title: Differential expression of a recombinant adeno-associated virus 2 vector in human CD34+ cells and breast cancer cells.
abstract: The use of autologous hematopoietic stem cell (HSC) grafts after high-dose chemotherapy protocols may be hampered by contamination of the grafts with tumor cells. Because epithelial cells seem to be the natural hosts of adeno-associated virus 2 (AAV-2), we speculated that epithelial tumor cells in HSC grafts might be selective targets for AAV-2-based vectors. To test this hypothesis, the breast cancer cell lines T47D and MCF-7 were infected with a recombinant AAV-2 vector expressing the green fluorescent protein (GFP) gene; in addition, human CD34+ mobilized peripheral progenitor cells were infected with the same vector. At a multiplicity of infection of 100, only 1.39% +/- 0.51% CD34+ cells expressed the GFP gene whereas, 36.06% +/- 6.53% of the infected T47D cells and 41.52% +/- 3.16% of the infected MCF-7 cells expressed the transduced GFP gene. After further optimizing the transduction procedure by using higher multiplicities of infection (100-500) and preincubation of samples with the tyrosine kinase inhibitor genistein, up to 82.52% and 85.35% GFP+ T47D and MCF-7 cells, respectively, were observed. The GFP fluorescence intensity in transduced mammary tumor cells was up to 3 logs higher than that of transduced CD34+ cells. The differential expression of recombinant AAV-2 vectors in hematopoietic and epithelial tumor cells warrants further research with this vector system, including the use of suicide genes for the purging of autologous HSC grafts.
authors.affiliation: Research Program Diagnostics and Experimental Therapy, German Cancer Research Center, Heidelberg, Germany. m.veldwijk@dkfz-heidelberg.de
authors.forename: M R
authors.initials: MR
authors.lastname: Veldwijk
authors.forename: S
authors.initials: S
authors.lastname: Fruehauf
authors.forename: B
authors.initials: B
authors.lastname: Schiedlmeier
authors.forename: J A
authors.initials: JA
authors.lastname: Kleinschmidt
authors.forename: W J
authors.initials: WJ
authors.lastname: Zeller
mesh_terms: D018952:Antigens, CD34; D001943:Breast Neoplasms / Q000473:pathology*; D002478:Cells, Cultured; D000229:Dependovirus / Q000235:genetics*; D005260:Female; D017930:Genes, Reporter; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D019650:Hematopoietic Stem Cell Mobilization; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000821:virology; D006801:Humans; D008164:Luminescent Proteins / Q000032:analysis / Q000235:genetics; D011995:Recombination, Genetic; D014162:Transfection / Q000379:methods*; D014407:Tumor Cells, Cultured
chemical_list: D018952:Antigens, CD34; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins