Review of S100A9 biology and its role in cancer

A computational study of gene expression patterns in head and neck squamous cell carcinoma using TCGA data

Aim: Head and Neck squamous cell carcinoma (HNSCC) is the second most prevalent cancer in Pakistan. Methods: Gene expression data from TCGA and GETx for normal genes to analyze Differentially Expressed Genes (DEGs). Data was further investigated using the Enrichr tool to perform Gene Ontology (GO). Results: Our analysis identified most significantly differentially expressed genes and explored their established cellular functions as well as their potential involvement in tumor development. We found that the highly expressed Keratin family and S100A9 genes. The under-expressed genes KRT4 and KRT13 provide instructions for the production of keratin proteins. Conclusion: Our study suggests that factors such as poor oral hygiene and smokeless tobacco can result in oral stress and cellular damage and cause cancer.

S100A9, as a potential predictor of prognosis and immunotherapy response for GBM, promotes the malignant progression of GBM cells and migration of M2 macrophages

In the past decades, the therapeutic effect of glioblastoma (GBM) has not been significantly improved. Generous evidence indicates that S100A9 has a wide range of functions in tumors, but its exploration in GBM is less. The purpose of this study is to conduct a comprehensive bioinformatics analysis and cytological experiment on S100A9 in GBM. The expression data and clinical data of GBM samples were downloaded from the public database, and comprehensive bioinformatics analysis was performed on S100A9 in GBM using R software. Wound healing assay and transwell assay were used to detect the migration activity of cells, and colony formation assay, EdU staining, and CCK-8 assay were used to detect the proliferation activity of cells. The effect of S100A9 on the migration activity of M2 macrophages was verified by the cell co-culture method. The protein expression was detected by western blotting and immunohistochemical staining. S100A9 is an independent prognostic factor in GBM patients and is related to poor prognosis. It can be used as an effective tool to predict the response of GBM patients to immune checkpoint inhibitors (ICIs). In addition, S100A9 can promote the malignant progression of GBM and the migration of M2 macrophages. On the whole, our study highlights the potential value of S100A9 in predicting prognosis and immunotherapeutic response in GBM patients. More importantly, S100A9 may promote the malignant progress of GBM by involving in some carcinogenic pathways and remodeling the tumor microenvironment (TME).

S100A9 interacts with a dynamic region on CD14 to activate Toll-like receptor 4

S100A9 is a Damage Associated Molecular Pattern (DAMP) that activates inflammatory pathways via Toll-like receptor 4 (TLR4). This activity plays important homeostatic roles in tissue repair, but can also contribute to inflammatory diseases. The mechanism of activation is unknown. Here, we follow up on a previous observation that the protein CD14 is an important co-receptor that enables S100A9 to activate TLR4. Using cell-based functional assays and a combination of mutations and pharmocological perturbations, we found that CD14 must be membrane bound to potentiate TLR4 activation by S100A9. Additionally, S100A9 is sensitive to inhibitors of pathways downstream of TLR4 internalization. Together, this suggests that S100A9 induces activity via CD14-dependent internalization of TLR4. We then used mutagenesis, structural modeling, and in vitro binding experiments to establish that S100A9 binds to CD14's N-terminus in a region that overlaps with, but is not identical to, the region where CD14 binds its canonical ligand, lipopolysaccharide (LPS). In molecular dynamics simulations, this region of the protein is dynamic, allowing it to reorganize to recognize both S100A9 (a soluble protein) and LPS (a small hydrophobic molecule). Our work is the first attempt at a molecular characterization of the S100A9/CD14 interaction, bringing us one step closer to unraveling the full mechanism by which S100A9 activates TLR4/MD-2.

Proteomic Assessment of SKBR3/HER2+ Breast Cancer Cellular Response to Lapatinib and Investigational Ipatasertib Kinase Inhibitors

Modern cancer treatment approaches aim at achieving cancer remission by using targeted and personalized therapies, as well as harnessing the power of the immune system to recognize and eliminate the cancer cells. To overcome a relatively short-lived response due to the development of resistance to the administered drugs, combination therapies have been pursued, as well. To expand the outlook of combination therapies, the objective of this study was to use high-throughput data generation technologies such as mass spectrometry and proteomics to investigate the response of HER2+ breast cancer cells to a mixture of two kinase inhibitors that has not been adopted yet as a standard treatment regime. The broader landscape of biological processes that are affected by inhibiting two major pathways that sustain the growth and survival of cancer cells, i.e., EGFR and PI3K/AKT, was investigated by treating SKBR3/HER2+ breast cancer cells with Lapatinib or a mixture of Lapatinib/Ipatasertib small molecule drugs. Changes in protein expression and/or activity in response to the drug treatments were assessed by using two complementary quantitative proteomic approaches based on peak area and peptide spectrum match measurements. Over 900 proteins matched by three unique peptide sequences (FDR<0.05) were affected by the exposure of cells to the drugs. The work corroborated the anti-proliferative activity of Lapatinib and Ipatasertib, and, in addition to cell cycle and growth arrest processes enabled the identification of several multi-functional proteins with roles in cancer-supportive hallmark processes. Among these, immune response, adhesion and migration emerged as particularly relevant to the ability to effectively suppress the proliferation and dissemination of cancer cells. The supplementation of Lapatinib with Ipatasertib further affected the expression or activity of additional transcription factors and proteins involved in gene expression, trafficking, DNA repair, and development of multidrug resistance. Furthermore, over fifty of the affected proteins represented approved or investigational targets in the DrugBank database, which through their protein-protein interaction networks can inform the selection of effective therapeutic partners. Altogether, our findings exposed a broad plethora of yet untapped opportunities that can be further explored for enhancing the anti-cancer effects of each drug as well as of many other multi-drug therapies that target the EGFR/ERBB2 and PI3K/AKT pathways. The data are available via ProteomeXchange with identifier PXD051094.

Identification of Transcriptomic Signatures of Pancreatic Ductal Adenocarcinoma-Derived Exosomes That Promote Macrophage M2 Polarization and Predict Prognosis: S100A9 Reveals Tumor Progression

Background

Exosomes play a role in intercellular communication and participate in the interaction between pancreatic ductal adenocarcinoma (PDAC) cells and immune cells. Macrophages can receive tumor cell-derived exosomes to polarize into M2-type macrophages, which can enhance the invasion and metastasis of pancreatic cancer, leading to poor prognosis. However, the mechanism by which pancreatic cancer cell-derived exosomes promote M2-type macrophages is still unclear.

Methods

M2 macrophage-associated exosome-derived key module genes were identified by differentially expressed genes (DEGs) and weighted gene co-expression network analysis (WGCNA) analysis using exoRbase 2.0, The Cancer Genome Atlas (TCGA), and The International Cancer Genome Consortium (ICGC) databases. Multivariate Cox regression analysis was used to identify key prognostic genes and obtain regression coefficients to establish prognostic signature. Immune infiltration, tumor mutations, and GSEA among different risk groups were compared. exoRbase 2.0, Gene Expression Profiling Interactive Analysis 2 (GEPIA2), HPA, and TISCH2 databases were used to further analyze the expression pattern of S100A9 in pancreatic cancer. In vitro experiments, cell-derived exosome isolation, quantitative polymerase chain reaction (qPCR), western blot, flow cytometry analysis, cell transfection, transwell assay, and CCK-8 assay were applied to investigate the roles of S100A9 in macrophage M2 polarization and tumor progression.

Results

The key genes of PDAC-derived exosomes promoting M2-type macrophage polarization were identified, and a risk score model was established. The risk score is related to the expression of common immune checkpoints, immune score, and stromal score, and the tumor mutational burden and biological function of high- and low-risk groups were also different. S100A9 was positively correlated with M2-type macrophage marker. In addition, scRNA-seq data from the TISCH2 database revealed that S100A9 is predominantly expressed in pancreatic cancer cells and mono/macrophage cells, suggesting that S100A9 in pancreatic cancer cells could be received by macrophages, thereby inducing macrophage polarization. In vitro, we used exosomes from BxPC-3 cell lines to coculture macrophages and found that macrophages were mainly polarized toward M2 type, which further promoted the proliferation and metastasis of PDAC.

Conclusions

Our study established a reliable risk score model for PDAC-derived exosomes and M2 macrophages, identified the important role of S100A9 in macrophage M2 polarization, which provides a new strategy for the diagnosis and treatment of PDAC, and strengthened the understanding of the mechanism of tumor development and metastasis.

