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 ...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.展开更多
Objective: To explore and investigate the selection of effective antisense oligodeoxynuleotides with the help of computer and RNAstructure folding software. Methods: Bcl-2 gene was used as the target gene and five a...Objective: To explore and investigate the selection of effective antisense oligodeoxynuleotides with the help of computer and RNAstructure folding software. Methods: Bcl-2 gene was used as the target gene and five antisense oligodeoxynuleotides were designed to be bound to Bcl-2 mRNA optimal secondary structure regions that were predicted free from intramolecular fold or instability of free energy. The five antisense oligodeoxynucleotides were studied with experimental assay of leukemia cells, including cell grow assay with tropan blue exclusion, expression of Bcl-2 protein detected with immunochemistry and flowcytometry, Bcl-2 mRNA content detected with RT-PCR technique, as well as apoptosis observed and determined with morphonological method, electrophoresis and flowcytometry. Results: The results showed that two of the five antisense oligodeoxynucleotides were effective antisense oligodeoxynucleotides, which were able to inhibit cell growth in leukemia, to decrease the level of Bcl-2 mRNA and protein, to induce apoptosis of leukemia cells significantly. Conclusion: The computational prediction of antisense efficacy is faster than other methods and more efficient, which can potentially speed the development of sequences for both research and clinical applications.展开更多
Objective To study the differences and similarities of the antisense drugs with different structures on the biological functions of HL60 cells. Methods Cytotoxic effects were measured by cell viability assay. The e...Objective To study the differences and similarities of the antisense drugs with different structures on the biological functions of HL60 cells. Methods Cytotoxic effects were measured by cell viability assay. The expression levels of protein were assayed by immunofluorescence using fluoresce isothiocyanate label. The morphological changes in apoptotic cells were observed. Flow cytometric analysis of DNA fragmentation was also performed. Results Antisense peptide nucleic acid (PNA) targeting the coding region of the Bcl-2 mRNA could effectively inhibit the growth of HL60 cells, down-regulate the synthesis of Bcl-2 protein and induce apoptosis. After HL60 cells were treated with 10 μmol/L Bcl-2 antisense PNA or antisense oligonucleotide for 72 h respectively, apoptotic rates of HL60 cells were 17.80±1.53 and 13.17±1.12, respectively( P <0.05). Conclusion Antisense PNA targeting the coding region of Bcl-2 mRNA may have stronger antisense effects than the antisense oligonucleotides and could induce apoptosis of HL60 cells.展开更多
Objective: To investigate the effect of two antisense oligonucleotides on cell surviving, bcl-2 expression and apoptosis of leukemia cells. Methods: The experimental assays were performed with cell culture, immunochem...Objective: To investigate the effect of two antisense oligonucleotides on cell surviving, bcl-2 expression and apoptosis of leukemia cells. Methods: The experimental assays were performed with cell culture, immunochemistry and flowcytometry. Results: The two antisense oligodeoxynucleotides, combined with Vp16 or Ara-c or DNR, were able to decline the survival rate of myeleukemic cells, downregulate bcl-2 gene expression and induce apoptosis of leukemic cells significantly, as compared with Vp16 or Ara-c or DNR alone. Conclusion: It is possible for the two new bcl-2 antisenses to be developed into clinical trials for leukemia and tumor with bcl-2 gene overexpression. Key words Leukemia - Antisense oligodeoxynucleotides - bcl-2 gene - drug-resistance CLC number R733.7 Foundation item: this work was supported by the Key Foundation of Science & Technology Program of Guangzhou (No. 2001-Z-037-01); and the Nature Science key Foundation of Guangdong Province(No. 021195).Biography: LEI Xiao-yong(1970–), male, associate professor, doctor of medicine, Institute of Pharmacy and Pharmacology, Nanhua University, majors in tumor pharmacology.展开更多
