Increased expression of calcium-binding protein S100 in human uterine smooth muscle tumours

The Calcium Binding Protein S100A11 and Its Roles in Diseases

The calcium binding protein S100 family in humans contains 21 known members, with each possessing a molecular weight between 10 and 14 kDa. These proteins are characterized by a unique helix-loop-helix EF hand motif, and often form dimers and multimers. The S100 family mainly exists in vertebrates and exerts its biological functions both inside cells as a calcium sensor/binding protein, as well as outside cells. S100A11, a member of the S100 family, may mediate signal transduction in response to internal or external stimuli and it plays various roles in different diseases such as cancers, metabolic disease, neurological diseases, and vascular calcification. In addition, it can function as chemotactic agent in inflammatory disease. In this review, we first detail the discovery of S100 proteins and their structural features, and then specifically focus on the tissue and organ expression of S100A11. We also summarize its biological activities and roles in different disease and signaling pathways, providing an overview of S100A11 research thus far.

Characterisation of the developing heart in a pressure overloaded model utilising RNA sequencing to direct functional analysis

Cardiogenesis is influenced by both environmental and genetic factors, with blood flow playing a critical role in cardiac remodelling. Perturbation of any of these factors could lead to abnormal heart development and hence the formation of congenital heart defects. Although abnormal blood flow has been associated with a number of heart defects, the effects of abnormal pressure load on the developing heart gene expression profile have to date not clearly been defined. To determine the heart transcriptional response to haemodynamic alteration during development, outflow tract (OFT) banding was employed in the chick embryo at Hamburger and Hamilton stage (HH) 21. Stereological and expression studies, including the use of global expression analysis by RNA sequencing with an optimised procedure for effective globin depletion, were subsequently performed on HH29 OFT-banded hearts and compared with sham control hearts, with further targeted expression investigations at HH35. The OFT-banded hearts were found to have an abnormal morphology with a rounded appearance and left-sided dilation in comparison with controls. Internal analysis showed they typically had a ventricular septal defect and reductions in the myocardial wall and trabeculae, with an increase in the lumen on the left side of the heart. There was also a significant reduction in apoptosis. The differentially expressed genes were found to be predominately involved in contraction, metabolism, apoptosis and neural development, suggesting a cardioprotective mechanism had been induced. Therefore, altered haemodynamics during development leads to left-sided dilation and differential expression of genes that may be associated with stress and maintaining cardiac output.

S100 proteins: An emerging cynosure in pregnancy & adverse reproductive outcome

S100 proteins are calcium (Ca²⁺)-binding proteins and these have an important function in progression, manifestation and therapeutic aspects of various inflammatory, metabolic and neurodegenerative disorders. Based on their involvement in intracellular or extracellular regulatory effects, S100 proteins are classified into three subgroups: one subgroup is specialized in exerting only intracellular effects, other performs both intracellular and extracellular functions and the third subgroup members only display extracellular regulatory effects. S100 proteins are expressed particularly in vertebrates and have cell-specific expression. Functionally, S100 proteins act through their surface receptors and regulate cell functions in autocrine or paracrine mode. Receptor for advanced glycation end products (RAGEs) and toll-like receptor 4 are the main surface receptors. S100 proteins participate in the regulation of cellular differentiation, proliferation, apoptosis and inflammation along with Ca²⁺ homeostasis, energy metabolism and cellular migration, and perform the respective functions through their interaction with transcription factors, nucleic acids, enzymes, receptors, cytoskeleton system, etc. Currently, their role in adverse pregnancy outcomes and compromised reproductive health is being explored. These proteins are present in amniotic fluid, endometrium tissue and foetal brain; therefore, it is quite likely that alterations in the expression levels of S100 family members will be affecting the particular function they are involved in and ultimately affecting the pregnancy in adverse manner. The current review discusses about an association of S100 proteins in pregnancy disorders such as endometriosis, intrauterine growth retardation and miscarriage.

Serum concentrations of TFF3, S100-A11 and AIF-1 in association with systemic inflammatory response, disease stage and nodal involvement in endometrial cancer

To compare preoperative intestinal trefoil factor 3 (TFF3), allograft inflammatory factor-1 (AIF-1) and calgizzarin (S100-A11) serum levels in patients with endometrial cancer, endometrial hyperplasia and in healthy female controls. Serum levels of TFF3, S100- A11 and AIP-1 were analyzed in 98 consecutive patients with histologically verified endometrial cancer, in 43 patients with endometrial hyperplasia diagnosed during hysteroscopy and 24 controls with benign disease. Results were correlated with urinary neopterin/creatinine ratio, serum kynurenine, tryptophan, retinol, alpha-tocopherol, vitamin D, citrulline, C-reactive protein, interleukin-6 and clinical characteristics. S100-A11, and AIF-1 levels were higher in endometrial hyperplasia patients than in controls, and also significantly higher in endometrial cancer than in patients with endometrial hyperplasia. Serum concentrations of TFF3 and S100-A11 were associated with tumor stage and lymph node status. TFF3 exhibited positive correlation with age, IL-6, vitamin D, kynurenine, urinary neopterin/creatinine ratio and kynurenine/tryptophan ratio. S100-A11, as well as AIF-1 correlated positively with Il-6 and TFF3. TFF3, S100-A11 and AIF-1 represent potential biomarkers in patients with endometrial cancer. TFF3 and S100-A11 increase with tumor stage and lymph node involvement, reflecting higher tumor mass that is also associated with increased concentration of biomarkers of immune dysfunction.

