Expression of calcium-binding protein S100A2 in breast lesions

NFIC1 inhibits the migration and invasion of MDA-MB-231 cells through S100A2-mediated inactivation of MEK/ERK pathway

NFIC is a potent transcriptional factor involved in many physiological and pathological processes, including tumorigenesis. However, the role of NFIC1, the longest isoform of NFIC, in the progression of triple negative breast cancer (TNBC) remains elusive. Our study demonstrates that overexpression of NFIC1 inhibits the migration and invasion of TNBC MDA-MB-231 cells. NFIC1 regulates the expression of S100A2, and knockdown of S100A2 reverses the inhibitive effects of NFIC1 on the migration and invasion of MDA-MB-231 cells. Furthermore, knockdown of S100A2 activates the MEK/ERK signaling transduction pathway that is inhibited by NFIC1 overexperssion. Treatment with MEK/ERK pathway inhibitor, U0126, abolishes the effects of S100A2 knockdown. In addition, overexpression of NFIC1 in MDA-MB-231 cells increases the expression of epithelial markers and decreases the expression of mesenchymal markers, and these effects could also be reversed by knockdown of S100A2. Collectively, these results demonstrate that NFIC1 inhibits the Epithelial-mesenchymal transition (EMT) of MDA-MB-231 cells by regulating S100A2 expression, which suppress the activation of MEK/ERK pathway. Therefore, our study confirms the role of NFIC1 as a tumor repressor in TNBC, and reveals the molecular mechanism through which NFIC1 inhibits the migration and invasion of MDA-MB-231 cells.

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.

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.

Prognostic values of S100 family members in ovarian cancer patients

Objective

Exhibiting high consistence in sequence and structure, S100 family members are interchangeable in function and they show a wide spectrum of biological processes, including proliferation, apoptosis, migration, inflammation and differentiation and the like. While the prognostic value of each individual S100 in ovarian cancer is still elusive. In current study, we investigated the prognostic value of S100 family members in the ovarian cancer.

Methods

We used the Kaplan Meier plotter (KM plotter) database, in which updated gene expression data and survival information are from 1657 ovarian cancer patients, to assess the relevance of individual S100 family mRNA expression to overall survival in various ovarian cancer subtypes and different clinicopathological features.

Results

It was found that high expression of S100A2 (HR = 1.18, 95%CI: 1.04–1.34, P = 0.012), S100A7A (HR = 1.3, 95%CI: 1.04–1.63, P = 0.02),S100A10 (HR = 1.2, 95%CI: 1.05–1.38, P = 0.0087),and S100A16 (HR = 1.23, 95%CI: 1–1.51, P = 0.052) were significantly correlated with worse OS in all ovarian cancer patients, while the expression of S100A1 (HR = 0.87, 95%CI: 0.77–0.99, P = 0.039), S100A3 (HR = 0.83, 95%CI: 0.71–0.96, P = 0.0011), S100A5 (HR = 0.84, 95%CI: 0.73–0.97, P = 0.017), S100A6 (HR = 0.84, 95%CI: 0.72–0.98, P = 0.024), S100A13 (HR = 0.85, 95%CI:0.75–0.97, P = 0.014) and S100G (HR = 0.86, 95%CI: 0.74–0.99, P = 0.041) were associated with better prognosis. Furthermore, we assessed the prognostic value of S100 expression in different subtypes and the clinicopathological features, including pathological grades, clinical stages and TP53 mutation status, of ovarian cancer patients.

Conclusion

Comprehensive understanding of the S100 family members may have guiding significance for the diagnosis and outcome of ovarian cancer patients.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5170-3) contains supplementary material, which is available to authorized users.

Primary Malignant Melanoma of the Breast: A Report of Two Cases

Primary malignant melanoma of the breast (PMMB) is a rare tumor with only a few case reports available in the literature. We report two cases of PMMB, one derived from the breast parenchyma and the other from the breast skin. The first case consisted of atypical epithelioid cells without overt melanocytic differentiation like melanin pigments. The tumor cells showed diffuse positivity for S100 protein, tyrosinase, and BRAF V600E. However, the tumor cells were negative for cytokeratin, epithelial membrane antigen, and HMB-45. The second case showed atypical melanocytic proliferation with heavy melanin pigmentation. The tumor cells were positive for S100 protein, HMB-45, tyrosinase, and BRAF V600E. These two cases represent two distinct presentations of PMMB in terms of skin involvement, melanin pigmentation, and HMB-45 positivity. Although PMMB is very rare, the possibility of this entity should be considered in malignant epithelioid neoplasms in the breast parenchyma.

HGF-mediated S100A11 overexpression enhances proliferation and invasion of gastric cancer

S100 proteins are a group of low molecular weight (10-12 kDa) acidic proteins belonging to the largest family of EFhand calciumbinding proteins. S100A11, also known as S100C or calgizzarin, is an important member of the S100 family. S100A11 overexpression has been reported in a number of cancers including papillary thyroid carcinoma, colon, pancreatic, and breast cancer. One other study demonstrated that increased S100A11 expression is correlated with gastric cancer metastasis and poor overall disease prognosis. This study aimed to identify the function of S100A11 associated with cell proliferation and invasion in gastric cancer. We used cell culture, western blotting, reverse transcription-polymerase chain reaction, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and S100A11 knock-down with short hairpin ribonucleic acid (shRNA). First, we confirmed that the S100A11 expression was upregulated by hepatocyte growth factor (HGF). The role of S100A11 was determined via knock down of S100A11. S100A11-shRNA cells showed decreased levels of metalloproteinase-9 (MMP9) and nuclear factor kappa-B (NF-κB). We also examined and confirmed the role of HGF-mediated S100A11 expression. HGF-mediated cell proliferation and in vitro invasion increased, and HGF-mediated apoptosis decreased in S100A11 knockdown cells. We identified the putative binding site of NF-κB in the MMP9 promoter region and confirmed its function via chromatin immunoprecipitation (CHIP) assay. Our results showed that S100A11 is upregulated by HGF through the NF-κB pathway in gastric cancer and plays a role in cell proliferation and invasion in gastric cancer. It may thus be a possible target for gastric cancer therapy.

A review of S100 protein family in lung cancer

S100 protein family, representing 25 relatively small calcium binding proteins, has been reported to be involved in multiple stages of tumorigenesis and progression. These proteins are considered having potential value to be adopted as novel biomarkers in the detection and accurate prediction of many kinds of tumors, including lung cancer. As the one having the highest morbidity and mortality among all cancers, lung carcinoma is still occult for detection, especially at early stage. S100 proteins take participation in the lung neoplasia through playing intracellular and/or extracellular functions, therefore getting involved in a variety of biological processes such as differentiation, proliferation, and migration. A few members have also been testified to modulate TGF-β/Smad-3 mediated transcriptional activity of target genes involved in tumor promotion. In addition to that, a number of proteins in this family have already been reported to experience an abnormal trend in lung cancer at cell, serum and tissue levels. Thus, S100 proteins may serve as effective biomarkers for suspected or already diagnosed lung cancer patients. In future, S100 protein family might be applied as therapeutic targets in clinical treatment of lung cancer. In this review, we firstly summed up the biological and clinical evidence connecting S100 proteins and lung cancer, which has not been summarized before.

Exhaled breath condensate biomarkers for the early diagnosis of lung cancer using proteomics

We explored whether the proteomic analysis of exhaled breath condensate (EBC) may provide biomarkers for noninvasive screening for the early detection of lung cancer (LC). EBC was collected from 192 individuals [49 control (C), 49 risk factor-smoking (S), 46 chronic obstructive pulmonary disease (COPD) and 48 LC]. With the use of liquid chromatography and tandem mass spectrometry, 348 different proteins with a different pattern among the four groups were identified in EBC samples. Significantly more proteins were identified in the EBC from LC compared with other groups (C: 12.4 ± 1.3; S: 15.3 ± 1; COPD: 14 ± 1.6; LC: 24.2 ± 3.6; P = 0.0001). Furthermore, the average number of proteins identified per sample was significantly higher in LC patients, and receiver operating characteristic curve (ROC) analysis showed an area under the curve of 0.8, indicating diagnostic value. Proteins frequently detected in EBC, such as dermcidin and hornerin, along with others much less frequently detected, such as hemoglobin and histones, were identified. Cytokeratins (KRTs) were the most abundant proteins in EBC samples, and levels of KRT6A, KRT6B, and KRT6C isoforms were significantly higher in samples from LC patients ( P = 0.0031, 0.0011, and 0.0009, respectively). Moreover, the amount of most KRTs in EBC samples from LC patients showed a significant positive correlation with tumor size. Finally, we used a random forest algorithm to generate a robust model using EBC protein data for the diagnosis of patients with LC where the area under the ROC curve obtained indicated a good classification (82%). Thus this study demonstrates that the proteomic analysis of EBC samples is an appropriated approach to develop biomarkers for the diagnosis of lung cancer.

