Murine Sarcoma Viral Oncogene Homolog Research Articles

Clinical pathological characteristics of resectable papillary thyroid microcarcinoma

Objective: To investigate the difference of prognostic factors and recurrence rates between papillary thyroid microcarcinoma (PTMC) and lager papillary thyroid carcinoma (PTC) and analyze the clinical pathological characteristics of PTMC suitable for surgery. Methods: A retrospective analysis on the clinicopathological features, expression level of of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E gene mutation and pigment epithelium-derived factor (PEDF), and postoperative follow-up results of the 251 PTC patients who underwent surgical treatment from October 2011 to October 2013, including 169 cases with PTMC and 82 with lager PTC (Tumor diameter>1 cm). Results: The BRAF V600E mutation rates of PTMC and lager PTC patients are 65.1%(110/169)and 78.0% (64/82) respectively, and the difference is statistically significant (P<0.05). The prevalence of extrathyroidal invasion (7.1%) and lymph nodes metastasis (27.2%) of the patients with PTMC were significantly lower than those of the patients with larger PTC (15.9% and 46.3%, respectively)(P<0.01). The follow-up durations for PTMC and lager PTC were (45.6±3.6) months and (45.0±3.4) months, respectively (P>0.05). There was no statistic significance for the difference in age, gender, coexistent hashimoto's thyroiditis, PEDF expression, and recurrence rate between the patients with PTMC and with larger PTC (P>0.05). The recurrence rate of the patients who have the high risk factors of PTMC was 1.6%(2/122)and that of larger PTC was 4.9% (4/82). Conclusions: Extrathyroid invasion, lymph node metastases and BRAF V600E gene mutation are the high risk factors of recurrent PTMC. The same treatment strategy should be considered for PTMC with coexistent high risk factors as that for larger PTC. For PTMC with BRAF V600E gene mutation, earlier surgical treatment is suggested. PTMC patients with BRAF V600E gene mutation and high cell subtype are suggested to undergo total thyroidectomy for the first operation in order to reduce the potential risk of recurrence.

BRAF V600E/TERT promoter mutations and NIS/TSHR expression in differentiated thyroid carcinoma and their clinical significance ⁎

Abstract Objective Telomerase reverse transcriptase (TERT) promoter mutations have recently been described in thyroid carcinoma. The purpose of this study was to investigate the clinical significance of (v-raf murine sarcoma viral oncogene homolog B1) BRAF V600E and TERT promoter mutations in differentiated thyroid carcinoma (DTC). The relationship between the two mutations and NIS/TSHR expression was also analyzed. Methods We have detected BRAF V600E and TERT promoter mutations by direct sequencing and NIS/TSHR expression by immunohistochemistry in 229 cases of DTC, 52 cases of benign nodular goiter, and 31 cases of normal thyroid tissue. Results The BRAF V600E mutation was detected in 142 (62.0%) of 229 cases of DTC [141 cases of papillary thyroid carcinoma (PTC) and 1 case of follicular thyroid carcinoma (FTC)]. TERT promoter mutations were detected in 18 (7.9%) of 229 cases of DTC (14 cases of PTC and 4 cases of FTC), including the mutations C228T (0.9%) and C250T (7.0%), which were mutually exclusive. Moreover, 11 (61.1%) cases also harbored the BRAF V600E mutation, which was not associated with gender, age, tumor size, lymph node metastasis, and recurrence risk stratification (P &gt;0.05). The rate of TERT promoter mutation was higher in males, age ≥45, and in the middle/high-risk group (P &lt;0.05), and the rate of simultaneous BRAF V600E and TERT promoter mutations were higher in the middle/high-risk group (P &lt;0.05). In addition, NIS positive rate in the concurrent BRAF V600E and TERT promoter mutation group (45.5 %) was lower than in other groups (that is, the DTC group with BRAF V600E or TERT promoter mutations (55.1%), the DTC group with no BRAF V600E or TERT promoter mutation (57.5%), the nodules and normal group (75.9%); | r | = 0.171, P = 0.002). Conclusion TERT promoter mutations were lower in patients with DTC, with the C250T mutation being the most common. The detection of BRAF V600E mutation combined with TERT promoter mutations was instructive for the prognosis assessment and treatment of DTC.

