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1.
J Wound Care ; 28(9): 564-565, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31513490
3.
Sci Rep ; 9(1): 13461, 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31530872

RESUMO

The importance of the human-microbiome relationship for positive health outcomes has become more apparent over the last decade. Influencing the gut microbiome via modification of diet represents a possibility of maintaining a healthy gut flora. Fermented food and lactic acid bacteria (LAB) display a preventive way to inhibit microbial dysbioses and diseases, but their ecology on plants is poorly understood. We characterized the microbiome of medicinal plants (Matricaria chamomilla L. and Calendula officinalis L.) using 16S rRNA gene profiling from leaves that were fermented over a six-week time course. The unfermented samples were characterized by a distinct phyllosphere microbiome, while the endosphere revealed a high similarity. During fermentation, significant microbial shifts were observed, whereby LAB were enhanced in all approaches but never numerically dominated. Among the LAB, Enterococcaceae were identified as the most dominant family in both plants. M. chamomilla community had higher relative abundances of Lactobacillaceae and Carnobacteriaceae, while C. officinalis showed a higher presence of Leuconostocaceae and Streptococcaceae. The natural leaf microbiome and the indigenous LAB communities of field-grown Asteraceae medicinal plants are plant-specific and habitat-specific and are subjected to significant shifts during fermentation. Leaf surfaces as well as leaf endospheres were identified as sources for biopreservative LAB.

4.
Clin Cancer Res ; 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363002

RESUMO

Lineage plasticity has emerged as an important mechanism of treatment resistance in prostate cancer (PC). Treatment refractory PCs are increasingly associated with loss of luminal prostate markers, and in many cases induction of developmental programs, stem cell-like phenotypes, and neuroendocrine/neuronal features. Clinically, lineage plasticity may manifest as low prostate specific antigen (PSA) progression, resistance to AR pathway inhibitors, and sometimes small cell/neuroendocrine pathologic features observed on metastatic biopsy. This mechanism is not restricted to prostate cancer as other malignancies also demonstrate lineage plasticity during resistance to targeted therapies. At present, there is no established therapeutic approach for patients with advanced prostate cancer developing lineage plasticity or small cell/neuroendocrine prostate cancer (NEPC) due to knowledge gaps in the underlying biology, few clinical trials address questions in this space, and the outlook for patients remains poor. To move forward, urgently needed are: (i) a fundamental understanding of how lineage plasticity occurs and how it can best be defined; (ii) the temporal contribution and cooperation of emerging drivers; (iii) preclinical models that recapitulate biology of the disease and the recognized phenotypes; (iv) identification of therapeutic targets; and (v) novel trial designs dedicated to the entity as it is defined. This Perspective represents a consensus arising from the National Cancer Institute (NCI) Workshop on Lineage Plasticity and Androgen Receptor-Independent Prostate Cancer. We focus on the critical questions underlying lineage plasticity and AR-independent prostate cancer, outline knowledge and resource gaps, and identify strategies to facilitate future collaborative clinical translational and basic studies in this space.

5.
Pancreas ; 48(8): 1086-1091, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31404024

RESUMO

OBJECTIVES: The appropriate timing of chemotherapy following surgery for resectable pancreatic adenocarcinoma is controversial. Using the National Cancer Database we evaluated time to initiation of chemotherapy postresection and correlated with outcome. METHODS: We identified stage I-III pancreatic adenocarcinoma treated surgically with adjuvant chemoradiotherapy. Receiver operator curve analysis identified an interval of 66 days as the a priori value for largest discrepancy in outcome. Multivariable logistic regression analysis identified variables associated with increased time to chemotherapy postoperatively (>66 days). Propensity matching was performed to account for indication bias. RESULTS: In total, 6873 and 3348 patients received chemotherapy before and after the 66-day cutoff, respectively. Predictors of expedited chemotherapy included lower comorbidity, treatment outside a community program in an urban location, having insurance, white race, and treatment after 2009. Propensity-matched median survival was 21.8 months for all patients, and of these, 6462 were stage 1. Five-year survival was 20% in patients receiving chemotherapy within 66 days and 18% in those not (P = 0.0266). In stage 1 patients, 5-year survival was 23% versus 21% (P = 0.0116) in favor of expedited chemotherapy. CONCLUSIONS: The present propensity-matched analysis showed a significant association with survival for earlier delivery of chemotherapy in the adjuvant setting.

