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:P10415 (
Bcl-2
)
33,771
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
NCTD is a demethylated form of cantharidin with antitumor properties, which is now in use as a routine anticancer drug against hepatoma. However, there is limited information on the effect of NCTD on human cancer cells. In the present study, NCTD inhibited proliferation, caused mitotic arrest, then progressed to apoptosis within 96 hr in 3 human hepatoma cell lines: HepG2, Hep3B and Huh-7. NCTD treatment (5 microg/ml) enhanced the expression of Cdc25C and p21(Cip1/Waf1), increasing the phosphorylation of these 2 proteins. In addition, NCTD treatment induced an earlier increase in
cyclin B1
-associated histone H1 kinase activity within 48 hr, but an approximately 70% reduction of both protein level and kinase activity of
cyclin B1
was observed at 72 hr. Treatment with NCTD significantly decreased the expression of p53 protein but did not affect the expression of Cdk1 and p27(Kip1). Moreover, NCTD treatment also increased the phosphorylation of
Bcl-2
and Bcl-X(L) but did not affect the expression of Bax or Bad.
Bcl-2
phosphorylation appears to inhibit its binding to Bax since less Bax was detected in immunocomplex with
Bcl-2
in NCTD-treated HepG2 cells. In addition, NCTD treatment caused activation of caspase-9 and caspase-3, preceding DNA fragmentation and morphologic features of apoptosis. Pretreatment with the broad-spectrum caspase inhibitor z-VAD-fmk markedly inhibited NCTD-induced caspase-3 activity and cell death. These results suggest that phosphorylation of p21(Cip1/Waf1) and Cdc25C and biphasic regulation of
cyclin B1
-associated kinase activity may contribute to NCTD-induced M-phase cell-cycle arrest. Furthermore, the increase of p21(Cip1/Waf1), phosphorylation of
Bcl-2
and Bcl-X(L), activation of caspase-9 and caspase-3 may be the molecular mechanism through which NCTD induces apoptosis.
...
PMID:Effector mechanisms of norcantharidin-induced mitotic arrest and apoptosis in human hepatoma cells. 1211 64
Arsenic trioxide (As(2)O(3)) has been found to induce apoptosis in leukemia cell lines and clinical remissions in patients with acute promyelocytic leukemia. In this study, we investigated the cytotoxic effect and mechanisms of action of As(2)O(3) in human tumor cell lines. As(2)O(3) caused inhibition of cell growth (IC(50) range, 3-14 microM) in a variety of human solid tumor cell lines, including four human non-small-cell lung cancer cell lines (H460, H322, H520, H661), two ovarian cancer cell lines (SK-OV-03, A2780), cervical cancer HeLa, and breast carcinoma MCF-7, as assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry analysis showed that As(2)O(3) treatment resulted in a time-dependent accumulation of cells in the G(2)/M phase. We observed, using Wright-Giemsa and 4',6-diamidine-2-phenylindole-dihydrochloride staining, that As(2)O(3) blocked the cell cycle in mitosis. In vitro examination revealed that As(2)O(3) markedly promoted tubulin polymerization without affecting GTP binding to beta-tubulin. Immunocytochemical and EM studies of treated MCF-7 cells showed that As(2)O(3) treatment caused changes in the cellular microtubule network and formation of polymerized microtubules. Similar to most anti-tubulin agents, As(2)O(3) treatment induced up-regulation of the
cyclin B1
levels and activation of p34(cdc2)/cyclinB1 kinase, as well as
Bcl-2
phosphorylation. Furthermore, activation of caspase-3 and -7 and cleavage of poly(ADP-ribose) polymerase and beta-catenin occurred only in As(2)O(3)-induced mitotic cells, not in interphase cells, suggesting that As(2)O(3)-induced mitotic arrest may be a requirement for the activation of apoptotic pathways. In addition, As(2)O(3) exhibited similar inhibitory effects against parental MCF-7, P-glycoprotein-overexpressing MCF-7/doxorubicin cells, and multidrug resistance protein (MRP)-expressing MCF-7/etoposide cells (resistance indices, 2.3 and 1.9, respectively). Similarly, As(2)O(3) had similar inhibitory effect against parental ovarian carcinoma A2780 cells and tubulin mutation paclitaxel-resistant cell lines PTx10 and PTx22 (resistance indices, 0.86 and 0.93, respectively), suggesting that its effect on tubulin polymerization and G(2)/M phase arrest is distinct from that of paclitaxel. Taken together, our data demonstrate that As(2)O(3) has a paclitaxel-like effect, markedly promotes tubulin polymerization, arrests cell cycle at mitosis, and induces apoptosis. In addition, As(2)O(3) is a poor substrate for transport by P-glycoprotein and MRP, and non-cross-resistant with paclitaxel resistant cell lines due to tubulin mutation, suggesting that As(2)O(3) may be useful for treatment of human solid tumors, particularly in patients with paclitaxel resistance.
