Generating tumor-selective conditionally active biologic anti-CTLA4 antibodies via protein-associated chemical switches

Anticytotoxic T lymphocyte-associated protein 4 (CTLA4) antibodies have shown potent antitumor activity, but systemic immune activation leads to severe immune-related adverse events, limiting clinical usage. We developed novel, conditionally active biologic (CAB) anti-CTLA4 antibodies that are active only in the acidic tumor microenvironment. In healthy tissue, this binding is reversibly inhibited by a novel mechanism using physiological chemicals as protein-associated chemical switches (PaCS). No enzymes or potentially immunogenic covalent modifications to the antibody are required for activation in the tumor. The novel anti-CTLA4 antibodies show similar efficacy in animal models compared to an analog of a marketed anti-CTLA4 biologic, but have markedly reduced toxicity in nonhuman primates (in combination with an anti-PD1 checkpoint inhibitor), indicating a widened therapeutic index (TI). The PaCS encompass mechanisms that are applicable to a wide array of antibody formats (e.g., ADC, bispecifics) and antigens. Examples shown here include antibodies to EpCAM, Her2, Nectin4, CD73, and CD3. Existing antibodies can be engineered readily to be made sensitive to PaCS, and the inhibitory activity can be optimized for each antigen's varying expression level and tissue distribution. PaCS can modulate diverse physiological molecular interactions and are applicable to various pathologic conditions, enabling differential CAB antibody activities in normal versus disease microenvironments.

High-dimensional analysis of the adenosine pathway in high-grade serous ovarian cancer

BACKGROUND

Hydrolysis of extracellular ATP to adenosine (eADO) is an important immune checkpoint in cancer immunology. We here investigated the impact of the eADO pathway in high-grade serous ovarian cancer (HGSC) using multiparametric platforms.

METHODS

We performed a transcriptomic meta-analysis of eADO-producing CD39 and CD73, an eADO signaling gene signature, immune gene signatures and clinical outcomes in approximately 1200 patients with HGSC. Protein expression, localization and prognostic impact of CD39, CD73 and CD8 were then performed on approximately 1000 cases on tissue microarray, and tumor-infiltrating lymphocytes (TILs) were analyzed by flow cytometry and single-cell RNA sequencing on a subset of patients.

RESULTS

Concomitant CD39 and CD73 gene expression, as well as high levels of an eADO gene signature, were associated with worse prognosis in patients with HGSC, notably in the immunoregulatory molecular subtype, characterized by an immune-active microenvironment. CD39 was further associated with primary chemorefractory and chemoresistant human HGSC and platinum-based chemotherapy of murine HGSC was significantly more effective in CD39-deficient mice. At protein level, CD39 and CD73 were predominantly expressed by cancer-associated fibroblasts, and CD39 was expressed on severely exhausted, clonally expanded and putative tissue-resident memory TILs.

CONCLUSIONS

Our study revealed the clinical, immunological, subtype-specific impacts of eADO signaling in HGSC, unveiled the chemoprotective effect of CD39 and supports the evaluation of eADO-targeting agents in patients with ovarian cancer.

Mesothelin blockage by Amatuximab suppresses cell invasiveness, enhances gemcitabine sensitivity and regulates cancer cell stemness in mesothelin-positive pancreatic cancer cells

BACKGROUND

Mesothelin is a 40-kDa glycoprotein that is highly overexpressed in various types of cancers, however molecular mechanism of mesothelin has not been well-known. Amatuximab is a chimeric monoclonal IgG1/k antibody targeting mesothelin. We recently demonstrated that the combine therapy of Amatuximab and gemcitabine was effective for peritonitis of pancreatic cancer in mouse model.

METHODS

We discover the role and potential mechanism of mesothelin blockage by Amatuximab in human pancreatic cells both expressing high or low level of mesothelin in vitro experiment and peritonitis mouse model of pancreatic cancer.

RESULTS

Mesothelin blockage by Amatuximab lead to suppression of invasiveness and migration capacity in AsPC-1 and Capan-2 (high mesothelin expression) and reduce levels of pMET expression. The combination of Amatuximab and gemcitabine suppressed proliferation of AsPC-1 and Capan-2 more strongly than gemcitabine alone. These phenomena were not observed in Panc-1 and MIA Paca-2 (Mesothelin low expression). We previously demonstrated that Amatuximab reduced the peritoneal mass in mouse AsPC-1 peritonitis model and induced sherbet-like cancer cell aggregates, which were vanished by gemcitabine. In this study, we showed that the cancer stem cell related molecule such as ALDH1, CD44, c-MET, as well as proliferation related molecules, were suppressed in sherbet-like aggregates, but once sherbet-like aggregates attached to peritoneum, they expressed these molecules strongly without the morphological changes.

