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BACKGROUND: Patients with detectable ctDNA after radical-intent treatment of metastatic spread from colorectal cancer (mCRC) have a very high risk of recurrence, which may be prevented with intensified adjuvant chemotherapy (aCTh). In the OPTIMISE study, we investigate ctDNA-guided aCTh after radical-intent treatment of mCRC. Here we present results from the preplanned interim analysis. MATERIAL AND METHODS: The study is an open-label 1:1 randomized clinical trial comparing ctDNA-guided aCTh against standard of care (SOC), with a run-in phase investigating feasibility measures. Key inclusion criteria; radical-intent treatment for mCRC and clinically eligible for triple-agent chemotherapy. Patients underwent a PET-CT scan before randomization. ctDNA analyses of plasma samples were done by ddPCR, detecting CRC-specific mutations and methylation of the NPY gene. In the ctDNA-guided arm, ctDNA positivity led to an escalation strategy with triple-agent chemotherapy, and conversely ctDNA negativity led to a de-escalation strategy by shared-decision making. Patients randomized to the standard arm were treated according to SOC. Feasibility measures for the run-in phase were; the inclusion of 30 patients over 12 months in two Danish hospitals, compliance with randomization >80%, rate of PET-CT-positive findings <20%, and eligibility for triple-agent chemotherapy >80%. RESULTS: Thirty-two patients were included. The rate of PET-CT-positive cases was 22% (n = 7/32). Ninety-seven percent of the patients were randomized. Fourteen patients were randomly assigned to SOC and sixteen to ctDNA-guided adjuvant treatment and follow-up. All analyses of baseline plasma samples in the ctDNA-guided arm passed the quality control, and 19% were ctDNA positive. The median time to result was three working days. All ctDNA-positive patients were eligible for triple-agent chemotherapy. CONCLUSION: The study was proven to be feasible and continues in the planned large-scale phase II trial. Results from the OPTIMISE study will potentially optimize the adjuvant treatment of patients undergoing radical-intent treatment of mCRC, thereby improving survival and reducing chemotherapy-related toxicity.
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Neoplasias Colorretais , Humanos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Biomarcadores Tumorais/genética , Hormônio AdrenocorticotrópicoRESUMO
BACKGROUND: We investigate the current knowledge on circulating tumour DNA (ctDNA) and its clinical utility in predicting outcomes in patients with metastatic colorectal cancer (mCRC). METHODS: PubMed, Embase, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials were searched. Last search 16/12/2020. We included studies on patients with mCRC reporting the predictive or prognostic value of ctDNA. We performed separate random-effects meta-analyses to investigate if baseline ctDNA and early changes in ctDNA levels during treatment were associated with survival. The risk of bias was assessed according to the Quality in Prognosis Studies tool. RESULTS: Seventy-one studies were included with 6930 patients. Twenty-four studies were included in meta-analyses. High baseline ctDNA level was associated with short progression-free survival (PFS) (HR = 2.2; 95% CI 1.8-2.8; n = 509) and overall survival (OS) (HR = 2.4; 95% CI 1.9-3.1; n = 1336). A small or no early decrease in ctDNA levels during treatment was associated with short PFS (HR = 3.0; 95% CI 2.2-4.2; n = 479) and OS (HR = 2.8; 95% CI 2.1-3.9; n = 583). Results on clonal evolution and lead-time were inconsistent. A majority of included studies (n = 50/71) had high risk of bias in at least one domain. CONCLUSIONS: Plasma ctDNA is a strong prognostic biomarker in mCRC. However, true clinical utility is lacking.
