Search results for "TYROSINE KINASE"
showing 10 items of 362 documents
Development and biological investigations of hypoxia-sensitive prodrugs of the tyrosine kinase inhibitor crizotinib
2019
Despite the huge success of tyrosine kinase inhibitors as anticancer agents, severe side effects are a major problem. In order to overcome this drawback, the first hypoxia-activatable 2-nitroimidazole-based prodrugs of the clinically approved ALK and c-MET inhibitor crizotinib were developed. The 2-aminopyridine functionality of crizotinib (essential for target kinase binding) was considered as ideal position for prodrug derivatization. Consequently, two different prodrugs were synthesized with the nitroimidazole unit attached to crizotinib either via carbamoylation (A) or alkylation (B) of the 2-aminopyridine moiety. The successful prodrug design could be proven by docking studies and a dr…
BCR-ABL as a target for novel therapeutic interventions.
2002
The BCR-ABL oncogene is the result of a reciprocal translocation between the long arms of chromosome 9 and 22 t(9; 22). There is good experimental evidence demonstrating that BCR-ABL is the single causative abnormality in chronic myeloid leukaemia (CML), making it a unique model for the development of molecular targets. In addition to CML, BCR-ABL transcripts can be found in a minority of acute lymphoblastic leukaemias and very rarely in acute myeloid leukaemia (AML). Elucidating the molecular mechanisms and downstream pathways of BCR-ABL has led to the design of several novel therapeutic approaches. In this review, molecular targeting of BCR-ABL will be discussed based on the inhibition of…
Cationic lipide mediated transfer of c-abl and bcr antisense oligonucleotides to immature normal myeloid cells: Uptake, biological effects and modula…
1996
Uptake and biochemical and biological effects of antisense oligodeoxynucleotides (ODN) specific for c-abl and bcr genes were studied in normal immature myeloid cells. CD34-positive cells were purified by positive and negative selection and cultured in liquid culture for 7 days. These cells were then incubated with ODNs, either alone or in combination with cationic lipids. The uptake of ODNs was enhanced by the use of cationic lipids. In addition, very low concentrations of ODNs in combination with cationic lipids were capable of specifically inhibiting the expression of the c-abl gene. In contrast, no effects were seen on the expression of bcr. However, despite the effective blocking of c-a…
Aberrant copy numbers of ALK gene is a frequent genetic alteration in neuroblastomas.
2009
A total of 50 neuroblastomas were assessed for frequency of ALK gene copy number aberrations by interphase fluorescence in situ hybridization using a break-apart fluorescence in situ hybridization probe. The data were compared with status of MYCN, 11q, 17q, and 1p36. We observed ALK aberrations (amplification, 1 of 45; gain, 15 of 45 and loss/imbalance, 11 of 45) in a total of 27 (60%) of 45 neuroblastomas. Synchronic MYCN and ALK aberrations accounted for 23 of 45 (51%) tumors; however, MYCN alterations were also detected in 11 (60%) of 18 tumors without ALK aberrations. Our data suggest that copy number aberrations of the ALK gene is a frequent genetic event in the development of neurobla…
Ethanol inhibits astroglial cell proliferation by disruption of phospholipase D-mediated signaling.
