Quantitative evaluation of gut microbiota composition in pancreatic cancer: A pooled study.

BACKGROUND: Prior research has demonstrated a positive association between the composition of gut microbiota and the incidence of pancreatic cancer. Nevertheless, a thorough quantitative and systematic evaluation of the distinct properties of gut microbiota in individuals diagnosed with pancreatic cancer has yet to be conducted. The objective of this study is to examine alterations in the diversity of intestinal microbiota in individuals diagnosed with pancreatic cancer. METHODS: Search for relevant literature published before July 2023 in 4 databases: PubMed, Embase, Web of Science, and Cochrane Library, without any language restrictions. RESULTS: A total of 12 studies were included, including 535 patients with pancreatic cancer and 677 healthy controls. Analysis was conducted on 6 phyla, 16 genera, and 6 species. The study found significant and distinctive changes in the α-diversity of gut microbiota, as well as in the relative abundance of multiple gut bacterial groups at the phylum, genus, and species levels in pancreatic cancer patients. CONCLUSION: Overall, there are certain characteristic changes in the gut microbiota of pancreatic cancer patients. However, further research is warranted to elucidate the specific mechanism of action and the potential for treatment.

Using Pre-Clinical Studies to Explore the Potential Clinical Uses of Exosomes Secreted from Induced Pluripotent Stem Cell-Derived Mesenchymal Stem cells.

Recent studies of exosomes derived from mesenchymal stem cells (MSCs) have indicated high potential clinical applications in many diseases. However, the limited source of MSCs impedes their clinical research and application. Most recently, induced pluripotent stem cells (iPSCs) have become a promising source of MSCs. Exosome therapy based on iPSC-derived MSCs (iMSCs) is a novel technique with much of its therapeutic potential untapped. Compared to MSCs, iMSCs have proved superior in cell proliferation, immunomodulation, generation of exosomes capable of controlling the microenvironment, and bioactive paracrine factor secretion, while also theoretically eliminating the dependence on immunosuppression drugs. The therapeutic effects of iMSC-derived exosomes are explored in many diseases and are best studied in wound healing, cardiovascular disease, and musculoskeletal pathology. It is pertinent clinicians have a strong understanding of stem cell therapy and the latest advances that will eventually translate into clinical practice. In this review, we discuss the various applications of exosomes derived from iMSCs in clinical medicine.

STAT3 potentiates RNA polymerase I-directed transcription and tumor growth by activating RPA34 expression.

BACKGROUND: Deregulation of either RNA polymerase I (Pol I)-directed transcription or expression of signal transducer and activator of transcription 3 (STAT3) correlates closely with tumorigenesis. However, the connection between STAT3 and Pol I-directed transcription hasn't been investigated. METHODS: The role of STAT3 in Pol I-directed transcription was determined using combined techniques. The regulation of tumor cell growth mediated by STAT3 and Pol I products was analyzed in vitro and in vivo. RNAseq, ChIP assays and rescue assays were used to uncover the mechanism of Pol I transcription mediated by STAT3. RESULTS: STAT3 expression positively correlates with Pol I product levels and cancer cell growth. The inhibition of STAT3 or Pol I products suppresses cell growth. Mechanistically, STAT3 activates Pol I-directed transcription by enhancing the recruitment of the Pol I transcription machinery to the rDNA promoter. STAT3 directly activates Rpa34 gene transcription by binding to the RPA34 promoter, which enhances the occupancies of the Pol II transcription machinery factors at this promoter. Cancer patients with RPA34 high expression lead to poor survival probability and short survival time. CONCLUSION: STAT3 potentiates Pol I-dependent transcription and tumor cell growth by activating RPA34 in vitro and in vivo.

TFIIB-related factor 1 is a nucleolar protein that promotes RNA polymerase I-directed transcription and tumour cell growth.

