V-raf Murine Sarcoma Viral Oncogene Research Articles

Clinicopathological and genetic association between epithelioid glioblastoma and pleomorphic xanthoastrocytoma.

Epithelioid glioblastoma (eGBM) is a rare variant of GBM which was adopted in the 2016 WHO classification. eGBM and pleomorphic xanthoastrocytoma (PXA) sometimes show overlapping features histologically and genetically, such as epithelioid pattern and a highly frequent V600E mutation in the gene for vRAF murine sarcoma viral oncogene homolog B1 (BRAF), respectively. Accurate diagnosis of these rare tumors is challenging according to the new criteria in the revised 2016 WHO classification. It is an urgent task to elucidate the biological properties of the tumors and to select appropriate treatment. Twenty consecutive cases diagnosed as PXA or eGBM histologically were investigated. Twelve of the 20 cases were PXAs and eight were eGBMs. Morphologically, mitotic activity, necrosis and degenerative changes such as intracellular lipid accumulation, eosinophilic granular bodies and reticulin fiber deposits were scored. Immunohistochemical and molecular biological assessment for isocitrate dehydrogenases 1 and 2 (IDH1/2), α-thalassemia/mental-retardation-syndrome-X-linked gene (ATRX), p53, BRAF, telomere reverse transcriptase promoter (TERT-p), H3F3A, and integrase interactor 1 (INI1) were performed. eGBM tended to lack the degenerative changes characteristic for PXA. Of the 20 cases tested, Sanger technique showed no mutation in IDH1/2. BRAF mutation at T1799 > A (V600E) was detected in 4/12 (33.3%) PXA and 4/8 (50.0%) eGBM, while TERT-p mutation was detected at C228 > T in 2/12 (16.7%) PXA and at C250 > T in 1/8 (12.5%) eGBM. Retained nuclear ATRX was observed in 12/12 (100%) PXA and 6/7 (85.7%) eGBM while p53 mutation was observed in 2/10 (20%) PXA and 7/7 (100%) eGBM. All tumors retained INI1 expression in their nuclei. None of the tumors harbored H3F3A mutation. One PXA without BRAF mutation acquired TERT-p mutation at recurrence and one eGBM harbored both BRAF and TERT-p mutation. Molecular biological similarity between eGBM and PXA was suggested in our series, while degenerative changes reflected the features of PXA. It was speculated that the common genetic alterations for development and progression of eGBM and PXA might include BRAF and TERT-p mutations.

Phosphorylation of p70 Ribosomal Protein S6 Kinase β-1 is an Independent Prognostic Parameter in Metastatic Colorectal Cancer

BackgroundDeregulation of signal transduction pathways plays a critical role in oncogenesis of colorectal cancer (CRC) and directly affects sensitivity to targeted therapies. Against this background we developed a comprehensive biomarker profiling program including markers of downstream signaling to study their association with clinical outcomes. Patients and MethodsA prospectively studied cohort of 160 patients with metastatic CRC was included. Standard diagnostic workup included mutational analyses of Kirsten rat sarcoma viral oncogene homolog (KRAS), neuroblastoma RAS viral oncogene homolog (NRAS), and v-Raf murine sarcoma viral oncogene homolog B (BRAF). In addition, markers of mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) and mammalian target of rapamycin pathway activation (phosphorylation of extracellular signal-regulated kinase [ERK], AKT, and p70 ribosomal protein S6 kinase β-1 [p70S6K]) were studied using standardized immunohistochemistry. ResultsThere was a significant correlation between markers of ERK and AKT activation in the full cohort. In addition, phosphorylation of p70S6K correlated strongly with ERK and AKT phosphorylation and primary tumor localization in the right colon. Subgroup analyses specified these correlations to patients with all-RAS wild type tumors. In contrast, tumors harboring RAS mutations predominantly exhibited ERK phosphorylation. Interestingly, patients with CRC showing high p70S6K phosphorylation (highest quartile) had a significantly inferior overall survival (hazard ratio [HR], 2.4; P = .002) irrespective of RAS mutational status. This effect remained significant in multivariate analysis (P = .002). A patient subgroup characterized by high p70S6K phosphorylation and right-sided primary tumors had a particularly poor prognosis with a dramatically inferior overall survival (HR, 5.2; P < .001). Patients with right-sided primary tumor and low p70S6K phosphorylation had responses to anti-epidermal growth factor receptor antibody-based therapies and overall survival similar to patients with left-sided primary tumors. ConclusionHigh phosphorylation of p70S6K is a novel, independent biomarker for poor prognosis, in particular in patients with right-sided primary tumors.

