Expression of MRP14 gene is frequently down-regulated in Chinese human esophageal cancer

Urinary protein biomarker panel predicts esophageal squamous carcinoma from control cases and other tumors

PURPOSE

Discovery of noninvasive urinary biomarkers for the early diagnosis of esophageal squamous carcinoma (ESCC).

METHODS

We conducted proteomic analyses of 499 human urine samples obtained from healthy individuals (n = 321) and ESCC (n = 83), bladder cancer (n = 17), breast cancer (n = 12), colorectal cancer (n = 16), lung cancer (n = 33) and thyroid cancer (n = 17) patients from multiple medical centers. Those samples were divided into a discovery set (n = 247) and an independent validation set (n = 157).

RESULTS

Among urinary proteins identified in the comprehensive quantitative proteomics analysis, we selected a panel of three urinary biomarkers (ANXA1, S100A8, TMEM256), and established a logistic regression model in the discovery set that can correctly classify the majority of ESCC cases in the validation sets with the area under the curve (AUC) values of 0.825. This urinary biomarker panel not only discriminates ESCC patients from healthy individuals but also differentiates ESCC from other common tumors. Notably, the panel distinguishes stage I ESCC patients from healthy individuals with AUC values of 0.886. On the analysis of stage-specific biomarkers, another combination panel of protein (ANXA1, S100A8, SOD3, TMEM256) demonstrated a good AUC value of 0.792 for stage I ESCC.

CONCLUSIONS

Urinary biomarker panel represents a promising auxiliary diagnostic tool for ESCC, including early-stage ESCC.

Serum proteomics unveil characteristic protein diagnostic biomarkers and signaling pathways in patients with esophageal squamous cell carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is a common digestive tract malignant tumor with high incidence and dismal prognosis worldwide. However, the reliable biomarkers for clinical diagnosis and the underlying signaling pathways insights of ESCC are not unequivocally understood yet. The serum proteome may provide valuable clues for the early diagnosis of ESCC and the discovery of novel molecular insights.

Methods

In the current study, an optimized proteomics approach was employed to discover novel serum-based biomarkers for ESCC, and unveil abnormal signal pathways. Gene ontology (GO) enrichment analysis was done by Gene Set Enrichment Analysis (GSEA) and Metascape database, respectively. Pathway analysis was accomplished by GeneCards database. The correlation coefficient was assessed using Pearson and distance correlation analyses. Prioritized candidates were further verified in two independent validation sets by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) staining.

Results

A total of 633 non-redundant proteins were identified in the serum of patients with ESCC, of which 59 and 10 proteins displayed a more than 1.5-fold increase or decrease compared with healthy controls. Verification was performed for six candidate biomarkers, including S100A8/A9, SAA1, ENO1, TPI1 and PGAM1. Receiver operating characteristics (ROC) curve plotting showed the high diagnostic sensitivity and specificity of these six protein molecules as a biomarker panel: the area under characteristic curve (AUC) is up to 0.945. Differentially expressed proteins were subjected to functional enrichment analysis, which revealed the dysregulation of signaling pathways mainly involved in glycolysis, TLR4, HIF-1α, Cori cycle, TCA cycle, folate metabolism, and platelet degranulation. The latter finding was all the more noteworthy as a strong positive correlation was discovered between activated glycolysis and TLR4 pathways and unfavorable clinicopathological TNM stages in ESCC.

Conclusions

Our findings propose a potential serum biomarker panel for the early detection and diagnosis of ESCC, which could potentially broaden insights into the characteristics of ESCC from the proteomic perspective.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12014-022-09357-x.

S100A8/A9 Induced by Interaction with Macrophages in Esophageal Squamous Cell Carcinoma Promotes the Migration and Invasion of Cancer Cells via Akt and p38 MAPK Pathways

Tumor-associated macrophages are associated with more malignant phenotypes of esophageal squamous cell carcinoma (ESCC) cells. Previously, an indirect co-culture assay of ESCC cells and macrophages was used to identify several factors associated with ESCC progression. Herein, a direct co-culture assay of ESCC cells and macrophages was established, which more closely simulated the actual cancer microenvironment. Direct co-cultured ESCC cells had significantly increased migration and invasion abilities, and phosphorylation levels of Akt and p38 mitogen-activated protein kinase (MAPK) compared with monocultured ESCC cells. According to a cDNA microarray analysis between monocultured and co-cultured ESCC cells, both the expression and release of S100 calcium binding protein A8 and A9 (S100A8 and S100A9), which commonly exist and function as a heterodimer (herein, S100A8/A9), were significantly enhanced in co-cultured ESCC cells. The addition of recombinant human S100A8/A9 protein induced migration and invasion of ESCC cells via Akt and p38 MAPK signaling. Both S100A8 and S100A9 silencing suppressed migration, invasion, and phosphorylation of Akt and p38 MAPK in co-cultured ESCC cells. Moreover, ESCC patients with high S100A8/A9 expression exhibited significantly shorter disease-free survival (P = 0.005) and cause-specific survival (P = 0.038). These results suggest that S100A8/A9 expression and release in ESCC cells are enhanced by direct co-culture with macrophages and that S100A8/A9 promotes ESCC progression via Akt and p38 MAPK signaling pathways.

