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1.
bioRxiv ; 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38948837

RESUMO

A single arm trial (NCT007773097) and a double-blind, placebo controlled randomized trial ( NCT02134925 ) were conducted in individuals with a history of advanced colonic adenoma to test the safety and immunogenicity of the MUC1 tumor antigen vaccine and its potential to prevent new adenomas. These were the first two trials of a non-viral cancer vaccine administered in the absence of cancer. The vaccine was safe and strongly immunogenic in 43% (NCT007773097) and 25% ( NCT02134925 ) of participants. The lack of response in a significant number of participants suggested, for the first time, that even in a premalignant setting, the immune system may have already been exposed to some level of suppression previously reported only in cancer. Single-cell RNA-sequencing (scRNA-seq) on banked pre-vaccination peripheral blood mononuclear cells (PBMCs) from 16 immune responders and 16 non-responders identified specific cell types, genes, and pathways of a productive vaccine response. Responders had a significantly higher percentage of CD4+ naive T cells pre-vaccination, but a significantly lower percentage of CD8+ T effector memory (TEM) cells and CD16+ monocytes. Differential gene expression (DGE) and transcription factor inference analysis showed a higher level of expression of T cell activation genes, such as Fos and Jun, in CD4+ naive T cells, and pathway analysis showed enriched signaling activity in responders. Furthermore, Bayesian network analysis suggested that these genes were mechanistically connected to response. Our analyses identified several immune mechanisms and candidate biomarkers to be further validated as predictors of immune responses to a preventative cancer vaccine that could facilitate selection of individuals likely to benefit from a vaccine or be used to improve vaccine responses.

2.
Elife ; 132024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38921956

RESUMO

BRAFV600E mutation is a driver mutation in the serrated pathway to colorectal cancers. BRAFV600E drives tumorigenesis through constitutive downstream extracellular signal-regulated kinase (ERK) activation, but high-intensity ERK activation can also trigger tumor suppression. Whether and how oncogenic ERK signaling can be intrinsically adjusted to a 'just-right' level optimal for tumorigenesis remains undetermined. In this study, we found that FAK (Focal adhesion kinase) expression was reduced in BRAFV600E-mutant adenomas/polyps in mice and patients. In Vil1-Cre;BRAFLSL-V600E/+;Ptk2fl/fl mice, Fak deletion maximized BRAFV600E's oncogenic activity and increased cecal tumor incidence to 100%. Mechanistically, our results showed that Fak loss, without jeopardizing BRAFV600E-induced ERK pathway transcriptional output, reduced EGFR (epidermal growth factor receptor)-dependent ERK phosphorylation. Reduction in ERK phosphorylation increased the level of Lgr4, promoting intestinal stemness and cecal tumor formation. Our findings show that a 'just-right' ERK signaling optimal for BRAFV600E-induced cecal tumor formation can be achieved via Fak loss-mediated downregulation of ERK phosphorylation.


Assuntos
Neoplasias do Ceco , Quinase 1 de Adesão Focal , Proteínas Proto-Oncogênicas B-raf , Animais , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Fosforilação , Camundongos , Humanos , Neoplasias do Ceco/metabolismo , Neoplasias do Ceco/genética , Neoplasias do Ceco/patologia , Quinase 1 de Adesão Focal/metabolismo , Quinase 1 de Adesão Focal/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/genética , Sistema de Sinalização das MAP Quinases , Receptores ErbB/metabolismo , Receptores ErbB/genética , Carcinogênese/genética , Carcinogênese/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Masculino
3.
medRxiv ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38766010

RESUMO

Self-antigens abnormally expressed on tumors, such as MUC1, have been targeted by therapeutic cancer vaccines. We recently assessed in two clinical trials in a preventative setting whether immunity induced with a MUC1 peptide vaccine could reduce high colon cancer risk in individuals with a history of premalignant colon adenomas. In both trials, there were immune responders and non-responders to the vaccine. Here we used PBMC pre-vaccination and 2 weeks after the first vaccine of responders and non-responders selected from both trials to identify early biomarkers of immune response involved in long-term memory generation and prevention of adenoma recurrence. We performed flow cytometry, phosflow, and differential gene expression analyses on PBMCs collected from MUC1 vaccine responders and non-responders pre-vaccination and two weeks after the first of three vaccine doses. MUC1 vaccine responders had higher frequencies of CD4 cells pre-vaccination, increased expression of CD40L on CD8 and CD4 T-cells, and a greater increase in ICOS expression on CD8 T-cells. Differential gene expression analysis revealed that iCOSL, PI3K AKT MTOR, and B-cell signaling pathways are activated early in response to the MUC1 vaccine. We identified six specific transcripts involved in elevated antigen presentation, B-cell activation, and NF-kB1 activation that were directly linked to finding antibody response at week 12. Finally, a model using these transcripts was able to predict non-responders with accuracy. These findings suggest that individuals who can be predicted to respond to the MUC1 vaccine, and potentially other vaccines, have greater readiness in all immune compartments to present and respond to antigens. Predictive biomarkers of MUC1 vaccine response may lead to more effective vaccines tailored to individuals with high risk for cancer but with varying immune fitness.