...
PMID:Arsenic trioxide produces polymerization of microtubules and mitotic arrest before apoptosis in human tumor cell lines. 1218 29
K-ras codon 12 mutation is more oncogenic in in vitro and in vivo experimental systems than K-ras codon 13 mutation. Moreover, human colorectal tumors bearing a codon 12 mutation are more aggressive, invasive, and metastatic than the same tumor types carrying a codon 13 mutation. However, despite the association between specific sarcoma types and codon 12 or codon 13 mutations, the relationship between the position of the mutated codon at ras genes and tumor aggressiveness has not been studied in this tumor type. Here, we used a nude mice model to evaluate the tumorogenic capacity of stable transfectants of NIH3T3 fibroblasts, expressing K-ras mutated at codon 12 (K12) or 13 (K13), and morphologically, functionally, and molecularly compared these tumors. We found histopathological differences between them, K12-derived tumors showing fibrosarcoma-like features, whereas K13-derived tumors resembled malignant fibrous histiocytomas. Moreover, K12 tumors showed shorter latency of appearance, lower apoptotic and mitotic rates, and higher expression of markers for sarcoma aggressiveness (Ki67, p53 and c-myc) than K13 tumors. They also showed differences in the expression or activation of Ras, Ras downstream pathways [c-Jun N-terminal kinase (JNK), MAPK and AKT], and apoptotic [AKT,
Bcl-2
, Focal adhesion kinase (FAK)] and mitotic (
cyclin B1
) regulators, which could explain their functional differences. Most remarkably, the significantly diminished apoptotic rate observed in K12-derived tumors was associated with enhanced antiapoptotic signaling through the AKT pathway. These morphological, functional, and molecular differences demonstrate that codon 12 and codon 13 mutations in the K-ras oncogene can induce two different soft tissue sarcoma types in our in vivo model.
...
PMID:Codon 12 and codon 13 mutations at the K-ras gene induce different soft tissue sarcoma types in nude mice. 1220 5
Previously we showed that cardiac fibroblasts are cellular targets of estrogen and that there are significant differences in proliferative response of male and female cardiac fibroblasts under hypoxia, a condition of myocardial ischemia. Here, we tested the hypothesis that signaling pathways that control cell cycle progression and apoptosis in cardiac fibroblasts may be activated in a gender-specific manner. Cardiac fibroblasts from adult, age-matched male and female rat heart were exposed to hypoxia (2% O2) and normoxia. Western analysis of cell lysate was used to compare the level of basal and hypoxia-induced expression of signal transduction proteins, known to control cell cycle progression and cell death. Hypoxia led to significant activation of MAP (mitogen-activated protein) kinase and Jun kinase pathways, as shown by phosphorylated extracellular signal-regulated kinase (ERK1/2) and Jun kinase isotypes in male cells but this effect was modest in female cells. Male cells expressed higher levels of basal expression for transcription factors c-jun and NF-kB as well as the inhibitor of NF-kB (lk-B). Although hypoxia did not induce changes in the level of c-Jun in either cell type, it moderately increased the level of NF-kB in male cells but led to its decrease in female cells. Basal and hypoxia-induced expression of cyclin D1, c-fos, and PCNA seemed to be comparable in both male and female cells. However, hypoxia-induced activation of
cyclin B1
, which occurred in both cells, was stronger in female cells. Basal expression of apoptosis-associated transcription factor, p53, was comparable in both cells. However, under hypoxia, there was an increase in the p53 level only in female cells. Although female cells showed higher basal expression for survival-associated protein,
Bcl-2
, the level of this protein remained unchanged under hypoxia in both cells. Together, these data demonstrate differences in basal and hypoxia-induced expression of proteins with an established role in cell cycle progression and apoptosis in male and female cardiac fibroblasts. These differences may further point to gender-related differences in signal transduction pathways that control the proliferative response of those cells under hypoxia.
...