Bisarylureas Based on 1H-Pyrazolo[3,4-d]pyrimidine Scaffold as Novel Pan-RAF Inhibitors with Potent Anti-Proliferative Activities: Structure-Based Design, Synthesis, Biological Evaluation and Molecular Modelling Studies.

RAF (Ras activating factor) kinases are important and attractive targets for cancer therapy. With the aim of discovering RAF inhibitors that bind to DFG-out inactive conformation created by the movement of Asp-Phe-Gly (DFG), we conducted structure-based drug design using the X-ray cocrystal structures of BRAF (v-raf murine sarcoma viral oncogene homolog B1), starting from bisarylurea derivative based on 1H-pyrazolo[3,4-d]pyrimidine scaffold 1a. Most of the synthesized compounds showed good to excellent inhibitory activities against BRAFV600E kinase, possessed moderate to potent anti-proliferative activities against four tumor cell lines (A375, HT-29, PC-3 and A549) and good selectivity towards cancer cells rather normal cells (Madin-Darby canine kidney, MDCK). The most promising compound, 1v, exhibited potent inhibitory activity against not only BRAFV600E (half maximal inhibitory concentration, IC50 = 23.6 nM) but also wild-type BRAF (IC50 = 51.5 nM) and C-RAF (IC50 = 8.5 nM), and effective cellular anti-proliferative activities against A375, HT-29, PC-3 and A549 cell lines as well as a very good selectivity profile. Moreover, compound 1v mainly arrested the A375 cell line in the G0/G1 stage, and showed significant suppression of MEK (mitogen-activated protein kinase kinase) phosphorylation in A375 and HT-29 cell lines. Taken together, the optimal compound 1v showed excellent in vitro potency as a pan-RAF inhibitor. In addition, the promise of compound 1v was further confirmed by molecular dynamics simulation and binding free energy calculations.

The expression and clinical significance of tumor suppressor phosphatase-tension protein gene in differentiated thyroid carcinoma

Objective To analyze the expression and clinical significance of tumor suppressor phosphatase-tension protein gene(PTEN) in differentiated thyroid carcinoma and the relationship with the V600E gene site mutation of murine sarcoma viral oncogene homolog B1(BRAF). Methods The expression of PTEN was assayed by immunohistochemical staining in differentiated thyroid carcinoma and adjacent tissues.The differences were compared between clinical pathological features.The BRAF V600E gene mutation was detected by fluorescence quantitative polymerase chain reaction(PCR) and to investigate the correlation between the expression of PTEN and BRAF V600E mutation. Results The negative rate of PTEN was 78.75%(63/80) in differentiated thyroid carcinoma, 13.75%(11/80) in adjacent tissues(χ2=27.236, P=0.000). There were significant differences in the expression of PTEN between I-II and III-IV in TNM stage, grade I and II, and lymph node metastasis(χ2=10.395, 6.948, 9.263, P=0.000, 0.006, 0.000). The differences were not significant in the expression of PTEN between different gender, ≤45 years and >45 years different pathological types and tumor diameter<2cm and ≥2cm(χ2=1.113, 0.941, 2.301, 1.567, P=0.185, 0.213, 0.087, 0.181). There was correlation between the expression of PTEN and BRAF V600E mutations(r=0.301, P=0.004). Conclusion The expression of PTEN is involved in the occurrence and development of differentiated thyroid cancer and is associated with BRAF V600E.The PTEN has the predictive value of prognosis in tumors. Key words: Thyroid neoplasms; Genes, suppressor; Mutation

Histopathological aspects of cutaneous erythematous-papular eruptions induced by immune checkpoint inhibitors for the treatment of metastatic melanoma.

