Nectin-2 in ovarian cancer: How is it expressed and what might be its functional role?

NECTIN2 is a prognostic biomarker and potential therapeutic target in lung adenocarcinoma

INTRODUCTION

NECTINs are transmembrane proteins mediating cell-to-cell adhesion. NECTINs interact with integrins or other membrane receptors to trigger multiple cellular functions. Aberrant NECTIN expression is associated with cancer progression and poor outcomes. While NECTIN2 is overexpressed in various cancer types, its role in lung cancer is not well understood.

MATERIAL AND METHODS

We investigated the function of NECTIN2 in lung adenocarcinoma (LUAD) using the Cancer Genome Atlas (TCGA) dataset and clinical samples of 105 LUAD patients who had undergone surgical resection. Cell proliferation, apoptosis, migration and invasion were investigated using human lung adenocarcinoma cell lines.

RESULTS

We found that high NECTIN2 expression correlated with reduced overall survival in LUAD in TCGA database. In clinical samples, high NECTIN2 expression was associated with lower recurrence-free survival in all patients (P < 0.001) and in stage I patients (P = 0.001). Functional analyses demonstrated that NECTIN2 knockout promoted cell apoptosis and diminished cell proliferation and migration capacity. NECTIN2 overexpression did not significantly affect cellular functions.

DISCUSSION

Our results suggest that NECTIN2 plays a significant role in cell apoptosis and cancer cell migration, leading to increased postoperative recurrence. Furthermore, NECTIN2 serves as a prognostic indicator and a potential therapeutic target in LUAD.

CONCLUSIONS

High NECTIN2 expression in LUAD was found to be associated with postoperative recurrence, and was observed to play an important role in cell apoptosis and migration.

Killer instincts: natural killer cells as multifactorial cancer immunotherapy

Natural killer (NK) cells integrate heterogeneous signals for activation and inhibition using germline-encoded receptors. These receptors are stochastically co-expressed, and their concurrent engagement and signaling can adjust the sensitivity of individual cells to putative targets. Against cancers, which mutate and evolve under therapeutic and immunologic pressure, the diversity for recognition provided by NK cells may be key to comprehensive cancer control. NK cells are already being trialled as adoptive cell therapy and targets for immunotherapeutic agents. However, strategies to leverage their naturally occurring diversity and agility have not yet been developed. In this review, we discuss the receptors and signaling pathways through which signals for activation or inhibition are generated in NK cells, focusing on their roles in cancer and potential as targets for immunotherapies. Finally, we consider the impacts of receptor co-expression and the potential to engage multiple pathways of NK cell reactivity to maximize the scope and strength of antitumor activities.

Prognostic Potential of Nectin Expressions in Colorectal Cancer: An Exploratory Study

Colorectal cancer (CRC) is a pressing global health challenge, with an estimated 1.9 million new cases in 2020. Ranking as the third most diagnosed cancer globally, CRC accounts for nearly 930,000 cancer-related deaths annually. Nectins, immunoglobulin-like adhesion molecules, are pivotal in intercellular adhesion formation and cellular function regulation. Altered nectin expression patterns have been identified in various cancers. However, the intricacies of their role in cancer development and progression remain underexplored. This study aimed to evaluate the expression of specific nectins in CRC tumors, explore their association with clinicopathological factors, and ascertain their potential as prognostic indicators for CRC patients post-resection. We retrospectively analyzed the medical records of 92 CRC patients who underwent surgical treatment between 2013 and 2014. Tumor specimens were re-evaluated to determine nectin expression using immunohistochemistry. The study identified heterogeneous expressions of nectin-2, -3, and -4 in 58%, 62.6%, and 87.9% of specimens, respectively. Elevated nectin-4 expression correlated with worse 5-year and overall survival rates, presenting a negative prognostic value (HR = 4, 95% CI: 2.4-6.8, p < 0.001). Conversely, reduced nectin-3 expression was linked to poorer CRC prognosis (HR = 0.54; 95% CI: 0.31-0.96; p = 0.036). Nectin-4 expression positively correlated with elevated carcinoembryonic antigen (CEA) levels and advanced disease stages. In contrast, nectin-3 expression negatively correlated with CEA levels, tumor size, presence of distant metastases, and disease stage. Notably, tumors in the right colon were statistically more likely to express nectin-2 compared to those in the left. This study underscores the potential prognostic significance of nectins in CRC. The high prevalence of nectin-4-expressing cells offers promising avenues for further evaluation in targeted therapeutic interventions with already available agents such as PADCEV.

