Expression of the pS2 gene in normal, benign and neoplastic human stomach

Immunoexpression of Trefoil Factor 1 in Non-Neoplastic and Neoplastic Canine Gastric Tissues

Simple Summary

Gastric carcinoma (GC) is the second leading cause of death in humans and the most frequent malignancy in the stomach of dogs. As in humans, the prognosis of canine gastric cancer is generally poor owing to the advanced stage at the time of diagnosis, resulting in limited treatment options. In dogs, the molecular mechanisms involved in the growth and progression of gastric cancer remain largely unknown. Trefoil factor 1 (TFF1) protein is a mucin-associated secretory molecule that plays an important role in the maintenance and protection of epithelial surface integrity. Some human studies showed that TFF1 can protect mucosa against damage and suppress carcinogenesis, while other studies showed that TFF1 can restrict cell adhesion, promote tumor cell invasion, and block necrosis of tumor cells. In human gastric cancer, TFF1 has been found to decrease, and it has been proposed that it might act as a tumor suppressor factor. The present study was carried out to investigate whether there is a relationship between TFF1 and canine gastric carcinogenesis. We found an association between reduced expression of TFF1 and the development and progression of gastric cancer in dogs. The pathological and behavioral similarities between spontaneous canine GC and human counterparts make it logical to assume that dogs may be a useful model for human gastric cancer.

Abstract

TFF1 expression is markedly reduced in human GCs, suggesting that TFF1 is a tumor suppressor for human gastric cancer. The present study evaluated the expression and distribution pattern of TFF1 in paraffin-embedded canine gastric tissue samples, including normal mucosa (n = 3), polyps (n = 8), carcinomas (n = 31) and their adjacent non-neoplastic mucosa (n = 30), neoplastic emboli (n = 14), and metastatic lesions (n = 9), by immunohistochemistry (IHC). All normal gastric tissues expressed TFF1 in the superficial foveolar epithelium and mucopeptic cells of the neck region. Most gastric polyps (GPs) displayed immunoreactivity for TFF1 in >75% of the epithelial component. In GCs, the expression of TFF1 was found reduced in 74.2% of the cases. The level of TFF1 expression had a decreased tendency from normal gastric mucosa to GPs and GCs (p < 0.05). No significant differences in the expression of TFF1 were found in GCs, according to age, sex, histological type based on World Health Organization (WHO) and Lauren classification, tumor location, depth of tumor invasion, presence of neoplastic emboli or metastatic lesions. The median survival time of GC patients with preserved and reduced TFF1 immunoexpression were 30 and 12 days, respectively. Kaplan–Meier analysis revealed no significant survival differences between the two groups (p > 0.05). These findings suggest that TFF1 protein may play a role in canine gastric carcinogenesis, and further studies are necessary to define its usefulness as a prognostic indicator in canine gastric carcinoma.

Disruption of the Tff1 gene in mice using CRISPR/Cas9 promotes body weight reduction and gastric tumorigenesis

Trefoil factor 1 (TFF1, also known as pS2) is strongly expressed in the gastrointestinal mucosa and plays a critical role in the differentiation of gastric glands. Since approximately 50% of all human gastric cancers are associated with decreased TFF1 expression, it is considered a tumor suppressor gene. TFF1 deficiency in mice results in histological changes in the antral and pyloric gastric mucosa, with severe hyperplasia and dysplasia of epithelial cells, resulting in the development of antropyloric adenoma. Here, we generated TFF1-knockout (KO) mice, without a neomycin resistant (Neo^R) cassette, using the clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9 (CRSIPR/Cas9) system. Though our TFF1-KO mice showed phenotypes very similar to the previous embryonic stem (ES)-cell-based KO mice, they differed from the previous reports in that a reduction in body weight was observed in males. These results demonstrate that these newly established TFF1-KO mice are useful tools for investigating genetic and environmental factors influencing gastric cancer, without the effects of artificial gene insertion. Furthermore, these findings suggest a novel hypothesis that TFF1 expression influences gender differences.

Prognostic Significance of Cytosolic pS2 Protein Content in Gastric Cancer

pS2, a 60-amino-acid chain peptide which is the most widespread estrogen-induced RNA messenger in MCF-7 breast cancer cells, is normally detected in the epithelium of gastric mucosa. The aims of this work were to evaluate the cytosolic pS2 content and its clinical significance in gastric carcinomas. Cytosolic pS2 levels were examined by immunoradiometric methods in 108 patients with primary gastric adenocarcinomas. The mean follow-up period was 23.3 months. The cytosolic pS2 levels of the tumors ranged widely, i.e., from 0.1 to 3217 ng/mg protein. There were no significant differences in pS2 content between tumors (mean ± standard error: 137.2±31.4 ng/mg protein) and paired adjacent mucosa samples (n=84; mean ± standard error: 249.6±32.6 ng/mg protein), nor were there any significant differences in tumoral pS2 levels with respect to clinicopathologic parameters such as patient age and sex or tumor location, stage, histologic type or grade. However, the results indicated that high intratumoral pS2 levels were significantly and independently associated with an unfavorable outcome in the overall group of patients (p=0.0266) and in patients with resectable gastric cancer (p=0.003). In conclusion, pS2 may represent a useful biological marker in gastric cancer.

Cytosolic Levels of An Estrogen-Induced Breast Cancer-Associated Peptide (TFF1/pS2) in Colorectal Cancer: Clinical Significance and Relationship with Steroid Receptors

Background

The Trefoil Factor 1 (TFF1/pS2), a peptide consisting of 60 amino acids, is the most abundant estrogen-induced messenger RNA in MCF-7 breast cancer cells and is also expressed by colorectal carcinomas. The objective of this work was to evaluate the cytosolic TFF1 content in colorectal carcinomas, its possible relationship with estrogen and progesterone receptors as well as with clinicopathological tumor parameters, and its potential prognostic significance.

Methods

Cytosolic TFF1 levels were examined by immunoradiometric assay in 178 patients with resectable colorectal cancer. The mean follow-up period was 32 months.

Results

There was a wide variability of cytosolic TFF1 levels in tumor-surrounding mucosa samples (0.09-42.5 ng/mg protein) as well as in tumors (0.01-270 ng/mg protein). Comparison of paired mucosa and carcinoma samples showed significantly higher TFF1 levels in tumors (mean: 17.1 ng/mg protein) than in mucosa samples (10 ng/mg protein) (p=0.027). TFF1 levels were significantly higher in mucosa samples surrounding distal colon and rectal tumors (p=0.0001) and in tumor samples obtained from older patients (p=0.007). However, there were no significant differences in tumor TFF1 levels with respect to clinicopathological parameters such as the patient's sex, tumor location, stage, histological grade, ploidy, S-phase, or tumor estrogen and progesterone receptors. In addition, there was no significant relationship between tumor TFF1 levels and disease outcome.

Conclusions

TFF1 may play an as yet undetermined role in the tumorigenesis of colorectal carcinomas. However, cytosolic levels of TFF1 do not seem to have any prognostic significance in colorectal carcinomas.

Pharmacology and clinical application of compound Qifang Weitong formula

Previous studies on the pharmacology and clinical application of compound Qifang Weitong formula have shown that it can ameliorate inflammation-induced gastric mucosal injury, protect the gastric mucosa, improve the structure of regenerated tissue, promote gastric ulcer healing and regeneration, and inhibit gastric ulcer recurrence. Therefore, this formula can be used to treat gastric ulcer, chronic atrophic gastritis (CAG), CAG with atypical hyperplasia, irritable bowel syndrome and functional dyspepsia.

miRNA423-5p regulates cell proliferation and invasion by targeting trefoil factor 1 in gastric cancer cells

TFF1 is a small, secreted protein in the TFF family that has a pivotal role as a motogenic factor in epithelial restitution and cell motility, and as a tumor suppressor gene in the stomach. In this study, we identified TFF1 as a novel target gene of miRNA-423-5p. miRNA-423-5p negatively regulated the expression of TFF1 by binding to its 3'UTR and participated in proliferation/invasion-related processes via a TFF1-dependent manner in gastric cancer cells. Our findings suggested that miR-423-5p may be a novel target for the future development of specific therapeutic interventions for gastric cancer.

