Stat3 介导的 Atg7 表达调控小鼠黑色素瘤中的抗肿瘤免疫。
Stat3-mediated Atg7 expression regulates anti-tumor immunity in mouse melanoma.
机构信息
Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA.
Division of Oncology, Molecular Oncology Section, Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA.
出版信息
Cancer Immunol Immunother. 2024 Sep 5;73(11):218. doi: 10.1007/s00262-024-03804-4.
Epigenetic modifications to DNA and chromatin control oncogenic and tumor-suppressive mechanisms in melanoma. Ezh2, the catalytic component of the Polycomb Repressive Complex 2 (PRC2), which mediates methylation of lysine 27 on histone 3 (H3K27me3), can regulate both melanoma initiation and progression. We previously found that mutant Ezh2 interacts with the immune regulator Stat3 and together they affect anti-tumor immunity. However, given the numerous downstream targets and pathways affected by Ezh2, many mechanisms that determine its oncogenic activity remain largely unexplored. Using genetically engineered mouse models, we further investigated the role of pathways downstream of Ezh2 in melanoma carcinogenesis and identified significant enrichment in several autophagy signatures, along with increased expression of autophagy regulators, such as Atg7. In this study, we investigated the effect of Atg7 on melanoma growth and tumor immunity within the context of a wild-type or Ezh2 epigenetic state. We found that the Atg7 locus is controlled by multiple Ezh2 and Stat3 binding sites, Atg7 expression is dependent on Stat3 expression, and that deletion of Atg7 slows down melanoma cell growth in vivo, but not in vitro. Atg7 deletion also results in increased CD8 + T cells in Ezh2 melanomas and reduced myelosuppressive cell infiltration in the tumor microenvironment, particularly in Ezh2 melanomas, suggesting a strong immune system contribution in the role of Atg7 in melanoma progression. These findings highlight the complex interplay between genetic mutations, epigenetic regulators, and autophagy in shaping tumor immunity in melanoma.
DNA 和染色质的表观遗传修饰控制着黑色素瘤中的致癌和肿瘤抑制机制。Ezh2 是多梳抑制复合物 2(PRC2)的催化亚基,介导组蛋白 3(H3K27me3)赖氨酸 27 的甲基化,可调节黑色素瘤的起始和进展。我们之前发现突变型 Ezh2 与免疫调节因子 Stat3 相互作用,它们共同影响抗肿瘤免疫。然而,鉴于 Ezh2 有许多下游靶标和途径受到影响,许多决定其致癌活性的机制仍在很大程度上未被探索。使用基因工程小鼠模型,我们进一步研究了 Ezh2 下游途径在黑色素瘤发生中的作用,并发现几种自噬特征明显富集,同时自噬调节剂如 Atg7 的表达增加。在这项研究中,我们研究了 Atg7 在野生型或 Ezh2 表观遗传状态下对黑色素瘤生长和肿瘤免疫的影响。我们发现 Atg7 基因座受多个 Ezh2 和 Stat3 结合位点的控制,Atg7 的表达依赖于 Stat3 的表达,并且 Atg7 的缺失会减缓体内黑色素瘤细胞的生长,但不会减缓体外的生长。Atg7 的缺失还会导致 Ezh2 黑色素瘤中 CD8+T 细胞增加,并减少肿瘤微环境中的骨髓抑制细胞浸润,尤其是在 Ezh2 黑色素瘤中,这表明在 Atg7 对黑色素瘤进展的作用中,免疫系统有很强的贡献。这些发现强调了遗传突变、表观遗传调节剂和自噬之间的复杂相互作用在塑造黑色素瘤中的肿瘤免疫。