Clinical Significance of Nectins in HCC and Other Solid Malignant Tumors: Implications for Prognosis and New Treatment Opportunities-A Systematic Review

The nectin family comprises four proteins, nectin-1 to -4, which act as cell adhesion molecules. Nectins have various regulatory functions in the immune system and can be upregulated or decreased in different tumors. The literature research was conducted manually by the authors using the PubMed database by searching articles published before 2023 with the combination of several nectin-related keywords. A total of 43 studies were included in the main section of the review. Nectins-1-3 have different expressions in tumors. Both the loss of expression and overexpression could be negative prognostic factors. Nectin-4 is the best characterized and the most consistently overexpressed in various tumors, which generally correlates with a worse prognosis. New treatments based on targeting nectin-4 are currently being developed. Enfortumab vedotin is a potent antibody-drug conjugate approved for use in therapy against urothelial carcinoma. Few reports focus on hepatocellular carcinoma, which leaves room for further studies comparing the utility of nectins with commonly used markers.

Nectins and Nectin-like molecules drive vascular development and barrier function

Angiogenesis, barriergenesis, and immune cell migration are all key physiological events that are dependent on the functional characteristics of the vascular endothelium. The protein family of Nectins and Nectin-like molecules (Necls) is a group of cell adhesion molecules that are widely expressed by different endothelial cell types. The family includes four Nectins (Nectin-1 to -4) and five Necls (Necl-1 to -5) that either interact with each other by forming homo- and heterotypical interactions or bind to ligands expressed within the immune system. Nectin and Necl proteins are mainly described to play a role in cancer immunology and in the development of the nervous system. However, Nectins and Necls are underestimated players in the formation of blood vessels, their barrier properties, and in guiding transendothelial migration of leukocytes. This review summarizes their role in supporting the endothelial barrier through their function in angiogenesis, cell-cell junction formation, and immune cell migration. In addition, this review provides a detailed overview of the expression patterns of Nectins and Necls in the vascular endothelium.

Exploring the cellular and molecular differences between ovarian clear cell carcinoma and high-grade serous carcinoma using single-cell RNA sequencing and GEO gene expression signatures

The two most prevalent subtypes of epithelial ovarian carcinoma (EOC) are ovarian clear cell carcinoma (OCCC) and high-grade serous ovarian carcinoma (HGSC). Patients with OCCC have a poor prognosis than those with HGSC due to chemoresistance, implying the need for novel treatment target. In this study, we applied single-cell RNA sequencing (scRNA-seq) together with bulk RNA-seq data from the GEO (Gene Expression Omnibus) database (the GSE189553 dataset) to characterize and compare tumor heterogeneity and cell-level evolution between OCCC and HGSC samples. To begin, we found that the smaller proportion of an epithelial OCCC cell subset in the G2/M phase might explain OCCC chemoresistance. Second, we identified a possible pathogenic OCCC epithelial cell subcluster that overexpresses LEFTY1. Third, novel biomarkers separating OCCC from HGSC were discovered and subsequently validated on a wide scale using immunohistochemistry. Amine oxidase copper containing 1 (AOC1) was preferentially expressed in OCCC over HGSC, while S100 calcium-binding protein A2 (S100A2) was detected less frequently in OCCC than in HGSC. In addition, we discovered that metabolic pathways were enriched in the epithelial compartment of the OCCC samples. In vitro experiments verified that inhibition of oxidative phosphorylation or glycolysis pathways exerted direct antitumor effects on both OCCC and HGSC cells, while targeting glutamine metabolism or ferroptosis greatly attenuated chemosensitivity only in OCCC cells. Finally, to determine whether there were any variations in immune cell subsets between OCCC and HGSC, data from scRNA-seq and mass cytometry were pooled for analysis. In summary, our work provides the first holistic insights into the cellular and molecular distinctions between OCCC and HGSC and is a valuable source for discovering new targets to leverage in clinical treatments to improve the poor prognosis of patients with OCCC.