Single-cell transcriptomic analysis reveals the critical molecular pattern of UV-induced cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the second most common nonmelanoma skin cancer characterized by high invasiveness, heterogeneity, and mainly occurs in the ultraviolet (UV)-exposed regions of the skin, but its pathogenesis is still unclear. Here, we generated single-cell transcriptome profiles for 350 cells from six primary UV-induced cSCCs, together with matched adjacent skin samples, and three healthy control skin tissues by single-cell RNA-sequencing technology based on Smart-seq2 strategy. A series of bioinformatics analyses and in vitro experiments were used to decipher and validate the critical molecular pattern of cSCC. Results showed that cSCC cells and normal keratinocytes were significantly distinct in gene expression and chromosomal copy number variation. Furthermore, cSCC cells exhibited 18 hallmark pathways of cancer by gene set enrichment analysis. Differential expression analysis demonstrated that many members belonging to S100 gene family, SPRR gene family, and FABP5 were significantly upregulated in cSCC cells. Further experiments confirmed their upregulation and showed that S100A9 or FABP5 knockdown in cSCC cells inhibited their proliferation and migration through NF-κB pathway. Taken together, our data provide a valuable resource for deciphering the molecular pattern in UV-induced cSCC at a single-cell level and suggest that S100A9 and FABP5 may provide novel targets for therapeutic intervention of cSCC in the future.

The expression of S100A8/S100A9 is inducible and regulated by the Hippo/YAP pathway in squamous cell carcinomas

Background

S100A8 and S100A9, two heterodimer-forming members of the S100 family, aberrantly express in a variety of cancer types. However, little is known about the mechanism that regulates S100A8/S100A9 co-expression in cancer cells.

Methods

The expression level of S100A8/S100A9 measured in three squamous cell carcinomas (SCC) cell lines and their corresponding xenografts, as well as in 257 SCC tissues. The correlation between S100A8/S100A9, Hippo pathway and F-actin cytoskeleton were evaluated using western blot, qPCR, ChIP and Immunofluorescence staining tests. IncuCyte ZOOM long time live cell image monitoring system, qPCR and Flow Cytometry measured the effects of S100A8/S100A9 and YAP on cell proliferation, cell differentiation and apoptosis.

Results

Here, we report that through activation of the Hippo pathway, suspension and dense culture significantly induce S100A8/S100A9 co-expression and co-localization in SCC cells. Furthermore, these expressional characteristics of S100A8/S100A9 also observed in the xenografts derived from the corresponding SCC cells. Importantly, Co-expression of S100A8/S100A9 detected in 257 SCC specimens derived from five types of SCC tissues. Activation of the Hippo pathway by overexpression of Lats1, knockdown of YAP, as well as disruption of F-actin indeed obviously results in S100A8/S100A9 co-expression in attached SCC cells. Conversely, inhibition of the Hippo pathway leads to S100A8/S100A9 co-expression in a manner opposite of cell suspension and dense. In addition, we found that TEAD1 is required for YAP-induced S100A8/S100A9-expressions. The functional studies provide evidence that knockdown of S100A8/S100A9 together significantly inhibit cell proliferation but promote squamous differentiation and apoptosis.

Conclusions

Our findings demonstrate for the first time that the expression of S100A8/S100A9 is inducible by changes of cell shape and density through activation of the Hippo pathway in SCC cells. Induced S100A8/S100A9 promoted cell proliferation, inhibit cell differentiation and apoptosis.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5784-0) contains supplementary material, which is available to authorized users.

Urinary biomarkers for the diagnosis of cervical cancer by quantitative label-free mass spectrometry analysis

Due to the invasive procedure associated with Pap smears for diagnosing cervical cancer and the conservative culture of developing countries, identifying less invasive biomarkers is of great interest. Quantitative label-free mass spectrometry was performed to identify potential biomarkers in the urine samples of patients with cervical cancer. This technique was used to study the differential expression of urinary proteomes between normal individuals and cancer patients. The alterations in the levels of urinary proteomes in normal and cancer patients were analyzed by Progenesis label-free software and the results revealed that 60 proteins were upregulated while 73 proteins were downregulated in patients with cervical cancer. This method could enrich high molecular weight proteins from 100 kDa. The protein-protein interactions were obtained by Search Tool for the Retrieval of Interacting Genes/Proteins analysis and predicted the biological pathways involving various functions including cell-cell adhesion, blood coagulation, metabolic processes, stress response and the regulation of morphogenesis. Two notable upregulated urinary proteins were leucine-rich α-2-glycoprotein (LRG1) and isoform-1 of multimerin-1 (MMRN1), while the 3 notable downregulated proteins were S100 calcium-binding protein A8 (S100A8), serpin B3 (SERPINB3) and cluster of differentiation-44 antigen (CD44). The validation of these 5 proteins was performed by western blot analysis and the biomarker sensitivity of these proteins was analyzed individually and in combination with receiver operator characteristic curve (ROC) analysis. Quantitative mass spectrometry analysis may allow for the identification of urinary proteins of high molecular weight. The proteins MMRN1 and LRG1 were presented, for the first time, to be highly expressed urinary proteins in cervical cancer. ROC analysis revealed that LRG1 and SERPINB3 could be individually used, and these 5 proteins could also be combined, to detect the occurrence of cervical cancer.

Effect of tumor microenvironment on pathogenesis of the head and neck squamous cell carcinoma: a systematic review

The tumor microenvironment (TME) is comprised of many different cell populations, such as cancer-associated fibroblasts and various infiltrating immune cells, and non-cell components of extracellular matrix. These crucial parts of the surrounding stroma can function as both positive and negative regulators of all hallmarks of cancer development, including evasion of apoptosis, induction of angiogenesis, deregulation of the energy metabolism, resistance to the immune detection and destruction, and activation of invasion and metastasis. This review represents a summary of recent studies focusing on describing these effects of microenvironment on initiation and progression of the head and neck squamous cell carcinoma, focusing on oral squamous cell carcinoma, since it is becoming clear that an investigation of differences in stromal composition of the head and neck squamous cell carcinoma microenvironment and their impact on cancer development and progression may help better understand the mechanisms behind different responses to therapy and help define possible targets for clinical intervention.

