Extended Figure 9. NSD3-dependency renders PDXs from LUSC patients therapeutically vulnerable to BETi.

a-c, Tumor volume quantification of PDX^CTR-1 (a), PDX^CTR-2 (b) and PDX^AMP-2 (c) growing in immunocompromised mice (n = 5 mice, for each treatment group). Western blots with the indicated antibodies of lysates from the PDX ± sgNSD3 is shown. Actin is shown as a loading control. d, BRD4 interacts with NSD3 in PSC_N cells. Left panel: Western blot of whole cell lysates from PSC_N cells ± sgNSD3 to show the relative position of NSD3 and NSD3_Short in PSC_N cells. Tubulin used as a loading control. Right panel: BRD4 interacts with both NSD3 and NSD3_Short isoforms in PSC_N cells. Co-immunoprecipitation (IP) experiments in PSC_N cells with indicated antibodies for IPs and western analyses. Input, PSC_N cell nuclear extract. e, Proliferation assay of PSC_C and PSC_N treated with vehicle control or 20nM AZD5153 (BETi). Data represent mean ± s.e.m. of three technical replicates in two independent experiments. f, Treatment of PSC_N cells with the BETi JQ1 inhibits expression of the indicated NSD3 target genes. Real-time (RT) qPCR analysis of the indicated mRNAs from PSC_N cells treated with DMSO or 100nM of JQ1. The RT-qPCR data for each target gene were normalized to Actb and presented as fold change relative to DMSO treated sample. Error bars represent mean ± s.d. from three independent experiments. P values were determined by two-tailed unpaired t-test. g-h, Tumor volume quantification of PDX^CTR-1 (g) and PDX^CTR-2 (h) treated with BETi or vehicle (control). Arrowhead indicates start of the treatment. P values were determined by two-tailed unpaired t-test. (a-c, f) or two-way ANOVA with Tukey’s post hoc test (e, g-h). Data are represented as mean ± s.e.m. (a-c, e, f-h).