Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Melanoma cells are relatively resistant to Apo2L/TRAIL (TNF-related apoptosis-inducing ligand). We postulated that resistance might result from higher expression of inhibitors of apoptosis including Bcl-2, FLIP (FLICE-like inhibitory protein) or IAPs such as XIAP (X-linked inhibitor of apoptosis) or survivin. Compared to scrambled or mismatch controls, targeting individual inhibitors with siRNA (si-Bcl-2, si-XIAP, si-FLIP or si-Surv), followed by Apo2L/TRAIL resulted in marked increase in apoptosis in melanoma cells. Compared to Bcl-2 or FLIP, siRNAs against XIAP and survivin were most potent in sensitizing melanoma cells. A similar substantial increase in apoptosis was seen in renal carcinoma cells (SKRC-45, Caki-2), following the inhibition of either XIAP or survivin by siRNAs. Apo2L/TRAIL treatment in IAP-targeted cells resulted in cleavage of Bid, activation of caspase-9 and cleavage of PARP (poly ADP-ribose polymerase). Thus, Apo2L/TRAIL resistance can be overcome by interfering with expression of inhibitors of apoptosis regulating both extrinsic (death receptor) or intrinsic (mitochondrial) pathways of apoptosis in melanoma cells.
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PMID:Downregulation of Bcl-2, FLIP or IAPs (XIAP and survivin) by siRNAs sensitizes resistant melanoma cells to Apo2L/TRAIL-induced apoptosis. 1511 63

Interferon alpha (IFNalpha) is used to treat patients with advanced renal cell carcinoma (RCC) despite limited clinical benefit. IFNalpha can induce Fas receptor-mediated apoptosis by direct activation of pro-caspase-8 followed by activation of caspase-3. Alternative, indirect activation of caspase-3 via mitochondrial release of cytochrome c can occur and may explain the rescue from Fas-activated cell death by the antiapoptotic members of the Bcl-2 family. In this study, we examined G3139, a novel antisense compound targeting Bcl-2, in combination with IFNalpha. Human RCC lines (SK-RC-44 and SK-RC-07) were treated with IFNalpha, G3139 or a combination of the two. Fas-mediated cytotoxicity was induced by anti-Fas mAb, CH11. An analysis of Bcl-2, Fas and the cleavage of PARP was performed. IFNalpha induced Fas and Bcl-2 in SK-RC-44 and SK-RC-07. IFNalpha sensitised SK-RC-44 to anti-Fas and induced PARP cleavage confirming that IFNalpha has a cytotoxic effect on RCC lines by induction of the Fas antigen. Cytotoxicity was not evident in SK-RC-07 cells treated with IFNalpha. G3139 induced a specific downregulation of Bcl-2 in SK-RC-07 cells, which were then sensitised to anti-Fas after treatment with IFNalpha. Taken together, these results suggest that Fas-dependent pathways as well as alternative pathways, which can be inhibited by Bcl-2, exist in renal cell carcinoma. G3139 in combination with IFNalpha is a potential therapy in patients with metastatic renal cell carcinoma.
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PMID:Downregulation of Bcl-2 sensitises interferon-resistant renal cancer cells to Fas. 1518 8

Ischemic damage plays an important role in post-transplant organ failure. Activation of the apoptotic cascade is crucially involved in post-ischemic inflammation resulting in tissue damage and organ dysfunction. Here we investigate the initiation of the apoptotic cascade during normothermic ischemia in human kidneys using a model for normothermic ischemia with kidneys nephrectomized because of renal cell carcinoma. Ex vivo, kidneys were stored at 37 degrees C, and consecutive biopsies were taken from disease-free tissue. Pro- and anti-apoptotic proteins were assessed by Western blotting and immunofluorescence. During normothermic ischemia the pro-apoptotic proteins Bax and activated caspase-9 increased with ischemia time, whereas caspase-8 was not activated. The anti-apoptotic proteins Bcl-2 and cFLIP decreased in time. Data on Bcl-2 and Bax were supported by immunofluorescence for Bcl-2 and activated Bax. However, activation of the central effector caspase-3, essential for execution of the apoptotic process, was not detected. In conclusion, during normothermic ischemia the apoptotic cascade in the human kidney is initiated, but not fulfilled. Our data show that the duration of ischemia significantly correlates with activation of the apoptotic cascade. These findings provide insight in the initiation of apoptotic cell-death during warm ischemia and may be useful in the assessment of ischemic injury.
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PMID:Apoptotic cell death is initiated during normothermic ischemia in human kidneys. 1563 13

