scholarly journals BRAF Mutation in Colorectal Cancers: From Prognostic Marker to Targetable Mutation

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3236
Author(s):  
Izuma Nakayama ◽  
Toru Hirota ◽  
Eiji Shinozaki
Keyword(s):  
Braf Mutation ◽  
Mapk Pathway ◽  
Treatment Strategies ◽  
Growth Factor Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Colorectal Cancers ◽  
Strongly Correlated ◽  
Recent Success ◽  
Molecular Features ◽  
Mitogen Activated Protein

The Raf murine sarcoma viral oncogene homolog B (BRAF) mutation is detected in 8–12% of metastatic colorectal cancers (mCRCs) and is strongly correlated with poor prognosis. The recent success of the BEACON CRC study and the development of targeted therapy have led to the determination of BRAF-mutated mCRCs as an independent category. For nearly two decades, a growing body of evidence has established the significance of the BRAF mutation in the development of CRC. Herein, we overview both basic and clinical data relevant to BRAF-mutated CRC, mainly focusing on the development of treatment strategies. This review is organized into eight sections, including clinicopathological features, molecular features, prognosis, the predictive value of anti-epidermal growth factor receptor (EGFR) therapy, resistant mechanisms for BRAF-targeting treatment, the heterogeneity of the BRAF mutation, future perspectives, and conclusions. A characterization of the canonical mitogen-activated protein kinase (MAPK) pathway is essential for controlling this malignancy, and the optimal combination of multiple interventions for treatments remains a point of debate.

scholarly journals KRAS G13D sensitivity to neurofibromin-mediated GTP hydrolysis

2019 ◽  
Vol 116 (44) ◽  
pp. 22122-22131 ◽  
Author(s):  
Dana Rabara ◽  
Timothy H. Tran ◽  
Srisathiyanarayanan Dharmaiah ◽  
Robert M. Stephens ◽  
Frank McCormick ◽  
...  
Keyword(s):  
Mapk Pathway ◽  
Growth Factor Receptor ◽  
Egfr Inhibitors ◽  
Mitogen Activated Protein Kinase ◽  
Structural Basis ◽  
Colorectal Cancers ◽  
Dependent Manner ◽  
Gtp Hydrolysis ◽  
Promote Tumor Growth ◽  
Mitogen Activated Protein

KRAS mutations occur in ∼35% of colorectal cancers and promote tumor growth by constitutively activating the mitogen-activated protein kinase (MAPK) pathway. KRAS mutations at codons 12, 13, or 61 are thought to prevent GAP protein-stimulated GTP hydrolysis and render KRAS-mutated colorectal cancers unresponsive to epidermal growth factor receptor (EGFR) inhibitors. We report here that KRAS G13-mutated cancer cells are frequently comutated with NF1 GAP but NF1 is rarely mutated in cancers with KRAS codon 12 or 61 mutations. Neurofibromin protein (encoded by the NF1 gene) hydrolyzes GTP directly in complex with KRAS G13D, and KRAS G13D-mutated cells can respond to EGFR inhibitors in a neurofibromin-dependent manner. Structures of the wild type and G13D mutant of KRAS in complex with neurofibromin (RasGAP domain) provide the structural basis for neurofibromin-mediated GTP hydrolysis. These results reveal that KRAS G13D is responsive to neurofibromin-stimulated hydrolysis and suggest that a subset of KRAS G13-mutated colorectal cancers that are neurofibromin-competent may respond to EGFR therapies.

scholarly journals Regulation of EphB2 activation and cell repulsion by feedback control of the MAPK pathway

2008 ◽  
Vol 183 (5) ◽  
pp. 933-947 ◽  
Author(s):  
Alexei Poliakov ◽  
Maria L. Cotrina ◽  
Andrea Pasini ◽  
David G. Wilkinson
Keyword(s):  
Feedback Loop ◽  
Fibroblast Growth Factor Receptor ◽  
Mapk Pathway ◽  
Tyrosine Phosphatase ◽  
Growth Factor Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Eph Receptor ◽  
Mitogen Activated Protein ◽  
Mediate Cell ◽  
Cell Repulsion

