Genetic Study of BRAF V600E and SMO L412F Mutations in Japanese Patients with Ameloblastoma

2022 ◽  
pp. 106689692110642
Author(s):  
Katsutoshi Kokubun ◽  
Kei Yamamoto ◽  
Yoshihiko Akashi ◽  
Takatoshi Chujo ◽  
Kei Nakajima ◽  
...  

Background and aim: Ameloblastoma is a benign, intraosseous, progressively growing, epithelial, odontogenic neoplasm. BRAF and SMO mutations have been reported in ameloblastoma. In this study, we evaluated BRAF V600E and SMO L412F mutations; and assessed the relationship between BRAF V600E mutant expression and the clinicopathological features in Japanese patients with ameloblastoma. Methods: We examined 24 formalin-fixed paraffin-embedded samples. All specimens were from patients with mandibular ameloblastoma: 20 were conventional ameloblastoma and 4 were unicystic ameloblastoma. The BRAF V600E mutation was assessed by Sanger sequencing and immunohistochemistry, and the SMO L412F mutation was assessed only by Sanger sequencing. Results: Twenty of the 24 (83%) ameloblastoma samples carried the BRAF V600E mutation; 22 of the 24 (92%) samples were immunohistochemically positive for BRAF V600E. However, the SMO L412F mutation was not detected in any of them. The BRAF V600E mutation status did not correlate with the clinicopathological features, such as age, sex, location, method, recurrence, and subtype. Conclusion: BRAF inhibitors could be a potential treatment option for Japanese patients with ameloblastoma, harboring the BRAF V600E mutation.

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Justyna Durślewicz ◽  
Anna Klimaszewska-Wiśniewska ◽  
Paulina Antosik ◽  
Anna Kasperska ◽  
Dariusz Grzanka ◽  
...  

The BRAF V600E mutation is an important oncological target in certain central nervous system (CNS) tumors, for which a possible application of BRAF-targeted therapy grows continuously. In the present study, we aim to determine the prevalence of BRAF V600E mutations in a series of ganglioglioma (GG) and pilocytic astrocytoma (PA) cases. Simultaneously, we decided to verify whether the combination of fully automated tests—BRAF-VE1 immunohistochemistry (IHC) and Idylla BRAF mutation assay—may be useful to accurately predict it in the case of specified CNS tumors. The study included 49 formalin-fixed, paraffin-embedded tissues, of which 15 were GG and 34 PA. Immunohistochemistry with anti-BRAF V600E (VE1) antibody was performed on tissue sections using the VentanaBenchMark ULTRA platform. All positive or equivocal cases on IHC and selected negative ones were further assessed using the Idylla BRAF mutation assay coupled with the Idylla platform. The BRAF-VE1 IHC was positive in 6 (6/49; 12.3%) and negative in 39 samples (39/49; 79.6%). The interpretation of immunostaining results was complicated in 4 cases, of which 1 tested positive for the Idylla BRAF mutation assay. Therefore, the overall positivity rate was 14.3%. This included 2 cases of GG and 5 cases of PA. Our study found that BRAF V600E mutations are moderately frequent in PA and GG and that for these tumor entities, IHC VE1 is suitable for screening purposes, but all negative, equivocal, and weak positive cases should be further tested with molecular biology techniques, of which the Idylla system seems to be a promising tool.


2019 ◽  
Vol 78 (9) ◽  
pp. 788-790 ◽  
Author(s):  
Letícia Ferro Leal ◽  
Rodrigo de Oliveira Cavagna ◽  
Nathalia Cristina Campanella ◽  
Bruna Mançano ◽  
Gisele Caravina Almeida ◽  
...  