Mechanistic attributes of S100A7 (psoriasin) in resistance of anoikis resulting tumor progression in squamous cell carcinoma of the oral cavity

Background

Squamous cell carcinoma of the oral cavity (SCCOC) is the dominant origin of cancer associated mortality. Previous findings by our study reported that acquisition of anoikis resistance has a significant role in tumor progression of oral cavity. Several genes were over-expressed in anoikis-resistant cells under detached conditions which we confirmed earlier by microarray. Normal oral squamous epithelia grow adherent to a basement membrane, and when detached from the extracellular matrix, undergoes programmed cell death. The acquisition of anoikis-resistance is crucial phenomena in oral tumor advancement. In the current study, we have identified S100A7 expression as contributing factor for anoikis resistance and tumorigenicity in human oral cancer cells. Further, we have explored that elevated S100A7 expression in anoikis-sensitive oral keratinocytes and cancer cells reshape them more resistant to anoikis and apoptosis inducers via activation of cellular intrinsic and extrinsic avenue.

Methods

A subset of human cancer cell lines TU167, JMAR, JMARC39, JMARC42 and MDA-MB-468 were utilized for the generation of resistant stable cell lines. Further, immunohistochemistry, western blot and immunoprecipitation, assays of apoptosis, soft agar assay, orthotopic animal model and signaling elucidation were performed to establish our hypothesis.

Results

S100A7 gene is found to be responsible for anoikis resistance and tumorigenicity in human oral cancer cells. We have observed up-regulation of S100A7 in anoikis resistant cell lines, orthotropic model and patients samples with head and neck cancer. It is also noticed that secretion of S100A7 protein in conditioned medium by anoikis resistant head & neck cancer cell and in saliva of head and neck cancer patients. Up-regulation of S100A7 expression has triggered enhanced tumorigenicity and anchorage-independent growth of cancer cells through Akt phosphorylation leading to development of aniokis resistance in head and neck cancer cells.

Conclusions

These data have led us to conclude that S100A7 is the major contributing factor in mediating anoikis-resistance of oral cancer cells and local tumor progression, and S100A7 might be useful as diagnostic marker for early detection of primary and recurrent squamous cell cancer.

A functional in vitro model of heterotypic interactions reveals a role for interferon-positive carcinoma associated fibroblasts in breast cancer

BACKGROUND

Cancer-associated fibroblasts (CAFs) play an important role in breast cancer pathogenesis by paracrine regulation of breast cancer cell biology. Several in vitro and mouse models have characterized the role of cell contact and cytokine molecules mediating this relationship, although few reports have used human CAFs from breast tumors.

METHODS

Primary breast CAF cultures were established and gene expression profiles analysed in order to guide subsequent co-culture models. We used a combination of colorimetric proliferation assays and gene expression profiling to determine the effect of CAFs on the MCF-7 breast cancer cell in an indirect co-culture system.

RESULTS

Using gene expression profiling, we found that a subgroup of breast CAFs are positive for a type one interferon response, confirming previous reports of an activated type one interferon response in whole tumor datasets. Interferon positive breast cancer patients show a poor prognostic outcome in an independent microarray dataset. In addition, CAFs positive for the type one interferon response promoted the growth of the MCF-7 breast cancer cell line in an indirect co-culture model. The addition of a neutralizing antibody against the ligand mediating the type one response in fibroblasts, interferon-β, reverted this co-culture phenotype. CAFs not expressing the interferon response genes also promoted the growth of the MCF-7 breast cancer cell line but this phenotype was independent of the type one fibroblast interferon ligand.

CONCLUSIONS

Primary breast CAFs show inter-patient molecular heterogeneity as evidenced by interferon response gene elements activated in a subgroup of CAFs, which result in paracrine pro-proliferative effects in a breast cancer cell line co-culture model.

S100A2 protein and non-small cell lung cancer. The dual role concept

S100A2 is a member of the EF-hand motif family S100. Its role has been recently implicated in carcinogenesis and metastasis. Although its precise role in NSCLC patients is debated and conflicting results have been published, it has been associated with patient survival. S100A2 expression was downregulated in some studies while others disagree that S100A2 is strongly expressed in lung cancer. It has been recently published by Hountis et al. that there is a significant association between nuclear S100A2 positivity and better disease-free interval. Intensity of expression was the highest in the early and advanced stages, and equally distributed in the middle stages. This is indicative for a dual role of this protein in carcinogenesis. The expression of S100A2 in operable NSCLC varies widely, and this differential location and expression pattern (nuclear or cytoplasmic or both) seem to correlate with prognosis. The precise role for the movement of S100A2 protein between cytoplasm and nucleus is still unclear. We present here a literature review, and we propose the dual concept on its substantial role as a prognostic or predictive indicator in this unfavorable group of patients.

Joining S100 proteins and migration: for better or for worse, in sickness and in health

The vast diversity of S100 proteins has demonstrated a multitude of biological correlations with cell growth, cell differentiation and cell survival in numerous physiological and pathological conditions in all cells of the body. This review summarises some of the reported regulatory functions of S100 proteins (namely S100A1, S100A2, S100A4, S100A6, S100A7, S100A8/S100A9, S100A10, S100A11, S100A12, S100B and S100P) on cellular migration and invasion, established in both culture and animal model systems and the possible mechanisms that have been proposed to be responsible. These mechanisms involve intracellular events and components of the cytoskeletal organisation (actin/myosin filaments, intermediate filaments and microtubules) as well as extracellular signalling at different cell surface receptors (RAGE and integrins). Finally, we shall attempt to demonstrate how aberrant expression of the S100 proteins may lead to pathological events and human disorders and furthermore provide a rationale to possibly explain why the expression of some of the S100 proteins (mainly S100A4 and S100P) has led to conflicting results on motility, depending on the cells used.

S100A2 is a BRCA1/p63 coregulated tumour suppressor gene with roles in the regulation of mutant p53 stability

Here, we show for the first time that the familial breast/ovarian cancer susceptibility gene, BRCA1, along with interacting ΔNp63 proteins, transcriptionally upregulate the putative tumour suppressor protein, S100A2. Both BRCA1 and ΔNp63 proteins are required for S100A2 expression. BRCA1 requires ΔNp63 proteins for recruitment to the S100A2 proximal promoter region, while exogenous expression of individual ΔNp63 proteins cannot activate S100A2 transcription in the absence of a functional BRCA1. Consequently, mutation of the ΔNp63/p53 response element within the S100A2 promoter completely abrogates the ability of BRCA1 to upregulate S100A2. S100A2 shows growth control features in a range of cell models. Transient or stable exogenous S100A2 expression inhibits the growth of BRCA1 mutant and basal-like breast cancer cell lines, while short interfering RNA (siRNA) knockdown of S100A2 in non-tumorigenic cells results in enhanced proliferation. S100A2 modulates binding of mutant p53 to HSP90, which is required for efficient folding of mutant p53 proteins, by competing for binding to HSP70/HSP90 organising protein (HOP). HOP is a cochaperone that is required for the efficient transfer of proteins from HSP70 to HSP90. Loss of S100A2 leads to an HSP90-dependent stabilisation of mutant p53 with a concomitant loss of p63. Accordingly, S100A2-deficient cells are more sensitive to the HSP-90 inhibitor, 17-N-allylamino-17-demethoxygeldanamycin, potentially representing a novel therapeutic strategy for S100A2- and BRCA1-deficient cancers. Taken together, these data demonstrate the importance of S100A2 downstream of the BRCA1/ΔNp63 signalling axis in modulating transcriptional responses and enforcing growth control mechanisms through destabilisation of mutant p53.

