活体动物基因表达的分子影像学研究方法.ppt

Imaging stem cell survival, proliferation and migration in vivo 2. Imaging therapeutic gene delivery Thymidine kinase serves as a PET reporter gene when [18F]-FHBG is used in pico-nanomolar concentration. Thymidine kinase serves as suicide gene when ganciclovir is administered in milligram dosages. VEGF therapeutic geneHSVTK imaging gene Rats injected with 1x1010 pfu Ad-CMV-VEGF121-CMV-HSV1-sr39tk during the peri-infarct period. In vivo perfusion/metabolism defects confirmed by histology. HSV1-sr39tk reporter gene confirmed by thymidine kinase antibody stain. At 2 months, VEGF treated animals show significant increases in capillaries (CD31 stain; 747±104 vs. 450±101 /mm2) and small blood vessels (α-SMA stain; 8.1±0.8 vs. 5.1±1.2 /mm2). 3. Imaging promoter activation in transgenic mice Imaging TGFalpha pathway 4. Imaging TGF-beta pathway TβRE -mouse germline immunoglobulin Igα promoter 5. Imaging protein protein interaction MyoD and ID Protein-Protein Interaction Thank You ! * * * * * Molecular imaging(gene expression imaging) What is molecular resolution? Imaging gene expression product -Protein Imaging reporter gene expression HaubnerR et al., Cancer Res. 61:1781,2001. Smith-Jones, et al. Nature Biotechnology22, 701 -706 (2004) Imaging reporter gene Tracer Trapping Methods Enzymes as reporter genes Enzymes as reporter genes Phosphorylation HSV1-TK traps radiolabeled acyclovir (nucleotide-5’-monophosphates cannot cross plasma membrane) Deamination Cytosine deaminate traps radiolabeled 5-fluorocytosine X=O, Y=OH, Z=H X=CH , Y=OH, Z=H X=O, Y=OH, Z=F X=CH , Y=OH, Z=F X=O, Y=F, Z=H GCV PCV FGCV FPCV FHBG HSV-TK substrates Yaghoubi S, et al. “Human pharmaco-kinetic and dosimetry studies of [18F]FHBG: A reporter probe for imaging HSV1-tk reporter gene expression” J Nucl Med 2001. PET Imaging of Ad-CMV-HSV1-tk Transgene Expression in Liver Cancer Patients Penuelas I, et al. Gastroenterology 2005 MRI Other enzymatic systems Galactopyronose cap b-galactosidase Mea