T-box Transcription Factor Brachyury Research Articles

An ancestral Wnt-Brachyury feedback loop in axial patterning and recruitment of mesoderm-determining target genes.

Transcription factors are crucial drivers of cellular differentiation during animal development and often share ancient evolutionary origins. The T-box transcription factor Brachyury plays a pivotal role as an early mesoderm determinant and neural repressor in vertebrates; yet, the ancestral function and key evolutionary transitions of the role of this transcription factor remain obscure. Here, we present a genome-wide target-gene screen using chromatin immunoprecipitation sequencing in the sea anemone Nematostella vectensis, an early branching non-bilaterian, and the sea urchin Strongylocentrotus purpuratus, a representative of the sister lineage of chordates. Our analysis reveals an ancestral gene regulatory feedback loop connecting Brachyury, FoxA and canonical Wnt signalling involved in axial patterning that predates the cnidarian-bilaterian split about 700 million years ago. Surprisingly, we also found that part of the gene regulatory network controlling the fate of neuromesodermal progenitors in vertebrates was already present in the common ancestor of cnidarians and bilaterians. However, while several endodermal and neuronal Brachyury target genes are ancestrally shared, hardly any of the key mesodermal downstream targets in vertebrates are found in the sea anemone or the sea urchin. Our study suggests that a limited number of target genes involved in mesoderm formation were newly acquired in the vertebrate lineage, leading to a dramatic shift in the function of this ancestral developmental regulator.

A 37 kb region upstream of brachyury comprising a notochord enhancer is essential for notochord and tail development.

ABSTRACTThe node-streak border region comprising notochord progenitor cells (NPCs) at the posterior node and neuro-mesodermal progenitor cells (NMPs) in the adjacent epiblast is the prime organizing center for axial elongation in mouse embryos. The T-box transcription factor brachyury (T) is essential for both formation of the notochord and maintenance of NMPs, and thus is a key regulator of trunk and tail development. The T promoter controlling T expression in NMPs and nascent mesoderm has been characterized in detail; however, control elements for T expression in the notochord have not been identified yet. We have generated a series of deletion alleles by CRISPR/Cas9 genome editing in mESCs, and analyzed their effects in mutant mouse embryos. We identified a 37 kb region upstream of T that is essential for notochord function and tailbud outgrowth. Within that region, we discovered a T-binding enhancer required for notochord cell specification and differentiation. Our data reveal a complex regulatory landscape controlling cell type-specific expression and function of T in NMP/nascent mesoderm and node/notochord, allowing proper trunk and tail development.

Clinical impact of brachyury expression in Ewing sarcoma patients

PurposeThe T-box transcription factor brachyury has been demonstrated as a prognostic factor in a variety of cancer types and considered a novel oncotarget in solid tumors. Brachyury acts as a regulator of the epithelial-mesenchymal transition (EMT) process, leading to more aggressive behavior and poorer prognosis. However, recent literature evidence suggests a tumor suppressor role in other neoplasms. In the present study, we aimed to study brachyury expression and its prognostic impact in Ewing sarcoma, an aggressive neoplasm of young individuals. MethodsWe analyzed the expression of brachyury by immunohistochemistry in a series of 96 Ewing sarcomas in a tissue microarray and investigated the association of the protein expression with the clinical parameters and overall survival. ResultsMore than half of the cases (51%, n ​= ​49) depicted positive nuclear brachyury expression, while a lack of expression was observed in 49% (n ​= ​47) of cases. Nuclear brachyury staining was significantly associated with non-white ethnicity (p ​= ​0.04) and axial localization (p ​= ​0.025). Importantly, lack of brachyury expression was significantly associated with lower overall survival in multivariate analyses (hazard ratio – HR: 2.227, p ​= ​0.008). ConclusionsOur findings indicate, that brachyury is an independent prognostic biomarker in Ewing sarcoma, which might suggest a tumor suppressor role and which yet to be fully elucidated.

Transfection of T-Box Transcription Factor BRACHYURY and SOX2 Synergistically Promote Self-Renewal and Invasive Phenotype in Oral Cancer Cells.

