title: Visualization of endogenous p53-mediated transcription in vivo using sodium iodide symporter.
abstract: OBJECTIVE
  To develop a gamma camera imaging method for the determination of endogenous gene expression, we evaluated the expression of endogenous p53 gene using human sodium iodide symporter (hNIS) gene as reporter.
  
  
  METHODS
  We constructed cis-p53RE-hNIS reporter vector placed under control of an artificial enhancer (p53RE). Moreover, we transfected it into human hepatoma cell line SK-Hep1 by liposome. Geneticin was used for the selection of stable transfectant (SK-Hep1p53NIS). To evaluate the function of hNIS, the inhibition study was examined with 1 mmol/L potassium perchlorate. After treatment of Adriamycin with serial dose for 24 hours, we measured the uptake of 125I and did Western blot analysis to evaluate expression of p53 protein. Tumor xenografts were produced in nude mice by s.c. injection of SK-Hep1p53NIS cells. After 7 days, scintigraphic images of nude mice before and after Adriamycin treatment were obtained using [99mTc]-pertechnetate.
  
  
  RESULTS
  In the SK-Hep1p53NIS cells, Adriamycin-treated cells accumulated up to three times higher than did nontreated cells. Potassium perchlorate inhibited completely the uptake of 125I. As Adriamycin dose increased, radioiodide uptake was significantly correlated with activated p53 as well as total p53 protein level. When Adriamycin (2 mg/kg) was treated in the same mice, a significantly higher uptake of [99mTc]-pertechnetate was observed in SK-Hep1p53NIS xenografts compared with nontreated xenografts (P < 0.05, unpaired t test).
  
  
  CONCLUSIONS
  These results suggest that p53 expression level can be monitored by NIS gene expression using cis-p53RE-hNIS system in vitro and in vivo.
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kwang Il
authors.initials: KI
authors.lastname: Kim
authors.forename: June-Key
authors.initials: JK
authors.lastname: Chung
authors.forename: Joo Hyun
authors.initials: JH
authors.lastname: Kang
authors.forename: Yong Jin
authors.initials: YJ
authors.lastname: Lee
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Shin
authors.forename: Hyun Jeong
authors.initials: HJ
authors.lastname: Oh
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; D001692:Biological Transport; D015153:Blotting, Western; D045744:Cell Line, Tumor; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic; D017930:Genes, Reporter; D005822:Genetic Vectors; D005839:Gentamicins / Q000494:pharmacology; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D010472:Perchlorates / Q000494:pharmacology; D010957:Plasmids / Q000378:metabolism; D017680:Potassium Compounds / Q000494:pharmacology; D011877:Radionuclide Imaging; D020133:Reverse Transcriptase Polymerase Chain Reaction; D027981:Symporters / Q000378:metabolism*; D013997:Time Factors; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D015854:Up-Regulation; D000099209:Sodium-Iodide Symporters
chemical_list: D018076:DNA, Complementary; D004317:Doxorubicin; D005839:Gentamicins; D010472:Perchlorates; D017680:Potassium Compounds; D027981:Symporters; D016159:Tumor Suppressor Protein p53; D000099209:Sodium-Iodide Symporters; C009006:potassium perchlorate; C010680:antibiotic G 418