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Background: Bladder cancer with divergent differentiation (BCDD) comprises a heterogenous group of tumors with a poor prognosis, and differential expression of nectin‐4 and programmed death ligand‐1 (PD‐L1) has been reported in BCDD. Importantly, nectin‐4 expression in bladder cancer is associated with response to enfortumab vedotin, and PD‐L1 expression is associated with responses to immune checkpoint inhibitors (ICIs). Methods: The authors conducted a retrospective review identifying 117 patients with advanced or metastatic BCDD who were treated at Winship Cancer Institute from 2011 to 2021. They performed immunohistochemistry staining for nectin‐4 and PD‐L1 expression by histologic subtype as well as genomic analysis of these patients, including RNA sequencing, whole‐exome sequencing, and fusion detection analysis as well as a subgroup genomic analysis of patients with BCDD who received ICIs. Results: The results indicated that nectin‐4 expression was highest in the groups who had the squamous and plasmacytoid subtypes, whereas the group that had the sarcomatoid subtype (70.8%) had the highest proportion of PD‐L1–positive patients. Genomic analysis yielded several key findings, including a 50% RB1 mutation rate in patients who had small cell BCDD, targetable PIK3CA mutations across multiple subtypes of BCDD, and significantly higher expression of TEC in responders to ICIs. Conclusions: In this study, the authors identified clinically relevant data on nectin‐4 and PD‐L1 expression in patients with rare bladder tumors. They also identified several novel findings in the genomic analysis that highlight the role of precision medicine in this population of patients. Larger, prospective studies are needed to validate these hypothesis‐generating data. In this study, the authors performed a retrospective analysis focused on the histologic and genomic characterization of bladder cancer with divergent differentiation. The results indicated that nectin‐4 expression was highest in patients with squamous and plasmacytoid differentiation, whereas patients who had sarcomatoid differentiation (70.8%) had the highest proportion of programmed death ligand‐1–positive disease, and several novel findings were identified in the genomic analysis that have potential clinical implications for these patients with rare tumors. [ABSTRACT FROM AUTHOR]

Advanced urothelial carcinoma (aUC) has a dismal prognosis, with a 5-year survival rate of approximately 10%. Platinum-based chemotherapy has been the backbone of the first-line treatment of aUC for over 40 years. Only in the last decade, the treatment of aUC has evolved and been enriched with new classes of drugs that demonstrated pivotal improvements in terms of oncological responses and, ultimately, survival. Thus, the approach to aUC is becoming more and more tailored to the single patient, particularly owing to targeted therapies, such as fibroblast growth factor receptor (FGFR) inhibitors, antibody-drug conjugates (ADCs) targeting TROP2 and Nectin-4, anti-Her-2 therapies and others. However, due to the rapidly evolving scenario, the optimal sequence of systemic treatment is unknown and several important research questions remain unanswered, including the identification of reliable biomarkers to guide treatment decisions. Through ongoing research and clinical trials, we can continue to refine personalized treatment strategies and ultimately enhance patient care in this challenging disease setting. In this review, we provide a comprehensive overview of the current and emerging landscape of targeted therapies for aUC. We delved into the opportunities and challenges presented by personalized treatment approaches and explored potential future directions in this rapidly evolving field.

Antibody‐drug conjugates (ADCs) represent a novel type of targeted cancer therapy combining the specificity of monoclonal antibodies with the cytotoxicity of conventional chemotherapy. Recently, ADCs have demonstrated practice‐changing efficacy across diverse solid cancers. The anti‐NECTIN‐4 ADC enfortumab vedotin (EV) has just been approved for patients with urothelial cancer and is currently under investigation for patients with castration‐resistant prostate cancer (CRPC e.g. Phase II ENCORE trial). Our objective was to evaluate the efficacy of EV in established prostate cancer (PCa) cell lines and to examine the membranous NECTIN‐4 expression in primary tumours (PRIM) and distant metastases (MET). NECTIN‐4 was heterogeneously expressed in the panel of PCa cell lines. EV led to growth inhibition in NECTIN‐4 expressing PCa cells (22Rv1 and LNCaP), whereas the NECTIN‐4‐negative PC‐3 cells were significantly less responsive to EV, emphasizing the dependence of EV response on its target expression. Immunohistochemical staining revealed moderate membranous NECTIN‐4 expression only in a small subgroup of CRPC patients with lung and peritoneal MET [n = 3/22 with H‐score ≥100, median H‐score 140 (IQR 130–150)], while 100% of PRIM (n = 48/48) and 86.4% of common MET sites (n = 19/22), including lymph node, bone and liver MET, were NECTIN‐4 negative. In summary, EV may be effective in NECTIN‐4‐positive PCa. However, our findings demonstrate that the tumoural NECTIN‐4 expression is predominantly low in metastatic PCa, which suggests that EV may only be effective in a biomarker‐stratified subgroup. [ABSTRACT FROM AUTHOR]

IntroductionT cell Antigen Coupler (TAC) T cells harness all signaling subunits of endogenous T cell receptor (TCR) to trigger T-cell activation and tumor cell lysis, with minimal release of cytokines. Some of the major obstacles to cellular immunotherapy in solid tumors include inefficient cell infiltration into tumors, lack of prolonged cellular persistence, and therapy-associated toxicity.MethodsTo boost the cytotoxic potential of TAC-T cells against solid tumors, we generated a novel NECTIN-4-targeted TAC-T variant, NECTIN-4 TAC28-T, which integrated the co-stimulatory CD28 cytoplasmic region, and compared the anti-tumor activities between NECTIN-4 TAC-T cells and NECTIN-4 TAC28-T cells in vitro and vivo.ResultsWe demonstrated NECTIN-4 TAC28-Tcells could be effectively activated by NECTIN-4 protein-coated magnetic beads (NECTIN-4-beads), and further revealed that the incorporated CD28 co-stimulatory domain enhanced their activation and proliferation capabilities. Notably, NECTIN-4 TAC28-T cells exhibited better anti-tumor effects both in vitro and in vivo than the original NECTIN-4 TAC-T cells.DiscussionOur data highlighted that NECTIN-4 TAC28-T cells may represent a promising, safe and effective cell therapy for NECTIN-4-overexpressing solid tumors.

The study explores the increased expression of Nectin-4 in patients with atopic dermatitis (AD) and psoriasis vulgaris (PsV). Serum Nectin-4 levels were found to be higher in AD and PsV patients compared to healthy individuals, and correlated with disease severity markers. The study suggests a possible association between Nectin-4 expression and keratinocyte differentiation in inflammatory skin diseases, highlighting the potential role of Nectin-4 in disease progression. Further research with larger sample sizes is needed to validate these findings. [Extracted from the article]