4.
Rev Soc Bras Med Trop ; 57: e00404, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38597523

RESUMO

BACKGROUND: Chikungunya fever is an emerging global infection transmitted by Aedes mosquitoes that manifests as an acute febrile illness with joint pain and can lead to chronic arthritis. The mechanism underlying chronic joint damage remains unclear; however, chronic chikungunya arthritis shares similarities with rheumatoid arthritis. Disease-modifying antirheumatic drugs have revolutionized rheumatoid arthritis treatment by preventing joint damage. However, the role of these therapies in chronic chikungunya arthritis has not been determined. We conducted a systematic review to evaluate the burden of joint structural damage in chronic chikungunya arthritis to help to define the role of disease-modifying therapy in this disease. METHODS: This systematic review included retrospective and prospective studies, trials, and case reports evaluating joint damage caused by chikungunya virus. Various databases were searched without any date or language restrictions. Study selection was conducted independently by two researchers, and data were extracted from the articles selected. RESULTS: A total of 108 studies were initially evaluated, with 8 meeting the inclusion criteria. Longitudinal studies have reported persistent joint pain from chikungunya infection and the progression of radiographic joint damage up to 13 years post-infection. Joint imaging revealed synovial inflammation, bone erosion, and cartilage destruction in patients with chronic chikungunya arthritis. CONCLUSIONS: Few studies have addressed chikungunya-induced joint damage, limiting our understanding of chronic chikungunya arthritis. Nevertheless, chronic chikungunya arthritis has similarities to rheumatoid arthritis. The success of early disease-modifying antirheumatic drug therapy in rheumatoid arthritis underscores the need for comprehensive research on its role in chikungunya arthritis.


Assuntos
Antirreumáticos , Artrite Reumatoide , Febre de Chikungunya , Vírus Chikungunya , Humanos , Antirreumáticos/uso terapêutico , Artralgia/etiologia , Artrite Reumatoide/complicações , Artrite Reumatoide/tratamento farmacológico , Febre de Chikungunya/complicações , Estudos Prospectivos , Estudos Retrospectivos
5.
EBioMedicine ; 103: 105130, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38653188

RESUMO

BACKGROUND: Active surveillance pharmacovigilance is an emerging approach to identify medications with unanticipated effects. We previously developed a framework called pharmacopeia-wide association studies (PharmWAS) that limits false positive medication associations through high-dimensional confounding adjustment and set enrichment. We aimed to assess the transportability and generalizability of the PharmWAS framework by using medical claims data to reproduce known medication associations with Clostridioides difficile infection (CDI) or gastrointestinal bleeding (GIB). METHODS: We conducted case-control studies using Optum's de-identified Clinformatics Data Mart Database of individuals enrolled in large commercial and Medicare Advantage health plans in the United States. Individuals with CDI (from 2010 to 2015) or GIB (from 2010 to 2021) were matched to controls by age and sex. We identified all medications utilized prior to diagnosis and analysed the association of each with CDI or GIB using conditional logistic regression adjusted for risk factors for the outcome and a high-dimensional propensity score. FINDINGS: For the CDI study, we identified 55,137 cases, 220,543 controls, and 290 medications to analyse. Antibiotics with Gram-negative spectrum, including ciprofloxacin (aOR 2.83), ceftriaxone (aOR 2.65), and levofloxacin (aOR 1.60), were strongly associated. For the GIB study, we identified 450,315 cases, 1,801,260 controls, and 354 medications to analyse. Antiplatelets, anticoagulants, and non-steroidal anti-inflammatory drugs, including ticagrelor (aOR 2.81), naproxen (aOR 1.87), and rivaroxaban (aOR 1.31), were strongly associated. INTERPRETATION: These studies demonstrate the generalizability and transportability of the PharmWAS pharmacovigilance framework. With additional validation, PharmWAS could complement traditional passive surveillance systems to identify medications that unexpectedly provoke or prevent high-impact conditions. FUNDING: U.S. National Institute of Diabetes and Digestive and Kidney Diseases.