Comparative proteomic profiling of human dental pulp stem cells and periodontal ligament stem cells under in vitro osteogenic induction

OBJECTIVE

This study aimed to compare the proteomic profiling of human dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) under in vitro osteogenic induction, which imitates the microenvironment during osteo-/odontogenesis of DPSCs and PDLSCs.

DESIGN

The proteomic profiles of osteoinduced DPSCs and PDLSCs from a single donor were compared using the isobaric tag for relative and absolute quantitation (iTRAQ) technique and subsequent bioinformatics analysis.

RESULTS

A total of 159 differentially expressed proteins in PDLSCs and DPSCs were identified, 82 of which had a higher expression level in PDLSCs, while 77 were more highly expressed in DPSCs. Among these enriched proteins, certain members from the collagen, heat shock protein and protein S100 families may distinguish osteoinduced PDLSCs and DPSCs. Gene ontology (GO) classification revealed that a large number of the enriched terms distinguishing PDLSCs and DPSCs are involved in catalytic activity, protein binding, regulation of protein metabolic processes and response to stimulus. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated several involved pathways, including the fatty acid biosynthesis pathway, pantothenate and CoA biosynthesis pathway, arachidonic acid metabolism pathway and PPAR signaling pathway. Further verification showed that the mineralization and migration capacities of PDLSCs were greater than those of DPSCs, in which heat shock protein beta-1, Protein S100-A10 and S100-A11 may play a part.

CONCLUSIONS

Less than 5% of the differentially expressed proteins make up the comparative proteomic profile between osteoinduced PDLSCs and DPSCs. This study helps to characterize the differences between osteoinduced PDLSCs and DPSCs in vitro.

Helicobacter pylori outer inflammatory protein A (OipA) suppresses apoptosis of AGS gastric cells in vitro

Outer inflammatory protein A (OipA) is an important virulence factor associated with gastric cancer and ulcer development; however, the results have not been well established and turned out to be controversial. This study aims to elucidate the role of OipA in Helicobacter pylori infection using clinical strains harbouring oipA "on" and "off" motifs. Proteomics analysis was performed on AGS cell pre-infection and postinfection with H. pylori oipA "on" and "off" strains, using liquid chromatography/mass spectrometry. AGS apoptosis and cell cycle assays were performed. Moreover, expression of vacuolating cytotoxin A (VacA) was screened using Western blotting. AGS proteins that have been suggested previously to play a role or associated with gastric disease were down-regulated postinfection with oipA "off" strains comparing to oipA "on" strains. Furthermore, oipA "off" and ΔoipA cause higher level of AGS cells apoptosis and G0/G1 cell-cycle arrest than oipA "on" strains. Interestingly, deletion of oipA increased bacterial VacA production. The capability of H. pylori to induce apoptosis and suppress expression of proteins having roles in human disease in the absence of oipA suggests that strains not expressing OipA may be less virulent or may even be protective against carcinogenesis compared those expressing OipA. This potentially explains the higher incidence of gastric cancer in East Asia where oipA "on" strains predominates.

Identification of Protein Markers Specific for Papillary Renal Cell Carcinoma Using Imaging Mass Spectrometry

Since the emergence of proteomics methods, many proteins specific for renal cell carcinoma (RCC) have been identified. Despite their usefulness for the specific diagnosis of RCC, such proteins do not provide spatial information on the diseased tissue. Therefore, the identification of cancer-specific proteins that include information on their specific location is needed. Recently, matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS) based imaging mass spectrometry (IMS) has emerged as a new tool for the analysis of spatial distribution as well as identification of either proteins or small molecules in tissues. In this report, surgical tissue sections of papillary RCC were analyzed using MALDI-IMS. Statistical analysis revealed several discriminative cancer-specific m/z-species between normal and diseased tissues. Among these m/z-species, two particular proteins, S100A11 and ferritin light chain, which are specific for papillary RCC cancer regions, were successfully identified using LC-MS/MS following protein extraction from independent RCC samples. The expressions of S100A11 and ferritin light chain were further validated by immunohistochemistry of human tissues and tissue microarrays (TMAs) of RCC. In conclusion, MALDI-IMS followed by LC-MS/MS analysis in human tissue identified that S100A11 and ferritin light chain are differentially expressed proteins in papillary RCC cancer regions.