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DNA Tumoral Circulante , Neoplasias Colorretais , DNA Tumoral Circulante/genética , Neoplasias Colorretais/patologia , Humanos , Prognóstico , Intervalo Livre de ProgressãoRESUMO
The mechanical properties of extracellular vesicles (EVs) are known to influence their biological function, in terms of, e.g., cellular adhesion, endo/exocytosis, cellular uptake, and mechanosensing. EVs have a characteristic nanomechanical response which can be probed via force spectroscopy (FS) and exploited to single them out from nonvesicular contaminants or to discriminate between subtypes. However, measuring the nanomechanical characteristics of individual EVs via FS is a labor-intensive and time-consuming task, usually limiting this approach to specialists. Herein, we describe a simple atomic force microscopy based experimental procedure for the simultaneous nanomechanical and morphological analysis of several hundred individual nanosized EVs within the hour time scale, using basic AFM equipment and skills and only needing freely available software for data analysis. This procedure yields a "nanomechanical snapshot" of an EV sample which can be used to discriminate between subpopulations of vesicular and nonvesicular objects in the same sample and between populations of vesicles with similar sizes but different mechanical characteristics. We demonstrate the applicability of the proposed approach to EVs obtained from three very different sources (human colorectal carcinoma cell culture, raw bovine milk, and Ascaris suum nematode excretions), recovering size and stiffness distributions of individual vesicles in a sample. EV stiffness values measured with our high-throughput method are in very good quantitative accord with values obtained by FS techniques which measure EVs one at a time. We show how our procedure can detect EV samples contamination by nonvesicular aggregates and how it can quickly attest the presence of EVs even in samples for which no established assays and/or commercial kits are available (e.g., Ascaris EVs), thus making it a valuable tool for the rapid assessment of EV samples during the development of isolation/enrichment protocols by EV researchers. As a side observation, we show that all measured EVs have a strikingly similar stiffness, further reinforcing the hypothesis that their mechanical characteristics could have a functional role.
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Vesículas Extracelulares/química , Ensaios de Triagem em Larga Escala , Microscopia de Força Atômica , Nanotecnologia , Animais , Ascaris suum/química , Bovinos , Células HCT116 , Humanos , Lipossomos/química , Leite/químicaRESUMO
BACKGROUND: Local treatment of liver and/or lung metastases from colorectal cancer (CRC) is increasingly used in daily practice and comprises resection, radiofrequency ablation (RFA) and stereotactic radiotherapy (SBRT). The need for prognostic markers for patients undergoing such treatment is currently unmet. We investigated post-treatment circulating tumor-specific DNA (ctDNA) analysis and address a possible prognostic value in a pilot study. MATERIALS: From July 2015 to September 2017, patients undergoing standard of care local treatment of liver and/or lung metastases were included in a prospective translational study. Blood samples were drawn 2 weeks after local treatment and during follow-up. CtDNA was detected by ddPCR and a mass spectrometry-based platform MassARRAY®. RESULTS: Post treatment blood samples were available for 35 patients including five with detectable ctDNA (KRAS mutation, n = 2; NRAS mutation, n = 2; BRAF mutation, n = 1) by ddPCR. 17 out of 35 patients (49%) developed recurrence within a median of 273 days (95%CI 95-NA) among patients positive for ctDNA, while the median time to recurrence was not reached for the group of patients negative for ctDNA (p = .03). CONCLUSION: The presence of ctDNA following local treatment of metastatic CRC is associated with an increased risk of recurrence and a short time to failure.
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DNA Tumoral Circulante , Neoplasias do Colo , Neoplasias Colorretais , Biomarcadores Tumorais/genética , DNA Tumoral Circulante/genética , Neoplasias Colorretais/genética , Humanos , Recidiva Local de Neoplasia/genética , Neoplasia Residual , Projetos Piloto , Estudos ProspectivosRESUMO
About 10-20% of patients with metastatic colorectal cancer (mCRC) are candidates for metastasis directed therapies such as surgical resection, ablation and stereotactic radiotherapy. We examined the temporal changes in use of metastasis directed therapies and established prognostic factors for survival in a nationwide cohort study. The Danish nationwide medical registries were used to retrieve data on treatment for liver and/or lung metastasis in patients with metastatic colorectal cancer in the period 2000-2013. Overall survival through 2014 was calculated from the time of treatment of metastases by Kaplan-Meier method and mortality between groups was assessed using Cox regression. We report 2,912 patients undergoing a total of 3,602 procedures with an increased use of all modalities during 14 calendar years. Median survival was 3.7 years (interquartile range (IQR) 2.0-9.7 years). In the multivariate analysis, the nodal stage of the primary tumor had the most pronounced association with survival with a hazard ratio for mortality of 1.56 (95% CI: 1.33-1.83) for N2 stage with reference to N0. Furthermore, female gender, age, comorbidity, surgical treatment, administration of chemotherapy, and left-sided primary tumors were associated with improved prognosis in the multivariate analysis.
