title: Cotransfecting norepinephrine transporter and vesicular monoamine transporter 2 genes for increased retention of metaiodobenzylguanidine labeled with iodine 131 in malignant hepatocarcinoma cells.
abstract: Norepinephrine transporter (NET) transfection leads to significant uptake of iodine-131-labeled metaiodobenzylguanidine (131I-MIBG) in non-neuroendocrine tumors. However, the use of131I-MIBG is limited by its short retention time in target cells. To prolong the retention of131I-MIBG in target cells, we infected hepatocarcinoma (HepG2) cells with Lentivirus-encoding human NET and vesicular monoamine transporter 2 (VMAT2) genes to obtain NET-expressing, NET-VMAT2-coexpressing, and negative-control cell lines. We evaluated the uptake and efflux of131I-MIBG both in vitro and in vivo in mice bearing transfected tumors. NET-expressing and NET-VMAT2-coexpressing cells respectively showed 2.24 and 2.22 times higher131I-MIBG uptake than controls. Two hours after removal of131I-MIBG-containing medium, 25.4% efflux was observed in NET-VMAT2-coexpressing cells and 38.6% in NET-expressing cells. In vivo experiments were performed in nude mice bearing transfected tumors; results revealed that NET-VMAT2-coexpressing tumors had longer131I-MIBG retention time than NET-expressing tumors. Meanwhile, NET-VMAT2-coexpressing and NET-expressing tumors displayed 0.54% and 0.19%, respectively, of the injected dose per gram of tissue 24 h after131I-MIBG administration. Cotransfection of HepG2 cells with NET and VMAT2 resulted in increased131I-MIBG uptake and retention. However, the degree of increase was insufficient to be therapeutically effective in target cells.
authors.affiliation: Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China.
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhong
authors.affiliation: Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China. xiaohong_ou@163.com.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Ou
authors.affiliation: Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China.
authors.forename: Huawei
authors.initials: H
authors.lastname: Cai
authors.affiliation: Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China.
authors.forename: Xiaoai
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Huang
mesh_terms: D019797:3-Iodobenzylguanidine; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D004195:Disease Models, Animal; D015316:Genetic Therapy; D056945:Hep G2 Cells; D006801:Humans; D007457:Iodine Radioisotopes; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D050484:Norepinephrine Plasma Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D014162:Transfection; D050493:Vesicular Monoamine Transport Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D007457:Iodine Radioisotopes; D050484:Norepinephrine Plasma Membrane Transport Proteins; D019275:Radiopharmaceuticals; C493452:SLC18A2 protein, human; C493227:SLC6A2 protein, human; D050493:Vesicular Monoamine Transport Proteins; D019797:3-Iodobenzylguanidine
keywords: 131I-MIBG; gene therapy; lentivirus vector; norepinephrine transporter; vesicular monoamine transporter 2