Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Survivin has recently been identified as a novel inhibitor of apoptosis (IAP). Unlike other members of the IAP family, survivin is characterized by a unique structure that contains a single baculovirus IAP repeat and no really interesting new gene (RING) finger motifs, and it is expressed in many common human cancers, but not in normal tissues. Survivin regulates the G(2)/M phase of the cell cycle by associating with mitotic spindle microtubules, and it directly inhibits caspase-3 and caspase-7 activity. During tumorigenesis, survivin expression is inversely correlated with apoptosis inhibition and positively correlated with proliferation and angiogenesis. Inhibition of apoptosis by survivin predicts poor prognosis and shorter survival in human cancers. The molecular detection of occult cancer by the targeting of survivin as a novel molecular marker is useful, and micrometastasis detected by immunohistochemical staining for survivin reveals inhibition of apoptosis and the acceleration of cell proliferation. In in-vitro and in-vivo studies, survivin targeting with antisense and survivin mutants induces apoptosis, reduces tumor growth potential, and sensitizes cells to chemotherapeutic drugs and X-irradiation. These results suggest that survivin may have the potential to function as a new target for the diagnosis and treatment of cancer.
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PMID:The role of survivin as a new target of diagnosis and treatment in human cancer. 1195 93

The effect of N-1-(3,5-dimethyladamantyl)maleimide (DMAMI) on the growth of Colo205 human colon cancer cells was examined both in vitro and in vivo. Flow cytometry analysis showed a decrease of G2/M Colo205 cells at 4-6 h after treatment with DMAMI prior to accumulation of apoptotic cells at 24 h. Significant changes in cell morphology, i.e. shrinkage and chromatin condensation of cells, were observed after treatment with DMAMI. In the analysis of the apoptosis markers, it was found that the increase of Annexin V binding to membrane, peroxide radicals, dissipation of the mitochondrial membrane potential, and the activation of caspase-3, -8 and -9 were all evident at 4-6 h after treatment with DMAMI. In vivo analysis showed that treatment of Colo205 tumor-bearing SCID mice with DMAMI (230 mg/kg, intratumoral, once) resulted in rapid tumor damage that leads to significant tumor growth inhibition and no obvious acute toxicity. These results suggest that DMAMI has potential for local treatment of cancer.
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PMID:Dimethyladamantylmaleimide-induced in vitro and in vivo growth inhibition of human colon cancer Colo205 cells. 1204 65

Differences in growth and in response to antineoplastic drugs between s.c. and orthotopically implanted tumors in nude mice and between the primary tumor and the metastases in human tumors suggest that implantation site may alter the molecular regulation of tumor cells. We assessed the influence of implantation site on cell cycle and apoptotic regulation and the possible contribution of the implantation site in directing the choice of metastatic site by comparing the behavior of tumor aliquots of two human pancreatic xenografts (NP18 and NP9) implanted in the organ where the tumor grows (orthotopically), in heterotopic sites (the site of metastases (liver), and in nonmetastatic sites (subcutis and colon). We observed that implantation site changes tumor growth by altering apoptotic or cell cycle regulation in a tumor-specific manner. In the NP18 tumor it occurs by altering apoptotic induction and activation of the Bad/Bcl-XL/caspase-3 pathway through AKT and Erk regulation, but in the NP9 tumor by changing the activation and/or expression of the proteins that regulate the cell cycle (Erk, PCNA, and cyclin B1). We also observed that implantation site alters the metastatic pattern of the NP9 tumor, originating a new metastatic site.
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PMID:Heterotopic implantation alters the regulation of apoptosis and the cell cycle and generates a new metastatic site in a human pancreatic tumor xenograft model. 1208 58

Cell death in the core of human brain tumors is triggered by hypoxia and lack of nutrients, but the mode of cell death whether necrosis or apoptosis is not clearly defined. To identify the role of apoptosis in brain tumor cell death, we investigated macromolecular (RNA and protein) synthesis and activity in the central to peripheral region of benign [desmoplastic infantile ganglioglioma (DIG) and transitional meningioma (TMG)] and malignant [ependymoma (END), anaplastic astrocytoma (APA), and glioblastoma multiforme (GBM)] brain tumors derived from five patients who had not received previously radiotherapy or chemotherapy. Normal brain tissue (NBT) served as control. RT-PCR analysis of tumor tissues covering central to peripheral regions detected mRNA overexpression of pro-apoptotic gene bax in malignant tumors, indicating a commitment to apoptosis. The mRNA expression of calpain (a Ca(2+)-dependent cysteine protease) and calpastatin (endogenous calpain inhibitor) was altered resulting in an elevated calpain/calpastatin ratio. Calpain content and activity were increased, suggesting a role for calpain in cell death. In the mitochondria-dependent death pathway, caspase-9 and caspase-3 were also overexpressed in tumors. The increased caspase-3 activity cleaved poly(ADP-ribose) polymerase (PARP). Agarose gel electrophoresis detected a mixture of random and internucleosomal DNA fragmentation in malignant brain tumors. Overexpression of pro-apoptotic bax, upregulation of calpain and caspase-3, and occurrence of internucleosomal DNA fragmentation are now presented indicating that one mechanism of cell death in malignant brain tumors is apoptosis, and that enhancement of this process therapeutically may promote decreased tumor growth.
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PMID:Molecular evidence of apoptotic death in malignant brain tumors including glioblastoma multiforme: upregulation of calpain and caspase-3. 1211 1

