scholarly journals GENE-04. THE ONCOGENIC FUNCTIONS OF YAP1-GENE FUSIONS CAN BE INHIBITED BY DISRUPTION OF YAP1-TEAD INTERACTION

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi98-vi98
Author(s):  
Frank Szulzewsky ◽  
Pia Hoellerbauer ◽  
Hua-Jun Wu ◽  
P J Cimino ◽  
Franziska Michor ◽  
...  
Keyword(s):  
Hippo Pathway ◽  
Point Mutations ◽  
Tumor Formation ◽  
In Vitro Assays ◽  
Gene Fusions ◽  
Genetic Ablation ◽  
Molecular Features ◽  
Cancer Types

Abstract Supratentorial ependymoma can be sub-stratified into clinically relevant subtypes characterized by distinct molecular features. The subtype defined by high YAP1 activity harbored two distinct YAP1 gene fusions, YAP1-MAMLD1 and YAP1-FAM118B. In addition, YAP1 gene fusions have been detected in several other cancer types, including Epithelioid Hemangioendothelioma and Endocervical Adenocarcinoma. YAP1 is a key transcriptional co-activator and proto-oncogene that is negatively regulated by the Hippo pathway. Here, we show that both YAP1-MAMLD1 and YAP1-FAM118B, as well as additional YAP1 fusion genes found in other cancer types, are potent oncogenic drivers that cause tumor formation in the brain and the hindlimb in mice upon overexpression by somatic cell gene transfer. Using different in vitro assays, including Luciferase, RNA-, and ChIP Seq, we show that both the N-terminal YAP1 part and the C-terminal fusion partners exert activity. We can show that the YAP1 activity still relies on the binding to TEAD transcription factors, whereas the C terminal activity does not. Furthermore, the different fusion proteins have become independent from negative Hippo pathway signaling by constitutive nuclear localization and protection from degradation. In addition, by introducing point mutations and truncations to block the YAP1 and the MAMLD1 function we can show that the activity of both halves contributes to the oncogenic function of YAP1-MAMLD1. Using in vitro and in vivo assays we can show that pharmacological and genetic ablation of YAP-TEAD interaction diminishes the oncogenic potential of the fusions, indicating that this might be a potential therapeutic approach for these tumors in the future.

scholarly journals Antioxidant supplements promote tumor formation and growth and confer drug resistance in hepatocellular carcinoma by reducing intracellular ROS and induction of TMBIM1

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vanilla Xin Zhang ◽  
Karen Man-Fong Sze ◽  
Lo-Kong Chan ◽  
Daniel Wai-Hung Ho ◽  
Yu-Man Tsui ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Hepatoma Cell ◽  
Tumor Formation ◽  
In Vitro Assays ◽  
Migration And Invasion ◽  
Intracellular Ros ◽  
Antioxidant Supplements ◽  
Sphere Formation

Abstract Background Controversy over the benefits of antioxidants supplements in cancers persists for long. Using hepatocellular carcinoma (HCC) as a model, we investigated the effects of exogenous antioxidants N-acetylcysteine (NAC) and glutathione (GSH) on tumor formation and growth. Methods Multiple mouse models, including diethylnitrosamine (DEN)-induced and Trp53KO/C-MycOE-induced HCC models, mouse hepatoma cell and human HCC cell xenograft models with subcutaneous or orthotopic injection were used. In vitro assays including ROS assay, colony formation, sphere formation, proliferation, migration and invasion, apoptosis, cell cycle assays were conducted. Western blot was performed for protein expression and RNA-sequencing to identify potential gene targets. Results In these multiple different mouse and cell line models, we observed that NAC and GSH promoted HCC tumor formation and growth, accompanied with significant reduction of intracellular reactive oxygen species (ROS) levels. Moreover, NAC and GSH promoted cancer stemness, and abrogated the tumor-suppressive effects of Sorafenib both in vitro and in vivo. Exogenous supplementation of NAC or GSH reduced the expression of NRF2 and GCLC, suggesting the NRF2/GCLC-related antioxidant production pathway might be desensitized. Using transcriptomic analysis to identify potential gene targets, we found that TMBIM1 was significantly upregulated upon NAC and GSH treatment. Both TCGA and in-house RNA-sequence databases showed that TMBIM1 was overexpressed in HCC tumors. Stable knockdown of TMBIM1 increased the intracellular ROS; it also abolished the promoting effects of the antioxidants in HCC cells. On the other hand, BSO and SSA, inhibitors targeting NAC and GSH metabolism respectively, partially abrogated the pro-oncogenic effects induced by NAC and GSH in vitro and in vivo. Conclusions Our data implicate that exogenous antioxidants NAC and GSH, by reducing the intracellular ROS levels and inducing TMBIM expression, promoted HCC formation and tumor growth, and counteracted the therapeutic effect of Sorafenib. Our study provides scientific insight regarding the use of exogenous antioxidant supplements in cancers.

