Alu antisense RNA ameliorates methylglyoxal-induced human lens epithelial cell apoptosis by enhancing antioxidant defense

AIM:To determine whether an antisense RNA corresponding to the human Alu transposable element(Aluas RNA)can protect human lens epithelial cells(HLECs)from methylglyoxal-induced apoptosis.METHODS:Cell counting kit-8(CCK-8)and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assays were used to assess HLEC viability.HLEC viability/death was detected using a Calcein-AM/PI double staining kit;the annexin V-FITC method was used to detect HLEC apoptosis.The cytosolic reactive oxygen species(ROS)levels in HLECs were determined using a reactive species assay kit.The levels of malondialdehyde(MDA)and the antioxidant activities of total-superoxide dismutase(T-SOD)and glutathione peroxidase(GSH-Px)were assessed in HLECs using their respective kits.RT-q PCR and Western blotting were used to measure m RNA and protein expression levels of the genes.RESULTS:Aluas RNA rescued methylglyoxal-induced apoptosis in HLECs and ameliorated both the methylglyoxalinduced decrease in Bcl-2 m RNA and the methylglyoxalinduced increase in Bax m RNA.In addition,Aluas RNA inhibited the methylglyoxal-induced increase in Alu sense RNA expression.Aluas RNA inhibited the production of ROS induced by methylglyoxal,restored T-SOD and GSHPx activity,and moderated the increase in MDA content after treatment with methylglyoxal.Aluas RNA significantly restored the methylglyoxal-induced down-regulation of Nrf2 gene and antioxidant defense genes,including glutathione peroxidase,heme oxygenase 1,γ-glutamylcysteine synthetase and quinone oxidoreductase 1.Aluas RNA ameliorated methylglyoxal-induced increases of the m RNA and protein expression of Keap1 that is the negative regulator of Nrf2.CONCLUSION:Aluas RNA reduces apoptosis induced by methylglyoxal by enhancing antioxidant defense.

Anti-aging Effects of Alu Antisense RNA on Human Fibroblast Senescence Through the MEK-ERK Pathway Mediated by KIF15

Objective:To investigate whether human short interspersed nuclear element antisense RNA(Alu antisense RNA;Alu asRNA)could delay human fibroblast senescence and explore the underlying mechanisms.Methods:We transfected Alu asRNA into senescent human fibroblasts and used cell counting kit-8(CCK-8),reactive oxygen species(ROS),and senescence-associated beta-galactosidase(SA-β-gal)staining methods to analyze the anti-aging effects of Alu asRNA on the fibroblasts.We also used an RNA-sequencing(RNA-seq)method to investigate the Alu asRNA-specific mechanisms of anti-aging.We examined the effects of KIF15 on the anti-aging role induced by Alu asRNA.We also investigated the mechanisms underlying a KIF15-induced proliferation of senescent human fibroblasts.Results:The CCK-8,ROS and SA-β-gal results showed that Alu asRNA could delay fibroblast aging.RNA-seq showed 183 differentially expressed genes(DEGs)in Alu asRNA transfected fibroblasts compared with fibroblasts transfected with the calcium phosphate transfection(CPT)reagent.The KEGG analysis showed that the cell cycle pathway was significantly enriched in the DEGs in fibroblasts transfected with Alu asRNA compared with fibroblasts transfected with the CPT reagent.Notably,Alu asRNA promoted the KIF15 expression and activated the MEK-ERK signaling pathway.Conclusion:Our results suggest that Alu asRNA could promote senescent fibroblast proliferation via activation of the KIF15-mediated MEK-ERK signaling pathway.