Objective: To study the differences and similarities of the antisense drugs with different structures on the biological functions of K562 cells. Methods: Cytotoxic effects were measured by use of a cell viability assa...Objective: To study the differences and similarities of the antisense drugs with different structures on the biological functions of K562 cells. Methods: Cytotoxic effects were measured by use of a cell viability assay. Flow cytometric analysis and agarose gel electrophoresis of DNA fragmentation were also performed. The expression level of protein was assayed by immunofluorescence using fluoresce isothiocyanate label. Results: PNA targeting the coding region of the Bcl-2 messenger RNA could effectively inhibit K562 cell viability, down-regulate the synthesis of the Bcl-2 protein and increase cell apoptosis. By 72 h after the Bcl-2 antisense PNA treatment, K562 cells showed more reduction in the level of Bcl-2 protein compared with cells treated with the antisense ODN. After treatment with 10 μmol/L of Bcl-2 antisense PNA or antisense ODN for 72 h, apoptotic rates of K562 cells were 13.15±1.13 and 11.72±1.12, respectively. Furthermore, there was significant difference in the percentage of apoptotic cells between antisense PNA group and antisense ODN group. Conclusion: The results suggest that antisense PNA targeting the coding region of Bcl-2 mRNA has better antisense effects than the antisense oligonucleotides on inducing apoptosis of K562 cells. Key words Bcl-2 - Antisense peptide nucleic acid - Antisense oligonucleotide - K562 cells - Apoptosis CLC number Q255 Foundation item: This work was supported by the Key Foundation of Science & Technology Program of Guangzhou (No.2001-Z-037-01), and the Nature Science Key Foundation of Guangdong Province (No. 021195).Biography: LEI Xiao-yong(1970–), male, associate professor, doctor of medicine, Institute of Pharmacy and Pharmacology, Nanhua University, majors in tumor pharmacology.展开更多
Objective: To analyze the effect of bcl-2 antisense RNA on the apoptosis of promyelocytic cell line HL-60. Methods: A plasmid pDOR-AB containing bcl-2 antisense cDNA was trans fected into HL-6O cells by lipofectin, an...Objective: To analyze the effect of bcl-2 antisense RNA on the apoptosis of promyelocytic cell line HL-60. Methods: A plasmid pDOR-AB containing bcl-2 antisense cDNA was trans fected into HL-6O cells by lipofectin, and the effect of transfection was assured by DNA and RNA dot blottingI the change of bcl-2 expression and cell cycle was tested by flow cytometry; a morphologica1 change was observed by light microscope and electron microscope; and finally the sensitivity of trans fected cells to etoposide was compared with that of non-trans fected cells by gel electrophoresis. Results: pDOR-AB was successfully trans fected into HL-6o cells and its transcript was observed; Bcl-2 was down-regulated significantly ; apoptosis peak appeared before G1 phase in flow cy-tometry analysis: apoptotic cells could be seen by electron microscope, and during DNA gel electrophoresis the DNA ladder apppeared more frequently in the group trans fected with pDOR-AB than in transfected with pDOR and untransfected groups. Conclusion: Transient expression of bcl-2 antisense RNA can promote apoptosis of HL-60 cells and bco-2 plays a key role in the apoptosis of HL-60 cells.展开更多
OBJECTIVE To explore the effect of liposomal G3139 and transfected antisense phosphorothioate oligodeoxynucleotides directed against the coding region of the bcl-2 messenger RNA and the translation site on apoptosis i...OBJECTIVE To explore the effect of liposomal G3139 and transfected antisense phosphorothioate oligodeoxynucleotides directed against the coding region of the bcl-2 messenger RNA and the translation site on apoptosis in Raji cells.METHODS Cytotoxic effects were measured by use of the MTT method; The expression levels of Bcl-2 protein were assayed by immunofiuorescence using a fluoresce isothiocyanate label. Apoptosis was determined by morphological observation and flow cytometric analysis.RESULTS The 2 antisense oligonucleotides and G3139 can reduce Bcl-2 protein levels and Raji cell viability (IC50=4.54, 4.72 and 4.26 μmol/L, respectively), and induce apoptosis. A scrambled sequence control oligonucleotide and empty liposomes did not alter cell viability, Bcl-2 protein expression or apoptosis rates. There was no difference in reducing Bcl-2 protein levels and apoptosis rates found among the 3 antisense oligonucleotides.CONCLUSION The 2 antisense oligodeoxynucleotides of bcl-2 messenger RNA can effectively induce apoptosis of Raji cells. The 2 antisense sequences and G3139 have a similarity in their antisense effect.展开更多
