Tff1-expressing Tregs in lung prevent exacerbation of Bleomycin-induced pulmonary fibrosis.

Bleomycin (BLM) induces lung injury, leading to inflammation and pulmonary fibrosis. Regulatory T cells (Tregs) maintain self-tolerance and control host immune responses. However, little is known about their involvement in the pathology of pulmonary fibrosis. Here we show that a unique Treg subset expressing trefoil factor family 1 (Tff1) emerges in the BLM-injured lung. These Tff1-expressing Tregs (Tff1-Tregs) were induced by IL-33. Moreover, although Tff1 ablation in Tregs did not change the pathological condition, selective ablation of Tff1-Tregs using an intersectional genetic method promoted pro-inflammatory features of macrophages in the injured lung and exacerbated the fibrosis. Taken together, our study revealed the presence of a unique Treg subset expressing Tff1 in BLM-injured lungs and their critical role in the injured lung to ameliorate fibrosis.

Trefoil factor 1 (TFF1) reduces cerebral edema and gastric mucosal injury by regulating the EGFR/Src/FAK pathway in an intracerebral hemorrhage rat model.

The destruction of the blood-brain barrier and damage to the gastrointestinal mucosa after intracerebral hemorrhage (ICH) are important reasons for its high disability and mortality rates. However, the exact etiology is not yet clear. In addition, there are currently no effective treatments for improving cerebral edema and gastric mucosal damage after ICH. Trefoil factor 1 (TFF1) is a secretory protein that plays a crucial role in maintaining the integrity and barrier function of the gastric mucosa, and it has been reported to have a protective effect on brain damage induced by various causes. This study utilized a rat model of ICH induced by type IV collagenase was utilized, and intervened with recombinant TFF1 protein from an external institute to investigate the protective mechanisms of TFF1 against brain edema and gastric mucosal damage after ICH. The results demonstrated that TFF1 alleviated the neurological function and gastric mucosal damage in the rat model of ICH induced by type IV collagenase. TFF1 may ensure the integrity of the blood-brain and gastric mucosal barriers by regulating the EGFR (epidermal growth factor receptor)/Src (non-receptor tyrosine kinase)/FAK (focal adhesion kinase) pathway. Clearly, the disruption of the blood-brain barrier and the destruction of the gastric mucosal barrier are key pathological features of ICH, and TFF1 can improve the progression of blood-brain barrier and gastric mucosal barrier disruption in ICH by regulating the EGFR/Src/FAK pathway. Therefore, TFF1 may be a potential target for the treatment of ICH.

Secretory Trefoil Factor 1 (TFF1) promotes gemcitabine resistance through chemokine receptor CXCR4 in Pancreatic Ductal Adenocarcinoma.

Gemcitabine is the first-line treatment option for patients with locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC). However, the frequent adoption of resistance to gemcitabine by cancer cells poses a significant challenge in treating this aggressive disease. In this study, we focused on analyzing the role of trefoil factor 1 (TFF1) in gemcitabine resistance in PDAC. Analysis of PDAC TCGA and cell line datasets indicated an enrichment of TFF1 in the gemcitabine-resistant classical subtype and suggested an inverse correlation between TFF1 expression and sensitivity to gemcitabine treatment. The genetic ablation of TFF1 in PDAC cells enhanced their sensitivity to gemcitabine treatment in both in vitro and in vivo tumor xenografts. The biochemical studies revealed that TFF1 contributes to gemcitabine resistance through enhanced stemness, increasing migration ability of cancer cells, and induction of anti-apoptotic genes. We further pursued studies to predict possible receptors exerting TFF1-mediated gemcitabine resistance. Protein-protein docking investigations with BioLuminate software revealed that TFF1 binds to the chemokine receptor CXCR4, which was supported by real-time binding analysis of TFF1 and CXCR4 using SPR studies. The exogenous addition of TFF1 increased the proliferation and migration of PDAC cells through the pAkt/pERK axis, which was abrogated by treatment with a CXCR4-specific antagonist AMD3100. Overall, the present study demonstrates the contribution of the TFF1-CXCR4 axis in imparting gemcitabine resistance properties to PDAC cells.