Establishment of nucleic acid sensing pathways-based model in predicting response to immunotherapy and targeted drug in hepatitis virus-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) accounts for 80% of liver cancers, while 70%-80% of HCC developed from chronic liver disease with hepatitis B virus (HBV) and hepatitis C virus (HCV) infection as the major etiology. Immunotherapy is assuming a role as a pillar of HCC treatment, but the remarkable immune-mediated responses are restricted in a minority of patients. Nucleic acid sensing (NAS) pathways are the central pathway of the innate immune system and antiviral immune response to viral infection, but their role in hepatitis virus-related HCC remains undetermined. In our study, we performed a comprehensive bioinformatics analysis based on transcriptomic data of hepatitis virus related-HCC tissues collected from multiple public data sets. Two subgroups were validated based on NAS-related genes in virus-related HCC patients, which were defined as NAS-activated subgroups and NAS-suppressed subgroups based on the expression of NAS-related genes. On this basis, a NAS-related risk score (NASRS) predictive model was established for risk stratification and prognosis prediction in the hepatitis virus-related HCC (TCGA-LIHC and ICGC cohorts). The predictive values of the NASRS in prognosis and immunotherapy were also verified in multiple data sets. A nomogram was also established to facilitate the clinical use of NASRS and demonstrate its effectiveness through different approaches. Additionally, six potential drugs binding to the core target of the NAS signature were predicted via molecular docking strategy. We subsequently evaluated the cytotoxic capabilities of potential drug in vitro and in vivo. Based on these results, we conclude that the NASRS model could serve as a power prognostic biomarker and predict responses to immunotherapy, which is meaningful in clinical decision-making of hepatitis virus-related HCC patients.

Nuclear proinflammatory cytokine S100A9 enhances expression of human papillomavirus oncogenes via transcription factor TEAD1

Transcription of the human papillomavirus (HPV) oncogenes, E6 and E7, is regulated by the long control region (LCR) of the viral genome. Although various transcription factors have been reported to bind to the LCR, little is known about the transcriptional cofactors that modulate HPV oncogene expression in association with these transcription factors. Here, we performed in vitro DNA-pulldown purification of nuclear proteins in cervical cancer cells, followed by proteomic analyses to identify transcriptional cofactors that bind to the HPV16 LCR via the transcription factor TEAD1. We detected the proinflammatory cytokine S100A9 that localized to the nucleus of cervical cancer cells and associated with the LCR via direct interaction with TEAD1. Nuclear S100A9 levels and its association with the LCR were increased in cervical cancer cells by treatment with a proinflammatory phorbol ester. Knockdown of S100A9 decreased HPV oncogene expression and reduced the growth of cervical cancer cells and their susceptibility to cisplatin, whereas forced nuclear expression of S100A9 using nuclear localization signals exerted opposite effects. Thus, we conclude that nuclear S100A9 binds to the HPV LCR via TEAD1 and enhances viral oncogene expression by acting as a transcriptional coactivator. IMPORTANCE Human papillomavirus (HPV) infection is the primary cause of cervical cancer, and the viral oncogenes E6 and E7 play crucial roles in carcinogenesis. Although cervical inflammation contributes to the development of cervical cancer, the molecular mechanisms underlying the role of these inflammatory responses in HPV carcinogenesis are not fully understood. Our study shows that S100A9, a proinflammatory cytokine, is induced in the nucleus of cervical cancer cells by inflammatory stimuli, and it enhances HPV oncogene expression by acting as a transcriptional coactivator of TEAD1. These findings provide new molecular insights into the relationship between inflammation and viral carcinogenesis.

The Stabilization of S100A9 Structure by Calcium Inhibits the Formation of Amyloid Fibrils

The calcium-binding protein S100A9 is recognized as an important component of the brain neuroinflammatory response to the onset and development of neurodegenerative disease. S100A9 is intrinsically amyloidogenic and in vivo co-aggregates with amyloid-β peptide and α-synuclein in Alzheimer's and Parkinson's diseases, respectively. It is widely accepted that calcium dyshomeostasis plays an important role in the onset and development of these diseases, and studies have shown that elevated levels of calcium limit the potential for S100A9 to adopt a fibrillar structure. The exact mechanism by which calcium exerts its influence on the aggregation process remains unclear. Here we demonstrate that despite S100A9 exhibiting α-helical secondary structure in the absence of calcium, the protein exhibits significant plasticity with interconversion between different conformational states occurring on the micro- to milli-second timescale. This plasticity allows the population of conformational states that favour the onset of fibril formation. Magic-angle spinning solid-state NMR studies of the resulting S100A9 fibrils reveal that the S100A9 adopts a single structurally well-defined rigid fibrillar core surrounded by a shell of approximately 15-20 mobile residues, a structure that persists even when fibrils are produced in the presence of calcium ions. These studies highlight how the dysregulation of metal ion concentrations can influence the conformational equilibria of this important neuroinflammatory protein to influence the rate and nature of the amyloid deposits formed.

Nanoparticle stereochemistry-dependent endocytic processing improves in vivo mRNA delivery

Stereochemistry can alter small-molecule pharmacokinetics, safety and efficacy. However, it is unclear whether the stereochemistry of a single compound within a multicomponent colloid such as a lipid nanoparticle (LNP) can influence its activity in vivo. Here we report that LNPs containing stereopure 20α-hydroxycholesterol (20α) delivered mRNA to liver cells up to 3-fold more potently than LNPs containing a mixture of both 20α- and 20β-hydroxycholesterols (20mix). This effect was not driven by LNP physiochemical traits. Instead, in vivo single-cell RNA sequencing and imaging revealed that 20mix LNPs were sorted into phagocytic pathways more than 20α LNPs, resulting in key differences between LNP biodistribution and subsequent LNP functional delivery. These data are consistent with the fact that nanoparticle biodistribution is necessary, but not sufficient, for mRNA delivery, and that stereochemistry-dependent interactions between LNPs and target cells can improve mRNA delivery.

Analysis of RNA processing directly from spatial transcriptomics data reveals previously unknown regulation

Technical advances have led to an explosion in the amount of biological data available in recent years, especially in the field of RNA sequencing. Specifically, spatial transcriptomics (ST) datasets, which allow each RNA molecule to be mapped to the 2D location it originated from within a tissue, have become readily available. Due to computational challenges, ST data has rarely been used to study RNA processing such as splicing or differential UTR usage. We apply the ReadZS and the SpliZ, methods developed to analyze RNA process in scRNA-seq data, to analyze spatial localization of RNA processing directly from ST data for the first time. Using Moran's I metric for spatial autocorrelation, we identify genes with spatially regulated RNA processing in the mouse brain and kidney, re-discovering known spatial regulation in Myl6 and identifying previously-unknown spatial regulation in genes such as Rps24, Gng13, Slc8a1, Gpm6a, Gpx3, ActB, Rps8, and S100A9. The rich set of discoveries made here from commonly used reference datasets provides a small taste of what can be learned by applying this technique more broadly to the large quantity of Visium data currently being created.

S100A8/S100A9 Promote Progression of Multiple Myeloma via Expansion of Megakaryocytes

Multiple myeloma is characterized by clonal proliferation of plasma cells that accumulate preferentially in the bone marrow (BM). The tumor microenvironment is one of the leading factors that promote tumor progression. Neutrophils and monocytes are a major part of the BM tumor microenvironment, but the mechanism of their contribution to multiple myeloma progression remains unclear. Here, we describe a novel mechanism by which S100A8/S100A9 proteins produced by BM neutrophils and monocytes promote the expansion of megakaryocytes supporting multiple myeloma progression. S100A8/S100A9 alone was not sufficient to drive megakaryopoiesis but markedly enhanced the effect of thrombopoietin, an effect that was mediated by Toll-like receptor 4 and activation of the STAT5 transcription factor. Targeting S100A9 with tasquinimod as a single agent and in combination with lenalidomide and with proteasome inhibitors has potent antimyeloma effect that is at least partly independent of the adaptive immune system. This newly identified axis of signaling involving myeloid cells and megakaryocytes may provide a new avenue for therapeutic targeting in multiple myeloma.

Significance

We identified a novel mechanism by which myeloid cells promote myeloma progression independently of the adaptive immune system. Specifically, we discovered a novel role of S100A8/S100A9, the most abundant proteins produced by neutrophils and monocytes, in regulation of myeloma progression via promotion of the megakaryocyte expansion and angiogenesis. Tasquinimod, an inhibitor of S100A9, has potent antimyeloma effects as a single agent and in combination with lenalidomide and with proteasome inhibitors.

