Computational Study on the Effect of Inactivating/Activating Mutations on the Inhibition of MEK1 by Trametinib

Activation of the mitogen-activated protein kinase (MAPK) signaling pathway regulated by human MAP kinase 1 (MEK1) is associated with the carcinogenesis and progression of numerous cancers. In addition, two active mutations (P124S and E203K) have been reported to enhance the activity of MEK1, thereby eventually leading to the tumorigenesis of cancer. Trametinib is an MEK1 inhibitor for treating EML4-ALK-positive, EGFR-activated, and KRAS-mutant lung cancers. Therefore, in this study, molecular docking and molecular dynamic (MD) simulations were performed to explore the effects of inactive/active mutations (A52V/P124S and E203K) on the conformational changes of MEK1 and the changes in the interaction of MEK1 with trametinib. Moreover, steered molecular dynamic (SMD) simulations were further utilized to compare the dissociation processes of trametinib from the wild-type (WT) MEK1 and two active mutants (P124S and E203K). As a result, trametinib had stronger interactions with the non-active MEK1 (WT and A52V mutant) than the two active mutants (P124S and E203K). Moreover, two active mutants may make the allosteric channel of MEK1 wider and shorter than that of the non-active types (WT and A52V mutant). Hence, trametinib could dissociate from the active mutants (P124S and E203K) more easily compared with the WT MEK1. In summary, our theoretical results demonstrated that the active mutations may attenuate the inhibitory effects of MEK inhibitor (trametinib) on MEK1, which could be crucial clues for future anti-cancer treatment.

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MEK-inhibitor-mediated rescue of skeletal myopathy caused by activating Hras mutation in a Costello syndrome mouse model

Disease Models & Mechanisms ◽

10.1242/dmm.049166 ◽

2021 ◽

Author(s):

William E. Tidyman ◽

Alice F. Goodwin ◽

Yoshiko Maeda ◽

Ophir D. Klein ◽

Katherine A. Rauen

Keyword(s):

Mouse Model ◽

Mapk Pathway ◽

Mek Inhibitor ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Costello Syndrome ◽

Skeletal Myopathy ◽

Mitogen Activated Protein

Costello syndrome (CS) is a congenital disorder caused by heterozygous activating germline HRAS mutations in the canonical Ras/mitogen-activated protein kinase (Ras/MAPK) pathway. CS is one of the RASopathies, a large group of syndromes due to mutations within various components of the Ras/MAPK pathway. An important part of the phenotype that greatly impacts quality of life is hypotonia. To gain a better understanding of the mechanisms underlying hypotonia in CS, a mouse model with an activating HrasG12V allele was utilized. We identified a skeletal myopathy that was due in part to an inhibition of embryonic myogenesis and myofiber formation, resulting in a reduction of myofiber size and number that led to reduced muscle mass and strength. In addition to hyperactivation of the Ras/MAPK and PI3K/AKT pathways, there was a significant reduction of p38 signaling, as well as global transcriptional alterations consistent with the myopathic phenotype. Inhibition of Ras/MAPK pathway signaling using a MEK inhibitor rescued the HrasG12V myopathy phenotype both in vitro and in vivo, demonstrating that increased MAPK signaling is the main cause of the muscle phenotype in CS.

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Reacquisition of RAI uptake in RAI-refractory metastatic thyroid cancers by pretreatment with the MEK inhibitor selumetinib.

Journal of Clinical Oncology ◽

10.1200/jco.2012.30.15_suppl.5509 ◽

2012 ◽

Vol 30 (15_suppl) ◽

pp. 5509-5509 ◽

Cited By ~ 2

Author(s):

Alan Loh Ho ◽

Rebecca Leboeuf ◽

Ravinder K. Grewal ◽

Eric Jeffrey Sherman ◽

Desiree Deandreis ◽

...

Keyword(s):

