Effects of PKC-α asODN and PKA-ⅠasODN on growth and proliferation of the CNE-2Z cells of nasopharyngeal carcinoma

AIM:To investigate the effects of antisense oligonucleotides (asODN) of PKC-α and PKA-Ⅰon growth and proliferation of the CNE-2Z cells.METHODS:The expression of PKC-α and PKA-Ⅰ was observed with immunohistochemistry method. The asODNs of (1)PKC-α, (2)PKA-Ⅰ, (3)PKC-α and PKA-Ⅰ, were transfected into CNE-2Z cells by lipofectin (LP), and a random sequence as a control was used. The cell growth index (GI) and the clone formation rate of CNE-2Z were detected by MTT colorimetric assay and soft agar assy, respectively.RESULTS:The expression of PKC-α or PKA-Ⅰin CNE-2Z in experimental group were both significantly lower than that of control group(P<0.05). The GI and clone formation rates of CNE-2Z cells transfected by PKC-α and PKA-ⅠasODN with concentrations ranging from 0.05 μM to 1.00 μM were lower significantly than that of control groups(P<0.05), and there was a dose-dependent relationship among them. The inhibitory effects of PKC-α and PKA-ⅠasODNs both on the cell growth index (GI) and clone formation rates were more significant than that of control group(P<0.01),and the GI were significantly lower than that of the other experimental groups(P<0.05).CONCLUSION:PKC-α asODN and PKA-ⅠasODN inhibited CNE-2Z growth and proliferation in vitro, and a synergetic inhibitory effect of PKC-α asODN and PKA-ⅠasODN was also observed.     

EGCG depresses migration and invasion of human glioma cell line by downregulating COX-2 and MMP-2 expression

AIM: To investigate the mechanism that epigallocatechin-3-gallate (EGCG) depresses the migration and invasion in human glioma cell line SWO-38 by downregulation of cyclocxygenase-2(COX-2) and matrix metalloproteinase-2(MMP-2). METHODS: The effect of EGCG on the apoptosis of SWO-38 cell line was examined by the method of MTT. The migration and invasion of the SWO-38 cells were determined by Transwell assay. The expression of COX-2 and MMP-2 was measured by Western blotting. Meanwhile, TNF-α was used to stimulate the expression of COX-2 for determining if the mechanism of COX-2 pathway is involved in the inhibitory effect of EGCG on the migration and invasion of the tumor cells. RESULTS: After treated with EGCG for 24 h, the migration and invasion abilities of SWO-38 cells were lower than that of the cells before treatment. The results of Western blotting revealed that the 24 h treatment of EGCG on SWO-38 cell line inhibited the expression levels of COX-2 and MMP-2, indicating that the degradation of the extracellular matrix in SWO-38 cells was related to the COX-2 signaling pathway. CONCLUSION: EGCG inhibits the migration and invasion of SWO-38 cell line. The correlation between COX-2 expression and enzymatic degradation in the extracellular matrix determines the abilities of migration and invasion of tumor cells.     

Change of nestin expression in differentiation of human glioma cells induced by CDA-2

AIM: To investigate the change and significance of nestin expression in differentiation of human glioma cell line SWO-38 induced by CDA-2 (uroacitide, a healthy human urine extract). METHODS: Cellular differentiation of SWO-38 cells induced by CDA-2 was determined by light microscopy. The change of nestin expression in SWO-38 cells induced by CDA-2 was detected by munofluorescence, RT-PCR and Western blotting. RESULTS: Light microscopic observation revealed that CDA-2 induced SWO-38 cells to differentiate into astrocytes with increased cytoplasm and cytoplasmic processes and decreased nucleus/cytoplasm ratio. Nestin was expressed in cytoplasm and stained like filament by immunofluorescence staining. Nestin expression was downregulated in differentiated SWO-38 cells induced by CDA-2. CONCLUSION: Nestin expression is downregulated in differentiation of SWO-38 cells induced by CDA-2, which verifies the relationship between nestin expression and cell differentiation. Nestin may be a new differentiation marker of glioma.     