PMID:Gender-related differences in basal and hypoxia-induced activation of signal transduction pathways controlling cell cycle progression and apoptosis, in cardiac fibroblasts. 1237 61
In order to investigate the role and the mechanism of protein tyrosine phosphatase (PTPase) signaling pathway in the regulation of proliferation, cell cycle and apoptosis in lymphoma cells, the effects of sodium orthovanadate, Na(3)VO(4), a specific PTPase inhibitor, were explored on Raji lymphoblast-like cell line by MTT assay and CFU-Raji culture, morphologic observation, DNA gel electrophoresis, FCM and RT-PCR. Results showed that MTT assay and CFU-Raji culture demonstrated that sodium or thovanadate inhibited the growth of Raji cells in a concentration-dependent fashion; morphologic observations showed that Raji cells exhibited cytoplasm shrinkage, cytoplasm membrane blebbing, nuclear fragmentation and chromatin condensation forming crescents along nuclear membrane characteristic of apoptosis in the presence of Na(3)VO(4); DNA gel electrophoresis revealed typical DNA ladder reminiscent of DNA cleavage at internucleosomal sites in Na(3)VO(4) treated cells; FCM and RT-PCR indicated that Na(3)VO(4) intervention increased the fraction of annexin V(+) PI(-) cells, reduced the value of mitochondrial transmembrane potential, induced G(2)/M arrest and down-regulated the expression of
Bcl-2
and
cyclin B1
at both mRNA and protein level in a concentration-dependent manner. It was concluded that PTPase pathway might be implicated in the regulation of cell proliferation, cell cycle and apoptosis, and PTPase specific inhibitor Na(3)VO(4) could induce Raji cell growth inhibition, G(2)/M arrest and apoptosis via down-regulation of
Bcl-2
and
cyclin B1
, and reduction of mitochondrial transmembrane potential.
...
PMID:[Effects of sodium orthovanadate on proliferation and apoptosis in raji cells and its mechanism]. 1251 65
The cytotoxic activity of oxysterols, 7 beta-hydroxycholesterol (7 beta-OHC) and 25-hydroxycholesterol (25-OHC), has been evaluated using various leukemia cell lines. Among the tested cell lines, both oxysterols showed the highest cytotoxicity to THP-1, human monocytic leukemia cell line. These oxysterols induced apoptosis through down-regulation of
Bcl-2
expression and activation of caspases. Also, the oxysterols showed the accumulation at G(2)/M phase of cell cycle through down-regulation of
cyclin B1
expression. Taken together, these results indicated that both 7 beta-OHC and 25-OHC inhibited the proliferation of THP-1 cells through apoptosis and cell cycle accumulation at G(2)/M phase.
...
PMID:Oxysterols induce apoptosis and accumulation of cell cycle at G(2)/M phase in the human monocytic THP-1 cell line. 1252 36
Previously, we showed that monensin, Na+ ionophore, potently inhibited the growth of acute myelogenous leukemia and lymphoma cells. Here, we demonstrate that monensin inhibited the proliferation of renal cell carcinoma cells with IC50 of about 2.5 micro M. Monensin induced a G1 or a G2-M phase arrest in these cells. When we examined the effects of this drug on ACHN cells, monensin decreased the levels of CDK2, CDK6, cdc2, cyclin A and
cyclin B1
proteins. p21 and p27 proteins were increased by monensin. In addition, monensin markedly enhanced the binding of p21 with CDK2 and the binding of p27 with CDK6. Furthermore, the activities of CDK2- and CDK6-associated kinase were reduced in association with hypophosphorylation of Rb protein. Monensin also induced the apoptosis in several renal cell carcinoma cells. Apoptotic process of Caki-2 cells was associated with the changes of
Bcl-2
, Bcl-XL, caspase-9, caspase-3, caspase-7 proteins as well as mitochondria transmembrane potential (DeltaPsim) loss. Taken together, these results demonstrate for the first time that monensin inhibits the growth of renal cell carcinoma cells via cell cycle arrest or apoptosis.
...