Activation of the NF-kB pathway downregulates TFF-1 in gastric carcinogenesis

Trefoil factor 1 (TFF1) is expressed in the normal superficial epithelium of the stomach and is implicated in the maintenance of gastric epithelial structure and function. During gastric carcinogenesis, in which pro-inflammatory cytokines play a crucial role, its expression level decreases suggesting a role as tumor suppressor factor. We have compared expression of TFF1 in gastric mucosa from cancer patients, in which several degrees of inflammatory infiltrate are present, with that in normal mucosa from non-cancer patients without infiltrating inflammatory cells. TFF1 is less expressed in the superficial gastric epithelium from cancer patients than in that from normal individuals in which the nuclear factor (NF)-κB pathway is not activated. We analyzed TFF1 expression in ex vivo samples of gastric mucosa from cancer patients, and in MKN45 gastric cancer cell line after exposure to proinflammatory cytokines interleukin (IL)-1β or tumor necrosis factor (TNF)-α, that activate the NF-κB pathway. We found that IL-1β and TNF-α activate the NF-κB pathway, as reflected in the nuclear expression of p65 and the activation of p-IκBα, and downregulate TFF1 expression after 1 or 2 h of exposure. Moreover, cells in the superficial gastric epithelium in ex vivo samples co-expressed TFF1/p65 at cellular level, whereas tumor cells did not. In summary, downregulation of TFF1 expression during gastric neoplastic transformation is associated with activation of the NF-κB pathway through IL-1β or TNF-α, but other regulatory mechanisms might also be involved.

Reduced expression of TFF1 and increased expression of TFF3 in gastric cancer: correlation with clinicopathological parameters and prognosis

OBJECTIVES

The trefoil factor family (TFF) is composed of three thermostable, and protease-resistant proteins, named TFF1, TFF2 and TFF3, and plays a role in gastrointestinal mucosal defence and repair. Recently, TFFs have been found to be related to the development of various types of cancer. This study assessed the relationship between the expression of TFF1 and TFF3 and the clinicopathological parameters in gastric carcinoma (GC).

MATERIALS AND METHODS

The expression of TFF1 and TFF3 was analyzed by immunohistochemistry in 292 GCs and 20 normal gastric tissues.

RESULTS

All normal gastric tissues expressed TFF1, but 53.8% of GCs showed reduced TFF1 expression. However, TFF3 was not detected in normal gastric tissues and 44.2% of GCs showed a high level of expression. Highly expressed TFF3 was significantly correlated with lymph node metastasis, lymphatic invasion, vein invasion, and advanced stage. The overall survival was shorter in patients with high expression of TFF3 than in those with low expression of TFF3 in 292 GCs and in 125 early GCs (EGCs). Moreover, in patients with EGCs, high expression of TFF3, associated with reduced expression of TFF1, was determined as an independent poor prognostic marker.

CONCLUSIONS

Reduced expression of TFF1 and increased expression of TFF3 may play a role in the carcinogenesis of gastric cancer. Furthermore, high expression of TFF3 with reduced expression of TFF1 may be a marker of poor prognosis for patients with EGC.

Tests for serum levels of trefoil factor family proteins can improve gastric cancer screening

BACKGROUND & AIMS

Improving methods for early detection of gastric cancer could reduce mortality. Measurements of serum pepsinogen levels have been used for screening in Japan without satisfactory levels of sensitivity or specificity. Trefoil factor family (TFF) proteins (TFF1, TFF2, and TFF3) are small and stable molecules secreted by the mammalian gastrointestinal tract. Foveolar hyperplasia, spasmolytic polypeptide (TFF2)-expressing metaplasia, and intestinal metaplasia are histologic changes observed in patients with atrophic gastritis; they express TFF1, TFF2, and TFF3, respectively. We investigated whether serum levels of TFF can be used as markers for gastric cancer screening.

METHODS

Serum was collected from 183 patients with gastric cancer and 280 healthy individuals without cancer. Serum levels of anti-Helicobacter pylori immunoglobulin G, pepsinogen I, pepsinogen II, TFF1, TFF2, and TFF3 were measured by enzyme-linked immunosorbent assay and associated with gastric cancer.

RESULTS

Using a cutoff of 3.6 ng/mL, the level of TFF3 was significantly increased in serum samples from patients with cancer (odds ratio, 18.1; 95% confidence interval, 11.2-29.2); using this test, patients with cancer were identified with 80.9% sensitivity and 81.0% specificity. The test for TFF3 had a significantly higher odds ratio than that for pepsinogen. A test for the combination of TFF3 and pepsinogen had better results than the test for only pepsinogen.

CONCLUSIONS

Serum levels of TFF3 are a better marker of gastric cancer than pepsinogen; a test for the combined levels of serum pepsinogen and TFF3 could improve gastric cancer screening.

Expression of trefoil factor 1 in gastric cancer and its correlation with neovascularization

AIM: To investigate the expression of trefoil factor 1 (TFF1) and vascular endothelial growth factor (VEGF) in normal gastric mucosa, adjacent carcinoma and gastric carcinoma and to explore its role in neovas-cularization.

METHODS: The expressions of TFF1, VEGF and MVD (CD34 monoclonal antibody labeling) were determined by immunohistochemical method in 174 gastric specimens including 42 normal gastric mucosa, 66 adjacent carcinoma and 66 gastric carcinomas.

RESULTS: In normal control group, adjacent carcinoma and gastric carcinoma group, the expression of TFF1 had a decreasing tendency (209.40 ± 16.00, 199.12 ± 16.68, 189.17 ± 16.20, P < 0.01), but the expression of VEGF and the MVD had a increasing tendency (69.7%, 40.9%, 35.7%; 38.90 ± 6.74, 28.68 ± 5.08, 25.13 ± 4.46). MVD was positively correlated with grey levels of TFF1 (r = 0.811, P < 0.01), in other words, there was a negative correlation between the MVD values and the expression of TFF1.

CONCLUSION: TFF1, a specific anti-oncogene for gastric carcinoma, doesn't have a close correlation with tumor vessel neogenesis.

Expression of trefoil factors 1 and 2 in precancerous condition and gastric cancer

AIM: To study the expression of trefoil factor 1 (TFF1) and TFF2 in precancerous condition and gastric cancer and to explore the relationship between TFFs and tumorigenesis, precancerous condition and gastric cancer.

METHODS: The expression of TFF1 and TFF2 was immunohistochemically analyzed in paraffin-embedded samples from 140 patients including 35 cases of chronic superficial gastritis (CSG), 35 cases of gastric ulcer (GU), 35 cases of chronic atrophic gastritis (CAG) and 35 cases of gastric cancer (GC).

RESULTS: TFF1 and TFF2 were located in cytoplasm of gastric mucous cells. In CSG, GU, CAG and GC, the level of TFF1 expression had a decreased tendency (P < 0.05). The expression of TFF2 was higher in GU than in CSG, but the difference was not significant. The expression of TFF2 also had a decreased tendency in GU, CAG, and GC (P < 0.05).