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Neoplasias Colorretais/patologia , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/terapia , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/terapia , Vigilância da População , Idoso , Quimioterapia Adjuvante , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/cirurgia , Dinamarca/epidemiologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/cirurgia , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Ablação por Radiofrequência , Radiocirurgia , Sistema de RegistrosRESUMO
The cytoskeleton is an integral part of skeletal muscle structure, and reorganization of the cytoskeleton occurs during various modes of remodeling. We previously found that the extracellular matrix protein secreted protein acidic and rich in cysteine (SPARC) is up-regulated and expressed intracellularly in developing muscle, during regeneration and in myopathies, which together suggests that SPARC might serve a specific role within muscle cells. Using co-immunoprecipitation combined with mass spectrometry and verified by staining for direct protein-protein interaction, we find that SPARC binds to actin. This interaction is present in regenerating myofibers of patients with Duchenne muscular dystrophy, polymyositis, and compartment syndrome. Analysis of the α-, ß-, and γ-actin isoforms in SPARC knockout myoblasts reveals a changed expression pattern with dominance of γ-actin. In SPARC knockout mice, we performed an injury study to investigate whether lack of SPARC would compromise the ability to repair muscle. We report that these mice develop normal skeletal muscle with retained ability to regenerate. However, when we subject muscle from SPARC-deficient mice to an in vitro fatigue stimulation protocol, we find a defective force recovery. Therefore, SPARC appears to be an important modulator of the actin cytoskeleton, implicating maintenance of muscular function. This direct interaction with actin suggests a new role of SPARC during tissue remodeling.
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Actinas/metabolismo , Músculo Esquelético/fisiologia , Mioblastos/metabolismo , Osteonectina/metabolismo , Animais , Western Blotting , Modelos Animais de Doenças , Humanos , Imuno-Histoquímica , Imunoprecipitação , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos mdx , Camundongos Knockout , Microscopia Eletrônica de Transmissão , Doenças Musculares/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , RegeneraçãoRESUMO
BACKGROUND: Circulating DNA can be detected and quantified in the blood of cancer patients and used for detection of tumor-specific genetic alterations. The clinical utility has been intensively investigated for the past 10 years. The majority of reports focus on analyzing the clinical potential of tumor-specific mutations, whereas the use of total cell-free DNA (cfDNA) quantification is somehow controversial and sparsely described in the literature, but holds important clinical information in itself. The purpose of the present report was to present a systematic review and meta-analysis of the prognostic value of total cfDNA in patients with metastatic colorectal cancer (mCRC) treated with chemotherapy. In addition, we report on the overall performance of cfDNA as source for KRAS mutation detection. MATERIALS AND METHODS: A systematic literature search of PubMed and Embase was performed by two independent investigators. Eligibility criteria were (a) total cfDNA analysis, (b) mCRC, and (c) prognostic value during palliative treatment. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed, and meta-analysis applied on both aggregate data extraction and individual patients' data. RESULTS: Ten eligible cohorts were identified, including a total of 1,076 patients. Seven studies used quantitative polymerase chain reaction methods, two BEAMing [beads, emulsification, amplification, and magnetics] technology, and one study digital droplet polymerase chain reaction. The baseline levels of cfDNA was similar in the presented studies, and all studies reported a clear prognostic value in favor of patients with lowest levels of baseline cfDNA. A meta-analysis revealed a combined estimate of favorable overall survival hazard ratio (HR) in patients with levels below the median cfDNA (HR = 2.39, 95% confidence interval 2.03-2.82, p < .0001). CONCLUSION: The total cfDNA levels are high in patients with mCRC and bear strong prognostic information, which should be tested prospectively by using a predefined cut-off value based on normal values in healthy cohorts. Finally, the potential use of cfDNA for detection of tumor-specific mutations was emphasized in a large individual patients' data meta-analysis. IMPLICATIONS FOR PRACTICE: Reliable prognostic markers could help to guide patients and treating physicians regarding the relevance and choice of systemic therapy. Small fragments of circulating cell-free DNA (cfDNA) can be measured in a simple blood sample. This report presents the first meta-analysis of the prognostic value of total cfDNA measurement in patients with metastatic colorectal cancer. Data from 1,076 patients confirmed that patients with the lowest pre-treatment levels of cfDNA had a significantly higher chance of longer survival than those with higher levels. Cell-free DNA analysis can also be used for detection of tumor-specific mutations, and hold potential as a valuable tool in colorectal cancer treatment.