Contribution of eIF-4E inhibition to heparanase expression at both mRNA and protein levels in human colon adenocarcinoma cell line LS-174T

AIM: To determine whether the eukaryotic initiation factor-4E (eIF-4E) inhibition facilitates the degradation of heparanase mRNA and alters heparanase protein expression in human colon adenocarcinoma cell line, LS-174T. METHODS: A 20-mer antisense s-oligodeoxynucleotide (asODN) targeted against the translation start site of eIF-4E mRNA were introduced into LS-174T cells by lipid-mediated DNA-transfection. eIF-4E protein and mRNA levels were detected by Western blot and RT-PCR, respectively. The mRNA levels of heparanase were determined by Northern blot. The alterations of heparanase expression were confirmed by Western blot analysis. RESULTS: The 20-mer asODN against eIF-4E specifically and significantly inhibited eIF-4E protein expression. Following eIF-4E inhibition, a significant reduction of heparanase mRNA was observed on Northern blot, and at the same time, heparanase protein expression significantly decreased as well. CONCLUSIONS: The results indicate that the inhibition of eIF-4E strongly reduces the stability of heparanase mRNA in colon adenocarcinoma cell line, LS-174T and resultes in an apparent reduction in the expression of heparanase protein.     

Bcl-2 antisense oligodeoxynucleotide increases the sensitivity of HL60 and K562 cells to daunorubicin

AIM:To investigate whether the bcl-2 antisense oligonucleotide increases the sensitivity of HL60 and K562 cell lines to daunorubicin.METHODS:IC50 for HL60 and K562 was determined with MTT method, the expression levels of Bcl-2 protein were assayed by immunofluorescence using fluoresce isothiocyanate labeling. In addition, apoptosis was detected by morphological observation and flow cytometric analysis of DNA fragmentation.RESULTS:It was found that the two oligonucleotides directed against the coding region and the translation initiation of bcl-2 mRNA, combined respectively with daunorubicin, inhibited expression of bcl-2 protein, increased apoptosis in HL60 and K562 cells, and decreased IC50 of daunorubicin significantly (P＜0.05). Compared to the antisense oligonucleotide directed against the translation initiation of bcl-2 mRNA, the antisense oligonucleotide directed against the coding region showed stronger effects in the aspects of increasing the sensitivity of HL60 cells to daunorubicin (P＜0.05).CONCLUSIONS:These two antisense sequences in the translation initiation and the coding region of bcl-2 mRNA increased the sensitivity of HL60 and K562 cell lines to daunorubicin in a sequence-specific manner.     

Reversal of multidrug resistance by transfection of tumor necrosis factor α and MDR1 antisense RNA into multidrug resistant breast cancer cell line

AIM: To study the reversal effects of multidrug resistance by transfecting tumor necrosis factor α (TNF-α) cDNA and multidrug resistant 1 (MDR1) gene antisense RNA into multidrug resistant breast cancer cell line MCF-7/ADR. METHODS: The recombinant vector of enhanced green fluorescent protein (EGFP) with MDR1 antisense RNA and recombinant vector of red fluorescent protein (DsRed2) with TNF-α cDNA were constructed by RT-PCR and DNA recombinant techniques. The recombinant vectors were transfected into multidrug resistant breast cancer cell line MCF-7/ADR. The cell growth curves, cell apoptosis rates, MDR1 gene expression at mRNA and P-gp levels, and the sensitivity to ADR were determined before and after the transfection. RESULTS: After the transfection, cells showed lower growth rate, higher apoptosis rate, lower MDR1 expression at mRNA and P-gp levels, and the sensitivity to ADR increased significantly. CONCLUSION: Transfection of TNF-α cDNA and MDR1 antisense RNA into multidrug resistant breast cancer cells may have good effects on reversal of multidrug resistance.     

Inhibition of K562 cell growth by antisense drug targeting with VEGF mRNA in vitro

AIM: To investigate inhibition of K562 cell growth by antisense drug targeted VEGF mRNA. METHODS: X7, 20-mer antisense sequences were selected, synthesized and modified with phosphorothioate. The drug was transfected into K562 cells in the present of lipofection. Cell growth was assayed by trypan blue dye exclusion assay and MTT. The level of VEGF protein in the media was determined by ELISA. The morphology of apoptotic cells were observed by Giemsa staining, and the propotion of apoptotic cells was detected by flow cytometry. RESULTS: The antisense drug inhibited growth of K562 and downregulated expression of VEGF protein significantly, compared with Scrambed control group and showed dose-dependent relation. Signs of apoptosis of K562 cells were not observed. CONCLUSION: Inhibition of K562 cell proliferation, but not cells apoptosis induction is the mechanism of inhibing growth of K562 cells by antisense drug targeted VEGF mRNA. At same time, VEGF has function of promoting K562 cell proliferation, and VEGF mRNA may be a new target attached by drugs.     

