Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P42574 (caspase-3)
 45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In chronic myeloid leukemia (CML), resistance to imatinib is diverse. In addition to BCR-ABL-dependent mechanisms, BCR-ABL-independent mechanisms have been proposed. Here we established and characterized novel CML cell lines, an imatinib-sensitive cell line, MYL, and an imatinib-resistant subline, MYL-R. Treatment with imatinib inhibited phosphorylation of BCR-ABL and CrkL in both MYL and MYL-R, even though imatinib-induced apoptosis was preferentially observed in MYL than MYL-R, indicating that the resistance is based on a BCR-ABL-independent mechanism. MYL-R showed elevated expressions of Lyn mRNA, Lyn protein, phosphorylated Lyn, and phosphorylated STAT5. Silencing of Lyn by short-interfering RNA (siRNA) in MYL-R, but not in MYL, induced significant growth-inhibition, increased caspase-3 activity, and induced partial recovery from imatinib-resistance. Expression of Bcl-2, previously reported to be associated with Lyn-mediated resistance, was not elevated in MYL-R. Expression of Bim, which plays an important role in imatinib-induced cell-killing, was not suppressed in MYL-R. These results imply that diverse mechanisms of resistance exist among cell types. Treatment of MYL-R cells with various reagents known to have anti-leukemic activity revealed that zoledronic acid and the farnesyl transferase inhibitor (SCH 66336) showed strong synergism with imatinib; interferon alpha, PP2, CGP76030, and FK228 (depsipeptide) showed synergism; whereas soluble TRAIL and As2O3 showed additivity or antagonism, and 17-AAG and radicicol showed antagonism. Treatment with either PP2 or zoledronic acid induced greater growth-reduction in MYL-R than MYL. Taken together, Lyn may play an important role in imatinib-resistance in MYL-R. Some novel reagents, including siRNA targeting Lyn, may have good potential to overcome this resistance.
 ...
PMID:Establishment and characterization of a novel imatinib-sensitive chronic myeloid leukemia cell line MYL, and an imatinib-resistant subline MYL-R showing overexpression of Lyn. 1743 77

Protein kinase C delta (PKCdelta plays a major role in the regulation of cell apoptosis and survival. PKCdelta is cleaved by caspase 3 to generate a constitutively active catalytic domain that mediates both its apoptotic and anti-apoptotic effects. The caspase cleavage site of PKCdelta in the hinge region is flanked by the two tyrosine residues, Y311 and Y332. Here, we examined the role of the phosphorylation of tyrosines 311 and 332 in the cleavage and apoptotic function of PKCdelta using the apoptotic stimuli, TRAIL and cisplatin. Tyrosine 332 was constitutively phosphorylated in the A172 and HeLa cells and was further phosphorylated by TRAIL and cisplatin. This phosphorylation was inhibited by the Src inhibitors, PP2 and SU6656, and by silencing of Src. Treatment of the A172 and HeLa cells with TRAIL induced cleavage of the WT PKCdelta and of the PKCdeltaY311F mutant, whereas a lower level of cleavage was observed in the PKCdeltaY332F mutant. Similarly, a smaller degree of cleavage of the PKCdeltaY332 mutant was observed in LNZ308 cells treated with cisplatin. Mutation of Y332F affected the apoptotic function of PKCdelta; overexpression of the PKCdeltaY332 mutant increased the apoptotic effect of TRAIL, whereas it decreased the apoptotic effect of cisplatin. Inhibition of Src decreased the cleavage of PKCdelta and modified the apoptotic responses of the cells to TRAIL and cisplatin, similar to effect of the PKCdeltaY332F mutant. These results demonstrate that the phosphorylation of tyrosine 332 by Src modulates the cleavage of PKCdelta and the sensitivity of glioma cells to TRAIL and cisplatin.
 ...
PMID:The phosphorylation of tyrosine 332 is necessary for the caspase 3-dependent cleavage of PKCdelta and the regulation of cell apoptosis. 1765 31

