Combination of telomerase antisense oligonucleotides simultaneously targeting hTR and hTERT produces synergism of inhibition of telomerase activity and growth in human colon cancer cell line

AIM: To investigate synergism of inhibition of telomerase activity and proliferation of human colon cancer cells by combination of telomerase antisense oligonucleotides (ASODNs) simultaneously targeting human telomerase RNA (hTR) and human telomerase reverse transcriptase (hTERT) in vitro. METHODS: ASODN of hTR and ASODN of hTERT were transfected into human colon cancer SW480 cells by liposomal transfection reagents. Telomerase activity of SW480 cells was examined using telomeric repeat amplification protocol (TRAP)-enzyme-linked immunosorbent assay (PCR-ELISA). Proliferation activity of SW480 cells was tested by methyl thiazolyl tetrazolium assay. Apoptosis and cell cycle were analyzed by flow cytometry. RESULTS: The telomerase activity and cell survival rate in SW480 cells transfected with 0.2 μmol/L of ASODN of hTR or ASODN of hTERT for 24-72 h were significantly decreased in a time-dependent manner compared with those after treatment with sense oligonucleotides and untreated (telomerase activity: 24 h, 73%, 74% vs99%, 98%; 48 h, 61%, 55% vs98%, 99%; 72 h, 41%, 37% vs 99%, 97%; P<0.01; cell survival rate: 24 h, 88%, 86% vs594%, 98%; 48 h, 49%, 47% vs94%, 97%; 72 h, 44%, 42% vs92%, 96%; P<0.01). Moreover, the telomerase activity and the cell survival rate in SW480 cells treated by the combination of telomerase anti-hTR and anti-hTERT were more significantly suppressed than single anti-hTR or anti-hTERT (telomerase activity: 24 h, 59% vs 73%, 74%; 48 h, 43% vs61%, 55%; 72 h, 18% vs41%, 37%; P<0.01; cell survival rate: 24 h, 64% vs88%, 86%; 48 h, 37% vs49%, 47%; 72 h, 25% vs44%, 42%; P<0.01). Meanwhile, the apoptosis rates in the combination group were markedly increased compared with those in the single group (24 h, 18.0% vs7.2%, 7.4%; 48 h, 23.0% vs13.0%, 14.0%; 72 h, 28.6% vs 13.2%, 13.75; P<0.01). Cells in combination group were arrested at G0/G1 phase. CONCLUSION: Telomerase anti-hRT and anti-hTERT suppress telomerase activity, and inhibit growth of human colon cancer cells probably via induction of apoptosis and retardation of cell cycle. Additionally, combined use of telomerase ASODNs targeting both hTR and hTERT yields synergistic action selective for human colon cancer.

Effect of Dexamethasone and Aquaporin-1 Antisense Oligonucleotides on the Aquaporin-1 Expression in Cultured Human Trabecular Meshwork Cells

The changes in the expression of aquaporin-1 （AQP1） mRNA and protein in cultured human trabecular meshwork （HTM） cells treated with dexamethasone and transfected with antisense oligonucleotides （AS-ODN） were studied, and the implication of AQP1 regulation in corticosteroid-glaucoma and the possibility of AS-ODN inhibiting the AQP1 expression were evaluated. The cultured HTM cells in vitro were treated with different concentrations of dexamethasone and transfected with oligonucleotides for 5 days respectively. Then, total RNA and protein of HTM cells were extracted. The changes of AQP1 mRNA and protein were demonstrated qualitatively and quantitatively by RT-PCR and Western blot. Band intensities were detected by imaging analysis. There was a parallel relationship between the results of RT-PCR and those of Western blot. The expression levels of AQP1 mRNA and protein in dexamethasone-treated groups were increased initially and decreased later as dexamethasone concentration was stepped up. In the 0.04 μg/mL and 0.4 μg/mL groups, the levels of AQP1 were higher than in control group （0 μg/mL）. In the 4 μg/ mL and 40 μg/mL groups, the AQP1 expression levels were lower than in control group. AS-ODN could down-regulate the expression of AQP1 mRNA and protein in a dose-dependent manner. At 5 μg/mL, down-regulation efficiency reached the maximum. There was no statistically significant difference in the expression of AQP1 mRNA and protein between all sense oligonucleotides groups and control group. It was suggested that dexamethasone may induce the changes of the AQP1 expression in HTM cells to be involved in the occurrence of corticosteroid-glaucoma. AS-ODN can down-regulate the AQP1 expression in HTM cells to some extent.