A subset of calcium-binding S100 proteins show preferential heterodimerization

The assembly of proteins into dimers and oligomers is a necessary step for the proper function of transcription factors, muscle proteins, and proteases. In uncontrolled states, oligomerization can also contribute to illnesses such as Alzheimer's disease. The S100 protein family is a group of dimeric proteins that have important roles in enzyme regulation, cell membrane repair, and cell growth. Most S100 proteins have been examined in their homodimeric state, yet some of these important proteins are found in similar tissues implying that heterodimeric molecules can also be formed from the combination of two different S100 members. In this work, we have established co-expression methods in order to identify and quantify the distribution of homo- and heterodimers for four specific pairs of S100 proteins in their calcium-free states. The split GFP trap methodology was used in combination with other GFP variants to simultaneously quantify homo- and heterodimeric S100 proteins in vitro and in living cells. For the specific S100 proteins examined, NMR, mass spectrometry, and GFP trap experiments consistently show that S100A1:S100B, S100A1:S100P, and S100A11:S100B heterodimers are the predominant species formed compared to their corresponding homodimers. We expect the tools developed here will help establish the roles of S100 heterodimeric proteins and identify how heterodimerization might alter the specificity for S100 protein action in cells.

A nutrigenetic approach for investigating the chemopreventive effects of black raspberries during the development of preneoplastic esophagi in rats

BACKGROUND

Large epidemiological studies have shown that diets high in fruits reduce the risk of esophageal squamous cell carcinoma (ESCC).

OBJECTIVE

The current study investigated the effects of black raspberries (BRBs) on gene expression during the development of preneoplastic esophagi in rats.

METHODS

Using a post-initiation protocol, F344 rats were injected with N-nitrosomethylbenzylamine (NMBA) and then fed either a control diet or 5% BRBs. At weeks 9, 15, and 35, we euthanized subgroups of the rats and collected preneoplastic esophagi to isolate RNA samples for DNA microarray.

RESULTS

Along the development of NMBA-induced preneoplastic esophagi, NMBA injections led to differential expression of 1181 genes comparing to control rats, and dietary BRBs modulated 428 genes in esophagi from NMBA-treated rats. There are 137 common genes between 1181 and 428 gene sets, and BRBs significantly reversed the expression of 133 genes. These genes are associated with multiple gene oncology functions. BRBs induced an 8.8-fold gene enrichment on the pathway of inflammatory response and regulated 10 genes involved in this pathway. Among them, BRBs significantly reversed the expression of pro-inflammatory cytokines, such as CCL2, S100A8, and IL19.

CONCLUSIONS

BRBs exhibit strong anti-inflammatory effects against NMBA-induced rat esophageal tumorigenesis.

Comparative two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) of human milk to identify dysregulated proteins in breast cancer

Breast cancer (BC) remains a major cause of mortality, and early detection is considered important for reducing BC-associated deaths. Early detection of BC is challenging in young women, due to the limitations of mammography on the dense breast tissue of young women. We recently reported results of a pilot proteomics study, using one-dimensional polyacrylamide gel electrophoresis (1D-PAGE) and mass spectrometry (MS) to investigate differences in milk proteins from women with and without BC. Here, we applied two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and MS to compare the protein pattern in milk from the breasts of a single woman who was diagnosed with BC in one breast 24 months after donating her milk. Statistically different gel spots were picked for protein digestion followed by nanoliquid chromatography tandem MS (nanoLC-MS/MS) analysis. The upregulated proteins in BC versus control are alpha-amylase, gelsolin isoform a precursor, alpha-2-glycoprotein 1 zinc isoform CRA_b partial, apoptosis-inducing factor 2 and vitronectin. Several proteins were downregulated in the milk of the breast later diagnosed with cancer as compared to the milk from the healthy breast, including different isoforms of albumin, cholesterol esterase, different isoforms of lactoferrin, different proteins from the casein family and different isoforms of lysozyme. Results warrant further studies to determine the usefulness of these milk proteins for assessing risk and detecting occult disease. MS data is available via ProteomeXchange with identifier PXD009860.

