Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Survivin, a novel member of the inhibitor of apoptosis protein (IAP) family, reduces the susceptibility of tumor cells to proapoptotic stimuli, thereby promoting tumor cell survival during tumor progression and treatment with anticancer drugs. Recently, we identified 2 novel alternative splice variants of survivin, survivin-2B and survivin-Delta Ex3, which differ in their antiapoptotic properties. Survivin-2B has lost its antiapoptotic potential and may act as a naturally occurring antagonist of antiapoptotic survivin and survivin-Delta Ex3. Because the in vivo expression of these splice variants in human cancer has not been analyzed so far, 57 renal cell carcinomas (RCCs) were explored using quantitative reverse transcriptase polymerase chain reaction. We found that all RCCs express survivin-Delta Ex3, survivin-2B and survivin, the latter being the dominant transcript. When we compared early and intermediate stages with late stages of clear cell RCCs, no significant changes in the expression levels of survivin and survivin-Delta Ex3 became evident. However, a significant decrease was observed for the mRNA ratio between survivin-2B and survivin in late tumor stages (p = 0.036). Chromophilic/papillary RCCs, which are known to be less aggressive than clear cell RCCs, did not show significantly lower expression levels of antiapoptotic survivin and survivin-Delta Ex3, compared with stage-adjusted clear cell RCCs. Our study demonstrates for the first time in vivo expression of functionally different survivin variants and suggests a role of these survivin splice variants in the progression and clinical behavior of human RCCs.
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PMID:Distinct in vivo expression patterns of survivin splice variants in renal cell carcinomas. 1211 83

Survivin is a new member of the inhibitors of apoptosis proteins (IAP) family, selectively overexpressed in common human cancers but not in normal adult tissues, and associated with aggressiveness of the disease and unfavorable outcomes. Recent study also found that survivin expression is associated with cell proliferation. In order to gain insight into the role of survivin in ovarian tumors, we investigated the expression of survivin in a group of epithelial ovarian tumors, and examined the relationship of its expression with cell proliferation and clinical outcome. Immunohistochemical analysis was performed in 103 cases of epithelial ovarian tumors. Twenty-six of the 103 cases were evaluated by Western blot analysis. The results showed that survivin overexpression was detected in 21.2% (7 of 33) of benign tumors, 47.8% (11 of 23) of borderline tumors, and 51.1% (24 of 47) of ovarian carcinomas. The positive ratio was significantly higher in malignant or borderline tumors than in benign tumors, and the overexpression of survivin was significantly correlated with the size of residual disease. A positive correlation between survivin expression and proliferative activity of tumor cell measured by PCNA index was found. Kaplan-Meier analysis demonstrated that the patients with survivin overexpression have a short overall survival. These findings suggest that survivin overexpression may play a pivotal role in the progression of ovarian tumors and may provide an important prognostic implication for epithelial ovarian carcinomas.
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PMID:Survivin expression and its correlation with cell proliferation and prognosis in epithelial ovarian tumors. 1211 27

Phorbol esters are tumor promoters that bind and activate both conventional and new Protein kinase C (PKC) isoforms. In various circumstances, PKC-dependent signaling pathways can promote cell survival and protect against cell death. This was first analysed in Jurkat T cells where Phorbol Myristate Acetate (PMA) was found to inhibit Fas-mediated apoptosis as judged by DiOC6(3) staining, caspase activation and DNA fragmentation, indicating that PMA exerts its protective effect upstream or at the mitochondrial level in these cells. PMA activated most of the main kinase pathways in T cells such as PKCs, p42/44MAPK, p38MAPK and p90Rsk but not JNK and Akt. A pharmacological approach allowed us to identify that nPKCs are both necessary and likely sufficient to promote T cell survival. Besides this post-transcriptional regulation, nPKCs may also regulate apoptosis at the transcriptional level. cDNA arrays were used to identify a set of genes whose expression was modulated in death versus survival conditions. Following PMA treatment, expression of Mcl-1 and Bcl-x increased while that of c-Myc was significantly reduced. Moreover, survivin expression decreased upon CH11 or PMA treatment. c-Myc, survivin and Bcl-x modulation seems to be regulated at the transcriptional level while decrease in Mcl-1 protein in CH11-treated cells resulted especially from a caspase-dependent proteolysis. Taken together, our data demonstrate that PMA-mediated inhibition of apoptosis is a complex process that is integrated at both the transcriptional and post-transcriptional level and point out to the potential role of Mcl-1, Bcl-x, c-Myc and survivin in this process.
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PMID:The protective effect of phorbol esters on Fas-mediated apoptosis in T cells. Transcriptional and postranscriptional regulation. 1211 74