CONCLUSIONS

Our work suggested that Amatuximab inhibits the adhesion of cancer cells to peritoneum and suppresses the stemness and viability of those, that lead to enhance the sensitivity for gemcitabine.

Impact of Reck expression and promoter activity in neuronal in vitro differentiation

Reck (REversion-inducing Cysteine-rich protein with Kazal motifs) tumor suppressor gene encodes a multifunctional glycoprotein which inhibits the activity of several matrix metalloproteinases (MMPs), and has the ability to modulate the Notch and canonical Wnt pathways. Reck-deficient neuro-progenitor cells undergo precocious differentiation; however, modulation of Reck expression during progression of the neuronal differentiation process is yet to be characterized. In the present study, we demonstrate that Reck expression levels are increased during in vitro neuronal differentiation of PC12 pheochromocytoma cells and P19 murine teratocarcinoma cells and characterize mouse Reck promoter activity during this process. Increased Reck promoter activity was found upon induction of differentiation in PC12 cells, in accordance with its increased mRNA expression levels in mouse in vitro models. Interestingly, Reck overexpression, prior to the beginning of the differentiation protocol, led to diminished efficiency of the neuronal differentiation process. Taken together, our findings suggest that increased Reck expression at early stages of differentiation diminishes the number of neuron-like cells, which are positive for the beta-3 tubulin marker. Our data highlight the importance of Reck expression evaluation to optimize in vitro neuronal differentiation protocols.

Omentin-1: Protective impact on ischemic stroke via ameliorating atherosclerosis

Omentin-1, a newly identified adipokine, has recently been revealed as a novel biomarker for ischemic stroke (IS). Low circulating omentin-1 levels could indicate a high risk of IS, and elevated omentin-1 levels exert a favorable impact on cerebral ischemia. Furthermore, omentin-1 has anti-atherosclerotic, anti-inflammatory, and cardiovascular protective capabilities through the intracellular Akt/AMP-activated protein kinase (AMPK)/ nuclear factor-κB (NF-κB) and certain protein kinase (ERK, JNK, and p38) signaling pathways. Omentin-1 also alleviates endothelial cell dysfunction, improves revascularization via the Akt-endothelial nitric-oxide synthase (eNOS) regulatory axis, promotes endothelium-dependent vasodilation through endothelium-derived NO in an eNOS fashion, and inhibits VSMC proliferation by means of AMPK/ERK signaling pathways, VSMC migration via inactivation of the NADPH oxidase (NOX)/ROS/p38/HSP27 pathways and artery calcification via the PI3K-Akt pathway. These findings indicate that omentin-1 may be a negative mediator of IS. Pharmacologically, several lines of clinical evidence indicate that metformin and statins could elevate omentin-1 levels, although the specific mechanism has not been precisely delineated until now. This study is the first to summarize the comprehensive mechanisms between omentin-1 and atherosclerosis and to review the shielding effect of omentin-1 on IS. We shed light on omentin-1 as a novel therapeutic target for combating IS.

Human CD34-negative hematopoietic stem cells: The current understanding of their biological nature

Hematopoietic stem cell (HSC) heterogeneity and hierarchy are a current topic of interest, having major implications for clinical HSC transplantation and basic research on human HSCs. It was long believed that the most primitive HSCs in mammals, including mice and humans, were CD34 antigen positive (CD34⁺). However, 2 decades ago, it was reported that murine long-term multilineage reconstituting HSCs were lineage marker negative (Lin^-, i.e., c-kit⁺Sca-1⁺CD34^low/-), known as CD34^low/- KSL cells. In contrast, human CD34^- HSCs, a counterpart of murine CD34^low/- KSL cells, were hard to identify for a long time mainly because of their rarity. We previously identified very primitive human cord blood (CB)-derived CD34^- severe combined immunodeficiency (SCID)-repopulating cells (SRCs) using the intra-bone marrow injection method and proposed the new concept that CD34^- SRCs (HSCs) reside at the apex of the human HSC hierarchy. Through a series of studies, we identified two positive/enrichment markers: CD133 and GPI-80. The combination of these two markers enabled the development of an ultrahigh-resolution purification method for CD34^- as well as CD34⁺ HSCs and the successful purification of both HSCs at the single-cell level. Cell population purity is a crucial prerequisite for reliable biological and molecular analyses. Clonal analyses of highly purified human CD34^- HSCs have revealed their potent megakaryocyte/erythrocyte differentiation potential. Based on these observations, we propose a revised road map for the commitment of human CB-derived CD34^- HSCs. This review updates the current understanding of the stem cell nature of human CB-derived primitive CD34^- as well as CD34⁺ HSCs.