Development of encorafenib for BRAF-mutated advanced melanoma.

Purpose of reviewTo describe the pharmacological properties, preclinical and clinical data of the novel V-Raf Murine Sarcoma Viral Oncogene Homolog B (BRAF)-inhibitor encorafenib (LGX818) and to compare these with established BRAF-inhibitors in the treatment of locally advanced or metastatic melanoma.Recent findingsEncorafenib has shown improved efficacy in the treatment of metastatic melanoma in comparison with vemurafenib. Combination with the MEK inhibitor (MEKi) binimetinib allows for higher dose intensities of encorafenib further improving response rates (RRs).SummaryCombination therapy with BRAF and MEKi has evolved as a standard of care in the treatment of locally advanced or metastatic BRAFV600-mutated melanoma. Despite compelling initial RRs, development of treatment resistance eventually leads to tumor progression in the majority of BRAF/MEK-inhibitor treated patients. Moreover, treatment-related adverse events are frequent, resulting in a substantial proportion of dose modifications and/or treatment discontinuations. The second-generation BRAF inhibitor encorafenib has been developed aiming at improved efficacy and tolerability through modifications in pharmacological properties. Clinical phase 3 data show improved progression-free survival both for encorafenib monotherapy and combination therapy with binimetinib compared with vemurafenib. Overall survival data and regulatory approval of this novel substance are eagerly awaited.

Ocular Changes in Metastatic Melanoma Patients Treated with MEK Inhibitor Cobimetinib and BRAF Inhibitor Vemurafenib.

BackgroundMitogen-activated protein kinase kinase (MEK) inhibitor cobimetinib and V-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitor vemurafenib have significantly improved the prognosis of BRAF-mutated metastatic melanoma. Some ocular symptoms and signs were recently recognized to follow this treatment. The study was aimed to investigate ocular toxicity in patients with metastatic melanoma treated with cobimetinib in combination with vemurafenib.Patients and methodsIn the prospective, observational study, patients with BRAF-mutated metastatic melanoma treated with cobimetinib in combination with vemurafenib at the Institute of Oncology Ljubljana were asked to participate. Ophthalmic examination was performed including measurement of visual acuity and intraocular pressure, slit lamp examination, funduscopy (CF), infrared-reflectance (IR) imaging and optical coherence tomography (OCT).ResultsFive out of 7 patients noticed changes in vision few days after starting the therapy with cobimetinib. In all patients, small circular lesions, described as MEKAR lesions, were documented in outer retinal layers demonstrated with OCT, IR, and CF. Changes were in the center and/or scattered over the retina almost symmetrical in both eyes in 6 patients, and asymmetrical in one patient, the latter presented also with unilateral anterior uveitis and cystoid macular edema.ConclusionsMultiple bilateral foveal and extrafoveal small retinal lesions in the outer retinal layers develop in patients treated with MEK inhibitor in combination with BRAF inhibitor. Ophthalmologists and oncologists need to be aware of this common, yet relatively benign and often transient ocular side effect to avoid needless intervention, including the discontinuance of a potentially life-prolonging therapy.

Progress study of circulating V-raf murine sarcoma viral oncogene homolog B1 V600E mutation in papillary thyroid carcinoma

Detection of V-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E mutation is important for clinical diagnosis, treatment decision-making, effect judgement and prognosis evaluation in papillary thyroid carcinoma (PTC). Research has shown that peripheral blood BRAF V600E is closely related to the histological level of BRAF V600E. Detection of peripheral blood BRAF V600E mutation will be less traumatic, more convenient and dynamic, indicating that it will be the future development trend of PTC research. Key words: V-raf murine sarcoma viral oncogene homolog B1 oncogene; Circulating tumor DNA; Papillary thyroid carcinoma; Progress

Detection of EGFR, KRAS and BRAF mutations in metastatic cells from cerebrospinal fluid.

