尽管大量研究表明，激活的细胞焦亡可以增强多种肿瘤抗肿瘤治疗的疗效，但结直肠癌 (CRC) 中细胞焦亡的确切机制仍不清楚。使用多种技术评估了经抗肿瘤药物处理的 CRC 细胞的焦亡，包括蛋白质印迹法、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 测序转座酶可及染色质分析来评估染色质变化和 NLRP3 启动子组蛋白修饰。采用染色质免疫沉淀定量聚合酶链反应研究 NLRP3 转录调控机制。此外，还构建了异种移植和患者来源的异种移植模型来验证药物组合的效果。作为炎症小体的核心分子，NLRP3在CRC中表达被沉默，从而限制gasdermin D（GSDMD）介导的细胞焦亡。补充 NLRP3 可以挽救抗肿瘤治疗引起的细胞焦亡。 CRC 中 HDAC2 的过度表达通过表观遗传调控沉默 NLRP3。从机制上讲，HDAC2 通过消除 H3K27 乙酰化来抑制染色质可及性。 HDAC2 敲除促进 H3K27ac 介导的 BRD4-p-P65 复合物募集，从而增强 NLRP3 转录。在CRC异种移植动物中，Santacruzamate A与经典抗肿瘤药物（5-氟尿嘧啶或瑞格非尼）联合抑制HDAC2可显着激活CRC异种移植物，并取得显着的治疗效果。临床上，HDAC2 与 H3K27ac/p-P65/NLRP3 呈负相关，是 CRC 患者的预后因素。总的来说，我们的数据揭示了 HDAC2 在抑制 NLRP3/GSDMD 介导的 CRC 细胞焦亡中的关键作用，并强调 HDAC2 作为潜在的抗肿瘤治疗的治疗靶标。NLRP3 的沉默限制了结直肠癌中 GSDMD 依赖性细胞焦亡。 HDAC2 介导的组蛋白脱乙酰化导致 NLRP3 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 可激活细胞焦亡并增强治疗效果。© 2024 作者。约翰·威利出版的《临床与转化医学》

Although numerous studies have indicated that activated pyroptosis can enhance the efficacy of antitumour therapy in several tumours, the precise mechanism of pyroptosis in colorectal cancer (CRC) remains unclear.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.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.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.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.© 2024 The Author(s). Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.