Nectin2 influences cell apoptosis by regulating ANXA2 expression in neuroblastoma

Neuroblastoma (NB) is a pediatric cancer of the peripheral sympathetic nervous system and represents the most frequent solid malignancy in infants. Nectin2 belongs to the immunoglobulin superfamily and has been shown to play a role in tumorigenesis. In the current study, we demonstrate that serum Nectin2 level is increased in NB patients compared with that in healthy controls and Nectin2 level is correlated with neuroblastoma international neuroblastoma staging system (INSS) classification. There is a positive correlation between Nectin2 level and shorter overall survival in NB patients. Knockdown of Nectin2 reduces the migration of SH-SY5Y and SK-N-BE2 cells and induces their apoptosis and cell cycle arrest. RNA-seq analysis demonstrates that Nectin2 knockdown affects the expressions of 258 genes, including 240 that are upregulated and 18 that are downregulated compared with negative controls. qRT-PCR and western blot analysis confirm that ANXA2 expression is decreased in Nectin2-knockdown SH-SY5Y cells, consistent with the RNA-seq results. ANXA2 overexpression rescues the percentage of apoptotic NB cells induced by Nectin2 knockdown and compensates for the impact of Nectin2 knockdown on cleaved caspase3 and bax expressions. In addition, western blot analysis results show that ANXA2 overexpression rescues the effect of Nectin2 knockdown on MMP2 and MMP9 expressions. The current data highlight the importance of Nectin2 in NB progression and the potential of Nectin2 as a novel candidate target for gene therapy.

The Prognostic Significance of Nectin-2 and Nectin-4 expression in glial tumors

Glial tumors are the most frequent neoplasms of the central nervous system in adults and despite recent advances in diagnosis and treatment of the disease, the prognosis of glioma is poor. Therefore, there is a great need to identify new prognostic factors and potential immunotherapeutic targets. Members of the Nectin family of proteins are gaining significant attention as possible diagnostic and immunotherapeutic targets in many solid tumors, but they have not been extensively investigated in glial tumors. The aim of the present study was to evaluate the expression of Nectin-2 and Nectin-4 in glial tumors of different grades, and to assess their prognostic value. The results showed heterogeneous expression of Nectin-2 and Nectin-4 in tumor cells and neuropil, with significantly higher Nectin-2 expression compared to Nectin-4, but without differences among tumor grades. In addition, the expression of Nectin-2 and Nectin-4 was associated with shorter survival times in patients with grade II/III gliomas. These results suggest that Nectin-2 and Nectin-4 expression may be used as an independent prognostic indicator for patients with II/III gliomas. This study contributes to the development of personalized care for patients with glioma and provides a basis for further research on nectin-based immunotherapy for brain tumors.

Development of the Peritoneal Metastasis: A Review of Back-Grounds, Mechanisms, Treatments and Prospects

Peritoneal metastasis is a malignant disease which originated from several gastrointestinal and gynecological carcinomas and has been leading to a suffering condition in patients for decades. Currently, as people have gradually become more aware of the severity of peritoneal carcinomatosis, new molecular mechanisms for targeting and new treatments have been proposed. However, due to the uncertainty of influencing factors involved and a lack of a standardized procedure for this treatment, as well as a need for more clinical data for specific evaluation, more research is needed, both for preventing and treating. We aim to summarize backgrounds, mechanisms and treatments in this area and conclude limitations or new aspects for treatments.

Transcriptome analysis of PK-15 cells expressing CSFV NS4A

BACKGROUND

Classical swine fever (CSF) is a severe disease of pigs that results in huge economic losses worldwide and is caused by classical swine fever virus (CSFV). CSFV nonstructural protein 4 A (NS4A) plays a crucial role in infectious CSFV particle formation. However, the function of NS4A during CSFV infection is not well understood.  RESULTS: In this study, we used RNA-seq to investigate the functional role of CSFV NS4A in PK-15 cells. A total of 3893 differentially expressed genes (DEGs) were identified in PK-15 cells expressing NS4A compared to cells expressing the empty vector (NC). Twelve DEGs were selected and further verified by RT‒qPCR. GO and KEGG enrichment analyses revealed that these DEGs were associated with multiple biological functions, including cell adhesion, apoptosis, host defence response, the inflammatory response, the immune response, and autophagy. Interestingly, some genes associated with host immune defence and inflammatory response were downregulated, and some genes associated with host apoptosis and autophagy were upregulated.

CONCLUSION

CSFV NS4A inhibits the innate immune response, and suppresses the expression of important genes associated with defence response to viruses and inflammatory response, and regulates cell adhesion, apoptosis and autophagy.

