Effects Of Antisense Oligonucleotides Research Articles

Antisense oligonucleotides and nucleic acids generate hypersensitive platelets

IntroductionDespite the great promise for therapies using antisense oligonucleotides (ASOs), their adverse effects, which include pro-inflammatory effects and thrombocytopenia, have limited their use. Previously, these effects have been linked to the phosphorothioate (PS) backbone necessary to prevent rapid ASO degradation in plasma. The main aim of this study was to assess the impact of the nucleic acid portion of an ASO-type drug on platelets and determine if it may contribute to thrombosis or thrombocytopenia. MethodsPlatelets were isolated from healthy donors and men with advanced prostate cancer. Effects of antisense oligonucleotides (ASO), oligonucleotides, gDNA, and microRNA on platelet activation and aggregation were evaluated. A mouse model of lung thrombosis was used to confirm the effects of PS-modified oligonucleotides in vivo. ResultsPlatelet exposure to gDNA, miRNA, and oligonucleotides longer than 16-mer at a concentration above 8 mM resulted in the formation of hypersensitive platelets, characterized by an increased sensitivity to low-dose thrombin (0.1 nM) and increase in p-Selectin expression (6–8 fold greater than control; p < 0.001). The observed nucleic acid (NA) effects on platelets were toll-like receptor (TLR) -7 subfamily dependent. Injection of a p-Selectin inhibitor significantly (p = 0.02) reduced the formation of oligonucleotide-associated pulmonary microthrombosis in vivo. ConclusionOur results suggest that platelet exposure to nucleic acids independent of the presence of a PS modification leads to a generation of hypersensitive platelets and requires TLR-7 subfamily receptors. ASO studies conducted in cancer patients may benefit from testing the ASO effects on platelets ex vivo before initiation of patient treatment.

The effect of miRNA-34a antisense oligonucleotide on non-small cell lung cancer cell line HCC827

Objective To investigate the effect of antisense oligonucleotides of miRNA-34a on non-small cell lung cancer (NSCLC) and its molecular mechanism. Methods The expression of miRNA-34a in human non-small cell lung cancer cell line HCC827 and human normal lung cell MRC-5 was detected by real time fluorescence quantitative polymerase chain reaction (qRT-PCR). HCC827 cells were divided into three groups: blank control group, negative control group, anti-sense oligonucleotide group(liposome 2000 transfected anti-sense oligonucleotide miRNA-34a); cell counting kit-8 (CCK-8) method was used to detect cell proliferation, Jimsa staining was used to detect cell cloning ability, Transwell test was used to detect cell migration and invasion ability; RT-PCR and Western blot were used to detect phosphatase and tensin homolog (PTEN), phosphorylation-protein kinase B (p-Akt), phosphatidylinositol-3-kinase (PI3K) mRNA and protein expression. Results The relative expression of miRNA34a in HCC827 cells was significantly higher than that in human normal lung cells (P 0.05). At 48 h, 72 h and 96 h, the proliferation level of HCC827 cells in anti-sense oligonucleotide miRNA-34a group was significantly lower than that in negative control group and blank control group (P<0.05). The cell cloning rate of antisense oligonucleotide miRNA-34a group was significantly lower than that of negative control group and blank control group (P<0.01). The number of migration and invasion of HCC827 cells in antisense oligonucleotide RNA-34a group was significantly lower than that in negative control group and blank control group (P<0.01). The relative expression of PTEN mRNA and protein in antisense oligonucleotide miRNA-34a group was significantly higher than that in negative control group and blank control group (P<0.05); the relative expression of p-Akt, PI3K mRNA and protein in antisense oligonucleotide miRNA-34a group were significantly lower than that in negative control group and blank control group (P<0.05). Conclusions The expression level of miRNA-34a in human non-small cell lung cancer cells is significantly higher than that in human normal lung cells. Antisense oligonucleotides of miRNA-34a can inhibit the proliferation, cloning, migration and invasion of human non-small cell lung cancer cells. The mechanism may be related to the negative regulation of PTEN/p-Akt/PI3K signaling pathway. Key words: Oligonucleotides, antisense; miRNA-34a; Carcinoma, non-small-cell lung; Cell line, tumor

Antisense-Mediated Transcript Knockdown Triggers Premature Transcription Termination.