Inhibition of PCNA Antisense Oligonucleotides Mediated by Liposome on mRNA Expression and Proliferation of h-RPE Cells

Summary： The proliferating cell nuclear antigen （PCNA） gene expression was blocked and retinal pigment epithelium （RPE） proliferation was inhibited by using antisense oligonucleotides （AS-ODN） mediated by liposome, to find a new genetic therapy of proliferative vitreoretinopathy （PVR）. RPE cells cultured in vitro were transfected with synthetic fluorescence labled AS-ODN mediated by liposome-Lipofectamine, and the intracellular distribution and persistence time of AS-ODN were dynamically observed. AS-ODN （0.07, 0.28 and 1.12 μ mol/L and sense oligonucleotides （S-ODN with the same concentrations as AS-ODN） mediated by liposome were delivered to the RPE cells cultured in vitro, and CPM values were measured by ^3H-TdR incorporation assay and analyzed statistically by variance by comparison with blank control group. Expression ofPCNA mRNA in RPE cells was detected by in situ hybridization after the treatment of different concentrations of PCNA AS-ODN and S-ODN, and the average optic density （AOD） was measured by image analysis system and was subjected to q-test and correlation analysis with CPM. Our results showed that AS-ODN mediated by liposome could quickly aggregate in cellular plasma and nuclei in 30 min and 6 h, and stayed for as long as 6 days. AS-ODN （0.28 and 1.12 μmol/L） markedly suppressed proliferation of RPE cells in a dose-dependent manner with the difference being statistically significant （P〈0.05 and P〈0.01, repectively） as compared with blank control group. AOD was well correlated with CPM （r=0.975）. It is concluded that liposome could increase transfection efficiency of AS-ODN in RPE cells, and AS-ODN could sequence-specifically suppress PCNA mRNA expression and proliferation of human RPE cells.

Effects of connective tissue growth factor antisense oligonucleotides on the proliferation and collagen synthesis of the cultured human keloid fibroblasts in vitro

Objective: To explore the effects of connective tissue growth factor (CTGF) on the pathogenesis of human keloid. Methods: CTGF antisense oligonucleotides (ASODN) conjugated with isothiocyananate fluorescence was encapsulated by liposome, and then added into the human keloid fibroblasts (HKFs) culture media. The intracellular distribution of CTGF ASODN was observed by fluorescence microscopy in the fixed HKFs. The proliferation of HKFs was measured by MTT test. The collagen synthesis of HKFs was measured by 3H-proline incorporation method. Results: Compared with control group, the CTGF ASODN can inhibit the proliferation and collagen synthesis of the HKFs (P<0.01). Conclusion: CTGF ASODN has anti-fibrotic effects on keloid in vitro, and CTGF play an important role in promoting the fibrosis of keloid.

Study on Apoptosis-Inducing Effect of XIAP Antisense Oligonucleotides on Glioblastoma Cells in Vitro