Abstract Background Gastric cancer represents a highly lethal malignancy with an elevated mortality rate among cancer patients, coupled with a suboptimal postoperative survival prognosis. Nectin-4, an overexpressed oncological target for various cancers, has been exploited to create antibody-drug conjugates (ADCs) to treat solid tumors. However, there is limited research on Nectin-4 ADCs specifically for gastric cancer, and conventional immunoglobulin G (IgG)-based ADCs frequently encounter binding site barriers. Based on the excellent tumor penetration capabilities inherent in nanobodies (Nbs), we developed Nectin-4-targeting Nb drug conjugates (NDCs) for the treatment of gastric cancer. Results An immunized phage display library was established and employed for the selection of Nectin-4-specific Nbs using phage display technology. Subsequently, these Nbs were engineered into homodimers to enhance Nb affinity. To prolong in vivo half-life and reduce immunogenicity, we fused an Nb targeting human serum albumin (HSA), resulting in the development of trivalent humanized Nbs. Further, we site-specifically conjugated a monomethyl auristatin E (MMAE) at the C-terminus of the trivalent Nbs, creating Nectin-4 NDC (huNb26/Nb26-Nbh-MMAE) with a drug-to-antibody ratio (DAR) of 1. Nectin-4 NDC demonstrated excellent in vitro cell-binding activities and cytotoxic efficacy against cells with high Nectin-4 expression. Subsequent administration of Nectin-4 NDC to mice bearing NCI-N87 human gastric cancer xenografts demonstrated rapid tissue penetration and high tumor uptake through in vivo imaging. Moreover, Nectin-4 NDC exhibited noteworthy dose-dependent anti-tumor efficacy in in vivo studies. Conclusion We have engineered a Nectin-4 NDC with elevated affinity and effective tumor uptake, further establishing its potential as a therapeutic agent for gastric cancer. Graphical abstract

Introduction: Nectin-4 is a member of the nectin family and a calcium-independent immunoglobulin-like transmembrane protein that contributes to tumor growth and angiogenesis in malignant tumors. A nectin-4-directed antibody drug conjugate, enfortumab vedotin-ejf, has recently been approved for treatment in urothelial cancer and is currently under investigation in other tumor entities such as breast, lung, and prostate cancer. In non-clear cell renal cell carcinoma (RCC), vascular endothelial growth factor (VEGF)-directed tyrosine kinase inhibitors and checkpoint inhibitors are currently treatments of choice. However, due to the rarity of disease treatment recommendations for chromophobe RCC (chRCC) are limited and new therapeutic agents urgently needed. In this study, we investigated the expression and prognostic impact of nectin-4 in a large cohort of chRCC. Methods: Patients who underwent renal surgery due to chRCC were recruited. Clinical data were retrospectively evaluated. Tumor specimen was analyzed for nectin-4 expression by immunohistochemistry. Results: Eighty-one chRCC patients were eligible for analysis. In 15 (18.5%) samples, tumors were positive for nectin-4. No significant associations were found for nectin-4 expression and clinical attributes in patients with chRCC. Kaplan-Meier analysis disclosed a 5-year overall survival for nectin-4-negative and nectin-4-positive tumors of 91.8% versus 100.0% (p = 0.316, log rank). Conclusions: In chRCC, a small subset of tumors expresses nectin-4 potentially amenable to nectin-4-directed treatment. Expression of nectin-4 is not associated with parameters of aggressiveness or survival. Due to the rare incidence of chRCC, further studies with larger cohorts are warranted. [ABSTRACT FROM AUTHOR]

Simple Summary: Cancer of the penis is a relatively uncommon cancer that nevertheless can be life threatening when it is at an advanced stage. We summarized the published laboratory results that might lead to new and better treatment approaches, including those that harness the immune system. We identified several opportunities for drug development and corresponding clinical trials that are or will soon be testing these ideas in patients. In conclusion, we outline how these ongoing efforts will hopefully improve outcomes for patients with advanced penile cancer. Discovery of effective systemic therapies for patients with advanced penile cancer has been slow to occur. Comprehensive genomic profiling from several studies shed light on the molecular oncogenesis of penile squamous cell carcinoma (PSCC) and differences between HPV-related and unrelated tumors. While these two subsets of PSCC appear distinct in their biology, there are not yet specific treatment strategies recommended on that basis. Cell surface proteins have been identified that may potentially serve as drug targets for monoclonal antibodies or small molecule inhibitors. Here, we review some of the new biological insights regarding PSCC that could lead to improved therapies, as well as the related clinical trials recently completed or in progress. We conclude that antibody-drug conjugates are especially promising, as are the combinations of immune checkpoint inhibitors with other types of drugs. [ABSTRACT FROM AUTHOR]

Background: Enfortumab vedotin (EV) is an antibody‐drug conjugate directed against Nectin‐4 that is used to treat urothelial carcinoma. Nectin‐4 is inherently expressed in the skin and adnexal structures. Since therapeutic options for cutaneous adnexal carcinomas are limited, we sought to evaluate Nectin‐4 expression in adnexal carcinomas and benign adnexal neoplasms to identify tumors that are potentially targetable with EV. Methods: Eight sebaceous carcinomas (seven periocular and one lymph node metastasis), eight digital papillary adenocarcinomas, seven squamoid eccrine ductal carcinomas, eight poromas, eight trichilemmomas, and seven sebaceous adenomas were subjected to immunohistochemical staining for anti‐Nectin‐4 antibody. H‐scores for Nectin‐4 expression were calculated. Results: Benign adnexal neoplasms had a significantly lower mean (±SD) Nectin‐4 H‐score (142.6 ± 39.1) than did the adnexal carcinomas (198 ± 90.8; p = 0.006). Nectin‐4 was expressed in 91% (21/23) of adnexal carcinomas. Sebaceous carcinomas frequently exhibited high expression of Nectin‐4 (88% [7/8]), with a mean (±SD) H‐score (258.1 ± 58.4) significantly higher than those for digital papillary adenocarcinomas (197.5 ± 52.5; p = 0.035) and squamoid eccrine ductal carcinomas (131.4 ± 114.1; p = 0.031). Sebaceous carcinomas also had significantly higher H‐scores than did sebaceous adenomas (186.4 ± 25.0; p = 0.013). Conclusions: Increased Nectin‐4 expression in a subset of cutaneous adnexal carcinomas, particularly sebaceous carcinomas, reveals that EV is a potential therapeutic option for these tumors. [ABSTRACT FROM AUTHOR]

Nectin-4 is a Ca2+-independent immunoglobulin-like protein that exhibits significantly elevated expression in malignant tumors while maintaining extremely low levels in healthy adult tissues. In recent years, overexpression of Nectin-4 has been implicated in tumor occurrence and development of various cancers, including breast cancer, urothelial cancer, and lung cancer. In 2019, the Food and Drug Administration approved enfortumab vedotin, the first antibody-drug conjugate targeting Nectin-4, for the treatment of urothelial carcinoma. This has emphasized the value of Nectin-4 in tumor targeted therapy and promoted the implementation of more clinical trials of enfortumab vedotin. In addition, many new drugs targeting Nectin-4 for the treatment of malignant tumors have entered clinical trials, with the aim of exploring potential new indications. However, the exact mechanisms by which Nectin-4 affects tumorigenesis and progression are still unclear, and the emergence of drug resistance and treatment-related adverse reactions poses challenges. This article reviews the diagnostic potential, prognostic significance, and molecular role of Nectin-4 in tumors, with a focus on clinical trials in the field of Nectin-4-related tumor treatment and the development of new drugs targeting Nectin-4. [ABSTRACT FROM AUTHOR]

Introduction In addition to reduced nectin‐4 expression, the upregulation of ATP‐binding cassette transporters has been suggested as a potential mechanism of resistance to enfortumab vedotin. Case presentation A 76‐year‐old man previously treated with platinum‐containing chemotherapy and pembrolizumab for metastatic bladder cancer was administered enfortumab vedotin because of disease progression. Subsequently, metastasectomy was performed for oligometastatic lesions (in the lung and adrenal gland) that exhibited growth during enfortumab vedotin therapy. Immunostaining analysis revealed decreased nectin‐4 expression and elevated MDR1, MRP1, and BCRP expression in the metastatic lesions. Conclusion Decreased nectin‐4 expression and increased ATP‐binding cassette transporter expression are potential factors in the development of enfortumab vedotin resistance in urothelial carcinoma. Immunohistochemical evaluation of these proteins may aid in predicting treatment efficacy.