Mek Inhibitor ◽

Mapk Signaling ◽

Pet Scan ◽

Mitogen Activated Protein Kinase ◽

Iodine Uptake ◽

Sodium Iodide Symporter ◽

Serum Thyroglobulin ◽

Thyroid Cancers ◽

Positron Emission ◽

Mitogen Activated Protein

5509^ Background: Therapies for radioactive iodine (RAI)-refractory thyroid cancers of follicular origin (TC-FCO) are desperately needed. TC-FCO mouse models show that blocking mitogen-activated protein kinase (MAPK) signaling with a MAP kinase kinase 1/2 (MEK1/2) inhibitor increases sodium iodide symporter expression and iodine incorporation. This 20 patient (pt) pilot study aimed to evaluate if the MEK1/2 inhibitor selumetinib (AZD6244, ARRY-142866) can reverse RAI-refractoriness in TC-FCO pts (NCT00970359). Methods: RAI-refractory TC-FCO disease was defined as: 1) non-RAI-avid lesion/s on a diagnostic or post-therapy RAI scan, 2) RAI-avid lesion/s that was stable or increased in size after RAI therapy, or 3) fluorodeoxyglucose (FDG)-avid lesion/s by positron emission tomography (PET) scan. rhTSH-stimulated lesional dosimetry with 124I PET was performed prior to and after 4 weeks of treatment with selumetinib (75 mg orally bid). If the second 124I PET scan predicted a lesional RAI dose of > 2000 cGy, therapeutic RAI was administered while on the drug. Primary endpoints were to evaluate changes in tumor iodine uptake and RECIST response after RAI therapy; changes in serum thyroglobulin (TG) after RAI was a secondary endpoint. Results: 24 pts were enrolled, 22 eligible, and 20 evaluable. For the 20 evaluable pts, median age was 61 (range 44-77 yrs), 11 were men. 19 pts had tumors analyzed for BRAF and N-,K- RAS mutations. 8 pts had BRAF mutant (MUT), 11 BRAF wild-type (WT) tumors; 1 pt to be analyzed. Selumetinib increased 124I uptake in 12 of the 20 pts (4 of 8 BRAF MUT; 8 of the 12 other pts). The 8 of those 12 pts achieving sufficient iodine avidity to warrant RAI therapy included all 5 pts known to be NRAS MUT to date and 1 BRAF MUT pt. Of the 7 pts who have received RAI, 5 had partial responses (PRs); 2 stable disease (SD). Mean percent reduction in TG in this group (pre- vs 2 months post- RAI) was 91%. No > grade 2 CTCAE toxicities attributable to selumetinib were observed. 1 pt was diagnosed with myelodysplastic syndrome > 51 weeks after RAI (unrelated to selumetinib). Conclusions: Selumetinib can enhance iodine uptake in a subset of RAI-refractory TC-FCO and may be particularly effective for RAS MUT tumors.

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The BRAF–MAPK signaling pathway is essential for cancer-immune evasion in human melanoma cells

Journal of Experimental Medicine ◽

10.1084/jem.20051848 ◽

2006 ◽

Vol 203 (7) ◽

pp. 1651-1656 ◽

Cited By ~ 395

Author(s):

Hidetoshi Sumimoto ◽

Fumie Imabayashi ◽

Tomoko Iwata ◽

Yutaka Kawakami

Keyword(s):

Immune Evasion ◽

Cellular Proliferation ◽

Mapk Pathway ◽

Synergistic Effects ◽

Mek Inhibitor ◽

Melanoma Cells ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Mitogen Activated Protein ◽

Factor Α

The mitogen-activated protein kinase (MAPK) pathway is frequently activated in human cancers, leading to malignant phenotypes such as autonomous cellular proliferation. Here, we demonstrate a novel role of the activated MAPK pathway in immune evasion by melanoma cells with the mutation of BRAF, which encodes a MAPKKs, (BRAFV600E). MEK inhibitor U0126 or RNA interference (RNAi) for BRAFV600E decreased production of the immunosuppressive soluble factors interleukin (IL)-10, VEGF, or IL-6 from melanoma cells to levels comparable to those after signal transducer and activator of transcription (STAT)3 inactivation. The suppressive activity of the culture supernatants from the melanoma cells on the production of inflammatory cytokines IL-12 and tumor necrosis factor α by dendritic cells upon lipopolysaccharide stimulation was markedly reduced after transduction with BRAFV600E RNAi, comparable to the effects observed with STAT3 RNAi transduction. No additive or synergistic effects were observed by the simultaneous transduction of RNAi for both BRAFV600E and STAT3. Furthermore, specific DNA binding and transcriptional activity of STAT3 were not affected by down-regulation of the MAPK signaling with the BRAF RNAi. These results indicate that the MAPK signal, along with the STAT3 signal, is essential for immune evasion by human melanomas that have constitutively active MAPK signaling and is a potential molecular target for overcoming melanoma cell evasion of the immune system.

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Combined VEGFR and MAPK pathway inhibition in angiosarcoma

Scientific Reports ◽

10.1038/s41598-021-88703-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Michael J. Wagner ◽

Yasmin A. Lyons ◽

Jean H. Siedel ◽

Robert Dood ◽

Archana S. Nagaraja ◽

...