Anti-Menopausal Effect of Heat-Killed Bifidobacterium breve HDB7040 via Estrogen Receptor-Selective Modulation in MCF-7 Cells and Ovariectomized Rats.

Menopause is induced by spontaneous ovarian failure and leads to life quality deterioration with various irritating symptoms. Hormonal treatment can alleviate these symptoms, but long-term treatment is closely associated with breast and uterine cancer, and stroke. Therefore, developing alternative therapies with novel anti-menopausal substances and improved safety is needed. In our study, heat-killed Bifidobacterium breve HDB7040 significantly promoted MCF-7 cell proliferation in a dose-dependent manner under estrogen-free conditions, similar to 17ß-estradiol. This strain also triggered ESR2 expression, but not ESR1, in MCF-7 cells. Moreover, administrating HDB7040 to ovariectomized (OVX) Sprague-Dawley (SD) female rats reduced estrogen deficiency-induced weight gain, fat mass, blood triglyceride, and total cholesterol levels. It also recovered collapsed trabecular microstructure by improving trabecular morphometric parameters (bone mineral density, bone volume per tissue volume, trabecular number, and trabecular separation) and decreasing blood alkaline phosphatase levels with no significant changes in uterine size and blood estradiol. HDB7040 also significantly regulated the expression of Tff1, Pgr, and Esr2, but not Esr1 in uteri of OVX rats. Heat-killed B. breve HDB7040 exerts an anti-menopausal effect via the specific regulation of ERß in vitro and in vivo, suggesting its potential as a novel substance for improving and treating menopausal syndrome.

Trefoil factor 1 suppresses stemness and enhances chemosensitivity of pancreatic cancer.

BACKGROUND AND AIMS: Pancreatic cancer is one of the most lethal malignancies, partly due to resistance to conventional chemotherapy. The chemoresistance of malignant tumors is associated with epithelial-mesenchymal transition (EMT) and the stemness of cancer cells. The aim of this study is to investigate the availability and functional mechanisms of trefoil factor family 1 (TFF1), a tumor-suppressive protein in pancreatic carcinogenesis, to treat pancreatic cancer. METHODS: To investigate the role of endogenous TFF1 in human and mice, specimens of human pancreatic cancer and genetically engineered mouse model of pancreatic cancer (KPC/TFF1KO; Pdx1-Cre/LSL-KRASG12D/LSL-p53R172H/TFF1-/-) were analyzed by immunohistochemistry (IHC). To explore the efficacy of extracellular administration of TFF1, recombinant and chemically synthesized TFF1 were administered to pancreatic cancer cell lines, a xenograft mouse model and a transgenic mouse model. RESULTS: The deficiency of TFF1 was associated with increased EMT of cancer cells in mouse models of pancreatic cancer, KPC. The expression of TFF1 in cancer cells was associated with better survival rate of the patients who underwent chemotherapy, and loss of TFF1 deteriorated the benefit of gemcitabine in KPC mice. Extracellular administration of TFF1 inhibited gemcitabine-induced EMT, Wnt pathway activation and cancer stemness, eventually increased apoptosis of pancreatic cancer cells in vitro. In vivo, combined treatment of gemcitabine and subcutaneous administration of TFF1 arrested tumor growth in xenograft mouse model and resulted in the better survival of KPC mice by inhibiting EMT and cancer stemness. CONCLUSION: These results indicate that TFF1 can contribute to establishing a novel strategy to treat pancreatic cancer patients by enhancing chemosensitivity.

Impaired Glycosylation of Gastric Mucins Drives Gastric Tumorigenesis and Serves as a Novel Therapeutic Target.