Clinical significance of S100A2 expression in gastric cancer

Gastric carcinoma (GC) is one of the most common malignancies worldwide. To identify the candidate carcinoma-related biomarker in GC, comparative proteome technique was performed in resected GC tissues and matched adjacent non-cancerous gastric tissues (ANGT). As a result, S100A2 was successfully identified to be down-regulated significantly in GC compared with ANGT. Western blot analysis validated decreased expression of S100A2, and its expression level was related with the degree of tumor differentiation and status of lymph node metastasis in GC. Furthermore, immunohistochemistry analysis showed S100A2 down-expression was significantly associated with poor differentiation (P < 0.05), advanced depth of invasion (P < 0.05) and lymph node metastasis (P < 0.05) in GC. Kaplan-Meier curves showed that the relapse-free probability and the overall survival rate were significantly decreased with S100A2 expression decreasing (P < 0.05). Cox regression analysis indicated S100A2 down-expression was a negative independent prognostic biomarker for GC. A supplement of S100A2 protein by S100A2 expression vector significantly decreased the number of invaded cancer cells MGC-803. However, knockdown of S100A2 expression by siRNA interference compromised the invasion ability of MGC-803 cells. Moreover, S100A2 negatively regulated MEK/ERK signaling pathway, and activation of this signaling pathway by S100A2 down-regulation increased in vitro invasion of MGC-803 cells. In conclusion, this study demonstrated the clinical significance of S100A2 expression in GC, and loss of S100A2 expression contributes to GC development and progression. Therefore, the determination of S100A2 expression levels contributes to predict the outcome of GC patients.

Prognostic significance of different immunohistochemical S100A2 protein expression patterns in patients with operable nonsmall cell lung carcinoma

S100 proteins are involved in carcinogenesis, metastasis, and survival. S100A2 is a member of the S100 family, and its expression and precise role in patients with non-small cell lung carcinoma (NSCLC) has been debated. Therefore, we examined the immunohistochemical expression patterns of S100A2 in NSCLC in relation to clinicopathological parameters, important molecular biomarkers, and patient outcome. Microarray data for 74 paraffin-embedded specimens from patients with NSCLC were immunostained for S100A2 and p53 proteins. Immunohistochemical staining patterns of S100A2 in the NSCLC tissue samples examined were either nuclear (nS100A2), cytoplasmic (cS100A2), or both. A significant association between nS100A2 positivity and better disease-free interval was observed (hazards ratio 0.47; 95% confidence interval 0.23–0.99; P = 0.047). Similarly, cS100A2 negativity was marginally associated with shorter overall survival (P = 0.07). Patients without lymphatic infiltration and an earlier disease stage had significantly better overall survival and disease-free interval. The S100A2 expression pattern in operable NSCLC varies widely, and this differential expression (nuclear, cytoplasmic or both) seems to correlate with prognosis. Intensity of expression was highest in the early and advanced stages, and equally distributed in the middle stages. This observation may be indicative of a dual role for this protein both during earlier and advanced disease stages, and may also explain the differential immunoexpression of S100A2. Analysis of the disease-free interval showed that nS100A2-negative and p53-positive expression was associated with a statistically significant (P = 0.003) shorter disease-free interval in comparison with nS100A2-positive and p53-negative expression (12 versus 30 months, respectively). Further studies are required to establish whether S100A2 protein may have a substantial role as a prognostic or predictive indicator in this unfavorable group of patients.

Hornerin, an S100 family protein, is functional in breast cells and aberrantly expressed in breast cancer

Background

Recent evidence suggests an emerging role for S100 protein in breast cancer and tumor progression. These ubiquitous proteins are involved in numerous normal and pathological cell functions including inflammatory and immune responses, Ca²⁺ homeostasis, the dynamics of cytoskeleton constituents, as well as cell proliferation, differentiation, and death. Our previous proteomic analysis demonstrated the presence of hornerin, an S100 family member, in breast tissue and extracellular matrix. Hornerin has been reported in healthy skin as well as psoriatic and regenerating skin after wound healing, suggesting a role in inflammatory/immune response or proliferation. In the present study we investigated hornerin’s potential role in normal breast cells and breast cancer.

Methods

The expression levels and localization of hornerin in human breast tissue, breast tumor biopsies, primary breast cells and breast cancer cell lines, as well as murine mammary tissue were measured via immunohistochemistry, western blot analysis and PCR. Antibodies were developed against the N- and C-terminus of the protein for detection of proteolytic fragments and their specific subcellular localization via fluorescent immunocytochemisty. Lastly, cells were treated with H₂O₂ to detect changes in hornerin expression during induction of apoptosis/necrosis.

Results

Breast epithelial cells and stromal fibroblasts and macrophages express hornerin and show unique regulation of expression during distinct phases of mammary development. Furthermore, hornerin expression is decreased in invasive ductal carcinomas compared to invasive lobular carcinomas and less aggressive breast carcinoma phenotypes, and cellular expression of hornerin is altered during induction of apoptosis. Finally, we demonstrate the presence of post-translational fragments that display differential subcellular localization.

Conclusions

Our data opens new possibilities for hornerin and its proteolytic fragments in the control of mammary cell function and breast cancer.

Significance of S100A2 and S100A4 Expression in the Progression of Prostate Adenocarcinoma

Purpose

The aim of this study was to investigate the expression pattern of calcium-binding proteins S100A2 and S100A4. We also sought to determine the prognostic value of these markers for patients with prostate adenocarcinoma.

Materials and Methods

Immunohistochemical staining was performed to detect S100A2 and S100A4 expression in 26 tissue samples obtained during transurethral resection from patients with benign prostatic hyperplasia (BPH) and in 67 tissue samples obtained during prostate biopsy and radical prostatectomy from patients with prostate carcinoma. The immunoreactivity of these proteins was stratified on a scale of 0 to 3 and was correlated with the pathologic features of prostate adenocarcinoma.

Results

High expression of S100A2 was observed in the tissue of patients with BPH, whereas low or no expression was observed in prostate cancer (CaP) cells. The protein level of S100A4 was significantly higher in CaP than in BPH cells. The higher level of S100A4 observed in CaP tissue correlated with increasing tumor grade.

Conclusions

Decreased expression of S100A2 and increased expression of S100A4 may be important in the progression of CaP. This finding could aid in identifying aggressive CaP. The simultaneous analysis of S100A2 and S100A4 expression in prostate tissues may be a useful prognostic marker for CaP.

S100A2 in cancerogenesis: a friend or a foe?

Owing to the exceptional intracellular distribution and the heterogeneous expression pattern during transformation and metastasis in various tumors, the EF-hand calcium-binding protein S100A2 attracts increasing attention. Unlike the majority of S100 proteins, S100A2 expression is downregulated in many cancers and the loss in nuclear expression has been associated with poor prognosis. On the other hand, S100A2 is upregulated in some cancers. This mini review highlights the general characteristics of S100A2 and discusses recent findings on its putative functional implication as a suppressor or promoter in cancerogenesis.

S100A8/A9: a Janus-faced molecule in cancer therapy and tumorgenesis

Correlations exist between the abundance of S100 proteins and disease pathologies. Indeed, this is evidenced by the heterodimeric S100 protein complex S100A8/A9 which has been shown to be involved in inflammatory and neoplastic disorders. However, S100A8/A9 appears as a Janus-faced molecule in this context. On the one hand, it is a powerful apoptotic agent produced by immune cells, making it a very fascinating tool in the battle against cancer. It spears the risk to induce auto-immune response and may serve as a lead compound for cancer-selective therapeutics. In contrast, S100A8/A9 expression in cancer cells has also been associated with tumor development, cancer invasion or metastasis. Clearly, there is a dichotomy and future investigations into the role of S100A8/A9 in cancer biology need to consider both sides of the same coin.

Expression and clinical significance of S100A2 and p63 in esophageal carcinoma

AIM: To investigate the expression and clinical significance of S100A2 mRNA and protein, p63 protein in esophageal squamous cell carcinoma (ESCC) and their roles in carcinogenesis and progression of esophageal carcinoma (EC).

METHODS: Immunohistochemical staining (S-P method) for S100A2 and p63 protein were performed in 40 samples of ESCC and 40 samples of normal esophageal mucosa. In situ hybridization (ISH) was used to detect the expression of S100A2 mRNA.

RESULTS: Expression of S100A2 mRNA in ESCC was positive in 77.5% of samples, which was lower than that in normal mucosa (100%) by ISH (P = 0.002). The expression level of S100A2 mRNA was closely related to differentiation and and node-metastasis (P = 0.012, P = 0.008). Expression of S100A2 protein was positive in 72.5% of ESCC samples and expression of p63 protein was positive in 37.5% of ESCC samples, and was lower than that in normal mucosa (100%) (P = 0.000). The expression of S100A2 protein was correlated with the differentiation and node-metastasis (P = 0.007, P = 0.001), but no relationship was observed between the expression of p63 protein and clinical pathological manifestations. S100A2 protein was positively correlated with the expression of S100A2 mRNA, and negatively associated with the expression of p63 protein (P = 0.000, P = 0.002).

