Neuropilin-2 (NRP2) is a prognostic indicator for reduced survival in bladder cancer (BCa) patients. Together with its major ligand, vascular endothelial growth factor (VEGF)-C, NRP2 expression is a predictive factor for treatment outcome in response to radiochemotherapy in BCa patients who underwent transurethral resection. Therefore, we investigated the benefit of combining cisplatin-based chemotherapy with irradiation treatment in the BCa cell line RT112 exhibiting or lacking endogenous NRP2 expression in order to evaluate NRP2 as potential therapeutic target. We have identified a high correlation of NRP2 and the glioma-associated oncogene family zinc finger 2 (GLI2) transcripts in the cancer genome atlas (TCGA) cohort of BCa patients and a panel of 15 human BCa cell lines. Furthermore, we used in vitro BCa models to show the transforming growth factor-beta 1 (TGFβ1)-dependent regulation of NRP2 and GLI2 expression levels. Since NRP2 was shown to bind TGFβ1, associate with TGFβ receptors, and enhance TGFβ1 signaling, we evaluated downstream signaling pathways using an epithelial-to-mesenchymal transition (EMT)-assay in combination with a PCR profiling array containing 84 genes related to EMT. Subsequent target validation in NRP2 knockout and knockdown models revealed secreted phosphoprotein 1 (SPP1/OPN/Osteopontin) as a downstream target positively regulated by NRP2.

Neuropilin‐2 (NRP2) is a member of the neuropilin receptor family and known to regulate autophagy and mTORC2 signaling in prostate cancer (PCa). Our study investigated the association of immunohistochemical NRP2 expression with clinicopathological data in PCa patients. For this purpose, we generated a tissue microarray with prostate tissue specimens from 400 PCa patients treated by radical prostatectomy. We focused on patients with high‐risk factors such as extraprostatic extension (pT ≥ 3), Gleason score ≥8 and/or the presence of regional lymph node metastases (pN1). Protein levels of NRP2, the vascular endothelial growth factor C (VEGFC) and oncogenic v‐ets avian erythroblastosis virus E26 oncogene homolog (ERG) gene as an indicator for TMPRSS2‐ERG fusion was assessed in relation to the patients' outcome. NRP2 emerged as an independent prognostic factor for cancer‐specific survival (CSS) (hazard ratio 2.360, 95% confidence interval = 1.2–4.8; p = 0.016). Moreover, the association between NRP2 expression and shorter CSS was also especially pronounced in patients at high risk for progression (log‐rank test: p = 0.010). We evaluated the association between NRP2 and the TMPRSS2‐ERG gene fusion status assessed by immunohistochemical nuclear ERG staining. However, ERG staining alone did not show any prognostic significance. NRP2 immunostaining is significantly associated with shorter CSS in ERG‐negative tumors (log‐rank test: p = 0.012). No prognostic impact of NRP2 expression on CSS was observed in ERG‐positive tumors (log‐rank test: p = 0.153). Our study identifies NRP2 as an important prognostic marker for a worse clinical outcome especially in patients with a high‐risk PCa and in patients with ERG‐negative PCa.

Background: Canonical androgen receptor (AR) signaling regulates a network of DNA repair genes in prostate cancer (PCA). Experimental and clinical evidence indicates that androgen deprivation not only suppresses DNA repair activity but is often synthetically lethal in combination with PARP inhibition. The present study aimed to elucidate the impact of AR splice variants (AR-Vs), occurring in advanced or late-stage PCA, on DNA repair machinery. Methods: Two hundred and seventy-three tissue samples were analyzed, including primary hormone-naïve PCA, primary metastases, hormone-sensitive PCA on androgen deprivation therapy (ADT) and castration refractory PCA (CRPC group). The transcript levels of the target genes were profiled using the nCounter platform. Experimental support for the findings was gained in AR/AR-V7-expressing LNCaP cells subjected to ionizing radiation. Results: AR-Vs were present in half of hormone-sensitive PCAs on androgen deprivation therapy (ADT) and two-thirds of CRPC samples. The presence of AR-Vs is highly correlated with increased activity in the AR pathway and DNA repair gene expression. In AR-V-expressing CRPC, the DNA repair score increased by 2.5-fold as compared to AR-V-negative samples. Enhanced DNA repair and the deregulation of DNA repair genes by AR-V7 supported the clinical data in a cell line model. Conclusions: The expression of AR splice variants such as AR-V7 in PCA patients following ADT might be a reason for reduced or absent therapy effects in patients on additional PARP inhibition due to the modulation of DNA repair gene expression. Consequently, AR-Vs should be further studied as predictive biomarkers for therapy response in this setting.

