scholarly journals Enhancing the Therapeutic Efficacy of KRASG12C Inhibitors in Lung Adenocarcinoma Cell Models by Cotargeting the MAPK Pathway or HSP90

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Ying Liu ◽  
Lei Wu ◽  
Hong Lu ◽  
En Wu ◽  
Jun Ni ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Lung Adenocarcinoma ◽  
Tyrosine Kinases ◽  
Tumor Regression ◽  
Mapk Pathway ◽  
Transcriptional Profiling ◽  
Multidrug Resistant ◽  
Mitogen Activated Protein Kinase

Background. KRASG12C inhibitors have shown promising efficacy in early clinical trials, but drug resistance compromises their long-term benefits. Therefore, it is critical to understand the mechanisms of drug resistance and to design appropriate combinatory treatments to improve efficacy. Methods. To understand the comprehensive mechanisms of drug resistance, we treated lung cancer cells with KRASG12C inhibitors for different periods and performed transcriptional profiling and signaling analysis to identify critical factors and pathways that drive drug tolerance and resistance. We also evaluated several drug combinations in vitro and in vivo to identify potentially effective therapeutics. Results. We found that the feedback activation of multiple receptor tyrosine kinases (RTKs) may have cooperatively induced intrinsic and adaptive resistance to KRASG12C inhibitors. Notably, continuous KRAS inhibition induced a multidrug-resistant phenotype, implying that upfront combinatory treatment might be required to treat this group of patients. We also demonstrated that concurrently targeting multiple nodes in the RTK/RAS/RAF/MEK/ERK axis improved the efficacy of KRASG12C inhibitors, mainly by suppressing the reactivation of the mitogen-activated protein kinase (MAPK) pathway. Moreover, the combined use of HSP90 and KRASG12C inhibitors effectively induced tumor regression in lung adenocarcinoma models in vitro and in vivo. Conclusion. Together, our findings revealed mechanisms underlying KRASG12C inhibitors resistance and provided novel candidate combinatory strategies to improve their anticancer activity.

LIF transduces contradictory signals on capillary outgrowth through induction of stat3 and (P41/43)MAP kinase

2000 ◽  
Vol 113 (23) ◽  
pp. 4331-4339 ◽  
Author(s):  
H. Paradis ◽  
R.L. Gendron
Keyword(s):  
Signaling Pathways ◽  
Tyrosine Kinases ◽  
Mapk Pathway ◽  
Present Report ◽  
Binding Activity ◽  
Negative Regulator ◽  
Mapk Cascade ◽  
Mitogen Activated Protein Kinase

The signaling pathways regulating blood vessel growth and development are not well understood. In the present report, an in vitro model was used to identify signaling pathways regulating capillary formation in embryonic endothelial cells. Basic fibroblast growth factor (bFGF) plus leukemia inhibitory factor (LIF) optimally stimulate the formation of capillary-like structures of the embryonic endothelial cell line IEM. LIF stimulation of IEM cells leads to activation of the Stat3 as well as the (P41/43)mitogen-activated protein kinase ((P41/43)MAPK) cascade, while bFGF does not activate Stat3 but does induce the (P41/43)MAPK cascade. Inhibition of Stat3 DNA-binding activity by expression of a dominant inhibitory Stat3 mutant increases the capillary outgrowth of the IEM cells induced by LIF. Increased Stat3 activity by overexpression of the wild-type Stat3 greatly reduced capillary outgrowth. In contrast, inhibition of the (P41/43)MAPK cascade using a MEK-1 inhibitor dramatically inhibits the LIF-induced capillary outgrowth. Moreover, the increased formation of capillary-like structures of the IEM cells mediated by Stat3 inhibition does not overcome the requirement for activation of the (P41/43)MAPK pathway for capillary outgrowth. Stat3 activity correlates with the LIF-induced expression of the negative feedback regulators of the Janus (JAK) family of tyrosine kinases, SOCS-1 and SOCS-3. These results provide evidence that Stat3 acts as a negative regulator of capillary outgrowth, possibly by increasing SOCS-1 or SOCS-3 expression. The contradictory signals stimulated by LIF could be necessary to control the intensity of the response leading to capillary outgrowth in vivo.

