The Emerging Role of c-Met in Carcinogenesis and Clinical Implications as a Possible Therapeutic Target

Background. c-MET is a receptor tyrosine kinase receptor (RTK) for the hepatocyte growth factor (HGF). The binding of HGF to c-MET regulates several cellular functions: differentiation, proliferation, epithelial cell motility, angiogenesis, and epithelial-mesenchymal transition (EMT). Moreover, it is known to be involved in carcinogenesis. Comprehension of HGF-c-MET signaling pathway might have important clinical consequences allowing to predict prognosis, response to treatment, and survival rates based on its expression and dysregulation. Discussion. c-MET represents a useful molecular target for novel engineered drugs. Several clinical trials are underway for various solid tumors and the development of new specific monoclonal antibodies depends on the recent knowledge about the definite c-MET role in each different malignance. Recent clinical trials based on c-MET molecular targets result in good safety profile and represent a promising therapeutic strategy for solid cancers, in monotherapy or in combination with other target drugs. Conclusion. The list of cell surface receptors crosslinking with the c-MET signaling is constantly growing, highlighting the importance of this pathway for personalized target therapy. Research on the combination of c-MET inhibitors with other drugs will hopefully lead to discovery of new effective treatment options.

HKSA secara In-Silico Senyawa 1-Benzil-3- Benzoilurea dan Analognya sebagai Penghambat Reseptor Bruton Tyrosine Kinase (BTK)

Abstract—In this study, a new anticancer drug design for non-Hodgkin’s lymphoma was carried out, with a molecular docking approach from the compound 1-benzyl-3-benzoylurea parent and its analog as an anticancer compound. The purpose of the study was to obtain the best quantitative structure-activity relationship (QSAR). The in-silico activity test was carried out on the new 1-benzyl-3-benzoilurea and its analog compound against the Bruton Tyrosine Kinase receptor (BTK) PDB code (5FBN) by using the Molegro Virtual Docker 5.5 program and producing a RS (Rerank Score) value for the test compound and Acalabrutinib was used as a comparison. This study also conducted bioavailability by predicting the value of F (intestinal human absorption) in the pkCSM program and toxicity studies by predicting LD50 values using the Protox II program. Correlation and regression were performed using the RS, F, and LD50 values that we obtained on the physicochemical properties of the test compound using the IBM SPSS version 24 program. The best equation is obtained as follows: (1) F = 0.851 Es Taft - 6.116 σ - 1.969 π² + 3.620 π + 90.809; (2) RS = 4.376 Es Taft - 88.802; (3) LD50 = 672.518 CMR - 669.385 ClogP - 813.806. From the results of the best equation is obtained that the activity is influenced by the parameters of steric physicochemical properties (Es Taft). Keywords: 1-benzyl-3-benzoylurea, code pdb:5fbn, in-silico, non-hodgkin lymphoma Abstrak—Pada penelitian ini dilakukan rancangan obat baru antikanker Limfoma non-Hodgkin, dengan pendekatan penambatan molekul dari senyawa induk 1-benzil-3-benzoilurea dan analognya sebagai senyawa antikanker.Tujuan penelitian ini untuk mendapatkan persamaan hubungan struktur aktivitas (HKSA) terbaik. Uji aktivitas in-silico dilakukan terhadap senyawa baru 1-benzil-3-benzoilurea dan analognya terhadap reseptor Bruton Tyrosine Kinase (BTK) kode PDB 5FBN dengan menggunakkan program Molegro Virtual Docker 5.5 dan menghasilkan nilai RS (Rerank Score) untuk senyawa uji dan Acalabrutinib digunakan sebagai pembanding. Penelitian ini juga dilakukan studi bioavaibilitas dengan memprediksi nilai F (intestinal human absorbtion) pada program pkCSM dan studi toksisitas dengan memprediksi nilai LD50 menggunakan program Protox II. Korelasi dan regresi dilakukan menggunakan nilai RS, F dan LD50 yang telah diperoleh terhadap parameter sifat fisikokimia senyawa uji menggunakan program IBM SPSS versi 24. Persamaan terbaik yang diperoleh sebagai berikut: (1) F = - 1.969 π² + 0.851 Es Taft - 6.116 σ + 3.620 π + 90.809 (2) RS = 4.376 Es Taft - 88.802 (3) LD50 = 672.518 CMR - 669.385 ClogP - 813.806. Dari hasil persamaan terbaik tersebut diperoleh bahwa aktivitas dipengaruhi oleh parameter sifat fisikokimia sterik (Es Taft). Kata kunci: 1-benzil-3-benzoilurea, in-silico, kode pdb: 5fbn, limfoma non-hodgkin