Discovery of natural product ellagic acid as a potent CD73 and CD39 dual inhibitor

The ATP-adenosine pathway has been recently identified as an attractive immune-oncology target and several drug candidates have been entered clinic trials. Inspired by the report of the first small-molecule CD73inhibitor AB680, we describe the discovery of natural product ellagic acid as a dual CD73 and CD39 inhibitor with an IC₅₀ value of 1.85 ± 0.21 μM and 0.50 ± 0.22 μM, respectively. The result of cytotoxicity assays indicated that ellagic acid is a valuable lead compound with low cytotoxicity effect for immune therapy.

Pseudorabies Virus Infection Causes Downregulation of Ligands for the Activating NK Cell Receptor NKG2D

Herpesviruses display a complex and carefully balanced interaction with important players in the antiviral immune response of immunocompetent natural hosts, including natural killer (NK) cells. With regard to NK cells, this delicate balance is illustrated on the one hand by severe herpesvirus disease reported in individuals with NK cell deficiencies and on the other hand by several NK cell evasion strategies described for herpesviruses. In the current study, we report that porcine cells infected with the porcine alphaherpesvirus pseudorabies virus (PRV) display a rapid and progressive downregulation of ligands for the major activating NK cell receptor NKG2D. This downregulation consists both of a downregulation of NKG2D ligands that are already expressed on the cell surface of an infected cell and an inhibition of cell surface expression of newly expressed NKG2D ligands. Flow cytometry and RT-qPCR assays showed that PRV infection results in downregulation of the porcine NKG2D ligand pULBP1 from the cell surface and a very substantial suppression of mRNA expression of pULBP1 and of another potential NKG2D ligand, pMIC2. Furthermore, PRV-induced NKG2D ligand downregulation was found to be independent of late viral gene expression. In conclusion, we report that PRV infection of host cells results in a very pronounced downregulation of ligands for the activating NK cell receptor NKG2D, representing an additional NK evasion strategy of PRV.

Impact of PSCA Polymorphisms on the Risk of Duodenal Ulcer

BACKGROUND

While duodenal ulcer (DU) and gastric cancer (GC) are both H. pylori infection-related diseases, individuals with DU are known to have lower risk for GC. Many epidemiological studies have identified the PSCA rs2294008 T-allele as a risk factor of GC, while others have found an association between the rs2294008 C-allele and risk of DU and gastric ulcer (GU). Following these initial reports, however, few studies have since validated these associations. Here, we aimed to validate the association between variations in PSCA and the risk of DU/GU and evaluate its interaction with environmental factors in a Japanese population.

METHODS

Six PSCA SNPs were genotyped in 584 DU cases, 925 GU cases, and 8,105 controls from the Japan Multi-Institutional Collaborative Cohort (J-MICC). Unconditional logistic regression models were applied to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between the SNPs and risk of DU/GU.

RESULTS

PSCA rs2294008 C-allele was associated with per allele OR of 1.34 (95% CI, 1.18-1.51; P = 2.28 × 10-6) for the risk of DU. This association was independent of age, sex, study site, smoking habit, drinking habit, and H. pylori status. On the other hand, we did not observe an association between the risk of GU and PSCA SNPs.

CONCLUSIONS

Our study confirms an association between the PSCA rs2294008 C-allele and the risk of DU in a Japanese population.

MicroRNA-182 Suppresses Malignant Melanoma Proliferation by Targeting RECK

BACKGROUND

MicroRNAs (miRNAs) function as important post-transcriptional regulators involved in a wide range of biological behaviors. MicroRNA-182 (miR-182) has been shown to play a critical role in tumor pathogenesis. The present study aimed to investigate the role of miR-182 in malignant melanoma.

METHODS

MTT assay was performed to measure the viabilities of cancer cells. Quantitative real-time PCR (qRT-PCR) and western blot were used to detect the mRNA and protein expression, respectively. Moreover, the miRNA target genes were validated with luciferase activity assay.

RESULTS

In the current study, we found that the expression of miR-182 was significantly up-regulated in malignant melanoma tissues compared to the adjacent non-cancer tissues. MMT assay showed that down-regulation of miR-182 suppressed the proliferation of malignant melanoma cell line. By contrast, over-expression of miR-182 promoted the growth of malignant melanoma cells. In addition, the reversion-inducing cysteinerich protein with Kazal motifs (RECK) was down-expressed in human malignant melanoma tissues. Moreover, poor expression of miR-182 led to an increase in RECK expression, whereas over-expression of miR-182 reduced RECK levels in malignant melanoma cells. The luciferase reporter assay showed that RECK was a direct target of miR-182.