Background: Nectin-4 is a novel biomarker overexpressed in various types of cancer, including breast cancer, in which it has been associated with poor prognosis. Current literature suggests that nectin-4 has a role in cancer progression and may have prognostic and therapeutic implications. The present study aims to produce nectin-4-specific single-chain variable fragment (scFv) antibodies and evaluate their applications in breast cancer cell lines and clinical specimens. Methods: We generated recombinant nectin-4 ectodomain fragments as immunogens to immunize chickens and the chickens' immunoglobulin genes were amplified for construction of anti-nectin-4 scFv libraries using phage display. The binding capacities of the selected clones were evaluated with the recombinant nectin-4 fragments, breast cancer cell lines, and paraffin-embedded tissue sections using various laboratory approaches. The binding affinity and in silico docking profile were also characterized. Results: We have selected two clones (S21 and L4) from the libraries with superior binding capacity. S21 yielded higher signals when used as the primry antibody for western blot analysis and flow cytometry, whereas clone L4 generated cleaner and stronger signals in immunofluorescence and immunohistochemistry staining. In addition, both scFvs could diminish attachment-free cell aggregation of nectin-4-positive breast cancer cells. As results from ELISA indicated that L4 bound more efficiently to fixed nectin-4 ectodomain, molecular docking analysis was further performed and demonstrated that L4 possesses multiple polar contacts with nectin-4 and diversity in interacting residues. Conclusion: Overall, the nectin-4-specific scFvs could recognize nectin-4 expressed by breast cancer cells and have the merit of being further explored for potential diagnostic and therapeutic applications. [ABSTRACT FROM AUTHOR]

Phocine distemper virus (PDV) is a significant cause of mortality for phocid seals; however, the susceptibility of otariids to this virus is poorly understood. The authors used a lymph-node explant culture system from California sea lions (Zalophus californianus, CSL) to investigate: (1) the role of signaling lymphocyte activation molecule (SLAM) and nectin-4 in PDV infection and their cellular expression patterns, (2) if PDV induces transcriptional regulation of cell-entry receptors, and (3) the involvement of apoptosis in PDV infection. PDV replicated in the lymph-node explants with peak replication 3 days post-infection (dpi), but the replication was not sustained 4 to 5 dpi. The PDV+ cells co-localized SLAM and nectin-4. These cells expressed IBA1, indicating a histiocytic lineage. Comparison of receptor expression between infected and mock-infected lymph nodes suggested transcriptional downregulation of both receptors during the initial stage of infection and upregulation during the late stage of infection, but the values lack of statistical significance. Cleaved caspase-3+ cells were slightly increased in the infected lymph nodes compared with the mock-infected lymph node from 1 to 4 dpi, but without statistical significance, and a few apoptotic cells co-expressed PDV. The results suggest that lymph-node explants might be an important model to study PDV pathogenesis. CSLs have the potential to be infected with PDV, as they express both cell-entry receptors in histiocytes. The lack of statistical significance in the PDV replication, transcriptional regulation of viral receptors, and changes in apoptosis suggest that although CSL might be infected by PDV, they might be less susceptible than phocid species. [ABSTRACT FROM AUTHOR]

Enfortumab vedotin is an antibody-drug conjugate against nectin-4 that is recently being used in the management of patients with urothelial carcinoma. The common adverse events include rashes, peripheral neuropathy, and hyperglycemia. Only a few cases of associated respiratory symptoms have been reported. Herein, we describe 2 patients with advanced urothelial carcinoma who experienced asthma exacerbation after initiating enfortumab vedotin treatment. Both patients improved with inhalation therapy. Since nectin-4 is expressed in the tracheal epithelium, its association with asthma is likely. This study highlights that clinicians should caution patients with a history of asthma against the worsening of respiratory symptoms when enfortumab vedotin is administered.

Opinion statement: The treatment landscape for urothelial cancer has changed dramatically in the last 10 years, with the approval of several new treatments. At the same time, profiling of individual tumors has become more commonplace with widespread availability of molecular testing and immunohistochemistry. For urothelial cancer, this has led to current guidelines recommending that molecular testing be obtained in the metastatic setting, and that it be considered in the setting of locally advanced disease. Between molecular testing and immunohistochemistry testing of tumors, the only current guideline-directed application of these tests is in the identification of FGFR3 or FGFR2 alterations for use of FGFR inhibitors. While additional recurrent molecular alterations linked to the pathogenesis of urothelial cancer have been identified, the ability to successfully "drug" the pathways association with such alterations remains limited. There has been extensive research into whether expression of particular proteins might inform specific treatment approaches such as the use of PD-L1 testing to guide immune checkpoint blockade. With the integration of antibody-drug conjugates into the treatment armamentarium for urothelial cancer, ongoing research is seeking to determine whether expression of the targets of these therapies, such as Nectin 4, Trop-2, or HER2, could help to guide treatment. [ABSTRACT FROM AUTHOR]

We report the case of a 68-year-old man who developed a sigmoidorectal fistula after marked response to enfortumab vedotin for advanced bladder cancer. The patient had undergone radical cystectomy with ileal conduit after neoadjuvant chemotherapy. Six months after surgery, local recurrence in the pelvic cavity and multiple lung metastases were found, and the patient was administered pembrolizumab as second-line therapy. Due to worsening local recurrence and suspected invasion of the sigmoid colon and rectum, enfortumab vedotin was initiated as third-line therapy and comprehensive genomic profiling was simultaneously performed. Enfortumab vedotin was remarkably effective, the lung metastases disappeared, and the local recurrent lesion shrank in volume although a sigmoidorectal fistula was found to form through the tumor cavity. Immunohistochemical analysis of the tumor specimens exhibited increased nectin-4 expression. This rare case of metastatic bladder cancer with sigmoidorectal fistula associated with effective enfortumab vedotin therapy suggests that nectin-4 expression and comprehensive genomic profiling might be useful in predicting treatment response to enfortumab vedotin. [ABSTRACT FROM AUTHOR]

Penile squamous cell carcinoma is a rare disease with very limited data to guide treatment decisions. In particular, there is minimal evidence for effective therapies in the metastatic setting. Here, we present a case of metastatic penile squamous cell carcinoma with response to the Nectin-4 inhibitor enfortumab-vedotin-ejfv (EV). EV was selected due to the evidence of the high expression of Nectin-4 in squamous cell carcinomas, including penile carcinoma. The patient had both radiographic and symptomatic improvement after two cycles of treatment, despite having been treated with multiple prior lines of traditional chemotherapy. This case provides support for the use of antibody–drug conjugates (ADC), including EV, in this disease with few other options in the advanced setting. Further studies examining Nectin-4 and ADCs in penile squamous cell carcinoma should be completed, as high-quality evidence is needed to guide treatment after initial progression for these patients. [ABSTRACT FROM AUTHOR]

TIGIT (T cell immunoglobulin and ITIM domain) is an inhibitory receptor expressed on T and NK cells that interact with cell surface glycoprotein belonging to the nectin and nectin-like family of cell adhesion molecules, particularly nectin-2 and nectin-like 5 (PVR). Nectin-4 has been recently identified as a novel ligand for TIGIT and the interaction among them inhibits NK cell cytotoxicity. In this study, biophysical experiments were conducted to decipher the mechanism of this novel interaction, followed by structure-guided mutagenesis studies to map the nectin-4 binding interface on TIGIT. Using surface plasmon resonance, we deduced that TIGIT recognizes the membrane distal ectodomain of nectin-4 and the interaction is weaker than the well-characterized TIGIT: nectin-2 interaction. Deciphering the molecular basis of this newly identified interaction between TIGIT and nectin-4 will provide us important insight into the manipulation of this inhibitory signaling pathway, especially targeting cancer cells overexpressing nectin-4 that evade the immune surveillance of the body. • Interaction between TIGIT and nectin-4 inhibits NK cell cytotoxicity. • SPR-based binding studies reveal the nectin-4 binding interface on TIGIT. • Nectin-2 exhibits a higher binding affinity for TIGIT in comparison to nectin-4. • Nectin-2 and nectin-4 utilize similar binding interfaces on TIGIT. [ABSTRACT FROM AUTHOR]

