Differential gene expression between flat adenoma and normal mucosa in the colon in a microarray analysis

Calcium-binding protein S100P is a new target gene of MACC1, drives colorectal cancer metastasis and serves as a prognostic biomarker

Background

The metastasis inducing gene MACC1 is a prognostic and predictive biomarker for metastasis in several cancers. Its mechanism of inducing metastasis includes the transcriptional control of other cancer-related target genes. Here, we investigate the interplay with the metastasis driver S100P in CRC progression.

Methods

MACC1-dependent S100P expression was analysed by qRT-PCR. The binding of MACC1 to the S100P promoter was determined by ChIP. Alterations in cell proliferation and motility were determined by functional in vitro assays. In vivo metastasis after intrasplenic transplantation was assessed by bioluminescence imaging and evaluation of tumour growth and liver metastasis. The prognostic value of S100P was determined in CRC patients by ROC-based Kaplan–Meier analyses.

Results

Expression of S100P and MACC1 correlated positively in CRC cells and colorectal tumours. MACC1 was found binding to the S100P promoter and induces its expression. The overexpression of S100P increased proliferation, migration and invasion in vitro and significantly induced liver metastasis in vivo. S100P expression was significantly elevated in metachronously metastasising CRC and was associated with shorter metastasis-free survival.

Conclusions

We identified S100P as a transcriptional target gene of MACC1. Expression of S100P increases the metastatic potential of CRC cells in vitro and in vivo, and serves as a prognostic biomarker for metastasis-free survival of CRC patients, emphasising novel therapeutic interventions targeting S100P.

P-Cadherin Regulates Intestinal Epithelial Cell Migration and Mucosal Repair, but Is Dispensable for Colitis Associated Colon Cancer

Recurrent chronic mucosal inflammation, a characteristic of inflammatory bowel diseases (IBD), perturbs the intestinal epithelial homeostasis resulting in formation of mucosal wounds and, in most severe cases, leads to colitis-associated colon cancer (CAC). The altered structure of epithelial cell-cell adhesions is a hallmark of intestinal inflammation contributing to epithelial injury, repair, and tumorigenesis. P-cadherin is an important adhesion protein, poorly expressed in normal intestinal epithelial cells (IEC) but upregulated in inflamed and injured mucosa. The goal of this study was to investigate the roles of P-cadherin in regulating intestinal inflammation and CAC. P-cadherin expression was markedly induced in the colonic epithelium of human IBD patients and CAC tissues. The roles of P-cadherin were investigated in P-cadherin null mice using dextran sulfate sodium (DSS)-induced colitis and an azoxymethane (AOM)/DSS induced CAC. Although P-cadherin knockout did not affect the severity of acute DSS colitis, P-cadherin null mice exhibited faster recovery after colitis. No significant differences in the number of colonic tumors were observed in P-cadherin null and control mice. Consistently, the CRISPR/Cas9-mediated knockout of P-cadherin in human IEC accelerated epithelial wound healing without affecting cell proliferation. The accelerated migration of P-cadherin depleted IEC was driven by activation of Src kinases, Rac1 GTPase and myosin II motors and was accompanied by transcriptional reprogramming of the cells. Our findings highlight P-cadherin as a negative regulator of IEC motility in vitro and mucosal repair in vivo. In contrast, this protein is dispensable for IEC proliferation and CAC development.

Genetic Study of Chemokine Ligand 1 in Colorectal Carcinoma using Quantitative Real-Time PCR

Background: Carcinoma of colon is one of the prevalence carcinoma in the world and it is the most important cause of death in Western countries. The disease process is multifactorial; with etiology include inflammatory conditions of the digestive tract, environmental liableness and genetic factors. Chemokine Ligand1 was share in several mechanisms such as inflammatory process, chemo attraction, and others. Objective: The current study was conducted to analyze gene expression level of chemokine ligand 1 in colonic carcinoma and to deliberate the participant of it as genetic factors in its evolving and prognosis. Material and method: Chemokine Ligand1 gene expression level was evaluated in formalin-fixed, paraffin embedded tissue blocks that is retrospectively collected from 40 patients (8 women and 32 men) with carcinoma, and 40 patients of normal colonic tissues as control specimen by using Real-Time PCR. Results: The expression of Chemokine ligand 1 gene were established as 12.4112 folds in carcinoma specimen in relation to control tissue (1.3492).  Chemokine ligand 1 genes were found to be over-expressed in advanced stage tumors and elderly patients. Conclusions: Chemokine ligand1 can be considered as a recent biomarker and the possibility to use it as therapeutic target in the treatment of colonic carcinoma.

FASN Knockdown Inhibited Anoikis Resistance of Gastric Cancer Cells via P-ERK1/2/Bcl-xL Pathway

Anoikis resistance (AR) is a crucial step in tumor metastasis. The overexpression of fatty acid synthase (FASN) is not only related to the AR of osteosarcoma cells, but also evidenced on gastric cancer (GC). This study investigated the role of FASN in the AR of GC cells. Plates coated with poly-HEMA were used for the culture of cells with AR. Small interfering RNA targeting FASN (siFASN) was transfected into MNK-45 and AGS cells. The number and apoptosis of cells were assessed by a hemacytometer and Annexin-V-FITC/PI assay, respectively. Aggregated cells and colony numbers were manually counted under a microscope. The migration and invasion rates were measured via wound healing and Transwell invasion assays, respectively. The levels of FASN, phosphorylated (p)-ERK1/2, ERK1/2 and Bcl-xL were detected through western blot or quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The results showed that the cell numbers of MNK-45 and AGS were increased while that of GES-1 cell was decreased during the culture in suspension. A higher apoptosis rate and a smaller number of aggregated cells were observed in GES-1 cells in comparison with MNK-45 and AGS cells. A larger colony number, greater migration and invasion rates, and higher mRNA and protein expressions of FASN were presented in the AR group compared with the control group. Cells transfected with siFASN possessed lower migration and invasion rates, reduced expressions of FASN mRNA and protein, p-ERK1/2 and Bcl-xL, and induced a significantly declined ratio of p-ERK1/2 to ERK1/2. These findings suggest that down-regulation of FASN suppresses the AR of GC cells, which may be related to the inhibition of p-ERK1/2/Bcl-xL pathway.

A truncated protein product of the germline variant of the DUOX2 gene leads to adenomatous polyposis

Objective:

In some patients with adenomatous polyposis, an identifiable pathogenic variant of known associated genes cannot be found. Researchers have studied this for decades; however, few new genes have been identified.

Methods:

Adenomatous polyposis coli (APC) negative polyposis patients were identified through next-generation sequencing and multiplex ligation-dependent probe amplification. Then, whole-exome sequencing (WES) was used to determine candidate genes harboring pathogenic variants. Functional experiments were performed to explore their effects. Subsequently, using Sanger sequencing, we found other polyposis patients carrying variants of the DUOX2 gene, encoding dual oxidase 2, and analyzed them.