CDA-2 induces differentiation and inhibits proliferation of human SWO-38 glioma cells

AIM: To investigate the differentiation-inducing effect of cell differentiation agent-2 (CDA-2) in human SWO-38 glioma cell line in vitro.METHODS: The inhibitory effect of CDA-2 on cell proliferation was assessed by MTT assay and colony formation assay.Cell morphology was determinded by light microscopy observation,and the expression of GFAP (glial fibrillary acidic protein) was detected by immunohistochemistry and Western blotting.Western blotting was also applied to explore the expression of PPARγ and COX-2.RESULTS: The data showed that CDA-2 inhibited proliferation and induced differentiation of SWO-38 cells.The inhibition efficiency was time-dependent and dose-dependent .The IC₅₀ of CDA-2 was (2.33±0.37) g/L and (0.51±0.01) g/L,respectively when cells were treated for 72 h and 10 days.CDA-2 caused differentiation of human glioma cells as indicated by outgrowth of long processes and expression of astrocyte marker GFAP.Simultaneously,the expression of PPARγ increased after 3 h of CDA-2 treatment，while the expression of COX-2 decreased after 48 h of CDA-2 treatment.CONCLUSION: CDA-2 inhibits proliferation and induces differentiation of SWO-38 cells.These effects may be through increasing cellular GFAP,PPARγ level and decreasing COX-2 expression induced by CDA-2.     

Effect of bFGF on cyclin D1 and GADD153 expression in human ovarian cancer CAOV3 cells

AIM: To evaluate the effect of basic fibroblast growth factor (bFGF) on the expression of cyclin D1, growth arrest, DNA damage inducible gene 153 (GADD153), and its roles involved in cell cycle regulation and DNA repair in starvation-induced ovarian cancer CAOV3 cells apoptosis. METHODS: Apoptosis of ovarian cancer CAOV3 cells was induced by serum-free culture (starvation). After bFGF treatment, the cell proliferation rate, cell cycle and apoptosis were determined by MTT, FACS analysis and agarose electrophoresis, respectively. The expression of c-Fos, c-Jun and cyclin D1, GADD153 were detected by Western blotting. RESULTS: bFGF increased the cell proliferation and prevented starvation-induced cell apoptosis. In a time-dependent manner, bFGF induced the expression of c-Fos, c-Jun and cyclin D1 and inhibited GADD153. CONCLUSION: bFGF plays a critical role in anti-apoptosis and the proliferation in human ovarian cancer by upregulating the expression of c-Fos, c-Jun and cyclin D1 and inhibiting GADD153.     

Effect of basic fibroblast growth factor on synthesis of C-type natriuretic peptide in cultured human umbilical vein endothelial cells

AIM: To investigate the effect of basic fibroblast growth factor (bFGF) on C-type natriuretic peptide (CNP) production, release and mRNA expression. METHODS: Human endothelial cell cultured;CNP was mea sured by radioimmunoassay method;CNP mRNA expression was determined by RT-PCR technique.RESULTS: bFGF could augment CNP synthesis in human endothelial cells. Compared with control group,25 ng, 50 ng, 100 ng bFGF increased CNP contents in endothelial cells by 88% (P＜0.05), 95% (P＜0.05), 187% (P＜0.01), respectively.100 ng bFGF also stimulated CNP release from cultured human endothelial cell. In addition, 25 ng, 50 ng and 100 ng bFGF stimulated CNP mRNA expression of cultured human endothelial cells in a dose-dependent manner. CONCLUSION: bFGF might regulate CNP synthesis,release and mRNA expression in cultured umbilical human endothelial cells.     

Effect of CLCN2 antisense oligonucleotide on U251 cells injury by cisplatin

AIM: To investigate the effect of chloride channel CLCN2 antisense oligonucleotide on the cell injury of malignant U251 glioma cells induced by cisplatin (DDP). METHODS: The experiment was divided into 4 groups: control group (nonsense oligonucleotide), CLCN2 antisense oligonucleotide group, DDP group (DDP＋nonsense oligonucleotide), DDP＋CLCN2 antisense oligonucleotide group. The viability of U251 cells was measured by MTT assay, CLCN2 mRNA level was determined by RT-PCR, cell apoptosis was measured by TUNEL assay. RESULTS: Compared to the control group, the cell viability, CLCN2 and cyclinD1 mRNA decreased in CLCN2 antisense oligonucleotide group, DDP treated group and CLCN2 antisense oligonucleotide with DDP treated group, cells apoptosis increased. Compared to DDP group, the cell viability (P<0.05) and CLCN2 mRNA decreased in CLCN2 antisense oligonucleotide with DDP treated group, and cells apoptosis increased (P<0.01). Compared to CLCN2 antisense oligonucleotide group, CLCN2 mRNA significantly decreased (P<0.01) in CLCN2 antisense oligonucleotide with DDP treated group. CONCLUSION: CLCN2 antisense oligonucleotide inhibits the expression of CLCN2 mRNA in U251 cells. Inhibition of CLCN2 mRNA facilitates the cell injury of U251 cells induced by DDP. The decrease in CLCN2 mRNA is involved in the mechanism of cell injury by DDP.     

