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

Knockdown of S100A2 inhibits the aggressiveness of endometrial cancer by activating STING pathway

BACKGROUND

Endometrial cancer is a kind of gynaecological cancer. S100A2 is a newfound biomarker to diagnose endometrial cancer. This study was to investigate the role of S100A2 on regulating migration and invasion of endometrial cancer.

METHODS

The mRNA and protein levels of S100A2 were obtained by quantitative real-time polymerase chain reaction, immunohistochemistry and western blot methods. Cell viability was measured by the Cell Counting Kit-8 assay. Cell migration and invasion were quantified using transwell assays. Western blot assay was conducted to quantify protein expressions of epithelial to mesenchymal transition-related proteins (N-cadherin and E-cadherin). Furthermore, in vivo tumour formation experiments were performed to evaluate the role of S100A2 on tumour xenografts.

RESULTS

S100A2 was significantly up-regulated in endometrial cancer tissues. Knockdown of S100A2 inhibited cell viability, migration and invasion of endometrial cancer cells. Meanwhile, STING pathway was activated by the inhibited S100A2. STING inhibitor C-176 significantly reversed the effects of S100A2 knockdown on aggressive behaviours of endometrial cancer cells. Inhibition of S100A2 dramatically suppresses the tumour growth in vivo.

CONCLUSIONS

S100A2 functions as an oncogene in endometrial cancer. Targeting S100A2 may be a promising therapeutic method to treat endometrial carcinoma.

S100A8-Mediated Inflammatory Signaling Drives Colorectal Cancer Progression via the CXCL5/CXCR2 Axis

Background: S100A8/S100A9 belong to the S100 calcium-binding protein family and play an essential role in the progression of chronic inflammation in diseases. It also regulates various biological processes such as tumor cell survival, apoptosis, and invasive metastasis. The extracellular form of S100A8/S100A9 functions by modulating cellular oxidative metabolism and facilitating inflammation-to-cancer progression. This modulation occurs through specific binding to receptors like RAGE and TLR4 and activation of signaling pathways including STAT3 and NF-κB. In tumor cells, S100A8 and S100A9 induce phenotypic changes by influencing calcium ion concentrations and other pathways. However, the precise function of high S100A8/S100A9 expression in colorectal cancer cells remains unclear. Methods: To explore the role of S100A8/S100A9 in colorectal cancer, we used immunohistochemistry and data from GEO and TCGA databases to analyze its expression in colorectal cancer cells, normal intestinal mucosa, and adjacent tissues. Functional models of high S100A8/S100A9 expression in colorectal cancer cells were established through transfection with overexpression plasmids. Protein microarrays, enzyme-linked immunosorbent assays (ELISAs), and real-time PCR were employed to assess the expression and secretion of 40 cytokines. MTT and Transwell invasion assays were conducted to evaluate changes in cell proliferation, invasion, and chemotaxis. Finally, tail vein and subcutaneous tumorigenesis assays assessed cell proliferation and migration in vivo. Results: We observed significantly higher expression of S100A8/S100A9 in colorectal cancer epithelial cells compared to normal intestinal mucosa and adjacent tissues. Overexpression of S100A8/S100A9 in mouse colon cancer cells CT26.WT led to differential increases in the secretion levels of various cytokines (CXCL5, CXCL11, GM-CSF, G-CSF, IL1a, IL1b, sTNF RI, and CCL3). Additionally, this overexpression activated signaling pathways such as STAT3, NF-κB, and ERK-MAPK. The synthesis and secretion of inflammatory factors could be inhibited by using NF-κB and ERK-MAPK pathway inhibitors. Moreover, S100A8 promotes the proliferation and invasion of colon cancer cells. Notably, the CXCR2 inhibitor (SB265610) effectively reversed the phenotypic changes induced by the CXCL5/CXCR2 biological axis. Conclusions: Our findings indicate that increased expression of S100A8 and S100A9 in colon cancer epithelial cells enhances the secretion of inflammatory factors by activating NF-κB, ERK-MAPK, and other signaling pathways. S100A8 facilitates colon cancer cell proliferation, invasion, and metastasis through the CXCL5/CXCR2 biological axis.