Antisense oligonucleotides (ASOs) that trigger RNase-H-mediated cleavage are commonly used to knock down transcripts for experimental or therapeutic purposes. In particular, ASOs are frequently used to functionally interrogate long noncoding RNAs (lncRNAs) and discriminate lncRNA loci that produce functional RNAs from those whose activity is attributable to the act of transcription. Transcription termination is triggered by cleavage of nascent transcripts, generally during polyadenylation, resulting in degradation of the residual RNA polymerase II (Pol II)-associated RNA by XRN2 and dissociation of elongating Pol II. Here, we show that ASOs act upon nascent transcripts and, consequently, induce premature transcription termination downstream of the cleavage site in an XRN2-dependent manner. Targeting the transcript 3'end with ASOs, however, allows transcript knockdown while preserving Pol II association with the gene body. These results demonstrate that the effects of ASOs on transcription must be considered for appropriate experimental and therapeutic use of these reagents.

Antisense oligonucleotide against insulin-like growth factor I receptor inhibits tumor growth in human hepatocellular carcinoma orthotopic implantation models and its influence on the blood indicators in nude mice in vivo

Objective To investigate the inhibitory effect of antisense oligonucleotide against insulin-like growth factor 1 receptor (IGR-1R) on tumor growth in human hepatocellular carcinoma orthotopic implantation models and its influence on the blood indicators in nude mice. Methods We did the experiment 3 times, and 40 models for each time were divided into 5 groups randomly: NS control group, three IGF-1R antisense oligdeoxynucleotides (ASODN) [75, 50, 25 mg/(kg·day)] groups and 5-fluorouracil (5-Fu) control group. Eighty nude mice served as normal control group. The agents were given for 25 times through intravenous injection in human hepatocellular carcinoma orthotopic implantation models. When the experiment was over, the volume and weight of tumor were measure, the inhibitory rate of tumor growth was calculate, and the pathomorphological change was examined. Alpha fetal protein (AFP), routine blood test and biochemical indexes were determined in three experiments respectively. Results The average volume and weight of tumor in IGF-1R ASODN group was significantly reduced as compared with those in NS control group. The inhibitory rate of tumor growth in 75 mg/(kg·day) IGF-1R APSODN group in three experiments were 76.36%, 71.81% and 78.81%, 55.65%, 61.74% and 63.58% in 50 mg/(kg·day) group, and 47.72%, 50.34% and 54.30% in 25 mg/(kg·day) group respectively. Large piece of necrosis and fibrosis could be seen under a light microscope in IGF-1R ASODN groups. AFP in IGF-1R ASODN groups was lower (P<0.05) than in NS control group, PLT in IGF-1R ASODN group [75 mg/(kg·day)] was lower than in NS control group (P<0.05), and GLU in IGF-1R ASODN group [75 mg/(kg·day) and 50 mg/(kg·day)] was higher than in normal control group (P<0.05). There was no significant difference between IGF-1R ASODN group and normal control group in other blood indicators. Conclusion IGF-1R ASODN is an anti-hepatoma biological agent with high efficiency and low side-effect. Key words: Carcinoma, hepatocellular; Insulin-like growth factor 1 receptor; Antisense oligdeoxynucleotides; Inhibitory rates of tumor growth

Inhibiting miRNA Function by Antisense Oligonucleotides in Cultured Mammalian Cells.

Methods for transfecting antisense oligonucleotides (ASOs) into mammalian cells for suppression of miRNA function are described in this protocol. The effects of ASOs on the miRNA are evaluated by measuring the protein level of the putative miRNA target or the activity of a reporter bearing a 3' untranslated region (3' UTR) derived from the putative miRNA target.

Inhibiting miRNA Function by Antisense Oligonucleotides in Drosophila S2 Cells.

This protocol describes methods to transfect antisense oligonucleotides (ASOs) into Drosophila S2 cells for suppression of miRNA function. The effects of ASOs on the miRNA are evaluated by measuring the protein level of the putative miRNA target or the activity of a reporter bearing a 3' UTR derived from the putative miRNA target.

