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Enzyme
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Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
FAK
is a nonreceptor tyrosine kinase involved in adhesion-mediated signal transduction whose level of expression is related to the invasiveness of malignant tumors. In seeking strategies to downregulate
FAK
, we treated various cell lines in vitro with the benzoquinone ansamycin geldanamycin (GA) which was previously described as a tyrosine kinase inhibitor, but recently has been shown to exert its effects by interfering with the chaperone function of members of the hsp90 family of heat-shock proteins. We evaluated the effects of benzoquinone ansamycins on
FAK
steady-state protein level and
FAK
half-life in breast and prostate
carcinoma
, Ewing's sarcoma, and 3T3 fibroblasts. Our data demonstrate that GA stimulates the proteolytic degradation of
FAK
in all cell lines examined and markedly reduces the half-life of newly synthesized
FAK
protein without significantly altering the level of
FAK
mRNA. These data demonstrate
FAK
to be another tyrosine kinase sensitive to the destabilizing effects of benzoquinone ansamycins and further show that small molecule-mediated pharmacologic modulation of
FAK
protein level is a feasible approach to the interdiction of
FAK
function.
...
PMID:The benzoquinone ansamycin geldanamycin stimulates proteolytic degradation of focal adhesion kinase. 997 44
An in vivo lung tumor model system for radioimmunotherapy of lung metastases was used to test the relative effectiveness of the vascular- targeted beta-particle emitter 90Y, and alpha-particle emitter, 213Bi. Yttrium-90 was shown to be stably bound by CHXa" DTPA-MAb 201B conjugates and delivered efficiently to lung tumor blood vessels. Dosimetry calculations indicated that the lung received 16.2 Gy/MBq from treatment with 90Y MAb 201B, which was a sevenfold greater absorbed dose than any other organ examined. Therapy was optimal for 90Y with 3 MBq injected. Bismuth-213 MAb 201B also delivered a similar absorbed dose (15Gy/MBq) to the lung. Yttrium-90 was found to be slightly more effective against larger tumors than 213Bi, consistent with the larger range of 2 MeV beta particles from 90Y than the 8 MeV alpha particles from 213Bi. Treatment of
EMT
-6 tumors growing in immunodeficient SCID mice with 90Y or 213Bi MAb 201 resulted in significant destruction of tumor colonies; however, 90Y MAb 201B was toxic for the SCID mice, inflicting acute lung damage. In another tumor model, IC-12 rat tracheal
carcinoma
growing in SCID mouse lungs, 90Y therapy was more effective than 213Bi at destroying lung tumors. However, 90Y MAb 201B toxicity for the lung limited any therapeutic effect. We conclude that, although vascular-targeted 90Y MAb can be an effective therapeutic agent, particularly for larger tumors, in this model system, acute damage to the lung may limit its application.
...
PMID:Treatment of lung tumor colonies with 90Y targeted to blood vessels: comparison with the alpha-particle emitter 213Bi. 1009 15
Understanding the functional roles of the molecular alterations that are involved in the oncogenesis of prostate cancer, the second most frequent cause of cancer-related deaths among men in the United States is the focus of numerous investigations. To examine the possible significance of alterations associated with the tumor suppressor gene, MMAC/PTEN, in prostate
carcinoma
, the biological and biochemical effects of MMAC/PTEN expression were examined in LNCaP cells, which are devoid of a functional gene product. Acute expression of MMAC/PTEN via an adenoviral construct resulted in a dose-dependent and specific inhibition of Akt/
PKB
activation, consistent with the phosphatidylinositol phosphatase activity of MMAC/PTEN. MMAC/PTEN expression induced apoptosis in LNCaP cells, although to a lesser extent than that observed with p53 via an adenoviral construct. However, MMAC/PTEN expression produced a growth inhibition that was significantly greater than that achieved with p53. Overexpression of Bcl-2 in LNCaP cells blocked MMAC/PTEN- and p53-induced apoptosis but not the growth-suppressive effects of MMAC/ PTEN, suggesting that the growth regulatory effects of MMAC/PTEN involve multiple pathways. These studies further implicate the loss of MMAC/PTEN as a significant event in prostate cancer and suggest that reintroduction of MMAC/PTEN into deficient prostate cancer cells may have therapeutic implications.
