Effects of 2-deoxy-D-glucose and oxaliplatin on proliferation and apoptosis of human hepatoma cell line SMMC-7721

AIM: To investigate the effects of 2-deoxy-D-glucose (2-DG) or oxaliplatin (L-OHP) alone and the combination of both on the proliferation and apoptosis of hepatoma cell line SMMC-7721 in vitro. METHODS: Human hepatoma cell line SMMC-7721 was treated with 2-DG or L-OHP alone, or both. The inhibitory effect on the proliferation of SMMC-7721 cells was estimated by MTT method. The q value, which represents synergistic effect, was determined. Apoptotic rate and cell cycle were assayed by flow cytometry. The activity of caspase-3 was detected by a caspase-3 activity assay kit. RESULTS: 2-DG or L-OHP at different concentrations inhibited the growth of SMMC-7721 cells obviously and the inhibitory effect on SMMC-7721 cell growth strongly depended on the exposure time and dose. When the 2 drugs worked together, the inhibitory effect was improved (P<0.05). 2-DG induced cell apoptosis and arrested the cells at G₂/M phase. When combined with L-OHP,the 2 drugs induced more severe apoptosis and arrested the cells at S and G₂/M phase. Meanwhile, the activity of caspase-3 increased when the 2 drugs used together. CONCLUSION: 2-DG inhibits the growth of hepatoma cell line SMMC-7721. The combination of 2-DG and L-OHP improves the ability of L-OHP to attack the tumor cells. The mechanism might be related to increasing the activity of caspase-3.     

Effect of Beclin 1 RNA interference on Vit K3 injured SMMC-7721 cells

AIM: To observe the effect of Beclin 1 silencing by RNA interference (RNAi) technique to the injury of SMMC-7721 hepatoma cells by vitamin K3 (Vit K3).METHODS: The recombinant plasmid Psilencer 3.1-siRNA-Beclin 1 was transfected into SMMC-7721 hepatoma cells by eukaryotic cell transfection technique. Plasmid vector and cell culture medium were used as negative and control, respectively. The cells were collected 48 h later to extract cell RNA and total protein and to detect Beclin 1 gene expression by RT-PCR and Western blotting. 40 μmol/L Vit K3 was used to treate the Beclin 1-siRNA cells, Hoechst33342 staining was used for the determination of the percentage of cell apoptosis.RESULTS: Compared with the control group, the synthetic siRNA of Beclin 1 significantly decreased the levels of Beclin 1 mRNA and protein expressions. Beclin 1 mRNA was up-regulated in 40 μmol/L Vit K3 treated SMMC-7721 hepatoma cells, the percentage of apoptosis cells increased (P﹤0.01). In beclin 1-siRNA cells, Beclin 1 mRNA was down-regulated obviously, the percentage of apoptosis cells increased significantly compared with the 40 μmol/L Vit K3 group (P﹤0.01).CONCLUSION: The transfection of SMMC-7721 hepatoma cells by Psilencer3.1-siRNA-Beclin 1 effectively inhibits the expressions of Beclin 1 mRNA and protein, inhibits the activation of Beclin 1 dependent autophagic signaling pathway, and aggravates the apoptosis induced by Vit K3.     

Effect of abnormal expression of miR-141 on malignant biological behaviors of human hepatocarcinoma cells