OBJECTIVE To investigate the apoptosis-inducing effect of XIAP antisense oligonucleotides on glioblastoma cells in vitro. METHODS There were 4 groups in our experiment. Group A, as a cell control group, had normal cell culture and no treatment applied. Group B, as a blank control group, had normal cell culture and no liposome control of ASODN. Group C was N-ODN. Group D was the ASODN group. RT-PCR and Western blot assay were conducted to detect the expression of XIAP in all A-172 ceil groups after treatment with XIAP antisense oligonucleotides （ASODN）. MTT assay and flow-cytometry （FCM） detection were used to detect the ability of cell anchoring growth and apoptotic rates of all groups. The processing time was 72 h. RESULTS The expression of XIAP in the A-172 cells was greatly down-regulated, after treated with XIAP-ASODN. Among different concentrations of ASODN, the 300nM was the most optimal one. The down-regulation of XIAP obviously inhibited the succinate dehydrogenase （SDH） activity of the A-172 cells and the increased apoptotic rate of A-172 cells （87.45%） was significantly higher than that of the A-172 in the control groups. There was a statistically significant difference between the treatment and control groups （P 〈 0.01）. CONCLUSION The XIAP-ASODN can effectively regulate the expression of the XIAP down, as a result, inhibit the growth of the glioblastoma cells （A-172） and obviously increase the apoptotic rate of the A-172 cells. The results killing role of XIAP-ASODN to the of the study manifest an overt glioblastoma cells.

Depressive Effect of the Antisense Oligonucleotides of C-myc and PCNA on the Proliferation of VSMC

Objectives To study the depressive effect of the antisense oligonuceotides （ASODN） of c-myc and proliferating cell nuclear antigen （PCNA） on the proliferation of VSMC. Methods Taking the VSMC obtained from rat aorta tho- racalis cultured 4 - 8 generation as research object. The objects were divided into three groups to carry out control study： control group, PCNA ASODN group and c-myc ASODN group. The ASODNs＇ working concentration all were 1 ： 50. The depressive effect of ASODN on VSMC proliferation was investigated by cell counting, MTT and ^3H-TdR incorporation assay; PCNA and c-myc expression were detected by immunohistochemical method after transferring PCNA and c-myc ASODN into VSMC. Results ① PCNA and c-myc ASODN could inhibit the proliferation of VSMC significantly, compared with control group （ P 〈 0. 05）. ②Transferring PCNA and c-myc ASODN into VSMC obtained successfully ; the corresponding gene was inhibited obviously ; compared with control group （ P 〈 0. 05 ）. Conclusions PCNA and c-myc might play a considerable role in the VSMC proliferation process. The corresponding gene could be depressed successfully after transferring PCNA and c-myc ASODN into VSMC, and then the proliferation of VSMC was slowed down. This study presented a beneficial proposal and theoretical fundament for atherosclerotic treatment.

Effects of antisense oligonucleotides on theexpression of macrophage migration inhibitoryfactor on macrophages

To investigate the effects of antisense oligonucleotides on the expression of macrophage migration inhibitory factor (MIF) on macrophages, the mouse phosphorothioate oligonucleotides were designed and synthesized with the sequences of antisense, 5′-TACGGATACAAGTAGCAC-3′; Sense, 5′-ATGCCTATGTTCATCGTG-3′; Missense, 5′-CTCTCAGACTCGATCTGT-3′. These phosphorothioate oligonucleotides were then transfected into cultured macrophages ( RAW264.7 ) by luciferase vector, and the transfected macrophages were incubated with Lipopolysaccharide (LPS) (1?ng/ml) for various periods of times and collected afterwards. The content of MIF protein in the cultural supernatants was determined by ELISA, cellular RNA extracted and the expression of MIF mRNA was examined by RT-PCR analysis. The experimental results showed that LPS could induce a time-dependent specific expression of MIF on macrophages, in which the MIF mRNA in cells and the MIF protein in cultural supernatants appeared after 3 h and reached their highest concentration at 9-12?h after LPS stimulation. The levels of mRNA and proteins in the macrophages treated with antisense olignucleotides were decreased significantly after stimulation with LPS in comparison with that of stimulation with LPS alone or with that with LPS plus sense or missense oligonucleotides. There were no differences among those without LPS stimulation. It is concluded that macrophages stimulated with LPS express MIF, and the antisense olignucleotides of MIF inhibit the expression of MIF mRNA as well as the secretion of MIF proteins in macrophages.

