Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
CHO cells expressing the human insulin receptors (IR) were used to evaluate the effect of the potent
farnesyltransferase
inhibitor, manumycin, on insulin antiapoptotic function. Cell treatment with manumycin blocked insulin's ability to suppress pro-apoptotic
caspase-3
activity which led to time-dependent proteolytic cleavage of two nuclear target proteins. The Raf-1/MEK/ERK cascade and the serine/threonine protein kinase Akt are two survival pathways that may be activated in response to insulin. We tested the hypothesis that inhibition of farnesylated Ras was causally related to manumycin-induced apoptosis and showed that the response to manumycin was found to be independent of K-Ras function because membrane association and activation of endogenous K-Ras proteins in terms of GTP loading and ERK activation were unabated following treatment with manumycin. Moreover, blocking p21Ras/Raf-1/MEK/ERK cascade by the expression of a transdominant inhibitory mSOS1 mutant in CHO-IR cells kept cells sensitive to the antiapoptotic action of insulin. Insulin-dependent activation of Akt was blocked by 4 h treatment with manumycin (P < 0.01), a kinetic too rapid to be explained by Ras inhibition. This study suggests that the depletion of short-lived farnesylated proteins by manumycin suppresses the antiapoptotic action of insulin at least in part by disrupting Akt activation but not that of the K-Ras/Raf-1/ERK-dependent cascade.
...
PMID:Akt-dependent antiapoptotic action of insulin is sensitive to farnesyltransferase inhibitor. 1102 30
Caspase plays an important role in apoptosis. We report here that
farnesyltransferase
/geranylgeranyltransferase (FTase/GGTase)-alpha, a common subunit of FTase (alpha/beta(FTase)) and GGTase I (alpha/beta(GGTase)), was cleaved by
caspase-3
during apoptosis. FTase/GGTase-alpha (49 kDa) was cleaved to 35 kDa (p35) in the Rat-2/H-ras, W4 and Rat-1 cells treated with FTase inhibitor (LB42708), anti-Fas antibody and etoposide, respectively. This cleavage was inhibited by caspase-inhibitors (YVAD-cmk, DEVD-cho). Serial N-terminal deletions and site-directed mutagenesis showed that Asp59 of FTase/GGTase-alpha was cleaved by
caspase-3
. The common FTase/GGTase-alpha subunit, but not the beta subunits, of the FTase or GGTase I protein complexes purified from baculovirus-infected SF-9 cells was cleaved to be inactivated by purified
caspase-3
. In contrast, FTase mutant protein complex [(D(59)A)alpha/beta(FTase)] was resistant to
caspase-3
. Expression of either the cleavage product (60-379) or anti-sense of FTase/GGTase-alpha induced cell death in Rat-2/H-ras cells. Furthermore, expression of (D(59)A)FTase/GGTase-alpha mutant significantly desensitized cells to etoposide-induced death. Taken together, we suggest that cleavage of prenyltransferase by caspase contributes to the progression of apoptosis.
...
PMID:Inactivation of farnesyltransferase and geranylgeranyltransferase I by caspase-3: cleavage of the common alpha subunit during apoptosis. 1131 65
We previously demonstrated that the combination of a
farnesyltransferase
inhibitor, manumycin A, and paclitaxel had a synergistic antineoplastic effect on anaplastic thyroid cancer. In this study we investigated the apoptosis pathway involved. In ARO and KAT-4 cells, manumycin- plus paclitaxel-induced DNA fragmentation was blocked by the inhibitors of caspase-9, caspase-8, and
caspase-3
. The drug combination enhanced the activation of caspase-9, caspase-8, and
caspase-3
and cytochrome c release into the cytosol. Cytochrome c release was not affected by the inhibitors of caspase-9, caspase-8 and
caspase-3
. In a cell-free reconstitution assay, DNA fragmentation occurred after incubating nuclei purified from untreated KAT-4 cells with deoxy-ATP, exogenous cytochrome c and S-100 extracts from control KAT-4 cells, and also after incubation of purified KAT-4 nuclei with S-100 extracts from KAT-4 cells treated with manumycin-plus-paclitaxel. In both cases, the DNA fragmentation was blocked by the inhibitors of caspase-9, caspase-8 and
caspase-3
. We concluded that the cytochrome c release was upstream of the activation of caspase-9, caspase-8, and
caspase-3
in the enhanced apoptosis of anaplastic thyroid cancer cells treated with manumycin plus paclitaxel, and that the interaction between manumycin and paclitaxel occurred at or upstream of cytochrome c in the apoptosis regulatory pathway in anaplastic thyroid cancer cells.
