Achievements and Challenges of Molecular Targeted Therapy in Melanoma

2015 ◽  
pp. 177-186 ◽  
Author(s):  
Ryan Sullivan ◽  
Patricia LoRusso ◽  
Scott Boerner ◽  
Reinhard Dummer
Keyword(s):  
Tumor Suppressor ◽  
Mapk Pathway ◽  
Single Agent ◽  
Braf Inhibitor ◽  
Clinical Trial Data ◽  
Great Majority ◽  
Mek Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Loss Of Function ◽  
Early Clinical Trial

The treatment of melanoma has been revolutionized over the past decade with the development of effective molecular and immune targeted therapies. The great majority of patients with melanoma have mutations in oncogenes that predominantly drive signaling through the mitogen activated protein kinase (MAPK) pathway. Analytic tools have been developed that can effectively stratify patients into molecular subsets based on the identification of mutations in oncogenes and/or tumor suppressor genes that drive the MAPK pathway. At the same time, potent and selective inhibitors of mediators of the MAPK pathway such as RAF, MEK, and ERK have become available. The most dramatic example is the development of single-agent inhibitors of BRAF (vemurafenib, dabrafenib, encorafenib) and MEK (trametinib, cobimetinib, binimetinib) for patients with metastatic BRAFV600-mutant melanoma, a subset that represents 40% to 50% of patients with metastatic melanoma. More recently, the elucidation of mechanisms underlying resistance to single-agent BRAF inhibitor therapy led to a second generation of trials that demonstrated the superiority of BRAF inhibitor/MEK inhibitor combinations (dabrafenib/trametinib; vemurafenib/cobimetinib) compared to single-agent BRAF inhibitors. Moving beyond BRAFV600targeting, a number of other molecular subsets—such as mutations in MEK, NRAS, and non-V600 BRAF and loss of function of the tumor suppressor neurofibromatosis 1 ( NF1)—are predicted to respond to MAPK pathway targeting by single-agent pan-RAF, MEK, or ERK inhibitors. As these strategies are being tested in clinical trials, preclinical and early clinical trial data are now emerging about which combinatorial approaches might be best for these patients.

scholarly journals MDM2 Antagonists Induce a Paradoxical Activation of Erk1/2 through a P53-Dependent Mechanism in Dedifferentiated Liposarcomas: Implications for Combinatorial Strategies

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2253
Author(s):  
Shomereeta Roy ◽  
Audrey Laroche-Clary ◽  
Stephanie Verbeke ◽  
Marie-Alix Derieppe ◽  
Antoine Italiano
Keyword(s):  
Tyrosine Kinases ◽  
Mapk Pathway ◽  
Single Agent ◽  
Immunoblot Analysis ◽  
Mek Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Synergistic Activity ◽  
Mdm2 Gene ◽  
Mdm2 Antagonist ◽  
The Impact

The MDM2 gene is amplified in dedifferentiated liposarcoma (DDLPS). Treatment with MDM2 antagonists is a promising strategy to treat DDLPS; however, drug resistance is a major limitation when these drugs are used as a single agent. This study examined the impact of MDM2 antagonists on the mitogen-activated protein kinase (MAPK) pathway in DDLPS and investigated the potential synergistic activity of a MAPK kinase (MEK) inhibitor in combination with MDM2 antagonists. We identified a synergistic effect and identified the mechanism behind it. Combination effects of MDM2 antagonists and a MEK inhibitor were analyzed in a patient-derived xenograft mouse model and in DDLPS and leiomyosarcoma cell lines using different cell proliferation assays and immunoblot analysis. MDM2 antagonist (RG7388)-resistant IB115 [P4] cells and p53-silenced DDLPS cells were also established to understand the importance of functional p53. We found that MDM2 antagonists induced an upregulation of phosphorylated extracellular signal-regulated kinase (p-ERK) in DDLPS cells. The upregulation of p-ERK occurred due to mitochondrial translocation of p53, which resulted in increased production of reactive oxygen species, causing the activation of receptor tyrosine kinases (RTKs). Activated RTKs led to the activation of the downstream MEK/ERK signaling pathway. Treatment with a MEK inhibitor resulted in decreased expression of p-ERK, causing significant anti-tumor synergy when combined with MDM2 antagonists. Our results provide a framework for designing clinical studies of combination therapies in DDLPS patients.