Enhanced therapeutic effects of combined chemotherapeutic drugs and midkine antisense oligonucleotides for hepatocellular carcinoma

AIM: To evaluate the effect of combined antisense oligonucleotides targeting midkine (MK-AS) and chemotherapeutic drugs [cisplatin(DDP), 5-fluorouracil (5-FU) and adriamycin (ADM)] on inhibition of HepG2 cell proliferation, and to analyze the efficacy of MK-AS used in combined ADM in in situ human hepatocellular carcinoma (HCC) model. METHODS: HepG2 cells were treated with MK-AS and/or chemotherapeutic drugs mediated by Lipofectin, and cell growth activity was determined by MTS assay. An in situ HCC model was used in this experiment. MK- AS, ADM and MK-AS + ADM were given intravenously for 20 d, respectively. The animal body weight and their tumor weight were measured to assess the effect of the combined therapy in vivo. RESULTS: Combined treatment with MK-AS reduced the IC50 of DDP, 5-FU and ADM in HepG2 cells. MK-AS significantly increased the inhibition rate of DDP, 5-FU and ADM. Additionally, synergism (Q 1.15) occurred at a lower concentration of ADM, 5-FU and DDP with combined MK-AS. Combined treatment with MK-AS and ADM resulted in the more growth inhibition on in situ human HCC model compared with treatment with chemotherapeutic drugs alone. CONCLUSION: MK-AS increases the chemosensitivity in HepG2 cells and in situ human HCC model, and thecombination of MK-AS and ADM has a much better in vitro and in vivo synergism.

Inhibiting effect of antisense oligonucleotides phosphorthioate on gene expression of TIMP-1 in rat liver fibrosis

AIM: To observe the inhibition of antisense oligonucleotides (asON) phosphorthioate to the tissue inhibitors metalloproteinase-1 (TIMP-1) gene and protein expression in the liver tissue of immunologically induced hepatic fibrosis rats. The possibility of reversing hepatic fibrosis through gene therapy was observed. METHODS: Human serum albumin (HSA) was used to attack rats, as hepatic fibrosis model, in which asONs were used to block the gene and protein expressing TIMP-1. According to the analysis of modulator, structure protein, coding series of TIMP-1 genome, we designed four different asONs. These asONs were injected into the hepatic fibrosis models through coccygeal vein. The results was observed by RT-PCR for measuring TIMP-1 mRNA expression, immunohistochemistry and in situ hybridization for collagen I, II, special staining of collagen fiber, and electron microscopic examination. RESULTS: Hepatic fibrosis could last within 363 days in our modified model. The expressing level of TIMP-1 was high during hepatic fibrosis process. It has been proved by the immunohistochemical and the electron microscopic examination that the asON phosphorthioate of TIMP-1 could exactly express in vivo. The effect of colchicine was demonstrated to inhibit the expressing level of mRNA and the content of collagen I, III in the liver of experimental hepatic fibrosis rats. However, the electron microscopy research and the pathologic grading of hepatic fibrosis showed that there was no significant difference between the treatment group and the model group (P】 0.05). CONCLUSION: The experimental rat model of hepatic fibrosis is one of the preferable models to estimate the curative effect of anti-hepatic fibrosis drugs. The asON phosphorthioate of TIMP-1 could block the gene and protein expression of TIMP-1 in the liver of experimental hepatic fibrosis rats at the mRNA level. It is possible to reverse hepatic fibrosis, and it is expected to study a new drug of antihepatic fibrosis on the genetic level. Colchicine has very limited therapeutic effect on hepatic fibrosis, furthermore, its toxicity and side effects are obvious.