Immune checkpoint blockade therapy (ICBT) for the treatment of melanoma has led to an important improvement of overall survival in advanced stage patients. However, secondary cutaneous maculopapular eruptions (CMPEs) are frequent and remain poorly characterized. We performed a retrospective analysis of melanoma patients from our institution who developed CMPEs during ICBT. Clinical information was retrieved, and histopathological and immunohistochemical characterization was performed by two pathologists. For comparison, a group of biopsies from CMPE caused by anti-v-raf murine sarcoma viral oncogene homolog B1 (BRAF) therapy was analyzed. Eleven patients met the inclusion criteria. On clinical grounds, CMPE developed mainly on early onset of immunotherapy and were of low grade. Typical lesions included erythematous papules and macules affecting the trunk and/or extremities with associated pruritus. The histopathological patterns consisted of a superficial perivascular lymphocytic dermatitis (SPLD) with eosinophils followed by a granulomatous dermatitis. Other patterns included lichenoid, spongiotic, and a case of Grover's disease. The inflammatory infiltrate consisted of T lymphocytes (CD3+ ) with a predominance of CD4+ over CD8+ cells; isolated Foxp3+ cells were invariably present, and PD-1 was not expressed. Biopsies from CMPE caused by anti-BRAF therapy showed an SPLD and a similar lymphocytic immunophenotype. Our study showed the clinical features of a group of melanoma patients with CMPE for ICBT and emphasized the wide spectrum of histological findings as well as their immunohistochemical profile. Differential diagnosis can be difficult with CMPE provoked by other therapies as was seen in our comparison group of anti-BRAF-induced eruptions.

Metastatic Pattern of Stage IV Colorectal Cancer with High-Frequency Microsatellite Instability as a Prognostic Factor.

A recent clinical trial on the immune check-point inhibitor pembrolizumab demonstrated that microsatellite instability (MSI) is a good biomarker for response to this inhibitor. However, clinicopathological features of advanced colorectal cancer (CRC) with high-frequency MSI (MSI-H) are unclear. A total of 2,439 surgically resected CRC tissues were analyzed for MSI status, and mutational status of V-Ki-Ras2 Kirsten rat sarcoma 2 viral oncogene homolog (KRAS), neuroblastoma RAS viral oncogene homolog (NRAS) and v-Raf murine sarcoma viral oncogene homolog B (BRAF). Stage IV cases were selected, and clinical and molecular features were evaluated. There was no significant survival difference observed between MSI-H CRC and microsatellite-stable (MSS) CRC in patients with stage IV disease (3.92 vs. 2.50 years; p=0.766). However, hematogenous and lymphogenous metastasis-dominant CRC with MSI-H demonstrated poor prognosis, whereas peritoneal metastasis-dominant CRC with MSI-H demonstrated good prognosis, (1.33 vs. 5.2 years; p=0.006). Prognosis of stage IV CRC with MSI-H depended on the metastatic pattern. These findings provide useful information for the adaptation of CRC immunotherapy.

Mitogen-Activated Protein Kinase Signaling Pathway in Cutaneous Melanoma: An Updated Review.

The mitogen-activated protein kinase (MAPK) signaling pathway is a cascade of protein kinases that act in a sequential and predominantly linear fashion, albeit displaying some cross talk with other signaling cascades. Mutations in proteins integral to the MAPK signaling pathway are present in more than 50% of cutaneous melanomas. The most frequently mutated protein is v-raf murine sarcoma viral oncogene homolog B (BRAF), followed by neuroblastoma Ras viral oncogene homolog (NRAS). Recently, the development of targeted drugs for the treatment of BRAF-mutant melanoma has led to the widespread implementation of molecular assays for the detection of specific BRAF mutations. There have been some attempts to standardize testing of BRAF mutations, but this has not been achieved so far. Here we provide an updated review on the role of the MAPK signaling pathway in the pathogenesis of cutaneous melanoma, focusing on several different BRAF mutations and their diagnostic and therapeutic implications.

Multiple Squamous Cell Carcinoma after Vemurafenib Therapy

Vemurafenib is a low molecular weight, orally available, inhibitor of oncogenic V600 BRAF serine–threonine kinase. It is effective in the treatment of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600-located melanomas.1 The drug specifically targets tumor cells that harbor activating mutations in BRAF gene, most commonly the substitution of glutamic acid for valine at codon 600 (V600E). Selective BRAF inhibition therapy is associated with malignant and benign growths. Among these are keratoacanthomas, cutaneous squamous cell carcinomas, warty dyskeratomas, verrucous keratoses, acantholytic dyskeratoses, and widespread eruptions. Recent studies showed that squamous cell carcinoma (SCC) and keratoacanthomas developed in 20%–57% of patients who are on vemurafenib therapy.2,3 Cutaneous malignancies occur more frequently than other kinase inhibitor molecules after vemurafenib therapy

Perioperative bevacizumab improves survival following lung metastasectomy for colorectal cancer in patients harbouring v-Ki-ras2 Kirsten rat sarcoma viral oncogene homologue exon 2 codon 12 mutations†.

