scholarly journals Biological Rationale for Targeting MEK/ERK Pathways in Anti-Cancer Therapy and to Potentiate Tumour Responses to Radiation

2019 ◽  
Vol 20 (10) ◽  
pp. 2530 ◽  
Author(s):  
Francesco Marampon ◽  
Carmela Ciccarelli ◽  
Bianca Maria Zani
Keyword(s):  
Mapk Pathway ◽  
Cell Signalling ◽  
Acquired Resistance ◽  
Mitogen Activated Protein Kinases ◽  
Anti Cancer ◽  
Mitogen Activated Protein ◽  
Splicing Isoforms ◽  
Shed Light ◽  
Pathological Tissues

ERK1 and ERK2 (ERKs), two extracellular regulated kinases (ERK1/2), are evolutionary-conserved and ubiquitous serine-threonine kinases involved in regulating cell signalling in normal and pathological tissues. The expression levels of these kinases are almost always different, with ERK2 being the more prominent. ERK1/2 activation is fundamental for the development and progression of cancer. Since their discovery, much research has been dedicated to their role in mitogen-activated protein kinases (MAPK) pathway signalling and in their activation by mitogens and mutated RAF or RAS in cancer cells. In order to gain a better understanding of the role of ERK1/2 in MAPK pathway signalling, many studies have been aimed at characterizing ERK1/2 splicing isoforms, mutants, substrates and partners. In this review, we highlight the differences between ERK1 and ERK2 without completely discarding the hypothesis that ERK1 and ERK2 exhibit functional redundancy. The main goal of this review is to shed light on the role of ERK1/2 in targeted therapy and radiotherapy and highlight the importance of identifying ERK inhibitors that may overcome acquired resistance. This is a highly relevant therapeutic issue that needs to be addressed to combat tumours that rely on constitutively active RAF and RAS mutants and the MAPK pathway.

scholarly journals Ancestral resurrection reveals mechanisms of kinase regulatory evolution

2018 ◽  
Author(s):  
Dajun Sang ◽  
Sudarshan Pinglay ◽  
Sezen Vatansever ◽  
Hua Jane Lou ◽  
Benjamin Turk ◽  
...  
Keyword(s):  
Protein Kinases ◽  
Loop Length ◽  
Regulatory Evolution ◽  
Evolutionary Mechanisms ◽  
Mitogen Activated Protein Kinases ◽  
Kinase Activation ◽  
Mitogen Activated Protein ◽  
Dynamics Simulations ◽  
Shed Light

AbstractProtein kinases are crucial to coordinate cellular decisions and therefore their activities are strictly regulated. We used ancestral resurrection to uncover a mechanism underlying the evolution of kinase control within the ERK family of Mitogen Activated Protein Kinases (MAPKs). Kinase activities switched from high to low intrinsic autophosphorylation at the transition from the ancestors of ERKs1-5 and ERKs1-2. A shortening of the loop between β3-αC and a mutation in the gatekeeper residue drove this transition. Molecular dynamics simulations suggested that the change in the β3-αC loop length affected kinase cis-autophosphorylation by altering the positioning of catalytic residues and by allowing greater flexibility in the L16 kinase loop. This latter effect likely synergizes with the known role of gatekeeper mutations in facilitating domain closure and thus kinase activation, providing a rationale for the synergy between the two evolutionary mutations. Our results shed light on the evolutionary mechanisms that led to tight regulation of a central kinase in development and disease.

scholarly journals Mechanisms of Colorectal Cancer Prevention by Aspirin—A Literature Review and Perspective on the Role of COX-Dependent and -Independent Pathways

2020 ◽  
Vol 21 (23) ◽  
pp. 9018
Author(s):  
Ranjini Sankaranarayanan ◽  
D. Ramesh Kumar ◽  
Meric A. Altinoz ◽  
G. Jayarama Bhat
Keyword(s):  
Salicylic Acid ◽  
Cancer Prevention ◽  
Protective Actions ◽  
Direct Exposure ◽  
Anti Cancer ◽  
Chemopreventive Effect ◽  
Colorectal Cancer Prevention ◽  
Preclinical And Clinical Studies ◽  
Shed Light