6.
PLoS One ; 14(8): e0221015, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31419245

RESUMO

INTRODUCTION: There is evidence demonstrating that certain lifestyle factors have a detrimental effect on fertility. Since such factors often coexist, possible synergistic effects merit further investigation. Thus we aimed to examine the cumulative impact of lifestyle factors on in vitro fertilization (IVF) early reproductive treatment outcomes and their interaction with measures of ovarian reserve. MATERIALS AND METHODS: By following women who were starting their first fresh IVF cycle in 2 cohorts, the "Lifestyle study cohort" (hypothesis generating cohort, n = 242) and the "UppSTART study" (validation cohort, n = 432) in Sweden, we identified two significant risk factors acting independently, smoking and BMI, and then further assessed their cumulative effects. RESULTS: Women with both these risk factors had an Incidence Rate Ratio (IRR) of 0.75 [(95% CI 0.61-0.94)] regarding the number of aspirated oocytes compared to women without these risk factors. Concerning the proportion of mature oocytes in relation to the total number of aspirated oocytes, the interaction between BMI and Antral Follicle Count (AFC) was significant (p-value 0.045): the lower the value of AFC, the more harmful the effect of BMI with the outcome. CONCLUSIONS: Data shows that there is an individual as well as a cumulative effect of smoking and BMI on the number of aspirated and mature oocytes in fresh IVF treatment cycles. AFC might modify associations between BMI and the proportion of mature oocytes in relation to the total number of aspirated oocytes. These results highlight the importance of lifestyle factors on IVF early reproductive outcomes and provide additional evidence for the importance of preconception guidance for the optimization of IVF cycle outcome.

7.
BMC Med ; 17(1): 163, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31422772

RESUMO

BACKGROUND: Despite the increasing popularity of multi-model comparison studies and their ability to inform policy recommendations, clear guidance on how to conduct multi-model comparisons is not available. Herein, we present guidelines to provide a structured approach to comparisons of multiple models of interventions against infectious diseases. The primary target audience for these guidelines are researchers carrying out model comparison studies and policy-makers using model comparison studies to inform policy decisions. METHODS: The consensus process used for the development of the guidelines included a systematic review of existing model comparison studies on effectiveness and cost-effectiveness of vaccination, a 2-day meeting and guideline development workshop during which mathematical modellers from different disease areas critically discussed and debated the guideline content and wording, and several rounds of comments on sequential versions of the guidelines by all authors. RESULTS: The guidelines provide principles for multi-model comparisons, with specific practice statements on what modellers should do for six domains. The guidelines provide explanation and elaboration of the principles and practice statements as well as some examples to illustrate these. The principles are (1) the policy and research question - the model comparison should address a relevant, clearly defined policy question; (2) model identification and selection - the identification and selection of models for inclusion in the model comparison should be transparent and minimise selection bias; (3) harmonisation - standardisation of input data and outputs should be determined by the research question and value of the effort needed for this step; (4) exploring variability - between- and within-model variability and uncertainty should be explored; (5) presenting and pooling results - results should be presented in an appropriate way to support decision-making; and (6) interpretation - results should be interpreted to inform the policy question. CONCLUSION: These guidelines should help researchers plan, conduct and report model comparisons of infectious diseases and related interventions in a systematic and structured manner for the purpose of supporting health policy decisions. Adherence to these guidelines will contribute to greater consistency and objectivity in the approach and methods used in multi-model comparisons, and as such improve the quality of modelled evidence for policy.

