TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

Antisense oligonucleotide targeting at the initiator of hTERT arrests growth of hepatoma cells

AIM:To evaluate the inhibitory effect of antisense phosphorothioate oligonucleotide (asON) complementary to the initiator of human telomerase catalytic subunit (hTERT) on the growth of hepatoma cells.METHODS:The as-hTERT was synthesized by using a DNA synthesizer. HepG2.2.15 cells were treated with ashTERT at the concentration of 10μmol/L. After 72h, these cells were obtained for detecting growth inhibition,telomerase activity using the methods of MTT,TRAP-PCR-ELISA, respectively. BALB/c(nu/nu) mice were injected HepG2.2.15 cells and a human-nude mice model was obtained. There were three groups for anti-tumor activity study. Once tumors were established, these animals in the first group were administered as-hTERT and saline.Apoptosis of tumor cells was detected by FCM. In the 2nd group, the animals were injected HepG2.2.15 cells together with as-hTERT. In the third group, the animals were given as-hTERT 24 hours postinjection of HepG2.2.15 cells. The anti-HBV effects were assayed with ELISA in vitro and in vivo.RESULTS: Growth inhibition was observed in cells treated with as-hTERT in vitro. A significant different in the value of A570-A630 was found between cells treated with as-hTERT and control (P<0.01) by MTT method. The telomerase activity of tumor cells treated with as-hTERT was reduced,the value of A4so nm was 0.42 compared to control (1.49) with TRAP-PCR-ELISA. The peak of apoptosis in tumor cells given as-hTERT was 21.12%, but not seen in saline-treated control. A prolonged period of carcinogenesis was observed in the second and third group animals. There was inhibitory effect on the expression of HBsAg and HBeAg in vivo and in vitro.CONCLUSION: As-hTERT has an anti-tumor activity, which may be useful for gene therapy of tumors.     

A rapid and efficient method to express target genes in mammalian cells by baculovirus

AIM: To investigate the modification of baculovirus vector and the feasibility of delivering exogenous genes into mammalian cells with the culture supernatant of Spodoptera frugiperta (Sf9) cells infected by recombinant baculoviruses. METHODS: Two recombinant baculoviruses (BacV-CMV-EGFPA, BacV-CMV-EGFPB) containing CMV-EGFP expression cassette were constructed. HepG2 cells were directly incubated with the culture supernatant of Sf9 cells infected by recombinant baculoviruses, and reporter gene transfer and expression efficiencies were analyzed by flow cytometry (FCM). The optimal transduction conditions were investigated by FCM assay in HepG2 cells. Gene-transfer and expression efficiencies in HepG2 or CV1 cells by baculovirus vectors were compared with lipofectAMINE, recombinant retrovirus and vaccinia virus expression systems. Twenty different mammalian cell lines were used to investigate the feasibility of delivering exogenous genes into different mammalian cells with the culture supernatant of infected Sf9 cells. RESULTS: CMV promoter could directly express reporter genes in Sf9 cells with a relatively low efficiency. Target cells incubated with the 1:1 diluted culture supernatant (moi=50) for 12 h at 37 ℃ could achieve the highest transduction and expression efficiencies with least impairment to cell viability. Under similar conditions the baculovirus vector could achieve the highest gene-transfer and expression efficiency than lipofectAMINE, recombinant retrovirus and vaccinia virus expression systems. Most mammalian cell lines could be transduced with recombinant baculovirus. In primate adherent culture cells the recombinant baculovirus could arrive the highest infection and expression efficiencies, but it was not very satisfactory in the cell lines from mice and suspended culture cells. CONCLUSION: Mammalian cells incubated with the culture supernatant of infected Sf9 cells could serve as a very convenient way for rapid and efficient expression of foreign genes in mammalian cells, but it might be more suitable for primate adherent culture cells.     