Aspirin, synthesized and marketed in 1897 by Bayer, is one of the most widely used drugs in the world. It has a well-recognized role in decreasing inflammation, pain and fever, and in the prevention of thrombotic cardiovascular diseases. Its anti-inflammatory and cardio-protective actions have been well studied and occur through inhibition of cyclooxygenases (COX). Interestingly, a vast amount of epidemiological, preclinical and clinical studies have revealed aspirin as a promising chemopreventive agent, particularly against colorectal cancers (CRC); however, the primary mechanism by which it decreases the occurrences of CRC has still not been established. Numerous mechanisms have been proposed for aspirin’s chemopreventive properties among which the inhibition of COX enzymes has been widely discussed. Despite the wide attention COX-inhibition has received as the most probable mechanism of cancer prevention by aspirin, it is clear that aspirin targets many other proteins and pathways, suggesting that these extra-COX targets may also be equally important in preventing CRC. In this review, we discuss the COX-dependent and -independent pathways described in literature for aspirin’s anti-cancer effects and highlight the strengths and limitations of the proposed mechanisms. Additionally, we emphasize the potential role of the metabolites of aspirin and salicylic acid (generated in the gut through microbial biotransformation) in contributing to aspirin’s chemopreventive actions. We suggest that the preferential chemopreventive effect of aspirin against CRC may be related to direct exposure of aspirin/salicylic acid or its metabolites to the colorectal tissues. Future investigations should shed light on the role of aspirin, its metabolites and the role of the gut microbiota in cancer prevention against CRC.

scholarly journals Role of mitogen-activated protein kinases in pulmonary endothelial cells exposed to cyclic strain

2000 ◽  
Vol 89 (6) ◽  
pp. 2391-2400 ◽  
Author(s):  
Hiroyuki Kito ◽  
Emery L. Chen ◽  
Xiujie Wang ◽  
Masataka Ikeda ◽  
Nobuyoshi Azuma ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Kinases ◽  
Cyclic Strain ◽  
Cell Alignment ◽  
Mitogen Activated Protein Kinases ◽  
Mitogen Activated Protein ◽  
Pulmonary Arterial ◽  
And Migration ◽  
Sb 203580

The aim of this study was to examine the role of mitogen-activated protein kinases (MAPKs) activation in bovine pulmonary arterial endothelial cells (EC) exposed to cyclic strain. EC were subjected to 10% average strain at 60 cycles/min. Cyclic strain induced activation of extracellular signal-regulated kinase (ERK; 1.5-fold), c-Jun NH2-terminal protein kinase (JNK; 1.9-fold), and p38 (1.5-fold) with a peak at 30 min. To investigate the functional role of the activated MAPKs, we analyzed cells after treatment with PD-98059, a specific ERK kinase inhibitor, or SB-203580, a catalytic inhibitor for p38, and after transient transfection with JNK(K-R), and MEKK(K-M) the respective catalytically inactive mutants of JNK1 and MAPK kinase kinase-1. Cyclic strain increased activator protein-1 (AP-1) binding activity, which was blocked by PD-98059 and SB-203580. Activity of AP-1-dependent luciferase reporter driven by 12- O-tetradecanoyl-phorbol-13-acetate-responsive element (TRE) was induced by cyclic strain, and this was attenuated by PD-98059, MEKK(K-M), JNK(K-R), and SB-203580. PD-98059 and SB-203850 did not inhibit cell alignment and migration induced by cyclic strain. MEKK(K-M) and JNK(K-R) transfection did not block cyclic strain-induced cell alignment. In conclusion, cyclic strain activates ERK, JNK, and p38, and their activation plays a role in transcriptional activation of AP-1/TRE but not in cell alignment and migration changes in bovine pulmonary arterial EC.

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