Nectin-3 and nectin-4 belong to the immunoglobulin (Ig) superfamily, and are Ca2+-independent homophilic cell adhesion molecules. Nectin-3 is ubiquitous in adult tissues, and it enhances normal levels of synaptic formation. In contrast, nectin-4 is weakly-to-moderately expressed in normal human tissues. In recent years, studies have shown that nectin-3 is highly expressed in the nervous system. Moreover, it is associated with poor prognostic factors in distant metastases and malignant tumors with high vascular invasion such as pancreatic, lung and breast cancers. In particular, nectin-4 is overexpressed in various malignant tumors, and it is associated with proliferation, angiogenesis, metastasis, drug resistance, tumor relapse, DNA repair, cancer stemness, and poor prognosis. Unlike nectin-3, nectin-4 has become a potential prognostic biomarker and specific therapeutic target for cancer as there is no consensus on the significance of abnormal expression of nectin-3 in various cancers. [ABSTRACT FROM AUTHOR]

Many locally advanced and metastatic salivary gland carcinomas (SGC) lack therapeutic targets. Enfortumab vedotin, an antibody–drug conjugate binding to Nectin-4, recently gained FDA approval for third-line urothelial carcinoma. Therefore, the aim of this study was to assess the expression of Nectin-4 in primary SGC and corresponding lymph node metastases and to correlate it with clinicopathological data. Immunohistochemical staining for Nectin-4 was performed for patients who had undergone surgery with curative intent for primary SGC of the parotid or submandibular gland in a tertiary referral center between 1990 and 2019. One hundred twenty-two primary SGC and twenty corresponding lymph node metastases were included. Nectin-4 was expressed in 80.3% of primary SGC with a mean Histo(H-)score of 61.2 and in 90.0% of lymph node metastases with a mean H-score of 75.6. A moderate or high Nectin-4 expression was found in 25.9% of salivary duct carcinomas (SaDu) and in 30.7% of adenoid cystic carcinomas (ACC). SaDu patients with a lower T-stage (p = 0.04), no loco-regional lymph node metastases (p = 0.049), no vascular invasion (p = 0.04), and no perineural spread (p = 0.03) showed a significantly higher mean Nectin-4 H-score. There was a statistical tendency towards a more favorable disease-free survival among SaDu patients with a higher Nectin-4 expression (p = 0.09). Nectin-4 is expressed in SGC and therefore represents a potential therapeutic target, especially in entities with a high rate of local recurrence and metastatic spread such as SaDu and ACC. [ABSTRACT FROM AUTHOR]

Metastatic urothelial carcinoma (mUC) is an aggressive malignancy with a dismal prognosis. Enfortumab vedotin (EV) is an antibody-drug conjugate consisting of an antibody targeting Nectin-4. This protein is highly expressed in UC cells. After binding, monomethyl auristatin E is released into cells, causing UC cell death. EV has been approved as a single agent for pre-treated mUC, with interesting improvements in response rate and survival in a setting with limited treatment options. More recently, EV approval occurred in cisplatin-ineligible naïve mUC patients in combination with pembrolizumab. Our review aims to summarize the pharmacological properties, clinical studies, and future developments of EV inmUC. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Nectin-4 is a transmembrane protein belonging to the nectin family of immunoglobulin-like molecules which is found in the placenta and trachea under physiological conditions and its expression has been shown in many cancer types. We aimed to investigate for the 1st time nectin-4 expression in human prostate cancer tissues. METHODS: We retrospectively analyzed the prostate pathology specimens of 82 patients who underwent initial transrectal ultrasound-guided prostate biopsy or transurethral prostate resection and were found to have atypical small acinar proliferation (ASAP) and incidentally prostate cancer. Tissue samples with prostatic cancer were used as a control for alpha-methylacyl-CoA racemase (AMACR), and benign prostatic glands in the same tissue provided the negative control. The intensity and extent of nectin-4 expression were determined microscopically using the histochemical scoring system which was defined as the product of the staining intensity (score: 0-3) and percentage of stained cells (0-100) at a given intensity. RESULTS: We conducted immunohistochemical analysis of nectin-4 and AMACR expression in all 82 samples. While AMACR expression was positive in prostate cancer tissues with a GS of <7 (n=24, 100%), 7 (n=18, 100%), and =8 (n=15, 100%), it was negative in all ASAP samples (n=25, 100%) (p<0.001). Nectin-4 expression was not detected in any of the GS <7, GS 7, or GS =8 samples but was found in benign prostatic gland tissues and all 25 (100%) ASAP samples (p<0.001). CONCLUSION: We found that nectin-4 was not expressed in prostate cancer tissues but was expressed in ASAP-and benign prostate gland containing tissues. We believe that prospective studies with more patients and samples including radical prostatectomy materials will reveal the relationship between nectin-4 and prostate cancer more clearly. [ABSTRACT FROM AUTHOR]

Penile squamous cell carcinoma (PSCC) remains a worldwide healthcare concern with poor outcomes and inadequate therapeutic options. Molecular characterization continues to describe the intricacies of PSCC biology, which vary by human papillomavirus (HPV) infection. Despite these advancements in our understanding, utilization of targeted therapies remains limited and underexplored. In this study, we evaluated the transcript and protein expression of Nectin-4 (PVRL4) in PSCC tumors and evaluated whether this is related to tumor features or clinical outcomes. Using two separate PSCC cohorts, we demonstrate that the majority of tumors have active transcription of Nectin-4. We then validated our findings using immunohistochemistry in a tissue microarray representing 57 patients with PSCC. We identified that Nectin-4 was expressed at higher levels in patients with high-risk HPV infection. No significant differences were identified in tumor characteristics or various clinical endpoints when comparing tumors with high and low Nectin-4 expression. This study demonstrates that Nectin-4 is expressed in PSCC and may represent a novel therapeutic target. Patient summary: In this study, we evaluated the expression of Nectin-4, a cell surface protein, in tumors from patients with nonmetastatic penile squamous cell carcinoma (PSCC). To our knowledge, this is the first study to describe elevated expression of Nectin-4 in PSCC, which may suggest its utility as a therapeutic target.