scholarly journals Critical role of the extracellular signal–regulated kinase–MAPK pathway in osteoblast differentiation and skeletal development

2007 ◽  
Vol 176 (5) ◽  
pp. 709-718 ◽  
Author(s):  
Chunxi Ge ◽  
Guozhi Xiao ◽  
Di Jiang ◽  
Renny T. Franceschi
Keyword(s):  
Transcriptional Activity ◽  
Mapk Pathway ◽  
Skeletal Development ◽  
Critical Role ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal

The extracellular signal–regulated kinase (ERK)–mitogen-activated protein kinase (MAPK) pathway provides a major link between the cell surface and nucleus to control proliferation and differentiation. However, its in vivo role in skeletal development is unknown. A transgenic approach was used to establish a role for this pathway in bone. MAPK stimulation achieved by selective expression of constitutively active MAPK/ERK1 (MEK-SP) in osteoblasts accelerated in vitro differentiation of calvarial cells, as well as in vivo bone development, whereas dominant-negative MEK1 was inhibitory. The involvement of the RUNX2 transcription factor in this response was established in two ways: (a) RUNX2 phosphorylation and transcriptional activity were elevated in calvarial osteoblasts from TgMek-sp mice and reduced in cells from TgMek-dn mice, and (b) crossing TgMek-sp mice with Runx2+/− animals partially rescued the hypomorphic clavicles and undemineralized calvaria associated with Runx2 haploinsufficiency, whereas TgMek-dn; Runx2+/− mice had a more severe skeletal phenotype. This work establishes an important in vivo function for the ERK–MAPK pathway in bone that involves stimulation of RUNX2 phosphorylation and transcriptional activity.

Combined SHP2 and ERK inhibition for the treatment of KRAS-driven Pancreatic Ductal Adenocarcinoma

2021 ◽  
Author(s):  
Katrin J Ciecielski ◽  
Antonio Mulero-Sanchez ◽  
Alexandra Berninger ◽  
Laura Ruiz Canas ◽  
Astrid Bosma ◽  
...  
Keyword(s):  
Pancreatic Ductal Adenocarcinoma ◽  
Tumor Regression ◽  
Mapk Pathway ◽  
Single Agent ◽  
Ductal Adenocarcinoma ◽  
Good Tolerability ◽  
Recent Emergence ◽  
Erk Inhibition

Mutant KRAS is present in over 90% of pancreatic as well as 30-40% of lung and colorectal cancers and is one of the most common oncogenic drivers. Despite decades of research and the recent emergence of isoform-specific KRASG12C-inhibitors, most mutant KRAS isoforms, including the ones frequently associated with pancreatic ductal adenocarcinoma (PDAC), cannot be targeted directly. Moreover, targeting single RAS downstream effectors induces adaptive mechanisms leading to tumor recurrence or resistance. We report here on the combined inhibition of SHP2, a non-receptor tyrosine phosphatase upstream of KRAS, and ERK, a serine/threonine kinase and a key molecule downstream of KRAS in PDAC. This combination shows synergistic anticancer activity in vitro, superior disruption of the MAPK pathway, and significantly increased apoptosis induction compared to single-agent treatments. In vivo, we demonstrate good tolerability and efficacy of the combination. Concurrent inhibition of SHP2 and ERK induces significant tumor regression in multiple PDAC mouse models. Finally, we show evidence that 18F-FDG PET scans can be used to detect and predict early drug responses in animal models. Based on these compelling results, we will investigate this drug combination in a clinical trial (SHERPA, SHP2 and ERK inhibition in pancreatic cancer, NCT04916236), enrolling patients with KRAS-mutant PDAC.

scholarly journals MiR-1307-5p targeting TRAF3 upregulates the MAPK/NF-κB pathway and promotes lung adenocarcinoma proliferation

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Xinyue Du ◽  
Shuangmiao Wang ◽  
Xingyan Liu ◽  
Tao He ◽  
Xiangui Lin ◽  
...  
Keyword(s):  
Western Blot ◽  
Lung Adenocarcinoma ◽  
High Throughput Sequencing ◽  
Mapk Pathway ◽  
Early Stage ◽  
Lung Squamous Cell Carcinoma ◽  
Luciferase Assay ◽  
Migration Ability