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Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/sangue , DNA Tumoral Circulante/sangue , Neoplasias Colorretais/sangue , Neoplasias Colorretais/genética , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/mortalidade , Intervalo Livre de Doença , Humanos , Prognóstico , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Accurate staging of rectal cancer remains essential for optimal patient selection for combined modality treatment, including radiotherapy, chemotherapy and surgery. We aimed at examining the correlation of cell free DNA with the pathologic stage and subsequent risk of recurrence for patients with locally advanced rectal cancer undergoing preoperative chemoradiation. We examined 75 patients with locally advanced rectal cancer receiving preoperative chemoradiation. Blood samples for translational use were drawn prior to rectal surgery. The level of cell free DNA was quantified by digital droplet PCR and expressed as copy number of beta 2 microglobulin. We found a median level of cell free DNA in the AJCC stages I-III of 3100, 8300, and 10,700 copies/mL respectively. For patients with 12 sampled lymph nodes or above, the median level of cell free DNA were 2400 copies/mL and 4400 copies/mL (p = 0.04) for node negative and node positive disease respectively. The median follow-up was 39 months and 11 recurrences were detected (15%). The median level for patients with recurrent disease was 13,000 copies/mL compared to 5200 copies/mL for non-recurrent patients (p = 0.08). We have demonstrated a correlation between the level of total cell free DNA and the pathologic stage and nodal involvement. Furthermore, we have found a trend towards a correlation with the risk of recurrence following resection of localized rectal cancer.
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Adenocarcinoma/sangue , Adenocarcinoma/patologia , DNA/sangue , Recidiva Local de Neoplasia/sangue , Neoplasias Retais/sangue , Neoplasias Retais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimiorradioterapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Neoplasias Retais/terapia , Resultado do TratamentoRESUMO
BACKGROUND: Hypercalcemia is the most common oncologic metabolic emergency but very rarely observed in patients with gastrointestinal stromal tumour, which is a rare mesenchymal malignancy of the gastrointestinal tract. We describe a case of hypercalcemia caused by elevated levels of activated vitamin D in a patient with gastrointestinal tumour. Prior to this case report, only one paper has reported an association between hypercalcemia, gastrointestinal stromal tumours and elevated levels of vitamin D. CASE PRESENTATION: An otherwise healthy 70-year-old Caucasian woman, previously treated for duodenal gastrointestinal stromal tumour, was diagnosed with liver metastasis, and relapse of gastrointestinal stromal tumour was confirmed by biopsy. At presentation, the patient suffered from severe symptoms of hypercalcemia. The most common causes of hypercalcemia, hyperparathyrodism, parathyroid hormone-related peptide secretion from tumour cells, and metastatic bone disease, were all dismissed as the etiology. Analysis of vitamin D subtypes revealed normal levels of both 25-OH Vitamin D2 and 25-OH Vitamin D3, whereas the level of activated vitamin D, 1,25 OH Vitamin D3, also referred to as calcitriol, was elevated. CONCLUSION: The fact that plasma calcitriol decreased after initiation of oncological treatment and the finding that hypercalcemia did not recur during treatment support the conclusion that elevated calcitriol was a consequence of the gastrointestinal stromal tumour. We suggest that gastrointestinal stromal tumours should be added to the list of causes of humoral hypercalcemia in malignancy, and propose that gastrointestinal stromal tumour tissue may have high activity of the specific enzyme 1α-hydroxylase, which can lead to increased levels of calcitriol and secondarily hypercalcemia.