CONCLUSION: S100A2 and p63 protein both play important roles in the carcinogenesis of ESCC. An investigation into the combined expression of S100A2 and p63 may be helpful in early diagnosis and in evaluating the prognosis of ESCC.

S100A2 induces metastasis in non-small cell lung cancer

PURPOSE

S100 proteins are implicated in metastasis development in several cancers. In this study, we analyzed the prognostic role of mRNA levels of all S100 proteins in early stage non-small cell lung cancer (NSCLC) patients as well as the pathogenetic of S100A2 in the development of metastasis in NSCLC.

EXPERIMENTAL DESIGN

Microarray data from a large NSCLC patient cohort was analyzed for the prognostic role of S100 proteins for survival in surgically resected NSCLC. Metastatic potential of the S100A2 gene was analyzed in vitro and in a lung cancer mouse model in vivo. Overexpression and RNAi approaches were used for analysis of the biological functions of S100A2.

RESULTS

High mRNA expression levels of several S100 proteins and especially S100A2 were associated with poor survival in surgically resected NSCLC patients. Upon stable transfection into NSCLC cell lines, S100A2 did not alter proliferation. However, S100A2 enhanced transwell migration as well as transendothelial migration in vitro. NOD/SCID mice injected s.c. with NSCLC cells overexpressing S100A2 developed significantly more distant metastasis (64%) than mice with control vector transfected tumor cells (17%; P < 0.05). When mice with S100A2 expressing tumors were treated i.v. with shRNA against S100A2, these mice developed significantly fewer lung metastasis than mice treated with control shRNA (P = 0.021).

CONCLUSIONS

These findings identify S100A2 as a strong metastasis inducer in vivo. S100A2 might be a potential biomarker as well as a novel therapeutic target in NSCLC metastasis.

Molecular signatures associated with transformation and progression to breast cancer in the isogenic MCF10 model

Comparative microarray analyses provided insight into understanding transcript changes during cancer progression; however, a reproducible signature underlying breast carcinogenesis has yet to be little available. We utilized gene expression profiling to define molecular signatures associated with transformation and cancer progression in a series of isogenic human breast cancer cell lines including a normal, benign, noninvasive and invasive carcinoma. Clustering analysis revealed four distinct expression patterns based on upregulation or downregulation patterns. These profiles proved quite useful for describing breast cancer tumorigenesis and invasiveness. Downregulation of TNFSF7, S100A4, S100A7, S100A8, and S100A9 (calcium-binding protein family), and upregulation of kallikrein-5 and thrombospondin-1 were associated with transformation and progression of breast cancer cells. Importantly, downregulation of the genes was reversed by treatment with silencing inhibitors, implying the potential roles of epigenetic inactivation in breast carcinogenesis. Exogenous expressions of S100A8 and S100A9 inhibit growth in benign and noninvasive carcinoma cells, suggesting their negative role in cell proliferation. The data presented here may facilitate the identification and functional analyses of prognostic biomarkers for breast cancer.

S100A6 expression and function in human osteosarcoma

There is a critical need to identify markers that can accurately identify existing or predict future metastatic disease in patients with osteosarcoma since the majority of patients present with undetectable micrometastatic disease. We previously reported S100A6 is overexpressed in human osteosarcoma and increased expression of S100A6 by immunohistochemistry correlated with decreased clinical metastasis. We have established 11 primary cultures from biopsies of patients with osteosarcoma and ten of the 11 primary cultures have increased expression of S100A6 relative to normal human osteoblasts. To further explore possible mechanisms for metastasis suppression previously reported, we used in this report siRNA-mediated knockdown of S100A6 in four commonly used human osteosarcoma lines, then examined their cell adhesion, migration, and invasion properties. Knockdown of S100A6 expression inhibited cell adhesion and promoted cell migration and invasion in these lines. Conversely, S100A6 overexpression enhanced cell adhesion and inhibited cell invasion. Our data demonstrate S100A6 is commonly overexpressed in human osteosarcoma. S100A6 may inhibit osteosarcoma metastasis by promoting cell adhesion and inhibiting cell motility and invasion. Thus, S100A6 may be considered a potential marker for human osteosarcoma with prognostic value for identifying patients without metastases.

Expression of S100A2 mRNA and protein and its clinical significance in esophageal cancer

AIM: To investigate the expression of S100A2 mRNA and its protein in esophageal squamous cell cancer(ESCC) and their relationship with clinicopathologic features, and explore their roles in carcinogenesis and progression of esophageal cancer and to evaluate their clinicopathologic significance.

METHODS: Immunohistochemical staining (S-P method) was performed to detect S100A2 protein expression in 40 ESCC samples and 40 samples from normal esophageal mucosa. In situ hybridization (ISH) was performed to detect the expression of S100A2 mRNA.

RESULTS: The positive rates of S100A2 mRNA and S100A2 protein in ESCC samples were both markedly lower than that in normal mucosa (77.5% vs 100%, 72.5% vs 100%, both P < 0.01). The differences were both significant among the well differentiated, the moderately differentiated and the lowly differentiated groups (all P < 0.05). The expression levels of S100A2 mRNA and S100A2 protein were significantly higher in well and moderately differentiated groups than that in lowly differentiated group (93.3% vs 85.7%, 86.7% vs 85.7%, both P < 0.05). There was significant difference between the lymph node-positive group and the lymph node-negative group (92% vs 53.3%, 92% vs 40%, both P < 0.01). A positive correlation was found between the expression of S100A2 mRNA and S100A2 protein (r = 0.607, P < 0.001).

CONCLUSION: S100A2 plays an important role in ESCC carcinogenesis. S100A2 might be an important reference biomarker for ESCC biological behavior.

Differential expression of S100 protein subtypes in malignant melanoma, and benign and malignant peripheral nerve sheath tumors

BACKGROUND

Desmoplastic melanoma (DM) may simulate various benign and malignant lesions, including benign peripheral nerve sheath tumors (BPNSTs) and malignant peripheral nerve sheath tumors (MPNSTs). The latter case is diagnostically challenging because DM generally show only S100 protein expression but no reaction to melanocytic markers. S100 family of proteins consists of over 20 members. We report on S100 subtypes in malignant melanomas (MMs), and BPNSTs and MPNSTs to investigate differential expression.

DESIGN

S100A1, S100A2, S100A4, S100A6 and S100B immunostains were performed on 80 MMs including conventional and desmoplastic types, 86 BPNSTs and 77 MPNSTs.

RESULTS

S100A1 expression was seen in > 91% of MMs in a diffuse reaction, whereas BPNSTs showed focal or no reaction. Sixteen percent of MPNSTs focally expressed S100A1 except for one case with diffuse reaction. S100A2 staining was negative or focal in all three groups whereas S100A4 reaction was variable in all three. S100A6 was diffusely expressed in MMs, BPNSTs and MPNSTs. S100B was stained diffusely in MMs and BPNSTs, but its reaction was observed in 30% of MPNSTs in a focal fashion.

CONCLUSION

S100A1 expression was diffuse in most of MMs but absent or focal in BPNSTs and MPNSTs. This may be helpful to distinguish between the two entities.

Over-expression of S100A2 in pancreatic cancer correlates with progression and poor prognosis

Controversy exists regarding the clinical significance of S100A2 in the progression of tumours. In pancreatic cancer, little is known about the role of S100A2. The aim of this study was to clarify the clinical significance of S100A2 expression in pancreatic carcinogenesis. We microdissected invasive ductal carcinoma (IDC) cells from 22 lesions, pancreatic intraepithelial neoplasia (PanIN) cells from five lesions, intraductal papillary mucinous neoplasm (IPMN) cells from 38 lesions, pancreatitis-affected epithelial (PAE) cells from 16 lesions, and normal ductal cells from 18 normal pancreatic tissues. S100A2 expression in 14 pancreatic cancer cell lines, microdissected cells and formalin-fixed paraffin-embedded (FFPE) samples was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Microdissection analyses revealed that IDC cells expressed higher levels of S100A2 than did IPMN, PAE or normal cells (all comparisons, p < 0.007). Cell lines from metastatic sites expressed higher levels of S100A2 than those from primary sites. PanIN cells expressed higher levels of S100A2 than normal cells (p = 0.018). IDC cells associated with poorly differentiated adenocarcinoma expressed higher levels of S100A2 than did IDC cells without poorly differentiated adenocarcinoma (p = 0.006). Analyses of FFPE samples revealed that levels of S100A2 were higher in samples from patients who survived < 1000 days after surgery than in those from patients who survived > 1000 days (p = 0.043). Immunohistochemical analysis was consistent with qRT-PCR. S100A2 may be a marker of tumour progression or prognosis in pancreatic carcinogenesis and pancreatic cancer.