Abstract Background Non-small cell lung cancer (NSCLC) includes lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). MicroRNA (miRNA) plays an important role in the regulation of post-transcriptional gene expression in animals and plants, especially in lung adenocarcinoma. Methods MiR-1307-5p is an miRNA with significant differences screened by the second generation of high-throughput sequencing in the early stage of our research group. In the current study, a series of in vitro and in vivo experiments were carried out. MiR-1307-5p mimic, miR-1307-5p inhibitor, and NC were transfected into A549 and H1299 lung adenocarcinoma cells. The correlation between miR-1307-5p and clinicopathological features in pathological samples was analyzed using a lung adenocarcinoma tissue microarray, and miR-1307-5p expression was detected by qPCR. CCK-8, EdU, colony formation, scratch test, and Transwell assays were used to observe cell proliferation and migration. Double luciferase assay, western blot, qPCR, and immunohistochemistry were employed in confirming the target relationship between miR-1307-5p and TRAF3. Western blotting was used to analyze the relationship between miR-1307-5p and the NF-κB/MAPK pathway. Finally, the effect of miR-1307-5p on tumor growth was studied using a subcutaneous tumorigenesis model in nude mice. Results Increased miR-1307-5p expression was significantly related to decreased overall survival rate of lung adenocarcinoma patients, revealing miR-1307-5p as a potential oncogene in lung adenocarcinoma. MiR-1307-5p mimic significantly promoted while miR-1307-5p inhibitor reduced the growth and proliferation of A549 and H1299 cells. MiR-1307-5p overexpression significantly enhanced the migration ability while miR-1307-5p inhibition reduced the migration ability of A549 and H1299 cells. Target binding of miR-1307-5p to TRAF3 was confirmed by double luciferase assay, western blot, qPCR, and immunohistochemistry. miR-1307-5p caused degradation of TRAF3 mRNA and protein. MiR-1307-5p targeted TRAF3 and activated the NF-κB/MAPK pathway. TRAF3 colocalized with p65 and the localization of TRAF3 and p65 changed in each treatment group. Tumor volume of the lv-miR-1307-5p group was significantly larger than that of the lv-NC group, and that of the lv-miR-1307-5p-inhibitor group was significantly smaller than that of the lv-NC group. Conclusion In conclusion, miR-1307-5p targets TRAF3 and activates the NF-κB/MAPK pathway to promote proliferation in lung adenocarcinoma.

Phosphorylation of Argonaute 2 at serine-387 facilitates its localization to processing bodies

2008 ◽  
Vol 413 (3) ◽  
pp. 429-436 ◽  
Author(s):  
Yan Zeng ◽  
Heidi Sankala ◽  
Xiaoxiao Zhang ◽  
Paul R. Graves
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Phosphorylation Site ◽  
Mitogen Activated Protein Kinase ◽  
Processing Bodies ◽  
Mitogen Activated Protein

Ago (Argonaute) proteins are essential effectors of RNA-mediated gene silencing. To explore potential regulatory mechanisms for Ago proteins, we examined the phosphorylation of human Ago2. We identified serine-387 as the major Ago2 phosphorylation site in vivo. Phosphorylation of Ago2 at serine-387 was significantly induced by treatment with sodium arsenite or anisomycin, and arsenite-induced phosphorylation was inhibited by a p38 MAPK (mitogen-activated protein kinase) inhibitor, but not by inhibitors of JNK (c-Jun N-terminal kinase) or MEK [MAPK/ERK (extracellular-signal-regulated kinase) kinase]. MAPKAPK2 (MAPK-activated protein kinase-2) phosphorylated bacterially expressed full-length human Ago2 at serine-387 in vitro, but not the S387A mutant. Finally, mutation of serine-387 to an alanine residue or treatment of cells with a p38 MAPK inhibitor reduced the localization of Ago2 to processing bodies. These results suggest a potential regulatory mechanism for RNA silencing acting through Ago2 serine-387 phosphorylation mediated by the p38 MAPK pathway.

