title: Purging of human breast cancer cells from stem cell products with an adenovirus containing p53.
abstract: Tumor cell contamination of stem cell products can contribute to tumor relapse following high-dose chemotherapy and stem cell rescue. Numerous techniques have been used to remove the tumor cells from stem cell products with the objective of prolonging relapse-free survival. However, to date these techniques have been relatively ineffectual and/or toxic to hematopoietic stem and progenitor cells. The differential infectivity of adenovirus (Adv) vectors for breast cancer cells, compared with hematopoietic cells, has suggested that Adv-p53 might provide an effective purging strategy. To facilitate the use of Adv-p53 as a clinical strategy, we undertook studies to determine the parameters necessary for optimal stem cell product purging. The parameters studied were the particle number to nucleated cell ratio, the duration of coincubation, the incubation volume, and the presence or absence of hematopoietic progenitor cells. We have found that these parameters are interdependent and conclude that a 4-hour coincubation with an Adv-p53 particle to nucleated cell ratio of 2000:1 with 2 x 10(8) nucleated cells/mL is optimal for tumor cell purging. Furthermore, this appeared to be a safe procedure, with total loss of clonogenic growth of breast cancer cells as well as no significant effect on progenitor cell function as determined by granulocyte-macrophage colony-forming unit assays.
authors.affiliation: Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, 68198-5660, USA.
authors.forename: M
authors.initials: M
authors.lastname: Hirai
authors.forename: L S
authors.initials: LS
authors.lastname: Kelsey
authors.forename: M
authors.initials: M
authors.lastname: Vaillancourt
authors.forename: D C
authors.initials: DC
authors.lastname: Maneval
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: J E
authors.initials: JE
authors.lastname: Talmadge
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology / Q000628:therapy / Q000821:virology*; D016923:Cell Death / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D002469:Cell Separation / Q000379:methods; D002999:Clone Cells / Q000473:pathology; D018920:Coculture Techniques; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism; D006131:Growth Inhibitors / Q000235:genetics / Q000633:toxicity; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D014407:Tumor Cells, Cultured; D014410:Tumor Stem Cell Assay; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D006131:Growth Inhibitors; D016159:Tumor Suppressor Protein p53; D016178:Granulocyte-Macrophage Colony-Stimulating Factor