The role of perioperative chemotherapy (POC) and targeted therapies in lung metastasectomy for colorectal cancer (CRC) is still subject to debate. We aimed to evaluate whether POC and targeted therapies were associated with different outcomes according to the mutational status. We reviewed data from 223 patients who underwent pulmonary metastasectomy for CRC from 1998 to 2015 and for whom the V-Ki-ras2 Kirsten sarcoma viral oncogene homologue (KRAS) and V-raf Murine sarcoma viral oncogene homologue B1 (BRAF) mutational statuses were known. A total of 167 patients (74%) underwent POC: 62 (37%) received neoadjuvant therapy, 59 (35%) were in the adjuvant setting and 46 (28%) were in both the neoadjuvant and adjuvant settings. POC did not significantly influence either the loco-regional recurrence free survival (LRRFS) (P = 0.21) or the overall survival (OS) (P = 0.29). Furthermore, in cases of adjuvant chemotherapy, outcomes were not significantly different in cases of neoadjuvant chemotherapy or both neoadjuvant and adjuvant treatment (P = 0.26 for OS, P = 0.14 for LRRFS). For patients with KRAS mutation, perioperative bevacizumab was associated with a significant improvement in both LRRFS [70 months (41.58–98.42) vs 24 months (1.15–46.86), P = 0.001] and OS [101 vs 55 months (49.77–60.23), P = 0.004]. However, this benefit was only significant in cases of KRAS exon 2 codon 12 mutations [median OS: 101 months (83.97–118.02) vs 60 months (53–66.99), P < 0.001; median LRRFS: 76 months (64.62–87.38) vs 44 months (35.27–52.73), P < 0.001]. Perioperative bevacizumab appears to be beneficial in patients with exon 2 codon 12 KRAS mutations who have undergone lung metastasectomy for CRC.

Progress in the Treatment of Non-small Cell Lung Cancer with BRAF Inhibitors

近年来，靶向药物在非小细胞肺癌（non-small cell lung cancer, NSCLC）的治疗中占据着举足轻重的地位，针对表皮生长因子受体（epidermal growth factor receptor, EGFR）的靶向药物已在临床上广泛应用，具有里程碑意义。BRAF抑制剂是针对鼠类肉瘤病毒癌基因同源物B1（V-raf murine sarcoma viral oncogene homolog B1, BRAF）基因突变为靶点的靶向药物，对特定优势人群有明显的临床疗效，且毒副作用小，患者易耐受。近期发现，与其他靶向药物一样，BRAF抑制剂也存在耐药现象，其耐药机制正在研究中。本文就BRAF抑制剂的作用机制、临床应用、不良反应及耐药问题进行综述。

Loss of cohesin complex components STAG2 or STAG3 confers resistance to BRAF inhibition in melanoma.

The protein kinase V-Raf murine sarcoma viral oncogene homolog B (BRAF) is an oncogenic driver and therapeutic target in melanoma. Inhibitors of BRAF (BRAFi) have shown high response rates and extended survival in melanoma patients bearing tumors that express BRAF Val600 mutations, but a vast majority of these patients develop drug resistance. Here we show that loss of Stromal antigen 2 or 3 (STAG2 or STAG3), which encode subunits of the cohesin complex, in melanoma cells results in resistance to BRAFi. We identified loss-of-function mutations in STAG2 as well as decreased expression of STAG2 or STAG3 proteins in several tumor samples from patients with acquired resistance to BRAFi and in BRAFi-resistant melanoma cell lines. Knockdown of STAG2 or STAG3 decreased sensitivity of Val600Glu BRAF-mutant melanoma cells and xenograft tumors to BRAFi. Loss of STAG2 inhibited CCCTC-binding factor (CTCF)-mediated expression of dual specificity phosphatase 6 (DUSP6), leading to reactivation of ERK signaling. Our studies unveil a previously unknown genetic mechanism of BRAFi resistance and provide new insights into the tumor suppressor function of STAG2 and STAG3.