Neutrophil S100A9 supports M2 macrophage niche formation in granulomas

Mycobacterium infection gives rise to granulomas predominantly composed of inflammatory M1-like macrophages, with bacteria-permissive M2 macrophages also detected in deep granulomas. Our histological analysis of Mycobacterium bovis bacillus Calmette-Guerin-elicited granulomas in guinea pigs revealed that S100A9-expressing neutrophils bordered a unique M2 niche within the inner circle of concentrically multilayered granulomas. We evaluated the effect of S100A9 on macrophage M2 polarization based on guinea pig studies. S100A9-deficient mouse neutrophils abrogated M2 polarization, which was critically dependent on COX-2 signaling in neutrophils. Mechanistic evidence suggested that nuclear S100A9 interacts with C/EBPβ, which cooperatively activates the Cox-2 promoter and amplifies prostaglandin E2 production, followed by M2 polarization in proximal macrophages. Because the M2 populations in guinea pig granulomas were abolished via treatment with celecoxib, a selective COX-2 inhibitor, we propose the S100A9/Cox-2 axis as a major pathway driving M2 niche formation in granulomas.

Decreased S100A9 expression alleviates Clostridium perfringens beta2 toxin-induced inflammatory injury in IPEC-J2 cells

Background

S100 calcium-binding protein A9 (S100A9) is a commonly known pro-inflammatory factor involved in various inflammatory responses. Clostridium perfringens (C. perfringens ) type C is known to cause diarrhea in piglets. However, the role of S100A9 in C. perfringens type C-induced infectious diarrhea is unclear.

Methods

Here, the S100A9 gene was overexpressed and knocked down in the IPEC-J2 cells, which were treated with C. perfringens beta2 (CPB2) toxin. The role of S100A9 in CPB2 toxin-induced injury in IPEC-J2 cells was assessed by measuring the levels of inflammatory cytokines, reactive oxygen species (ROS), lactate dehydrogenase (LDH), cell proliferation, and tight junction-related proteins.

Results

The results showed elevated expression of S100A9 in diarrhea-affected piglet tissues, and the elevation of S100A9 expression after CPB2 toxin treatment of IPEC-J2 was time-dependent. In CPB2 toxin-induced IPEC-J2 cells, overexpression of S100A9 had the following effects: the relative expression of inflammatory factors IL-6, IL8, TNF-α, and IL-1β was increased; the ROS levels and LDH viability were significantly increased; cell viability and proliferation were inhibited; the G0/G1 phase cell ratio was significantly increased. Furthermore, overexpression of S100A9 reduced the expression of tight junction proteins in CPB2-induced IPEC-J2 cells. The knockdown of S100A9 had an inverse effect. In conclusion, our results confirmed that S100A9 exacerbated inflammatory injury in CPB2 toxin-induced IPEC-J2 cells, inhibited cell viability and cell proliferation, and disrupted the tight junctions between cells. Thus, decreased S100A9 expression alleviates CPB2 toxin-induced inflammatory injury in IPEC-J2 cells.

Serum neurofilament light chain in myasthenia gravis subgroups: An exploratory cohort and case-Control study

Background

This study aimed to evaluate the association of neurofilament light chain (Nfl) with neuromuscular destruction and disease severity in the serum of patients with myasthenia gravis (MG).

Materials and methods

Sera from 134 patients with MG with varying degrees of disease severity and autoantibody (Abs) status were analyzed and compared to controls in a cross-sectional design. Prospectively, we additionally measured serum NfL (sNfl) levels in patients with MG longitudinally for up to 3 years. Based on linear regression, differences between patients and controls were assessed. With correlation coefficients and mixed linear regression, the association among sNfl levels, socio-demographics, disease activity (Quantitative Myasthenia Gravis (QMG) score and Myasthenia Gravis Activities of Daily Living (MG-ADL) scale), Abs-status (acetylcholine receptor antibody (AChR-Abs), muscle-specific receptor tyrosine kinase antibody (MuSK-Abs), lipoprotein-related protein 4 (LRP4), and seronegative), Abs titer, treatment regime (pyridostigmine, steroids, and immunosuppressive therapies), and thymectomy were investigated.

Results

sNfl levels were higher in patients with MG compared to controls (median: 11.2 vs. 7.88), where sNfl levels were highest in anti-AChR-Abs positive patients (median 12.6), followed by anti-MuSK-Abs positive, anti-LRP4-Abs positive, and seronegative patients. Adjusting for age and sex, sNfl levels of patients with MG were on average 35% higher compared to controls (35.1, 95% CI: 8.4;68.3) and highest for patients with seronegative MG (44.35; 95% CI 16.47; 78.90). We found no relevant relationship between individual changes in sNfl and changes in QMG and MG-ADL scores.

Conclusion

sNfl levels are higher in patients with MG than in controls but were not consistently associated with clinical severity. Thus, sNfl is not a suitable biomarker to monitor individual disease progression in patients with MG.

Metastatic Colon Cancer Treatment Using S100A9-Targeted Cowpea Mosaic Virus Nanoparticles

Peritoneal metastases (PMs) occur due to the metastasis of gynecological and gastrointestinal cancers such as ovarian, colon, pancreatic, or gastric tumors. PM outgrowth is often fatal, and patients with PMs have a median survival of 6 months. Cowpea mosaic virus (CPMV) has been shown, when injected intratumorally, to act as an immunomodulator reversing the immunosuppressive tumor microenvironment, therefore turning cold tumors hot and priming systemic antitumor immunity. However, not all tumors are injectable, and PMs especially will require targeted treatments to direct CPMV toward the disseminated tumor nodules. Toward this goal, we designed and tested a CPMV nanoparticle targeted to S100A9, a key immune mediator for many cancer types indicated in cancer growth, invasiveness, and metastasis. Here, we chose to use an intraperitoneal (IP) colon cancer model, and analysis of IP gavage fluid demonstrates that S100A9 is upregulated following IP challenge. S100A9-targeted CPMV particles displaying peptide ligands specific for S100A9 homed to IP-disseminated tumors, and treatment led to improved survival and decreased tumor burden. Targeting CPMV to S100A9 improves preclinical outcomes and harbors the potential of utilizing CPMV for the treatment of IP-disseminated diseases.

Screening and Analysis of Serum Protein Biomarkers Infected by Coronavirus Disease 2019 (COVID-19)

Coronavirus disease 2019 (COVID-19) has spread widely around the world, and in-depth research on COVID-19 is necessary for biomarkers and target drug discovery. This analysis collected serum from six COVID-19-infected patients and six healthy people. The protein changes in the infected and healthy control serum samples were evaluated by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and high-performance liquid chromatography (HPLC). The differential protein signature in both groups was retrieved and analyzed by the Kyoto Encyclopedia of Gene and Genomes (KEGG), Gene ontology, COG/KOG, protein-protein interaction, and protein domain interactions tools. We shortlisted 24 differentially expressed proteins between both groups. Ten genes were significantly up-regulated in the infection group, and fourteen genes were significantly down-regulated. The GO and KEGG pathway enrichment analysis suggested that the chromosomal part and chromosome were the most enriched items. The oxytocin signaling pathway was the most enriched item of KEGG analysis. The netrin module (non-TIMP type) was the most enriched protein domain in this study. Functional analysis of S100A9, PIGR, C4B, IL-6R, IGLV3-19, IGLV3-1, and IGLV5-45 revealed that SARS-CoV-2 was closely related to immune response.

Human RAD51 Protein Forms Amyloid-like Aggregates In Vitro

RAD51 is a central protein of homologous recombination and DNA repair processes that maintains genome stability and ensures the accurate repair of double-stranded breaks (DSBs). In this work, we assessed amyloid properties of RAD51 in vitro and in the bacterial curli-dependent amyloid generator (C-DAG) system. Resistance to ionic detergents, staining with amyloid-specific dyes, polarized microscopy, transmission electron microscopy (TEM), X-ray diffraction and other methods were used to evaluate the properties and structure of RAD51 aggregates. The purified human RAD51 protein formed detergent-resistant aggregates in vitro that had an unbranched cross-β fibrillar structure, which is typical for amyloids, and were stained with amyloid-specific dyes. Congo-red-stained RAD51 aggregates demonstrated birefringence under polarized light. RAD51 fibrils produced sharp circular X-ray reflections at 4.7 Å and 10 Å, demonstrating that they had a cross-β structure. Cytoplasmic aggregates of RAD51 were observed in cell cultures overexpressing RAD51. We demonstrated that a key protein that maintains genome stability, RAD51, has amyloid properties in vitro and in the C-DAG system and discussed the possible biological relevance of this observation.