Obstructive Effects of Ultrasonic Microbubble Intensifier on CHG-5 Cell with Survivin Antisense Oligonucleotides Transfection

Objective： To study the effects on human glioma cell line CHG-5 by ultrasonic microbubble intensifier with survivin antisense oligonucleotides （ASODN） transfection. Methods： Antisense oligonucleotides targeting survivin mRNA was designed and synthesized. Four regimen groups were designed, group A： survivin antisense oligonucleotides transfected with ultrasonic microbubble intensifier combined with ultrasound irradiation, group B： survivin antisense oligonucleotides transfected with lipofectamine combined with ultrasound irradiation, group C： survivin antisense oligonucelotides with lipofectamine transfection, group D： blank control. The expression changes of surviving protein were measured by immunohistochemical staining and Western blotting, and MTT assay was used to measure the changes of proliferation. Results： Survivin protein expression in group A was decreased significantly in human glioma cell line CHG-5 than other groups（P〈0.05）, and the proliferating rate of CHG-5 in group A was also significantly inhibited（P〈0.05）. Conclusion： Ultrasonic microbubble intensifier transfection combined with ultrasound irradiation is a promising method in gene transfection effectively and noninvasively.

SELECTION AND THEIR ANTITUMOR ACTIVITY OF ANTISENSE OLIGONUCLEOTIDES TARGETING MESSENGER RNA OF VASCULAR ENDOTHELIAL GROWTH FACTOR RECEPTOR 2

Objective： To select the antisense oligonucleotides （asONs） which hybridize with the mRNA of vascular endothelial growth factor receptor2 （VEGFR2, also named as kinase insert domain-containing receptor：KDR） in an effective and specific way, and to investigate their antitumor activity in MCF-7 cells. Methods： The effective antisense oligonucleotides were chosen by computer prediction combined with oligonucleotide microarrays. The inhibition effect on MCF-7 cells proliferation was measured by MTT; and VEGFR2 expression was surveyed by Western-blotting and RT- PCR. Results： Using predicting secondary structure of VEGFR2 mRNA with RNA folding program, computer prediction designed 30 antisense oligonucleotide probes that were directed to local loose regions of RNA structure. In 30 probes, 4（4/30, 13.33%） antisense oligonucleotides showed strong hybridization intensities in oligonucleotide microarrays test and were selected. All these antisense oligonucleotides targeting 4 different sites of VEGFR2 mRNA lowered the level of VEGFR2 mRNA and protein present in MCF-7 cells. Proliferation of MCF-7 cells was reduced by 4 antisense oligonucleotides, respectively, in which asON1 was the most effective, with the inhibitory rates being 53.06% at 0.8 I.tmol/L. Conclusion： Combination of computer prediction with oligonucleotide microarrays is an effective way in selecting optimal antisense oligonucleotides. The antisense oligonucleotides showed good correlation between their antitumor activity and the hybridization intensities. The antisense oligonucleotides targeting VEGFR2 mRNA demonstrated prominent antitumor role in vitro.

P53 Regulation of Leukemia Cells with the Blockage of MDM2 by Antisense Oligonucleotides

Summary： The changes of expression and function of MDM2 and P53 by MDM2 specific antisense oligonucleotides were investigated in HL60 cells. Cells were divided into control group, AS group （MDM2 specific antisense oligonucleotides group）, cisplatin group, and combined treatment group. FCM analysis and Western blot and RT-PCR were used to estimate apoptosis and the expression of MDM2 and P53. Our results showed that the transfection of MDM2 specific antisense oligonucleotides obviously inhibited MDM2 expression （P〈0.01） and increased the expression of P53 （P〈0.05）. Apoptosis rate were reduced by MDM2 specific antisense oligonucletides and cisplatin （P〈0.01）. It is concluded that MDM2 specific antisense oligonucletides can inhibit the expression of MDM2, induce the expression of P53 and increase the apoptosis of leukemia cells after chemotherapy.