Recent studies suggest that epithelial–mesenchymal transition (EMT) correlates with cancer metastasis. In addition, there is growing evidence of the association of EMT with cancer stem cells (CSCs). Recently, we showed that the T-box transcription factor BRACHYURY could be a strong regulator of EMT and the CSC phenotype, which were effectively suppressed by a BRACHYURY knockdown in an adenoid cystic carcinoma cell line. In this study, we further tested whether BRACHYURY is a regulator of cancer stemness by means of forced expression of BRACHYURY in oral cancer cell lines. BRACHYURY, SOX2, or both were stably transfected into oral carcinoma cell lines. We analysed these transfectants with respect to self-renewal phenotypes using a sphere-formation assay, and we assessed the expression levels of EMT markers and stem cell markers using real-time reverse transcription-polymerase chain reaction (RT-PCR). Cell migration and invasiveness in vitro were evaluated using a wound healing assay and a tumour cell dissemination assay, respectively. Forced expression of BRACHYURY or SOX2 slightly increased expression of EMT and stem cell markers and the self-renewal phenotype. The expression levels, however, were much lower compared to those of cancer stem cell-like cells. Forced co-expression of BRACHYURY and SOX2 strongly upregulated EMT and stem cell markers and the self-renewal phenotype. Cell migration and invasiveness in vitro were also remarkably enhanced. These synergistic effects increased expression levels of FIBRONECTIN, SNAIL, SLUG, ZEB1, and TGF-β2. In particular, the effects on FIBRONECTIN and TGF-β2 were significant. We found that BRACHYURY and SOX2 synergistically promote cancer stemness in oral cancer cells. This finding points to the importance of gene or protein networks associated with BRACHYURY and SOX2 in the development and maintenance of the CSC phenotype.

Penaeid shrimp brachyury: sequence analysis and expression during gastrulation.

Gastrulation occurs by a variety of morphogenetic movements, often correlated with diverse expression of the T-box transcription factor Brachyury (Bra). Bra may be expressed in ectoderm, mesoderm, or endoderm, but its role in cell fate specification or regulation of gastrulation movements has not been studied in the development of crustaceans. Penaeid shrimp (Decapoda: Dendrobranchiata: Penaeidae) develop by complete cleavage and gastrulation by invagination to a free-swimming nauplius larva. Penaeid gastrulation diverges from other decapods and from insects, occurring early at a low cell number with the formation of a radial invagination. Toward a better understanding of gastrulation movements in penaeid shrimp, bra was identified from newly available penaeid shrimp genomes and transcriptomes of Litopenaeus vannamei, Marsupenaeus japonicus, and Penaeus monodon. Additional bra homologs were obtained from the outgroups Sicyonia ingentis (Decapoda: Dendrobranchiata: Sicyoniidae) and the caridean shrimp Caridina multidentata (Decapoda: Pleocymata). The genes encoded penaeid shrimp Bra proteins of 551-552 amino acids, containing the highly conserved T-box DNA-binding region. The N-terminal Smad1-binding domain, conserved in most animals, was absent in shrimp Bra. The R1 repressor domain was the best conserved of the C-terminal regulatory domains, which were widely divergent compared to other species. The penaeid shrimp bra gene consisted of six exons, with splice sites conserved with other phyla across the animal kingdom. Real-time qPCR and FPKM analysis showed that shrimp bra mRNA was strongly expressed during gastrulation. These findings begin to address the evolution of gastrulation in shrimp at the molecular level.

Brachyury oncogene is a prognostic factor in high-risk testicular germ cell tumors.

The T-box transcription factor Brachyury has been considered a cancer-specific marker and a novel oncotarget in solid tumors. Brachyury overexpression has been described in various cancers, being associated with epithelial-mesenchymal transition, metastasis, and poor prognosis. However, its clinical association with testicular germ cell tumor is unknown. We analyzed the expression of Brachyury by immunohistochemistry in a series of well-characterized testicular germ cell tumor samples and at transcript level by in silico analysis. Additionally, we aimed to investigate the clinical significance of Brachyury in testicular germ cell tumor. Brachyury cytoplasm immunostaining was present in 89.6% (86/96) of cases with nuclear staining observed in 24% (23/96) of testicular germ cell tumor. Bioinformatics microarray expression analysis of two independent cohorts of testicular germ cell tumors showed similar results with increased levels of Brachyury in testicular germ cell tumors and metastasis compared with normal testis. Clinically, Brachyury nuclear staining was statistically associated with lower event-free survival (p=0.04) and overall survival (p=0.01) in intermediate/high-risk testicular germ cell tumors. Univariate analysis showed that Brachyury nuclear subcellular localization was a predictor of poor prognosis (p=0.02), while a tendency was observed by multivariate analysis (HR: 3.56, p=0.06). In conclusion, these results indicate that Brachyury plays an oncogenic role in testicular germ cell tumors and its subcellular localization in the nucleus may constitute a novel biomarker of poor prognosis and a putative oncotarget for intermediate/high-risk testicular germ cell tumor patients.

