BRAFV600E Mutation Expression Research Articles

Detection and evaluation of the presence of the BRAF V600E mutation in ameloblastomas in an Indian population

Ameloblastoma is a benign epithelial odontogenic neoplasm that constitutes approximately 1% of all oral tumors and about 9 to 11% of all odontogenic tumors. They are slow-growing, locally invasive, and demonstrate a potential for metastasis and malignant transformation. The molecular pathogenesis of ameloblastoma is attributed to aberrant activity of the signal transduction pathways relating to developmental stages of odontogenesis including the mitogen-activated protein kinase (MAPK) pathway. The BRAF V600E mutation was identified as the most frequently mutated gene in this neoplasm. Studies have shown that use of BRAF inhibitors in patients diagnosed with ameloblastomas led to a significant reduction in tumor volume. To detect the expression of BRAF V600E mutation in ameloblastomas in an Indian population using immunohistochemistry. To compare the difference in the occurrence of the BRAF V600E mutation between mandibular and maxillary cases. Thirty-three formalin-fixed paraffin-embedded tissues of histopathologically proven cases of ameloblastoma were assessed for the BRAF V600E mutation by immunohistochemistry using the BRAF V600E monoclonal antibody. Patient data such as age, sex, anatomical site, recurrence were documented. The statistical analysis was performed using the Pearson Chi-square test and Student's t-test. The present study revealed a high expression of the BRAFV600E mutation in mandibular cases of ameloblastoma among Indians irrespective of the age, sex, site, recurrence or histological pattern. The identification of this driver mutation opens the possibility of an adjuvant therapeutic modality to reduce the significant facial disfigurement and morbidity following surgical management.

Correlation of the Expression of BRAF V600E Mutation With Various Phenotypic Expressions of Thyroid Neoplasms.

AimsWe aimed to assess the incidence of the BRAF V600E mutation in thyroid neoplasms at a tertiary care center and its association with various phenotypic features.Methods and materialWe included all cases diagnosed as thyroid neoplasm in the past decade at the Department of Pathology of our institute and obtained their clinical details from the medical records department of the institute after obtaining permission from the authorities and due International Human Epigenome Consortium clearance. We included data on age, sex, clinical presentation, hormone status, and T and N status of the malignant neoplasms. Hematoxylin and eosin (H&E) slides of all cases were evaluated for the type of neoplasm, nuclear features, invasion into the capsule and vascular spaces, extrathyroidal extension, lymph node metastases, mitoses, necrosis, and presence/absence of amyloid. Paraffin blocks of sections with high tumor density and less normal tissue were chosen for evaluation after H&E staining. The slides showing tumors with large areas of hemorrhage, cystic change, or necrosis were excluded. Two primers were used to amplify a 339-bp fragment containing the V600E mutation in exon 15 of BRAF. Tissues were prepared from formalin-fixed paraffin-embedded (FFPE) blocks, and DNA was isolated using a standard protocol BRAF NF and BRAF NR Primer Standardized Protocol For FFPE Tissue DNA. Percentages and tables have been used for data presentation.ResultsAmong 47 identified cases, 14 were positive for the BRAF V600E mutation and had papillary carcinoma (n = 9) or follicular neoplasms (n = 5; follicular adenoma, n = 3; follicular carcinoma, n = 2). In the BRAF-positive papillary carcinomas, five cases were aged 20-30 years, eight were female, eight (88.88%) were euthyroid, and one was hypothyroid. Furthermore, 55.55% (5/9 cases) of BRAF-positive cases were stage I, 33.3% (3/9 cases) were stage II, and 0.02% (1/9 cases) were stage III.ConclusionsIn our cohort, 31% of cases of papillary thyroid carcinoma (PTC) and 18.72% of follicular neoplasms expressed the BRAF V600E mutation.BRAF V600E mutation-positive papillary thyroid carcinomas consistently showed all characteristic nuclear features, such as nuclear crowding, overlapping, and grooves.Considering the greater prevalence in the younger age group, the importance of mutation surveillance in PTCs for a total thyroidectomy may be warranted in mutation-positive patients.

Expression of B-type RAF V600E in Thyroid Carcinoma and its Association with Histological Type

