The activation of SIRT1 by resveratrol reduces breast cancer metastasis to lung through inhibiting neutrophil extracellular traps

Neutrophil extracellular traps (NETs) play a crucial role in breast cancer metastasis. However, the therapeutic target of NETs in breast cancer metastasis is still unknown. Using a natural metabolite library and single-cell sequencing data analysis, we identified resveratrol (RES), a polyphenolic natural phytoalexin, and agonist of silent information regulator-1 (SIRT1) that suppressed NETs formation after cathepsin C (CTSC) treatment. <i>In vivo</i>, RES significantly hindered breast cancer metastasis in a murine orthotopic 4T1 breast cancer model. Serum levels of myeloperoxidase-DNA and neutrophil elastase-DNA in mouse breast cancer model were significantly lower after RES treatment. Correspondingly, the tumour infiltrated CD8⁺T cells in the lungs increased after the treatment. Mechanistically, RES targets SIRT1 in neutrophils and significantly inhibits the citrullination of histones H3, which is essential for chromatin decondensation and NETs formation. Furthermore, we identified that the NETs were suppressed by RES in bone marrow neutrophils after CTSC treatment, while specific deficiency of SIRT1 in neutrophils promoted NETs formation and breast cancer to lung metastasis. Thus, our results revealed that RES could be potentially identified as a viable therapeutic drug to prevent neutrophil cell death and breast cancer metastasis.

中性粒细胞胞外陷阱（Neutrophil extracellular traps，NETs）在乳腺癌转移过程中发挥关键作用。然而，NETs在乳腺癌转移中的治疗靶点仍未明确。本研究通过天然代谢物文库与单细胞测序数据分析，筛选出白藜芦醇（resveratrol，RES）——一种多酚类天然植物抗毒素，同时是沉默信息调节因子1（silent information regulator-1，SIRT1）的激动剂——其可在组织蛋白酶C（cathepsin C，CTSC）处理后抑制NETs形成。体内实验显示，RES可显著抑制小鼠原位4T1乳腺癌模型中的乳腺癌转移。经RES治疗后，小鼠乳腺癌模型血清中的髓过氧化物酶-DNA与中性粒细胞弹性蛋白酶-DNA水平显著降低。相应地，治疗后小鼠肺部的肿瘤浸润性CD8⁺T细胞数量显著增加。从机制上讲，RES可靶向中性粒细胞中的SIRT1，并显著抑制组蛋白H3的瓜氨酸化，该过程对染色质解聚与NETs形成至关重要。此外，我们发现经CTSC处理后，RES可抑制骨髓中性粒细胞中的NETs形成；而中性粒细胞中SIRT1的特异性缺失则会促进NETs形成与乳腺癌肺转移。综上，本研究结果表明RES有望被开发为一种可行的治疗药物，用于阻断中性粒细胞死亡并抑制乳腺癌转移。