title: Establishment of a human hepatocellular carcinoma cell line highly expressing sodium iodide symporter for radionuclide gene therapy.
abstract: To evaluate the possibility of radionuclide gene therapy and imaging in hepatocellular carcinoma cancer, we investigated the iodine accumulation of a human hepatocellular carcinoma cell line, SK-Hep1, by transfer of human sodium iodide symporter (hNIS) gene. By targeting NIS expression in SK-Hep1, we could also investigate whether these cells concentrate 99mTc-pertechnetate and 188Re-perrhenate as well as 125I in vitro and in vivo.
  
  
  METHODS
  The hNIS gene was transfected to human hepatocellular carcinoma SK-Hep1 cell lines using lipofectamine plus reagent. The uptake and efflux of 125I, 99mTc-pertechnetate, and 188Re-perrhenate were measured in the transfected and parental cells. Biodistribution was studied in nude mice bearing SK-Hep1 and SK-Hep1-NIS at 10 and 30 min and at 1, 2, 6, 16, and 23 h after injection of 125I, 99mTc- pertechnetate, or 188Re-perrhenate. In tumor imaging studies, the nude mice were intravenously injected with 188Re-perrhenate and imaged with a gamma-camera equipped with a pinhole collimator at 30 and 60 min after injection. The survival rate (%) was determined by the clonogenic assay after 37 MBq/10 mL (1 mCi/10 mL) 131I and 188Re-perrhenate treatment.
  
  
  RESULTS
  SK-Hep1-NIS, stably expressing the NIS gene, accumulated 125I up 150 times higher than that of SK-Hep1. Iodine uptake of SK-Hep1-NIS is completely blocked by perchlorate. NIS gene transfection into SK-Hep1 also resulted in 112- and 87-fold increases of 99mTc-pertechnetate and 188Re-perrhenate uptake, respectively. Iodide efflux from SK-Hep1-NIS was relatively slow, with only 10% released during the initial 5 min, and 60% remained at 25 min. In the biodistribution study using SK-Hep1-NIS-xenographed mice, the tumor uptake of 125I, 188Re-perrhenate, and 99mTc-pertechnetate was 68.0 +/- 15.0, 46.2 +/- 9.1, and 59.6 +/- 16.2 %ID/g (percentage injected dose per gram) at 2 h after injection, respectively. After 188Re-perrhenate injection in SK-Hep1 and SK-Hep1-NIS-xenographed nude mice, whole-body images clearly visualized the SK-Hep1-NIS tumor, whereas the control tumor was not visualized. The survival rate (%) of SK-Hep1-NIS was markedly reduced to 46.3% +/- 10.1% and 28.9% +/- 5.2% after 37 MBq/mL (1 mCi/10 mL) 131I and 188Re-perrhenate treatment compared with the survival rates of the parental cells. These results demonstrated that SK-Hep1-NIS could be selectively killed by the induced 131I and 188Re-perrhenate accumulation through NIS gene expression.
  
  
  CONCLUSIONS
  NIS-based gene therapy using beta-emitting radionuclides has the potential to be used in hepatocellular carcinoma management.
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Joo Hyun
authors.initials: JH
authors.lastname: Kang
authors.forename: June-Key
authors.initials: JK
authors.lastname: Chung
authors.forename: Yong Jin
authors.initials: YJ
authors.lastname: Lee
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Shin
authors.forename: Jae Min
authors.initials: JM
authors.lastname: Jeong
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
authors.forename: Myung Chul
authors.initials: MC
authors.lastname: Lee
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000235:genetics / Q000378:metabolism* / Q000532:radiotherapy*; D045744:Cell Line, Tumor; D003131:Combined Modality Therapy; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000235:genetics / Q000378:metabolism / Q000532:radiotherapy; D008657:Metabolic Clearance Rate; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D011868:Radioisotopes / Q000493:pharmacokinetics / Q000627:therapeutic use*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics / Q000627:therapeutic use; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D027981:Symporters / Q000235:genetics / Q000378:metabolism*; D014018:Tissue Distribution; D014162:Transfection / Q000379:methods; D016896:Treatment Outcome; D000099209:Sodium-Iodide Symporters
chemical_list: D011868:Radioisotopes; D019275:Radiopharmaceuticals; D011994:Recombinant Proteins; D027981:Symporters; D000099209:Sodium-Iodide Symporters