Eukaryotic RNA polymerase I (Pol I) products play fundamental roles in ribosomal assembly, protein synthesis, metabolism and cell growth. Abnormal expression of both Pol I transcription-related factors and Pol I products causes a range of diseases, including ribosomopathies and cancers. However, the factors and mechanisms governing Pol I-dependent transcription remain to be elucidated. Here, we report that transcription factor IIB-related factor 1 (BRF1), a subunit of transcription factor IIIB required for RNA polymerase III (Pol III)-mediated transcription, is a nucleolar protein and modulates Pol I-mediated transcription. We showed that BRF1 can be localized to the nucleolus in several human cell types. BRF1 expression correlates positively with Pol I product levels and tumour cell growth in vitro and in vivo. Pol III transcription inhibition assays confirmed that BRF1 modulates Pol I-directed transcription in an independent manner rather than through a Pol III product-to-45S pre-rRNA feedback mode. Mechanistically, BRF1 binds to the Pol I transcription machinery components and can be recruited to the rDNA promoter along with them. Additionally, alteration of BRF1 expression affects the recruitment of Pol I transcription machinery components to the rDNA promoter and the expression of TBP and TAF1A. These findings indicate that BRF1 modulates Pol I-directed transcription by controlling the expression of selective factor 1 subunits. In summary, we identified a novel role of BRF1 in Pol I-directed transcription, suggesting that BRF1 can independently regulate both Pol I- and Pol III-mediated transcription and act as a key coordinator of Pol I and Pol III.

The novel prolyl hydroxylase-2 inhibitor caffeic acid upregulates hypoxia inducible factor and protects against hypoxia.

BACKGROUND & AIMS: Hypoxia inducible factor (HIF) is a hypoxia-associated transcription factor that has a protective role against hypoxia-induced damage. Prolyl hydroxylase-2 (PHD2) is a dioxygenase enzyme that specifically hydroxylates HIF targeting it for degradation, therefore, inhibition of the PHD2 enzyme activity acts to upregulate HIF function. This study was to identify novel PHD2 inhibitors. METHODS: An established fluorescence-based PHD2 activity assay was used for inhibitors screening. Western blot and quantitative real-time PCR was used to detect the protein and mRNA levels respectively. Further animal experiment was carried out. RESULTS: Caffeic acid was screened and identified as a novel PHD2 inhibitor. Caffeic acid treated PC12 and SH-SY5Y neuronal cell lines stabilized endogenous HIF-1α protein levels and consequently increased mRNA levels of its downstream regulated genes VEGF and EPO. Caffeic acid treatment reduced hypoxia-induced cell apoptosis and promoted HIF/BNIP3-mediated mitophagy. Moreover, animal studies indicated that caffeic acid increased the level of HIF-1α protein and mRNA levels of VEGF and EPO in the brain of mice exposed to hypoxia. Conventional brain injury markers including malondialdehyde, lactic acid and lactate dehydrogenase in the caffeic acid treated mice were shown to be reduced to the levels of the control group. CONCLUSIONS: This study suggests that caffeic acid inhibits PHD2 enzyme activity which then activates the hypoxia-associated transcription factor HIF leading to a neuroprotective effect against hypoxia.

C-Reactive Protein Levels and Clinical Prognosis in LAA-Type Stroke Patients: A Prospective Cohort Study.

METHODS: We prospectively included 200 patients with LAA-type AIS and tested their CRP levels on admission. We followed these patients consecutively. The primary outcome was an adverse event, defined as a modified Rankin Scale score of 2-6 at months 3, 6, and 12 after discharge. A logistic regression model was used to analyze the relationship between CRP and the functional outcome of LAA stroke. RESULTS: We divided 200 patients into 3 groups evenly based on CRP level. After adjustment for gender, age, smoking history, drinking history, history of hyperlipidemia, history of diabetes, lipid levels, and blood glucose levels, logistic regression showed that the incidence of LAA-type AIS poor outcome was positively associated with CRP level at admission, whether it was 3 months, 6 months, or 12 months after discharge, respectively (OR: 2.574, 95% CI: 1.213-5.463; OR: 2.806, 95% CI: 1.298-6.065; OR: 2.492, 95% CI: 1.167-5.321. In the highest tertile vs. the lowest tertile as a reference), and both were statistically different. CONCLUSIONS: High CRP level predicts poor functional outcome in LAA-type AIS patients, which provides a strong basis for clinicians to make treatment decisions for these patients.