Reactive oxygen species (ROS) have been implicated in vascular smooth muscle cell (VSMC) apoptosis, a hallmark of advanced atherosclerotic lesions. Transient oxidation and inactivation of protein-tyrosine phosphatases play a critical role in cellular response to ROS production. However, the function of leukocyte antigen-related (LAR) protein-tyrosine phosphatase in ROS signaling is not known. To determine the expression of LAR in ROS-induced apoptosis, we investigated hydrogen peroxide-induced cell death and signaling in aortic VSMCs from wild-type and LAR(-/-) mice. Histone-associated DNA fragmentation and caspase-3/7 activity were significantly enhanced, mitochondrial membrane integrity was compromised, and cell viability was significantly decreased following H(2)O(2) treatment in LAR(-/-) VSMCs compared with wild-type cells. Stronger and sustained increase in autophosphorylation and activity of Fyn, an Src family tyrosine kinase, was observed in LAR(-/-) cells compared with wild-type cells following H(2)O(2) treatment. LAR binds to activated Fyn in H(2)O(2)-treated VSMCs, and recombinant LAR dephosphorylates phosphorylated-Fyn in vitro. In addition, LAR deficiency enhanced H(2)O(2)-induced phosphorylation of Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), and p38 mitogen-activated protein kinase (MAPK). PP2, a Fyn-specific inhibitor, blocked JAK2, STAT3, and p38 MAPK activation and significantly attenuated apoptosis induced by H(2)O(2). AG490, a JAK2-specific inhibitor, significantly attenuated H(2)O(2)-induced apoptosis, and blocked H(2)O(2)-induced activation of STAT3, but not p38 MAPK in both wild-type and LAR(-/-) VSMCs. Attenuation of Fyn expression by short hairpin RNA significantly decreased H(2)O(2)-induced downstream signaling and apoptosis in VSMCs. Together, these data indicate that LAR regulates Fyn/JAK2/STAT3 and Fyn/p38 MAPK pathways involved in ROS-induced apoptosis.
 ...
PMID:Leukocyte antigen-related protein tyrosine phosphatase negatively regulates hydrogen peroxide-induced vascular smooth muscle cell apoptosis. 1885 10

Recent advances in identifying the salivary constituents capable of influencing the oral mucosal inflammatory responses have brought to focus the importance of a peptide hormone, ghrelin. Here, we report on the involvement of ghrelin in controlling the apoptotic processes induced in sublingual salivary gland acinar cells by the lipopolysaccharide (LPS) of a periodontopathic bacterium, Porphyromonas gingivalis. We show that the countering effect of ghrelin on the LPS-induced acinar cell apoptosis was associated with the increase in constitutive nitric oxide synthase (cNOS) activity, and the reduction in caspase-3 and inducible nitric oxide synthase (iNOS). The loss in countering effect of ghrelin on the LPS-induced changes in apoptosis and caspase-3 activity was attained with Src kinase inhibitor, PP2, as well as Akt inhibitor, SH-5, and cNOS inhibitor, L-NAME, but not the iNOS inhibitor, 1400W. The effect of ghrelin on the LPS-induced changes in cNOS activity, moreover, was reflected in the increased cNOS phosphorylation that was sensitive to PP2 as well as SH-5. Furthermore, the ghrelin-induced up-regulation in cNOS activity was associated with the increase in caspase-3 S-nitrosylation that was susceptible to the blockage by SH-5 and L-NAME. The findings point to the involvement of ghrelin in Src/Akt kinase-mediated cNOS activation and the apoptogenic signal inhibition through the NO-induced caspase-3 S-nitrosylation.
 ...
PMID:Constitutive nitric oxide synthase-mediated caspase-3 S-nitrosylation in ghrelin protection against Porphyromonas gingivalis-induced salivary gland acinar cell apoptosis. 2015 28

Naphtho[1,2-b]furan-4,5-dione (NFD), prepared from 2-hydroxy-1,4-naphthoquinone and chloroacetaldehyde in an efficient one-pot reaction, exhibits an anti-carcinogenic effect. NFD-induced apoptosis in MDA-MB-231 cells, as indicated by the accumulation of sub-G1 population, externalization of phosphatidylserine, loss of mitochondrial membrane potential (DeltaPsim) with subsequent release of cytochrome c, and activation of both capase-9 and caspase-3. This correlated with up-regulation in Bax and Bad, and down-regulation of various anti-apoptotic proteins, including Bcl-2, Bcl-X(L), Mcl-1, and survivin in NFD-treated cells. In the analysis of signal transduction pathway, NFD suppressed the phosphorylation of JAK2 in MDA-MB-231 cells without altering the expression of JAK2 protein. Activation of STAT3, Src, and PI3K/Akt were also inhibited by NFD. Moreover, the JAK2 inhibitor AG490 blocked JAK2, STAT3, Src, PI3K, and Akt activation, whereas both Src inhibitor PP2 and PI3K inhibitor wortmannin did not affect JAK2 activation. This suggests that STAT3, Src, and PI3K/Akt are downstream molecules of the JAK2 signaling pathway. AG490 treatment also mimics the cytotoxic effects of NFD. Taken together, these results indicate that NFD disrupts JAK2 pathway and induces apoptosis in MDA-MB-231 cells.
 ...
PMID:Naphtho[1,2-b]furan-4,5-dione disrupts Janus kinase-2 and induces apoptosis in breast cancer MDA-MB-231 cells. 2019 88