MiR-579-3p controls melanoma progression and resistance to target therapy

Therapy of melanoma patients harboring activating mutations in the BRAF (V-raf murine sarcoma viral oncogene homolog B1) oncogene with a combination of BRAF and MEK inhibitors is plagued by the development of drug resistance. Mutational events, as well as adaptive mechanisms, contribute to the development of drug resistance. In this context we uncover here the role of a miRNA, miR-579-3p. We first show that low expression of miR-579-3p is a negative prognostic factor correlating with poor survival. Expression levels of miR-579-3p decrease from nevi to stage III/IV melanoma samples and even further in cell lines resistant to BRAF/MEK inhibitors. Mechanistically, we demonstrate that miR-579-3p acts as an oncosuppressor by targeting the 3'UTR of two oncoproteins: BRAF and an E3 ubiquitin protein ligase, MDM2. Moreover miR-579-3p ectopic expression impairs the establishment of drug resistance in human melanoma cells. Finally, miR-579-3p is strongly down-regulated in matched tumor samples from patients before and after the development of resistance to targeted therapies.

Advances in the research of BRAF(V600E) gene mutation correlated with papillary thyroid carcinoma

The increase in the incidence of papillary thyroid carcinoma (PTC) is a serious threat to public health. V-raf murine sarcoma viral oncogene homolog B(BRAF)(V600E) gene mutation is not only the common genetics factors, but also is the early event in process of thyroid carcinogenesis. We mainly illustrate the mechanism of BRAF(V600E) gene in genesis and development of PTC and the correlation of BRAF(V600E) gene mutation and the clinicopathological characteristics of PTC. Finally, we briefly summarize some scientific achievements about tyrosine kinase inhibitors targeted for BRAF(V600E) gene and their clinical prospect in terms of translation medicine concept. In summary, BRAF(V600E) gene is expected to be a new molecular marker of PTC, which will take a new hope for individualized precise treatment for patients with PTC.

MEK inhibitor-associated retinopathy (MEKAR) in metastatic melanoma: Long-term ophthalmic effects

BackgroundMitogen-activated protein kinase kinase (MEK) inhibitors have aroused considerable interest in oncology. Activity has been demonstrated in various types of cancer, especially melanoma. MEK inhibitors induce a transient retinopathy, considered to be a class effect. At present, only sparse data are available on retinal effects with long-term MEK inhibition. Patients and methodsIn this prospective, observational study, patients with advanced melanoma participating in different phase 1/2 or phase 3 clinical trials were treated with the MEK inhibitor binimetinib, with a v-Raf murine sarcoma viral oncogene homolog B (BRAF) inhibitor, or with combination therapy. They underwent regular ophthalmological examinations including determination of visual function, biomicroscopy, dilated fundoscopy and optical coherence tomography (OCT) for a period of up to 2 years. Retinopathy was diagnosed on defined OCT criteria. ResultsSixty-two patients were investigated between 1st October 2011 and 31st July 2015: 13 were treated with the MEK inhibitor binimetinib alone, 10 with a selective BRAF inhibitor, and 39 with combination therapy. In 92% of patients on monotherapy and 100% of those on combination treatment, binimetinib caused dose-related lesions with serous neuroretinal detachments and oedema, strongly dependent on the time after medication. With continued treatment, retinal volume and thickness decreased to levels below baseline, without any apparent functional deficits or changes in structural integrity. ConclusionsBinimetinib induces a specific retinopathy with daily fluctuations depending on the time interval after medication. The retinopathy partially recovers, but can still be detected many months later. Retinal thinning, possible first signs of retinal atrophy have been observed after long-term treatment, but, so far, without functional relevance.