Calprotectin and the Initiation and Progression of Head and Neck Cancer

Calprotectin (S100A8/A9), a heterodimeric complex of calcium-binding proteins S100A8 and S100A9, is encoded by genes mapping to the chromosomal locus 1q21.3 of the epidermal differentiation complex. Whereas extracellular calprotectin shows proinflammatory and antimicrobial properties by signaling through RAGE and TLR4, intracytoplasmic S100A8/A9 appears to be important for cellular development, maintenance, and survival. S100A8/A9 is constitutively expressed in myeloid cells and the stratified mucosal epithelia lining the oropharyngeal and genitourinary mucosae. While upregulated in adenocarcinomas and other cancers, calprotectin mRNA and protein levels decline in head and neck squamous cell carcinoma (HNSCC). S100A8/A9 is also lost during head and neck preneoplasia (dysplasia). Calprotectin decrease does not correlate with the clinical stage (TNM) of HNSCC. When expressed in carcinoma cells, S100A8/A9 downregulates matrix metalloproteinase 2 expression and inhibits invasion and migration in vitro. S100A8/A9 regulates cell cycle progression and decelerates cancer cell proliferation by arresting at the G2/M checkpoint in a protein phosphatase 2α-dependent manner. In HNSCC, S100A8 and S100A9 coregulate with gene networks controlling cellular development and differentiation, cell-to-cell signaling, and cell morphology, while S100A8/A9 appears to downregulate expression of invasion- and tumorigenesis-associated genes. Indeed, tumor formation capacity is attenuated in S100A8/A9-expressing carcinoma cells in vivo. Hence, intracellular calprotectin appears to function as a tumor suppressor in head and neck carcinogenesis. When compared with S100A8/A9-low HNSCC based on analysis of TCGA, S100A8/A9-high HNSCC shows significant upregulation of apoptosis-related genes, including multiple caspases. Accordingly, S100A8/A9 facilitates DNA damage responses in HNSCC, promotes apoptotic cell death, and confers sensitivity to cisplatin and X-radiation in vitro. In the tumor milieu, loss of S100A8/A9 strongly associates with poor squamous differentiation and higher tumor grading, EGFR upregulation, increased DNA methylation, and, finally, poorer overall survival for patients with HNSCC. Hence, intracellular calprotectin shows a multifaceted protective role against the development of HNSCC.

Involvement of calprotectin (S100A8/A9) in molecular pathways associated with HNSCC

Calprotectin (S100A8/A9), a heterodimeric protein complex of calcium-binding proteins S100A8 and S100A9, plays key roles in cell cycle regulation and inflammation, with potential functions in squamous cell differentiation. While upregulated in many cancers, S100A8/A9 is downregulated in squamous cell carcinomas of the cervix, esophagus, and the head and neck (HNSCC). We previously reported that ectopic S100A8/A9 expression inhibits cell cycle progression in carcinoma cells. Here, we show that declining expression of S100A8/A9 in patients with HNSCC is associated with increased DNA methylation, less differentiated tumors, and reduced overall survival. Upon ectopic over-expression of S100A8/A9, the cancer phenotype of S100A8/A9-negative carcinoma cells was suppressed in vitro and tumor growth in vivo was significantly decreased. MMP1, INHBA, FST, LAMC2, CCL3, SULF1, and SLC16A1 were significantly upregulated in HNSCC but were downregulated by S100A8/A9 expression. Our findings strongly suggest that downregulation of S100A8/A9 through epigenetic mechanisms may contribute to increased proliferation, malignant transformation, and disease progression in HNSCC.

Gene function analysis and underlying mechanism of esophagus cancer based on microarray gene expression profiling

Esophageal cancer (EC) is one of the most common digestive malignant tumors worldwide. Over the past decades, there have been minimal improvements in outcomes for patients with EC. New targets and novel therapies are needed to improve outcomes for these patients. This study aimed to explore the molecular mechanisms of EC by integrated bioinformatic analyses of the feature genes associated with EC and correlative gene functions which can distinguish cancerous tissues from non-cancerous tissues. Gene expression profile GSE20347 was downloaded from Gene Expression Omnibus (GEO) database, including 17 EC samples and their paired adjacent non-cancerous samples. The differentially expressed genes (DEGs) between EC and normal specimens were identified and then applied to analyze the GO enrichment on gene functions and KEGG pathways. Corresponding Pathway Relation Network (Pathway-net) and Gene Signal Network (signal-net) of DEGs were established based on the data collected from GCBI datasets. The results showed that DEGs mainly participated in the process of cell adhesion, cell proliferation, survival, invasion, metastasis and angiogenesis. Aberrant expression of PTK2, MAPK signaling pathway, PI3K-Akt signaling pathway, p53 signaling pathway and MET were closely associated with EC carcinogenesis. Importantly, Interleukin 8 (IL8) and C-X-C chemokine receptor type 7 (CXCR-7) were predicted to be significantly related to EC. These findings were further validated by analyzing both TCGA database and our clinical samples of EC. Our discovery provides a registry of genes and pathways that are disrupted in EC, which has the potential to be used in clinic for diagnosis and target therapy of EC in future.

Cellular Distribution and Gene Expression Pattern of Metastasin (S100A4), Calgranulin A (S100A8), and Calgranulin B (S100A9) in Oral Lesions as Markers for Molecular Pathology

The objective of this study was to analyze cellular localization and expression levels of oncologic relevant members of the S100 family in common oral lesions.Biopsies of various oral lesions were analyzed. S100A4 showed a higher expression rate in leukoplakias and oral squamous cell carcinomas. Transcript levels of S100A8 and S100A9 were significantly decreased in malignant OSCCs. A correlation could be drawn between the expression levels of these genes and the pathological characteristics of the investigated lesions. S100A4, A8, and A9 proteins represent promising marker genes to evaluate the risk potential of suspicious oral lesions in molecular pathology.

Enhancement of radiosensitivity of lung adenocarcinoma using a decoction from the Fuzhengzengxiao formula

OBJECTIVE

To study the effects of a decoction of Fuzhengzengxiao formula on lung adenocarcinoma regarding the inflammatory protein S100A9 known to enhance cancer cell sensitivity.