Effect of Antisense RNA Targeting Polo-like Kinase 1 on Cell Growth in A549 Lung Cancer Cells

In order to investigate the effect of Polo-like kinase-1 （Plk1） depletion on cell cycle progression and cell growth in lung cancer cells, a recombinant plasmid containing antisense RNA targeting Plk1 （pcDNA3-Plk1） was transfected into A549 cells by lipofectine. RT-PCR and Western-blot were used to detect the Plk1 gene expression. Cell proliferation was evaluated by direct cell counting and bromodeoxyuridine （BrdU） labeling. Cell cycle distribution and apoptosis were examined by flow cytometry, and the inhibition rate （IR） by vinorebline （NVB） was determined by MTF assay. The results showed that after transfection of pcDNA3-Plk1 into A549 cells, the expression levels of Plk1 mRNA and protein were greatly decreased. In pcDNA3-Plk1 transfected groups, abnormal morphological changes of cells and growth inhibition were observed, and the BrdU labeling index was significantly lower than in the control groups （P〈0.05）. Cells in pcDNA3-Plk1 transfected groups were arresed in G2/M phase and apoptosis was detectable 72 h post transfection. IR induced by vinorebline in pcDNA3-Plk1 transfected groups was significantly higher than in other groups. These data suggested that antisense RNA targeting Plk1 could suppress the Plk1 expression, and therefore, significantly inhibit cell proliferation and induce cell cycle arrest and apoptosis. Moreover, it sensitized lung cancer cells to chemotherapy.

Antisense RNA of Survivin Gene Inhibits the Proliferation of Leukemia Cells and Sensitizes Leukemia Cell Line to Taxol-induced Apoptosis

The effects of survivin antisense RNA on proliferation of leukemia cell line HL-60 and taxol-induced chemotherapy was explored. A cDNA fragment of survivin obtained by RT-PCR was inserted into a plamid vector named pcDNA3 in the reverse direction. The vector encoding antisense RNA of survivin was confirmed by restriction enzyme digestion and DNA sequencing. The recombinant plasmid was delivered into HL-60 cells by electroporation. Growth curves were plotted based on cell counting. Trypan blue dye exclusion assay and MTT assay were carried out after the cells were incubated with taxol. DNA gel electrophoresis and nuclear staining were performed for cell apoptosis assay. The correct construction of the recombinant plasmid has been identified by restriction enzyme digestion and DNA sequencing. A stable down-regulation has been achieved in HL-60 SVVas cells after G418 selection. Compared to HL-60 cells, the proliferation of HL-60 SVVas cells was significantly inhibited （P〈0.05）. Cytotoxicity assays indicated that IC50 of HL-60 SVVas for taxol was relatively lower than controls （P〈0.01）. Apoptosis assays revealed that taxol-induced apoptosis was detected in HL-60 SVVas cells incubated with 50 ng/ml taxol for 12 h, while in HL-60 cells incubated with 100 ng/ml taxol for 72 h. It was suggested that Survivin antisense RNA could inhibit the proliferation of HL-60 cells and enhance taxol-induced apoptosis in HL-60 cells, which may lay an experimental foundation for further research on gene therapy in leukemia.

ANTISENSE RNA OF SURVIVIN ENHANCES THE SENSITIVITY OF PANCREATIC CANCER CELL LINE PANC-1 TO DOXORUBICIN

Objective： This paper attempts to discuss the effects of surviving antisense RNA on doxorubicin-induced apoptosis in pancreatic cancer cell line PANC-1. Methods： A surviving antisense eukaryotic vector pcDNA3-SV Vas prepared in previous study was delivered into PANC-1 by electroperforation. Cell survival fraction and MTT assay were used to investigate the sensibility of transfected cells to doxorubicin. Apoptosis was detected by DNA gel electrophoresis. Results： We obtained two positive cell clone PANC-1/SVVas and PANC-1/neo cells, the growth of PANC-1/SV Vas cells was significantly reduced （P〈0.05）. By MTT assay, the IC50 to doxorubicin of PANC-1/SV Vas, PANC-1/neo and PANC-1 cells were （0.285±0.012） μmol/L, （1.528±0.317） μmol/L and （1.540±0.253） μmol/L respectively, the difference was significant by statistic analysis （P〈0.01）. Agarose gel electrophoresis of genomic DNA from PANC/SV Vas showed typical DNA ladder, but DNA from PANC-1/neo and PANC-1 did not. Conclusion： Survivin antisense RNA could enhance doxorubicin-induced apoptosis in pancreatic cancer cell line PANC-I. This may lay an experimental foundation for further research of gene therapy in pancreatic cancer.