8.
J Diabetes Complications ; 33(10): 107405, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31405797

RESUMO

OBJECTIVE: Depression is common in patients with type 2 diabetes and associated with poor diabetes-related outcomes. We evaluated the factors associated with antidepressant use in a low-income, racially and ethnically diverse sample of patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: We performed a cross-sectional study of baseline data from participants in a cluster randomized trial evaluating a health literacy intervention for diabetes care in safety net clinics. Depressive symptoms were measured by the Center for Epidemiological Studies Depression Scale (CES-D); antidepressant use was abstracted from medication lists. Multivariable mixed effects logistic regression was used to evaluate the relationship between antidepressant use and race/ethnicity adjusting for depressive symptoms, age, gender, income, and health literacy. RESULTS: Of 403 participants, 58% were non-Hispanic White, 18% were non-Hispanic Black, and 24% were Hispanic. Median age was 51 years old; 60% were female, 52% of participants had a positive screen for depression, and 18% were on antidepressants. Black and Hispanic participants were significantly less likely to be on an antidepressant compared with white participants, adjusted odds ratios 0.31(95% CI: 0.12 to 0.80) and 0.26 (95% CI: 0.10 to 0.74), respectively. CONCLUSIONS: In this vulnerable population with type 2 diabetes, we found a high prevalence of depressive symptoms, and a small proportion of participants were on an antidepressant. Black and Hispanic participants were significantly less likely to be treated with an antidepressant. Our findings suggest depression may be inadequately treated in low-income, uninsured patients with type 2 diabetes, especially racial and ethnic minorities.

9.
Sci Rep ; 9(1): 11126, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31366947

RESUMO

Achieving the WHO End-Tuberculosis (TB) targets requires approaches to prevent progression to TB among individuals with Mycobacterium tuberculosis (M.tb) infection. Effective preventive therapy (PT) exists, but current tests have low specificity for identifying who, among those infected, is at risk of developing TB. Using mathematical models, we assessed the potential population-level impact on TB incidence of using a new more specific mRNA expression signature (COR) to target PT among HIV-uninfected adults in South Africa. We compared the results to the use of the existing interferon-γ release assay (IGRA). With annual screening coverage of 30% COR-targeted PT could reduce TB incidence in 2035 by 20% (95% CI 15-27). With the same coverage, IGRA-targeted PT could reduce TB incidence by 39% (31-48) but would require greater use of PT resulting in a higher number needed to treat per TB case averted (COR: 49 (29-77); IGRA: 84 (59-123)). The relative differences between COR and IGRA were not sensitive to screening coverage. COR-targeted PT could contribute to reducing total TB burden in high incidence countries like South Africa by allowing more efficient targeting of treatment. To maximise impact, COR-like tests may be best utilised in the highest burden regions, or sub-populations, within these countries.

10.
Am Surg ; 85(7): 690-694, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31405409

RESUMO

Some authors report that patients receiving neoadjuvant chemotherapy have fewer lymph nodes harvested during axillary dissection and more dissections with < 10 nodes compared with patients who undergo surgery initially. We sought to determine whether there was a difference between these patient groups in terms of number of nodes harvested and number of dissections with < 10 nodes. Retrospective review of 258 patients diagnosed with breast cancer who underwent an axillary lymph node dissection between July 1, 2015, and December 31, 2017 was performed. Chi-squared test was used to assess differences between patient groups. Of 258 patients undergoing dissection, 48 per cent received neoadjuvant chemotherapy; 52 per cent underwent surgery as first therapeutic intervention. Mean number of nodes resected; 14.3 + 6.3 for patients with no prior chemotherapy versus 14.9 + 6.6 for patients with neoadjuvant chemotherapy (P = 0.48). For patients undergoing surgery as first intervention, 21 per cent had < 10 nodes harvested. For patients receiving neoadjuvant chemotherapy, 20 per cent had < 10 nodes harvested. Patients who received neoadjuvant chemotherapy showed no statistically significant difference in the number of lymph nodes harvested during axillary dissection compared with patients undergoing surgery as first intervention. Neoadjuvant chemotherapy does not reduce the node harvest at the time of axillary dissection.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Excisão de Linfonodo/estatística & dados numéricos , Linfonodos/patologia , Terapia Neoadjuvante , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos
11.
Br J Nurs ; 28(15): S4, 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31393757
12.
Infect Immun ; 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31405960

