Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
400 result(s) for "braf v600e"
Sort by:
BRAFV600E mutation impinges on gut microbial markers defining novel biomarkers for serrated colorectal cancer effective therapies
Background Colorectal cancer (CRC) harboring BRAF V600E mutation exhibits low response to conventional therapy and poorest prognosis. Due to the emerging correlation between gut microbiota and CRC carcinogenesis, we investigated in serrated BRAF V600E cases the existence of a peculiar fecal microbial fingerprint and specific bacterial markers, which might represent a tool for the development of more effective clinical strategies. Methods By injecting human CRC stem-like cells isolated from BRAF V600E patients in immunocompromised mice, we described a new xenogeneic model of this subtype of CRC. By performing bacterial 16S rRNA sequencing, the fecal microbiota profile was then investigated either in CRC-carrying mice or in a cohort of human CRC subjects. The microbial communities’ functional profile was also predicted. Data were compared with Mann-Whitney U, Welch’s t-test for unequal variances and Kruskal-Wallis test with Benjamini–Hochberg false discovery rate (FDR) correction, extracted as potential BRAF class biomarkers and selected as model features. The obtained mean test prediction scores were subjected to Receiver Operating characteristic (ROC) analysis. To discriminate the BRAF status, a Random Forest classifier (RF) was employed. Results A specific microbial signature distinctive for BRAF status emerged, being the BRAF -mutated cases closer to healthy controls than BRAF wild-type counterpart. In agreement, a considerable score of correlation was also pointed out between bacteria abundance from BRAF -mutated cases and the level of markers distinctive of BRAF V600E pathway, including those involved in inflammation, innate immune response and epithelial-mesenchymal transition. We provide evidence that two candidate bacterial markers, Prevotella enoeca and Ruthenibacterium lactatiformans , more abundant in BRAF V600E and BRAF wild-type subjects respectively, emerged as single factors with the best performance in distinguishing BRAF status (AUROC = 0.72 and 0.74, respectively, 95% confidence interval). Furthermore, the combination of the 10 differentially represented microorganisms between the two groups improved performance in discriminating serrated CRC driven by BRAF mutation from BRAF wild-type CRC cases (AUROC = 0.85, 95% confidence interval, 0.69–1.01). Conclusion Overall, our results suggest that BRAF V600E mutation itself drives a distinctive gut microbiota signature and provide predictive CRC-associated bacterial biomarkers able to discriminate BRAF status in CRC patients and, thus, useful to devise non-invasive patient-selective diagnostic strategies and patient-tailored optimized therapies.
A Robust Immunohistochemistry‐Based Classification for BRAF V600E‐Mutant Colorectal Cancer With Clinical Implications
BRAF V600E‐mutant colorectal cancer (CRC) represents a distinct molecular subtype with considerable heterogeneity in tumor biology and therapeutic response. Although gene expression‐based classifications (BM1/BM2 subtypes) provide valuable insights into underlying molecular and immune features, their clinical application is limited by the need for high‐throughput sequencing. This study aims to establish an immunohistochemistry (IHC)‐based classification system to enable practical subtype stratification and aid prognostic and therapeutic evaluation. Using two independent cohorts (public dataset, n = 218; institutional cohort, n = 122), we performed differential expression analysis, machine learning modeling, and clinical feasibility evaluation. Fourteen candidate markers were identified, and a decision tree algorithm selected CD8 and ARHGEF17 as optimal classifiers. Based on these markers, two IHC‐based subtypes were established: iBM1 (CD8+/ARHGEF17−) and iBM2 (CD8− with any ARHGEF17 expression or CD8+/ARHGEF17+). The IHC‐based subtypes showed concordance with transcriptomic BM subtypes (training: 82.69%, κ = 0.55; validation: 72.22%, κ = 0.44; prospective: 83.33%, κ = 0.57). Transcriptomic profiling revealed enrichment of immune activation and epithelial–mesenchymal transition in iBM1, and cell cycle‐related pathways in iBM2. In clinical validation, iBM1 was associated with poorer survival but greater sensitivity to immune checkpoint inhibitors. This IHC‐based classification provides a practical and accessible approach for BM subtype stratification, reflecting underlying molecular and immune characteristics, and may support prognostic assessment and therapeutic decision‐making in BRAF V600E‐mutant CRC. This study develops an immunohistochemistry (IHC)‐based classification system for BRAF V600E‐mutant colorectal cancer, enabling practical stratification into iBM1 and iBM2 subtypes using CD8 and ARHGEF17 markers. The IHC‐defined subtypes demonstrated concordance with transcriptomic BM1/BM2 classifications and reflected distinct molecular and immune features, with iBM1 associated with poorer prognosis but enhanced responsiveness to immune checkpoint blockade.
