QR-1011 restores defective ABCA4 splicing caused by multiple severe ABCA4 variants underlying Stargardt disease

Stargardt disease type 1 (STGD1), the most common form of hereditary macular dystrophy, can be caused by biallelic combinations of over 2200 variants in the ABCA4 gene. This leads to reduced or absent ABCA4 protein activity, resulting in toxic metabolite accumulation in the retina and damage of the retinal pigment epithelium and photoreceptors. Approximately 21% of all ABCA4 variants that contribute to disease influence ABCA4 pre-mRNA splicing. This emphasizes the need for therapies to restore disrupted ABCA4 splicing and halt STGD1 progression. Previously, QR-1011, an antisense oligonucleotide (AON), successfully corrected splicing abnormalities and restored normal ABCA4 protein translation in human retinal organoids carrying the prevalent disease-causing variant c.5461-10T>C in ABCA4. Here, we investigated whether QR-1011 could also correct splicing in four less common non-canonical splice site (NCSS) variants flanking ABCA4 exon 39: c.5461-8T>G, c.5461-6T>C, c.5584+5G>A and c.5584+6T>C. We administered QR-1011 and three other AONs to midigene-transfected cells and demonstrate that QR-1011 had the most pronounced effect on splicing compared to the others. Moreover, QR-1011 significantly increased full-length ABCA4 transcript levels for c.5461-8T>G and c.5584+6T>C. Splicing restoration could not be achieved in the other two variants, suggesting their more severe effect on splicing. Overall, QR-1011, initially developed for a single ABCA4 variant, exhibited potent splice correction capabilities for two additional severe NCSS variants nearby. This suggests the possibility of a broader therapeutic impact of QR-1011 extending beyond its original target and highlights the potential for treating a larger population of STGD1 patients affected by multiple severe ABCA4 variants with a single AON.

A Novel Peptide-Equipped Exosomes Platform for Delivery of Antisense Oligonucleotides

Exosomes are natural delivery vehicles because of their original feature such as low immunogenicity, excellent biocompatibility, and migration capability. Engineering exosomes with appropriate ligands are effective approaches to improve the low cellular uptake efficiency of exosomes. However, current strategies face considerable challenges due to the tedious and labor-intensive operational process. Here, we designed a novel peptides-equipped exosomes platform which can be assembled under convenient and mild reaction condition. Cell-penetrating peptides (CPPs) was conjugated on HepG2 cells-derived exosomes surface which can not only enhance the penetrating capacity of exosomes but also assist exosomes in loading antisense oligonucleotides (ASOs). The cellular uptake mechanism was investigated and we compared the difference between natural exosomes and modified exosomes. The resulting nanosystem demonstrated a preferential tropism for cells that are parented to their source tumor cells and could remarkably increase the cellular delivery of G3139 with efficient downregulation of antiapoptotic Bcl-2. This work developed a rapid strategy for intracellular delivery of nucleic acids, thus providing more possibilities toward personalized cancer medicine.

Therapeutic IDOL Reduction Ameliorates Amyloidosis and Improves Cognitive Function in APP/PS1 Mice

Brain lipoprotein receptors have been shown to regulate the metabolism of ApoE and β-amyloid (Aβ) and are potential therapeutic targets for Alzheimer's disease (AD). Previously, we identified E3 ubiquitin ligase IDOL as a negative regulator of brain lipoprotein receptors. Genetic ablation of Idol increases low-density lipoprotein receptor protein levels, which facilitates Aβ uptake and clearance by microglia. In this study, we utilized an antisense oligonucleotide (ASO) to reduce IDOL expression therapeutically in the brains of APP/PS1 male mice. ASO treatment led to decreased Aβ pathology and improved spatial learning and memory. Single-cell transcriptomic analysis of hippocampus revealed that IDOL inhibition upregulated lysosomal/phagocytic genes in microglia. Furthermore, clustering of microglia revealed that IDOL-ASO treatment shifted the composition of the microglia population by increasing the prevalence of disease-associated microglia. Our results suggest that reducing IDOL expression in the adult brain promotes the phagocytic clearance of Aβ and ameliorates Aβ-dependent pathology. Pharmacological inhibition of IDOL activity in the brain may represent a therapeutic strategy for the treatment of AD.

Specific Delivery of Oligonucleotides to the Cell Nucleus via Gentle Compression and Attachment of Polythymidine

Nonviral delivery of nucleic acids to the cell nucleus typically requires chemical methods that do not guarantee specific delivery (e.g., transfection agent) or physical methods that may require extensive fabrication (e.g., microfluidics) or an elevated pressure (e.g., 10⁵ Pa for microneedles). We report a method of delivering oligonucleotides to the nucleus with high specificity (relative to the cytosol) by synergistically combining chemical and physical approaches. Particularly, we demonstrate that DNA oligonucleotides appended with a polythymidine [poly(T)] segment (chemical) profusely accumulate inside the nucleus when the cells are under gentle compression imposed by the weight of a single glass coverslip (physical; ∼2.2 Pa). Our "compression-cum-poly(T)" delivery method is simple, can be generalizable to three "hard-to-transfect" cell types, and does not induce significant levels of cytotoxicity or long-term oxidative stress to the treated cells when provided the use of suitable compression times and oligonucleotide concentrations. In bEnd.3 endothelial cells, compression-aided intranuclear delivery of poly(T) is primarily mediated by importin β and nucleoporin 62. Our method significantly enhances the intranuclear delivery of antisense oligonucleotides to bEnd.3 endothelioma cells and the inhibition of two target genes, including a reporter gene encoding the enhanced green fluorescent protein and an intranuclear lncRNA oncogene (metastasis-associated lung adenocarcinoma transcript 1), when compared with delivery without gentle compression or poly(T) attachment. Our data underscore the critical roles of pressure and nucleotide sequence on the intranuclear delivery of nucleic acids.

p21Waf1/Cip1: its paradoxical effect in the regulation of breast cancer

p21^Waf1/Cip1, the cyclin-dependent kinase (CDK) inhibitor belonging to the KIP/CIP family, was initially regarded as a tumor suppressor protein because it was recognized as the chief mediator of p53-dependent cell cycle arrest elicited by DNA damage. Conversely, it has been proposed that p21^Waf1/Cip1 may also function as an oncogene because it can inhibit apoptosis. Thus, p21^Waf1/Cip1 is regarded as a protein with a dual behavior, as its expression might cause potential benefits or dangerous effects in breast cancer. Consequently, careful planning is required in targeting p21^Waf1/Cip1 expression for therapy of breast cancer patients. This review illustrates the discovery and mechanisms of induction of p21^Waf1/Cip1. Then, we focus on elucidating the paradoxical effect of p21^Waf1/Cip1 expression on human breast carcinogenesis and explaining how the subcellular localization (nuclear or cytoplasmic) of p21^Waf1/Cip1 has an impact on both determining its fate as either cell-growth inhibitor or antiapoptotic molecule and, its effect on clinicopathological factors and prognosis of breast cancer patients. Moreover, we explore how the pattern of the p21^Waf1/Cip1 could affect the responsiveness of human breast cancer to chemotherapy. Furthermore, the pharmacological approaches to target p21^Waf1/Cip1 expression for therapy of breast cancer are clarified.

Characterizing the interaction between insulin-like growth factor 2 mRNA-binding protein 1 (IMP1) and KRAS expression

Insulin-like growth factor 2 mRNA-binding protein-1 (IMP1) has high affinity for KRAS mRNA, and it can regulate KRAS expression in cells. We first characterized the molecular interaction between IMP1 and KRAS mRNA. Using IMP1 variants with a point mutation in the GXXG motif at each KH domain, we showed that all KH domains play a critical role in the binding of KRAS RNA. We mapped the IMP1-binding sites on KRAS mRNA and show that IMP1 has the highest affinity for nts 1-185. Although it has lower affinity, IMP1 does bind to other coding regions and the 3'-UTR of KRAS mRNA. Eight antisense oligonucleotides (AONs) were designed against KRAS RNA in the nts 1-185 region, but only two, SM6 and SM7, show potent inhibition of the IMP1-KRAS RNA interaction in vitro To test the activity of these two AONs in SW480 human colon cancer cells, we used 2'-O-methyl-modified versions of SM6 and SM7 in an attempt to down-regulate KRAS expression. To our surprise, both SM6 and SM7 had no effect on KRAS mRNA and protein expression, but significantly inhibited IMP1 protein expression without altering IMP1 mRNA level. On the other hand, knockdown of IMP1 using siRNA lowered the expression of KRAS. Using Renilla luciferase as a reporter, we found that IMP1 translation is significantly reduced in SM7-treated cells with no change in let-7a levels. The present study shows that the regulation of KRAS expression by IMP1 is complex and may involve both the IMP1 protein and its mRNA transcript.

Intracellular Progesterone Receptor Mediates the Increase in Glioblastoma Growth Induced by Progesterone in the Rat Brain

BACKGROUND AND AIMS

Progesterone (P) is a steroid hormone involved in the development of several types of cancer including astrocytomas, the most common and malignant brain tumors. We undertook this study to investigate the effects of P on the growth and infiltration of a tumor caused by the xenotransplant of U87 cells derived from a human astrocytoma grade IV (glioblastoma) in the cerebral cortex of male rats and the participation of intracellular progesterone receptor (PR) on these effects.

METHODS

Eight weeks after the implantation of U87 cells in the cerebral cortex, we administered phosphorothioated antisense oligodeoxynucleotides (ODNs) to silence the expression of PR. This treatment lasted 15 days and was administered at the site of glioblastoma cells implantation using Alzet osmotic pumps. Vehicle (propylene glycol) or P₄ (400 μg/100 g) was subcutaneously injected for 14 days starting 1 day after the beginning of ODN administration.