Clinical significance of HBME-1, Galectin-3, and CK19 expression and the status of BRAF mutation in papillary thyroid carcinoma

Abstract Objective The aim of this study was to explore the clinical significance of the expression of proteins human bone marrow endothelial cell markers (HBME-1), Galectin-3, and cytokeratin19 (CK19), as well as the status of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutation in papillary thyroid carcinoma (PTC). Methods Immunohistochemical staining was performed in 82 specimens each of PTC and papillary benign lesions to detect the expression of HBME-1, Galectin-3, and CK19. Polymerase chain reaction (PCR) and gene sequencing were performed on 60 specimens each of PTC and papillary benign lesions to detect the status of BRAF mutation. Results The positive expression ratios of HBME-1, Galectin-3, and CK19 in PTC were 98.8%, 97.6% and 100% respectively, which were significantly higher than the expressions in papillary benign lesions (P &lt; 0.05). No significant relationship was observed between the expression of these makers and the clinicopathological features of PTC. The sensitivity of co-expression of HBME-1 and CK19 or HBME-1 and Galectin-3 as diagnostic criteria of PTC was 99.9%, with a specificity of 95.4%. BRAF mutation was detected in 40 of 60 PTC (66.7%) specimens. There was a statistical difference in BRAF mutations between PTC and papillary benign lesions (P &lt; 0.05); there were no associations between BRAF mutation and the clinicopathological features of PTC. Conclusion Combined immunohistochemical staining of HBME-1, Galectin-3, and CK19 can further improve the sensitivity and specificity of differential diagnosis of PTC. BRAF mutation is a significant genetic event, which may have diagnostic value for PTC.

Theranostic near-infrared fluorescent nanoplatform for imaging and systemic siRNA delivery to metastatic anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC), one of the most aggressive solid tumors, is characterized by rapid tumor growth and severe metastasis to other organs. Owing to the lack of effective treatment options, ATC has a mortality rate of ∼100% and median survival of less than 5 months. RNAi nanotechnology represents a promising strategy for cancer therapy through nanoparticle (NP) -mediated delivery of RNAi agents (e.g., siRNA) to solid tumors for specific silencing of target genes driving growth and/or metastasis. Nevertheless, the clinical success of RNAi cancer nanotherapies remains elusive in large part because of the suboptimal systemic siRNA NP delivery to tumors and the fact that tumor heterogeneity produces variable NP accumulation and thus, therapeutic response. To address these challenges, we here present an innovative theranostic NP platform composed of a near-infrared (NIR) fluorescent polymer for effective in vivo siRNA delivery to ATC tumors and simultaneous tracking of the tumor accumulation by noninvasive NIR imaging. The NIR polymeric NPs are small (∼50 nm), show long blood circulation and high tumor accumulation, and facilitate tumor imaging. Systemic siRNA delivery using these NPs efficiently silences the expression of V-Raf murine sarcoma viral oncogene homolog B (BRAF) in tumor tissues and significantly suppresses tumor growth and metastasis in an orthotopic mouse model of ATC. These results suggest that this theranostic NP system could become an effective tool for NIR imaging-guided siRNA delivery for personalized treatment of advanced malignancies.

Management of Brain Metastases in Patients With Melanoma.

Melanoma is the third most common systemic cancer that leads to brain metastases. The annual incidence of melanoma has increased over time, with brain metastases developing in 40% to 50% of patients with advanced melanoma. Traditional management of melanoma-related brain metastases has focused on symptom control as a result of the significant neurologic morbidity associated with the disease. Median overall survival for these patients, if untreated, is approximately 3 months. As with other brain metastases, a multidisciplinary treatment approach that includes surgery and radiation therapy is typically used, with historically little role for systemic, cytotoxic therapy. During the past decade, advancement within the field of genomics has led to the identification of melanoma-specific mutations, namely, v-Raf murine sarcoma viral oncogene homolog B and neuroblastoma RAS viral oncogene homolog, as well as to the development of agents that target these driver mutations. In addition, the advent of immunotherapies, specifically, agents that target cytotoxic T-lymphocyte antigen-4, anti-programmed death-1, and programmed death ligand-1, has increased the potential therapeutic options available to patients with both systemic and brain disease. With these advances, early trials have demonstrated improved overall survival in patients with brain metastases who receive these therapies either as single agents or as part of multimodality treatment regimens.