Results:

From 88 patients with suspected familial adenomatous polyposis, 25 unrelated APC negative polyposis patients were identified. Based on the WES results of 3 patients and 2 healthy relatives from a family, the germline nonsense variant (c.1588A>T; p.K530X) of the DUOX2 gene was speculated to play a decisive role in the pedigree in relation to adenomatous polyposis. During functional experiments, we observed that the truncated protein, hDuox2 K530, was overexpressed in the adenoma in a carrier of the DUOX2 nonsense variant, causing abnormal cell proliferation through endoplasmic reticulum (ER) retention. In addition, we found two unrelated APC negative patients carrying DUOX2 missense variants (c.3329G>A, p.R1110Q; c.4027C>T, p.L1343F). Given the results of the in silico analysis, these two missense variants might exert a negative influence on the function of hDuox2.

Conclusions:

To our knowledge, this is the first study that reports the possible association of DUOX2 germline variants with adenomatous polyposis. With an autosomal dominant inheritance, it causes ER retention, inducing an unfolded protein response.

IL-4 and IL-17A Cooperatively Promote Hydrogen Peroxide Production, Oxidative DNA Damage, and Upregulation of Dual Oxidase 2 in Human Colon and Pancreatic Cancer Cells

Dual oxidase 2 (DUOX2) generates H₂O₂ that plays a critical role in both host defense and chronic inflammation. Previously, we demonstrated that the proinflammatory mediators IFN-γ and LPS enhance expression of DUOX2 and its maturation factor DUOXA2 through STAT1- and NF-κB‒mediated signaling in human pancreatic cancer cells. Using a panel of colon and pancreatic cancer cell lines, we now report the induction of DUOX2/DUOXA2 mRNA and protein expression by the T_H2 cytokine IL-4. IL-4 activated STAT6 signaling that, when silenced, significantly decreased induction of DUOX2. Furthermore, the T_H17 cytokine IL-17A combined synergistically with IL-4 to increase DUOX2 expression in both colon and pancreatic cancer cells mediated, at least in part, by signaling through NF-κB. The upregulation of DUOX2 was associated with a significant increase in the production of extracellular H₂O₂ and DNA damage-as indicated by the accumulation of 8-oxo-dG and γH2AX-which was suppressed by the NADPH oxidase inhibitor diphenylene iodonium and a DUOX2-specific small interfering RNA. The clinical relevance of these experiments is suggested by immunohistochemical, microarray, and quantitative RT-PCR studies of human colon and pancreatic tumors demonstrating significantly higher DUOX2, IL-4R, and IL-17RA expression in tumors than in adjacent normal tissues; in pancreatic adenocarcinoma, increased DUOX2 expression is adversely associated with overall patient survival. These data suggest a functional association between DUOX2-mediated H₂O₂ production and induced DNA damage in gastrointestinal malignancies.

Transcriptomic profiles differentiate normal rectal epithelium and adenocarcinoma

Adenocarcinoma is a histologic diagnosis based on subjective findings. Transcriptional profiles have been used to differentiate normal tissue from disease and could provide a means of identifying malignancy. The goal of this study was to generate and test transcriptomic profiles that differentiate normal from adenocarcinomatous rectum. Comparisons were made between cDNA microarrays derived from normal epithelium and rectal adenocarcinoma. Results were filtered according to standard deviation to retain only highly dysregulated genes. Genes differentially expressed between cancer and normal tissue on two-groups t test (P < 0.05, Bonferroni P value adjustment) were further analyzed. Genes were rank ordered in terms of descending fold change. For each comparison (tumor versus normal epithelium), those 5 genes with the greatest positive fold change were grouped in a classifier. Five separate tests were applied to evaluate the discriminatory capacity of each classifier. Genetic classifiers derived comparing normal epithelium with malignant rectal epithelium from pooled stages had a mean sensitivity and specificity of 99.6% and 98.2%, respectively. The classifiers derived from comparing normal and stage I cancer had comparable mean sensitivities and specificities (97% and 98%, respectively). Areas under the summary receiver-operator characteristic curves for each classifier were 0.981 and 0.972, respectively. One gene was common to both classifiers. Classifiers were tested in an independent Gene Expression Omnibus-derived dataset. Both classifiers retained their predictive properties. Transcriptomic profiles comprising as few as 5 genes are highly accurate in differentiating normal from adenocarcinomatous rectal epithelium, including early-stage disease.

KIAA1199 as a potential diagnostic biomarker of rheumatoid arthritis related to angiogenesis

Introduction

Our previous proteomic study on fibroblast-like synoviocytes (FLSs) derived from the synovial tissues found that the expression of KIAA1199 was higher in rheumatoid arthritis (RA) patients than in healthy controls. The aim of this study was to examine the biological function of KIAA1199 and evaluate its clinical diagnosis value in RA.

Methods

The over-expression of KIAA1199 was verified by quantitative real-time polymerase chain reaction (qPCR), Immunohistochemistry, Immunofluorescence and enzyme linked immunosorbent assay (ELISA) in inactive and active RA patients and healthy controls. The effect of KIAA1199 expression on FLSs proliferation, angiogenesis and related pathway were analyzed by MTT, cell migration, tube formation, chorioallantoic membrane (CAM) assay, qPCR and western-blotting after KIAA1199 knockdown and over-expression.

Results

The verification results show the up-regulation of KIAA1199 in RA patients at mRNA and protein level as compared to that in healthy controls. ELISA and receiver operator characteristic (ROC) analysis shows that KIAA1199 concentration in serum, synovial fluid and synovial tissues could be used as dependable biomarkers for the diagnosis of active RA, provided an area under roc curve (AUC) of 0.83, 0.92 and 0.92. Sensitivity and specificity, which were determined by cut-off points, reached 72% 84% and 80% in sensitivity and 80%, 93.3%, 93.3% in specificity, respectively. Moreover, KIAA1199 also enhance the proliferation and angiogenesis of synovial membrane, and KIAA1199/ PLXNB3/ SEMA5A/CTGF axis may be a newly found pathway enhancing cell proliferation and angiogenesis.

Conclusion

KIAA1199 may be a potential diagnostic biomarker of RA related to angiogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0637-y) contains supplementary material, which is available to authorized users.