Nectins and Nectin-like Molecules in Colorectal Cancer: Role in Diagnostics, Prognostic Values, and Emerging Treatment Options: A Literature Review

In 2020, colorectal cancer was the third most common type of cancer worldwide with a clearly visible increase in the number of cases each year. With relatively high mortality rates and an uncertain prognosis, colorectal cancer is a serious health problem. There is an urgent need to investigate its specific mechanism of carcinogenesis and progression in order to develop new strategies of action against this cancer. Nectins and Nectin-like molecules are cell adhesion molecules that take part in a plethora of essential processes in healthy tissues as well as mediating substantial actions for tumor initiation and evolution. Our understanding of their role and a viable application of this in anti-cancer therapy has rapidly improved in recent years. This review summarizes the current data on the role nectins and Nectin-like molecules play in colorectal cancer.

A Novel Antibody-Drug Conjugate Targeting Nectin-2 Suppresses Ovarian Cancer Progression in Mouse Xenograft Models

Ovarian cancer is the fifth leading cause of cancer, followed by front line is mostly platinum agents and PARP inhibitors, and very limited option in later lines. Therefore, there is a need for alternative therapeutic options. Nectin-2, which is overexpressed in ovarian cancer, is a known immune checkpoint that deregulates immune cell function. In this study, we generated a novel anti-nectin-2 antibody (chimeric 12G1, c12G1), and further characterized it using epitope mapping, enzyme-linked immunosorbent assay, surface plasmon resonance, fluorescence-activated cell sorting, and internalization assays. The c12G1 antibody specifically bound to the C2 domain of human nectin-2 with high affinity (K_D = 2.90 × 10^-10 M), but not to mouse nectin-2. We then generated an antibody-drug conjugate comprising the c12G1 antibody conjugated to DM1 and investigated its cytotoxic effects against cancer cells in vitro and in vivo. c12G1-DM1 induced cell cycle arrest at the mitotic phase in nectin-2-positive ovarian cancer cells, but not in nectin-2-negative cancer cells. c12G1-DM1 induced ~100-fold cytotoxicity in ovarian cancer cells, with an IC₅₀ in the range of 0.1 nM~7.4 nM, compared to normal IgG-DM1. In addition, c12G1-DM1 showed ~91% tumor growth inhibition in mouse xenograft models transplanted with OV-90 cells. These results suggest that c12G1-DM1 could be used as a potential therapeutic agent against nectin-2-positive ovarian cancers.

Analysis of Protein-Protein Interactions Identifies NECTIN2 as a Target of N,N-Bis (5-Ethyl-2-hydroxybenzyl) Methylamine for Inhibition of Lung Cancer Metastasis

BACKGROUND/AIM

Metastasis negatively affects the survival of lung cancer patients, however, relatively few compounds have potential in metastasis suppression. This study investigated the molecular targets of N,N-bis (5-ethyl-2-hydroxybenzyl) methylamine (EMD) for metastatic inhibition.

MATERIALS AND METHODS

Proteins were analyzed by proteomic and bioinformatic analyses. Protein-protein interaction (PPI) networks were created with the Search Tool for the Retrieval of Interacting Genes. The Kyoto Encyclopedia of Genes and Genomes database and hub genes were used to determine dominant pathways. Immunofluorescence and western blot analyses validated the proteomic results and investigated signaling pathways in NCI-H23 lung cancer cells.

RESULTS

A total of 1,751 proteins were common to the control, EMD and N,N-bis(5-methoxy-2-hydroxybenzyl) methylamine (MeMD) groups; 1,980 different proteins were categorized using metastatic capacity category and analyzed for unique proteins affected by EMD. Fifteen proteins were associated with cell adhesion and six with cell migration. Nectin cell adhesion molecule 2 (NECTIN2) was expressed in the control and MeMD-treated groups but not the EMD-treated group, suggesting NECTIN2 as an EMD target. PPI network showed association of NECTIN2 with proteins regulating cancer metastasis. Kyoto Encyclopedia of Genes and Genomes pathways revealed that NECTIN2 is an upstream target of cytoskeletal regulation via SRC signaling. Western blot and immunofluorescence analyses confirmed that EMD suppressed NECTIN2, and its downstream targets, including p-SRC (Y146 and Y527) and the epithelial-to-mesenchymal transition markers tight junction protein 1, vimentin, β-catenin, snail family transcriptional repressor 1 (SNAI1), and SNAI2, while increasing E-cadherin.

CONCLUSION

EMD suppressed NECTIN2-induced activation of EMT signaling. These data support the development of EMD to prevent metastasis of lung cancer.

High expression of nectin-1 indicates a poor prognosis and promotes metastasis in hepatocellular carcinoma

Objectives

Nectins are a new class of cell-adhesion molecules that play an important role in tumorigenesis and disease progression. The aim of this study was to investigate the prognostic and pathogenetic roles of nectins in hepatocellular carcinoma (HCC).