Backgound: Pancreatic cancer (PC) is one of the deadliest cancers worldwide, and cell proliferation and angiogenesis play an important role in its occurrence and development. High levels of lncRNANORAD have been detected in many tumors, including PC, yet the effect and mechanism of lncRNA NORAD on PC cell angiogenesis are unexplored. Methods: qRT.PCR was applied to quantify lncRNA NORAD and miR-532-3p expression in PC cells, and a dual luciferase reporter gene was used to verify the targeting effects of NORAD, miR-532-3p and Nectin-4. Then, we regulated NORAD and miR-532-3p expression in PC cells and detected their effects on PC cell proliferation and angiogenesis using cloning experiments and HUVEC tube formation experiments. Results: LncRNA NORAD was upregulated and miR-532-3p was downregulated in PC cells compared with normal cells. Knockdown of NORAD inhibited PC cell proliferation and angiogenesis. LncRNA NORAD and miR-532-3p competitively bound to promote the expression of the miR-532-3p target gene Nectin-4, thereby promoting proliferation and angiogenesis of PC cells in vitro. Conclusion: LncRNA NORAD promotes the proliferation and angiogenesis of PC cells by regulating the miR-532-3p/Nectin-4 axis, which may be a potential biological target in the diagnosis and treatment of clinical PC. [ABSTRACT FROM AUTHOR]

Simple Summary: Endometrial cancer has become increasingly common owing to the recent westernization of diet and lifestyle, with 1.7% of cancer patients dying annually. Furthermore, the 5-year endometrial cancer survival rate is barely 15%. Nectin-4 has emerged as a possible biomarker and therapeutic target. Nectin-4 is highly expressed in various cancers. However, no studies have been conducted to determine the clinical importance of Nectin-4 expression in endometrial cancer. Here, we examined 320 tissue samples from patients with endometrial cancer to determine the relevance of Nectin-4 expression in the diagnosis and prognosis of endometrial cancer. Our findings emphasize the importance of Nectin-4 as a novel diagnostic tool and screening marker for assessing endometrial cancer and improving the accuracy of approaches used to predict high-risk endometrial cancer. The adhesion molecule Nectin-4 is a new potential therapeutic target for different types of cancer; however, little is known about its diagnosis significance in endometrial cancer (EC). We found that Nectin-4 expression was significantly higher in EC tissues than in nonadjacent normal tissue. The area under the receiver operating characteristic curve value of 0.922 indicated good diagnostic accuracy for Nectin-4 expression in EC. Furthermore, Nectin-4 expression was associated with DNA mismatch repair (MMR) protein deficiency. Notably, the high Nectin-4 expression group of patients with MSH2/6-deficient EC had shorter progression-free survival than that of the low Nectin-4 expression group. The number of lymphovascular space invasion-positive patients in groups with MMR deficiency and high Nectin-4 expression was also increased compared with that in the low Nectin-4 expression group. Bioinformatics analysis revealed that alteration in Nectin-4 and MMR genes is associated with Nectin-4 expression in EC. To the best of our knowledge, this is the first study to show that Nectin-4 expression may be a potential biomarker for EC diagnosis and that high Nectin-4 expression in MMR-deficient patients with EC can predict short progression-free survival, thus providing clues to identify patients for adjuvant therapy. [ABSTRACT FROM AUTHOR]

Metastatic urothelial carcinoma (mUC) is an aggressive malignancy with a dismal prognosis. Enfortumab vedotin (EV) is an antibody-drug conjugate consisting of an antibody targeting Nectin-4. This protein is highly expressed in UC cells. After binding, monomethyl auristatin E is released into cells, causing UC cell death. EV has been approved as a single agent for pre-treated mUC, with interesting improvements in response rate and survival in a setting with limited treatment options. More recently, EV approval occurred in cisplatin-ineligible naïve mUC patients in combination with pembrolizumab. Our review aims to summarize the pharmacological properties, clinical studies, and future developments of EV in mUC.

Abstract Background Canine primary lung adenocarcinoma (CPLA) is suspected by radiography or computed tomography; however, since there are no tumour markers, early diagnosis is difficult, and the prognosis is poor due to increased tumour volume. Nectin‐4 has been reported to be expressed in human lung, ovarian, and pancreatic cancers and promotes tumour growth. It has been reported to be a tumour marker and prognostic factor, and oncolytic virotherapy is being investigated using nectin‐4 as a therapeutic target. Objectives The purpose of this study was to investigate the expression of Nectin‐4 in CPLA and its clinical significance in dogs with pulmonary adenocarcinomas. Methods The relationships between Nectin‐4 expression and signalling, tumour volume, tumour weight, and prognosis were analyzed in 34 CPLA patients. Results The expression of canine Nectin‐4 (high Nectin‐4) was found in 25 of 34 cases (73%), and Nectin‐4 expression levels did not show any significant associations with gender, body weight, and tumour stage. However, there was a significant positive correlation between Nectin‐4 expression and tumour volume (r = 0.623, p

Abstract Purpose Nectin-4 is specifically up-regulated in various tumors, exert crucial effects on tumor occurrence and development. Nevertheless, the role and molecular mechanism of Nectin-4 in osteosarcoma (OS) are rarely studied. Methods The expression of Nectin-4 and its relationship with clinical characteristics of OS were investigated using OS clinical tissues, tissue microarrays, TCGA, and GEO databases. Moreover, the effect of Nectin-4 on cell growth and mobility was detected by CCK-8, colony formation, transwell, and wound-healing assays. The RT-qPCR, Western blotting, and luciferase reporter assays were performed to explore molecular mechanisms through which Nectin-4 mediates the expression of miR-520c-3p, thus modulating PI3K/AKT/NF-κB signaling. In vivo mice models constructed by subcutaneous transplantation and tail vein injection were used to validate the functional roles of Nectin-4 and miR-520c-3p. Results Nectin-4 displayed a higher expression in OS tumor tissues compared with normal tissues, and its overexpression was positively associated with tumor stage and metastasis in OS patients. Functionally, Nectin-4 enhanced OS cells growth and mobility in vitro. Mechanistically, Nectin-4 down-regulated the levels of miR-520c-3p that directly targeted AKT-1 and P65, thus leading to the stimulation of PI3K/AKT/NF-κB signaling. In addition, the expression of miR-520c-3p was apparently lower in OS tissues than in normal tissues, and its low expression was significantly related to tumor metastasis. Furthermore, ectopic expression of miR-520c-3p markedly blocked the effect of Nectin-4 on OS cell growth and mobility. Knockdown of Nectin-4 could suppress the tumorigenesis and metastasis in vivo, which could be remarkably reversed by miR-520c-3p silencing. Conclusions Nectin-4 as an oncogene can promote OS progression and metastasis by activating PI3K/AKT/NF-κB signaling via down-regulation of miR-520c-3p, which could represent a novel avenue for identifying a potential therapeutic target for improving patient outcomes.

Canine distemper (CD) is a highly contagious viral disease worldwide. Although live attenuated vaccine is available as a preventive measure against the disease, cases of vaccination failure highlight the importance of potential alternative agent against canine distemper virus (CDV). CDV infects cells mainly by binding signaling lymphocyte activation molecule (SLAM) and Nectin-4 receptor. Here, to develop a new and safe antiviral biological agent for CD, we constructed and expressed CDV receptor proteins fused with Fc region of canine IgG-B, namely, SLAM-Fc, Nectin-Fc and SLAM-Nectin-Fc in HEK293T cells, and antiviral activity of these receptor-Fc proteins was subsequently evaluated. The results showed that the receptor-Fc proteins efficiently bound to receptor binding domain (RBD) of CDV-H, meanwhile, these receptor-Fc proteins competitively inhibited the binding of His-tagged receptor proteins (SLAM-His or Nectin-His) to CDV-H-RBD-Flag protein. Importantly, receptor-Fc proteins exhibited potent anti-CDV activity in vitro. Treatment with receptor-Fc proteins at the pre-entry stage dramatically suppressed CDV infectivity in Vero cells stably expressing canine SLAM. The minimum effective concentration (MEC) of SLAM-Fc, Nectin-Fc and SLAM-Nectin-Fc was 0.2 μg/mL, 0.2 μg/mL, 0.02 μg/mL. The 50% inhibition concentration (IC50) of three proteins was 0.58 μg/mL, 0.32 μg/mL and 0.18 μg/mL, respectively. Moreover, treatment with receptor-Fc proteins post viral infection can also inhibit CDV reproduction, the MEC of SLAM-Fc, Nectin-Fc and SLAM-Nectin-Fc was same as pre-treatment, and the IC50 of receptor-Fc proteins was 1.10 μg/mL, 0.99 μg/mL and 0.32 μg/mL, respectively. The results suggested that the receptor-Fc proteins were more effective for pre-entry treatment than post-infection treatment, furthermore, SLAM-Nectin-Fc was more effective than SLAM-Fc and Nectin-Fc. These findings revealed the receptor-Fc proteins were promising candidates as inhibitor against CDV.