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Calcitriol/sangue , Neoplasias Gastrointestinais/sangue , Neoplasias Gastrointestinais/diagnóstico , Tumores do Estroma Gastrointestinal/sangue , Tumores do Estroma Gastrointestinal/diagnóstico , Hipercalcemia/sangue , Hipercalcemia/diagnóstico , Idoso , Biomarcadores Tumorais/sangue , Feminino , Neoplasias Gastrointestinais/complicações , Tumores do Estroma Gastrointestinal/complicações , Humanos , Hipercalcemia/complicaçõesAssuntos
Neoplasias Abdominais/tratamento farmacológico , Neoplasias Colorretais/patologia , Meios de Contraste , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Compostos de Fenilureia/uso terapêutico , Piridinas/uso terapêutico , Intensificação de Imagem Radiográfica/métodos , Neoplasias Abdominais/diagnóstico por imagem , Idoso , Biomarcadores , Feminino , Tomografia Computadorizada Quadridimensional/métodos , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Critérios de Avaliação de Resposta em Tumores Sólidos , Resultado do Tratamento , Ácidos Tri-IodobenzoicosRESUMO
Renal fibrosis, characterized by excessive extracellular matrix accumulation, leads to a progressive decline of renal function and is a common endpoint of chronic kidney disease (CKD). Current treatments primarily focus on managing underlying diseases, offering limited direct intervention for the fibrotic process. This study explores the anti-fibrotic potential of human adipose-derived mesenchymal stromal cells (MSCs) and their derived extracellular vesicles (EVs) in the context of CKD, emphasizing the effects of systemic versus local delivery methods. Preconditioned MSCs (Pr-MSCs) were treated with TNF-α and IFN-γ to enhance their immunomodulatory capabilities, and demonstrated significant anti-fibrotic effects in vitro, reducing mRNA expression of fibrosis markers in TGF-ß stimulated HKC-8 cells. Our in vivo findings from a murine unilateral ureteral obstruction (UUO) model of CKD showed that local deliveries of Pr-MSCs reduced collagen deposition and increased expression of the anti-inflammatory cytokine IL-10. Systemic administration of Pr-MSCs did not show any significant effect on UUO-induced injury. In addition, EVs did not replicate the anti-fibrotic effects observed with their parent cells, suggesting that soluble proteins or metabolites secreted by Pr-MSCs might be the primary mediators of the anti-fibrotic and immunomodulatory effects. This study provides critical insights into the therapeutic efficacy of MSCs, highlighting the importance of delivery methods and the potential of preconditioning strategies in enhancing MSC-based therapies for renal fibrosis.
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The intestinal helminth Ascaris lumbricoides infects over 800 million people. Infections are often chronic and immunity is not sterilizing due to host-immune modulation, therefore reinfection is common after antihelmintic treatment. We have previously demonstrated a role for Ascaris spp. extracellular vesicles (EVs) in host immune modulation but whether EVs are recognized by the adaptive immune system and are present systemically in the host remains unknown. Therefore, we employed a well-established trickle infection model in pigs to mimic natural Ascaris infection in humans. EVs were isolated from adult Ascaris suum followed by immunoblotting of EV and EV-depleted secretory fractions using plasma from infected and uninfected pigs. Next, EVs were isolated from pig plasma at day 56 post first infection and subjected to deep small RNAseq analysis. RNAs were aligned to A. suum and Sus scrofa miRNA complements to detect A. suum EVs and elucidate the host EV micro RNA (miRNA) response to infection, respectively. Infection generates robust antibody responses against A. suum EVs that is distinct from EV-depleted fractions. However, A. suum miRNAs were not detectable in EVs from the peripheral blood. Notably, host plasma-derived EV miRNA profiles showed significant changes between infected and uninfected pigs, indicating that Ascaris infection drives systemic changes in host EV composition.
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The Apiospora genus comprises filamentous fungi with promising potential, though its full capabilities remain undiscovered. In this study, we present the first genome assembly of an Apiospora arundinis isolate, demonstrating a highly complete and contiguous assembly estimated to 48.8 Mb, with an N99 of 3.0 Mb. Our analysis predicted a total of 15,725 genes, with functional annotations for 13,619 of them, revealing a fungus capable of producing very high amounts of carbohydrate-active enzymes (CAZymes) and secondary metabolites. Through transcriptomic analysis, we observed differential gene expression in response to varying growth media, with several genes related to carbohydrate metabolism showing significant upregulation when the fungus was cultivated on a hay-based medium. Finally, our metabolomic analysis unveiled a fungus capable of producing a diverse array of metabolites.