AIM To compare the expression level of Fas gene and Bcl-2 gene in gastric cancer cells SGC7901 and gastric cancer MDR (multidrug resistant) cells SGC7901/VCR, to transduce Fas cDNA and Bcl-2 antisense nucleic acid int...AIM To compare the expression level of Fas gene and Bcl-2 gene in gastric cancer cells SGC7901 and gastric cancer MDR (multidrug resistant) cells SGC7901/VCR, to transduce Fas cDNA and Bcl-2 antisense nucleic acid into SGC7901/VCR cells respectively, and to observe the expression of two genes in transfectants and non-transfectants as well as their drug sensitivity.METHODS Eukaryotic expression vector pBK-Fas cDNA and pDOR-anti Bcl-2 were constructed and transfected into SGC7901/VCR cells by lipofectamine, respectively. Northern blot and Western blot were used to detect the expression of mRNA and protein in SGC7901/VCR and SGC7901 cells and transfectants, and drug sensitivity of transfectants for VCR, CDDP and 5-FU was analyzed with MTT assay.RESULTS After gene transfection, 80 for Fas and 120 for antisense Bcl-2 drug-resistant clones were selected from 2×105 cells, transfection rate being 0.04% and 0.06%. Two clones of SGC7901 Fas/VCR cells and SGC7901 anti Bcl-2/VCR cells were randomly selected for further incubation. Hybridization results showed that the expression level of Fas mRNA and protein in SGC7901/VCR cells was much lower, but that of Bcl-2 mRNA and protein was higher than that in SGC7901 cells. The expression of Fas mRNA and protein in SGC7901 Fas/VCR cells was higher, and of Bcl-2 mRNA and protein was lower in SGC7901 anti Bcl-2/VCR cells than that in non-transfectants. MTT assay showed that transfectants were more sensitive to VCR, CDDP, 5-FU than non-transfectants.CONCLUSION Bcl-2 gene displayed high expression while Fas gene had low expression in drug resistant gastric cancer cells. Expression of Bcl-2 protein was effectively blocked in SGC7901 anti Bcl-2/VCR cells by gene transfection. In contrast, the expression of Fas mRNA and protein in SGC7901 Fas/VCR cells increased. Fas gene and Bcl-2 antisense nucleic acid transfection sensitized drug resistant gastric cancer cells to chemotherapeutic drugs. These results suggest cell apoptosis plays an important role in the mechanism of MDR, and enhancing apoptosis might reverse MDR.展开更多
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 a...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.展开更多
Antisense oligonucleotides (oligos) have targeted growth regulatory proteins in prostate cancer models. To identify compensatory alterations in the expression of non-targeted genes we evaluate mono- and bispecific oli...Antisense oligonucleotides (oligos) have targeted growth regulatory proteins in prostate cancer models. To identify compensatory alterations in the expression of non-targeted genes we evaluate mono- and bispecific oligos targeting and equally suppressing the expression of the apoptosis inhibitory protein bcl-2. Bcl-2 is chosen because oligos directed towards it have entered clinical trials to restore apoptosis in cancer patients. Treated LNCaP cells compensate for the diminished bcl-2 by suppressing caspase-3 (an apoptosis promoter) while enhancing expression of AKT-1 (another apoptosis inhibitor), androgen receptor (AR) and its (p300 and IL-6) coactivators. Additional proteins are enhanced including PD-1, its ligand PD-L1 (immune checkpoint blockade markers) and fas-ligand, which activate apoptosis through the signal transduction, along with suppressor protein p53, polymerase transcription mediator MED-12 and signal transducer STAT-3. These alterations in expression may contribute to a greatly enhanced expression of the proliferation marker KI-67. This suggests that therapeutic approaches to restore apoptosis through suppression of bcl-2 lead to an altered expression in non-targeted genes involving apoptosis, androgen sensitivity, transcriptional activity and immune responsiveness, leads to an increase in proliferation (and a more androgen driven aggressive phenotype). In this study we evaluate the expression of two oncogenes (v-myc and K-ras) and find a large and significant enhancement of v-myc activity, which is produced by oligos targeting bcl-2 at the 5’ position. For K-ras, although significant suppression is produced by the bispecific targeting bcl-2 at the 3’ position, the percent change is relatively small compared with other compensatory alterations we have measured, and much less than in v-myc. Therefore, for the two oncogenes being evaluated, only increased v-myc activity is probably large enough to contribute to increased tumor aggressiveness in compensation for bcl-2 suppression.展开更多