Effects of microRNA-21 on apoptosis by regulating the expression of PTEN in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is an aggressive malignancy and the most common subtype of non-Hodgkin lymphoma in China. However, many cases still remain biologically and clinically heterogeneous, indicating that the DLBCL mechanism remains unclear. MicroRNAs (miRNAs) are critically responsible for lymphomagenesis. We found that plasma miR-21 level was significantly higher in B-cell lymphoma. However, the exact contribution of miR-21 in DLBCL remains unknown.To determine the function and mechanism of miR-21 in DLBCL, miR-21 and phosphatase and tensin homolog (PTEN) expressions were examined through real-time PCR and immunohistochemical methods. Moreover, the effects of antisense oligonucleotide (ASO) targeting miR-21 (ASO-21) were observed in DLCBL cell line.MiR-21 expressions in cell line and tissues of patients were significantly higher than those in normal controls, which were inversely correlated with PTEN expression. MiR-21 expression was significantly higher in stage III/IV patients than in stage I/II patients. PTEN protein was expressed positively in only 6 patients with DLBCL (6/26). MiR-21 expression level in the PTEN-negative group was 11.73 (2.13–64.29), which was significantly higher than that in the PTEN-positive group (1.04, 0.67–15.15; P = .038). After down-regulating the miR-21 expression, apoptosis of DLBCL cells increased and PTEN protein was up-regulated in ASO-21-treated cells compared with SCO-21-treated cells by western blot.These results suggested that miR-21 affects apoptosis of lymphoma cells by regulating the expression of PTEN in DLBCL, which may be associated with increased poor prognosis for DLBCL patients and represents a useful approach for DLBCL treatment.

Effects of Antisense Oligonucleotides against C-Reactive Protein on the Development of Atherosclerosis in WHHL Rabbits

Increased plasma levels of C-reactive protein (CRP) are closely associated with cardiovascular diseases, but whether CRP is directly involved in the pathogenesis of atherosclerosis is still under debate. Many controversial and contradictory results using transgenic mice and rabbits have been published but it is also unclear whether CRP lowering can be used for the treatment of atherosclerosis. In the current study, we examined the effects of the rabbit CRP antisense oligonucleotides (ASO) on the development of atherosclerosis in WHHL rabbits. CRP ASO treatment led to a significant reduction of plasma CRP levels; however, both aortic and coronary atherosclerotic lesions were not significantly changed compared to those of control WHHL rabbits. These results suggest that inhibition of plasma CRP does not affect the development of atherosclerosis in WHHL rabbits.

Delivery of radioiodinated antisense oligonucleotides in long circulating liposomes in vivo

The anionic long circulating liposomes (ALCLs) prepared in previous studies enabled high loading efficiency, small particle size, and good stability. In addition, the uptake by tumor cells and delivery of radioiodinated antisense oligonucleotides (ASON) to MCF-7 breast cancer cell line was improved. The liposomes also displayed valuable pharmacologic properties characterized by a long half-life, slow clearance, and a significant area under the concentration–time curve (AUC) in vivo. This study emphasizes the contribution of ALCLs to the anti-tumor effect of ASON and radiation therapy. Our results show that ALCLs improve biodistribution and delivery of radioiodinated ASON in tumor bearing rats, which is characterized by the suppression of tumor growth, decreased bcl-2 expression, and increased tumor cell necrosis in the mammary tumor.

Effect of antisense oligonucleotides targeting bcl-2 on addition proteins that regulate prostatic apoptosis and differentiation in LNCaP cells.

e13511 Background: Our lab has evaluated bispecific oligos targeting unrelated genes and reported inhibition of both growth and targeted protein expression. Mono- and bispecific oligos against bcl-...

Vascular endothelial growth factor antisense oligonucleotides inhibit leptomeningeal metastasis in vivo

To determine the level of vascular endothelial growth factor (VEGF) protein produced in tumor tissues and to evaluate the effect of antisense oligonucleotides directed against VEGF on tumor growth and animal survival in a rabbit model of leptomeningeal carcinomatosis. New Zealand White (NZW) rabbits were injected with VX2 tumor cells transfected with or without VEGF antisense constructs. The time course of VEGF protein expression in tumor tissues was then examined by immunohistochemistry and western blot analysis. VEGF concentrations in serum and cerebrospinal fluid (CSF) were determined by enzyme-linked immunosorbent assay (ELISA). The efficacy of VEGF antisense therapy was evaluated by calculation of the survival rate and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Immunohistochemical analysis and immunoblotting showed that VEGF protein expression was significantly decreased in tissues from rabbits given VEGF antisense treatment. Serum and CSF VEGF concentrations were also markedly reduced during the first 15days after tumor inoculation in antisense-treated animals. VEGF antisense therapy resulted in prolonged animal survival. Furthermore, while some meningeal nodular enhancement was evident in almost all of the VX2-inoculated rabbits, meningeal enhancement and thickening was clearly suppressed after VEGF antisense treatment. These results indicate that VEGF antisense oligonucleotides have a potent anti-tumor activity in a rabbit model of VX2 leptomeningeal carcinomatosis. In addition, DCE-MRI provides highly accurate measurements for the detection of experimentally induced leptomeningeal carcinomatosis and could be used as a suitable method for assessing in vivo tumor growth and angiogenesis.