scholarly journals P.022 Myasthenia gravis following dabrafenib and trametinib for metastatic melanoma

2019 ◽  
Vol 46 (s1) ◽  
pp. S19 ◽  
Author(s):  
A Zaloum ◽  
JR Falet ◽  
A Elkrief ◽  
C Chalk
Keyword(s):  
Protein Kinase ◽  
Myasthenia Gravis ◽  
Metastatic Melanoma ◽  
Mapk Pathway ◽  
Braf Inhibitor ◽  
Mek Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Proximal Muscle Weakness ◽  
Proximal Muscle ◽  
Mitogen Activated Protein

Background: Inhibitors of BRAF and MEK, enzymes in the mitogen-activated protein kinase (MAPK) pathway, are now widely used in the treatment of metastatic melanoma. We report a case of acetylcholine receptor (AChR) antibody-positive myasthenia gravis developing after exposure to dabrafenib, a BRAF inhibitor, and trametinib, a MEK inhibitor. Methods: A 68-year-old man presented with dysarthria, dysphagia, cough, dyspnea, and fever. Examination revealed fatigable ptosis and proximal muscle weakness. He had started dabrafenib and trametinib for metastatic melanoma two weeks prior. He was diagnosed with myasthenia gravis and superimposed aspiration pneumonia. AChR antibodies were positive. Dabrafenib and trametinib were stopped. He improved rapidly with pyridostigmine alone, and remained free of myasthenic symptoms for the next two months. Another course of dabrafenib and trametinib was given, and seven weeks later, his myasthenic symptoms recurred. Pyridostigmine produced only partial improvement, and treatment with intravenous immunoglobulin and prednisone was initiated. Results: We are unaware of prior reports of an association between BRAF/MEK inhibitors and seropositive myasthenia gravis. The development of myasthenic symptoms twice after BRAF/MEK inhibitor exposure suggests that the association is more than coincidental. Conclusions: Myasthenia gravis may be a complication of treatment of melanoma with dabrafenib and trametinib. The mechanism by which this occurs is unknown.

scholarly journals Registered report: COT drives resistance to RAF inhibition through MAP kinase pathway reactivation

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Vidhu Sharma ◽  
Lisa Young ◽  
Miguel Cavadas ◽  
Kate Owen ◽  
Keyword(s):  
Cancer Biology ◽  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Single Agent ◽  
Braf Inhibitor ◽  
Open Science ◽  
Mek Inhibitors ◽  
Erk Phosphorylation ◽  
Erk Activity ◽  
A375 Cells

The Reproducibility Project: Cancer Biology seeks to address growing concerns about reproducibility in scientific research by conducting replications of selected experiments from a number of high-profile papers in the field of cancer biology. The papers, which were published between 2010 and 2012, were selected on the basis of citations and Altmetric scores (<xref ref-type="bibr" rid="bib4">Errington et al., 2014</xref>). This Registered Report describes the proposed replication plan of key experiments from “COT drives resistance to RAF inhibition through MAPK pathway reactivation” by Johannessen and colleagues, published in Nature in 2010 (<xref ref-type="bibr" rid="bib10">Johannessen et al., 2010</xref>). The key experiments to be replicated are those reported in Figures 3B, 3D-E, 3I, and 4E-F. In Figures 3B, D-E, RPMI-7951 and OUMS023 cells were reported to exhibit robust ERK/MEK activity concomitant with reduced growth sensitivity in the presence of the BRAF inhibitor PLX4720. MAP3K8 (COT/TPL2) directly regulated MEK/ERK phosphorylation, as the treatment of RPMI-7951 cells with a MAP3K8 kinase inhibitor resulted in a dose-dependent suppression of MEK/ERK activity (Figure 3I). In contrast, MAP3K8-deficient A375 cells remained sensitive to BRAF inhibition, exhibiting reduced growth and MEK/ERK activity during inhibitor treatment. To determine if RAF and MEK inhibitors together can overcome single-agent resistance, MAP3K8-expressing A375 cells treated with PLX4720 along with MEK inhibitors significantly inhibited both cell viability and ERK activation compared to treatment with PLX4720 alone, as reported in Figures 4E-F. The Reproducibility Project: Cancer Biology is collaboration between the Center for Open Science and Science Exchange and the results of the replications will be published in eLife.

