title: Immunobead filtration: a novel approach for the isolation and propagation of tumor cells.
abstract: We have developed a method to facilitate the isolation and expansion of tumor cells from body fluids and tissue biopsies. Antibody-conjugated magnetic beads (immunobeads) were used to isolate tumor cells from blood, bone marrow, ascitic/pleural fluids, and enzyme-digested tissue biopsies. Filtration of the resulting cell suspension through a 20-micron nylon monofilament filter secured to the base of polystyrene 96-well strips purged the bead-rosetting cell fraction of contaminating normal cells and unbound beads. Tumor cells that bound the magnetic beads were retained on the membrane due to their increased size and concentrated into a small area (0.332 cm2), thus maintaining a high cell density. The filters provided a stable and uniform three-dimensional matrix for cell growth, with a total surface area of 1.42 cm2 available for cell attachment. The filters could be easily removed from the base of the 96-well strips to facilitate handling and transfer between culture vessels. Tumor cells grown on the filters could subsequently be harvested using trypsin/EDTA or left in situ for immunostaining with conventional immunohistochemical procedures. Filter-grown cells have shown extended passage in conventional cell culture in six cases. In two of five cases, the orthotopic implantation of confluent filters that contained approximately 10(4) cells/8 x 8 mm filter successfully produced tumors in nude mice after only 4 weeks. Our new approach may be of value in improving the success rate of generating long-term cultures from previously unproductive sources of tumor cells and thus may yield a greater variety of cell lines/strains for the study of malignant disease.
authors.affiliation: Department of Tumor Biology, Norwegian Radium Hospital, Oslo, Norway.
authors.forename: P D
authors.initials: PD
authors.lastname: Rye
authors.forename: H K
authors.initials: HK
authors.lastname: Høifødt
authors.forename: G E
authors.initials: GE
authors.lastname: Overli
authors.forename: O
authors.initials: O
authors.lastname: Fodstad
mesh_terms: D000818:Animals; D002460:Cell Line; D002469:Cell Separation / Q000295:instrumentation / Q000379:methods*; D005374:Filtration / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007150:Immunohistochemistry; D008546:Melanoma, Experimental / Q000737:chemistry / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008863:Microspheres; D014183:Transplantation, Heterologous