In lung adenocarcinoma, molecular profiling of actionable genes has become essential to set up targeted therapies. However, the feasibility and the relevance of molecular profiling from the cerebrospinal fluid (CSF) in the context of meningeal metastasis have been poorly assessed. We selected patients with stage IV lung adenocarcinoma harbouring metastatic cells in the CSF after cytological analysis. Seven samples from six patients were eligible for molecular testing of epidermal growth factor receptor (EGFR), V-Ki-ras2 Kirsten rat sarcoma viral oncogene homologue (KRAS), v-Raf murine sarcoma viral oncogene homologue B1 (BRAF) and human epidermal growth factor receptor 2 (HER2) mutations using quantitative polymerase chain reaction (PCR) high-resolution melting curve analysis and Sanger sequencing after DNA extraction from the cell pellets of the CSF. Five patients showed mutations in one or two actionable genes, two harboured an EGFR mutation (exons 19 and 21), one only a KRAS mutation, one both EGFR and KRAS mutations and one a BRAF mutation. In all cases, the results of mutation testing provided new major information for patient management, leading to therapeutic adaptation. CSF molecular analysis identified mutations not detected in other neoplastic sites for two patients. In one case, the EGFR p.Thr790Met was identified. CSF was also the only sample available for genetic testing for almost all patients at the time of disease progression. When cancer cells are present in the CSF, the molecular profiling from the cell pellets is relevant, as it can detect supplemental or different mutations compared to a previous analysis of the primitive tumour or plasma cell-free DNA and allows the adaptation of the treatment strategy.

Pharmacokinetic Evaluation of [11C]CEP-32496 in Nude Mice Bearing BRAFV600E Mutation-Induced Melanomas.

CEP-32496, also known as RXDX-105 or Agerafenib, is a new orally active inhibitor for the mutated v-raf murine sarcoma viral oncogene homolog B1 (BRAFV600E), which has attracted considerable attention in clinical trials for the treatment of human cancers. Here, we used carbon-11-labeled CEP-32496 ([11C]CEP-32496) as a positron emission tomography (PET) radiotracer to evaluate its pharmacokinetic properties and explore its potential for in vivo imaging. Following radiotracer synthesis, we performed in vitro binding assays and autoradiography of [11C]CEP-32496 in the A375 melanoma cell line and on tumor tissue sections from mice harboring the BRAFV600E mutation. These were followed by PET scans and biodistribution studies on nude mice bearing subcutaneous A375 cell-induced melanoma. [11C]CEP-32496 showed high binding affinity for BRAFV600E-positive A375 melanoma cells and densely accumulated in the respective tissue sections; this could be blocked by the BRAFV600E selective antagonist sorafenib and by unlabeled CEP-32496. The PET and biodistribution results revealed that [11C]CEP-32496 accumulated continuously but slowly into the tumor within a period of 0 to 60 minutes postinjection in A375-melanoma-bearing nude mice. Metabolite analysis showed high in vivo stability of [11C]CEP-32496 in plasma. Our results indicate that [11C]CEP-32496 has excellent specificity and affinity for the BRAFV600E mutation in vitro, while its noninvasive personalized diagnostic role needs to be studied further.

V-raf murine sarcoma viral oncogene homolog B1 V600E mutations in different subtypes of papillary thyroid carcinoma and the association with pathological features

Objective To investigate the V600E mutations of V-raf murine sarcoma viral oncogene homolog B1 (BRAF) gene in different subtypes of papillary thyroid carcinoma (PTC). Methods We analyzed retrospectively a series of 411 patients, treated for PTC from 2014 to 2016. The BRAF V600E mutation was detected by real-time quantitative polymerase chain reaction (Real-time PCR). Results Among 411 cases, BRAF V600E mutation was found in 88.4% (321/363) of classical PTCs, in 41.7% (5/12) of follicular variant, in 100.0% (23/23) of tall cell PTCs, and in 80.0% (4/5) of oncocytic variant. Chi square analysis showed that there were significant differences in BRAF mutation between the follicular variant and classical PTCs (χ2=18.435, P=0.001), and in the tumor size and capsule invasion between the classical and tall cell PTCs (χ2=13.563, P=0.000; χ2=4.115, P=0.043). Univariat binary Logistic regression analysis revealed that there was no significant correlation between BRAF V600E mutation and age, sex, tumor size, lymph node metastasis and capsule invasion in classical and follicular variant PTCs (P values were 0.529, 0.682, 0.271, 0.623, 0.550 and 0.921, 1.000, 0.560, 0.560, 0.999 respectively). Conclusion The mutation rate of BRAF gene in high-risk subtypes was higher than that of low-risk subtypes of PTC in general, while the tall cell subtype has larger size and further capsule invasion than classical PTCs. There was no significant correlation between BRAF mutation and age, sex, tumor size, lymph node metastasis and capsule invasion in classical, follicular variant PTCs and tall cell PTCs. Key words: Papillary thyroid carcinoma; Pathological subtype; V-raf murine sarcoma viral oncogene homolog B1 V600E