Keyword(s):

Protein Kinase ◽

Mapk Pathway ◽

Combined Treatment ◽

Mek Inhibitor ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

In Vivo Model ◽

Mitogen Activated Protein

AbstractAngiosarcoma is an aggressive malignancy of endothelial cells that carries a high mortality rate. Cytotoxic chemotherapy can elicit clinical responses, but the duration of response is limited. Sequencing reveals multiple mutations in angiogenesis pathways in angiosarcomas, particularly in vascular endothelial growth factor (VEGFR) and mitogen-activated protein kinase (MAPK) signaling. We aimed to determine the biological relevance of these pathways in angiosarcoma. Tissue microarray consisting of clinical formalin-fixed paraffin embedded tissue archival samples were stained for phospho- extracellular signal-regulated kinase (p-ERK) with immunohistochemistry. Angiosarcoma cell lines were treated with the mitogen-activated protein kinase kinase (MEK) inhibitor trametinib, pan-VEGFR inhibitor cediranib, or combined trametinib and cediranib and viability was assessed. Reverse phase protein array (RPPA) was performed to assess multiple oncogenic protein pathways. SVR angiosarcoma cells were grown in vivo and gene expression effects of treatment were assessed with whole exome RNA sequencing. MAPK signaling was found active in over half of clinical angiosarcoma samples. Inhibition of MAPK signaling with the MEK inhibitor trametinib decreased the viability of angiosarcoma cells. Combined inhibition of the VEGF and MAPK pathways with cediranib and trametinib had an additive effect in in vitro models, and a combinatorial effect in an in vivo model. Combined treatment led to smaller tumors than treatment with either agent alone. RNA-seq demonstrated distinct expression signatures between the trametinib treated tumors and those treated with both trametinib and cediranib. These results indicate a clinical study of combined VEGFR and MEK inhibition in angiosarcoma is warranted.

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PD-L1 blockade in combination with inhibition of MAPK oncogenic signaling in patients with advanced melanoma

Nature Communications ◽

10.1038/s41467-020-19810-w ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Antoni Ribas ◽

Alain Algazi ◽

Paolo A. Ascierto ◽

Marcus O. Butler ◽

Sunandana Chandra ◽

...

Keyword(s):

Phase 1 ◽

Treatment Options ◽

Braf Inhibitor ◽

Mek Inhibitor ◽

Mapk Signaling ◽

Advanced Melanoma ◽

Mitogen Activated Protein Kinase ◽

Oncogenic Signaling ◽

Open Label ◽

Mitogen Activated Protein

AbstractCombining PD-L1 blockade with inhibition of oncogenic mitogen-activated protein kinase (MAPK) signaling may result in long-lasting responses in patients with advanced melanoma. This phase 1, open-label, dose-escalation and -expansion study (NCT02027961) investigated safety, tolerability and preliminary efficacy of durvalumab (anti–PD-L1) combined with dabrafenib (BRAF inhibitor) and trametinib (MEK inhibitor) for patients with BRAF-mutated melanoma (cohort A, n = 26), or durvalumab and trametinib given concomitantly (cohort B, n = 20) or sequentially (cohort C, n = 22) for patients with BRAF-wild type melanoma. Adverse events and treatment discontinuation rates were more common than previously reported for these agents given as monotherapy. Objective responses were observed in 69.2% (cohort A), 20.0% (cohort B) and 31.8% (cohort C) of patients, with evidence of improved tumor immune infiltration and durable responses in a subset of patients with available biopsy samples. In conclusion, combined MAPK inhibition and anti–PD-L1 therapy may provide treatment options for patients with advanced melanoma.

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Specific Functional Features of the Cell Integrity MAP Kinase Pathway in the Dimorphic Fission Yeast Schizosaccharomyces japonicus

Journal of Fungi ◽

10.3390/jof7060482 ◽

2021 ◽

Vol 7 (6) ◽

pp. 482

Author(s):

Elisa Gómez-Gil ◽

Alejandro Franco ◽

Beatriz Vázquez-Marín ◽

Francisco Prieto-Ruiz ◽

Armando Pérez-Díaz ◽

...

