【Abstract】Objective To construct a recombinant adenoviral vector carrying antisense matrix metalloproteinase2 (MMP2) for use in the gene therapy to inhibit the invasiveness and migratory capacity of hepatocellular carcinoma (HCC) cell line HepG2 in vitro and in vivo models. Methods Total RNA was extracted from HCC, and then a 500 bp fragment at the 5′ end of human MMP2 cDNA was synthesized by polymerase chain reaction (PCR) and was reversely inserted into the multiclone site (MCS) of the shuttle plasmid pAdTrack-CMV,with the resultant plasmid and the backbone plasmid pAdEasy-1,the homologous recombination took place in the E.coli BJ5183 and the recombinant adenoviral plasmid carrying the antisense MMP2 gene was constructed and generated. The adenoviruses(Ad-MMP2AS) were packaged and amplified in the HEK 293 cells.Then the viral titer was checked by GFP. Results The recombinant adenovirus vector carrying antisense MMP2 was constructed successfully, the b green fluorescence was observed in HEK 293 cells under a fluorescence microscopy. The viral titer was 1×108/ml. Conclusion The recombinant adenovirus Ad-MMP2AS constructed by us could introduce the antisense MMP2 into HepG2 effectively,which would provide experimental basis for reversing the overexpression of MMP2 in HCC and for inhibiting the invasiveness and migratory capacity of HepG2 in vitro and in vivo models.
【Abstract】ObjectiveTo construct an mdr1 expression vector and detect its expression in HepG2 cells in vitro. MethodsThe 4.5-kb mdr1 cDNA was obtained from the plasmid pHaMDR1 cloned into the PCIneo mammalian expression vector, which was later transferred into human hepatocarcinoma cell line HepG2 by liposome. Then the HepG2 cells resisting G418 were clustered and proliferated，and the specific fragment of mdr1 cDNA, mRNA and the Pgp in these HepG2 cells were detected by means of PCR, RT-PCR and FCM respectively. ResultsThe mdr1 expression vector was constructed successfully，and the stable multidrug resistance(MDR) hepatocarcinoma cell line （HepG2/mdr1） was developed as well. The outcome of PCR analysis showed that the specific fragment of mdr1 cDNA could be found in HepG2/mdr1 cells, but not in the nontransfection HepG2 cells. Furthermore,the content of the specific fragment of mdr1 mRNA and the expression of P-gp in HepG2/mdr1 cells were (59.7±7.9)% and (12.5±5.45)% respectively, the corresponding value in HepG2 cells were (16.9±3.2)% and (4.63±2.59)% respectively. The difference was statistically significant (P＜0.05). ConclusionIt is praticable to develop MDR hepatocarcinoma cell line by transferring mdr1 cDNA into HepG2 cells, which is useful in the research of MDR mechanism.
ObjectiveTo construct the recombinant adenovirus vector carrying antisense multidrug resistanceassociated protein (MRP) and transfect the human drugresistant hepatocellular carcinoma cell line(SMMC7721/ADM). MethodsThe fragment of MRP gene encoding 5′region was cloned reversely into the shuttle plasmid pAdTrackCMV, with the resultant plasmid and the backbone plasmid pAdEasy1,the homologous recombination took place in the bacteria and the recombinant adenoviral plasmid was generated. The adenoviruses were packaged and amplified in 293 cells. Then the cell line of SMMC7721/ADM was transfected with the resultant adenoviruses.ResultsThe recombinant adenovirus vector carrying antisense MRP was constructed successfully. The viral titer was 2.5×109 efu/ml, and more than 90% SMMC7721/ADM cells could be transfected when the multiplicity of infection（MOI） was 100. ConclusionThe recombinant adenovirus vector constructed by us could introduce the antisense MRP into the human drugresistant hepatocellular cell line effectively, which would provide experimental basis for the mechanisms and reversal methods of the multidrug resistance in human hepatocellular carcinoma.