AIM: To investigate the expression of microRNA-141 (miR-141) in human hepatocellular carcinoma (HCC) cell line SMMC-7721 and normal hepatocyte line HL-7702, and to analyze the effect of abnormal expression of miR-141 on the malignant biological behaviors of human hepatocarcinoma cells. METHODS: The RNA from SMMC-7721 cells and HL-7702 cells was extracted. SYBR Green real-time PCR was performed to detect the expression of miR-141. Synthetic miR-141 mimic and its negative control were transfected into the SMMC-7721 cells, and miR-141 inhibitor and its negative control were transfected into the HL-7702 cells by the method of Lipofectamine. After transfection, MTS assay and BrdU-ELISA were employed to evaluate the effect of miR-141 on the cell proliferation. Flow cytometry was used to detect cell cycle and apoptosis. The changes of migration ability were investigated by Transwell invasion assay. RESULTS: The expression of miR-141 in the SMMC-7721 cells was significantly lower than that in the HL-7702 cells (P < 0.05). Compared with blank group, Lipofectamine group and negative control group, the proliferation of the SMMC-7721 cells transfected with 25 nmol/L miR-141 mimic was significantly inhibited in a time-dependent manner (P < 0.05). The percentages of G₁ phase cells and early apoptotic rate were significantly increased when miR-141 was up-regulated, but the migration ability was inhibited (P < 0.05). Compared with blank group, Lipofectamine group and negative control group, the proliferation of HL-7702 cells transfected with 50 nmol/L miR-141 inhibitor was significantly increased in a time-dependent manner (P < 0.05). When miR-141 was down-regulated, the percentages of G₁ phase cells and early apoptotic rate were significantly decreased, but the migration ability was enhanced (P < 0.05). CONCLUSION: miR-141 is down-regulated in human hepatocarcinoma cell line. Up-regulation of miR-141 will not only inhibit cell proliferation and migration ability, but also affect the cell cycle and apoptosis of SMMC-7721 cells. miR-141 may function as a tumor suppressor gene during HCC development.     

Effect of NANOG silencing on cyclin D1 expression and proliferation in human hepatoma HepG2 cells

AIM:To investigate the effect of NANOG silencing on cyclin D1 expression and proliferation in human hepatoma HepG2 cells. METHODS:Transient transfection of NANOG targeting siRNA into HepG2 cells was performed. The expression of NANOG and cyclin D1 at mRNA and protein levels was detected by real-time PCR and Western blotting. Cell proliferation was examined by CCK-8 assay and colony formation assay, and cell cycle was tested by flow cytometry. RESULTS:After transfection with NANOG-targeting siRNA, the inhibition of NANOG expression was observed. Compared with mock group, the mRNA and protein expression levels of NANOG and cyclin D1 were decreased (P<005). In addition, knockdown of NANOG expression inhibited the cell proliferation and increased the proportion of G 0/G 1-phase cells (P<0.05). CONCLUSION:Silencing of NANOG expression in HepG2 cells causes down-regulation of cyclin D1 expression and decreases the cell proliferation ability.     

Effect of ginsenoside Rh2 on cell proliferation and cytoskeleton in hepatocarcinoma SMMC-7721 cells

AIM: To investigate the changes of cell growth and cytoskeleton in hepatocarcinoma SMMC-7721 cells treated with ginsenoside Rh₂.METHODS: Cell viability and apoptosis under the conditions of ginsenoside Rh₂ exposure at different concentrations were measured by MTT test and flow cytometry,respectively. The morphological changes of F-actin labeled with FITC-phalloidin were observed under confocal laser scanning microscope. The structures of nuclear matrix-intermediate fibre system were observed under transmission electron microscope (TEM).RESULTS: Rh₂ at 40 mg/L for 4 days inhibited the proliferation and induced apoptosis in SMMC-7721 cells more than those in control group, 10 mg/L Rh₂ group and 20 mg/L Rh₂ group. The F-actin in the cells treated with Rh₂ was well-distributed, lined up in order and the number of fibers increased, while those in the control cells were in disorder and punctiform. The results of whole mount TEM indicated that the intermediate fiber was plentiful, well-distributed and interweaved into a regular network in Rh₂ treated cells.CONCLUSION: Rh₂ effectively inhibits the cell proliferation, increases the cell apoptosis and induces the change of the cytoskeleton alignment in SMMC-7721 cells.     