Construction of Antisense RNA Expression Plasmid for u-PAR and Its Transfection to Highly Invasive PC-3M Cell Subclones

To evaluate the specific inhibition of antisense u PAR on the u PAR expressions in highly invasive cell subclones and to determine its blocking function in the invasion by those cells, a cDNA fragment of u PAR obtained by RT PCR was inserted into a plasmid vector named pcDNA3 in antisense orientation. Then the antisense u PAR recombinant was transfected into highly invasive cell subclones. The u PAR expression in neo resistant cells was examined by RT PCR and immunohistochemical assay. Compared to the control cells, the content of mRNA and protein of u PAR in transfected cells decreased sharply, and the rate of inhibition was 53 % and 73 %, respectively, indicating that an antisense u PAR might have played a specific inhibitory role in its expression in the cells, which may provide a good cell model for making further investigation of the inhibitory effects of the antisense u PAR on invasion in highly invasive cell subclones of human prostate carcinoma.

Effect of preS2 antisense RNA on hepatocellular carcinoma with a novel delivery system

Objectives To construct a hepatoma directed gene delivery system which could transfer preS2 antisense RNA to liver cancer cells specifically, and to explore a new therapeutic strategy for hepatocellular carcinoma by blocking hepatitis B virus (HBV) with antisense RNA targeting hepatocellular carcinoma. Methods GE7 and HA20 were synthesized and mixed with pEBAF-as-preS2, a hepatocarcinoma specific HBV antisense expression vector, to construct a novel HBV antisense RNA delivery system named AFP-enhancing 4-element complex. Nude mice bearing hepatocelluar carcinoma cells HepG2.2.15 were injected with AFP-enhancing 4-element complex via a tail vein. Total RNA from tissues was extracted, and reversal transcription-ploymerase chain reaction (RT-PCR) was used to detect the expression of preS2. Different doses of AFP-enhancing 4-element complex was injected into nude mice at different time points, and tumor diameter was measured.Results AFP-enhancing 4-element complex was constructed successfully. RT-PCR showed preS2 antisense RNA delivered by AFP-enhancing 4-element complex only expressed in liver tumor HepG2.2.15 cells of the mice. After the treatment of AFP-enhancing 4-element complex with dose of 0.2 μg per mouse (once a week for 4 weeks), the mean tumor diameter of nude mice was significantly shorter than that of the control groups (0.995±0.35 cm vs 2.125±0.25 cm, P<0.01). Conclusions An HBV antisense RNA gene delivery system targeting hepatocellular carcinoma, AFP-enhancing 4-element complex, was constructed successfully. PreS2 antisense RNA expressed specifically in hepatocelluar carcinoma cells significantly inhibits tumor growth of mice bearing hepatocarcinoma HepG2.2.15 and may have therapeutic potential in HBV related hepatocarcinoma.

REVERSION OF MALIGNANT PHENOTYPES OF HUMAN LUNG SQUAMOUS CARCINOMA CELLS BY ORNITHINE DECARBOXYLASE ANTISENSE RNA

Abnormally elevated activity of ornithine decarboxylase (ODC), and subsequent polyamine accumulation are intimately associated with the genesis.development and metastasis of cancer. In the present study, to control the growth of tumor cells, ODC antisense RNA was used to transfect human lung squamous carcinoma cell line LTEP-78. Compared with the parental cells, growth of the antisense transfected LTEP-78 cells arrested in G0/Gl phase and colony formation in soft agarose and tumorigenicity in nude mice were significantly reduced. Nucleic acid hybridization demonstrated that the transfectants expressed a high level of ODC antisense RNA and a significantly reduced level of endogenous ODC mRNA.The results suggest that the reversion of malignant phenotypes of human lung squamous carcinoma cells transfected with ODC antisense RNA is associated with the inhibition of polyamine biosynthesis.