Ghrelin, a peptide hormone produced mainly in the stomach, has emerged as an important modulator of the inflammatory responses that are of significance to the maintenance of gastric mucosal integrity. Here, we report on the role of ghrelin in controlling the apoptotic processes induced in gastric mucosal cells by H. pylori lipopolysaccharide (LPS). The countering effect of ghrelin on the LPS-induced mucosal cell apoptosis was associated with the increase in constitutive nitric oxide synthase (cNOS) activity, and the reduction in caspase-3 and inducible nitric oxide synthase (NOS-2). The loss in countering effect of ghrelin on the LPS-induced changes in apoptosis and caspase-3 activity was attained with Src kinase inhibitor, PP2, as well as Akt inhibitor, SH-5, and cNOS inhibitor, L-NAME. Moreover, the effect of ghrelin on the LPS-induced changes in cNOS activity was reflected in the increased cNOS phosphorylation that was sensitive to SH-5. Furthermore, the ghrelin-induced up-regulation in cNOS activity was associated with the increase in caspase-3 S-nitrosylation that was susceptible to the blockage by L-NAME. Therefore, ghrelin protection of gastric mucosal cells against H. pylori LPS-induced apoptosis involves Src/Akt-mediated up-regulation in cNOS activation that leads to the apoptotic signal inhibition through the NO-induced caspase-3 S-nitrosylation.
 ...
PMID:Ghrelin protection against lipopolysaccharide-induced gastric mucosal cell apoptosis involves constitutive nitric oxide synthase-mediated caspase-3 S-nitrosylation. 2036

Urocortin is a 40 amino acid peptide of the corticotrophin-releasing factor (CRF) family that is synthesized and released by cardiac myocytes. Endogenous urocortin expression is increased during ischemia/reperfusion (I/R) and addition of exogenous urocortin reduces cell death caused by I/R injury. Studies have also showed that the protective action of urocortin is mediated by the activation of ERK1/2. We discovered that a non-receptor tyrosine kinase, Src, is involved in the urocortin-induced activation of ERK1/2 in mouse atrial HL-1 myocytes. The selective Src family kinase inhibitor, PP2, reduced the urocortin-induced phosphorylation of ERK1/2, and so did the expression of a dominant-negative mutant of Src in transfected HL-1 cells. Inhibition of Src by PP2 also reduced urocortin's protective effects in HL-1 cells after hypoxia/reoxygenation (H/R), as assessed by flow cytometry and caspase-3 activation assay. Titration studies indicated that as little as 10(-8)M urocortin was sufficient to induce Src activation. Maximal phosphorylation/activation of Src and ERK1/2 were both detected after 5 min incubation with urocortin. These effects of urocortin were largely mediated by CRF receptor-1, although a minor contribution of CRF receptor-2 cannot be excluded. Here we report for the first time that short-term treatment with urocortin causes rapid phosphorylation of Src, and that the urocortin-activated Src kinase serves as an upstream modulator of ERK1/2 activation, playing an essential role in urocortin-mediated cardioprotection.
 ...
PMID:Activation of Src protein tyrosine kinase plays an essential role in urocortin-mediated cardioprotection. 2041 57