Characterisation of Novel Angiogenic and Potent Anti-Inflammatory Effects of Micro-Fragmented Adipose Tissue.

Adipose tissue and more specifically micro-fragmented adipose tissue (MFAT) obtained from liposuction has recently been shown to possess interesting medicinal properties whereby its application supports pain reduction and may enhance tissue regeneration particularly in osteoarthritis. Here we have characterised samples of MFAT produced using the Lipogems® International Spa system from eight volunteer individuals in order to understand the critical biological mechanisms through which they act. A variation was found in the MFAT cluster size between individual samples and this translated into a similar variation in the ability of purified mesenchymal stem cells (MSCs) to form colony-forming units. Almost all of the isolated cells were CD105/CD90/CD45+ indicating stemness. An analysis of the secretions of cytokines from MFAT samples in a culture using targeted arrays and an enzyme-linked immunosorbent assay (ELISA) showed a long-term specific and significant expression of proteins associated with anti-inflammation (e.g., interleukin-1 receptor alpha (Il-1Rα) antagonist), pro-regeneration (e.g., hepatocyte growth factor), anti-scarring and pro-angiogenesis (e.g., transforming growth factor beta 1 and 2 (TGFß1/2) and anti-bacterial (e.g., chemokine C-X-C motif ligand-9 (CXCL-9). Angiogenesis and angiogenic signalling were notably increased in primary bovine aortic endothelial cells (BAEC) to a different extent in each individual sample of the conditioned medium whilst a direct capacity of the conditioned medium to block inflammation induced by lipopolysaccharides was shown. This work characterises the biological mechanisms through which a strong, long-lasting, and potentially beneficial effect can be observed regarding pain reduction, protection and regeneration in osteoarthritic joints treated with MFAT.

CD105 (Endoglin): A Potential Anticancer Therapeutic Inhibits Mitogenesis and Map Kinase Pathway Activation.

BACKGROUND: CD105 is highly expressed on human activated endothelial cells (ECs), is an important component of the TGF-ß1 receptor complex and is essential for angiogenesis. CD105 expression is up-regulated in activated ECs and is an important potential marker for cancer prognosis. MATERIALS AND METHODS: In vitro rat myoblasts transfected with the L-CD105 and S-CD105 transfectants. The transfectants were treated with TGF-ß1 for the angiogenesis study. RESULTS: L-CD105 affects cell proliferation in the presence and absence of TGF-ß1, and inhibits p-ERK1/2, p-MEK1/2 and p-c-Jun in L-CD105 transfectants compared to controls. The induction of phospho-ERK1/2 following treatment with TGF-ß1 remained significantly lower in L-CD105 transfectants compared to controls. CONCLUSION: L-CD105 inhibits the phosphorylation of ERK1/2, MEK1/2, c-Jun1/2/3, and associated signalling intermediates. CD105 modulates cell growth and TGF-ß1 induced cell signalling through ERK-c-Jun expression.

Blood biomarker levels of methylation capacity in autism spectrum disorder: a systematic review and meta-analysis.

OBJECTIVE: To compare the peripheral blood levels of methionine (Met), S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), and the SAM/SAH ratio (the most core and predictive indices of cellular methylation ability) between patients with autism spectrum disorder (ASD) and control subjects. METHODS: PubMed, Embase, PsycINFO, Web of Science, and Cochrane Library were searched from inception to August 2, 2019, without language restriction. The random-effects model was used to summarize effect sizes. RESULTS: We retrieved 1,493 records, of which 22 studies met inclusion criteria. Our overall analyses revealed that individuals with ASD had significantly decreased levels of Met (22 studies; Hedges' g = -0.62; 95% confidence interval [CI]: -0.89, -0.35), SAM (8 studies; Hedges' g = -0.60; 95% CI: -0.86, -0.34), and the SAM/SAH ratio (8 studies; Hedges' g = -0.98; 95% CI: -1.30, -0.66) and significantly increased levels of SAH (8 studies; Hedges' g = 0.69; 95% CI: 0.43, 0.94). The findings of the overall analyses were quite stable after being verified by sensitivity analyses and in agreement with the corresponding outcomes of subgroup analyses. Additionally, our results from meta-analytic techniques confirmed that the effect estimates of this meta-analysis did not originate from publication bias. CONCLUSION: Individuals with ASD have substantially aberrant peripheral blood levels of Met, SAM, SAH, and the SAM/SAH ratio, which supports the association between impaired methylation capacity and ASD. Therefore, further investigations into these indices as potential biomarkers for diagnosis and therapeutic targets of ASD are warranted.

