Abstract. Background/Aim: Rhabdomyosarcoma is the most common type of pediatric soft-tissue sarcoma. Among the subsets of this disease, alveolar rhabdomyosarcoma (ARMS) expressing paired box 3 (PAX3) and forkhead box O1 (PAX3-FOXO1Rhabdomyosarcoma (RMS) is the most common type of pediatric soft tissue sarcoma and accounts for approximately 50% of all soft-tissue sarcomas (1). RMS occurs predominantly in the sites of skeletal muscle lineage. RMS is categorized into two subtypes based on histological observations (2); embryonal (ERMS) and alveolar (ARMS). Between these two subtypes, ARMS has the worse prognosis and is associated with a higher frequency of metastasis (3, 4). ARMS is characterized by the translocation t(2;13)(q35;q14) or t(1;13)(q36;q14) that lead to paired box 3-forkhead box O1 (PAX3-FOXO1) and paired box 7-forkhead box O1 (PAX7-FOXO1) gene fusions, respectively. PAX3-FOXO1 is present in about 55% of ARMS harboring overexpression of this fusion gene at both RNA and protein levels. PAX7-FOXO1 is present in 22% of ARMS, and the remaining 23% of ARMS is fusion-negative (3, 5). PAX3-FOXO1-positive ARMS is the most clinically intractable subtype among RMS types (2, 3, 6, 7). Mutation of tumor protein p53 (TP53) is infrequent in RMS, occurring in fewer than 10% of patients (8), and inactive TP53 is more common in fusion-negative RMS (9).Sphingolipids are practically ubiquitous and are found in all eukaryotic cell membranes, some prokaryotes, and in foods such as dairy and soy products (10, 11). Animal studies showed complex dietary sphingolipids (e.g. sphingomyelin, dihydrosphingomyelin, glucosylceramide, lactosylceramide, and ganglioside GD 3 ), reduced aberrant colonic foci in CF1 mice (12-17) and reduced tumors in all regions of the intestine in multiple intestinal neoplasia (Min) mice with truncated adenomatous polyposis coli (17, 18). These anti-tumorigenic effects of sphingolipids against colon carcinogenesis could be the result of the conversion of complex sphingolipids to sphingolipid metabolites. Sphingolipid metabolites, such as ceramide (acylated form of sphingosine) and sphingoid bases (sphingosine, 71