Abstract 253: The Tyrosine Kinase ErbB2 Inhibitor Lapatinib and the Anti-ErbB2 Antibody Trastuzumab Depress Cardiac Function Without Inducing Left Ventricular Dilation in Mice

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Carlo G Tocchetti ◽  
Carmela Coppola ◽  
Domenica Rea ◽  
Antonio Barbieri ◽  
Giuseppe Palma ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Systolic Dysfunction ◽  
Myocardial Strain ◽  
Kinase Domain ◽  
Left Ventricular ◽  
Tyrosine Kinase Receptor ◽  
Lv Function ◽  
Tyrosine Kinase Domain ◽  
Breast Cancers

Background: ErbB2, tyrosine kinase receptor of the EGFR family, overexpressed in about 25% of breast cancers, modulates development and function in the myocardium. Lapatinib (LAP) is a small molecule that inhibits ErbB2-tyrosine kinase domain. The few existing trials report it to be associated with a low risk of LV dysfunction (2%), while the prototypical antibody Trastuzumab (TRAS) increases the frequency of asymptomatic ejection fraction decrease by 3-18%, and the risk of heart failure by 2-4%. Here, we characterize our LAP murine cardiotoxicity model in vivo by echocardiography, comparing it to TRAS and doxorubicin (DOX) cardiotoxicities. Methods: LV end-diastolic and end-systolic diameters (LVEDD and LVESD) were assessed. LV function was measured with fractional shortening (FS) by M-mode echo, and with radial myocardial strain (%) with speckle tracking (ST) in sedated C57BL6 mice (2-4 mo. old) at day 0, and after 2 and 7 days of daily administration of LAP (100mg/kg/day orally), and in control mice. For comparison we used our well-established models with TRAS (2.25 mg/kg/day, ip), and DOX (2.17 mg/kg/day ip) as positive control. Results: FS was already reduced with DOX at 2 days: 52±.2%, p<.001 vs 60±.4% (sham), while LAP and TRAS decreased FS only at 7 days (56±2 and 49±1.5%, respectively, both p<.05 vs 60±.5% for sham). Interestingly, FS reduction with LAP was milder than with TRAS (p=.01). At 7 days, both LAP and TRAS only increased LVESD: 1.23±.07 and 1.49±.07mm, respectively, both p<.05 vs 1.1±.03mm (sham). On the other hand, at 7 days DOX induced LV dilation, with significant enlargement of both LVESD (1.55±.08mm) and LVEDD (3.04±.06mm; sham=2.81±.03mm), both p<.005. Importantly, from a diagnostic point of view, myocardial strain was reduced early at 2 days with LAP and TRAS, predicting cardiotoxicity: 34±7% for LAP, 44±7% for TRAS, both p<.05 vs sham (66±.6%). Conclusions: Differently from DOX, ErbB2 inhibition in mice does not produce LV dilation, but only decreases LV function. In particular, specifically targeting ErbB2-tyrosine kinase domain with LAP confers less cardiotoxicity than TRAS. Myocardial strain identifies LV systolic dysfunction earlier than conventional echo and can be a useful tool to predict ErbB2 inhibitors cardiotoxicity.

Effect of inhibition of ErbB2-tyrosine kinase domain with lapatinib on cardiac dysfunction compared to the antibody trastuzumab in mice.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e11052-e11052
Author(s):  
Carlo G. Tocchetti ◽  
Carmela Coppola ◽  
Domenica Rea ◽  
Noemi Castaldo ◽  
Lorena Guarino ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Cardiac Dysfunction ◽  
Systolic Dysfunction ◽  
Myocardial Strain ◽  
Kinase Domain ◽  
Positive Control ◽  
Point Of View ◽  
Tyrosine Kinase Domain ◽  
Cardiac Inflammation ◽  
The Impact