Newly Identified BRAF Mutation in Rheumatoid Arthritis

ObjectiveRheumatoid arthritis (RA)–associated autoantibodies include those directed at the kinase site of BRAF (v‐Raf murine sarcoma viral oncogene homolog B1), a serine–threonine kinase involved in the MAPK signaling pathway. To understand anti‐BRAF immunization, we sought to identify BRAF mutations in the peripheral blood lymphocytes (PBLs) of patients with RA.MethodsWe first cloned the major BRAF region known for mutations in the pCR2.1 vector, using genomic DNA from the PBLs of 8 RA patients. For each patient, 100 clones were sequenced. In 5 of 8 patients, we detected a new BRAF mutation in 1 clone. The frequency of this new mutation was evaluated by droplet digital polymerase chain reaction in PBLs from RA patients and controls. To test whether p.Val600Ala influences the kinase activity of BRAF, we developed an in vitro assay based on phosphorylation of MEK‐1, a major BRAF substrate.ResultsA BRAF mutation, p.Val600Ala, was identified in 1 of 8,000 PBLs and 1 of 6,000 T lymphocytes from RA patients and in 1 of 12,500 PBLs and 1 of 12,500 T lymphocytes from controls. The BRAF p.Val600Ala mutation was not correlated with the presence of anti‐BRAF autoantibodies. The p.Val600Ala mutation activated phosphorylation of MEK‐1 in vitro.ConclusionMost RA patients have a p.Val600Ala mutation in the BRAF gene. This mutation activates the kinase activity of BRAF. The p.Val600Ala mutation could activate the MAPK pathway, leading to the activation of T lymphocytes.

BRAF-Directed Therapy in Metastatic Colorectal Cancer.

Activating BRAF (V-raf murine sarcoma viral oncogene homolog B) mutations occur in approximately 5% to 10% of patients with metastatic colorectal cancer, mostly V600E mutation, and it is associated with distinct clinical and pathological features. To date, there are no approved treatments to target this mutation. BRAF inhibitor monotherapy has limited efficacy, in contrast to metastatic melanoma. Combination strategies that block not only BRAF mutated kinase but other alternative pathways are ongoing and have demonstrated improved activity. This review aims to provide data about new strategies to target to BRAF gene mutation in metastatic colorectal cancer.

High co-expression of PD-L1 and HIF-1α correlates with tumour necrosis in pulmonary pleomorphic carcinoma

BackgroundPulmonary pleomorphic carcinomas (PPCs) are uncommon malignant tumours characterised by an aggressive clinical course and poor survival. These neoplasms frequently exhibit marked confluent necrosis, in which hypoxia levels are extremely high, causing low responsiveness to chemotherapy and conferring basic resistance to anti-cancer drugs. Programmed death ligand 1 (PD-L1)–mediated immune escape may be an underlying source of resistance and a suitable target for specific therapy, but its role in PPCs is unclear. Materials and methodsIn total, 122 PPCs were investigated. Paraffin-embedded tumour sections were stained with PD-L1 and hypoxia-inducible factor-1α (HIF-1α) antibodies. Overexpression was denoted by moderate-to-strong PD-L1 membrane staining in ≥5% of tumour cells and HIF-1α nuclear staining in ≥10% of tumour cells. The presence of driver mutations in the epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS), v-raf murine sarcoma viral oncogene homolog B (BRAF), telomerase reverse harscriptase gene (TERT), phosphoinositide 3-kinase catalytic alpha (PIK3CA), anaplastic lymphoma kinase (ALK), and ROS1 (ROS1 proto-oncogene receptor tyrosine kinase) genes were examined. ResultsThe overall frequencies of PD-L1 and HIF-1α overexpression and EGFR mutation were 70.5, 75.4, and 22.1%, respectively. High PD-L1 expression was significantly correlated with that of HIF-1α (p < 0.001) and tumour necrosis (p < 0.001). HIF-1α expression was associated with EGFR mutation (p = 0.015). Advanced stage and high PD-L1 expression were two independent risks for poor overall survival. ConclusionsHigh PD-L1 and HIF-1α co-expression was observed in PPCs compared with their expression in conventional non-small-cell lung carcinoma. The aggressive behaviour of PPC could be partially related to PD-L1–mediated immune escape and intratumoural hypoxia. High PD-L1 expression correlates with poor prognosis and may provide a rationale for the use of targeted immunotherapy in this subtype of high-grade PPC.