Antitumor effects of mutant endostatin are enhanced by Bcl-2 antisense oligonucleotides in UM-UC-3 bladder cancer cell line

Background Endostatin is a potent inhibitor of tumor angiogenesis. In the preliminary studies, we developed a mutant endostatin containing Arg-Gly-Asp-Arg-Gly-Asp （RGDRGD） sequences. In this study, we compared the antitumor effects of mutant endostatin and Bcl-2 antisense oligonucleotides both in combination and individually. Methods The artificially synthesized Bcl-2 ASODN （antisense oligonucleotides） included a translation-initiation site and was transfected into the bladder cancer cells by Lipofectamine. Cell growth was investigated by the tumor cell growth chart, MTT assay, caspase-3 activity detection assay, AO/EB fluorescein stain, and the annexin V-FITC apoptosis detection assay. In the in vivo study, UM-UC-3 bladder cancer cells were subcutaneously implanted into nude mice and the growth of tumor was examined. The ultrastructure of the tumor tissues in the treated and control groups were observed. Results The cell growth chart showed that the cell population of the treated combination group decreased by 52.04% compared to the control group. The inhibition rate of the treated combination group was （79.66＋6.79）%, whereas those of the individual ASODN and ES groups were （53.39＋3.22）% and （50.22＋5.46）% respectively. In the caspase-3 activity detection using AO/EB fluorescein stain and annexin V-FITC apoptosis detection assay, the co-inhibitory effect was higher than the individual inhibitory effects （P〈0.05）. There were significant differences in the inhibition of the solid tumor growth in the in vivo study. Conclusions Our findings indicated that Bcl-2 antisense oligonucleotides enhance the antitumor effects of mutant endostatin both in vitro and in vivo. We noted the synergistic effects of Bcl-2 antisense oligonucleotides combined with mutant endostatin.

Inhibitory effect of 2＇-o-methoxyethyl-modified antisense oligonucleotides targeting vascular endothelial growth factor A on SKOV3 human ovarian cancer cells

Background Ovarian cancers are often at an advanced stage at diagnosis because early detection is difficult. The poor prognosis of ovarian cancers highlights the crucial need to develop better therapeutic agents and strategies. The objective of this study was to investigate the inhibitory effects of a new modified antisense oligonucleotides targeting vascular endothelial growth factor A （VEGF-A） in SKOV3 ovarian cancer cells.Methods Antisense oligonucleotides targeting VEGF-A was designed, synthesized and transfected into SKOV3ovarian cancer cells. Western blotting and real-time RT-PCR were used to analyze the inhibitory effects of antisense oligonucleotides on VEGF-A protein and mRNA expression. Transwell matrix assay was used to detect cell migration inhibition.Results The antisense oligonucleotides targeting VEGF-A significantly decreased VEGF-A protein and mRNA expression and inhibited cell migration in SKOV3 ovarian cancer cells.Conclusions This new modified antisense oligonucleotides targeting VEGF-A can decrease VEGF-A expression and inhibit cell migration in SKOV3 ovarian cancer cells. This new oligonucleotides may be a promising therapeutic agent for ovarian cancers

Bladder cancer therapy using combined proliferating cell nuclear antigen antisense oligonucleotides and recombinant adenovirus p53

Objective To evaluate the antitumor efficacy of proliferating cell nuclear antigen antisense oligonucleotide (PCNA-ASO) in combination with recombinant adenovirus p53 (Ad-p53) against bladder cancer EJ and BIU-87 cells in vitro and in vivo. Methods Cells were transfected with Ad-p53 (100 MOI), and PCNA-ASO (1.6 μmol/L) was then introduced into the cells using a cationic lipid (lipofectamine, 20 μl/ml). In vitro and in vivo antitumor effects of combining PCNA-ASO with Ad-p53 were measured using the MTT assay, flow cytometry, clone formation, and a nude mice model. Results The combination of PCNA-ASO and Ad-p53 inhibited cell viability in both the EJ (89.3%) and BIU-87 (78.6%) cell lines. The ability of the cells to form foci was also reduced by 74.8% in EJ cells and by 67.5% in BIU-87 cells (P<0.01). A significant decrease of cells in the S phase (11.4% in EJ cells, 14.6% in BIU-87 cells) and a significant increase of cells in G1 phase (62.2% in EJ, 56.8% in BIU-87) were noted. The mean tumor volume after 7 days of treatment with PCNA-ASO or Ad-p53 in combination decreased to 47.6% or 36.4% of the initial tumor size in the two cell lines respectively. Conclusion These results indicate that combined PCNA-ASO and Ad-p53 in the treatment of bladder cancer with mutant p53 has important therapeutic potential, significantly suppressing the growth of human bladder cancer both in vitro and in vivo.