Biological characteristics of side population cells sorted from hepatoma SMMC-7721 cell line

AIM: To study the biological characteristics of side population (SP) cells sorted from hepatoma SMMC-7721 cell line. METHODS: Fluorescence-activated cell sorter (FACS) was used to sort SP cells and non-SP (NSP) cells from SMMC-7721 cell line. The colony-formation ability and proliferation ability between SP cells and NSP cells were compared in terms of plate colony assay and growth curve. The migratory and invasive properties of SP cells and NSP cells were tested by Transwell method. The cell cycle and apoptosis were analyzed by flow cytometry. The oncogenicity of the cells was analyzed by nude mouse transplantation tumor experiment in vivo. RESULTS: The results of FACS analysis indicated that (9.2±0.2)% of the SMMC-7721 cells were SP cells. The proportion of G₀/G₁ phase of SP cells was higher, and the apoptotic rate was lower than those of NSP cells (P<0.05). The proliferation ability and colony-forming ability and migratory and invasive properties of SP cells were significantly higher than those of NSP cells (P<0.05). The nude mouse transplantation tumor experiment displayed that the oncogenicity of SP cells was higher than that of NSP cells. CONCLUSION: The SP cells sorted from SMMC-7721 cell line may enrich tumor stem cells.     

Role of up-regulated microRNA145 in viability,apoptosis, invasion and metastasis of hepatoma cells

AIM: To investigate the effects of microRNA145 (miRNA145) on the viability, apoptosis, invasion and metastasis of hepatoma HepG2 cells. METHODS: HepG2 cells were randomly allocated into 3 groups: blank control group, empty mimic transfected group and miRNA145 mimic transfected group. Under the induction of Lipofectamine^TM 2000, the recombinant was transfected into HepG2 cells. After transfection, the expression level of miRNA145 was detected by real-time PCR. The protein level of N-cadherin and the mRNA expression levels of miRNA145 and N-cadherin were detected by Western blot and real-time PCR. The cell viability was detected by MTS assay. The cell cycle and apoptosis were analyzed by flow cytometry. Invasion and metastasis were detected by Transwell assay. RESULTS: Compared with negative control, miRNA145 expression was up-regulated significantly, while the expression of N-cadherin was down-regulated significantly. Meanwhile, the cell viability, cell cycle, apoptosis, invasion and metastasis of hepatoma HepG2 cells were all significantly inhibited (P<0.05). CONCLUSION: miRNA145 dramatically inhibits viability, apoptosis, invasion and metastasis of hepatoma cells.     

Effects of RNA interference targeting CDC25agene on proliferation of human liver cancer HepG2 cells

AIM: To investigate the effect of silencing cell division cycle 25a (CDC25a) gene on the proliferation of human hepatoma HepG2 cells. METHODS: CDC25agene in human hepatoma HepG2 cells was silenced by RNA interference. Real-time PCR was applied to detect the expression of CDC25a, cyclin E and CDK2 at mRNA levels in the HepG2 cells. Western blotting was applied to detect the expression of CDC25a at protein level. In addition, MTT assay, Giemsa staining and flow cytometry were used to measure the proliferation of human hepatoma HepG2 cells. RESULTS: The expression of CDC25a at mRNA and protein levels in RNA silence group was lower than those in negative control group and normal control group (P＜0.05). The mRNA expression of cyclin E and CDK2 in silence group was lower than that in negative control group and normal control group (P＜0.05). The cell proliferation in silence group was lower than that in negative control group and normal control group (P＜0.05). The results of flow cytometry revealed that the cells in silence group were blocked in G1 phase. CONCLUSION: Infection of LV-CDC25a-RNAi recombinant to the HepG2 cells effectively inhibits the CDC25agene expression and the proliferation of human hepatoma cells, and arrests the cells in G1 phase, suggesting that CDC25agene may be a key target for the treatment of liver cancer.     

