Prognostic values and immune suppression of the S100A family in pancreatic cancer

Activation of Hypoxia Inducible Factor-1 Alpha-Mediated DNA Methylation Enzymes (DNMT3a and TET2) Under Hypoxic Conditions Regulates S100A6 Transcription to Promote Lung Cancer Cell Growth and Metastasis

Aims: This research was aimed at investigating the effects of hypoxia inducible factor-1 alpha (HIF-1α)-mediated DNA methylation enzymes (ten-eleven translocase-2 [TET2] and DNA methyltransferase-3a [DNMT3a]) under hypoxic conditions on S100A6 transcription, thereby promoting the growth and metastasis of lung cancer cells. Methods: The expression of HIF-1α or S100A6 in lung cancer cells was interfered with under normoxic and hypoxic conditions, and the cell proliferative, migratory, and invasive properties were assessed. The mechanism of HIF-1α-regulated TET2 and DNMT3 effects on S100A6 transcription under hypoxic conditions was further investigated. Results: Functionally, S100A6 over-expression promoted lung cancer cell proliferation and metastasis. S100A6 over-expression reversed the inhibitory effects of HIF-1α interference on the proliferation and metastasis of lung cancer cells. S100A6 was induced to express in an HIF-1α-dependent manner under hypoxic conditions, and silencing S100A6 or HIF-1α suppressed lung cancer cell proliferation and metastasis under hypoxic conditions. Further, The Cancer Genome Atlas-lung adenocarcinoma database analysis revealed that S100A6 mRNA levels had a negative correlation with methylation levels. Mechanistically, CpG hypomethylation status in the S100A6 promoter hypoxia response element had an association with HIF-1α induction. TET2 was enriched in S100A6 promoter region of lung cancer cells under hypoxic conditions, whereas DNMT3a enrichment was reduced in S100A6 promoter region. HIF-1α-mediated S100A6 activation was linked to DNMT3a-associated epigenetic inactivation and TET2 activation. Innovation: The activation of HIF-1α-mediated DNA methylation enzymes under hypoxic conditions regulated S100A6 transcription, thereby promoting lung cancer cell growth and metastasis. Conclusion: In lung cancer progression, hypoxia-induced factor HIF-1α combined with DNA methylation modifications co-regulates S100A6 transcriptional activation and promotes lung cancer cell growth and metastasis.

S100A family is a group of immune markers associated with poor prognosis and immune cell infiltration in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common human cancers with poor prognosis in the world. HCC has become the second leading cause of cancer-related death in China. It is urgent to identify novel biomarker and valid target to effectively diagnose, treat or predict the prognosis of HCC. It has been reported that S100A family is closely related to cell proliferation and migration of different cancers. However, the values of S100As in HCC remain to be further analyzed.

METHODS

We investigated the transcriptional and translational expression of S100As, as well as the value of this family in HCC patients from the various databases.

RESULTS

S100A10 was most relevant to HCC.

CONCLUSIONS

The results from HCC patients' tissues and different cells also confirmed the role of S100A10 in HCC. Furthermore, we proved that S100A10 could influenced the cell proliferation of HCC cells via ANXA2/Akt/mTOR pathway. However, it would appear that the relationship between S100A10 and HCC is complex and requires more research.

An Update on S100A16 in Human Cancer

S100A16 is a member of the S100 protein family. S100A16 is expressed in a variety of human tissues, although at varying levels. S100A16 expression is especially high in tissues rich in epithelial cells. mRNA and protein levels of S100A16 have been reported to be differentially expressed in the majority of human cancers. Functionally, S100A16 has been linked to several aspects of tumorigenesis, for example, cell proliferation, differentiation, migration, invasion, and epithelial-mesenchymal transition (EMT). Accordingly, S100A16 has been suggested to have both tumour-promoting and suppressive roles in human cancers. S100A16-mediated cellular functions are suggested to be mediated by the regulation of various signaling pathways/proteins including EMT-related proteins E-cadherin and Vimentin, PI3K-AKT, p53, MMP1-1, MMP-2, MMP-9, JNK/p38, etc. In addition to the functional roles, expression of S100A16 has been suggested to have prognostic potential in various cancer types. The aims of this review are to summarise the expression profile, identify common molecular partners and functional roles, and explore the prognostic potential of S100A16 in human cancers.