Previously we have shown that when LNCaP cells are treated with antisense oligonucleotides (oligos) directed against BCL-2, compensatory changes in non-targeted genes take place in attempts to restore apoptosis and pr...Previously we have shown that when LNCaP cells are treated with antisense oligonucleotides (oligos) directed against BCL-2, compensatory changes in non-targeted genes take place in attempts to restore apoptosis and promote tumor aggressiveness. In addition to the inhibition of BCL-2, we find that the apoptosis promoter caspase-3 activity is suppressed, the transcription activity of STAT-3 is enhanced, while other regulators (bax, clusterin, AKT-1) associated with mitochondrial regulated apoptosis and caspase cascade are either unchanged or undetectable. We now evaluate proteins associated with the second pathway of apoptosis activation mediated by direct signal transduction involving fas, fas-ligand (a tumor necrosis factor-like cell surface receptor aka CD95), as well as the similar programmed death cell surface receptor (PD-1) and its respective ligand (PD-1L). This study evaluates the growth inhibition of in vitro propagating LNCaP cells employing mono- and bispecific oligos directed against BCL-2 [the second binding site was directed against the epidermal growth factor receptor (EGFR)];and employing RT-PCR. The expression of these four proteins was evaluated. Expression of fas-ligand, PD-1 and PD-L1 were all significantly enhanced, whereas fas itself was undetectable. This suggests that in addition to pathways associated with the mitochondrial pathway of apoptosis, compensatory changes occur in the direct signal transduction pathway of this process. In addition to alterations in androgen sensitivity, growth factor expression and oncogene expression, these data suggest that suppressive BCL-2 therapy involves multiple pathways, including those involved with immune targeting and cytotoxicity and must be taken into account to make gene therapy more efficacious.展开更多
AIM To demonstrate whether bcl 2 gene can affect or alter biological behavior of a stomach carcinoma cell line MGC 803. METHODS To transduct a retrovirus containing bcl 2 antisense RNA to MGC 803 cells ...AIM To demonstrate whether bcl 2 gene can affect or alter biological behavior of a stomach carcinoma cell line MGC 803. METHODS To transduct a retrovirus containing bcl 2 antisense RNA to MGC 803 cells and then to analyse the Bcl 2 protein expression in the cells by Western blotting. To observe the morphology alteration, detect the G1 phase arrest by FCM, inhibition of proliferation by MTT method and tumorigenicity in nude mice. RESULTS The MGC anti bcl 2 cells shows contact inhibition, morphological alteration, from round or near round to shuttle like, decelerated growth rate, G1 phase arrest and weakened tumorigenicity in nude mice unlike the control (MGC neo cells). CONCLUSION Antisense RNA to bcl 2, not only can induce apoptosis, but also reverse the biological behavior of MGC 803 cells. This would be a potential application to the gene therapy for stomach cancers.展开更多
基金This project was supported by Natural Science Program Foundation of the Guangdong Provincial (021195) and The GuangzhouCity Key Foundation of Science and Technology Program (2001-Z-037-01)
文摘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.
文摘Objective: To explore and investigate the selection of effective antisense oligodeoxynuleotides with the help of computer and RNAstructure folding software. Methods: Bcl-2 gene was used as the target gene and five antisense oligodeoxynuleotides were designed to be bound to Bcl-2 mRNA optimal secondary structure regions that were predicted free from intramolecular fold or instability of free energy. The five antisense oligodeoxynucleotides were studied with experimental assay of leukemia cells, including cell grow assay with tropan blue exclusion, expression of Bcl-2 protein detected with immunochemistry and flowcytometry, Bcl-2 mRNA content detected with RT-PCR technique, as well as apoptosis observed and determined with morphonological method, electrophoresis and flowcytometry. Results: The results showed that two of the five antisense oligodeoxynucleotides were effective antisense oligodeoxynucleotides, which were able to inhibit cell growth in leukemia, to decrease the level of Bcl-2 mRNA and protein, to induce apoptosis of leukemia cells significantly. Conclusion: The computational prediction of antisense efficacy is faster than other methods and more efficient, which can potentially speed the development of sequences for both research and clinical applications.