Interleukin-6 (IL-6) and insulin-like growth factor-1 (IGF-1) promote the proliferation of multiple myeloma (MM) cells and protect them against dexamethasone (Dex)-induced apoptosis. We have previously shown that Apo2 ligand/TNF-Related apoptosis inducing ligand (Apo2L/TRAIL) induces apoptosis of MM cells, including cells either sensitive or resistant to Dex and cytotoxic drugs, and overcomes the growth and survival effect of IL-6; conversely, NF-kappaB transcriptional activity attenuates their Apo2L/TRAIL-sensitivity. In the current study, we demonstrate that IGF-1 stimulates sustained activation of NF-kappaB and Akt; induces phosphorylation of the FKHRL-1 Forkhead transcription factor; upregulates a series of intracellular anti-apoptotic proteins including FLIP, survivin, cIAP-2, A1/Bfl-1, and XIAP; and decreases Apo2L/TRAIL-sensitivity of MM cells. In contrast, IL-6 does not cause sustained NF-kappaB activation, induces less pronounced Akt activation and FKHRL-1 phosphorylation than IGF-1, and increases the expression of only survivin. Forced overexpression of constitutively active Akt in MM-1S cells reduced their sensitivity to Apo2L/TRAIL and to doxorubicin (Doxo). In contrast, the Akt inhibitor IL-6-Hydroxymethyl-chiro-inositol 2-(R)-2-O-methyl-3-O-octadecylcarbonate induced cell death of both Dex- and Doxo-sensitive and -resistant cells; opposed the protective effect of constitutive Akt activity against Apo2L/TRAIL; and abrogated the NF-kappaB activation, increase of anti-apoptotic proteins and protection against Apo2L/TRAIL induced by IGF-1. These findings therefore define an important role of the Akt pathway in modulating tumor cell responsiveness to Apo2L/TRAIL, delineate molecular mechanisms for the survival effects of IGF-1, and characterize differential pathophysiologic sequelae of IGF-1 vs IL-6 on MM cells. Importantly, they provide the basis for future clinical trials in MM combining conventional or novel agents with strategies designed to neutralize IGF-1.
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PMID:Activation of NF-kappaB and upregulation of intracellular anti-apoptotic proteins via the IGF-1/Akt signaling in human multiple myeloma cells: therapeutic implications. 1217 37

We examined the expression of survivin using immunohistochemistry in 102 cases of laryngeal squamous cell carcinoma (LSCC). Overall, 65.7% (67 out of 102) of tumors were positive for survivin expression and significantly associated with tumor site, poor differentiation, tumor size, lymph node metastasis and advanced stage. Kaplan-Meier analysis showed that survivin expression was significantly associated with shorter disease-free and overall survival respectively. When survivin expression and clinical stage were combined, patients with both survivin-positive and advanced stage (III, IV) revealed poorer disease-free and overall survival when compared with the other cases (p = 0.0002 and p = 0.0002, respectively). Additionally, in early stage (I, II) cases, survivin expression also showed a significant prognostic trend for disease-free and overall survival (p = 0.0727 and p = 0.0701, respectively). By the multivariate analysis, tumor size, lymph node metastasis and survivin expression were independent prognostic factors both in disease-free and overall survival. These findings indicate that survivin expression is associated with unfavorable clinicopathological parameters and represents an independent marker for prognosis of LSCC.
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PMID:Survivin expression in laryngeal squamous cell carcinomas and its prognostic implications. 1217 30