Expression, prognostic value and mechanism of SP100 family in pancreatic adenocarcinoma

BACKGROUND

Pancreatic adenocarcinoma (PAAD) is one of the most aggressive malignancies with a very poor prognosis. Exploring more therapeutic targets and prognostic biomarkers is of great significance to improve the prognosis of PAAD patients. Increasing evidence supports that the speckled protein (SP) 100 family is associated with human cancer and immune disorders. However, the function of the SP100 family members in PAAD is still unclear.

METHODS

R, Cytoscape, cBioPortal, and other software and online databases were used to comprehensively analyze the expression characteristics, prognostic value, and oncogenic mechanism of the SP100 family in PAAD.

RESULTS

The high expression of SP100 family members in PAAD was significantly correlated with poor clinicopathological features and poor prognosis of PAAD patients. Mechanistically, TP53 mutations were significantly associated with the expression levels of the SP100 family members, which were significantly coexpressed with M6A methylation regulators and were activated in multiple oncogenic pathways, including the EMT pathways. Moreover, we found that their expression levels were significantly correlated with the sensitivity of multiple traditional chemotherapeutic drugs.

CONCLUSION

The SP100 family is closely related to the occurrence and development of PAAD and can be used as a new biomarker and therapeutic target for patients with PAAD.

High-dimensional single-cell analysis unveils distinct immune signatures of peripheral blood in patients with pancreatic ductal adenocarcinoma

Introduction

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies with poor response to immune checkpoint inhibitors. The mechanism of such poor response is not completely understood.

Methods

We assessed T-cell receptor (TCR) repertoire and RNA expression at the single-cell level using high-dimensional sequencing of peripheral blood immune cells isolated from PDAC patients and from healthy human controls. We validated RNA-sequencing data by performing mass cytometry (CyTOF) and by measuring serum levels of multiple immune checkpoint proteins.

Results

We found that proportions of T cells (CD45+CD3+) were decreased in PDAC patients compared to healthy controls, while proportion of myeloid cells was increased. The proportion of cytotoxic CD8+ T cells and the level of cytotoxicity per cell were increased in PDAC patients, with reduced TCR clonal diversity. We also found a significantly enriched S100A9+ monocyte population and an increased level of TIM-3 expression in immune cells of peripheral blood in PDAC patients. In addition, the serum level of soluble TIM-3 (sTIM-3) was significantly higher in PDAC patients compared to the non-PDAC participants and correlated with worse survival in two independent PDAC cohorts. Moreover, sTIM-3 exhibited a valuable role in diagnosis of PDAC, with sensitivity and specificity of about 80% in the training and validation groups, respectively. We further established an integrated model by combining sTIM-3 and carbohydrate antigen 19- 9 (CA19-9), which had an area under the curve of 0.974 and 0.992 in training and validation cohorts, respectively.

Conclusion

Our RNA-seq and proteomic results provide valuable insight for understanding the immune cell composition of peripheral blood of patients with PDAC.

An amino acid metabolism-based seventeen-gene signature correlates with the clinical outcome and immune features in pancreatic cancer