Therapeutic Potential of Sunitinib in Ameliorating Endothelial Dysfunction in Type 2 Diabetic Rats

<b><i>Introduction:</i></b> Sunitinib, a multi-targeted tyrosine kinase receptor inhibitor used to treat renal-cell carcinoma and gastrointestinal stromal tumor, was recently shown to have a beneficial effect on metabolism in type 2 diabetes (T2D). Endothelial dysfunction is a key factor behind macro- and microvascular complications in T2D. The effect of sunitinib on endothelial function in T2D remains, however, unclear. We therefore tested the hypothesis that sunitinib ameliorates endothelial dysfunction in T2D. <b><i>Methods:</i></b> Sunitinib (2 mg/kg/day, by gavage) was administered to T2D Goto-Kakizaki (GK) rats for 6 weeks, while water was given to GK and Wistar rats as controls. Hemodynamic, inflammatory, and metabolic parameters as well as endothelial function were measured. <b><i>Results:</i></b> Systolic, mean arterial blood pressures, plasma tumor necrosis factor α levels, kidney weight to body weight (BW) ratio, and glucose levels were higher, while BW was lower in GK rats than in Wistar rats. Six-week treatment with sunitinib in GK rats did not affect these parameters but suppressed the increase in glucose levels. Endothelium-dependent relaxations were reduced in both aortas and mesenteric arteries isolated from GK as compared to Wistar rats, which was markedly reversed in both types of arteries from GK rats treated with sunitinib. <b><i>Conclusions:</i></b> This study demonstrates that sunitinib has a glucose-lowering effect and ameliorates endothelial dysfunction in both conduit and resistance arteries of GK rats.

Synergy of epidermal growth factor (EGFR) and angiotensin II (AT1R) receptor determines composition and temporal pattern of transcriptome variation

The tyrosine kinase receptor EGFR and the G-protein-coupled receptor AT1R induce essential cellular responses, in part via receptor crosstalk with an unknown role in nuclear information transfer and transcription regulation. We investigated whether this crosstalk results in linear, EGFR-mediated nuclear signalling or in parallel, synergistic information transfer leading to qualitative and temporal variations, relevant for gene expression and environment interaction. AT1R and EGFR synergistically activate SRF via the ERK1/2-TCF and actin-MRTF pathways. Synergism, comprised of switch-like and graded single cell response, converges on the transcription factors AP1 and EGR, resulting in synergistic transcriptome alterations, in qualitative (over-additive number of genes), quantitative (over-additive expression changes of individual genes) and temporal (more late onset and prolonged expressed genes) terms. Gene ontology and IPA® pathway analysis indicate prolonged cell stress (e.g. hypoxia-like) and dysregulated vascular biology. Synergism occurs during separate but simultaneous activation of both receptors and during AT1R-induced EGFR transactivation. EGFR and AT1R synergistically regulate gene expression in qualitative, quantitative and temporal terms with (patho)physiological relevance, extending the importance of EGFR-AT1R crosstalk beyond cytoplasmic signalling.