METHODS

A nude mouse model of human lung adenocarcinoma was established. The mice were randomly divided into four groups using the random number table method: Group I, control; Group II, treatment with a decoction of the Fuzhengzengxiao formula alone; Group III, treatment with radiotherapy alone; and Group IV, treatment with radiotherapy plus a decoction of Fuzhengzengxiao formula. When the tumor body was 1 cm3 in diameter, the tumor bearing mice in Groups III and IV were irradiated at a single dose of 10 Gy and the tumor inhibition rate was evaluated. The expression of S100A9 was determined using Western blotting and q-PCR (Real-time Quantitative PCR Detecting System). The sensitivity of cells containing RNAi S100A9 to radiotherapy was evaluated using the Click multiple target model,and the cell cycle was analyzed using flow cytometry.

RESULTS

Relative to the control group, the expression of S100A9 in the tumors in each treatment group was decreased, especially in Group IV. The sensitizing enhancement ratio (SER) Dq was > 1 after RNAi S100A9; it decreased the surviving fraction after a 2 Gy dose exposure,and also the D0 and Dq of the tumor cells; in addition, the radiosensitivity of G2/M cells was significantly increased.

CONCLUSION

The decoction of the Fuzhengzengxiao formula downregulated the expression of S100A9 in lung adenocarcinoma cells.

S100A8 is a novel therapeutic target for anaplastic thyroid carcinoma

CONTEXT

Anaplastic thyroid carcinoma (ATC) is one of the most deadly human malignancies. It is 99% lethal, and patients have a median survival of only 6 months after diagnosis. Despite these grim statistics, the mechanism underlying the tumorigenic capability of ATC cells is unclear.

OBJECTIVE

S100A8 and S100A9 proteins have emerged as critical mediators in cancer. The aim was to investigate the expression and function of S100A8 and S100A9 in ATC and the mechanisms involved.

DESIGN

We determined the expression of S100A8 and S100A9 in human ATC by gene array analysis and immunohistochemistry. Using RNAi-mediated stable gene knockdown in human ATC cell lines and bioluminescent imaging of orthotopic and lung metastasis mouse models of human ATC, we investigated the effects of S100A8 and S100A9 on tumorigenesis and metastasis.

RESULTS

We demonstrated that S100A8 and S100A9 were overexpressed in ATC but not in other types of thyroid carcinomas. In vivo analysis in mice using ATC cells that had S100A8 knocked down revealed reduced tumor growth and lung metastasis, as well as significantly prolonged animal survival. Mechanistic investigations showed that S100A8 promotes ATC cell proliferation through an interaction with RAGE, which activates the p38, ERK1/2 and JNK signaling pathways in the tumor cells.

CONCLUSIONS

These findings establish a novel role for S100A8 in the promoting and enhancing of ATC progression. They further suggest that the inhibition of S100A8 could represent a relevant therapeutic target, with the potential of enabling a more effective treatment path for this deadly disease.

Downregulation of S100 Calcium Binding Protein A9 in Esophageal Squamous Cell Carcinoma

The development of esophageal squamous cell carcinoma (ESCC) is poorly understood and the major regulatory molecules involved in the process of tumorigenesis have not yet been identified. We had previously employed a quantitative proteomic approach to identify differentially expressed proteins in ESCC tumors. A total of 238 differentially expressed proteins were identified in that study including S100 calcium binding protein A9 (S100A9) as one of the major downregulated proteins. In the present study, we carried out immunohistochemical validation of S100A9 in a large cohort of ESCC patients to determine the expression and subcellular localization of S100A9 in tumors and adjacent normal esophageal epithelia. Downregulation of S100A9 was observed in 67% (n = 192) of 288 different ESCC tumors, with the most dramatic downregulation observed in the poorly differentiated tumors (99/111). Expression of S100A9 was restricted to the prickle and functional layers of normal esophageal mucosa and localized predominantly in the cytoplasm and nucleus whereas virtually no expression was observed in the tumor and stromal cells. This suggests the important role that S100A9 plays in maintaining the differentiated state of epithelium and suggests that its downregulation may be associated with increased susceptibility to tumor formation.

High S100A8 and S100A12 protein expression is a favorable prognostic factor for survival of oropharyngeal squamous cell carcinoma

S100/calgranulins (S100A8, S100A9 and S100A12) are key players of innate immune function and elevated levels are a characteristic feature of acute and chronic inflammation, and inflammation-associated carcinogenesis. However, reduced S100A8 and S100A9 expression has been detected for squamous cell carcinoma, including the head and neck region (HNSCC), which originate from mucosal epithelia with abundant expression of both proteins under physiological conditions. In contrast to S100A8 and S100A9, only sparse information is available for S100A12 and a comparative study of all three S100/calgranulins in HNSCC is still missing. We analyzed S100/calgranulin protein levels in a retrospective patient cohort (n = 131) of oropharyngeal squamous cell carcinoma (OPSCC) by immunohistochemical staining of tissue microarrays. Common characteristics of all three S100/calgranulins were: (i) abundant expression in supra-basal keratinocytes of normal mucosa with predominant nuclear staining, (ii) low expression in 30.4-51.9% of primary OPSCCs and (iii) variable accumulation of S100/calgranulin-positive immune cells in the tumor stroma. These features were associated with histopathological characteristics, such as tumor grade, lymph node metastasis and tumor stage. Furthermore, univariate and multivariate analysis revealed worse overall survival of OPSCC patients with simultaneous reduction of S100A8 and S100A12 expression, while expression of S100A9 or presence of the S100A8/S100A9 heterodimer had no impact, suggesting distinct regulation and function of individual S100/calgranulins in the pathogenesis of HNSCCs.