Connexin (Cx) genes exert negative growth effects on tumor cells with certain cell specificity. We have recently reported that Cx32 acts as a tumor suppressor gene in renal cancer cells due to the inhibition of Src-dependent signaling. In line with the previous study, here we examined if a Src family inhibitor (PP1) could potentiate tumor-suppressive effect of Cx32 in Caki-2 cell from human renal cell carcinoma. In order to clarify the potentialization of PP1, using Cx32-transfected Caki-2 cells and mock-transfected Caki-2 cells, we estimated difference in cytotoxic effect of PP1 on the two cell clones in vitro as well as in vivo. PP1 showed more cytotoxic effect on Caki-2 cells having Cx32 positive expression than that of Cx32 negative expression at lower doses. This potentialization was also observed in xenograft model of nude mice. The potentialization of the effect mainly depended on the induction of apoptosis but not the control of cell growth. In conjugation with this event, the reduction of anti-apoptotic molecules (Bcl-2 and Bcl-xL) was caused by the combination of Cx32 expression and PP1 treatment in Caki-2 cells. These results suggest that PP1 potentiates tumor-suppressive effect of connexin 32 gene in renal cancer cells through the reduction of anti-apoptotic molecules.
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PMID:A Src family inhibitor (PP1) potentiates tumor-suppressive effect of connexin 32 gene in renal cancer cells. 1579 37

Interferon alpha (IFN-alpha) is an approved treatment in metastatic renal cell carcinoma (RCC). The underlying mechanisms are far from being clear, but are presumed to be a combination of stimulation of cell-mediated cytotoxicity, direct antiproliferative activity and antiangiogenic effects. Recently, the role of p53 in the cellular response to IFN-alpha has been proposed in other tumor models (hepatoblastoma). We therefore studied the expression of p53 during IFN-alpha treatment using two freshly established RCC cell lines RCC5 and RCC7. While IFN-alpha treatment significantly enhanced the expression of p53 in RCC7, no changes were observed in RCC5. Cell viability under IFN-alpha remained unchanged in both cell lines. Following gamma-irradiation, a p53-activating stimulus, an enhanced cell death was observed in IFN-alpha-treated RCC7 but not in RCC5. We further demonstrate that there were no changes in Bcl-2- and Bax-expression, two target genes regulated by p53. However, intracellular staining revealed that cell death induced by IFN-alpha and gamma-irradiation was preceded by a shift of Bax to the mitochondria in RCC7. Our results suggest a role of p53 and its downstream target Bax, in the control of RCC sensitivity to IFN-alpha.
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PMID:The sensitivity of renal cell carcinoma cells to interferon alpha correlates with p53-induction and involves Bax. 1594 83

We report for the first time inactivation of a tissue-specific Bcl-2 homology domain 3 (BH3)-only protein as a common aspect in human cancer. In detail, we show that loss of the BH3-only protein natural born killer (Nbk)/Bcl-2-interacting killer (Bik) is a common feature of clear-cell renal cell carcinoma (RCC). While strong Nbk expression is found in the renal tubuli and the epithelial lining of the glomerula, a consistent loss of Nbk expression was observed in primary RCC tissue and RCC cell lines. Mutation of Nbk is, however, rare, whereas deletion of the Nbk gene at 22q13.2 is frequent. In addition to loss of heterozygosity (LOH), DNA methylation mediates transcriptional silencing of the Nbk gene. The conditional restoration of Nbk/Bik expression led to apoptotic death of RCC but not of nonmalignant renal epithelia. A broader expression analysis of RCC cell lines for BH3-only proteins revealed that loss of Nbk coincides with failure to express Bim, whereas Puma, Bid and BNIP3 are readily detectable and, in case of Puma, inducible by p53. These data delineate a role for defects in BH3-only proteins as tumor suppressors in RCC and may explain at the same time the impressive clinical apoptosis resistance of RCC.
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PMID:Loss of the tissue-specific proapoptotic BH3-only protein Nbk/Bik is a unifying feature of renal cell carcinoma. 1632 56

