A method to culture human alveolar rhabdomyosarcoma cell lines as rhabdospheres demonstrates an enrichment in stemness and notch signaling

• Published in: Biology open 2020-01
• Main Authors: Slemmons, Katherine K, Deel, Michael D, Lin, Yi-Tzu, Oristian, Kristianne M, Kuprasertkul, Nina, Genadry, Katia C, Chen, Po-Han, Chi, Jen-Tsan Ashley, Linardic, Corinne M
• Format: Article
• Language: English
• ISSN: 2046-6390
• DOI: 10.1242/bio.050211

The development of three-dimensional cell culture techniques has allowed cancer researchers to study the stemness properties of cancer cells in in vitro culture. However, a method to grow PAX3-FOXO1 fusion-positive rhabdomyosarcoma (FP-RMS) - an aggressive soft tissue sarcoma of childhood - has to date not been reported, hampering efforts to identify the dysregulated signaling pathways that underlie FP-RMS stemness. Here, we first examine the expression of canonical stem cell markers in human RMS tumors and cell lines. We then describe a method to grow FP-RMS cell lines as rhabdospheres and demonstrate that these spheres are enriched in expression of canonical stemness factors as well as Notch signaling components. Specifically, FP-RMS rhabdospheres have increased expression of SOX2, POU5F1 (OCT4), and NANOG, and several receptors and transcriptional regulators in the Notch signaling pathway. FP-RMS rhabdospheres also exhibit functional stemness characteristics including multipotency, increased tumorigenicity in vivo, and chemoresistance. This method provides a novel practical tool to support research into FP-RMS stemness and chemoresistance signaling mechanisms.