journal contribution
posted on 2025-02-17, 08:20 authored by Juan Jin, Jun Luo, Xiaodong Jin, Kiat Shenq Lim, Yang He, Jiawei Ding, Yan Shen, Yuchen Hou, Hanqing Liu, Xiaoyu Zhu, Jing Zhao, Wenjie Zhou, Hai Huang, Yi Gao, Jun Xiao, Hongchao He, Qunyi Li, Lianxin Liu, Li Chen, Qiang He, Chuanjie Zhang Supplementary Figure 3. CHD6 is essential for FH-deficient RCC cells, related to Figure 4. A-B. MTT analysis of FH-WT PRCC (A) or canonical ccRCC (B) cells with or without CHD6-KD. C. Competition-based assay to measure the effect of CHD4 shRNA on the growth of UOK-262 cells (n = 3 per time point). CHD4-KD cells were identified by coexpression of green fluorescent protein (GFP) (LMN vector). The percentage of GFP+ cells was thus tracked over 12 days and normalized to GFP percentage on day 2. D. Quantified BIL signals of orthotopic (FH-intact Caki-2) renal tumors with or without CHD6 ablation. E. Serum VEGF concentrations in treated BALC/c nude mice from indicated groups were compared. F. Ki-67 (IHC) and TUNEL (IF) staining from xenografts derived from FH-KD and FH/CHD6-KD Caki-2 cells, and the quantitative results are shown in the right panel. Scale bar, 20 μm. G. Kaplan-Meier survival curve analysis of mice from Figure 4F. H. Schematic graph showing the zebrafish tumour xenograft model construction at each time point. I. Quantified tumour sizes derived from indicated cells implanted in the zebrafish embryos. J. Quantitation of organoid sizes from human FH-WT or FM-RCC samples with or without CHD6 depletion. P values were calculated using 2-way ANOVA followed by Tukey’s multiple comparisons tests (A, B), 2-tailed Student’s t-test (C-F, I-J), and log-rank test (G). *p < 0.05, **p < 0.01, and ***p < 0.001. ns, no significance.
Funding
National Natural Science Foundation of China (NSFC)
Natural Science Foundation of Shanghai Municipality (上海市自然科学基金)
History
ARTICLE ABSTRACT
Fumarate hydratase (FH) deficiency causes hereditary leiomyomatosis and renal cell carcinoma (RCC). FH-deficient tumors lack effective therapeutic options. Here, we utilized an epigenetic-focused single-guide RNA library to elucidate potential drug targets in FH-deficient tumors. The screen identified chromodomain helicase DNA-binding protein 6 (CHD6) as an essential regulator of the growth of FH-mutated RCC. Mechanically, FH loss induced fumarate-mediated succinylation and inactivation of KEAP1, blocking subsequent ubiquitin–proteasome degradation of CHD6. Stabilized CHD6 formed a complex with p65 to establish proinflammatory enhancers and thereby regulate NF-κB–mediated transcription. Moreover, CHD6 recruited mSWI/SNF ATPases to maintain chromatin accessibility at CHD6-bound enhancers. The PROTAC degrader of SMARCA2/4 AU-15330 effectively abolished structures of cis-regulatory elements bound by CHD6 and suppressed the growth of FH-mutated, but not FH-intact, RCC in vivo. Collectively, these data indicate that CHD6 is a molecular bridge between FH deficiency and proinflammatory enhancer assembly that endows FH-deficient tumors with epigenetic vulnerabilities.Significance: CHD6 links FH deficiency to aberrant NF-κB activity in renal cell carcinoma, highlighting an epigenetic vulnerability for this rare tumor subtype.