e11052 Background: Lapatinib (L) inhibits ErbB2-tyrosine kinase domain and has been reported (in the few existing trials) to be associated with a low risk of cardiac dysfunction (2%), while the prototypical Trastuzumab (T) increases the frequency of asymptomatic ejection fraction decrease by 3-18%, and the risk of heart failure by 2-4%. Here, we characterize our L murine cardiotoxicity model. Methods: Cardiac function was measured with fractional shortening (FS) by M-mode echocardiography, and with radial myocardial strain (%) with speckle tracking (ST) in sedated C57BL6 mice (2-4 mo. old) at day 0, and after 2 and 7 days of daily administration of L (100mg/kg/day orally), and in control mice. For comparison we used our well-established models with T (2.25 mg/kg/day, ip), and Doxorubicin (D, 2.17 mg/kg/day ip) as positive control. On excised hearts, we evaluated TNFα and CD68 by immunohistochemistry. Results: FS was reduced with D at 2 days: 52±0.2%, p<.001 vs 60±0.4% (sham), while L and T decreased FS only at 7 days (56±2 and 49±1.5%, respectively, both p<.05 vs 60±0.5% for sham). Interestingly, FS reduction with L was milder (p=.01) than with T. By immunohistochemistry, all treatments increased cardiac inflammation significantly vs controls. In particular, with T more myocytes were positive for TNFα (6±1%), and there were more CD68 cells/mm2 (72±6) compared to L (2±.2% and 27±4, respectively, both p<.02 vs T). D-treated hearts exhibited the highest values. Importantly, from a diagnostic point of view, with ST-echocardiogaphy, myocardial strain was reduced early at 2 days with L and T, predicting cardiotoxicity: 34±7% for L, 44±7% for T (p=NS), both p<.05 vs sham (66±.6%). Conclusions: Specifically targeting the tyrosine kinase domain of ErbB2 with L is less cardiotoxic than T. Nevertheless, both dysfunctions occur later than D. Myocardial strain identifies systolic dysfunction earlier than conventional echo and can be useful to predict cardiotoxicity in these settings. From a clinical point of view, we plan to evaluate the impact of ST echocardiography in early prediction of anti-ErbB2 toxicity in patients, while dissecting myocardial toxicity mechanisms in our animal models.

scholarly journals A Novel Activating Mutation in the RET Tyrosine Kinase Domain Mediates Neoplastic Transformation

2006 ◽  
Vol 20 (7) ◽  
pp. 1633-1643 ◽  
Author(s):  
Aaron Cranston ◽  
Cristiana Carniti ◽  
Sam Martin ◽  
Piera Mondellini ◽  
Yvette Hooks ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Cell Line ◽  
Glial Cell ◽  
Neurotrophic Factor ◽  
Functional Characterization ◽  
Kinase Domain ◽  
Tyrosine Kinase Domain ◽  
Exogenous Substrate

Abstract We report the finding of a novel missense mutation at codon 833 in the tyrosine kinase of the RET proto-oncogene in a patient with a carcinoma of the thyroid. In vitro experiments demonstrate that the R833C mutation induces transformed foci only when present in the long 3′ splice isoform and, in keeping with a model in which the receptor has to dimerize to be completely activated, glial cell line-derived neurotrophic factor stimulation leads the RETR833C receptor to a higher level of activation. Tyrosine kinase assays show that the RETR833C long isoform has weak intrinsic kinase activity and phosphorylation of an exogenous substrate is not elevated even in the presence of glial cell line-derived neurotrophic factor. Furthermore, the R833C mutation is capable of sustaining the transformed phenotype in vivo but does not confer upon the transformed cells the ability to degrade the basement membrane in a manner analogous to metastasis. Our functional characterization of the R833C substitution suggests that, like the V804M and S891A mutations, this tyrosine kinase mutation confers a weak activating potential upon RET. This is the first report demonstrating that the introduction of an intracellular cysteine can activate RET. However, this does not occur via dimerization in a manner analogous to the extracellular cysteine mutants.