Se-methylselenocysteine (Se-MSC) is a potent chemopreventive agent in many test systems and has been shown to inhibit tumor promotion and induce apoptosis, but its mechanism of action is still not well understood. The present study was designed to assess the mechanism of Se-MSC on the induction of apoptosis in SKOV-3 ovarian cancer cells. Se-MSC displayed strong inhibitory effects on cell proliferation and viability of SKOV-3 cells in dose and time dependent manners and induced apoptosis. Investigation of the mechanism of Se-MSC-induced apoptosis revealed that treatment with Se-MSC produced morphological features of apoptosis and DNA fragmentation. This was associated with caspase-3 activation and cleavage of poly(ADP-ribose) polymerase and phospholipase C-gamma1 proteins. However, SKOV-3 cells treated with Se-MSC did not demonstrate cytochrome c accumulation in the cytosol during apoptosis induction. Pretreatment of cells with the caspase inhibitors (z-VAD-fmk and DEVD-CHO) prevented Se-MSC-induced apoptosis. These results suggested that Se-MSC induces apoptosis through cytochrome c-independent caspase-3 activation in SKOV-3 cells. In late stage of apoptosis, p18kDa fragment of Bax was generated with the down-regulation of the expressions of survivin, X-linked inhibitor of apoptosis protein, and human inhibitor of apoptosis protein 1 following Se-MSC treatment, suggesting that the modulation of Bax and IAP (inhibitors of apoptosis) family proteins play some role in Se-MSC-mediated apoptosis. Pre-treatments of z-VAD-fmk and the calpain inhibitor, calpeptin inhibited Bax cleavage. These results suggested that Bax cleavage is mediated by calpain, and calpain activation may be a caspase-dependent one. Taken together, the chemopreventive effects of Se-MSC may be related in part to the caspase-3 activation, the down-regulation of IAP family proteins, and Bax cleavage mediated by caspase-dependent calpain activation.
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PMID:Se-methylselenocysteine induces apoptosis through caspase activation and Bax cleavage mediated by calpain in SKOV-3 ovarian cancer cells. 1217 27

Survivin functions to suppress cell death and regulate cell division, and is observed uniquely in tumor cells and developmental cells. However, the expression and regulation of survivin in non-transformed cells are not well elucidated. Therefore, we investigated the expression of survivin in a murine liver regeneration model after partial hepatectomy and intraperitoneal carbon tetrachloride (CCl(4)) injection. We found that the expression of survivin transcript and protein were markedly elevated with the onset of DNA synthesis and remained elevated during G2 and M phases during liver regeneration. In a normal mouse liver cell line, over-expression of survivin resulted in a decrease in the G0/G1 phase and an increase in the S and G2/M phases, resulting in Rb phosphorylation. These findings suggest that survivin is dramatically expressed in a cell cycle-dependent manner during liver regeneration and provide a new insight into the regulation of cell proliferation and differentiation.
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PMID:Expression of survivin during liver regeneration. 1222 May 8

Survivin is a novel member of the inhibitor of apoptosis protein (IAP) family. Here we report that the chemotherapeutic drug doxorubicin, a DNA-damaging agent, activates a p53-survivin signaling pathway inducing cell cycle arrest and apoptosis in childhood acute lymphoblastic leukemia (ALL). Treatment of wild-type (wt) p53 ALL cells (EU-3 cell line) with doxorubicin caused accumulation of p53, resulting in dramatic down-regulation of survivin, depletion of cells in G(2)/M, and apoptosis (increased sub-G(1) compartment). In contrast, doxorubicin treatment of mutant (mut) p53 cells (EU-6/ALL line) up-regulated survivin and induced G(2)/M arrest without inducing apoptosis. However, treating EU-6 with anti-survivin antisense resensitized these cells to doxorubicin, resulting in apoptosis. With a p53-null cell line (EU-4), although doxorubicin treatment arrested cells in G(2)/M, survivin expression was unchanged, and cells underwent only limited apoptosis. However, re-expression of wt-p53 in EU-4 cells could restore the doxorubicin-p53-survivin pathway, resulting in significantly decreased survivin expression and increased apoptosis in these cells after doxorubicin treatment. Following cotransfection of p53-null EU-4 cells with survivin promoter-luciferase constructs and either wt-p53 or different mut-p53 expression vectors, wt-p53 inhibited survivin promoter activity; p53-mediated inhibition could be abrogated by overexpression of murine double minute2 (MDM2) protein. Together, these studies define a novel p53-survivin signaling pathway activated by DNA damage that results in down-regulation of survivin, cell cycle arrest, and apoptosis. Furthermore, our data indicate that loss of wt-p53 function in tumor cells may contribute to up-regulation of survivin and resistance to DNA-damaging agents.
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PMID:DNA damage induces a novel p53-survivin signaling pathway regulating cell cycle and apoptosis in acute lymphoblastic leukemia cells. 1223 42

