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

Tumour recurrence following chemotherapy remains a major obstacle to the cure of many cancers. This is exemplified by small-cell lung cancer (SCLC). Host-tumour interactions are central to tumour survival and proliferation. We hypothesized that a factor(s) within the local environment of SCLC cells could provide a survival signal or block a death signal, thereby accounting for the protection of SCLC cells from chemotherapy-induced apoptosis. Here we review recent work undertaken in our laboratory addressing this issue. We have shown that, in vivo, SCLC cells are surrounded by an extensive stroma of extracellular matrix (ECM) at both primary and metastatic sites which contains, among other proteins, fibronectin, laminin and collagen IV. Furthermore, adhesion of SCLC cells to fibronectin, laminin and collagen IV through beta1 integrins enhances tumorigenicity and confers resistance to apoptosis induced by standard chemotherapeutic agents, including etoposide, cis-platinum and adriamycin. Adhesion to ECM proteins stimulated protein tyrosine kinase (PTK) activity in both untreated and etoposide-treated cells. This effect could be completely blocked by a selective PTK inhibitor or by a function-blocking beta1 integrin antibody. PTK activation was found to block chemotherapy-induced activation of the death protease caspase-3 and, hence, apoptosis. Adhesion to ECM or treatment with a PTK inhibitor did not affect etoposide inhibition of topoisomerase II. Thus adhesion to ECM through beta1 integrins protects SCLC cells from chemotherapy-induced caspase-3 activation and apoptosis by activating PTK signalling downstream of DNA damage. Survival of tumour cells attached to ECM within this microenvironment could explain the local recurrence of SCLC and other tumours that is often seen clinically after chemotherapy.
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PMID:Extracellular matrix regulation of drug resistance in small-cell lung cancer. 1191 4

The physical interactions between B cells and stromal cells from the lymphoid tissue microenvironment are critical to the survival of normal and malignant B cells. They are principally mediated by integrins expressed on B cells and counterreceptors on stromal cells. Specifically, alpha4beta1 integrin engagement rescues B cells from physiological or drug-induced apoptosis. Therefore, in order to understand the mechanisms by which integrins prevent apoptosis in leukemia B cells, we compared the temporal gene expression profiles induced by beta1-integrin ligation with fibronectin (Fn) or adhesion by poly-L-Lysine in serum-starved precursor B leukemia cells. Among the 38 selected differentially expressed genes, 6 genes involved in adhesion (VAV2, EPB41L1, CORO1A), proliferation (FRAP1, CCT4), and intercellular communication (GJB3) were validated by real-time quantitative polymerase chain reaction (RT-Q-PCR). Gene expression modulation could also be validated at the protein level for 5 other genes. We show that integrin stimulation up-regulated FBI-1 expression but inhibited CD79a, Requiem, c-Fos, and caspase 7 induction when the cells underwent apoptosis. We further demonstrate that Fn stimulation also inhibits caspase 3 activation but increases XIAP and survivin expression. Moreover, integrin stimulation also prevents caspase activation induced by doxorubicin. Therefore, we identified genes modulated by adhesion of human precursor B leukemia cells that regulate proliferation and apoptosis, highlighting new pathways that might provide insights into future therapy aiming at targeting apoptosis of leukemia cells.
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PMID:Temporal gene expression profile of human precursor B leukemia cells induced by adhesion receptor: identification of pathways regulating B-cell survival. 1239 20

We previously demonstrated caspase-mediated cleavage of p130cas during apoptosis and identified two caspase-3 cleavage sites [1]. In this study, we investigated the phosphorylation-dependent cleavage of p130cas in apoptotic Rat-1 fibroblast cells. Lysophosphatidic acid and fibronectin induced p130cas phosphorylation, which in turn resulted in resistance to caspase-mediated cleavage. Alternatively, dephosphorylation by calf intestinal alkaline phosphatase, PP1, and LAR stimulated cleavage of p130cas by caspase-3, generating a 31-kDa fragment. During apoptosis, p130cas dephosphorylation seems to precede its cleavage. The phosphorylation of tyrosine and serine residues immediately adjacent to the two cleavage sites (DVPD(416) and DSPD(748)) strongly affected p130cas cleavage by caspase-3, both in vitro and in vivo. Furthermore, the generation of the 31-kDa cleavage fragment was strongly regulated by phosphorylation of a tyrosine residue at position 751 (DSPD(748) and GQY(751)). Our results collectively suggest that degradation of p130cas during apoptosis is modulated in a phosphorylation-dependent manner.
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PMID:Phosphorylation-dependent cleavage of p130cas in apoptotic rat-1 cells. 1248 May 33