Candidate agents for papillary thyroid cancer identified by gene expression analysis

A better understanding of the molecular mechanisms involved in papillary thyroid cancer (PTC) is needed to manage these patients effectively. Our objectives were to expand our understanding of this disease, and to identify biologically active small molecules capable to reverse PTC. We downloaded gene expression data of PTC from Gene Expression Omnibus database and employed computational bioinformatics analysis to compare gene expression patterns with normal tissues. Small molecules that induced inverse gene changes to the PTC were identified. A total of 2,154 differentially expressed genes (DEGs) with a false discovery rate of 0.01 were identified. These 2,154 DEGs were significantly enriched in 17 pathways, including pathways associated with signal transduction, tumorigenesis and lipid or amino acid metabolism. In addition, we identified large amount of small molecules that capable to reverse PTC. We found a group of small molecules that can provide new ideas for the therapeutic studies in PTC. These drugs are clearly a direction that warrants additional consideration.

S100A11 is a migration-related protein in laryngeal squamous cell carcinoma

OBJECTIVE

As a member of the S100 proteins family, the involvement of S100A11 has been suggested in a wide range of biological processes such as cell growth and motility, cell-cycle progression, transcription, differentiation and smooth muscle cell migration. However, the expression of S100A11 and its exact function in laryngeal squamous cell carcinoma (LSCC) have not been elucidated.

METHODS

The protein and mRNA expression levels of S100A11 were analyzed in primary tumors and matched tumor-adjacent tissues of LSCC by western blotting and semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) or quantitative real time PCR (Q-RT-PCR), respectively. Cell proliferation, colony formation, migration and wound-healing assays were performed to assess whether the knockdown of S100A11 by small interfering RNA (siRNA) could influence the biological behavior of human laryngeal carcinoma Hep-2 cells in vitro.

RESULTS

We found that both protein and mRNA levels of S100A11 were overexpressed in laryngeal tumor tissues when compared to the corresponding noncancerous tissues. Further, it was demonstrated that the expression of S100A11 could induce migration but not proliferation of Hep-2 cells. Additionally, S100A11 altered a series of intracellular events, including the down-regulation of epidermal growth factor receptor (EGFR), CD44 and MMP2.

CONCLUSIONS

These results highlight the significance of S100A11 in LSCC progression and suggest that the dysregulation of S100A11 might contribute to the metastatic progression of LSCC.

Expression of p53 and p21(WAF-1), apoptosis, and proliferation of smooth muscle cells in normal myometrium during the menstrual cycle: implication of DNA damage and repair for leiomyoma development

Uterine leiomyoma is the most common tumor in the female genital tract, although its pathogenesis remains unclear. Molecular analyses have demonstrated that each leiomyoma nodule is monoclonal and harbors various DNA abnormalities, suggesting that DNA damage in normal smooth muscle cells plays an important role in the pathogenesis of leiomyoma. The aim of this study is to evaluate precisely when and where DNA damage occurs in the myometrium. The localization of damaged, apoptotic, and proliferating cells was evaluated by immunohistochemical staining of p53, p21(WAF-1), TUNEL, and the cell proliferation marker, Ki-67, in normal myometrium during the menstrual cycle. p53-positive cells and p21(WAF-1)-positive cells were observed during the follicular phase, mostly in the submucosal layer of the myometrium. TUNEL-positive cells were sporadically identified in this layer during either the menstrual or follicular phase. In contrast, the number of Ki-67-positive cells was higher in the luteal phase. These results suggest that DNA damage, repair, and apoptosis occur cyclically in normal myometrium during the follicular phase. In addition, smooth muscle cells proliferate in the luteal phase, which may be a vulnerable period for DNA damage. Thus, these cyclic events during the menstrual cycle may contribute to a high incidence of leiomyoma development.

Application of SELDI-TOF-MS and LCM to screen protein markers for early diagnosis of liver metastasis of colorectal carcinoma

AIM: To screen protein markers for liver metastases of colorectal cancer using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry protein chip (SELDI-TOF-MS) in combination with laser capture microdissection (LCM) technology.

METHODS: Normal colorectal cells, primary tumor cells and liver metastatic cells were obtained from 24 colorectal cancer patients with liver metastases using the LCM technology. Protein profiling was performed using SELDI-TOF-MS technology. Differentially expressed proteins were analyzed using Biomarker Wizard software and identified by querying the database.

RESULTS: Fifteen differentially expressed proteins were found between primary tumor cells and normal colorectal cells, of which 12 were up-regulated and 3 down-regulated. Nine differentially expressed proteins were found between liver metastatic cells and primary tumor cells, of which 5 were up-regulated and 4 down-regulated. Twenty differentially expressed proteins were identified by querying ExPasy protein database, including integral membrane protein 2C, DNA repair protein RAD51 homolog 4, cell cycle checkpoint protein RAD1, human epididymis protein 4, centromere protein R, and pleckstrin homology domain family member 3. Apoptosis regulator Bax-γ, S100A11, Raf kinase inhibitor protein (RKIP) and heat shock protein 27 (HSP-27) displayed most obvious differential expression among normal colorectal cells, primary tumor cells and liver metastatic cells (all P < 0. 01).

CONCLUSION: SELDI-TOF-MS technology combined with LCM may allow to screen highly sensitive and specific protein markers for colorectal cancer and liver metastases of colorectal cancer.