2002
The activation of phospholipase D (PLD) is a common response to mitogenic stimuli in various cell types. As PLD-mediated signaling is known to be disrupted in the presence of ethanol, we tested whether PLD is involved in the ethanol-induced inhibition of cell proliferation in rat cortical primary astrocytes. Readdition of fetal calf serum (FCS) to serum-deprived astroglial cultures caused a rapid, threefold increase of PLD activity and a strong mitogenic response; both effects were dependent on tyrosine kinases but not on protein kinase C. Ethanol (0.1-2%) suppressed the FCS-induced, PLD-mediated formation of phosphatidic acid (PA) as well as astroglial cell proliferation in a concentration…
Regulation of the human bradykinin B2 receptor expressed in sf21 insect cells: A possible role for tyrosine kinases
2000
The functional regulation of the human bradykinin B2 receptor expressed in sf21 cells was studied. Human bradykinin B2 receptors were immunodetected as a band of 75–80 kDa in membranes from recombinant baculovirus-infected cells and visualized at the plasma membrane, by confocal microscopy, using an antibody against an epitope from its second extracellular loop. B2 receptors, detected in membranes by [3H-bradykinin] binding, showed a Kd of 0.66 nmol/L and an expression level of 2.57 pmol/mg of protein at 54 h postinfection. In these cells, bradykinin induced a transient increase of intracellular calcium ([Ca2+]i) in fura 2-AM loaded sf21 cells, and promoted [35S]-GTPγS binding to membranes.…
Specific mutations of the RET proto-oncogene are related to disease phenotype in MEN 2A and FMTC.
1994
We have analysed 118 families with inherited medullary thyroid carcinoma (MTC) for mutations of the RET proto-oncogene. These included cases of multiple endocrine neoplasia types 2A (MEN 2A) and 2B (MEN 2B) and familial MTC (FMTC). Mutations at one of 5 cysteines in the extracellular domain were found in 97% of patients with MEN 2A and 86% with FMTC but not in MEN 2B patients or normal controls. 84% of the MEN2A mutations affected codon 634. MEN 2A patients with a Cys634 to Arg substitution had a greater risk of developing parathyroid disease than those with other codon 634 mutations. Our data show a strong correlation between disease phenotype and the nature and position of the RET mutatio…
Endothelial Bmx tyrosine kinase activity is essential for myocardial hypertrophy and remodeling
2015
Cardiac hypertrophy accompanies many forms of heart disease, including ischemic disease, hypertension, heart failure, and valvular disease, and it is a strong predictor of increased cardiovascular morbidity and mortality. Deletion of bone marrow kinase in chromosome X (Bmx), an arterial nonreceptor tyrosine kinase, has been shown to inhibit cardiac hypertrophy in mice. This finding raised the possibility of therapeutic use of Bmx tyrosine kinase inhibitors, which we have addressed here by analyzing cardiac hypertrophy in gene-targeted mice deficient in Bmx tyrosine kinase activity. We found that angiotensin II (Ang II)-induced cardiac hypertrophy is significantly reduced in mice deficient i…
Bafetinib inhibits functional responses of human eosinophils in vitro
2012
Eosinophils play a prominent role in the process of allergic inflammation. Non-receptor associated Lyn tyrosine kinases generate key initial signals in eosinophils. Bafetinib, a specific Abl/Lyn tyrosine kinase inhibitor has shown a potent antiproliferative activity in leukemic cells, but its effects on eosinophils have not been reported. Therefore, we studied the effects of bafetinib on functional and mechanistic responses of isolated human eosinophils. Bafetinib was more potent than non-specific tyrosin kinase comparators genistein and tyrphostin inhibiting superoxide anion triggered by N-formyl-Met-Leu-Phe (fMLF; 100 nM) (−log IC50=7.25±0.04 M; 6.1±0.04 M; and 6.55±0.03 M, respectively).…
FLT3 as a therapeutic target in AML: still challenging after all these years
2010
Abstract Mutations within the FMS-like tyrosine kinase 3 (FLT3) gene on chromosome 13q12 have been detected in up to 35% of acute myeloid leukemia (AML) patients and represent one of the most frequently identified genetic alterations in AML. Over the last years, FLT3 has emerged as a promising molecular target in therapy of AML. Here, we review results of clinical trials and of correlative laboratory studies using small molecule FLT3 tyrosine kinase inhibitors (TKIs) in AML patients. We also review mechanisms of primary and secondary drug resistance to FLT3-TKI, and from the data currently available we summarize lessons learned from FLT3-TKI monotherapy. Finally, for using FLT3 as a molecul…