NADPH oxidases and cancer

The mechanism by which reactive oxygen species (ROS) are produced by tumour cells remained incompletely understood until the discovery over the last 15 years of the family of NADPH oxidases (NOXs 1–5 and dual oxidases DUOX1/2) which are structural homologues of gp91phox, the major membrane-bound component of the respiratory burst oxidase of leucocytes. Knowledge of the roles of the NOX isoforms in cancer is rapidly expanding. Recent evidence suggests that both NOX1 and DUOX2 species produce ROS in the gastrointestinal tract as a result of chronic inflammatory stress; cytokine induction (by interferon-γ, tumour necrosis factor α, and interleukins IL-4 and IL-13) of NOX1 and DUOX2 may contribute to the development of colorectal and pancreatic carcinomas in patients with inflammatory bowel disease and chronic pancreatitis, respectively. NOX4 expression is increased in pre-malignant fibrotic states which may lead to carcinomas of the lung and liver. NOX5 is highly expressed in malignant melanomas, prostate cancer and Barrett's oesophagus-associated adenocarcinomas, and in the last it is related to chronic gastro-oesophageal reflux and inflammation. Over-expression of functional NOX proteins in many tissues helps to explain tissue injury and DNA damage from ROS that accompany pre-malignant conditions, as well as elucidating the potential mechanisms of NOX-related damage that contribute to both the initiation and the progression of a wide range of solid and haematopoietic malignancies.

S100P, a calcium-binding protein, is preferentially associated with the growth of polypoid tumors in colorectal cancer

Colorectal cancer (CRC) is a genetically heterogeneous disease with distinct morphological patterns. It has been shown that polypoid and ulcerative CRC displays different genetic alterations. In the present study, we aimed to investigate genes with differential expression patterns between ulcerative and polypoid CRC. cDNA microarray analysis was performed to compare the gene expression profiles in samples of ulcerative and polypoid CRC with paired normal mucosa samples. Potential candidate genes were further validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot analysis and immunohistochemistry. The epigenetic regulation of gene expression was investigated using methylation-specific PCR (MSP). cDNA microarray analysis identified 11 upregulated and 14 downregulated genes which were differentially expressed in samples from both tumor types compared to the matched normal mucosa samples. Among these, S100P was the only upregulated gene preferentially associated with polypoid CRC (P=0.032). The samples of polypoid CRC displayed significantly higher S100P protein and mRNA expression levels than the samples of ulcerative CRC (P<0.05, respectively). Using semi-quantitative immunohistochemical analyses, S100P overexpression was found to be preferentially associated with polypoid CRC (24/30 vs. 14/40, P<0.001). The relative methylation level determined by MSP did not differ significantly between the samples of polypoid and ulcerative CRC (43.36 vs. 49.10%, P=0.168), indicating that promoter hypomethylation was not directly related to the upregulation of S100P mRNA. Our results demonstrate that the upregulation of S100P mRNA and protein expression is a predominant characteristic in polypoid CRC, whereas ulcerative CRC presents with a wide range of expression levels, indicating that S100P overexpression is not a key determinant in conferring invasion properties. The clinicopathological significance of S100P in CRC requires further investigation in well-controlled studies.

Gene expression in the chicken caecum in response to infections with non-typhoid Salmonella

Chickens can be infected with Salmonella enterica at any time during their life. However, infections within the first hours and days of their life are epidemiologically the most important, as newly hatched chickens are highly sensitive to Salmonella infection. Salmonella is initially recognized in the chicken caecum by TLR receptors and this recognition is followed by induction of chemokines, cytokines and many effector genes. This results in infiltration of heterophils, macrophages, B- and T-lymphocytes and changes in total gene expression in the caecal lamina propria. The highest induction in expression is observed for matrix metalloproteinase 7 (MMP7). Expression of this gene is increased in the chicken caecum over 4000 fold during the first 10 days after the infection of newly hatched chickens. Additional highly inducible genes in the caecum following S. Enteritidis infection include immune responsive gene 1 (IRG1), serum amyloid A (SAA), extracellular fatty acid binding protein (ExFABP), serine protease inhibitor (SERPINB10), trappin 6-like (TRAP6), calprotectin (MRP126), mitochondrial ES1 protein homolog (ES1), interferon-induced protein with tetratricopeptide repeats 5 (IFIT5), avidin (AVD) and transglutaminase 4 (TGM4). The induction of expression of these proteins exceeds a factor of 50. Similar induction rates are also observed for chemokines and cytokines such as IL1β, IL6, IL8, IL17, IL18, IL22, IFNγ, AH221 or iNOS. Once the infection is under control, which happens approx. 2 weeks after infection, expression of IgY and IgA increases to facilitate Salmonella elimination from the gut lumen. This review outlines the function of individual proteins expressed in chickens after infection with non-typhoid Salmonella serovars.

Repurposing the FDA-approved pinworm drug pyrvinium as a novel chemotherapeutic agent for intestinal polyposis

Mutations in the WNT-pathway regulator ADENOMATOUS POLYPOSIS COLI (APC) promote aberrant activation of the WNT pathway that is responsible for APC-associated diseases such as Familial Adenomatous Polyposis (FAP) and 85% of spontaneous colorectal cancers (CRC). FAP is characterized by multiple intestinal adenomas, which inexorably result in CRC. Surprisingly, given their common occurrence, there are few effective chemotherapeutic drugs for FAP. Here we show that the FDA-approved, anti-helminthic drug Pyrvinium attenuates the growth of WNT-dependent CRC cells and does so via activation of CK1α. Furthermore, we show that Pyrvinium can function as an in vivo inhibitor of WNT-signaling and polyposis in a mouse model of FAP: APC^min mice. Oral administration of Pyrvinium, a CK1α agonist, attenuated the levels of WNT-driven biomarkers and inhibited adenoma formation in APC^min mice. Considering its well-documented safe use for treating enterobiasis in humans, our findings suggest that Pyrvinium could be repurposed for the clinical treatment of APC-associated polyposes.

NADPH oxidases: a perspective on reactive oxygen species production in tumor biology

SIGNIFICANCE

Reactive oxygen species (ROS) promote genomic instability, altered signal transduction, and an environment that can sustain tumor formation and growth. The NOX family of NADPH oxidases, membrane-bound epithelial superoxide and hydrogen peroxide producers, plays a critical role in the maintenance of immune function, cell growth, and apoptosis. The impact of NOX enzymes in carcinogenesis is currently being defined and may directly link chronic inflammation and NOX ROS-mediated tumor formation.

RECENT ADVANCES

Increased interest in the function of NOX enzymes in tumor biology has spurred a surge of investigative effort to understand the variability of NOX expression levels in tumors and the effect of NOX activity on tumor cell proliferation. These initial efforts have demonstrated a wide variance in NOX distribution and expression levels across numerous cancers as well as in common tumor cell lines, suggesting that much remains to be discovered about the unique role of NOX-related ROS production within each system. Progression from in vitro cell line studies toward in vivo tumor tissue screening and xenograft models has begun to provide evidence supporting the importance of NOX expression in carcinogenesis.

CRITICAL ISSUES

A lack of universally available, isoform-specific antibodies and animal tumor models of inducible knockout or over-expression of NOX isoforms has hindered progress toward the completion of in vivo studies.

FUTURE DIRECTIONS

In vivo validation experiments and the use of large, existing gene expression data sets should help define the best model systems for studying the NOX homologues in the context of cancer.