CONCLUSION: The reduced expression of TFF1 and TFF2 in precancerous conditions and gastric cancer may be associated with the proliferation and malignant transformation of gastric mucosa. More investigations are needed to explore the mechanism of TFFs and the relationship between TFFs and gastric cancer.

Trefoil factor family-1 mutations enhance gastric cancer cell invasion through distinct signaling pathways

BACKGROUND & AIMS

Trefoil factor family-1 (TFF1) is a key gastric tumor-suppressor gene. TFF1 knockout mice develop multiple gastric adenomas and carcinomas, and human gastric cancers typically lack TFF1 expression. Recently, TFF1 mutations have been found in human gastric cancer. The purpose of this study was to determine the functionality of these mutants.

METHODS

Recombinant wild-type TFF1 and the gastric cancer-associated TFF1 mutants (A10D and E13K) were produced and tested for their effect on gastric cancer cell proliferation, apoptosis, and invasion. Molecular modeling was used to guide the choice of mutants and to evaluate structure-function relationships.

RESULTS

Molecular modeling suggested that A10D and E13K altered the surface charge of the loop 1 region of TFF1 without disturbing protein stability. Recombinant wild-type TFF1 significantly inhibited cell growth; A10D and E13K lost this tumor-suppressive property along with the ability to block etoposide-induced apoptosis. Although wild-type TFF1 promoted cell invasion, A10D and E13K were even more pro-invasive. Invasion induced by both mutants was blocked by inhibiting PI3-kinase or phospholipase-C, but inhibiting Rho-associated kinase (ROCK) blocked only E13K-induced invasion.

CONCLUSIONS

The loss of tumor-suppressor activity and gain of invasiveness from single point mutations constitute evidence for a functional role of TFF1 mutations in gastric cancer. These site-directed mutagenesis experiments provide the tools for continued probing of signal transduction mechanisms and structural elements responsible for TFF1 functions.

Cytosolic levels of TFF1/pS2 in breast cancer: Their relationship with clinical-pathological parameters and their prognostic significance

BACKGROUND

The Trefoil Factor 1 (TFF1/pS2), a peptide consisting of 60 amino acids, is the most abundant estrogen-induced messenger RNA present in MCF-7 breast cancer cells. The objective of this work was to evaluate the cytosolic TFF1 content in breast carcinomas, its possible relationship with different clinical-pathological parameters, and its potential prognostic significance and predictive value.

METHODS

Cytosolic TFF1 levels were examined by immunoradiometric assay in 1031 patients with invasive breast cancer. The median follow-up period was of 50 months.

RESULTS

There was a wide variability of cytosolic TFF1 levels in tumors (0.9-743.2 ng/mg protein). Statistical analysis showed that TFF1 levels were significantly higher in premenopausal patients (p = 0.001), as well as in tumors showing any of the following characteristics: good differentiation (p = 0.0001), ER and PgR positivity (p = 0.0001 and p = 0.001, respectively), diploidy (p = 0.045) and a high S-phase fraction (p = 0.001). In addition, the presence of high intratumoral TFF1 levels (cut-off: 2 ng/mg protein) was independently associated with a shorter overall survival in the group of patients as a whole (p = 0.001) as well as in the subgroup with node-negative breast cancer (p = 0.0004). Likewise, high intratumoral TFF1 levels were associated with a more prolonged overall survival in patients who received adjuvant tamoxifen (p = 0.004).

CONCLUSIONS

In breast cancer patients, intratumoral TFF1 levels are associated with a better clinical outcome, especially in those with node-negative tumors. In addition, TFF1 levels have a low but significant predictive value in regards to response to adjuvant therapy with tamoxifen.

Trefoil factor family-3 is associated with aggressive behavior of colon cancer cells

BACKGROUND AND AIM

Trefoil factor family 3 (TFF3) is expressed by intestinal epithelial cells and it mainly functions to protect the mucosa from injury. Expression of TFF3 has been correlated with a poor prognosis in patients with cancer, but little is known about whether TFF3 directly contributes to the malignant behavior of cancer cells. The present study was conducted to determine whether TFF3 expression contributes to the malignant behavior of cancer cells in vitro and in vivo.

METHODS

Two subclones of a metastatic rat colorectal cancer cell line, demonstrated previously to manifest aggressive (LN cells) and non-aggressive (LP cells) growth in vivo, were analyzed for expression of TFF3 and tested in assays of cancer cell migration, invasion, and apoptosis in vitro, and mortality in vivo.

RESULTS

The aggressive LN cell line endogenously expressed TFF3 and supported the transcription of a TFF3 promoter-driven reporter construct, whereas the non-aggressive LP cell line did not express TFF3. LN cells demonstrated enhanced migration, invasion, and less apoptosis compared to LP cells. Transfecting TFF3 into LP cells enhanced their ability to migrate, invade, block apoptosis, and behave more aggressively in vivo, thereby resembling the phenotype of LN cells.

CONCLUSIONS

In rat colon cancer cells, both endogenous and constitutive expression of TFF3 correlates with an aggressive phenotype. These data provide direct evidence that TFF3 contributes to the malignant behavior of cancer cells.

Altered expression of TFF-1 and CES-2 in Barrett's Esophagus and associated adenocarcinomas

Identification of biomarkers to recognize individuals with Barrett's esophagus (BE) predisposed to develop malignancy is currently a pressing issue. We utilized gene expression profiling to compare molecular signatures of normal esophagus and stomach, BE, and adenocarcinoma (AC) to identify such potential biomarkers. Over 22,000 genes were analyzed by oligonucleotide microarrays on 38 unique RNA Unsupervised and supervised clusterings were performed on a subset of 2849 genes that varied most significantly across the specimens. Immunohistochemistry (IHC) for two of the significantly differentially expressed gene products was performed on tissue microarrays. Unsupervised clustering identified two discernable molecular BE profiles, one of which was similar to normal gastric tissue ("BE1"), and another that was shared by several of the AC specimens ("BE2"). The BE1 profile included expression of several genes that have been described as tumor-suppressor genes, most notably trefoil factor 1 (TFF-1). The BE2 profile included expression of genes previously found overexpressed in cancers, such as carboxylesterase-2 (CES-2). IHC demonstrated the loss of TFF-1 late in the progression of BE to AC. It also revealed CES-2 as being upregulated in AC documented to have arisen in the presence of BE. These potential biomarkers, as well as the relative expression of genes from BE1 versus those from BE2, may be validated in the future to aid in risk stratification and guide treatment protocols in patients with BE and associated AC.

Gene Expression Profiling to Identify Oncogenic Determinants of Autocrine Human Growth Hormone in Human Mammary Carcinoma

We have exploited a discrepancy in the oncogenic potential of autocrine and exogenous human growth hormone (hGH) in an attempt to identify molecules that could potentially be involved in oncogenic transformation of the human mammary epithelial cell. Microarray analysis of 19,000 human genes identified a subset of 305 genes in a human mammary carcinoma cell line that were remarkably different in their response to autocrine and exogenous hGH. Autocrine and exogenous hGH also regulated 167 common genes. Semiquantitative reverse transcription-PCR confirmed differential regulation of genes by either autocrine or exogenous hGH. Functional analysis of one of the identified autocrine hGH-regulated genes, TFF3, determined that its expression is sufficient to support anchorage-independent growth of human mammary carcinoma cells. Small interfering RNA-mediated knockdown of TFF3 concordantly abrogated anchorage-independent growth of mammary carcinoma cells and abrogated the ability of autocrine hGH to stimulate oncogenic transformation of immortalized human mammary epithelial cells. Further functional characterization of the identified subset of specifically autocrine hGH regulated genes will delineate additional novel oncogenes for the human mammary epithelial cell.