RESULTS

We observed that P significantly increased glioblastoma tumor area and infiltration length as compared with vehicle, whereas PR antisense ODNs blocked these effects.

CONCLUSION

P, through the interaction with PR, increases the area and infiltration of a brain tumor formed from the xenotransplant of human glioblastoma-derived U87 cells in the cerebral cortex of the rat.

Effects of hTERT antisense oligodeoxynucleotide on cell apoptosis and expression of hTERT and bcl-2 mRNA in keloid fibroblasts

OBJECTIVE

This study was purposed to investigate the effects of hTERT antisense oligodeoxynucleotide (ASODN) on cell apoptosis and expression of hTERT and bcl-2 mRNA in keloid fibroblasts and to explore its anti-keloid effect.

MATERIALS AND METHODS

Primary cultures of dermal fibroblasts derived from 12 keloid samples were established, strains of fibroblasts at passages 3 to 4 were used in this study. After treated by hTERT ASODN the proliferation of the fibroblasts was measured by cell count and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay method, the apoptosis was analyzed by flow cytometry (FCM), and the expression of hTERT and bcl-2 mRNA were observed by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). The data was analyzed by statistical software (SPSS11.5).

RESULTS

The results showed that after sealing hTERT gene with ASODN for 72 h, the fibroblasts growth was repressed and the ability of proliferation decreased as the fibroblasts were treated with 1.0 mol/L ASODN for 72 h, the fibroblasts apoptosis was induced and the expression of hTERT and bcl-2 mRNA was lower than that of controlled group. The result was significantly different between control group and treatment group and was related to the treatment time of ASODN (p<0.01), but the difference was no significant when compared 1.0 μmol/L SODN group with untreated group (p>0.05).

CONCLUSIONS

As a negative modutory factor, hTERT-ASODN can suppress growth and proliferation of keloid fibroblasts. Decreasing the telomerase activity of keloid fibroblasts may be one of the most important mechanisms. That hTERT-ASODN inhibited telomerase activity in keloid fibroblasts is an important pathway that may play a key role in the anti- keloid therapy.

Effects of liposome-based local suppression of nerve growth factor in the bladder on autonomic dysreflexia during urinary bladder distention in rats with spinal cord injury

PURPOSE

To examine (1) whether spinal cord injury (SCI) time-dependently increases the severity of autonomic dysreflexia (AD) and expression levels of bladder nerve growth factor (NGF) protein, and (2) whether local suppression of NGF in the bladder improves SCI-induced AD in rats.

MATERIALS AND METHODS

SCI was produced by the transection of the T2/3 spinal cord in female Sprague-Dawley rats. At 4 or 8weeks after SCI, differences in the mean arterial blood pressure (ΔMAP) and heart rate (ΔMHR) during graded increases in intravesical pressure to 20, 40 and 60cm H₂O from those before bladder distention and NGF protein levels in the bladder wall were evaluated in spinal intact and SCI rats under urethane anesthesia. Seven weeks after SCI liposome-NGF antisense conjugates were administered intravesically to the animals. At 1week after intravesical treatment (8weeks after SCI), ΔMAP and ΔMHR during bladder distention and bladder NGF protein expression were evaluated.

RESULTS

The ΔMAP and ΔMHR were increased in a graded manner in response to bladder distention at intravesical pressures of 20, 40 and 60cm H₂O in SCI rats. These AD-like cardiovascular responses and NGF protein expression in the bladder mucosal and muscle layers were increased after SCI in a time-dependent manner. The liposome-NGF antisense treatment significantly reduced the NGF protein overexpression in the mucosal layer of SCI rat bladder and reduced ΔMAP and ΔMHR elicited by bladder distention.

CONCLUSIONS

These results indicate that the duration of the post-SCI recovery period affects the severity of AD induced by bladder distention as well as the level of bladder NGF protein, and that local suppression of NGF expression in the bladder reduces SCI-induced AD. Thus, Intravesical application of liposome-NGF antisense conjugates can be a new effective therapy for bladder distention-induced AD after SCI.

Apolipoprotein B100 is required for hepatitis C infectivity and Mipomersen inhibits hepatitis C

AIM

To characterize the role of apolipoprotein B100 (apoB100) in hepatitis C viral (HCV) infection.

METHODS

In this study, we utilize a gene editing tool, transcription activator-like effector nucleases (TALENs), to generate human hepatoma cells with a stable genetic deletion of APOB to assess of apoB in HCV. Using infectious cell culture-competent HCV, viral pseudoparticles, replicon models, and lipidomic analysis we determined the contribution of apoB to each step of the viral lifecycle. We further studied the effect of mipomersen, an FDA-approved antisense inhibitor of apoB100, on HCV using in vitro cell-culture competent HCV and determined its impact on viral infectivity with the TCID50 method.

RESULTS

We found that apoB100 is indispensable for HCV infection. Using the JFH-1 fully infectious cell-culture competent virus in Huh 7 hepatoma cells with TALEN-mediated gene deletion of apoB (APOB KO), we found a significant reduction in HCV RNA and protein levels following infection. Pseudoparticle and replicon models demonstrated that apoB did not play a role in HCV entry or replication. However, the virus produced by APOB KO cells had significantly diminished infectivity as measured by the TCID-50 method compared to wild-type virus. Lipidomic analysis demonstrated that these virions have a fundamentally altered lipidome, with complete depletion of cholesterol esters. We further demonstrate that inhibition of apoB using mipomersen, an FDA-approved anti-sense oligonucleotide, results in a potent anti-HCV effect and significantly reduces the infectivity of the virus.

CONCLUSION

ApoB is required for the generation of fully infectious HCV virions, and inhibition of apoB with mipomersen blocks HCV. Targeting lipid metabolic pathways to impair viral infectivity represents a novel host targeted strategy to inhibit HCV.

Paeoniflorin inhibits excitatory amino acid agonist-and high-dose morphine-induced nociceptive behavior in mice via modulation of N-methyl-D-aspartate receptors

BACKGROUND

Pain, the most common reasons for physician consultation, is a major symptom in many medical conditions that can significantly interfere with a person's life quality and general functioning. Almost all painkillers have its untoward effects. Therefore, seeking for a safe medication for pain relieve is notable nowadays. Paeonia lactiflora is a well-known traditional Chinese medicine. Paeoniflorin is an active component found in Paeonia lactiflora, which has been reported to inhibit formalin-induced nociceptive behavior in mice. Aims of this present study were to investigate effects of paeoniflorin on excitatory amino acid agonist- or high-dose morphine-induced nociceptive behaviors in mice.

RESULTS

Paeoniflorin (100, 200, 500 nmol, i.c.v.) alone and combined with glutamatergic antagonists (MK-801 14.8 pmol, or NBQX 5 nmol, i.t.) inhibited nociception. Those agents also inhibited the clonic seizure-like excitation induced by high-dose morphine (250 nmol, i.t) in mice. Antisense oligodeoxynucleotides of NMDA receptor subunits NR1, NR2A, NR2B significantly enhanced the inhibition of paeoniflorin on excitatory amino acid-and high-dose morphine-induced nociception. Docking energy data revealed that paeoniflorin had stronger binding activity in NR2A and NR2B than NR2C of NMDA receptors.

CONCLUSIONS

Results of this study indicate that paeoniflorin-induced inhibition of excitatory amino acid agonist- and high-dose morphine-induced nociceptive behaviors might be due to modulation of NMDA receptors, specifically the NR2B subunit.

Developmental exposure to acetaminophen does not induce hyperactivity in zebrafish larvae

First line pain relief medication during pregnancy relies nearly entirely on the over-the-counter analgesic acetaminophen, which is generally considered safe to use during gestation. However, recent epidemiological studies suggest a risk of developing attention-deficit/hyperactivity disorder (ADHD)-like symptoms in children if mothers use acetaminophen during pregnancy. Currently, there are no experimental proofs that prenatal acetaminophen exposure causes developmental brain alterations of progeny. Exposure to high acetaminophen concentrations causes liver toxicity, which is well investigated in different model organisms. However, sub-liver-toxic concentrations have not been experimentally investigated with respect to ADHD endophenotypes such as hyperactivity. We used zebrafish to investigate the potential impact of acetaminophen exposure on locomotor activity levels, and compared it to the established zebrafish Latrophilin 3 (Lphn3) ADHD-model. We determined the sub-liver-toxic concentration of acetaminophen in zebrafish larvae and treated wild-type and lphn3.1 knockdown larvae with increasing concentrations of acetaminophen. We were able to confirm that lphn3.1 knockdown alone causes hyperactivity, strengthening the implication of Lphn3 dysfunction as an ADHD risk factor. Neither acute nor chronic exposure to acetaminophen at sub-liver-toxic concentrations in wild-type or lphn3.1 knock-downs increases locomotor activity levels. Together our findings show that embryonic to larval exposure to acetaminophen does not cause hyperactivity in zebrafish larvae. Furthermore, there are no additive and/or synergistic effects of acetaminophen exposure in a susceptible background induced by knock-down of lphn3.1. Our experimental study suggests that there is, at least in zebrafish larvae, no direct link between embryonic acetaminophen exposure and hyperactivity. Further work is necessary to clarify this issue in humans.

Welcome to the splice age: antisense oligonucleotide-mediated exon skipping gains wider applicability

Exon skipping uses antisense oligonucleotides (ASOs) to alter transcript splicing for the purpose of rescuing or modulating protein expression. In this issue of the JCI, Lee and colleagues developed and evaluated an ASO-dependent method for treating certain molecularly defined diseases associated with alterations in lamin A/C (LMNA) splicing. Exon skipping by ASOs is gaining traction as a therapeutic strategy, and the use of ASOs is now being applied to bypass mutations and generate modified but functional proteins for an array of genetic disorders.

