METHODS: Pyroptosis in CRC cells treated with antitumour agents was assessed using various techniques, including Western blotting, lactate dehydrogenase release assay and microscopy analysis. To uncover the epigenetic mechanisms that regulate NLRP3, chromatin changes and NLRP3 promoter histone modifications were assessed using Assay for Transposase-Accessible Chromatin using sequencing and RNA sequencing. Chromatin immunoprecipitation‒quantitative polymerase chain reaction was used to investigate the NLRP3 transcriptional regulatory mechanism. Additionally, xenograft and patient-derived xenograft models were constructed to validate the effects of the drug combinations.
RESULTS: As the core molecule of the inflammasome, NLRP3 expression was silenced in CRC, thereby limiting gasdermin D (GSDMD)-mediated pyroptosis. Supplementation with NLRP3 can rescue pyroptosis induced by antitumour therapy. Overexpression of HDAC2 in CRC silences NLRP3 via epigenetic regulation. Mechanistically, HDAC2 suppressed chromatin accessibility by eliminating H3K27 acetylation. HDAC2 knockout promotes H3K27ac-mediated recruitment of the BRD4-p-P65 complex to enhance NLRP3 transcription. Inhibiting HDAC2 by Santacruzamate A in combination with classic antitumour agents (5-fluorouracil or regorafenib) in CRC xenograft-bearing animals markedly activated pyroptosis and achieved a significant therapeutic effect. Clinically, HDAC2 is inversely correlated with H3K27ac/p-P65/NLRP3 and is a prognostic factor for CRC patients.
CONCLUSIONS: Collectively, our data revealed a crucial role for HDAC2 in inhibiting NLRP3/GSDMD-mediated pyroptosis in CRC cells and highlighted HDAC2 as a potential therapeutic target for antitumour therapy.
CONCLUSIONS: Silencing of NLRP3 limits the GSDMD-dependent pyroptosis in colorectal cancer. HDAC2-mediated histone deacetylation leads to epigenetic silencing of NLRP3. HDAC2 suppresses the NLRP3 transcription by inhibiting the formation of H3K27ac/BRD4/p-P65 complex. Targeting HDAC2 activates pyroptosis and enhances therapeutic effect.
方法:使用各种技术评估用抗肿瘤药物处理的CRC细胞中的焦亡,包括西方印迹,乳酸脱氢酶释放测定和显微镜分析。为了揭示调节NLRP3的表观遗传机制,使用测序和RNA测序的转座酶可接近染色质测定评估染色质变化和NLRP3启动子组蛋白修饰。染色质免疫沉淀-定量聚合酶链反应用于研究NLRP3转录调控机制。此外,我们构建了异种移植和患者来源的异种移植模型,以验证药物组合的效果.
结果:作为炎症小体的核心分子,NLRP3表达在CRC中沉默,从而限制gasderminD(GSDMD)介导的焦亡。补充NLRP3可以挽救抗肿瘤治疗引起的焦亡。CRC中HDAC2的过表达通过表观遗传调控沉默NLRP3。机械上,HDAC2通过消除H3K27乙酰化抑制染色质可及性。HDAC2敲除促进H3K27ac介导的BRD4-p-P65复合物的募集以增强NLRP3转录。SantacruzamateA与经典抗肿瘤剂(5-氟尿嘧啶或雷戈拉非尼)联合抑制CRC异种移植动物的HDAC2,显着激活了焦亡,并取得了显着的治疗效果。临床上,HDAC2与H3K27ac/p-P65/NLRP3呈负相关,是CRC患者的预后因素。
结论:总的来说,我们的数据揭示了HDAC2在抑制NLRP3/GSDMD介导的CRC细胞焦凋亡中的关键作用,并强调HDAC2是抗肿瘤治疗的潜在治疗靶点.
结论:NLRP3的沉默限制了结直肠癌中GSDMD依赖性焦亡。HDAC2介导的组蛋白去乙酰化导致NLRP3的表观遗传沉默。HDAC2通过抑制H3K27ac/BRD4/p-P65复合物的形成来抑制NLRP3转录。靶向HDAC2激活焦亡并增强治疗效果。