Positron emission tomography (PET) with 89Zr-labeled trastuzumab (89Zr-trastuzumab): Monitoring HER2 expression in HER2-positive gastric cancer in vivo.

2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 35-35
Author(s):  
Y. Y. Janjigian ◽  
N. T. Villegas ◽  
J. P. Holland ◽  
M. A. Shah ◽  
V. Divilov ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Specific Activity ◽  
Gastric Cancer Cell Line ◽  
In Vivo Studies ◽  
In Vitro Assays ◽  
Organ Distribution ◽  
Her2 Positive ◽  
Bibw 2992

35 Background: The ToGA study established HER2 is a target in the treatment of gastric cancer. Trastuzumab pharmacokinetics and organ distribution is varied in each patient and is heavily affected by the extent of tumor load (Oude Munnink, JCO 2010). 89Zr-trastuzumab HER2 PET can be used to image that variability and may aid in detection and staging of HER2-positive tumors. We are implementing 89Zr-radiolabeled trastuzumab PET in vivo for imaging of HER2-positive gastric cancer and for future non-invasive assessment of HER2 inhibition with a dual irreversible HER1/HER2 inhibitor, BIBW-2992. Methods: 89Zr (t1/2 = 3.17 days) was prepared via the 89Y(p,n)89Zr transmutation with high radiochemical yields (1.52±0.11 mCi/μAh) and purity (>99.99%). Trastuzumab was functionalized with the tris-hydroxamate chelate, desferrioxamine B (DFO) and radiolabeled with [89Zr]Zr-oxalate at room temperature. 89Zr-trastuzumab PET experiments in athymic nu/nu mice bearing sub-cutaneous NCI-N87 (HER2+) and/or SNU1 (HER2-) tumors were conducted. NCI-N87 gastric cancer cells were treated with BIBW-2992. Results: 89Zr-trastuzumab radiolabeling proceeded in high radiochemical yield and specific-activity of 2.82±0.05 mCi/mg. In vitro assays demonstrated >99% radiochemical purity with an immunoreactive fraction of 0.87±7. In vivo biodistribution experiments revealed high and specific uptake in HER2-positive tumors after 72 h (85.2±11.1% ID/g) with retention of activity for over 120 h. No uptake was seen in HER2-negative gastric cancer xenografts. In vitro, BIBW-2992 demonstrates dose dependent growth inhibition in the HER2+ gastric cancer cell line. Conclusions: 89Zr-trastuzumab provides quantitative and highly-specific delineation of HER2-positive gastric cancer. In vivo studies of BIBW2-2992 in gastric cancer with 89Zr-trastuzumab HER2 PET response assessment are underway. A Phase I study of 89Zr-trastuzumab PETin HER2-positive patients is to open at MSKCC imminently. No significant financial relationships to disclose.

Liquid biopsies to track trastuzumab resistance in metastatic HER2-positive gastric cancer

Gut ◽  
2018 ◽  
Vol 68 (7) ◽  
pp. 1152-1161 ◽  
Author(s):  
De-Shen Wang ◽  
Ze-Xian Liu ◽  
Yun-Xin Lu ◽  
Hua Bao ◽  
Xue Wu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
In Situ Hybridisation ◽  
Targeted Sequencing ◽  
In Vivo Studies ◽  
Fluorescence In Situ Hybridisation ◽  
Trastuzumab Resistance ◽  
Liquid Biopsies ◽  
Her2 Positive

ObjectiveTo monitor trastuzumab resistance and determine the underlying mechanisms for the limited response rate and rapid emergence of resistance of HER2+ metastatic gastric cancer (mGC).DesignTargeted sequencing of 416 clinically relevant genes was performed in 78 paired plasma and tissue biopsy samples to determine plasma-tissue concordance. Then, we performed longitudinal analyses of 97 serial plasma samples collected from 24 patients who were HER2+  to track the resistance during trastuzumab treatment and validated the identified candidate resistance genes.ResultsThe results from targeted sequencing-based detection of somatic copy number alterations (SCNA) of HER2 gene were highly consistent with fluorescence in situ hybridisation data, and the detected HER2 SCNA was better than plasma carcinoembryonic antigen levels at predicting tumour shrinkage and progression. Furthermore, most patients with innate trastuzumab resistance presented high HER2 SCNA during progression compared with baseline, while HER2 SCNA decreased in patients with acquired resistance. PIK3CA mutations were significantly enriched in patients with innate resistance, and ERBB2/4 genes were the most mutated genes, accounting for trastuzumab resistance in six (35.3%) and five (29.4%) patients in baseline and progression plasma, respectively. Patients with PIK3CA/R1/C3 or ERBB2/4 mutations in the baseline plasma had significantly worse progression-free survival. Additionally, mutations in NF1 contributed to trastuzumab resistance, which was further confirmed through in vitro and in vivo studies, while combined HER2 and MEK/ERK blockade overcame trastuzumab resistance.ConclusionLongitudinal circulating tumour DNA sequencing provides novel insights into gene alterations underlying trastuzumab resistance in HER2+mGC.