Emodin Alleviates Sodium Taurocholate-Induced Pancreatic Ductal Cell Damage by Inhibiting the S100A9/VNN1 Signaling Pathway

OBJECTIVES

Because the pathogenesis of the disease is unclear, the treatment of patients with acute pancreatitis, especially severe acute pancreatitis, is still a major challenge for clinicians. Emodin is an anthraquinone compound extracted from rhubarb that can alleviate the damage to pancreatic ductal epithelial cells induced by adenosine triphosphate, but whether it has a similar protective effect on sodium taurocholate (STC)-stimulated pancreatic ductal cells and the underlying mechanism has not yet been reported.

METHODS

A model of STC-induced HPDE6-C7 human pancreatic ductal epithelial cell injury was established, and then apoptosis and the levels of reactive oxygen species (ROS), glutathione, gamma-glutamylcysteine synthetase, and inflammatory cytokines were assessed in the presence or absence of emodin pretreatment. S100 calcium binding protein A9 (S100A9) and Vanin1 (VNN1) protein expression was also measured.

RESULTS

Emodin significantly increased HPDE6-C7 cell viability, inhibited apoptosis and ROS release, and elevated glutathione levels and gamma-glutamylcysteine synthetase activity. Furthermore, emodin downregulated S100A9 and VNN1 protein expression and inhibited the production of inflammatory factors, such as interleukin (IL)-1β, IL-6, IL-8, and IL-18.

CONCLUSIONS

Emodin attenuates STC-induced pancreatic ductal cell injury possibly by inhibiting S100A9/VNN1-mediated ROS release. This finding provides evidence for the future development of emodin as a therapeutic agent.

Psoriatic Dermal-Derived Mesenchymal Stem Cells Induced C3 Expression in Keratinocytes

Purpose

Patients and Methods

Results

Conclusion

Pre-clinical Studies Identifying Molecular Pathways of Neuroinflammation in Parkinson's Disease: A Systematic Review

Parkinson's disease (PD), the second most common neurodegenerative disorder, is characterized by neuroinflammation, formation of Lewy bodies, and progressive loss of dopaminergic neurons in the substantia nigra of the brain. In this review, we summarize evidence obtained by animal studies demonstrating neuroinflammation as one of the central pathogenetic mechanisms of PD. We also focus on the protein factors that initiate the development of PD and other neurodegenerative diseases. Our targeted literature search identified 40 pre-clinical in vivo and in vitro studies written in English. Nuclear factor kappa B (NF-kB) pathway is demonstrated as a common mechanism engaged by neurotoxins such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 6-hydroxydopamine (6-OHDA), as well as the bacterial lipopolysaccharide (LPS). The α-synuclein protein, which plays a prominent role in PD neuropathology, may also contribute to neuroinflammation by activating mast cells. Meanwhile, 6-OHDA models of PD identify microsomal prostaglandin E synthase-1 (mPGES-1) as one of the contributors to neuroinflammatory processes in this model. Immune responses are used by the central nervous system to fight and remove pathogens; however, hyperactivated and prolonged immune responses can lead to a harmful neuroinflammatory state, which is one of the key mechanisms in the pathogenesis of PD.

Interactions between S100A9 and Alpha-Synuclein: Insight from NMR Spectroscopy

S100A9 is a pro-inflammatory protein that co-aggregates with other proteins in amyloid fibril plaques. S100A9 can influence the aggregation kinetics and amyloid fibril structure of alpha-synuclein (α-syn), which is involved in Parkinson's disease. Currently, there are limited data regarding their cross-interaction and how it influences the aggregation process. In this work, we analyzed this interaction using solution 19F and 2D ¹⁵N-¹H HSQC NMR spectroscopy and studied the aggregation properties of these two proteins. Here, we show that α-syn interacts with S100A9 at specific regions, which are also essential in the first step of aggregation. We also demonstrate that the 4-fluorophenylalanine label in alpha-synuclein is a sensitive probe to study interaction and aggregation using 19F NMR spectroscopy.

The Potential Role of Exosomal Proteins in Prostate Cancer

Prostate cancer is the most prevalent malignant tumor in men across developed countries. Traditional diagnostic and therapeutic methods for this tumor have become increasingly difficult to adapt to today’s medical philosophy, thus compromising early detection, diagnosis, and treatment. Prospecting for new diagnostic markers and therapeutic targets has become a hot topic in today’s research. Notably, exosomes, small vesicles characterized by a phospholipid bilayer structure released by cells that is capable of delivering different types of cargo that target specific cells to regulate biological properties, have been extensively studied. Exosomes composition, coupled with their interactions with cells make them multifaceted regulators in cancer development. Numerous studies have described the role of prostate cancer-derived exosomal proteins in diagnosis and treatment of prostate cancer. However, so far, there is no relevant literature to systematically summarize its role in tumors, which brings obstacles to the later research of related proteins. In this review, we summarize exosomal proteins derived from prostate cancer from different sources and summarize their roles in tumor development and drug resistance.

Neutrophils as potential therapeutic targets in hepatocellular carcinoma

The success of atezolizumab plus bevacizumab treatment contributed to a shift in systemic therapies for hepatocellular carcinoma (HCC) towards combinations that include cancer immunotherapeutic agents. Thus far, the principal focus of cancer immunotherapy has been on interrupting immune checkpoints that suppress antitumour lymphocytes. As well as lymphocytes, the HCC environment includes numerous other immune cell types, among which neutrophils are emerging as an important contributor to the pathogenesis of HCC. A growing body of evidence supports neutrophils as key mediators of the immunosuppressive environment in which some cancers develop, as well as drivers of tumour progression. If neutrophils have a similar role in HCC, approaches that target or manipulate neutrophils might have therapeutic benefits, potentially including sensitization of tumours to conventional immunotherapy. Several neutrophil-directed therapies for patients with HCC (and other cancers) are now entering clinical trials. This Review outlines the evidence in support of neutrophils as drivers of HCC and details their mechanistic roles in development, progression and metastasis, highlighting the reasons that neutrophils are well worth investigating despite the challenges associated with studying them. Neutrophil-modulating anticancer therapies entering clinical trials are also summarized.

Patient parameters and response after administration of rituximab in pediatric mature B-cell non-Hodgkin lymphoma

BACKGROUND

Mature aggressive B-cell lymphomas are heterogenous malignancies that make up more than half of all diagnosed non-Hodgkin lymphoma in children and adolescents. The overall survival rate increased over the last decades to 80%-90% due to fine tuning of polychemotherapy. However, new therapeutic implications are needed to further increase the overall survival. Current clinical trials analyze the therapeutic effect of rituximab in pediatric patients, while the mechanism of action in vivo is still not fully understood.

METHODS

Effector molecules important for tumor defense were analyzed before and at day 5 after rituximab treatment via flow cytometry. Serum rituximab levels were measured with an ELISA.

RESULTS

We evaluated patient parameters that may affect treatment response in relation to rituximab administration and serum rituximab levels. We indeed found a reduction of Fcγ receptor (FcγR) II levels after rituximab treatment in monocyte subtypes, whereas FcγRI expression was significantly increased. Serum levels of proinflammatory marker proteins S100A8/A9 and S100A12 significantly decreased after treatment to normal levels from an overall proinflammatory state before treatment. CD57, perforin, and granzyme B expression decreased after treatment, comprising a less cytolytic natural killer (NK) cell population.

CONCLUSION

The highlighted effects of rituximab treatment on patient's immune response help in understanding the biology behind tumor defense mechanisms and effector function. After subsequent studies, these novel insights might be translated into patient care and could contribute to improve treatment of pediatric patients with mature aggressive B-cell lymphoma.

High levels of plasma S100A9 at admission indicate an increased risk of death in severe tuberculosis patients

Objective

This study aims to evaluate plasma S100A9 levels in tuberculosis (TB) patients with admission to the ICU as a marker to predict the risk of death for pulmonary severe TB.

Methods

This study enrolled 256 severe TB patients admitted to Beijing Chest Hospital from Jan to Dec 2019. The S100A9 levels were measured by ELISA. Standard clinical parameters were collected. The non-parametric Mann-Whitney test, t-test, and chi-square test were applied to statistical comparison. A multivariable analysis was performed to identify risk factors for death.