Favourable Prognosis Associated with FLT3 Tyrosine Kinase Domain Mutations in AML in Contrast to the Adverse Outcome Associated with Internal Tandem Duplications.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 334-334 ◽  
Author(s):  
Adam Mead ◽  
David Linch ◽  
Robert Hills ◽  
Keith Wheatley ◽  
Alan Burnett ◽  
...  
Keyword(s):  
Overall Survival ◽  
Tyrosine Kinase ◽  
Relapse Rate ◽  
Poor Prognosis ◽  
Disease Free Survival ◽  
Kinase Domain ◽  
Small Sample ◽  
Tyrosine Kinase Receptor ◽  
Tyrosine Kinase Domain ◽  
Tandem Duplications

Abstract It is widely accepted that internal tandem duplications (ITDs) of the juxtamembrane domain of FLT3 occur in about one quarter of cases of acute myeloid leukaemia (AML) in young adults and predict for early relapse from complete remission (CR). Constitutive activation of FLT3 can also arise from mutations in the tyrosine kinase domain (TKD) but there is controversy as to the clinical significance of this class of mutation. This is partly due to the small sample size of some studies and the inclusion of elderly patients who have a poor prognosis regardless of their FLT3 status. To definitively resolve this issue we have screened for TKD mutations in AML blast cells from 1339 young adult patients included in the UK MRC AML 10 and 12 trials using a sensitive denaturing HPLC technique (Transgenomic WAVE®). Mutant samples were confirmed by sequencing or specific restriction digest. 161 of 1339 (12%) patients had a TKD mutation which is a higher frequency than previously reported both because of the sensitivity of the technique and the detection of mutations outside the EcoRV digest site. 91 patients (6.8%) were deemed to have high level mutant arbitrarily defined as ≥ 20% of all FLT3 alleles and 70 (5.2%) had a low level mutant. 79 of the 161 (49%) mutants were Asp835Tyr. 8 mutants occurred outside the EcoRV digest site and 3 novel mutations were characterised. 372 (28%) patients in this cohort had an ITD. There was a negative correlation between the presence of an ITD and a TKD mutation with only 2.5% having evidence of both mutations. Furthermore, high levels of both class of mutation in the same patient were not seen so that it is possible that both mutations never arise in the same cell. The demographics of patients with a TKD mutation differed from those with a FLT3 ITD in that the presence of TKD mutations were not correlated with FAB type and were infrequent in patients with secondary AML. Both types of mutation were more frequent in patients with a high white count but were infrequent in patients with adverse cytogenetics. The presence of TKD mutations did not impact on CR rate, the incidence of resistant disease or the induction death rate. In contrast to FLT3 ITDs, TKD mutations were associated with a reduced relapse rate (odds ratio [OR] 0.77, 95% confidence intervals [CI] 0.59–0.99, P.04), improved disease free survival (OR 0.75, CI 0.60–0.93, P.008) and increased overall survival (OR 0.79, CI 0.64–0.97, P.02). In patients with wild type FLT3 the actuarial relapse rate at 5 years was 46%, compared to 57% with an ITD (excluding rare double mutants) and 34% in those with a TKD mutation. The overall survival at 5 years was 44%, 35% and 55% respectively. In multivariate analysis, the presence of a TKD mutation still had an effect on the relapse rate (OR 0.82, CI 0.67–1.01, P.05) and overall survival (OR 0.83, CI 0.70–0.98, P.03). These data suggest that different classes of activating mutation of the same tyrosine kinase receptor can be associated with markedly different clinical outcomes. FLT3 ITDs are associated with a poor prognosis and FLT3 TKD mutations with a relatively good prognosis. This unexpected genotype-phenotype relationship has not previously been described with oncogenic mutations and is significant to the understanding of the pathophysiology of chemoresistance as well as prognostic stratification.

scholarly journals BH4 Increases nNOS Activity and Preserves Left Ventricular Function in Diabetes

2021 ◽  
Author(s):  
Ricardo Carnicer Hijazo ◽  
Drew Duglan ◽  
Klemen Ziberna ◽  
Alice Recalde ◽  
Svetlana Reilly ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Glucose Transporter ◽  
Systolic Dysfunction ◽  
Left Ventricular ◽  
Creatine Kinase Activity ◽  
Lv Function ◽  
Diabetic Patients ◽  
Myocardial Glucose Uptake ◽  
Glut 1