S100A8/A9 regulates MMP-2 expression and invasion and migration by carcinoma cells

Intracellular calprotectin (S100A8/A9) functions in the control of the cell cycle checkpoint at G2/M. Dysregulation of S100A8/A9 appears to cause loss of the checkpoint, which frequently characterizes head and neck squamous cell carcinoma (HNSCC). In the present study, we analyzed carcinoma cells for other S100A8/A9-directed changes in malignant phenotype. Using a S100A8/A9-negative human carcinoma cell line (KB), transfection to express S100A8 and S100A9 caused selective down-regulation of MMP-2 and inhibited in vitro invasion and migration. Conversely, silencing of endogenous S100A8 and S100A9 expression in TR146 cells, a well-differentiated HNSCC cell line, increased MMP-2 activity and in vitro invasion and migration. When MMP-2 expression was silenced, cells appeared to assume a less malignant phenotype. To more closely model the architecture of cell growth in vivo, cells were grown in a 3D collagen substrate, which was compared to 2D. Growth on 3D substrates caused greater MMP-2 expression. Whereas hypermethylation of CpG islands occurs frequently in HNSCC, S100A8/A9-dependent regulation of MMP-2 could not be explained by modification of the upstream promoters of MMP2 or TIMP2. Collectively, these results suggest that intracellular S100A8/A9 contributes to the cancer cell phenotype by modulating MMP-2 expression and activity to regulate cell migration and mobility.

Clinicopathological roles of S100A8 and S100A9 in cutaneous squamous cell carcinoma in vivo and in vitro

S100A8 and S100A9 are members of the S100 protein family and exist in neutrophils, monocytes, and macrophages. Recent studies have shown that S100A8 and S100A9 are associated with various neoplastic disorders; however, their roles in cutaneous squamous cell carcinoma (SCC) are not well defined. To investigate the expression and function of S100A8 and S100A9 in skin tumors, we examined the expression levels of S100A8 and S100A9 between premalignant and malignant skin tumors and investigated the functional roles of S100A8 and S100A9 in vitro and in vivo using recombinant adenovirus expressing S100A8 or S100A9. The immunopositive staining rates and intensities of S100A8 and S100A9 were higher in SCC than in premalignant skin tumors. When S100A8 and/or S100A9 were overexpressed in SCC12 cells using a recombinant adenovirus, cell growth and motility were increased. Similarly, when mouse skin was intradermally injected with SCC12 cells overexpressing S100A8 and/or S100A9, there were remarkable increases in tumor growth and volume. Both S100A8 and S100A9 are highly expressed in cutaneous SCC and play important roles in tumorigenesis. We suggest that S100A8 and S100A9 may be potential therapeutic targets for the prevention or treatment of SCC in skin.

S100A8/A9 (calprotectin) negatively regulates G2/M cell cycle progression and growth of squamous cell carcinoma

Malignant transformation results in abnormal cell cycle regulation and uncontrolled growth in head and neck squamous cell carcinoma (HNSCC) and other cancers. S100A8/A9 (calprotectin) is a calcium-binding heterodimeric protein complex implicated in cell cycle regulation, but the specific mechanism and role in cell cycle control and carcinoma growth are not well understood. In HNSCC, S100A8/A9 is downregulated at both mRNA and protein levels. We now report that downregulation of S100A8/A9 correlates strongly with a loss of cell cycle control and increased growth of carcinoma cells. To show its role in carcinogenesis in an in vitro model, S100A8/A9 was stably expressed in an S100A8/A9-negative human carcinoma cell line (KB cells, HeLa-like). S100A8/A9 expression increases PP2A phosphatase activity and p-Chk1 (Ser345) phosphorylation, which appears to signal inhibitory phosphorylation of mitotic p-Cdc25C (Ser216) and p-Cdc2 (Thr14/Tyr15) to inactivate the G2/M Cdc2/cyclin B1 complex. Cyclin B1 expression then downregulates and the cell cycle arrests at the G2/M checkpoint, reducing cell division. As expected, S100A8/A9-expressing cells show both decreased anchorage-dependent and -independent growth and mitotic progression. Using shRNA, silencing of S100A8/A9 expression in the TR146 human HNSCC cell line increases growth and survival and reduces Cdc2 inhibitory phosphorylation at Thr14/Tyr15. The level of S100A8/A9 endogenous expression correlates strongly with the reduced p-Cdc2 (Thr14/Tyr14) level in HNSCC cell lines, SCC-58, OSCC-3 and UMSCC-17B. S100A8/A9-mediated control of the G2/M cell cycle checkpoint is, therefore, a likely suppressive mechanism in human squamous cell carcinomas and may suggest new therapeutic approaches.

Review of S100A9 biology and its role in cancer

S100A9 is a calcium binding protein with multiple ligands and post-translation modifications that is involved in inflammatory events and the initial development of the cancer cell through to the development of metastatic disease. This review has a threefold purpose: 1) describe the S100A9 structural elements important for its biological activity, 2) describe the S100A9 biology in the context of the immune system, and 3) illustrate the role of S100A9 in the development of malignancy via interactions with the immune system and other cellular processes.

Presence of S100A9-positive inflammatory cells in cancer tissues correlates with an early stage cancer and a better prognosis in patients with gastric cancer

Background

S100A9 was originally discovered as a factor secreted by inflammatory cells. Recently, S100A9 was found to be associated with several human malignancies. The purpose of this study is to investigate S100A9 expression in gastric cancer and explore its role in cancer progression.

Methods

S100A9 expression in gastric tissue samples from 177 gastric cancer patients was assessed by immunohistochemistry. The expression of its dimerization partner S100A8 and the S100A8/A9 heterodimer were also assessed by the same method. The effect of exogenous S100A9 on motility of gastric cancer cells AGS and BGC-823 was then investigated.