Establishment of mice model with human viral hepatitis B

AIM:To establish a mice model of hepatitis B by using HBV-transgenic mice, and to transfer HBV-specific cytotoxic T lymphoo/tes (CTL) induced from syngeneic BALB/c mice immunized by a eukaryotic expression vector containing HBV complete genome DNA.METHODS: HBV DNA was obtained from digested pBR3222HBV and ligated with the vector pcDNA3. Recombinant pcDNA3-HBV was identified by restriction endonuclease assay and transfected into human hepatoma cell line HepG2 with lipofectin. ELISA was used to detect the expression of HBsAg in culture supernatant, and RT-PCR to determine the existence of HBV PreS1 mRNA.BALB/c mice were immunized with pcDNA3-HBV or pcDNA3 by intramuscular injection.ELISA was used to detect the expression of HBsAb in serum. MTT assay was used to measure non-specific or specific proliferation ability and specific killing activity of spleen lymphocytes. Lymphocytes from immunized mice were transferred into HBV-transgenic mice (2.5×10^7 per mouse).Forty-eight hours later,the level of serum protein and transaminase was detected with biochemical method,liver and kidney were sectioned and stained by HE to observe the pathological changes.RESULTS: By enzyme digestion with Eco RI, Xho I and Hind Ⅲ,the recombinant pcDNA3-HBV was verified to contain a single copy of HBV genome,which was inserted in the positive direction.HepG2 cells transfected with the recombinant could stably express PreS1 mRNA and HBsAg.After immunized by pcDNA3-HBV for 4 weeks,HBsAb was detected in the serum of BALB/c mice. The potential of spleen lymphoo/tes for both non-specific and specific proliferation and the specific killing activity against target cells were enhanced. The transgenic mice in model group had no significant changes in the level of serum protein but had an obvious increase of ALT and AST. The liver had obvious pathological changes, while the kidney had no evident damage.CONCLUSION:A eukaryotic expression vector pcDNA3-HBV containing HBV complete genome is constructed successfully. HepG2 cells transfected with the recombinant can express PreS1 mRNA and HBsAg stably.Specific cellular immune response can be induced in mice immunized by pcDNA3-HBV.A mice model of acute hepatitis with HBV has been established.     

Inhibitory Effects of Atorvastatin on the mRNA Expression of ICAM-1 and VCAM-1 Activated by TNF-α in Cultured Human Umbilical Vein Endothelial Cells

Objectives To investigate the effects of atorvastatin on the mRNA expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) activated by TNF-α in cultured human umbilical vein endothelial cells (HUVEC). Methods and Results Lactic dehydrogenase (LDH) activity in the culture media increased when HUVEC were incubated with TNF-α, suggesting a cytotoxic effect of TNF-α on HUVEC. The mRNA expression of ICAM-1 and VCAM-1 increased in HUVEC incubated with 10μg/L TNF-α and reached peak in HUVEC incubated with 30μg/L TNF-α. The mRNA expression of ICAM-1 and VCAM-1 in HUVEC incubated with 30μg/L TNF-α began to increase at 6 h, reached peak at 48 h, and kept a plateau until 72 h. Atorvastatin dose-dependently inhibited the mRNA expressions of ICAM-1 and VCAM-1 activated by incubating HUVEC with 30μg/L TNF-α for 48 hours. Conclusions Atorvastatin might stabilize plaque and decelerate the process of AS by inhibiting the mRNA expressions of ICAM-1 and VCAM-1.     

Establishment of mice model with human viral hepatitis B

AIM:To establish a mice model of hepatitis B by usingHBV-transgenic mice,and to transfer HBV-specific cytotoxicT lymphocytes (CTL) induced from syngeneic BALB/c miceimmunized by a eukaryotic expression vector containing HBVcomplete genome DNA.METHODS:HBV DNA was obtained from digested pBR322-2HBV and ligated with the vector pcDNA3.RecombinantpcDNA3-HBV was identified by restriction endonucleaseassay and transfected into human hepatoma cell line HepG2with lipofectin.ELISA was used to detect the expression ofHBsAg in culture supernatant,and RT-PCR to determinethe existence of HBV PreS1 mRNA.BALB/c mice wereimmunized with pcDNA3-HBV or pcDNA3 by intramuscularinjection.ELISA was used to detect the expression of HBsAbin serum.MTT assay was used to measure non-specific orspecific proliferation ability and specific killing activity ofspleen lymphocytes.Lymphocytes from immunized micewere transferred into HBV-transgenic mice (2.5×10~7 permouse).Forty-eight hours later,the level of serum proteinand transaminase was detected with biochemical method,liver and kidney were sectioned and stained by HE to observethe pathological changes.RESULTS:By enzyme digestion with Eco RI,Xho Ⅰ andHind Ⅲ,the recombinant pcDNA3-HBV was verified tocontain a single copy of HBV genome,which was insertedin the positive direction.HepG2 cells transfected with therecombinant could stably express PreS1 mRNA and HBsAg.After immunized by pcDNA3-HBV for 4 weeks,HBsAb wasdetected in the serum of BALB/c mice.The potential of spleenlymphocytes for both non-specific and specific proliferationand the specific killing activity against target cells wereenhanced.The transgenic mice in model group had nosignificant changes in the level of serum protein but had anobvious increase of ALT and AST.The liver had obviouspathological changes,while the kidney had no evidentdamage.CONCLUSION:A eukaryotic expression vector pcDNA3-HBV containing HBV complete genome is constructedsuccessfully.HepG2 cells transfected with the recombinantcan express PreS1 mRNA and HBsAg stably.Specific cellular immune response can be induced in mice immunized bypcDNA3-HBV.A mice model of acute hepatitis with HBV hasbeen established.