BRCA2 represses the transcriptional activity of pS2 by E2-ERα

Germline mutations to the breast cancer 2 (BRCA2) gene have been associated with hereditary breast cancer. In addition to estrogen uptake, BRCA2 expression increases in the S phase of the cell cycle and largely contributes to DNA damage repair associated with DNA replication. However, the role of BRCA2 in estrogen induction remains unclear. An expression plasmid was created to induce BRCA2 activation upon the addition of estradiol by introducing mutations to the binding sequences for the transcription factors USF1, E2F1, and NF-κB within the promoter region of BRCA2. Then, the estrogen receptor (ER) sites of the proteins that interact with BRCA2 upon the addition of estradiol were identified. Both proteins were bound by the helical domain of BRCA2 and activation function-2 of the ER, suggesting that this binding may regulate the transcriptional activity of pS2, a target gene of the estradiol-ER, by suppressing the binding of SRC-1, a coactivator required for activation of the transcription factor.

Trefoil factor-1 upregulation in estrogen-receptor positive breast cancer correlates with an increased risk of bone metastasis

Bone is one of the most preferred sites of metastatic spread from different cancer types, including breast cancer. However, different breast cancer subtypes exhibit distinct metastatic behavior in terms of kinetics and anatomic sites of relapse. Despite advances in the diagnosis, the identification of patients at high-risk of bone recurrence is still an unmet clinical need. We conducted a retrospective analysis, by gene expression and immunohistochemical assays, on 90 surgically resected breast cancer samples collected from patients who experienced no evidence of distant metastasis, bone or visceral metastasis in order to identify a primary tumor-derived marker of bone recurrence. We identified trefoil factor-1 (pS2 or TFF1) as strictly correlated to bone metastasis from ER+ breast cancer. In silico analysis was carried out to confirm this observation, linking gene expression data with clinical characteristics available from public clinical datasets. Then, we investigated TFF1 function in ER+ breast cancer tumorigenesis and bone metastasis through xenograft in vivo models of MCF 7 breast cancer with gain and loss of function of TFF1. As a response to microenvironmental features in primary tumors, TFF1 expression could modulate ER+ breast cancer growth, leading to a less proliferative phenotype. Our results showed it may not play a role in late stages of bone metastasis, however further studies are warranted to understand whether it could contribute in the early-stages of the metastatic cascade. In conclusion, TFF1 upregulation in primary ER+ breast cancer could be useful to identify patients at high-risk of bone metastasis. This could help clinicians in the identification of patients who likely can develop bone metastasis and who could benefit from personalized treatments and follow-up strategies to prevent metastatic disease.

TFF1 Induces Aggregation and Reduces Motility of Helicobacter pylori

Gastric cancer is considered one of the most common malignancies in humans and Helicobacter pylori infection is the major environmental risk factor of gastric cancer development. Given the high spread of this bacterium whose infection is mostly asymptomatic, H. pylori colonization persists for a long time, becoming chronic and predisposing to malignant transformation. The first defensive barrier from bacterial infection is constituted by the gastric mucosa that secretes several protective factors, among which is the trefoil factor 1 (TFF1), that, as mucin 5AC, binds the bacterium. Even if the protective role of TFF1 is well-documented, the molecular mechanisms that confer a beneficial function to the interaction among TFF1 and H. pylori remain still unclear. Here we analyze the effects of this interaction on H. pylori at morphological and molecular levels by means of microscopic observation, chemiotaxis and motility assays and real-time PCR analysis. Our results show that TFF1 favors aggregation of H. pylori and significantly slows down the motility of the bacterium across the mucus. Such aggregates significantly reduce both flgE and flaB gene transcription compared with bacteria not incubated with TFF1. Finally, our results suggest that the interaction between TFF1 and the bacterium may explain the frequent persistence of H. pylori in the human host without inducing disease.