V-raf murine sarcoma viral oncogene homolog B1 V600E mutation and the expression of galectin-3, cytokcratin 19, MK in papillary thyroid microcarcinoma

Objective To explore the significance of the expression levels of galectin-3 (Gal-3), MC and cytokcratin 19 (CK19) proteins, and V-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E mutation in papillary thyroid microcarcinoma (PTMC). Methods BRAF gene V600E mutation was tested using real-time quantitative polymerase chain reaction (Real-time PCR) and the protein expression levels of Gal-3, MC and CK19 were detected using immunohistochemistry in both PTMC and thyroid benign lesions. Results BRAF mutation rate in PTMC was significantly higher than in thyroid benign disease (67.6% vs. 4.1%, P=0.000). The expression levels of Gal-3, MC and CK19 proteins in PTMC were significantly higher than those in thyroid benign lesions (91.2% vs. 8.1%, 83.8% vs. 13.5%, and 95.9% vs. 4.1, P=0.000). The protein expression of Gal-3, MC and CK19 was associated with cervical lymphatic metastasis (P=0.007, 0.000, 0.036). BRAF gene V600E mutation was associated with capsular invasion and cervical lymphatic metastasis (P=0.005, P=0.000). The sensitivity of BRAF+ Gal-3, BRAF+ MC and BRAF+ CK19 in PTMC was 93.2%, 85.1% and 96.6%, and combination of BRAF+ CK19 showed the highest sensitivity in PTMC. Conclusion BRAF geneV600E mutation and the protein expression of Gal-3, MC and CK19 have important referenced value to PTMC. Combination of BRAF geneV600E mutation and the protein expression of Gal -3, MC and CK19 is helpful to improve the diagnosis of PTMC. The protein expression of Gal-3, MC and CK19 may remind cervical lymphatic metastasis. BRAF gene mutation may make the tumor more aggressive, and lymphatic metastasis can be found more easily. Key words: Papillary thyroid microcarcinoma; Galectin-3; Cytokcratin 19; V-raf murine sarcoma viral oncogene homolog B1

Association between the ALK Gene Status and the Efficacy of First-line Pemetrexed Chemotherapy in Patients with Advanced Lung Adenocarcinoma

背景与目的间变性淋巴瘤激酶（anaplastic lymphoma kinase, ALK）是非小细胞肺癌（non-small cell lung cancer, NSCLC）的重要驱动基因之一，多项研究显示培美曲塞在ALK阳性肺癌中的疗效存在争议。本研究旨在继续探索以培美曲塞为基础的化疗在ALK阳性和阴性肺腺癌患者中的疗效。方法回顾性分析郑州大学第一附属医院2015年1月-2016年4月经组织病理学证实的98例表皮生长因子受体（epidermal growth factor receptor, EGFR）、鼠类肉瘤病毒癌基因（kirsten rat sarcoma viral oncogene, KRAS）、鼠类肉瘤滤过性毒菌致癌同源体B1（V-rafmurine sarcoma viral oncogene homolog B1, BRAF）均为阴性的晚期肺腺癌患者的临床资料。分析ALK基因状态、临床特征、化疗疗效及无疾病进展生存期（progression-free survival, PFS）之间的关系。结果98例患者均进行了ALK基因检测，ALK基因断裂融合34例（34.7%），未发生断裂融合64例（65.3%）。全部患者均接受一线培美曲塞联合铂类的化疗，客观缓解率（objective response rate, ORR）为21.4%，疾病控制率（disease control rate, DCR）为84.7%。ALK阳性肺腺癌患者的ORR和DCR均高于阴性患者（41.2% vs 10.9%, χ2=23.389, P < 0.001; 91.2% vs 81.3%, χ2=4.153, P=0.042），差异有统计学意义。ALK基因状态与年龄、性别、吸烟史、临床分期均无明显关系。ALK阳性肺腺癌的中位PFS为7.1个月（95%CI: 6.1-8.1），阴性4.7个月（95%CI: 3.818-5.582），二者的PFS差异有统计学意义（χ2=13.269, P < 0.001）。Cox回归多因素分析显示：培美曲塞联合铂类化疗的PFS与性别、年龄、吸烟、分期、与铂类药物的种类均无明显关系，ALK基因断裂融合是PFS相关的唯一变量（HR=0.392, 95%CI: 0.243-0.634, P < 0.001）。结论ALK阳性相比ALK阴性肺腺癌患者一线应用以培美曲塞为基础的化疗有更大的临床获益。

Glioblastoma in neurofibromatosis 1 patients without IDH1, BRAF V600E, and TERT promoter mutations.