Cardiotoxin III (CTX III), a basic polypeptide with 60-amino acid residues isolated from Naja naja atra venom, has been reported to have cytotoxic activity. CTX III exerted cytotoxicity with the S-phase cell cycle arrest, correlated with a marked decrease in the expression levels of cyclin A, cyclin B, and cyclin-dependent kinase 1 (CDK1), and apoptosis, accompanied with Bax and Bad up-regulation, and the down-regulation of Bcl-2, p-Bad, and X-linked inhibitor of apoptosis (XIAP) with cytochrome c release and sequential activation of caspase-9 and caspase-3 in Ca9-22 cells. Mechanistic studies showed that CTX III suppressed the phosphorylation of Src, EGFR, STAT3, STAT5, Akt, and activation of PI3 K (p110). Moreover, Src inactivation was observed earlier than that of the EGFR and the Src inhibitor PP2 suppressed the levels of phospho-EGFR, phospho-STAT3, phospho-STAT5, phospho-Akt, and PI3 K(p110). The PP2 also caused the S-phase arrest and apoptosis, and led to down-regulation of Bcl-2, p-Bad, XIAP, cyclin A, cyclin B, and CDK1, and up-regulation of Bax and Bad, similar to that observed in CTX III treatment. Taken together, these results indicate that CTX III induces apoptosis and S-phase arrest in Ca9-22 cells via concomitant inactivation of the Src, EGFR, STAT3, STAT5, PI3 K(p110), and Akt signaling pathways.
 ...
PMID:Taiwan cobra cardiotoxin III inhibits Src kinase leading to apoptosis and cell cycle arrest of oral squamous cell carcinoma Ca9-22 cells. 2049 3

Transferrin receptor 1 (TfR1) is a ubiquitous type II membrane receptor with 61 amino acids in the N-terminal cytoplasmic region. TfR1 is highly expressed in cancer cells, particularly under iron deficient conditions. Overexpression of TfR1 is thought to meet the increased requirement of iron uptake necessary for cell growth. In the present study, we used transferrin (Tf), a known ligand of TfR1, and gambogic acid (GA), an apoptosis-inducing agent and newly identified TfR1 ligand to investigate the signaling role of TfR1 in breast cancer cells. We found that GA but not Tf induced apoptosis in a TfR1-dependent manner in breast cancer MDA-MB-231 cells. Estrogen receptor-positive MCF-7 cells lack caspase-3 and were not responsive to GA treatment. GA activated the three major signaling pathways of the MAPK family, as well as caspase-3, -8, and Poly(ADP-ribose)polymerase apoptotic pathway. Interestingly, only Src inhibitor PP2 greatly sensitized the cells to GA-mediated apoptosis. Further investigations by confocal fluorescence microscopy and immunoprecipitation revealed that Src and TfR1 are constitutively bound. Using TfR1-deficient CHO TRVB cells, point mutation studies showed that Tyr(20) within the (20)YTRF(23) motif of the cytoplasmic region of TfR1 is the phosphorylation site by Src. TfR1 Tyr(20) phosphomutants were more sensitive to GA-mediated apoptosis. Our results indicate that, albeit its iron uptake function, TfR1 is a signaling molecule and tyrosine phosphorylation at position 20 by Src enhances anti-apoptosis and potentiates breast cancer cell survival.
 ...
PMID:Src regulates Tyr(20) phosphorylation of transferrin receptor-1 and potentiates breast cancer cell survival. 2185 9

In the central nervous system, members of the Src family of tyrosine kinases (SFKs) are widely expressed and are abundant in neurons. The purpose of this study is to examine whether glycogen synthase-3 (GSK-3) is involved in SFK inhibitor-induced apoptosis. PP2 and SU6656, SFK inhibitors, increased apoptotic cell death with morphological changes that were characterized by cell shrinkage, chromatin condensation, or nuclear fragmentation. Moreover, both activation of caspase-9 and caspase-3 were accompanied by the cell death. GSK-3 inhibitors, such as alsterpaullone and SB216763, prevented the PP2-induced apoptosis. In addition, insulin-like growth factor-I prevented the PP2-induced cell death and PP2 inhibited phosphorylation of focal adhesion kinase (FAK). Phosphorylation of FAK on Tyr 576 by Src activates FAK. These results suggest that inhibition of SFK induces apoptosis possibly via blocking of FAK/phosphatidylinositol-3 kinase/Akt signaling pathway and activation of GSK-3 is involved in the cell death in rat cortical neurons.
 ...
PMID:Apoptosis induced by SRC-family tyrosine kinase inhibitors in cultured rat cortical cells. 2200 18


<< Previous 1 2 3 4 5 Next >>