C57bl 6 129 sv 77

C2C12, HEK293T and RD cell lines were purchased from ATCC (Manassas, VA). JR1, Rh36, Rh30 and Rh41 cell lines were generously donated by Dr. Peter Houghton (Columbus, OH, USA). Mouse embryonic fibroblasts (MEFs) were isolated from E13.5 embryos of mixed C57BL/6 × 129/Sv 77 background (Jackson Laboratory, Maine) using the procedure approved by the Institutional Care and Use Committee (IACUC) at the American University of Beirut, and following the IACUC-approved guidelines. C2C12 cells were maintained in Dulbecco’s Modified Eagles Medium (DMEM) with 20% FBS, 1% glutamine, and 1% Pen/Strep (Sigma). Other cells were cultured in RPMI-1640 medium with 10% fetal bovine serum, 1% glutamine, and 1% Pen/Strep (Sigma). All cells maintained under standard conditions (humidified atmosphere, 95% air, 5% CO₂, 37 °C).

The human ERMS cell lines JR1 and Rh36, and the ARMS cell lines Rh30 and Rh41, were generously donated by Dr. Peter Houghton (Columbus, OH, USA), and have been previously described (reviewed in ref. 65 (link)). RD (human ERMS), BJ (human foreskin fibroblast), IMR90 (human fetal lung fibroblast), HUVEC (human umbilical vein endothelial cells) and HEK293T (human embryonic kidney) cell lines were purchased from ATCC (Manassas, VA). Mouse embryonic fibroblasts (MEFs) were isolated from E13.5 embryos of wild type mice of a mixed C57BL/6 × 129/Sv 77 genetic background (Jackson Laboratory, Maine). All RMS cells were tested and authenticated by DDC Medical (London, UK). Cells were cultured in Dulbecco’s Modified Eagles Medium or RPMI-1640 medium supplemented with 10% fetal bovine serum, 1% glutamine, and 1% Pen/Strep (all from Sigma), maintained under standard incubator conditions (humidified atmosphere, 95% air, 5% CO_2, 37 °C) and passaged twice weekly by trypsinization.