Effect of antisense RNA targeting Polo-like kinase 1 on cell growth in A549 lung cancer cells

AIM: To investigate the effect of Polo-like kinase-1 (Plk1) depletion on cell cycle progression and cell growth in lung cancer cells.METHODS: A recombinant plasmid containing antisense RNA targeting Plk1 (pcDNA3-Plk1) was transfected into A549 cells by lipofectine. RT-PCR and Western blotting were used to examine Plk1 gene expression. Cell proliferation was evaluated by cell counting and BrdU labeling. Cell cycle distribution and apoptosis were examined by flow cytometry. Inhibition rate (IR) of vinorebline (NVB) was determined by MTT assay. RESULTS: After transfected with pcDNA3-Plk1 into A549 cells, the expression levels of Plk1 mRNA and protein were greatly decreased. Abnormal morphological changes of cells and growth inhibition were observed in pcDNA3-Plk1 transfected cells. The BrdU labeling index was significantly lower than that in control group (P<0.05). Cells showed a strong G₂/M arrest and apoptosis 72 h post transfection. IR of vinorebline in pcDNA3-Plk1 transfected groups was significantly higher than that in other groups. CONCLUSION: Antisense RNA targeting Plk1 is capable of suppressing Plk1 expression, and therefore, significantly inhibits cellular proliferation, induces cell cycle arrest and apoptosis. Moreover, the sensitivity of lung cancer cells to chemotherapy is increased.     

Induction of apoptosis by c-myc antisense oligonucleotide in osteosarcoma cell MG-63

AIM: To study the induction of apoptosis by c-myc antisense oligonucleotide in osteosarcoma cell (MG-63).METHODS: The designed c-myc antisense oligonucleotide fragment was transfected into human osteosarcoma MG-63 cells. The cell growth and apoptosis were measured by the methods of MTT, FCM, HE staining and transmission electron microscopy.RESULTS: The results showed that the proliferation of human osteosarcoma MG-63 cells was inhibited and apoptotic rate was 37.92% when treated with c-myc antisense oligonucleotide at the does of 10.0 μmol/L for 48 h. c-myc antisense oligonucleotide (10.0 μmol/L) also inhibited the expression of c-myc protein.CONCLUSION: c-myc antisense oligonucleotide is able to induce apoptosis in human osteosarcoma MG-63 cells.     

Effect of acyl coenzyme A: cholesteryl acyltransferase 1 antisense oligonucleotides on the formation of foam cells

AIM: To study the effect of acyl coenzyme A: cholesteryl acyltransferase 1 (ACAT1) antisense oligonucleotides on the formation of foam cells (FC). METHODS: THP-1 cells were cultured and differentiated into macrophages (MP) by phorbol myristate acetate (PMA). Over-expressing ACAT1 gene THP-1 cells were constructed. The ACAT1 antisense and missense oligonucleotides conducted by LipofectamineTM 2000 were incubated with above cells. Ac-LDL was added 6 h later and incubated for 24 h. The expression of ACAT1 protein was detected by Western blotting. The ACAT activity was measured by quantifying the incorporation of ［1-14C］ oleoyl CoA into cholesteryl esters. The formation of foam cells was detected by oil red O staining. RESULTS: The ACAT1 antisense oligonucleotides inhibited the activity of ACAT in macrophages and over-expressing ACAT1 gene THP-1 cells. It also inhibited the formation of foam cell in macrophages and over-expressing ACAT1 gene THP-1 cells with lipid loading. The missense oligonucleotides did not show the inhibitory effects. CONCLUSION: The ACAT1 antisense oligonucleotides inhibit the activity of ACAT and the formation of foam cells.     