scholarly journals LGG-26. DIFFUSE LEPTOMENINGEAL GLIONEURONAL TUMOR (DLGNT) IN CHILDREN: DIFFERENT CLINICAL PRESENTATIONS AND OUTCOMES

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii371-iii371
Author(s):  
Andge Valiakhmetova ◽  
Ludmila Papusha ◽  
Ludmila Yasko ◽  
Alexander Druy ◽  
Alexander Karachunsky ◽  
...  
Keyword(s):  
Mapk Pathway ◽  
Braf Inhibitor ◽  
Complete Response ◽  
Mek Inhibitor ◽  
Braf V600e ◽  
Glioneuronal Tumor ◽  
Low Grade ◽  
Conventional Chemotherapy ◽  
Diffuse Leptomeningeal Glioneuronal Tumor ◽  
Braf Fusion

Abstract Diffuse leptomeningeal glioneuronal tumor (DLGNT) is an extremely rare disease, newly recognized in the 2016 WHO classification of tumors of the CNS. Most DLGNTs are low-grade neuroepithelial tumors with variable elements of neuronal/neurocytic and glial differentiation, have diffuse leptomeningeal enhancement on MRI, and typically harbor KIAA1549-BRAF fusions. Other alterations, such as the BRAF V600E substitution, are less common. Here, we present three cases of DLGNT with different presentations and outcomes. The first patient is a 2yr-old male with KIAA1549-BRAF fusion, and was treated with Carbo/VCR chemotherapy after a biopsy, with resultant ongoing stable disease for 3.5 years. The second patient, an 8yr-old male had the BRAF V600E point mutation and was treated with conventional chemotherapy (VCR/carboplatin). On progression, he received the BRAF inhibitor vemurafenib, achieving a complete response which last 14 month. The third patient, a 27 month old male, harbored a KIAA1549-BRAF fusion and was treated at diagnosis with the MEK inhibitor trametinib. The tumor has been radiographically stable in the context of clinical improvement for 21 months since the treatment initiation, ongoing 24 month. In summary, we present further evidence of MAPK pathway alterations in children with DLGNT. We describe a range of molecular presentations and clinical outcomes, including one patient treated with conventional chemotherapy with further stabilization of disease during 3.5 years and two patients who were successfully treated with targeted therapy.

scholarly journals Response to Ipilimumab/Nivolumab Rechallenge and BRAF Inhibitor/MEK Inhibitor Rechallenge in a Patient with Advanced Metastatic Melanoma Previously Treated with BRAF Targeted Therapy and Immunotherapy

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Caitlyn N. Myrdal ◽  
Srinath Sundararajan
Keyword(s):  
Targeted Therapy ◽  
Metastatic Melanoma ◽  
Checkpoint Inhibitors ◽  
Single Agent ◽  
Objective Response ◽  
Braf Inhibitor ◽  
Mek Inhibitor ◽  
Optimal Sequencing ◽  
The Right

Little is known about the optimal sequencing of targeted therapy and immunotherapy in the treatment of patients with BRAFV600-mutated metastatic melanoma. BRAF/MEK inhibition often has the benefit of rapid disease regression; however, resistance is frequently seen with long-term use. Treatment with immune checkpoint inhibitors offers the potential for long-term response but displays a lower rate of objective response. The benefit of synergy between therapies is apparent; however, there is limited data regarding optimal sequencing in the treatment of advanced melanoma. We present the case of a 62-year-old gentleman with advanced BRAFV600-mutated melanoma who followed an unconventional treatment path. After progressing on single-agent vemurafenib, he had response to multiple modalities of immunotherapy before progression. After, he had a substantial response to multiple BRAF/MEK inhibitor rechallenges before developing resistance. The patient is now stable after a retrial of combination immunotherapy. Our case illustrates that with the right sequencing of therapy, meaningful clinical responses can be elicited with rechallenging of targeted therapy and immunotherapy in metastatic melanoma.