...
PMID:Regulation of Akt/PKB activity, cellular growth, and apoptosis in prostate carcinoma cells by MMAC/PTEN. 1036 71
Urokinase-type plasminogen activator (uPA) and its receptor (uPAR) participate in matrix degradation and cell migration by focusing proteolysis and functioning as a signaling ligand/receptor complex. uPAR, anchored by a lipid moiety in the membrane, is thought to require a transmembrane adapter to transduce signals into the cytoplasm. To study uPAR signaling, we transfected the prostate
carcinoma
cell line LNCaP, which does not express endogenous uPA or uPAR, with a uPAR encoding cDNA, resulting in high-level surface expression. We studied migration of these cells on fibronectin, which is mediated by the integrin alpha5beta1. Ligation of uPAR with uPA or its amino-terminal fragment enhanced haptotactic migration to fibronectin. In cells on fibronectin, but not on poly-l-lysine, ligation of uPAR also resulted in tyrosine phosphorylation of several proteins, including two proteins involved in integrin signaling,
focal adhesion kinase
and the crk-associated substrate p130(Cas). Furthermore, after uPAR ligation, uPAR was co-immunoprecipitated with beta1 integrins from the detergent-insoluble fraction of cell lysates. Thus, our data suggest that uPAR occupancy results in an interaction between uPAR and integrins and a potentiation of integrin-mediated signaling, which leads to enhanced cell migration.
...
PMID:Urokinase-type plasminogen activator binding to its receptor stimulates tumor cell migration by enhancing integrin-mediated signal transduction. 1038 37
A novel homology model of the kinase domain of Janus kinase (JAK) 3 was used for the structure-based design of dimethoxyquinazoline compounds with potent and specific inhibitory activity against
JAK3
. The active site of
JAK3
in this homology model measures roughly 8 A x 11 A x 20 A, with a volume of approximately 530 A3 available for inhibitor binding. Modeling studies indicated that 4-(phenyl)-amino-6,7-dimethoxyquinazoline (parent compound WHI-258) would likely fit into the catalytic site of
JAK3
and that derivatives of this compound that contain an OH group at the 4' position of the phenyl ring would more strongly bind to
JAK3
because of added interactions with Asp-967, a key residue in the catalytic site of
JAK3
. These predictions were consistent with docking studies indicating that compounds containing a 4'-OH group, WHI-P131 [4-(4'-hydroxyphenyl)-amino-6,7-dimethoxyquinazoline], WHI-P154 [4-(3'-bromo-4'-hydroxylphenyl)-amino-6,7-dimethoxyquinazoline], and WHI-P97 [4-(3',5'-dibromo-4'-hydroxylphenyl)-amino-6,7-dimethoxyquinazolin e], were likely to bind favorably to
JAK3
, with estimated K(i)s ranging from 0.6 to 2.3 microM. These compounds inhibited
JAK3
in immune complex kinase assays in a dose-dependent fashion. In contrast, compounds lacking the 4'-OH group, WHI-P79 [4-(3'-bromophenyl)-amino-6,7-dimethoxyquinazoline], WHI-P111 [4-(3'-bromo-4'-methylphenyl)-amino-6,7-dimethoxyquinazoline], WHI-P112 [4-(2',5'-dibromophenyl)-amino-6,7-dimethoxyquinazoline], WHI-P132 [4-(2'-hydroxylphenyl)-amino-6,7-dimethoxyquinazoline], and WHI-P258 [4-(phenyl)-amino-6,7-dimethoxyquinazoline], were predicted to bind less strongly, with estimated K(i)s ranging from 28 to 72 microM. These compounds did not show any significant
JAK3
inhibition in kinase assays. Furthermore, the lead dimethoxyquinazoline compound, WHI-P131, which showed potent
JAK3
-inhibitory activity (IC50 of 78 microM), did not inhibit
JAK1
and
JAK2
, the ZAP/
SYK
family tyrosine kinase
SYK
, the
TEC
family tyrosine kinase
BTK
, the
SRC
family tyrosine kinase
LYN
, or the receptor family tyrosine kinase insulin receptor kinase, even at concentrations as high as 350 microM. WHI-P131 induced apoptosis in
JAK3
-expressing human leukemia cell lines NALM-6 and LC1;19 but not in melanoma (M24-MET) or squamous
carcinoma
(SQ20B) cells. Leukemia cells were not killed by dimethoxyquinazoline compounds that were inactive against
JAK3
. WHI-P131 inhibited the clonogenic growth of
JAK3
-positive leukemia cell lines DAUDI, RAMOS, LC1;19, NALM-6, MOLT-3, and HL-60 (but not
JAK3
-negative BT-20 breast cancer, M24-MET melanoma, or SQ20B squamous
carcinoma
cell lines) in a concentration-dependent fashion. Potent and specific inhibitors of
JAK3
such as WHI-P131 may provide the basis for the design of new treatment strategies against acute lymphoblastic leukemia, the most common form of childhood cancer.