Pilocytic astrocytomas and low-grade gliomas are more common compared with glioblastomas in patients with neurofibromatosis 1 (NF1). A recent genome-wide analysis has shown frequent NF1 gene alterations in the mesenchymal subtype of a glioblastoma; however, little is known about clinicopathological features of glioblastomas in NF1 patients (NF1 glioblastomas). We analyzed four NF1 glioblastomas. Radiographical and intraoperative findings showed well-circumscribed tumors from surrounding brain. Pathological analysis presented a paucity of processes with an eosinophilic cytoplasm, bizarre nuclei, xanthomatous-like appearance, multinucleated giant cells, and histiocytoid appearance. During the follow-up period, one patient died at 49months and others remained alive for 60, 87, and 106months; thus, patients with NF1 glioblastoma presented a relatively favorable survival. None of the NF1 glioblastomas harbored isocitrate dehydrogenase 1 (IDH1) gene mutation, v-RAF murine sarcoma viral oncogene homolog B1 (BRAF) gene mutation, and telomerase reverse transcriptase (TERT) gene promoter mutation. We identified that NF1 glioblastoma is a unique subset of glioblastoma.

Anaplastic gliomas in adults: an update.

The current review summarizes recent advances on the oncogenesis, classification and treatment of adult anaplastic gliomas. According to the 2016 WHO classification, three main molecular subgroups of adult diffuse anaplastic gliomas can be distinguished based on the 1p/19q codeletion and isocitrate dehydrogenase (IDH) mutation status. In the future, this classification may be further refined based on the telomerase reverse transcriptase promoter and alpha thalassemia/mental retardation syndrome X-linked mutation status, gene expression, DNA methylation and genomic profiling. Both newly diagnosed 1p/19q codeleted and 1p/19q-intact anaplastic gliomas benefit from the addition of chemotherapy to radiotherapy. However, in 1p/19q codeleted anaplastic gliomas, Procarbazine, CCNU and Vincristine chemotherapy seems more effective than temozolomide. At recurrence, 1p/19q-intact anaplastic gliomas do not benefit from the addition of bevacizumab to temozolomide. The use of poly(adenosine 5'-diphosphate-ribose) inhibitors may be another way of specifically targeting IDH-mutant gliomas in addition to specific inhibitors, demethylating agents and anti-IDH vaccines. v-raf murine sarcoma viral oncogene homolog B1 (BRAF)-mutant anaplastic xanthoastrocytomas and gangliogliomas may benefit from BRAF and mitogen-activated protein kinase inhibitors. Molecular characterization is mandatory for integrated diagnosis and appropriate management of adult anaplastic gliomas. Both 1p/19q codeleted and 1p/19q-intact anaplastic diffuse gliomas benefit from early chemotherapy. At recurrence, preliminary data suggest a potential role for targeted therapies in specific molecular subgroups.

The MEK Inhibitors Trametinib and Cobimetinib Induce a Type I Interferon Response in Human Keratinocytes.

Mitogen-activated protein kinase kinases (MEK) 1 and 2 have crucial roles in tumorigenesis, cell proliferation, and protection from apoptosis, and their inhibition is therefore an attractive therapeutic strategy in cancer. Orally available and highly selective MEK inhibitors have been developed and assessed in numerous clinical trials, either alone or in combination with cytotoxic chemotherapy and/or other targeted agents. Of note, a complex picture of class-specific adverse effects associates with these drugs, frequently including inflammatory skin rash. Here, we investigated the response of normal human keratinocytes to the MEK inhibitors trametinib and cobimetinib, alone and in combination with the v-Raf murine sarcoma viral oncogene homolog B (BRAF) inhibitors dabrafenib and vemurafenib, in terms of signal transduction and de novo gene expression. MEK inhibitors triggered enhanced expression of interferon regulatory factor 1 (IRF1) and phosphorylation of signal transducer and activator of transcription 1 (STAT1), and up-regulated the keratinocyte-specific type I interferon κ (IFN-κ), the anti-viral effectors interferon-induced tetratricopeptide repeats (IFIT) 1 and 2, and the pro-inflammatory chemokine (C-C motif) ligand 2 (CCL2) and the C-X-C motif chemokine 10 (CXCL10), both at the mRNA and protein level. Impairment of IRF1 expression, or abrogation of STAT1 phosphorylation due to IFN-κ gene silencing, suppressed anti-viral and pro-inflammatory gene expression. These data suggest that, similar to what we observed for epidermal growth factor receptor (EGFR) blockade, MEK inhibition activates a type I interferon response, which is now recognized as an effective anti-cancer response, in human epidermal keratinocytes.