Fatty acid-binding protein 5 is a functional biomarker and indicator of ferroptosis in cerebral hypoxia

The progression of human degenerative and hypoxic/ischemic diseases is accompanied by widespread cell death. One death process linking iron-catalyzed reactive species with lipid peroxidation is ferroptosis, which shows hallmarks of both programmed and necrotic death in vitro. While evidence of ferroptosis in neurodegenerative disease is indicated by iron accumulation and involvement of lipids, a stable marker for ferroptosis has not been identified. Its prevalence is thus undetermined in human pathophysiology, impeding recognition of disease areas and clinical investigations with candidate drugs. Here, we identified ferroptosis marker antigens by analyzing surface protein dynamics and discovered a single protein, Fatty Acid-Binding Protein 5 (FABP5), which was stabilized at the cell surface and specifically elevated in ferroptotic cell death. Ectopic expression and lipidomics assays demonstrated that FABP5 drives redistribution of redox-sensitive lipids and ferroptosis sensitivity in a positive-feedback loop, indicating a role as a functional biomarker. Notably, immunodetection of FABP5 in mouse stroke penumbra and in hypoxic postmortem patients was distinctly associated with hypoxically damaged neurons. Retrospective cell death characterized here by the novel ferroptosis biomarker FABP5 thus provides first evidence for a long-hypothesized intrinsic ferroptosis in hypoxia and inaugurates a means for pathological detection of ferroptosis in tissue.

S-100 Proteins: Basics and Applications as Biomarkers in Animals with Special Focus on Calgranulins (S100A8, A9, and A12)

S100 proteins are a group of calcium-binding proteins which received this name because of their solubility in a 100% saturated solution of ammonium sulphate. They have a similar molecular mass of 10-12 KDa and share 25-65% similarity in their amino acid sequence. They are expressed in many tissues, and to date 25 different types of S100 proteins have been identified. This review aims to provide updated information about S100 proteins and their use as biomarkers in veterinary science, with special emphasis on the family of calgranulins that includes S100A8 (calgranulin A; myeloid-related protein 8, MRP8), S100A9 (calgranulin B; MRP14), and S100A12 (calgranulin C). The proteins SA100A8 and S100A9 can be linked, forming a heterodimer which is known as calprotectin. Calgranulins are related to the activation of inflammation and the immune system and increase in gastrointestinal diseases, inflammation and sepsis, immunomediated diseases, and obesity and endocrine disorders in different animal species. This review reflects the current knowledge about calgranulins in veterinary science, which should increase in the future to clarify their role in different diseases and potential as biomarkers and therapeutic targets, as well as the practical use of their measurement in non-invasive samples such as saliva or feces.

S100A8 and S100A9 in Cancer

S100A8 and S100A9 are Ca²⁺ binding proteins that belong to the S100 family. Primarily expressed in neutrophils and monocytes, S100A8 and S100A9 play critical roles in modulating various inflammatory responses and inflammation-associated diseases. Forming a common heterodimer structure S100A8/A9, S100A8 and S100A9 are widely reported to participate in multiple signaling pathways in tumor cells. Meanwhile, S100A8/A9, S100A8, and S100A9, mainly as promoters, contribute to tumor development, growth and metastasis by interfering with tumor metabolism and the microenvironment. In recent years, the potential of S100A8/A9, S100A9, and S100A8 as tumor diagnostic or prognostic biomarkers has also been demonstrated. In addition, an increasing number of potential therapies targeting S100A8/A9 and related signaling pathways have emerged. In this review, we will first expound on the characteristics of S100A8/A9, S100A9, and S100A8 in-depth, focus on their interactions with tumor cells and microenvironments, and then discuss their clinical applications as biomarkers and therapeutic targets. We also highlight current limitations and look into the future of S100A8/A9 targeted anti-cancer therapy.

