Search results for "B-RAF"

Cardiotoxicity mechanisms of the combination of BRAF-inhibitors and MEK-inhibitors.

2018

Many new drugs have appeared in last years in the oncological treatment scenario. Each drug carries an important set of adverse events, not less, cardiovascular adverse events. This aspect is even more important considering the increasing use of combination therapies with two drugs, or three drugs as in some ongoing clinical trials. Besides it represents a growing problem for Cardiologists, that face it in every day clinical practice and that will face it probably more and more in the coming years. This work reviews the mechanism of action of BRAF-inhibitors and MEK-inhibitors used together, the pathophysiological mechanisms that lead to cardiovascular toxicity. Particularly, it focuses on …

Adverse events associated with encorafenib plus binimetinib in the COLUMBUS study: incidence, course and management.

2019

Abstract Background Dual inhibition of the mitogen-activated protein kinase pathway with BRAF/MEK inhibitor (BRAFi/MEKi) therapy is a standard treatment for BRAFV600-mutant metastatic melanoma and has historically been associated with grade III pyrexia or photosensitivity depending on the combination used. The objective of this study was to fully describe adverse events from the COLUMBUS study evaluating the most recent BRAF/MEK inhibitor combination encorafenib+binimetinib. Patients and methods Patients with locally advanced, unresectable or metastatic BRAFV600-mutant melanoma were randomised to receive encorafenib 450 mg once daily plus binimetinib 45 mg twice daily, encorafenib 300 mg on…

Atypical Phacomatosis Pigmentokeratotica as the Expression of a Mosaic RASopathy With the BRAF-Glu586Lys Mutation

2016

BRAFV600E mutation, TIMP-1 upregulation, and NF-κB activation: closing the loop on the papillary thyroid cancer trilogy.

2011

BRAFV600E is the most common mutation found in papillary thyroid carcinoma (PTC). Tissue inhibitor of metalloproteinases (TIMP-1) and nuclear factor (NF)-κB have been shown to play an important role in thyroid cancer. In particular, TIMP-1 binds its receptor CD63 on cell surface membrane and activates Akt signaling pathway, which is eventually responsible for its anti-apoptotic activity. The aim of our study was to evaluate whether interplay among these three factors exists and exerts a functional role in PTCs. To this purpose, 56 PTC specimens were analyzed for BRAFV600E mutation, TIMP-1 expression, and NF-κB activation. We found that BRAFV600E mutation occurs selectively in PTC nodules an…

The Genetic Landscape of Clinical Resistance to RAF Inhibition in Metastatic Melanoma.

2013

Abstract Most patients with BRAFV600-mutant metastatic melanoma develop resistance to selective RAF kinase inhibitors. The spectrum of clinical genetic resistance mechanisms to RAF inhibitors and options for salvage therapy are incompletely understood. We performed whole-exome sequencing on formalin-fixed, paraffin-embedded tumors from 45 patients with BRAFV600-mutant metastatic melanoma who received vemurafenib or dabrafenib monotherapy. Genetic alterations in known or putative RAF inhibitor resistance genes were observed in 23 of 45 patients (51%). Besides previously characterized alterations, we discovered a “long tail” of new mitogen-activated protein kinase (MAPK) pathway alterations (…

Emerging Raf inhibitors

2009

The Raf/MAPK kinase/extracellular-signal-regulated kinase pathway is often activated by genetic alterations in upstream signaling molecules. An integral component of this pathway, BRAF, is also activated by mutation, especially in melanoma and thyroid cancers. The Raf/MAPK kinase/extracellular-signal-regulated kinase pathway has profound effects on proliferative, apoptotic and differentiation pathways as well as the sensitivity and resistance to chemotherapeutic drugs.This review discusses targeting of Raf which could control abnormal proliferation in cancer and other proliferative diseases. The important roles that genetics plays in the response of patients to Raf inhibitors is also evalua…

B-Raf-mediated signaling pathway regulates T cell development

2008

The activities of the Raf kinase family proteins control extracellular signal-regulated kinase (ERK) activation in many aspects of cellular responses. However, the relative contributions of individual isozymes to cellular functions including T cell responses are still unclear. In addition to Raf-1, another Raf family kinase, B-Raf, is expressed in murine thymocytes and peripheral T cells, and its activation was induced by TCR stimulation. Here, we investigated the function of B-Raf in development of T cells by generating chimeric mice in which a T cell-compromised host was reconstituted with fetal liver-derived cells from embryonic lethal B-Raf-deficient mice. Although B-Raf was dispensable…

BRAF mutations in non-small cell lung cancer : has finally Janus opened the door?

2016

Abstract: B-Raf mutations occur in about 1-2% of non-small cell lung cancers (NSCLC). These mutations generate a permanent activation of the mitogen activated protein kinase (MAPK) pathway, which promotes tumor growth and proliferation. In the present review, we discuss B-Raf mutation epidemiology, diagnostic methods to detect B-Raf mutations, the role of B-Raf as a driver mutation and a potential therapeutic target in NSCLC. The results of clinical trials involving B-Raf or MAPK pathway inhibitors for the treatment of NSCLC are also discussed. Clinical trials evaluating B-Raf inhibitors in BRAF mutated NSCLC patients have shown promising results, and larger prospective studies are warrante…

Dimerization of the kinase ARAF promotes MAPK pathway activation and cell migration.

2014

The RAF family of kinases mediates RAS signaling, and RAF inhibitors can be effective for treating tumors with BRAF V600E mutant protein. However, RAF inhibitors paradoxically accelerate metastasis in RAS -mutant tumors and become ineffective in BRAF V600E tumors because of reactivation of downstream mitogen-activated protein kinase (MAPK) signaling. We found that the RAF isoform ARAF has an obligatory role in promoting MAPK activity and cell migration in a cell type–dependent manner. Knocking down ARAF prevented the activation of MAPK kinase 1 (MEK1) and extracellular signal–regulated kinase 1 and 2 (ERK1/2) and decreased the number of protrusions from tumor cell spheroids in three-dimensi…

Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascade inhibitors: How mutations can result in therapy resistance and how to overcome resistance

2012

// James A. McCubrey 1 , Linda S. Steelman 1 , William H. Chappell 1 , Stephen L. Abrams 1 , Richard A. Franklin 1 , Giuseppe Montalto 2 , Melchiorre Cervello 3 , Massimo Libra 4 , Saverio Candido 4 , Grazia Malaponte 4 , Maria C. Mazzarino 4 , Paolo Fagone 4 , Ferdinando Nicoletti 4 , Jorg Basecke 5 , Sanja Mijatovic 6 , Danijela Maksimovic-Ivanic 6 , Michele Milella 7 , Agostino Tafuri 8 , Francesca Chiarini 9 , Camilla Evangelisti 9 , Lucio Cocco 10 , Alberto M. Martelli 9,10 1 Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, USA 2 Department of Internal Medicine and Specialties, University of Palermo, Palermo, Italy 3 Consi…