Abstract CN07-03: Brachyury and the interleukin-8 axis in tumor progression

Abstract Carcinomas exhibit remarkable plasticity and may undergo profound phenotypic changes during progression towards metastasis. These changes, collectively termed “carcinoma mesenchymalization,” involve the acquisition of mesenchymal features; invasiveness and propensity to disseminate; acquisition of stemness features, including a relatively quiescent state; and conversion into a refractory, therapy-resistant state. In search of drivers of the mesenchymalization phenomenon that could be targeted via immunotherapy, our laboratory previously identified the embryonic T-box transcription factor brachyury as a tumor-associated antigen that is highly expressed in various human carcinomas, including lung and triple-negative breast cancer and in the rare tumor type chordoma, among others. High brachyury levels at the primary tumor site have now been shown to associate with poor survival in patients with various cancer types. Two vector-based cancer vaccine platforms developed against brachyury, a yeast-brachyury and a poxvirus-based MVA-brachyury-TRICOM vaccine, have now completed phase I clinical evaluation, both demonstrating safety and the ability to significantly expand brachyury-specific CD4+ and CD8+ T cells in vaccinated patients. Based on evidence of clinical activity in patients with chordoma, the yeast-brachyury vaccine is currently being evaluated in a randomized, double-blind phase II study of radiation +/- vaccine in this rare tumor type. An emerging concept in the field of tumor immunology is that mesenchymalization may also confer resistance to antitumor immune responses. Our laboratory has shown that human carcinoma cells undergoing mesenchymalization exhibit decreased susceptibility to lysis mediated by immune effector cells, including antigen-specific CD8+ T cells, innate natural killer (NK) cells, and lymphokine-activated killer (LAK) cells. Based on these observations, we are currently investigating potential strategies aimed at blocking tumor microenvironment-derived signals that control phenotypic plasticity, with the ultimate goal of combining these approaches with immunotherapy. The chemokine interleukin-8 (IL-8) is overexpressed in multiple cancer types, where it promotes the acquisition of mesenchymal features, stemness, resistance to therapies, and the recruitment of immune-suppressive cells to the tumor site. We have now shown that blockade of the IL-8/IL-8R axis is effective at reverting the phenotype of the tumor cells towards a more epithelial one, decreasing stemness features, and significantly enhancing tumor sensitivity to chemotherapy, small-molecule targeted therapies, and immune-mediated lysis with NK and antigen-specific T cells in vitro. These results formed the rationale for using anti-IL8 approaches in combination with cytotoxic or immune-based therapies for the treatment of advanced cancer. Citation Format: Claudia Palena, James L. Gulley, Jeffrey Schlom. Brachyury and the interleukin-8 axis in tumor progression [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr CN07-03.

Brachyury, a driver of epithelial mesenchymal transition, as an independent prognostic factor in high-grade testicular germ cell tumors.

e16039 Background: The T-box transcription factor Brachyury has been considered a cancer-specific marker and a novel oncotarget in solid tumors. Brachyury overexpression has been described in various cancers, being associated with epithelial-mesenchymal transition, metastasis and poor prognosis. However, its clinical association with testicular germ cell tumor (TGCT) is unknown. Methods: We analyzed the expression of Brachyury both at protein and transcript levels in a series of 96 TGCT samples and by in silico analysis, respectively. Additionally, we investigated the clinical significance of Brachyury in TGCT. Results: Brachyury protein showed to be over-represented in 89.6% (86/96) of TGCT cases with nuclear staining in 24% (23/96) of them. Microarray expression analysis in two independent cohorts of TGCTs showed similar results with increased levels of Brachyury in TGCTs and metastasis compared with normal testis. Clinically, Brachyury nuclear staining was statistically associated with event-free survival (p = 0.04) and overall survival (p = 0.01) in intermediate/high-risk TGCTs. Multivariate analysis showed that Brachyury nuclear subcellular localization was an independent predictor of poor prognosis (HR: 3.56, p = 0.06). Conclusions: These results indicate that Brachyury plays an oncogenic role in TGCTs and its subcellular localization in the nucleus is a potential novel biomarker of poor prognosis and an oncotarget for intermediate/high-risk TGCTs treatment.