Background: Pancreatic cancer is an aggressive tumor with a low 5-year survival rate and primary resistance to most therapy. Amino acid (AA) metabolism is highly correlated with tumor growth, crucial to the aggressive biological behavior of pancreatic cancer; nevertheless, the comprehensive predictive significance of genes that regulate AA metabolism in pancreatic cancer remains unknown. Methods: The mRNA expression data downloaded from The Cancer Genome Atlas (TCGA) were derived as the training cohort, and the GSE57495 cohort from Gene Expression Omnibus (GEO) database was applied as the validation cohort. Random survival forest (RSF) and the least absolute shrinkage and selection operator (LASSO) regression analysis were employed to screen genes and construct an AA metabolism-related risk signature (AMRS). Kaplan-Meier analysis and receiver operating characteristic (ROC) curve were performed to assess the prognostic value of AMRS. We performed genomic alteration analysis and explored the difference in tumor microenvironment (TME) landscape associated with KRAS and TP53 mutation in both high- and low-AMRS groups. Subsequently, the relationships between AMRS and immunotherapy and chemotherapy sensitivity were evaluated. Results: A 17-gene AA metabolism-related risk model in the TCGA cohort was constructed according to RSF and LASSO. After stratifying patients into high- and low-AMRS groups based on the optimal cut-off value, we found that high-AMRS patients had worse overall survival (OS) in the training cohort (a median OS: 13.1 months vs. 50.1 months, p < 0.0001) and validation cohort (a median OS: 16.2 vs. 30.5 months, p = 1e-04). Genetic mutation analysis revealed that KRAS and TP53 were significantly more mutated in high-AMRS group, and patients with KRAS and TP53 alterations had significantly higher risk scores than those without. Based on the analysis of TME, low-AMRS group displayed significantly higher immune score and more enrichment of T Cell CD8⁺ cells. In addition, high-AMRS-group exhibited higher TMB and significantly lower tumor immune dysfunction and exclusion (TIDE) score and T Cells dysfunction score, which suggested a higher sensitive to immunotherapy. Moreover, high-AMRS group was also more sensitive to paclitaxel, cisplatin, and docetaxel. Conclusion: Overall, we constructed an AA-metabolism prognostic model, which provided a powerful prognostic predictor for the clinical treatment of pancreatic cancer.

A Comprehensive Transcriptional Signature in Pancreatic Ductal Adenocarcinoma Reveals New Insights into the Immune and Desmoplastic Microenvironments

Pancreatic ductal adenocarcinoma (PDAC) prognoses and treatment responses remain devastatingly poor due partly to the highly heterogeneous, aggressive, and immunosuppressive nature of this tumor type. The intricate relationship between the stroma, inflammation, and immunity remains vaguely understood in the PDAC microenvironment. Here, we performed a meta-analysis of stroma-, and immune-related gene expression in the PDAC microenvironment to improve disease prognosis and therapeutic development. We selected 21 PDAC studies from the Gene Expression Omnibus and ArrayExpress databases, including 922 samples (320 controls and 602 cases). Differential gene enrichment analysis identified 1153 significant dysregulated genes in PDAC patients that contribute to a desmoplastic stroma and an immunosuppressive environment (the hallmarks of PDAC tumors). The results highlighted two gene signatures related to the immune and stromal environments that cluster PDAC patients into high- and low-risk groups, impacting patients' stratification and therapeutic decision making. Moreover, HCP5, SLFN13, IRF9, IFIT2, and IFI35 immune genes are related to the prognosis of PDAC patients for the first time.

Dialog beyond the Grave: Necrosis in the Tumor Microenvironment and Its Contribution to Tumor Growth

Damage-associated molecular patterns (DAMPs) are endogenous molecules released from the necrotic cells dying after exposure to various stressors. After binding to their receptors, they can stimulate various signaling pathways in target cells. DAMPs are especially abundant in the microenvironment of malignant tumors and are suspected to influence the behavior of malignant and stromal cells in multiple ways often resulting in promotion of cell proliferation, migration, invasion, and metastasis, as well as increased immune evasion. This review will start with a reminder of the main features of cell necrosis, which will be compared to other forms of cell death. Then we will summarize the various methods used to assess tumor necrosis in clinical practice including medical imaging, histopathological examination, and/or biological assays. We will also consider the importance of necrosis as a prognostic factor. Then the focus will be on the DAMPs and their role in the tumor microenvironment (TME). We will address not only their interactions with the malignant cells, frequently leading to cancer progression, but also with the immune cells and their contribution to immunosuppression. Finally, we will emphasize the role of DAMPs released by necrotic cells in the activation of Toll-like receptors (TLRs) and the possible contributions of TLRs to tumor development. This last point is very important for the future of cancer therapeutics since there are attempts to use TLR artificial ligands for cancer therapeutics.