Results

The plasma S100A9 levels were higher in non-survivors (25.88, 16.77-44.64) compared to survivors (15.51, 13.67-19.94). S100A9 performed better than Acute Physiology and Chronic Health Evaluation (APACHE II) score in predicting death, with AUC of 0.725, sensitivity of 65.5%, and specificity of 80.3%. By combining APACHE II score together with the S100A9 levels we got an AUC of 0.754 (95% CI 0.68 to 0.82) in predicting death. Lastly, S100A9 levels were significantly higher in patients with APACHE II score >17.5, sputum smear-positive, early death, and high cavitary lesions numbers, all of which were related to TB progression.

Conclusion

Measurement and monitoring levels of plasma S100A9 in severe TB patients could facilitate the evaluation of patients with high risk at the early stage, which may help to improve the treatment outcome for TB patients.

Identification of Key Genes Associated with Progression and Prognosis of Bladder Cancer through Integrated Bioinformatics Analysis

Simple Summary

Bladder cancer is a heterogeneous disease with high recurrence rates. The current prognostication depends on tumor stage and grade and there is a need for predictive biomarkers that can distinguish between progressive versus non-progressive disease. We have identified a 3-gene signature panel having prognostic value in bladder cancer, which could aid in clinical decision making.

Abstract

Bladder cancer prognosis remains dismal due to lack of appropriate biomarkers that can predict its progression. The study aims to identify novel prognostic biomarkers associated with the progression of bladder cancer by utilizing three Gene Expression Omnibus (GEO) datasets to screen differentially expressed genes (DEGs). A total of 1516 DEGs were identified between non-muscle invasive and muscle invasive bladder cancer specimens. To identify genes of prognostic value, we performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. A total of seven genes, including CDKN2A, CDC20, CTSV, FOXM1, MAGEA6, KRT23, and S100A9 were confirmed with strong prognostic values in bladder cancer and validated by qRT-PCR conducted in various human bladder cancer cells representing stage-specific disease progression. ULCAN, human protein atlas and The Cancer Genome Atlas datasets were used to confirm the predictive value of these genes in bladder cancer progression. Moreover, Kaplan–Meier analysis and Cox hazard ratio analysis were performed to determine the prognostic role of these genes. Univariate analysis performed on a validation set identified a 3-panel gene set viz. CDKN2A, CTSV and FOXM1 with 95.5% sensitivity and 100% specificity in predicting bladder cancer progression. In summary, our study screened and confirmed a 3-panel biomarker that could accurately predict the progression and prognosis of bladder cancer.

Oral microbiota transplantation fights against head and neck radiotherapy-induced oral mucositis in mice

Oral mucositis is a common radiotherapy-induced complication among nasal, oral and laryngeal cancer (NOALC) patients. This complication leads to decreased quality of life and has few treatments. Here, fractionated radiation was performed to mimic radiotherapy for NOALCs in mouse models. Oral microbiota transplantation (OMT) mitigated oral mucositis, as judged by reconstructed epithelium and tongue papillae, fewer infiltrated leukocytes and more proliferative cells in the oral epithelium. The gut microbiota impacted oral mucositis progression, and OMT restructured oral and gut bacteria configurations and reprogrammed the gene expression profile of tongue tissues. In vivo silencing of glossal S100 calcium binding protein A9 debilitated the radioprotection of OMT. In light of clinical samples, we identified that patients with different alteration trends of Lactobacillaceae frequency presented different primary lesions and prognoses of NOALC following radiotherapy. Together, our findings provide new insights into the oral-gut microbiota axis and underpin the suggestion that OMT might be harnessed as a novel remedy to fight against oral mucositis in NOALC patients following radiotherapy in preclinical settings. Of note, oral microorganisms, such as Lactobacillaceae, might be employed as biomarkers to predict the prognosis of NOALC with radiotherapy.

S100A9-Targeted Cowpea Mosaic Virus as a Prophylactic and Therapeutic Immunotherapy against Metastatic Breast Cancer and Melanoma

Prognosis and treatment of metastatic cancer continues to be one of the most difficult and challenging areas of oncology. Treatment usually consists of chemotherapeutics, which may be ineffective due to drug resistance, adverse effects, and dose-limiting toxicity. Therefore, novel approaches such as immunotherapy have been investigated to improve patient outcomes and minimize side effects. S100A9 is a calcium-binding protein implicated in tumor metastasis, progression, and aggressiveness that modulates the tumor microenvironment into an immunosuppressive state. S100A9 is expressed in and secreted by immune cells in the pre-metastatic niche, as well as, post-tumor development, therefore making it a suitable targeted for prophylaxis and therapy. In previous work, it is demonstrated that cowpea mosaic virus (CPMV) acts as an adjuvant when administered intratumorally. Here, it is demonstrated that systemically administered, S100A9-targeted CPMV homes to the lungs leading to recruitment of innate immune cells. This approach is efficacious both prophylactically and therapeutically against lung metastasis from melanoma and breast cancer. The current research will facilitate and accelerate the development of next-generation targeted immunotherapies administered as prophylaxis, that is, after surgery of a primary breast tumor to prevent outgrowth of metastasis, as well as, therapy to treat established metastatic disease.

Liver-specific over-expression of Cripto-1 in transgenic mice promotes hepatocyte proliferation and deregulated expression of hepatocarcinogenesis-related genes and signaling pathways

In this study, we investigated the role of embryonic gene Cripto-1 (CR-1) in hepatocellular carcinoma (HCC) using hepatocyte-specific CR-1-overexpressing transgenic mice. The expression of truncated 1.7-kb CR-1 transcript (SF-CR-1) was significantly higher than the full-length 2.0-kb CR-1 transcript (FL-CR-1) in a majority of HCC tissues and cell lines. Moreover, CR-1 mRNA and protein levels were significantly higher in HCC tissues than adjacent normal liver tissues. Hepatocyte-specific over-expression of CR-1 in transgenic mice enhanced hepatocyte proliferation after 2/3 partial hepatectomy (2/3 PHx). CR-1 over-expression significantly increased in vivo xenograft tumor growth of HCC cells in nude mice and in vitro HCC cell proliferation, migration, and invasion. CR-1 over-expression in the transgenic mouse livers deregulated HCC-related signaling pathways such as AKT, Wnt/β-catenin, Stat3, MAPK/ERK, JNK, TGF-β and Notch, as well as expression of HCC-related genes such as CD5L, S100A8, S100A9, Timd4, Orm2, Orm3, PDK4, DMBT1, G0S2, Plk2, Plk3, Gsta1 and Gsta2. However, histological signs of precancerous lesions, hepatocyte dysplasia or HCC formation were not observed in the livers of 3-, 6- or 8-month-old hepatocyte-specific CR-1-overexpressing transgenic mice. These findings demonstrate that liver-specific CR-1 overexpression in transgenic mice deregulates signaling pathways and genes associated with HCC.

Calprotectin as potential novel biomarker in myasthenia gravis

Myasthenia gravis (MG) is the most common autoimmune disease affecting the neuromuscular junction by specific autoantibodies. The etiology of MG and its heterogeneity in clinical courses are poorly understood, although it was recently shown that gut microbial dysbiosis plays a critical role. Since levels of Calprotectin (CLP) seem to correlate with level of dysbiosis, we hypothesize that CLP may serve as potential disease activity biomarker in MG. Sera from 251 patients with MG and 90 controls were analyzed in an explorative, cross-sectional design. Prospectively, we tested CLP levels in MG patients up to 3 years. Association of CLP levels with socio-demographics, disease activity (quantitative myasthenia gravis (QMG) score, myasthenia gravis-specific Activities of Daily Living scale (MG-ADL)), antibody (Abs) status, history of myasthenic crisis, treatment regime, and history of thymectomy were investigated using univariate analysis. Mean baseline serum levels of CLP were significantly higher in MG patients compared to controls (4.3 μg/ml vs. 2.1 μg/ml; p < 0.0001). Higher levels of CLP were associated with a higher clinical disease severity measured by MGFA classification and QMG score. Nevertheless, the only weak correlation of CLP with clinical outcome parameters needs confirmation in future studies. Currently, there are no validated blood biomarkers for MG. The significantly elevated CLP and mild correlation with parameters of disease activity suggests that CLP holds promise as a biomarker for measurement of individual disease severity.