Rationale: In diabetic patients, heart failure with predominant left ventricular (LV) diastolic dysfunction is a common complication for which there is no effective treatment. Oxidation of the nitric oxide synthase (NOS) co-factor tetrahydrobiopterin (BH4) and dysfunctional NOS activity have been implicated in the pathogenesis of the diabetic vascular and cardiomyopathic phenotype. Objective: Using mice models and human myocardial samples, we evaluated whether and by which mechanism increasing myocardial BH4 availability prevented or reversed LV dysfunction induced by diabetes. Methods and Results: In contrast to the vascular endothelium, BH4 levels, superoxide production and NOS activity (by liquid chromatography) did not differ in the LV myocardium of diabetic mice or in atrial tissue from diabetic patients. Nevertheless, the impairment in both cardiomyocyte relaxation and [Ca2+]i decay and in vivo LV function (echocardiography and tissue Doppler) that developed in wild type mice (WT) 12 weeks post-DM induction (streptozotocin, 42-45mg/kg) was prevented in mice with elevated myocardial BH4 content secondary to overexpression of GTP-cyclohydrolase 1 (mGCH1-Tg) and reversed in WT mice receiving oral BH4 supplementation from the 12th to the 18th week after DM induction. The protective effect of BH4 was abolished by CRISPR/Cas9-mediated knockout of neuronal NOS (nNOS) in mGCH1-Tg. In HEK cells, S-nitrosoglutathione led to a PKG-dependent increase in plasmalemmal density of the insulin-independent glucose transporter, GLUT-1. In cardiomyocytes, mGCH1 overexpression induced a NO/sGC/PKG-dependent increase in glucose uptake via GLUT-1, which was instrumental in preserving mitochondrial creatine kinase activity, oxygen consumption rate, LV energetics (by 31P MRS) and myocardial function. Conclusions: We uncovered a novel mechanism whereby myocardial BH4 prevents and reverses LV diastolic and systolic dysfunction associated with diabetes via a nNOS-mediated increase in non-insulin dependent myocardial glucose uptake and utilization. These findings highlight the potential of GCH1/BH4-based therapeutics in human diabetic cardiomyopathy.

Selective binding and internalisation by truncated receptors restrict the availability of BDNF during development

Development ◽  
1995 ◽  
Vol 121 (8) ◽  
pp. 2461-2470 ◽  
Author(s):  
S. Biffo ◽  
N. Offenhauser ◽  
B.D. Carter ◽  
Y.A. Barde
Keyword(s):  
Chick Embryo ◽  
Tyrosine Kinase ◽  
Neurotrophic Factor ◽  
Neuronal Cells ◽  
In Situ Hybridisation ◽  
Brain Derived Neurotrophic Factor ◽  
Kinase Domain ◽  
Otic Vesicle ◽  
Tyrosine Kinase Receptor ◽  
Tyrosine Kinase Domain

The tyrosine kinase receptor trkB is thought to mediate the biological actions of brain-derived neurotrophic factor. This receptor is expressed by a large variety of neurons during development. Truncated trkB molecules lacking the tyrosine kinase domain have also been described, but their functions remain elusive. In order to gain insight into their role, we studied the pattern of expression and properties of these truncated receptors in the chick embryo. mRNA coding for truncated trkB was detected already early during neurogenesis and in situ hybridisation experiments indicated that the expression was in non-neuronal cells, as previously observed in the brain of adult rodents. Ependymal and leptomeningeal cells expressing high levels of truncated trkB were found to completely surround the developing brain and the spinal cord throughout development. In the otic vesicle, mesenchymal cells expressing truncated trkB surround cells producing brain-derived neurotrophic factor, as well as neurons expressing trkB with its tyrosine kinase domain. Non-neuronal cells were found not to express trkB mRNA coding for the tyrosine kinase domain. Studies with radioiodinated brain-derived neurotrophic factor performed on frozen sections of the chick embryo revealed that non-neuronal cells expressing truncated trkB bind brain-derived neurotrophic factor with high affinity and selectivity. In addition, experiments with dissociated leptomeningeal cells revealed that binding is rapidly followed by selective internalisation of the ligand. These results suggest that truncated trkB molecules form an efficient and selective barrier preventing the diffusion of brain-derived neurotrophic factor and eliminating it by internalisation.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals 1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as VEGFR-2 Tyrosine Kinase Inhibitors: Synthesis, Biological Evaluation, and Molecular Modelling Studies