APPLICATIONS OF ANTISENSE RNA AND DNA IN CARDIOVASCULAR RESEARCH

Antisense nucleic acids are DNA or RNA fragments which bind specifically to complementary

Proliferative response of human prostate cancer cell to hormone inhibited by androgen receptor antisense RNA

Background The failure of endocrine treatment for advanced prostate cancer might be related to aberrant activation of androgen receptor (AR) Prostate cancer cell line LNCaP contains AR that can be activated by androgen, estrogen and progesterone This study was set to investigate the effects of antisense AR RNA on growth of LNCaP cultured in medium containing varied concentrations of R1881, 17β-estradiol, and progesterone, respectively Methods LNCaP cells transfected with antisense AR RNA retroviral vector pL-AR-SN were designated as LNCaP as-AR . LNCaP cells containing empty vector pLXSN served as LNCaP Neo . LNCaP and LNCaP Neo were taken as controls In vitro cell growth assay, proliferative cells of LNCaP and tranfected LNCaPs were counted by typan staining when they cultured with synthetic androgen R1881, 17β-estradiol, and progesterone, respectively Results Growth of LNCaP as-AR was inhibited significantly ( P <0 05) compared with that of LNCaP and LNCaP Neo at 1 nmol/L R1881, 10 nmol/L 17β-estradiol, and 1 nmol/L progesterone, respectively No difference was seen between LNCaP and LNCaP Neo ( P >0 05) Microscopic observation showed that LNCaP and LNCaP Neo cells grew well, but only few LNCaP as-AR cells were alive Conclusions Our observations indicate that antisense AR RNA retroviral vector pL-AR-SN could change androgen-independent characteristics of LNCaP cells, which might shed some novel insights into the treatment of androgen-independent prostate cancer

Prognostic value of the long noncoding RNA AFAP1-AS1 in cancers

Objective This meta-analysis explored whether the expression of actin filament-associated protein 1 antisense RNA 1(AFAP1-AS1)is related to the prognosis and clinicopathological features of patients with cancer.Methods PubMed,EMBASE,and Cochrane Library were systematically searched.Hazard ratios(HRs)with 95%confidence intervals(CIs)were used to assess the prognostic value based on overall survival(OS),disease-free survival(DFS),and progression-free survival(PFS).Odds ratios(ORs)with 95%CIs were used to determine the relationships between AFAP1-AS1 and clinicopathological features,such as large tumor size(LTS),high tumor stage(HTS),poor histological grade(PHG),lymph node metastasis(LNM),and distant metastasis(DM).Results Thirty-five eligible articles and 3433 cases were analyzed.High AFAP1-AS1 expression,compared to low AFAP1-AS1 expression,correlated with significantly shorter OS(HR=2.15,95%CI=1.97-2.34,P<0.001),DFS(HR=1.37,95%CI=1.19-1.57,P<0.001),and PFS(HR=1.97,95%CI=1.56-2.50,P<0.001)in patients with cancer.In various cancers,elevated AFAP1-AS1 expression was significantly associated with LTS(OR=2.76,95%CI=2.16-3.53,P<0.001),HTS(OR=2.23,95%CI=1.83-2.71,P<0.001),and PHG(OR=1.39,95%CI=1.08-1.79,P=0.01)but not LNM(OR=1.59,95%CI=0.88-2.85,P=0.12)or DM(OR=1.81,95%CI=0.90-3.66,P=0.10).Conclusion High AFAP1-AS1 expression was associated with prognostic and clinicopathological features,suggesting that AFAP1-AS1 is a prognostic biomarker for human cancers.

HOX transcript antisense intergenic RNA represses E-cadherin expression by binding to EZH2 in gastric cancer