FGF and canonical Wnt signaling cooperate to induce paraxial mesoderm from tailbud neuromesodermal progenitors through regulation of a two-step epithelial to mesenchymal transition.

Mesoderm induction begins during gastrulation. Recent evidence from several vertebrate species indicates that mesoderm induction continues after gastrulation in neuromesodermal progenitors (NMPs) within the posteriormost embryonic structure, the tailbud. It is unclear to what extent the molecular mechanisms of mesoderm induction are conserved between gastrula and post-gastrula stages of development. Fibroblast growth factor (FGF) signaling is required for mesoderm induction during gastrulation through positive transcriptional regulation of the T-box transcription factor brachyury We find in zebrafish that FGF is continuously required for paraxial mesoderm (PM) induction in post-gastrula NMPs. FGF signaling represses the NMP markers brachyury (ntla) and sox2 through regulation of tbx16 and msgn1, thereby committing cells to a PM fate. FGF-mediated PM induction in NMPs functions in tight coordination with canonical Wnt signaling during the epithelial to mesenchymal transition (EMT) from NMP to mesodermal progenitor. Wnt signaling initiates EMT, whereas FGF signaling terminates this event. Our results indicate that germ layer induction in the zebrafish tailbud is not a simple continuation of gastrulation events.

Regulation of brachyury by fibroblast growth factor receptor 1 in lung cancer.

Recent evidence suggests that T-box transcription factor brachyury plays an important role in lung cancer development and progression. However, the mechanisms underlying brachyury-driven cellular processes remain unclear. Here we found that fibroblast growth factor receptor 1/mitogen-activated protein kinase (FGFR1/MAPK) signaling regulated brachyury in lung cancer. Analysis of FGFR1-4 and brachyury expression in human lung tumor tissue and cell lines found that only expression of FGFR1 was positively correlated with brachyury expression. Specific knockdown of FGFR1 by siRNA suppressed brachyury expression and epithelial–mesenchymal transition (EMT) (upregulation of E-cadherin and β-catenin and downregulation of Snail and fibronectin), whereas forced overexpression of FGFR1 induced brachyury expression and promoted EMT in lung cancer cells. Activation of fibroblast growth factor (FGF)/FGFR1 signaling promoted phosphorylated MAPK extracellular signal-regulated kinase (ERK) 1/2 translocation from cytoplasm to nucleus, upregulated brachyury expression, and increased cell growth and invasion. In addition, human lung cancer cells with higher brachyury expression were more sensitive to inhibitors targeting FGFR1/MAPK pathway. These findings suggest that FGFR1/MAPK may be important for brachyury activation in lung cancer, and this pathway may be an appealing therapeutic target for a subset of brachyury-driven lung cancer.

Abstract 2021: Identification of novel brachyury target genes in lung cancer

Abstract Lung cancer is the leading cause of cancer-related death worldwide. Previous studies have shown that the T-box transcription factor brachyury is commonly expressed in advanced lung cancer and is associated with a poor prognosis. The activation of brachyury promotes lung cancer progression, aggressiveness and resistance to conventional antitumor therapies. However, the mechanism by which brachyury drives lung cancer is unknown. Here we have sought to identify novel gene targets of brachyury to better understand the molecular pathogenesis of lung cancer. We used a bioinformatics approach and found a shortlist of putative potential brachyury target genes. We subsequently explored the modulation of candidate brachyury target genes in lung cancer. RNA interference analysis for lung cancer cell line H460 overexpressing brachyury demonstrated that fibroblast growth factor 8 (FGF8), MAS1 Proto-Oncogene G Protein-Coupled Receptor (MAS1) and Ran GTPase Activating Protein 1 (RANGAP1) played essential roles in cell growth, whereas transmembrane protein 37 (TMEM37) was involved in cell migration and invasion. ChIP-qPCR experiments confirmed the strong binding of brachyury to these functional target genes. Analysis of datasets derived from patients with lung cancer and a panel of lung cancer cell lines revealed that brachyury expression was positively correlated with FGF8, MAS1, RANGAP1 and TMEM37. In addition, the expression levels of FGF8, MAS1 and RANGAP1 were significantly associated with non-metastasis (early-stage and locally advanced lung cancer), whereas TMEM37 was associated with metastasis. Taken together, our findings suggest that brachyury may influence lung cancer progression and/or metastasis via direct regulation of FGF8, MAS1, RANGAP1 and TMEM37 expression. Identification of potential brachyury transcriptional targets provides novel insights into the molecular pathobiology of lung cancer. Citation Format: Yunping Hu, Wesley Hsu. Identification of novel brachyury target genes in lung cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2021.

