Antisense RNA molecule represents a unique type of DNA transcript that comprises 19-23 nucleotides and is complementary to mRNA. Antisense RNAs play the crucial role in regulating gene expression at multiple levels, such as at replication, transcription, and translation. In addition, artificial antisense RNAs can effectively regulate the expression of related genes in host cells. With the development of antisense RNA, investigating the functions of antisense RNAs has emerged as a hot research field. This review summarizes our current understanding of antisense RNAs, particularly of the formation of antisense RNAs and their mechanism of regulating the expression of their target genes. In addition, we detail the effects and applications of antisense RNAs in antivirus and anticancer treatments and in regulating the expression of related genes in plants and microorganisms. This review is intended to highlight the key role of antisense RNA in genetic research and guide new investigators to the study of antisense RNAs.
Animals ; Antineoplastic Agents/therapeutic use* ; Antiviral Agents/therapeutic use* ; Gene Expression Regulation ; Genetic Research ; Humans ; MicroRNAs/physiology* ; RNA, Antisense/physiology* ; RNA, Long Noncoding/physiology* ; RNA, Small Interfering/physiology*

With the development of genome-wide sequencing technology, 195 types of functional long non-coding RNAs (lncRNAs) have so far been found, and their cellular roles are gradually being revealed. Now lncRNAs have become a hotspot in the life science. These small molecules exist in almost all higher eukaryotes, and have very important regulatory roles in these organisms. This review briefly summarizes recent progress in researches on antisense non-coding RNA in the INK4 locus.
Animals ; Cyclin-Dependent Kinase Inhibitor Proteins ; genetics ; Genetic Loci ; Humans ; RNA, Antisense ; physiology ; RNA, Long Noncoding ; physiology

Helicobacter pylori (H. pylori) is an important risk factor for chronic gastritis, peptic ulcer, and gastric cancer. Proteinase-activated receptor 2 (PAR2), subgroup of G-protein coupled receptor family, is highly expressed in gastric cancer, and chronic expression of cyclooxygenase-2 (COX-2) plays an important role in H. pylori-associated gastric carcinogenesis and inflammation. We previously demonstrated that H. pylori induced the expression of PAR2 and COX-2 in gastric epithelial cells. Present study aims to investigate whether COX-2 expression induced by H. pylori in Korean isolates is mediated by PAR2 via activation of Gi protein and Src kinase in gastric epithelial AGS cells. Results showed that H. pylori-induced COX-2 expression was inhibited in the cells transfected with antisense oligonucleotide for PAR2 or treated with Gi protein blocker pertussis toxin, Src kinase inhibitor herbimycin A and soybean trypsin inbitor, indicating that COX-2 expression is mediated by PAR2 through activation of Gi protein and Src kinase in gastric epithelial cells infected with H. pylori in Korean isolates. Thus, targeting the activation of PAR2 may be beneficial for prevention or treatment of gastric inflammation and carcinogenesis associated with H. pylori infection.
Benzoquinones/*pharmacology ; Cell Line, Tumor ; Cyclooxygenase 2/genetics/*metabolism ; Epithelial Cells/enzymology/metabolism/microbiology ; GTP-Binding Protein alpha Subunits, Gi-Go/metabolism ; Gastric Mucosa/enzymology/metabolism/*microbiology ; *Helicobacter pylori ; Humans ; Lactams, Macrocyclic/*pharmacology ; Oligonucleotides, Antisense ; Pertussis Toxin/*pharmacology ; RNA, Messenger/metabolism ; Receptor, PAR-2/*physiology ; src-Family Kinases/metabolism

OBJECTIVESTo investigate molecular mechanisms of PAR-1 regulation on intracellular Ca²(+) mobilization in lung giant cell carcinoma cells in vitro and its involvement in tumor metastasis.

METHODSFree intracellular Ca²(+) ([Ca²(+)]i) was measured in lung giant cell carcinoma PLA801C and PLA801D cells by confocal microscopy. Sense and anti-sense PAR-1 expression vectors were transfected into PLA801C (C+)and PLA801D(D-) cells, respectively. The effects of PAR-1 expression were investigated by thrombin and TRAP-induced mobilization of [Ca²(+)]i in the C+ and D-cells.

RESULTSThere were significant differences of the mean values of [Ca²(+)]i between PLA801D (59.55) and PLA801C cells (35.46, P < 0.01). The mean [Ca²(+)]i of C+ cells (45.77) was significantly higher than that of its control CV cells (35.46, P < 0.05), and the mean [Ca²(+)]i of D-cells (48.42) was significantly lower than that of its control DV cells (59.55, P < 0.05). The peaks of [Ca²(+)]i of C+ and CV cells were 48.19 ± 9.84 and 45.64 ± 9.87 (P < 0.05) respectively at 80 s and 100 s after thrombin treatment, but were 111.31 ± 25.00 and 52.93 ± 11.21 (P < 0.05) respectively at 60 s after TRAP treatment. The peaks of [Ca²(+)]i of D- and DV cells were 40.71 ± 5.89 and 61.07 ± 21.36 (P < 0.05) respectively at 60 s after thrombin treatment, but were 84.98 ± 11.23 and 102.58 ± 21.48 (P < 0.05) respectively at 40 s after TRAP treatment.