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.

scholarly journals TGFβ signalling acts as a molecular brake of myoblast fusion

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Julie Melendez ◽  
Daniel Sieiro ◽  
David Salgado ◽  
Valérie Morin ◽  
Marie-Julie Dejardin ◽  
...  
Keyword(s):  
Dynamic Control ◽  
Muscle Growth ◽  
Myoblast Fusion ◽  
In Vivo Studies ◽  
In Vitro Assays ◽  
Receptor Complex ◽  
Tgfβ Signalling ◽  
Molecular Brake

AbstractFusion of nascent myoblasts to pre-existing myofibres is critical for skeletal muscle growth and repair. The vast majority of molecules known to regulate myoblast fusion are necessary in this process. Here, we uncover, through high-throughput in vitro assays and in vivo studies in the chicken embryo, that TGFβ (SMAD2/3-dependent) signalling acts specifically and uniquely as a molecular brake on muscle fusion. While constitutive activation of the pathway arrests fusion, its inhibition leads to a striking over-fusion phenotype. This dynamic control of TGFβ signalling in the embryonic muscle relies on a receptor complementation mechanism, prompted by the merging of myoblasts with myofibres, each carrying one component of the heterodimer receptor complex. The competence of myofibres to fuse is likely restored through endocytic degradation of activated receptors. Altogether, this study shows that muscle fusion relies on TGFβ signalling to regulate its pace.

scholarly journals Long noncoding RNA FAM225A promotes the malignant progression of gastric cancer through the miR-326/PADI2 axis

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiang Ma ◽  
Gang Wang ◽  
Hao Fan ◽  
Zengliang Li ◽  
Wangwang Chen ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Noncoding Rna ◽  
Molecular Mechanisms ◽  
Therapeutic Targets ◽  
In Vitro Assays ◽  
Advanced Tumor Stage ◽  
Advanced Tumor ◽  
Mechanistic Investigation

AbstractGastric cancer (GC) is a global health problem and further studies of its molecular mechanisms are needed to identify effective therapeutic targets. Although some long noncoding RNAs (lncRNAs) have been found to be involved in the progression of GC, the molecular mechanisms of many GC-related lncRNAs remain unclear. In this study, a series of in vivo and in vitro assays were performed to study the relationship between FAM225A and GC, which showed that FAM225A levels were correlated with poor prognosis in GC. Higher FAM225A expression tended to be correlated with a more profound lymphatic metastasis rate, larger tumor size, and more advanced tumor stage. FAM225A also promoted gastric cell proliferation, invasion, and migration. Further mechanistic investigation showed that FAM225A acted as a miR-326 sponge to upregulate its direct target PADI2 in GC. Overall, our findings indicated that FAM225A promoted GC development and progression via a competitive endogenous RNA network of FAM225A/miR-326/PADI2 in GC, providing insight into possible therapeutic targets and prognosis of GC.

scholarly journals Pleckstrin-2 as a Prognostic Factor and Mediator of Gastric Cancer Progression

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Jun Wang ◽  
Zhigang He ◽  
Bo Sun ◽  
Wenhai Huang ◽  
Jianbin Xiang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Patients ◽  
Cancer Progression ◽  
Epithelial Mesenchymal Transition ◽  
In Vivo Studies ◽  
Vimentin Expression ◽  
Mesenchymal Transition ◽  
Gastric Cancer Patients