High expression of S100A11 in pancreatic adenocarcinoma is an unfavorable prognostic marker

S100A11 is a member of S100 protein family, and our previous study showed that S100A11 is one of the up-regulated proteins that have not been reported to be associated with pancreatic carcinoma. The purpose of this study was to investigate the relation between S100A11 expression and the clinicopathological variables and clinical outcome in patients with pancreatic adenocarcinoma. Immunohistochemistry analysis was performed for S100A11 in 78 pairs of specimens of human pancreatic adenocarcinoma tissues and adjacent nontumorous tissues. The univariate and multivariate survival analyses were also performed to determine its prognostic significance. S100A11 expression in pancreatic adenocarcinoma (62/78) was significantly higher than that in the adjacent nontumorous tissues (19/78) (P = 0.000). High expression of S100A11 was associated with the lymph node metastasis and histological differentiation (P = 0.003 and 0.004, respectively). Univariate analysis showed that S100A11 expression was associated with poor prognosis (P = 0.0000). Multivariate analysis using the Cox regression model indicated that age ≥ 65 years, CA19-9 ≥ 1,000 U/ml and positive S100A11 were independent prognostic indicators of pancreatic adenocarcinoma (P = 0.002, 0.004 and 0.001, respectively). These results suggested that S100A11 might be a significant tumor marker for pancreatic adenocarcinoma and an unfavorable predictor for prognosis of patients who have undergone surgical resection.

Selective expression of S100A11 in lung cancer and its role in regulating proliferation of adenocarcinomas cells

S100A11, one secreted protein, is overexpressed in certain cancers. We investigated S100A11 expression in various subtypes of lung cancer and explored its role in cell proliferation. S100A11 mRNA level was examined in 45 pairs of frozen lung cancer tissues by reverse transcriptase PCR (RT-PCR). The specific expression and subcellular distribution of S100A11 were examined in 78 paraffin-embedded lung cancers, 2 benign lung diseases as well as 22 healthy lung tissues by immunohistochemistry. S100A11 protein level was further analyzed in the sera of 86 lung cancer patients and 50 healthy individuals by enzyme-linked immunosorbent assay. We found that both mRNA and protein levels of S100A11 were overexpressed in adenocarcinomas (ADC) and squamous cell carcinomas (SCC) compared with paired non-cancerous lung tissues, while S100A11 was detected downregulated in small cell lung cancers (SCLC). Further immunohistochemistry staining was positive for S100A11 only in non-small cell lung cancer (NSCLC) (ADC, SCC, large cell carcinomas, et al.), but not SCLC. Conclusively, we found S100A11 protein level increased in the sera of NSCLC patients. Furthermore, when S100A11 expression was knocked down in lung adenocarcinoma cells A549 and LTEP-a-2, the cell proliferation was significantly inhibited in vitro and in vivo.

Spinal cord injury markedly altered protein expression patterns in the affected rat urinary bladder during healing stages

The influence of spinal cord injury (SCI) on protein expression in the rat urinary bladder was assessed by proteomic analysis at different time intervals post-injury. After contusion SCI between T9 and T10, bladder tissues were processed by 2-DE and MALDI-TOF/MS at 6 hr to 28 days after SCI to identify proteins involved in the healing process of SCI-induced neurogenic bladder. Approximately 1,000 spots from the bladder of SCI and sham groups were visualized and identified. At one day after SCI, the expression levels of three protein were increased, and seven spots were down-regulated, including heat shock protein 27 (Hsp27) and heat shock protein 20 (Hsp20). Fifteen spots such as S100-A11 were differentially expressed seven days post-injury, and seven proteins including transgelin had altered expression patterns 28 days after injury. Of the proteins with altered expression levels, transgelin, S100-A11, Hsp27 and Hsp20 were continuously and variably expressed throughout the entire post-SCI recovery of the bladder. The identified proteins at each time point belong to eight functional categories. The altered expression patterns identified by 2-DE of transgelin and S100-A11 were verified by Western blot. Transgelin and protein S100-A11 may be candidates for protein biomarkers in the bladder healing process after SCI.

Identification of distinctive protein expression patterns in colorectal adenoma

PURPOSE

As a pre-malignant precursor, adenoma provides an ideal tissue for proteome profiling to investigate early colorectal cancer development and provide possible targets for preventive interventions. The aim of this study was to identify patterns of differential protein expression that distinguish colorectal adenoma from normal tissue.

EXPERIMENTAL DESIGN

Twenty paired samples of adenoma and normal mucosa were analysed by 2-DE and MALDI-TOF/TOF MS to detect proteins with ≥2-fold differential expression.

RESULTS

Four proteins were up-regulated in adenoma (Annexin A3, S100A11, S100P and eIF5A-1) and three were down-regulated (Galectin-1, S100A9 and FABPL). S100P, galectin-1, S100A9 and FABPL expression was localised by immunohistochemistry.