scholarly journals SPDR-1 HSP90 inhibition overcomes resistant to molecular targeted therapy in BRAFV600E mutant glioblastoma

2021 ◽  
Vol 3 (Supplement_6) ◽  
pp. vi3-vi3
Author(s):  
Jo Sasame ◽  
Naoki Ikegaya ◽  
Yohei Miyake ◽  
Takahiro Hayashi ◽  
Akito Oshima ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Molecular Targeted Therapy ◽  
Mapk Pathway ◽  
Mek Inhibitor ◽  
Mtor Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Hsp90 Inhibition ◽  
Pdx Models

Abstract The BRAFV600E mutation results in the constitutive activation of downstream mitogen activated protein kinase (MAPK) pathway that promotes tumor growth. Recently, molecular targeted therapy using BRAF/MEK inhibitor has been reported for BRAFV600E mutant high-grade glioma, but the therapeutic effect is limited by the emergence of drug resistance. Herein, we established paired BRAFV600E mutant glioblastoma (GBM) patient-derived xenograft (PDX) models, which were derived from tumors at prior to and recurrence after molecular targeted therapy. These PDX models were found to extensively recapitulate the histology, genetic abnormalities, and even the clinical course of the patients. Furthermore, BRAF/MEK inhibitor gradually caused resistance in cell lines derived from specimens that initially responded to molecular targeted therapy. In this study, genomic and epigenomic changes had little effect on the resistance mechanism. On the other hand, we found that hyperactivation of the MAPK pathway through c-Raf and the AKT/mTOR pathway primarily caused resistance to molecular targeted therapy in BRAFV600E mutant GBM. Through a high throughput drug screening, we find that HSP90 inhibitor with BRAF/MEK inhibitor coordinately deactivates MAPK pathway and AKT/mTOR pathway, and mediates potent toxicity in vitro and in vivo in refractory and acquired resistant models. These findings support that this therapeutic approach can overcome the limitation of current molecular targeted therapy in BRAFV600E mutant GBM.

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

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.

scholarly journals Pazopanib and Trametinib as a Synergistic Strategy against Osteosarcoma: Preclinical Activity and Molecular Insights

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1519
Author(s):  
Giulia Chiabotto ◽  
Giovanni Grignani ◽  
Maja Todorovic ◽  
Valentina Martin ◽  
Maria Laura Centomo ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Tyrosine Kinases ◽  
Molecular Mechanisms ◽  
Mitogen Activated Protein Kinase ◽  
Osteosarcoma Cell ◽  
Antitumor Effects ◽  
Interleukin 7 ◽  
Nanostring Technology

Receptor tyrosine kinases (RTKs) inhibitors’ activity in advanced osteosarcoma is significant but short-lived. To prevent or at least delay drug resistance, we explored a vertical inhibition by combining drugs acting at different levels of the RTK pathways (pazopanib + trametinib). We studied pazopanib + trametinib antitumor activity both in vitro and in vivo (MNNG-HOS and KHOS xenografts in NOD/SCID mice) investigating the molecular mechanisms and potential escapes. The involvement of MAPK-PI3K pathways was validated by Nanostring technology, western blot and by silencing/overexpression experiments. Pazopanib targets were expressed on seven osteosarcoma cell lines and their pathways were activated. Pazopanib + trametinib exhibited synergistic antitumor activity by inducing apoptosis and inhibiting ERK1/2 and Akt. In vivo antitumor activity was shown in osteosarcoma-bearing mice. The drug combination significantly down-modulated RTK Ephrin Type-A Receptor 2 (EphA2) and Interleukin-7 Receptor (IL-7R), whereas induced mitogen-activated protein-kinase kinase (MAPKK) MEK6. EphA2 silencing significantly reduced osteosarcoma cell proliferation and migration, while impeding MEK6 up-regulation in the treated cells significantly increased the antitumor effect of the studied drugs. Moreover, the up-regulation of MEK6 reduced combination activity. Pazopanib + trametinib demonstrated synergistic antitumor effects in osteosarcoma models through ERK and Akt inhibition and EphA2 and IL-7R down-modulation. MEK6 up-regulation might evoke escaping mechanism.