Developmental Disruption of Erbb4 in Pet1+ Neurons Impairs Serotonergic Sub-System Connectivity and Memory Formation

The serotonergic system of mammals innervates virtually all the central nervous system and regulates a broad spectrum of behavioral and physiological functions. In mammals, serotonergic neurons located in the rostral raphe nuclei encompass diverse sub-systems characterized by specific circuitry and functional features. Substantial evidence suggest that functional diversity of serotonergic circuits has a molecular and connectivity basis. However, the landscape of intrinsic developmental mechanisms guiding the formation of serotonergic sub-systems is unclear. Here, we employed developmental disruption of gene expression specific to serotonergic subsets to probe the contribution of the tyrosine kinase receptor ErbB4 to serotonergic circuit formation and function. Through an in vivo loss-of-function approach, we found that ErbB4 expression occurring in a subset of serotonergic neurons, is necessary for axonal arborization of defined long-range projections to the forebrain but is dispensable for the innervation of other targets of the serotonergic system. We also found that Erbb4-deletion does not change the global excitability or the number of neurons with serotonin content in the dorsal raphe nuclei. In addition, ErbB4-deficiency in serotonergic neurons leads to specific behavioral deficits in memory processing that involve aversive or social components. Altogether, our work unveils a developmental mechanism intrinsically acting through ErbB4 in subsets of serotonergic neurons to orchestrate a precise long-range circuit and ultimately involved in the formation of emotional and social memories.

A MEKK1 – JNK mitogen activated kinase (MAPK) cascade module is active in Echinococcus multilocularis stem cells

Background The metacestode larval stage of the fox-tapeworm Echinococcus multilocularis causes alveolar echinococcosis by tumour-like growth within the liver of the intermediate host. Metacestode growth and development is stimulated by host-derived cytokines such as insulin, fibroblast growth factor, and epidermal growth factor via activation of cognate receptor tyrosine kinases expressed by the parasite. Little is known, however, concerning signal transmission to the parasite nucleus and cross-reaction with other parasite signalling systems. Methodology/Principal findings Using bioinformatic approaches, cloning, and yeast two-hybrid analyses we identified a novel mitogen-activated kinase (MAPK) cascade module that consists of E. multilocularis orthologs of the tyrosine kinase receptor interactor Growth factor receptor-bound 2, EmGrb2, the MAPK kinase kinase EmMEKK1, a novel MAPK kinase, EmMKK3, and a close homolog to c-Jun N-terminal kinase (JNK), EmMPK3. Whole mount in situ hybridization analyses indicated that EmMEKK1 and EmMPK3 are both expressed in E. multilocularis germinative (stem) cells but also in differentiated or differentiating cells. Treatment with the known JNK inhibitor SP600125 led to a significantly reduced formation of metacestode vesicles from stem cells and to a specific reduction of proliferating stem cells in mature metacestode vesicles. Conclusions/Significance We provide evidence for the expression of a MEKK1-JNK MAPK cascade module which, in mammals, is crucially involved in stress responses, cytoskeletal rearrangements, and apoptosis, in E. multilocularis stem cells. Inhibitor studies indicate an important role of JNK signalling in E. multilocularis stem cell survival and/or maintenance. Our data are relevant for molecular and cellular studies into crosstalk signalling mechanisms that govern Echinococcus stem cell function and introduce the JNK signalling cascade as a possible target of chemotherapeutics against echinococcosis.

RhANP attenuates endotoxin-derived cognitive dysfunction through subdiaphragmatic vagus nerve-mediated gut microbiota–brain axis