In this study, we investigated whether the ability of Eph receptor signaling to mediate cell repulsion is antagonized by fibroblast growth factor receptor (FGFR) activation that can promote cell invasion. We find that activation of FGFR1 in EphB2-expressing cells prevents segregation, repulsion, and collapse responses to ephrinB1 ligand. FGFR1 activation leads to increased phosphorylation of unstimulated EphB2, which we show is caused by down-regulation of the leukocyte common antigen–related tyrosine phosphatase receptor that dephosphorylates EphB2. In addition, FGFR1 signaling inhibits further phosphorylation of EphB2 upon stimulation with ephrinB1, and we show that this involves a requirement for the mitogen-activated protein kinase (MAPK) pathway. In the absence of activated FGFR1, EphB2 activates the MAPK pathway, which in turn promotes EphB2 activation in a positive feedback loop. However, after FGFR1 activation, the induction of Sprouty genes inhibits the MAPK pathway downstream of EphB2 and decreases cell repulsion and segregation. These findings reveal a novel feedback loop that promotes EphB2 activation and cell repulsion that is blocked by transcriptional targets of FGFR1.

scholarly journals Decreased Phosphorylated ERK 1/2 in Individuals with Autism

2019 ◽  
Author(s):  
Anthony Russo ◽  
Albert Mensah ◽  
Judith Bowman
Keyword(s):  
Intracellular Signaling ◽  
Mapk Pathway ◽  
Growth Factor Receptor ◽  
Autism Spectrum ◽  
Mitogen Activated Protein Kinase ◽  
Signaling Cascades ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Epidermal Growth ◽  
Spectrum Disorders

Autism spectrum disorders (ASDs) are complex, highly heritable neurodevelopmental disorders affecting ∼1 in 60-100 children. The extracellular signal-regulated kinases, ERK1 and ERK2, are central elements of one of the most prominent intracellular signaling cascades, the mitogen activated protein kinase (MAPK) pathway. They are genetically linked to ASDs and other syndromes typified by intellectual disability. In this study, we measured the concentration of phosphorylated (activated) ERK 1 and 2. We present evidence that ERK is decreased in individuals with autism, and that ERK levels are associated with decreased Epidermal Growth Factor Receptor (EGFR).

scholarly journals Proliferation of Peripheral Blood-derived Endothelial Progenitor Cells from Stable Angina Subjects

2014 ◽  
Vol 6 (2) ◽  
pp. 91 ◽  
Author(s):  
Yudi Her Oktaviono ◽  
Djanggan Sargowo ◽  
Mohammad Aris Widodo ◽  
Yanni Dirgantara ◽  
Angliana Chouw ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Stable Angina ◽  
Peripheral Blood ◽  
Mapk Pathway ◽  
Growth Factor Receptor ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Endothelial Progenitor ◽  
Mitogen Activated Protein

BACKGROUND: A population of circulating Endothelial Progenitor Cells (EPCs) has been reported to play important role in maintaining endothelial function and integrity. Since EPCs culture is crucial and an optimized medium is currently available. Therefore we conducted a study to investigate whether stable angina subjects peripheral blood-derived EPCs could be cultured in this medium. Here, we performed study to detect EPCs characteristics and extracellular signalregulated kinase (Erk)1/2 Mitogen-Activated Protein Kinase (MAPK) pathway as possible underlying pathway for EPCs proliferation.METHODS: Peripheral blood EPCs from 8 stable angina subjects were cultured in an optimized medium with/without addition of supplement for 1 or 3 days. Then, the membrane of cultured EPCs were detected with immunofluorescence method for CD34, Vascular Endothelial Growth Factor Receptor 2 (VEGFR-2) and CD133. Colony forming unit (CFU) enumeration was performed. XTT Cell proliferation assay was performed to assess EPCs growth after 1 and 3-days culture. The western blot analysis was performed to detect possible activation of Erk1/2 MAPK.RESULTS: Number of EPCs and CFU cultured for 3 days were significantly higher than the ones cultured for 1 day (p=0.012). EPCs membrane markers from stable angina subjects were detected as well as CFUs were formed. There were significant increase of EPCs number, CFUs number and phosphorylated-Erk2 amount when the groups with and without supplement were compared (p<0.05). Meanwhile U0126, a MAPK Erk1/2 (MEK1/2) inhibitor, significantly inhibited the supplement-induced EPCs number, CFUs number and phosphorylated-Erk2 amount (p<0.05).CONCLUSION: Our results showed that ERK2 MAPK signaling pathway might play an important role in supplement-induced peripheral blood EPCs proliferation in subjects with stable angina.KEYWORDS: endothelial progenitor cell, EPC, p42, Erk2, proliferation