文摘Objective To study the differences and similarities of the antisense drugs with different structures on the biological functions of HL60 cells. Methods Cytotoxic effects were measured by cell viability assay. The expression levels of protein were assayed by immunofluorescence using fluoresce isothiocyanate label. The morphological changes in apoptotic cells were observed. Flow cytometric analysis of DNA fragmentation was also performed. Results Antisense peptide nucleic acid (PNA) targeting the coding region of the Bcl-2 mRNA could effectively inhibit the growth of HL60 cells, down-regulate the synthesis of Bcl-2 protein and induce apoptosis. After HL60 cells were treated with 10 μmol/L Bcl-2 antisense PNA or antisense oligonucleotide for 72 h respectively, apoptotic rates of HL60 cells were 17.80±1.53 and 13.17±1.12, respectively( P <0.05). Conclusion Antisense PNA targeting the coding region of Bcl-2 mRNA may have stronger antisense effects than the antisense oligonucleotides and could induce apoptosis of HL60 cells.
基金this work was supported by the Key Foundation of Science & Technology Program of Guangzhou (No. 2001-Z-037-01) and the Nature Science key Foundation of Guangdong Province(No. 021195).
文摘Objective: To investigate the effect of two antisense oligonucleotides on cell surviving, bcl-2 expression and apoptosis of leukemia cells. Methods: The experimental assays were performed with cell culture, immunochemistry and flowcytometry. Results: The two antisense oligodeoxynucleotides, combined with Vp16 or Ara-c or DNR, were able to decline the survival rate of myeleukemic cells, downregulate bcl-2 gene expression and induce apoptosis of leukemic cells significantly, as compared with Vp16 or Ara-c or DNR alone. Conclusion: It is possible for the two new bcl-2 antisenses to be developed into clinical trials for leukemia and tumor with bcl-2 gene overexpression. Key words Leukemia - Antisense oligodeoxynucleotides - bcl-2 gene - drug-resistance CLC number R733.7 Foundation item: this work was supported by the Key Foundation of Science & Technology Program of Guangzhou (No. 2001-Z-037-01); and the Nature Science key Foundation of Guangdong Province(No. 021195).Biography: LEI Xiao-yong(1970–), male, associate professor, doctor of medicine, Institute of Pharmacy and Pharmacology, Nanhua University, majors in tumor pharmacology.
基金This work was supported by the KeyFoundation of Science & Technology Program of Guangzhou(No.2001-Z-037-01) and the Nature Science Key Foundationof Guangdong Province (No. 021195).
文摘Objective: To study the differences and similarities of the antisense drugs with different structures on the biological functions of K562 cells. Methods: Cytotoxic effects were measured by use of a cell viability assay. Flow cytometric analysis and agarose gel electrophoresis of DNA fragmentation were also performed. The expression level of protein was assayed by immunofluorescence using fluoresce isothiocyanate label. Results: PNA targeting the coding region of the Bcl-2 messenger RNA could effectively inhibit K562 cell viability, down-regulate the synthesis of the Bcl-2 protein and increase cell apoptosis. By 72 h after the Bcl-2 antisense PNA treatment, K562 cells showed more reduction in the level of Bcl-2 protein compared with cells treated with the antisense ODN. After treatment with 10 μmol/L of Bcl-2 antisense PNA or antisense ODN for 72 h, apoptotic rates of K562 cells were 13.15±1.13 and 11.72±1.12, respectively. Furthermore, there was significant difference in the percentage of apoptotic cells between antisense PNA group and antisense ODN group. Conclusion: The results suggest that antisense PNA targeting the coding region of Bcl-2 mRNA has better antisense effects than the antisense oligonucleotides on inducing apoptosis of K562 cells. Key words Bcl-2 - Antisense peptide nucleic acid - Antisense oligonucleotide - K562 cells - Apoptosis CLC number Q255 Foundation item: This work was supported by the Key Foundation of Science & Technology Program of Guangzhou (No.2001-Z-037-01), and the Nature Science Key Foundation of Guangdong Province (No. 021195).Biography: LEI Xiao-yong(1970–), male, associate professor, doctor of medicine, Institute of Pharmacy and Pharmacology, Nanhua University, majors in tumor pharmacology.