Assuntos
Clostridioides difficile , Infecções por Clostridium , Hemorragia Gastrointestinal , Farmacovigilância , Humanos , Infecções por Clostridium/epidemiologia , Infecções por Clostridium/etiologia , Infecções por Clostridium/tratamento farmacológico , Estudos de Casos e Controles , Masculino , Hemorragia Gastrointestinal/induzido quimicamente , Hemorragia Gastrointestinal/epidemiologia , Hemorragia Gastrointestinal/etiologia , Feminino , Idoso , Pessoa de Meia-Idade , Antibacterianos/efeitos adversos , Antibacterianos/uso terapêutico , Estados Unidos/epidemiologia , Fatores de Risco , Adulto , Idoso de 80 Anos ou mais
6.
Gastroenterology ; 167(2): 378-391, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38552670

RESUMO

BACKGROUND & AIMS: Colorectal cancer (CRC) screening is highly effective but underused. Blood-based biomarkers (liquid biopsy) could improve screening participation. METHODS: Using our established Markov model, screening every 3 years with a blood-based test that meets minimum Centers for Medicare & Medicaid Services' thresholds (CMSmin) (CRC sensitivity 74%, specificity 90%) was compared with established alternatives. Test attributes were varied in sensitivity analyses. RESULTS: CMSmin reduced CRC incidence by 40% and CRC mortality by 52% vs no screening. These reductions were less profound than the 68%-79% and 73%-81%, respectively, achieved with multi-target stool DNA (Cologuard; Exact Sciences) every 3 years, annual fecal immunochemical testing (FIT), or colonoscopy every 10 years. Assuming the same cost as multi-target stool DNA, CMSmin cost $28,500/quality-adjusted life-year gained vs no screening, but FIT, colonoscopy, and multi-target stool DNA were less costly and more effective. CMSmin would match FIT's clinical outcomes if it achieved 1.4- to 1.8-fold FIT's participation rate. Advanced precancerous lesion (APL) sensitivity was a key determinant of a test's effectiveness. A paradigm-changing blood-based test (sensitivity >90% for CRC and 80% for APL; 90% specificity; cost ≤$120-$140) would be cost-effective vs FIT at comparable participation. CONCLUSIONS: CMSmin could contribute to CRC control by achieving screening in those who will not use established methods. Substituting blood-based testing for established effective CRC screening methods will require higher CRC and APL sensitivities that deliver programmatic benefits matching those of FIT. High APL sensitivity, which can result in CRC prevention, should be a top priority for screening test developers. APL detection should not be penalized by a definition of test specificity that focuses on CRC only.


Assuntos
Colonoscopia , Neoplasias Colorretais , Análise Custo-Benefício , Detecção Precoce de Câncer , Sangue Oculto , Humanos , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/economia , Colonoscopia/economia , Detecção Precoce de Câncer/economia , Detecção Precoce de Câncer/métodos , Biópsia Líquida/economia , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/análise , Cadeias de Markov , Anos de Vida Ajustados por Qualidade de Vida , Pessoa de Meia-Idade , Masculino , Feminino , Idoso , Fezes/química , Estados Unidos , Incidência , Valor Preditivo dos Testes , Pesquisa Comparativa da Efetividade , Custos de Cuidados de Saúde
7.
Curr Opin Rheumatol ; 36(3): 155-162, 2024 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-38411201

RESUMO

PURPOSE OF REVIEW: Postinfectious inflammatory arthritis can result from various pathogens, including bacteria, viruses, fungi, and parasites. Prompt identification and treatment of acute infection is vital, but some cases progress to chronic arthritis despite successful treatment of infection. Postinfectious inflammatory arthritis varies from mild, self-limited arthralgia to severe, refractory arthritis, necessitating ongoing disease-modifying treatment. This review explores the spectrum of postinfectious inflammatory arthritis to provide insights into effective management. RECENT FINDINGS: Research continues regarding the benefit of antimicrobial therapy, beyond treatment of the acute infection, to diminish the severity of postinfectious inflammatory arthritis. Following treatment of acute infection, most cases are self-limited so treatment is symptomatic. However, a difficult-to-predict fraction of cases develop chronic postinfectious inflammatory arthritis that can be challenging to manage. Recently, as more biologic, and targeted synthetic DMARDs have become available, treatment options have expanded. SUMMARY: In this article, we use the term 'postinfectious inflammatory arthritis' rather than 'reactive arthritis' because it describes a broader spectrum of diseases and emphasizes the common pathogenesis of a postinfectious inflammatory process. We summarize the conventional therapies and recent management developments for the most frequently encountered postinfectious inflammatory arthritides.