The role of S100A9 in the interaction between pancreatic ductal adenocarcinoma cells and stromal cells

BACKGROUND

A major feature of the microenvironment in pancreatic ductal adenocarcinoma (PDAC) is the significant amount of extracellular matrix produced by pancreatic stellate cells (PSCs), which have been reported to enhance the invasiveness of pancreatic cancer cells and negatively impact the prognosis.

METHODS

We analyzed the data from two publicly available microarray datasets deposited in the Gene Expression Omnibus and found candidate genes that were differentially expressed in PDAC cells with metastatic potential and PDAC cells cocultured with PSCs. We studied the interaction between PDAC cells and PSCs in vitro and verified our finding with the survival data of patients with PDAC from the website of The Human Protein Atlas.

RESULTS

We found that PSCs stimulated PDAC cells to secrete S100A9, which attracted circulatory monocytes into cancer tissue and enhanced the expression of programmed death-ligand 1 (PD-L1) on macrophages. When analyzing the correlation of S100A9 and PD-L1 expression with the clinical outcomes of patients with PDAC, we ascertained that high expression of S100A9 and PD-L1 was associated with poor survival in patients with PDAC.

CONCLUSIONS

PSCs stimulated PDAC cells to secrete S100A9, which acts as a chemoattractant to attract circulatory monocytes into cancer microenvironment and induces expression of PD-L1 on macrophages. High expression of S100A9 and PD-L1 was associated with worse overall survival in a cohort of patients with PDAC.

Effects of Cancer Presence and Therapy on the Platelet Proteome

Platelets are involved in tumor angiogenesis and cancer progression. Previous studies indicated that cancer could affect platelet content. In the current study, we investigated whether cancer-associated proteins can be discerned in the platelets of cancer patients, and whether antitumor treatment may affect the platelet proteome. Platelets were isolated from nine patients with different cancer types and ten healthy volunteers. From three patients, platelets were isolated before and after the start of antitumor treatment. Mass spectrometry-based proteomics of gel-fractionated platelet proteins were used to compare patients versus controls and before and after treatment initiation. A total of 4059 proteins were detected, of which 50 were significantly more abundant in patients, and 36 more in healthy volunteers. Eight of these proteins overlapped with our previous cancer platelet proteomics study. From these data, we selected potential biomarkers of cancer including six upregulated proteins (RNF213, CTSG, PGLYRP1, RPL8, S100A8, S100A9) and two downregulated proteins (GPX1, TNS1). Antitumor treatment resulted in increased levels of 432 proteins and decreased levels of 189 proteins. In conclusion, the platelet proteome may be affected in cancer patients and platelets are a potential source of cancer biomarkers. In addition, we found in a small group of patients that anticancer treatment significantly changes the platelet proteome.

S100A9 Alters the Pathway of Alpha-Synuclein Amyloid Aggregation

The formation of amyloid fibril plaques in the brain creates inflammation and neuron death. This process is observed in neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases. Alpha-synuclein is the main protein found in neuronal inclusions of patients who have suffered from Parkinson's disease. S100A9 is a calcium-binding, pro-inflammation protein, which is also found in such amyloid plaques. To understand the influence of S100A9 on the aggregation of α-synuclein, we analyzed their co-aggregation kinetics and the resulting amyloid fibril structure by Fourier-transform infrared spectroscopy and atomic force microscopy. We found that the presence of S100A9 alters the aggregation kinetics of α-synuclein and stabilizes the formation of a particular amyloid fibril structure. We also show that the solution's ionic strength influences the interplay between S100A9 and α-synuclein, stabilizing a different structure of α-synuclein fibrils.

Identification of differentially expressed proteins involved in fetal scarless wound healing using a rat model of cleft lip

In early pregnancy, fetal skin wounds can heal quickly and undergo a transition period from scarless healing to scar formation. The aim of the present study was to identify potential biomarkers associated with scarless repair of cleft lips, in order to determine the intrinsic factors leading to scar formation in embryonic tissue. A stable model of cleft lip was established using microsurgery by constructing a wedge-shaped cleft lip-like defect in fetal rats at gestational age (GA) 16.5 and GA18.5. The GA16.5 and GA18.5 groups were used to model scarless healing and scar formation, respectively. The fetuses were returned to the uterus following surgery, then removed 72 h after the procedure. Macroscopic observation of the cleft defect and histological examination were carried out. Reverse transcription-quantitative (RT-q) PCR and parallel reaction monitoring (PRM) were used to detect mRNA and protein expression levels, respectively. The upper-left lip completely healed 72 h after surgery in the GA16.5 group of fetal rats. However, this was not the case in the GA18.5 group. Histological examination indicated new follicles visible under the epidermis of the scarless group (GA16.5). Scarring was visible on the upper-left cleft lip wound of the fetal rats in the GA18.5 group. The expression of some growth and pro-inflammatory factors, including TNF-α, were also different between two groups. Label-free quantification was used to identified differentially expressed proteins and five differentially expressed proteins (Smad4, Fabp5, S100a4, S100a8 and S100a9) were identified. The relative expression of these molecules at the mRNA and protein levels were measured using RT-qPCR and PRM. These molecules may represent potential biomarkers for the scarless repair of fetal rat cleft lip wounds.

Natural Compound from Olive Oil Inhibits S100A9 Amyloid Formation and Cytotoxicity: Implications for Preventing Alzheimer's Disease

Polyphenolic compounds in the Mediterranean diet have received increasing attention due to their protective properties in amyloid neurodegenerative and many other diseases. Here, we have demonstrated for the first time that polyphenol oleuropein aglycone (OleA), which is the most abundant compound in olive oil, has multiple potencies for the inhibition of amyloid self-assembly of pro-inflammatory protein S100A9 and the mitigation of the damaging effect of its amyloids on neuroblastoma SH-SY5Y cells. OleA directly interacts with both native and fibrillar S100A9 as shown by intrinsic fluorescence and molecular dynamic simulation. OleA prevents S100A9 amyloid oligomerization as shown using amyloid oligomer-specific antibodies and cross-β-sheet formation detected by circular dichroism. It decreases the length of amyloid fibrils measured by atomic force microscopy (AFM) as well as reduces the effective rate of amyloid growth and the overall amyloid load as derived from the kinetic analysis of amyloid formation. OleA disintegrates already preformed fibrils of S100A9, converting them into nonfibrillar and nontoxic aggregates as revealed by amyloid thioflavin-T dye binding, AFM, and cytotoxicity assays. At the cellular level, OleA targets S100A9 amyloids already at the membranes as shown by immunofluorescence and fluorescence resonance energy transfer, significantly reducing the amyloid accumulation in GM1 ganglioside containing membrane rafts. OleA increases overall cell viability when neuroblastoma cells are subjected to the amyloid load and alleviates amyloid-induced intracellular rise of reactive oxidative species and free Ca²⁺. Since S100A9 is both a pro-inflammatory and amyloidogenic protein, OleA may effectively mitigate the pathological consequences of the S100A9-dependent amyloid-neuroinflammatory cascade as well as provide protection from neurodegeneration, if used within the Mediterranean diet as a potential preventive measure.

Diverse roles of bitter melon (Momordica charantia) in prevention of oral cancer

Oral squamous cell carcinoma (OSCC) is one of the common lethal malignancies which is increasing rapidly in the world. Increasing risks from alcohol and tobacco habits, lack of early detection markers, lack of effective chemotherapeutic agents, recurrence and distant metastasis make the disease more complicated to manage. Laboratory-based studies and epidemiological studies indicate important roles of nutraceuticals to manage different cancers. The plant bitter melon (Momordica charantia) is a good source of nutrients and bio-active phytochemicals such as triterpenoids, triterpene glycosides, phenolic acids, flavonoids, lectins, sterols and proteins. The plant is widely grown in Asia, Africa, and South America. Bitter melon has traditionally been used as a folk medicine and Ayurvedic medicine in Asian culture to treat diseases such as diabetes, since ancient times. The crude extract and some of the isolated pure compounds of bitter melon show potential anticancer effects against different cancers. In this review, we shed light on its effect on OSCC. Bitter melon extract has been found to inhibit cell proliferation and metabolism, induce cell death and enhance the immune defense system in the prevention of OSCC in vitro and in vivo. Thus, bitter melon may be used as an attractive chemopreventive agent in progression towards OSCC clinical study.