Objective To examine the effect of zinc finger protein A20 on regeneration of small-for-sized liver allograft, graft rejection and recipient rat survival time. Methods Small-for-sized liver transplantation with 30% partial liver allograft was performed by using a b-rejection combination rat model of DA (RT1a) to Lewis (RT1l) rats. The rats were grouped into rAdEasy-A20 treatment group （A20 group）, the control empty Ad vector rAdEasy treatment group (rAdEasy group) and PS control treatment group (PS group). Ex vivo gene transfer in donor liver graft was performed through portal vein infusion. Animals were assessed for survival days, expression of A20 in liver graft, liver graft regeneration, hepatocyte apoptosis, graft rejection, NF-κB activation and ICAM-1 mRNA expression in liver graft sinusoidal endothelial cells (LSECs), number of liver graft infiltrating mononuclear cells (LIMCs) and the subproportion of NK/NKT cells, and serum IFN-γ level. Results Survival day of A20 group rats was prominently longer than that of PS group rats and rAdEasy group rats (P=0.001 8), whereas survival day of rAdEasy group rats was remarkably shorter than that of PS group rats (P=0.001 8). Regeneration of the small-for-sized liver allograft was markedly augmented by A20, BrdU labelling index of hepatocyte on postoperative day 4 was significantly increased in the A20 group compared with the PS group and rAdEasy group (P＜0.01). Hepatocyte apoptosis on postoperative day 4 was significantly inhibited by A20 (P＜0.01). On postoperative day 4, histologic examination revealed a mild rejection in the A20 group but a more severe rejection in the PS and rAdEasy groups. NF-κB activity and ICAM-1 mRNA expression in LSECs on postoperative day 1 were notably suppressed by A20 overexpression. Flow cytometry analysis showed a marked downregulation of LIMCs number by A20, including more prominent decrease in the subproportion of NK/NKT cells on postoperative day 1 and 4, respectively (P＜0.05). Serum IFN-γ level on postoperative day 4 was also significantly suppressed by A20 overexpression (P＜0.05). Conclusion These data suggest that A20 could effectively promote small-for-sized liver allograft regeneration, suppresses rejection and prolong survival days of recipient rats. These effects of A20 could be related to an inhibition of LSECs activation, suppression of infiltration of LIMCs and the subpopulations such as NK cells and NKT cells into liver graft, and inhibition of hepatocyte apoptosis.
【Abstract】ObjectiveTo construct a recombinant adeno-associated virus(rAAV2) vectors carrying the combined transcriptional regulatory sequences of α-fetoprotein enhancer and albumin promoter for the purpose of targeted gene therapy for hepatocellular carcinoma (HCC). MethodsThe fragment of combined transcriptional regulatory sequences of α-fetoprotein enhancer and albumin promoter was amplified through polymerase chain reaction (PCR) and cloned into the promoter site of pAAV-IRES-hrGFP instead of the CMV promotor in AAV Helper-Free System to construct the rAAV2 expression plasmid pAAV-IRES-hrGFP-EP. Then the packaging cell lines (HEK 293 cell) was co-transfected with the pAAV-IRES-hrGFP-EP together with the control plasmid pAAV-RC and pHelper in AAV Helper-Free System by means of lipofectamine.The recombinant adenoassociated virus vector(rAAV2-EP) carrying the combined transcriptional regulatory sequences of α-fetoprotein enhancer and albumin promoter was packaged and amplified in the HEK 293 cell. Then the viral titer was checked by GFP. ResultsThe recombinant adeno-associated virus vector(rAAV2-EP) carrying the combined transcriptional regulatory sequences of α-fetoprotein enhancer and albumin promoter was constructed successfully, the b green fluorescence was observed in HEK 293 cells under fluorescence microscope. The viral titer was 1.2×105. ConclusionConstruction of the recombinant adeno-associated virus vector rAAV2-EP driven by the combined transcriptional regulatory sequences of α-fetoprotein enhancer and albumin promoter would provide a sound basis and improved vector for targeted gene therapy for HCC.