OBJECTIVETo observe the targeted therapeutic effects of plasmid AF-pGL3-hTERT-TK on HepG2 cells.

METHODSHepG2 cells were cultured and pGL3-hTERT-TK and AF-liposome were constructed. HepG2 and L02 cells were transfected with AF-pGL3-hTERT-TK. The growth, apoptosis of the cells and the bystander effects were studied using liquid scintillation analysis and tunnel and flow cytometry.

RESULTSAfter the suicide gene was inserted into the downstream of hTERT, TK was effectively driven by the hTERT promoter, making the TK highly expressed in the HepG2 cells. The AF made the therapeutic gene enter the HepG2 cells more easily by recognizing and combining the ASGPR receptor protein on the HepG2 cell surfaces and induced their apoptosis and suicide with bystander effect. The apoptosis rate was 85%+/-3% in the HepG2 cells whereas in the normal L02 hepatic cells it was 16%+/-2%.

CONCLUSIONAF-pGL3-hTERT-TK can target and attack HepG2 cells and has almost no influence on normal L02 hepatic cells. AF-pGL3-hTERT-TK has a potential in the treatment of hepatocellular carcinomas.

Apoptosis ; Asialoglycoproteins ; Bystander Effect ; Fetuins ; Ganciclovir ; metabolism ; Genes, Transgenic, Suicide ; Genetic Therapy ; Hep G2 Cells ; Humans ; Telomerase ; metabolism ; Thymidine Kinase ; metabolism ; Transfection ; alpha-Fetoproteins

AIMTo target for hepatocytic cell, liposomes was modified by special ligand.

METHODSSterically stabilized liposomes (SSL) was conjugated with asialofeticin (AF), the ligand of asialoglycoprotein receptor (ASGP-R) of hepatocyte. ASGP-R-BLM is the ASGP-R reconstructed on bilayer lipid membrane (BLM). The recognition reaction between AF-SSL and ASGP-R-BLM can be monitored by the varieties of membrane electrical parameters. The targetability of AF-SSL mediated to hepatocyte was detected by radioisotopic labeled in vitro and in vivo. The therapeutic effect of antihepatocarcinoma was observed also.

RESULTSThe lifetime of ASGP-R-BLM decreased with the added amount of AF-SSL. It was demonstrated that there was recognition reaction between AF-SSL and ASGP-R-BLM. The combination of AF-SSL with hepatocyte was significantly higher than that of SSL without AF-modified in vitro and in vivo. The survival time of rat for AF-SSL carriered ADM (adriamycin) group was much longer and the toxicities on heart, kidney and lung were lower than those SSL carried ADM group.

CONCLUSIONIt is possible to actively target the cell with specific receptor by ligand modified liposomes. The result prvide scientific basis of hepatocyte targeted liposomes.

Animals ; Antineoplastic Agents ; administration & dosage ; therapeutic use ; Asialoglycoprotein Receptor ; Asialoglycoproteins ; chemistry ; Doxorubicin ; administration & dosage ; therapeutic use ; Drug Carriers ; Drug Delivery Systems ; Fetuins ; Hepatocytes ; metabolism ; Ligands ; Lipid Bilayers ; Liposomes ; chemistry ; metabolism ; Liver ; metabolism ; Liver Neoplasms, Experimental ; drug therapy ; Male ; Mice ; Random Allocation ; Rats ; alpha-Fetoproteins ; chemistry

AIMTo study the transfection and anti-hepatitis B virus (HBV) effect of the co-modified hepatocytes-targeting cationic liposomes encapsulating anti-HBV antisense oligonucleotides (asON) , and to investigate the transfection mechanisms of the liposomes.

METHODSDipalmitoylphosphatidylcholine (DPPC) and 3beta-[N-(N',N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) were used as the lipids, beta-sitosterol-beta-D-glucoside (sito-G) and Brij 35 were used to modify the liposomes. Flow cytometry (FCM), fluorescence microscopy and enzyme-linked immunosorbent assay (ELISA) were utilized to evaluate the transfection improvement of the asON encapsulated in the liposomes in primary rat hepatocytes and the antigens inhibition activity in HepG 2.2.15 cells. The transfection mechanisms were evaluated based on the influence of wortmannin, nigericin, and asialofetuin on the antigens inhibition in HepG 2.2.15 cells by ELISA.

RESULTSThe co-modification with sito-G and Brij 35 significantly improved the transfection of the liposomes in primary rat hepatocytes and antigens inhibition effect in HepG 2.2.15 cells. Both transfection efficiency and antigens inhibition effect showed to be concentration-dependent with the asON-encapsulating liposomes. In fluorescence microscopy, the transfected cells showed strong fluorescence in primary rat hepatocytes, especially in the nuclei. Wortmannin, nigericin and asialofetuin decreased the antigens inhibition of the asON-encapsulating liposomes to different levels. Cationic liposomes modification with sito-G and Brij 35 could improve the transfection and antigens inhibition effect of the asON. The transfection mechanisms of the co-modified liposomes included endocytosis and membrane fusion. The ligand sito-G was confirmed to be able to enhance asialoglycoprotein receptor (ASGPR)-mediated endocytosis.

CONCLUSIONCo-modified hepatocytes-targeting cationic liposomes would be a specific and effective carrier to transfer asON into hepatocytes.

Androstadienes ; pharmacology ; Animals ; Asialoglycoproteins ; pharmacology ; Cell Line, Tumor ; Cell Nucleus ; metabolism ; Cell Survival ; Cells, Cultured ; Endocytosis ; drug effects ; Female ; Fetuins ; Flow Cytometry ; Hepatitis B Antigens ; metabolism ; Hepatitis B virus ; genetics ; immunology ; Hepatocytes ; cytology ; drug effects ; metabolism ; Humans ; Liposomes ; Microscopy, Fluorescence ; Nigericin ; pharmacology ; Oligonucleotides, Antisense ; chemistry ; genetics ; Polyethylene Glycols ; chemistry ; Rats ; Rats, Wistar ; Sitosterols ; chemistry ; Transfection ; methods ; alpha-Fetoproteins ; pharmacology