Objective The dysregulation of the axon guidance pathway is common in pancreatic ductal adenocarcinoma (PDAC), yet our understanding of its biological relevance is limited. Here, we investigated the functional role of the axon guidance cue SEMA3A in supporting PDAC progression. Design We integrated bulk and single-cell transcriptomic datasets of human PDAC with in situ hybridisation analyses of patients’ tissues to evaluate SEMA3A expression in molecular subtypes of PDAC. Gain and loss of function experiments in PDAC cell lines and organoids were performed to dissect how SEMA3A contributes to define a biologically aggressive phenotype. Results In PDAC tissues, SEMA3A is expressed by stromal elements and selectively enriched in basal-like/squamous epithelial cells. Accordingly, expression of SEMA3A in PDAC cells is induced by both cell-intrinsic and cell-extrinsic determinants of the basal-like phenotype. In vitro , SEMA3A promotes cell migration as well as anoikis resistance. At the molecular level, these phenotypes are associated with increased focal adhesion kinase signalling through canonical SEMA3A-NRP1 axis. SEMA3A provides mouse PDAC cells with greater metastatic competence and favours intratumoural infiltration of tumour-associated macrophages and reduced density of T cells. Mechanistically, SEMA3A functions as chemoattractant for macrophages and skews their polarisation towards an M2-like phenotype. In SEMA3Ahigh tumours, depletion of macrophages results in greater intratumour infiltration by CD8+T cells and better control of the disease from antitumour treatment. Conclusions Here, we show that SEMA3A is a stress-sensitive locus that promotes the malignant phenotype of basal-like PDAC through both cell-intrinsic and cell-extrinsic mechanisms. All data relevant to the study are included in the article or uploaded as online supplemental information. Data will be made available following acceptance.

中文翻译：

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轴突引导信号SEMA3A促进基底样PDAC的攻击性表型

目的 轴突引导通路失调在胰腺导管腺癌（PDAC）中很常见，但我们对其生物学相关性的了解有限。在这里，我们研究了轴突引导信号 SEMA3A 在支持 PDAC 进展中的功能作用。设计我们将人类 PDAC 的大量和单细胞转录组数据集与患者组织的原位杂交分析相结合，以评估 PDAC 分子亚型中的 SEMA3A 表达。在 PDAC 细胞系和类器官中进行功能获得和丧失实验，以剖析 SEMA3A 如何有助于定义生物攻击性表型。结果在PDAC组织中，SEMA3A由基质成分表达并选择性富集于基底样/鳞状上皮细胞中。因此，SEMA3A在PDAC细胞中的表达是由基底样表型的细胞内在和细胞外在决定因素诱导的。在体外，SEMA3A 促进细胞迁移以及失巢凋亡抵抗。在分子水平上，这些表型与通过规范 SEMA3A-NRP1 轴增加的粘着斑激酶信号传导相关。 SEMA3A 为小鼠 PDAC 细胞提供了更强的转移能力，有利于肿瘤相关巨噬细胞的瘤内浸润并降低 T 细胞密度。从机制上讲，SEMA3A 充当巨噬细胞的化学引诱剂，并使它们的极化偏向 M2 样表型。在 SEMA3Ahigh 肿瘤中，巨噬细胞的消耗导致 CD8+T 细胞更大的肿瘤内浸润，并通过抗肿瘤治疗更好地控制疾病。结论 在这里，我们表明SEMA3A是一个应激敏感位点，它通过细胞内在和细胞外在机制促进基底样PDAC的恶性表型。与研究相关的所有数据都包含在文章中或作为在线补充信息上传。数据将在接受后提供。