Roles of DUOX-mediated hydrogen peroxide in metabolism, host defense, and signaling

SIGNIFICANCE

Among the NADPH oxidases, the dual oxidases, DUOX1 and DUOX2, constitute a distinct subfamily initially called thyroid oxidases, based on their high level of expression in thyroid tissue. Genetic alterations causing inherited hypothyroidism clearly demonstrate their physiological implication in thyroid hormonogenesis. However, a growing list of biological functions triggered by DUOX-dependent reactive oxygen species (ROS) in highly differentiated mucosae have recently emerged.

RECENT ADVANCES

A role of DUOX enzymes as ROS providers for lactoperoxidase-mediated killing of invading pathogens has been well established and a role in bacteria chemorepulsion has been proposed. Control of DUOX expression and activity by inflammatory molecules and immune receptor activation consolidates their contributions to innate immune defense of mucosal surfaces. Recent studies conducted in ancestral organisms have identified effectors of DUOX redox signaling involved in wound healing including epithelium regeneration and leukocyte recruitment. Moreover, local generation of hydrogen peroxide (H2O2) by DUOX has also been suggested to constitute a positive feedback loop to promote receptor signaling activation.

CRITICAL ISSUES

A correct balance between H2O2 generation and detoxification mechanisms must be properly maintained to avoid oxidative damages. Overexpression of DUOX genes has been associated with an increasing number of chronic inflammatory diseases. Furthermore, H2O2-mediated DNA damage supports a mutagenic function promoting tumor development.

FUTURE DIRECTIONS

Despite the high sequence similarity shared between DUOX1 and DUOX2, the two isoforms present distinct regulations, tissue expression and catalytic functions. The phenotypic characterization of novel DUOX/DUOXA invalidated animal models will be very useful for defining their medical importance in pathological conditions.

Di-ethylhexylphthalate (DEHP) modulates cell invasion, migration and anchorage independent growth through targeting S100P in LN-229 glioblastoma cells

Glioblastoma multiforme (GBM) is the most aggressive brain cancer with a median survival of 1-2 years. The treatment of GBM includes surgical resection, radiation and chemotherapy, which minimally extends survival. This poor prognosis necessitates the identification of novel molecular targets associated with glioblastoma. S100P is associated with drug resistance, metastasis, and poor clinical outcomes in many malignancies. The functional role of S100P in glioblastoma has not been fully investigated. In this study, we examined the role of S100P mediating the effects of the environmental contaminant, DEHP, in glioblastoma cells (LN-229) by assessing cell proliferation, apoptosis, anchorage independent growth, cell migration and invasion following DEHP exposure. Silencing S100P and DEHP treatment inhibited LN-229 glioblastoma cell proliferation and induced apoptosis. Anchorage independent growth study revealed significantly decreased colony formation in shS100P cells. We also observed reduced cell migration in cells treated with DEHP following S100P knockdown. Similar results were observed in spheroid formation and expansion. This study is the first to demonstrate the effects of DEHP on glioblastoma cells, and implicates S100P as a potential therapeutic target that may be useful as a drug response biomarker.

DUOX2 and DUOXA2 form the predominant enzyme system capable of producing the reactive oxygen species H2O2 in active ulcerative colitis and are modulated by 5-aminosalicylic acid

BACKGROUND

NADPH oxidase-derived reactive oxygen species, such as H2O2, are part of the intestinal innate immune system but may drive carcinogenesis through DNA damage. We sought to identify the predominant enzyme system capable of producing H2O2 in active ulcerative colitis and assess whether it is affected by 5-aminosalicylic acid (5-ASA).

METHODS

We studied human mucosal biopsies by expression arrays, quantitative real-time polymerase chain reaction for NADPH oxidase family members, in situ hybridization (DUOX2 and DUOXA2) and immunofluorescence for DUOX, 8-OHdG (DNA damage), and γH2AX (DNA damage response) and sought effects of 5-ASA on ex vivo cultured biopsies and cultured rectal cancer cells.

RESULTS

DUOX2 with maturation partner DUOXA2 forms the predominant system for H2O2 production in human colon and is upregulated in active colitis. DUOX2 in situ is exclusively epithelial, varies between and within individual crypts, and increases near inflammation. 8-OHdG and γH2AX were observed in damaged crypt epithelium. 5-ASA upregulated DUOX2 and DUOXA2 levels in the setting of active versus quiescent disease and altered DUOX2 expression in cultured biopsies. Ingenuity pathway analysis confirmed that inflammation status and 5-ASA increase expression of DUOX2 and DUOXA2. An epithelial cell model confirmed that cultured cancer cells expressed DUOX protein and produced H2O2 in response to hypoxia and 5-ASA exposure.

CONCLUSIONS

Both DUOX2 and DUOXA2 expression are involved specifically in inflammation and are regulated on a crypt-by-crypt basis in ulcerative colitis tissues. Synergy between inflammation, hypoxia, and 5-ASA to increase H2O2 production could explain how 5-ASA supports innate defense, although potentially increasing the burden of DNA damage.

Identification of putative immunologic targets for colon cancer prevention based on conserved gene upregulation from preinvasive to malignant lesions

The length of time required for preinvasive adenoma to progress to carcinoma, the immunogenicity of colorectal cancer (CRC), and the identification of high-risk populations make development and testing of a prophylactic vaccine for the prevention of CRC possible. We hypothesized that genes upregulated in adenoma relative to normal tissue, which maintained increased expression in CRC, would encode proteins suitable as putative targets for immunoprevention. We evaluated existing adenoma and CRC microarray datasets and identified 160 genes that were ≥2-fold upregulated in both adenoma and CRC relative to normal colon tissue. We further identified 23 genes that showed protein overexpression in colon adenoma and CRC based on literature review. Silencing the most highly upregulated genes, CDH3, CLDN1, KRT23, and MMP7, in adenoma and CRC cell lines resulted in a significant decrease in viability (P < 0.0001) and proliferation (P < 0.0001) as compared to controls and an increase in cellular apoptosis (P < 0.05 for CDH3, KRT23). Results were duplicated across cell lines representing microsatellite instability, CpG island methylator, and chromosomal instability phenotypes, suggesting immunologic elimination of cells expressing these proteins could impact the progression of all CRC phenotypes. To determine whether these proteins were immunogens, we interrogated sera from early stage CRC patients and controls and found significantly elevated CDH3 (P = 0.006), KRT23 (P = 0.0007), and MMP7 (P < 0.0001) serum immunoglobulin G in cases as compared to controls. These data show a high throughput approach to the identification of biologically relevant putative immunologic targets for CRC and identified three candidates suitable for vaccine development.

Balancing reactive oxygen species in the epigenome: NADPH oxidases as target and perpetrator

SIGNIFICANCE

NADPH oxidases are important sources for regulated generation of reactive oxygen species (ROS). The main ROS produced are superoxide and hydrogen peroxide, both of which are redox signaling molecules in the context of various cellular functions. Redox imbalance due to excessive or insufficient ROS is a hallmark of pathophysiological aspects, including cancer development and progression.