Pleckstrin-2 (PLEK2) is a crucial mediator of cytoskeletal reorganization. However, the potential roles of PLEK2 in gastric cancer are still unknown. PLEK2 expression in gastric cancer was examined by western blotting and real-time PCR. Survival analysis was utilized to test the clinical impacts of the levels of PLEK2 in gastric cancer patients. In vitro and in vivo studies were used to estimate the potential roles played by PLEK2 in modulating gastric cancer proliferation, self-renewal, and tumourigenicity. Bioinformatics approaches were used to monitor the effect of PLEK2 on epithelial-mesenchymal transition (EMT) signalling pathways. PLEK2 expression was significantly upregulated in gastric cancer as compared with nontumour samples. Kaplan-Meier plotter analysis revealed that gastric cancer patients with higher PLEK2 levels had substantially poorer overall survival compared with gastric cancer patients with lower PLEK2 levels. The upregulation or downregulation of PLEK2 in gastric cancer cell lines effectively enhanced or inhibited cell proliferation and proinvasive behaviour, respectively. Additionally, we also found that PLEK2 enhanced EMT through downregulating E-cadherin expression and upregulating Vimentin expression. Our findings demonstrated that PLEK2 plays a potential role in gastric cancer and may be a novel therapeutic target for gastric cancer.

scholarly journals In Vitro Characterization of Rabbit Thrombin, Antithrombin III, and Thrombin-Antithrombin III Complex, and Determination of Their Survival Times in Vivo

1977 ◽  
Author(s):  
Christine N. Vogel ◽  
Kingdon S. Henry ◽  
Roger L. Lundblad
Keyword(s):  
Gel Electrophoresis ◽  
Half Life ◽  
Antithrombin Iii ◽  
Specific Activity ◽  
Sodium Dodecyl ◽  
In Vivo Studies ◽  
Survival Times ◽  
At Iii

Our intention is to study the interaction of rabbit thrombin with antithrombin III (AT-III) in vitro and in vivo. After activation of crude prothrombin with tissue thromboplastin and CaCl2, thrombin was purified and showed two species of thrombin with molecular weights of 36,000 and 39,000 daltons as determined by sodium dodecyl sulfate discontinuous gel electrophoresis. Rabbit AT-III was purified using a heparin agarose column and had a molecular weight of 55,000 daltons. The inhibition of thrombin by AT-III was followed by fibrinogen clotting assays and an AT-III-thrombin complex was observed on gel electrophoresis. For the in vivo studies both thrombin and AT-III were radiolabelled with Na125i using the solid state lactoperoxidase method and retained 99% of the pre-iodinated specific activity. Radiolabelled thrombin and a radiolabelled AT-III-thrombin complex were injected into different rabbits. The rate of removal of both was very similar with a half-life of approximately 9 hours. When radiolabelled AT-III was injected, the half-life was approximately 60 hours. Since the disappearance rate of thrombin more closely approximates that of the preformed AT-III-thrombin complex and is clearly shorter than the turnover rate of AT-III, the possibility is raised that thrombin combines in vivo with a native inhibitor such as AT-III and may in fact be removed from the circulation as a complex rather than as a native molecule.

scholarly journals [18F]Amylovis as a Potential PET Probe for β-Amyloid Plaque: Synthesis, In Silico, In vitro and In vivo Evaluations

2019 ◽  
Vol 12 (1) ◽  
pp. 58-71 ◽  
Author(s):  
Suchitil Rivera-Marrero ◽  
Laura Fernández-Maza ◽  
Samila León-Chaviano ◽  
Marquiza Sablón-Carrazana ◽  
Alberto Bencomo-Martínez ◽  
...  
Keyword(s):  
In Silico ◽  
Specific Activity ◽  
Senile Plaques ◽  
Coupling Reaction ◽  
In Vitro Assays ◽  
Mice Model ◽  
Wild Mice ◽  
In Silico Studies