Introduction: Thyroid cancer is one of the most common cancers amongst all endocrine cancers. Incidence of thyroid malignancy is about 3-4% of all malignancy in India and 80% of thyroid malignancy belongs to Papillary Thyroid Carcinoma (PTC). Factors affecting the prognosis of PTC include patient’s gender, age, histological findings, tumour size, lymph node metastasis, extrathyroidal extension, and remote metastasis. Presence of B-type RAF V600E (BRAF V600E) mutation in thyroid carcinoma patients tends to present with more aggressive clinicopathological behaviours of PTC, prompting more aggressive radioiodine treatment. Aim: To find out the frequency of occurrence and expression of BRAF V600E mutation by Immunohistochemistry (IHC) in thyroid cancer and its association with histological type and Tumour Nodes Metastases (TNM) Staging. Materials and Methods: The present observational retrospective study included patients treated for thyroid carcinoma between January 2014 to February 2019 at RL Jalappa hospital and Research centre, Kolar, Karnataka, India. The IHC was done with rabbit monoclonal anti-BRAF V600E antibody IgG Clone RM8 (VE1). Clinical records, Fine Needle Aspiration Cytology (FNAC) diagnosis were analysed for 45 thyroid carcinoma cases. Immunopositivity was scored positive when unambiguous clear cytoplasmic staining for the antibody was observed in tumour cells. Categorical data was presented in the form of frequencies and proportions and continuous data was presented as mean and standard deviation. The t-test were applied to find out the difference in means among the groups. The p-value <0.05 was considered statistically significant. Results: Out of total 45 cases, 18 were classical PTC, 18 were Follicular Variant of Papillary Thyroid Cancer (FV-PTC), 4 were micropapillary carcinomas, 3 were Follicular carcinomas, 1 was Oncocytic variant of PTC and 1 undifferentiated thyroid carcinoma. Out of total 45 cases, 33 cases (73%) were found to be BRAF V600E positive and 12 (26%) were negative for BRAF V600E. Out of the total 33 BRAF V600E positive cases, 19 cases showed strong staining, 14 cases showed moderately positive staining. Conclusion: The PTC is the most frequent type of thyroid carcinoma amongst all the sub-types. BRAF V600E expression is commonly seen in higher tumour size (T3, T4) and classical PTC. Tumours with extrathyroidal extension and capsular invasion showed strong positivity.

Abstract LB-103: Molecular exploitation of oncogenic stress in melanoma management

Abstract Oncogenic B-RAF and N-RAS mutations are frequently reported in mitogen-activated protein kinase pathways of tumors. BRAF and NRAS mutations are found in more than 30% of all human tumors and 43% (88% V600E, 10% V600K) and 30% (48% Q61K, 40% Q61R) of malignant melanoma. These mutations were considered mutually exclusive except a few (0.7%) cases. BRAF and NRAS mutations are an important clinical marker and prognostic factor in metastatic melanoma. Recently developed BRAFV600E targeted therapies demonstrate significant clinical benefit but the targeted therapeutic options for NRAS-mutant melanomas are still under intense investigation. Importantly, BRAF and NRAS mutations are mutually exclusive, meaning that tumors are rarely found with these two mutations and are reported as lethal to the cancer cells. Hence, molecular behavior and interaction between BRAF and NRAS mutant proteins underline phenotypic complexity which is poorly understood. In the current study, we aimed to determine the translational significance of BRAF and NRAS mutations and their products in cell based studies with metastatic melanoma cell lines. Our lab sought to investigate the common molecular therapeutic target(s) of these genes, responsible for synthetic lethality. By using remote inducible expression system of BRAFV600E mutant gene in NRASQ61R mutant cell lines and vice versa. It is found that 25% (2/8) NRASQ61R mutant cell lines are sensitive to BRAFV600E and NRASQ61R mutation co-expression and have slow-growth phenotype with cells displaying hallmarks of oncogene-induced senescence, apoptosis and cell cycle arrest, more over rescued with BAP1 ectopic expression. While some NRAS mutant cell lines showed no lethal effect to BRAFV600E mutation expression which is well explained by human phospho-kinase array. These preliminary results suggest a complex interplay of tumor drivers (BRAF and NRAS) and passengers (X-factors) in cancer biology that need to be investigated in detail in melanoma. Citation Format: Raj Kumar, Zhenyu Ji, Benchun Miao, Ching-Ni Jenny Njauw, Hensin Tsao. Molecular exploitation of oncogenic stress in melanoma management. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-103.

Expression of BRAF V600E mutation in different thyroid lesions

To evaluate the expression of BRAF V600E mutation in 240 Chinese patients with thyroid lesions. Two hundred and forty Chinese patients with thyroid lesions, including 129 papillary thyroid carcinomas (PTC), 12 follicular carcinomas, 4 medullary carcinomas, 30 adenomas, 30 nodular goiters, and 35 papillary hyperplasia. DNA was extracted from thyroid biopsy and paraffin embedded thyroid tissues, and the expression of BRAF V600E mutation was detected by polymerase chain reaction and DNA sequencing assays. The presence of BRAF V600E mutation was found in 61 of the total group of 240 cases (25.4%). It was only detected in PTC (47.3%), and not detected in other types of malignant and benign thyroid lesions. There was a statistically significant difference between the expression of BRAF V600E mutation in classic type PTC (49.6%) and in follicular type PTC (12.5%,P < 0.05), but statistical data did not show any correlation between BRAF V600E mutation and clinicopathologic parameters in PTC (P > 0.05). BRAF V600E mutation has a significant correlation with PTC and the detection of BRAF V600E mutation may be used as an important prognostic marker of PTC. Our new method of DNA extraction from paraffin embedded tissues is efficient and inexpensive.