Many types of cancer cells widely express cytokeratin 19 (CK19). Clinical investigations have suggested that serum CYFRA 21-1, a fragment of CK19, is one of the most useful tumor markers. In the present study, we hypothesized that released CYFRA 21-1 is closely associated with cellular apoptosis during tumor growth. Apoptosis was induced by tumor necrosis factor-alpha (TNF-alpha) in the HuH-7 hepatocellular carcinoma cell line. Both TNF-alpha-treated and non-treated cells of HuH-7 were simultaneously examined by immunoradiometric assay, annexin-V apoptosis analysis, immunohistochemical staining and colorimetric protease measurement. Levels of CYFRA 21-1 increased significantly in TNF-alpha-treated cells displaying a high percentage of apoptosis, granular-like aggregation of CK19, and elevated activity of caspase-3 in contrast to non-treated cells. Levels of CYFRA 21-1 decreased significantly after caspase-3 was inhibited in TNF-alpha-treated cells. Thus, the release of CYFRA 21-1 may suggest cellular apoptosis in the process of tumor growth.
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PMID:CYFRA 21-1 is released in TNF-alpha-induced apoptosis in the hepatocellular carcinoma cell line HuH-7. 1211 43

Hyaluronan oligosaccharides (molecular weight: approximately 2.5 x 10(3)) inhibit growth of several types of tumors in vivo. In vitro, the oligomers inhibit anchorage-independent growth of several tumor cell types. In accordance with this finding, the oligomers also induce apoptosis and stimulate caspase-3 activity under anchorage-independent conditions. Since inhibitors of phosphoinositide 3-kinase (PI 3-kinase) mimic the action of hyaluronan oligomers and since the PI 3-kinase/Akt (protein kinase B) cell survival pathway has previously been implicated in anchorage-independent growth of tumor cells, we examined the effect of oligomers on PI 3-kinase and its downstream activities in TA3/St murine mammary carcinoma and HCT 116 human colon carcinoma cells. We observed that 50-150 microg/ml hyaluronan oligomers inhibit PI 3-kinase activity and phosphorylation of Akt to approximately the same extent as optimal doses of wortmannin and LY294002, known inhibitors of PI 3-kinase. Similar inhibition of downstream events, i.e. phosphorylation of BAD and FKHR, was also observed. These effects were not observed on treatment with similar concentrations of chitin oligomers, chondroitin sulfate, or hyaluronan polymer. High molecular weight (approximately 2 x 10(6)) and low molecular weight (approximately 8 x 10(4)) preparations of hyaluronan polymer were equally ineffective. The effects of hyaluronan oligomers on these parameters were similar in magnitude to the effect of treatment with activity-blocking antibody against CD44. We interpret these results to indicate that the oligomers competitively block binding of endogenous hyaluronan polymer to CD44, consequently giving rise to attenuated signaling. Finally, we observed that hyaluronan oligomers, but not chitin oligomers, chondroitin sulfate, or hyaluronan polymer, stimulate expression of PTEN, a phosphatase that degrades the major signaling product of PI 3-kinase action, phosphoinositide 3,4,5-trisphosphate. We conclude that perturbation of hyaluronan-CD44 binding leads to suppression of the PI 3-kinase/Akt cell survival pathway and consequently to inhibition of anchorage-independent growth in culture and tumor growth in vivo.
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PMID:Hyaluronan oligosaccharides inhibit anchorage-independent growth of tumor cells by suppressing the phosphoinositide 3-kinase/Akt cell survival pathway. 1214 77

Thymidine phosphorylase (TP) has chemotactic and angiogenic activities resulting from its enzymatic activity in vitro, and it also promotes tumor growth and inhibits apoptosis in vivo. Recently, we have reported that TP plays an important role in Fas-induced apoptosis. Caspase-8 cleavage, subsequent cytochrome c release, and caspase-3 cleavage were prevented in KB cells transfected with a TP cDNA (KB/TP cells). In this study, treatment with thymidine phosphorylase inhibitor (TPI) or thymidine did not affect cell survival of KB/TP cells during Fas-induced apoptosis. Moreover, treatment with thymine or 2-deoxy-D-ribose (degradation products of thymidine generated by TP) also did not affect cell survival of control transfectant (KB/CV) cells during Fas-induced apoptosis. These findings indicate that TP suppresses Fas-induced apoptotic signal transduction independent of its enzymatic activity.
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PMID:Thymidine phosphorylase suppresses Fas-induced apoptotic signal transduction independent of its enzymatic activity. 1215 Sep 47