Modulation of LMNA splicing as a strategy to treat prelamin A diseases

The alternatively spliced products of LMNA, lamin C and prelamin A (the precursor to lamin A), are produced in similar amounts in most tissues and have largely redundant functions. This redundancy suggests that diseases, such as Hutchinson-Gilford progeria syndrome (HGPS), that are caused by prelamin A-specific mutations could be treated by shifting the output of LMNA more toward lamin C. Here, we investigated mechanisms that regulate LMNA mRNA alternative splicing and assessed the feasibility of reducing prelamin A expression in vivo. We identified an exon 11 antisense oligonucleotide (ASO) that increased lamin C production at the expense of prelamin A when transfected into mouse and human fibroblasts. The same ASO also reduced the expression of progerin, the mutant prelamin A protein in HGPS, in fibroblasts derived from patients with HGPS. Mechanistic studies revealed that the exon 11 sequences contain binding sites for serine/arginine-rich splicing factor 2 (SRSF2), and SRSF2 knockdown lowered lamin A production in cells and in murine tissues. Moreover, administration of the exon 11 ASO reduced lamin A expression in wild-type mice and progerin expression in an HGPS mouse model. Together, these studies identify ASO-mediated reduction of prelamin A as a potential strategy to treat prelamin A-specific diseases.

Preparation of Pluronic Grafted Dendritic alpha,epsilon-poly(L-lysine)s and Characterization as a Delivery Adjuvant of Antisense Oligonucleotide

A series of pluronic grafted dendritic alpha,epsilon-poly(L-lysine)s (DPL-PF127) were synthesized by a conjugation reaction and evaluated the potential use of DPL-PF127 as a delivery agent of antisense oligonucleotide into A375 B3 cells. The structural features of the DPL-PF127 were identified by NMR and FT-IR. The number of pluronic F127 on DPL surface, determined by fluorescamine assay, increased proportionally to the mole ratio between DPL and activated PF127 in reaction. DPL- PF127 showed the physical properties of decrease in zetapotential and increase in size as the mole ratio of PF127 to DPL increased. The complex formation of DPL-PF127 with oligonucleotide was confirmed by running capillary zone electrophoresis (CZE) and agarose gel electrophoresis. DPL-PF127, prepared at the mole ratio of 1:10 in reaction, was the most suitable as a delivery adjuvant of oligonucleotide. In addition, DPL-PF127/oligonucleotide complexes were taken into A375B3 cell without cellular toxicity and delivered antisense oligonucleotide into cell.

No effect on QT intervals of mipomersen, a 2'-O-methoxyethyl modified antisense oligonucleotide targeting ApoB-100 mRNA, in a phase I dose escalation placebo-controlled study, and confirmed by a thorough QT (tQT) study, in healthy subjects

PURPOSE

The aim of this study to evaluate the effect of mipomersen on QT intervals in a phase I dose escalation, placebo-controlled study, and a thorough QT (tQT) study in healthy subjects.

METHODS

In the initial phase I study, 29 healthy subjects received either single or multiple (for 4 weeks) ascending doses of mipomersen (50-400 mg) administered subcutaneously (SC) or via a 2-h intravenous (IV) infusion, and 7 subjects received placebo. In the confirmative tQT study, 58 healthy subjects received placebo, 400 mg IV moxifloxacin, 200 mg SC, or 200 mg IV of mipomersen in a double-blind, 4-way crossover design with a minimum 5-day washout between treatments. ECG measurements were performed at baseline and selected time points (including Tmax). The correlation between QTcF intervals corrected for baseline and time-matched placebo when available with PK plasma exposure was evaluated by linear regression analysis.

RESULTS

In the phase I study, no positive correlation between the PK exposure and ∆QTcF or ∆∆QTcF was observed within the wide dose or exposure range tested. Similar results were observed in the tQT study, where the predicted ΔΔQTcF and its upper bound of the 90% CI at Cmax of therapeutic and supratherapeutic dose were approximately -1.7 and 2.9 ms, respectively.

CONCLUSIONS

Mipomersen showed no effect on QT intervals in both the phase I dose escalation study and the tQT study. These results support the proposal that QT assessment can be made in a phase I dose escalation study, and no tQT study may be necessary if the phase I dose escalation study showed a negative QT effect.

Clinical and preclinical pharmacokinetics and pharmacodynamics of mipomersen (kynamro(®)): a second-generation antisense oligonucleotide inhibitor of apolipoprotein B

Mipomersen (Kynamro^®), a second-generation 2′-O-methoxyethyl chimeric antisense oligonucleotide (ASO), inhibits the synthesis of apolipoprotein B (apoB) and is indicated in the US as an adjunct therapy for homozygous familial hypercholesterolemia (HoFH) at a dose of 200 mg subcutaneously (SC) once weekly. The pharmacokinetic (PK) properties of mipomersen are generally consistent across all species studied, including mouse, rat, monkey, and humans. After SC administration, mipomersen is rapidly and extensively absorbed. It has an apparent plasma and tissue terminal elimination half-life of approximately 30 days. Mipomersen achieves steady-state tissue concentrations within approximately 4–6 months of once-weekly dosing. It does not exhibit PK-based drug–drug interactions with other concomitant medications, either involving competition for plasma protein binding or alterations in disposition of any evaluated drugs. Furthermore, mipomersen does not prolong the corrected QT (QTc) interval. There have been no ethnic- or gender-related differences in PK observed. In clinical trials, both as a single agent and in the presence of maximal lipid-lowering therapy, mipomersen has demonstrated significant dose-dependent reductions in all measured apoB-containing atherogenic lipoproteins. Overall, mipomersen has well-characterized PK and pharmacodynamic properties in both animals and humans, and is an efficacious adjunct treatment for patients with HoFH.

Non-aggregating tau phosphorylation by cyclin-dependent kinase 5 contributes to motor neuron degeneration in spinal muscular atrophy

Mechanisms underlying motor neuron degeneration in spinal muscular atrophy (SMA), the leading inherited cause of infant mortality, remain largely unknown. Many studies have established the importance of hyperphosphorylation of the microtubule-associated protein tau in various neurodegenerative disorders, including Alzheimer's and Parkinson's diseases. However, tau phosphorylation in SMA pathogenesis has yet to be investigated. Here we show that tau phosphorylation on serine 202 (S202) and threonine 205 (T205) is increased significantly in SMA motor neurons using two SMA mouse models and human SMA patient spinal cord samples. Interestingly, phosphorylated tau does not form aggregates in motor neurons or neuromuscular junctions (NMJs), even at late stages of SMA disease, distinguishing it from other tauopathies. Hyperphosphorylation of tau on S202 and T205 is mediated by cyclin-dependent kinase 5 (Cdk5) in SMA disease condition, because tau phosphorylation at these sites is significantly reduced in Cdk5 knock-out mice; genetic knock-out of Cdk5 activating subunit p35 in an SMA mouse model also leads to reduced tau phosphorylation on S202 and T205 in the SMA;p35(-/-) compound mutant mice. In addition, expression of the phosphorylation-deficient tauS202A,T205A mutant alleviates motor neuron defects in a zebrafish SMA model in vivo and mouse motor neuron degeneration in culture, whereas expression of phosphorylation-mimetic tauS202E,T205E promotes motor neuron defects. More importantly, genetic knock-out of tau in SMA mice rescues synapse stripping on motor neurons, NMJ denervation, and motor neuron degeneration in vivo. Altogether, our findings suggest a novel mechanism for SMA pathogenesis in which hyperphosphorylation of non-aggregating tau by Cdk5 contributes to motor neuron degeneration.

[Oxygen glucose deprivation induced glutamate release in primary cultured astrocytes]

OBJECTIVE

To investigate the effect of oxygen glucose deprivation (OGD) on the glutamate release and the role of connexin 43 (Cx43) hemichannels in the OGD-induced glutamate release in primary cultured astrocytes.

METHODS

The astrocytes were randomly divided into four groups: normal control, OGD group, Gap26 (Cx43 hemichannel blocker) plus OGD group, Cx43-specific antisense oligodeoxynucleotide (ASODN) plus OGD group. In the OGD group, the astrocytes were cultured in the oxygen- and glucose-free culture medium (950 mL/L N₂ and 50 mL/L CO₂) for different durations (0, 15, 30, 60, 90, 120 minutes) at 37 Degrees Celsius, while the astrocytes in the control group were cultured in the ordinary culture medium. In the Gap26 plus OGD group or Cx43-ASODN plus OGD group, the astrocytes were incubated with Gap26 or Cx43-ASODN before and during the OGD. The extracelluar glutamate level was measured by high performance liquid chromatography (HPLC).

RESULTS

After OGD, the extracelluar glutamte level significantly increased, and reached the maximum (5.00±0.30) nmol/mL at 90 minutes of OGD, which was significantly higher than that of the normal control (2.36±0.15) nmol/mL(P<0.05). After treatment by Cx43-ASODN or Gap26, the increase was inhibited. At 90 minutes of OGD, the extracellular glutamate levels were respectively (4.02±0.18) nmol/mL and (3.93±0.32) nmol/mL. They were signficalty lower than that of the OGD group at the same time (P<0.05).

CONCLUSION

OGD induced glutamate release through Cx43 hemichannel in primary cultured astrocytes.