RECENT ADVANCES

Epigenetic silencing of NADPH oxidases by hypermethylation of their promoter region or of the genes required for their assembly and activity occurs in diseases, such as lung cancer, and may represent an early stage of neoplastic transformation.

CRITICAL ISSUES

Loss of ROS-mediated signaling by epigenetic silencing may promote tumorigenesis. Conversely, increased oxidative stress caused by oncogene-induced overexpression of NADPH oxidases may also drive epigenetic instability. Thus, the cellular redox balance is likely vital in carcinogenesis.

FUTURE DIRECTIONS

NADPH oxidases may serve as prognostic tumor biomarker, especially when their individual expression is confined to accessible tissues, such as mucosal epithelia or blood. Further validation of NADPH oxidase/dual oxidase enzymes as candidate markers will require well controlled, large-scale clinical data sets. This review is focused on NADPH oxidases as targets of epigenetic changes in cancer and on the emerging role of ROS as inducers of epigenetic changes.

Activation of TLR4 is required for the synergistic induction of dual oxidase 2 and dual oxidase A2 by IFN-γ and lipopolysaccharide in human pancreatic cancer cell lines

Pancreatitis is associated with release of proinflammatory cytokines and reactive oxygen species and plays an important role in the development of pancreatic cancer. We recently demonstrated that dual oxidase (Duox)2, an NADPH oxidase essential for reactive oxygen species-related, gastrointestinal host defense, is regulated by IFN-γ-mediated Stat1 binding to the Duox2 promoter in pancreatic tumor lines. Because LPS enhances the development and invasiveness of pancreatic cancer in vivo following TLR4-related activation of NF-κB, we examined whether LPS, alone or combined with IFN-γ, regulated Duox2. We found that upregulation of TLR4 by IFN-γ in BxPC-3 and CFPAC-1 pancreatic cancer cells was augmented by LPS, resulting in activation of NF-κB, accumulation of NF-κB (p65) in the nucleus, and increased binding of p65 to the Duox2 promoter. TLR4 silencing with small interfering RNAs, as well as two independent NF-κB inhibitors, attenuated LPS- and IFN-γ-mediated Duox2 upregulation in BxPC-3 cells. Induction of Duox2 expression by IFN-γ and LPS may result from IFN-γ-related activation of Stat1 acting in concert with NF-κB-related upregulation of Duox2. Sustained extracellular accumulation of H(2)O(2) generated by exposure to both LPS and IFN-γ was responsible for an ∼50% decrease in BxPC-3 cell proliferation associated with a G(1) cell cycle block, apoptosis, and DNA damage. We also demonstrated upregulation of Duox expression in vivo in pancreatic cancer xenografts and in patients with chronic pancreatitis. These results suggest that inflammatory cytokines can interact to produce a Duox-dependent pro-oxidant milieu that could increase the pathologic potential of pancreatic inflammation and pancreatic cancer cells.

Functional activity and tumor-specific expression of dual oxidase 2 in pancreatic cancer cells and human malignancies characterized with a novel monoclonal antibody

Dual oxidase 2 (Duox2), one of the seven members of the NADPH oxidase gene family, plays a critical role in generating H₂O₂ for thyroid hormone biosynthesis and as an integral part of the host defense system of the respiratory epithelium and the gastrointestinal tract. Recent evidence suggests that the regulation of Duox2 expression is under the control of pro-inflammatory cytokines and that Duox2-induced reactive oxygen species (ROS) contribute to the inflammation-related tissue injury that occurs in two pre-malignant, inflammatory conditions: chronic pancreatitis and inflammatory bowel disease. Because no reliable Duox antibodies are commercially available, we report the development of a murine monoclonal antibody (MAb) to Duox2 (clone Duox S-12) and its use for the characterization of Duox2 expression in human tumors, tumor cell lines and normal tissues. Duox S-12 specifically detected both endogenously- and ectopically-expressed Duox2 protein by immunoblotting, immunofluorescence microscopy and immunohistochemistry (where both membranous and cytoplasmic staining were present). Duox2 expression detected by Duox S-12 was functionally coupled to the generation of H₂O₂ in pancreatic cancer cells that expressed Duox2 and its cognate maturation factor DuoxA2. Although Duox S-12 recognizes ectopically expressed Duox1 protein because of the extensive amino acid homology between Duox1 and Duox2, the lack of substantial Duox1 mRNA expression in human tumors (except thyroid cancer) allowed us to evaluate Duox2 expression across a wide range of normal and malignant tissues by immunohistochemistry. Duox2 was expressed at elevated levels in many human cancers, most notably tumors of the prostate, lung, colon and breast while brain tumors and lymphomas demonstrated the lowest frequency of expression. The Duox-specific monoclonal antibody described here provides a promising tool for the further examination of the role of Duox-dependent reactive oxygen production in inflammation-related carcinogenesis, where alterations in oxidant tone play a critical role in cell growth and proliferation.

Analysis of cell adhesion during early stages of colon cancer based on an extended multi-valued logic approach

Cell adhesion in the normal colon is typically associated with differentiated cells, whereas in cancerous colon it is associated with advanced tumors. For advanced tumors growing evidence supports the existence of stem-like cells that have originated from transdifferentiation. Because stem cells can also be transformed in their own niche, at the base of the Lieberkühn's crypts, we conjectured that cell adhesion can also be critical in early tumorigenesis. To assess this hypothesis we built an annotated, multi-valued logic model addressing cell adhesion of normal and tumorigenic stem cells in the human colon. The model accounts for (i) events involving intercellular adhesion structures, (ii) interactions involving cytoskeleton-related structures, (iii) compartmental distribution of α/β/γ/δ-catenins, and (iv) variations in critical cell adhesion regulators (e.g., ILK, FAK, IQGAP, SNAIL, Caveolin). We developed a method that can deal with graded multiple inhibitions, something which is not possible with conventional logical approaches. The model comprises 315 species (including 26 genes), interconnected by 269 reactions. Simulations of the model covered six scenarios, which considered two types of colonic cells (stem vs. differentiated cells), under three conditions (normal, stressed and tumor). Each condition results from the combination of 92 inputs. We compared our multi-valued logic approach with the conventional Boolean approach for one specific example and validated the predictions against published data. Our analysis suggests that stem cells in their niche synthesize high levels of cytoplasmatic E-cadherin and CdhEP(Ser684,686,692), even under normal-mitogenic stimulus or tumorigenic conditions. Under these conditions, E-cadherin would be incorporated into the plasmatic membrane, but only as a non-adhesive CdhE_β-catenin_IQGAP complex. Under stress conditions, however, this complex could be displaced, yielding adhesive CdhE_β-catenin((cis/trans)) complexes. In the three scenarios tested with stem cells, desmosomes or tight junctions were not assembled. Other model predictions include expected levels of the nuclear complex β-catenin_TCF4 and the anti-apoptotic protein Survivin for both normal and tumorigenic colonic stem cells.