Limited proliferative capacity is a characteristic of most normal human cells and results in a growth-arrested state, called replicative senescence. Functional expression of the telomerase catalytic subunit (human telomerase reverse transcriptase; hTERT) in human activated hepatic stellate cells (HSCs) rescues them from death with immortalization and maintains an activated HSC phenotype. The aim of this study was to evaluate alterations in gene and protein expression of in vitro aged human activated HSCs and to define the pathway by which senescent-activated HSCs are eliminated in culture. Altered patterns of gene expression in senescent human HSCs were assessed using DNA microarray analysis and compared with early passage HSCs or hTERT immortalized HSCs. Senescent HSCs showed higher expression of inflammation and stress-associated genes as compared with early passage HSCs. Senescent HSCs expressed reduced levels of extracellular matrix proteins, including collagens, tenascin, and fibronectin. TUNEL staining of senescent HSCs showed approximately 21% positive cells, indicating DNA fragmentation and apoptosis. Apoptosis involved the mitochondrial pathway with decreased levels of Bcl-2 and Bcl-x(L) protein, release of cytochrome c, and increased caspase-3 activity. In contrast, 4% to 5% of early activated HSCs or telomerase positive HSCs were TUNEL positive. In conclusion, cultured human HSCs undergo a switch from a fibrogenic to an inflammatory phenotype, suggesting that senescent human HSCs might modulate chronic wound healing processes. Maintenance of telomere length represents an important survival factor for activated human HSCs.
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PMID:Replicative senescence of activated human hepatic stellate cells is accompanied by a pronounced inflammatory but less fibrogenic phenotype. 1260 63

Plasminogen activator inhibitor-1 (PAI-1) and two-chain high molecular weight kininogen (HKa) exert anti-adhesive properties in vitronectin-dependent cell adhesion. Here, the hypothesis was tested that these anti-adhesive components promote apoptosis in vascular cells. PAI-1 or HKa induced a 2- to 3-fold increase in apoptosis of human umbilical-vein endothelial cells (HUVEC) and vascular smooth muscle cells (VSMC) adherent to vitronectin, as determined by annexin V-FACS assay, similar to alphav-integrin inhibitor cyclo-(Arg-Gly-Asp-D-Phe-Val)-peptide (cRGDfV). Apoptosis occurred after 12 h incubation and was attributable to caspase 3 activation that in turn induced DNA fragmentation. Induction of apoptosis strongly correlated with the anti-adhesive effect of PAI-1 and HKa on these cells. In contrast, PAI-1 and HKa did not affect fibronectin-dependent adhesion or cell survival. uPA did not influence apoptosis in vitronectin- or fibronectin-adherent cells. In atherosclerotic vessel sections, congruent distribution of vitronectin, PAI-1, HK, and of components of the urokinase plasminogen activator/receptor system with apoptotic cells lining foam cell lesions was demonstrated by immunostaining. These results indicate that inhibition of vitronectin-dependent cell adhesion through PAI-1 and HKa correlates with apoptosis induction in vascular cells mediated through the caspase 3 pathway. Co-distribution of apoptosis with plasminogen activation system components in atherosclerosis exemplifies the significance of anti-adhesive mechanisms and apoptosis for tissue remodeling, such as in neointima development.
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PMID:Induction of apoptosis in vascular cells by plasminogen activator inhibitor-1 and high molecular weight kininogen correlates with their anti-adhesive properties. 1271 93