Methods

The expression levels of the nectin family in HCC and their role in prognosis were analyzed by bioinformatics analysis based on The Cancer Genome Atlas (TCGA) liver hepatocellular carcinoma database. The correlations between nectins and immune cells were analyzed using TIMER. The functional enrichment of the nectin-1 coexpression network was evaluated in TCGA cohort, and the expression levels of nectin-1 were detected by immunohistochemistry and Western blot analysis. A Transwell kit was used for cell migration experiments. Cell proliferation was analyzed using Cell Counting Kit-8.

Results

The expression levels of nectin-1 protein in the cancer tissues of 28 patients with HCC were higher than those in paracancerous tissues. The Kaplan–Meier plotter analysis showed that the high expression of all nectin family numbers was related to the poor prognosis of HCC patients. The abnormal expression of nectin-1 effectively distinguished the prognosis at different stages and grades of HCC. The high expression of 17 methylation sites of the nectin-1 gene was related to the high overall survival of HCC patients. Kyoto Encyclopedia of Genes and Genomes analysis of genes negatively correlated with nectin-1, revealing their close relation to the regulation of the immune-effector process. Pearson’s correlation analysis showed that nectin-1 was significantly positively correlated with multiple immune genes and B cells, CD4+ T cells, macrophages, neutrophils, and dendritic cell infiltration. Cell proliferation of the knockdown (KD) group decreased significantly compared to the NC-KD group. The number of metastatic cells in the KD group decreased significantly compared to that in the NC-KD group.

Conclusions

Abnormal expression of nectins and multiple methylation sites closely correlates with poor prognosis in HCC patients. Nectins are related to immune cell infiltration and immune-related genes. In particular, nectin-1 can promote the proliferation and migration of liver cancer cells and distinguish the prognosis at different stages and grades of HCC. Nectin-1 might be a new potential molecular marker for prognostic evaluation and also a therapeutic target for HCC.

Cancer Angiogenesis and Opportunity of Influence on Tumor by Changing Vascularization

Based on the study of recent scientific literature devoted to neovascularization and angiogenesis in malignant neoplasms, it was concluded that there are many publications on each of the problems of tumor angiogenesis and vascularization. The formation of blood vessels in a tumor and certain aspects of the prognostic value of the severity of vascularization in almost all forms of cancer are considered. Special attention is paid to the peculiarities of angiogenesis in tumors of the female reproductive system. A large number of vessels in the tumor often indicates a poor prognosis. The influence of various factors on the initiation of angiogenesis and the process itself, as well as the possibility of suppressing such signals to slow down the formation of blood vessels and thus the development of the tumor are widely studied. The results of pharmacological suppression of tumor vessel formation demonstrate a good clinical outcome but one accompanied by a large number of severe adverse side effects. Such a significant amount of studies on each of the problems of tumor vascularization indicates the increasing importance of this area of oncology. At the same time, only a very small number of works are devoted to the study of the differences in angiogenesis and number of vessels between different parts of the tumor, as well as between the primary tumor node and its metastases. The refinement of the results is still to be done. It was noted that the expression of proangiogenic factors in metastases is usually higher than in the source of metastasis, and the expression in lymphogenous metastases is higher than in hematogenous ones.

Establishment of the SIS scaffold-based 3D model of human peritoneum for studying the dissemination of ovarian cancer

Ovarian cancer is the second most common gynecological malignancy in women. More than 70% of the cases are diagnosed at the advanced stage, presenting as primary peritoneal metastasis, which results in a poor 5-year survival rate of around 40%. Mechanisms of peritoneal metastasis, including adhesion, migration, and invasion, are still not completely understood and therapeutic options are extremely limited. Therefore, there is a strong requirement for a 3D model mimicking the in vivo situation. In this study, we describe the establishment of a 3D tissue model of the human peritoneum based on decellularized porcine small intestinal submucosa (SIS) scaffold. The SIS scaffold was populated with human dermal fibroblasts, with LP-9 cells on the apical side representing the peritoneal mesothelium, while HUVEC cells on the basal side of the scaffold served to mimic the endothelial cell layer. Functional analyses of the transepithelial electrical resistance (TEER) and the FITC-dextran assay indicated the high barrier integrity of our model. The histological, immunohistochemical, and ultrastructural analyses showed the main characteristics of the site of adhesion. Initial experiments using the SKOV-3 cell line as representative for ovarian carcinoma demonstrated the usefulness of our models for studying tumor cell adhesion, as well as the effect of tumor cells on endothelial cell-to-cell contacts. Taken together, our data show that the novel peritoneal 3D tissue model is a promising tool for studying the peritoneal dissemination of ovarian cancer.