Different inhibition of hepatocarcinoma cell growth by As2O3 in SMMC-7721 and BEL-7402 cell lines

AIM: To explore the different inhibitory effect of arsenic trioxide (As₂O₃) on hepatocarcinoma cell growth in SMMC-7721 and BEL-7402 cell lines and its mechanism. METHODS: The cell culture and trypan blue staining were used to study the inhibitory effect of arsenic trioxide on cell growth, and the glutathione (GSH) contents in hepatocarcinoma cells treated with arsenic trioxide were detected. RESULTS: Arsenic trioxide inhibited the growth of BEL-7402 cells in a time and dose-dependent manner. The inhibitory effect was significant at a lower dose of 0.50 μmol/L for 24 h, however, to SMMC-7721 cells, a higher dose of 2.00 μmol/L for 96 h was needed. The inhibitory rate of arsenic trioxide (0.25-2.00 μmol/L) on BEL-7402 cell growth was higher than that on SMMC-7721 cells. The content of GSH in SMMC-7721 cells was much higher than that in BEL-7402 cells . CONCLUSION: There was a significant difference in inhibition of hepatocarcinoma cell growth by arsenic trioxide between BEL-7402 and SMMC-7721 cell lines, the cause of which may be due to the difference in GSH content in BEL-7402 and SMMC-7721 cells.     

Effects of marrow stromal cell-mediated microenvironment on human hepatocellular carcinoma cell line SMMC-7721

AIM: To investigate the effects of marrow stromal HS-5 cells on hepatocellular carcinoma SMMC-7721 cells in the tumor microenvironment. METHODS: The effects of HS-5 cell-conditioned medium (HS-5-CM) on the proliferation, migration and invasion abilities of SMMC-7721 cells were detected by MTT, wound-healing and Transwell assays. After co-culture of SMMC-7721 cells with HS-5 cells in the Transwell chamber, the expression of chemokine CCL5 and its receptor CCR5 at mRNA and protein levels in SMMC-7721 cells was examined by quantitative real-time PCR (qRT-PCR), ELISA or Western blotting. Akt and p-Akt473 protein levels in SMMC-7721 cells treated with PI3K inhibitor LY294002 were observed by Western blotting. RESULTS: HS-5-CM promoted the proliferation, migration and invasion abilities of SMMC-7721 cells. The expression of CCL5 and CCR5 at mRNA and protein levels in SMMC-7721 cells was increased after co-cultured with HS-5 cells. PI3K inhibitor LY294002 inhibited the activation of PI3K-Akt signaling pathway and the secretion of CCL5 in SMMC-7721 cells after co-cultured with HS-5 cells. CONCLUSION: HS-5 cells significantly promote the proliferation, migration and invasion abilities of SMMC-7721 cells. Co-culture of SMMC-7721 cells with HS-5 cells activates PI3K-Akt signaling pathway to increase the secretion of CCL5 in SMMC-7721 cells.     

Antitumor activity of Paecilomyces tenuipes polysaccharide and its mechanism in vitro

AIM:To investigate the antitumor activity and mechanism of Paecilomyces tenuipes polysaccharide(PTPS).METHODS:PTPS-I was obtained by water extraction and alcohol precipitation, and purified by DEAE-cellulose and Sephadex G-100 chromatography. Human erythroleukemia cell line K562, laryngocarcinoma cell line Hep2 and hepatic carcinoma cell line SMMC-7721were co-cultured with PTPS-I or the conditioned medium which prepared with PTPS-I-stimulated human mononuclear cells (PTPS-I-MNC-CM), and the proliferation of tumor cells was determined. The cell counting kit-8 (CCK-8) was used to determine the proliferation of MNCs. The FQ-RT-PCR was applied to investigate the expression of TNF-α and IL-6 mRNA in MNCs. RESULTS:PTPS-I-MNC-CM inhibited the proliferation of K562, Hep2 and SMMC-7721 cells in vitro (P<0.01). Cytotoxicity of PTPS-I against K562, Hep2 and SMMC-7721 cells was not observed (P<0.01). PTPS-I stimulated the proliferation of MNCs (P<0.01) and significantly enhanced the expression of TNF-α and IL-6 mRNA in MNCs (P<0.05, P<0.01). CONCLUSION:The results suggest that PTPS-I is an immunomodulator and its antitumoral activity is through the immunomodulatory mechanism rather than the direct cytotoxicity against tumor cells.     