Apoptosis of drug-resistant human ovarian carcinoma cell line COCl/DDP induced by survivin antisense oligonucleotides

Currently, surgery-oriented treatment plays a major role in the treatment of ovarian cancer patients. But 5-year survival rate of patients is still around 30%. One of the main reasons for the low survival rate is the drug resistance of tumor cells against chemotherapy. The function of anti- apoptosis in the course of initiation and progress of cancer has a close relationship with drug resistance of tumor cells. Survivin is a new discovered anti-apoptosis gene, its expression levels correlating with more aggressive disease and poor clinical outcome in many of these tumors. It has been reported that survivin is expressed during fetal development and in cancer tissues. Furthermore, survivin overexpression, by disrupting the balance between cell proliferation/differentiation and apoptosis, may relate with the resistance to a variety of apoptotic stimuli, including chemotherapy. We designed antisense oligonucleotides of survivin to treat the drug-resistant human ovarian carcinoma cell line COC1/DDP, and studied its effects on inducing COC1/DDP apoptosis. The purpose of this study was to find a novel approach to improve the sensitivity of ovarian carcinoma chemotherapy.

Antisense therapy:a potential breakthrough in the treatment of neurodegenerative diseases

Neurodegenerative diseases are a group of disorders characterized by the progressive degeneration of neurons in the central or peripheral nervous system.Currently,there is no cure for neurodegenerative diseases and this means a heavy burden for patients and the health system worldwide.Therefore,it is necessary to find new therapeutic approaches,and antisense therapies offer this possibility,having the great advantage of not modifying cellular genome and potentially being safer.Many preclinical and clinical studies aim to test the safety and effectiveness of antisense therapies in the treatment of neurodegenerative diseases.The objective of this review is to summarize the recent advances in the development of these new technologies to treat the most common neurodegenerative diseases,with a focus on those antisense therapies that have already received the approval of the U.S.Food and Drug Administration.

Effect of Bcl-2 Antisense Oligodeoxynucleotides on Human Lung Carcinoma Transplanted Subcutaneously in Nude Mice

Objective： To investigate the inhibitory effects of the Bcl-2 antisense oligodeoxynucleotides （ASODN） on tumor formation and growth of human lung carcinoma transplanted subcutaneously in nude mice. Methods： Human NCI-H460 cells treated with Bcl-2 ASODN or nonesense oligodeoxynucleotide （NSODN） and untreated NCI-H460 cells were respectively implanted subcutaneously into nude mice. When the diameters of tumor were above 0.5 cm after untreated NCI-H460 cells injection, the mice bearing tumor were randomly divided into three groups： saline control group, Bcl-2 ASODN group, NSODN group. ODN was directly injected into the tumor body for 3 weeks. The weight and volume of subcutaneous tumors were measured, and the morphology of tumor cells was observed. Results： The tumorigenic ability of the treated NCI-H460 cells by Bcl-2 ASODN was reduced. The mean time at which tumor can be detected was prolonged up to 12.6 days （P〈0.01）. The maximum tumor growth inhibitory rate was 87.5%. In therapeutic efficacy, growth of tumor was significantly inhibited in Bcl-2 ASODN group as compared with that in NSODN group, saline-treated group （P〈0.01）. The NSODN control was ineffective. In comparison with NSODN-treated, saline-treated mice, those treated with Bcl-2 ASODN showed a significant decrease in median weight of subcutaneous tumors （P〈0.01）. The growth inhibitory rate was 71.0% in ASODN group. Conclusion： Bcl-2 ASODN could inhibit tumor formation and tumor growth in nude mice.

