修复DNA不匹配的蛋白质MSH6是一种PD-L1表达的新型调节剂
Kirsten Brooksbank1, Charlotte Smith1, Eleni Maniati2
1Centre for Cancer Cell & Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK.
概括
丢失的DNA修复基因MLH1,MSH2和PMS2在癌症中增加PD-L1,但MSH6的损失不是由于MSH6.
科学领域:
- 在瘤学瘤学.
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
背景情况:
- 免疫检查点抑制剂 (ICI) 在不匹配修复缺陷 (MMRd) 癌症中显示出有效性.
- 大约50%的MMRd癌症患者表现出对ICI的耐药性.
- 针对MMR基因丢失的响应因子的差异调节是产生耐药性的潜在原因.
研究的目的:
- 研究不同MMR基因损失对影响ICI反应的因素的影响.
- 阐明MSH6在PD-L1转录中的新型调节作用.
- 检查MMR基因状态,微卫星不稳定性和突变负担之间的关系.
主要方法:
- 在MMR基因淘汰 (KO) 癌细胞中分析PD-L1表达.
- 通过SETD2招募调查MSH6在PD-L1转录中的作用.
- MLH1和MSH6KO细胞的下一代测序 (NGS),以评估微卫星的不稳定性和突变负担.
主要成果:
- 失去MLH1,MSH2和PMS2与增加PD-L1表达相关.
- 由于MSH6的直接转录调节PD-L1.1,MSH6的损失不会增加PD-L1的表达.
- 尽管突变负担较高,但MSH6KO细胞的微卫星不稳定性低于MLH1KO细胞.
结论:
- MSH6作为PD-L1转录的直接调节者,依赖于SETD2.
- 在MMRd癌症队列中的基因特异分层对于预测ICI反应至关重要.
- 了解MMR基因功能是克服ICI耐药性的关键.
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