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Small regulatory RNA molecules have recently been recognized as important regulatory elements of developmental processes in both eukaryotes and bacteria. We here describe a striking example in Escherichia coli that can switch between a single-cell motile lifestyle and a multi-cellular, sessile and adhesive state that enables biofilm formation on surfaces. For this, the bacterium needs to reprogramme its gene expression, and in many E. coli and Salmonella strains the lifestyle shift relies on control cascades that inhibit flagellar expression and activate the synthesis of curli, extracellular adhesive fibres important for co-aggregation of cells and adhesion to biotic and abiotic surfaces. By combining bioinformatics, genetic and biochemical analysis we identified three small RNAs that act by an antisense mechanism to downregulate translation of CsgD, the master regulator of curli synthesis. Our demonstration that basal expression of each of the three RNA species is sufficient to downregulate CsgD synthesis and prevent curli formation indicates that all play a prominent role in the curli regulatory network. Our findings provide the first clue as to how the Rcs signalling pathway negatively regulates curli synthesis and increase the number of small regulatory RNAs that act directly on the csgD mRNA to five.
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Aderência Bacteriana , Proteínas de Escherichia coli/metabolismo , Escherichia coli/fisiologia , RNA Bacteriano/metabolismo , Transativadores/metabolismo , Proteínas de Bactérias/biossíntese , Sequência de Bases , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Fator Proteico 1 do Hospedeiro/metabolismo , Conformação de Ácido Nucleico , Biossíntese de Proteínas , Estabilidade de RNA , RNA Antissenso/genética , RNA Antissenso/metabolismo , RNA Bacteriano/genética , Transativadores/genéticaRESUMO
We present a case of a previously healthy and active 64-year-old man who experienced a rapid neuropsychiatric decline. All tests for metabolic causes, neuroinfection, intracranial infarction or tumor were negative. By the means of magnetic resonance imaging, electroencephalography and the anti-Hu antibody test the patient was diagnosed with paraneoplastic limbic encephalitis related to prostate cancer. The patient died within 6 months. We review the literature on prostate cancer-related paraneoplastic limbic encephalitis. High-risk prostate cancer can trigger paraneoplastic limbic encephalitis, a rapidly progressive neurological syndrome with a bad prognosis.
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Encefalite Límbica/etiologia , Encefalite Límbica/patologia , Imageamento por Ressonância Magnética , Neoplasias da Próstata/complicações , Evolução Fatal , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Polymyxin B (PMB) is a peptide based antibiotic that binds the lipid A moiety of lipopolysaccharide (LPS) with a resultant bactericidal effect. The interaction of PMB with LPS presented on outer membrane vesicles (OMVs) is not fully known, however, a sacrificial role of OMVs in protecting bacterial cells by sequestering PMB has been described. Here we assess the ability of PMB to neutralize the immune-stimulatory properties of OMVs whilst modulating the uptake of OMVs in human immune cells. We show for the first time that PMB increases immune cell uptake of Escherichia coli derived OMVs whilst inhibiting TNF and IL-1ß production. Therefore, we present a potential new role for PMB in the neutralization of OMVs via LPS masking and increased immune cell uptake.
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Escherichia coli , Polimixina B , Humanos , Polimixina B/farmacologia , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/metabolismo , Antibacterianos/farmacologia , Peptídeos/farmacologiaRESUMO
This explorative prospective observational pilot study investigated if suggested risk factors, rectal cancer and lung metastases, could add to a relevant detection rate of asymptomatic brain metastases (BM) from colorectal cancer (CRC). Secondary, prognostic biological aspects were investigated by translational analysis of plasma samples. The study enrolled patients with rectal cancer and lung metastases. At inclusion, patients underwent a standard MRI scan of the brain. Cell-free DNA (cfDNA) level was measured by a direct fluorescence assay (DFA), and circulating tumor DNA (ctDNA) by ddPCR. BM was detected in one of twenty-nine included patients. Patients had higher cfDNA levels than healthy subjects (p < 0.01). Patients with the primary tumor in situ had higher cfDNA levels than those with resected primary tumor (p < 0.01). Patients with liver involvement had higher cfDNA levels (p = 0.12) and circulating tumor DNA levels (p = 0.01) than those without liver involvement. In conclusion, the modest incidence of BM does not justify routine MRI of the brain in this selected population. cfDNA by DFA could be a valuable tool when planning treatment and follow-up for CRC patients. Future studies should focus on identifying further characteristics and biomarkers associated with a high risk of BM, enhancing the possibility for early intervention.