In vitro growth inhibition effects of rhHGF/cHGF on SMMC-7721 human HCC cell line

AIM:To examine the effects of recombinant human hepatocyte growth factor(rhHGF) and native calf HGF(cHGF) on SMMC-7721 human hepatocellular carcinoma(HCC) cell line. METHODS:Human HCC cell line culture, photometric assay, and flow cytometric assay were used in this study .RESULTS:A similar type of dose-dependent cell growth inhibition effect on SMMC-7721 human HCC cells by rhHGF(5-20 μg/L) as well as by cHGF(25-100 mg/L) had been found, with the maximal effect at the highest concentration used. Approximately over 50% of the cells treated with rhHGF(5 μg/L, 10 μg/L, 20 μg/L) accumulated in the quiescent G₀/G₁ phase of the cell cycle over incubation periods for 3 d. CONCLUSION:The growth of SMMC-7721 human HCC cells was strongly inhibited by both rhHGF and cHGF. This might be because the cells exposed to HGF became arrested in the G₀/G₁ phase.     

Proliferation of human hepatoma cells are regulated by the intracrine and autocrine loop of the macrophage colony-stimulating factor system

AIM: To study the expression and characterization of intracellular macrophage colony-stimulating factor (M-CSF) in human hepatoma cell line, SMMC 7721 cell, and to explore the mechanism by which M-CSF regulates the proliferation of human hepatoma cells. METHODS: The immunohistochemical staining, flow cytometry, antisense technique and Western blotting were used to study the effects and mechanisms of intracellular M-CSF on the proliferation of human hepatoma cells. RESULTS: SMMC 7721 cells highly expressed M-CSF and its receptor. The localization of positive reactions was mainly in cytoplasma and nucleus in SMMC 7721 cells. In cytoplasma and nucleus, one isoforms of M-CSF was found with the molecular weight (MW) of 20 kD, while one type of M-CSFR was discovered with MW of 120 kD. Immunoprecipitation assay showed that these ligands existed in binding with its receptor. Monoclonal antibody (McAb) against M-CSF and antisense oligodeoxynucleotides (ASODN) blocking M-CSF expression inhibited the proliferation of SMMC 7721 cells. McAb and ASODN regulated the expression of cyclin D1/E and p16. Simultaneous administration of both McAb and ASODN inhibited the proliferation of SMMC 7721 cells and modulated the expression of cyclins at greater degrees. CONCLUSION: Our results suggest that an autocrine and an intracrine loop of M-CSF/M-CSFR are present in SMMC 7721 cells.     

miR-15a-5p inhibits proliferation and migration of human hepatocellular carcinoma SMMC-7721 cells

AIM: To observe the influence of high expression of miR-15a-5p on the proliferation and migration of human hepatocellular carcinoma SMMC-7721 cells.METHODS: The miR-15a-5p oligonucleotide, which was reconstructed with additional restriction sites of EcoR Ⅰ and Hind Ⅲ, was chemically synthesized and confirmed by sequencing. The miR-15a-5p eukaryotic expression system was constructed by pcDNA6.2-GW/Em-GFP-pre-miR-15a-5p plasmid. The miR-15a-5p was transfected into the SMMC-7721 cells transiently by plasmid, and quantified by quantitative real-time PCR at the mRNA level. The cell viability was measured by CCK-8 assay, and the living cell counting was performed by the method of Trypan blue exclusion. The migration ability of the SMMC-7721 cells with high expression of miR-15a-5p was detected by wound healing test.RESULTS: The sequence of miR-15a-5p oligonucleotide 100% matched the designed sequence. Compared with control group, the miR-15a-5p expression was increased significantly (P<0.05). The viability, the living cell number and the migration ability of the SMMC-7721 cells were decreased in high expression of miR-15a-5p group with statistically significant difference (P<0.05).CONCLUSION: The abilities of proliferation and migration in human hepatocellular carcinoma SMMC-7721 cells are decreased by high expression of miR-15a-5p.     