Urothelial bladder cancer ranks among the 10 most frequently diagnosed cancers worldwide. In our previous study, the transmembrane protein neuropilin-2 (NRP2) emerged as a predictive marker in patients with bladder cancer. NRP2 consists of several splice variants; the most abundant of these, NRP2a and NRP2b, are reported to have different biological functions in lung cancer progression. For other cancer types, there are no published data on the role of these transcript variants in cancer progression and the clinical outcome. Here, we correlate NRP2 and its two most abundant transcript variants, NRP2A and NRP2B, with the clinical outcome using available genomic data with subsequent validation in our own cohort of patients with muscle-invasive bladder cancer. In addition to NRP2, NRP1 and the NRP ligands PDGFC and PDGFD were studied. Only NRP2A emerged as an independent prognostic marker for shorter cancer-specific survival in muscle-invasive bladder cancer in our cohort of 102 patients who underwent radical cystectomy between 2008 and 2014 with a median follow-up time of 82 months. Additionally, we demonstrate that high messenger expression of NRP2, NRP1, PDGFC and PDGFD associates with a more aggressive disease (i.e., a high T stage, positive lymph node status and reduced survival).

Coronavirus disease 2019 (COVID-19) is associated with hyperinflammation, endothelialitis, hypoxemia, and hypercoagulation, contributing to thrombosis in acute severe and long COVID. While ACE2 is the primary severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor, its low expression in certain infected cell types suggests alternative co-receptors. Neuropilins (NRP1 and NRP2), widely expressed, have been proposed as co-factors for viral entry. We analyzed NRP1 and NRP2 expression in autopsy tissues from heart, lung, and hematolymphoid organs using immunohistochemistry ( n = 20) and compared findings with public single-cell RNA sequencing (scRNAseq) data. Selected cases were further examined by spatial multiplex immunofluorescence (CODEX). In vitro binding of NRP1/NRP2 to SARS-CoV-2 spike fragments S1 and S1′ was assessed by immunofluorescence microscopy. NRP1 was abundantly expressed in myocardial capillary endothelial cells (ECs) and macrophages in the heart and lung; NRP2 was found in alveolar macrophages and mast cells. scRNAseq re-analysis confirmed these in situ patterns. In vitro , NRP1 exclusively bound S1, while NRP2 bound both S1 and S1′. SARS-CoV-2 RNA was detected in neuropilin-positive, ACE2 / TMPRSS2 -negative vascular EC and mast cells. The detection of SARS-CoV-2 RNA in neuropilin-positive but ACE2 / TMPRSS2 -negative cell clusters supports that neuropilins are involved in systemic viral dissemination. NRP1 on vascular EC may contribute to angiogenesis, vascular damage, and microangiopathy, while NRP2 represents a potential immunomodulatory target to regulate macrophage activity, resolve inflammation, and potentially prevent the progression of pulmonary fibrosis and limit excessive mast cell activation in long COVID. IMPORTANCE: The well-known severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor, angiotensin-converting enzyme 2 (ACE2), exhibits low expression in key cell types implicated in coronavirus disease 2019 (COVID-19) pathology, such as endothelial cells and B cells, macrophages, and mast cells. In contrast, neuropilins, identified as co-receptors for SARS-CoV-2, are abundantly expressed in these cells under physiological conditions and may be involved in virus-host interactions. This study presents a detailed in situ analysis of Neuropilin 1 (NRP1) and Neuropilin 2 (NRP2) expression in fatal COVID-19 cases using immunohistochemistry and spatial multiplex immunofluorescence phenotyping, complemented by single cell RNA sequencing. Additionally, it demonstrates differential binding affinities of NRP1 and NRP2 to SARS-CoV-2 spike protein fragments S1 and S1′ in vitro , suggesting distinct roles for these neuropilins in viral recognition. This study highlights the impact of the unique furin cleavage site in SARS-CoV-2, which may contribute to increased pathogenicity through its interaction with NRP1.