Assuntos
Antirreumáticos , Artrite , Infecções , Humanos , Artrite/etiologia , Inflamação/complicações , Antirreumáticos/uso terapêutico , Infecções/complicações
8.
EBioMedicine ; 101: 105010, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38350331

RESUMO

BACKGROUND: Obesity has been positively associated with most molecular subtypes of colorectal cancer (CRC); however, the magnitude and the causality of these associations is uncertain. METHODS: We used Mendelian randomization (MR) to examine potential causal relationships between body size traits (body mass index [BMI], waist circumference, and body fat percentage) with risks of Jass classification types and individual subtypes of CRC (microsatellite instability [MSI] status, CpG island methylator phenotype [CIMP] status, BRAF and KRAS mutations). Summary data on tumour markers were obtained from two genetic consortia (CCFR, GECCO). FINDINGS: A 1-standard deviation (SD:5.1 kg/m2) increment in BMI levels was found to increase risks of Jass type 1MSI-high,CIMP-high,BRAF-mutated,KRAS-wildtype (odds ratio [OR]: 2.14, 95% confidence interval [CI]: 1.46, 3.13; p-value = 9 × 10-5) and Jass type 2non-MSI-high,CIMP-high,BRAF-mutated,KRAS-wildtype CRC (OR: 2.20, 95% CI: 1.26, 3.86; p-value = 0.005). The magnitude of these associations was stronger compared with Jass type 4non-MSI-high,CIMP-low/negative,BRAF-wildtype,KRAS-wildtype CRC (p-differences: 0.03 and 0.04, respectively). A 1-SD (SD:13.4 cm) increment in waist circumference increased risk of Jass type 3non-MSI-high,CIMP-low/negative,BRAF-wildtype,KRAS-mutated (OR 1.73, 95% CI: 1.34, 2.25; p-value = 9 × 10-5) that was stronger compared with Jass type 4 CRC (p-difference: 0.03). A higher body fat percentage (SD:8.5%) increased risk of Jass type 1 CRC (OR: 2.59, 95% CI: 1.49, 4.48; p-value = 0.001), which was greater than Jass type 4 CRC (p-difference: 0.03). INTERPRETATION: Body size was more strongly linked to the serrated (Jass types 1 and 2) and alternate (Jass type 3) pathways of colorectal carcinogenesis in comparison to the traditional pathway (Jass type 4). FUNDING: Cancer Research UK, National Institute for Health Research, Medical Research Council, National Institutes of Health, National Cancer Institute, American Institute for Cancer Research, Brigham and Women's Hospital, Prevent Cancer Foundation, Victorian Cancer Agency, Swedish Research Council, Swedish Cancer Society, Region Västerbotten, Knut and Alice Wallenberg Foundation, Lion's Cancer Research Foundation, Insamlingsstiftelsen, Umeå University. Full funding details are provided in acknowledgements.


Assuntos
Neoplasias Colorretais , Proteínas Proto-Oncogênicas B-raf , Humanos , Feminino , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Análise da Randomização Mendeliana , Metilação de DNA , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Instabilidade de Microssatélites , Mutação , Fenótipo , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Tamanho Corporal , Ilhas de CpG
9.
JAMA Netw Open ; 7(2): e240007, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38421651

