Differential expression of a recombinant adeno-associated virus 2 vector in human CD34+ cells and breast cancer cells

• Published in: Cancer gene therapy Vol. 7; no. 4; pp. 597 - 604
• Main Authors: Veldwijk, M R, Fruehauf, S, Schiedlmeier, B, Kleinschmidt, J A, Zeller, W J
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.04.2000
• Subjects: Antigens, CD34; Autografts; Breast cancer; Breast Neoplasms - pathology; CD34 antigen; Cells, Cultured; Chemotherapy; Contamination; Dependovirus - genetics; Enzyme inhibitors; Epithelial cells; Expression vectors; Female; Genes, Reporter; Genetic Vectors; Genistein; Green fluorescent protein; Green Fluorescent Proteins; Hematopoietic Stem Cell Mobilization; Hematopoietic stem cells; Hematopoietic Stem Cells - cytology; Hematopoietic Stem Cells - virology; Humans; Kinases; Luminescent Proteins - analysis; Luminescent Proteins - genetics; Mammary gland; Multiplicity of infection; Progenitor cells; Protein-tyrosine kinase; Recombination, Genetic; Stem cells; Suicide; Suicide genes; Transfection - methods; Tumor cell lines; Tumor cells; Tumor Cells, Cultured
• ISSN: 0929-1903; 1476-5500
• DOI: 10.1038/sj.cgt.7700159

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.