灵芝提取物对人肝癌SMMC─7721细胞DNA合成的影响

本文以人肝癌ＳＭＭＣ－７７２１细胞为材料，对水溶性灵芝提取物（ＥＧＬ）抗癌作用机理进行了研究。结果表明，ＥＧＬ能明显抑制ＳＭＭＣ－７７２１细胞的ＤＮＡ合成：ＥＧＬ在５０ｕｇ／ｍｌ到３００ｕｇ／ｍｌ范围表现出明显的剂量效应；ＥＧＬ最小有效作用剂量为１００ｕｇ／ｍｌ，最大有效作用剂量为３００ｕｇ／ｍｌ。结果提示ＥＧＬ的抗癌机理主要是通过抑制癌细胞ＤＮＡ合成而起作用的。     

Effects of shRNA targeting SIAH2 gene on proliferation and apoptosis of human hepatoma cell line HepG2

AIM：To investigate the effects of shRNA-mediated seven in absentia homolog 2 (SIAH2; one of ubiquitin ligases) gene silencing on cell cycle and apoptosis of human hepatoma cell line HepG2. METHODS：The specific recombinant vector pGenesil-SIAH2 was transiently transfected into HepG2 cells with Lipofectamine 2000. RT-PCR and Western blotting were performed to detect the mRNA and protein expression levels of SIAH2. MTS assay was employed to evaluate the cell proliferation. Flow cytometry was used to determine the cell cycle and apoptosis of the transfected cells. RESULTS：Compared with control groups, the mRNA and protein levels of SIAH2 were reduced by pGenesil-SIAH2 transfection in HepG2-SIAH2 group. The proliferation of HepG2-SIAH2 cells was significantly inhibited. The percentage of G1-phase cells and the early apoptotic rate were significantly higher in HepG2-SIAH2 cells. CONCLUSION: Tansfection of pGenesil-SIAH2 effectively inhibits the proliferation of HepG2 cells, arrests the cells in G1 phase and induces apoptosis, indicating an experimental basis of SIAH2-targeting gene therapy for hepatocellular carcinoma.     

Construction of siRNA-survivin and GRIM-19 coexpression plasmid and its growth inhibitory effect on prostatic cancer DU145 cells

AIM: To construct the recombinant plasmid that expresses siRNA-survivin and GRIM-19 simultaneously, and to identify the validity of the recombinant plasmid and observe its effect on expression of survivin and GRIM-19 and proliferation ability of prostate cancer DU145 cells. METHODS: The recombinant plasmid coexpressing siRNA-survivin and GRIM-19 was constructed using gene cloning technique. The prostatic cancer DU145 cells were transfected with the coexpression plasmid and control plasmids. Survivin and GRIM-19 mRNA expression was detected by semi-quantitative RT-PCR. The proliferation ability affected by coexpression plasmid was measured by MTT assay. RESULTS: The coexpression plasmid pGRIM-19-si-survivin was successfully constructed according to DNA recombinant technique and identified through restriction enzyme digestion and plasmid sequencing. Compared with the mock, survivin mRNA expression levels were 0.55?0.05,0.62?0.08 and 0.35?0.05 in psi-survivin, pGRIM-19 and pGRIM-19-si-survivin groups, respectively. Compared with psi-survivin and pGRIM-19, pGRIM-19-si-survivin inhibited survivin mRNA expression markedly (P<0.05), while the expression levels of GRIM-19 mRNA were 1.93?0.14, 2.57?0.20 and 4.12?0.21 in psi-survivin, pGRIM-19 and pGRIM-19-si-survivin groups, respectively (P<0.01). Compared with pGRIM-19 group, pGRIM-19-si-survivin enhanced GRIM-19 mRNA expression more obviously (P<0.05). After transfection for 48 h, the proliferation rates were 58.0%?7.2%, 62.1%?6.1% and 50.2%?4.8% in the 3 experiment groups compared with the mock (P<0.05). After transfection for 72 h, the proliferation rate were 43.4%?4.3%, 51.3%?6.7% and 26.8%?7.1% in experiment groups compared with the mock (P<0.05). Compared with psi-survivin and pGRIM-19, pGRIM-19-si-survivin significantly inhibited the cell growth (P<0.05). CONCLUSION: Transfection of coexpression plasmid pGRIM-19-si-survivin dramatically changes the mRNA expression of survivin and GRIM-19 and inhibits the cell growth.     