Decitabine up-regulates S100A2 expression and synergizes with IFN-gamma to kill uveal melanoma cells

PURPOSE

Metastatic uveal melanoma is resistant to conventional chemotherapy and immunotherapy. In this study, we investigated the responsiveness of uveal melanoma cell lines to IFNs and the hypomethylating agent decitabine.

EXPERIMENTAL DESIGN

The uveal melanoma cell lines 92-1, UW-1, OCM-1, and MKT-BR were exposed to varying concentrations of IFN-alpha, IFN-gamma, and decitabine, alone and in combination. The effects of decitabine on gene expression were examined using DNA microarray analysis.

RESULTS

We found that IFN-gamma and decitabine induced cell death in uveal melanoma. Whereas a high concentration of IFN-gamma (1,000 units/mL) was required to induce cell death, we observed a dose-related increase in cell death when decitabine was used at a range of 0.1 to 10 micromol/L. Strikingly, 1 micromol/L decitabine synergized with 10 to 1,000 units/mL IFN-gamma to induce massive cell death. In contrast, decitabine had no effect on three cutaneous melanoma cell lines and exhibited no synergy with either IFN. In uveal melanoma, decitabine up-regulated the expression of genes involved in growth control and apoptosis and down-regulated genes that have been implicated in the malignant phenotype of cutaneous melanoma. The gene up-regulated to the greatest degree by decitabine and whose expression showed a dose-effect across the three concentrations of decitabine was S100A2, a putative tumor suppressor. The genes modulated by decitabine in uveal melanoma were largely unaffected in cutaneous melanoma.

CONCLUSIONS

These findings form a basis for testing the decitabine/IFN-gamma combination in metastatic uveal melanoma and for exploring the role of S100A2 in the susceptibility of uveal melanoma to IFN-mediated cell death.

Expression of S100A2 and S100A4 predicts for disease progression and patient survival in bladder cancer

OBJECTIVES

To determine the expression patterns and prognostic value of S100A2 and S100A4 in surgical specimens from radical cystectomy for transitional cell carcinoma of the urinary bladder.

METHODS

Immunohistochemical staining for S100A2 and S100A4 was performed in 92 archived radical cystectomy and 38 normal specimens. The immunoreactivity of these proteins was stratified on a 0 to 6 scale and then correlated with the pathologic features and clinical outcome.

RESULTS

S100A2 expression was significantly decreased in the bladder cancer specimens compared with the controls (P <0.0001), and S100A4 expression was significantly greater in the bladder cancer specimens (P = 0.03). The loss of expression of S100A2 and increased expression of S100A4 were associated with muscle invasion (P <0.05). These alterations in expression were also associated with a greater risk of disease progression and a decreased chance of cancer-specific survival at a median follow-up of 25.3 months (P <0.0001 for both). After adjusting for the effects of the pathologic findings, S100A4 expression remained a significant predictor of disease progression (P <0.0001) and cancer-specific survival (P <0.0001).

CONCLUSIONS

S100A4 appeared to be an independent predictor for the treatment outcome in bladder cancer. The expression patterns of S100A2 and S100A4 correlated well with the pathologic stage, disease progression, and cancer-specific mortality. This finding could aid in identifying more biologically aggressive cancers and thus patients who might benefit from more intensive adjuvant therapy.

Precancerous model of human breast epithelial cells induced by NNK for prevention

Epidemiological investigations have suggested that exposure to tobacco and environmental carcinogens increase the risk of developing human breast cancer. In light of the chronic exposure of human breast tissues to tobacco and environmental carcinogens, we have taken an approach of analyzing cellular changes of immortalized non-cancerous human breast epithelial MCF10A cells during the acquisition of cancerous properties induced by repeated exposure to the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) at a low concentration of 100 pM. We found that accumulated exposures of MCF10A cells to NNK result in progressive development of cellular carcinogenesis from a stage of immortalization to precancerous sub-stages of acquiring a reduced dependence on growth factors and acquiring anchorage-independent growth. Using Matrigel for MCF10A cells to form size-restricted acini, we detected that exposures to NNK resulted in altered acinar conformation. Analysis of gene expression profiles by cDNA microarrays revealed up- and down-regulated genes associated with NNK-induced carcinogenesis. Using this cellular carcinogenesis model as a target system to identify anticancer agents, we detected that grape seed proanthocyanadin extract significantly suppressed NNK-induced carcinogenesis of MCF10A cells. Our studies provide a carcinogenesis-cellular model mimicking the accumulative exposure to carcinogens in the progression of human breast epithelial cells to increasingly acquire cancerous properties, as likely occurs in the development of precancerous human breast cells. Our cellular model also serves as a cost-efficient, in vitro system to identify preventive agents that inhibit human breast cell carcinogenesis induced by chronic exposures to carcinogens.

A review of the S100 proteins in cancer

AIM

In the quest to reduce mortality and morbidity from cancer, there is continued effort to identify novel biomarkers to aid in the early detection and the accurate prediction of tumour behaviour. One group of proteins that is emerging as a potentially important group of markers in multiple tumour types is the S100 family. This review summarises the biological and clinical relevance of these proteins in relation to different tumour types.

METHODS

A literature search was performed using the PubMed database and the reference lists of relevant articles. Single case studies were excluded and only reports with a clinical relevance from 1961 to 2007 were included.

RESULTS

The search yielded over 1000 published articles and reports. Important reports and studies were reviewed, screened and tracked for further relevant publications. Only the most relevant publications are discussed with relation to individual members of the S100 family.

CONCLUSION

There is increasing evidence that altered expression of S100 family members is seen in many cancers including breast, lung, bladder, kidney, thyroid, gastric, prostate and oral cancers. S100 proteins are commonly up-regulated in tumours and this is often associated with tumour progression. In contrast S100A2, S100A11 and S100A9 have been documented as tumour suppressors in some cancers but as tumour promoters in others. This demonstrates the complexity of the family and variability of their functions. Although the precise roles of these proteins in cancer is still to be discovered many of the family are associated with promoting metastases through interactions with matrix metalloproteinases or by acting as chemoattractants. There is also evidence that some members can regulate transcription factors such as p53. S100B already has a role in a clinical setting in the diagnosis and therapeutic monitoring of malignant melanoma. As our understanding of this family develops it is likely that many more members will aid the diagnosis, monitoring and potential treatment of cancers in the future.

Involvement of deterioration in S100C/A11-mediated pathway in resistance of human squamous cancer cell lines to TGFβ-induced growth suppression

Recently, we demonstrated that S100C/A11 comprises an essential pathway for growth suppression by TGFbeta in normal human keratinocytes. Nuclear transfer of S100C/A11 was a hallmark of the activation of the process. In the present study, we examined the possible deterioration in the pathway in human squamous cancer cell lines, focusing on intracellular localization of S100C/A11 and its functional partners Smad3 and Smad4. All four human squamous cancer cell lines examined (A431, BSCC-93, DJM-1, and HSC-5) were resistant to growth suppression by TGFbeta. In BSCC-93, DJM-1, and HSC-5 cells exposed to TGFbeta, S100C/A11 was not transferred to the nuclei, and p21(WAF1) was not induced. Overexpression of nucleus-targeted S100C/A11 partially recovered induction of p21(WAF1) and p15(INK4B) and growth suppression by TGFbeta1 in these cells. These results indicate that the deterioration in the S100C/A11-mediated pathway conferred upon the cancer cell lines resistance to TGFbeta. In A431 cells, S100C/A11, Smad3, and Smad4 were simultaneously transferred to the nuclei, and p21(WAF1) was induced upon exposure to TGFbeta. We provide evidence to indicate that refractoriness of A431 cells to TGFbeta was probably because the amount of p21(WAF1) induced by TGFbeta was insufficient to counteract cyclin A, which is highly overexpressed in A431 cells. Thus, the newly found S100C/A11-mediated pathway is at least partly involved in conferring upon human squamous cell cancers resistant to TGFbeta-induced growth suppression, which is considered to play a critical role for the initiation and progression of many human cancers.