Abstract Medulloblastoma is the most frequent malignant brain tumor in children, representing 20% of all childhood brain tumors. Currently, medulloblastomas are molecularly classified in 4 subgroups that are associated with distinctive clinicopathological features. KBTBD4 mutations were recently described in a subset of MBGRP3 and MBGRP4 medulloblastomas subgroups. However, no other studies reported KBTBD4 mutations in medulloblastomas. Thus, our aim was to investigate KBTBD4 mutations in a Brazilian series of medulloblastoma. We evaluated 128 medulloblastoma patients molecularly classified from 4 Brazilian reference centers. DNA from formalin-fixed, paraffin-embedded samples was screened for KBTBD4 hotspot mutations by Sanger sequencing. Most of the patients were male, average age was 16.5 years old and average overall survival was 55.9 months. The predominant histological subtype was the classic subtype, followed by nodular/desmoplastic, and the predominant medulloblastoma molecular subtype was the MBSHH subgroup (46%), followed by MBGRP3 and MBGRP4 (19%/each), and MBWNT (16%). Among the 128 samples, 111 were successfully sequenced. No KBTBD4 mutations were identified in 111 samples. Our findings suggest that KBTBD4 mutations are uncommon in Brazilian MBGRP3 and MBGRP4 medulloblastomas subgroups. Further studies in a larger series of MBGRP3 and MBGRP4 medulloblastomas are warranted to better assess role of KBTBD4 mutations.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e19007-e19007
Author(s):  
Maria Eugenia Mazzei ◽  
Jimena Hochman ◽  
Gonzalo Manrique ◽  
Ana Luisa Marino ◽  
Lucia Beatriz Delgado ◽  
...  

e19007 Background: Vemurafenib approval by the FDA determines a new era for the treatment of metastatic melanoma in those patients with BRAF V600E mutation. This mutation is reported in about 50% of melanomas and is more common in melanomas on skin without chronic sun induced damage. The aim of this study was to evaluate the frequency of BRAF V600E mutation in Uruguayan melanoma patients, in order to analyze whether the use of vemurafenib would impact on our population. Methods: Formalin fixed, paraffin embedded tissues from 27 primary cutaneous melanomas, were obtained from files of the the Dermatopathology Unit, Department of Dermatology, Hospital de Clínicas in Montevideo, Uruguay. Most were Superficial Spreading Melanomas from skin without chronic sun induced damage. Microdissection of melanoma cells from paraffin embedded tissue was performed under microscopic visualization using a micromanipulator equipment. ADN extraction was performed and the BRAF V600E was detected by ASO-PCR. Results: Of the 27 melanoma samples analyzed, we detected the BRAF V600E mutation in 21. This determines a 77.8% frequency of mutation, a higher percentage than reported in the literature. This could be explained in different ways. The demographic characteristics of Uruguayan population are very peculiar, complying with a genetic admixture of Europeans(mostly from Spain), Amerindians (10%) and alow percentage of Africans (6%), which could explain the high incidence of BRAF V600E mutation. On the other hand, these melanomas were from skin without chronic sun induced damage, this type of melanomas have the highest rate of mutation. Finally, this mutation was analyzed in samples microdissected from melanoma biopsies, the fact that the cells were precisely removed from the tumor could also explain the high frequency of mutation. Conclusions: In this study we found a high frequency of BRAF V600E mutation in Uruguayan malignant melanoma patients, this could be explained by population genetic admixture, the melanoma subtype or technical characteristics. Further studies comparing techniques should be performed in our country to clarify this point.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gabriel A. Colozza-Gama ◽  
Fabiano Callegari ◽  
Nikola Bešič ◽  
Ana C. de J. Paviza ◽  
Janete M. Cerutti

AbstractSomatic mutations in cancer driver genes can help diagnosis, prognosis and treatment decisions. Formalin-fixed paraffin-embedded (FFPE) specimen is the main source of DNA for somatic mutation detection. To overcome constraints of DNA isolated from FFPE, we compared pyrosequencing and ddPCR analysis for absolute quantification of BRAF V600E mutation in the DNA extracted from FFPE specimens and compared the results to the qualitative detection information obtained by Sanger Sequencing. Sanger sequencing was able to detect BRAF V600E mutation only when it was present in more than 15% total alleles. Although the sensitivity of ddPCR is higher than that observed for Sanger, it was less consistent than pyrosequencing, likely due to droplet classification bias of FFPE-derived DNA. To address the droplet allocation bias in ddPCR analysis, we have compared different algorithms for automated droplet classification and next correlated these findings with those obtained from pyrosequencing. By examining the addition of non-classifiable droplets (rain) in ddPCR, it was possible to obtain better qualitative classification of droplets and better quantitative classification compared to no rain droplets, when considering pyrosequencing results. Notable, only the Machine learning k-NN algorithm was able to automatically classify the samples, surpassing manual classification based on no-template controls, which shows promise in clinical practice.