scholarly journals Molecular aspects of gefitinib antiproliferative and pro-apoptotic effects in PTEN-positive and PTEN-negative prostate cancer cell lines

2005 ◽  
Vol 12 (4) ◽  
pp. 983-998 ◽  
Author(s):  
C Festuccia ◽  
P Muzi ◽  
D Millimaggi ◽  
L Biordi ◽  
G L Gravina ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Growth Factor ◽  
Growth Inhibition ◽  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Growth Factor Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Growth Modulation ◽  
Mitogen Activated Protein ◽  
Phosphoinositide 3 Kinase

To date, no effective therapeutic treatment allows abrogation of the progression of prostate cancer (PCa) to more invasive forms. One of the major targets for the therapy in PCa can be epidermal growth factor receptor (EGFR), which signals via the phosphoinositide 3′-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK) pathways, among others. Despite multiple reports of overexpression in PCa, the reliance on activated EGFR and its downstream signalling to the PI3K and/or MAPK/extracellular signal-regulated kinase (ERK) pathways has not been fully elucidated. We reported that the EGFR-selective tyrosine kinase inhibitor gefitinib (ZD1839; Iressa) is able to induce growth inhibition, G1 arrest and apoptosis in PCa cells and that its effectiveness is associated primarily with phosphatase and tensin homologue deleted from chromosome 10 (PTEN) expression (and thus Akt activity). In fact PTEN-negative PCa cells are slowly sensitive to gefitinib treatment, because this molecule is unable to downregulate PI3K/Akt activity. PI3K inhibition, by LY294002 or after PTEN transfection, restores EGFR-stimulated Akt signalling and sensitizes the cells to pro-apoptotic action of gefitinib. The MAPK pathway seems to be involved primarily on cell-growth modulation because dual blockade of EGFR and ERK1/2 phosphorylation potentiates growth inhibition (both not cell apoptosis) in PTEN-positive PCa cells and reduced EGF-mediated growth in PTEN-negative cells. Thus the effectiveness of gefitinib requires growth factor receptor-stimulated PI3K/Akt and MAPK signalling to be intact and functional. The loss of the PTEN activity leads to uncoupling of this signalling pathway, determining a partial gefitinib resistance. Moreover, gefitinib sensitivity may be maintained in these cells through its inhibitory potential in MAPK/ERK pathway activity, modulating proliferative EGFR-triggered events. Therefore, our data suggest that the inhibition of EGFR signalling can result in a significant growth reduction and in increased apoptosis in EGFR-overexpressing PCa cells with different modalities, which are regulated by PTEN status, and this may have relevance in the clinical setting of PCa.