The transcription factor Sp1 modulates RNA polymerase III gene transcription by controlling BRF1 and GTF3C2 expression in human cells.

Specificity protein 1 (Sp1) is an important transcription factor implicated in numerous cellular processes. However, whether Sp1 is involved in the regulation of RNA polymerase III (Pol III)-directed gene transcription in human cells remains unknown. Here, we first show that filamin A (FLNA) represses Sp1 expression as well as expression of TFIIB-related factor 1 (BRF1) and general transcription factor III C subunit 2 (GTF3C2) in HeLa, 293T, and SaOS2 cell lines stably expressing FLNA-silencing shRNAs. Both BRF1 promoter 4 (BRF1P4) and GTF3C2 promoter 2 (GTF3C2P2) contain putative Sp1-binding sites, suggesting that Sp1 affects Pol III gene transcription by regulating BRF1 and GTF3C2 expression. We demonstrate that Sp1 knockdown inhibits Pol III gene transcription, BRF1 and GTF3C2 expression, and the proliferation of 293T and HeLa cells, whereas Sp1 overexpression enhances these activities. We obtained a comparable result in a cell line in which both FLNA and Sp1 were depleted. These results indicate that Sp1 is involved in the regulation of Pol III gene transcription independently of FLNA expression. Reporter gene assays showed that alteration of Sp1 expression affects BRF1P4 and GTF3C2P2 activation, suggesting that Sp1 modulates Pol III-mediated gene transcription by controlling BRF1 and GTF3C2 gene expression. Further analysis revealed that Sp1 interacts with and thereby promotes the occupancies of TATA box-binding protein, TFIIAα, and p300 at both BRF1P4 and GTF3C2P2. These findings indicate that Sp1 controls Pol III-directed transcription and shed light on how Sp1 regulates cancer cell proliferation.

Proteomic Analysis of an Induced Pluripotent Stem Cell Model Reveals Strategies to Treat Juvenile Myelomonocytic Leukemia.

Juvenile myelomonocytic leukemia (JMML) is an aggressive myeloproliferative neoplasm of early childhood with a poor survival rate, thus there is a requirement for improved treatment strategies. Induced pluripotent stem cells offer the ability to model disease and develop new treatment strategies. JMML is frequently associated with mutations in PTPN11. Children with Noonan syndrome, a development disorder, have an increased incidence of JMML associated with specific germline mutations in PTPN11. We undertook a proteomic assessment of myeloid cells derived from induced pluripotent stem cells obtained from Noonan syndrome patients with PTPN11 mutations, either associated or not associated with an increased incidence of JMML. We report that the proteomic perturbations induced by the leukemia-associated PTPN11 mutations are associated with TP53 and NF-Kκb signaling. We have previously shown that MYC is involved in the differential gene expression observed in Noonan syndrome patients associated with an increased incidence of JMML. Thus, we employed drugs to target these pathways and demonstrate differential effects on clonogenic hematopoietic cells derived from Noonan syndrome patients, who develop JMML and those who do not. Further, we demonstrated these small molecular inhibitors, JQ1 and CBL0137, preferentially extinguish primitive hematopoietic cells from sporadic JMML patients as opposed to cells from healthy individuals.

p17 from HIV induces brain endothelial cell angiogenesis through EGFR-1-mediated cell signalling activation.