S100A6 Protein-Expression and Function in Norm and Pathology

S100A6, also known as calcyclin, is a calcium-binding protein belonging to the S100 protein family. It was first identified and purified more than 30 years ago. Initial structural studies, focused mostly on the mode and affinity of Ca²⁺ binding and resolution of the resultant conformational changes, were soon complemented by research on its expression, localization and identification of binding partners. With time, the use of biophysical methods helped to resolve the structure and versatility of S100A6 complexes with some of its ligands. Meanwhile, it became clear that S100A6 expression was altered in various pathological states and correlated with the stage/progression of many diseases, including cancers, indicative of its important, and possibly causative, role in some of these diseases. This, in turn, prompted researchers to look for the mechanism of S100A6 action and to identify the intermediary signaling pathways and effectors. After all these years, our knowledge on various aspects of S100A6 biology is robust but still incomplete. The list of S100A6 ligands is growing all the time, as is our understanding of the physiological importance of these interactions. The present review summarizes available data concerning S100A6 expression/localization, interaction with intracellular and extracellular targets, involvement in Ca²⁺-dependent cellular processes and association with various pathologies.

Treatment Strategies and Mechanisms Associated with the Prevention of NASH-Associated HCC by a Toll-like Receptor 4 Inhibitor

We evaluated the cancer preventive efficacy of TAK-242, an inhibitor of Toll-like receptor 4 (TLR4), in a mouse model of hepatocellular carcinoma (HCC) occurring in the context of nonalcoholic steatohepatitis (NASH). We also assessed the cellular events associated with the preventive treatment efficacy. We tested oral administration of TAK-242, at clinically relevant but toxicity-reducing doses and scheduling, in mice with hepatocyte-specific deletion of Pten (HepPten-). The optimal dose and oral gavage formulation of TAK-242 were determined to be 30 mg/kg in 5% DMSO in 30% 2-hydroxypropyl-β-cyclodextrin. Daily oral administration of 30 mg/kg TAK-242 over 18 weeks was well tolerated and resulted in reduced development of tumors (lesions > 7.5 mm3) in HepPten- mice. This effect was accompanied by reduced macrovesicular steatosis and serum levels of alanine aminotransferase. In addition, 30 mg/kg TAK-242 daily treatment of small preexisting adenomas (lesions < 7.5 mm3) over 18 weeks, significantly reduced their progression to HCC. RNA sequencing identified 220 hepatic genes significantly altered upon TAK-242 treatment, that significantly correlated with tumor burden. Finally, cell deconvolution analysis revealed that TAK-242 treatment resulted in reduced hepatic populations of endothelial cells and myeloid-derived immune cells (Kupffer cells, Siglec-H high dendritic cells, and neutrophilic granule protein high neutrophils), while the proportion of mt-Nd4 high hepatocytes significantly increased, suggesting a decrease in hepatic inflammation and concomitant increase in mitochondrial function and oxidative phosphorylation upon TLR4 inhibition. In conclusion, this study identified treatment strategies and novel molecular and cellular mechanisms associated with the prevention of HCC in the context of NASH that merit further investigations.

PREVENTION RELEVANCE

Means to prevent development of HCC or progression of small adenomas to HCC in patients with NASH are urgently needed to reduce the growing mortality due to HCC. We characterized the chemopreventive effect of oral administration of the TLR4 inhibitor TAK-242 in a model of NASH-associated HCC.

Identification of tumour-infiltrating myeloid subsets associated with overall survival in lung squamous cell carcinoma

Lung squamous cell carcinoma (LUSC) is a primary subtype of lung cancer with limited therapeutic options and poor prognosis, and tumour-infiltrating myeloid cells (TIMs) are key regulators of LUSC. However, the correlation between the abundance of TIM subtypes and clinical outcomes of LUSC remains unexplored. This study aimed to develop and validate a prognostic model for low- and high-risk patients with LUSC based on myeloid cell microenvironments. TIM markers in the tumoural (T) and stromal (S) regions were quantified using immunohistochemistry for 502 LUSC patients. L1-penalized Cox regression was used to develop a myeloid survival score (MSS) model based on the training cohort, followed by validation in distinct cohorts from multiple centres. RNA sequencing and immunostaining were used to examine the mechanisms of myeloid cells in LUSC progression and predict potential drug targets and therapeutic agents. Of the 12 myeloid markers, CD163T, CD163S, and S100A12T were highly associated with overall survival (OS) in LUSC patients. The MSS of the three myeloid signatures accurately categorized LUSC patients into risk categories, with an observable difference in OS between the training and validation cohorts. Tumours with high MSS were associated with enhanced antioxidative ability and hedgehog signalling and a shift to a more pro-tumorigenic microenvironment, accompanied by a reduced tumour cell immunogenicity and increased CD8⁺ T cell exhaustion patterns. Additionally, in high-risk patients, potential drug targets and compounds regulating hedgehog signalling were identified. Our study provides the first prognostic myeloid signature for LUSC, which may help advance precision medicine. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