CONCLUSIONS

These findings demonstrated that miR-182 inhibited malignant melanoma cell proliferation via RECK, providing a novel target for the molecular treatment of malignant melanoma.

Common Variants in NUS1 and GP2 Genes Contributed to the Risk of Gestational Diabetes Mellitus

BACKGROUND

Recently, NUS1 and GP2 genes were reported to be associated with the risk of type 2 diabetes (T2D) in a Japanese population. Given the sharing of pathogenic contribution from genetic factors between T2D and gestational diabetes mellitus (GDM), we conducted the study to systematically examine the relationship of NUS1 and GP2 genes with the susceptibility to GDM in Chinese Han population.

METHODS

A total of 4,250 subjects comprised of 1,282 patients with GDM and 2,968 controls were recruited, and 20 tag single nucleotide polymorphisms (SNPs) (10 from NUS1 and 10 from GP2) were selected for genotyping. Association analyses were conducted for GDM and its related biomedical indexes including fasting glucose and HbA1c levels.

RESULTS

Two SNPs, rs80196932 from NUS1 (P=2.93×10^-5) and rs117267808 from GP2 (P=5.68×10^-5), were identified to be significantly associated with the risk of GDM. Additionally, SNP rs80196932 was significantly associated with HbA1c level in both patients with GDM (P=0.0009) and controls (P=0.0003), while SNP rs117267808 was significantly associated with fasting glucose level in both patients with GDM (P=0.0008) and controls (P=0.0007). Serum levels of protein NUS1 and GP2 were measured for the study subjects, and significant differences were identified among groups with different genotypes of SNP rs80196932 and rs117267808, respectively.

CONCLUSIONS

Our findings indicate that NUS1 and GP2 genes contribute to the risk of GDM, which would help to offer the potential to improve our understanding of the etiology of GDM and, in turn, could facilitate the development of novel medicines and treatments for GDM.

MicroRNA expression in lung tissues of asbestos-exposed mice: Upregulation of miR-21 and downregulation of tumor suppressor genes Pdcd4 and Reck

OBJECTIVES

Asbestos causes lung cancer and malignant mesothelioma in humans, but the precise mechanism has not been well understood. MicroRNA (miRNA) is a short non-coding RNA that suppresses gene expression and participates in human diseases including cancer. In this study, we examined the expression levels of miRNA and potential target genes in lung tissues of asbestos-exposed mice by microarray analysis.

METHODS

We intratracheally administered asbestos (chrysotile and crocidolite, 0.05 or 0.2 mg/instillation) to 6-week-old ICR male mice four times weekly. We extracted total RNA from lung tissues and performed microarray analysis for miRNA and gene expression. We also carried out real-time polymerase chain reaction (PCR), Western blotting, and immunohistochemistry to confirm the results of microarray analysis.

RESULTS

Microarray analysis revealed that the expression levels of 14 miRNAs were significantly changed by chrysotile and/or crocidolite (>2-fold, P < .05). Especially, miR-21, an oncogenic miRNA, was significantly upregulated by both chrysotile and crocidolite. In database analysis, miR-21 was predicted to target tumor suppressor genes programmed cell death 4 (Pdcd4) and reversion-inducing-cysteine-rich protein with kazal motifs (Reck). Although real-time PCR showed that Pdcd4 was not significantly downregulated by asbestos exposure, Western blotting and immunohistochemistry revealed that PDCD4 expression was reduced especially by chrysotile. Reck was significantly downregulated by chrysotile in real-time PCR and immunohistochemistry.

CONCLUSIONS

This is the first study demonstrating that miR-21 was upregulated and corresponding tumor suppressor genes were downregulated in lung tissues of asbestos-exposed animals. These molecular events are considered to be an early response to asbestos exposure and may contribute to pulmonary toxicity and carcinogenesis.

The Role of RECK in Hepatobiliary Neoplasia Reveals Its Therapeutic Potential in NASH

Non-alcoholic fatty liver disease (NAFLD) is a multimorbidity disorder ranging from excess accumulation of fat in the liver (steatosis) to steatohepatitis (NASH) and end-stage cirrhosis, and the development of hepatocellular carcinoma (HCC) in a subset of patients. The defining features of NASH are inflammation and progressive fibrosis. Currently, no pharmaceutical therapies are available for NAFLD, NASH and HCC; therefore, developing novel treatment strategies is desperately needed. Reversion Inducing Cysteine Rich Protein with Kazal motifs (RECK) is a well-known modifier of the extracellular matrix in hepatic remodeling and transition to HCC. More recently, its role in regulating inflammatory and fibrogenic processes has emerged. Here, we summarize the most relevant findings that extend our current understanding of RECK as a regulator of inflammation and fibrosis, and its induction as a potential strategy to blunt the development and progression of NASH and HCC.

