Purpose: Although numerous cell-signaling receptors have been described in the setting of osteosarcoma, the comprehensive characterization of receptors on the cell-surface has not been described. The goal of the current study was to characterize and quantify the expression of cell-surface receptors across multiple standard osteosarcoma cell lines and patient samples placed in culture.

Methods: Both standard (n=4) and patient derived (n=10) osteosarcoma cell lines were cultured and labelled with a panel of commercially available flurophore-bound antibodies including antibodies to EGFR, HER-2, HER-3, HER-4, IGF-1R, IGF-2R, IR, VEGFR-1, VEGFR-2, VEGFR-3, CMET, FGFR-2, FGFR-3, PDGF alpha, and PDGF beta. Standard cell lines utilized were 143b, HOS, Saos, and U205. Patient samples included samples 229, 231, 232, 238, 252, 293, 308, 311, 242, and 290. Background fluorescence was accounted for using either a known negative control cell line if available or the antibody-specific IgG isotype. Unlabelled cells were also evaluated for inherent fluorescence. Cell analysis was performed using flow cytometry (FACS) and data was analyzed using FloJo software. The geometric fluorescent means were calculated and compared against positive controls.

Results: Although a degree of variability in cell-surface receptor expression existed between the different cell lines, preliminary results show high expression of PDGFR-beta in all 14 cell lines, with an average geometric mean of 1376 (range 93.8 - 4496). A higher expression of IGF-1R was also noted across all cell lines, with an average geometric mean of 881 (range 122 - 3191). In depth analysis of receptor expression and the interrelationship of these various receptors is ongoing.

Conclusion: Preliminary results demonstrate PDGFR-Beta and to a lesser extent IGF-1R to be consistently expressed on the cell-surface in all tested osteosarcomas cell lines. Data analysis of receptor expression and interrelationships between receptor expression is ongoing.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5104.

©2010 American Association for Cancer Research
2010