CONCLUSIONSThe high metastatic potential of PLA801D and PLA801C may be related to [Ca²(+)]i of the tumor cells. PAR-1 may play an important role in the metastasis of lung giant cell carcinoma cells by up-regulating the intracellular Ca²(+).

Calcium ; metabolism ; Calcium Signaling ; drug effects ; Carcinoma, Giant Cell ; metabolism ; pathology ; Cell Line, Tumor ; DNA, Antisense ; genetics ; Humans ; Lung Neoplasms ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Receptor, PAR-1 ; genetics ; metabolism ; physiology ; Receptors, Thrombin ; metabolism ; Thrombin ; pharmacology ; Transfection ; Up-Regulation

Animals ; Humans ; RNA Interference ; RNA, Antisense ; genetics ; RNA, Small Interfering ; genetics ; SARS Virus ; genetics ; physiology ; Severe Acute Respiratory Syndrome ; virology

BACKGROUNDTelomerase activity is found in 85%-90% of all human cancers but not in their adjacent normal cells. Human telomerase reverse transcriptase (hTERT) is an essential component in the telomerase complex that plays an important role in telomerase activity. This study investigated the effect of the telomerase inhibition with an hTERT antisense oligodeoxynucleotide (ODN) in bladder cancer cells (T24) on tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis.

METHODSAntisense phosphorothioate oligodeoxynucleotide (AS PS-ODN) was synthesized and purified. Telomerase activity was measured by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA). hTERT mRNA expression was measured by reverse transcription polymerase chain reaction (RT-PCR) assay and a gel-image system. hTERT protein was detected by immunochemistry and flow cytometry. Cell viability was measured by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-Diphenyltetrazolium (MTT) assay. Cell apoptosis was observed by a morphological method and determined by flow cytometry.

RESULTSAS PS-ODN significantly inhibited telomerase activity and decreased the levels of hTERT mRNA which preceded the decline in the telomerase activity. AS PS-ODN significantly reduced the percentage of positive cells expressing hTERT protein following the decline of hTERT mRNA levels. There was no difference seen in the telomerase activity, hTERT mRNA expression or the protein levels between the sense phosphorothioate oligodeoxynucleotide (SPS-ODN) and the control group. AS PS-ODN treatment significantly decreased the cell viability and enhanced the apoptotic rate of T24 cells in response to TNF-alpha while there was no difference in cell viability and apoptotic rate between the S PS-ODN and the control group.

CONCLUSIONSAS PS-ODN can significantly inhibit telomerase activity by downregulating the hTERT mRNA and protein expression. Treatment with AS PS-ODN may be a potential and most promising strategy for bladder cancer with telomerase activity.

Apoptosis ; Cell Line, Tumor ; Flow Cytometry ; Humans ; Oligonucleotides, Antisense ; therapeutic use ; RNA, Messenger ; analysis ; Telomerase ; analysis ; antagonists & inhibitors ; genetics ; Thionucleotides ; therapeutic use ; Tumor Necrosis Factor-alpha ; physiology ; Urinary Bladder Neoplasms ; enzymology ; pathology ; therapy

OBJECTIVETo study the effects of antisense oligonucleotide (ASODN) targeting ST6Gal I on cell adhesion and invasiveness of human cervical carcinoma cell line HeLa which over-expressed ST6Gal I .

METHODSASODN and sense oligonucleotide (SODN) targeting ST6Gal I were designed and constructed, and transfected into a cervical cancer cell line, HeLa, by lipofectmine 2000. HeLa cells were cultured and divided into 4 groups: blank control group, liposome group, SODN group and ASODN group. RT-PCR was used to examine the ST6Gal I mRNA expression. Flow cytometry was used to examine the amount of alpha2, 6-sialylation on the HeLa cell surface. The HeLa cell adhesion and invasiveness to extracellular matrix ( ECM) were analyzed by using CytoMatrixTM kit and cell invasion assay kit, respectively.

RESULTSThe expression of ST6Gal I mRNA in HeLa cells at 48 hrs after transfection in the ASODN group was significantly decreased in comparison with that in the blank control group, liposome group, and SODN group(P <0. 01). The amount of alpha2,6-sialylation on cell surface in ASODN group was significantly lower than that of the other 3 groups ( P <0. 05). The adhesion and invasiveness of the cells in the ASODN group decreased remarkably, both significantly lower than those of the other 3 groups ( all P < 0. 05).

CONCLUSIONSpecific ASODN targeting ST6Gal I effectively inhibits HeLa cell ST6Gal I expression, decreases the amount of alpha2,6-sialylation on cell surface and leads to a decline of cell adhesion and invasiveness to ECM. This result also established a fine base for further studying on anti-tumor treatment with antisense oligonucleotide.