Keyword(s):

Fission Yeast ◽

Environmental Changes ◽

Yeast Species ◽

Mapk Signaling ◽

Fine Tuning ◽

Mitogen Activated Protein Kinase ◽

Major Influence ◽

Cell Integrity ◽

Mitogen Activated Protein ◽

Functional Features

Mitogen activated protein kinase (MAPK) signaling pathways execute essential functions in eukaryotic organisms by transducing extracellular stimuli into adaptive cellular responses. In the fission yeast model Schizosaccharomyces pombe the cell integrity pathway (CIP) and its core effector, MAPK Pmk1, play a key role during regulation of cell integrity, cytokinesis, and ionic homeostasis. Schizosaccharomyces japonicus, another fission yeast species, shows remarkable differences with respect to S. pombe, including a robust yeast to hyphae dimorphism in response to environmental changes. We show that the CIP MAPK module architecture and its upstream regulators, PKC orthologs Pck1 and Pck2, are conserved in both fission yeast species. However, some of S. pombe’s CIP-related functions, such as cytokinetic control and response to glucose availability, are regulated differently in S. japonicus. Moreover, Pck1 and Pck2 antagonistically regulate S. japonicus hyphal differentiation through fine-tuning of Pmk1 activity. Chimeric MAPK-swapping experiments revealed that S. japonicus Pmk1 is fully functional in S. pombe, whereas S. pombe Pmk1 shows a limited ability to execute CIP functions and promote S. japonicus mycelial development. Our findings also suggest that a modified N-lobe domain secondary structure within S. japonicus Pmk1 has a major influence on the CIP signaling features of this evolutionarily diverged fission yeast.

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Effect of Static Magnetic Field on Monascus ruber M7 Based on Transcriptome Analysis

Journal of Fungi ◽

10.3390/jof7040256 ◽

2021 ◽

Vol 7 (4) ◽

pp. 256

Author(s):

Shuyan Yang ◽

Hongyi Zhou ◽

Weihua Dai ◽

Juan Xiong ◽

Fusheng Chen

Keyword(s):

Magnetic Field ◽

Static Magnetic Field ◽

Morphological Characteristics ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Primary Metabolism ◽

Monascus Ruber ◽

Growing Period ◽

Monascus Pigments ◽

Mitogen Activated Protein

The effects of a static magnetic field (SMF) on Monascus ruber M7 (M. ruber M7) cultured on potato dextrose agar (PDA) plates under SMF treatment at different intensities (5, 10, and 30 mT) were investigated in this paper. The results revealed that, compared with the control (CK, no SMF treatment), the SMF at all tested intensities did not significantly influence the morphological characteristics of M. ruber M7, while the intracellular and extracellular Monascus pigments (MPs) and extracellular citrinin (CIT) of M. ruber M7 were increased at 10 and 30 mT SMF but there was no impact on the MPs and CIT at 5 mT SMF. The transcriptome data of M. ruber M7 cultured at 30 mT SMF on PDA for 3 and 7 d showed that the SMF could increase the transcriptional levels of some relative genes with the primary metabolism, including the carbohydrate metabolism, amino acid metabolism, and lipid metabolism, especially in the early growing period (3 d). SMF could also affect the transcriptional levels of the related genes to the biosynthetic pathways of MPs, CIT, and ergosterol, and improve the transcription of the relative genes in the mitogen-activated protein kinase (MAPK) signaling pathway of M. ruber M7. These findings provide insights into a comprehensive understanding of the effects of SMF on filamentous fungi.

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The Emerging Role of Macrophages in Immune System Dysfunction under Real and Simulated Microgravity Conditions

International Journal of Molecular Sciences ◽

10.3390/ijms22052333 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2333

Author(s):

Yulong Sun ◽

Yuanyuan Kuang ◽

Zhuo Zuo

Keyword(s):

Immune System ◽

Mapk Signaling ◽

Immune Defense ◽

Mitogen Activated Protein Kinase ◽

Therapeutic Drugs ◽

Physiological Processes ◽

Immune System Dysfunction ◽

Cell Immunity ◽

Mitogen Activated Protein ◽

Microgravity Conditions

In the process of exploring space, the astronaut’s body undergoes a series of physiological changes. At the level of cellular behavior, microgravity causes significant alterations, including bone loss, muscle atrophy, and cardiovascular deconditioning. At the level of gene expression, microgravity changes the expression of cytokines in many physiological processes, such as cell immunity, proliferation, and differentiation. At the level of signaling pathways, the mitogen-activated protein kinase (MAPK) signaling pathway participates in microgravity-induced immune malfunction. However, the mechanisms of these changes have not been fully elucidated. Recent studies suggest that the malfunction of macrophages is an important breakthrough for immune disorders in microgravity. As the first line of immune defense, macrophages play an essential role in maintaining homeostasis. They activate specific immune responses and participate in large numbers of physiological activities by presenting antigen and secreting cytokines. The purpose of this review is to summarize recent advances on the dysfunction of macrophages arisen from microgravity and to discuss the mechanisms of these abnormal responses. Hopefully, our work will contribute not only to the future exploration on the immune system in space, but also to the development of preventive and therapeutic drugs against the physiological consequences of spaceflight.