2021 ◽  
Vol 10 (11) ◽  
pp. 2304
Author(s):  
Karolina Skubisz ◽  
Joanna Januszkiewicz-Caulier ◽  
Patrycja Cybula ◽  
Elwira Bakuła-Zalewska ◽  
Krzysztof Goryca ◽  
...  

The data demonstrating a correlation between sonographic markers of malignancy of thyroid cancer (TC) and its genetic status are scarce. This study aimed to assess whether the addition of genetic analysis at the preoperative step of TC patients’ stratification could aid their clinical management. The material consisted of formalin-fixed paraffin-embedded tumor fragments of 49 patients who underwent thyroidectomy during the early stages of papillary TC (PTC). Tumor DNA and RNA were subjected to next-generation sequencing (NGS) on Ion Proton using the Oncomine™ Comprehensive Assay panel. We observed a significant correlation between BRAF V600E and a higher EU-TIRADS score (p-value = 0.02) with a correlation between hypoechogenicity and taller-than-wide tumor shape in analysed patients. There were no other significant associations between the identified genetic variants and other clinicopathological features. For TC patient’s stratification, a strong suspicion of BRAF V600E negativity in preoperative management of TC patients could limit the over-treatment of asymptomatic, very low-risk, indolent disease and leave room for active surveillance.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yan Helen Yan ◽  
Sherry X. Chen ◽  
Lauren Y. Cheng ◽  
Alyssa Y. Rodriguez ◽  
Rui Tang ◽  
...  

AbstractWhole exome sequencing (WES) is used to identify mutations in a patient’s tumor DNA that are predictive of tumor behavior, including the likelihood of response or resistance to cancer therapy. WES has a mutation limit of detection (LoD) at variant allele frequencies (VAF) of 5%. Putative mutations called at ≤ 5% VAF are frequently due to sequencing errors, therefore reporting these subclonal mutations incurs risk of significant false positives. Here we performed ~ 1000 × WES on fresh-frozen and formalin-fixed paraffin-embedded (FFPE) tissue biopsy samples from a non-small cell lung cancer patient, and identified 226 putative mutations at between 0.5 and 5% VAF. Each variant was then tested using NuProbe NGSure, to confirm the original WES calls. NGSure utilizes Blocker Displacement Amplification to first enrich the allelic fraction of the mutation and then uses Sanger sequencing to determine mutation identity. Results showed that 52% of the 226 (117) putative variants were disconfirmed, among which 2% (5) putative variants were found to be misidentified in WES. In the 66 cancer-related variants, the disconfirmed rate was 82% (54/66). This data demonstrates Blocker Displacement Amplification allelic enrichment coupled with Sanger sequencing can be used to confirm putative mutations ≤ 5% VAF. By implementing this method, next-generation sequencing can reliably report low-level variants at a high sensitivity, without the cost of high sequencing depth.


1996 ◽  
Vol 44 (11) ◽  
pp. 1251-1259 ◽  
Author(s):  
J R Reeves ◽  
J J Going ◽  
G Smith ◽  
T G Cooke ◽  
B W Ozanne ◽  
...  

The relationship between expression of the c-erbB-2 proto-oncogene and the biology of breast cancer has been investigated widely, most studies using immunohistochemistry in formalin-fixed, paraffin-embedded tissues. This technique is at best semiquantitative and there is a high degree of interstudy variability because of its subjective nature and poor methodological standardization. The relationship between the levels of expression and biology can be examined thoroughly only with an accurately quantitative technique. We have developed a radioimmunohistochemical assay to measure p185(erbB-2) in tissue biopsy specimens. The method involves incubating frozen sections with 125I-labeled monoclonal antibody, microautoradiograpy, and grain counting with image analysis. Sections of cell pellets with known c-erbB-2 levels are processed with each batch of samples as internal calibration standards. We have quantified c-erbB-2 expression in 60 breast carcinomas and compared the results with conventional immunohistochemistry. Radioimmunohistochemistry measured receptor levels throughout the range of expression in breast carcinomas, whereas conventional immunohistochemistry detected the protein only in the highest expressing tumors. The quantitative, objective data produced by radioimmunohistochemistry allow a more thorough evaluation of the relationship between c-erbB-2 expression and tumor biology. This technique may have applications in other fields where quantitative data is required and relevant monoclonal antibodies are available.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3588-3588
Author(s):  
Ko Kudo ◽  
Rika Kanezaki ◽  
Akie Kobayashi ◽  
Tomohiko Sato ◽  
Takuya Kamio ◽  
...  