Heat shock protein 70 antisense oligonucleotide inhibits cell growth and induces apoptosis in human gastric cancer cell line SGC-7901

AIM: Heat shock protein (HSP)70 is over-expressed in human gastric cancer and plays an important role in the progression of this cancer. We investigated the effects of antisense HSP70 oligomer on human gastric cancer cell line SGC-7901, and its potential role in gene therapy for this cancer.METHODS: Human gastric cancer cell line SGC-7901 was treated in vitro with various concentrations of antisense HSP70 oligonucleotides at different intervals. Growth inhibition was determined as percentage by trypan blue dye exclusion test. Extracted DNA was electrophoresed on agarose gel, and distribution of cell cycle and kinetics of apoptosis induction were analyzed by propidium iodide DNA incorporation using flow cytometry, which was also used to detect the effects of antisense oligomer pretreatment on the subsequent apoptosis induced by heat shock in SGC-7901 cells. Proteins were extracted for simultaneous measurement of HSP70 expression level by SDS-PAGE Western blotting.RESULTS: The number of viable cells decreased in a doseand time-dependent manner, and ladder-like patterns of DNA fragments were observed in SGC-7901 cells treated with antisense HSP70 oligomers at a concentration of 10 μmol/L for 48 h or 8 μmol/L for 72 h, which were consistent with inter-nucleosomal DNA fragmentation. Flow cytometric analysis showed a dose- and time-dependent increase in apoptotic rate by HSP70 antisense oligomers. This response was accompanied with a decrease in the percentage of cells in the G1 and S phases of the cell cycle, suggesting inhibition of cell proliferation. In addition, flow cytometry also showed that pretreatment of SGC-7901 cells with HSP70 antisense oligomers enhanced the subsequent apoptosis induced by heat shock treatment. Western blotting demonstrated that HSP70 antisense oligomers inhibited HSP70 expression, which preceded apoptosis, and HSP70 was undetectable at the concentration of 10 μmol/L for 48 h or 8 μmol/L for 72 h.CONCLUSION: Antisense HSP70 oligomers can abrogate HSP70 expression in SGC-7901 cells, which may in turn induce apoptosis and inhibit cell proliferation, conversely suggesting that HSP70 is required for the proliferation and survival of human gastric cancer cells under normal conditions.

Effect of VEGF-targeted antisense gene therapy on retinoblastoma cell line SO-RB50 in vitro and in vivo

AIM: To evaluate the possibility of generation 4 polyamidoamine (G4PAMAM) dendrimers acting as the delivery system of vascular endothelial growth factor (VEGF) antisense oligodeoxynucleotides (VEGFASODN), and to investigate the anti-tumor effect of G4PAMAM/VEGFASODN complex on the cultured cells and the mouse tumor xenograft model. METHODS: The transfection efficiency was assessed by Row cytometry (FCM). Thiazolyl tetrazolium (MU) assay was performed to determine the relative growth rate (RGR) of the cells after transfection. Then a mouse tumor xenograft model of human retinoblastoma was established. Different interventions were given to the mice by intratumoral injection and the tumor growth was monitored. The expression of VEGF mRNA was detected by reverse transcription PCR (RT-PCR), the expression of VEGF protein was determined by western blot analysis, and the microvessel density (MVD) was measured by immunohistochemistry (IHC) staining. RESULTS: G4PAMAM/VEGFASODN exhibited a high transfection rate in vitro, and the transfection rates of different doses of G4PAMAM/VEGFASODN groups increased with higher doses. This effect was accompanied by a dose-depended reduction in cell viability. The tumor growth in the tumor-bearing athymic mice was significantly inhibited in the G4PAMAM/VEGFASODN group. The expressions of VEGF mRNA and protein were obviously inhibited in the G4PAMAM/VEGFASODN group (p<0.05), and the MVD of the G4PAMAM/VEGFASODN group was lower than that of the other groups(p<0.05). CONCLUSION: VEGFASODN can be delivered into the cultured and transplanted retinoblastoma cells efficiently by G4PAMAM, suppress the expressions of VEGF mRNA and protein, and reduce the MVD of tumor tissues. The G4PAMAM/VEGFASODN complex has antitumor properties vitro and in vivo.