Common Molecular Marker for Glioma: BRAF V600E
Introduction:
The BRAF V600E mutation is the most common mutation site of the BRAF gene and serves as a biomarker for targeted therapy with significant clinical implications in various solid tumors. Several BRAF inhibitors have been clinically approved for use in solid tumors such as melanoma and colorectal cancer. BRAF V600E mutations occur in multiple subtypes of glioma, with limited value in differentiation and prognosis, but its relationship with specific tissue locations is important for the diagnostic classification of glioma.。
Overview of BRAF V600E
The BRAF gene is located at 7q34 and is a member of the RAF family, which also includes the ARAF and RAF1 (CRAF) genes. It is a key transducer in the RAS/RAF/MEK/ERK/MAPK pathway, involved in regulating various intracellular biological events such as cell growth, differentiation, and apoptosis.In solid tumors, the BRAF mutation has the highest incidence, with the V600E substitution accounting for approximately 80% of the mutations.The BRAF V600E mutation can lead to sustained activation of the MAPK signaling pathway, causing changes in tumor cell differentiation, proliferation, metabolism, and growth. Simply put, BRAF V600E is a mutant oncogene.
Pathological Significance of BRAF V600E
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Diagnosis and Differential Diagnosis:It has strong diagnostic value in ganglioglioma, pleomorphic xanthoastrocytoma, and pilocytic astrocytoma.
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BRAF V600E is a biomarker for targeted therapy:Patients with BRAF gene mutations can benefit from targeted drugs.
Detection of BRAF V600E
Multiplestudies have shown a 1:1 correspondence between BRAF V600E mutation and IHC results in epithelioid glioblastoma, pleomorphic xanthoastrocytoma, etc.The sensitivity and specificity of IHC for detecting BRAF V600E are 94%.It is recommended to first use IHC for detection; if the result is negative, further genetic testing should be performed.
Figure 1: Example of BRAF V600E IHC staining in glioblastoma (source literature)
BRAF V600E and Targeted Therapy
BRAF V600E is a biomarker for targeted therapy. Currently, inhibitors targeting the BRAF mutation site include MEK inhibitors and RAF inhibitors.BRAF inhibitors approved by NMPA include trametinib (a MEK inhibitor) and dabrafenib, vemurafenib (RAF inhibitors), primarily used in thyroid cancer, non-small cell lung cancer, and melanoma.In glioma research, a 2017 Canadian study found that six pediatric patients with low-grade glioma harboring BRAF V600E mutations, who had disease progression after conventional therapy, responded significantly to BRAF inhibitors, with tumor shrinkage ranging from 49% to 80%.Combining BRAF inhibitors with specific drugs may maximize benefits for glioma patients with BRAF V600E mutations.Ongoing related trials will clarify the therapeutic effects of BRAF inhibitors combined with radiotherapy; we only need to await good news.
Related Antibodies from Maxin
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Antibody Name |
Product Number |
Clone Number |
Positive Location |
|
BRAF V600E |
RMA-0839 |
RM8 |
Cytoplasm |
References:
[1] Chinese Glioma Cooperative Group, Chinese Glioma Genome Atlas Project. Chinese guidelines for molecular diagnosis and treatment of glioma[J]. Chinese Journal of Neurosurgery, 2014, 30(5):435-444. DOI:10.3760/cma.j.issn.1001-2346.2014.05.002.
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[4] Kleinschmidt-DeMasters, Aisner, Foreman, et al. BRAF V600E mutation in epithelioid glioblastoma: BRAF VE1 immunostaining pattern[J]. Journal of Clinical and Experimental Pathology, 2015(11):1320-1320.
[5] Zeynep T , Melin G , Mustafa H , et al. BRAF V600E mutation and BRAF VE1 immunoexpression profiles in different types of glioblastoma[J]. Oncology Letters, 2018, 16:2402-2408.
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