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Neoplasias Encefálicas , Ácidos Nucleicos Livres , DNA Tumoral Circulante , Neoplasias Colorretais , Neoplasias Pulmonares , Neoplasias Retais , Humanos , Estudos Prospectivos , Neoplasias Pulmonares/genética , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Biomarcadores Tumorais/genética , Neoplasias Colorretais/patologiaRESUMO
INTRODUCTION: Both quantitative and molecular changes in ctDNA can hold important information when treating metastatic colorectal cancer (mCRC), but its clinical utility is yet to be established. Before conducting a large-scale randomized trial, it is essential to test feasibility. This study investigates whether ctDNA is feasible for detecting patients who will benefit from treatment with epidermal growth factor receptor inhibitors and the prognostic value of circulating tumor DNA (ctDNA) response. MATERIALS AND METHODS: Patients with mCRC, who were considered for systemic palliative treatment and were eligible for ctDNA analysis. Mutational testing on cell-free DNA (cfDNA) was done by ddPCR. ctDNA response from baseline to the third treatment cycle was evaluated in patients with detectable ctDNA at baseline. ctDNA maximum response was defined as undetectable ctDNA at the third treatment cycle, ctDNA partial response as any decrease in the ctDNA level, and ctDNA progression as any increase in the ctDNA level. RESULTS: Forty-nine patients were included. The time to test results for mutational testing on cfDNA was significantly shorter than on tumor tissue (p < .001). Progression-free survival were 11.2 months (reference group), 7.5 months (HR = 10.7, p= .02), and 4.6 months (HR = 11.4, p= .02) in patients with ctDNA maximum response, partial response, and progression, respectively. Overall survival was 31.2 months (reference group), 15.2 months (HR = 4.1, p= .03), and 9.0 months (HR = 2.6, p= .03) in patients with ctDNA maximum response, partial response, and progression, respectively. CONCLUSION: Pretreatment mutational testing on cfDNA in daily clinic is feasible and can be applied in randomized clinical trials evaluating the clinical utility of ctDNA. Early dynamics in ctDNA during systemic treatment hold prognostic value.
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DNA Tumoral Circulante , Neoplasias Colorretais , Humanos , Estudos de Viabilidade , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Prognóstico , DNA Tumoral Circulante/genética , Mutação , Biomarcadores Tumorais/genéticaRESUMO
Introduction: Unlike glycosylation of proteins expressed in mammalian systems, bacterial glycosylation is often neglected in the development of recombinant vaccines. Methods: Here, we compared the effects of glycosylation of YghJ, an Escherichia coli protein important for mucus attachment of bacteria causing in urinary tract infections (UTIs). A novel method based on statistical evaluation of phage display for the identification and comparison of epitopes and mimotopes of anti-YghJ antibodies in the sera was used. This is the first time that the effect of glycosylation of a recombinant bacterial antigen has been studied at the peptide epitope level. Results: The study identifies differences in the immune response for (non)-glycosylated antigens in rabbits and pigs and compares them to a large group of patients with UTI, which have been diagnosed as positive for various bacterial pathogens. We identified glycosylation-specific peptide epitopes, a large immunological similarity between different UTI pathogens, and a broad peptide epitope pattern in patients and animals, which could result in a variable response in patients upon vaccination. Discussion: This epitope analysis indicates that the vaccination of rabbits and pigs raises antibodies that translate well into the human immune system. This study underlines the importance of glycosylation in bacterial vaccines and provides detailed immune diagnostic methods to understand individual immune responses to vaccines.