...
PMID:Structure-based design of specific inhibitors of Janus kinase 3 as apoptosis-inducing antileukemic agents. 1038 46
A model system has been used to test the efficacy of vascular targeting of alpha-particle emitter 213Bi for therapy of small, 'artificial' metastases in mouse lung. Specific monoclonal antibody (mAb) 201 B was used to deliver greater than 30% of the injected dose to lung where tumours had developed due to intravenous injection of cells. Specific 213Bi-mAb 201B treatment of BALB/c mammary
carcinoma
EMT
-6 tumours in lung resulted in a dose-dependent destruction of tumours and an extended lifespan of treated animals relative to controls. Significant reduction of lung tumour burden was noted in animals treated with 0.93 MBq injected dose or as little as 14 Gy absorbed dose to the lung. Animals treated with higher doses (2.6-6.7 MBq) had nearly complete cure of lung tumours but eventually died of lung fibrosis induced by the treatment. Four other tumour cell types were studied: murine Line 1 lung carcinomas in syngeneic BALB/c mice, rat IC-12 tracheal
carcinoma
growing in severe combined immune deficient (SCID) mice, and two human tumours--epidermoid carcinoma A431 and lung carcinoma A549--growing in SCID mice. In all cases, the number of lung tumour colonies was reduced in animals treated with specific, labelled mAb relative to those in animals treated with control 213Bi MAb or EDTA complexed 213Bi. Tumours treated in immunodeficient SCID mice were partially destroyed or at least retarded in growth, but ultimately regrew and proved fatal, indicating that an intact immune function is necessary for complete cure. The data show that the short-lived alpha-particle emitter 213Bi can be effectively targeted to lung blood vessels and that tumour cells growing in the lung are killed. The mechanism may involve direct killing of tumour cells from alpha-particle irradiation, killing through destruction of blood supply to the tumour, or a combination of the two.
...
PMID:Radioimmunotherapy of micrometastases in lung with vascular targeted 213Bi. 1038 94
The NBT-II rat bladder
carcinoma
cell line, which displays epithelial to mesenchymal transition or
EMT
in response to FGF-1 stimulation, was used to study the interrelationships between cell cycle and cell scattering and locomotion. Time-lapse video microscopy experiments were performed with asynchronous growing cells and lovastatin-arrested cells. FGF-1 stimulation induced cell movement in cells in all phases of the cell cycle, except G2 + M phase, in which cells did not respond to stimulation. The delay between cell stimulation and cell movement depended on the age of the cell at the beginning of cell stimulation: cells less than 4 h old when stimulated by FGF-1 had a 1-h delay whereas cells more than 4 h old had a 3-h delay. Cells stimulated before they were 4 h old were temporarily arrested in their cell cycle progression. Older cells underwent mitosis on schedule. Lovastatin-treated cells were shown to be synchronized in the G1 phase and to migrate simultaneously after FGF-1 stimulation. These results indicate that the G1 phase was a critical phase for FGF-1 induced cell migration during epithelial to fibroblastoid transition.
...
