FIGURE 4_Optimization of rhabdomyosarcoma disseminated disease assessment by flow cytometry

To determine the sensitivity of the PAX3 cytometric assay in 10-fold-increasing serial dilutions of RMS cells in 107 mononuclear cells (MNC) from peripheral blood of healthy donors. The RMS cells used for the serial dilutions were RH30 (aRMS bearing PAX3/FOXO1 translocation), CW9019 (aRMS bearing PAX7/FOXO1 translocation) and RD (eRMS)
Conclusion:
PAX3 detection by flow cytometry shows more specificity than the PCR-based standard method of MRD disease detection in RMS. For flow cytometry analysis, samples treated with the appropriate IgG were used as a negative control. Cell lines expressing high PAX3 levels and blood samples of healthy donors were used as positive controls of PAX3 and CD45 expression, respectively. In order to establish the sensitivity of the PAX3 detection method, spiking experiments (10-fold-increasing serial dilutions of RMS cells in 107 mononuclear cells from healthy donors) were performed. All determinations were made in triplicate.