Treatment and Survival Outcome of BRAF-Mutated Metastatic Colorectal Cancer: A Retrospective Matched Case-Control Study

BackgroundSomatic v-Raf murine sarcoma viral oncogene homolog B (BRAF) mutation, present in approximately 10% of metastatic colorectal cancer (mCRC) cases, is associated with poor prognosis. Patient outcome outside of clinical trials has only been reported in small series. We report real-world data on treatment and survival for BRAF-mutated (MT) patients at a single tertiary center, compared with a matched BRAF wild type (WT) control group. Patients and MethodsAll colorectal cancer patients tested for BRAF mutation, from October 2010 to November 2014 were identified. BRAF-MT mCRC cases were compared with an age and sex-matched BRAF-WT control group. Clinicopathological data were collected and survival calculated using the Kaplan–Meier method and comparisons made using Cox regression. ResultsForty-three of 503 patients (8.5%) tested had BRAF-MT mCRC and were compared with 88 BRAF-WT controls. Median overall survival (mOS) was 18.2 months for BRAF-MT and 41.1 months for BRAF-WT mCRC patients (hazard ratio, 2.74; 95% confidence interval, 1.60-4.70; P < .001). Progression-free survival for BRAF-MT and WT patients, respectively, was: 8.1 months versus 9.2 months (P = .571) first-line, 5.5 months versus 8.3 months (P = .074) second-line, and 1.8 months versus 5.6 months (P = .074) third-line. Treatment using sequential fluoropyrimidine-based doublet chemotherapy was similar between both groups. Anti-epidermal growth factor receptor (EGFR) therapy was mainly given third-line with progressive disease in 90% (n = 9 of 10) of BRAF-MT patients at first restaging. ConclusionIn this case-control study, the poor mOS of BRAF-MT mCRC was associated with reduced treatment benefit beyond first-line. Sequential doublet chemotherapy remains a reasonable option in appropriately selected patients. BRAF-MT patients did not benefit from anti-EGFR therapy in this study. Recruitment to clinical trials is recommended to improve outcomes in BRAF-MT mCRC.

Clinicopathologic features and treatment efficacy of Chinese patients with BRAF-mutated metastatic colorectal cancer: a retrospective observational study

BackgroundThe prognostic role of the V600E mutation of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) in metastatic colorectal cancer (mCRC) is well established, but the therapeutic regimen targeting this disease is lacking. This study aimed to analyze the clinicopathologic features of and treatment efficacy of commonly used regimens on BRAF-mutated mCRCs.MethodsWe collected and reviewed the medical records of mCRC patients treated at Peking University Cancer Hospital & Institute (Beijing, China) between July 2011 and July 2016. Kirsten rat sarcoma viral oncogene homolog (KRAS), neuroblastoma RAS viral oncogene homolog (NRAS), and BRAF mutational status was assayed using direct sequencing. The details of clinicopathologic characteristics of patients and their responses to FOLFOXIRI regimen or standard therapy were obtained by reviewing the medical records. The progression-free survival (PFS) and overall survival (OS) were assessed using Kaplan–Meier analysis and compared using the log-rank test.ResultsOf 1694 patients studied, 75 had BRAF exon 15 mutations. Of these 75 patients, 71 had V600E mutation, 1 had D594G mutation, 2 had K601E mutation, and 1 had a novel T599_V600insAGA alteration. No patients had KRAS or NRAS mutations. Of 63 patients with BRAF V600E-mutated mCRC and sufficient clinical data, 27 (42.9%) had right-sided colon tumors, 19 (30.2%) had left-sided colon tumors, and 17 (26.9%) had rectal tumors; 26 (41.3%) had peritoneal metastases, and 50 (79.4%) had distant lymph node metastases. The patients with BRAF K601E- and T599_V600insAGA-mutated tumors had similar clinicopathologic features to those with BRAF V600E-mutated tumors. Patients with the BRAF V600E mutation benefited more from FOLFOXIRI regimen compared with patients who underwent standard therapy (overall response rate 83.3% vs. 14.0%; median PFS 6.4 months vs. 2.8 months, P = 0.220; median OS 11.0 months vs. 6.9 months, P = 0.048).ConclusionsBRAF V600E mutations were commonly identified in right-sided tumors and showed a high incidence of peritoneal and distant lymph nodes metastases. This subtype of mCRC was characterized by short OS and unique patterns of metastasis. Compared with standard treatment regimens, the FOLFOXIRI regimen had acceptable and manageable toxicities and favorable efficacy on patients with BRAF-mutated mCRC.