Gamma aminobutyric acidergic and neuronal structural markers in the nucleus accumbens core underlie trait-like impulsive behavior

BACKGROUND

Pathological forms of impulsivity are manifest in a number of psychiatric disorders listed in DSM-5, including attention-deficit/hyperactivity disorder and substance use disorder. However, the molecular and cellular substrates of impulsivity are poorly understood. Here, we investigated a specific form of motor impulsivity in rats, namely premature responding, on a five-choice serial reaction time task.

METHODS

We used in vivo voxel-based magnetic resonance imaging and ex vivo Western blot analyses to investigate putative structural, neuronal, and glial protein markers in low-impulsive (LI) and high-impulsive rats. We also investigated whether messenger RNA interference targeting glutamate decarboxylase 65/67 (GAD65/67) gene expression in the nucleus accumbens core (NAcbC) is sufficient to increase impulsivity in LI rats.

RESULTS

We identified structural and molecular abnormalities in the NAcbC associated with motor impulsivity in rats. We report a reduction in gray matter density in the left NAcbC of high-impulsive rats, with corresponding reductions in this region of glutamate decarboxylase (GAD65/67) and markers of dendritic spines and microtubules. We further demonstrate that the experimental reduction of de novo of GAD65/67 expression bilaterally in the NAcbC is sufficient to increase impulsivity in LI rats.

CONCLUSIONS

These results reveal a novel mechanism of impulsivity in rats involving gamma aminobutyric acidergic and structural abnormalities in the NAcbC with potential relevance to the etiology and treatment of attention-deficit/hyperactivity disorder and related disorders.

Integration of scaffolds into full-thickness skin wounds: the connexin response

Scaffolds have been reported to promote healing of hard-to-heal wounds such as burns and chronic ulcers. However, there has been little investigation into the cell biology of wound edge tissues in response to the scaffolds. Here, we assess the impact of collagen scaffolds on mouse full-thickness wound re-epithelialisation during the first 5 days of healing. We find that scaffolds impede wound re-epithelialisation, inducing a bulbous thickening of the wound edge epidermis as opposed to the thin tongue of migratory keratinocytes seen in normal wound healing. Scaffolds also increase the inflammatory response and the numbers of neutrophils in and around the wound. These effects were also produced by scaffolds made of alginate in the form of fibers and microspheres, but not as an alginate hydrogel. In addition, we find the gap junction protein connexin 43, which normally down-regulates at the wound edge during re-epithelialisation, to be up-regulated in the bulbous epidermal wound edge. Incorporation of connexin 43 antisense oligodeoxynucleotides into the scaffold can be performed to reduce inflammation whilst promoting scaffold biocompatibility.

Membrane progestin receptors in the midbrain ventral tegmental area are required for progesterone-facilitated lordosis of rats

Progesterone (P₄) and its metabolites, rapidly facilitate lordosis of rats partly through actions in the ventral tegmental area (VTA). The study of membrane progestin receptors (mPRs), of the Progestin and AdipoQ Receptor (PAQR) superfamily, has been limited to expression and regulation, instead of function. We hypothesized that if mPRs are required for progestin-facilitated lordosis in the VTA, then mPRs will be expressed in this region and knockdown will attenuate lordosis. First, expression of mPR was examined by reverse-transcriptase polymerase chain reaction (RT-PCR) in brain and peripheral tissues of proestrous Long-Evans rats. Expression of mPRα (paqr7) was observed in peripheral tissues and brain areas, including hypothalamus and midbrain. Expression of mPRβ (paqr8) was observed in brain tissues and was abundant in the midbrain and hypothalamus. Second, ovariectomized rats were estrogen (E₂; 0.09 mg/kg, SC), and P₄ (4 mg/kg, SC) or vehicle-primed, and infused with antisense oligodeoxynucleotides (AS-ODNs) targeted against mPRα and/or mPRβ intracerebroventricularly or to the VTA. Rats were assessed for motor (open field), anxiety (elevated plus maze), social (social interaction), and sexual (lordosis) behavior. P₄-facilitated lordosis was significantly reduced with administration of AS-ODNs for mPRα, mPRβ, or co-administration of mPRα and mPRβ to the lateral ventricle, compared to vehicle. P₄-facilitated lordosis was reduced, compared to vehicle, by administration of mPRβ AS-ODNs, or co-administration of mPRα and mPRβ AS-ODNs, but not mPRα AS-ODNs alone, to the VTA. No differences were observed for motor, anxiety, or social behaviors. Thus, mPRs in the VTA are targets of progestin-facilitated lordosis of rats.

[The apoptosis effect of antisense oligodeoxynucleotides targeting ATM on the laryngeal squamous cell carcinoma treated with radiation]

OBJECTIVE

To designed antisense oligodeoxynucleotides (AS-ODNs) to reduce the expression of ATM and to study its effect on the apoptosis of Hep-2 (human epidermoid laryngeal carcinoma) cells treated with radiation in vitro.

METHODS

Experiment was divided into AS-Lipo, Sen-Lipo, Mis-Lipo, Lipo and Hep-2 group. The expression of ATM mRNA in Hep-2 cells was examined by real-time quantitative PCR. About 18 hours after transfection, they were irradiated simultaneously with different doses of X-ray radiation (0, 2, 4, 6, and 8 Gy) respectively. Clonogenic survival assay was carried out to detect the survival ability of Hep-2 cells after irradiation. After exposed to 4 Gy radiation, flow cytometry was carried out to analyze the cell apoptosis.

RESULTS

The relative ATM mRNA expression in Hep-2 cells treated with ATM AS-ODNs was decreased to (11.03 +/- 2.51)% which was much lower than that of untreated cells (P < 0.05). After irradiation, the survival fraction (SF) of cells treated with ATM AS-ODNs was lower than that of other groups at the same dose of radiation. There was statistical significance between the group treated with ATM AS-ODNs and other groups (P < 0.05). The apoptotic rate for the group irradiated with ATM AS-ODNs was (30.7 +/- 1.31)%, which was significantly higher than that of others (P < 0.05).

CONCLUSION

AS-ODNs of ATM reduce ATM mRNA expression and enhance Hep-2 cells apoptosis to radiation in vitro.

Hypothalamic galanin-like peptide rescues the onset of puberty in food-restricted weanling rats

Galanin-like peptide (GALP) is a known mediator of metabolism and reproduction; however, the role that GALP plays in the onset of puberty is unknown. First, we tested the hypothesis that central GALP administration could rescue puberty in food-restricted weanling rats. GALP treatment in food-restricted rats of both sexes rescued the timing of the onset of puberty to that seen in ad lib. fed controls. Second, we tested whether GALP translation knocked-down in ad lib. fed, prepubertal rats would alter the timing of puberty. Knock-down females, but not males, showed a significant (P < 0.01) delay in the onset of puberty compared to controls. Third, we sought evidence that the role of GALP in pubertal onset is mediated by the kisspeptin system. In situ hybridisation analyses showed a significant (P < 0.01) reduction in Kiss1 mRNA within the hypothalamic arcuate nucleus in food-restricted rats compared to ad lib. fed controls and this reduction was prevented with i.c.v. GALP administration. Furthermore, analyses of Fos-immunoreactivity (-IR) after i.c.v. GALP treatment did not elicit Fos-IR within any kisspeptin neurones, nor are GALP and kisspeptin peptides or mRNA colocalised. These data demonstrate that hypothalamic GALP infusion maintained the onset of puberty in food-restricted weanling rats, although probably not via direct innervation of kisspeptin neurones.

Beneficial metabolic effects of CB1R anti-sense oligonucleotide treatment in diet-induced obese AKR/J mice

An increasing amount of evidence supports pleiotropic metabolic roles of the cannibinoid-1 receptor (CB1R) in peripheral tissues such as adipose, liver, skeletal muscle and pancreas. To further understand the metabolic consequences of specific blockade of CB1R function in peripheral tissues, we performed a 10-week-study with an anti-sense oligonucleotide directed against the CB1R in diet-induced obese (DIO) AKR/J mice. DIO AKR/J mice were treated with CB1R ASO Isis-414930 (6.25, 12.5 and 25 mg/kg/week) or control ASO Isis-141923 (25 mg/kg/week) via intraperitoneal injection for 10 weeks. At the end of the treatment, CB1R mRNA from the 25 mg/kg/week CB1R ASO group in the epididymal fat and kidney was decreased by 81% and 63%, respectively. Body weight gain was decreased in a dose-dependent fashion, significantly different in the 25 mg/kg/week CB1R ASO group (46.1±1.0 g vs veh, 51.2±0.9 g, p<0.05). Body fat mass was reduced in parallel with attenuated body weight gain. CB1R ASO treatment led to decreased fed glucose level (at week 8, 25 mg/kg/week group, 145±4 mg/dL vs veh, 195±10 mg/dL, p<0.05). Moreover, CB1R ASO treatment dose-dependently improved glucose excursion during an oral glucose tolerance test, whereas control ASO exerted no effect. Liver steatosis was also decreased upon CB1R ASO treatment. At the end of the study, plasma insulin and leptin levels were significantly reduced by 25 mg/kg/week CB1R ASO treatment. SREBP1 mRNA expression was decreased in both epididymal fat and liver. G6PC and fatty acid translocase/CD36 mRNA levels were also reduced in the liver. In summary, CB1R ASO treatment in DIO AKR/J mice led to improved insulin sensitivity and glucose homeostasis. The beneficial effects of CB1R ASO treatment strongly support the notion that selective inhibition of the peripheral CB1R, without blockade of central CB1R, may serve as an effective approach for treating type II diabetes, obesity and the metabolic syndrome.