Trefoil Factor Family (TFF) Peptides and Their Diverse Molecular Functions in Mucus Barrier Protection and More: Changing the Paradigm

Trefoil factor family peptides (TFF1, TFF2, TFF3) are typically co-secreted together with mucins. Tff1 represents a gastric tumor suppressor gene in mice. TFFs are also synthesized in minute amounts in the immune and central nervous systems. In mucous epithelia, they support rapid repair by enhancing cell migration ("restitution") via their weak chemotactic and anti-apoptotic effects. For a long time, as a paradigm, this was considered as their major biological function. Within recent years, the formation of disulfide-linked heterodimers was documented for TFF1 and TFF3, e.g., with gastrokine-2 and IgG Fc binding protein (FCGBP). Furthermore, lectin activities were recognized as enabling binding to a lipopolysaccharide of Helicobacter pylori (TFF1, TFF3) or to a carbohydrate moiety of the mucin MUC6 (TFF2). Only recently, gastric TFF1 was demonstrated to occur predominantly in monomeric forms with an unusual free thiol group. Thus, a new picture emerged, pointing to diverse molecular functions for TFFs. Monomeric TFF1 might protect the gastric mucosa as a scavenger for extracellular reactive oxygen/nitrogen species. Whereas, the TFF2/MUC6 complex stabilizes the inner layer of the gastric mucus. In contrast, the TFF3-FCGBP heterodimer (and also TFF1-FCGBP) are likely part of the innate immune defense of mucous epithelia, preventing the infiltration of microorganisms.

Chemical synthesis of human trefoil factor 1 (TFF1) and its homodimer provides novel insights into their mechanisms of action

TFF1 is a key peptide for gastrointestinal protection and repair. Its molecular mechanism of action remains poorly understood with synthetic intractability a recognised bottleneck. Here we describe the synthesis of TFF1 and its homodimer and their interactions with mucins and Helicobacter pylori. Synthetic access to TFF1 is an important milestone for probe and therapeutic development.

The Tumor Suppressor TFF1 Occurs in Different Forms and Interacts with Multiple Partners in the Human Gastric Mucus Barrier: Indications for Diverse Protective Functions

TFF1 is a protective peptide of the Trefoil Factor Family (TFF), which is co-secreted with the mucin MUC5AC, gastrokine 2 (GKN2), and IgG Fc binding protein (FCGBP) from gastric surface mucous cells. Tff1-deficient mice obligatorily develop antropyloric adenoma and about 30% progress to carcinomas, indicating that Tff1 is a tumor suppressor. As a hallmark, TFF1 contains seven cysteine residues with three disulfide bonds stabilizing the conserved TFF domain. Here, we systematically investigated the molecular forms of TFF1 in the human gastric mucosa. TFF1 mainly occurs in an unusual monomeric form, but also as a homodimer. Furthermore, minor amounts of TFF1 form heterodimers with GKN2, FCGBP, and an unknown partner protein, respectively. TFF1 also binds to the mucin MUC6 in vitro, as shown by overlay assays with synthetic ¹²⁵I-labeled TFF1 homodimer. The dominant presence of a monomeric form with a free thiol group at Cys-58 is in agreement with previous studies in Xenopus laevis and mouse. Cys-58 is likely highly reactive due to flanking acid residues (PPEEEC⁵⁸EF) and might act as a scavenger for extracellular reactive oxygen/nitrogen species protecting the gastric mucosa from damage by oxidative stress, e.g., H₂O₂ generated by dual oxidase (DUOX).

Molecular Alterations in the Stomach of Tff1-Deficient Mice: Early Steps in Antral Carcinogenesis

TFF1 is a peptide of the gastric mucosa co-secreted with the mucin MUC5AC. It plays a key role in gastric mucosal protection and repair. Tff1-deficient (Tff1^KO) mice obligatorily develop antropyloric adenoma and about 30% progress to carcinomas. Thus, these mice represent a model for gastric tumorigenesis. Here, we compared the expression of selected genes in Tff1^KO mice and the corresponding wild-type animals (RT-PCR analyses). Furthermore, we systematically investigated the different molecular forms of Tff1 and its heterodimer partner gastrokine-2 (Gkn2) in the stomach (Western blot analyses). As a hallmark, a large portion of murine Tff1 occurs in a monomeric form. This is unexpected because of its odd number of seven cysteine residues. Probably the three conserved acid amino acid residues (EEE) flanking the 7th cysteine residue allow monomeric secretion. As a consequence, the free thiol of monomeric Tff1 could have a protective scavenger function, e.g., for reactive oxygen/nitrogen species. Furthermore, a minor subset of Tff1 forms a disulfide-linked heterodimer with IgG Fc binding protein (Fcgbp). Of special note, in Tff1^KO animals a homodimeric form of Gkn2 was observed. In addition, Tff1^KO animals showed strongly reduced Tff2 transcript and protein levels, which might explain their increased sensitivity to Helicobacter pylori infection.