HIV-associated neurocognitive disorder in HIV patients substantially reduces their quality of life. We previously showed that the HIV matrix protein, p17 could stimulate lymph-angiogenesis in vitro potentially contributing to lymphoma tumour growth and in addition is associated with vascular activation in neuro-degenerating brain tissue; here, therefore, we have investigated the detailed molecular mechanisms of this action. We performed in vitro cell culture, angiogenesis experiments, phospho-protein microarrays and Western blotting to identify cellular signalling induced by p17 within human brain endothelial cells (HbMEC), and inhibitor studies to block p17-induced vascular growth. We also characterised the effects of hippocampal CA1 injection of p17 on epidermal growth factor receptor-1 (EGFR1) expression linked to our murine model of dementia. p17 strongly induced angiogenesis of HbMEC (migration, tube formation and spheroid growth). p17 concomitantly increased phosphorylation of EGFR1 as well as down-stream intermediates ERK1/2, FAK, PLC-γ and PKC-ß whilst an inhibitor peptide of EGFR, blocked cell signalling and angiogenesis. Finally, Mice that showed reduced cognitive function and behavioural deficiencies after p17 injection, demonstrated that p17 localised in cortical microvessels and also neurones many of which stained positive for p-EGFR1 by histology/IHC. This work provides strong support that p17 may be involved in initiating and/or perpetuating vascular tissue pathophysiology associated with comorbidity in HIV patients.

Induced pluripotent stem cells as a potential therapeutic source for corneal epithelial stem cells.

Corneal blindness caused by limbal stem cell deficiency (LSCD) is one of the most common debilitating eye disorders. Thus far, the most effective treatment for LSCD is corneal transplantation, which is often hindered by the shortage of donors. Pluripotent stem cell technology including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have opened new avenues for treating this disease. iPSCs-derived corneal epithelial cells provide an autologous and unlimited source of cells for the treatment of LSCD. On the other hand, iPSCs of LSCD patients can be used for iPSCs-corneal disease model and new drug discovery. However, prior to clinical trial, the efficacy and safety of these cells in patients with LSCD should be proved. Here we focused on the current status of iPSCs-derived corneal epithelial cells used for cell therapy as well as for corneal disease modeling. The challenges and potential of iPSCs-derived corneal epithelial cells as a choice for clinical treatment in corneal disease were also discussed.

Acetylcholine Inhibits Monomeric C-Reactive Protein Induced Inflammation, Endothelial Cell Adhesion, and Platelet Aggregation; A Potential Therapeutic?

Objectives: In this study, we examined the possibility of using targeted antibodies and the potential of small molecular therapeutics (acetylcholine, nicotine and tacrine) to block the pro-inflammatory and adhesion-related properties of monomeric C-reactive protein (mCRP). Methods: We used three established models (platelet aggregation assay, endothelial leucocyte binding assay and monocyte inflammation via ELISA and Western blotting) to assess the potential of these therapeutics. Results: The results of this study showed that monocyte induced inflammation (raised tumor necrosis factor-alpha-TNF-α) induced by mCRP was significantly blocked in the presence of acetylcholine and nicotine, whilst tacrine and targeted antibodies (clones 8C10 and 3H12) had less of or no significant effects. Western blotting confirmed the ability of acetylcholine to inhibit mCRP-induced cell signaling phosphorylation of extracellular signal regulated kinase 1/2 (ERK1/2), p38 and nuclear factor-kappa B (NF-κB). There was no evidence of direct binding between small molecules and mCRP. mCRP also induced endothelial cell-monocyte adhesion in a dose dependent fashion, however, both acetylcholine and nicotine as well as targeting antibodies notably inhibited adhesion. Finally, we investigated their effects on mCRP-induced platelet aggregation. All three small molecules significantly attenuated platelet aggregation as did the antibody 8C10, although 3H12 had a weaker effect. Discussion: Acetylcholine and to a lesser extent nicotine show potential for therapeutic inhibition of mCRP-induced inflammation and cell and platelet adhesion. These results highlight the potential of targeted antibodies and small molecule therapeutics to inhibit the binding of mCRP by prevention of membrane interaction and subsequent activation of cellular cascade systems, which produce the pro-inflammatory effects associated with mCRP.

Puerarin reduces ischemia/reperfusion-induced myocardial injury in diabetic rats via upregulation of vascular endothelial growth factor A/angiotensin-1 and suppression of apoptosis.