Results

S100A9 was specifically expressed by inflammatory cells such as macrophages and neutrophils in human gastric cancer and gastritis tissues. Statistical analysis showed that a high S100A9 cell count (> = 200) per 200x magnification microscopic field in cancer tissues was predictive of early stage gastric cancer. High S100A9-positive cell count was negatively correlated with lymph node metastasis (P = 0.009) and tumor invasion (P = 0.011). S100A9 was identified as an independent prognostic predictor of overall survival of patients with gastric cancer (P = 0.04). Patients with high S100A9 cell count were with favorable prognosis (P = 0.021). Further investigation found that S100A8 distribution in human gastric cancer tissues was similar to S100A9. However, the number of S100A8-positive cells did not positively correlate with patient survival. The inflammatory cells infiltrating cancer were S100A8/A9 negative, while those in gastritis were positive. Furthermore, exogenous S100A9 protein inhibited migration and invasion of gastric cancer cells.

Conclusions

Our results suggested S100A9-positive inflammatory cells in gastric cancer tissues are associated with early stage of gastric cancer and good prognosis.

Identification of the up-regulation of TP-alpha, collagen alpha-1(VI) chain, and S100A9 in esophageal squamous cell carcinoma by a proteomic method

Esophageal squamous cell carcinoma (ESCC) is one of the most common primary malignant tumor of digestive tract. However, the early diagnosis and molecular mechanisms that underlie tumor formation and progression have been progressed less. To identify new biomarkers for ESCC, we performed a comparative proteomic research. Isobaric tags for relative and absolute quantitation-based proteomic method was used to screen biomarkers between ESCC and normal. 802 non-redundant proteins were identified, 39 of which were differentially expressed with 1.5-fold difference (29 up-regulated and 10 down-regulated). Through Swiss-Prot and GO database, the location and function of differential proteins were analyzed, which are related to the biological processes of binding, cell structure, signal transduction, cell adhesion, etc. Among the differentially expressed proteins, TP-alpha, collagen alpha-1(VI) chain and S100A9 were verified to be upregulated in 77.19%, 75.44% and 59.65% of ESCC by immunohistochemistry and western-blot. Diagnostic value of these three proteins was validated. These results provide new insights into ESCC biology and potential diagnostic and therapeutic biomarkers, which suggest that TP-alpha, collagen alpha-1(VI) chain and S100A9 are potential biomarkers of ESCC, and may play an important role in tumorigenesis and development of ESCC.

S100A8/A9 induces apoptosis and inhibits metastasis of CasKi human cervical cancer cells

S100 proteins, a family of Ca(2+)-binding proteins, have been linked to several human diseases in recent years. Deregulated expression of S100 proteins, including S100A9 and its partner S100A8, was reported to be associated with neoplastic disorders. In our previous study using serial analysis of gene expression, we identified decreased expressions of S100A9 and S100A8 in human cervical squamous cell carcinoma. To investigate the functions of S100A8 and S100A9 in cervical cancer, we purified recombinant S100A8 and S100A9 proteins and treated CaSki human cervical cancer cells with these proteins. We found that S100A8/A9 induced apoptosis and inhibited migration of CaSki cells; S100A8/A9 also reduced the expression of matrix metalloproteinase (MMP)-2 in CaSki cells. In summary, this study suggests that S100A8 and S100A9 have inhibitory effects on the proliferation of CaSki carcinoma cells by inducing cell apoptosis and on the invasiveness of CaSki cells.

A novel p53 target gene, S100A9, induces p53-dependent cellular apoptosis and mediates the p53 apoptosis pathway

S100A9 (S100 calcium-binding protein A9) is a calcium-binding protein of the S100 family, and its differential expression has been associated with acute and chronic inflammation and several human cancers. Our previous work showed that S100A9 was severely down-regulated in human ESCC (oesophageal squamous cell carcinoma). To further investigate the transcriptional regulation of S100A9, we analysed the S100A9 promoter region and found several putative p53BS (p53-binding sites). Luciferase reporter assays showed that constructs carrying the p53BS exhibited enhanced luciferase activity in response to wild-type p53 activation. Further study demonstrated that S100A9 mRNA and protein expression could be positively regulated in a p53-dependent manner and p53 could bind to p53BS on the S100A9 promoter. Overexpression of S100A9 could induce cellular apoptosis, and this was partly p53-dependent. Knockdown of S100A9 impaired the apoptosis induced by p53. Thus we conclude that a gene down-regulated in ESCC, S100A9, is a novel p53 transcriptional target, induces cellular apoptosis in a partly p53-dependent manner and mediates the p53 apoptosis pathway.

MicroRNA-196a is a potential marker of progression during Barrett's metaplasia-dysplasia-invasive adenocarcinoma sequence in esophagus