Calreticulin is involved in the protection of hypoxic preconditioning against cardiomyoblast H9c2 cell oxidative injury

AIM: To investigate whether hypoxic preconditioning (HPC) protects cardiomyoblast H9c2 cells against oxidative injury, and to discuss whether calreticulin (CRT) contribute to this protection through p38 MAPK signaling pathway. METHODS: Cardiomyoblast H9c2 cells were randomly divided into eight groups as follows: hydrogen peroxide stress (H₂O₂); brief hypoxic exposure of 20 min to simulate hypoxic preconditioning (HPC); 20 min of hypoxic exposure followed by 24 h of normoxic reoxygenation before hydrogen peroxide stress (HPC+H₂O₂), SB203580 (the specific inhibitors of p38 MAPK)+HPC+H₂O₂, antisense oligonucleotides transfection of calreticulin (AS), AS+H₂O₂, AS+HPC+H₂O₂ and control. Morphological studies, estimation of lactate dehydrogenase (LDH) leakage and flow cytometry were employed to assess the cell apoptosis and necrosis. RT-PCR and Western blotting analysis was used to detect calreticulin expression and phosphorylation of p38 MAPK. RESULTS: The results obtained are as follows: (1) HPC relieved cell injury caused by H₂O₂. Compared with those in H₂O₂ group, apoptosis rate and LDH leakage in culture medium in HPC + H₂O₂ group decreased 13.4% and 44.0%, respectively (P<0.05), and cell survive rate increased 12.7% (P<0.05). SB203580, a selective p38 MAPK inhibitor presented before HPC, eliminated the cytoprotection of HPC. Compared with HPC+H₂O₂ group, apoptosis rate and LDH leakage increased 5.4% and 45.0%, respectively (P<0.05), and cell survive rate decreased 5.0%(P<0.05). (2) Brief hypoxia intimating HPC resulted in mild CRT up-regulation (1.4-fold increased vs control group, P<0.05), but this up-regulation was lower than that of 3.6-fold increase induced by oxidative stress. HPC relieved the over-expression of CRT induced by H₂O₂ (26% decreased vs H₂O₂ group, P<0.05). (3) Transfection of antisense oligonucleotides of CRT before HPC reduced cytoprotection against oxidative stress. Correlative analysis indicated that mild up-regulation of CRT induced by HPC was positively correlated with survive rate (r=0.8573, P<0.05). (4) SB203580 suppressed CRT up-regulation (the expression of CRT decreased 38% or 23%, vs HPC+H₂O₂ group or HPC group, respectively). CONCLUSION: These results suggest that hypoxic preconditioning up-regulates calreticulin expression through p38 MAPK signaling pathway and protects cardiomyoblast H9c2 cells against oxidative injury.     

The effect of antisense bcr-abl oligonucleotides on the growth of K562 cells

AIM:To study the effect of bcr- abl gene antisense phosphorothioate oligonucleotides(Aspo) on K562 cell line and explore its significance in chrenic myelogeneous leukemia (CML) gene therapy.METHODS:Cells were exposed to oligomeis, observed by inverted microscope.Cells inhibitory rate were determined by 0.4 trypan blue exclusion . CFU-K562 were cultured in 0.8 % methylcellulose . P210 was measured by flow cytomety RESULTS: K562 cells were treated with Aspo, they still grew in clone state and show antisense sequence specific and dose dependent. When the concentration of Aspo was more than Spznol/L, the growth of cells was inhibited and P210 was down regulated or completely suppressed, and the greatest growth inhibition was at 120h . There was signifi-cant inhibition of cell proliferation in a rang‘cells number from 1×10⁴/mL to 5×10⁴/mL after treatment with 10unol/L Aspo. b2a2 Aspo was also effect on K562 cells which expressing b3a2 mRNA.CONCLUSION: bcr-abl Aspo has a specific growth inhibition effect on K562 cells, and worths further study in CML gene therapy.     

Effect of MIF antisense oligonucleotides on expression of MIF in macrophages

AIM: To investigate the effect of antisense oligonucleotides on expression of macrophage migration inhibitory factor (MIF) in macrophages. METHODS: MIF phosphorothioate oligonucleotides was designed and synthesized. The phosphorothioate antisense, sense and missense oligonucleotides of mouse MIF was transfected into macrophages, separately. After that, macrophages were incubated with LPS. Cell culture medium was collected for MIF protein detection by EIA. Cellular RNA was extracted and the expression of MIF mRNA was examined by RT-PCR analysis. RESULTS: LPS stimulation resulted in a specific time-dependent expression of MIF derived from macrophages. MIF mRNA and MIF protein level increased at 6 h and reached a plateau at 9-12 h after LPS stimulation. The macrophages treated with antisense oligonucleotides showed a significant decrease in MIF mRNA and MIF protein after LPS stimulation than those with LPS stimulation only and LPS plus sense or missense oligonucleotides (P<0.05). CONCLUSION: Antisense oligonucleotides of MIF inhibit the expression of MIF mRNA and MIF protein in macrophages treated with LPS.