleotide (ASPSODN) targeting hTERT mRNA on gene of interest in K562 cells and influence of ASPSODN on telomerase activity and apoptosis of K562 cells. Human leukemia cell line K562 was transfected by liposome with ASPSODN and SPSODN (sense phosphorothioate oligodeoxynucleotide) at different concentrations (0.2, 0.6, 1.0 micromol/L). At the same time, blank control, liposome control and SPSODN groups were designed for comparison. The transfected cells were collected and detected at 24 and 48 hours; the expression of target gene hTERT mRNA and telomerase activity were detected by RT-PCR and TRAP-ELISA respectively, and cell apoptosis was assayed by flow cytometry. The results showed that after K562 cells were transfected for 24 hours, the expression of hTERT mRNA had no difference between liposome control (0.80+/-0.24), 0.2 micromol/L ASPSODN (0.69+/-0.12), 0.2 micromol/L SPSODN (0.72+/-0.25) and blank control (0.85+/-0.28), but the expression of hTERT mRNA in 0.6 micromol/L ASPSODN group (0.42+/-0.16) remarkably decreased as compared with liposome control group, 0.6 micromol/L SPSODN (0.69 +/- 0.26) had no obvious effect on the expression of hTERT mRNA, the expression of hTERT mRNA in 1.0 micromol/L ASPSODN and SPSODN groups both decreased; mortality of K562 cells transfected by liposome with 1.0 micromol/L ASPSODN and SPSODN remarkably increased. After 24 hours, telomerase relative activity of K562 cells showed no significant difference between blank control (88.9%) and liposome control (77.7%). The telomerase relative activities of K562 cells treated with 0.2, 0.6, 1.0 micromol/L ASPSODN were 60.6%, 52%, 58.2% respectively. There was significant difference as compared with blank control; 0.6 micromol/L ASPSODN showed significant difference (p=0.037), as compared with liposome control group. The telomerase relative activities in K562 cells treated with 0.2, 0.6, 1.0 micromol/L SPSODN were 76.1%, 72.2%, 65.7% respectively, but the telomerase relative activities of K562 cells in 0.2, 0.6 micromol/L SPSODN groups was not inhibited obviously. When K562 cells were treated for 48 hours, telomerase relative activity of K562 cells in each ASPSODN groups restored. It showed that telomerase relative activities of K562 cells treated with 0.2, 0.6, 1.0 micromol/L ASPSODN were 84.1%, 82.3%, 79.6% respectively, while telomerase relative activities of K562 cells treated with 0.2, 0.6, 1.0 micromol/L SPSODN for 48 hours were 74.8%, 74.5%, 67.9% respectively. Telomerase activity of K562 cells could not be inhibited by 0.2 and 0.6 micromol/L SPSODN. After culturing for 48 hours, the cell apoptosis rates of K562 in 0.6 micromol/L ASPSODN, 0.6 micromol/L SPSODN, liposome control and blank control groups were (4.82+/-0.39)%, (1.83+/-0.34)%, 1.84+/-1.04)%, (1.07+/-0.74)% respectively. There was difference between ASPSODN and SPSODN groups (p<0.05), but the significant difference was found in ASPSODN group as compared with liposome control and blank control (p<0.01). It is concluded that the ASPSODN targeting hTERT can specifically inhibit the expression of hTERT mRNA in K562 cells and significantly suppress the telomerase activity of K562 cells at 0.6 micromol/L, which inhibitory time is short. The ASPSODN at high concentration (1.0 micromol/L) shows definite cytotoxicity. 0.6 micromol/L of ASPSODN significantly induces cell apoptosis, while no such effect was seen in SPSODN group.
Apoptosis ; drug effects ; Humans ; K562 Cells ; Oligonucleotides, Antisense ; pharmacology ; Telomerase ; genetics ; metabolism

OBJECTIVETo develop a novel real-time PCR for sensitively quantitative detection of JAK2 V617F allele burden in peripheral blood.

METHODSBased on the real-time allele-specific PCR (AS-qPCR), the locked nucleic acid (LNA)-modified oligonucleotide probe was used for selectively blocking amplification of wild-type alleles in AS-qPCR, and then a novel AS-LNA-qPCR method was established. The percentages of sample JAK2 V617F alleles were directly calculated by its threshold cycle (Ct) values according to the standard curve which generated by JAK2 V617F alleles with its Ct values. We validated intra- and inter-assay variability for quantifying JAK2 V617F. We also assayed 623 apparent healthy donors by our method to validate its clinical application value.

RESULTSThe quantitative lower limit of this method for JAK2 V617F was 0.01%, and the intra- and inter-assay average variability for quantifying percentage of JAK2 V617F in total DNA was 6.3% and 8.6%, respectively. Nineteen JAK2 V617F-positive individuals were identified using AS-LNA-qPCR in blood of 623 apparently healthy donors, and the range of percentages of JAK2 V617F alleles were 0.01%-5.49%.

CONCLUSIONThe AS-LNA-qPCR with highly sensitive and reproducible quantification of JAK2 V617F mutant burden can be used clinically for diagnosis as well as evaluation of disease prognosis and efficacy of therapy in patients with myeloproliferative neoplasms.

Alleles ; Humans ; Janus Kinase 2 ; genetics ; Mutation ; Oligonucleotide Probes ; genetics ; Oligonucleotides ; genetics ; Real-Time Polymerase Chain Reaction ; methods ; Sensitivity and Specificity

OBJECTIVETo investigate the effect of functional blocking of endogenous miR-23a with a specific antisense oligonucleotide (ASO) on the proliferation and invasiveness of gastric adenocarcinoma cell line MGC803 in vitro.

METHODSA specific ASO targeting miR-23a, namely ASO-23a, was transfected into MGC803 cells to block endogenous miR-23a. The mRNA level of miR-23a in the transfected cells was detected with quantitative real-time PCR. The changes of cell proliferation following the transfection were detected with MTT assay and colony formation assay, and TUNEL assay and Transwell assay were employed to evaluate the changes in cell apoptosis and invasiveness, respectively.

RESULTSQuantitative real-time PCR demonstrated efficient functional blocking of endogenous miR-23a in MGC803 cells by ASO-23a. Suppression of miR-23a with ASO-23a obviously inhibited cell growth, colony formation and invasiveness of MGC803 cells and significantly enhanced the cell apoptosis.

CONCLUSIONASO-23a can efficiently block the function of endogenous miR-23a in MGC803 cells to inhibit cell proliferation and invasion and promote cell apoptosis.

Adenocarcinoma ; genetics ; pathology ; Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Humans ; MicroRNAs ; genetics ; Oligonucleotides, Antisense ; Stomach Neoplasms ; genetics ; pathology ; Transfection