Background: Many reports have described that abnormal nectin-4 expression may be used as a prognostic marker in many tumors. However, these studies failed to reach a consensus. Here, we performed a meta-analysis to comprehensively evaluate the prognostic value of nectin-4 in cancers. Methods: Relevant studies were identified through a comprehensive search of PubMed, EMBASE and Web of science until August 31, 2022. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were used to evaluate the relationship between nectin-4 expression and overall survival (OS) and disease-free survival/ progression-free survival/relapse-free survival (DFS/PFS/RFS). Odds ratios (ORs) with 95% CIs were applied to assess the relationship between nectin-4 expression and clinicopathologic features. Subgroup analysis was performed to explore the sources of heterogeneity. Sensitivity analysis and funnel plot were used to test the reliability of the results. All data analyses were performed using STATA version 12.0 software. Results: Fifteen articles involving 2245 patients were included in the metaanalysis. The pooled analysis showed that high nectin-4 expression was significantly associated with poor OS (HR: 1.75, 95% CI: 1.35-2.28). There was no relationship between high nectin-4 expression and DFS/PFS/RFS (HR: 178, 95% CI: 0.78-4.08).Subgroup analyses revealed that that high nectin-4 expression mainly presented adverse OS in esophageal cancer (EC) (HR: 1.78, 95% CI: 1.30-2.44) and gastric cancer (GC) (HR: 1.92, 95% CI: 1.43-2.58). We also found that high nectin-4 expression was associated with tumor diameter (big vs small) (OR: 1.96, 95% CI: 1.02-3.75), tumor stage (III-IV vs I-II) (OR: 2.04, 95% CI: 1.01-4.12) and invasion depth (T3+T4 vs T2+T1) (OR: 3.95, 95% CI: 2.06- 7.57). Conclusions: Nectin-4 can be used as an effective prognostic indicator for specific cancers. [ABSTRACT FROM AUTHOR]

Purpose of Review: This study aims to gather the current state of the literature about anti-Nectin-4 innovative associations in solid tumors and to investigate underlying resistance mechanisms. Recent Findings: Antibody–drug conjugate (ADC) targeting Nectin-4 efficacy gained attention and offers a promising association with other antineoplastic drugs especially in urothelial carcinoma. The heterogeneity of Nectin-4 expression across the molecular subtypes was highlighted especially in urothelial cancers. A unique study using preclinical models demonstrated an upregulation of P-gp expression, which may explain the anti-Nectin-4 resistance mechanisms. Summary: Further studies are urgently needed to understand anti-Nectin-4 sensitivity and resistance phenomenon. The growing therapeutic associations of enfortumab vedotin offer optimistic opportunities in management and treatment of wide range of solid tumors including rare aggressive malignancies. [ABSTRACT FROM AUTHOR]

Enfortumab vedotin is an antibody-drug conjugate against nectin-4 that is recently being used in the management of patients with urothelial carcinoma. The common adverse events include rashes, peripheral neuropathy, and hyperglycemia. Only a few cases of associated respiratory symptoms have been reported. Herein, we describe 2 patients with advanced urothelial carcinoma who experienced asthma exacerbation after initiating enfortumab vedotin treatment. Both patients improved with inhalation therapy. Since nectin-4 is expressed in the tracheal epithelium, its association with asthma is likely. This study highlights that clinicians should caution patients with a history of asthma against the worsening of respiratory symptoms when enfortumab vedotin is administered. [ABSTRACT FROM AUTHOR]

Abstract Background Triple-negative breast cancer (TNBC) is more prone to distant metastasis and visceral recurrence in comparison to other breast cancer subtypes, and is related to dismal prognosis. Nevertheless, TNBC has an undesirable response to targeted therapies. Therefore, to tackle the huge challenges in the diagnosis and treatment of TNBC, Nectin-4 was selected as a theranostic target because it was recently found to be highly expressed in TNBC. We developed anti-Nectin-4 monoclonal antibody (mAbNectin-4)-based theranostic pair, 99mTc-HYNIC-mAbNectin-4 and mAbNectin-4-ICG. 99mTc-HYNIC-mAbNectin-4 was applied to conduct immuno-single photon emission computed tomography (SPECT) for TNBC diagnosis and classification, and mAbNectin-4-ICG to mediate photothermal therapy (PTT) for relieving TNBC tumor growth. Methods Nectin-4 expression levels of breast cancer cells (MDA-MB-468: TNBC cells; and MCF-7, non-TNBC cells) were proved by western blot, flow cytometry, and immunofluorescence imagning. Cell uptake assays, SPECT imaging, and biodistribution were performed to evaluate Nectin-4 targeting of 99mTc-HYNIC-mAbNectin-4. A photothermal agent (PTA) mAbNectin-4-ICG was generated and characterized. In vitro photothermal therapy (PTT) mediated by mAbNectin-4-ICG was conducted under an 808 nm laser. Fluorescence (FL) imaging was performed for mAbNectin-4-ICG mapping in vivo. In vivo PTT treatment effects on TNBC tumors and corresponding systematic toxicity were evaluated. Results Nectin-4 is overexpressed in MDA-MB-468 TNBC cells, which could specifically uptake 99mTc-HYNIC-mAbNectin-4 with high targeting in vitro. The corresponding immunoSPECT imaging demonstrated exceptional performance in TNBC diagnosis and molecular classification. mAbNectin-4-ICG exhibited favourable biocompatibility, photothermal effects, and Nectin-4 targeting. FL imaging mapped biodistribution of mAbNectin-4-ICG with excellent tumor-targeting and retention in vivo. Moreover, mAbNectin-4-ICG-mediated PTT provided advanced TNBC tumor destruction efficiency with low systematic toxicity. Conclusion mAbNectin-4-based radioimmunoimaging provides visualization tools for the stratification and diagnosis for TNBC, and the corresponding mAbNectin-4-mediated PTT shows a powerful anti-tumor effect. Our findings demonstrate that this Nectin-4 targeting strategy offers a simple theranostic platform for TNBC.

Abstract Background Upper urinary tract urothelial carcinoma (UTUC) accounts for only about 5–10% of all urothelial cancers and is characterized by an aggressive and frequently rapidly fatal behavior. However, detailed knowledge of its molecular profile is still lacking. Materials and methods We identified, by chart analysis, patients who underwent radical nephroureterectomy or diagnostic biopsy for UTUC between January 2015 and August 2020 at the Santa Maria Hospital of Terni, in Italy. Eligible patients were required to have also adequate clinical informations and follow-up details. The primary objective of the study was to evaluate DNA mismatch repair (MMR) proteins and Nectin-4 immunohistochemical expression in UTUC, looking also for an eventual correlation between these molecular features. The secondary objective was to investigate genomic instability in the case of a MMR protein loss. Expression of proteins was assessed by using immunohistochemistry and microsatellite instability (MSI) performed by next generation sequencing. Nectin-4 expression was reported using an intensity scoring system (score, 0–3+), instead the expression of DNA MMR proteins was indicated as present (no loss) or not present (loss). Results Thirty four cases have been evaluated and 27 considered eligible for the study with their tumor samples analyzed. Nectin-4 was found to be expressed in 44% of cases and 18.5% of patients showed defective-MMR phenotype. We found a significant correlation between Nectin-4 expression and MSH2/MSH6 protein loss. Out of 7 patients with DNA MMR proteins loss or equivocal phenotype, 3 showed MSI. Conclusions Our pilot study suggest a possible relationship between Nectin-4 and DNA MMR protein expression in UTUC and a clinically significant correlation between defective MMR phenotype and genomic instability. Because of the possible implications of these data for innovative treatment approaches, the need for further studies in this area is warranted.