Human Synovia Contains Trefoil Factor Family (TFF) Peptides 1-3 Although Synovial Membrane Only Produces TFF3: Implications in Osteoarthritis and Rheumatoid Arthritis

Objective: Trefoil factor family peptide 3 (TFF3) has been shown to support catabolic functions in cases of osteoarthritis (OA). As in joint physiology and diseases such as OA, the synovial membrane (SM) of the joint capsule also plays a central role. We analyze the ability of SM to produce TFF compare healthy SM and its secretion product synovial fluid (SF) with SM and SF from patients suffering from OA or rheumatoid arthritis (RA). Methods: Real-time PCR and ELISA were used to measure the expression of TFFs in healthy SM and SM from patients suffering from OA or RA. For tissue localization, we investigated TFF1-3 in differently aged human SM of healthy donors by means of immunohistochemistry, real-time PCR and Western blot. Results: Only TFF3 but not TFF1 and -2 was expressed in SM from healthy donors as well as cases of OA or RA on protein and mRNA level. In contrast, all three TFFs were detected in all samples of SF on the protein level. No significant changes were observed for TFF1 at all. TFF2 was significantly upregulated in RA samples in comparison to OA samples. TFF3 protein was significantly downregulated in OA samples in comparison to healthy samples and cases of RA significantly upregulated compared to OA. In contrast, in SM TFF3 protein was not significantly regulated. Conclusion: The data demonstrate the production of TFF3 in SM. Unexpectedly, SF contains all three known TFF peptides. As neither articular cartilage nor SM produce TFF1 and TFF2, we speculate that these originate with high probability from blood serum.

Differential Expression of TFF1 and TFF3 in Patients Suffering from Chronic Rhinosinusitis with Nasal Polyposis

Trefoil family factor (TFF) proteins contribute to antimicrobial defense and the maintenance of sinonasal epithelial barrier integrity. Dysregulation of TFF expression may be involved in the development of chronic inflammation and tissue remodeling characteristically found in chronic rhinosinusitis with nasal polyposis (CRSwNP). Expressions of TFF1 and TFF3 were determined in specimens of middle nasal turbinate (MNT-0), bulla ethmoidalis (BE), and nasal polyps (NP) from CRSwNP patients (n = 29) and inferior nasal turbinate from a group of control patients (underwent nasal septoplasty, n = 25). An additional MNT sample was collected 6 months after functional endoscopic sinus surgery (FESS, MNT-6). TFF1 mRNA levels were significantly reduced in all specimens by approximately three- to five-fold, while TFF3 was increased in MNT-0, as compared with controls. Six months after surgery their levels were reversed to control values. CRSwNP patients with S. epidermidis isolated from sinus swabs showed upregulation of TFF3 in MNT and NP as compared with patients with sterile swabs. Target gene regulation was not affected by the presence of type 2 inflammation in patients with confirmed allergy. Results of this study imply participation of TFFs genes in the development of CRSwNP.

TFF1 hypermethylation and decreased expression in esophageal squamous cell carcinoma and histologically normal tumor surrounding esophageal cells

Background

Esophageal squamous cell carcinoma (ESCC) is one of the 10 most incident cancer types in the world, and it is mainly associated with tobacco and alcohol consumption. ESCC mortality rates stand very close to its incidence, which is a direct consequence of a late diagnosis and an inefficient treatment. Although this scenery is quite alarming, the major molecular alterations that drive this carcinogenesis process remain unclear. We have previously shown through the first ESCC methylome analysis that TFF1 promoter is frequently hypermethylated in ESCC. Here, to evaluate TFF1 methylation as a potential biomarker of early ESCC diagnosis, we investigated the status of TFF1 promoter methylation and its expression in ESSC and histologically normal tumor surrounding tissue of ESCC patients in comparison to healthy esophagus of non-cancer individuals.

Results

Analysis of TFF1 promoter methylation, and gene and protein expression in 65 ESCC patients and 88 controls revealed that TFF1 methylation levels were already increased in histologically normal tumor surrounding tissue of ESCC patients when compared to healthy esophagus of non-cancer individuals. This increase in DNA methylation was followed by the reduction of TFF1 mRNA expression. Interestingly, TFF1 expression was capable of distinguishing tumor surrounding normal tissue from normal mucosa of healthy individuals with 92% accuracy. In addition, TFF1 protein was undetectable both in tumor and surrounding mucosa by immunohistochemistry, while submucosa glands of the healthy esophagus showed positive staining. Furthermore, treatment of TE-1 and TE-13 ESCC cell lines with decitabine led to a reduction of promoter methylation and consequent upregulation of TFF1 gene and protein expression. Finally, using TCGA data we showed that TFF1 loss is observed in ESCC, but not in esophageal adenocarcinoma, highlighting the different molecular mechanisms involved in the development of each histological subtype of esophageal cancer.