Down-regulation of S100A2 in lymph node metastases of head and neck cancer

BACKGROUND

Our cDNA microarray analysis of squamous cell carcinoma of the head and neck (SCCHN) previously identified that S100A2 was down-regulated in highly metastatic 686LN-M3s cell lines established through in vivo selection using a metastatic xenograft mouse model. S100A2, a putative tumor suppressor, has been found to be down-regulated in several types of primary tumor as compared with the normal tissue. Only a few reports have explored its expression status and function in metastasis.

METHODS

To further confirm down-regulation of S100A2 in human metastasis, we examined S100A2 expression using immunohistochemical analysis of paraffin-embedded SCCHN tissues. The samples included primary SCCHN tumors (Tu-1) and involved lymph nodes (Met-1) from the same patients, and primary tumors in node-negative patients (Tu-2).

RESULTS

Most of these tumors expressed S100A2 but lymph node metastases showed a pattern of reduced staining for S100A2 compared with primary tumors. A similar expression pattern of S100A2 was also observed in several SCCHN cell lines by reverse transcription-polymerase chain reaction (RT-PCR) and immunoblotting. Particularly, S100A2 expression was lower in 686LN than Tu686 and hardly detectable in the metastatic derivatives 686LN-M3s. Further study of S100A2 promoter showed higher methylation intensity in these metastatic derivatives than in Tu686 and 686LN.

CONCLUSIONS

S100A2 was down-regulated in lymph node metastasis of SCCHN, suggesting that instead of being a putative tumor suppressor, S100A2 may play a role in the metastasis of SCCHN.

Specific expression of annexin A8 in adult murine stratified epithelia

Annexin A8 is a member of the annexin family of calcium-regulated membrane-binding proteins. In this report, we investigated the expression of annexin A8 in adult mouse organs. Northern blot analysis of adult mouse organs showed that a single annexin A8 transcript of 1.9 kb is expressed most strongly in skin, eye and tongue. In situ hybridisations using annexin A8-specific probes revealed that in the stratified epithelia of the tongue and the early postnatal epidermis, annexin A8 transcription could be detected in basal and suprabasal layers of these stratified epithelia. Western blot analyses using a murine ANXA8-specific antiserum showed, that the 36 kD ANXA8 protein was most abundant in the skin and tongue. The abundance of ANXA8 protein in the skin increased during postnatal days 1-18 and was immunohistochemically localised in suprabasal layers of the epidermis. In the tongue epithelium as well, ANXA8 protein was found in suprabasal layers. ANXA8 immunoreactivity was also found in suprabasal layers of the stratified epithelia of the oesophagus and the forestomach, while it was detected in all layers of the cornea epithelium and in the cornea endothelium of the eye. We also investigated the expression of retinoic acid receptor alpha protein (RARA) and ANXA8 in the epidermis immunohistochemically. While RARA immunoreactivity was exclusively detected in the basal layer, ANXA8 immunoreactivity was restricted to suprabasal layers of the epidermis. Thus, ANXA8 protein is most abundant in stratified epithelia of the postnatal mouse. Its location in the suprabasal layers suggests that ANXA8 may be associated with the terminal differentiation of epithelial cells in these tissues.

Differential expression of S100A2 and S100A4 in lung adenocarcinomas: clinicopathological significance, relationship to p53 and identification of their target genes

Previous studies suggest that some S100 proteins are involved in the progression of certain types of cancer. However, no comprehensive data is currently available on the expression of S100 family genes in lung adenocarcinomas. Oligonucleotide array, quantitative reverse transcription-polymerase chain reaction and western blot analyses of lung adenocarcinoma cell lines and bronchiolar epithelial cells (SAEC and NHBE) revealed that S100A2 and S100A4 were the most strikingly downregulated and upregulated members of the S100 family, respectively. Immunohistochemical analyses of 94 primary lung adenocarcinomas showed that positive S100A2 expression (33/94, 35.1%) was significantly associated with lymphatic invasion (P=0.0233) and positive S100A4 expression (19/94, 20.2%) with vascular invasion (P=0.0454). Interestingly, a strong inverse relationship was found between S100A4 and p53 expression (P=0.0008). Survival analyses showed that S100A4 positivity was associated with poor patient prognosis (P=0.042). S100A2 positivity was not associated with patient survival when the whole patient group was analyzed; however, S100A2 positivity was a favorable prognostic indicator in patients with p53-negative tumors (P=0.0448). Finally, we used oligonucleotide array analyses and identified potential S100A2 and S100A4 target genes involved in cancer progression: S100A2 induced RUNX3 and REPRIMO; S100A4 induced EZRIN, RUNX1 and WISP1; S100A2 repressed EGFR, NFKB2 and RELA2; and S100A4 repressed ANXA10 and IL1RN. Thus, the present study demonstrates involvement of S100A2 and S100A4 in the progression of lung adenocarcinomas and an inverse association between S100A4 and p53 expression, and provides a list of targets regulated by S100A2 and S100A4.

Promoter hyper-methylation of calcium binding proteins S100A6 and S100A2 in human prostate cancer

BACKGROUND

S100A6 and S100A2 are members of the S100 family of calcium binding proteins, which are down regulated in prostate cancer, however the molecular mechanism(s) underlying their loss of expression is unknown.

METHODS

The promoter and exon 1 region of the S100A6 and S100A2 genes was sequenced in bisulfite modified DNA from non-malignant, benign prostatic hyperplasia (BPH), malignant and metastatic prostate tissues and in cell lines. Immunohistochemistry was performed to correlate S100A2 expression with methylation status.

RESULTS

S100A6 methylation was absent or occurred at isolated sites in 14/14 cases of non-malignant epithelium and 5/5 cases of BPH tissues, whereas methylation was seen in 14/27 (52%) cases of prostatic cancer (P<0.0001), 2/2 cases of metastatic cancer and in the CWR22 prostatic cancer xenograft. Critical CpG sites within the S100A2 promoter were methylated in LNCaP, LNCaP-LN3, and CWR22 cells but not in Du145, PC3 or BPH45 cells. In tissues, S100A2 methylation was seen in 32/34 (94%) cases of adenocarcinoma and 5/5 cases of metastatic cancer. However, S100A2 methylation was also seen in 9/12 (75%) cases of non-malignant tissues and in 5/5 cases of BPH. Immunostaining, showed absent S100A2 expression all 41 cases of prostatic cancer, whereas staining was seen in the basal cells of non-malignant epithelium.

CONCLUSIONS

Loss of S100A6 and S100A2 proteins is frequent in human prostatic cancer. A major mechanism underlying the loss of S100A6 expression appears to involve promoter hyper-methylation. However, mechanisms other than methylation of the known promoter are involved in silencing S100A2 in the prostate.

Increased expression of S100A6 is associated with decreased metastasis and inhibition of cell migration and anchorage independent growth in human osteosarcoma

While most osteosarcoma patients have metastatic or micrometastatic lesions, less than 15% of them have clinically detectable metastatic diseases at presentation. To identify potential markers that may predict osteosarcoma metastasis, we analyzed the expression of S100A6 in 50 osteosarcoma cases and found that 84% of the analyzed specimens stained positive for S100A6. There is a trend towards decreased clinically evident metastasis with increased S100A6 staining. Overexpression of S100A6 in osteosarcoma cells decreases cell motility and anchorage independent growth on collagen gels. Our findings provide evidence that, while S100A6 is commonly overexpressed in human osteosarcoma, loss of its expression correlates with a metastatic phenotype.

Establishment of an immortalized cell line from a precancerous lesion of lung adenocarcinoma, and genes highly expressed in the early stages of lung adenocarcinoma development

Atypical adenomatous hyperplasia (AAH) is classified as a precancerous lesion of lung adenocarcinoma. We established an immortalized AAH cell line (PL16T) and a human non-neoplastic bronchial epithelial cell line (PL16B) from the same patient by transfection with the gene for SV40 large T antigen. The expression profile of PL16T was compared with that of PL16B by the suppression subtractive hybridization method. From 704 selectively hybridized clones, we finally selected 25 fragments of mRNA that showed transcription levels more than three times higher in PL16T than in PL16B. Thirteen (52%) and eight (32%) of them encoded tumor-associated calcium signal transducer 2 (TACSTD2) and S100 calcium binding protein A2 (S100A2), respectively. The high transcription of TACSTD2 and S100A2 in PL16T was confirmed by in situ hybridization. In normal lung tissue, both TACSTD2 and S100A2 were expressed at very low levels, but seven and five of 14 AAH were positive for TACSTD2 and S100A2, respectively. The frequency of TACSTD2 positivity was increased in 16 of 22 bronchioloalveolar carcinomas (BAC) and adenocarcinoma with mixed subtype with BAC component (mixed BAC). Positivity for S100A2 occurred in four of 22 BAC and mixed BAC. The abnormal transcription of TACSTD2 and S100A2 are thought to be unique molecular markers of the preinvasive stage of lung adenocarcinoma.