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Topical Spilanthol Inhibits MAPK Signaling and Ameliorates Allergic Inflammation in DNCB-Induced Atopic Dermatitis in Mice

International Journal of Molecular Sciences ◽

10.3390/ijms20102490 ◽

2019 ◽

Vol 20 (10) ◽

pp. 2490 ◽

Cited By ~ 4

Author(s):

Wen-Chung Huang ◽

Chun-Hsun Huang ◽

Sindy Hu ◽

Hui-Ling Peng ◽

Shu-Ju Wu

Keyword(s):

Atopic Dermatitis ◽

Mast Cells ◽

Protein Kinase ◽

Allergic Inflammation ◽

Skin Lesions ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Mapk Pathways ◽

Mitogen Activated Protein ◽

Cox 2

Atopic dermatitis (AD) is a recurrent allergic skin disease caused by genetic and environmental factors. Patients with AD may experience immune imbalance, increased levels of mast cells, immunoglobulin (Ig) E and pro-inflammatory factors (Cyclooxygenase, COX-2 and inducible NO synthase, iNOS). While spilanthol (SP) has anti-inflammatory and analgesic activities, its effect on AD remains to be explored. To develop a new means of SP, inflammation-related symptoms of AD were alleviated, and 2,4-dinitrochlorobenzene (DNCB) was used to induce AD-like skin lesions in BALB/c mice. Histopathological analysis was used to examine mast cells and eosinophils infiltration in AD-like skin lesions. The levels of IgE, IgG1 and IgG2a were measured by enzyme-linked immunosorbent assay (ELISA) kits. Western blot was used for analysis of the mitogen-activated protein kinase (MAPK) pathways and COX-2 and iNOS protein expression. Topical SP treatment reduced serum IgE and IgG2a levels and suppressed COX-2 and iNOS expression via blocked mitogen-activated protein kinase (MAPK) pathways in DNCB-induced AD-like lesions. Histopathological examination revealed that SP reduced epidermal thickness and collagen accumulation and inhibited mast cells and eosinophils infiltration into the AD-like lesions skin. These results indicate that SP may protect against AD skin lesions through inhibited MAPK signaling pathways and may diminish the infiltration of inflammatory cells to block allergic inflammation.

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Platyphyllenone Induces Autophagy and Apoptosis by Modulating the AKT and JNK Mitogen-Activated Protein Kinase Pathways in Oral Cancer Cells

International Journal of Molecular Sciences ◽

10.3390/ijms22084211 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4211

Author(s):

Yen-Tze Liu ◽

Hsin-Yu Ho ◽

Chia-Chieh Lin ◽

Yi-Ching Chuang ◽

Yu-Sheng Lo ◽

...

Keyword(s):

Protein Kinase ◽

Oral Cancer ◽

Protein Expression ◽

Caspase 3 ◽

Therapeutic Option ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Dependent Manner ◽

Cancer Proliferation ◽

Mitogen Activated Protein

Platyphyllenone is a type of diarylheptanoid that exhibits anti-inflammatory and chemoprotective effects. However, its effect on oral cancer remains unclear. In this study, we investigated whether platyphyllenone can promote apoptosis and autophagy in SCC-9 and SCC-47 cells. We found that it dose-dependently promoted the cleavage of PARP; caspase-3, -8, and -9 protein expression; and also led to cell cycle arrest at the G2/M phase. Platyphyllenone up-regulated LC3-II and p62 protein expression in both SCC-9 and SCC-47 cell lines, implying that it can induce autophagy. Furthermore, the results demonstrated that platyphyllenone significantly decreased p-AKT and increased p-JNK1/2 mitogen-activated protein kinase (MAPK) signaling pathway in a dose-dependent manner. The specific inhibitors of p-JNK1/2 also reduced platyphyllenone-induced cleavage of PARP, caspase-3, and caspase -8, LC3-II and p62 protein expression. These findings are the first to demonstrate that platyphyllenone can induce both autophagy and apoptosis in oral cancers, and it is expected to provide a therapeutic option as a chemopreventive agent against oral cancer proliferation.

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