Pharmacological inhibition of Vanin-1 is not protective in models of acute and chronic kidney disease

Oxidative stress is a key concept in basic, translational, and clinical research to understand the pathophysiology of various disorders, including cardiovascular and renal diseases. Although attempts to directly reduce oxidative stress with redox-active substances have until now largely failed to prove clinical benefit, indirect approaches to combat oxidative stress enzymatically have gained further attention as potential therapeutic strategies. The pantetheinase Vanin-1 is expressed on kidney proximal tubular cells, and its reaction product cysteamine is described to negatively affect redox homeostasis by inhibiting the replenishment of cellular antioxidative glutathione stores. Vanin-1-deficient mice were shown to be protected against oxidative stress damage. The aim of this study was to elucidate whether pharmacological inhibition of Vanin-1 protects mice from oxidative stress-related acute or chronic kidney injury as well. By studying renal ischemia-reperfusion injury in Col4α3-/- (Alport syndrome) mice and in vitro hypoxia-reoxygenation in human proximal tubular cells we found that treatment with a selective and potent Vanin-1 inhibitor resulted in ample inhibition of enzymatic activity in vitro and in vivo. However, surrogate parameters of metabolic and redox homeostasis were only partially and insufficiently affected. Consequently, apoptosis and reactive oxygen species level in tubular cells as well as overall kidney function and fibrotic processes were not improved by Vanin-1 inhibition. We thus conclude that Vanin-1 functionality in the context of cardiovascular diseases needs further investigation and the biological relevance of pharmacological Vanin-1 inhibition for the treatment of kidney diseases remains to be proven.

LY6D-induced macropinocytosis as a survival mechanism of senescent cells

Although senescent cells display various morphological changes including vacuole formation, it is still unclear how these processes are regulated. We have recently identified the gene, lymphocyte antigen 6 complex, locus D (LY6D), to be upregulated specifically in senescent cells. LY6D is a glycosylphosphatidylinositol-anchored cell-surface protein whose function remains unknown. Here, we analyzed the functional relationship between LY6D and the senescence processes. We found that overexpression of LY6D induced vacuole formation and knockdown of LY6D suppressed the senescence-associated vacuole formation. The LY6D-induced vacuoles were derived from macropinocytosis, a distinct form of endocytosis. Furthermore, Src family kinases and Ras were found to be recruited to membrane lipid rafts in an LY6D-dependent manner, and inhibition of their activity impaired the LY6D-induced macropinocytosis. Finally, reduction of senescent-cell survival induced by glutamine deprivation was recovered by albumin supplementation to the culture media in an LY6D-dependent manner. Because macropinocytosis acts as an amino acid supply route, these results suggest that LY6D-mediated macropinocytosis contributes to senescent-cell survival through the incorporation of extracellular nutrients.

Investigation of Candidate Genes and Pathways in Basal/TNBC Patients by Integrated Analysis

PURPOSE

This study aims to identify the key pathway and related genes and to further explore the potential molecular mechanisms of triple negative breast cancer (TNBC).

METHODS

The transcriptome data and clinical information of breast cancer patients were downloaded from the TCGA database, including 94 cases of paracancerous tissue, 225 cases of Basal like type, 151 cases of Her2 type, 318 cases of Luminal type A, 281 cases of Luminal type B, and 89 cases of Normal Like type. The differentially expressed genes (DEGs) were identified based on the criteria of |logFC|≥1.5 and adjust P < 0.001.Their functions were annotated by gene ontology (GO) analysis and Kyoto Encyclopedia of differentially expressed genes & Genomes (KEGG) pathway analysis. Cox regression univariate analysis and Kaplan-Meier survival curves (Log-rank method) were used for survival analysis. FOXD1, DLL3 and LY6D were silenced in breast cancer cell lines, and cell viability was assessed by CCK-8 assay. Further, the expression of FOXD1, DLL3 and LY6D were explored by immunohistochemistry on triple negative breast tumor tissue and normal breast tissue.