Gene expression profiling reveals upregulated UCA1 and BMF in gallbladder epithelia of children with pancreaticobiliary maljunction

BACKGROUND

Pancreaticobiliary maljunction is usually associated with choledochal cysts and often causes biliary carcinoma; however, the mechanism of carcinogenesis remains unknown. No study has analyzed overall changes in genetic expression beginning during childhood in gallbladder epithelia with pancreaticobiliary maljunction.

PATIENTS AND METHODS

The genomewide expression of gallbladder epithelia was analyzed in 6 children with pancreaticobiliary maljunction and in 4 pediatric controls. Selected genes that were expressed differentially were further analyzed by the real-time reverse transcription-polymerase chain reaction (RT-PCR). The products of upregulated genes confirmed by real-time RT-PCR were immunohistochemically analyzed using gallbladders from 19 children with pancreaticobiliary maljunction, 5 pediatric controls, and 5 children with gallstones.

RESULTS

Microarray analysis identified 188 upregulated and 160 downregulated genes. RT-PCR confirmed upregulation in 5 of 6 genes and downregulation in 1 of 5 genes, including UCA1, DUOX2, DUOXA2, ID1, BMF, and GP2. Immunohistochemistry showed a significantly higher expression of BMF in the pancreaticobiliary maljunction patients than in the controls and gallstone patients.

CONCLUSIONS

This study identified several deregulated genes in the gallbladder of children with pancreaticobiliary maljunction, which may contribute to the pathophysiology. UCA1, a noncoding RNA, is an oncofetal gene, and its upregulation may be important for biliary carcinogenesis. The elevated expression of BMF may function as an apoptotic activator in proliferative gallbladder epithelia.

Up-regulation and sustained activation of Stat1 are essential for interferon-gamma (IFN-gamma)-induced dual oxidase 2 (Duox2) and dual oxidase A2 (DuoxA2) expression in human pancreatic cancer cell lines

Dual oxidase 2 is a member of the NADPH oxidase (Nox) gene family that plays a critical role in the biosynthesis of thyroid hormone as well as in the inflammatory response of the upper airway mucosa and in wound healing, presumably through its ability to generate reactive oxygen species, including H2O2. The recently discovered overexpression of Duox2 in gastrointestinal malignancies, as well as our limited understanding of the regulation of Duox2 expression, led us to examine the effect of cytokines and growth factors on Duox2 in human tumor cells. We found that exposure of human pancreatic cancer cells to IFN-γ (but not other agents) produced a profound up-regulation of the expression of Duox2, and its cognate maturation factor DuoxA2, but not other members of the Nox family. Furthermore, increased Duox2/DuoxA2 expression was closely associated with a significant increase in the production of both intracellular reactive oxygen species and extracellular H2O2. Examination of IFN-γ-mediated signaling events demonstrated that in addition to the canonical Jak-Stat1 pathway, IFN-γ activated the p38-MAPK pathway in pancreatic cancer cells, and both played an important role in the induction of Duox2 by IFN-γ. Duox2 up-regulation following IFN-γ exposure is also directly associated with the binding of Stat1 to elements of the Duox2 promoter. Our findings suggest that the pro-inflammatory cytokine IFN-γ initiates a Duox2-mediated reactive oxygen cascade in human pancreatic cancer cells; reactive oxygen species production in this setting could contribute to the pathophysiologic characteristics of these tumors.

A bioinformatical and functional approach to identify novel strategies for chemoprevention of colorectal cancer

Comparing normal colorectal mucosa and adenomas focusing on deregulated pathways obtains insight into the biological processes of early colorectal carcinogenesis. Publicly available microarray expression data from 26 normal mucosa and 47 adenoma samples were analyzed. Biological pathways enriched in adenomas were identified with Gene Set Enrichment Analysis (GSEA). The analysis revealed 10, 11 and 16 gene sets distinguishing adenomas from normal mucosa according to Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Map Annotator and Pathway Profiler (GenMAPP) and Biocarta databases, respectively. Biological pathways known to be involved in colon carcinogenesis such as cell cycle (P=0.002) and Wnt signaling (P=0.007) were enriched in adenomas. In addition, we found enrichment of novel pathways such as retinoblastoma (Rb) pathway (P=0.002), Src pathway (P=0.004), folate biosynthesis (P=0.019) and Hedgehog signaling (P=0.037) in adenomas. Microarray results for Rb and Src pathway genes were validated by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) on mRNA isolated from an independent set of adenoma and normal colon samples. A high correlation between microarray data and qRT-PCR expression data was found. The relevance of targeting of identified pathways was shown using the Rb pathway inhibitors roscovitine and PD-0332991 and the Src pathway inhibitor dasatinib. All inhibitors used induced cell growth reduction in adenoma cells. This study shows a bioinformatical and functional approach leading to potentially new options for chemoprevention of colorectal cancer.

The inflammatory microenvironment in colorectal neoplasia

Colorectal cancer (CRC) is a major cause of mortality and morbidity worldwide. Inflammatory activity within the stroma of invasive colorectal tumours is known to be a key predictor of disease activity with type, density and location of immune cells impacting on patient prognosis. To date, there has been no report of inflammatory phenotype within pre-malignant human colonic adenomas. Assessing the stromal microenvironment and particularly, inflammatory activity within colorectal neoplastic lesions is central to understanding early colorectal carcinogenesis. Inflammatory cell infiltrate was assessed by immunohistochemistry in paired colonic adenoma and adjacent normal colonic mucosa samples, and adenomas exhibiting increasing degrees of epithelial cell dysplasia. Macrophage phenotype was assessed using double stain immunohistochemistry incorporating expression of an intracellular enzyme of function. A targeted array of inflammatory cytokine and receptor genes, validated by RT-PCR, was used to assess inflammatory gene expression. Inflammatory cell infiltrates are a key feature of sporadic adenomatous colonic polyps with increased macrophage, neutrophil and T cell (specifically helper and activated subsets) infiltration in adenomatous colonic polyps, that increases in association with characteristics of high malignant potential, namely, increasing degree of cell dysplasia and adenoma size. Macrophages within adenomas express iNOS, suggestive of a pro-inflammatory phenotype. Several inflammatory cytokine genes (CXCL1, CXCL2, CXCL3, CCL20, IL8, CCL23, CCL19, CCL21, CCL5) are dysregulated in adenomas. This study has provided evidence of increased inflammation within pre-malignant colonic adenomas. This may allow potential mechanistic pathways in the initiation and promotion of early colorectal carcinogenesis to be identified.