BACKGROUND & AIMS: Gastric cancer is often accompanied by a loss of mucin 6 (MUC6), but its pathogenic role in gastric carcinogenesis remains unclear. METHODS: Muc6 knockout (Muc6-/-) mice and Muc6-dsRED mice were newly generated. Tff1Cre, Golph3-/-, R26-Golgi-mCherry, Hes1flox/flox, Cosmcflox/flox, and A4gnt-/- mice were also used. Histology, DNA and RNA, proteins, and sugar chains were analyzed by whole-exon DNA sequence, RNA sequence, immunohistochemistry, lectin-binding assays, and liquid chromatography-mass spectrometry analysis. Gastric organoids and cell lines were used for in vitro assays and xenograft experiments. RESULTS: Deletion of Muc6 in mice spontaneously causes pan-gastritis and invasive gastric cancers. Muc6-deficient tumor growth was dependent on mitogen-activated protein kinase activation, mediated by Golgi stress-induced up-regulation of Golgi phosphoprotein 3. Glycomic profiling revealed aberrant expression of mannose-rich N-linked glycans in gastric tumors, detected with banana lectin in association with lack of MUC6 expression. We identified a precursor of clusterin as a binding partner of mannose glycans. Mitogen-activated protein kinase activation, Golgi stress responses, and aberrant mannose expression are found in separate Cosmc- and A4gnt-deficient mouse models that lack normal O-glycosylation. Banana lectin-drug conjugates proved an effective treatment for mannose-rich murine and human gastric cancer. CONCLUSIONS: We propose that Golgi stress responses and aberrant glycans are important drivers of and promising new therapeutic targets for gastric cancer.

IFNγ-dependent silencing of TFF1 during Helicobacter pylori infection.

Chronic Helicobacter pylori infection is the leading cause of intestinal-type adenocarcinoma, as prolonged Helicobacter colonization triggers chronic active gastritis, which may evolve into adenocarcinoma of the intestinal type. In this environment, cytokines play a significant role in determining the evolution of the infection. In combination with other factors (genetic, environmental and nutritional), the pro-inflammatory response may trigger pro-oncogenic mechanisms that lead to the silencing of tumour-suppressor genes, such as trefoil factor 1 (TFF1). The latter is known to play a protective role by maintaining the gastric mucosa integrity and retaining H. pylori in the mucus layer, preventing the progression of infection and, consequently, the development of gastric cancer (GC). Since TFF1 expression is reduced during chronic Helicobacter infection with a loss of gastric mucosa protection, we investigated the molecular pathways involved in this reduction. Specifically, we evaluated the effect of some pro-inflammatory cytokines on TFF1 regulation in GC and primary gastric cells by RT-qPCR and luciferase reporter assay analyses and the repressor role of the transcription factor C/EBPß, overexpressed in gastric-intestinal cancer. Our results show that, among several cytokines, IFNγ stimulates C/EBPß expression, which acts as a negative regulator of TFF1 by binding its promoter at three different sites.

Runx1 regulates Tff1 expression to expedite viability of retinal microvascular endothelial cells in mice with diabetic retinopathy.

Diabetic retinopathy (DR) represents a major complication of diabetes, and molecular mechanisms related to vascular dysfunction, particularly endothelial dysfunction, in DR remains unclear. In the present work, we generated a DR animal model using mice and a cell model in mouse retinal microvascular endothelial cells (mRMECs) to examine the role of Trefoil factor family 1 (Tff1) in DR. Tff1 was poorly expressed in DR mice and high glucose (HG)-treated mRMECs. Overexpression of Tff1 significantly attenuated streptozotocin-induced retinal proliferation and angiogenesis in DR mice and reduced the secretion of inflammatory factors. In HG-treated mRMECs, overexpression of Tff1 remarkably reduced the proliferation and angiogenesis of mRMECs. In further experiments, we found that Tff1 was transcriptionally repressed by Runt-related transcription factor 1 (Runx1) directly, and Tff1 expression was indirectly modulated by Runx1 via the core-binding factor subunit beta (CBF-ß)/nuclear factor, erythroid 2/microRNA-423-5p axis and the CBF-ß/estrogen receptor 1 (ESR1) axis. Moreover, Tff1 could inhibit the activation of NF-κB signaling pathway, which in turn attenuated retinal endothelial cell proliferation and angiogenesis. It was thus proposed that Runx1/Tff1/NF-κB axis may be a potential target for the treatment strategy of DR, and further studies are needed.