RESUMO

It was previously determined that the type II secretion system (T2SS) promotes the ability of Legionella pneumophila to grow in co-culture with amoebae. Here, we discerned the stage of intracellular infection that is potentiated, by comparing the wild-type and T2SS mutant legionellae for their capacity to parasitize Acanthamoeba castellanii Whereas the mutant behaved normally for entry into the host cells and subsequent evasion of degradative lysosomes, it was impaired in the ability to replicate, with that defect being first evident at approx. 9 h post-entry. The replication defect was initially documented in three ways; i.e., determining the numbers of CFU recovered from the lysates of the infected monolayers, monitoring the levels of fluorescence associated with amoebal monolayers infected with GFP-expressing bacteria, and utilizing flow cytometry to quantitate the amounts of GFP-expressing bacteria in individual amoebae. By employing confocal microscopy and newer imaging techniques, we further determined the progression in volume and shape of the bacterial vacuoles and found that the T2SS mutant grows at a decreased rate and does not attain maximally-sized phagosomes. Overall, the entire infection cycle (i.e., entry to egress) was considerably slower for the T2SS mutant than it was for the wild-type strain, and the mutant's defect was maintained over multiple rounds of infection. Thus, the T2SS is absolutely required for L. pneumophila to grow to larger numbers in its intravacuolar niche within amoebae. Combining these results with those of our recent analysis of macrophage infection, T2SS is clearly a major component of L. pneumophila intracellular infection.

13.
Ann Surg Oncol ; 26(12): 3874-3882, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31342378

RESUMO

INTRODUCTION: The role of sentinel lymph node biopsy (SLNB) when ductal carcinoma in situ with microinvasion (DCISM) is identified on core biopsy is unclear. OBJECTIVE: Our aim was to assess the upstage rate to invasive cancer and axillary lymph node metastasis in patients diagnosed with DCISM, and whether predictive variables could be identified that may help inform who would most likely benefit from a surgical axillary evaluation. METHODS: We performed a retrospective review of 70 patients diagnosed with DCISM on core biopsy. Patients with concomitant or prior invasive cancer were excluded. Demographic, clinical, radiographic, histologic, and treatment data were collected. Fisher's exact test and univariable and multivariable logistic regression were performed to identify variables that may be associated with tumor upstaging and nodal metastasis. Time-to-event distributions were summarized using the Kaplan-Meier method. RESULTS: On final surgical pathology, 49 patients (70%) had a final diagnosis of DCISM or T1mi cancer, whereas 21 patients (30%) were upstaged to measurable invasive cancer (> 1 mm). One of 49 patients (2%) with DCISM on final pathology and 4 of 21 patients (19%) with measurable invasive cancer showed sentinel lymph node metastases. CONCLUSION: Although the upstage rate to measurable invasive cancer in our cohort of patients with DCISM on core biopsy was 30%, findings of a positive SLNB remain low at 7%. No predictive variables were identified to inform whether the routine practice of SLNB may be omitted in some patients with DCISM.

14.
PLoS Genet ; 15(6): e1008213, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31199790

RESUMO

The neural crest (NC) is a vertebrate-specific cell type that contributes to a wide range of different tissues across all three germ layers. The gene regulatory network (GRN) responsible for the formation of neural crest is conserved across vertebrates. Central to the induction of the NC GRN are AP-2 and SoxE transcription factors. NC induction robustness is ensured through the ability of some of these transcription factors to compensate loss of function of gene family members. However the gene regulatory events underlying compensation are poorly understood. We have used gene knockout and RNA sequencing strategies to dissect NC induction and compensation in zebrafish. We genetically ablate the NC using double mutants of tfap2a;tfap2c or remove specific subsets of the NC with sox10 and mitfa knockouts and characterise genome-wide gene expression levels across multiple time points. We find that compensation through a single wild-type allele of tfap2c is capable of maintaining early NC induction and differentiation in the absence of tfap2a function, but many target genes have abnormal expression levels and therefore show sensitivity to the reduced tfap2 dosage. This separation of morphological and molecular phenotypes identifies a core set of genes required for early NC development. We also identify the 15 somites stage as the peak of the molecular phenotype which strongly diminishes at 24 hpf even as the morphological phenotype becomes more apparent. Using gene knockouts, we associate previously uncharacterised genes with pigment cell development and establish a role for maternal Hippo signalling in melanocyte differentiation. This work extends and refines the NC GRN while also uncovering the transcriptional basis of genetic compensation via paralogues.