MEK inhibitors impair insulin-stimulated glucose uptake in 3T3-L1 adipocytes

2004 ◽  
Vol 287 (4) ◽  
pp. E758-E766 ◽  
Author(s):  
Anne W. Harmon ◽  
David S. Paul ◽  
Yashomati M. Patel
Keyword(s):  
Plasma Membrane ◽  
Glucose Uptake ◽  
Glucose Transporter ◽  
Mapk Pathway ◽  
Mek Inhibitor ◽  
Pi3k Pathway ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Mek Inhibitors ◽  
Transport Assay

In 3T3-L1 adipocytes, insulin activates three major signaling cascades, the phosphoinositide 3-kinase (PI3K) pathway, the Cbl pathway, and the mitogen-activated protein kinase (MAPK) pathway. Although PI3K and Cbl mediate insulin-stimulated glucose uptake by promoting the translocation of the insulin-responsive glucose transporter (GLUT4) to the plasma membrane, the MAPK pathway does not have an established role in insulin-stimulated glucose uptake. We demonstrate in this report that PI3K inhibitors also inhibit the MAPK pathway. To investigate the role of the MAPK pathway separately from that of the PI3K pathway in insulin-stimulated glucose uptake, we used two specific inhibitors of MAPK kinase (MEK) activity, PD-98059 and U-0126, which reduced insulin-stimulated glucose uptake by ∼33 and 50%, respectively. Neither MEK inhibitor affected the activation of Akt or PKCζ/λ, downstream signaling molecules in the PI3K pathway. Inhibition of MEK with U-0126 did not prevent GLUT4 from translocating to the plasma membrane, nor did it inhibit the subsequent docking and fusion of GLUT4- myc with the plasma membrane. MEK inhibitors affected glucose transport mediated by GLUT4 but not GLUT1. Importantly, the presence of MEK inhibitors only at the time of the transport assay markedly impaired both insulin-stimulated glucose uptake and MAPK signaling. Conversely, removal of MEK inhibitors before the transport assay restored glucose uptake and MAPK signaling. Collectively, our studies suggest a possible role for MEK in the activation of GLUT4.

Results from the biomarker-driven basket trial of RO5126766 (CH5127566), a potent RAF/MEK inhibitor, in RAS- or RAF-mutated malignancies including multiple myeloma.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 2506-2506 ◽  
Author(s):  
Maxime Chenard-Poirier ◽  
Martin Kaiser ◽  
Kevin Boyd ◽  
Priya Sriskandarajah ◽  
Anastasia Constantinidou ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Partial Response ◽  
Single Agent ◽  
Braf Inhibitor ◽  
Response Assessment ◽  
Mek Inhibitor ◽  
Solid Tumours ◽  
Tumour Regression ◽  
Wide Range ◽  
Braf Mutant

2506 Background: RO5126766 is a potent RAF and MEK inhibitor with activity in xenografts models of RAS and RAF-mutated cancers. We present data from the RAS/RAF-mutated advanced solid tumor cohort and the initial results for the multiple myeloma (MM) cohort. Methods: Patients with KRAS, NRAS or BRAF-mutant tumours were treated with RO5127566 using a novel schedule:4mg twice weekly in 4-week cycles. For MM patients, it was given 3 weeks out of 4 and co-administration of weekly dexamethasone was authorised. Response assessment was completed using RECIST 1.1 criteria for solid tumours and the International Myeloma Working Group (IMWG) criteria were used for MM. Results: A total of 20 patients with solid tumours (10 NSCLC, 5 gynaecological cancers and 5 miscellaneous cancers) and 1 MM patients were evaluable. Among the 10 KRAS-mutant NSCLC patients, tumour regression was seen in 6/10 (60 %), of which 3/10 (30 %) were partial responses. Two of these patients had maintained response for over 1 year and one patient is still on study after 30 cycles. Of the gynaecological cancers, 3/5 patients (60%) achieved a partial response ( KRAS-mutant endometrial and ovarian cancer and BRAF-mutant ovarian). Of these patients, 1 of the KRAS mutants had received 2 previous lines of MEK inhibitors and the BRAF mutant had previously received a BRAF inhibitor. In the miscellaneous group, 4 patients with colorectal cancer (2 BRAF and 2 NRAS) and 1 patient with NRAS-mutant melanoma were treated and none responded. Two patients with MM have been treated so far (1 KRAS, 1 KRAS+NRAS). The one evaluable patient has had an IMWG partial response (PR) after 1 cycle (FLC-λ from 324 mg/L to 161mg/L, ratio 0.03 to 0.08) without concomittant dexamethasone. This patient was previously treated with an immunomodulatory drug, a proteasome inhibitor and two ASCTs. Conclusions: RO5126766 has shown exciting preliminary activity across a wide range of RAS- and RAF-mutated malignancies, with significant response rates in lung and gynaecological cancers. To our knowledge, the PR seen in our MM patient represents one of the first responses to a single-agent RAF/MEK inhibitor in multiple myeloma in a trial context. Clinical trial information: NCT02407509.