Establishment of a novel ferroptosis-related lncRNA pair prognostic model in colon adenocarcinoma

Long non-coding RNAs (lncRNAs) have been reported to be prognostic factors for cancer. Ferroptosis is an iron-dependent process of programmed cell death. Here, we established a ferroptosis-related lncRNA (frlncRNA) pair signature and revealed its prognostic value in colon adenocarcinoma (COAD) by analyzing the data from The Cancer Genome Atlas (TCGA). FrlncRNAs were identified based on co-expression analysis using the Pearson correlation. Differentially expressed frlncRNAs (DEfrlncRNAs) were recognized and paired, followed by prognostic assessment using univariate Cox regression analysis. The least absolute shrinkage and selection operator (LASSO) penalized Cox analysis was used to determine and construct a risk score prognostic model, by which the receiver operating characteristic (ROC) curves for predicting the overall survival (OS) were conducted. Following the evaluation of whether it was an independent prognostic factor, correlations between the risk score model and clinicopathological characteristics, hypoxia- and immune-related factors, and somatic variants were investigated. In total, 148 DEfrlncRNA pairs were identified, 25 of which were involved in a risk score prognostic signature. The area under ROC curves (AUCs) representing the predictive effect for 1-, 3-, and 5-year survival rates were 0.860, 0.885, and 0.934, respectively. The risk score model was confirmed as an independent prognostic factor and was significantly superior to the clinicopathological characteristics. Correlation analyses showed disparities in clinicopathological characteristics, hypoxia- and immune-related factors, and somatic variants, as well as specific signaling pathways between high- and low-risk groups. The novel risk score prognostic model constructed by pairing DEfrlncRNAs showed promising clinical prediction value in COAD.

The CD112R/CD112 axis: a breakthrough in cancer immunotherapy

The recent discovery of immune checkpoint inhibitors is a significant milestone in cancer immunotherapy research. However, some patients with primary or adaptive drug resistance might not benefit from the overall therapeutic potential of immunotherapy in oncology. Thus, it is becoming increasingly critical for oncologists to explore the availability of new immune checkpoint inhibitors. An emerging co-inhibitory receptor, CD112R (also called PVRIG), is most commonly expressed on natural killer (NK) and T cells. It binds to its ligand (CD112 or PVRL2/nectin-2) and inhibits the strength with which T cells and NK cells respond to cancer. Therefore, CD112R is being presented as a new immune checkpoint inhibitor with high potential in cancer immunotherapy. CD112 is easily detectable on antigen-presenting or tumor cells, and its high level of expression has been linked with tumor progression and poor outcomes in most cancer patients. This review explores the molecular and functional relationship between CD112R, TIGIT, CD96, and CD226 in T cell responses. In addition, this review comprehensively discusses the recent developments of CD112R/CD112 immune checkpoints in cancer immunotherapy and prognosis.

Emerging roles of the nectin family of cell adhesion molecules in tumour-associated pathways

Tumour cells achieve maximum survival by modifying cellular machineries associated with processes such as cell division, migration, survival, and apoptosis, resulting in genetically complex and heterogeneous populations. While nectin and nectin-like cell adhesion molecules control development and maintenance of multicellular organisation in higher vertebrates by mediating cell-cell adhesion and related signalling processes, recent studies indicate that they also critically regulate growth and development of different types of cancers. In this review, we detail current knowledge about the role of nectin family members in various tumours. Furthermore, we also analyse the seemingly opposing roles of some members of nectin family in tumour-associated pathways, as they function as both tumour suppressors and oncogenes. Understanding this functional duality of nectin family in tumours will further our knowledge of molecular mechanisms regulating tumour development and progression, and contribute to the advancement of tumour diagnosis and therapy.