Linking obesity to colorectal cancer: application of nutrigenomics

Diet is one of the most affective environmental factors in cancer development. Due to complicated nature of the diet, it has been very difficult to provide clear explanations for the role of dietary components in carcinogenesis. However, as high-throughput omics techniques became available, researchers are now able to analyze large sets of gene transcripts, proteins, and metabolites to identify molecules involved in disease development. Bioinformatics uses these data to perform network analyses and suggest possible interactions between metabolic processes and environmental factors. Obesity is known as one of the most closely related risk factors of colorectal cancer (CRC). Metabolic disturbances due to a positive energy balance may trigger and accelerate CRC development. In this review, we have summarized reports on genes, proteins and metabolites that are related to either obesity or CRC, and suggested candidate molecules linking obesity and CRC based on currently available literature. Possible application of bioinformatics for a large scale network analysis in studying cause-effect relationship between dietary components and CRC are suggested.

The induction of S100p expression by the Prostaglandin E₂ (PGE₂)/EP4 receptor signaling pathway in colon cancer cells

BACKGROUND

Prostaglandin E₂ (PGE₂) levels are frequently elevated in colorectal carcinomas. PGE₂ is perceived via four transmembrane G protein coupled receptors (EP1-4), among which the EP4 receptor is most relevant. PGE₂/EP4-receptor interaction activates CREB via the ERK/MEK pathway. However, the downstream target genes activated by this pathway remained to be investigated.

METHODOLOGY/PRINICIPAL FINDINGS

Here, we have identified S100P (an EF-hand calcium binding protein) as a novel downstream target. We show by realtime RT-PCR that S100P mRNA levels are elevated in 14/17 (82%) colon tumor tissues as compared to paired adjacent normal colonic tissues. S100P expression is stimulated in the presence of PGE₂ in a time dependent manner at mRNA and protein levels in colon, breast and pancreatic cancer cells. Pharmacological and RNAi-mediated inhibition of the EP4 receptor attenuates PGE₂-dependent S100P mRNA induction. RNA(i)-mediated knockdown of CREB inhibits endogenous S100P expression. Furthermore, using luciferase reporter analysis and EMSA we show that mutation and/or deletion of the CRE sequence within the S100P promoter abolished PGE₂-mediated transcriptional induction. Finally, we demonstrate that RNA(i)-mediated knockdown of S100P compromised invadopodia formation, colony growth and motility of colon cancer cells. Interestingly, endogenous knock down of S100P decreases ERK expression levels, suggesting a role for ERK in regulating S100P mediated cell growth and motility.

CONCLUSIONS/SIGNIFICANCE

Together, our findings show for the first time that S100P expression is regulated by PGE₂/EP4-receptor signaling and may participate in a feedback signaling that perpetuates tumor cell growth and migration. Therefore, our data suggest that dysregulated S100P expression resulting from aberrant PGE₂/EP4 receptor signaling may have important consequences relevant to colon cancer pathogenesis.

Genetic aspects of non-polypoid colorectal neoplasms

Colorectal cancer is a heterogeneous disease arising through multiple possible pathways. Elucidating the genetic factors controlling molecular phenotype, morphology, histology, and prognosis of different tumor types continues to be a challenge. Non-polypoid colorectal neoplasms provide opportunities for ongoing study of their underlying genetic abnormalities and molecular phenotypes. The varied data from different groups, however, highlight the need for further studies in different populations.

S100P: a novel therapeutic target for cancer

S100P expression is described in many different cancers, and its expression is associated with drug resistance, metastasis, and poor clinical outcome. S100P is member of the S100 family of small calcium-binding proteins that have been reported to have either intracellular or extracellular functions, or both. Extracellular S100P can bind with the receptor for advanced glycation end products (RAGE) and activate cellular signaling. Through RAGE, S100P has been shown to mediate tumor growth, drug resistance, and metastasis. S100P is specifically expressed in cancer cells in the adult. Therefore, S100P is a useful marker for differentiating cancer cells from normal cells, and can aid in the diagnosis of cancer by cytological examination. The expression of S100P in cancer cells has been related to hypomethylation of the gene. Multiple studies have confirmed the beneficial effects of blocking S100P/RAGE in cancer cells, and different blockers are being developed including small molecules and antagonist peptides. This review summarizes the role and significance of S100P in different cancers.

Fas/CD95 deficiency in ApcMin/+ mice increases intestinal tumor burden

BACKGROUND

Fas, a member of the tumor necrosis family, is responsible for initiating the apoptotic pathway when bound to its ligand, Fas-L. Defects in the Fas-mediated apoptotic pathway have been reported in colorectal cancer.

METHODOLOGY/PRINCIPAL FINDINGS

In the present study, a variant of the Apc(Min/+) mouse, a model for the human condition, Familial Adenomatous Polyposis (FAP), was generated with an additional deficiency of Fas (Apc(Min/+)/Fas(lpr)) by cross-breeding Apc(Min/+) mice with Fas deficient (Fas(lpr)) mice. One of the main limitations of the Apc(Min/+) mouse model is that it only develops benign polyps. However, Apc(Min/+)/Fas(lpr) mice presented with a dramatic increase in tumor burden relative to Apc(Min/+) mice and invasive lesions at advanced ages. Proliferation and apoptosis markers revealed an increase in cellular proliferation, but negligible changes in apoptosis, while p53 increased at early ages. Fas-L was lower in Apc(Min/+)/Fas(lpr) mice relative to Apc(Min/+) cohorts, which resulted in enhanced inflammation.

CONCLUSIONS/SIGNIFICANCE

This study demonstrated that imposition of a Fas deletion in an Apc(Min/+) background results in a more aggressive phenotype of the Apc(Min/+) mouse model, with more rapid development of invasive intestinal tumors and a decrease in Fas-L levels.

Normal colon epithelium: a dataset for the analysis of gene expression and alternative splicing events in colon disease

Background

Studies using microarray analysis of colorectal cancer have been generally beleaguered by the lack of a normal cell population of the same lineage as the tumor cell. One of the main objectives of this study was to generate a reference gene expression data set for normal colonic epithelium which can be used in comparisons with diseased tissues, as well as to provide a dataset that could be used as a baseline for studies in alternative splicing.

Results

We present a dependable expression reference data set for non-neoplastic colonic epithelial cells. An enriched population of fresh colon epithelial cells were obtained from non-neoplastic, colectomy specimens and analyzed using Affymetrix GeneChip EXON 1.0 ST arrays. For demonstration purposes, we have compared the data derived from these cells to a publically available set of tumor and matched normal colon data. This analysis allowed an assessment of global gene expression alterations and demonstrated that adjacent normal tissues, with a high degree of cellular heterogeneity, are not always representative of normal cells for comparison to tumors which arise from the colon epithelium. We also examined alternative splicing events in tumors compared to normal colon epithelial cells.

Conclusions

The findings from this study represent the first comprehensive expression profile for non-neoplastic colonic epithelial cells reported. Our analysis of splice variants illustrate that this is a very labor intensive procedure, requiring vigilant examination of the data. It is projected that the contribution of this set of data derived from pure colonic epithelial cells will enhance studies in colon-related disease and offer a vital baseline for studies aimed at elucidating the mechanisms of alternative splicing.