scholarly journals A Cdo–Bnip-2–Cdc42 signaling pathway regulates p38α/β MAPK activity and myogenic differentiation

2008 ◽  
Vol 182 (3) ◽  
pp. 497-507 ◽  
Author(s):  
Jong-Sun Kang ◽  
Gyu-Un Bae ◽  
Min-Jeong Yi ◽  
Youn-Joo Yang ◽  
Ji-Eun Oh ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Cell Surface ◽  
Mapk Pathway ◽  
Myogenic Differentiation ◽  
Negative Regulator ◽  
Mitogen Activated Protein Kinase ◽  
Cell Surface Receptor ◽  
Myoblast Differentiation ◽  
Loss Of Function ◽  
Surface Receptor

The p38α/β mitogen-activated protein kinase (MAPK) pathway promotes skeletal myogenesis, but the mechanisms by which it is activated during this process are unclear. During myoblast differentiation, the promyogenic cell surface receptor Cdo binds to the p38α/β pathway scaffold protein JLP and, via JLP, p38α/β itself. We report that Cdo also interacts with Bnip-2, a protein that binds the small guanosine triphosphatase (GTPase) Cdc42 and a negative regulator of Cdc42, Cdc42 GTPase-activating protein (GAP). Moreover, Bnip-2 and JLP are brought together through mutual interaction with Cdo. Gain- and loss-of-function experiments with myoblasts indicate that the Cdo–Bnip-2 interaction stimulates Cdc42 activity, which in turn promotes p38α/β activity and cell differentiation. These results reveal a previously unknown linkage between a cell surface receptor and downstream modulation of Cdc42 activity. Furthermore, interaction with multiple scaffold-type proteins is a distinctive mode of cell surface receptor signaling and provides one mechanism for specificity of p38α/β activation during cell differentiation.

scholarly journals Establishment of Canine Transitional Cell Carcinoma Cell Lines Harboring BRAF V595E Mutation as a Therapeutic Target

2021 ◽  
Vol 22 (17) ◽  
pp. 9151
Author(s):  
Hyojik Jung ◽  
Kieun Bae ◽  
Ja Young Lee ◽  
Jung-Hyun Kim ◽  
Hyun-Jung Han ◽  
...  
Keyword(s):  
Transitional Cell Carcinoma ◽  
Cell Carcinoma ◽  
Cell Lines ◽  
Mapk Pathway ◽  
Human Cancer ◽  
Transitional Cell ◽  
Braf Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Braf V600e ◽  
Tumor Tissues

Transitional cell carcinoma (TCC) is the most common malignant tumor of the canine urinary tract and tends to have a poor prognosis due to its invasive potential. Recent studies have reported that up to 80% of canine urothelial carcinoma has the BRAF V595E mutation, which is homologous to the human V600E mutation. Activating the BRAF mutation is an actionable target for developing effective therapeutic agents inhibiting the BRAF/mitogen-activated protein kinase (MAPK) pathway in canine cancer as well as human cancer. We established novel canine TCC cell lines from two tumor tissues and one metastatic lymph node of canine TCC patients harboring the BRAF V595E mutation. Tumor tissues highly expressed the BRAF mutant and phosphorylated extracellular signal-related kinases (ERK)1/2 proteins. The derived cell lines demonstrated activated MAPK pathways. We also evaluated the cell lines for sensitivity to BRAF inhibitors. Sorafenib, a multiple kinase inhibitor targeting RAF/vascular endothelial growth factor receptor (VEGFR), successfully inhibited the BRAF/MAPK pathway and induced apoptosis. The established canine TCC cell lines responded with greater sensitivity to sorafenib than to vemurafenib, which is known as a specific BRAF inhibitor in human cancer. Our results demonstrated that canine TCC cells showed different responses compared to human cancer with the BRAF V600E mutation. These cell lines would be valuable research materials to develop therapeutic strategies for canine TCC patients.

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