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.

The trefoil factor family 1 (TFF-1) and 3 (TFF-3) are upregulated in the saliva, gingival crevicular fluid and serum of periodontitis patients.

OBJECTIVE: This study aimed to investigate the levels of trefoil factor family (TFF)-1, TFF-3 and interleukin (IL)-1ß in gingival crevicular fluid (GCF), saliva and serum of patients with gingivitis, stage 3 periodontitis and healthy individuals. MATERIALS AND METHODS: A total of 100 individuals consisting of 25 periodontally healthy, 25 gingivitis and 50 stage 3 periodontitis, were enrolled in the study. Clinical periodontal examinations were recorded and GCF, saliva and serum samples were obtained. TFF-1, TFF-3 and IL-1ß were measured by ELISA. RESULTS: TFF-1 and TFF-3 levels in both GCF, saliva and serum were higher in periodontitis patients than healthy controls (p < .001) and gingivitis group (p < .01). The levels of these peptides in all biofluids were similar between gingivitis and healthy control groups (p > .05). GCF, saliva and serum IL-1ß levels were also higher in periodontitis patients than the controls (p < .01). Periodontitis patients had elevated GCF and saliva IL-ß levels than gingivitis group (p < .001). CONCLUSION: Elevated TFF-1 and TFF-3 levels both locally and systemically in periodontitis in parallel to increased IL-1ß levels might suggest that these peptides are involved in host response during the periodontal tissue destruction.

Mechanisms of Dendrobium officinale polysaccharides in repairing gastric mucosal injuries based on mitogen-activated protein kinases (MAPK) signaling pathway.

The present study aimed to investigate the protective effects and molecular mechanisms of Dendrobium officinale polysaccharides on gastric mucosal injuries. Following one week of continuous intragastric administration, a gastric mucosal injury model was established using intragastric administration of anhydrous ethanol. The area of gastric ulcer was measured, the contents of interleukin- 6 (IL-6), epidermal growth factor receptor (EGFR), and thyroid transcription factor 1 (TFF-1) in serum were detected by enzyme linked immunosorbent assay (ELISA), and the expressions of EGFR, TFF-1, IL-6, Raf-2, MAP kinase kinase 1 (MEK1), MEK2, and ERK1 in the gastric tissue were determined utilizing qPCR, Western blotting and immunohistochemistry. Simultaneously, Dendrobium officinale polysaccharides and anhydrous ethanol were added to the gastric mucosal cells (GES1) cultured in vitro, and the protective effects of Dendrobium officinale polysaccharides on cell viability was detected using Cell Counting Kit (CCK)-8. The addition of Dendrobium officinale polysaccharides markedly improved the gastric epithelial defect, inflammatory cell infiltration, and redness and swelling stemmed from gastric mucosal injuries and greatly reduced the area of gastric ulcer. The inhibition rates of gastric ulcer were 48.12 ± 2.98, 42.95 ± 1.52, and 27.96 ± 2.05% in the high, medium, and low concentration Dendrobium officinale polysaccharide groups, respectively. Dendrobium officinale polysaccharides could increase the expressions of EGFR and TFF-1 and decrease the expressions of IL-6, Raf-2, MEK1, MEK2, and ERK1. Dendrobium officinale polysaccharides could reduce the level of inflammatory factors and protect gastric mucosa by inhibiting the expression of MAPK pathway genes and proteins.