Anti-sense trefoil factor family-3 (intestinal trefoil factor) inhibits cell growth and induces chemosensitivity to adriamycin in human gastric cancer cells

Intestinal trefoil factor (ITF), which is normally absent in gastric mucosa, is over-expressed in gastric cancer. However, the functional significance of ITF in gastric cancer is unknown. We examined the effects of blocking ITF expression on the growth of gastric cancer cells and their responses to chemotherapeutic agents. Anti-sense ITF cDNA was cloned into mammalian expression vector pcDNA3 and was transfected into an ITF-expressing gastric cancer cell line SNU-1. We assessed the doubling time and anchorage dependent growth of the transfected cells using growth curve and soft agar assay respectively. Cell cycle analysis and apoptosis were determined by flow cytometry and cell death ELISA. The response to chemotherapeutic agents after transfecting anti-sense ITF was also examined. Anti-sense ITF transfectant (3A-5) had a significantly longer doubling time as compared to control cells which were transfected with empty vector (32.4 hr vs 26.9 hr, p < 0.05). In the soft agar assay, 3A-5 formed fewer colonies than control (3.5 colonies vs 23.5 colonies, p < 0.05). Although there was no significant difference in the cell cycle distribution between 3A-5 and control, anti-sense ITF resulted in marked increase in adriamycin-induced apoptosis. Our results demonstrated that blocking the expression of ITF inhibits growth of gastric cancer cells and enhances the response to chemotherapy.

Trefoil factor family (TFF) peptides and cancer progression

TFF peptides are involved in mucosal maintenance and repair through motogenic and antiapoptotic activities. These peptides are overexpressed during inflammatory processes and cancer progression. They also function as scatter factors, proinvasive and angiogenic agents. Such a divergence is related to the pathophysiological state of tissues submitted to persistent aggressive situations during digestive processes in the normal gastrointestinal tract, inflammatory and neoplastic diseases. In agreement with this model, TFF peptides are connected with multiple oncogenic pathways. As a consequence, the TFF signaling pathways may serve as potential targets in the control of chronic inflammation and progression of human solid tumors.

Profiling trefoil factor family (TFF) expression in the mouse: identification of an antisense TFF1-related transcript in the kidney and liver

The expression of the trefoil factor family (TFF) genes (TFF1, TFF2, and TFF3) was systematically analyzed in 18 different organs from male or female mice using RT-PCR analysis. The expression patterns showed some gender-specific differences, e.g., TFF3 transcripts in the urinary bladder and liver. Furthermore, the murine expression profile differed from that in human, e.g., in the respiratory tract and uterine cervix. As a hallmark, an aberrant TFF1-related transcript was detected specifically in the kidney and liver of several mouse strains. Molecular characterization of this rare 1.8kb long transcript from the kidney clearly revealed that its 3' region originated from the antisense strand of the TFF1 locus containing particularly large parts of the antisense strands of introns 1 and 2. Homology searches using various databases revealed that this antisense TFF1-related transcript is subject of intense alternative splicing and no protein product encoded by this antisense TFF1-related transcript could be identified. Although the function of this transcript is not known currently, we can speculate that this antisense TFF1-related transcript might have a gene silencing effect particularly on TFF1 expression in the murine kidney and liver.

Urinary pS2/TFF1 levels in the management of hormonodependent breast carcinomas

pS2/TFF1 overexpression in breast carcinomas correlates with response to hormonotherapy. We evaluated the clinical relevance of urinary pS2/TFF1 in breast cancer patients. In healthy controls (100 cases), it represents an individual and relatively stable parameter. Although 24 out 83 pre-operative breast cancer patients showed elevated levels, both the sensitivity and specificity of the test were too low for breast cancer screening. However, neoadjuvant hormonotherapy decreased pS2/TFF1 levels in nine out of 20 patients. Furthermore, among 22 patients receiving long-term adjuvant hormonotherapy, four exhibited elevated levels, two of them at the time of relapse. Thus, urinary pS2/TFF1 quantification might be suitable as an in vivo diagnosis for tumor hormonodependency, and disease follow-up during hormonotherapy.

Decreased abundance of trefoil factor 1 transcript in the majority of gastric carcinomas

BACKGROUND

Gastric carcinoma is one of the leading causes of cancer-related death worldwide, but the mechanisms underlying its development and progression still remain largely uncharacterized. As loss of trefoil factor 1 (TFF1) expression leads to neoplastic growth in the antropyloric mucosa of mice, the authors sought to comprehensively study the human TFF1 gene in primary gastric carcinomas.

METHODS

The authors studied the human TFF1 gene in primary gastric carcinomas and normal gastric mucosa at the DNA, RNA, and protein levels through DNA sequencing, quantitative real-time reverse transcriptase-polymerase chain reaction, and immunohistochemistry.

RESULTS

Strikingly, TFF1 mRNA expression was significantly decreased in all 37 gastric carcinomas studied compared with normal gastric mucosa. Furthermore, six tumor/normal pairs with available histologic samples demonstrated a marked decrease in protein expression in tumor samples. Screening of the entire TFF1 coding region in a panel of 42 human gastric tumors did not reveal any somatic mutations, although a few rare germline sequence variants were identified.

CONCLUSIONS

These findings demonstrated a significant decrease in the TFF1 transcript in the majority of human gastric carcinomas along with a corresponding reduction in protein expression, both of which occurred in the absence of gene mutation. Dysregulation of TFF1 expression at the transcript level was a critical event in the development of most gastric carcinomas.

Trefoil factors: initiators of mucosal healing

Maintaining the integrity of the gastrointestinal tract, despite the continual presence of microbial flora and injurious agents, is essential. Epithelial continuity depends on a family of small, yet abundant, secreted proteins--the trefoil factors (TFFs). TFFs protect mucous epithelia from a range of insults and contribute to mucosal repair, although the signalling events that mediate these responses are only partially understood.

Expression of trefoil peptides (TFF1, TFF2, and TFF3) in gastric carcinomas, intestinal metaplasia, and non-neoplastic gastric tissues

Trefoil factor family (TFF) domain peptides consist of three members that play a role in intestinal mucosal defence and repair, and in tumourigenesis. The role of the three TFF members in the gastric carcinogenesis cascade remains poorly defined. This study examined seven gastric cell lines, 50 gastric cancers and their adjacent non-cancer tissues, and tissues from 40 non-cancer patients, in order to elucidate the chronology of TFF expression in various stages of gastric carcinogenesis. TFF expression was determined by RT-PCR, immunohistochemistry, and western blot. Aberrant expression of TFF1, TFF2, and TFF3 was frequently detected in gastric cell lines. Specifically, TFF1 was detected in all non-cancer patients, but was detected in only 50% of gastric cancer and 66% of adjacent normal tissues. TFF2 expression was demonstrated in 87.5% of non-cancer patients, 34% of gastric carcinomas, and 58% of adjacent non-cancer tissues. There was a significant correlation between TFF1 and TFF2 expression in gastric cancer and adjacent non-cancer tissues (p<0.001). By contrast, TFF3 was detected in 25% of non-cancer patients and showed a predilection for areas with intestinal metaplasia (p=0.005). Sixty-two per cent of gastric cancers and 24% of neighbouring non-cancer tissues showed TFF3 expression. Immunoreactivity against TFF3 was demonstrated in goblet cells of intestinal metaplasia and within the cytoplasm and nuclei of tumour cells. Progressive loss of TFF1 and TFF2, together with the induction of TFF3, is likely to be involved in the early stage of the multi-step gastric carcinogenesis pathway.

