Cpi203

For treatment of monolayer neuronal cultures (e.g. cortical INs and general cortical neurons), 75 nM JQ1 (ApexBio A1910) was added to the media starting from 2 weeks of neuronal maturation (day 32). Media containing JQ1 was replenished every four days. For treatment with other BET bromodomain inhibitors, 50 nM CPI203 (Cayman 15479) or 100 nM IBET762 (Cayman 10676) was added to the media from day 32, and drug-containing media was replenished every four days. For treatment at later stages (Figure S4K and S4L), day 65 INs were treated with 75 nM JQ1 for 24 hours, or day 61 INs were treated with 75 nM, 150 nM or 300 nM JQ1 for 10 days, followed by depolarization and gene expression assays. For treatment of brain organoids, 75 nM JQ1 was added to the media starting from day 25, and drug-containing media was replenished every four days. For in vivo treatment, JQ1 was administered to mice starting from 2 weeks of age via intraperitoneal injections. Each mouse was injected daily with JQ1 (15 mg/kg) dissolved in DMSO or DMSO along, which was diluted into cyclodextrin (Sigma C0926). Mice were subjected to weekly phenotypic scoring starting from 7 weeks of age as previously described (Guy et al., 2007 (link); Tillotson et al., 2017 (link)). Body weights of mice were weekly measured. Mice survival was graphed using the Kaplan-Meier survival plot.

Primary mouse MPNST (mMPNST) cells were generated via a mouse MPNST model as described previously (34 (link), 50 (link), 51 (link)). Human S462 MPNST cells were a kind gift from Karen Cichowski (Harvard Medical School). Human MPNST cells were authenticated with human-specific PCR primers on 9/18/18 to confirm the absence of mouse tumor cell contamination. All leukemia cell lines were a kind gift from Dr. Chengcheng Zhang (UT Southwestern, Dallas, TX). Routine mycoplasma testing of the cell lines was not performed. All cells were cultured in DMEM (10% FBS, 1% L-glutamine, 1% sodium pyruvate, 1% penicillin-streptomycin). Drugs used: JQ1 (Cayman Chemical and MedChem Express), OTX-015 (Cayman Chemical), CPI-203 (Cayman Chemical), CPI-0610 (Axon Medchem), ARV-771 and ARV-825 (MedChem Express).