New progress with calcium-binding protein S100A16 in digestive system disease

INTRODUCTION

This review summarizes and analyzes the abnormal expression and mechanism of S100A16 in digestive system diseases, which is expected to provide new ideas and methods for adjuvant treatment and prognosis evaluation of digestive system diseases.

AREAS COVERED

Based on original publications found in database systems (PubMed, Cochrane), we introduce the mechanism and research progress of S100A16 in digestive system tumors, inflammatory bowel disease and fatty liver.

EXPERT OPINION

S100A16 is closely related to the proliferation, migration, and invasion of digestive system tumor cells. Further, it plays an important role in inflammatory bowel disease and fatty liver.

SEdb 2.0: a comprehensive super-enhancer database of human and mouse

Super-enhancers (SEs) are cell-specific DNA cis-regulatory elements that can supervise the transcriptional regulation processes of downstream genes. SEdb 2.0 (http://www.licpathway.net/sedb) aims to provide a comprehensive SE resource and annotate their potential roles in gene transcriptions. Compared with SEdb 1.0, we have made the following improvements: (i) Newly added the mouse SEs and expanded the scale of human SEs. SEdb 2.0 contained 1 167 518 SEs from 1739 human H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq) samples and 550 226 SEs from 931 mouse H3K27ac ChIP-seq samples, which was five times that of SEdb 1.0. (ii) Newly added transcription factor binding sites (TFBSs) in SEs identified by TF motifs and TF ChIP-seq data. (iii) Added comprehensive (epi)genetic annotations of SEs, including chromatin accessibility regions, methylation sites, chromatin interaction regions and topologically associating domains (TADs). (iv) Newly embedded and updated search and analysis tools, including 'Search SE by TF-based', 'Differential-Overlapping-SE analysis' and 'SE-based TF-Gene analysis'. (v) Newly provided quality control (QC) metrics for ChIP-seq processing. In summary, SEdb 2.0 is a comprehensive update of SEdb 1.0, which curates more SEs and annotation information than SEdb 1.0. SEdb 2.0 provides a friendly platform for researchers to more comprehensively clarify the important role of SEs in the biological process.

A Risk-Assessing Signature Based on Hypoxia- and Immune-Related Genes for Prognosis of Lung Adenocarcinoma Patients

Lung Adenocarcinoma (LUAD) drastically influences human health. Tumor hypoxia and immunity impact hugely on the immunotherapeutic effect of LUAD patients. This study is aimed at exploring the prognostic markers associated with hypoxia and immunity in LUAD patients and evaluates their reliability. The relationship between hypoxia and immune-related genes and prognoses of LUAD patients was investigated by the univariate regression analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) methods were used to reveal the enriched pathways and biological processes of prognosis-related genes. Univariate, LASSO, and multivariate Cox regression analyses were used to construct a prognostic signature and verify its independence. The reliability of the signature was evaluated by the Principal Component Analysis (PCA), the Kaplan-Meier (K-M) curve, and the receiver operating characteristic (ROC) curve. Gene set enrichment analysis (GSEA), tumor mutational burden (TMB), and single-sample GSEA (ssGSEA) further verified the performance of the signature. Finally, a prognostic signature for LUAD was constructed based on 7 hypoxia- and immune-related genes. According to riskScores acquired from the signature, the test set was divided into groups, where the prognosis of high-risk patients was poor. The feature genes had good reliability, and the riskScore could be used as an independent prognostic factor for LUAD patients. Meanwhile, high TMB scores and low immune scores were found in high-risk patients, and feature genes were enriched in signaling pathways such as cell cycle and p53 signaling pathway. In sum, a prognostic signature based on 7 hypoxia- and immune-related genes was constructed.