Abstract 3005: Significant roles of aberrant miRNA expressions in NK-cell lymphomagenesis

Abstract Background: Natural Killer (NK) cell lymphomas/leukemias are characterized groups of highly aggressive lymphoid malignancies, which are comprised of “extranodal NK/T cell lymphoma, nasal type” and “aggressive NK-cell leukemia”. Notably, these two subtypes show many similarities in their morphologic features, immmunophenotypes and genotypes, and are invariably associated with Epstein-Barr virus (EBV), which suggests they may share the same genetic alterations. The gene(s) responsible for natural killer (NK)-cell lymphoma/leukemia have not been identified. Materials and Methods: In the present study, we used miRNA array, Northern and quantitative PCR analyses to screen for and quantitatively assess miRNA expression in NK-cell lymphomas/leukemias using 70 probe sets of miRNAs. For function analysis, we conducted antisense oligonucleotides and lentivirus transfection assays using NK-cell lymphoma cell lines. Results: We found that in NK-cell lymphoma lines (n=10) and specimens of primary lymphoma (n=10), levels of miR-21 and miR-155 expression were significantly higher than those seen in normal natural killer (CD3-CD56+) cells (n=8). Furthermore, miR-150 expression of primary samples and cell lines was significantly lower than CD3-CD56+ normal cells. To determine the functions of these microRNAs in lymphomagenesis, we examined the effects of antisense oligonucleotides targeting miR-21 (ASO-21) and/or miR-155 (ASO-155) in NK-cell lymphoma lines overexpressing one or both of these miRNAs. Conversely, cells showing little endogenous expression of miR-21, miR-155 and miR-150 were transduced using lentiviral vectors, leading to their overexpression. Reducing expression of miR-21 or miR-155 led to upregulation of phosphatase and tensin homologue (PTEN), programmed cell death 4 (PDCD4), or Src homology-2 domain-containing inositol 5-phosphatase 1 (SHIP1). ASO-21- and ASO-155-treated cell lines all showed downregulation of phosphorylated AKTser473 (pAKT). Moreover, transduction with either miR-21 or miR-155 led to downregulation of PTEN and PDCD4, or SHIP1 with upregulation of pAKT. Because apoptosis and cell cycle arrest were induced by transduction of miR-150 into NK-cell lymphoma cell lines, the miRNA is possible candidate of tumor suppressive miRNA in this tumor entity. Detection for direct target of the miR-150 is now underway. Conclusions: Because recent reports suggest that EBV infection can lead directly to upregulation of miR-21 and miR-155, aberrant overexpressions of these miRNAs via EBV infection could be the first-hit genetic alterations during NK-cell lymphomagenesis. Collectively, these results provide important new insight into the pathogenesis of NK-cell lymphoma/leukemia and suggest targeting these miRNAs may represent a useful approach to treating NK-cell lymphoma/leukemia. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3005.

Expression of vascular endothelial growth factor C in pancreatic cancer and its effect upon lymph node metastasis

To investigate the expression of vascular endothelial growth factor C (VEGF-C) and the effect of antisense oligonucleotide (ASODN) upon lymph node metastasis of pancreatic cancer cell. We selected 15 cases of human pancreatic cancer and detected the expression of VEGF-C in primary tumor and lymph node metastasis tissues with immunohistochemistry. Meanwhile, the spontaneous lymphatic metastasis model in nude mice was established with orthotopic implantation for the human pancreatic cancer cell line PANC-1, isolation and culture of primary tumor and spontaneous lymphatic metastasis. The effect of VEGF-C special ASODN upon the apoptosis of pancreatic cancer cell derived from primary tumor and spontaneous lymphatic metastasis were detected by reverse transcription polymerase chain reaction (RT-PCR), enzyme linked immunosorbent assay (ELISA), flow cytometer and terminal deoxynucleotidyl transferase mediated-dUTP nick end labeling (TUNEL). In tissues of human pancreatic cancer, the values of VEGF-C on lymph nodes metastasis were more higher than primary tumor (P < 0.05). About the expression of VEGF-C on pancreatic cancer cell derived from spontaneous lymphatic metastasis and primary tumor in nude mice model, the mRNA levels of VEGF-C were 0.87 +/- 0.11 and 0.61 +/- 0.15 respectively, the VEGF-C levels in culture supernatants were (1682 +/- 157) pg/ml and (1404 +/- 128) pg/ml. The expression of VEGF-C on pancreatic cancer cells derived from lymphatic metastasis were also more higher than primary tumor (P < 0.05). In vitro and vivo, transfection of VEGF-C ASODN decreased the expression of VEGF-C in pancreatic cancer cell. In control group, scramble-sense oligonucleotide (SODN) group and ASODN group, the apoptosis rates of pancreatic cancer cells derived from lymph node metastasis were (2.8 +/- 1.0)%, (5.0 +/- 2.1)%, (13.2 +/- 2.2)% respectively in vitro, and were (1.8 +/- 0.5)%, (2.0 +/- 0.7)%, (4.4 +/- 1.0)% respectively in vivo, the apoptosis was increased significantly after transfection of VEGF-C ASODN (all P < 0.01). But pancreatic cancer cells derived from primary tumor were not effected (all P > 0.05). In human pancreatic cancer and nude mice model, the expression of VEGF-C on lymphatic metastasis was higher than primary tumor. The apoptosis of pancreatic cancer cells derived from spontaneous lymphatic metastasis were promoted by transfection of VEGF-C ASODN specially.