Introduction: The BRAF mutation V600E, the most common somatic mutation in Langerhans cell histiocytosis (LCH), has been reported in approximately 50% of LCH patients and is associated with certain high-risk clinical features. Precursors harboring this mutation can differentiate into Langerhans cells resulting in infiltrates in multiple organs under inflammatory conditions. However, BRAF status in the bone marrow of pediatric LCH patients is unclear. The present study examined somatic mutations in paired tumor and bone marrow samples, using a highly sensitive assay involving next-generation targeted sequencing and droplet digital polymerase chain reaction (PCR) for pediatric LCH patients. Methods: Between 1996 and 2019, in total of 17 Japanese pediatric patients with LCH were enrolled. The male/female ratio was 7/11. Ages of onset of LCH were median 13 months (range 5-193 months). At diagnosis of LCH, 2 patients were positive for risk organ involvement, 15 were negative. We retrospectively performed mutational analyses of 17 LCH cases using formalin-fixed paraffin-embedded LCH tumor specimens to provide templates for PCR-based targeted amplicon sequencing with customized primers to detect mutations in exons 12 and 15 in BRAF, and exons 2 and 3 in MAP2K1. Thereafter, we identified somatic mutations in the 17 paired bone marrow samples via droplet digital allele-specific PCR, targeting BRAF V600E and BRAF exon 12 in-frame deletion 496-500 (Ex12 in-del). Results: We detected BRAF V600E in 11 of 17 tumor samples (65%) and the BRAF Ex 12 in-del in 3 of 17 tumors (18%). We identified BRAF V600E in bone marrow samples in 10 of the 11 cases (90%) with the mutation in the tumor at low variant allele frequency (median 0.25%, range 0.14-7.0%). BRAF Ex 12 in-del was not detected in the bone marrow. Cases with detectable bone marrow involvement included eight patients with multi-system disease affecting multiple organs, one patient with multi-focal bone disease, and one patient with single-system disease. Clinical phenotypes including relapse did not correlate with BRAF V600E upon detection in the bone marrow. Conclusion: We established the sensitive assay based on PCR-based targeted NGS for detecting somatic mutations in LCH even accessible for formalin-fixed, paraffin-embedded clinical specimens. Bone marrow involvement is frequently detectable at the molecular level in pediatric LCH with the BRAF V600E mutation. A prospective study is warranted to evaluate the clinical impact of mutational burden in bone marrow. Disclosures Kudo: Unum Therapeutics: Patents & Royalties. Imai:Juno Therapeutics: Patents & Royalties.


2020 ◽  
Author(s):  
Mahmoud Al-Masri ◽  
Tawfiq Al-Shobaki ◽  
Hani Al-Najjar ◽  
Rafal Iskanderian ◽  
Enas Younis ◽  
...  

Abstract Introduction BRAF V600E is one of the most common mutations in Papillary Thyroid Cancer (PTC). Its clinical correlation has been extensively studied with contradictory results. The aim of this study is to evaluate the oncological impact of BRAF V600E mutation on a cohort of Middle Eastern PTC patients treated at a single institute.Methods Patients with histologically confirmed PTC that were treated surgically between 2006 to 2015 were included in the study. Formalin fixed paraffin embedded tumor blocks were sectioned and tested for BRAF V600E mutation. Short- and long-term oncological outcomes were collected. Results 128 patients (68% females) were included with a mean age of 38 years (±13.8). Median follow-up was 50 months. BRAF V600E mutation was found in 71% of patientsIThe BRAF negative tumors were significantly larger than the BRAF positive (3.47 cm versus 2.31 cm respectively, P = 0.009). All other clinicopathological characteristics were comparable between BRAF V600E mutation positive and negative groups. The two groups showed similar 5-year Disease-free (P= 0.37) and Overall survival rates (P = 0.94).Conclusion BRAF V600E mutation did not affect loco-reginal recurrence, distant metastasis, overall and disease-free survival. These results support the diversity of BRAF V600E significance among various ethnicities.


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