Oesophageal squamous cell carcinoma is one of the most malignant tumours. To identify patients with a high risk of recurrence of oesophageal squamous cell carcinoma, we investigated the prognostic significance of survivin mRNA expression in oesophageal squamous cell carcinoma, which has recently been reported to be a good marker for unfavourable prognosis in various tumours. Tumours and non-cancerous epitheliums adjacent to tumours were obtained by surgical resection from 57 patients with oesophageal squamous cell carcinoma. Expression levels of survivin and glyceraldehyde-3-phosphate dehydrogenase mRNA were analysed quantitatively by real-time reverse transcriptase polymerase chain reaction (RT-PCR). The survivin/glyceraldehyde-3-phosphate dehydrogenase ratios of tumours were higher than those of non-cancerous tissues (P=0.0003). Tumour-survivin/glyceraldehyde-3-phosphate dehydrogenase ratio did not correlate with histologic type, lymph node metastasis, and stage of tumours. In 53 surviving patients, the 5-year survival rate of 17 patients with high survivin mRNA expressed oesophageal squamous cell carcinoma (14.1%) was significantly poorer than that of 36 with low survivin mRNA expressed oesophageal squamous cell carcinoma (46.8%, P=0.0018). In these patients, tumour-survivin mRNA expression was recognised as a good marker of cancer recurrence independently from tumour stage. These findings indicate that survivin mRNA expression in oesophageal squamous cell carcinoma may be a good biomarker for identifying patients with high risk of cancer recurrence.
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PMID:survivin messenger RNA expression is a good prognostic biomarker for oesophageal carcinoma. 1237 3

In B-cell chronic lymphocytic leukemia (B-CLL), malignant cells seem to be arrested in the G(0)/early G(1) phase of the cell cycle, and defective apoptosis might be involved in disease progression. However, increasing evidence exists that B-CLL is more than a disease consisting of slowly accumulating resting B cells: a proliferating pool of cells has been described in lymph nodes and bone marrow and might feed the accumulating pool in the blood. Rapamycin has been reported to inhibit cell cycle progression in a variety of cell types, including human B cells, and has shown activity against a broad range of human tumor cell lines. Therefore, we investigated the ability of rapamycin to block cell cycle progression in proliferating B-CLL cells. We have recently demonstrated that stimulation with CpG-oligonucleotides and interleukin-2 provides a valuable model for studying cell cycle regulation in malignant B cells. In our present study, we demonstrated that rapamycin induced cell cycle arrest in proliferating B-CLL cells and inhibited phosphorylation of p70s6 kinase (p70(s6k)). In contrast to previous reports on nonmalignant B cells, the expression of the cell cycle inhibitor p27 was not changed in rapamycin-treated leukemic cells. Treatment with rapamycin prevented retinoblastoma protein (RB) phosphorylation in B-CLL cells without affecting the expression of cyclin D2, but cyclin D3 was no longer detectable in rapamycin-treated B-CLL cells. In addition, rapamycin treatment inhibited cyclin-dependent kinase 2 activity by preventing up-regulation of cyclin E and cyclin A. Interestingly, survivin, which is expressed in the proliferation centers of B-CLL patients in vivo, is not up-regulated in rapamycin-treated cells. Therefore, rapamycin interferes with the expression of many critical molecules for cell cycle regulation in cycling B-CLL cells. We conclude from our study that rapamycin might be an attractive substance for therapy for B-CLL patients by inducing a G(1) arrest in proliferating tumor cells.
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PMID:Rapamycin-induced G1 arrest in cycling B-CLL cells is associated with reduced expression of cyclin D3, cyclin E, cyclin A, and survivin. 1239 42


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