Novel basic protein, PfN23, functions as key macromolecule during nacre formation

The fine microstructure of nacre (mother of pearl) illustrates the beauty of nature. Proteins found in nacre were believed to be "natural hands" that control nacre formation. In the classical view of nacre formation, nucleation of the main minerals, calcium carbonate, is induced on and by the acidic proteins in nacre. However, the basic proteins were not expected to be components of nacre. Here, we reported that a novel basic protein, PfN23, was a key accelerator in the control over crystal growth in nacre. The expression profile, in situ immunostaining, and in vitro immunodetection assays showed that PfN23 was localized within calcium carbonate crystals in the nacre. Knocking down the expression of PfN23 in adults via double-stranded RNA injection led to a disordered nacre surface in adults. Blocking the translation of PfN23 in embryos using morpholino oligomers led to the arrest of larval development. The in vitro crystallization assay showed that PfN23 increases the rate of calcium carbonate deposition and induced the formation of aragonite crystals with characteristics close to nacre. In addition, we constructed the peptides and truncations of different regions of this protein and found that the positively charged C-terminal region was a key region for the function of PfN23 Taken together, the basic protein PfN23 may be a key accelerator in the control of crystal growth in nacre. This provides a valuable balance to the classic view that acidic proteins control calcium carbonate deposition in nacre.

CaMKII antisense oligodeoxynucleotides protect against ischemia-induced neuronal death in the rat hippocampus

The present study was performed to investigate the effects of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) antisense oligodeoxynucleotides (ODNs) on the assembly of the CaMKII·GluR6·PSD-95 signaling module, GluR6 serine phosphorylation and c-Jun N-terminal kinase 3 (JNK3) activation. A further aim was to determine the neuroprotective mechanism of CaMKII antisense ODNs against ischemia-reperfusion (I/R)-induced neuronal death in the rat hippocampus. CaMKII antisense ODNs were intracerebroventricularly infused to inhibit CaMKII expression once daily for 3 days prior to the induction of ischemia. Transient cerebral ischemia (15 min) and reperfusion were induced by four-vessel occlusion in Sprague-Dawley rats as an animal model for transient cerebral I/R. The expression of related proteins was examined by immunoprecipitation and immunoblotting. Neuronal death in the rat hippocampus was detected by histology and histochemistry. The results indicate that CaMKII antisense ODNs inhibit several of the processes that are normally induced by cerebral I/R, including CaMKII expression, increased CaMKII·GluR6·PSD-95 signaling module assembly, GluR6 serine phosphorylation and JNK3 activation. Alternatively, CaMKII antisense ODNs also exhibit a significant neuroprotective role against cerebral I/R-induced cell death. These results provide the first evidence that CaMKII antisense ODNs can exert neuroprotective effects on cerebral I/R-induced cell death. The possible molecular mechanisms underlying this effect include 1) an inhibition of CaMKII expression and subsequent suppression of the assembly of the CaMKII·GluR6·PSD-95 signaling module, 2) GluR6 serine phosphorylation, and 3) reduced JNK3 activation.

Augmenter of liver regeneration (alr) promotes liver outgrowth during zebrafish hepatogenesis

Augmenter of Liver Regeneration (ALR) is a sulfhydryl oxidase carrying out fundamental functions facilitating protein disulfide bond formation. In mammals, it also functions as a hepatotrophic growth factor that specifically stimulates hepatocyte proliferation and promotes liver regeneration after liver damage or partial hepatectomy. Whether ALR also plays a role during vertebrate hepatogenesis is unknown. In this work, we investigated the function of alr in liver organogenesis in zebrafish model. We showed that alr is expressed in liver throughout hepatogenesis. Knockdown of alr through morpholino antisense oligonucleotide (MO) leads to suppression of liver outgrowth while overexpression of alr promotes liver growth. The small-liver phenotype in alr morphants results from a reduction of hepatocyte proliferation without affecting apoptosis. When expressed in cultured cells, zebrafish Alr exists as dimer and is localized in mitochondria as well as cytosol but not in nucleus or secreted outside of the cell. Similar to mammalian ALR, zebrafish Alr is a flavin-linked sulfhydryl oxidase and mutation of the conserved cysteine in the CxxC motif abolishes its enzymatic activity. Interestingly, overexpression of either wild type Alr or enzyme-inactive Alr(C131S) mutant promoted liver growth and rescued the liver growth defect of alr morphants. Nevertheless, alr(C131S) is less efficacious in both functions. Meantime, high doses of alr MOs lead to widespread developmental defects and early embryonic death in an alr sequence-dependent manner. These results suggest that alr promotes zebrafish liver outgrowth using mechanisms that are dependent as well as independent of its sulfhydryl oxidase activity. This is the first demonstration of a developmental role of alr in vertebrate. It exemplifies that a low-level sulfhydryl oxidase activity of Alr is essential for embryonic development and cellular survival. The dose-dependent and partial suppression of alr expression through MO-mediated knockdown allows the identification of its late developmental role in vertebrate liver organogenesis.

S-nitrosylation of mixed lineage kinase 3 contributes to its activation after cerebral ischemia

Previous studies in our laboratory have shown that mixed lineage kinase 3 (MLK3) can be activated following global ischemia. In addition, other laboratories have reported that the activation of MLK3 may be linked to the accumulation of free radicals. However, the mechanism of MLK3 activation remains incompletely understood. We report here that MLK3, overexpressed in HEK293 cells, is S-nitrosylated (forming SNO-MLK3) via a reaction with S-nitrosoglutathione, an exogenous nitric oxide (NO) donor, at one critical cysteine residue (Cys-688). We further show that the S-nitrosylation of MLK3 contributes to its dimerization and activation. We also investigated whether the activation of MLK3 is associated with S-nitrosylation following rat brain ischemia/reperfusion. Our results show that the administration of 7-nitroindazole, an inhibitor of neuronal NO synthase (nNOS), or nNOS antisense oligodeoxynucleotides diminished the S-nitrosylation of MLK3 and inhibited its activation induced by cerebral ischemia/reperfusion. In contrast, 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (an inhibitor of inducible NO synthase) or nNOS missense oligodeoxynucleotides did not affect the S-nitrosylation of MLK3. In addition, treatment with sodium nitroprusside (an exogenous NO donor) and S-nitrosoglutathione or MK801, an antagonist of the N-methyl-D-aspartate receptor, also diminished the S-nitrosylation and activation of MLK3 induced by cerebral ischemia/reperfusion. The activation of MLK3 facilitated its downstream protein kinase kinase 4/7 (MKK4/7)-JNK signaling module and both nuclear and non-nuclear apoptosis pathways. These data suggest that the activation of MLK3 during the early stages of ischemia/reperfusion is modulated by S-nitrosylation and provides a potential new approach for stroke therapy whereby the post-translational modification machinery is targeted.

Repression of meiotic genes by antisense transcription and by Fkh2 transcription factor in Schizosaccharomyces pombe

In S. pombe, about 5% of genes are meiosis-specific and accumulate little or no mRNA during vegetative growth. Here we use Affymetrix tiling arrays to characterize transcripts in vegetative and meiotic cells. In vegetative cells, many meiotic genes, especially those induced in mid-meiosis, have abundant antisense transcripts. Disruption of the antisense transcription of three of these mid-meiotic genes allowed vegetative sense transcription. These results suggest that antisense transcription represses sense transcription of meiotic genes in vegetative cells. Although the mechanism(s) of antisense mediated transcription repression need to be further explored, our data indicates that RNAi machinery is not required for repression. Previously, we and others used non-strand specific methods to study splicing regulation of meiotic genes and concluded that 28 mid-meiotic genes are spliced only in meiosis. We now demonstrate that the "unspliced" signal in vegetative cells comes from the antisense RNA, not from unspliced sense RNA, and we argue against the idea that splicing regulates these mid-meiotic genes. Most of these mid-meiotic genes are induced in mid-meiosis by the forkhead transcription factor Mei4. Interestingly, deletion of a different forkhead transcription factor, Fkh2, allows low levels of sense expression of some mid-meiotic genes in vegetative cells. We propose that vegetative expression of mid-meiotic genes is repressed at least two independent ways: antisense transcription and Fkh2 repression.

Nucleolin antisense oligodeoxynucleotides induce apoptosis and may be used as a potential drug for nasopharyngeal carcinoma therapy

Nucleolin (C23, NCL) mRNA was up-regulated in nasopharyngeal carcinoma (NPC) cells compared to that of normal nasomucosal (NNM) cells using a cDNA microarray approach. The level of nucleolin protein was also up-regulated in 13 NPC cell lines, 30 biopsy specimens and nine other cancer cell lines compared to five NNM cells or normal stromal cells, which were analyzed using immunoblotting or immunohistochemistry. We transfected nucleolin antisense oligodeoxynucleotides (phosphorothioate-modified oligodeoxynucleotides; S-ODNs) into NPC-TW01 cells to knockdown nucleolin expression to evaluate the function of nucleolin in cancer cells. Nucleolin knockdown induced NPC cells but not NNM cells to undergo apoptosis. Furthermore, treatment of NPC-TW01 xenograft tumors with nucleolin antisense oligodeoxynucleotides suppressed the growth of xenograft tumors without obvious side effects. Therefore, we suggest that nucleolin may be a potential cancer therapeutic target and that nucleolin antisense oligodeoxynucleotides may be used as a potential drug for therapy in NPC.

