在炎症和组织再生过程中，警报蛋白高迁移率族盒 1 (HMGB1) 以其还原异构体增强趋化因子 CXCL12 的活性，形成通过趋化因子受体 CXCR4 发挥作用的异质复合物。尽管 HMGB1 和 CXCL12 在肿瘤进展和远端转移扩散中的作用已被确定，但 CXCL12/HMGB1 异质复合物在癌症中的作用从未被研究过。通过采用新建立的质谱分析方案，可以明确区分细胞裂解物中还原的 (red-HMGB1) 和氧化的 (ox-HMGB1) HMGB1 亚型，我们证明源自乳腺的人上皮细胞（MCF-7 和 MDA-MB） -231) 和前列腺 (PC-3) 癌主要表达红色 HMGB1，而来自外周血的原代 CD3 T 淋巴细胞表达两种 HMGB1 亚型。所有这些癌细胞在细胞外微环境中释放 HMGB1 以及不同浓度的硫氧还蛋白和硫氧还蛋白还原酶。 CXCL12/HMGB1 异质复合物通过 CXCR4 增强癌细胞的定向迁移和侵袭力，这些癌细胞具有完全活跃的硫氧还蛋白系统，具有高转移潜力，有助于维持红色-HMGB1。相反，转移潜力低、缺乏硫氧还蛋白还原酶的癌细胞会迅速摄取CXCL12，并且无法对异源复合物做出反应。我们的研究表明，癌细胞对 CXCL12/HMGB1 异质复合物的反应性（导致细胞迁移和侵袭性增强）取决于 HMGB1 以其还原异构体的维持，并表明破坏异质复合物作为抑制侵袭和侵袭的潜在治疗靶点。癌症治疗中的转移扩散。版权所有 © 2024 Pirani、Paparoditis、Pecoraro、Danelon、Thelen、Cecchinato 和 Uguccioni。

During inflammation and tissue regeneration, the alarmin High Mobility Group Box 1 (HMGB1), in its reduced isoform, enhances the activity of the chemokine CXCL12, forming a heterocomplex that acts via the chemokine receptor CXCR4. Despite the established roles of both HMGB1 and CXCL12 in tumor progression and metastatic spread to distal sites, the role of the CXCL12/HMGB1 heterocomplex in cancer has never been investigated. By employing a newly established mass spectrometry protocol that allows an unambiguous distinction between reduced (red-HMGB1) and oxidized (ox-HMGB1) HMGB1 isoforms in cell lysates, we demonstrate that human epithelial cells derived from breast (MCF-7 and MDA-MB-231) and prostate (PC-3) cancer predominantly express red-HMGB1, while primary CD3+ T lymphocytes from peripheral blood express both HMGB1 isoforms. All these cancer cells release HMGB1 in the extracellular microenvironment together with varying concentrations of thioredoxin and thioredoxin reductase. The CXCL12/HMGB1 heterocomplex enhances, via CXCR4, the directional migration and invasiveness of cancer cells characterized by high metastatic potential that possess a fully active thioredoxin system, contributing to maintain red-HMGB1. On the contrary, cancer cells with low metastatic potential, lack thioredoxin reductase, promptly uptake CXCL12 and fail to respond to the heterocomplex. Our study demonstrates that the responsiveness of cancer cells to the CXCL12/HMGB1 heterocomplex, resulting in enhanced cell migration and invasiveness, depends on the maintenance of HMGB1 in its reduced isoform, and suggests disruption of the heterocomplex as a potential therapeutic target to inhibit invasion and metastatic spread in cancer therapies.Copyright © 2024 Pirani, Paparoditis, Pecoraro, Danelon, Thelen, Cecchinato and Uguccioni.