title: Optimization of rhabdomyosarcoma disseminated disease assessment by flow cytometry.
abstract: Rhabdomyosarcoma (RMS) is the most common type of soft tissue sarcoma in children. Circulating tumor cells in peripheral blood or disseminated to bone marrow, a concept commonly referred to as minimal residual disease (MRD), are thought to be key to the prediction of metastasis and treatment efficacy. To date, two MRD markers, MYOD and MYOGENIN, have been tested; however, MRD detection continues to be challenging mainly owing to the closeness of the detection limit and the discordance of both markers in some samples. Therefore, the addition of a third marker could be useful for more accurate MRD assessment. The PAX3 gene is expressed during embryo development in all myogenic precursor cells in the dermomyotome. As RMS cells are thought to originate from these muscle precursor cells, they are expected to be positive for PAX3. In this study, PAX3 expression was characterized in cancer cell lines and tumors, showing wide expression in RMS. Detection sensitivities by quantitative polymerase chain reaction (qPCR) of the previously proposed markers, MYOD and MYOGENIN, were similar to that of PAX3, thereby indicating the feasibility of its detection. Interestingly, the flow cytometry experiments supported the usefulness of this technique in the quantification of MRD in RMS using PAX3 as a marker. These results indicate that flow cytometry, albeit in some cases slightly less sensitive, can be considered a good approach for MRD assessment in RMS and more consistent than qPCR, especially owing to its greater specificity. Furthermore, fluorescence-activated cell sorting permits the recovery of cells, thereby providing material for further characterization of circulating or disseminated cancer cells.
authors.affiliation: Laboratory of Translational Research in Pediatric Cancer, Vall d'Hebron Research Institute, Barcelona, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Almazán-Moga
authors.forename: Josep
authors.initials: J
authors.lastname: Roma
authors.forename: Carla
authors.initials: C
authors.lastname: Molist
authors.forename: Isaac
authors.initials: I
authors.lastname: Vidal
authors.forename: Luz
authors.initials: L
authors.lastname: Jubierre
authors.forename: Aroa
authors.initials: A
authors.lastname: Soriano
authors.forename: Miguel Francisco
authors.initials: MF
authors.lastname: Segura
authors.forename: Anna
authors.initials: A
authors.lastname: Llort
authors.forename: Josep
authors.initials: J
authors.lastname: Sánchez de Toledo
authors.forename: Soledad
authors.initials: S
authors.lastname: Gallego
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D045744:Cell Line, Tumor; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012208:Rhabdomyosarcoma / Q000175:diagnosis*; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D000072041:PAX3 Transcription Factor; C489409:PAX3 protein, human; D051761:Paired Box Transcription Factors
keywords: PAX3; flow cytometry; minimal residual disease; pediatric cancer; rhabdomyosarcoma; soft tissue sarcomas