RESUMO

Importance: Randomized clinical screening trials have shown that sigmoidoscopy screening reduces colorectal cancer (CRC) incidence and mortality. Colonoscopy has largely replaced sigmoidoscopy for CRC screening, but long-term results from randomized trials on colonoscopy screening are still lacking. Objective: To estimate the additional screening benefit of colonoscopy compared with sigmoidoscopy. Design, Setting, and Participants: This comparative effectiveness simulation study pooled data on 358 204 men and women randomly assigned to sigmoidoscopy screening or usual care in 4 randomized sigmoidoscopy screening trials conducted in Norway, Italy, the US, and UK with inclusion periods in the years 1993 to 2001. The primary analysis of the study was conducted from January 19 to December 30, 2021. Intervention: Invitation to endoscopic screening. Main Outcomes and Measures: Primary outcomes were CRC incidence and mortality. Using pooled 15-year follow-up data, colonoscopy screening effectiveness was estimated assuming that the efficacy of colonoscopy in the proximal colon was similar to that observed in the distal colon in the sigmoidoscopy screening trials. The simulation model was validated using data from Norwegian participants in a colonoscopy screening trial. Results: This analysis included 358 204 individuals (181 971 women [51%]) aged 55 to 64 years at inclusion with a median follow-up time ranging from 15 to 17 years. Compared with usual care, colonoscopy prevented an estimated 50 (95% CI, 42-58) CRC cases per 100 000 person-years, corresponding to 30% incidence reduction (rate ratio, 0.70 [95% CI, 0.66-0.75]), and prevented an estimated 15 (95% CI, 11-19) CRC deaths per 100 000 person-years, corresponding to 32% mortality reduction (rate ratio, 0.68 [95% CI, 0.61-0.76]). The additional benefit of colonoscopy screening compared with sigmoidoscopy was 12 (95% CI, 10-14) fewer CRC cases and 4 (95% CI, 3-5) fewer CRC deaths per 100 000 person-years, corresponding to percentage point reductions of 6.9 (95% CI, 6.0-7.9) for CRC incidence and 7.6 (95% CI, 5.7-9.6) for CRC mortality. The number needed to switch from sigmoidoscopy to colonoscopy screening was 560 (95% CI, 486-661) to prevent 1 CRC case and 1611 (95% CI, 1275-2188) to prevent 1 CRC death. Conclusions and Relevance: The findings of this comparative effectiveness study assessing long-term follow-up after CRC screening suggest that there was an additional preventive effect on CRC incidence and mortality associated with colonoscopy screening compared with sigmoidoscopy screening, but the additional preventive effect was less than what was achieved by introducing sigmoidoscopy screening where no screening existed. The results probably represent the upper limit of what may be achieved with colonoscopy screening compared with sigmoidoscopy screening.


Assuntos
Detecção Precoce de Câncer , Neoplasias , Feminino , Humanos , Masculino , Colonoscopia , Simulação por Computador , Sigmoidoscopia , Pesquisa Comparativa da Efetividade
10.
Sci Transl Med ; 16(731): eadi3883, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38266106

RESUMO

We previously described an approach called RealSeqS to evaluate aneuploidy in plasma cell-free DNA through the amplification of ~350,000 repeated elements with a single primer. We hypothesized that an unbiased evaluation of the large amount of sequencing data obtained with RealSeqS might reveal other differences between plasma samples from patients with and without cancer. This hypothesis was tested through the development of a machine learning approach called Alu Profile Learning Using Sequencing (A-PLUS) and its application to 7615 samples from 5178 individuals, 2073 with solid cancer and the remainder without cancer. Samples from patients with cancer and controls were prespecified into four cohorts used for model training, analyte integration, and threshold determination, validation, and reproducibility. A-PLUS alone provided a sensitivity of 40.5% across 11 different cancer types in the validation cohort, at a specificity of 98.5%. Combining A-PLUS with aneuploidy and eight common protein biomarkers detected 51% of the cancers at 98.9% specificity. We found that part of the power of A-PLUS could be ascribed to a single feature-the global reduction of AluS subfamily elements in the circulating DNA of patients with solid cancer. We confirmed this reduction through the analysis of another independent dataset obtained with a different approach (whole-genome sequencing). The evaluation of Alu elements may therefore have the potential to enhance the performance of several methods designed for the earlier detection of cancer.


Assuntos
Neoplasias , Humanos , Reprodutibilidade dos Testes , Neoplasias/diagnóstico , Neoplasias/genética , Elementos Nucleotídeos Curtos e Dispersos , Aprendizado de Máquina , Aneuploidia
11.
Curr Rheumatol Rev ; 20(3): 337-346, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38173199