...
PMID:Cytochrome c release is upstream to activation of caspase-9, caspase-8, and caspase-3 in the enhanced apoptosis of anaplastic thyroid cancer cells induced by manumycin and paclitaxel. 1160 May 33
Geranylgeranylation of RhoA small G-protein is essential for its localization to cell membranes and for its biological functions. Many RhoA effects are mediated by its downstream effector RhoA kinase. The role of protein geranylgeranylation and the RhoA pathway in the regulation of endothelial cell survival has not been elucidated. The hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitor lovastatin depletes cellular pools of geranylgeranyl pyrophosphate and farnesol pyrophosphate and thereby inhibits both geranylgeranylation and farnesylation. Human umbilical vein endothelial cells (HUVECs) were exposed to lovastatin (3 microm-30 microm) for 48 h, and cell death was quantitatively determined by cytoplasmic histone-associated DNA fragments as well as
caspase-3
activity. The assays showed that lovastatin caused a dose-dependent endothelial cell death. The addition of geranylgeraniol, which restores geranylgeranylation, rescued HUVEC from apoptosis. The geranylgeranyltransferase inhibitor GGTI-298, but not the
farnesyltransferase
inhibitor FTI-277, induced apoptosis in HUVEC. Cell death was also induced by a blockade of RhoA function by exoenzyme C3. In addition, treatment of HUVEC with the RhoA kinase inhibitors Y-27632 and HA-1077 caused dose-dependent cell death. Y-27632 did not inhibit other well known survival pathways, such as NF-kappa B, ERK, and phosphatidylinositol 3-kinase/Akt. However, there was an increase in p53 protein level concomitant with Y-27632-induced cell death. Unlike the apoptosis induced by TNF-alpha, which occurs only with inhibition of new protein synthesis, apoptosis induced by inhibitors of HMG-CoA reductase, geranylgeranyltransferase, or RhoA kinase was blocked by cycloheximide. Our data indicate that inhibition of protein geranylgeranylation and RhoA pathways induce apoptosis in HUVEC and that induction of p53 or other proapoptotic proteins is required for this process.
...
PMID:Inhibition of protein geranylgeranylation and RhoA/RhoA kinase pathway induces apoptosis in human endothelial cells. 1183 65
Interleukin 6 (IL-6) is an important survival and growth factor for myeloma cells and exerts its effects by activating several transduction pathways, including the Ras cascade. As farnesylation of the activated Ras oncogene product by protein farnesyltransferase (
FTase
) is a critical step for Ras functional activity,
FTase
has emerged as a potential target for the development of new anti-cancer agents. Based on our previous demonstration that IL-6-producing myeloma cells are refractory to drug-induced apoptosis, we have analysed the effect of manumycin, a natural
FTase
inhibitor, on IL-6-producing myeloma cells resistant to Fas-, dexamethasone- and doxorubicin-induced apoptosis. Treatment of myeloma cells with manumycin prevented cell proliferation and induced apoptosis. Western blotting experiments demonstrated that this effect was related to inhibition of the post-translational Ras processing.Further analysis showed that manumycin-induced apoptosis involved
caspase-3
. Activation of
caspase-3
, in fact, was observed in 6 h-treated myeloma cells expressing Apo 2.7 antigen, the marker of early apoptosis, whereas their treatment with cell-permeable DEVD-fmk, that irreversibly inhibits
caspase-3
activity, prevented their apoptosis. Over-expression of
caspase-3
was also demonstrated by reverse transcription-polymerase chain reaction. Finally, over-expression of Bcl-2 and its homologue Bcl-xL was observed in manumycin-treated cells as well as in control myeloma cells, implying that the Bcl-2 family is not involved.