The trefoil factor 1 participates in gastrointestinal cell differentiation by delaying G1-S phase transition and reducing apoptosis

Trefoil factor (TFF)1 is synthesized and secreted by the normal stomach mucosa and by the gastrointestinal cells of injured tissues. The link between mouse TFF1 inactivation and the fully penetrant antropyloric tumor phenotype prompted the classification of TFF1 as a gastric tumor suppressor gene. Accordingly, altered expression, deletion, and/or mutations of the TFF1 gene are frequently observed in human gastric carcinomas. The present study was undertaken to address the nature of the cellular and molecular mechanisms targeted by TFF1 signalling. TFF1 effects were investigated in IEC18, HCT116, and AGS gastrointestinal cells treated with recombinant human TFF1, and in stably transfected HCT116 cells synthesizing constitutive or doxycycline-induced human TFF1. We observed that TFF1 triggers two types of cellular responses. On one hand, TFF1 lowers cell proliferation by delaying G1-S cell phase transition. This results from a TFF1-mediated increase in the levels of cyclin-dependent kinase inhibitors of both the INK4 and CIP subfamilies, leading to lower E2F transcriptional activity. On the other hand, TFF1 protects cells from chemical-, anchorage-free-, or Bad-induced apoptosis. In this process, TFF1 signalling targets the active form of caspase-9. Together, these results provide the first evidence of a dual antiproliferative and antiapoptotic role for TFF1. Similar paradoxical functions have been reported for tumor suppressor genes involved in cell differentiation, a function consistent with TFF1.

Molecular and biologic basis of upper gastrointestinal malignancy. Gastric carcinoma

Gastric cancer is one of the world's most common cancers and is a leading cause of cancer death worldwide. Neoplasia of the stomach is mainly composed of adenocarcinomas, which for more than 95% of cases. Although mesenchymal tumors (i.e., stromal tumors, leiomyomas and leiomyosarcomas, and schwannomas), primary lymphomas, and carcinoid tumors can also arise in the stomach, malignant tumors of these types occur much less often.

Biliary epithelial trefoil peptide expression is increased in biliary diseases

AIMS

Maintenance of the cellular integrity of the biliary epithelium may involve the production of mucins and mucin-associated peptides. In the luminal gastrointestinal tract, mucins and the mucin-associated trefoil peptides (TFF) are integral to cytoprotection and cellular repair of the mucosa.

METHODS AND RESULTS

Samples of normal and diseased human liver tissue were examined using histological and immunohistochemical techniques, for the expression of TFF and mucins. Bile ducts were classified as small, medium or large depending upon the number of biliary epithelial cells. TFF expression was demonstrated in biliary epithelial cells of both normal and diseased liver tissue. TFF expression was greatest in the large bile ducts. In normal liver tissue, expression of at least one TFF was demonstrated in 2-7% of small bile ducts, 5-31% of medium bile ducts and 31-85% of large bile ducts. Seventy-seven percent of large bile ducts secreted mucins and all three TFF concurrently, compared with 3% of medium bile ducts and no small bile ducts. Biliary disease resulted in an increased expression of TFF1 and TFF3 in the medium bile ducts.

CONCLUSIONS

The biliary epithelial cells in normal and diseased human liver tissue express TFF, particularly in the larger bile ducts. TFF expression may be up-regulated or induced in biliary diseases as a response to injury, as is seen in epithelial damage elsewhere in the gastrointestinal tract.

[Analysis of the cytosolic content of the pS2 protein in breast cancer]

OBJECTIVE

To analyze pS2 cytosolic levels in breast carcinomas and their correlation with different clinical characteristics of the patients and their tumours.

MATERIAL AND METHODS

Cytosolic pS2 levels were measured by radioimmunometric assay in tumours from 168 breast cancer patients.

RESULTS

The pS2 values ranged from 0 to 251 ng/mg protein (mean SD: 21.8 38.1; median: 7.9 ng/mg protein). These protein levels were significantly (p < 0.05) higher in premenopausal patients (27.6 45.2) than in postmenopausal patients (19.5 33.8). Intratumour pS2 levels were also significantly (p < 0.05) correlated with histologic grade of the tumours, and were higher in well diferentiated tumours (grade I: 28.8 42.8) than in moderately differentiated tumours (grade II: 19.7 35.6) and than in poorly differentiated tumours (grade III: 18.9 37.3). Similarly, significant differences in pS2 content were found between positive estrogen receptor (ER) tumours and ER-negative tumours (29.1 46.5 vs 11.3 15.9, respectively; p<0.0001), as well as between positive progesterone receptor (PR) tumours and PR-negative tumours (29.1 49.8 vs 15.3 21.5, respectively; p < 0.05).

CONCLUSIONS

The results suggest that pS2 may be a useful prognostic marker in breast cancer, and may also be useful to identify patients who are likely to benefit from hormone therapy.

Somatic mutations of the trefoil factor family 1 gene in gastric cancer

BACKGROUND & AIMS

There is increasing evidence that trefoil factor family 1 (TFF1) is a stabilizer of the mucous gel overlying the gastrointestinal mucosa that provides a physical barrier against various noxious agents. TFF1 knockout mice developed multiple gastric adenomas and carcinomas, suggesting that TFF1 is a gastric-specific tumor-suppressor gene.

METHODS

We analyzed the somatic mutations and loss of heterozygosity (LOH) of the TFF1 gene using an intragenic polymorphic marker in 61 gastric tumors. The expression pattern of TFF1 was also examined by immunohistochemistry.

RESULTS

We detected a total of 8 somatic mutations-1 (5.5%) of 18 adenomas and 7 (16.3%) of 43 carcinomas-that were all missense mutations confined to the loop I and loop II structure of TFF1. We detected LOH in 5 (1 in adenoma and 4 in cancer) of 30 (16.7%) informative gastric tumors with an intragenic polymorphic marker -2 base pairs (bp) upstream of the coding region of the TFF1 gene. Although 2 cases were noninformative, the 7 gastric cancers with mutation seemed to show the loss of the remaining allele except in 1 case, suggesting that TFF1 is a tumor-suppressor gene. We found loss of TFF1 expression in 44.2% of the gastric carcinomas, but there is no correlation between immunoreactivity and genetic alterations of the TFF1 gene.

CONCLUSIONS

These results indicate that genetic alterations of TFF1 may lead to gastric mucosal barrier defects and contribute to the pathogenesis of gastric cancer.

Differential RNA expression of the pS2 gene in the human benign and malignant prostatic tissue

PURPOSE

The pS2 trefoil protein has been detected in close association with neuro-endocrine differentiation in prostate cancer and prostatic intraepithelial neoplasia. These preliminary results have suggested that pS2 is a candidate as a specific marker for prostate cancer tissue. To ascertain the specificity of pS2 in prostate cancer tissue, we have used an RT-PCR method from prostate biopsies provided from human malignant and benign prostatic hyperplasia (BPH) tissue.

MATERIALS AND METHODS

Prostate biopsies were obtained from transrectal biopsies from 153 patients with an abnormal DRE or a PSA more than 4 ng./ml. or symptoms of BPH and a PSA more than 4 ng./ml. Total RNA was extracted from fresh frozen specimens of tissue samples. Detection of pS2 transcript compared with GADPH transcripts was done using RT-PCR.

RESULTS

Biopsy results showed that 108 patients had prostate cancer (average Gleason score 6.39+/-0.74) and 45 patients had BPH. PS2 RT-PCR results showed that PS2 RNA expression was negative in 83% of the BPH cases. Conversely, 92% of prostate cancer specimens were positive (Chi-square: 86.09, p<0.001). There was no correlation with tumor stage or the Gleason score. Comparing the expression of pS2 in BPH and localized prostate cancer, we found a sensitivity of 92% and a specificity of 82%.