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Pedro Soares ◽  
Raquel Costa ◽  
Hugo J. C. Froufe ◽  
Ricardo C. Calhelha ◽  
Daniela Peixoto ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tyrosine Kinase ◽  
Kinase Inhibitors ◽  
Umbilical Vein ◽  
Growth Factor Receptor ◽  
Kinase Domain ◽  
Docking Studies ◽  
Biological Evaluation ◽  
Tyrosine Kinase Receptor ◽  
Tyrosine Kinase Domain

The vascular endothelial growth factor receptor-2 (VEGFR-2) is a tyrosine kinase receptor involved in the growth and differentiation of endothelial cells that are implicated in tumor-associated angiogenesis. In this study, novel 1-aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas were synthesized and evaluated for the VEGFR-2 tyrosine kinase inhibition. Three of these compounds showed good VEGFR-2 inhibition presenting low IC50values (150–199 nM) in enzymatic assays, showing also a significant proliferation inhibition of VEGF-stimulated human umbilical vein endothelial cells (HUVECs) at low concentrations (0.5–1 µM), using the Bromodeoxyuridine (BrdU) assay, not affecting cell viability. The determination of the total and phosphorylated (active) VEGFR-2 was performed by western blot, and it was possible to conclude that the compounds significantly inhibit the phosphorylation of the receptor at 1 µM pointing to their antiproliferative mechanism of action in HUVECs. The molecular rationale for inhibiting the tyrosine kinase domain of VEGFR-2 was also performed and discussed using molecular docking studies.

scholarly journals Profiling Receptor Tyrosine Kinase Fusions in Chinese Breast Cancers

2021 ◽  
Vol 11 ◽  
Author(s):  
Zhonghua Tao ◽  
Jianxia Liu ◽  
Ting Li ◽  
Hong Xu ◽  
Kai Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tyrosine Kinase ◽  
Cancer Patients ◽  
Tyrosine Kinases ◽  
Chromosomal Rearrangements ◽  
Cell Communication ◽  
Kinase Domain ◽  
Tyrosine Kinase Domain ◽  
Breast Cancers ◽  
Breast Cancer Patients

BackgroundReceptor tyrosine kinases (RTKs) are a class of tyrosine kinases that regulate cell-to-cell communication and control a variety of complex biological functions. Dysregulation of RTK signaling partly due to chromosomal rearrangements leads to novel tyrosine kinase fusion oncoproteins that are possibly driver alterations to cancers. Targeting some RTK fusions with specific tyrosine kinases inhibitors (TKIs) is an effective therapeutic strategy across a spectrum of RTK fusion-related cancers. However, there is still a paucity of extensive RTK fusion investigations in breast cancer. This study aims to characterize RTK fusions in Chinese breast cancer patients.MethodsAn in-house DNA sequencing database of 1440 Chinese breast cancer patients with a capture-based panel (520 gene or 108 gene-panel) was thoroughly reviewed. A total of 2,229 samples including 1,045 tissues and 1,184 plasmas were analyzed. RTK fusion was defined as an in-frame fusion with the tyrosine kinase domain of the RTK completely retained. Concomitant mutations were also analyzed and tumor mutational burden (TMB) was calculated. Patients’ clinical characteristics were retrieved from case records.ResultsA total of 30 RTK fusion events were identified from 27 breast cancer patients with a prevalence of 1.875%%. FGFR2 fusions were seen the most commonly (n=7), followed by RET (n=5), ROS1 (n=3), NTRK3 (n=3), BRAF (n=2), and NTRK1 (n=2). Other RTK fusions including ALK, EGFR, FGFR1, FGFR3, MET, and NTRK2 were identified in one patient each. A total of 27 unique resultant fusion proteins (22 with a novel partner) were discovered including 19 intrachromosomal rearrangements and 8 interchromosomal ones. Twenty-one fusions had the tyrosine kinase domain in-frame fused with a partner gene and six were juxtaposed with an intergenic space. Among the 27 fusions, FGFR2-WDR11 (E17: intergenic) (n=3) and ETV6-NTRK3 (E5:E15) (n=2) occurred recurrently. Of note, the normalized abundance of RTK fusion (fusion AF/max AF) correlated negatively with TMB (r=-0.48, P=0.017). Patients with TMB &lt; 8 (Mutations/Mb) displayed a higher fusion abundance than those with TMB ≥ 8 (Mutations/Mb) (P=0.025). Moreover, CREBBP mutation only co-occurred with FGFR2 fusion (P=0.012), while NTRK3 fusion and TP53 mutation were mutually exclusive (P=0.019).ConclusionThis is the first study comprehensively delineating the prevalence and spectrum of RTK fusions in Chinese breast cancers. Further study is ongoing to identify the enriched subpopulation who may benefit from RTK fusion inhibitors.