Effect of antisense oligonucleotide targeting bFGF on apoptosis of hepatoma cells

To investigate the cell cycle changes of hepatoma cells and the role of antisense oligonucleotide targeting bFGF. Inhibition of bFGF protein expression was investigated by confocal microscopy analysis and Western blot in the best condition of transfecting antisense oligonucleotide targeting bFGF. Cell cycle and apoptosis were detected with flow cytometry analysis. Treatment with antisense oligonucleotide of bFGF not only reduced the expression of bFGF by confocal microscopy and Western blot analysises, but also increased the apoptosis of HepG2 cells (P < 0.01). bFGF may take part in apoptosis regulation of hepatoma cells and be used as a target of hepatocellular carcinoma therapy.

Effects of antisense oligonucleotides targeting VEGF on radio sensitivity of uterine cervix cancer Hela cells

Objective To determine the impact of antisense oligonucleotides targeting vascular endothelial growth factor (VEGF) on radiosensitivity of uterine cervix cancer Hela cells.

Differences in DBA/1J and DBA/2J reveal lipid QTL genes

Recent advances in mouse genomics have revealed considerable variation in the form of single-nucleotide polymorphisms (SNPs) among common inbred strains. This has made it possible to characterize closely related strains and to identify genes that differ; such genes may be causal for quantitative phenotypes. The mouse strains DBA/1J and DBA/2J differ by just 5.6% at the SNP level. These strains exhibit differences in a number of metabolic and lipid phenotypes, such as plasma levels of triglycerides (TGs) and HDL. A cross between these strains revealed multiple quantitative trait loci (QTLs) in 294 progeny. We identified significant TG QTLs on chromosomes (Chrs) 1, 2, 3, 4, 8, 9, 10, 11, 12, 13, 14, 16, and 19, and significant HDL QTLs on Chrs 3, 9, and 16. Some QTLs mapped to chromosomes with limited variability between the two strains, thus facilitating the identification of candidate genes. We suggest that Tshr is the QTL gene for Chr 12 TG and HDL levels and that Ihh may account for the TG QTL on Chr 1. This cross highlights the advantage of crossing closely related strains for subsequent identification of QTL genes.

Pharmacokinetics of oligonucleotides.

The effectiveness of antisense oligonucleotides as therapeutic agents depends on their pharmacokinetics, tissue disposition, stability, elimination and safety profile. Pharmacokinetic data allow one to determine the frequency of administration and any potential toxicity associated with chronic administration. Phosphorothioate oligonucleotides degrade from the 3' end, the 5' end, and both the 3' and 5' ends in a time- and tissue-dependent manner. After intravenous administration in mice, rats and monkeys, phosphorothioate oligonucleotides are detected in plasma; they distribute rapidly and are retained in the majority of tissues. The major route of elimination is the urine. The pharmacokinetic profile is similar following subcutaneous, intradermal or intraperitoneal administration, but with lower maximum plasma concentrations. Phosphorothioate oligonucleotides have a short plasma half-life in humans. End-modified, mixed-backbone oligonucleotides (MBOs) contain nuclease-resistant 2'-O-alkylribonucleotides or methylphosphonate internucleotide linkages at both the 3' and 5' ends of phosphorothioate oligonucleotides. These end-modified MBOs have pharmacokinetic profiles similar to those of the parent phosphorothioate oligonucleotides, but they are significantly more stable in vivo and they can be administered orally. Centrally modified MBOs contain modified RNA or DNA in the centre of a phosphorothioate oligonucleotide. They show controlled degradation and elimination following administration in rats. The pharmacokinetics of antisense oligonucleotides depends on the sequence, the nature of the oligonucleotide linkages and the secondary structure.