Background: Alzheimer’s disease (AD) is the most common form of dementia. Neuroimaging methods have widened the horizons for AD diagnosis and therapy. The goals of this work are the synthesis of 2-(3-fluoropropyl)-6-methoxynaphthalene (5) and its [18F]-radiolabeled counterpart ([18F]Amylovis), the in silico and in vitro comparative evaluations of [18F]Amylovis and [11C]Pittsburg compound B (PIB) and the in vivo preclinical evaluation of [18F]Amylovis in transgenic and wild mice. </p><p> Methods: Iron-catalysis cross coupling reaction, followed by fluorination and radiofluorination steps were carried out to obtain 5 and 18F-Amylovis. Protein/A&#223; plaques binding, biodistribution, PET/CT Imaging and immunohistochemical studies were conducted in healthy/transgenic mice. </p><p> Results: The synthesis of 5 was successful obtained. Comparative in silico studies predicting that 5 should have affinity to the A&#946;-peptide, mainly through &#960;-&#960; interactions. According to a dynamic simulation study the ligand-A&#946; peptide complexes are stable in simulation-time (&#916;G = -5.31 kcal/mol). [18F]Amylovis was obtained with satisfactory yield, high radiochemical purity and specific activity. The [18F]Amylovis log Poct/PBS value suggests its potential ability for crossing the blood brain barrier (BBB). According to in vitro assays, [18F]Amylovis has an adequate stability in time. Higher affinity to A&#946; plaques were found for [18F]Amylovis (Kd 0.16 nmol/L) than PIB (Kd 8.86 nmol/L) in brain serial sections of 3xTg-AD mice. Biodistribution in healthy mice showed that [18F]Amylovis crosses the BBB with rapid uptake (7 %ID/g at 5 min) and good washout (0.11&#177;0.03 %ID/g at 60 min). Comparative PET dynamic studies of [18F]Amylovis in healthy and transgenic APPSwe/PS1dE9 mice, revealed a significant high uptake in the mice model. </p><p> Conclusion: The in silico, in vitro and in vivo results justify that [18F]Amylovis should be studied as a promissory PET imaging agent to detect the presence of A&#946; senile plaques.

STUDIES ON THE ANTICOAGULANT AND ANTITHROMBOTIC ACTIONS OF DERMATANS AND THEIR SULFATED DERIVATIVES

1987 ◽  
Author(s):  
D Hoppensteadt ◽  
A Kumar ◽  
J Fareed ◽  
J Mardigian
Keyword(s):  
Antithrombin Iii ◽  
Femoral Vein ◽  
In Vivo Studies ◽  
In Vitro Assays ◽  
Protease Inhibition ◽  
Thrombosis Model ◽  
Antithrombotic Effects ◽  
Activated Prothrombin Complex Concentrates

Non-antithrombin III mediated effects such as interaction with heparin cofactor II, modulation of endothelium and polymorphonuclear leukocytes contribute to the overall antithrombotic effects of glycosaminoglycans. In order to study the role of these dermatans, we investigated their in vitro anticoagulant effects using the clot based (PT, APTT, TT, and Heptest), antiprotease (anti IIa and anti Xa) and Thromboplastin C activated fibrinopeptide A generation test. The in vivo antithrombotic actions were investigated, against activated and non activated prothrombin complex concentrates, and in combination with Russells viper venom in jugular and femoral vein stasis thrombosis models (rabbit). The dermatans studied consisted of a standard dermatan of porcine intestinal origin and four sulfated dermatans with varying degrees of sulfation. All of the dermatans studied showed weak anticoagulant effects on the routinely performed clot based assays. Marked variability was seen on the protease inhibition (anti Xa and anti IIa) assays. In the in vivo studies all dermatans studied showed varying degrees of antithrombotic actions against various thrombogenic agents in a modified stasis thrombosis model. Sulfation appeared to produce stronger anticoagulant effects as determined by in vitro assays, whereas the intravenous antithrombotic actions of native dermatan were stronger than sulfated derivatives. This data suggests that dermatans produce their antithrombotic actions via non-antithrombin III mediated pathways. Furthermore, in vitro testing methods are of limited value in the evaluation of the biologic actions of dermatans and their derivatives.

Can in vitro assays substitute for in vivo studies in assessing the pulmonary hazards of fine and nanoscale materials?

2008 ◽  
Vol 11 (2) ◽  
pp. 421-431 ◽  
Author(s):  
Christie M. Sayes ◽  
Kenneth L. Reed ◽  
Shekhar Subramoney ◽  
Lloyd Abrams ◽  
David B. Warheit
Keyword(s):  
In Vivo Studies ◽  
In Vitro Assays ◽  
Nanoscale Materials
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