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.

Clinicopathologic significance of KIAA1199 overexpression in human gastric cancer

BACKGROUND

KIAA1199 is an inner-ear-specific gene which encodes KIAA1199 protein, the function of which is unknown. KIAA1199 might be a novel, positively regulated target of Wnt signaling. The aim of this study was to examine the expression of KIAA1199 in surgical specimens of gastric cancer to evaluate the clinical outcome.

METHODS

The expression of KIAA1199 mRNA was studied by semiquantitative reverse-transcription polymerase chain reaction (RT-PCR), and the expression status was analyzed from the viewpoint of clinical and pathological factors. Univariate and multivariate analyses were performed. In addition, an immunohistochemical study was performed in the selected samples.

RESULTS

A significantly higher expression of KIAA1199 messenger RNA (mRNA) was recognized in tumor tissue compared with that of paired normal tissues (P < 0.01). The cases were divided into high- (n = 39) and low-expression (n = 71) groups according to KIAA1199 expression status in the tumor. The overall 5-year survival rate was significantly better in the KIAA1199 low-expression group (61.2%) than in the high-expression group (29.6%) (P < 0.05). Clinicopathological factors such as well and moderately tumor differentiation, positive lymph node metastasis, positive distant metastases, and positive peritoneal dissemination were more frequently observed in the high-expression group than in the low-expression group (P = 0.02, 0.08, 0.01, and 0.03, respectively). KIAA1199 expression was an independent prognostic factor (P = 0.03).

CONCLUSIONS

KIAA1199 was highly expressed in gastric cancer, and was associated with prognosis and lymph node metastasis in multivariate analyses. Taken together, KIAA1199 may be a novel gene that plays an important role in progression of gastric cancer.

Expression of odontogenic ameloblast-associated protein (ODAM) in dental and other epithelial neoplasms

We previously have communicated our discovery that the amyloid associated with calcifying epithelial odontogenic tumors is composed of N-terminal fragments of the structurally novel odontogenic ameloblast-associated protein designated ODAM. Subsequently, it was shown by other investigators that ODAM is expressed in rodent enamel organ and is likely involved in dental development. We now report that this molecule also is found in certain human tissues, principally the salivary gland and trachea, as evidenced by RNA array analysis and immunohistochemistry-utilizing antibodies prepared against synthetic ODAM-related peptides and recombinant protein. Notably, these reagents immunostained normal and malignant ameloblasts and other types of human neoplastic cells, including those of gastric, lung, and breast origin where the presence in the latter was confirmed by in situ hybridization using gene-specific molecular probes. Moreover, significant titers of anti-ODAM IgG antibodies were detected in the sera of patients with these malignancies. Our studies have provided the first evidence in humans for the cellular expression of ODAM in normal and diseased states. Based on our findings, we posit that ODAM is a developmental antigen that has an essential role in tooth maturation and in the pathogenesis of certain odontogenic and other epithelial neoplasms; further, we suggest that ODAM may serve as a novel prognostic biomarker, as well as a potential diagnostic and therapeutic target for patients with breast and other epithelial forms of cancer.

Sulindac treatment alters collagen and matrilysin expression in adenomas of ApcMin/+ mice

Non-steroidal anti-inflammatory drugs (NSAIDs) have shown potential as chemopreventive agents against cancer formation, especially colorectal cancers. However, the mechanisms by which these drugs act are not fully understood. In this study, Apc(Min/+) mice, a genetic model of human familial adenomatous polyposis, were treated with sulindac, and these mice demonstrated tumor reduction of >80%, consistent with previous reports. Gene microarray analyses of RNA from adenoma-derived dysplastic epithelial cells revealed that collagen genes, viz. Col1a2, Col5a2, Col6a2 and Col6a3, were upregulated, and matrilysin matrix metalloproteases-7 (Mmp7) was downregulated, in sulindac-treated mice. Reverse transcription-polymerase chain reaction validated gene expression of the Col6a2 subunit of collagen VI and of Mmp7. Confocal microscopy and immunofluorescence showed that within the tumors of non-treated mice, collagen VI was present in low amounts, but was enhanced within the tumors of sulindac-treated mice. Collagens I and V demonstrated similar patterns, but were not as prominent as collagen VI. Mmp7 was found in 'hot spot' areas within the tumors of Apc(Min/+) mice treated with the vehicle, but was greatly diminished in those mice treated with sulindac. Studies with Apc(Min/+)/Mmp7(-/-) double-deficient mice demonstrated the reciprocal relationships of Mmp7 expression and the levels of these three collagens in vivo. The results of this study demonstrated that sulindac was effective in increasing the expression of different collagens and decreasing the expression of Mmp7, effects that may contribute to altered tumor burden in cancer patients undergoing NSAIDs treatments.

NADPH oxidases in lung biology and pathology: host defense enzymes, and more

The deliberate production of reactive oxygen species (ROS) by phagocyte NADPH oxidase is widely appreciated as a critical component of antimicrobial host defense. Recently, additional homologs of NADPH oxidase (NOX) have been discovered throughout the animal and plant kingdoms, which appear to possess diverse functions in addition to host defense, in cell proliferation, differentiation, and in regulation of gene expression. Several of these NOX homologs are also expressed within the respiratory tract, where they participate in innate host defense as well as in epithelial and inflammatory cell signaling and gene expression, and fibroblast and smooth muscle cell proliferation, in response to bacterial or viral infection and environmental stress. Inappropriate expression or activation of NOX/DUOX during various lung pathologies suggests their specific involvement in respiratory disease. This review summarizes the current state of knowledge regarding the general functional properties of mammalian NOX enzymes, and their specific importance in respiratory tract physiology and pathology.

The calcium-binding protein S100P in normal and malignant human tissues

Background

S100P is a Ca²⁺ binding protein overexpressed in a variety of cancers, and thus, has been considered a potential tumor biomarker. Very little has been studied about its normal expression and functions.

Methods

We examined S100P expression in normal human tissues by quantitative reverse transcription polymerase chain reaction and immunohistochemistry. S100P protein expression was also studied in a series of tumors, consisting of 74 ovarian, 11 pancreatic, 56 gastric, 57 colorectal, 89 breast and 193 prostate carcinomas using a novel anti-S100P monoclonal antibody.

Results

Among the normal tissues, the highest S100P mRNA levels were observed in the placenta and esophagus. Moderate signals were also detected in the stomach, duodenum, large intestine, prostate and leukocytes. At the protein level, the highest reactions for S100P were seen in the placenta and stomach. Immunostaining of tumor specimens showed that S100P protein is expressed in all the tumor categories included in the study, being most prevalent in gastric tumors.

Conclusion

Based on our observations, S100P is widely expressed in both normal and malignant tissues. The high expression in some tumors suggests that it may represent a potential target molecule for future diagnostic and therapeutic applications.