Involvement of the T-box transcription factor Brachyury in early-stage embryonic mouse salivary gland

The mouse submandibular gland (SMG) is important organ for embryonic development, and branching morphogenesis is regulated by many molecules containing transcription factors. Real-time reverse transcriptase polymerase chain reaction revealed that the expression of Brachyury increased in the SMG and peaked between E12.5–E13.5, concomitant with the early stage of branching morphogenesis. The expression of Brachyury in SMG rudiments between E12.5–E13.5 was confirmed by western blotting. In addition, fibronectin and Btbd7 (regulated by fibronectin), which are both essential for cleft formation, were expressed strongly during the same period. The Sox2 and Wnt3a, which regulate cell growth, were also expressed strongly during E12.5–E13.5. On the other hand, cleft formation and branching morphogenesis was suppressed by knockdown of Brachyury gene, suggesting that Brachyury plays a central role in regulating cell growth and cleft formation in early-stage embryonic mouse salivary gland development.

A novel cold-sensitive mutant of ntla reveals temporal roles of brachyury in zebrafish.

With the exception of the head, the vertebrate embryonic body is formed progressively in an anterior-posterior direction, originating from a posteriorly located bipotential neural-mesodermal progenitor population. The T-box transcription factor Brachyury is expressed within the progenitors and is essential for the formation of the posterior mesoderm. A novel cold-sensitive mutant of Zebrafish Brachyury (ntla(cs) ) is described that allows exploration of the temporal role of this key factor. The ntla(cs) mutant is used to show that Ntla has an essential role during early gastrulation, but as gastrulation proceeds the importance of Ntla declines as Ntlb acquires a capacity to form the posterior mesoderm. Remarkably, ntla(cs) embryos held at the nonpermissive temperature just during the gastrula stages show recovery of normal levels of mesodermal gene expression, demonstrating the plasticity of the posterior progenitors. ntla(cs) is a valuable tool for exploring the processes forming the posterior body since it allows temporally specific activation and inactivation of Brachyury function. It is used here to show the changing roles of Ntla during early development and the dynamics of the neuromesodermal progenitors. Developmental Dynamics 245:874-880, 2016. © 2016 Wiley Periodicals, Inc.

T-boxtranscription factor brachyury promotes tumor cell invasion and metastasis in non-small cell lung cancer via upregulation of matrix metalloproteinase 12.

T-box transcription factor brachyury and matrix metalloproteinases (MMPs) play important roles in non-small cell lung cancer (NSCLC) cell invasion and metastasis. However, the association between Brachyury and the MMP family has not yet been fully investigated. The present study aimed to assess the influence of Brachyury on the expression of 23MMP members and to further explore the mechanisms involved in the promotion of NSCLC cell invasion by Brachyury and MMPs in the H460 and H1299 stable cell lines. The protein expression levels and correlations between the brachyury transcription factor and the targeted MMPs were also validated in 52NSCLC patient tissue samples. We observed that brachyury significantly upregulated MMP12 expression to promote NSCLC cell invasion. We also found a potential binding site for the brachyury transcription factor in the MMP12 promoter.