Puerarin is an active ingredient of pueraria, which has been developed for puerarin injections, used in the treatment of cardiovascular diseases including arrhythmia, myocardial ischemia and hypertension. However, the molecular mechanisms of puerarin on ischemia/reperfusion (I/R)­induced myocardial apoptosis in diabetic rats are not fully understood. The present study aimed to investigate whether puerarin can attenuate I/R­induced myocardial apoptosis in diabetic rats, and to investigate the underlying mechanism. A hemodynamic analyzing system was employed to analyze the left ventricular developed pressure (LVDP), the left ventricular end­systolic interior dimension (LVIDs) and the left ventricular end diastolic interior dimension (LVIDd). ELISA kits were used to analyze malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor­α (TNF­α) and interleukin (IL)­6 levels, NO production and caspase­3 activity. Nuclear factor (NF)­κB, ascular endothelial growth factor A (VEGFA), angiotensin (Ang)­I, phosphorylated (p)­endothelial nitric oxide synthase protein expression was analyzed using western blot analysis. Puerarin significantly reduced the myocardial infarct area, and increased left ventricular developed pressure in diabetic rats with myocardial I/R. Oxidative stress, inflammation and nuclear factor­κB protein expression were significantly reduced by puerarin. Furthermore, puerarin activated the protein expression levels of VEGFA and Ang­I, and increased nitric oxide production, phosphorylated­endothelial nitric oxide synthase protein expression and caspase­3 activity. These results demonstrated that the myocardial protective effect of puerarin serves to reduce myocardial I/R injury, via upregulation of VEGFA/Ang­1 and suppression of apoptosis, in diabetic rats with myocardial I/R.

The E3 ubiquitin ligase UBE3A is an integral component of the molecular circadian clock through regulating the BMAL1 transcription factor.

Post-translational modifications (such as ubiquitination) of clock proteins are critical in maintaining the precision and robustness of the evolutionarily conserved circadian clock. Ubiquitination of the core clock transcription factor BMAL1 (brain and muscle Arnt-like 1) has recently been reported. However, it remains unknown whether BMAL1 ubiquitination affects circadian pacemaking and what ubiquitin ligase(s) is involved. Here, we show that activating UBE3A (by expressing viral oncogenes E6/E7) disrupts circadian oscillations in mouse embryonic fibroblasts, measured using PER2::Luc dynamics, and rhythms in endogenous messenger ribonucleic acid and protein levels of BMAL1. Over-expression of E6/E7 reduced the level of BMAL1, increasing its ubiquitination and proteasomal degradation. UBE3A could bind to and degrade BMAL1 in a ubiquitin ligase-dependent manner. This occurred both in the presence and absence of E6/E7. We provide in vitro (knockdown/over-expression in mammalian cells) and in vivo (genetic manipulation in Drosophila) evidence for an endogenous role of UBE3A in regulating circadian dynamics and rhythmic locomotor behaviour. Together, our data reveal an essential and conserved role of UBE3A in the regulation of the circadian system in mammals and flies and identify a novel mechanistic link between oncogene E6/E7-mediated cell transformation and circadian (BMAL1) disruption.

The circadian clock regulates rhythmic activation of the NRF2/glutathione-mediated antioxidant defense pathway to modulate pulmonary fibrosis.

The disruption of the NRF2 (nuclear factor erythroid-derived 2-like 2)/glutathione-mediated antioxidant defense pathway is a critical step in the pathogenesis of several chronic pulmonary diseases and cancer. While the mechanism of NRF2 activation upon oxidative stress has been widely investigated, little is known about the endogenous signals that regulate the NRF2 pathway in lung physiology and pathology. Here we show that an E-box-mediated circadian rhythm of NRF2 protein is essential in regulating the rhythmic expression of antioxidant genes involved in glutathione redox homeostasis in the mouse lung. Using an in vivo bleomycin-induced lung fibrosis model, we reveal a clock "gated" pulmonary response to oxidative injury, with a more severe fibrotic effect when bleomycin was applied at a circadian nadir in NRF2 levels. Timed administration of sulforaphane, an NRF2 activator, significantly blocked this phenotype. Moreover, in the lungs of the arrhythmic Clock(Δ19) mice, the levels of NRF2 and the reduced glutathione are constitutively low, associated with increased protein oxidative damage and a spontaneous fibrotic-like pulmonary phenotype. Our findings reveal a pivotal role for the circadian control of the NRF2/glutathione pathway in combating oxidative/fibrotic lung damage, which might prompt new chronotherapeutic strategies for the treatment of human lung diseases, including idiopathic pulmonary fibrosis.