Specific activation of glycolytic enzyme enolase 2 in BRAF V600E‐mutated colorectal cancer
The BRAF V600E mutation occurs in approximately 10% of patients with metastatic colorectal cancer (CRC) and constitutes a distinct subtype of the disease with extremely poor prognosis. To address this refractory disease, we investigated the unique metabolic gene profile of BRAF V600E‐mutated tumors via in silico analysis using a large‐scale clinical database. We found that BRAF V600E‐mutated tumors exhibited a specific metabolic gene expression signature, including some genes that are associated with poor prognosis in CRC. We discovered that BRAF V600E‐mutated tumors expressed high levels of glycolytic enzyme enolase 2 (ENO2), which is mainly expressed in neuronal tissues under physiological conditions. In vitro experiments using CRC cells demonstrated that BRAF V600E‐mutated cells exhibited enhanced dependency on ENO2 compared to BRAF wild‐type cancer cells and that knockdown of ENO2 led to the inhibition of proliferation and migration of BRAF V600E‐mutated cancer cells. Moreover, inhibition of ENO2 resulted in enhanced sensitivity to vemurafenib, a selective inhibitor of BRAF V600E. We identified AP‐1 transcription factor subunit (FOSL1) as being involved in the transcription of ENO2 in CRC cells. In addition, both MAPK and PI3K/Akt signaling were suppressed upon inhibition of ENO2, implying an additional oncogenic role of ENO2. These results suggest the crucial role of ENO2 in the progression of BRAF V600E‐mutated CRC and indicate the therapeutic implications of targeting this gene. There was no significant difference in the expression of ENO1 in BRAF V600E‐mutated CRC and other types of CRC, but ENO2 levels were significantly higher in BRAF V600E‐mutated CRC.
Neoadjuvant BRAF and MEK inhibitor therapy elicits pathological complete response in stage IIIA non‐small cell lung cancer harboring BRAF V600E mutation: A case report
In recent years, significant improvement has been made in the management of non‐small cell lung cancer (NSCLC), primarily driven by advances in targeted therapy and immunotherapy. Research on neoadjuvant targeted therapy has also experienced considerable development, primarily directed towards NSCLC harboring epidermal growth factor receptor or anaplastic lymphoma kinase mutations. Nevertheless, there remains a dearth of studies investigating neoadjuvant targeted therapy in the context of BRAF (V‐Raf murine sarcoma viral oncogene homolog B) V600E mutant NSCLC. Herein, we describe the clinical trajectory of a stage IIIA NSCLC patient who underwent a two‐month course of neoadjuvant targeted therapy comprising BRAF and MEK (mitogen‐activated extracellular signal‐regulated kinase) inhibitors prior to surgical intervention, and subsequent postoperative evaluation unveiled a pathological complete response. The case reported here indicates the efficacy and safety of combining BRAF and MEK inhibitors as neoadjuvant targeted therapy in BRAF V600E‐mutant NSCLC and suggests the potential viability of such a therapeutic modality in improving treatment outcomes in this subset of NSCLC. This case report describes the clinical trajectory of a stage IIIA NSCLC patient who underwent a two‐month course of neoadjuvant targeted therapy comprising BRAF and MEK inhibitors prior to surgical intervention. Subsequent postoperative evaluation unveiled a pathological complete response.