Microplastics induce immune suppression via S100A8 downregulation

Microplastic (MP) pollution has been largely reported in the daily consumption of water and food, however, the toxicities of MPs to human beings remain largely uncovered. We found that MPs in drinking water significantly impaired mouse immune function by reducing spleen weight, CD8⁺ T cell amount and raising CD4⁺ to CD8⁺ T cell ratio. We performed proteomics and phosphoproteomics by LC-MS/MS and found MPs significantly induced 130 and 57 proteins upregulated in proteome and phosphoproteome, and 191 and 37 proteins downregulated in proteome and phosphoproteome, separately. Bioinformatic analysis show that asthma, mineral absorption, and the IL-17 signaling pathway were significantly enriched and may be involved in MP-induced spleen damage and immune suppression. We verified the top 3 differentially expressed proteins and phosphoproteins by western blot, and we further showed that S100A8 was significantly downregulated by MPs via histochemistry staining. Our results revealed that MPs can induce spleen damage and immune suppression by reducing S100A8 expression, suggesting an underestimated influence and mechanism of MPs on the mammalian immune system.

S100A10 Is a New Prognostic Biomarker Related to the Malignant Molecular Features and Immunosuppression Process of Adult Gliomas

OBJECTIVE

Previous studies have demonstrated the role of S100A10 in the progression of several tumors; however, few studies have investigated its immunological characteristics in adult gliomas. In this study, we systematically explored its biological features and clinical significance in adult gliomas.

METHODS

Altogether, 325 glioma cases from the Chinese Glioma Genome Atlas and 699 glioma cases from The Cancer Genome Atlas were included as the training and validation cohorts. R software was used for data analysis and mapping using the RNA sequencing data from these cases. One-way analysis of variance and Student's t-test were used to assess the differences between the groups. Differences were considered statistically significant at P < 0.05.

RESULTS

We found that S100A10 was remarkably highly expressed in high-grade glioma, isocitrate dehydrogenase wild type, 1p19q noncodeletion type, O⁶-methylguanine-DNA methyltransferase promoter unmethylation type, and mesenchymal-like molecular subtype. S100A10 specifically and sensitively indicates the mesenchymal-like molecular subtype. Upregulated S100A10 levels were independently correlated with poor survival. S100A10-related biological processes in gliomas mainly concentrate on immunoreaction and inflammatory response. We then proved that S100A10 was positively related to most inflammatory metagenes, except IgG, including HCK, LCK, MHC II, STAT1, and interferon. More importantly, the levels of glioma-infiltrating immune cells were positively associated with the expression of S100A10, especially in tumor-related macrophages, regulatory T cells, and myeloid-derived suppressor cells.

CONCLUSIONS

S100A10 is closely related to malignant pathological subtypes, worse prognosis, and immunosuppressive immune cell infiltration in adult gliomas, making it a promising biomarker and potential target in the diagnosis, treatment, and prognostic assessment of gliomas.

Tumor endothelial cell-derived extracellular vesicles contribute to tumor microenvironment remodeling

Cancer progression involves several biological steps where angiogenesis is a key tumorigenic phenomenon. Extracellular vesicles (EVs) derived from tumor cells and other cells in the tumor microenvironment (TME) help modulate and maintain favorable microenvironments for tumors. Endothelial cells (ECs) activated by cancer-derived EVs have important roles in tumor angiogenesis. Interestingly, EVs from ECs activate tumor cells, i.e. extracellular matrix (ECM) remodeling and provide more supplements for tumor cells. Thus, EV communications between cancer cells and ECs may be effective therapeutic targets for controlling cancer progression. In this review, we describe the current knowledge on EVs derived from ECs and we examine how these EVs affect TME remodeling.

Circ_0006790 carried by bone marrow mesenchymal stem cell-derived exosomes regulates S100A11 DNA methylation through binding to CBX7 in pancreatic ductal adenocarcinoma

