Department of Radiotherapy, GROW - School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands.
Department of Radiotherapy, GROW - School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands; Department of Pathology, GROW-School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands.
Radiother Oncol. 2024 Jan;190:109968. doi: 10.1016/j.radonc.2023.109968. Epub 2023 Oct 28.
Hypoxia is a common feature of tumours, associated with poor prognosis due to increased resistance to radio- and chemotherapy and enhanced metastasis development. Previously we demonstrated that GABARAPL1 is required for the secretion of extracellular vesicles (EV) with pro-angiogenic properties during hypoxia. Here, we explored the role of GABARAPL1 EV in the metastatic cascade.
GABARAPL1 deficient or control MDA-MB-231 cells were injected in murine mammary fat pads. Lungs were dissected and analysed for human cytokeratin 18. EV from control and GABARAPL1 deficient cells exposed to normoxia (21% O) or hypoxia (O < 0.02%) were isolated and analysed by immunoblot, nanoparticle tracking analysis, high resolution flow cytometry, mass spectrometry and next-generation sequencing. Cellular migration and invasion were analysed using scratch assays and transwell-invasion assays, respectively.
The number of pulmonary metastases derived from GABARAPL1 deficient tumours decreased by 84%. GABARAPL1 deficient cells migrate slower but display a comparable invasive capacity. Both normoxic and hypoxic EV contain proteins and miRNAs associated with metastasis development and, in line, increase cancer cell invasiveness. Although GABARAPL1 deficiency alters EV content, it does not alter the EV-induced increase in cancer cell invasiveness.
GABARAPL1 is essential for metastasis development. This is unrelated to changes in migration and invasion and suggests that GABARAPL1 or GABARAPL1 EV are essential in other processes related to the metastatic cascade.
缺氧是肿瘤的常见特征，由于对放化疗的抵抗力增强和转移发展增强，与预后不良相关。此前我们证明，GABARAPL1 是在缺氧期间分泌具有促血管生成特性的细胞外囊泡 (EV) 所必需的。在这里，我们探讨了 GABARAPL1 EV 在转移级联中的作用。
将缺乏 GABARAPL1 或对照 MDA-MB-231 细胞注射到小鼠乳腺脂肪垫中。解剖肺部并分析人细胞角蛋白 18。从对照和缺乏 GABARAPL1 的细胞中分离 EV，并在常氧 (21% O) 或低氧 (O < 0.02%) 下进行免疫印迹、纳米颗粒跟踪分析、高分辨率流式细胞术、质谱和下一代测序分析。使用划痕实验和 Transwell 侵袭实验分别分析细胞迁移和侵袭。
源自 GABARAPL1 缺陷肿瘤的肺转移数量减少了 84%。GABARAPL1 缺陷细胞迁移速度较慢，但具有相当的侵袭能力。常氧和低氧 EV 均含有与转移发展相关的蛋白质和 miRNAs，并且与增加癌细胞侵袭性一致。尽管 GABARAPL1 缺乏会改变 EV 内容物，但它不会改变 EV 诱导的癌细胞侵袭性增加。
GABARAPL1 是转移发展所必需的。这与迁移和侵袭的变化无关，表明 GABARAPL1 或 GABARAPL1 EV 在与转移级联相关的其他过程中是必不可少的。