Conclusions

This study shows that TFF1 expression is silenced in early phases of ESCC development, which seems to be mediated at least in part by promoter hypermethylation, and provides the basis for the use of TFF1 expression as a potential biomarker for early ESCC detection.

Trefoil factor family 1 expression in the invasion front is a poor prognostic factor associated with lymph node metastasis in pancreatic cancer

OBJECTIVES

Trefoil Factor Family protein 1 (TFF1) is secreted from mucus-producing cells. The relationship between TFF1 expression and clinical outcome in pancreatic ductal adenocarcinoma (PDAC) remains unknown. We aimed to evaluate the prognostic significance of TFF1 expression in PDAC.

METHODS

TFF1 expression was examined on paraffin-embedded sections from 91 patients with resected PDAC using immunohistochemistry. The relationships between TFF1 expression and clinicopathological features were analyzed.

RESULTS

Among 91 PDAC patients, 71 patients (79.7%) showed TFF1 expression in cancer cells. In a subgroup of 71 patients, TFF1 expression was predominantly observed in the central part of the tumor, whereas TFF1 expression in the invasion front was reduced in 33 patients (46.4%). A significant correlation between preserved TFF1 expression in the invasion front and lymph node metastasis was observed. Univariate survival analysis revealed that preserved TFF1 expression in the invasion front, positive lymphatic invasion, lymph node metastasis and R1 resection was a significant poor prognostic factor in TFF1-positive PDAC patients.

CONCLUSIONS

TFF1 expression is frequently lost or decreased in the invasion front of human PDAC, and preserved TFF1 expression in the invasion front might predict poor survival in patients with PDAC.

Expression of trefoil factors and TWIST1 in colorectal cancer and their correlation with metastatic potential and prognosis

AIM

To detect the expression of trefoil factors (TFFs) and TWIST1 in colorectal cancer (CRC) and analyze their correlation with metastasis and survival.

METHODS

This study examined the expression of TFF1, TFF3 and TWIST1 in a total of 75 tumor samples, 47 matched normal samples (15 cm from the lesion margin), 30 metastatic lymph nodes, and 10 liver metastatic cancer samples from patients with CRC. The relationship was then analyzed between the protein expression and different clinical records. TFF1, TFF3, TWIST1,E-cadherin, vimentin and β-catenin mRNA and protein expression levels were measured in colon cancer cell lines with different metastatic potentials (HIEC, HT29, SW620, and LoVo cells), and the correlation of the expression levels with epithelial-mesenchymal transition (EMT) was discussed.

RESULTS

It was found that 66.7% (50/75), 78.7% (59/75) and 54.7% (41/75) of tumor tissue samples exhibited positive staining for TFF1, TFF3 and TWIST1 and so did 27.3% (13/47), 100% (47/47) and 17% (8/47) of adjacent normal colorectal tissues. Compared with adjacent normal tissues, significant differences were found in the expression of all three proteins in different cancerous tissues (P < 0.05). Higher expression of TFF3 and TWIST1 was significantly correlated with lymph node metastasis (P = 0.034, P = 0.000), advanced stage (P = 0.031, P = 0.003), and poorer survival (P = 0.042 for the TFF3 group, P = 0.003 for the TWIST1 group). The expression of TFF3 and TWIST1 in cancer cell lines was higher than that in HIEC (a normal human intestinal epithelial cell line)(P < 0.05), and the expression intensity demonstrated a tendency to rise with increased metastatic potential both at the protein and mRNA levels. However, TFF1 expression demonstrated the opposite tendency. It was also observed that the expression of E-cadherin and β-catenin tended to decrease while that of vimentin, TWIST1 and Snail tended to rise with the increase in metastatic potential.

CONCLUSION

The expression of TFF3 and TWIST1 might be associated with the survival of patients with CRC after curative resection and might be pivotal predictors of disease progression. TFF3 may be correlated to the invasiveness of CRC.