Abstract A42: MK-1775, a WEE1 inhibitor alleviates resistance to immune attack of tumor cells undergoing an epithelial-mesenchymal transition

Abstract The phenomenon of epithelial-mesenchymal transition (EMT) is a phenotypic switch that allows epithelial tumor cells to acquire features of mesenchymal cells, including the ability to migrate and invade and, therefore, to disseminate from the primary site. In addition to promoting tumor dissemination, various reports have demonstrated that acquisition of features of EMT associates with tumor resistance to the cytotoxic effects of chemotherapy, radiation, and some targeted therapies. It is not well understood, however, the contribution of EMT to the escape of tumors from host immune-surveillance and immune-mediated rejection. Our laboratory has characterized the T-box transcription factor brachyury as a tumor-associated antigen and a regulator of EMT in human carcinomas. By generating isogenic cancer cell lines with various levels of brachyury expression, we demonstrated that high levels of brachyury significantly reduce the susceptibility of cancer cells to lysis by both antigen-specific T cells and natural killer cells, and render tumor cells less responsive to a cancer vaccine in syngeneic murine tumor models. This resistance was due to inefficient caspase-dependent apoptosis, manifested as inefficient nuclear lamin degradation in the presence of activated effector caspases. We correlated this phenomenon to loss of cell cycle kinase CDK1, which mediates lamin phosphorylation. In support of a causal connection, pre-treatment of tumor cells with MK-1775, a specific inhibitor of WEE1, which is known to be a negative regulator kinase of CDK1 activity, could counter the defective apoptosis of tumor cells expressing high levels of brachyury. Thus, our findings suggest reconstituting CDK1 activity to threshold levels might be sufficient to elevate immune-mediated lysis of mesenchymal-like cancer cells, and improve the efficacy of anti-tumor vaccines. Citation Format: Duane H. Hamilton, Romaine I. Fernando, Kwong-Yok Tsang, Claudia Palena. MK-1775, a WEE1 inhibitor alleviates resistance to immune attack of tumor cells undergoing an epithelial-mesenchymal transition. [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy: A New Chapter; December 1-4, 2014; Orlando, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2015;3(10 Suppl):Abstract nr A42.

The embryonic Brachyury transcription factor is a novel biomarker of GIST aggressiveness and poor survival.

The T-box transcription factor Brachyury was recently reported to be upregulated and associated with prognosis in solid tumors. Here, we proposed to evaluate the potential use of Brachyury protein expression as a new prognostic biomarker in gastrointestinal stromal tumors (GIST). Brachyury protein expression was analyzed by immunohistochemistry in a cohort of 63 bona fide GIST patients. Brachyury expression profiles were correlated with patients' clinicopathological features and prognostic impact. Additionally, an in silico analysis was performed using the Oncomine database to assess Brachyury alterations at DNA and mRNA levels in GISTs. We found that Brachyury was overexpressed in the majority (81.0 %) of primary GISTs. We observed Brachyury staining in the nucleus alone in 4.8 % of cases, 23.8 % depicted only cytoplasm staining, and 52.4 % of cases exhibited both nucleus and cytoplasm immunostaining. The presence of Brachyury was associated with aggressive GIST clinicopathological features. Particularly, Brachyury nuclear (with or without cytoplasm) staining was associated with the presence of metastasis, while cytoplasm sublocalization alone was correlated with poor patient survival. Herein, we demonstrate that Brachyury is overexpressed in GISTs and is associated with worse outcome, constituting a novel prognostic biomarker and a putative target for GIST treatment.

T-box transcription factor Brachyury in lung cancer cells inhibits macrophage infiltration by suppressing CCL2 and CCL4 chemokines.

Both intra-tumor macrophage and T-box transcription factor Brachyury (T) have been proved to play important roles in tumor progression and metastasis. However, it is still unknown whether T could regulate the infiltration of macrophages. Here, we report that the Brachyury expression in human lung tumors was inversely correlated with the infiltration of macrophages. Brachyury suppressed the capability of human lung cancer cells to attract macrophages. Using PCR array, we found that Brachyury inhibited expression of several chemokines, including CCL2, CCL4, and CXCL10. Accordingly, knockdown of CCL2 and CCL4 in lung cancer cells suppressed macrophage invasion under coculture conditions. Furthermore, we found that Brachyury expression was inversely correlated with CCL2 and CCL4 expression in human lung tumors. Taken together, our findings shed light on the novel role of Brachyury in regulation of macrophage infiltration.

Immune Targeting of Tumor Epithelial-Mesenchymal Transition via Brachyury-Based Vaccines.