Barrett's esophagus (BE)/Barrett's metaplasia (BM) is a recognized precursor of esophageal adenocarcinoma (EA) with an intermediary stage of dysplasia. The low yield and high cost of endoscopic screening of patients with BE underscores the need for novel biomarkers, such as microRNA (miRNA), which have emerged as important players in neoplastic progression for risk assessment of developing dysplasia/adenocarcinoma. Recently, we reported highly elevated levels of miRNA-196a (miR-196a) in EA and demonstrated its growth-promoting and anti-apoptotic functions. Here, we evaluated miR-196a as a marker of BE progression to low-grade dysplasia, high-grade dysplasia, and EA using microdissected paraffin-embedded tissues from 11 patients. Higher levels of miR-196a were observed in EA, BE, and dysplastic lesions compared with normal squamous mucosa, and in high-grade dysplasia compared with BE and low-grade dysplasia. Using frozen tumor tissues from 10 additional patients who had advanced EA, we evaluated the correlation of miR-196a with its in silico-predicted targets, keratin 5 (KRT5), small proline-rich protein 2C (SPRR2C), and S100 calcium-binding protein A9 (S100A9), which are down-regulated during BE progression. MiR-196a levels inversely correlated with the predicted target mRNA levels in EA. We confirmed that miR-196a specifically targets KRT5, SPRR2C, and S100A9 3' UTRs using miR-196a-mimic and luciferase reporter-based assays. In conclusion, this study identified miR-196a as a potential marker of progression of BE and KRT5, SPRR2C, and S100A9 as its targets.

S100A8/A9 at low concentration promotes tumor cell growth via RAGE ligation and MAP kinase-dependent pathway

The complex formed by two members of the S100 calcium-binding protein family, S100A8/A9, exerts apoptosis-inducing activity against various cells, especially tumor cells. Here, we present evidence that S100A8/A9 also has cell growth-promoting activity at low concentrations. Receptor of advanced glycation end product (RAGE) gene silencing and cotreatment with a RAGE-specific blocking antibody revealed that this activity was mediated via RAGE ligation. To investigate the signaling pathways, MAPK phosphorylation and NF-kappaB activation were characterized in S100A8/A9-treated cells. S100A8/A9 caused a significant increase in p38 MAPK and p44/42 kinase phosphorylation, and the status of stress-activated protein kinase/JNK phosphorylation remained unchanged. Treatment of cells with S100A8/A9 also enhanced NF-kappaB activation. RAGE small interfering RNA pretreatment abrogated the S100A8/A9-induced NF-kappaB activation. Our data indicate that S100A8/A9-promoted cell growth occurs through RAGE signaling and activation of NF-kappaB.

Comparative proteomic analysis of low stage and high stage endometrioid ovarian adenocarcinomas

Ovarian cancer, the second most common gynecological malignancy, accounts for 3% of all cancers among women in the United States, and has a high mortality rate, largely because existing therapies for widespread disease are rarely curative. Ovarian endometrioid adenocarcinoma (OEA) accounts for about 20% of the overall incidence of all ovarian cancer. We have used proteomics profiling to characterize low stage (FIGO stage 1 or 2) versus high stage (FIGO stage 3 or 4) human OEAs. In general, the low stage tumors lacked p53 mutations and had frequent CTNNB1, PTEN, and/or PIK3CA mutations. The high stage tumors had mutant p53, were usually high grade, and lacked mutations predicted to deregulate Wnt/β-catenin and PI3K/Pten/Akt signaling. We utilized 2-D liquid-based separation/mass mapping techniques to elucidate molecular weight and pI measurements of the differentially expressed intact proteins. We generated 2-D protein mass maps to facilitate the analysis of protein expression between both the low stage and high stage tumors. These mass maps (over a pI range of 5.6-4.6) revealed that the low stage OEAs demonstrated protein over-expression at the lower pI ranges (pI 4.8-4.6) in comparison to the high stage tumors, which demonstrated protein over-expression in the higher pI ranges (pI 5.4-5.2). These data suggest that both low and high stage OEAs have characteristic pI signatures of abundant protein expression probably reflecting, at least in part, the different signaling pathway defects that characterize each group. In this study, the low stage OEAs were distinguishable from high stage tumors based upon the proteomic profiles. Interestingly, when only high-grade (grade 2 or 3) OEAs were included in the analysis, the tumors still tended to cluster according to stage, suggesting that the altered protein expression was not solely dependent upon tumor cell differentiation. Further, these protein profiles clearly distinguish OEA from other types of ovarian cancer at the protein level.

Calcium-binding proteins S100A8 and S100A9 as novel diagnostic markers in human prostate cancer

PURPOSE

S100 proteins comprise a family of calcium-modulated proteins that have recently been associated with epithelial tumors. We examined the expression of two members of this family, S100A8 and S100A9, together with the S100 receptor RAGE (receptor for advanced glycation end products) in human prostate adenocarcinomas and in prostatic intraepithelial neoplasia.

EXPERIMENTAL DESIGN

Tissue specimens of 75 patients with organ-confined prostate cancer of different grades were analyzed by immunohistochemistry for expression of S100A8, S100A9, and RAGE. In addition, in situ hybridization of S100A8 and S100A9 was done for 20 cases. An ELISA was applied to determine serum concentrations of S100A9 in cancer patients compared with healthy controls or to patients with benign prostatic hyperplasia (BPH).

RESULTS

S100A8, S100A9, and RAGE were up-regulated in prostatic intraepithelial neoplasia and preferentially in high-grade adenocarcinomas, whereas benign tissue was negative or showed weak expression of the proteins. There was a high degree of overlap of S100A8 and S100A9 expression patterns and of S100A8 or S100A9 and RAGE, respectively. Frequently, a gradient within the tumor tissue with an increased expression toward the invaded stroma of the prostate was observed. S100A9 serum levels were significantly elevated in cancer patients compared with BPH patients or healthy individuals.

CONCLUSION

Our data suggest that enhanced expression of S100A8, S100A9, and RAGE is an early event in prostate tumorigenesis and may contribute to development and progression or extension of prostate carcinomas. Furthermore, S100A9 in serum may serve as useful marker to discriminate between prostate cancer and BPH.