Expression of Biomarkers CXCR4, IL11-RA, TFF1, MLF1P in Advanced Breast Cancer Patients with Bone Metastatic: a Diagnostic Study

AIM

to analyze expression of biomarkers CXCR4, IL11-RA, TFF1 and MLF1P, and clinicopathology in advanced breast cancer patients with bone metastatic.

METHODS

this is a cross-sectional study. Analysis was done against a total of 92 breast cancer patients, including 46 bone metastatic patients and 46 non-bone metastatic patients. Immunohistochemistry and microarray analysis was performed in 81 formalin fixed paraffin embedded (FFPE) samples from 81 patients were used. Data were collected through medical records, immunohistochemistry (IHC), and microarray with nanoString nCounterTM.

RESULTS

this article is part one of a two stage reporting research results. In part one we got the results of the IHC analysis, IL11-RA with cut-off ≥103.5 showed OR 3.803 (95 % confidence interval [CI], 1.375-10.581), p=0.010, MLF1P with cut-off ≥83.0 OR 2.784 (95% CI, 1.009-7.681), p=0.048, and ER+ OR 7.640 (95 % CI, 2.599-22.459), p<0.000, were associated with bone metastastic incidences in advanced breast cancer, and were statistically significantly different. A combination of IL-11RA, MLF1P and ER+, showed an accuracy of approaching 80% to discriminate between bone metastatic and non bone metastatic in advanced breast cancer patients.

CONCLUSION

IL11-RA, MLF1P, and ER+ were the determinants that were associated with increasing bone metastasis incidence.

Aberrant JAK/STAT Signaling Suppresses TFF1 and TFF2 through Epigenetic Silencing of GATA6 in Gastric Cancer

Aberrant Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling is crucial to the development of gastric cancer. In this study, we examined the role of STAT3 in the expression and methylation of its targets in gastric cancer patients. Results from RNA sequencing identified an inverse correlation between the expression of STAT3 and GATA6 in 23 pairs of gastric cancer patient samples. We discovered that the expression of GATA6 is epigenetically silenced through promoter methylation in gastric cancer cell lines. Interestingly, the inhibition of STAT3 using a novel STAT3 inhibitor restored the expression of GATA6 and its targets, trefoil factors 1 and 2 (TFF1/2). Moreover, disruption of STAT3 binding to GATA6 promoter by small hairpin RNA restored GATA6 expression in AGS cells. A clinically significant correlation was also observed between the expression of GATA6 and TFF1/2 among tissue samples from 60 gastric cancer patients. Finally, bisulfite pyrosequencing revealed GATA6 methylation in 65% (39/60) of the patients, and those with higher GATA6 methylation tended to have shorter overall survival. In conclusion, we demonstrated that aberrant JAK/STAT signaling suppresses TFF1/2 partially through the epigenetic silencing of GATA6. Therapeutic intervention of STAT3 in reversing the epigenetic status of GATA6 could benefit the treatment of gastric cancer and is worthy of further investigation.

C/EBPβ regulates homeostatic and oncogenic gastric cell proliferation

Abstract

Cancer of the stomach is among the leading causes of death from cancer worldwide. The transcription factor C/EBPβ is frequently overexpressed in gastric cancer and associated with the suppression of the differentiation marker TFF1. We show that the murine C/EBPβ knockout stomach displays unbalanced homeostasis and reduced cell proliferation and that tumorigenesis of human gastric cancer xenograft is inhibited by knockdown of C/EBPβ. Cross-species comparison of gene expression profiles between C/EBPβ-deficient murine stomach and human gastric cancer revealed a subset of tumors with a C/EBPβ signature. Within this signature, the RUNX1t1 tumor suppressor transcript was down-regulated in 38 % of gastric tumor samples. The RUNX1t1 promoter was frequently hypermethylated and ectopic expression of RUNX1t1 in gastric cancer cells inhibited proliferation and enhanced TFF1 expression. These data suggest that the tumor suppressor activity of both RUNX1t1 and TFF1 are mechanistically connected to C/EBPβ and that cross-regulation between C/EBPβ-RUNX1t1-TFF1 plays an important role in gastric carcinogenesis.

Key message

C/EBPβ controls proliferation and differentiation balance in the stomach.

Homeostatic differentiation/proliferation balance is altered in gastric cancer.

RUNX1t1 is a C/EBPβ-associated tumor suppressor.

RUNX1t1 negatively regulates C/EBPβ pro-oncogenic functions.

Electronic supplementary material

The online version of this article (doi:10.1007/s00109-016-1447-7) contains supplementary material, which is available to authorized users.