Simple Summary: Ovarian cancer is usually diagnosed in an advanced stage of the disease and is associated with a poor prognosis. Therefore, it is important to find reliable biomarkers that allow early diagnosis. In this study, we detected elevated Nectin-4 and HB-EGF serum levels in ovarian cancer patients which correlate with prognostically favorable parameters, such as early FIGO stage and successful tumor debulking. In addition, Nectin-4 was elevated in patients with low blood levels of Ca-125. This suggests that Nectin-4 and Ca-125 provide complementary diagnostic information. Therefore, Nectin-4 and HB-EGF appear to be promising blood-based biomarkers for the diagnosis of early stages of ovarian cancer. Ovarian cancer is the third most common gynecological malignancy and has the highest mortality rate. Owing to unspecific symptoms, ovarian cancer is not detected until an advanced stage in about two-thirds of cases. Therefore, it is crucial to establish reliable biomarkers for the early stages to improve the patients' prognosis. The aim of this study is to investigate whether the ADAM17 substrates Nectin-4, Heparin-binding EGF-like growth factor (HB-EGF) and Amphiregulin (AREG) could function as potential tumor markers for ovarian cancer. In this study a set of 231 sera consisting of 131 ovarian cancer patients and 100 healthy age-matched controls were assembled. Nectin-4, HB-EGF and AREG levels of preoperatively collected sera were determined by enzyme-linked immunosorbent assay (ELISA). Our analysis revealed that Nectin-4 and HB-EGF were significantly increased compared to the age-matched control group (p < 0.0001, p = 0.016). Strikingly, significantly higher Nectin-4 and HB-EGF levels were detected in early-stage FIGO I/II (p <0.001; p = 0.025) compared to healthy controls. Eighty-four percent (16/19) of patients with low Ca-125 levels showed increased Nectin-4 levels. Our study proposes Nectin-4 and HB-EGF as promising blood-based biomarkers for the detection of early stages of ovarian cancer patients that would not have been detected by Ca-125. [ABSTRACT FROM AUTHOR]

Currently, seven species of morbillivirus have been classified. Six of these species (Measles morbillivirus, Rinderpest morbillivirus, Small ruminant morbillivirus, Canine morbillivirus, Phocine morbillivirus, and Cetacean morbillivirus) are highly infectious and cause serious systemic diseases in humans, livestock, domestic dogs, and wild animals. These species commonly use the host proteins signaling lymphocytic activation molecule (SLAM) and nectin‐4 as receptors, and this usage contributes to their virulence. The seventh species (Feline morbillivirus: FeMV) is phylogenetically divergent from the six SLAM‐using species. FeMV differs from the SLAM‐using morbillivirus group in pathogenicity and infectivity, and is speculated to use non‐SLAM receptors. Recently, novel species of morbilliviruses have been discovered in bats, rodents, and domestic pigs. Because the ability to use SLAM and nectin‐4 is closely related to the infectivity and pathogenicity of morbilliviruses, investigation of the potential usage of these receptors is useful for estimating infectivity and pathogenicity. The SLAM‐binding sites in the receptor‐binding protein show high similarity among the SLAM‐using morbilliviruses. This feature may help to estimate whether novel morbillivirus species can use SLAM as a receptor. A novel morbillivirus species isolated from wild mice diverged from the classified morbilliviruses in the phylogenetic tree, forming a third group separate from the SLAM‐using morbillivirus group and FeMV. This suggests that the novel rodent morbillivirus may exhibit a different risk from the SLAM‐using morbillivirus group, and analyses of its viral pathogenicity and infectivity toward humans are warranted. [ABSTRACT FROM AUTHOR]

Abstract: Antibody-drug conjugates (ADCs) have joined the armamentarium against urothelial cancer (UC) as an effective therapy option. Since 2019, the US Food and Drug Administration has approved 2 ADCs for advanced previously treated UC: enfortumab vedotin, which targets nectin-4 and sacituzumab govitecan, which targets trophoblast cell-surface antigen 2. These ADCs are now being tested in earlier disease settings and in previously untreated patients. Furthermore, novel ADCs (e.g., anti-HER-2) are being tested in the clinic and show promising clinical benefit. The next frontier is to understand the mechanisms of resistance and response, gaining experience with ADC-related adverse events and learning the best strategy to sequence and combine these agents with existing therapies. Here, we highlight the recent advances in the development of ADCs for treating localized and metastatic UC. [ABSTRACT FROM AUTHOR]

Precisely assessing nectin-4 expression in tumors is important in identifying patients who may benefit from nectin-4-targeted therapies. In our previous work, we developed a bicyclic peptide-based nectin-4-targeting radiotracer 68 Ga-N188 and validated its nectin-4 detection efficacy. However, the relatively short half-life and low positron emission rate of 68 Ga limit its further application. In this study, we constructed three novel nectin-4-targeting ligands N230-232 based on a bicyclic peptide structure and labeled with radionuclide 18 F, which has a longer half-life and a higher positron emission rate, for PET imaging. Micro-PET/CT imaging-based screening showed that Al 18 F-N231 had the best imaging contrast with a tumor-to-muscle ratio of 10.97 ± 2.39. Further characterization demonstrated that ligand N231 had a high affinity to nectin-4 with a K d of 4.29 nM, and Al 18 F-N231 had a good stability and safety profile in vivo F-N231 to nectin-4 18 , with tumor uptake in the nectin-4 in vivo SW780 tumor group being 1.45- and 3.75-fold higher than that in the nectin-4 + SW780 tumor group being 1.45- and 3.75-fold higher than that in the nectin-4 - F-N231 has promising capability for noninvasive nectin-4 detection 18 F-N231 has promising capability for noninvasive nectin-4 detection in vivo .

Nectin-4 is a cell adhesion molecule which has gained more and more attention as a therapeutic target in cancer recently. Overexpression of Nectin-4 has been observed in various tumors, including breast cancer, and is associated with tumor progression. Enfortumab vedotin(EV)is an antibody-drug conjugate (ADC) targeting Nectin-4, which has been approved by FDA for the treatment of urothelial carcinoma. Notably, Nectin-4 was also investigated as a target for breast cancer in preclinical and clinical settings. Nectin-4-targeted approaches, such as ADCs, oncolytic viruses, photothermal therapy and immunotherapy, have shown promising results in early-phase clinical trials. These therapies offer novel strategies for delivering targeted treatments to Nectin-4-expressing cancer cells, enhancing treatment efficacy and minimizing off-target effects. In conclusion, this review aims to provide an overview of the latest advances in understanding the role of Nectin-4 in breast cancer and discuss the future development prospects of Nectin-4 targeted agents., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