FTase
inhibitors may thus be proposed as a potential pharmacological weapon, as they block the Ras pathway and induce the apoptosis of drug-resistant IL-6-producing myeloma cells.
...
PMID:Manumycin inhibits farnesyltransferase and induces apoptosis of drug-resistant interleukin 6-producing myeloma cells. 1210 Jan 43
Our previous studies demonstrated that manumycin (a
farnesyltransferase
inhibitor) enhanced the antineoplastic activity and induction of apoptosis when combined with paclitaxel against anaplastic thyroid cancer cells. We found that manumycin induces endogenous expression of p21 Waf-1 in anaplastic thyroid cancer cells. Manumycin increased the activity of the p21promoter, the level of p21mRNA, and the amount of p21 protein. We hypothesized that p21 had a proapoptotic effect in cells treated with manumycin, or paclitaxel, or both agents. By measuring viability and
caspase-3
activity, we found that stably transfected KAT-4 cells with p21 cDNA under the control of a metallothionein promoter were more sensitive to manumycin alone, paclitaxel alone, and manumycin plus paclitaxel when p21was induced. The increased sensitivity of the cells with induced p21 was associated with an increase in
caspase-3
activity (i.e. apoptosis). We also found that cells with both p21 alleles deleted were less sensitive to manumycin plus paclitaxel than its wild-type parent cells. Expression of p21 per se did not induce apoptosis but enhanced the cytotoxic effects of manumycin and paclitaxel. These findings suggested that p21 might be required to maintain cell sensitivity to the cytotoxic effects of manumycin and paclitaxel.
...
PMID:p21 Waf-1 (Cip-1) enhances apoptosis induced by manumycin and paclitaxel in anaplastic thyroid cancer cells. 1257 11
The mechanism of action of
farnesyltransferase
inhibitors (FTIs) has not been fully clarified. We investigated the cytotoxic effects of various FTIs in chronic myeloid leukemia (CML), using LAMA cells and marrow cells from 40 CML patients in chronic phase. FTI-mediated cytotoxic effect was observed in LAMA cells and in 65% of primary CML cells, whereas marrow cells from controls were only weakly affected. Cytotoxic effects were partially related to enhanced apoptosis; however, Fas-receptor (FasR) and Fas-ligand (FasL) expression were not modified by FTIs. Susceptibility to FTI-mediated inhibition did not correlate with FasR/FasL expression in CD34+ CML cells. Moreover, intra-cellular activation of caspase-1 and -8 were not altered by FTIs, and their blockade did not reverse FTI toxicity. However, we observed FTI-induced activation of
caspase-3
, and its inhibition partially reverted FTI-induced apoptosis. FTIs did not modulate bcl2, bclxL, and bclxS expression, whereas they increased inducible nitric oxide (iNOS) mRNA and protein levels, resulting in higher NO production. Furthermore, C3 exoenzyme, a Rho inhibitor, significantly increased iNOS expression in CML cells, suggesting that FTIs may up-regulate NO formation at least partially through FTI-mediated inhibition of Rho. We conclude that FTIs induce selective apoptosis in CML cells via activation of iNOS and
caspase-3
.
...