scholarly journals Effect of the Attenuating Deletion and of Sequence Alterations Evolving In Vivo on Simian Immunodeficiency Virus C8-Nef Function

1999 ◽  
Vol 73 (4) ◽  
pp. 2790-2797 ◽  
Author(s):  
Silke Carl ◽  
A. John Iafrate ◽  
Jacek Skowronski ◽  
Christiane Stahl-Hennig ◽  
Frank Kirchhoff
Keyword(s):  
Viral Replication ◽  
Simian Immunodeficiency Virus ◽  
Point Mutations ◽  
Residual Activity ◽  
Intermediate Phenotype ◽  
Cell Surface Expression ◽  
In Vitro Assays ◽  
Immunodeficiency Virus

ABSTRACT The simian immunodeficiency virus macC8 (SIVmacC8) variant has been used in a European Community Concerted Action project to study the efficacy and safety of live attenuated SIV vaccines in a large number of macaques. The attenuating deletion in the SIVmacC8nef-long terminal repeat region encompasses only 12 bp and is “repaired” in a subset of infected animals. It is unknown whether C8-Nef retains some activity. Since it seems important to use only well-characterized deletion mutants in live attenuated vaccine studies, we analyzed the relevance of the deletion, and the duplications and point mutations selected in infected macaques for Nef function in vitro. The deletion, affecting amino acids 143 to 146 (DMYL), resulted in a dramatic decrease in Nef stability and function. The initial 12-bp duplication resulted in efficient Nef expression and an intermediate phenotype in infectivity assays, but it did not significantly restore the ability of Nef to stimulate viral replication and to downmodulate CD4 and class I major histocompatibility complex cell surface expression. The additional substitutions however, which subsequently evolved in vivo, gradually restored these Nef functions. It was noteworthy that coinfection experiments in the T-lymphoid 221 cell line revealed that even SIVmac nef variants carrying the original 12-bp deletion readily outgrew an otherwise isogenic virus containing a 182-bp deletion in the nef gene. Thus, although C8-Nef is unstable and severely impaired in in vitro assays, it maintains some residual activity to stimulate viral replication.

scholarly journals L1CAM promotes ovarian cancer stemness and tumor initiation via FGFR1/SRC/STAT3 signaling

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Marco Giordano ◽  
Alessandra Decio ◽  
Chiara Battistini ◽  
Micol Baronio ◽  
Fabrizio Bianchi ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Genetic Manipulation ◽  
Tumor Formation ◽  
In Vitro Assays ◽  
Tumor Initiation ◽  
Loss Of Function ◽  
Stat3 Signaling

Abstract Background Cancer stem cells (CSC) have been implicated in tumor progression. In ovarian carcinoma (OC), CSC drive tumor formation, dissemination and recurrence, as well as drug resistance, thus contributing to the high death-to-incidence ratio of this disease. However, the molecular basis of such a pathogenic role of ovarian CSC (OCSC) has been elucidated only to a limited extent. In this context, the functional contribution of the L1 cell adhesion molecule (L1CAM) to OC stemness remains elusive. Methods The expression of L1CAM was investigated in patient-derived OCSC. The genetic manipulation of L1CAM in OC cells provided gain and loss-of-function models that were then employed in cell biological assays as well as in vivo tumorigenesis experiments to assess the role of L1CAM in OC cell stemness and in OCSC-driven tumor initiation. We applied antibody-mediated neutralization to investigate L1CAM druggability. Biochemical approaches were then combined with functional in vitro assays to study the molecular mechanisms underlying the functional role of L1CAM in OCSC. Results We report that L1CAM is upregulated in patient-derived OCSC. Functional studies showed that L1CAM promotes several stemness-related properties in OC cells, including sphere formation, tumor initiation and chemoresistance. These activities were repressed by an L1CAM-neutralizing antibody, pointing to L1CAM as a druggable target. Mechanistically, L1CAM interacted with and activated fibroblast growth factor receptor-1 (FGFR1), which in turn induced the SRC-mediated activation of STAT3. The inhibition of STAT3 prevented L1CAM-dependent OC stemness and tumor initiation. Conclusions Our study implicate L1CAM in the tumorigenic function of OCSC and point to the L1CAM/FGFR1/SRC/STAT3 signaling pathway as a novel driver of OC stemness. We also provide evidence that targeting this pathway can contribute to OC eradication.