During glomerular inflammation mesangial cells are the major source and target of nitric oxide that pro-foundly influences proliferation, adhesion, and death of mesangial cells. The effect of nitric oxide on the mRNA expression pattern of cultured rat mesangial cells was therefore investigated by RNA-arbitrarily-primed polymerase chain reaction. Employing this approach, biglycan expression turned out to be down-regulated time- and dose-dependently either by interleukin-1beta-stimulated endogenous nitric oxide production or by direct application of the exogenous nitric oxide donor, diethylenetriamine nitric oxide. There was a corresponding decline in the rate of biglycan biosynthesis and in the steady state level of this proteoglycan. In vivo, in a model of mesangioproliferative glomerulonephritis up-regulation of inducible nitric-oxide synthase mRNA was associated with reduced expression of biglycan in isolated glomeruli. Biglycan expression could be normalized, both in vitro and in vivo, by using a specific inhibitor of the inducible nitric-oxide synthase, l-N6-(l-iminoethyl)-l-lysine dihydrochloride. Further studies showed that biglycan inhibited cell adhesion on type I collagen and fibronectin because of its binding to these substrates. More importantly, biglycan protected mesangial cells from apoptosis by decreasing caspase-3 activity, and it counteracted the proliferative effects of platelet-derived growth factor-BB. These findings indicate a signaling role of biglycan and describe a novel pathomechanism by which nitric oxide modulates the course of renal glomerular disease through regulation of biglycan expression.
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PMID:Biglycan, a nitric oxide-regulated gene, affects adhesion, growth, and survival of mesangial cells. 1271 20

Parathyroid hormone-related protein (PTHrP) promotes or suppresses apoptosis in various settings depending on cell type and context. PTHrP 1-34 and PTHrP 67-86 are type II cell growth factors with effects on pneumocyte growth and surfactant secretion. This study investigated the effects of 24 h pretreatment with these two peptides on rat type II cell apoptosis after 0.3 J/cm2 ultraviolet-B irradiation. Adherent cells decreased in number by 15 +/- 5% and nonadherent cells increased > 5-fold 24 h after ultraviolet irradiation. Cell loss was due predominantly to apoptosis, based on ethidium bromide exclusion, nuclear condensation, and caspase 3 activity. Nuclear condensation increased from 15.6 +/- 2.2% of irradiated cells with no treatment to 25.6 +/- 4.9 and 22.9 +/- 1.8% of cells in ultraviolet/PTHrP 1-34 and ultraviolet/PTHrP 67-86 groups, respectively (P < 0.01), along with a 60% increase in caspase 3 activity. Effects on apoptosis were unaffected by the presence or absence of serum, but were ameliorated by growth to confluence or adherence to fibronectin. PTHrP 1-34 and PTHrP 67-86 augmented inositol phosphate levels, but had minimal effects on cAMP. Thus, PTHrP 1-34 and PTHrP 67-86 sensitize type II cells to apoptosis, possibly by a phospholipase C-dependent mechanism. The effects appear to be regulated by cell-matrix and cell-cell interactions.
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PMID:Proapoptotic effects of parathyroid hormone-related protein in type II pneumocytes. 1279 77

This study shows a strong association between cell attachment to substratum and activation of beta 1-integrin-signaling with resistance to the camptothecin derivative topotecan (TPT) in breast cancer cells. We propose a mechanistic-driven approach to sensitize the cells to camptothecins. ZR-75-1 anchorage-dependent breast cancer cell line, its derivative 9D3S suspension cells (9D3S-S), and 9D3S cells attached to fibronectin-coated plates (9D3S-A) were treated with TPT (1 microM) or CPT-11 (40 microM) for 48 h. Programmed cell death (PCD), as shown by poly(ADP-ribose) polymerase (PARP), pro-caspase-3 and pro-caspase-9 cleavage, was observed in 9D3S-S cells but not in ZR-75-1 or 9D3S-A cells. Because p125 focal adhesion kinase (FAK) is a transducer in the beta 1-integrin signaling pathway, it is essential to cell adhesion and it is overexpressed in metastatic breast cancer, we hypothesized that attenuation of FAK might enhance the sensitivity of breast cancer cells to camptothecins. Moreover, inhibition of FAK gene expression by a phosphorothioated antisense oligodeoxynucleotide targeting the portion of the gene encoding amino acids 262-268, increased the sensitivity of ZR-75-1, MDA-MB-231 and MCF7 breast cancer cells to treatment with TPT or CPT-11.
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PMID:Inhibition of focal adhesion kinase by antisense oligonucleotides enhances the sensitivity of breast cancer cells to camptothecins. 1284 14

