Changes in expression of cscs markers in rhabdomyosarcoma xenografted cell lines

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma among children. The identification of cancer stem cells (CSCs) represents one of the very relevant research topics because CSCs play important roles in tumor initiation and progression, as well as during metastasis formation and relapse of the disease. We examined the expression of several putative CSCs markers in tumor tissue sample obtained from 16-years-old female patient suffering from embryonal RMS and in the derived NSTS-11 cell line. This cell line was injected into immunodeficient mice and cell lines derived from all arising tumors were repeatedly xenografted. Both xenograft-induced tumors and respective cell lines were also analysed. Immunohistochemistry and immunofluorescence were used to examine FFPE samples; cell lines were analyzed by immunofluorescence, flow cytometry, and RT-PCR. We detected the following CSCs markers: CXCR4, CD133, nestin, ALDH, OCT3/4, nucleostemin, SOX2. Expression of these markers showed an increase in xenografted cell lines when compared with NSTS-11 cells; these results indicate an extended proportion of cells with CSCs phenotype during the process of repeated tumor-igenicity testing. This study was supported by grants IGA MZCR NT13443-4, MUNI/C/0956/2012 and by the European Regional Development Fund and the State Budget of the Czech Republic (RECAMO, CZ.1.05/2.1.00/03.0101).