scholarly journals miR-186 Suppresses the Progression of Cholangiocarcinoma Cells Through Inhibition of Twist1

2019 ◽  
Vol 27 (9) ◽  
pp. 1061-1068 ◽  
Author(s):  
Ming Zhang ◽  
Baochang Shi ◽  
Kai Zhang
Keyword(s):  
Cell Proliferation ◽  
Molecular Mechanisms ◽  
Epithelial Mesenchymal Transition ◽  
Tumor Formation ◽  
In Vitro Assays ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
Cycle Arrest

Deregulation of miR-186 and Twist1 has been identified to be involved in the progression of multiple cancers. However, the detailed molecular mechanisms underlying miR-186-involved cholangiocarcinoma (CCA) are still unknown. In this study, we found that miR-186 was downregulated in CCA tissues and cell lines, and negatively correlated with the expression of Twist1 protein. In vitro assays demonstrated that miR-186 mimics repressed cell proliferation, in vivo tumor formation, and caused cell cycle arrest. miR-186 mimics also inhibited the migration and invasion of CCLP1 and SG-231 cells. Mechanistically, the 3′-untranslated region (3′-UTR) of Twist1 mRNA is a direct target of miR-186. Further, miR-186 inhibited the expressions of Twist1, N-cadherin, vimentin, and matrix metallopeptidase 9 (MMP9) proteins, whereas it increased the expression of E-cadherin in CCLP1 and SG-231 cells. Silencing of Twist1 expression enhanced the inhibitory effects of miR-186 on the proliferation, migration, and invasion of CCLP1 and SG-231 cells. In conclusion, miR-186 inhibited cell proliferation, migration, invasion, and epithelial‐mesenchymal transition (EMT) through targeting Twist1 in human CCA. Thus, miR-186/Twist1 axis may benefit the development of therapies for CCA.

scholarly journals C3G Is Upregulated in Hepatocarcinoma, Contributing to Tumor Growth and Progression and to HGF/MET Pathway Activation

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2282
Author(s):  
Celia Sequera ◽  
Paloma Bragado ◽  
Sara Manzano ◽  
Maria Arechederra ◽  
Sylvie Richelme ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Tumor Formation ◽  
In Vitro Assays ◽  
Tumor Type ◽  
Mrna Levels ◽  
Nucleotide Exchange ◽  
Down Regulation ◽  
Hcc Cells

The complexity of hepatocellular carcinoma (HCC) challenges the identification of disease-relevant signals. C3G, a guanine nucleotide exchange factor for Rap and other Ras proteins, plays a dual role in cancer acting as either a tumor suppressor or promoter depending on tumor type and stage. The potential relevance of C3G upregulation in HCC patients suggested by database analysis remains unknown. We have explored C3G function in HCC and the underlying mechanisms using public patient data and in vitro and in vivo human and mouse HCC models. We found that C3G is highly expressed in progenitor cells and neonatal hepatocytes, whilst being down-regulated in adult hepatocytes and re-expressed in human HCC patients, mouse HCC models and HCC cell lines. Moreover, high C3G mRNA levels correlate with tumor progression and a lower patient survival rate. C3G expression appears to be tightly modulated within the HCC program, influencing distinct cell biological properties. Hence, high C3G expression levels are necessary for cell tumorigenic properties, as illustrated by reduced colony formation in anchorage-dependent and -independent growth assays induced by permanent C3G silencing using shRNAs. Additionally, we demonstrate that C3G down-regulation interferes with primary HCC tumor formation in xenograft assays, increasing apoptosis and decreasing proliferation. In vitro assays also revealed that C3G down-regulation enhances the pro-migratory, invasive and metastatic properties of HCC cells through an epithelial-mesenchymal switch that favors the acquisition of a more mesenchymal phenotype. Consistently, a low C3G expression in HCC cells correlates with lung metastasis formation in mice. However, the subsequent restoration of C3G levels is associated with metastatic growth. Mechanistically, C3G down-regulation severely impairs HGF/MET signaling activation in HCC cells. Collectively, our results indicate that C3G is a key player in HCC. C3G promotes tumor growth and progression, and the modulation of its levels is essential to ensure distinct biological features of HCC cells throughout the oncogenic program. Furthermore, C3G requirement for HGF/MET signaling full activation provides mechanistic data on how it works, pointing out the relevance of assessing whether high C3G levels could identify HCC responders to MET inhibitors.