15.
Microb Genom ; 5(6)2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31166887

RESUMO

The type II secretion system (T2SS) plays a major role in promoting bacterial survival in the environment and in human hosts. One of the best characterized T2SS is that of Legionella pneumophila, the agent of Legionnaires' disease. Secreting at least 25 proteins, including degradative enzymes, eukaryotic-like proteins and novel effectors, this T2SS contributes to the ability of L. pneumophila to grow at low temperatures, infect amoebal and macrophage hosts, damage lung tissue, evade the immune system, and undergo sliding motility. The genes encoding the T2SS are conserved across the genus Legionella, which includes 62 species and >30 pathogens in addition to L. pneumophila. The vast majority of effectors associated with L. pneumophila are shared by a large number of Legionella species, hinting at a critical role for them in the ecology of Legionella as a whole. However, no other species has the same repertoire as L. pneumophila, with, as a general rule, phylogenetically more closely related species sharing similar sets of effectors. T2SS effectors that are involved in infection of a eukaryotic host(s) are more prevalent throughout Legionella, indicating that they are under stronger selective pressure. The Legionella T2SS apparatus is closest to that of Aquicella (another parasite of amoebae), and a significant number of L. pneumophila effectors have their closest homologues in Aquicella. Thus, the T2SS of L. pneumophila probably originated within the order Legionellales, with some of its effectors having arisen within that Aquicella-like progenitor, while other effectors derived from the amoebal host, mimiviruses, fungi and less closely related bacteria.

17.
Infect Immun ; 87(9)2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31235638

RESUMO

Stenotrophomonas maltophilia is an emerging opportunistic and nosocomial pathogen. S. maltophilia is also a risk factor for lung exacerbations in cystic fibrosis patients. S. maltophilia attaches to various mammalian cells, and we recently documented that the bacterium encodes a type II secretion system which triggers detachment-induced apoptosis in lung epithelial cells. We have now confirmed that S. maltophilia also encodes a type IVA secretion system (VirB/VirD4 [VirB/D4] T4SS) that is highly conserved among S. maltophilia strains and, looking beyond the Stenotrophomonas genus, is most similar to the T4SS of Xanthomonas To define the role(s) of this T4SS, we constructed a mutant of strain K279a that is devoid of secretion activity due to loss of the VirB10 component. The mutant induced a higher level of apoptosis upon infection of human lung epithelial cells, indicating that a T4SS effector(s) has antiapoptotic activity. However, when we infected human macrophages, the mutant triggered a lower level of apoptosis, implying that the T4SS also elaborates a proapoptotic factor(s). Moreover, when we cocultured K279a with strains of Pseudomonas aeruginosa, the T4SS promoted the growth of S. maltophilia and reduced the numbers of heterologous bacteria, signaling that another effector(s) has antibacterial activity. In all cases, the effect of the T4SS required S. maltophilia contact with its target. Thus, S. maltophilia VirB/D4 T4SS appears to secrete multiple effectors capable of modulating death pathways. That a T4SS can have anti- and prokilling effects on different targets, including both human and bacterial cells, has, to our knowledge, not been seen before.