Anxiolytic effects of 5-HT₁A receptors and anxiogenic effects of 5-HT₂C receptors in the amygdala of mice

The aim of the present study is to test a hypothesis that 5-HT(1A) and 5-HT(2C) receptors in the amygdala play an important role in the regulation of anxiety behaviors. We examined alterations in anxiety-like behaviors after manipulation of the expression of 5-HT(1A) and 5-HT(2C) receptors in the amygdala using recombinant adenovirus approaches. Recombinant adenoviruses containing a 5-HT(1A) promoter-controlled 5-HT(1A) antisense sequence or a 5-HT(2C) promoter-controlled 5-HT(2C) sense sequence were injected into the amygdala. Elevated plus-maze (EPM) and open field tests were conducted to determine anxiety-like behavior and locomotor activity. Reductions in the expression of 5-HT(1A) receptors in the amygdala significantly attenuated the time spent in the open arms of EPM and time spent in the center of an open field. Reduction in the percent of time spent in the open arms of EPM is negatively correlated with the density of 5-HT(1A) receptors in the central amygdala. On the other hand, increased expression of 5-HT(2C) receptors reduced the time spent in the open arms of EPM and time spent in the center of an open field. The reductions in the time spent and distance traveled in the open arms of EPM were correlated to the density of 5-HT(2C) receptors in the basolateral nucleus of amygdala. These data suggest that amygdaloid 5-HT(1A) receptors produce anxiolytic and 5-HT(2C) receptors produce anxiogenic effects. Together, the present results demonstrate the important role of the amygdaloid 5-HT(1A) and 5-HT(2C) receptors in the regulation of anxiety-like behaviors. This article is part of a Special Issue entitled 'Anxiety and Depression'.

Macrophage migration inhibitory factor (MIF) expression in human malignant gliomas contributes to immune escape and tumour progression

Macrophage migration inhibitory factor (MIF), which inhibits apoptosis and promotes angiogenesis, is expressed in cancers suppressing immune surveillance. Its biological role in human glioblastoma is, however, only poorly understood. We examined in-vivo expression of MIF in 166 gliomas and 23 normal control brains by immunohistochemistry. MIF immunoreactivity was enhanced in neoplastic astrocytes in WHO grade II glioma and increased significantly in higher tumour grades (III-IV). MIF expression was further assessed in 12 glioma cell lines in vitro. Quantitative RT-PCR showed that MIF mRNA expression was elevated up to 800-fold in malignant glioma cells compared with normal brain. This translated into high protein levels as assessed by immunoblotting of total cell lysates and by ELISA-based measurement of secreted MIF. Wild-type p53-retaining glioma cell lines expressed higher levels of MIF, which may be connected with the previously described role of MIF as a negative regulator of wild-type p53 signalling in tumour cells. Stable knockdown of MIF by shRNA in glioma cells significantly increased tumour cell susceptibility towards NK cell-mediated cytotoxicity. Furthermore, supernatant from mock-transfected cells, but not from MIF knockdown cells, induced downregulation of the activating immune receptor NKG2D on NK and CD8+ T cells. We thus propose that human glioma cell-derived MIF contributes to the immune escape of malignant gliomas by counteracting NK and cytotoxic T-cell-mediated tumour immune surveillance. Considering its further cell-intrinsic and extrinsic tumour-promoting effects and the availability of small molecule inhibitors, MIF seems to be a promising candidate for future glioma therapy.

Semaphorin-PlexinD1 signaling limits angiogenic potential via the VEGF decoy receptor sFlt1

Sprouting angiogenesis expands the embryonic vasculature enabling survival and homeostasis. Yet how the angiogenic capacity to form sprouts is allocated among endothelial cells (ECs) to guarantee the reproducible anatomy of stereotypical vascular beds remains unclear. Here we show that Sema-PlxnD1 signaling, previously implicated in sprout guidance, represses angiogenic potential to ensure the proper abundance and stereotypical distribution of the trunk's segmental arteries (SeAs). We find that Sema-PlxnD1 signaling exerts this effect by antagonizing the proangiogenic activity of vascular endothelial growth factor (VEGF). Specifically, Sema-PlxnD1 signaling ensures the proper endothelial abundance of soluble flt1 (sflt1), an alternatively spliced form of the VEGF receptor Flt1 encoding a potent secreted decoy. Hence, Sema-PlxnD1 signaling regulates distinct but related aspects of angiogenesis: the spatial allocation of angiogenic capacity within a primary vessel and sprout guidance.

Histone deacetylation during brain development is essential for permanent masculinization of sexual behavior

Epigenetic histone modifications are emerging as important mechanisms for conveyance of and maintenance of effects of the hormonal milieu to the developing brain. We hypothesized that alteration of histone acetylation status early in development by sex steroid hormones is important for sexual differentiation of the brain. It was found that during the critical period for sexual differentiation, histones associated with promoters of essential genes in masculinization of the brain (estrogen receptor α and aromatase) in the medial preoptic area, an area necessary for male sexual behavior, were differentially acetylated between the sexes. Consistent with these findings, binding of histone deacetylase (HDAC) 2 and 4 to the promoters was higher in males than in females. To examine the involvement of histone deacetylation on masculinization of the brain at the behavioral level, we inhibited HDAC in vivo by intracerebroventricular infusion of the HDAC inhibitor trichostatin A or antisense oligodeoxynucleotide directed against the mRNA for HDAC2 and -4 in newborn male rats. Aspects of male sexual behavior in adulthood were significantly reduced by administration of either trichostatin A or antisense oligodeoxynucleotide. These results demonstrate that HDAC activity during the early postnatal period plays a crucial role in the masculinization of the brain via modifications of histone acetylation status.

Transcriptional and post-transcriptional mechanisms for oncogenic overexpression of ether à go-go K+ channel

The human ether-à-go-go-1 (h-eag1) K⁺ channel is expressed in a variety of cell lines derived from human malignant tumors and in clinical samples of several different cancers, but is otherwise absent in normal tissues. It was found to be necessary for cell cycle progression and tumorigenesis. Specific inhibition of h-eag1 expression leads to inhibition of tumor cell proliferation. We report here that h-eag1 expression is controlled by the p53−miR-34−E2F1 pathway through a negative feed-forward mechanism. We first established E2F1 as a transactivator of h-eag1 gene through characterizing its promoter region. We then revealed that miR-34, a known transcriptional target of p53, is an important negative regulator of h-eag1 through dual mechanisms by directly repressing h-eag1 at the post-transcriptional level and indirectly silencing h-eag1 at the transcriptional level via repressing E2F1. There is a strong inverse relationship between the expression levels of miR-34 and h-eag1 protein. H-eag1antisense antagonized the growth-stimulating effects and the upregulation of h-eag1 expression in SHSY5Y cells, induced by knockdown of miR-34, E2F1 overexpression, or inhibition of p53 activity. Therefore, p53 negatively regulates h-eag1 expression by a negative feed-forward mechanism through the p53−miR-34−E2F1 pathway. Inactivation of p53 activity, as is the case in many cancers, can thus cause oncogenic overexpression of h-eag1 by relieving the negative feed-forward regulation. These findings not only help us understand the molecular mechanisms for oncogenic overexpression of h-eag1 in tumorigenesis but also uncover the cell-cycle regulation through the p53−miR-34−E2F1−h-eag1 pathway. Moreover, these findings place h-eag1 in the p53−miR-34−E2F1−h-eag1 pathway with h-eag as a terminal effecter component and with miR-34 (and E2F1) as a linker between p53 and h-eag1. Our study therefore fills the gap between p53 pathway and its cellular function mediated by h-eag1.

Heparanase antisense suppression of A-549 lung carcinoma invasion

OBJECTIVE

Heparanase (HPSE), as the only enzyme which can degrade the extracellular matrix and heparin sulfate in basement membrane, plays an important role in invasion and metastasis of tumor cells. In this study, we evaluated the inhibitory effect of HPSE antisense oligoxydeonucleotide (ASODN) on lung carcinoma cell line A-549 invasion.

METHODS

Liposome-mediated ASODN was transfected into A-549 cells and expression of HPSE protein and mRNA were detected by flow cytometry and RT-PCR techniques. Matrigel invasion assays were employed to assess effects on invasiveness.

RESULTS

Lower expression of HPSE protein and mRNA and lower invasive ability to recombinate basal membrane were apparent after ASOND treatment (P<0.01). The inhibition rates of cell invasiveness were 55.6%, 82.3% and 91.2% treated by ASODN at final concentrations of 100, 200 and 400nmol/L, respectively.

CONCLUSIONS

HPSE ASODN can downregulate the expression of HPSE protein and mRNA in the A-549 cell line and can obviously inhibit its invasive ability in a dose-dependent manner in vitro.

Early growth response gene 1 (Egr-1) is required for new and reactivated fear memories in the lateral amygdala

The immediate-early gene early growth response gene-1 (EGR-1, zif-268) has been extensively studied in synaptic plasticity and memory formation in a variety of memory systems. However, a convincing role for EGR-1 in amygdala-dependent memory consolidation processes has yet to emerge. In the present study, we have examined the role of EGR-1 in the consolidation and reconsolidation of amygdala-dependent auditory Pavlovian fear conditioning. In our first series of experiments, we show that EGR-1 is regulated following auditory fear conditioning in the lateral nucleus of the amygdala (LA). Next, we use antisense oligodeoxynucleotide (ODN) knockdown of EGR-1 in the LA to show that training-induced expression of EGR-1 is required for memory consolidation of auditory fear conditioning; that is, long-term memory (LTM) is significantly impaired while acquisition and short-term memory (STM) are intact. In a second set of experiments, we show that EGR-1 is regulated in the LA by retrieval of an auditory fear memory. We then show that retrieval-induced expression of EGR-1 in the LA is required for memory reconsolidation of auditory fear conditioning; that is, post-retrieval (PR)-LTM is significantly impaired while memory retrieval and PR-STM are intact. Additional experiments show these effects to be restricted to the LA, to be temporally graded, and unlikely to be due to nonspecific toxicity within the LA. Collectively, our findings strongly implicate a role for EGR-1 in both the initial consolidation and in the reconsolidation of auditory fear memories in the LA.