scholarly journals Disruption of the ciliary GTPase Arl13b suppresses Sonic hedgehog overactivation and inhibits medulloblastoma formation

2018 ◽  
Vol 115 (7) ◽  
pp. 1570-1575 ◽  
Author(s):  
Sarah N. Bay ◽  
Alyssa B. Long ◽  
Tamara Caspary
Keyword(s):  
Sonic Hedgehog ◽  
Pediatric Brain Tumor ◽  
Resistance Mechanisms ◽  
Tumor Formation ◽  
Tumor Resistance ◽  
Shh Signaling ◽  
Genetic Ablation ◽  
Primary Mouse

Medulloblastoma (MB) is the most common malignant pediatric brain tumor, and overactivation of the Sonic Hedgehog (Shh) signaling pathway, which requires the primary cilium, causes 30% of MBs. Current treatments have known negative side effects or resistance mechanisms, so new treatments are necessary. Shh signaling mutations, like those that remove Patched1 (Ptch1) or activate Smoothened (Smo), cause tumors dependent on the presence of cilia. Genetic ablation of cilia prevents these tumors by removing Gli activator, but cilia are a poor therapeutic target since they support many biological processes. A more appropriate strategy would be to identify a protein that functionally disentangles Gli activation and ciliogenesis. Our mechanistic understanding of the ciliary GTPase Arl13b predicts that it could be such a target. Arl13b mutants retain short cilia, and loss of Arl13b results in ligand-independent, constitutive, low-level pathway activation but prevents maximal signaling without disrupting Gli repressor. Here, we show that deletion of Arl13b reduced Shh signaling levels in the presence of oncogenic SmoA1, suggesting Arl13b acts downstream of known tumor resistance mechanisms. Knockdown of ARL13B in human MB cell lines and in primary mouse MB cell culture decreased proliferation. Importantly, loss of Arl13b in a Ptch1-deleted mouse model of MB inhibited tumor formation. Postnatal depletion of Arl13b does not lead to any overt phenotypes in the epidermis, liver, or cerebellum. Thus, our in vivo and in vitro studies demonstrate that disruption of Arl13b inhibits cilia-dependent oncogenic Shh overactivation.

A in Vivo Assay for Standardizing Heparin Preparations

1979 ◽  
Vol 41 (03) ◽  
pp. 576-582
Author(s):  
A R Pomeroy
Keyword(s):  
In Vitro Assays ◽  
British Pharmacopoeia ◽  
In Vitro Method ◽  
Standard Preparation ◽  
Reliable Estimation ◽  
Assay Procedure ◽  
Accuracy And Precision ◽  
Heparin Preparation

SummaryThe limitations of currently used in vitro assays of heparin have demonstrated the need for an in vivo method suitable for routine use.The in vivo method which is described in this paper uses, for each heparin preparation, four groups of five mice which are injected intravenously with heparin according to a “2 and 2 dose assay” procedure. The method is relatively rapid, requiring 3 to 4 hours to test five heparin preparations against a standard preparation of heparin. Levels of accuracy and precision acceptable for the requirements of the British Pharmacopoeia are obtained by combining the results of 3 to 4 assays of a heparin preparation.The similarity of results obtained the in vivo method and the in vitro method of the British Pharmacopoeia for heparin preparations of lung and mucosal origin validates this in vivo method and, conversely, demonstrates that the in vitro method of the British Pharmacopoeia gives a reliable estimation of the in vivo activity of heparin.

Potentially Thrombogenic Materials in Factor IX Concentrates

1975 ◽  
Vol 33 (03) ◽  
pp. 617-631 ◽  
Author(s):  
H. S Kingdon ◽  
R. L Lundblad ◽  
J. J Veltkamp ◽  
D. L Aronson
Keyword(s):  
Human Plasma ◽  
Antithrombin Iii ◽  
Factor Ix ◽  
In Vitro Assays ◽  
Substantial Agreement ◽  
Coefficient Of Correlation

SummaryFactor IX concentrates manufactured from human plasma and intended for therapeutic infusion in man have been suspected for some time of being potentially thrombogenic. In the current studies, assays were carried out in vitro and in vivo for potentially thrombogenic materials. It was possible to rank the various materials tested according to the amount of thrombogenic material detected. For concentrates not containing heparin, there was substantial agreement between the in vivo and in vitro assays, with a coefficient of correlation of 0.77. There was no correlation between the assays for thrombogenicity and the antithrombin III content. We conclude that many presently available concentrates of Factor IX contain substantial amounts of potentially thrombogenic enzymes, and that this fact must be considered in arriving at the decision whether or not to use them therapeutically.