Extracellular vesicles, particularly exosomes, play a vital role via their cargoes. Their potential in pancreatic ductal adenocarcinoma (PDAC), one of the leading causes of cancer-related mortality worldwide is attracting interests. However, the roles and underlying mechanisms of exosomal circular RNAs (circRNAs) in the development of PDAC remain unclear yet. We aimed to illuminate the mechanisms of exosomal hsa_circ_0006790 (thereafter termed circ_6790) released by exosomes (Exo) derived from bone marrow mesenchymal stem cell (BM-MSC) during immune escape in PDAC in this study. BM-MSC-derived Exo inhibited growth, metastasis, and immune escape in PDAC. Exo enhanced circ_6790 expression in PDAC cells. Knockdown of circ_6790 in Exo significantly attenuated the anti-tumor effect of Exo. Circ_6790 facilitated the nuclear translocation of chromobox 7 (CBX7). CBX7 increased the DNA methylation of S100A11 by recruiting DNA methyltransferases to its promoter region, thereby inhibiting the transcription of S100A11. Inhibition of CBX7 or overexpression of S100A11 annulled the inhibitory effects of Exo on PDAC growth, metastasis, and immune escape. In conclusion, our results suggest that MSC-derived exosomal circ_6790 could downregulate S100A11 in PDAC cells and hamper immune escape via CBX7-catalyzed DNA hypermethylation.

The Urokinase Plasminogen Activation System in Pancreatic Cancer: Prospective Diagnostic and Therapeutic Targets

Pancreatic cancer is a highly aggressive malignancy that features high recurrence rates and the poorest prognosis of all solid cancers. The urokinase plasminogen activation system (uPAS) is strongly implicated in the pathophysiology and clinical outcomes of patients with pancreatic ductal adenocarcinoma (PDAC), which accounts for more than 90% of all pancreatic cancers. Overexpression of the urokinase-type plasminogen activator (uPA) or its cell surface receptor uPAR is a key step in the acquisition of a metastatic phenotype via multiple mechanisms, including the increased activation of cell surface localised plasminogen which generates the serine protease plasmin. This triggers multiple downstream processes that promote tumour cell migration and invasion. Increasing clinical evidence shows that the overexpression of uPA, uPAR, or of both is strongly associated with worse clinicopathological features and poor prognosis in PDAC patients. This review provides an overview of the current understanding of the uPAS in the pathogenesis and progression of pancreatic cancer, with a focus on PDAC, and summarises the substantial body of evidence that supports the role of uPAS components, including plasminogen receptors, in this disease. The review further outlines the clinical utility of uPAS components as prospective diagnostic and prognostic biomarkers for PDAC, as well as a rationale for the development of novel uPAS-targeted therapeutics.

Altered protein profile of plasma extracellular vesicles in oral squamous cell carcinoma development

Extracellular vesicles (EVs) are involved in a wide range of pathological processes and recognized as potential and novel biomarkers for oral squamous cell carcinoma (OSCC). Here, we describe the plasma EV proteome of rats with 4-nitroquinoline-1-oxide (4NQO)-induced OSCC or moderate dysplasia (MD), which can progress to OSCC, by tandem mass tag (TMT)-labeled mass spectrometry. The proteomic profiles suggest the differential expression of various proteins in MD and OSCC, some well-recognized pathological changes (e.g., translation, ATP metabolism, and mesenchymal transition), and some novel pathological changes (e.g., podosome, focal adhesion, and S100 binding). We re-examined the presence of traditional exosomal markers and the reported novel pan-EV markers. In summary, these results suggest potential EV biomarkers and underlying pathological changes in early OSCC as well as the presence of oral-derived EVs in plasma and the need for pan-EV markers. SIGNIFICANCE: This research suggests potential EV biomarkers and underlying pathological changes in early OSCC as well as the presence of oral-derived EVs in plasma and the need for pan-EV markers.