AIM To clarify the mechanisms of HOX transcript antisense intergenic RNA(HOTAIR) in gastric cancer(GC) migration and invasion.METHODS Quantitative real-time polymerase chain reaction(qp CR) was used to detect the expression level of HOTAIR in GC tissues. The correlation of its expression with clinicopathological features was analyzed. Area under receiver operating characteristic curve(AUCROC) was constructed to evaluate the diagnostic value of HOTAIR. Wound-healing assay and Transwell assay were performed to detect the biological effects of HOTAIR in GC cells. qp CR,western blot and immunohistochemistry were used to evaluate the m RNA and protein expression of E-cadherin. RNAbinding protein immunoprecipitation was used for the analysis of EZH2 interactions with HOTAIR. Chromatin immunoprecipitation assay was performed to investigate direct interactions between EZH2 and E-cadherin.RESULTS The expression of HOTAIR was up-regulated in GC tumorous tissues compared with the para-tumorous tissues(p < 0.001). Its over-expression was correlated with tumor-node-metastasis(TNM) stage(p = 0.024),tumor invasion(p = 0.018),lymph node metastasis(p = 0.023),and poor prognosis(p < 0.001). Multivariate Cox regression analysis confirmed expression of HOTAIR as an independent predictor of overall survival(p = 0.033),together with TNM stage(p = 0.002) and lymph node metastasis(p = 0.002). The AUCROC was up to 0.709(95%CI: 0.623-0.785,p < 0.001). Knockdown of HOTAIR by si RNA in GC cells suppressed the migration and invasion of GC cells. Significantly negative correlation between HOTAIR and E-cadherin was found in GC tissues and cell lines,and HOTAIR contributed to the regulation of E-cadherin through binding to EZH2 with the E-cadherin promoter. CONCLUSION HOTAIR may play a pivotal role in tumor cell migration and invasion. It can be used as a potential diagnostic and prognostic biomarker for GC.

THE EFFECT OF ANTISENSE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) RNA ON THE PROLIFERATION OF HUMAN GLIOMA CELLS AND INDUCTION OF CELL APOPTOSIS

Objective: To study the effect of antisense EGFR RNA on the growth of human glioma cells in vitro and evaluate the feasibility of targeting EGFR gene for gene therapy of gliomas. Methods: Southern and Northern blot analysis, in situ hybridization and immunohistochemical staining were used to detect the integration and expression of antisense EGFR constructs. MTT assay and the average number of AgNOR for evaluation of cell proliferation, and the TUNEL method and ultrastructural change for observation of cell apoptosis. Results: Exogenous antisense EGFR cDNA was integrated into the genome of glioma cells and highly expressed, which resulted in a dramatic decrease of endogenous EGFR mRNA and GEPR protein levels. Clones with high expression of the antisense construct showed a lower proliferation activity and the induction of apoptosis in vitro. Conclusion: This study suggests that EGFR plays an important role in the genesis of gliomas; it may be used as a target for antisense gene therapy of gliomas.

EXPERIMENTAL STUDY ON THE GENE THERAPY OF MALIGNANT GLIOMA WITH ANTISENSE VEGF RNA

Objective: To study the effect of antisense VEGF RNA on rat C6 gliomas in vivo and find out the feasibility ofantiangiogenesis therapy with antisense VEGF RNA formalignant gliomas. Methods: Parental rat C6 glioma cells and C6 cells transfected with antisense VEGF cDNA were implanted intracerebrally and subcutaneously into SD rats as control and transfected group. Rats bearing cerebral and subcutaneous C6 gliomas were treated with antisenseVEGF cDNA as treated group and sense VEGF cDNA and empty vector as control of treated group. The generalmanifestation, survival time, MRI and histopathologicalchanges of all rats were observed. The volume ofsubcutaneously implanted tumors was determinedregularly. In situ hybridization and immunohistochemicalstaining were used for detection of VEGF gene expression of gliomas while PCNA immunostaining and TUNELmethod for examination of proliferation activity andapoptosis of gliomas, respectively. Results: The survival of the rats in transfected and treated group was prolonged.There were two rats surviving over 90 d in the treatedgroup and their tumors disappeared. The VEGF geneexpression, the number of microvessels and theproliferation activity were decreased and a large amount of apoptotic cells could be found in cerebral and subcutaneous gliomas in treated and transfected groups. Conclusion:VEGF is one of the candidate genes for gene therapy ofmalignant gliomas. Antisense VEGF RNA combined with other therapies should be studied further for enhancing the therapeutic effect of malignant gliomas.