S100 Proteins in Fatty Liver Disease and Hepatocellular Carcinoma

Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent and slow progressing hepatic pathology characterized by different stages of increasing severity which can ultimately give rise to the development of hepatocellular carcinoma (HCC). Besides drastic lifestyle changes, few drugs are effective to some extent alleviate NAFLD and HCC remains a poorly curable cancer. Among the deregulated molecular mechanisms promoting NAFLD and HCC, several members of the S100 proteins family appear to play an important role in the development of hepatic steatosis, non-alcoholic steatohepatitis (NASH) and HCC. Specific members of this Ca²⁺-binding protein family are indeed significantly overexpressed in either parenchymal or non-parenchymal liver cells, where they exert pleiotropic pathological functions driving NAFLD/NASH to severe stages and/or cancer development. The aberrant activity of S100 specific isoforms has also been reported to drive malignancy in liver cancers. Herein, we discuss the implication of several key members of this family, e.g., S100A4, S100A6, S100A8, S100A9 and S100A11, in NAFLD and HCC, with a particular focus on their intracellular versus extracellular functions in different hepatic cell types. Their clinical relevance as non-invasive diagnostic/prognostic biomarkers for the different stages of NAFLD and HCC, or their pharmacological targeting for therapeutic purpose, is further debated.

Influence of S100A2 in Human Diseases

S100 proteins are a family of low-molecular-weight proteins characterized by two calcium-binding sites with a helix-loop-helix (“EF-hand-type”) domain. The S100 family of proteins is distributed across various organs and can interact with diverse molecules. Among the proteins of the S100 family, S100 calcium-binding protein A2 (S100A2) has been identified in mammary epithelial cells, glands, lungs, kidneys, and prostate gland, exhibiting various physiological and pathological actions in human disorders, such as inflammatory diseases and malignant tumors. In this review, we introduce basic knowledge regarding S100A2 regulatory mechanisms. Although S100A2 is a tumor suppressor, we describe the various influences of S100A2 on cancer and inflammatory diseases.

Identification of Novel Genes Involved in Hyperglycemia in Mice

Current attempts to prevent and manage type 2 diabetes have been moderately effective, and a better understanding of the molecular roots of this complex disease is important to develop more successful and precise treatment options. Recently, we initiated the collective diabetes cross, where four mouse inbred strains differing in their diabetes susceptibility were crossed with the obese and diabetes-prone NZO strain and identified the quantitative trait loci (QTL) Nidd13/NZO, a genomic region on chromosome 13 that correlates with hyperglycemia in NZO allele carriers compared to B6 controls. Subsequent analysis of the critical region, harboring 644 genes, included expression studies in pancreatic islets of congenic Nidd13/NZO mice, integration of single-cell data from parental NZO and B6 islets as well as haplotype analysis. Finally, of the five genes (Acot12, S100z, Ankrd55, Rnf180, and Iqgap2) within the polymorphic haplotype block that are differently expressed in islets of B6 compared to NZO mice, we identified the calcium-binding protein S100z gene to affect islet cell proliferation as well as apoptosis when overexpressed in MIN6 cells. In summary, we define S100z as the most striking gene to be causal for the diabetes QTL Nidd13/NZO by affecting β-cell proliferation and apoptosis. Thus, S100z is an entirely novel diabetes gene regulating islet cell function.