Effects of human growth arrest-specific homeobox gene delivery on proliferation,migration and cell cycle distribution of vascular smooth muscle cells

AIM: To explore a new gene therapeutic strategy for vein graft restenosis by investigating the effects of adenovirus-mediated human growth arrest-specific homeobox (Ad5-hGax) gene delivery on the proliferation, migration and cell cycle distribution of serum-induced rabbit vascular smooth muscle cells (VSMCs). METHODS: The recombinant adenovirus vector containing hGax gene was constructed and transfected into rabbit VSMCs. The expression of hGax in VSMCs was detected by RT-PCR and immunofluorescent staining. Methyl thiazolyl tetrazolium (MTT) assay was used to assess the effect of hGax over-expression on serum-induced proliferation of VSMCs. Wound healing method was applied to examine the distance of serum-induce VSMCs migration. Flow cytometry was employed to analyze the cell cycle distribution. RESULTS: The recombinant adenovirus vector Ad5-hGax was successfully constructed. The results of RT-PCR and immunofluorescent staining revealed that the hGax -transfected cells contained a 174 bp specific fragment of hGax gene and target protein 48 h after transfection. The proliferation of serum-induced VSMCs was significantly inhibited by overexpression of hGax gene as compared with control group. The migration of serum-induced VSMCs was inhibited after hGax gene delivery. Flow cytometry showed that 72 h after serum induction, the cells in G₀/G₁ phase in Ad5-hGax group were significantly increased, whereas the cells in G₂/M+S phase were significantly decreased. CONCLUSION: Overexpression of hGax gene inhibits the proliferation and migration of serum-induced rabbit VSMCs, and arrests the cells in G₀/G₁ phase. It is likely that hGax gene is a potential target for the gene therapy of vein graft restenosis.     

Killing effect and mIFN-γ expression of gene-viral therapeutic system CNHK300-mIFN-γ on malignant tumor cells in vitro

AIM: To investigate the cytotoxicity and mouse IFN-γ (mIFN-γ) expression of oncolytic adenovirus CNHK300-mIFN-γ (CNHK300-Mγ) containing mIFN-γ gene in malignant tumor cells in vitro . METHODS: Human lung cancer cell line A549, human liver cancer cell line SMMC-7721, human pancreatic cancer cell line PANC-1, and human normal fibroblast line BJ were cultured and treated with CNHK300-Mγ, CNHK300, ONYX-015 or AdEasy-mIFN-γ (AdEasy-Mγ). TCID₅₀ assay was used to evaluate the replication ability of CNHK300-Mγ, CNHK300 and ONYX-015 in carcinoma cell lines and normal cell line, and the cytotoxicity was evaluated by cytopathic effect assay and MTT assay. The mIFN-γ expression in the supernatant was detected by ELISA after CNHK300-Mγ or AdEasy-Mγ infection in carcinoma cell lines and normal cell line. RESULTS: The tumor-specific replication ability and cytotoxicity of CNHK300-Mγ were similar to those of CNHK300. The IC₅₀ was as low as MOI of 0.47 pfu/cell for A549 cells, 0.074 pfu/cell for SMMC-7721 cells, 0.532 pfu/cell for PANC-1 cells and was as high as MOI of 281.73 pfu/cell for BJ cells. CNHK300-Mγ was a more powerful killer of malignant tumor cells than ONYX-015 (P<0.01). The tumor cells infected with CNHK300-Mγ efficiently expressed mIFN-γ in vitro and mIFN-γ largely increased as the time prolonged in A549, SMMC-7721 and PANC-1 cells. The mIFN-γ expression in the carcinoma cell lines infected with CNHK300-Mγ was much higher than that in the cells infected with AdEasy-Mγ (P<0.01), but was similar to that in the normal cell line (P>0.05). CONCLUSION: CNHK300-Mγ selectively replicates and effectively promotes the expression of mIFN-γ in carcinoma cells, and specifically kills the tumor cells.