The ANXA2/S100A10 Complex—Regulation of the Oncogenic Plasminogen Receptor

The generation of the serine protease plasmin is initiated by the binding of its zymogenic precursor, plasminogen, to cell surface receptors. The proteolytic activity of plasmin, generated at the cell surface, plays a crucial role in several physiological processes, including fibrinolysis, angiogenesis, wound healing, and the invasion of cells through both the basement membrane and extracellular matrix. The seminal observation by Albert Fischer that cancer cells, but not normal cells in culture, produce large amounts of plasmin formed the basis of current-day observations that plasmin generation can be hijacked by cancer cells to allow tumor development, progression, and metastasis. Thus, the cell surface plasminogen-binding receptor proteins are critical to generating plasmin proteolytic activity at the cell surface. This review focuses on one of the twelve well-described plasminogen receptors, S100A10, which, when in complex with its regulatory partner, annexin A2 (ANXA2), forms the ANXA2/S100A10 heterotetrameric complex referred to as AIIt. We present the theme that AIIt is the quintessential cellular plasminogen receptor since it regulates the formation and the destruction of plasmin. We also introduce the term oncogenic plasminogen receptor to define those plasminogen receptors directly activated during cancer progression. We then discuss the research establishing AIIt as an oncogenic plasminogen receptor-regulated during EMT and activated by oncogenes such as SRC, RAS, HIF1α, and PML-RAR and epigenetically by DNA methylation. We further discuss the evidence derived from animal models supporting the role of S100A10 in tumor progression and oncogenesis. Lastly, we describe the potential of S100A10 as a biomarker for cancer diagnosis and prognosis.

Prognostic Values and Clinical Significance of S100 Family Member's Individualized mRNA Expression in Pancreatic Adenocarcinoma

Objective: Pancreatic adenocarcinoma (PAAD) is a common malignant tumor worldwide. S100 family (S100s) is wildly involved in regulating the occurrence, development, invasion, metastasis, apoptosis, and drug resistance of many malignant tumors. However, the expression pattern, prognostic value, and oncological role of individual S100s members in PAAD need to be elucidated.

Methods: The transcriptional expression levels of S100s were analyzed through the Oncomine and GEPIA, respectively. The protein levels of S100s members in PAAD were studied by Human Protein Atlas. The correlation between S100 mRNA expression and overall survival and tumor stage in PAAD patients was studied by GEPIA. The transcriptional expression correlation and gene mutation rate of S100s members in PAAD patients were explored by cBioPortal. The co-expression networks of S100s are identified using STRING and Gene MANIA to predict their potential functions. The correlation of S100s expression and tumor-infiltrating immune cells was tested by TIMER. Pathway activity and drug target analyzed by GSCALite.

Results: 13 S100s members were upregulated in PAAD tissues. 15 S100s members were associated with TP53 mutation. Expression levels of S100A3/A5/A6/A10/A11/A14/A16/B/P/Z were significantly correlated with the pathological stage. Prognosis analysis demonstrated that PAAD patients with low mRNA levels of S100A1/B/Z or high levels of S100A2/A3/A5/A10/A11/A14/A16 had a poor prognosis. Immuno-infiltration analysis showed that the mRNA levels of S100A10/A11/A14/A16 were correlated with the infiltration degree of macrophages in PAAD. Drug sensitivity analysis showed that PAAD expressing high levels of S100A2/A6/A10/A11/A13/A14/A16 maybe resistant to small molecule drugs.

Conclusion: This study identifies the clinical significance and biological functions of the S100s in PAAD, which may provide novel insights for the selection of prognostic biomarkers.

Development and Verification of the Hypoxia- and Immune-Associated Prognostic Signature for Pancreatic Ductal Adenocarcinoma

We aim to construct a hypoxia- and immune-associated risk score model to predict the prognosis of patients with pancreatic ductal adenocarcinoma (PDAC). By unsupervised consensus clustering algorithms, we generate two different hypoxia clusters. Then, we screened out 682 hypoxia-associated and 528 immune-associated PDAC differentially expressed genes (DEGs) of PDAC using Pearson correlation analysis based on the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression project (GTEx) dataset. Seven hypoxia and immune-associated signature genes (S100A16, PPP3CA, SEMA3C, PLAU, IL18, GDF11, and NR0B1) were identified to construct a risk score model using the Univariate Cox regression and the Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression, which stratified patients into high- and low-risk groups and were further validated in the GEO and ICGC cohort. Patients in the low-risk group showed superior overall survival (OS) to their high-risk counterparts (p < 0.05). Moreover, it was suggested by multivariate Cox regression that our constructed hypoxia-associated and immune-associated prognosis signature might be used as the independent factor for prognosis prediction (p < 0.001). By CIBERSORT and ESTIMATE algorithms, we discovered that patients in high-risk groups had lower immune score, stromal score, and immune checkpoint expression such as PD-L1, and different immunocyte infiltration states compared with those low-risk patients. The mutation spectrum also differs between high- and low-risk groups. To sum up, our hypoxia- and immune-associated prognostic signature can be used as an approach to stratify the risk of PDAC.