RESULTS

A total of 533 DEGs were identified. Functional annotation showed that DEGs were significantly enriched in intermediate filament cytoskeleton, DNA-binding transcription activator activity, epidermis development, and Neuroactive ligand-receptor interaction. Survival analysis found that FOXD1, DLL3, and LY6D showed significant correlation with the prognosis of patients with the Basal-like type (P < 0.05). CCK-8 assay showed that compared with Doxorubicin alone group, the cytotoxicity of Doxorubicin combined with siRNA-knockdown of FOXD1, DLL3, or LY6D was much significant.

CONCLUSION

The DEGs and their enriched functions and pathways identified in this study contribute to the understanding of the molecular mechanisms of TNBC. In addition, FOXD1, DLL3, and LY6D may be defined as the prognostic markers and potential therapeutic targets for TNBC patients.

CD73 contributes to anti-inflammatory properties of afferent lymphatic endothelial cells in humans and mice

CD73 is an important ectoenzyme responsible for the production of extracellular adenosine. It is involved in regulating inflammatory responses and cell migration and is overexpressed in various cancers. The functions of CD73 in blood endothelial cells are understood in detail, but its role on afferent lymphatics remains unknown. Moreover, anti-CD73 antibodies are now used in multiple clinical cancer trials, but their effects on different endothelial cell types have not been studied. This study reveals that a previously unknown role of CD73 on afferent lymphatics is to dampen immune responses. Knocking it out or suppressing it by siRNA leads to the upregulation of inflammation-associated genes on lymphatic endothelial cells and a more pro-inflammatory phenotype of interacting dendritic cells in vitro and in vivo. In striking contrast, anti-CD73 antibodies had only negligible effects on the gene expression of lymphatic- and blood-endothelial cells. Our data thus reveal new functions of lymphatic CD73 and indicate a low likelihood of endothelial cell-related adverse effects by CD73 targeting therapeutic antibodies.

MALAT-1: LncRNA ruling miR-182/PIG-C/mesothelin triad in triple negative breast cancer

Breast cancer (BC) remains a major health problem, despite the remarkable advances in cancer research setting. BC is the most common cancer affecting women worldwide. In the context of triple negative breast cancer (TNBC) treatment, major obstacles include late diagnoses and detrimental side effects of chemotherapy and radiotherapy. Research effort was rewarded with the discovery of mesothelin (MSLN), an oncogenic Glycosyl-Phosphatidyl-Inositol (GPI) anchored protein, over-expressed in TNBC. GPI pathway is a post-translational modification that attaches proteins to cellular membrane. MSLN targeted therapy succeeded in early clinical trials, nevertheless, to date, the epigenetic regulation of MSLN and GPI pathway by non-coding RNAs (nc-RNAs) in BC remains an untouched area. Accordingly, our aim is to investigate-for the first time- the impact of simultaneous targeting of MSLN and its associated GPI pathway member, PIG-C, by non-coding-RNAs. Expression profiling of PIG-C, MSLN in BC was performed. Using bioinformatics tools, MALAT-1 and miR-182 were found to target MSLN and PIG-C. MDA-MB-231 cells were transfected with synthetic nc-RNAs. Expression profiling of MSLN, miR-182 and MALAT-1 showed a dramatic over-expression in BC samples. MiR-182 ectopic expression and MALAT-1 silencing increased MSLN and PIG-C transcript levels. However, miR-182 inhibition and miR-182/si-MALAT-1 co-transfection lowered MSLN and PIG-C levels. Finally, si-PIG-C decreased MSLN and PIG-C levels. To conclude, our investigation unravels a new axis in TNBC, where miR-182 can manipulate MSLN and PIG-C. Meanwhile, MALAT-1 is the culprit lncRNA in this novel axis, possibly a sponge for miR-182. Altogether, this sheds light on new targets for BC immune-therapy.

CD109 regulates in vivo tumor invasion in lung adenocarcinoma through TGF-β signaling

Stromal invasion is considered an important prognostic factor in patients with lung adenocarcinoma. The mechanisms underlying the formation of tumor stroma and stromal invasion have been studied in the lung; however, they are still unclear. CD109 is a glycosylphosphatidylinositol-anchored glycoprotein highly expressed in several types of human malignant tumors including lung cancers. In this study, we investigated the in vivo functions of CD109 protein in malignant lung tumors. Initially, we identified an association between higher expression of CD109 protein in human lung adenocarcinoma and a significantly worse prognosis, according to immunohistochemical analysis. We also showed that CD109 deficiency significantly reduced the area of stromal invasive lesions in a genetically engineered CD109-deficient lung adenocarcinoma mouse model, which correlated with the results observed in human lung adenocarcinoma. Furthermore, we identified latent TGF-β binding protein-1 (LTBP1) as a CD109-interacting protein using mass spectrometry and confirmed their interaction by co-immunoprecipitation. Importantly, increased CD109 expression enhanced stromal TGF-β activation in the presence of LTBP1. Therefore, these data suggest the significance of the regulation of TGF-β signaling through CD109 and LTBP1 interaction in tumor stroma and also reveal the importance of CD109 expression levels in promoting lung cancer cell proliferation, migration, and invasion, and thus predicting the outcome of patients suffering from lung adenocarcinoma. Therefore, CD109 protein could be a potential therapeutic target for this disease.