18.
Cancer Med ; 8(8): 3855-3863, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31173487

RESUMO

IMPORTANCE: Primary Adenocarcinoma of the anus is a rare disease with a poor prognosis and thus tends to have a more aggressive treatment algorithm, typically involving a surgical approach. Prior to 2001, a few retrospective studies outlined improved outcomes with the incorporation of surgery with chemoradiation. However, since the publication of these studies, advancement in radiotherapy modalities and imaging have left the question of improved outcomes while reserving surgery for salvage. OBJECTIVE: We conducted this National Cancer Database (NCDB)-driven retrospective study to analyze treatment trends and outcomes in the current time from 2004 to 2015 with respect to chemoradiation and surgery. DESIGN: Retrospective NCDB tumor registry data review-using propensity score-adjusted multivariable analyses for survival. SETTING: Database review. PARTICIPANTS: We selected for patients listed in the NCDB with AJCC stage 1-3 anal adenocarcinoma diagnosed between 2004 and 2015 and selected out patients with undocumented/stage 4 disease, those with radiation outside the pelvis, not treated with systemic therapy and patients lost to follow-up. EXPOSURE(S): None. MAIN OUTCOMES AND MEASURES: Overall survival and use of surgery in the up-front management of anal adenocarcinoma. RESULTS: Of the 1729 patients eligible in this study, 1028 were treated with surgery as up-front management and 701 had definitive chemoradiation. Median overall survival for all patients was 55 months with a 5-year survival rate of 55%. Patients treated without surgery had worse overall survival, median survival of 45 months compared to 87 months (P < 0.0001) with 5-year survival rates of 42% and 55% in favor of incorporation of surgery. Analysis across patients treated with surgery alone, surgery followed by adjuvant chemoradiation, neoadjuvant chemoradiation followed by surgery, and chemoradiation alone had median survival rates of 78, 83, 92, and 46 months, respectively. Propensity score-adjusted multivariable analysis identified older age, grade 3, high comorbidity score, and lack of surgery as predictive of worse outcome. CONCLUSIONS AND RELEVANCE: The results of the NCDB analysis indicate improved overall survival with the incorporation of surgery into the initial management of anal adenocarcinoma when compared to chemoradiation alone, despite the omission of surgery in up to 50% of the cases logged. Our results corroborate earlier studies published prior to the year 2000 for surgery to be included in the definitive management of anal adenocarcinoma.

19.
Nat Commun ; 10(1): 2792, 2019 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-31243271

RESUMO

The Deciphering the Mechanisms of Developmental Disorders programme has analysed the morphological and molecular phenotypes of embryonic and perinatal lethal mouse mutant lines in order to investigate the causes of embryonic lethality. Here we show that individual whole-embryo RNA-seq of 73 mouse mutant lines (>1000 transcriptomes) identifies transcriptional events underlying embryonic lethality and associates previously uncharacterised genes with specific pathways and tissues. For example, our data suggest that Hmgxb3 is involved in DNA-damage repair and cell-cycle regulation. Further, we separate embryonic delay signatures from mutant line-specific transcriptional changes by developing a baseline mRNA expression catalogue of wild-type mice during early embryogenesis (4-36 somites). Analysis of transcription outside coding sequence identifies deregulation of repetitive elements in Morc2a mutants and a gene involved in gene-specific splicing. Collectively, this work provides a large scale resource to further our understanding of early embryonic developmental disorders.


Assuntos
Embrião de Mamíferos/metabolismo , Análise de Sequência de RNA , Transcrição Genética , Animais , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Mutação , Transcriptoma
20.
Dis Model Mech ; 12(7)2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31221659

RESUMO

The aberrant activation of developmental processes triggers diverse cancer types. Chordoma is a rare, aggressive tumor arising from transformed notochord remnants. Several potentially oncogenic factors have been found to be deregulated in chordoma, yet causation remains uncertain. In particular, sustained expression of TBXT - encoding the notochord regulator protein brachyury - is hypothesized as a key driver of chordoma, yet experimental evidence is absent. Here, we employ a zebrafish chordoma model to identify the notochord-transforming potential of implicated genes in vivo We find that Brachyury, including a form with augmented transcriptional activity, is insufficient to initiate notochord hyperplasia. In contrast, the chordoma-implicated receptor tyrosine kinases (RTKs) EGFR and Kdr/VEGFR2 are sufficient to transform notochord cells. Aberrant activation of RTK/Ras signaling attenuates processes required for notochord differentiation, including the unfolded protein response and endoplasmic reticulum stress pathways. Our results provide the first in vivo evidence against a tumor-initiating potential of Brachyury in the notochord, and imply activated RTK signaling as a possible initiating event in chordoma. Furthermore, our work points at modulating endoplasmic reticulum and protein stress pathways as possible therapeutic avenues against chordoma.

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