Measurement of Telomere Length in Colorectal Cancers for Improved Molecular Diagnosis.

All tumors have in common to reactivate a telomere maintenance mechanism to allow for unlimited proliferation. On the other hand, genetic instability found in some tumors can result from the loss of telomeres. Here, we measured telomere length in colorectal cancers (CRCs) using TRF (Telomere Restriction Fragment) analysis. Telomeric DNA content was also quantified as the ratio of total telomeric (TTAGGG) sequences over that of the invariable Alu sequences. In most of the 125 CRCs analyzed, there was a significant diminution in telomere length compared with that in control healthy tissue. Only 34 tumors exhibited no telomere erosion and, in some cases, a slight telomere lengthening. Telomere length did not correlate with age, gender, tumor stage, tumor localization or stage of tumor differentiation. In addition, while telomere length did not correlate with the presence of a mutation in BRAF (V-raf murine sarcoma viral oncogene homolog B), PIK3CA (phosphatidylinositol 3-kinase catalytic subunit), or MSI status, it was significantly associated with the occurrence of a mutation in KRAS. Interestingly, we found that the shorter the telomeres in healthy tissue of a patient, the larger an increase in telomere length in the tumor. Our study points to the existence of two types of CRCs based on telomere length and reveals that telomere length in healthy tissue might influence telomere maintenance mechanisms in the tumor.

V-raf murine sarcoma viral oncogene homolog B1 V600E mutation and urinary iodine concentration in papillary thyroid carcinoma

Objective To investigate the V-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E mutation and urinary iodine concentration in papillary thyroid carcinoma (PTC) and the relationship with clinicopathological features. Methods Polymerase chain reaction (PCR) and gene sequencing were performed to detect BRAF V600E mutation in 110 cases of PTC, 47 cases of nodular goiter and 26 of thyroid adenoma thyroid tissues. Simultaneously, the urinary iodine concentration was determined. The relationship between BRAF V600E mutation and urinary iodine concentration with clinicopathological features was studied. Results In 183 cases, BRAF V600E mutation was detected in 54 out of 110 PTC cases with a detection rate of 49% (χ2=50.838, P=0.000). BRAF V600E mutation was negative in nodular goiter and thyroid adenoma. BRAF V600E mutation in PTC was positively correlated with extra-thymidal extension (χ2=6.031, P=0.014), but not with gender (P=0.363), age (P=0.360), tumor number (P=0.593), tumor size (P=0.497), lymph nodal metastasis (P=0.554) and pTNM staging (P=0.785). The excessive iodine intake rate in PTC patients was 79%, obviously higher than that in nodular goiter (66%) and thyroid adenoma (58%) with significant difference (χ2=6.288, P=0.043). The urinary iodine concentration in PTC was negatively correlated with gender (P=0.187), age (P=0.138), tumor number (P=0.571), tumor size (P=0.454), extra-thymidal extension (P=0.345), lymph nodal metastasis (P=0.248) and pTNM staging (P=0.792). The BRAF V600E mutation was not associated with the concentration of iodide in the PTC (χ2=0.019, P=0.891). Conclusion BRAF V600E mutation was a common molecular event and may increase the ability of invasion in PTC. BRAF V600E mutation was a specificity marker in the diagnosis of PTC. The urinary iodine concentration in PTC was significantly higher than that in the benign thyroid nodule diseases. Key words: V-raf murine sarcoma viral oncogene homolog B1 gene; Mutation; Urinary iodine concentration; Papillary thyroid carcinoma

PD‐1 inhibition in congenital pigment synthesizing metastatic melanoma

A newborn female child was born with a congenital pigment synthesizing melanoma of the scalp. Further workup revealed metastatic disease within the liver, lungs, and left tibia. Whole exome sequencing was performed on multiple samples that revealed one somatic mutation, lysine methyltransferase 2C (KMT2C), at low allelic frequency but no v-Raf murine sarcoma viral oncogene homolog B (BRAF), NF-1 mutation. Programmed death ligand 1 was moderately expressed. Treatment was initiated with the programmed cell death protein 1 inhibitor nivolumab. The patient tolerated this treatment well with minimal toxicity. She is now over a year out from initial diagnosis, continuing on nivolumab, with stable disease.