Immune Modeling Analysis Reveals Immunologic Signatures Associated With Improved Outcomes in High Grade Serous Ovarian Cancer

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy worldwide, as patients are typically diagnosed at a late stage and eventually develop chemoresistant disease following front-line platinum-taxane based therapy. Only modest results have been achieved with PD-1 based immunotherapy in ovarian cancer patients, despite the fact that immunological responses are observed in EOC patients. Therefore, the goal of this present study was to identify novel immune response genes and cell subsets significantly associated with improved high grade serous ovarian cancer (HGSOC) patient prognosis. A transcriptomic-based immune modeling analysis was employed to determine levels of 8 immune cell subsets, 10 immune escape genes, and 22 co-inhibitory/co-stimulatory molecules in 26 HGSOC tumors. Multidimensional immune profiling analysis revealed CTLA-4, LAG-3, and Tregs as predictive for improved progression-free survival (PFS). Furthermore, the co-stimulatory receptor ICOS was also found to be significantly increased in patients with a longer PFS and positively correlated with levels of CTLA-4, PD-1, and infiltration of immune cell subsets. Both ICOS and LAG-3 were found to be significantly associated with improved overall survival in The Cancer Genome Atlas (TCGA) ovarian cancer cohort. Finally, PVRL2 was identified as the most highly expressed transcript in our analysis, with immunohistochemistry results confirming its overexpression in HGSOC samples compared to normal/benign. Results were corroborated by parallel analyses of TCGA data. Overall, this multidimensional immune modeling analysis uncovers important prognostic immune factors that improve our understanding of the unique immune microenvironment of ovarian cancer.

Establishment and histopathological study of patient-derived xenograft models and primary cell lines of epithelioid malignant peritoneal mesothelioma

Malignant peritoneal mesothelioma (MPM) is a rare malignancy with few experimental models. This study used the human surgical specimen to establish MPM patient-derived xenograft (PDX) models and primary cell lines to provide a study platform for MPM in vitro and in vivo, and conducted histopathological analysis. Our study used the experimental peritoneal cancer index (ePCI) score to evaluate gross pathology, and the results showed that the ePCI score of the female and male nude mice were 8.80 ± 1.75 and 9.20 ± 1.81 (P=0.6219), respectively. The Hematoxylin and eosin (HE) staining of animal models showed that the tumor was epithelioid mesothelioma and invaded multiple organs. Immunohistochemistry (IHC) staining showed that Calretinin, Cytokeratin 5/6, WT-1 and Ki-67 were all positive. The Swiss-Giemsa and Immunofluorescence (IF) staining of primary cell lines were also consistent with the pathological characteristics of mesothelioma. We also performed the whole-exome sequencing (WES) to identify the mutant genes between models and the patient. And the results showed that 21 mutant genes were shared between the two groups, and the genes related to tumorigenesis and development including BAP1, NF2, MTBP, NECTIN2, CDC23, LRPPRC, TRIM25, and DHRS2. In conclusion, the PDX models and primary cell lines of MPM were successfully established with the epithelioid mesothelioma identity confirmed by histopathological evidence. Moreover, our study has also illustrated the shared genomic profile between models and the patient.

The Perfect Combination: Enhancing Patient Response to PD-1-Based Therapies in Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy, with an overall 5-year survival of only 47%. As the development of novel targeted therapies is drastically necessary in order to improve patient survival, current EOC clinical trials have heavily focused on immunotherapeutic approaches, centered upon programmed cell death 1 (PD-1) inhibitors. While PD-1 monotherapies have only exhibited modest responses for patients, it has been theorized that in order to enhance EOC patient response to immunotherapy, combinatorial regimens must be investigated. In this review, unique challenges to EOC PD-1 response will be discussed, along with a comprehensive description of both preclinical and clinical studies evaluating PD-1-based combinatorial therapies. Promising aspects of PD-1-based combinatorial approaches are highlighted, while also discussing specific preclinical and clinical areas of research that need to be addressed, in order to optimize EOC patient immunotherapy response.

Mechanisms Ensuring Endothelial Junction Integrity Beyond VE-Cadherin

Endothelial junctions provide blood and lymph vessel integrity and are essential for the formation of a vascular system. They control the extravasation of solutes, leukocytes and metastatic cells from blood vessels and the uptake of fluid and leukocytes into the lymphatic vascular system. A multitude of adhesion molecules mediate and control the integrity and permeability of endothelial junctions. VE-cadherin is arguably the most important adhesion molecule for the formation of vascular structures, and the stability of their junctions. Interestingly, despite this prominence, its elimination from junctions in the adult organism has different consequences in the vasculature of different organs, both for blood and lymph vessels. In addition, even in tissues where the lack of VE-cadherin leads to strong plasma leaks from venules, the physical integrity of endothelial junctions is preserved. Obviously, other adhesion molecules can compensate for a loss of VE-cadherin and this review will discuss which other adhesive mechanisms contribute to the stability and regulation of endothelial junctions and cooperate with VE-cadherin in intact vessels. In addition to adhesion molecules, endothelial receptors will be discussed, which stimulate signaling processes that provide junction stability by modulating the actomyosin system, which reinforces tension of circumferential actin and dampens pulling forces of radial stress fibers. Finally, we will highlight most recent reports about the formation and control of the specialized button-like junctions of initial lymphatics, which represent the entry sites for fluid and cells into the lymphatic vascular system.