文摘Objective: To analyze the effect of bcl-2 antisense RNA on the apoptosis of promyelocytic cell line HL-60. Methods: A plasmid pDOR-AB containing bcl-2 antisense cDNA was trans fected into HL-6O cells by lipofectin, and the effect of transfection was assured by DNA and RNA dot blottingI the change of bcl-2 expression and cell cycle was tested by flow cytometry; a morphologica1 change was observed by light microscope and electron microscope; and finally the sensitivity of trans fected cells to etoposide was compared with that of non-trans fected cells by gel electrophoresis. Results: pDOR-AB was successfully trans fected into HL-6o cells and its transcript was observed; Bcl-2 was down-regulated significantly ; apoptosis peak appeared before G1 phase in flow cy-tometry analysis: apoptotic cells could be seen by electron microscope, and during DNA gel electrophoresis the DNA ladder apppeared more frequently in the group trans fected with pDOR-AB than in transfected with pDOR and untransfected groups. Conclusion: Transient expression of bcl-2 antisense RNA can promote apoptosis of HL-60 cells and bco-2 plays a key role in the apoptosis of HL-60 cells.
文摘OBJECTIVE To explore the effect of liposomal G3139 and transfected antisense phosphorothioate oligodeoxynucleotides directed against the coding region of the bcl-2 messenger RNA and the translation site on apoptosis in Raji cells.METHODS Cytotoxic effects were measured by use of the MTT method; The expression levels of Bcl-2 protein were assayed by immunofiuorescence using a fluoresce isothiocyanate label. Apoptosis was determined by morphological observation and flow cytometric analysis.RESULTS The 2 antisense oligonucleotides and G3139 can reduce Bcl-2 protein levels and Raji cell viability (IC50=4.54, 4.72 and 4.26 μmol/L, respectively), and induce apoptosis. A scrambled sequence control oligonucleotide and empty liposomes did not alter cell viability, Bcl-2 protein expression or apoptosis rates. There was no difference in reducing Bcl-2 protein levels and apoptosis rates found among the 3 antisense oligonucleotides.CONCLUSION The 2 antisense oligodeoxynucleotides of bcl-2 messenger RNA can effectively induce apoptosis of Raji cells. The 2 antisense sequences and G3139 have a similarity in their antisense effect.
文摘AIM To compare the expression level of Fas gene and Bcl-2 gene in gastric cancer cells SGC7901 and gastric cancer MDR (multidrug resistant) cells SGC7901/VCR, to transduce Fas cDNA and Bcl-2 antisense nucleic acid into SGC7901/VCR cells respectively, and to observe the expression of two genes in transfectants and non-transfectants as well as their drug sensitivity.METHODS Eukaryotic expression vector pBK-Fas cDNA and pDOR-anti Bcl-2 were constructed and transfected into SGC7901/VCR cells by lipofectamine, respectively. Northern blot and Western blot were used to detect the expression of mRNA and protein in SGC7901/VCR and SGC7901 cells and transfectants, and drug sensitivity of transfectants for VCR, CDDP and 5-FU was analyzed with MTT assay.RESULTS After gene transfection, 80 for Fas and 120 for antisense Bcl-2 drug-resistant clones were selected from 2×105 cells, transfection rate being 0.04% and 0.06%. Two clones of SGC7901 Fas/VCR cells and SGC7901 anti Bcl-2/VCR cells were randomly selected for further incubation. Hybridization results showed that the expression level of Fas mRNA and protein in SGC7901/VCR cells was much lower, but that of Bcl-2 mRNA and protein was higher than that in SGC7901 cells. The expression of Fas mRNA and protein in SGC7901 Fas/VCR cells was higher, and of Bcl-2 mRNA and protein was lower in SGC7901 anti Bcl-2/VCR cells than that in non-transfectants. MTT assay showed that transfectants were more sensitive to VCR, CDDP, 5-FU than non-transfectants.CONCLUSION Bcl-2 gene displayed high expression while Fas gene had low expression in drug resistant gastric cancer cells. Expression of Bcl-2 protein was effectively blocked in SGC7901 anti Bcl-2/VCR cells by gene transfection. In contrast, the expression of Fas mRNA and protein in SGC7901 Fas/VCR cells increased. Fas gene and Bcl-2 antisense nucleic acid transfection sensitized drug resistant gastric cancer cells to chemotherapeutic drugs. These results suggest cell apoptosis plays an important role in the mechanism of MDR, and enhancing apoptosis might reverse MDR.