Lung adenocarcinoma: from molecular basis to genome-guided therapy and immunotherapy.

Although adenocarcinoma (ADC) is the most frequent lung cancer, its diagnosis is often late, when the local invasion is important and/or the metastases have already appeared. Therefore, the mortality at 5 years is still very high, ranging from 51% to 99%, depending on the stage. The implementation of different molecular techniques has allowed genomic studies even in relatively small histological samples such as obtained with non-invasive or minimally invasive techniques, facilitating a better phenotyping of lung ADC. Thus, current classification differentiates between preinvasive lesions (atypical adenomatous hyperplasia and in situ ADC), minimally invasive ADC (MIA) and invasive ADC. 'Field cancerization' is a concept that refers to progressive loco-regional changes occurring in tissues exposed to carcinogens, due to the interaction of the latter with a predisposing genetic background and an appropriate tissue microenvironment. Somatic genetic alterations, including mutations but also other changes, are necessary for oncogenesis, being especially frequent in lung ADC. Changes in the epidermal growth factor receptor (EGFR) gene, Kirsten rat sarcoma viral oncogene (KRAS), v-Raf murine sarcoma viral oncogene homolog B (BRAF), gene encoding neurofibromin (NF1), anaplastic lymphoma kinase (ALK) and ROS1 are the main genes that suffer alterations in the tumors of patients with ADC. Molecular profiling of these tumors allows more targeted treatments through two distinct strategies, genome-guided therapy and immunotherapy. The former, targets the aberrant pathways secondary to the genomic alteration, whereas the latter may be based on the administration of antibodies [such as those against cytotoxic T-lymphocyte antigen 4 (CTLA-4) or the programmed cell death ligand 1/protein 1 pathway (PD-L1/PD-1)] or the stimulation of the patient's own immune system to produce a specific response. These strategies are obtaining better results in selected ADC patients.

Disruption of mitochondrial electron transport chain function potentiates the pro-apoptotic effects of MAPK inhibition

The mitochondrial network is a major site of ATP production through the coupled integration of the electron transport chain (ETC) with oxidative phosphorylation. In melanoma arising from the V600E mutation in the kinase v-RAF murine sarcoma viral oncogene homolog B (BRAFV600E), oncogenic signaling enhances glucose-dependent metabolism while reducing mitochondrial ATP production. Likewise, when BRAFV600E is pharmacologically inhibited by targeted therapies (e.g. PLX-4032/vemurafenib), glucose metabolism is reduced, and cells increase mitochondrial ATP production to sustain survival. Therefore, collateral inhibition of oncogenic signaling and mitochondrial respiration may help enhance the therapeutic benefit of targeted therapies. Honokiol (HKL) is a well tolerated small molecule that disrupts mitochondrial function; however, its underlying mechanisms and potential utility with targeted anticancer therapies remain unknown. Using wild-type BRAF and BRAFV600E melanoma model systems, we demonstrate here that HKL administration rapidly reduces mitochondrial respiration by broadly inhibiting ETC complexes I, II, and V, resulting in decreased ATP levels. The subsequent energetic crisis induced two cellular responses involving cyclin-dependent kinases (CDKs). First, loss of CDK1-mediated phosphorylation of the mitochondrial division GTPase dynamin-related protein 1 promoted mitochondrial fusion, thus coupling mitochondrial energetic status and morphology. Second, HKL decreased CDK2 activity, leading to G1 cell cycle arrest. Importantly, although pharmacological inhibition of oncogenic MAPK signaling increased ETC activity, co-treatment with HKL ablated this response and vastly enhanced the rate of apoptosis. Collectively, these findings integrate HKL action with mitochondrial respiration and shape and substantiate a pro-survival role of mitochondrial function in melanoma cells after oncogenic MAPK inhibition.