PMID:Involvement of nitric oxide in farnesyltransferase inhibitor-mediated apoptosis in chronic myeloid leukemia cells. 1271 96
Despite major advances, multiple myeloma (MM) remains an incurable malignancy. Recently we have found that disease stabilization was achieved in 64% of patients with advanced MM treated with the
farnesyltransferase
inhibitor R115777 (Zarnestra) in a phase 2 clinical trial. In order to enhance R115777 antitumor activity in MM, we examined the combination of this novel agent with other anticancer drugs in MM cell lines. In this study, R115777 was found to synergize with paclitaxel and docetaxel, but not with other chemotherapy agents, including doxorubicin, 5-fluorouracil, cisplastin, melphalan, mitoxantrone, and dexamethasone. R115777 synergized with paclitaxel to inhibit MM cell proliferation and to induce apoptosis. Synergism in the induction of apoptosis was accompanied by increase in cytochrome c release and
caspase-3
activation. Furthermore, flow cytometry analysis also showed that paclitaxel and R115777 synergized to induce G(2)/M cell-cycle arrest. Importantly, synergism was observed in taxane- and R115777-resistant MM cells. In the human severe combined immunodeficient (SCID-hu) bone model of myeloma growth, the ability of paclitaxel to inhibit tumor growth in vivo was enhanced by R115777. Combination of paclitaxel or docetaxel with R115777 in the treatment of MM cells from patients with multiple myeloma was more beneficial than treatment with single agents. Our results provide the basis for combination therapy clinical trials with paclitaxel or docetaxel with R115777 in MM patients.
...
PMID:Farnesyltransferase inhibitor R115777 (Zarnestra, Tipifarnib) synergizes with paclitaxel to induce apoptosis and mitotic arrest and to inhibit tumor growth of multiple myeloma cells. 1572 26
The combination of imatinib and a
farnesyltransferase
inhibitor might be effective for reducing the number of BCR/ABL-positive leukemia cells. In this study, we examined the differences in the mechanisms of the growth inhibitory effect of the combination of imatinib and R115777 (Zarnestra) among BCR/ABL-positive cell lines. Steel and Peckham isobologram analysis indicated that this combination had a strong synergistic inhibitory effect on growth in all imatinib-resistant cell lines and their parental cell lines. Levels of cleaved
caspase 3
were increased by the combination treatment in all cell lines. However, both the level of cleaved PARP and the number of annexin-V-positive cells were much less increased in KCL22 and KCL22/SR cells than in K562, KU812, K562/SR and KU812/SR cells. The combination treatment promoted p27(KIP1) accumulation and induced a significant increase in the percentage of G0/G1 KCL22 and KCL22/SR cells. In other cell lines, the percentage of G0/G1 cells was not increased but rather decreased. The results indicate that induction of apoptosis and blockage of the cell cycle were major mechanisms of the synergistic inhibitory effect of the combination treatment, but the relative importance of these mechanisms differed among cell types. Additional treatment for overriding the G1 checkpoint may be required to eradicate leukemia cells, in which the combination induces cell cycle arrest.
...
PMID:Relative importance of apoptosis and cell cycle blockage in the synergistic effect of combined R115777 and imatinib treatment in BCR/ABL-positive cell lines. 1589 38
Our previous studies demonstrated that manumycin A, a
farnesyltransferase
inhibitor, induced apoptosis of anaplastic thyroid cancer cells via the intrinsic apoptosis pathway and induced reactive oxygen species (ROS), which mediated DNA damage. In this study, we investigated the hypothesis that the mechanism of apoptosis induced by manumycin in anaplastic thyroid cancer cells fits the general pattern of the "xenobiotic apoptosis pathway," the hallmarks of which are induction of oxidative stress, mitogen-activated protein kinase (MAPK) signaling, and cytochrome c release, which activates the intrinsic apoptosis pathway. We found that manumycin reduced intracellular glutathione and generated ROS: nitric oxide and superoxide anions. Manumycin-induced apoptosis correlated with increase in ROS. Quenching of ROS with N-acetyl-L-cysteine prevented cytochrome c release by manumycin. Manumycin induced phosphorylation of p38 MAPK, which was blocked by N-acetyl-L-cysteine. p38 MAPK may be an important signaling mediator in the activation of the intrinsic apoptotic pathway by manumycin because the p38 MAPK inhibitor SB203580 inhibited cytochrome c release and activation of
caspase-3
by manumycin. In conclusion, manumycin activated the intrinsic apoptosis pathway via activation of p38 MAPK by oxidative stress. The mechanism of apoptosis induced by manumycin fits the emerging general pattern for apoptosis induced by xenobiotics.
...
PMID:Redox control of manumycin A-induced apoptosis in anaplastic thyroid cancer cells: involvement of the xenobiotic apoptotic pathway. 1641 Jul 25
1
2
Next >>