Background Atrial natriuretic peptide (ANP) secreted from atrial myocytes is shown to possess anti-inflammatory, anti-oxidant and immunomodulatory effects. The aim of this study is to assess the effect of ANP on bacterial lipopolysaccharide (LPS)-induced endotoxemia-derived neuroinflammation and cognitive impairment. Methods LPS (5 mg/kg) was given intraperitoneally to mice. Recombinant human ANP (rhANP) (1.0 mg/kg) was injected intravenously 24 h before and/or 10 min after LPS injection. Subdiaphragmatic vagotomy (SDV) was performed 14 days before LPS injection or 28 days before fecal microbiota transplantation (FMT). ANA-12 (0.5 mg/kg) was administrated intraperitoneally 30 min prior to rhANP treatment. Results LPS (5.0 mg/kg) induced remarkable splenomegaly and an increase in the plasma cytokines at 24 h after LPS injection. There were positive correlations between spleen weight and plasma cytokines levels. LPS also led to increased protein levels of ionized calcium-binding adaptor molecule (iba)-1, cytokines and inducible nitric oxide synthase (iNOS) in the hippocampus. LPS impaired the natural and learned behavior, as demonstrated by an increase in the latency to eat the food in the buried food test and a decrease in the number of entries and duration in the novel arm in the Y maze test. Combined prophylactic and therapeutic treatment with rhANP reversed LPS-induced splenomegaly, hippocampal and peripheral inflammation as well as cognitive impairment. However, rhANP could not further enhance the protective effects of SDV on hippocampal and peripheral inflammation. We further found that PGF mice transplanted with fecal bacteria from rhANP-treated endotoxemia mice alleviated the decreased protein levels of hippocampal polyclonal phosphorylated tyrosine kinase receptor B (p-TrkB), brain-derived neurotrophic factor (BDNF) and cognitive impairment, which was abolished by SDV. Moreover, TrkB/BDNF signaling inhibitor ANA-12 abolished the improving effects of rhANP on LPS-induced cognitive impairment. Conclusions Our results suggest that rhANP could mitigate LPS-induced hippocampal inflammation and cognitive dysfunction through subdiaphragmatic vagus nerve-mediated gut microbiota–brain axis.

Role of Endocytosis Proteins in Gefitinib-Mediated EGFR Internalisation in Glioma Cells

EGFR (epidermal growth factor receptor), a member of the ErbB tyrosine kinase receptor family, is a clinical therapeutic target in numerous solid tumours. EGFR overexpression in glioblastoma (GBM) drives cell invasion and tumour progression. However, clinical trials were disappointing, and a molecular basis to explain these poor results is still missing. EGFR endocytosis and membrane trafficking, which tightly regulates EGFR oncosignaling, are often dysregulated in glioma. In a previous work, we showed that EGFR tyrosine kinase inhibitors, such as gefitinib, lead to enhanced EGFR endocytosis into fused early endosomes. Here, using pharmacological inhibitors, siRNA-mediated silencing, or expression of mutant proteins, we showed that dynamin 2 (DNM2), the small GTPase Rab5 and the endocytosis receptor LDL receptor-related protein 1 (LRP-1), contribute significantly to gefitinib-mediated EGFR endocytosis in glioma cells. Importantly, we showed that inhibition of DNM2 or LRP-1 also decreased glioma cell responsiveness to gefitinib during cell evasion from tumour spheroids. By highlighting the contribution of endocytosis proteins in the activity of gefitinib on glioma cells, this study suggests that endocytosis and membrane trafficking might be an attractive therapeutic target to improve GBM treatment.

In Silico Screening of Potential Inhibitors of the Epidermal Growth Factor Receptor Kinase using Benzimidazole, Benzoxazole, Imidazole, and Tetrazole Derivatives

Background: Small molecule compounds are docked into receptor binding sites and the binding affinity of the complex is calculated using the structure-based drug design technique. Precise and quick docking processes, as well as the capacity to examine binding geometries and interactions, are required for a full knowledge of the structural principles that influence the strength of a protein/ligand complex. The present work deals with in-silico molecular docking studies of some heterocyclic compounds such as benzoxazole, benzimidazole, imidazole and tetrazole against the EGFR tyrosine kinase receptor. Methodology: Molecular docking studies of some heterocyclic compounds such as benzoxazole, benzimidazole, imidazole and tetrazole against the EGFR tyrosine kinase receptor using Schrodinger LLC (Maestro 9.2) software. Results: Our in silico observations reveal that, all the selected heterocyclic compounds (1-8) show good binding interaction and good docking score against selected target enzyme. Out of eight compounds selected for the study two compounds compound 3 and 7 shows higher glide score. Compound 3 binded to ASP855 with a docking score of −11.20 kcal/mol. Compound 7 binded to ASP855 with a docking score of −11.56kcal/mol. Conclusion: Docking results revealed that compounds (1-8) interact with EGFR kinase receptor active site. Among the compounds, compound 7 has shown the highest glide score of -11.56 kcal/mol.