As a manifestation of their inherent plasticity, carcinoma cells undergo profound phenotypic changes during progression toward metastasis. One such phenotypic modulation is the epithelial-mesenchymal transition (EMT), an embryonically relevant process that can be reinstated by tumor cells, resulting in the acquisition of metastatic propensity, stem-like cell properties, and resistance to a variety of anticancer therapies, including chemotherapy, radiation, and some small-molecule targeted therapies. Targeting of the EMT is emerging as a novel intervention against tumor progression. This review focuses on the potential use of cancer vaccine strategies targeting tumor cells that exhibit mesenchymal-like features, with an emphasis on the current status of development of vaccine platforms directed against the T-box transcription factor brachyury, a novel cancer target involved in tumor EMT, stemness, and resistance to therapies. Also presented is a summary of potential mechanisms of resistance to immune-mediated attack driven by EMT and the development of novel combinatorial strategies based on the use of agents that alleviate tumor EMT for an optimized targeting of plastic tumor cells that are responsible for tumor recurrence and the establishment of therapeutic refractoriness.

The T-box transcription factor Brachyury promotes renal interstitial fibrosis by repressing E-cadherin expression.

BackgroundEpithelial-to-mesenchymal transition (EMT) induced by TGF-β1 is one of well-recognized factors contributing to renal fibrosis. However, the underlying molecular mechanisms of EMT are not fully understood. Brachyury, an evolutionarily conserved transcription factor, was recently identified as an important factor promoting EMT in human carcinoma cell lines. There is no evidence that Brachyury is involved in renal tubular EMT.ResultsOur results demonstrated that Brachyury was prominently induced in TGF-β1-treated human proximal tubular epithelial (HK-2) cells and that this induction was accompanied by changes characteristic of EMT. Blockage of Brachyury expression by short interfering RNA (siRNA) in HK-2 cells effectively reversed the TGF-β1-induced EMT phenotype. Brachyury induction repressed E-cadherin transcription; the E-cadherin promoter contains a Brachyury binding site, and decreased expression of E-cadherin occurred in Brachyury-overexpressing cells when they were transfected with reporter constructs using the promoter. This effect was partially mediated by Slug and Snail, as knockdown of Snail and Slug by siRNA effectively reversed Brachyury-mediated EMT and partially restored E–cadherin expression. The expression of Brachyury also presented in a rat model of obstructive nephropathy and in tubulointerstitial fibrosis tissues of IgA nephropathy, suggesting that it may have a role in EMT and renal fibrosis in vivo.ConclusionOur results demonstrate for the first time that Brachyury plays an important role in regulating TGF-β1–mediated renal EMT and could be an attractive target for progression of renal disease therapies.

T-box transcription factor brachyury is associated with prostate cancer progression and aggressiveness.

Successful therapy of patients with prostate cancer is highly dependent on reliable diagnostic and prognostic biomarkers. Brachyury is considered a negative prognostic factor in colon and lung cancer; however, there are no reports on Brachyury's expression in prostate cancer. In this study, we aimed to assess the impact of Brachyury expression in prostate tumorigenesis using a large series of human prostate samples comprising benign tissue, prostate intraepithelial neoplasia (PIN) lesions, localized tumor, and metastatic tissues. The results obtained were compared with what can be inferred from the Oncomine database. In addition, multiple in vitro models of prostate cancer were used to dissect the biologic role of Brachyury in prostate cancer progression. We found that Brachyury is significantly overexpressed in prostate cancer and metastatic tumors when compared with normal tissues, both at protein and at mRNA levels. Brachyury expression in the cytoplasm correlates with highly aggressive tumors, whereas the presence of Brachyury in the nucleus is correlated with tumor invasion. We found that Brachyury-positive cells present higher viability, proliferation, migration, and invasion rates than Brachyury-negative cells. Microarray analysis further showed that genes co-expressed with Brachyury are clustered in oncogenic-related pathways, namely cell motility, cell-cycle regulation, and cell metabolism. Collectively, the present study suggests that Brachyury plays an important role in prostate cancer aggressiveness and points, for the first time, to Brachyury as a significant predictor of poor prostate cancer prognosis. Our work paves the way for future studies assessing Brachyury as a possible prostate cancer therapeutic target.