scholarly journals The DNA rearrangement that generates the TRK-T3 oncogene involves a novel gene on chromosome 3 whose product has a potential coiled-coil domain.

1995 ◽  
Vol 15 (11) ◽  
pp. 6118-6127 ◽  
Author(s):  
A Greco ◽  
C Mariani ◽  
C Miranda ◽  
A Lupas ◽  
S Pagliardini ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Germ Line ◽  
Coiled Coil ◽  
Kinase Domain ◽  
Chromosome 1 ◽  
Chromosome 3 ◽  
Tyrosine Kinase Domain ◽  
Novel Gene ◽  
Transforming Activity

Oncogenic rearrangements of the NTRK1 gene (also designated TRKA), encoding one of the receptors for the nerve growth factor, are frequently detected in thyroid carcinomas. Such rearrangements fuse the NTRK1 tyrosine kinase domain to 5'-end sequences belonging to different genes. In previously reported studies we have demonstrated that NTRK1 oncogenic activation involves two genes, TPM3 and TPR, both localized similarly to the receptor tyrosine kinase, on the q arm of chromosome 1. Here we report the characterization of a novel NTRK1-derived thyroid oncogene, named TRK-T3. A cDNA clone, capable of transforming activity, was isolated from a transformant cell line. Sequence analysis revealed that TRK-T3 contains 1,412 nucleotides of NTRK1 preceded by 598 nucleotides belonging to a novel gene that we have named TFG (TRK-fused gene). The TRK-T3 amino acid sequence displays, within the TFG region, a coiled-coil motif that could endow the oncoprotein with the capability to form complexes. The TRK-T3 oncogene encodes a 68-kDa cytoplasmic protein reacting with NTRK1-specific antibodies. By sedimentation gradient experiments the TRK-T3 oncoprotein was shown to form, in vivo, multimeric complexes, most likely trimers or tetramers. The TFG gene is ubiquitously expressed and is located on chromosome 3. The breakpoint producing the TRK-T3 oncogene occurs within exons of both the TFG gene and the NTRK1 gene and produces a chimeric exon that undergoes alternative splicing. Molecular analysis of the NTRK1 rearranged fragments indicated that the chromosomal rearrangement is reciprocal and balanced and involves loss of a few nucleotides of germ line sequences.

NIDDM associated with mutation in tyrosine kinase domain of insulin receptor gene

Diabetes ◽  
1992 ◽  
Vol 41 (4) ◽  
pp. 521-526 ◽  
Author(s):  
S. Cocozza ◽  
A. Porcellini ◽  
G. Riccardi ◽  
A. Monticelli ◽  
G. Condorelli ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Insulin Receptor ◽  
Receptor Gene ◽  
Kinase Domain ◽  
Tyrosine Kinase Domain ◽  
Insulin Receptor Gene
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