In-silico Studies of Isolated Phytoalkaloid Against Lipoxygenase: Study Based on Possible Correlation

2018 ◽  
Vol 21 (3) ◽  
pp. 215-221
Author(s):  
Haroon Khan ◽  
Muhammad Zafar ◽  
Helena Den-Haan ◽  
Horacio Perez-Sanchez ◽  
Mohammad Amjad Kamal
Keyword(s):  
In Silico ◽  
Docking Studies ◽  
In Vivo Studies ◽  
In Vitro Assays ◽  
Chronic Obstructive ◽  
Lipoxygenase Inhibitors ◽  
Lipoxygenase Inhibition ◽  
In Silico Studies

Aim and Objective: Lipoxygenase (LOX) enzymes play an important role in the pathophysiology of several inflammatory and allergic diseases including bronchial asthma, allergic rhinitis, atopic dermatitis, allergic conjunctivitis, rheumatoid arthritis and chronic obstructive pulmonary disease. Inhibitors of the LOX are believed to be an ideal approach in the treatment of diseases caused by its over-expression. In this regard, several synthetic and natural agents are under investigation worldwide. Alkaloids are the most thoroughly investigated class of natural compounds with outstanding past in clinically useful drugs. In this article, we have discussed various alkaloids of plant origin that have already shown lipoxygenase inhibition in-vitro with possible correlation in in silico studies. Materials and Methods: Molecular docking studies were performed using MOE (Molecular Operating Environment) software. Among the ten reported LOX alkaloids inhibitors, derived from plant, compounds 4, 2, 3 and 1 showed excellent docking scores and receptor sensitivity. Result and Conclusion: These compounds already exhibited in vitro lipoxygenase inhibition and the MOE results strongly correlated with the experimental results. On the basis of these in vitro assays and computer aided results, we suggest that these compounds need further detail in vivo studies and clinical trial for the discovery of new more effective and safe lipoxygenase inhibitors. In conclusion, these results might be useful in the design of new and potential lipoxygenase (LOX) inhibitors.

Discovery of 3-Cinnamamido-N-Substituted Benzamides as Potential Antimalarial Agents

2020 ◽  
Vol 16 ◽  
Author(s):  
Haicheng Liu ◽  
Yushi Futamura ◽  
Honghai Wu ◽  
Aki Ishiyama ◽  
Taotao Zhang ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Antimalarial Activity ◽  
In Vitro Assays ◽  
Compound Library ◽  
Antimalarial Agents ◽  
Phenotypic Screen ◽  
Ic50 Values ◽  
Substituted Benzamides

Background: Malaria is one of the most devastating parasitic diseases, yet the discovery of antimalarial agents remains profoundly challenging. Very few new antimalarials have been developed in the past 50 years, while the emergence of drug-resistance continues to appear. Objective: This study focuses on the discovery, design, synthesis, and antimalarial evaluation of 3-cinnamamido-N-substituted benzamides. Method: In this study, a screening of our compound library was carried out against the multidrug-sensitive Plasmodium falciparum 3D7 strain. Derivatives of the hit were designed, synthesized and tested against P. falciparum 3D7 and the in vivo antimalarial activity of the most active compounds was evaluated using the method of Peters’ 4-day suppressive test. Results: The retrieved hit compound 1 containing a 3-cinnamamido-N-substituted benzamide skeleton showed moderate antimalarial activity (IC50 = 1.20 µM) for the first time. A series of derivatives were then synthesized through a simple four-step workflow, and half of them exhibited slightly better antimalarial effect than the precursor 1 during the subsequent in vitro assays. Additionally, compounds 11, 23, 30 and 31 displayed potent activity with IC50 values of approximately 0.1 µM, and weak cytotoxicity against mammalian cells. However, in vivo antimalarial activity is not effective which might be ascribed to the poor solubility of these compounds. Conclusion: In this study, phenotypic screen of our compound library resulted in the first report of 3-cinnamamide framework with antimalarial activity and 40 derivatives were then designed and synthesized. Subsequent structure-activity studies showed that compounds 11, 23, 30 and 31 exhibited the most potent and selective activity against P. falciparum 3D7 strain with IC50 values around 0.1 µM. Our work herein sets another example of phenotypic screen-based drug discovery, leading to potentially promising candidates of novel antimalarial agents once given further optimization.

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