S100 family members: potential therapeutic target in patients with hepatocellular carcinoma: A STROBE study

Proteins in S100 family exhibit different expressions patterns and perform different cytological functions, playing substantial roles in certain cancers, carcinogenesis, and disease progression. However, the expression and role of S100 family members in the prognosis of hepatocellular carcinoma (HCC) remains unclear. To investigate the effect of S100 family members for the prognosis of liver cancer, we assessed overall survival (OS) using a Kaplan-Meier plotter (KM plotter) in liver cancer patients with different situation. Our results showed that 15 members of the S100 family exhibited high levels of expression and these levels were correlated with OS in liver cancer patients. The higher expression of S100A5, S100A7, S100A7A, S100A12, S100Z, and S100G was reflected with better survival in liver cancer patients. However, worse prognosis was related to higher levels of expression of S100A2, S100A6, S100A8, S100A9, S100A10, S100A11, S10013, S100A14, and S100P. We then evaluated the prognostic values of S100 family members expression for evaluating different stages of AJCC-T, vascular invasion, alcohol consumption, and the presence of hepatitis virus in liver cancer patients. Lastly, we studied the prognostic values of S100 family members expression for patients after sorafenib treatment. In conclusion, our findings show that the proteins of S100 family members exhibit differential expression and may be useful as targets for liver cancer, facilitating novel diagnostic and therapeutic strategies in cancer.

S100A9-Imaging Enables Estimation of Early Therapy-Mediated Changes in the Inflammatory Tumor Microenvironment

(1) Background: The prognosis of cancer is dependent on immune cells in the tumor microenvironment (TME). The protein S100A9 is an essential regulator of the TME, associated with poor prognosis. In this study, we evaluated early therapy effects on the TME in syngeneic murine breast cancer via S100A9-specific in vivo imaging. (2) Methods: Murine 4T1 cells were implanted orthotopically in female BALB/c mice (n = 59). Tumor size-adapted fluorescence imaging was performed before and 5 days after chemo- (Doxorubicin, n = 20), anti-angiogenic therapy (Bevacizumab, n = 20), or placebo (NaCl, n = 19). Imaging results were validated ex vivo (immunohistochemistry, flow cytometry). (3) Results: While tumor growth revealed no differences (p = 0.48), fluorescence intensities (FI) for S100A9 in Bevacizumab-treated tumors were significantly lower as compared to Doxorubicin (2.60 vs. 15.65 AU, p < 0.0001). FI for Doxorubicin were significantly higher compared to placebo (8.95 AU, p = 0.01). Flow cytometry revealed shifts in monocytic and T-cell cell infiltrates under therapy, correlating with imaging. (4) Conclusions: S100A9-specific imaging enables early detection of therapy effects visualizing immune cell activity in the TME, even before clinically detectable changes in tumor size. Therefore, it may serve as a non-invasive imaging biomarker for early therapy effects.

S100A8/S100A9 cytokine acts as a transcriptional coactivator during breast cellular transformation

Cytokines are extracellular proteins that convey messages between cells by interacting with cognate receptors at the cell surface and triggering signaling pathways that alter gene expression and other phenotypes in an autocrine or paracrine manner. Here, we show that the calcium-dependent cytokines S100A8 and S100A9 are recruited to numerous promoters and enhancers in a model of breast cellular transformation. This recruitment is associated with multiple DNA sequence motifs recognized by DNA binding transcription factors that are linked to transcriptional activation and are important for transformation. The cytokines interact with these transcription factors in nuclear extracts, and they activate transcription when artificially recruited to a target promoter. Nuclear-specific expression of S100A8/A9 promotes oncogenic transcription and leads to enhanced breast transformation phenotype. These results suggest that, in addition to its classical cytokine function, S100A8/A9 can act as a transcriptional coactivator.

Intracellular and extracellular S100A9 trigger epithelial-mesenchymal transition and promote the invasive phenotype of pituitary adenoma through activation of AKT1

Pituitary adenoma (PA) is mostly benign intracranial tumor, but it also displays invasive growth characteristics and provokes challenging clinical conditions. S100A9 protein enhances tumor progression. In this study, we firstly demonstrated that both intracellular and extracellular S100A9 promoted the expression of Vimentin and Intercellular cell adhesion molecule-1 (ICAM-1), coupled with reduced E-cadherin in PA. As a result, PA acquired the phenotype of Epithelial-Mesenchymal Transition (EMT), leading to proliferation, cell cycle progression, migration and invasion. In addition, we indicated S100A9-induced EMT was mediated by activation of AKT1. Furthermore, immunohistochemistry showed that S100A9 expression was higher in invasive PA than that in non-invasive PA. These data extended our understanding for the effects of S100A9 on PA invasion and contributed to further development of a promising therapeutic target for invasive PA.

Complement factor H-deficient mice develop spontaneous hepatic tumors

Hepatocellular carcinoma (HCC) is difficult to detect, carries a poor prognosis, and is one of few cancers with an increasing yearly incidence. Molecular defects in complement factor H (CFH), a critical regulatory protein of the complement alternative pathway (AP), are typically associated with inflammatory diseases of the eye and kidney. Little is known regarding the role of CFH in controlling complement activation within the liver. While studying aging CFH-deficient (fH-/-) mice, we observed spontaneous hepatic tumor formation in more than 50% of aged fH-/- males. Examination of fH-/- livers (3-24 months) for evidence of complement-mediated inflammation revealed widespread deposition of complement-activation fragments throughout the sinusoids, elevated transaminase levels, increased hepatic CD8+ and F4/80+ cells, overexpression of hepatic mRNA associated with inflammatory signaling pathways, steatosis, and increased collagen deposition. Immunostaining of human HCC biopsies revealed extensive deposition of complement fragments within the tumors. Investigating the Cancer Genome Atlas also revealed that increased CFH mRNA expression is associated with improved survival in patients with HCC, whereas mutations are associated with worse survival. These results indicate that CFH is critical for controlling complement activation in the liver, and in its absence, AP activation leads to chronic inflammation and promotes hepatic carcinogenesis.

Bitter Melon (Momordica Charantia), a Nutraceutical Approach for Cancer Prevention and Therapy

Cancer is the second leading cause of death worldwide. Many dietary plant products show promising anticancer effects. Bitter melon or bitter gourd (Momordica charantia) is a nutrient-rich medicinal plant cultivated in tropical and subtropical regions of many countries. Traditionally, bitter melon is used as a folk medicine and contains many bioactive components including triterpenoids, triterpene glycoside, phenolic acids, flavonoids, lectins, sterols and proteins that show potential anticancer activity without significant side effects. The preventive and therapeutic effects of crude extract or isolated components are studied in cell line-based models and animal models of multiple types of cancer. In the present review, we summarize recent progress in testing the cancer preventive and therapeutic activity of bitter melon with a focus on underlying molecular mechanisms. The crude extract and its components prevent many types of cancers by enhancing reactive oxygen species generation; inhibiting cancer cell cycle, cell signaling, cancer stem cells, glucose and lipid metabolism, invasion, metastasis, hypoxia, and angiogenesis; inducing apoptosis and autophagy cell death, and enhancing the immune defense. Thus, bitter melon may serve as a promising cancer preventive and therapeutic agent.

Friend or Foe: S100 Proteins in Cancer

S100 proteins are widely expressed small molecular EF-hand calcium-binding proteins of vertebrates, which are involved in numerous cellular processes, such as Ca²⁺ homeostasis, proliferation, apoptosis, differentiation, and inflammation. Although the complex network of S100 signalling is by far not fully deciphered, several S100 family members could be linked to a variety of diseases, such as inflammatory disorders, neurological diseases, and also cancer. The research of the past decades revealed that S100 proteins play a crucial role in the development and progression of many cancer types, such as breast cancer, lung cancer, and melanoma. Hence, S100 family members have also been shown to be promising diagnostic markers and possible novel targets for therapy. However, the current knowledge of S100 proteins is limited and more attention to this unique group of proteins is needed. Therefore, this review article summarises S100 proteins and their relation in different cancer types, while also providing an overview of novel therapeutic strategies for targeting S100 proteins for cancer treatment.