文摘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.
文摘Antisense oligonucleotides (oligos) have targeted growth regulatory proteins in prostate cancer models. To identify compensatory alterations in the expression of non-targeted genes we evaluate mono- and bispecific oligos targeting and equally suppressing the expression of the apoptosis inhibitory protein bcl-2. Bcl-2 is chosen because oligos directed towards it have entered clinical trials to restore apoptosis in cancer patients. Treated LNCaP cells compensate for the diminished bcl-2 by suppressing caspase-3 (an apoptosis promoter) while enhancing expression of AKT-1 (another apoptosis inhibitor), androgen receptor (AR) and its (p300 and IL-6) coactivators. Additional proteins are enhanced including PD-1, its ligand PD-L1 (immune checkpoint blockade markers) and fas-ligand, which activate apoptosis through the signal transduction, along with suppressor protein p53, polymerase transcription mediator MED-12 and signal transducer STAT-3. These alterations in expression may contribute to a greatly enhanced expression of the proliferation marker KI-67. This suggests that therapeutic approaches to restore apoptosis through suppression of bcl-2 lead to an altered expression in non-targeted genes involving apoptosis, androgen sensitivity, transcriptional activity and immune responsiveness, leads to an increase in proliferation (and a more androgen driven aggressive phenotype). In this study we evaluate the expression of two oncogenes (v-myc and K-ras) and find a large and significant enhancement of v-myc activity, which is produced by oligos targeting bcl-2 at the 5’ position. For K-ras, although significant suppression is produced by the bispecific targeting bcl-2 at the 3’ position, the percent change is relatively small compared with other compensatory alterations we have measured, and much less than in v-myc. Therefore, for the two oncogenes being evaluated, only increased v-myc activity is probably large enough to contribute to increased tumor aggressiveness in compensation for bcl-2 suppression.
文摘Previously we have shown that when LNCaP cells are treated with antisense oligonucleotides (oligos) directed against BCL-2, compensatory changes in non-targeted genes take place in attempts to restore apoptosis and promote tumor aggressiveness. In addition to the inhibition of BCL-2, we find that the apoptosis promoter caspase-3 activity is suppressed, the transcription activity of STAT-3 is enhanced, while other regulators (bax, clusterin, AKT-1) associated with mitochondrial regulated apoptosis and caspase cascade are either unchanged or undetectable. We now evaluate proteins associated with the second pathway of apoptosis activation mediated by direct signal transduction involving fas, fas-ligand (a tumor necrosis factor-like cell surface receptor aka CD95), as well as the similar programmed death cell surface receptor (PD-1) and its respective ligand (PD-1L). This study evaluates the growth inhibition of in vitro propagating LNCaP cells employing mono- and bispecific oligos directed against BCL-2 [the second binding site was directed against the epidermal growth factor receptor (EGFR)];and employing RT-PCR. The expression of these four proteins was evaluated. Expression of fas-ligand, PD-1 and PD-L1 were all significantly enhanced, whereas fas itself was undetectable. This suggests that in addition to pathways associated with the mitochondrial pathway of apoptosis, compensatory changes occur in the direct signal transduction pathway of this process. In addition to alterations in androgen sensitivity, growth factor expression and oncogene expression, these data suggest that suppressive BCL-2 therapy involves multiple pathways, including those involved with immune targeting and cytotoxicity and must be taken into account to make gene therapy more efficacious.
文摘AIM To demonstrate whether bcl 2 gene can affect or alter biological behavior of a stomach carcinoma cell line MGC 803. METHODS To transduct a retrovirus containing bcl 2 antisense RNA to MGC 803 cells and then to analyse the Bcl 2 protein expression in the cells by Western blotting. To observe the morphology alteration, detect the G1 phase arrest by FCM, inhibition of proliferation by MTT method and tumorigenicity in nude mice. RESULTS The MGC anti bcl 2 cells shows contact inhibition, morphological alteration, from round or near round to shuttle like, decelerated growth rate, G1 phase arrest and weakened tumorigenicity in nude mice unlike the control (MGC neo cells). CONCLUSION Antisense RNA to bcl 2, not only can induce apoptosis, but also reverse the biological behavior of MGC 803 cells. This would be a potential application to the gene therapy for stomach cancers.