scholarly journals MKK3 sustains cell proliferation and survival through p38DELTA MAPK activation in colorectal cancer

2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Lorenzo Stramucci ◽  
Angelina Pranteda ◽  
Arianna Stravato ◽  
Carla Azzurra Amoreo ◽  
Annarita Pennetti ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Map Kinases ◽  
Molecular Mechanisms ◽  
Malignant Tumors ◽  
Mapk Pathway ◽  
Primary Cultures ◽  
Mitogen Activated Protein Kinase ◽  
Antitumor Effects

Abstract Colorectal cancer (CRC) is one of the most common malignant tumors worldwide and understanding its underlying molecular mechanisms is crucial for the development of therapeutic strategies. The mitogen-activated protein kinase-kinase 3 (MKK3) is a specific activator of p38 MAP kinases (p38 MAPKs), which contributes to the regulation of several cellular functions, such as proliferation, differentiation, apoptosis as well as response to drugs. At present, the exact MKK3/p38 MAPK pathway contribution in cancer is heavily debated because of its pleiotropic function. In this work, we retrospectively explored the prognostic and pathobiologic relevance of MKK3 in a cohort of CRC patients and assessed MKK3 molecular functions in a panel of CRC lines and colonocytes primary cultures. We found increased MKK3 levels in late-stage CRC patients which correlated with shorter overall survival. Herein, we report that the MKK3 targeting by inducible RNA interference univocally exerts antitumor effects in CRC lines but not in primary colonocytes. While MKK3 depletion per se affects growth and survival by induction of sustained autophagy and death in some CRC lines, it potentiates response to chemotherapeutic drug 5-fluorouracil (5-FU) in all of the tested CRC lines in vitro. Here, we demonstrate for the first time that in CRC the MKK3 specifically activates p38delta MAPK isoform to sustain prosurvival signaling and that such effect is exacerbated upon 5-FU challenge. Indeed, p38delta MAPK silencing recapitulates MKK3 depletion effects in CRC cells in vitro and in vivo. Overall, our data identified a molecular mechanism through which MKK3 supports proliferation and survival signaling in CRC, further supporting MKK3 as a novel and extremely attractive therapeutic target for the development of promising strategies for the management of CRC patients.

scholarly journals The Combination of Sulfamethoxazole, Trimethoprim, and Isoniazid or Rifampin Is Bactericidal and Prevents the Emergence of Drug Resistance in Mycobacterium tuberculosis

2012 ◽  
Vol 56 (10) ◽  
pp. 5142-5148 ◽  
Author(s):  
Catherine Vilchèze ◽  
William R. Jacobs
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Multidrug Resistant ◽  
New Drugs ◽  
Drug Resistant ◽  
Content Type ◽  
The Past ◽  
Tb Treatment

ABSTRACTThe challenges of developing new drugs to treat tuberculosis (TB) are indicated by the relatively small number of candidates entering clinical trials in the past decade. To overcome these issues, we reexamined two FDA-approved antibacterial drugs, sulfamethoxazole (SMX) and trimethoprim (TMP), for use in TB treatment. SMX and TMP inhibit folic acid biosynthesis and are used in combination to treat infections of the respiratory, urinary, and gastrointestinal tracts. The MICs of SMX and TMP, alone and in combination, were determined for drug-susceptible, multidrug-resistant (MDR), and extensively drug-resistantMycobacterium tuberculosisstrains. While TMP alone was not effective againstM. tuberculosis, the combination of TMP and SMX was bacteriostatic againstM. tuberculosis. Surprisingly, the combination of SMX and TMP was also active against a subset of MDRM. tuberculosisstrains. Treatment ofM. tuberculosiswith TMP-SMX and a first-line anti-TB drug, either isoniazid or rifampin, was bactericidal, demonstrating that the combination of TMP and SMX with isoniazid or rifampin was not antagonistic. Moreover, the addition of SMX-TMP in combination with either isoniazid or rifampin also prevented the emergence of drug resistancein vitro. In conclusion, this study further illustrates the opportunity to reevaluate the activity of TMP-SMXin vivoto prevent the emergence of drug-resistantM. tuberculosis.

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