Epigallocatechin gallate-mediated protection against tumor necrosis factor-α-induced monocyte chemoattractant protein-1 expression is heme oxygenase-1 dependent

Flavonoids have been suggested to protect against atherosclerosis via their antioxidant and anti-inflammatory properties. Heme oxygenase-1 (HO-1) is an enzyme that plays an important role in the vascular system, and its induction may provide a protective role against atherosclerosis. We hypothesize that flavonoids can down-regulate endothelial inflammatory parameters by modulating HO-1-regulated cell signaling. We focused on the role of HO-1 and its major metabolic product, bilirubin, on mechanisms of tumor necrosis factor-α-induced endothelial cell activation and protection by the catechin epigallocatechin gallate (EGCG). Pretreatment with EGCG inhibited the secretion of monocyte chemoattractant protein-1 and the activation of activator protein-1 in porcine aortic endothelial cells stimulated with tumor necrosis factor-α. Moreover, EGCG up-regulated the expression of HO-1 and further induced the secretion of bilirubin. The observed anti-inflammatory effects of EGCG were mimicked by the HO-1 inducer cobalt protoporphyrin and abolished by HO-1 gene silencing. These data suggest that the protective properties of flavonoids, such as EGCG, against endothelial inflammation may be regulated in part though induction of HO-1 and subsequent activator protein-1 signaling.

The protective effects of Egr-1 antisense oligodeoxyribonucleotide on cardiac microvascular endothelial injury induced by hypoxia-reoxygenation

Early growth response 1 (Egr-1) over-expression has been demonstrated in myocardial ischemia-reperfusion injury, which is closely associated with endothelial dysfunction. In the present study we investigated the expression of Egr-1 on cultured cardiac microvascular endothelial cells (CMECs) to help define the mechanism of myocardial ischemia-reperfusion injury. A model of cultured CMECs exposed to hypoxia-reoxygenation was developed in which synthesized Egr-1 sense and antisense oligodeoxyribonucleotide were transfected into the cells. The expression of Egr-1 was examined by Western blot analysis. Lactate dehydrogenase, malondialdehyde, superoxide dismutase, tumor necrosis factor alpha, and intercellular adhesion molecule 1 were measured after hypoxia-reoxygenation to assess cell function and injury. Cell morphology, cell viability, and neutrophil adhesion to the CMECs were measured to assess the degree of injury and inflammation. Only cells transfected with Egr-1 antisense oligodeoxyribonucleotide showed a significant reduction in Egr-1 protein expression following hypoxia-reoxygenation. Consistent with the down-regulation of Egr-1 expression, other forms of cell injury were significantly reduced in this group of cells, as evidenced by less alteration in cell morphology, a decrease in expression of tumor necrosis factor alpha and intercellular adhesion molecule 1, improved cell survival, and reduced neutrophil adhesion.

A novel method of organotypic brain slice culture using connexin-specific antisense oligodeoxynucleotides to improve neuronal survival

Organotypic slice cultures obtained from immature brain tissue represent a well-established model system for neuroscience research. Current culture methods, however, do not allow long-term culture of mature brain slices. Slice cultures from mature animals would provide an in vitro experimental environment suitable for investigation of neuropathologies, which in human, predominate in aged individuals. We hypothesized that damage, incurred by slicing of the brain, is propagated through intercellular connexin43 (Cx43) gap junction channels and that this damage is not easily repaired in mature central nervous system (CNS) tissue that lacks the pluripotency of immature tissue. We investigated the role of Cx43 gap junctions in long-term survival of mature brain tissue using antisense oligodeoxynucleotide (AsODN) technology. The application of Cx43 AsODN immediately after slicing of the mature brain led to a significant but transient knockdown of Cx43 protein. This treatment was associated with the long-term survival of hippocampal neurons with normal morphology within whole brain slices taken from 14 and 40-day-old adult rats.

COL1A1 oligodeoxynucleotides decoy: biochemical and morphologic effects in an acute wound repair model

Type I collagen is an integral component of granulation tissue and scar, that is highly dependent on TGFβ1, a member of a pro-fibrotic family of cytokines, for its promotion and deposition. Blocking COL1A1 gene transcription obstructs type I collagen synthesis, hindering the progress of granulation tissue deposition and fibrosis. Local injections of a double stranded oligodeoxynucleotide (dsODN) decoy, containing the TGFβ1 regulatory element that is located in the distal promoter of the COL1A1 gene, were investigated in a rat polyvinyl alcohol (PVA) sponge granulation tissue implant model. The effects on the granulation tissue deposition by dsODN decoy therapy were evaluated by the synthesis of types I and III collagens as well as ED-A (cellular) fibronectin. Fluorescently labeled dsODN was used to identify the distribution of the decoy molecules in the sponge implant relative to the observed histological effects. Morphological alterations in cells and changes in the organization of connective tissue were documented and evaluated. Collagen levels were reduced by half in implants treated with 10 nM dsODN decoy compared to scrambled dsODN-treated implants. Histologically, dsODN decoy treated implants had an increased cellular density without a corresponding increase in deposited connective tissue. Polarized light birefringence pattern of Sirius red-stained sections showed less collagen fibers accumulating between fibroblasts. The highest concentration of fluorescently labeled dsODN was identified within the interior margin of sponge implants, correlating to increased cellular density and an altered birefringence patterns. In conclusion, 10 nM dsODN decoy therapy reduced collagen deposition and altered the organization of granulation tissue, supporting its potential as a localized anti-fibrotic therapy for limiting fibrotic conditions.

[Effect of extracellular signal-regulated kinase antisense oligodeoxynucleotides on the proliferation of passively sensitized human airway smooth muscle cells]

OBJECTIVE

Airway smooth muscle (ASM) cell proliferation is a key feature of airway remodeling in asthma. The extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway is one of the most important transduction pathways involved in the proliferation of ASM of asthmatic rats. However, its role in the human ASMCs proliferation remains unclear.

METHODS

HASMCs were cultured in vitro and passively sensitized with 10% serum from asthmatic patients, and non-asthmatic human serum treated HASMCs served as the control. Then, HASMCs were transfected with ERK sense, antisense and mismatched oligodeoxynucleotides (ODN). The proliferations of HASMCs were detected by flow cytometry analysis, MTT colorimetric assay, [³H] thymidine incorporation and proliferating cell nuclear antigen (PCNA) in immunofluorescence staining respectively. The apoptosis of HASMCs were detected by in situ end labeling and Annexin-V FITC PI double staining. The expressions of ERK mRNA, ERK protein and phosphorylation of ERK1/2(p-ERK1/2) protein were measured by RT-PCR and Western blotting, respectively.

RESULTS

The percentage of S + G₂/M phase, absorbance (A(490)) value, DNA synthesis value and the expression of PCNA protein in HASMCs passively sensitized with 10% serum from asthmatic patients were (22.48 ± 2.04)%, (0.507 ± 0.090), (3869 ± 396) cpm/10⁶ cells, (11.25 ± 1.21), respectively. After treated with ERK oligodeoxynucleotides, these measurements were decreased to (14.21 ± 1.21)%, (0.271 ± 0.021), (2811 ± 182) cpm/10⁶ cells and (5.25 ± 0.60), respectively (F = 65.594, 39.676, 61.111, 120.321, respectively, P < 0.05). The apoptotic index (13.96 ± 1.72) and the percentage of the early apoptotic cells (9.17 ± 0.47)% in HASMCs from group AODNs were significantly increased compared to those of chronic asthma group, which were (5.37 ± 0.05), (3.26 ± 0.04)%, respectively (F = 98.181, 65.444, respectively, P < 0.05). The expression of ERK mRNA (0.43 ± 0.06) and the activation ratio of ERK (63 ± 6)% in HASMCs from group AODNs were significantly decreased compared to those of chronic asthma group, which were (0.89 ± 0.09), (87 ± 8)%, respectively (F = 78.043, 87.288, respectively, P < 0.05). ERK antisense ODN inhibited the proliferation of HASMCs and induced the apoptosis of HASMCs, but the sense and the mismatched ones did not have these effects.

CONCLUSIONS

ERK antisense ODN inhibited the proliferation and increased the apoptosis in cultured HASMCs passively sensitized with 10% serum from asthmatic patients. The result suggests that ERK signaling pathway may contribute to the proliferation and apoptosis of HASMCs in asthmatic patients.

Inhibition of microglial P2X4 receptors attenuates morphine tolerance, Iba1, GFAP and mu opioid receptor protein expression while enhancing perivascular microglial ED2

Anti-nociceptive tolerance to opioids is a well-described phenomenon, which severely limits the clinical efficacy of opioids for the treatment of chronic pain syndromes. The mechanisms that drive anti-nociceptive tolerance, however, are less well understood. We have previously shown that glia have a central role in the development of morphine tolerance and that administration of a glial modulating agent attenuated tolerance formation. Recently, we have demonstrated that morphine enhances microglial Iba1 expression and P2X4 receptor-mediated microglial migration via direct mu opioid receptor signaling in in vitro microglial cultures. We hypothesize that P2X4 receptors drive morphine tolerance and modulate morphine-induced spinal glial reactivity. Additionally, we hypothesize that perivascular microglia play a role in morphine tolerance and that P2X4 receptor expression regulates perivascular microglia ED2 expression. To test these hypotheses, rats were implanted with osmotic minipumps releasing morphine or saline subcutaneously for seven days. Beginning three days prior to morphine treatment, P2X4 receptor antisense oligonucleotide (asODN) was injected intrathecally daily, to selectively inhibit P2X4 receptor expression. P2X4 receptor asODN treatment inhibited morphine-induced P2X4 receptor expression and blocked anti-nociceptive tolerance to systemically administered morphine. P2X4 receptor asODN treatment also attenuated the morphine-dependent increase of spinal ionized calcium binding protein (Iba1), glial fibrillary acidic protein (GFAP) and mu opioid receptor protein expression. Chronic morphine also decreased perivascular microglial ED2 expression, which was reversed by P2X4 receptor asODN. Together, these data suggest that the modulation of P2X4 receptor expression on microglia and perivascular microglia may prove an attractive target for adjuvant therapy to attenuate opioid-induced anti-nociceptive tolerance.