RESUMO

BACKGROUND: Chikungunya fever is a reemerging epidemic disease caused by a single-stranded RNA alphavirus transmitted throughout by Aedes mosquitoes. Chikungunya virus infection is a biphasic disease in which 72% to 95% of affected individuals manifest acute chikungunya fever. Following the acute phase, more than 40% of affected individuals develop arthritis, often lasting more than 3 months, referred to as chronic chikungunya arthritis, which frequently mimics rheumatoid arthritis. OBJECTIVE: This study aimed to evaluate the efficacy and safety of treatment of chronic chikungunya arthritis with methotrexate and dexamethasone in a randomized, double-blind, placebo-controlled clinical trial. METHODS: The patients were reassessed for treatment response by the DAS28-ESR, tender joint count and swollen joint count, Patient Global Assessment, and for secondary measures, including the Health Assessment Questionnaire Disability Index and Pain Visual Analog Scale. RESULTS: Thirty-one subjects were randomized (placebo, n = 16; methotrexate, n = 15); 27 completed treatment and 4 discontinued during the 8-week blinded period. Among the participants, 96.8% were female, with mean ± SD age was 52.9 ± 13. The mean ± SD disease duration prior to treatment was 220.9 ± 51.2 days. At 8 weeks, methotrexate-treated subjects showed a greater numerical trend towards improvement, but there were no significant differences between methotrexate- dexamethasone group and dexamethasone (placebo) group. CONCLUSION: In this relatively small cohort, all of whom received background dexamethasone, there was a greater numerical improvement trend in prespecified outcome measures, but methotrexate in combination with dexamethasone was not superior to dexamethasone in chronic chikungunya arthritis.


Assuntos
Febre de Chikungunya , Dexametasona , Quimioterapia Combinada , Metotrexato , Humanos , Febre de Chikungunya/tratamento farmacológico , Dexametasona/uso terapêutico , Dexametasona/administração & dosagem , Método Duplo-Cego , Feminino , Metotrexato/uso terapêutico , Masculino , Pessoa de Meia-Idade , Adulto , Resultado do Tratamento , Antirreumáticos/uso terapêutico , Idoso
12.
Res Sq ; 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36778401

RESUMO

BRAF V600E mutation is a driver mutation in the serrated pathway to colorectal cancers. BRAFV600E drives tumorigenesis through constitutive downstream extracellular signal-regulated kinase (ERK) activation, but high-intensity ERK activation can also trigger tumor suppression. Whether and how oncogenic ERK signaling can be intrinsically adjusted to a "just-right" level optimal for tumorigenesis remains undetermined. In this study, we found that FAK (Focal adhesion kinase) expression was reduced in BRAFV600E-mutant adenomas/polyps in mice and patients. In Vill-Cre;BRAFV600E/+;Fakfl/fl mice, Fak deletion maximized BRAFV600E's oncogenic activity and increased cecal tumor incidence to 100%. Mechanistically, our results showed that Fak loss, without jeopardizing BRAFV600E-induced ERK pathway transcriptional output, reduced EGFR (epidermal growth factor receptor)-dependent ERK phosphorylation. Reduction in ERK phosphorylation increased the level of Lgr4, promoting intestinal stemness and cecal tumor formation. Our findings show that a "just-right" ERK signaling optimal for BRAFV600E-induced cecal tumor formation can be achieved via Fak loss-mediated downregulation of ERK phosphorylation.

13.
medRxiv ; 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-37090539

RESUMO

Background and Aims: The microbiome has long been suspected of a role in colorectal cancer (CRC) tumorigenesis. The mutational signature SBS88 mechanistically links CRC development with the strain of Escherichia coli harboring the pks island that produces the genotoxin colibactin, but the genomic, pathological and survival characteristics associated with SBS88-positive tumors are unknown. Methods: SBS88-positive CRCs were identified from targeted sequencing data from 5,292 CRCs from 17 studies and tested for their association with clinico-pathological features, oncogenic pathways, genomic characteristics and survival. Results: In total, 7.5% (398/5,292) of the CRCs were SBS88-positive, of which 98.7% (392/398) were microsatellite stable/microsatellite instability low (MSS/MSI-L), compared with 80% (3916/4894) of SBS88 negative tumors (p=1.5x10-28). Analysis of MSS/MSI-L CRCs demonstrated that SBS88 positive CRCs were associated with the distal colon (OR=1.84, 95% CI=1.40-2.42, p=1x10-5) and rectum (OR=1.90, 95% CI=1.44-2.51, p=6x10-6) tumor sites compared with the proximal colon. The top seven recurrent somatic mutations associated with SBS88-positive CRCs demonstrated mutational contexts associated with colibactin-induced DNA damage, the strongest of which was the APC:c.835-8A>G mutation (OR=65.5, 95%CI=39.0-110.0, p=3x10-80). Large copy number alterations (CNAs) including CNA loss on 14q and gains on 13q, 16q and 20p were significantly enriched in SBS88-positive CRCs. SBS88-positive CRCs were associated with better CRC-specific survival (p=0.007; hazard ratio of 0.69, 95% CI=0.52-0.90) when stratified by age, sex, study, and by stage. Conclusion: SBS88-positivity, a biomarker of colibactin-induced DNA damage, can identify a novel subtype of CRC characterized by recurrent somatic mutations, copy number alterations and better survival. These findings provide new insights for treatment and prevention strategies for this subtype of CRC.