The objectives of this study were to analyze the association of clinical symptoms with several parameters in patients with organ-confined renal cell carcinoma (RCC), and investigate the difference in biologic characteristics between incidentally detected and symptomatic RCCs. This study included 132 patients who were pathologically diagnosed with organ-confined RCC after radical surgery, and their clinicopathologic features were compared to those in patients with incidentally detected and symptomatic diseases. In this series, 91 patients were incidentally diagnosed with RCC, while the remaining 41 had some clinical symptoms. The cause-specific survival in patients with incidental RCC was significantly higher than that in patients with symptomatic RCC, and the presence of clinical symptoms could be an independent predictor of cause-specific survival in these patients. Immunohistochemical staining of resected specimens from these patients were then performed with Ki-67, Bcl-2, matrix metalloproteinase (MMP)-2, MMP-9, and vascular endothelial growth factor antibodies. Despite the lack of differences in Ki-67, Bcl-2, and vascular endothelial growth factor expression between these 2 groups, significantly increased expressions of MMP-2 and MMP-9 in symptomatic RCCs were observed compared with those in incidental RCCs. Moreover, the presence of clinical symptoms in organ-confined RCC was significantly correlated with immunoreactivities of MMP-2 and MMP-9. These findings suggest that clinical symptoms have a significant impact on the prognosis of patients with organ-confined RCC and that the appearance of clinical symptoms may reflect the increased invasive potentials characterized by overexpression of MMPs.
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PMID:Clinical symptoms in localized renal cell carcinoma reflect its invasive potential: comparative study between incidentally detected and symptomatic diseases. 1667 49

Renal solitary fibrous tumors (SFTs) have been reported infrequently. We report a 76-year-old man with a left renal mass that had previously been shown radiographically to be stable, but was now growing. Grossly, the mass measured 12 cm, was poorly circumscribed, and invaded beyond the renal capsule. Approximately 10% of the neoplasm consisted of haphazardly arranged spindle cells admixed with dense collagenous bands, which is typical of benign SFT. However, the remainder of the mass was composed of pleomorphic, spindled sarcoma cells with frequent mitoses and foci of necrosis. Immunohistochemically, we observed CD34 labeling in the benign SFT component with loss of expression in the sarcomatous component, focal labeling for Bcl-2 protein in both areas, and absence of labeling for cytokeratin, renal cell carcinoma marker, S100 protein, CD117, and muscle markers in both areas. To our knowledge, this is the first reported case of malignant renal SFT, likely representing transformation from a histologically documented benign SFT component.
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PMID:Malignant solitary fibrous tumor of the kidney: report of a case and comprehensive review of the literature. 1674 40

Immunotherapy is the only available treatment for metastatic renal cell cancer (RCC), but the response rate is only about 20% and the treatment is occasionally associated with severe adverse effects. Thus, the selection of patients with a high susceptibility to immunotherapy is needed; however, there is no promising molecular marker that can predict the response to immunotherapy for RCC. This study was carried out to elucidate the potential role of apoptosis-related molecules Bcl-2 and Fas, as well as apoptotic and proliferating indexes (AI, PI) as predictors of the susceptibility of metastatic RCC to immunotherapy. Immunohistochemical examination of tumour tissues from 40 patients with metastatic RCC undergoing postoperative immunotherapy after radical nephrectomy was performed. Patients with progressive disease (PD) after immunotherapy presented with decreased survival (P=0.006). Progressive disease correlated with higher PI in the primary lesion (P=0.0087). All primary tumours of CR or PR patients were negative for Bcl-2, whereas among NC+PD patients, 40.6% were positive for Bcl-2 (P=0.0373). Patients in whom the primary tumours were both Bcl-2- and Fas-negative showed significantly better responses to immunotherapy in comparison with the remaining group (P=0.0022). The Bcl-2 and Fas status of the primary lesion may become useful criteria for the selection of patients with metastatic RCC for immunotherapy.
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PMID:Absence of Bcl-2 and Fas/CD95/APO-1 predicts the response to immunotherapy in metastatic renal cell carcinoma. 1703 6

A solitary fibrous tumor (SFT) is an unusual spindle cell neoplasm that usually occurs in the pleura but has recently been described in diverse extrapleural sites. Urogenital localization is rare, and only 19 cases of SFT of the kidney have been described. We report a case of a large SFT clinically thought to be renal cell carcinoma arising in the kidney of a 70-year-old man. The tumor was well circumscribed and composed of a mixture of spindle cells and dense collagenous bands, with areas of necrosis or cystic changes noted macroscopically and microscopically. Immunohistochemical studies revealed reactivity for CD34, CD99, and Bcl-2 protein, with no staining for keratin, S-100 protein, or muscle markers, confirming the diagnosis of SFT. This tumor is benign in up to 90% of cases. The immunohistochemical study is the key to diagnosis.
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PMID:Solitary fibrous tumor of the kidney: a case report and review of the literature. 1739 71


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