Epigenetic Regulation of S100A9 and S100A12 Expression in Monocyte-Macrophage System in Hyperglycemic Conditions

The number of diabetic patients in Europe and world-wide is growing. Diabetes confers a 2-fold higher risk for vascular disease. Lack of insulin production (Type 1 diabetes, T1D) or lack of insulin responsiveness (Type 2 diabetes, T2D) causes systemic metabolic changes such as hyperglycemia (HG) which contribute to the pathology of diabetes. Monocytes and macrophages are key innate immune cells that control inflammatory reactions associated with diabetic vascular complications. Inflammatory programming of macrophages is regulated and maintained by epigenetic mechanisms, in particular histone modifications. The aim of our study was to identify the epigenetic mechanisms involved in the hyperglycemia-mediated macrophage activation. Using Affymetrix microarray profiling and RT-qPCR we identified that hyperglycemia increased the expression of S100A9 and S100A12 in primary human macrophages. Expression of S100A12 was sustained after glucose levels were normalized. Glucose augmented the response of macrophages to Toll-like receptor (TLR)-ligands Palmatic acid (PA) and Lipopolysaccharide (LPS) i.e., pro-inflammatory stimulation. The abundance of activating histone Histone 3 Lysine 4 methylation marks (H3K4me1, H3K4me3) and general acetylation on histone 3 (AceH3) with the promoters of these genes was analyzed by chromatin immunoprecipitation. Hyperglycemia increased acetylation of histones bound to the promoters of S100A9 and S100A12 in M1 macrophages. In contrast, hyperglycemia caused a reduction in total H3 which correlated with the increased expression of both S100 genes. The inhibition of histone methyltransferases SET domain-containing protein (SET)7/9 and SET and MYND domain-containing protein (SMYD)3 showed that these specifically regulated S100A12 expression. We conclude that hyperglycemia upregulates expression of S100A9, S100A12 via epigenetic regulation and induces an activating histone code on the respective gene promoters in M1 macrophages. Mechanistically, this regulation relies on action of histone methyltransferases SMYD3 and SET7/9. The results define an important role for epigenetic regulation in macrophage mediated inflammation in diabetic conditions.

S100A4 is a Biomarker of Tumorigenesis, EMT, Invasion, and Colonization of Host Organs in Experimental Malignant Mesothelioma

Recent findings suggest that S100A4, a protein involved in communication between stromal cells and cancer cells, could be more involved than previously expected in cancer invasiveness. To investigate its cumulative value in the multistep process of the pathogenesis of malignant mesothelioma (MM), SWATH-MS (sequential window acquisition of all theoretical fragmentation spectra), an advanced and robust technique of quantitative proteomics, was used to analyze a collection of 26 preneoplastic and neoplastic rat mesothelial cell lines and models of MM with increasing invasiveness. Secondly, proteomic and histological analyses were conducted on formalin-fixed paraffin-embedded sections of liver metastases vs. primary tumor, and spleen from tumor-bearing rats vs. controls in the most invasive MM model. We found that S100A4, along with 12 other biomarkers, differentiated neoplastic from preneoplastic mesothelial cell lines, and invasive vs. non-invasive tumor cells in vitro, and MM tumors in vivo. Additionally, S100A4 was the only protein differentiating preneoplastic mesothelial cell lines with sarcomatoid vs. epithelioid morphology in relation to EMT (epithelial-to-mesenchymal transition). Finally, S100A4 was the most significantly increased biomarker in liver metastases vs. primary tumor, and in the spleen colonized by MM cells. Overall, we showed that S100A4 was the only protein that showed increased abundance in all situations, highlighting its crucial role in all stages of MM pathogenesis.

In silico assessment of human Calprotectin subunits (S100A8/A9) in presence of sodium and calcium ions using Molecular Dynamics simulation approach

Calprotectin is a heterodimeric protein complex which consists of two subunits including S100A8 and S100A9. This protein has a major role in different inflammatory disease and various types of cancers. In current study we aimed to evaluate the structural and thermodynamic changes of the subunits and the complex in presence of sodium and calcium ions using molecular dynamics (MD) simulation. Therefore, the residue interaction network (RIN) was visualized in Cytoscape program. In next step, to measure the binding free energy, the potential of mean force (PMF) method was performed. Finally, the molecular mechanics Poisson-Boltzmann surface area (MMPBSA) method was applied as an effective tool to calculate the molecular model affinities. The MD simulation results of the subunits represented their structural changes in presence of Ca2+. Moreover, the RIN and Hydrogen bond analysis demonstrated that cluster interactions between Calprotectin subunits in presence of Ca2+ were greater in comparison with Na+. Our findings indicated that the binding free energy of the subunits in presence of Ca2+ was significantly greater than Na+. The results revealed that Ca2+ has the ability to induce structural changes in subunits in comparison with Na+ which lead to create stronger interactions between. Hence, studying the physical characteristics of the human proteins could be considered as a powerful tool in theranostics and drug design purposes.

S100-A9 protein in exosomes derived from follicular fluid promotes inflammation via activation of NF-κB pathway in polycystic ovary syndrome

Exosomes have recently emerged as key mediators of different physiological and pathological processes. However, there has been few report about proteomic analysis of exosomes derived from human follicular fluid and their association with the occurrence of PCOS. Herein, we used TMT‐tagged quantitative proteomic approach to identify proteomic profiles in exosomes derived from follicular fluid of PCOS patients and healthy controls. We identified 662 proteins in exosomes derived from human ovarian follicular fluid. Eighty‐six differently expressed proteins (P < .05) were found between PCOS and healthy women. The alterations in the proteomic profile were related to the inflammation process, reactive oxygen species metabolic process, cell migration and proliferation. Importantly, we observed that follicular fluid exosomes contain S100 calcium‐binding protein A9 (S100‐A9) protein. Exosome‐enriched S100‐A9 significantly enhanced inflammation and disrupted steroidogenesis via activation of nuclear factor kappa B (NF‐κB) signalling pathway. These data demonstrate that exosomal proteins are differentially expressed in follicular fluid during disease process, and some proteins may play important roles in the regulation of granulosa cell function. These results highlight the importance of exosomes as extracellular communicators in ovarian follicular development.

S100A9 Regulates MDSCs-Mediated Immune Suppression via the RAGE and TLR4 Signaling Pathways in Colorectal Carcinoma

Myeloid-derived suppressor cells (MDSCs) are a major component of the immunosuppressive tumor microenvironment (TME) and have been recognized as a contributing factor to inflammation-related cancers. However, the molecular mechanisms of MDSCs accumulation and activation remain elusive. We previously showed that the proinflammatory molecule S100A9 in TME exerts a tumor-promoting effect in colorectal carcinoma (CRC). In this report, we investigated the effect and molecular mechanisms of S100A9 on the accumulation and immunosuppressive function of MDSCs in CRC. Elevated S100A9 and MDSCs were found in tumor tissue and peripheral blood from CRC patients. Circulating S100A9 and MDSCs were positively associated to each other, and both S100A9 and MDSCs were correlated to neoplastic progression. Using a CRC cell line LoVo-induced MDSCs model, we found that S100A9 stimulated chemotaxis and activation but not viability of MDSCs. Mechanistic studies demonstrated that activation of RAGE-mediated p38 MAPK and TLR4-mediated NF-κB signaling pathways were involved in S100A9-induced chemotaxis and MDSCs activation, respectively. Furthermore, ROC analysis showed that combination detection of S100A9 and MDSCs was superior to individual detection of these two factors for diagnosing CRC patients with advanced staging and lymphatic metastasis, which yielded an area under the ROC curve (AUC) of 0.92 with 86.7% sensitivity and 86.4% specificity, and an AUC of 0.82 with 75% sensitivity and 77.1% specificity, respectively. Collectively, our study suggests that the S100A9 plays a pivotal role in immunosuppressive TME by stimulating MDSCs chemotaxis and activation, and combination detection of S100A9 and MDSCs may serve as a potential marker for diagnosis of CRC progression.

Lung-Seeking Metastases

Metastases from different cancer types most often affect the lung parenchyma. Moreover, the lungs are among the most frequent sites of growth of metastatic masses of uncertain/unknown lineage of origin. Thus, with regards to pulmonary neoplastic parenchymal nodules, the critical issue is to determine if they are IN the lung or OF the lung. In this review, we highlight the clinical, instrumental and molecular features which characterize lung metastases, mainly focusing on recently advancing and emerging concepts regarding the metastatic niche, inflammation, angiogenesis, immune modulation and gene expression. A novel issue is related to the analysis of biomechanical forces which cooperate in the expansion of tumor masses in the lungs. We here aim to analyze the biological, genetic and pathological features of metastatic lesions to the lungs, here referred to as site of metastatic growth. This point should be a crucial part of the algorithm for a proper diagnostic and therapeutic approach in the era of personalized medicine.