Zhang Song, Ingram Hayley, Cooper Jack, Naveed Alina, Kathman Stefan G, Lindsey Garrett L, Liu Tao, Bond Charles S, Fletcher Jamie I, Cravatt Benjamin F, Fox Archa H
School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia.
Department of Chemistry, The Scripps Research Institute, La Jolla, California, USA.
FASEB J. 2025 Sep 30;39(18):e71051. doi: 10.1096/fj.202403267RR.
High-risk neuroblastoma is associated with upregulation of cholesterol biosynthesis through increased expression of sterol regulatory element-binding protein (SREBP). NONO, a multifunctional nuclear RNA binding protein, is an established oncogene in neuroblastoma and can stabilize SREBP in breast cancer. Hence, here we addressed the unexplored question of NONO regulation of SREBP in neuroblastoma. We show NONO knockdown reduces cholesterol in neuroblastoma patient-derived tumor cell lines and high-risk neuroblastoma KELLY cells. NONO knockdown also reduces mRNA and protein expression of SREBP family members in KELLY cells. RNA-seq of NONO knockdown confirmed cholesterol synthesis pathway genes are downregulated. Further, only overexpression of NONO wild-type, rather than NONO mutant lacking the RNA recognition motif 1, could elevate SREBP levels after endogenous NONO knockdown, revealing the importance of NONO RNA binding activity. Finally, (R)-SKBG-1, a small molecule that modulates the RNA binding activity of NONO, hence altering its subnuclear distribution, significantly decreased cholesterol levels and SREBP target gene expression in KELLY cells. These results lend weight to manipulating NONO RNA binding as a potential therapeutic avenue for treating aggressive neuroblastoma.
高危神经母细胞瘤与通过固醇调节元件结合蛋白（SREBP）表达增加导致的胆固醇生物合成上调有关。NONO是一种多功能核RNA结合蛋白，是神经母细胞瘤中已确定的癌基因，并且在乳腺癌中可稳定SREBP。因此，在此我们探讨了神经母细胞瘤中NONO对SREBP调节这一未被探索的问题。我们发现敲低NONO可降低神经母细胞瘤患者来源的肿瘤细胞系和高危神经母细胞瘤KELLY细胞中的胆固醇水平。敲低NONO还可降低KELLY细胞中SREBP家族成员的mRNA和蛋白表达。敲低NONO后的RNA测序证实胆固醇合成途径基因被下调。此外，只有野生型NONO的过表达，而不是缺乏RNA识别基序1的NONO突变体，能够在内源性NONO敲低后提高SREBP水平，揭示了NONO RNA结合活性的重要性。最后，（R）-SKBG-1是一种调节NONO的RNA结合活性从而改变其核内亚分布的小分子，可显著降低KELLY细胞中的胆固醇水平和SREBP靶基因表达。这些结果支持将调控NONO的RNA结合作为治疗侵袭性神经母细胞瘤的潜在治疗途径。