Integrins are cell surface heterodimeric transmembrane receptors that, in addition to mediating cell adhesion to extracellular matrix proteins modulate cell survival. This mechanism may be exploited in cancer where evasion from apoptosis invariably contributes to cellular transformation. The molecular mechanisms responsible for matrix-induced survival signals begin to be elucidated. Here we report that the inhibitor of apoptosis survivin is expressed in vitro in human prostate cell lines with the highest levels present in aggressive prostate cancer cells such as PC3 and LNCaP-LN3 as well as in vivo in prostatic adenocarcinoma. We also show that interference with survivin in PC3 prostate cancer cells using a Cys84--> Ala dominant negative mutant or survivin antisense cDNA causes nuclear fragmentation, hypodiploidy, cleavage of a 32-kDa proform caspase-3 to active caspase-3, and proteolysis of the caspase substrate poly(ADP-ribose) polymerase. We demonstrate that in the aggressive PC3 cell line, adhesion to fibronectin via beta1 integrins results in up-regulation of survivin and protection from apoptosis induced by tumor necrosis factor-alpha (TNF-alpha). In contrast, survivin is not up-regulated by cell adhesion in the non-tumorigenic LNCaP cell line. Dominant negative survivin counteracts the ability of fibronectin to protect cells from undergoing apoptosis, whereas wild-type survivin protects non-adherent cells from TNF-alpha-induced apoptosis. Evidence is provided that expression of beta1A integrin is necessary to protect non-adherent cells transduced with survivin from TNF-alpha-induced apoptosis. In contrast, the beta1C integrin, which contains a variant cytoplasmic domain, is not able to prevent apoptosis induced by TNF-alpha in non-adherent cells transduced with survivin. Finally, we show that regulation of survivin levels by integrins are mediated by protein kinase B/AKT. These findings indicate that survivin is required to maintain a critical anti-apoptotic threshold in prostate cancer cells and identify integrin signaling as a crucial survival pathway against death receptor-mediated apoptosis.
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PMID:Fibronectin protects prostate cancer cells from tumor necrosis factor-alpha-induced apoptosis via the AKT/survivin pathway. 1452 21

Ochratoxin A (OTA), a metabolite produced by strains of Aspergillus and Penicillium, has nephritogenic, carcinogenic, and teratogenic activity in animals and humans. Nanomolar concentrations of OTA promote apoptosis in a cell-type specific fashion. In this study, we have analyzed the molecular mechanism by which OTA affects COS cell adhesion and signaling resulting in an apoptotic response. OTA, at noncytotoxic doses, was able to detach collagen- and fibronectin-adherent cells from immobilized substratum. However, prior to inducing detachment of adherent cells, OTA caused apoptosis as measured by caspase-3 activation. The treatment of adherent cells by OTA caused a reduction of tyrosine phosphorylation levels of FAK and of the adapter protein paxillin. The down-regulation of FAK preceded apoptosis and cell detachment induced by OTA. The mycotoxin was also able to cause a decrease of the phosphorylation levels of the two Shc isoforms, P66 and P52, in adherent cells. Since these Shc isoforms have been implicated in the activation of protein kinase c-Src, which is required for FAK tyrosine phosphorylation, the observed dephosphorylation of FAK and of the FAK substrate paxillin by OTA could be ascribed to the early down-regulation of Shc isoforms. However, whether FAK and Shc phosphorylation contribute both to the same pathway leading to the induction of apoptosis by OTA or are involved in two parallel signaling pathways remains to be investigated.
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PMID:Ochratoxin A affects COS cell adhesion and signaling. 1457 39


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