Boosting Natural Killer Cell-Mediated Targeting of Sarcoma Through DNAM-1 and NKG2D

Sarcomas are malignancies of mesenchymal origin that occur in bone and soft tissues. Many are chemo- and radiotherapy resistant, thus conventional treatments fail to increase overall survival. Natural Killer (NK) cells exert anti-tumor activity upon detection of a complex array of tumor ligands, but this has not been thoroughly explored in the context of sarcoma immunotherapy. In this study, we investigated the NK cell receptor/ligand immune profile of primary human sarcoma explants. Analysis of tumors from 32 sarcoma patients identified the proliferative marker PCNA and DNAM-1 ligands CD112 and/or CD155 as commonly expressed antigens that could be efficiently targeted by genetically modified (GM) NK cells. Despite the strong expression of CD112 and CD155 on sarcoma cells, characterization of freshly dissociated sarcomas revealed a general decrease in tumor-infiltrating NK cells compared to the periphery, suggesting a defect in the endogenous NK cell response. We also applied a functional screening approach to identify relevant NK cell receptor/ligand interactions that induce efficient anti-tumor responses using a panel NK-92 cell lines GM to over-express 12 different activating receptors. Using GM NK-92 cells against primary sarcoma explants (n = 12) revealed that DNAM-1 over-expression on NK-92 cells led to efficient degranulation against all tested explants (n = 12). Additionally, NKG2D over-expression showed enhanced responses against 10 out of 12 explants. These results show that DNAM-1⁺ or NKG2D⁺ GM NK-92 cells may be an efficient approach in targeting sarcomas. The degranulation capacity of GM NK-92 cell lines was also tested against various established tumor cell lines, including neuroblastoma, Schwannoma, melanoma, myeloma, leukemia, prostate, pancreatic, colon, and lung cancer. Enhanced degranulation of DNAM-1⁺ or NKG2D⁺ GM NK-92 cells was observed against the majority of tumor cell lines tested. In conclusion, DNAM-1 or NKG2D over-expression elicited a dynamic increase in NK cell degranulation against all sarcoma explants and cancer cell lines tested, including those that failed to induce a notable response in WT NK-92 cells. These results support the broad therapeutic potential of DNAM-1⁺ or NKG2D⁺ GM NK-92 cells and GM human NK cells for the treatment of sarcomas and other malignancies.

Nectin-2 in ovarian cancer: How is it expressed and what might be its functional role?

Nectin‐2 is an adhesion molecule that has been reported to play a role in tumor growth, metastasis and tumor angiogenesis. Herein, we investigated Nectin‐2 in ovarian cancer patients and in cell culture. Tumor as well as peritoneal biopsies of 60 ovarian cancer patients and 22 controls were dual stained for Nectin‐2 and CD31 using immunohistochemistry. Gene expression of Nectin‐2 was quantified by real‐time PCR and differences analyzed in relation to various tumor characteristics. In the serum of patients, vascular endothelial growth factor (VEGF) was quantified by ELISA. Effect of VEGF on Nectin‐2 expression as well as permeability was investigated in HUVEC. In tumor biopsies, Nectin‐2 protein was mainly localized in tumor cells, whereas in peritoneal biopsies, clear colocalization was found in the vasculature. T3 patients had a significantly higher percentage of positive lymph nodes and this correlated with survival. Nectin‐2 was significantly upregulated in tumor biopsies in patients with lymph node metastasis and with residual tumor >1 cm after surgery. Nectin‐2 expression was significantly suppressed in the peritoneal endothelium of patients associated with significantly increased VEGF serum levels. In cell culture, VEGF stimulation led to a significant downregulation of Nectin‐2 which was reversed by VEGF‐inhibition. In addition, Nectin‐2 knockdown in endothelial cells was associated with significantly increased endothelial permeability. Nectin‐2 expression in ovarian cancer may support tumor cell adhesion, leading to growth and lymph node metastasis. In addition, VEGF‐induced Nectin‐2 suppression in peritoneal endothelium may support an increase in vascular permeability leading to ascites production.