Cell Adhesion ; genetics ; physiology ; Cell Movement ; genetics ; physiology ; Flow Cytometry ; Gene Silencing ; HeLa Cells ; Humans ; Neoplasm Invasiveness ; Oligodeoxyribonucleotides, Antisense ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sialyltransferases ; biosynthesis ; genetics ; Transfection

OBJECTIVE: To characterize the antisense c-fos oligonucleotides that control the expression of immediate-early gene c-fos in retina in order to better understand the mechanism by which antisense c-fos oligonucleotides induced myopia. In this study the signal transduction in the pathway linking visual experience and the regulation of the eye's growth was investigated. METHODS: Thirty-one 3-week guinea pigs were assigned into 3 groups: antisense and sense c-fos oligonucleotides were intravitreally injected every 3 days to the eyes of the experimental guinea pigs at different concentrations; and saline vehicle to control guinea pigs in the same way. The refraction and axial length of the eyes were measured before and after the treatment, and the immediate-early gene c-fos expression in the retina was quantified by immunohistochemistry and RT-PCR. RESULTS: The moderate myopia was induced in high (1 nmol) and low (0.1 nmol) level of antisense c-fos oligonucleotide intravitreous injection (-5.425 D and -5.575 D, respectively) compared with the control ateral eyes. The refraction and axial length of the treated eyes increased, and the expression of immediate-early gene c-fos decreased significantly in the antisense c-fos oligonucleotides intravitreously injected eyes compared with the sense c-fos oligonucleotide intravitreously and saline vehicle injected eyes (P<0.01). The refraction and axial length were of no statistically significant differences among the sense c-fos oligonucleotides-treated eyes and saline-treated eyes and non-treated eyes (P>0.05). CONCLUSION The obvious myopia can be induced by antisense c-fos oligonucleotides in guinea pigs; antisense c-fos oligonucleotides inhibit c-fos expression in the retina. Immediate-early gene c-fos may be a potential factor in the prevention of myopia and plays an important role in the signal transduction of the retina.
Animals ; Genes, Immediate-Early ; genetics ; Guinea Pigs ; Immunohistochemistry ; Microinjections ; Myopia ; chemically induced ; genetics ; physiopathology ; Oligonucleotides, Antisense ; administration & dosage ; genetics ; toxicity ; Proto-Oncogene Proteins c-fos ; biosynthesis ; genetics ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Retina ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; physiology

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

OBJECTIVETo study the molecular mechanism of the inhibitory effects of vitamin C on benzo[a]pyrene (B[a]P)-induced changes of cell cycle in human embryo lung fibroblast (HELF) cells.

METHODSThe stable transfectants, HELF transfected with antisense cyclin D1 and antisense CDK4, were established. Cells were cultured and pretreated with vitamin C before stimulation with B[a]P for 24 h. The expression levels of cyclin D1, CDK4, E2F1, and E2F4 were determined by Western blot. Flow cytometric analysis was employed to detect the distributions of cell cycle.

RESULTSB[a]P significantly elevated the expression levels of cyclin D1, E2F1, and E2F4 in HELF cells. Vitamin C decreased the expression levels of cyclin D1, E2F1, and E2F4 in B[a]P-stimulated HELF cells. Dose-dependent relationships were not found between the different concentrations of vitamin C (10, 100, 500, 1000, and 5000 micromol/L) and the expression levels of cyclin D1, E2F1, and E2F4 in HELF cells. The expression levels of cyclin D1, E2F1, and E2F4 in B[a]P-treated transfectants were lower than those in B[a]P-treated HELF cells. The expression levels of cyclin D1 and E2F4 treated with vitamin C and antisense cyclin D1 were decreased compared with those treated with antisense cyclin D1 alone. The effects of vitamin C combined with antisense CDK4 on the expression levels of cyclin D1 and E2F1/E2F4 were similar to those of antisense CDK4 alone. B[a]P progressed HELF cells from G1 to S phase. Both vitamin C and antisense cyclin D1 suppressed the changes of cell cycle progressed by B[a]P. However, antisense CDK4 did not attenuate the above changes. Vitamin C combined with antisense CDK4 markedly suppressed B[a]P-induced changes of cell cycle as compared with antisense CDK4. But the inhibitory effects of vitamin C combined with antisense cyclin D1 on B[a]P-induced changes of cell cycle were similar to those of vitamin C alone or antisense cyclin D1 alone.

CONCLUSIONSB[a]P progressed HELF cells from G1 to S phase via intracellular signaling pathway of cyclin D1/E2F. Vitamin C may modulate this signaling pathway to protect cells from injury caused by B[a]P.

Ascorbic Acid ; pharmacology ; Benzo(a)pyrene ; Blotting, Western ; methods ; Cell Cycle ; drug effects ; physiology ; Cells, Cultured ; Cyclin D1 ; metabolism ; Cyclin-Dependent Kinase 4 ; metabolism ; Dose-Response Relationship, Drug ; E2F1 Transcription Factor ; metabolism ; Fibroblasts ; cytology ; drug effects ; metabolism ; G1 Phase ; drug effects ; physiology ; Humans ; Lung ; cytology ; embryology ; RNA, Antisense ; genetics ; S Phase ; drug effects ; physiology ; Transfection ; methods