MEK and RAF inhibitors for BRAF-mutated cancers

2012 ◽  
Vol 14 ◽  
Author(s):  
Sarah Belden ◽  
Keith T. Flaherty
Keyword(s):  
Growth Factor ◽  
Protein Kinase ◽  
Drug Targets ◽  
Mapk Pathway ◽  
Growth Factor Receptor ◽  
Receptor Activation ◽  
Mitogen Activated Protein Kinase ◽  
Braf Mutations ◽  
Mitogen Activated Protein ◽  
Pharmacologic Inhibition

The mitogen-activated protein kinase (MAPK) pathway has been implicated in the pathophysiology of many cancers. Under normal physiologic conditions, the RAS–RAF–mitogen-activated protein kinase kinase (MEK)–mitogen-activated protein kinase (ERK) signalling cascade interaction is initiated by ligation of a receptor-linked tyrosine kinase by its cognate growth factor. It has been demonstrated in many systems that aberrant autocrine or paracrine stimulation of growth factor receptors is pathogenic in large part because of MAPK activation. As one of the key downstream effector pathways of mutated RAS (KRAS,NRASandHRAS), pharmacologic inhibition of components of the MAPK pathway has been pursued as a means to indirectly inhibit RAS, which remains a technical challenge for direct pharmacologic inhibition. RAF and MEK are the two non-membrane-bound, serine–threonine and tyrosine–threonine kinases, within the pathway that have been most extensively explored as drug targets. The discovery of activating BRAF mutations in cancer clarified which cancer types and subsets of certain cancers are most dependent on activation of the MAPK pathway for growth and survival. Now, with the successful translation of selective BRAF and MEK inhibitors into validated therapies for BRAF mutant melanoma, the field seeks to resolve the role for these agents in cancers harbouring RAS mutations or those driven by aberrant growth factor receptor activation.

scholarly journals The Genomic Landscape of Thyroid Cancer Tumourigenesis and Implications for Immunotherapy

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1082
Author(s):  
Amandeep Singh ◽  
Jeehoon Ham ◽  
Joseph William Po ◽  
Navin Niles ◽  
Tara Roberts ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Mapk Pathway ◽  
Treatment Options ◽  
Metastatic Potential ◽  
Pi3k Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Sequencing Data ◽  
Genetic Aberrations ◽  
Progression Model ◽  
Mitogen Activated Protein

Thyroid cancer is the most prevalent endocrine malignancy that comprises mostly indolent differentiated cancers (DTCs) and less frequently aggressive poorly differentiated (PDTC) or anaplastic cancers (ATCs) with high mortality. Utilisation of next-generation sequencing (NGS) and advanced sequencing data analysis can aid in understanding the multi-step progression model in the development of thyroid cancers and their metastatic potential at a molecular level, promoting a targeted approach to further research and development of targeted treatment options including immunotherapy, especially for the aggressive variants. Tumour initiation and progression in thyroid cancer occurs through constitutional activation of the mitogen-activated protein kinase (MAPK) pathway through mutations in BRAF, RAS, mutations in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) pathway and/or receptor tyrosine kinase fusions/translocations, and other genetic aberrations acquired in a stepwise manner. This review provides a summary of the recent genetic aberrations implicated in the development and progression of thyroid cancer and implications for immunotherapy.

Review of treatment and therapeutic targets in brain arteriovenous malformation

2021 ◽  
pp. 0271678X2110267
Author(s):  
Peipei Pan ◽  
Shantel Weinsheimer ◽  
Daniel Cooke ◽  
Ethan Winkler ◽  
Adib Abla ◽  
...  
Keyword(s):  
Animal Models ◽  
De Novo ◽  
Mapk Pathway ◽  
Treatment Options ◽  
Therapeutic Targets ◽  
Current Treatment ◽  
Mitogen Activated Protein Kinase ◽  
De Novo Mutations ◽  
Genetic Syndromes ◽  
Mitogen Activated Protein

Brain arteriovenous malformations (bAVM) are an important cause of intracranial hemorrhage (ICH), especially in younger patients. The pathogenesis of bAVM are largely unknown. Current understanding of bAVM etiology is based on studying genetic syndromes, animal models, and surgically resected specimens from patients. The identification of activating somatic mutations in the Kirsten rat sarcoma viral oncogene homologue (KRAS) gene and other mitogen-activated protein kinase ( MAPK) pathway genes has opened up new avenues for bAVM study, leading to a paradigm shift to search for somatic, de novo mutations in sporadic bAVMs instead of focusing on inherited genetic mutations. Through the development of new models and understanding of pathways involved in maintaining normal vascular structure and functions, promising therapeutic targets have been identified and safety and efficacy studies are underway in animal models and in patients. The goal of this paper is to provide a thorough review or current diagnostic and treatment tools, known genes and key pathways involved in bAVM pathogenesis to summarize current treatment options and potential therapeutic targets uncovered by recent discoveries.