CONCLUSIONS AND CLINICAL RELEVANCE

Distinctive patterns of in vivo protein expression in colorectal adenoma were identified for the first time. These proteins have important functions in cell differentiation, proliferation and metabolism, and may play a crucial role in early colorectal carcinogenesis. The ability to recognise premalignant lesions may have important applications in cancer prevention.

Proteomic analysis of the triglyceride-rich lipoprotein-laden foam cells

In hypertriglyceridaemic individuals, atherosclerogenesis is associated with the increased concentrations of very low density lipoprotein (VLDL) and VLDL-associated remnant particles. In vitro studies have suggested that VLDL induces foam cells formation. To reveal the changes of the proteins expression in the process of foam cells formation induced by VLDL, we performed a proteomic analysis of the foam cells based on the stimulation of differentiated THP-1 cells with VLDL. Using two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, 14 differentially expressed proteins, containing 8 up-regulated proteins and 6 down-regulated proteins were identified. The proteins are involved in energy metabolism, oxidative stress, cell growth, differentiation and apoptosis, such as adipose differentiation-related protein (ADRP), enolase, S100A11, heat shock protein 27 and so on. In addition, the expression of some selected proteins was confirmed by Western blot and RT-PCR analysis. The results suggest that VLDL not only induces lipid accumulation, but also brings about foam cells diverse characteristics by altering the expression of various proteins.

S100A11: diverse function and pathology corresponding to different target proteins

S100A11, as a member of S100 protein family, while featuring the common identities as the other EF-hand Ca(2+)-binding family members, has its own individual characteristics. S100A11 is widely expressed in multiple tissues, and is located in cytoplasm, nucleus, and even cell periphery. S100A11 exists as a non-covalent homodimer with an antiparallel conformation. Ca(2+) binding to S100A11 would trigger conformational changes which would expose the hydrophobic cleft of S100A11 and facilitate its interaction with target proteins. Since S100A11 appears to lack enzymatic activity, in this article, corresponding to a variety of its target proteins, we systematically describe the biological roles of S100A11 and its possible mechanism in the processes of inflammation, regulation of enzyme activity, and cell growth regulation. As a dual cell growth mediator, S100A11 acts as either a tumor suppressor or promoter in many different types of tumors and would play respective roles in influencing the proliferation of the cancer cells. We intend to illustrate the biological function of the S100 protein, and shed light on the further research, which will provide us with a better understanding of it.

Induction of S100A4, S100A6, and galectin-1 during the lineage commitment of CD4+CD8+ thymocyte cell line is suppressed by 2,3,7,8-tetrachlorodibenzo-p-dioxin

To study the mechanisms underlying the linage commitment of CD4+CD8+ thymocytes and the skewed differentiation of CD4+CD8+ into CD4-CD8+ thymocytes induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), we stimulated with antigen DPK cells, a CD4+CD8+ thymic lymphoma cell line which can differentiate into CD4+CD8- thymocytes and performed a comparative proteomic analysis of DPK cells stimulated with antigen or not. Among the 10 up-regulated or induced proteins upon antigenic stimulation, S100A4, S100A6, and galectin-1 were highly up-regulated. Kinetic studies revealed that expression of S100A4, S100A6, and galectin-1 was dramatically increased as early as 10min after antigen stimulation, similar to that of cKrox and Runx3, transcription factors intimately associated with the lineage commitment. Among four thymocyte subpopulations of the thymus examined, S100A4, S1006, and galectin-1 were most prominently expressed in CD4+CD8+ thymocytes, but not at all in CD4-CD8+ and CD4-CD8- thymocytes. In the spleen, expression of S100A4, S1006, and galectin-1 was greater in CD4 than in CD8 splenocytes. When TCDD was added to antigen-stimulated DPK cells, antigen-induced up-regulation of S100A4, S1006, and galectin-1 were remarkably inhibited, probably partly accounting for the skewed differentiation of CD4+CD8+ into CD4-CD8+ thymocytes induced by TCDD.

MUC4, a multifunctional transmembrane glycoprotein, induces oncogenic transformation of NIH3T3 mouse fibroblast cells

Numerous studies have established the association of MUC4 with the progression of cancer and metastasis. An aberrant expression of MUC4 is reported in precancerous lesions, indicating its early involvement in the disease process; however, its precise role in cellular transformation has not been explored. MUC4 contains many unique domains and is proposed to affect cell signaling pathways and behavior of the tumor cells. In the present study, to decipher the oncogenic potential of MUC4, we stably expressed the MUC4 mucin in NIH3T3 mouse fibroblast cells. Stable ectopic expression of MUC4 resulted in increased growth, colony formation, and motility of NIH3T3 cells in vitro and tumor formation in nude mice when cells were injected s.c. Microarray analysis showed increased expression of several growth-associated and mitochondrial energy production-associated genes in MUC4-expressing NIH3T3 cells. In addition, expression of MUC4 in NIH3T3 cells resulted in enhanced levels of oncoprotein ErbB2 and its phosphorylated form (pY(1248)-ErbB2). In conclusion, our studies provide the first evidence that MUC4 alone induces cellular transformation and indicates a novel role of MUC4 in cancer biology.