Cerebral infarction after treatment with dabrafenib plus trametinib for BRAF‐V600E‐positive non–small cell lung cancer: A case report
Dabrafenib plus trametinib is the standard treatment for BRAF V600E‐mutated non‐small cell lung cancer. No treatment‐related cerebral infarction (CI) has been reported in previous clinical trials. Here, we described a 61‐year‐old Japanese man with BRAF V600E‐mutated lung adenocarcinoma treated with dabrafenib plus trametinib as a third‐line treatment. On the 10th day of dabrafenib plus trametinib treatment, the patient developed fever and was urgently hospitalized on the 18th day owing to impaired consciousness. The patient had disseminated intravascular coagulation because of infection, was treated with thrombomodulin and ceftriaxone, and subsequently improved. On the 44th day, dabrafenib plus trametinib was resumed with a one‐step dose reduction. Three hours after the first oral administration, the patient developed chills, fever, and hypotension. He received intravenous fluids. On the 64th day, 20 mg prednisolone was administered from the previous day, and dabrafenib plus trametinib was resumed with a further one‐step reduction in dose. Five hours after the first oral administration, the patient developed fever, hypotension, paralysis of the right upper and lower limbs, and dysarthria appeared. Head magnetic resonance imaging revealed multiple cerebral infarcts. Hemoconcentration because of intravascular dehydration may have caused CI. In conclusion, CI should be taken into consideration during treatment with dabrafenib plus trametinib. We report a case of BRAF V600E‐mutated lung adenocarcinoma treated with dabrafenib plus trametinib as a third‐line treatment. Five hours after the first oral administration, the patient developed fever, hypotension, paralysis of the right upper and lower limbs, and dysarthria appeared. Head magnetic resonance imaging revealed multiple cerebral infarcts. Cerebral infarction should be taken into consideration during treatment with dabrafenib plus trametinib.
BRAF non-V600E more frequently co-occurs with IDH1/2 mutations in adult patients with gliomas than in patients harboring BRAF V600E but without a survival advantage
The effects of BRAF and BRAF on the outcomes and the molecular characteristics of adult glioma patients are unknown and need to be explored, although BRAF has been extensively studied in pediatric glioma. Co-occurring mutations and copy number alterations of associated genes in the MAPK and p53 pathways were investigated using data from The Cancer Genome Atlas (TCGA) public database retrieved by cBioPortal. The prognosis of available adult glioma cohorts with BRAF and BRAF mutations were also investigated. Ninety patients with BRAF or BRAF were enrolled in this study, and data from 52 nonredundant patients were investigated. Glioblastoma multiform was the most common cancer type, with BRAF and BRAF . TP53 (56.00% vs. 7.41%), IDH1/2 (36.00% vs. 3.70%), and ATRX (32.00% vs. 7.41%) exhibited more mutations in BRAF than in BRAF , and TP53 was an independent risk factor (56.00% vs. 7.41%). Both BRAF and BRAF frequently overlapped with CDKN2A/2B homozygous deletions (HDs), but there was no significant difference. Survival analysis showed no difference between the BRAF and BRAF cohorts, even after excluding the survival benefit of IDH1/2 mutations and considering the BRAF mutations in the glycine-rich loop (G-loop) and in the activation segment. The estimated mean survival of patients with BRAF & IDH1/2 with mutations in the G-loop groups was the shortest. BRAF exhibited a stronger association with IDH1/2 mutations than BRAF , but no survival advantage was found.
Lead Discovery of Type II BRAF V600E Inhibitors Targeting the Structurally Validated DFG-Out Conformation Based upon Selected Fragments
The success of the first approved kinase inhibitor imatinib has spurred great interest in the development of type II inhibitors targeting the inactive DFG-out conformation, wherein the Phe of the DFG motif at the start of the activation loop points into the ATP binding site. Nevertheless, kinase inhibitors launched so far are heavily biased toward type I inhibitors targeting the active DFG-in conformation, wherein the Phe of the DFG motif flips by approximately 180° relative to the inactive conformation, resulting in Phe and Asp swapping their positions. Data recently obtained with structurally validated type II inhibitors supported the conclusion that type II inhibitors are more selective than type I inhibitors. In our type II BRAF V600E inhibitor lead discovery effort, we identified phenylaminopyrimidine (PAP) and unsymmetrically disubstituted urea as two fragments that are frequently presented in FDA-approved protein kinase inhibitors. We therefore defined PAP and unsymmetrically disubstituted urea as privileged fragments for kinase drug discovery. A pharmacophore for type II inhibitors, 4-phenylaminopyrimidine urea (4-PAPU), was assembled based upon these privileged fragments. Lead compound SI-046 with BRAF V600E inhibitory activity comparable to the template compound sorafenib was in turn obtained through preliminary structure–activity relationship (SAR) study. Molecular docking suggested that SI-046 is a bona fide type II kinase inhibitor binding to the structurally validated “classical DFG-out” conformation of BRAF V600E. Our privileged fragments-based approach was shown to efficiently deliver a bona fide type II kinase inhibitor lead. In essence, the theme of this article is to showcase the strategy and rationale of our approach.