Purinergic Signaling in Pancreas-From Physiology to Therapeutic Strategies in Pancreatic Cancer

The purinergic signaling has an important role in regulating pancreatic exocrine secretion. The exocrine pancreas is also a site of one of the most serious cancer forms, the pancreatic ductal adenocarcinoma (PDAC). Here, we explore how the network of purinergic and adenosine receptors, as well as ecto-nucleotidases regulate normal pancreatic cells and various cells within the pancreatic tumor microenvironment. In particular, we focus on the P2X7 receptor, P2Y2 and P2Y12 receptors, as well as A2 receptors and ecto-nucleotidases CD39 and CD73. Recent studies indicate that targeting one or more of these candidates could present new therapeutic approaches to treat pancreatic cancer. In pancreatic cancer, as much as possible of normal pancreatic function should be preserved, and therefore physiology of purinergic signaling in pancreas needs to be considered.

LY6E impairs coronavirus fusion and confers immune control of viral disease

Zoonotic coronaviruses (CoVs) are substantial threats to global health, as exemplified by the emergence of two severe acute respiratory syndrome CoVs (SARS-CoV and SARS-CoV-2) and Middle East respiratory syndrome CoV (MERS-CoV) within two decades1-3. Host immune responses to CoVs are complex and regulated in part through antiviral interferons. However, interferon-stimulated gene products that inhibit CoVs are not well characterized4. Here, we show that lymphocyte antigen 6 complex, locus E (LY6E) potently restricts infection by multiple CoVs, including SARS-CoV, SARS-CoV-2 and MERS-CoV. Mechanistic studies revealed that LY6E inhibits CoV entry into cells by interfering with spike protein-mediated membrane fusion. Importantly, mice lacking Ly6e in immune cells were highly susceptible to a murine CoV-mouse hepatitis virus. Exacerbated viral pathogenesis in Ly6e knockout mice was accompanied by loss of hepatic immune cells, higher splenic viral burden and reduction in global antiviral gene pathways. Accordingly, we found that constitutive Ly6e directly protects primary B cells from murine CoV infection. Our results show that LY6E is a critical antiviral immune effector that controls CoV infection and pathogenesis. These findings advance our understanding of immune-mediated control of CoV in vitro and in vivo-knowledge that could help inform strategies to combat infection by emerging CoVs.

Upregulation of miR-9 and miR-193b over human Th17 cell differentiation

BACKGROUND

Th17 cells are a newly discovered subset of CD4⁺ T cells known as key participants in various immune responses and inflammatory conditions including autoimmune diseases. Mi(cro)RNAs are a family of non-coding RNAs that regulate numerous critical immune functions. Immuno-miRNAs modulate cell biological processes in T cells, such as differentiation and function of Th17 cells. The aim of the present study is to investigate the expression of miR-9-5p, miR-193b-3p, and autoimmunity-related genes during human Th17 cells differentiation.

METHODS

Human naïve CD4⁺ T cells were purified from peripheral blood mononuclear cells (PBMCs) by magnetic cell sorting system (MACS) and their purity was checked by flow-cytometric analysis. Naïve CD4⁺ T cells were cultured under Th17-polarizing condition for 6 days. IL- 17 secretion was determined by means of enzyme-linked immunosorbent assay (ELISA). Next, the expression levels of miRNAs and putative targets genes were assessed by qRT-PCR at different time points of differentiation.

RESULTS

Our result showed dramatic downregulation of TCF7, MAP3K1, ENTPD1, and NT5E genes during human Th17 differentiation. Polarization also had a significant inducible effect on the expression of miR-9 and miR-193b over differentiation of human Th17 cells. According to our results, miR-9-5p and miR-193b-3p may contribute to Th17 differentiation probably by inhibiting the expression of negative regulators of Th17 differentiation.

CONCLUSION

This study confirmed deregulation of TCF7, MAP3K1, ENTPD1, and NT5E genes in Th17 differentiation process and introduced miR-9 and miR-193b as Th17 cell-associated miRNAs, making them good candidates for further investigations.