Construction of the recombinant adenovirus vector carrying antisense multidrug resistance gene

BACKGROUND: Multidrug resistance proteins serve as transporters for chemical drugs in human malignancies. The objective of this study was to construct a homologous recombinant adenovirus carrying a reversal fragment of multidrug resistance gene 1 (mdr1) gene cDNA sequence. METHODS: The fragment of the mdr1 gene from the plasmid pHaMDRI-1 carrying the whole human mdr1 cDNA sequence was inserted reversely into the shuttle plasmid pAdTrack-CMV of adenoviral vector system AdEasy. The homologous recombination process was taken place in E. coli BJ5183 with the backbone plasmid pAdEasy-1. After packaging in 293 cells, recombinant adenoviral plasmid was generated. The recombinant adenoviral plasmid was identified by polymerase chain reaction (PCR), restriction endonucleases digest, DNA sequence analysis and fluorescence microscopic photograph, respectively. RESULTS: The recombinant adenovirus pAdEasy-GFPASmdr1 was successfully constructed and identified by PCR, restriction digest, and sequencing with strong green fluorescence expression in fluorescence microscopic photograph. CONCLUSIONS: The recombinant adenoviral mdr1 vector would introduce the antisense mdr1 gene into the human multidrug resistance hepatocellular cell fine effectively, which would provide an experimental basis to study the multidrug resistance in human hepatocellular carcinoma.

Effect of the Antisense BcMF12 Driven by the BcA9 Promoter on Gene Silencing in Brassica campestris L.ssp.chinensis

The study analyzed the silencing of BcMF12 gene regulated by BcA9 promoter in the transgenic pakchoi and confirmed the effect of antisense BcMF12 gene on the pollen development. A conserved BcMF12 gene fragment was amplified from the cDNA of flower buds in pakchoi （Brassica campestris L. ssp. chinensis, syn. B. rapa L. ssp. chinensis） and was fused to the anther specific BcA9 promoter. The plant antisense expression vector was constructed and then introduced into pakchoi via Agrobacterium-mediated transformation. The transgenic plants were screened by antibiotics and molecular analysis. PCR and Southern blot revealed that the antisense BcMF12-GUS fusion gene regulated by BcA9 promoter was integrated into transgenic plants. Northern blot suggested that the expression of BcMF12 gene was down-regulated significantly. The pollen germination rate of transgenic plants with antisense BcMF12 gene decreased as compared with that of the control plants. The expression of the gene BcMF12 related to the pollen development was inhibited by the antisense BcMF12 driven by BcA9 promoter, which consequently affected the pollen development in pakchoi.

A novel long non-coding RNA NFIA-AS1 is down-regulated in gastric cancer and inhibits proliferation of gastric cancer cells

Gastric cancer is one of the most common malignant gastrointestinal tumors whose morbidity and mortality account for the second and third place respectively in malignant tumors in China.As an important participant in tumor biology,the abnormal expression of long non-coding RNA(lncRNAs)in cancer cells is closely related to the occurrence and development of tumors and plays the role of oncogenes or tumor suppressor genes.In this study,we identified a novel lncRNA NFIA antisense RNA 1(NFIA-AS1)and explored its role and clinical significance in gastric cancer.Real-time quantitative PCR was performed to detect the expression of NFIA-AS1 in tumor tissues and corresponding normal tissues from 42 pairs of gastric cancer samples.The lower expression of NFIA-AS1 was significantly associated with larger tumor size,lower histological grade,and advanced TNM stage.Kaplan-meier analysis showed that NFIA-AS1 expression could be used as an independent predictor of overall survival.We also demonstrated that overexpression of NFIA-AS1 significantly inhibited the proliferation of gastric cancer cells through affecting p16 levels.In conclusion,our results suggest that the lncRNA NFIA-AS1 may play the role of tumor suppressor gene,and serve as a biomarker for prognosis or progression of gastric cancer.