S100A2, a potential marker for early recurrence in early-stage oral cancer

Early-stage oral cancer patients may have distinct clinical outcomes and respond differently to the same treatment. Up to now, there is still no individual marker to identify such patients with poor outcome. Down-regulation of a tumor suppressor gene, S100A2, in oral cancer cells was identified by mRNA profiling analysis then confirmed by RT-PCR and Southern blotting. The expression of nuclear S100A2 protein examined by immunohistochemistry was not significantly associated with any patient characteristic among the 70 early-stage oral squamous cell carcinoma (SCC) patients. Intriguingly, the loss of nuclear S100A2 positivity was significantly associated with shorter disease-free survival (p=0.019) while having no effect on the overall survival of these patients. Cox regression analysis with backward elimination identified S100A2 (p=0.006), tobacco smoking (p=0.013), and betel quid chewing (p=0.019) as independent predictors of disease-free survival. This is a first study to demonstrate that loss of nuclear S100A2 may serve as an independent prognostic marker for early-stage oral cancer patients at high risk of recurrence. A more aggressive treatment modality and intensive follow-up may be recommended for the patients with reduced expression of S100A2 in tumor cell nuclei.

Human homologue of cement gland protein, a novel metastasis inducer associated with breast carcinomas

A suppression subtractive cDNA library representing mRNAs expressed at a higher level in the malignant human breast cancer cell line, MCF-7, relative to a benign breast tumor-derived cell line, Huma 123, contained a cDNA, M36, which was expressed in estrogen receptor alpha (ERalpha)-positive breast carcinoma cell lines but not in cell lines from normal/benign/ERalpha-negative malignant breast lesions. M36 cDNA had an identical coding sequence to anterior gradient 2 (AGR2), the human homologue of the cement gland-specific gene (Xenopus laevis). Screening of breast tumor specimens using reverse transcription-PCR and immunocytochemistry with affinity-purified anti-AGR2 antibodies showed that the presence of AGR2 mRNA and protein were both statistically significantly associated with ERalpha-positive carcinomas (P = 0.007, Fisher's exact test) and with malignancy (P < or = 0.025). When an expression vector for AGR2 cDNA was introduced into benign nonmetastatic rat mammary tumor cells, and three separate clones and two pools of cells were transferred to the mammary glands of syngeneic hosts, there were no consistent differences in the mean latent periods of tumor formation. However, metastases occurred in the lungs of animals receiving the AGR2 transfectants in 77% to 92% of animals with primary tumors (P = 0.0001) compared with no metastases in the control groups. The AGR2 transfectants exhibited enhanced rates of adhesion to a plastic substratum and extracellular AGR2 enhanced the rate of attachment of AGR2-negative but not AGR2-positive cells. These experiments are the first to link mechanistically the developmental gene product, AGR2, with metastasis in vivo.

Expression of S100 proteins in normal human tissues and common cancers using tissue microarrays: S100A6, S100A8, S100A9 and S100A11 are all overexpressed in common cancers

AIMS

To survey the expression of members of the S100 family of calcium-binding proteins in normal human tissues and common cancers using tissue microarrays. S100A6, S100A8, S100A9 and S100A11 have all been suggested to have potential roles in carcinogenesis and tumour progression but their expression has not been described in a wide range of human tissues and tumours.

METHODS AND RESULTS

A custom-made tissue array, containing 291 tissue cores representing 28 tissue types and 21 tumour types, was used to produce sections that were immunostained for S100A2, S100A6, S100A8, S100A9, S100A11, calbindin 1, calbindin 2, S100B and parvalbumin. S100A6, S100A8 and S100A9 were expressed in 32%, 12% and 28% of breast cancers, respectively. There was a translocation of S100A11 expression from exclusively nuclear in normal tissues to cytoplasmic and nuclear in all common cancers.

CONCLUSIONS

S100A6, S100A8, S100A9 and S100A11 are all expressed in common cancers, especially breast cancer. In addition, S100A11 undergoes a nucleocytoplasmic translocation which may have a direct influence on the proliferation of the cancer cells.

Transcriptional response of bronchial epithelial cells to Pseudomonas aeruginosa: identification of early mediators of host defense

The airway epithelium responds to microbial exposure by altering expression of a variety of genes to increase innate host defense. We aimed to delineate the early transcriptional response in human primary bronchial epithelial cells exposed for 6 h to a mixture of IL-1beta and TNF-alpha or heat-inactivated Pseudomonas aeruginosa. Because molecular mechanisms of epithelial innate host defense are not fully understood, the open-ended expression-profiling technique SAGE was applied to construct gene expression profiles covering 30,000 genes: 292 genes were found to be differentially expressed. Expression of seven genes was confirmed by real-time qPCR. Among differentially expressed genes, four classes or families were identified: keratins, proteinase inhibitors, S100 calcium-binding proteins, and IL-1 family members. Marked transcriptional changes were observed for keratins that form a key component of the cytoskeleton in epithelial cells. Expression of antimicrobial proteinase inhibitors SLPI and elafin was elevated after microbial or cytokine exposure. Interestingly, expression of numerous S100 family members was observed, and eight members, including S100A8 and S100A9, were among the most differentially expressed genes. Differential expression was also observed for the IL-1 family members IL-1beta, IL-1 receptor antagonist, and IL-1F9, a newly discovered IL-1 family member. Clustering of differentially expressed genes into biological processes revealed that the early inflammatory response in airway epithelial cells to IL-1beta-TNF-alpha and P. aeruginosa is characterized by expression of genes involved in epithelial barrier formation and host defense.

Overexpression of S100A2 protein as a prognostic marker for patients with stage I non small cell lung cancer

S100A2, a calcium-binding protein, recently became of major interest because of its differential expression during transformation and metastasis in various tumors. The purpose of this study was to investigate the prognostic significance of S100A2 expression in the early-stage non small lung cancer (NSCLC). Immunohistochemical analysis to determine the percentage of cells staining positive for S100A2 was performed on 11 NSCLC tissue microarray slides containing samples from 113 patients with pathologic stage I NSCLC who had undergone curative surgery. S100A2 was expressed in samples from 79 patients (69.9%). Kaplan-Meier analysis showed that patients whose tumors had positive S100A2 expression had a significantly lower overall survival and disease-specific survival rate at 5 years after surgery than did patients with negative S100A2 expression (p < 0.001 and p < 0.001, respectively). Age at diagnosis, histologic type of cancer, degree of differentiation and smoking history did not have a statistically significant effect on survival. Multivariate analysis confirmed that S100A2 expression is a better predictor for disease-specific survival than were other clinical and histologic variables tested. Our results suggested that the expression of the S100A2 protein in stage I NSCLC indicates poor prognosis and may be used to identify patients with early-stage NSCLC who might benefit from adjuvant treatment.

S100A2 is strongly expressed in airway basal cells, preneoplastic bronchial lesions and primary non-small cell lung carcinomas

S100A2 gene products were shown to be frequently and dramatically over-represented in non-small cell lung cancer (NSCLC) lesions over normal tissue by microarray analysis. We have now analysed an independent series of NSCLC tumours and multiple matched normal bronchial epithelial sites by RT–PCR and immunohistochemistry to investigate: whether this expression pattern can be confirmed and whether elevated expression is associated with tumour histology, clinical outcome or preneoplasia. In this second series, S100A2 was strongly expressed in 76% (35 out of 46) of tumours, more frequently in squamous cell than adenocarcinomas (P<0.002). This strong expression was not related to high-level gene amplification, but was associated in one of five informative cases with an allele-specific imbalance in transcript levels. Most tumours strongly expressed the ΔNp63 transcript, the product of which is a putative regulator of S100A2 transcription and while all but one of the tumours positive for ΔNp63 expressed S100A2, others negative for this regulator also expressed the gene. Contrary to the hypothesis that S100A2 is a tumour suppressor, no somatic mutations were identified in the coding sequence in 44 tumours. Furthermore, an examination of multiple tumour-free epithelial sites from 20 patients showed that strong expression was often associated with increasing levels of disorder in preinvasive bronchial lesions (P<0.0001).