Our previous studies conducted in pancreatic cancer models established in nude mice and hamsters revealed that cloned somatostatin receptor subtype 2 (sst2) gene expression induced both antioncogenic and local antitumor bystander effects in vivo. In the present study, in vivo gene transfer of sst2 was investigated in two transplantable models of primary and metastatic pancreatic carcinoma developed in hamsters. LacZ reporter or mouse sst2 genes were expressed by means of two different delivery agents: an adenoviral vector and a synthetic polycationic carrier [linear polyethylenimine (PEI)]. sst2 was injected into either exponentially growing pancreatic primary tumors or hepatic metastases, and then transgene expression and tumor progression were investigated 5-6 days after gene transfer. Molecular mechanisms involved in the inhibition of tumor growth were also analyzed. Both adenovirus- and PEI-mediated in vivo gene transfer in primary pancreatic tumors induced an increase of beta-galactosidase activity and expression of sst2 transgene nRNA (100% and 86% of tumors for adenovirus and PEI vector, respectively). Adenoviral vector-based sst2 gene transfer resulted in significant reduction of pancreatic tumor growth (P < 0.05). Using PEI vector, both pancreatic primary tumor growth and metastatic tumor growth were also significantly slackened as compared with both LacZ-treated and untreated control groups (P < 0.02). Moreover, the proliferative index decreased significantly (P < 0.005), whereas apoptosis increased (P < 0.005) in tumors transferred with sst2 gene. The increase of apoptosis correlated with an activation of the caspase-3 and poly(ADP-ribose) polymerase pathways. We concluded that in both primary and metastatic pancreatic cancer models, the synthetic gene delivery system can achieve in vivo sst2 gene transfer and results in a significant antitumor effect characterized by an increase of apoptosis and an inhibition of cell proliferation. This new strategy of gene therapy allows the restoration of expression of an antioncogenic molecule and could be promising for the treatment of advanced pancreatic cancer.
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PMID:Antitumor effect of in vivo somatostatin receptor subtype 2 gene transfer in primary and metastatic pancreatic cancer models. 1241 37

Previously, we designed a ribozyme that targets the H-ras oncogene at the 12th codon mutation site (Chang et al., 1997). Ribozymes have antisense molecule and site-specific ribonuclease potential. In this study, an adenoviral vector was used to transduce the H-ras ribozyme into laryngeal cancer cells (HEp-2). This served to downregulate the H-ras gene expression in which this ribozyme performed antisense activity due to HEp-2 cells containing wild-type alleles in the 12th H-ras codon. Together, our data demonstrated that the recombinant adenovirus encoding H-ras ribozyme can be broadly regarded as a cytotoxic gene therapy in laryngeal cancer cells regardless of containing wild-type or mutant ras gene. In addition, the mechanism through which the H-ras ribozyme inhibited tumor growth was apoptosis and involved both caspase- and mitochondria-mediated pathways. The activators caspase-8 and -9 as well as the effector caspase-3 in the induction phase of apoptosis and the substrate PARP of caspase-3 in the execution phase were activated 48h following the H-ras ribozyme treatment. Mitochondrial events characterized by the production of superoxide anion and the release of cytochrome c started at 24h. Mitochondrial transmembrane potential loss occurred 48h after the ribozyme treatment. However, Bcl-2 delayed cytochrome c release to the cytosol, but it could not protect the apoptosis effect, suggesting that cytochrome c release from mitochondria may not play a role in H-ras ribozyme-induced apoptosis.
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PMID:Recombinant adenovirus encoding H-ras ribozyme induces apoptosis in laryngeal cancer cells through caspase- and mitochondria-dependent pathways. 1241 27

In an investigation of the antitumor effects of 2-methoxyestradiol (2-ME) in combination with other reactive oxygen generating treatments, 2-ME (0.5 microM) was found to completely inhibit cell proliferation of rat DS-sarcoma cells in vitro, with 71% of cells dying after exposure to 5 microM 2-ME. Concentration-dependent increases in ROS-formation, lipid peroxidation and mitochondrial changes were also observed, and an elevation in caspase-3 activity resulted in DNA fragmentation and apoptosis. Combination of 2-ME with hypoxanthine and xanthine oxidase enhanced in vitro cytotoxicity. In vivo, 2-ME caused a slight inhibition of tumor growth, with no tumors cured. Combination of 2-ME treatment with localized 44 degrees C hyperthermia, respiratory hyperoxia and xanthine oxidase caused a tumor growth delay with 51% of tumors cured. These results suggest that amplifying the levels of reactive oxygen species within tumor tissue with substances such as 2-ME may prove to be a promising strategy for adjuvant treatment of solid tumors.
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PMID:2-Methoxyestradiol enhances reactive oxygen species formation and increases the efficacy of oxygen radical generating tumor treatment. 1243 19


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