B7-H3 confers resistance to Vγ9Vδ2 T cell-mediated cytotoxicity in human colon cancer cells via the STAT3/ULBP2 axis

Immunotherapy based on γδT cells has limited efficiency in solid tumors, including colon cancer (CC). The immune evasion of tumor cells may be the main cause of the difficulties of γδT cell-based treatment. In the present study, we explored whether and how B7-H3 regulates the resistance of CC cells to the cytotoxicity of Vγ9Vδ2 (Vδ2) T cells. We observed that B7-H3 overexpression promoted, while B7-H3 knockdown inhibited, CC cell resistance to the killing effect of Vδ2 T cells in vitro and in vivo. Mechanistically, we showed that B7-H3-mediated CC cell resistance to the cytotoxicity of Vδ2 T cells involved a molecular pathway comprising STAT3 activation and decreased ULBP2 expression. ULBP2 blockade or knockdown abolished the B7-H3 silencing-induced increase in the cytotoxicity of Vδ2 T cells to CC cells. Furthermore, cryptotanshinone, a STAT3 phosphorylation inhibitor, reversed the B7-H3 overexpression-induced decrease in ULBP2 expression and attenuated the killing effect of Vδ2 T cells on CC cells. Moreover, there was a negative correlation between the expression of B7-H3 and ULBP2 in the tumor tissues of CC patients. Our results suggest that the B7-H3-mediated STAT3/ULBP2 axis may be a potential candidate target for improving the efficiency of γδT cell-based immunotherapy in CC.

ALPPL2 Is a Highly Specific and Targetable Tumor Cell Surface Antigen

Identification of tumor-specific cell surface antigens has proven challenging, as the vast majority of tumor-associated antigens are also expressed in normal tissues. In mesothelioma, we identified a highly specific tumor cell surface antigen that can be targeted for therapy development. Mesothelioma is caused by malignant transformation of the mesothelium, is incurable, and can be categorized into three histologic subtypes: epithelioid, biphasic, and sarcomatoid. To identity novel mesothelioma cell surface antigens with broad subtype coverage and high tissue specificity, we have previously selected phage antibody display libraries on live mesothelioma cells and tissues following counterselection on normal cells and identified a panel of human antibodies that bind all subtypes of mesothelioma, but not normal mesothelium. One of the antibodies, M25, showed high specificity against an antigen we identify here as ALPPL2. IHC on normal human tissues found that ALPPL2 is expressed only on placental trophoblasts, but not on any other normal tissues. This significant tissue specificity and broad tumor type coverage suggest that ALPPL2 could be an excellent cell surface target for therapeutic development against mesothelioma. To evaluate therapeutic potential of ALPPL2 targeting, an ALPPL2-targeted antibody-drug conjugate was developed and demonstrated potent and specific tumor killing in vitro and in vivo against both epithelioid and sarcomatoid mesothelioma. Thus, ALPPL2 belongs to a rare class of cell surface antigens classified as truly tumor specific and is well suited for therapy development against ALPPL2-expressing tumors. SIGNIFICANCE: These findings identify ALPP2 as a true tumor-specific cell surface antigen whose tissue specificity enables the development of novel therapies.

Structural Diversity and Dynamics of Human Three-Finger Proteins Acting on Nicotinic Acetylcholine Receptors

Ly-6/uPAR or three-finger proteins (TFPs) contain a disulfide-stabilized β-structural core and three protruding loops (fingers). In mammals, TFPs have been found in epithelium and the nervous, endocrine, reproductive, and immune systems. Here, using heteronuclear NMR, we determined the three-dimensional (3D) structure and backbone dynamics of the epithelial secreted protein SLURP-1 and soluble domains of GPI-anchored TFPs from the brain (Lynx2, Lypd6, Lypd6b) acting on nicotinic acetylcholine receptors (nAChRs). Results were compared with the data about human TFPs Lynx1 and SLURP-2 and snake α-neurotoxins WTX and NTII. Two different topologies of the β-structure were revealed: one large antiparallel β-sheet in Lypd6 and Lypd6b, and two β-sheets in other proteins. α-Helical segments were found in the loops I/III of Lynx2, Lypd6, and Lypd6b. Differences in the surface distribution of charged and hydrophobic groups indicated significant differences in a mode of TFPs/nAChR interactions. TFPs showed significant conformational plasticity: the loops were highly mobile at picosecond-nanosecond timescale, while the β-structural regions demonstrated microsecond-millisecond motions. SLURP-1 had the largest plasticity and characterized by the unordered loops II/III and cis-trans isomerization of the Tyr39-Pro40 bond. In conclusion, plasticity could be an important feature of TFPs adapting their structures for optimal interaction with the different conformational states of nAChRs.