CONCLUSIONS

On this large sample of prostate biopsies from patients at risk of having prostate cancer, pS2 was demonstrated as an interesting marker significantly associated with prostate cancer. Further work on the expression of pS2 according to differentiation and hormonal status is in progress.

The trefoil peptide TFF1 inhibits the growth of the human gastric adenocarcinoma cell line AGS

TFF1 is a 60-amino acid peptide produced in normal gastric mucosa which forms dimers spontaneously. Tumours of patients with gastric cancer usually have reduced TFF1 levels and disruption of the TFF1 gene causes animals to develop gastric adenomas and carcinomas. The effect of normal sequence human recombinant TFF1 and an analogue (Cys(58)-->Ser(58)), which is unable to dimerize, on the proliferation and morphology of the human gastric adenocarcinoma cell line AGS was therefore investigated. Proliferation, assessed by total cell number and [methyl-(3)H]thymidine incorporation, was reduced by dimeric TFF1 in a dose-dependent manner. Monomeric TFF1 also reduced proliferation but was less potent than the dimeric form. It is concluded that TFF1 may be an important controller of gastric cell proliferation, that dimerization of TFF1 is important in this effect, and that the reduced levels of TFF1 seen in gastric cancer may be of clinical relevance.

The pS2/TFF1 trefoil factor, from basic research to clinical applications

pS2/TFF1 trefoil factor is normally expressed in the stomach, and is found ectopically in gastrointestinal inflammatory disorders and in various carcinomas. It is involved in stomach ontogenesis and in the maintenance of the integrity of the mucosa, and may represent a pharmacological tool for prevention and healing of gastrointestinal ulcerations. In breast cancer, it can be used to select patients suitable for hormone therapy. pS2/TFF1 is a pleiotropic factor involved in mucin polymerization, cell motility, cell proliferation and/or differentiation, and possibly in the nervous system.

Loss of pS2 protein expression is an early event of intestinal-type gastric cancer

To investigate the prevalence of pS2 expression in gastric cancer with respect to tumor histopathology, intestinal metaplasia and Helicobacter pylori (H. pylori) infection, pathologic specimens of 91 patients with gastric cancer were immunostained for pS2. Such immunoreactivity was correlated with the status of H. pylori infection, tumor staging, histology, subtyping, and associated intestinal metaplasia. Positive pS2 staining was seen throughout all non-neoplastic epithelia, and in all 9 patients with the complete type of intestinal metaplasia. In contrast, 21 of 45 incomplete type of intestinal metaplasia had negative pS2 staining (P < 0.001), and 54 out of 91 tumors (59.3%) showed loss of pS2 expression in the cancer tissues proper. There was no correlation of pS2 expression with age, gender, depth of invasion, duodenal involvement, lymph node metastasis, venous invasion or H. pylori infection. Negative pS2 staining was significantly higher in the intestinal (74.5%) and Borrmann type I, II, III (64.2%) tumors than the diffuse (43.2%, P < 0.005) and Borrmann type IV (20%, P < 0.05) tumors. Our results indicate that loss of pS2 expression may occur as an early event in the malignant transformation process of intestinal-type tumors.

Estrogen receptor alpha and beta expression in upper gastrointestinal tract with regulation of trefoil factor family 2 mRNA levels in ovariectomized rats

This study compared expression of two estrogen receptor (ER alpha and ER beta) genes in the rat upper gastrointestinal tract and the effects of 17 beta-estradiol administration on gastric trefoil factor family (TFF) mRNA steady-state levels in ovariectomized rats. Estrogen receptor alpha and beta cDNA fragments from fundic mucosa were cloned by reverse transcriptase polymerase chain reaction (RT-PCR) and sequenced. Both ER subtypes were detected in fundus, antrum and duodenum by RT-PCR. Northern analysis of poly(A)+ mRNA from fundic mucosa showed that ER alpha mRNA is expressed as a single transcript at 6.5 kb and ER beta is expressed as multiple transcripts with major transcripts ranging from 1.1-4.7 kb. ER beta mRNA was expressed in greater abundance than ER alpha mRNA. Fundic TFF2 mRNA steady-state levels were increased by 17 beta-estradiol administration in ovariectomized rats with no significant change in TFF1 mRNA levels. These studies show expression of both ER subtypes in the rat upper gastrointestinal tract with regulation of TFF2 mRNA by 17 beta-estradiol. These results suggest that estrogens, probably acting via ER beta, have a direct role in regulating gastric physiology.

Identification of a motif within the 5' regulatory region of pS2 which is responsible for AP-1 binding and TCDD-mediated suppression

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and related compounds modulate several endocrine systems by altering hormone synthesis, enhancing ligand metabolism, and down-regulating receptor levels/binding activity. Previous studies have demonstrated that TCDD inhibits the 17beta-estradiol (E2)-induction of pS2, a human breast cancer prognostic marker. This inhibition occurs at the gene expression level and is Ah receptor (AhR)-mediated. Analysis of the 5' regulatory region has identified three motifs which resemble dioxin response element (DRE) core sequences. pS2-regulated luciferase deletion constructs identified the DRE-like motif located at -527 to -514 as being required for TCDD-mediated suppression. A point mutation within this core motif (T-518C) abolished the inhibition by TCDD while UV-induced protein-DNA cross-linking and competitive gel retardation assays demonstrated AhR complex binding to this motif. Further study of this region also revealed an adjacent putative AP-1 site, diverging by one base pair from the consensus sequence. Gel retardation assays using TPA-treated MCF-7 cell nuclear extracts showed an induced complex binding to the AP-1-like site. Competition studies and antibody supershifts confirmed that the retarded complex consists of AP-1-like proteins. pS2-regulated luciferase constructs containing mutations specific to the AP-1-like motif greatly diminished the inducibility in response to E2. These results suggest that an interaction between AhR complexes and AP-1-like proteins may be responsible for TCDD-mediated inhibition of E2-induced pS2 expression.

Characterization of monoclonal antibodies raised to C-terminal peptides of pS2: a major trefoil peptide and motility factor expressed in adenocarcinomas and regions of mucosal injury

Two novel monoclonal antibodies, GE1 and GE2 raised against the C-terminal 31 and 28 amino acids of the estrogen-inducible trefoil peptide pS2, are described. Both antibodies are able to detect pS2 in formalin-fixed, paraffin-embedded tissues. Conditions are presented under which pS2 can be shown in cell lines by immunohistochemistry that has previously been problematic. The antibodies can specifically show the presence of pS2 in cell lysates by Western blotting and immunoprecipitation. In the form of an affinity column, the GE1 monoclonal antibody can be used to purify pS2 from MCF-7 supernatants. The eluted peptide from the GE1 affinity column shows a single band at 6,600 Da (predicted size for pS2) on Western blotting. These antibodies are valuable reagents in the analysis of the role of trefoil peptides in the maintenance of mucosal integrity, and may have applications in the assessment of pS2 expression in chronic gastrointestinal ulceration and adenocarcinomas that secrete pS2, where it may serve as a prognostic marker.

Gastric mucosa abnormalities and tumorigenesis in mice lacking the pS2 trefoil protein

To determine the function of the pS2 trefoil protein, which is normally expressed in the gastric mucosa, the mouse pS2 (mpS2) gene was inactivated. The antral and pyloric gastric mucosa of mpS2-null mice was dysfunctional and exhibited severe hyperplasia and dysplasia. All homozygous mutant mice developed antropyloric adenoma, and 30 percent developed multifocal intraepithelial or intramucosal carcinomas. The small intestine was characterized by enlarged villi and an abnormal infiltrate of lymphoid cells. These results indicate that mpS2 is essential for normal differentiation of the antral and pyloric gastric mucosa and may function as a gastric-specific tumor suppressor gene.