Discovery and verification of head-and-neck cancer biomarkers by differential protein expression analysis using iTRAQ labeling, multidimensional liquid chromatography, and tandem mass spectrometry

Multidimensional LC-MS/MS has been used for the analysis of biological samples labeled with isobaric mass tags for relative and absolute quantitation (iTRAQ) to identify proteins that are differentially expressed in human head-and-neck squamous cell carcinomas (HNSCCs) in relation to non-cancerous head-and-neck tissues (controls) for cancer biomarker discovery. Fifteen individual samples (cancer and non-cancerous tissues) were compared against a pooled non-cancerous control (prepared by pooling equal amounts of proteins from six non-cancerous tissues) in five sets by on-line and off-line separation. We identified 811 non-redundant proteins in HNSCCs, including structural proteins, signaling components, enzymes, receptors, transcription factors, and chaperones. A panel of proteins showing consistent differential expression in HNSCC relative to the non-cancerous controls was discovered. Some of the proteins include stratifin (14-3-3sigma); YWHAZ (14-3-3zeta); three calcium-binding proteins of the S100 family, S100-A2, S100-A7 (psoriasin), and S100-A11 (calgizarrin); prothymosin alpha (PTHA); L-lactate dehydrogenase A chain; glutathione S-transferase Pi; APC-binding protein EB1; and fascin. Peroxiredoxin2, carbonic anhydrase I, flavin reductase, histone H3, and polybromo-1D (BAF180) were underexpressed in HNSCCs. A panel of the three best performing biomarkers, YWHAZ, stratifin, and S100-A7, achieved a sensitivity of 0.92 and a specificity of 0.91 in discriminating cancerous from non-cancerous head-and-neck tissues. Verification of differential expression of YWHAZ, stratifin, and S100-A7 proteins in clinical samples of HNSCCs and paired and non-paired non-cancerous tissues by immunohistochemistry, immunoblotting, and RT-PCR confirmed their overexpression in head-and-neck cancer. Verification of YWHAZ, stratifin, and S100-A7 in an independent set of HNSCCs achieved a sensitivity of 0.92 and a specificity of 0.87 in discriminating cancerous from non-cancerous head-and-neck tissues, thereby confirming their overexpressions and utility as credible cancer biomarkers.

S100A11, an dual mediator for growth regulation of human keratinocytes

We previously revealed a novel signal pathway involving S100A11 for inhibition of the growth of normal human keratinocytes (NHK) caused by high Ca(++) or transforming growth factor beta. Exposure to either agent resulted in transfer of S100A11 to nuclei, where it induced p21(WAF1). In contrast, S100A11 has been shown to be overexpressed in many human cancers. To address this apparent discrepancy, we analyzed possible new functions of S100A11, and we provide herein evidence that 1) S100A11 is actively secreted by NHK; 2) extracellular S100A11 acts on NHK to enhance the production of epidermal growth factor family proteins, resulting in growth stimulation; 3) receptor for advanced glycation end products, nuclear factor-kappaB, Akt, and cAMP response element-binding protein are involved in the S100A11-triggered signal transduction; and 4) production and secretion of S100A11 are markedly enhanced in human squamous cancer cells. These findings indicate that S100A11 plays a dual role in growth regulation of epithelial cells.

Genomic and proteomic profiling I: leiomyomas in African Americans and Caucasians

BACKGROUND

Clinical observations indicate that leiomyomas occur more frequently in African Americans compared to other ethnic groups with unknown etiology. To identify the molecular basis for the difference we compared leiomyomas form A. Americans with Caucasians using genomic and proteomic strategies.

METHODS

Microarray, realtime PCR, 2D-PAGE, mass spectrometry, Western blotting and immunohistochemistry.

RESULTS

Using Affymetrix U133A array and analysis based on P ranking (P < 0.01) 1470 genes were identified as differentially expressed in leiomyomas compared to myometrium regardless of ethnicity. Of these, 268 genes were either over-expressed (177 genes) or under-expressed (91 genes) based on P < 0.01 followed by 2-fold cutoff selection in leiomyomas of A. Americans as compared to Caucasians. Among them, the expression E2F1, RUNX3, EGR3, TBPIP, ECM2, ESM1, THBS1, GAS1, ADAM17, CST6, CST7, FBLN5, ICAM2, EDN1 and COL18 was validated using realtime PCR low-density arrays. 2D PAGE coupled with image analysis identified 332 protein spots of which the density/volume of 31 varied by greater than or equal to 1.5 fold in leiomyomas as compared to myometrium. The density/volume of 34 protein-spots varied by greater than or equal to 1.5 fold (26 increased and 8 decreased) in leiomyomas of A. Americans as compared to Caucasians. Tandem mass spectrometric analysis of 15 protein spots identified several proteins whose transcripts were also identified by microarray, including 14-3-3 beta and mimecan, whose expression was confirmed using western blotting and immunohistochemistry.

CONCLUSION

These findings imply that the level rather than the ethnic-specific expression of a number of genes and proteins may account for the difference between leiomyomas and possibly myometrium, in A. Americans and Caucasians. Further study using larger sample size is required to confirm these findings.