Long non-coding RNA FOXD3 antisense RNA 1 augments anti-estrogen resistance in breast cancer cells through the microRNA-363/ trefoil factor 1/ phosphatidylinositol 3-kinase/protein kinase B axis.

Long non-coding RNA (lncRNA) FOXD3 antisense RNA 1 (FOXD3-AS1) has been reported to participate in multiple processes that contribute toward the development of cancer. The present study aimed to explore the effect of lncRNA FOXD3-AS1 on anti-estrogen resistance in breast cancer (BC) cells. FOXD3-AS1 was found to be highly expressed in BC cell lines. Moreover, FOXD3-AS1 was highly expressed in estrogen receptor-negative (ER-) cells compared to the ER-positive (ER+) cells. FOXD3-AS1 overexpression in T47D and MCF-7 (ER+) cells enhanced the resistance of cells to tamoxifen (TMX), whereas FOX3-AS1 downregulation reduced the TMX resistance in MDA-MB-231 (ER-) cells. Similar results were reproduced in vivo that FOXD3-AS1 inhibition reduced the growth of xenograft tumors formed by MDA-MB-231 cells following TMX treatment whereas FOXD3-AS1 overexpression in T47D cells facilitated tumor growth. The bioinformatic analysis and luciferase assays indicated that FOXD3-AS1 sponged microRNA-363 (miR-363) to restore expression of trefoil factor 1 (TFF1) mRNA. Overexpression of miR-363 reduced T47D cell proliferation induced by FOXD3-AS1, whereas overexpression of TFF1 restored growth of MDA-MB-231 cells reduced after FOXD3-AS1 silencing. The phosphorylation of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) was increased by FOXD3-AS1 but attenuated by miR-363. Inhibition of PI3K/Akt blocked the role of FOXD3-AS1 and reduced the TMX resistance in T47D and MCF-7 cells. Taken together, the present study suggested that FOXD3-AS1 sponges miR-363 to upregulate TFF1 expression, leading to PI3K/Akt signaling activation and anti-estrogen resistance in BC cells.

Estrogen-related receptor-gamma influences Helicobacter pylori infection by regulating TFF1 in gastric cancer.

Helicobacter pylori infection is a crucial factor in the development of gastric cancer (GC). Molecular therapeutic targets and mechanisms contributing to H. pylori infection-associated GC induction are poorly understood and this study aimed to fill that research gap. We found that the nuclear receptor estrogen-related receptor gamma (ESRRG) is a candidate factor influencing H. pylori infection-driven GC. ESRRG suppressed H. pylori infection and cell growth induced by H. pylori infection in GC cells and organoid models In addition, H. pylori infection downregulates ESRRG expression. Gene expression profiling revealed that trefoil factor 1 (TFF1), a well-known tumor suppressor in GC, is a downstream target of ESRRG. Mechanistically, ESRRG directly binds to the TFF1 promoter and induces TFF1 gene expression. Furthermore, TFF1 activation by ESRRG was inhibited by nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)/p65, which is induced by inflammation, such as by H. pylori infection. Our current study provides new molecular insights into how ESRRG regulates H. pylori infection, contributing to GC development. We suggest that modulation of ESRRG-suppressing H. pylori infection could be a therapeutic target for the treatment of GC patients.

A novel gastroprotective effect of zeaxanthin against stress-induced gastritis in male rats targeting the expression of HIF-1α, TFF-1 and MMP-9 through PI3K/Akt/JNK signaling pathway.