Differential expression of gp200-MR6 molecule in benign hyperplasia and down-regulation in invasive carcinoma of the breast

In this study, we used immunohistochemical and biochemical analysis to show that gp200-MR6, a 200 kDa molecule that is functionally associated with the human interleukin 4 (IL-4) receptor complex, is expressed at high levels on normal breast epithelial tissues, at lower levels on in situ carcinomas, and that the expression is lost in the invasive carcinoma of the breast. Furthermore, a preliminary study showed that benign epithelial hyperplasia of the breast expresses the gp200-MR6 heterogeneously. Two populations of cells have been observed: MR6 positive and MR6 negative. Interestingly, MR6-positive cells were observed to have different morphology from those that were MR6 negative; the nuclei of the former were larger and rounded in shape, whereas the nuclei of the latter were relatively small and oval in shape. In sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting, monoclonal antibody MR6 detects the same molecular weight molecule in both normal and transformed tissue, indicating that the molecule is not a product of a truncated gene. The intensity of the gp200-MR6 bands correlates with the immunohistochemical data, indicating that the molecule is expressed at high levels in normal tissue and at lower levels in malignant tissue. These results suggest that analysis of gp200-MR6 expression may be useful in tumour grading and prognostic evaluation in breast cancer. Moreover, the molecule may be involved early in the process of tumorigenesis of the breast, in which a loss or a down-regulation of gp200-MR6 could contribute towards tumour development and progression via an effect on cell growth and differentiation.

cDNA cloning of rat pS2 peptide and expression of trefoil peptides in acetic acid-induced colitis

By using a combination of the methods of reverse transcription-PCR and rapid amplification of cDNA ends, a cDNA for rat pS2 peptide (rpS2) was successfully cloned and sequenced from rat stomach. By RNA blot analysis, the gene was shown to be expressed abundantly in the stomach and only faintly in the duodenum, but not in other tissues including the distal small and large intestines. rpS2 expression was also examined in the rectum during the course of acetic acid-induced colitis; rpS2 mRNA was detected during the acute phase of colitis but not in normal controls or during the recovery phase. On the other hand, expression of rat intestinal trefoil factor (rITF) was down-regulated during the acute phase of colitis and then up-regulated during the recovery phase, whereas rat spasmolytic peptide was not detectable throughout the course of the induced colitis. These results indicate that the patterns and timing of the expression of these trefoil peptides are different from each other. rpS2 may play an important role in the proliferation of intestinal epithelial cells during the acute phase of mucosal ulceration, whereas rITF may be involved in differentiation of the cells, particularly to form goblet cells, during the recovery phase.

pS2 protein expression in gastric carcinoma. An immunohistochemical and immunoradiometric study

The aim of this study was to examine the prevalence of pS2 expression in gastric carcinoma and to determine its prognostic significance. We analysed pS2 protein expression in 50 gastric carcinomas and respective adjacent mucosas by immunohistochemistry and immunoradiometric assay (IRMA). pS2 was consistently expressed in superficial and foveolar epithelium of non-neoplastic mucosa and in 66.0% of the carcinomas. pS2 immunoreactivity was significantly higher in diffuse than in intestinal carcinomas, and in those cases with nodal metastases than in those without. No correlation was found between pS2 immunostaining and gender, age, staging, depth of wall penetration, venous invasion, ploidy and S-phase fraction. The mean levels of pS2 (IRMA) were significantly lower in gastric carcinomas than in non-neoplastic mucosas, and were not correlated with any of the aforementioned clinicopathological features. The survival of patients with pS2-positive tumours was not significantly different from that of patients with pS2-negative tumours. We conclude that pS2 expression, which can be used as a marker of gastric-type differentiation, is associated with gastric carcinoma of diffuse type. The lack of correlation between pS2 expression and most features of tumor aggressiveness and patients' survival precludes its use as a prognostic tool in gastric carcinoma.

A second trefoil protein, ITF/hP1.B, is transcribed in human breast cancer

Trefoil proteins form a specific group of stable secreted polypeptides. They are expressed in a lot of human cancers and during inflammatory processes of the gastrointestinal tract. Recently a new human trefoil protein, ITF/hP1.B, was isolated. Until now no studies of the activity of this gene in human solid tumors exist. In our examination we show for the first time that this gene is transcribed in human breast cancer. In contrast to another trefoil protein, pS2, the expression of ITF/hP1.B is not under control of estrogen in the human breast cancer cell line MCF-7. We suggest that the gene activity of ITF/hP1.B in addition to pS2 expression may be an improved prognostic marker in human breast cancer.

Trefoil peptides

There is a growing body of evidence supporting the hypothesis that members of the trefoil peptide family are involved actively in maintaining the integrity of the gastrointestinal mucosa and facilitating its repair. To date, three trefoil peptides are known in man: pS2, ITF and SP. Each is a secretory peptide expressed in specific compartments throughout the gut, in patterns that appear generally to be conserved between mammalian species. Ulceration, whether due to common pathological processes or experimentally induced, results in altered local expression of trefoil peptides. In diverse chronic ulcerative conditions in man, glandular structures develop within the mucosa, derived from the UACL. These UACL glands express three trefoil peptides, EGF and lysozyme, all potentially able to contribute to the healing process. In fact local goblet and endocrine cell types may also be recruited to secrete pS2 into the local environment. In experimental ulcers, in rate stomach or intestinal resection margins, there is also accentuation of trefoil peptide expression at the margins and in the poorly differentiated mucous cells extending out presumably in attempts to restore epithelial integrity. Several trefoil peptides have been expressed as 'recombinant' proteins in bacterial, baculoviral or yeast systems, and these procedures have allowed some of the biological properties of these peptides to be determined. In vitro, rITF, hITF and hSP are motogens, able to promote migration of epithelial cells. In vivo, rITF and hSP are able to prevent much of the gastric damage effect by a single dose of indomethacin, when given systemically. There is synergy between EGF and rITF both in vitro and in vivo, which may allow the development of new peptide therapies for ulceration that will maximize repair and minimize cell proliferation.

Differential expression of the pS2 protein in the human prostate and prostate cancer: association with premalignant changes and neuroendocrine differentiation

The distribution of the estrogen inducible pS2 protein was investigated in benign and malignant prostate tissue by the avidin-biotin complex method. Prostate tissue obtained from 20 patients without clinical and histological evidence of malignant disease consistently lacked pS2 immunoreactivity. Conversely, nonneoplastic tissue from 36 total prostatectomies with locally advanced prostate cancer showed a variable degree of pS2 reactivity in normal or hyperplastic glands and in prostatic intraepithelial neoplasia (PIN) adjacent to the cancerous lesions. This suggests that the pS2 gene expression detected in nonmalignant tissue may be related to early premalignant changes of prostate glands harboring significant carcinomas. In prostate cancer the pS2 protein was detected in close association with neuroendocrine (NE) differentiation as assessed by Chromogranin A (Chr A) immunoreactivity. Double labeling techniques showed that pS2 immunoreactivity recognizes both endocrine (Chr A-positive) and adjacent exocrine (Chr A-negative) cell types within NE foci. Whereas pS2 expression was consistently confined to NE differentiation in untreated tumors, carcinomas that relapsed after hormonal therapy showed increased pS2 immunoreactivity, even in the absence of NE features. The differential expression of the pS2 peptide in nonneoplastic tissue from patients with and without malignant disease indicates that pS2 immunohistochemistry may be useful in the diagnostic evaluation of negative biopsy specimens. Furthermore, the results suggest that the immunohistochemical spectrum of pS2 in prostate cancer may include endocrine differentiated and presumably related cell populations.