Determination of metastasis-associated proteins in non-small cell lung cancer by comparative proteomic analysis

The development of metastasis is the leading cause of death and an enormous therapeutic challenge in cases of non-small cell lung cancer. To better understand the molecular mechanisms underlying the metastasis process and to discover novel potential clinical markers for non-small cell lung cancer, comparative proteomic analysis of two non-small cell lung cancer cell lines with different metastatic potentials, the non-metastatic CL1-0 and highly metastatic CL1-5 cell lines, was carried out using two-dimensional electrophoresis followed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and tandem mass spectrometry. Thirty-three differentially expressed proteins were identified unambiguously, among which 16 proteins were significantly upregulated and 17 proteins were downregulated in highly metastatic CL1-5 cells compared with non-metastatic CL1-0 cells. Subsequently, 8 of 33 identified proteins were selected for further validation at the mRNA level using real-time quantitative polymerase chain reaction, and three identified proteins, S100A11, PGP 9.5 and HSP27, were confirmed by western blotting. The protein S100A11 displaying significant differential expression at both the protein and mRNA levels was further analyzed by immunohistochemical staining in 65 primary non-small cell lung cancer tissues and 10 matched local positive lymph node specimens to explore its relationship with metastasis. The results indicated that the upregulation of S100A11 expression in non-small cell lung cancer tissues was significantly associated with higher tumor-node-metastasis stage (P = 0.001) and positive lymph node status (P = 0.011), implying that S100A11 might be an important regulatory molecule in promoting invasion and metastasis of non-small cell lung cancer.

Proteomic analysis of pancreatic endocrine tumor cell lines treated with the histone deacetylase inhibitor trichostatin A

Effects of the histone-deacetylases inhibitor trichostatin A (TSA) on the growth of three different human pancreatic endocrine carcinoma cell lines (CM, BON, and QGP-1) have been assessed via dosage-dependent growth inhibition curves. TSA determined strong inhibition of cell growth with similar IC(50) values for the different cell lines: 80.5 nM (CM), 61.6 nM (BON), and 86 nM (QGP-1), by arresting the cell cycle in G2/M phase and inducing apoptosis. 2DE and nano-RP-HPLC-ESI-MS/MS analysis revealed 34, 33, and 38 unique proteins differentially expressed after TSA treatment in the CM, BON, and QGP-1 cell lines, respectively. The most important groups of modulated proteins belong to cell proliferation, cell cycle, and apoptosis classes (such as peroxiredoxins 1 and 2, the diablo protein, and HSP27). Other proteins pertain to processes such as regulation of gene expression (nucleophosmin, oncoprotein dek), signal transduction (calcium-calmodulin), chromatin, and cytoskeleton organization (calgizzarin, dynein, and lamin), RNA splicing (nucleolin, HNRPC), and protein folding (HSP70). The present data are in agreement with previous proteomic analyses performed on pancreatic ductal carcinoma cell lines (Cecconi, D. et al.., Electrophoresis 2003; Cecconi, D. et al., J. Proteome Res. 2005) and place histone-deacetylases inhibitors among the potentially most powerful drugs for the treatment of pancreatic tumors.

Proteomics unveil corticoid-induced S100A11 shuttling in keratinocyte differentiation

Unlike classical protein extraction techniques, proteomic mapping using a selective subcellular extraction kit revealed S100A11 as a new member of the S100 protein family modulated by glucocorticoids in keratinocytes. Glucocorticoids (GC)-induced S100A11 redistribution in the "organelles and membranes" compartment. Microscopic examination indicated that glucocorticoids specifically routed cytoplasmic S100A11 toward perinuclear compartment. Calcium, a key component of skin terminal differentiation, directed S100A11 to the plasma membrane as previously reported. When calcium was added to glucocorticoids, minor change was observed at the proteomic level while confocal microscopy revealed a rapid and dramatic translocation of S100A11 toward plasma membrane. This effect was accompanied by strong nuclear condensation, loss of mitochondrial potential and DNA content, and increased high molecular weight S100A11 immunoreactivity, suggesting corticoids accelerate calcium-induced terminal differentiation. Finally, our results suggest GC-induced S100A11 relocalization could be a key step in both keratinocyte homeostasis and glucocorticoids side effects in human epidermis.

Diagnostic utility of S100A1 expression in renal cell neoplasms: an immunohistochemical and quantitative RT-PCR study