S100A7 and the progression of breast cancer

The S100 gene family comprises more than 20 members whose protein sequences encompass at least one EF-hand Ca²⁺ binding motif. The expression of individual family members is not ubiquitous for all tissues and there appears to be an element of tissue-specific expression. Molecular analysis of breast tumors has revealed that several S100s, including S100A2, S100A4 and S100A7, exhibit altered expression levels during breast tumorigenesis and/or progression. Subsequent studies have started to describe a functional role for these S100 proteins as well as their mechanism of action and the biochemical pathways they modify. The present review outlines what is known about S100A7 in breast cancer and summarizes the need to better understand the importance of this protein in breast cancer.

Differential expression of S100 gene family in human esophageal squamous cell carcinoma

PURPOSE

To study the differential expression of the S100 gene family at the RNA level in human esophageal squamous cell carcinoma (ESCC), and to find the relationship of the S100 gene family with ESCC.

METHODS

Firstly, the specific primers were designed for the different S100 genes with Software Primer 3, which required that both primer sequences of each S100 gene were from two different exons respectively. Then, the differential expression of 16 S100 genes was examined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) in 62 cases of ESCC versus the corresponding normal esophageal mucosa. All RT-PCR products were analyzed by 1.5% agarose gel. With Fluor-S MultiImager and Multi-Analyst software, the electrophoresis images were evaluated with statistics analysis using SAS 8.1 software.

RESULTS

Eleven out of 16 S100 genes were significantly downregulated ( p<0.05) in ESCC versus the normal counterparts such as S100A1, S100A2, S100A4, S100A8, S100A9, S100A10, S100A11, S100A12, S100A14, S100B, and S100P genes. Only the S100A7 gene in the S100 family was markedly upregulated ( p<0.05). Moreover, the S100B gene was significantly correlated with histological differentiation of ESCC ( p=0.0247), and the deregulation of some S100 genes was closely correlated ( p<0.05), such as S100A10/S100A11, S100A2/S100A8, S100A2/S100A14, S100A8/S100A14, and S100A2/S100P etc.

CONCLUSIONS

The S100 gene family is closely associated with ESCC.

S100A protein expression in the distinction between lentigo maligna and pigmented actinic keratosis

Lentigo maligna (LM), a type of malignant melanoma in situ, and pigmented actinic keratosis (PAK) may have similar clinical appearances but are different in prognosis and treatment. Diagnosis is established by skin biopsy. In certain cases, microscopic features may be very similar in both entities, making it difficult to determine whether the pigmented atypical cells are keratinocytes or melanocytes. Immunohistochemical markers can be useful for the identification of melanocytes in these cases. There are limitations to the use of some standard immunohistochemistry markers, however. S100 proteins are a varied group of proteins that are of special interest because of their dysregulated expression in neoplastic disorders. Their expression is changed during malignant transformation, progression, and/or metastasis in various cell lines and tumors, including melanomas. Our study analyzed the expression of several of the S100 protein subtypes (S100A2, S100A6, and S100A8/A9 or A12) in 38 LM cases and 44 PAK cases to define their potential value in the distinction between these entities together with their role in the development of early malignant melanoma of the skin. The results showed an upregulation of S100A2 protein in atypical keratinocytes in PAK and in normal keratinocytes adjacent to melanoma cells in LM. There was also an upregulation of S100A8/A9 or A12 protein, as detected by the antibody MAC387, in normal keratinocytes adjacent to both atypical keratinocytes and melanocytes in PAK and LM, respectively. There were statistically significant differences in the level of positive cells and in the pattern of immunoreactivity for anti-S100A2 and MAC387 in each entity, however. Moreover, the findings of our study support the notion that melanocyte-keratinocyte interactions are abnormal in both of these disease entities and may be involved in their progression.

Differential expression of S100A2 and S100A4 during progression of human prostate adenocarcinoma

PURPOSE

To establish the clinical significance of calcium binding proteins S100A2 and S100A4 during progression of human prostate adenocarcinoma.

PATIENTS AND METHODS

Expression pattern of S100A2 and S100A4 was determined in normal human prostate epithelial cells (NHPE); virally transformed prostate epithelial cells (PZ-HPV-7); several human prostate carcinoma cells (22Rv1, DU145, LNCaP, and PC3); tissue samples obtained during transuretheral prostatic resection from patients with benign prostate hyperplasia (BPH), prostatitis, and adenocarcinoma; and paraffin-embedded sections from pair-matched benign and cancer specimens of different tumor grade.

RESULTS

High constitutive protein expression of S100A2 was observed in NHPE and PZ-HPV-7 cells, whereas its complete absence was observed in 22Rv1, DU145, LNCaP, and PC3 cells. Tissue samples of BPH and prostatitis exhibited higher mRNA and protein levels of S100A2 than low-grade cancer (Gleason score <or= 6), whereas a complete loss was observed in high-grade cancer specimens (Gleason score > 6). Immunohistochemical analysis further confirmed high levels of S100A2 in benign tissues and a progressive loss with increasing tumor grade. The protein level of S100A4 was significantly higher in all carcinoma cells compared with NHPE and PZ-HPV-7 cells. The mRNA and protein level of S100A4 was significantly higher in high-grade cancer specimens compared with BPH, prostatitis, and low-grade cancer. The high levels of S100A4 observed in cancer tissue correlated with increasing tumor grade.

CONCLUSION

Loss of S100A2 and increased expression of S100A4 may be an important event during progression of prostate cancer in humans.

Expression profiling of primary non-small cell lung cancer for target identification

Using a panel of cDNA microarrays comprising 47 650 transcript elements, we have carried out a dual-channel analysis of gene expression in 39 resected primary human non-small cell lung tumours versus normal lung tissue. Whilst approximately 11 000 elements were scored as differentially expressed at least twofold in at least one sample, 96 transcripts were scored as over-represented fourfold or more in at least seven out of 39 tumours and 30 sequences 16-fold in at least two out of 39 tumours, including 24 transcripts in common. Transcripts (178) were found under-represented fourfold in at least seven out of 39 tumours, 31 of which are under-represented 16-fold in at least two out of 39 lesions. The relative expression levels of representative genes from these lists were analysed by comparative multiplex RT-PCR and found to be broadly consistent with the microarray data. Two dramatically over-represented genes, previously designated as potential tumour suppressors in breast (maspin) and lung and breast (S100A2) cancers, were analysed more extensively and demonstrate the effectiveness of this approach in identifying potential lung cancer diagnostic or therapeutic targets. Whilst it has been reported that S100A2 is downregulated in NSCLC at an early stage, our microarray, cmRT-PCR, Western and immunohistochemistry data indicate that it is strongly expressed in the majority of tumours.

Annexin VIII is differentially expressed by chondrocytes in the mammalian growth plate during endochondral ossification and in osteoarthritic cartilage

Endochondral ossification is the developmental process that leads to the formation and coordinated longitudinal growth of the majority of the vertebrate skeleton. Central to this process is chondrocyte differentiation occurring in the growth plate that lies at the junction between the epiphyseal cartilage and the bone. To identify novel factors involved in this differentiation process, suppression subtractive hybridization was performed to amplify preferentially cDNAs uniquely expressed in fetal bovine growth plate chondrocytes as opposed to epiphyseal chondrocytes. The subtracted product was used to screen a fetal bovine chondrocyte cDNA library. One of the cDNA clones identified encoded the bovine orthologue of annexin VIII, a protein not previously described in the growth plate. Northern and Western blotting confirmed that annexin VIII was expressed by growth plate chondrocytes and not by epiphyseal chondrocytes. Immunohistochemistry of the fetal bovine growth plate identified a gradient of increasing annexin VIII protein from the proliferative to the hypertrophic zone. Immunofluorescence localized annexin VIII largely to the chondrocyte cell membrane. In a preliminary study, we examined the distribution of annexin VIII in normal and osteoarthritic (OA) articular cartilage. In OA cartilage, the protein was located in a subset of mid- to deep zone chondrocytes and in the matrix surrounding these cells; no annexin VIII was detected in normal articular cartilage. Thus annexin VIII is a marker for chondrocyte differentiation during normal endochondral ossification and may act as a marker for cells undergoing inappropriate differentiation in OA.