The Inhibitory Effects of an Antisense u-PAR Vector on Invasion of Highly Invasive Human Prostate Carcinoma PC-3M Cell Subclones

To observe the inhibitory effects of an antisense u-PAR vector on invasion of highly invasive PC-3M cell subclones, the effects of the antisense u-PAR on activity of MMP-9 in those highly invasive cell subclones were detected by a quantitative RT-PCR and zymography. The monolayer invasion assay and colony formation assay in soft agar were used. And tumorigenesis rate and invasions by the cell subclones with or without the antisense u-PAR were observed in nude mice. It was found that in vitro growth of highly invasive PC-3M cell subclones transfected with the antisense u-PAR was declined, and the ability of anchorage-independent growth of those cell subclones was found decreased sharply, with the inhibiting rate becoming 79%and 60% , respectively. Although the anti-sense u-PAR didn't change MMP-9 gene transcription, they could inhibit the activation of MMP-9 of highly invasive PC-3M cell subclones. Moreover, the tumorigenesis rate of the cell subclones with the antisense u-PAR decreased and the growth of a neoplasm also slowed down. The t tests showed the difference between experimental and control groups was statistically significant (P<0.01). The anti-sense u-PAR vector could not only inhibit the invasion ability of highly invasive PC-3M cell subclones in vitro but also restrain the growth of those cell subclones in vivo.

Effect of antisense DNMT3b gene eukaryotic expression plasmid on expression of the DNMT3b gene in human biliary tract carcinoma cells

BACKGROUND: Hypermethylation of the promoter region is one of the major mechanisms of tumor suppressor gene inactivation. DNA methyltransferase 3b (DNMT3b), an enzyme that participates in the establishment of de novo methylation patterns, is highly expressed in many tumor cells and tissues, and it is closely associated with hypermethylation of the promoter of tumor suppressor genes. The aim of this study was to explore the effect of transfection with antisense DNMT3b gene eukaryotic expression plasmid on the expression of the DNMT3b gene in human biliary tract carcinoma cell. METHODS: The constructed antisense DNMT3b gene eukaryotic expression plasmid was transfected into the human biliary tract carcinoma cell line QBC-939 with lipofectamine transfection reagent, and positive cell clones were formed using G418 selection after transfection. The constructed recombinant plasmid was transfected into QBC-939 cells successfully and was confirmed by amplification of the exogenous neo^R gene with the polymerase chain reaction method. The expression of DNMT3b gene mRNA and protein was detected by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and flow cytometry respectively. RESULTS: Following transfection, the mRNA level of the DNMT3b gene decreased from 0.956±0.053 to 0.209±0.023, and the protein level of the DNMT3b gene also decreased from (75.38±3.22)% to (29.87±3.46)%. Very significant differences were observed both at the transcription and posttranscription levels in the expression of the DNMT3b gene between the non-tranfection group and the antisense DN- MT3b gene eukaryotic expression plasmid transfection group (P<0.01). CONCLUSIONS: Transfection with the antisense DNMT3b gene eukaryotic expression plasmid can significantly reduce the expression level of the DNMT3b gene in the human biliary tract carcinoma cell line QBC-939. This study may provide a valid method to investigate the function of the DNMT3b gene and its role in biliary tract carcinoma.

Effect of Antisense MBD1 Gene Eukaryotic Expression Plasmid on Expression of MBD1 Gene in Human Biliary Tract Carcinoma Cells

Hypermethylation of the promoter region is one of the major mechanism of tumor suppressor gene inactivation. In order to provide a research tool for the study on the function of MBD1 gene in DNA methylation and tumorigenesis, antisense MBD1 gene eukaryotic expression plasmid was constructed and transfected into human biliary tract carcinoma cell line QBC-939 to observe its effect on the expression of MBD1 mRNA and protein by using RT-PCR and FCM respectively. Following the transfection, the mRNA level of MBD1 gene decreased from 0. 912±0.022 to 0. 215±0. 017, and the protein level of MBD1 gene also decreased from （80.19±5.05） %to （35.11±4.05） %. There were very significant differences in the expression both at the transcription and post-transcription levels of MBD1 gene between non-tranfection group and the antisense MBD1 gene eukaryotic expression plasmid transfection group （P〈0.01）. It was suggested that transfection with the antisense MBD1 gene eukaryotic expression plasmid can significantly reduce the expression level of MBD1 gene in QBC-939, and this study may provide a valid tool for the investigation of the function of MBD1 gene and its role in biliary tract carcinoma.