BRAF‐V600E immunohistochemistry in a large series of glial and glial–neuronal tumors
Introduction Some glial–neuronal tumors (GNT) (pleomorphic xantho‐astrocytoma [PXA], ganglioglioma [GG]) display BRAF‐V600E mutation, which represents a diagnostic clue to these entities. Targeted therapies against BRAF‐V600 protein have shown promising results in GNT. The aim of this study was to assess the utility of BRAF‐V600E immunohistochemistry (IHC, clone VE1) in daily practice in a series of 140 glial, and GNT compared to molecular biology (MB) techniques. Methods We performed BRAF‐V600E IHC on all 140 cases. We used Sanger sequencing and allele‐specific quantitative PCR (ASQ‐PCR) to detect BRAF‐V600E mutation when sufficient amount of materiel was available. Results BRAF‐V600E immunostaining was detected in 29.5% of cases (41/140 cases; 61.5% GG/GC/AGG (32/52), 33% PXA, 6.6% pilocytic astrocytomas). In 47 cases, MB could be performed: Sanger sequencing and ASQ‐PCR in 34 cases, ASQ‐PCR only in 11 cases, and Sanger sequencing only in two cases. In initial tumors, Sanger sequencing identified BRAF‐V600E mutation in 19.5% tumors (seven of 36 tested cases). ASQ‐PCR showed mutation in 48.5% tumors (17/35 tested cases). In six cases (5 GG, one PXA), the results were discordant between IHC and MB; the five GG cases were immunopositive for BRAF‐V600E but wild type with both MB techniques. In another 7 GG, the percentage of mutated (ganglion) cells was low, and Sanger sequencing failed to detect the mutation, which was detected by IHC and ASQ‐PCR. Conclusions In tumors with few mutated cells (e.g., GG), anti‐BRAF‐V600E IHC appears more sensitive than Sanger sequencing. The latter, although considered as the gold standard, is not to be used up‐front to detect BRAF mutation in GG. The combination of IHC and ASQ‐PCR appears more efficient to appraise the indication of targeted therapies in these glioneuronal tumors. The aim of this study was to assess the utility of BRAF‐V600E immunohistochemistry (IHC, clone VE1) in daily practice in a series of 140 glial and glial–neuronal tumors compared to molecular biology (MB) techniques. This work shows that the combination of IHC and ASQ‐PCR appears more efficient to appraise the indication of targeted therapies in glioneuronal tumors.
MITF in melanoma: mechanisms behind its expression and activity
MITF (microphthalmia-associated transcription factor) represents a melanocytic lineage-specific transcription factor whose role is profoundly extended in malignant melanoma. Over the last few years, the function of MITF has been tightly connected to plasticity of melanoma cells. MITF participates in executing diverse melanoma phenotypes defined by distinct gene expression profiles. Mutation-dependent alterations in MITF expression and activity have been found in a relatively small subset of melanomas. MITF activity is rather modulated by its upstream activators and suppressors operating on transcriptional, post-transcriptional and post-translational levels. These regulatory mechanisms also include epigenetic and microenvironmental signals. Several transcription factors and signaling pathways involved in the regulation of MITF expression and/or activity such as the Wnt/β-catenin pathway are broadly utilized by various types of tumors, whereas others, e.g., BRAFⱽ⁶⁰⁰ᴱ/ERK1/2 are more specific for melanoma. Furthermore, the MITF activity can be affected by the availability of transcriptional co-partners that are often redirected by MITF from their own canonical signaling pathways. In this review, we discuss the complexity of a multilevel regulation of MITF expression and activity that underlies distinct context-related phenotypes of melanoma and might explain diverse responses of melanoma patients to currently used therapeutics.
Targeting Aberrant RAS/RAF/MEK/ERK Signaling for Cancer Therapy
The RAS/RAF/MEK/ERK (MAPK) signaling cascade is essential for cell inter- and intra-cellular communication, which regulates fundamental cell functions such as growth, survival, and differentiation. The MAPK pathway also integrates signals from complex intracellular networks in performing cellular functions. Despite the initial discovery of the core elements of the MAPK pathways nearly four decades ago, additional findings continue to make a thorough understanding of the molecular mechanisms involved in the regulation of this pathway challenging. Considerable effort has been focused on the regulation of RAF, especially after the discovery of drug resistance and paradoxical activation upon inhibitor binding to the kinase. RAF activity is regulated by phosphorylation and conformation-dependent regulation, including auto-inhibition and dimerization. In this review, we summarize the recent major findings in the study of the RAS/RAF/MEK/ERK signaling cascade, particularly with respect to the impact on clinical cancer therapy.