In recent years, considerable progress has been made in increasing the knowledge of tumour biology and drug resistance mechanisms in urothelial cancer. Therapeutic strategies have significantly advanced with the introduction of novel approaches such as immune checkpoint inhibitors and Fibroblast Growth Factor Receptor inhibitors. However, despite these novel agents, advanced urothelial cancer is often still progressive in spite of treatment and correlates with a poor prognosis. The introduction of antibody-drug conjugates consisting of a target-specific monoclonal antibody covalently linked to a payload (cytotoxic agent) is a novel and promising therapeutic strategy. In December 2019, the US Food and Drug Administration (FDA) granted accelerated approval to the nectin-4-targeting antibody-drug conjugate, enfortumab vedotin, for the treatment of advanced or metastatic urothelial carcinomas that are refractory to both immune checkpoint inhibitors and platinum-based treatment. Heavily pre-treated urothelial cancer patients reported a significant, 40% response to enfortumab vedotin while other antibody-drug conjugates are currently still under investigation in several clinical trials. We have comprehensively reviewed the available treatment strategies for advanced urothelial carcinoma and outlined the mechanism of action of antibody-drug conjugate agents, their clinical applications, resistance mechanisms and future strategies for urothelial cancer. [ABSTRACT FROM AUTHOR]

Background: Canine primary lung adenocarcinoma (CPLA) is suspected by radiography or computed tomography; however, since there are no tumour markers, early diagnosis is difficult, and the prognosis is poor due to increased tumour volume. Nectin‐4 has been reported to be expressed in human lung, ovarian, and pancreatic cancers and promotes tumour growth. It has been reported to be a tumour marker and prognostic factor, and oncolytic virotherapy is being investigated using nectin‐4 as a therapeutic target. Objectives: The purpose of this study was to investigate the expression of Nectin‐4 in CPLA and its clinical significance in dogs with pulmonary adenocarcinomas. Methods: The relationships between Nectin‐4 expression and signalling, tumour volume, tumour weight, and prognosis were analyzed in 34 CPLA patients. Results: The expression of canine Nectin‐4 (high Nectin‐4) was found in 25 of 34 cases (73%), and Nectin‐4 expression levels did not show any significant associations with gender, body weight, and tumour stage. However, there was a significant positive correlation between Nectin‐4 expression and tumour volume (r = 0.623, p < 0.05) and tumour weight (r = 0.735, p < 0.05). Regarding prognosis, the median survival time was 427 days in high Nectin‐4 cases and 420 days in cases with no Nectin‐4 expression. Conclusion: Our study demonstrated that Nectin‐4 is highly expressed in CPLA. In addition, nectin‐4 might be a tumour growth factor in CPLA and thus is a promising biomarker for CPLA. Further investigations on nectin‐4 in CPLA are warranted for its diagnosis and novel targets for oncolytic virotherapy. [ABSTRACT FROM AUTHOR]

Raccoons (Procyon lotor) are abundant in urban/wildland interfaces and are key sources of canine distemper virus (CDV) outbreaks in domestic, zoo, and free-ranging wildlife species. CDV is pantropic, which provides multiple potential routes of transmission (urine, respiratory secretions, feces), but the specific role of skin as a target of infection, as a diagnostic sample, or as a potential source of environmental persistence and transmission is unknown. We have characterized the distribution of CDV and its known receptor, nectin-4, in skin samples of 36 raccoons. Even with skin samples that were grossly and histologically normal, immunohistochemistry of skin was useful in the diagnosis of CDV infection, which was found in both epithelium and endothelium. Nectin-4 was codistributed with cellular targets of viral infection. Skin secretions, shed keratinocytes, and hair of CDV infected raccoons are all potential environmental fomites. [ABSTRACT FROM AUTHOR]

Purpose: Nectin-4 is specifically up-regulated in various tumors, exert crucial effects on tumor occurrence and development. Nevertheless, the role and molecular mechanism of Nectin-4 in osteosarcoma (OS) are rarely studied. Methods: The expression of Nectin-4 and its relationship with clinical characteristics of OS were investigated using OS clinical tissues, tissue microarrays, TCGA, and GEO databases. Moreover, the effect of Nectin-4 on cell growth and mobility was detected by CCK-8, colony formation, transwell, and wound-healing assays. The RT-qPCR, Western blotting, and luciferase reporter assays were performed to explore molecular mechanisms through which Nectin-4 mediates the expression of miR-520c-3p, thus modulating PI3K/AKT/NF-κB signaling. In vivo mice models constructed by subcutaneous transplantation and tail vein injection were used to validate the functional roles of Nectin-4 and miR-520c-3p. Results: Nectin-4 displayed a higher expression in OS tumor tissues compared with normal tissues, and its overexpression was positively associated with tumor stage and metastasis in OS patients. Functionally, Nectin-4 enhanced OS cells growth and mobility in vitro. Mechanistically, Nectin-4 down-regulated the levels of miR-520c-3p that directly targeted AKT-1 and P65, thus leading to the stimulation of PI3K/AKT/NF-κB signaling. In addition, the expression of miR-520c-3p was apparently lower in OS tissues than in normal tissues, and its low expression was significantly related to tumor metastasis. Furthermore, ectopic expression of miR-520c-3p markedly blocked the effect of Nectin-4 on OS cell growth and mobility. Knockdown of Nectin-4 could suppress the tumorigenesis and metastasis in vivo, which could be remarkably reversed by miR-520c-3p silencing. Conclusions: Nectin-4 as an oncogene can promote OS progression and metastasis by activating PI3K/AKT/NF-κB signaling via down-regulation of miR-520c-3p, which could represent a novel avenue for identifying a potential therapeutic target for improving patient outcomes. [ABSTRACT FROM AUTHOR]

Nectin-4 (Nectin cell adhesion molecule 4), a type I transmembrane cell adhesion protein, was demonstrated to be overexpressed in a variety of tumors, making it an attractive antigen for targeted therapies such as antibody-drug conjugates (ADCs). Of great note, the US Food and Drug Administration (FDA)-approval of the first Nectin-4-directed ADC, enfortumab vedotin (EV), in urothelial cancer (UC) not only introduced Nectin-4 as a clinically validated and reliable target antigen but also confirmed the evolving role of Nectin-4-directed ADCs as novel and promising cancer therapeutics. In addition to EV, there have been or are currently being seven and eleven Nectin-4-directed ADCs, respectively, in various stages of clinical trials and preclinical development, offering a promising future for the treatment of Nectin-4-positive cancer patients. This study reviewed clinical- and preclinical-stage Nectin-4-directed ADCs. [Display omitted] [ABSTRACT FROM AUTHOR]

Multilayered proliferation in an adherent culture as well as proliferation in a suspension culture is a characteristic feature of cancer cells. We previously showed using T47D human mammary cancer cells that nectin‐4, upregulated in many cancer cells, cis‐interacts with ErbB2 and its trastuzumab‐resistant splice variants, p95‐ErbB2 and ErbB2ΔEx16, and enhances DNA synthesis mainly through the PI3K‐AKT pathway in an adherent culture. We showed here that only the combination of nectin‐4 and p95‐ErbB2, but not that of nectin‐4 and ErbB2 or that of nectin‐4 and ErbB2ΔEx16, cooperatively enhanced multilayered T47D cell proliferation through the Hippo pathway–mediated SOX2 gene expression in an adherent culture. T47D cells expressed the components of the apical junctional complex (AJC) consisting of adherens junctions (AJs) and tight junctions and cell polarity molecules, but not the AJ component afadin. The AJC and apicobasal polarity were disorganized in T47D cells in a monolayer and T47D cells stably expressing both nectin‐4 and p95‐ErbB2 in multilayers. These results indicate that nectin‐4 and p95‐ErbB2 play a stimulatory role in multilayered proliferation in an adherent culture. [ABSTRACT FROM AUTHOR]