15.
Curr Rheumatol Rev ; 20(1): 65-71, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37605393

RESUMO

BACKGROUND: Chikungunya virus infection, transmitted by Aedes mosquito vectors, causes outbreaks of chikungunya fever (CHIKF), throughout the tropical and subtropical world. Following acute infection, many CHIKF patients develop a second phase, chronic and disabling arthritis. OBJECTIVE: To evaluate the impact of chikungunya arthritis (CHIKA) on quality of life and disability in a cohort of Brazilian CHIKA patients. METHODS: We conducted a descriptive, non-interventionist, retrospective cross-sectional study analysing data collected from the medical records of chikungunya virus-infected patients treated between June 1, 2022, and June 30, 2022, in the Brazilian rheumatology clinic of one of us (JKA). To assess disability, quality of life, and pain, patients were evaluated using the Health Assessment Questionnaire Disability Index (HAQ-DI), 12-Item Short-Form Health Survey (SF-12), and Visual Analog Scale (VAS) pain. RESULTS: Forty-two women with a mean (± SD) age of 57.83 (± 13.05) years had CHIKF confirmed by chikungunya-specific serology. The mean (± SD) time between the onset of chikungunya symptoms and the first clinic visit was 55.19 (± 25.88) days. At this visit, the mean (± SD) VAS pain score and DAS28-ESR were 77.26 (± 23.71) and 5.8 (± 1.29), respectively. The mean (± SD) HAQDI score was 1.52 (± 0.67). The mean (± SD) SF-12 PCS-12 was 29.57 (± 8.62) and SF-12 MCS-12 was 38.42 (± 9.85). CONCLUSION: CHIKA is often highly disabling. As the mosquito vectors that transmit this illness have spread to every continent except Antarctica, there is a potential for widespread public health impact from CHIKA and the need for more effective, early intervention to prevent CHIKA.


Assuntos
Artrite , Febre de Chikungunya , Animais , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/complicações , Qualidade de Vida , Estudos Transversais , Estudos Retrospectivos , Artrite/epidemiologia , Artrite/etiologia , Dor , Índice de Gravidade de Doença
16.
Rev. Soc. Bras. Med. Trop ; 57: e00404, 2024. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1559191

RESUMO

ABSTRACT Background: Chikungunya fever is an emerging global infection transmitted by Aedes mosquitoes that manifests as an acute febrile illness with joint pain and can lead to chronic arthritis. The mechanism underlying chronic joint damage remains unclear; however, chronic chikungunya arthritis shares similarities with rheumatoid arthritis. Disease-modifying antirheumatic drugs have revolutionized rheumatoid arthritis treatment by preventing joint damage. However, the role of these therapies in chronic chikungunya arthritis has not been determined. We conducted a systematic review to evaluate the burden of joint structural damage in chronic chikungunya arthritis to help to define the role of disease-modifying therapy in this disease. Methods: This systematic review included retrospective and prospective studies, trials, and case reports evaluating joint damage caused by chikungunya virus. Various databases were searched without any date or language restrictions. Study selection was conducted independently by two researchers, and data were extracted from the articles selected. Results: A total of 108 studies were initially evaluated, with 8 meeting the inclusion criteria. Longitudinal studies have reported persistent joint pain from chikungunya infection and the progression of radiographic joint damage up to 13 years post-infection. Joint imaging revealed synovial inflammation, bone erosion, and cartilage destruction in patients with chronic chikungunya arthritis. Conclusions: Few studies have addressed chikungunya-induced joint damage, limiting our understanding of chronic chikungunya arthritis. Nevertheless, chronic chikungunya arthritis has similarities to rheumatoid arthritis. The success of early disease-modifying antirheumatic drug therapy in rheumatoid arthritis underscores the need for comprehensive research on its role in chikungunya arthritis.

