前列腺癌（PC）的放射治疗可以通过部分涉及细胞粘附介导的信号传导的分子机制导致获得放射抗性。为了定义这些机制，我们采用 DU145 PC 模型对纯化的整合素连接进行基于比较质谱的蛋白质组学分析，即细胞-基质连接，其中整合素桥接组装的细胞外基质（基质成分）与粘附信号复合物（粘附体）成分）。当比较亲代细胞和放射抗性细胞时，整合素的表达没有改变，但细胞放射抗性与广泛的基质重塑和粘附信号蛋白补体的变化有关。在亲代细胞和抗辐射细胞中差异表达的 72 种蛋白质中，根据其与生化无复发生存的相关性，选择了四种蛋白质进行功能验证。在耐辐射的 DU145 细胞中，基底膜聚糖/硫酸乙酰肝素蛋白聚糖 2 (HSPG2) 和赖氨酰样氧化酶样 2 (LOXL2) 上调，而含有寿司重复的 X-连锁蛋白 (SRPX) 和层粘连蛋白亚基 β 3 (LAMB3) 下调。基底膜蛋白/HSPG2的敲低使放射抗性DU145 RR细胞对辐射敏感，而DU145亲代细胞的敏感性没有改变，表明基底膜蛋白/HSPG2及其相关蛋白在抑制肿瘤放射抗性中的潜在作用。在雄激素敏感的亲本和抗辐射 LNCaP 细胞中的验证进一步支持基底膜蛋白 / HSPG2 作为细胞辐射敏感性的调节剂。这些发现扩展了我们对细胞外基质重塑和 PC 放射抗性之间相互作用的理解，以及标志 perlecan/HSPG2 作为 PC 潜在治疗靶点和生物标志物。版权所有 © 2024 Samaržija, Lukiyanchuk, Lončarić, Rac-Justament, Stojanović, Gorodetska, Kahya, Humphries 、法蒂玛、汉弗莱斯、弗罗布、杜布罗夫斯卡和安布里奥维奇-里斯托夫。

Radiotherapy of prostate cancer (PC) can lead to the acquisition of radioresistance through molecular mechanisms that involve, in part, cell adhesion-mediated signaling. To define these mechanisms, we employed a DU145 PC model to conduct a comparative mass spectrometry-based proteomic analysis of the purified integrin nexus, i.e., the cell-matrix junction where integrins bridge assembled extracellular matrix (matrisome components) to adhesion signaling complexes (adhesome components). When parental and radioresistant cells were compared, the expression of integrins was not changed, but cell radioresistance was associated with extensive matrix remodeling and changes in the complement of adhesion signaling proteins. Out of 72 proteins differentially expressed in the parental and radioresistant cells, four proteins were selected for functional validation based on their correlation with biochemical recurrence-free survival. Perlecan/heparan sulfate proteoglycan 2 (HSPG2) and lysyl-like oxidase-like 2 (LOXL2) were upregulated, while sushi repeat-containing protein X-linked (SRPX) and laminin subunit beta 3 (LAMB3) were downregulated in radioresistant DU145 cells. Knockdown of perlecan/HSPG2 sensitized radioresistant DU145 RR cells to irradiation while the sensitivity of DU145 parental cells did not change, indicating a potential role for perlecan/HSPG2 and its associated proteins in suppressing tumor radioresistance. Validation in androgen-sensitive parental and radioresistant LNCaP cells further supported perlecan/HSPG2 as a regulator of cell radiosensitivity. These findings extend our understanding of the interplay between extracellular matrix remodeling and PC radioresistance and signpost perlecan/HSPG2 as a potential therapeutic target and biomarker for PC.Copyright © 2024 Samaržija, Lukiyanchuk, Lončarić, Rac-Justament, Stojanović, Gorodetska, Kahya, Humphries, Fatima, Humphries, Fröbe, Dubrovska and Ambriović-Ristov.