PMID:Relationship between cell migration and cell cycle during the initiation of epithelial to fibroblastoid transition. 1042 70
Distal alterations of the short arm of chromosome 1 are among the most frequent cytogenetic abnormalities in human breast
carcinoma
. We studied 96 primary human breast carcinomas for allelic imbalance using a panel of 31 polymorphic microsatellite, restriction fragment length polymorphism, and variable number of tandem repeat markers located mainly in the 1p32-pter region. Allelic imbalance at one or more loci was observed on the short arm of chromosome 1 in 56 (58.3%) of the 96 tumors. The 56 1p-altered tumor DNAs showed loss of heterozygosity (LOH), 12 (21.4%) at all informative loci tested and 44 (78.6%) at some loci. The LOH pattern of these 44 partially deleted tumors identified two distinct consensus regions of deletion on 1p32-pter (1p36.3 and 1p32). These regions match those described by other investigators but are considerably smaller. The 1p32 band is located within one of the two 1p regions of LOH in neuroblastoma, suggesting the involvement of the same unidentified tumor suppressor gene in both human breast cancer and neuroblastoma. The candidate tumor suppressor genes TNFR2, RIZ, DAN, RAP1GA1,
FGR
, MDGI, EXTL, and hRAD54 were excluded from the two consensus regions of deletion identified at 1p32-pter. Analysis of six polymorphic markers chosen to map within the other deleted regions described in breast tumors confirmed that two additional breast tumor suppressor genes are located in the proximal part (1p22 and 1p13) of chromosome arm 1p. Taken together, these results suggest that several unknown suppressor genes on 1p might be involved in the development of breast cancer. The refinement of the regions of LOH to within a few cM, and the recent publication of transcript maps of the human genome, mean that candidate genes and expressed sequence tags mapping to these deleted regions can now be investigated.
...
PMID:Deletion mapping of chromosomal region 1p32-pter in primary breast cancer. 1045 6
The anticancer activity of the boronic acid dipeptide proteasome inhibitor PS-341 was examined in vitro and in vivo. PS-341 was a potent cytotoxic agent toward MCF-7 human breast
carcinoma
cells in culture, producing an IC90 of 0.05 microM on 24 h of exposure to the drug. In the
EMT
-6 tumor cell survival assay, PS-341 was equally cytotoxic administered p.o. or by i.p. injection up to a dose of 2 mg/kg. PS-341 was also toxic to the bone marrow colony-forming unit-granulocyte macrophage. PS-341 increased the tumor cell killing of radiation therapy, cyclophosphamide, and cisplatin in the
EMT
-6/Parent tumor, but was not able to overcome the in vivo resistance of the
EMT
-6/CTX and
EMT
-6/CDDP tumors. In the tumor growth delay assay, PS-341 administered p.o. had antitumor activity against the Lewis lung carcinoma, both primary and metastatic disease. In combination, regimens with 5-fluorouracil, cisplatin, Taxol and adriamycin, PS-341 seemed to produce primarily additive tumor growth delays against the s.c. tumor and was highly effective against disease metastatic to the lungs. The proteasome is an interesting new target for cancer therapy, and the proteasome inhibitor PS-341 warrants continued investigation in cancer therapy.
...
PMID:The proteasome inhibitor PS-341 in cancer therapy. 1049 43
Hyperthermia is reported to act as a sensitizer to chemotherapeutic drugs in the treatment of cancer. Thyroid follicular
carcinoma
were used to elucidate the effects of hyperthermic treatment (41-43 degrees C) on cell morphology, cytoskeleton, and the focal adhesion complex. The critical temperature that resulted in inhibition of cell proliferation as the cell number in the same area did not increase over a 23 h time course and irreversible changes in cell morphology was 42-43 degrees C. An immunofluorescence study on heat-treated cells (43 degrees C, 1-5 h) demonstrated that depolymerization of actin filaments, intermediate filaments, and microtubules accounted for the rounding-up of cells and detachment from the substratum. Characteristic staining patterns for integrin alphav,
focal adhesion kinase
, and vinculin were noted in untreated cells, but the immunoreactive intensities for these proteins became weaker with time of heat treatment. Anti-phosphotyrosine staining revealed less immunoreactivity in the focal adhesions in treated cells compared with control cells. The disappearance of integrin alphav from the cell surface may result in inhibition of integrin-mediated activation of
focal adhesion kinase
, which results in dephosphorylation of focal adhesion components and its disassembly. These results indicate that hyperthermia induces disruption of integrin-mediated actin cytoskeleton assembly and, possibly, of other integrin-mediated signaling pathways.
...
PMID:Effects of hyperthermia on the cytoskeleton and focal adhesion proteins in a human thyroid carcinoma cell line. 1050 4
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