Calcium Binding Protein S100A16 Expedites Proliferation, Invasion and Epithelial-Mesenchymal Transition Process in Gastric Cancer

Gastric cancer (GC) is one of the most common malignant tumors of the digestive system, listed as the second cause of cancer-related deaths worldwide. S100 Calcium Binding Protein A16 (S100A16) is an acidic calcium-binding protein associated with several types of tumor progression. However, the function of S100A16 in GC is still not very clear. In this study, we analyzed S100A16 expression with the GEPIA database and the UALCAN cancer database. Meanwhile, 100 clinical GC samples were used for the evaluation of its role in the prognostic analysis. We found that S100A16 is significantly upregulated in GC tissues and closely correlated with poor prognosis in GC patients. Functional studies reveal that S100A16 overexpression triggers GC cell proliferation and migration both in vivo and in vitro; by contrast, S100A16 knockdown restricts the speed of GC cell growth and mobility. Proteomic analysis results reveal a large S100A16 interactome, which includes ZO-2 (Zonula Occludens-2), a master regulator of cell-to-cell tight junctions. Mechanistic assay results indicate that excessive S100A16 instigates GC cell invasion, migration, and epithelial-mesenchymal transition (EMT) via ZO-2 inhibition, which arose from S100A16-mediated ZO-2 ubiquitination and degradation. Our results not only reveal that S100A16 is a promising candidate biomarker in GC early diagnosis and prediction of metastasis, but also establish the therapeutic importance of targeting S100A16 to prevent ZO-2 loss and suppress GC metastasis and progression.

S100 Proteins in Pancreatic Cancer: Current Knowledge and Future Perspectives

Pancreatic cancer (PC) is a highly malignant tumor occurring in the digestive system. Currently, there is a lack of specific and effective interventions for PC; thus, further exploration regarding the pathogenesis of this malignancy is warranted. The S100 protein family, a collection of calcium-binding proteins expressed only in vertebrates, comprises 25 members with high sequence and structural similarity. Dysregulated expression of S100 proteins is a biomarker of cancer progression and prognosis. Functionally, these proteins are associated with the regulation of multiple cellular processes, including proliferation, apoptosis, growth, differentiation, enzyme activation, migration/invasion, Ca2+ homeostasis, and energy metabolism. This review highlights the significance of the S100 family in the diagnosis and prognosis of PC and its vital functions in tumor cell metastasis, invasion and proliferation. A further understanding of S100 proteins will provide potential therapeutic targets for preventing or treating PC.

Prognostic values and immune suppression of the S100A family in pancreatic cancer

S100 calcium‐binding protein A (S100A) family members regulate multiple biological functions related to pancreatic cancer (PC) progression and metastasis. However, the prognostic and oncologic values of S100A family have not been systematically investigated in PC. In the present study, the mRNA expression and potential functions of S100A family were investigated by bioinformatic analysis. Our results demonstrated that overexpression of S100A2, S100A6, S100A10, S100A11, S100A14 and S100A16 was significantly associated with higher T stage, advanced histologic grade and worse prognosis in PC. Besides, one CpG of S100A2, three CpG of S100A6, four CpG of S100A10, four CpG of S100A11, two CpG of S100A14 and five CpG of S100A16 were negatively associated with corresponding S100A family members expression and positively associated with overall survival (OS). The signature based on four CpGs showed good prediction ability of OS. Besides, S100A2 overexpression took part in the regulation of mitotic cell cycle, ECM‐receptor interaction and HIF‐1α transcription factor network. Overexpression of S100A6, S100A10, S100A11, S100A14 and S100A16 may impair the infiltration and cytolytic activity of CD8⁺ T cells through focal adhesion‐Ras‐stimulating signalling pathway in PC. Overall, this study explores the multiple prognostic values and oncologic functions of the S100A family in PC.