Immunolocalization of pS2, a putative growth factor, in pancreatic carcinoma

pS2 is a 60 amino acid secretory polypeptide which belongs to a newly described family of trefoil-shaped growth factors. It is widely distributed throughout the gastrointestinal tract, particularly adjacent to damaged mucosa, and is also expressed by some epithelial tumours such as breast carcinoma. The aim of this study was to examine the expression of pS2 in pancreatic cancer. The presence of pS2 was analysed immunohistochemically using two antibodies, a polyclonal (pNR-2) and a monoclonal (pS2TM) in 42 cases of pancreatic adenocarcinoma and 10 cases of ampullary carcinoma. The findings were compared with chronic pancreatitis and normal pancreas. No immunostaining was seen in normal pancreas, with the exception of one area of ductular proliferation, and although 8/10 cases of chronic pancreatitis expressed pS2, it was focal and confined to the occasional duct. In contrast, a significant proportion of malignant cells in 23/42 (55%) of pancreatic adenocarcinoma and 8/10 (80%) of ampullary tumours expressed immunoreactive pS2. The finding of pS2 expression in more than 50% of pancreatic and ampullary carcinomas in contrast to the findings seen in chronic pancreatitis and normal pancreas suggests that pS2 may play an important role in the growth of these highly malignant tumours.

Subcellular distribution of peptides associated with gastric mucosal healing and neoplasia

The trefoil peptides pS2 and human spasmolytic peptide are putative growth factors, particularly associated with mucus-producing cells of the gastrointestinal tract including those of the stomach. The receptor for transforming growth factor alpha (TGF alpha) takes its name from one of its alternative ligands, epidermal growth factor, and is called the epidermal growth factor receptor. Although there is immunoreactive epidermal growth factor in the stomach, it is TGF alpha and the epidermal growth factor receptor that are abundant. Immunolabelling at electron microscope level allows for subcellular localisation of antigens; pS2 and human spasmolytic peptide co-localise to cytomembranes, including the Golgi apparatus, and thecae of surface/pit mucous cells. TGF alpha is abundant on the membranes of tubulovesicles of parietal cells and is also present in chief cells: in mucous producing cells it can be detected but not in association with mucous. The distribution of the epidermal growth factor receptor mimics that of TGF alpha but with preferential clustering on the basolateral membranes of gastric cells. The trefoil peptides are associated with healing and probably act, together with mucus, to protect the gastric mucosa and maintain a viable environment. TGF alpha, transduced via the epidermal growth factor receptor, inhibits gastric acid secretion, thus aids the trefoils in the maintenance of a gastric microenvironment conducive to healing after damage. TGF alpha, however, is also a potent mitogen; while this property plays a vital part in repairing mucosal defects, if this peptide or indeed its receptor are overexpressed, the result can be neoplasia.

Significance of estrogen receptors and cathepsin D tissue detection in gastric adenocarcinoma

Estrogen receptors (ERs) have recently been reported to be present in carcinomas of stomach, an organ that has so far been considered as nontarget for sex hormones. Cathepsin D is an estrogen-regulated lysosomal protease that has been overexpressed in breast cancer. ER and cathepsin D immunohistochemical expression were studied in this research in order to estimate their association to known histopathological and clinical parameters and their possible prognostic significance as well. Sixty-two patients with gastric adenocarcinomas were included in this study. The cancers were studied immunohistochemically concerning ER positivity in tumor cell nuclei and cathepsin D cytoplasmic expression. Nuclear ER staining was detected in tumor cells of 25% of male and 27% of female patients. ER positivity was demonstrated mainly in the well and moderately differentiated carcinomas; 87.5% of ER(+) tumors were also characterized as cathepsin D positive and a significant correlation between ER and cathepsin D positive expression was demonstrated (P < 0.05). Cytoplasmic cathepsin D expression was observed in carcinomatous cells of 70.9% of gastric tumors. Early tumor stage and good differentiation were significantly associated with increased cathepsin D expression (P < 0.05, P < 0.001). Histologic type, degree of differentiation and tumor stage were significantly correlated to survival (P < 0.05, P < 0.001 and P < 0.001). The patients who were cathepsin D(+) had a significant prognostic advantage over the cathepsin D(-) patients (P < 0.001). The presence of ER and estrogen-regulated cathepsin D indicates the involvement of sex hormonal factors in these tumors and cathepsin D positive expression in tumor cells seems to be related to better prognosis. Their biological, clinical, and prognostic roles remain to be further elucidated.

Menstrual and reproductive factors and gastric-cancer risk in women

To understand possible correlates of the systematically higher gastric-cancer rates in males than in females, we investigated the role of menstrual, reproductive and hormonal factors in females, using data from a case-control study conducted in Northern Italy. Cases were 229 post-menopausal women with incident, histologically confirmed gastric cancer, and controls were 614 post-menopausal women in hospital for acute, non-neoplastic, non-digestive-tract conditions. After allowance for age, education, family history, and selected dietary correlates of stomach cancer, a reduced gastric-cancer risk was observed in women with later menopause (odds ratio, OR = 0.6, p value for trend < 0.05), and longer duration of fertile life (OR = 0.7, but the trend in risk was not significant). The risk of gastric cancer was elevated in multiparous women (OR = 1.7 for 3 and 1.9 for > or = 4 births as compared to nulliparae). No association was observed with age at menarche, age at first birth, and with number of spontaneous or induced abortions. Ever-users of oral contraceptives had a non-significant increased risk (OR = 1.3), and users of oestrogen-replacement treatment a non-significant reduced risk (OR = 0.5). Although the association with each factor was moderate, and the interpretation of these findings is not straightforward, these results are compatible with the hypothesis that some role is played by (endogenous and exogenous) female hormones in the process of gastric carcinogenesis.

Reproductive history and gastric cancer among post-menopausal women

A total of 339 post-menopausal women with gastric cancer (GC) and 515 population controls were interviewed in a multicenter study in Italy for information on reproductive history, dietary habits and other socio-demographic variables. After adjusting for these factors, GC risk was significantly higher among women reporting menopause below age 45, while no effect was shown for age at menarche, parity, age at first livebirth, and number of abortions. When age at menopause was considered together with age at menarche for an index of fertility years, GC risk showed a significant inverse relation to duration of fertility. These results suggest a protective role for endocrine or other factors related to late age at menopause or to length of fertility. These findings may be relevant to explain the fact that rates of GC reported among females are lower than among males around the world, and suggest the need for further research into hormonal and other related risk factors.

Prognostic significance of pS2 protein expression in pulmonary adenocarcinoma

In the present study, pS2 protein expression in pulmonary adenocarcinoma was investigated on paraffin-embedded sections obtained from 170 patients. 28 (16%) patients showed varying degrees of pS2 protein expression in the cytoplasm of tumour cells, as detected by immunohistochemical staining with anti-pS2 protein antibody. There was a significant association between pS2 protein expression and larger tumour size, and the acinar or bronchiolo-alveolar subtype. However, no significant correlations between pS2 protein status and the other clinicopathological factors, i.e. T-factor, N-factor, stage and histological differentiation, were shown. In contrast to breast cancer, patients with pS2-positive pulmonary adenocarcinomas had a significantly worse prognosis than those with pS2-negative pulmonary adenocarcinomas; this was true for stage I patients, as well as for all patients. Multivariate analysis showed that pS2 protein expression was a discriminating variable in overall survival. These findings suggest that pS2 protein status is a possible prognostic indicator in pulmonary adenocarcinoma.