Stress-induced gastritis is a common problem in the intensive care unit. Zeaxanthin (ZE), a non-provitamin A carotenoid has been known to exert antioxidant and anti-inflammatory effects. In this study, we examined the effect of ZE on water avoidance stress (WAS)-induced gastritis in rats. 24 Sprague' Dawley male rats were divided into four groups; control, ZE, WAS and WAS+ZE. In the stressed rats, treatment with ZE effectively downregulated the gastric levels of total oxidant status (TOS), myeloperoxidase (MPO) and malondialdehyde (MDA), with significant upregulation of the antioxidant enzymes' activities and gastric levels of prostagladin-E2 (PGE2) as compared to the untreated stressed one. As noticed in the present study, ZE significantly decrease the gastric levels of interleukin-1 ß (IL-1ß) and IL-6 as well as suppression of nuclear transcription factor kappa-B (NF-κB) immunohistochemical expression together with upregulation of trefoil factor-1 (TFF-1) gene expression. Moreover, in the untreated WAS-induced gastritis group, gastrin and corticosterone levels were significantly increased together with upregulation of the gene expression of hypoxia inducible factor-1α (HIF-1α), matrix metalloproteinase-9 (MMP-9), PI3K, Akt and JNK in the gastric tissues, which significantly improved by ZE administration. These all positive effects of ZE reflected on reduction of microscopic gastric mucosal damage and inflammatory cell infiltration with improvement of ulcer score. Our results discover that ZE has a new gastroprotective effect against stress-induced gastritis in rats, primarily through its antioxidative and anti-inflammatory effects, which are expressed in the regulation of the MMP-9 and HIF-1α signaling pathways.

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 Different Roles in the Mucosal Innate Immune Defense and More: An Update.

Mucous epithelia are protected by complex mucus barrier layers, which are part of the innate immune defense. Trefoil factor family peptides TFF1, TFF2, and TFF3 have lectin activities and are predominantly co-secreted together with mucins from these epithelia. TFF1 and TFF2 are mainly expressed in the gastric mucosa, whereas TFF3 is widely secreted from most mucous epithelia and their glands. TFF1 and TFF3 consist of a single TFF domain and an additional free 7th cysteine residue, whereas TFF2 contains two TFF domains. Systematic analyses of the molecular forms of TFFs gave new insights into their diverse molecular functions. TFF1 mainly exists as a monomer with an unusual free thiol group and only minor amounts form a disulfide-linked homodimer as well as heterodimers with gastrokine-2 and IgG-Fc-binding protein (FCGBP). TFF3 mainly forms a heterodimer with FCGBP in vivo, but also binds Deleted in Malignant Brain Tumors/gp340 (DMBT1gp340) in vitro. In contrast, TFF2 binds as a lectin to a conserved O-linked carbohydrate moiety of the mucin MUC6. Both FCGBP and DMBT1gp340 are secreted by most mucous epithelia and their glands and are involved in mucosal innate immunity. Thus, a new picture emerged pointing to functions of TFF3-FCGBP (and TFF1-FCGBP) for mucosal innate immune defense, e.g. supporting the clearing of the microorganisms. Such a function could be well be supported by DMBT1gp340. In contrast, the TFF2/MUC6 lectin complex probably physically stabilizes the inner adherent gastric mucus layer. Furthermore, there are indications that TFF3- FCGBP might also play a role in the blood vessels.

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.

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.

Trefoil factors share a lectin activity that defines their role in mucus.

The mucosal epithelium secretes a host of protective disulfide-rich peptides, including the trefoil factors (TFFs). The TFFs increase the viscoelasticity of the mucosa and promote cell migration, though the molecular mechanisms underlying these functions have remained poorly defined. Here, we demonstrate that all TFFs are divalent lectins that recognise the GlcNAc-α-1,4-Gal disaccharide, which terminates some mucin-like O-glycans. Degradation of this disaccharide by a glycoside hydrolase abrogates TFF binding to mucins. Structural, mutagenic and biophysical data provide insights into how the TFFs recognise this disaccharide and rationalise their ability to modulate the physical properties of mucus across different pH ranges. These data reveal that TFF activity is dependent on the glycosylation state of mucosal glycoproteins and alludes to a lectin function for trefoil domains in other human proteins.