Effects of antisense oligonucleotides to mRNA for the early gene zif268 on the mechanisms of synapse-specific plasticity

Acquisition of nociceptive sensitization in common snails was accompanied by long-term facilitation of the responses of defensive behavior command neuron LPl1 to sensory stimulation of chemoreceptors on the head and mechanoreceptors on the head and foot. Acquisition of sensitization during intracellular administration of antisense oligonucleotides to mRNA encoding the early gene zif268 showed suppression of synaptic facilitation in the responses of neuron LPl1 to tactile and chemical stimulation of the snail's head. Synaptic facilitation in the responses to tactile stimulation of the foot developed as in neurons of control sensitized animals. These results suggest that the early gene zif268 is selectively involved in the mechanisms of the specific regulation of the synaptic inputs of neuron LPl1 from sensory receptors on the snail's head.

Responsiveness to Androgens and Effectiveness of Antisense Oligonucleotides against the Androgen Receptor on Human Epidermal Keratinocytes is Dependent on the Age of the Donor and the Location of Cell Origin

Local androgen excess has been associated with attenuation of wound healing in elderly individuals and with a decline in permeability barrier homeostasis in adult human skin. In this study we have applied specific antisense oligonucleotides, whose activity has already been investigated in SZ95 sebocytes, to inactivate transiently the androgen receptor in a reconstituted epidermis model and in primary human epidermal keratinocytes of different origin (breast, abdomen, foreskin) and donor age (females, 30- and 60-year-old). Further a possible interaction between blockage of androgen receptor and the expression of tissue inhibitors of matrix metalloproteinases was investigated. Androgen receptor levels were similar in pooled keratinocytes of the two age groups. Cell transfection with antisense oligonucleotides against the androgen receptor resulted in decreasing protein levels detected in all epidermal keratinocytes tested, whereas cells of aged donors (60-year-old) exhibited a stronger response than cells of young individuals (30-year-old). Keratinocytes from aged donors also responded to androgens with a stronger regulation of proliferation than keratinocytes of young individuals. The pattern of the androgen-induced response was dependent on the skin region of keratinocyte origin. The expression levels of tissue inhibitor of matrix metalloproteinase-1 were not age-related. Our results demonstrate an enhanced androgen sensitivity of keratinocytes from aged individuals associated with an origin-specific type of response.

Effect of antisense oligodeoxynucleotide of vascular endothelial growth factor C on lymphangiogenesis and angiogenesis of pancreatic cancer

In order to investigate the effect of antisense oligonucleotide (ASODN) of vascular endothelial growth factor C (VEGF-C) on lymphangiogenesis and angiogenesis of pancreatic cancer, antisense and scamble-sense oligonucleotide of VEGF-C were constructed, and the model of nude mice with orthotopically xenografted human pancreatic cancer cells (Panc-1) was established. Thirty nude mice were randomly divided into 3 groups: PBS control group (group A), scramble-sense control group (group B) and antisense group (group C). All nude mice were treated once every 2 days as 3 times per week, for 3 weeks (oligonucleotide 10 mg/kg every time). After treatments were completed, ELISA method was used to examine the concentration of VEGF-C in plasma and immunohistochemical method to examine microvessel density (MVD), lymphtic vessel density (LVD) of pancreatic cancer. The results showed that the expression of VEGF-C was inhibited significantly in group C. The concentrations were 237.5+/-41.5, 221.5+/-52.3 and 108.6+/-14.9 pg/mL in groups A, B and C respectively (P<0.01). LVD in groups A, B and C was 13.8+/-2.1, 12.4+/-1.9 and 4.2+/-1.6 respectively (P<0.01). MVD in groups A, B and C was 27.5+/-8.7, 25.9+/-4.2 and 19.4+/-5.6 respectively with no significant difference among the groups (P>0.05). It was suggested that VEGF-C ASODN decreased the expression levels of VEGF-C in nude mice with orthotopically xenografted human pancreatic cancer, and it could inhibit lymphangiogenesis, but had no significant effect on angiogenesis.