The ERK MAP kinase-PEA3/ETV4-MMP-1 axis is operative in oesophageal adenocarcinoma.

BACKGROUND: Many members of the ETS-domain transcription factor family are important drivers of tumourigenesis. In this context, their activation by Ras-ERK pathway signaling is particularly relevant to the tumourigenic properties of many ETS-domain transcription factors. The PEA3 subfamily of ETS-domain transcription factors have been implicated in tumour metastasis in several different cancers. RESULTS: Here, we have studied the expression of the PEA3 subfamily members PEA3/ETV4 and ER81/ETV1 in oesophageal adenocarcinomas and determined their role in oesophageal adenocarcinoma cell function. PEA3 plays an important role in controlling both the proliferation and invasive properties of OE33 oesophageal adenocarcinoma cells. A key target gene is MMP-1. The ERK MAP kinase pathway activates PEA3 subfamily members and also plays a role in these PEA3 controlled events, establishing the ERK-PEA3-MMP-1 axis as important in OE33 cells. PEA3 subfamily members are upregulated in human adenocarcinomas and expression correlates with MMP-1 expression and late stage metastatic disease. Enhanced ERK signaling is also more prevalent in late stage oesophageal adenocarcinomas. CONCLUSIONS: This study shows that the ERK-PEA3-MMP-1 axis is upregulated in oesophageal adenocarcinoma cells and is a potentially important driver of the metastatic progression of oesophageal adenocarcinomas.

The LIM domain protein LPP is a coactivator for the ETS domain transcription factor PEA3.

PEA3 is a member of a subfamily of ETS domain transcription factors which is regulated by a number of signaling cascades, including the mitogen-activated protein (MAP) kinase pathways. PEA3 activates gene expression and is thought to play an important role in promoting tumor metastasis and also in neuronal development. Here, we have identified the LIM domain protein LPP as a novel coregulatory binding partner for PEA3. LPP has intrinsic transactivation capacity, forms a complex with PEA3, and is found associated with PEA3-regulated promoters. By manipulating LPP levels, we show that it acts to upregulate the transactivation capacity of PEA3. LPP can also functionally interact in a similar manner with the related family member ER81. Thus, we have uncovered a novel nuclear function for the LIM domain protein LPP as a transcriptional coactivator. As LPP continually shuttles between the cell periphery and the nucleus, it represents a potential novel link between cell surface events and changes in gene expression.

CD105 inhibits transforming growth factor-beta-Smad3 signalling.

CD105 (endoglin) is an important component of the transforming growth factor-beta (TGF-beta) receptor complex and is highly expressed in endothelial cells in tissues undergoing angiogenesis such as healing wounds, infarcts and in a wide range of tumours. In an attempt to understand the molecular mechanism by which CD105 exerts its effects on angiogenesis by modulating TGF-beta1 signalling, in this preliminary communication, CD105 transfected rat myoblasts were utilized as an in vitro model. Overexpression of CD105 in these transfectants antagonised TGF-beta1-mediated inhibition of cell proliferation and reduced TGF-beta1-mediated p3TP-Lux (PAI-1 promoter) luciferase activity. It also reduced (CAGA)12-Luc luciferase activity in response to TGF-beta1. The CAGA sequence is specific for Smad3/4 binding, implying that CD105 is involved in inhibition of TGF-beta1/Smad3 signalling. Furthermore, CD105 overexpression reduced serine phosphorylation of Smad3 and inhibited subsequent nuclear translocation of Smad3. CD105 resulted in high phosphorylation of JNK1, which is able to activate c-Jun. c-Jun is known to inhibit Smad3 transcriptional activity on CAGA sites, suggesting that CD105 may also inhibit Smad3 signalling through JNK1.