S100A1 is a calcium-binding protein, which has been recently found in renal cell neoplasms. We evaluated the diagnostic utility of immunohistochemical detection of S100A1 in 164 renal cell neoplasms. Forty-one clear cell, 32 papillary, and 51 chromophobe renal cell carcinomas, and 40 oncocytomas, 164 samples of normal renal parenchyma adjacent to the tumors and 13 fetal kidneys were analyzed. The levels of S100A1 mRNA detected by quantitative RT-PCR analysis of frozen tissues from seven clear cell, five papillary, and six chromophobe renal cell carcinomas, four oncocytomas, and nine samples of normal renal tissues adjacent to neoplasms were compared with the immunohistochemical detection of protein expression. Clear cell and papillary renal cell carcinomas showed positive reactions for S100A1 in 30 out of 41 tumors (73%) and in 30 out of 32 (94%) tumors, respectively. Thirty-seven renal oncocytomas out of 40 (93%) were positive for S100A1, whereas 48 of 51 (94%) chromophobe renal cell carcinomas were negative. S100A1 protein was detected in all samples of unaffected and fetal kidneys. S100A1 mRNA was detected by RT-PCR in all normal kidneys and renal cell neoplasms, although at very different levels. Statistical analyses comparing the different expression of S100A1 in clear cell and chromophobe renal cell carcinomas observed by immunohistochemical and RT-PCR methods showed significant values (P<0.001), such as when comparing by both techniques the different levels of S100A1 expression in chromophobe renal cell carcinomas and oncocytomas (P<0.001). Our study shows that S100A1 protein is expressed in oncocytomas, clear cell and papillary renal cell carcinomas but not in chromophobe renal cell carcinomas. Its immunodetection is potentially useful for the differential diagnosis between chromophobe renal cell carcinoma and oncocytoma. Further, S100A1 protein expression is constantly detected in the normal parenchyma of the adult and fetal kidney.

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.

Upregulation of pirin expression by chronic cigarette smoking is associated with bronchial epithelial cell apoptosis

Background

Cigarette smoke disrupts the protective barrier established by the airway epithelium through direct damage to the epithelial cells, leading to cell death. Since the morphology of the airway epithelium of smokers does not typically demonstrate necrosis, the most likely mechanism for epithelial cell death in response to cigarette smoke is apoptosis. We hypothesized that cigarette smoke directly up-regulates expression of apoptotic genes, which could play a role in airway epithelial apoptosis.

Methods

Microarray analysis of airway epithelium obtained by bronchoscopy on matched cohorts of 13 phenotypically normal smokers and 9 non-smokers was used to identify specific genes modulated by smoking that were associated with apoptosis. Among the up-regulated apoptotic genes was pirin (3.1-fold, p < 0.002), an iron-binding nuclear protein and transcription cofactor. In vitro studies using human bronchial cells exposed to cigarette smoke extract (CSE) and an adenovirus vector encoding the pirin cDNA (AdPirin) were performed to test the direct effect of cigarette smoke on pirin expression and the effect of pirin expression on apoptosis.

Results

Quantitative TaqMan RT-PCR confirmed a 2-fold increase in pirin expression in the airway epithelium of smokers compared to non-smokers (p < 0.02). CSE applied to primary human bronchial epithelial cell cultures demonstrated that pirin mRNA levels increase in a time-and concentration-dependent manner (p < 0.03, all conditions compared to controls).

Overexpression of pirin, using the vector AdPirin, in human bronchial epithelial cells was associated with an increase in the number of apoptotic cells assessed by both TUNEL assay (5-fold, p < 0.01) and ELISA for cytoplasmic nucleosomes (19.3-fold, p < 0.01) compared to control adenovirus vector.

Conclusion

These observations suggest that up-regulation of pirin may represent one mechanism by which cigarette smoke induces apoptosis in the airway epithelium, an observation that has implications for the pathogenesis of cigarette smoke-induced diseases.

CCNs, fibulin-1C and S100A4 expression in leiomyoma and myometrium: inverse association with TGF-beta and regulation by TGF-beta in leiomyoma and myometrial smooth muscle cells

Connective tissue growth factor (CTGF; CCN2) is considered to serve as downstream midiator of TGF-beta action in tissue fibrosis. We tested this hypothesis in paired leiomyoma and myometrium by evaluating the expression of TGF-beta1/TGF-beta3 and CCN2, the other members of the CCN family, CCN3 and CCN4, as well as fibulin-1C and S100A4, calcium-binding proteins that interact with CCNs. The regulatory function of TGF-beta1 on the expression of these genes was further evaluated using leiomyoma (L) and myometrial (M) smooth muscle cells (SMC). Real-time PCR, Western blotting and immunohistochemistry revealed that leiomyomas and myometrium express CCNs, fibulin-1C and S100A4, whose levels of expression with the exception of fibulin-1C were lower in leiomyomas and inversely correlated with the expression of TGF-beta1 and TGF-beta3 (P<0.05). The expression of these genes was menstrual cycle-independent and GnRHa therapy increased the expression of CCN2 in leiomyomas, while inhibiting CCN3, CCN4 and S100A4 in myometrium (P<0.05). TGF-beta (2.5 ng/ml) in a time- and cell-dependent manner, and through MAPK and Smad pathways, differentially regulated the expression of these genes in LSMC and MSMC. We concluded that CCNs, fibulin-1C and S100A4 are expressed in leiomyomas/myometrium with relative expression levels inversely correlating with TGF-betas and influenced by GnRHa and TGF-beta regulatory actions. The results suggest that unlike other fibrotic disorders, CCN2 (CTGF), at least at tissue level, may not serve as a downstream mediator of TGF-beta action in leiomyomas.