scholarly journals Expression of transgenes enriched in rare codons is enhanced by the MAPK pathway

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jackson Peterson ◽  
Siqi Li ◽  
Erin Kaltenbrun ◽  
Ozgun Erdogan ◽  
Christopher M. Counter
Keyword(s):  
Amino Acids ◽  
Protein Kinase ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Rare Codons ◽  
Synonymous Codons ◽  
Multiple Components ◽  
Human Genes ◽  
Regulatory Module ◽  
Mitogen Activated Protein

AbstractThe ability to translate three nucleotide sequences, or codons, into amino acids to form proteins is conserved across all organisms. All but two amino acids have multiple codons, and the frequency that such synonymous codons occur in genomes ranges from rare to common. Transcripts enriched in rare codons are typically associated with poor translation, but in certain settings can be robustly expressed, suggestive of codon-dependent regulation. Given this, we screened a gain-of-function library for human genes that increase the expression of a GFPrare reporter encoded by rare codons. This screen identified multiple components of the mitogen activated protein kinase (MAPK) pathway enhancing GFPrare expression. This effect was reversed with inhibitors of this pathway and confirmed to be both codon-dependent and occur with ectopic transcripts naturally coded with rare codons. Finally, this effect was associated, at least in part, with enhanced translation. We thus identify a potential regulatory module that takes advantage of the redundancy in the genetic code to modulate protein expression.

MKK3-p38 signaling promotes apoptosis and the early inflammatory response in the obstructed mouse kidney

2007 ◽  
Vol 293 (5) ◽  
pp. F1556-F1563 ◽  
Author(s):  
Frank Y. Ma ◽  
Greg H. Tesch ◽  
Richard A. Flavell ◽  
Roger J. Davis ◽  
David J. Nikolic-Paterson
Keyword(s):  
Inflammatory Response ◽  
P38 Mapk ◽  
Renal Injury ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Mrna Levels ◽  
Direct Role ◽  
Mitogen Activated Protein ◽  
Early Inflammatory Response ◽  
Induced Apoptosis

Activation of the p38 mitogen-activated protein kinase (MAPK) pathway induces inflammation, apoptosis, and fibrosis. However, little is known of the contribution of the upstream kinases, MMK3 and MKK6, to activation of the p38 kinase in the kidney and consequent renal injury. This study investigated the contribution of MKK3 to p38 MAPK activation and renal injury in the obstructed kidney. Groups of eight wild-type (WT) or Mkk3−/− mice underwent unilateral ureteric obstruction (UUO) and were killed 3 or 7 days later. Western blotting showed a marked increase in phospho-p38 (p-p38) MAPK in UUO WT kidney. The same trend of increased p-p38 MAPK was seen in the UUO Mkk3−/− kidney, although the actual level of p-p38 MAPK was significantly reduced compared with WT, and this could not be entirely compensated for by the increase in MKK6 expression in the Mkk3−/− kidney. Apoptosis of tubular and interstitial cells in WT UUO mice was reduced by 50% in Mkk3−/− UUO mice. Furthermore, cultured Mkk3−/− tubular epithelial cells showed resistance to H2O2-induced apoptosis, suggesting a direct role for MKK3-p38 signaling in tubular apoptosis. Upregulation of MCP-1 mRNA levels and macrophage infiltration seen on day 3 in WT UUO mice was significantly reduced in Mkk3−/− mice, but this difference was not evident by day 7. The development of renal fibrosis in Mkk3−/− UUO mice was not different from that seen in WT UUO mice. In conclusion, these studies identify discrete roles for MKK3-p38 signaling in renal cell apoptosis and the early inflammatory response in the obstructed kidney.

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