17.
Rev Soc Bras Med Trop ; 56: 0341, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38088664

RESUMO

Chikungunya fever (CHIK) is a neglected tropical disease associated with chronic arthritis. CHIK is usually a self-limiting condition; however, extra-articular manifestations present as atypical illness in a minority of patients. These atypical features may mimic other conditions and potentially distract physicians from the true diagnosis. This review analyzes the evidence of many unusual extra-articular manifestations reported in cases of CHIK. Depending on the affected system, these unusual manifestations include encephalitis, myocarditis, acute interstitial nephritis, cutaneous manifestations, acute anterior uveitis, abdominal pain, and depression. In addition, coinfections and comorbidities may cause atypical illness and obscure the diagnosis. Further studies are required to clarify the pathophysiology and natural history of CHIK, as it remains a burdening condition. Exploring its atypical symptoms may be the missing scientific piece of this puzzle.


Assuntos
Febre de Chikungunya , Vírus Chikungunya , Coinfecção , Humanos , Febre de Chikungunya/complicações , Febre de Chikungunya/diagnóstico , Doença Aguda , Dor Abdominal
18.
Cancer Med ; 2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38155458

RESUMO

BACKGROUND: Sedentary behaviours have been associated with increased risks of some common cancers in epidemiological studies; however, it is unclear if these associations are causal. METHODS: We used univariable and multivariable two-sample Mendelian randomisation (MR) to examine potential causal relationships between sedentary behaviours and risks of breast, colorectal and prostate cancer. Genetic variants associated with self-reported leisure television watching and computer use were identified from a recent genome-wide association study (GWAS). Data related to cancer risk were obtained from cancer GWAS consortia. A series of sensitivity analyses were applied to examine the robustness of the results to the presence of confounding. RESULTS: A 1-standard deviation (SD: 1.5 h/day) increment in hours of television watching increased risk of breast cancer (OR per 1-SD: 1.15, 95% confidence interval [CI]: 1.05-1.26) and colorectal cancer (OR per 1-SD: 1.32, 95% CI: 1.16-1.49) while there was little evidence of an association for prostate cancer risk (OR per 1-SD: 0.94, 95% CI: 0.84-1.06). After adjusting for years of education, the effect estimates for television watching were attenuated (breast cancer, OR per 1-SD: 1.08, 95% CI: 0.92-1.27; colorectal cancer, OR per 1-SD: 1.08, 95% CI: 0.90-1.31). Post hoc analyses showed that years of education might have a possible confounding and mediating role in the association between television watching with breast and colorectal cancer. Consistent results were observed for each cancer site according to sex (colorectal cancer), anatomical subsites and cancer subtypes. There was little evidence of associations between genetically predicted computer use and cancer risk. CONCLUSIONS: Our univariable analysis identified some positive associations between hours of television watching and risks of breast and colorectal cancer. However, further adjustment for additional lifestyle factors especially years of education attenuated these results. Future studies using objective measures of exposure can provide new insights into the possible role of sedentary behaviour in cancer development.

19.
bioRxiv ; 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38014263

RESUMO

Multiplexed imaging technologies have made it possible to interrogate complex tumor microenvironments at sub-cellular resolution within their native spatial context. However, proper quantification of this complexity requires the ability to easily and accurately segment cells into their sub-cellular compartments. Within the supervised learning paradigm, deep learning based segmentation methods demonstrating human level performance have emerged. Here we present an unsupervised segmentation (UNSEG) method that achieves deep learning level performance without requiring any training data. UNSEG leverages a Bayesian-like framework and the specificity of nucleus and cell membrane markers to construct an a posteriori probability estimate of each pixel belonging to the nucleus, cell membrane, or background. It uses this estimate to segment each cell into its nuclear and cell-membrane compartments. We show that UNSEG is more internally consistent and better at generalizing to the complexity of tissue samples than current deep learning methods. This allows UNSEG to unambiguously identify the cytoplasmic compartment of a cell, which we employ to demonstrate its use in an example biological scenario. Within the UNSEG framework, we also introduce a new perturbed watershed algorithm capable of stably and accurately segmenting a cell nuclei cluster into individual cell nuclei. Perturbed watershed can also be used as a standalone algorithm that researchers can incorporate within their supervised or unsupervised learning approaches to replace classical watershed. Finally, as part of developing UNSEG, we have generated a high-quality annotated gastrointestinal tissue dataset, which we anticipate will be useful for the broader research community. Segmentation, despite its long antecedents, remains a challenging problem, particularly in the context of tissue samples. UNSEG, an easy-to-use algorithm, provides an unsupervised approach to overcome this bottleneck, and as we discuss, can help improve deep learning based segmentation methods by providing a bridge between unsupervised and supervised learning paradigms.

20.
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