PMID:Monensin inhibits the growth of renal cell carcinoma cells via cell cycle arrest or apoptosis. 1263 79
The aim of this study was to investigate whether and how phosphodiesterase (PDE) inhibitors modulate the proliferation, cell cycle and apoptosis in lymphoma cells. The effects of aminophylline (AM), a non-specific PDE inhibitor, on Raji cells were explored in vitro. MTT assay, light and transmission electron microscopy and annexin V staining were used to observe cell proliferation, morphologic changes and apoptosis rate in AM-treated cells, and FCM and RT-PCR techniques were adopted to detect the effect on cell cycle, the expression of
cyclin B1
and
Bcl-2
and mitochondrial transmembrane potential in AM-treated cells. The results showed that AM inhibited the growth of Raji cells in a concentration-dependent manner. Morphologic observations showed apoptosis changes in AM-treated cells, including cytoplamic shrinkage, cytoplasmic bubbling, karyopyknosis and nuclear fragmentation. FCM and RT-PCR detection showed that AM intervention increased the fraction of annexin V(+) cells, reduced the value of mitochondrial transmembrane potential, induced S phase arrest, and down-regulated the expression of
Bcl-2
at both mRNA and protein level and
cyclin B1
protein in a concentration-dependent manner. It is concluded that PDE inhibitor aminophylline may induce Raji cell growth inhibition, S phase arrest, apoptosis via down-regulation of
Bcl-2
and reduction of mitochondrial transmembrane potential.
...
PMID:[Effects of aminophylline on proliferation and apoptosis in Raji lympho-blastoid cell line]. 1266 89
Interleukin-3 (IL-3) and stem cell factor (SCF) are important mast cell growth and differentiation factors. Since both cytokines activate the transcription factor signal transducer and activator of transcription 5 (Stat5), a known regulator of proliferation and survival, we investigated the effects of Stat5 deficiency on mast cell development and survival. Bone marrow-derived mast cell (BMMC) populations cultured from Stat5A/B-deficient mice survived in IL-3 + SCF, but not in either cytokine alone. These cells demonstrated reduced expression of
Bcl-2
, Bcl-x(L), cyclin A2, and
cyclin B1
, with increased apoptosis and delayed cell cycle progression during IL-3 or SCF culture. Finally, the absence of Stat5 resulted in loss of in vivo mast cell development, as judged by assessments of Stat5-deficient mice and transplantation of Stat5-deficient bone marrow cells to mast cell-deficient recipient mice. These results indicate that Stat5A and Stat5B are critical regulators of in vitro and in vivo mast cell development and survival.
...
PMID:Stat5 expression is critical for mast cell development and survival. 1271 18
There is increasing evidence that bcl6 and CD10 expression may be related to apoptosis and cell cycle progression. Therefore, 79 cases of de novo diffuse large B-cell lymphomas were studied for the expression of bcl6 and CD10 proteins in relation to 1) the apoptotic index; 2) the proliferation-associated proteins Ki67, cyclin A, and
cyclin B1
; and 3) the expression of the
bcl2
, p53, Rb, p16, and p27 proteins. Expression of bcl6, CD10, and
bcl2
proteins was found in 54/79 (68%), 28/79 (35%), and 47/74 (63%) cases, respectively. The bcl6/CD10 patterns were as follows: bcl6+/CD10+ (26 cases, 32%), bcl6+/CD10- (28 cases, 33%), bcl6-/CD10- (23 cases, 31%), and bcl6-/CD10+ (2 cases, 4%). Significant positive correlations were found between bcl6/Ki67 (r =.328, P =.003), bcl6/cyclin A (r =.265, P =.018), bcl6/apoptotic index (r =.327, P =.010), CD10/Ki67 (r =.296, P =.008), and CD10/apoptotic index (r =.397, P =.001). In addition, high expression of bcl6 showed significant correlation with negative (null/low)
bcl2
expression (chi(2) test, P =.002). The above findings indicate that increased expression of the bcl6 and CD10 proteins is associated with increased apoptosis and proliferation in diffuse large B-cell lymphomas. The association between increased bcl6 expression and enhanced apoptosis might be due, at least in part, to the null/low
bcl2
expression because previous in vitro data showed that bcl6 overexpression induces apoptosis accompanied by
bcl2
and bcl-xl downregulation. Moreover, significant correlation was found between increased apoptotic index and the bcl6+/CD10+ pattern (t test: P =.014, Mann-Whitney test: P =.046). This finding and the positive correlation of the apoptotic index with bcl6 and CD10 expression may be related to previous results showing that the expression of these proteins has favorable effects on the clinical outcome of diffuse large B-cell lymphomas.
...
PMID:Increased expression of the bcl6 and CD10 proteins is associated with increased apoptosis and proliferation in diffuse large B-cell lymphomas. 1274 54
<< Previous
1
2
3
4
5
6
7
8
9
10
Next >>