Co-stimulation with TLR7/8 and TLR9 agonists induce down-regulation of innate immune responses in sheep blood mononuclear and B cells

Toll-like receptors (TLRs) play an important role in the activation of innate and adaptive immune responses. Stimulation with multiple TLR agonists may result in synergistic, complimentary or inhibitory effects on innate immune responses. In this study, we investigated the effects of co-stimulation of sheep peripheral blood mononuclear cells (PBMC) and B cells with agonists for TLR3, 4, 7/8 and 9. Sheep PBMC stimulated with either CpG (TLR9 agonist) or RNA oligoribonucleotides ([ORNs], TLR7/8 agonist) exhibited significant IL-12 production, but only CpG induced IFNalpha, IgM and proliferative responses. In contrast, poly(I:C) (TLR3 agonist) and LPS (TLR4 agonist) did not induce any of these responses. Interestingly, we observed that co-stimulation of PBMC with CpG+ORN or CpG+imiquimod (another TLR7/8 agonist) resulted in significant reduction in CpG-induced IFNalpha production, B cell proliferation and IgM responses. Pre-incubation of cells with CpG prior to exposure of the cells to imiquimod resulted in similar inhibitory responses indicating that the down-regulatory mechanisms are not associated with competition for cellular uptake or for receptors of the two agonists. Sheep B cells constitutively expressed TLR7, TLR8 and TLR9 mRNA transcripts, suggesting a possible role of TLR cross-talk in the down-regulatory mechanisms. Down-regulation of responses by co-stimulation with closely related TLRs may be a regulatory mechanism by which the host prevents overstimulation of innate immune responses.

[P38 MAPK antisense oligodeoxynucleotide inhibited the brain ischemic tolerance induced by limb ischemic preconditioning]

OBJECTIVE

To better assess the role of p38 MAPK, this project was designed to investigate whether intraventricular injection of antisense oligodeoxynucleotide (As-ODN) directed against the p38 MAPK of pyramidal neurons in hippocampus could affect the brain ischemic tolerance induced by limb ischemic preconditioning (LIP).

METHODS

The rat 4-vessel occlusion global cerebral ischemic model was used. Forty-eight male Wistar rats with permanently occlusion of the bilateral vertebral arteries were divided into 8 groups (n=6): sham, LIP, brain ischemic insult, LIP + brain ischemic insult, distilled water + LIP + brain ischemic insult, p38 MAPK As-ODN and p38 MAPK As-ODN + LIP + brain ischemic insult (two doses of 5 nmol/5 microl and 10 nmol/5 microl were used) groups. Thionin staining was used for observing histological changes of the hippocampus.

RESULTS

No significant delayed neuronal death (DND) was detected in the CA1 hippocampus of the rats that underwent sham and LIP operation. Brain ischemic insult for 8 min induced obvious DND as represented with the increase in histological grade (HG) and decrease in neuronal density (ND) significantly compared with sham and LIP groups. LIP protected the CA1 hippocampal pyramidal neurons against DND induced by global brain ischemic insult, suggesting the occurrence of brain ischemic tolerance. However, pretreatment with p38 MAPK As-ODN effectively blocked the ischemic tolerance induced by LIP in a dose dependent manner.

CONCLUSION

It could be concluded that p38 MAPK plays an important role in the brain ischemic tolerance induced by LIP.

[Effect of hTERT antisense oligodeoxynucleotide on telomerase activity in bladder cancer cells in vitro]

OBJECTIVE

To investigate the effect of hTERT antisense oligodeoxynucleotide on telomerase activity in bladder cancer cells.

METHODS

Antisense phosphorothioate oligodeoxynucleotide (AS PS-ODN) was synthesized and purified. Telomerase activity was measured by telomerase PCR ELISA kit. hTERT mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR), and hTERT protein by immunohistochemistry and flow cytometry.

RESULTS

Telomerase activity was decreased in T24 cells 48 h after treatment with AS PS-ODN, and was significantly inhibited at 72 h.

CONCLUSION

AS PS-ODN can significantly inhibit telomerase activity by down-regulating hTERT mRNA and protein expression in bladder cancer cells.

[Effect of survivin antisense oligodeoxynucleotide on proliferation and apoptosis of human malignant melanoma cells]

OBJECTIVE

To investigate the effect of survivin antisense oligodeoxynucleotide (ASODN) on proliferation and apoptosis of human malignant melanoma cells.

METHODS

hMMC A375 colonies in log growth phase were collected and divided into control group (C, without transfection), sense chain group [SC, transfected with 600 nmol/L survivin sense oligodeoxynucleotide (ODN)], mismatch chain group (MC, transfected with 600 nmol/L survivin mismatch sense ODN), liposome group (L, treated with liposome), antisense chain group (AC, transfected with survivin ASODN, and subdivided into AC 200, 400, 600 nmol/L subgroups) according to the random number table. Transfection result was observed under inverted fluorescence microscope. Inhibition rate of cell proliferation was calculated after determination of cell viability with MTT method. Cell cycle and apoptosis rate were detected with bi-variable flow cytometry. Expression of survivin protein was determined with Western blot. Activity of caspase-3 was assessed with kinase method. Data were processed with analysis of variance.

RESULTS

(1) Cell transfection rates in SC, MC, AC 600 nmol/L groups were all above 80%. (2) Compared with those in SC group [(5.23 +/- 0.25)%], MC group [(5.09 +/- 0.13)%] and L group [(4.70 +/- 0.45)%], inhibition rates of cell proliferation in AC 200, 400, 600 nmol/L groups 24 hours after transfection [(10.30 +/- 0.56)%, (16.69 +/- 0.58)%, (24.67 +/- 0.67)%] were significantly increased (F = 746.91, and P values all below 0.05). As time after transfection went on, proliferation inhibition rate was increased obviously. (3) Apoptosis rate in AC 200, 400, 600 nmol/L groups 24 hours after transfection was respectively (13.5 +/- 1.9)%, (20.1 +/- 1.5)%, (32.1 +/- 2.9)%, which were significantly higher than those in C, SC, MC, and L groups [(6.5 +/- 0.6)%, (5.6 +/- 0.7)%, (6.4 +/- 1.0)%, (6.5 +/- 1.3)%, F = 139.9, P values all below 0.05]. Cells in AC group were blocked in G2/M stage. (4) Compared with those in C group, expression amount of survivin protein decreased, and caspase-3 activity obviously increased (F = 63.1, P values all below 0.05) in AC group. No significant difference in caspase-3 activity between SC, MC, L groups and C group was observed (F = 0.512, P values all above 0.05).

CONCLUSIONS

Survivin ASODN can inhibit the proliferation of hMMC A375 in a concentration-time dependent manner, and it induces G2/M stage block and promotes its apoptosis.

[Survivin antisense oligodeoxynucleotides inhibits the proliferation of hepatocellular carcinoma cells and enhances 5-FU sensitivity]

OBJECTIVE

To investigate the inhibitory effect of survivin antisense oligodeoxynuleotides (ASODN) mediated by polyethylenimine (PEI) on hepatocelluar carcinoma SMMC-7721 cell proliferation and its effect on chemosensitivity to 5-FU in tumor-bearing mice.

METHODS

The inhibitory effect of PEI-ASODN on SMMC-7721 cell proliferation was assayed by WST-8 test, Trypan blue exclusion test, and cell clone formation assay. In mouse models of transplanted H22 cell hepatocarcinoma and ascites tumor, the effect of 5-FU combined with PEI-ASODN on the weight and volume of the subcutaneous tumors was examined. The tumor inhibition rate in the tumor-bearing mice was calculated and the average survival time recorded.

RESULTS

SMMC-7721 cells incubated with different concentrations of PEI-ASODN for 48 h showed significantly reduced cell proliferation in comparison with the control cells, while PEI or ASODN alone produced no such inhibitory effect. Incubation of SMMC-7721 cells with 0.75 micromol/L PEI-ASODN for 24, 48, 72, and 96 h resulted in significantly suppressed cell proliferation, and a 7-day incubation of the cells with PEI-ASODN at different concentrations (0.25-0.75 micromol/L) significantly inhibited the cell clone formation. In the tumor-bearing mice, the tumor weight and volume were obviously reduced with a tumor inhibition rate of 56.91% and volume inhibition rate of 57.83%, significantly different from those in saline-treated mice (P<0.01). In the mice bearing ascites tumor, the average survival time was 22.0 days in saline group and 42.7 days in 5-FU+PEI-ASODN treatment group, showing a a life-prolonging rate of 94.09% in the latter group. A synergetic effect was noted between 5-FU and PEI-ASODN.

CONCLUSION

PEI-ASODN complex can significantly inhibit the proliferation of hepatocarcinoma SMMC-7721 cells and enhance 5-FU chemosensitivity of the tumor cells in vitro and transplanted H22 tumors in mice.