Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe a gene encoding p73, a protein that shares considerable homology with the tumor suppressor p53. p73 maps to 1p36, a region frequently deleted in neuroblastoma and other tumors and thought to contain multiple tumor suppressor genes. Our analysis of neuroblastoma cell lines with 1p and p73 loss of heterozygosity failed to detect coding sequence mutations in remaining p73 alleles. However, the demonstration that p73 is monoallelically expressed supports the notion that it is a candidate gene in neuroblastoma. p73 also has the potential to activate p53 target genes and to interact with p53. We propose that the disregulation of p73 contributes to tumorigenesis and that p53-related proteins operate in a network of developmental and cell cycle controls.
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PMID:Monoallelically expressed gene related to p53 at 1p36, a region frequently deleted in neuroblastoma and other human cancers. 928 59

Betulinic acid (BA), a melanoma-specific cytotoxic agent, induced apoptosis in neuroectodermal tumors, such as neuroblastoma, medulloblastoma, and Ewing's sarcoma, representing the most common solid tumors of childhood. BA triggered an apoptosis pathway different from the one previously identified for standard chemotherapeutic drugs. BA-induced apoptosis was independent of CD95-ligand/receptor interaction and accumulation of wild-type p53 protein, but it critically depended on activation of caspases (interleukin 1beta-converting enzyme/Ced-3-like proteases). FLICE/MACH (caspase-8), considered to be an upstream protease in the caspase cascade, and the downstream caspase CPP32/YAMA/Apopain (caspase-3) were activated, resulting in cleavage of the prototype substrate of caspases PARP. The broad-spectrum peptide inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone, which blocked cleavage of FLICE and PARP, also completely abrogated BA-triggered apoptosis. Cleavage of caspases was preceded by disturbance of mitochondrial membrane potential and by generation of reactive oxygen species. Overexpression of Bcl-2 and Bcl-XL conferred resistance to BA at the level of mitochondrial dysfunction, protease activation, and nuclear fragmentation. This suggested that mitochondrial alterations were involved in BA-induced activation of caspases. Furthermore, Bax and Bcl-xs, two death-promoting proteins of the Bcl-2 family, were up-regulated following BA treatment. Most importantly, neuroblastoma cells resistant to CD95- and doxorubicin-mediated apoptosis were sensitive to treatment with BA, suggesting that BA may bypass some forms of drug resistance. Because BA exhibited significant antitumor activity on patients' derived neuroblastoma cells ex vivo, BA may be a promising new agent for the treatment of neuroectodermal tumors in vivo.
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PMID:Betulinic acid triggers CD95 (APO-1/Fas)- and p53-independent apoptosis via activation of caspases in neuroectodermal tumors. 986 49

The p21 protein inhibits the activity of cyclin-Cdk complexes and suppresses cell cycle progression. Wild type p53 can induce p21, but mutated p53 cannot. Previous studies have demonstrated that mutation of p53 is absent in neuroblastoma (NB). These reports prompted us to examine whether p53 induced p21 in NB. We examined the expression of p21 and p53 mRNA in eight NB, two Ewing's sarcoma (ES) and two primitive neuroectodermal tumor (PNET) cell lines by Northern blot analysis, and sequenced p53 cDNA of these cells. Although p53 mRNA was detected in all analyzed cell lines by Northern blot analysis, p21 mRNA was detected in six NB but not in two NB, two ES and two PNET cell lines. We detected the point mutation of p53 at codon 273 (CGT to TGT) in one NB and two ES cell lines. The non-transforming substitution at codon 72 (CCC to CGC) was detected in all analyzed cell lines. One PNET cell line had a large deletion of p53 cDNA. These results showed that p21 mRNA was usually expressed in NB but not in ES and PNET. This may suggest that the down stream of the p53 signal transduction pathway in NB is different from that of the closely related tumors of ES and PNET.
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PMID:p21 (WAF1/Cip1/Sdi1/Pic1) mRNA is expressed in neuroblastoma cell lines but not in Ewing's sarcoma and primitive neuroectodermal tumor cell lines. 936 58

The use of RT in pediatric cancer has been virtually eliminated in certain diseases (NHL); greatly reduced in some (Wilms' tumor, ALL, neuroblastoma); and refined and modified in others (rhabdomyosarcoma, Ewing's sarcoma). At present, however, it seems clear that RT will continue to be an important modality (particularly in brain tumors) and a much greater understanding of its effects has been achieved and utilized. The knowledge of the occurrence of late effects and SMN in a child cured of cancer is continuing to modify initial treatment strategies: A classic example of such an effort is the common use of lower RT doses and nonalkylator-based chemotherapy in Hodgkin's disease. Further, the use of DNA testing in children may be able to identify the presence of germline RB and p53 mutations, which may identify a child at high risk for SMN, so that appropriate therapeutic modifications may be made. In addition, knowledge of these late consequences in children mandates that they be carefully monitored and closely followed, so that prompt and effective treatment can be administered to give them a better chance for a long and healthy life.
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PMID:Pediatric radiotherapy. An overview. 937 90

Process extension was induced in cells of the N18-RE-105 neuroblastoma-retinal hybrid line by toxic agents, including glutamate and the p53-inducing anticancer agents adriamycin and etoposide. Both adriamycin and glutamate activated p53 as measured by a plasmid transfection assay. It was therefore hypothesized that SV40 large T antigen, which binds p53, would interfere with cellular differentiation. To test this hypothesis, the temperature-sensitive form of SV40 large T was transduced into N18-RE-105 cells by retroviral infection. SV40 large T-infected cells became de-differentiated, grew in tightly-packed colonies, lost expression of neurofilament, and lost the ability to differentiate in response to glutamate and adriamycin. The de-differentiating effect of SV40 large T antigen may be due to binding and inactivation of cellular proteins, such as p53, p107, p130, p300, and retinoblastoma protein, which are important in cellular growth and differentiation. It is suggested that p53 may play a role in cellular differentiation, perhaps under unusual circumstances involving stress or cytotoxicity.
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PMID:N18-RE-105 cells: differentiation and activation of p53 in response to glutamate and adriamycin is blocked by SV40 large T antigen tsA58. 942 7

Infection with human cytomegalovirus (HCMV) is a common and generally asymptomatic affection in childhood. Its role in neuroblastoma (NB) patients has not yet been elucidated. As evidence grows that HCMV interacts with apoptotic signaling due to the interaction of HCMV gene products with cellular proteins of apoptotic pathways, we used human NB cell line UKF-NB-2 persistently infected with HCMV strain AD169 to study the effects of long-term HCMV infection on programmed cell death of neuroectodermal tumor cells. The cells designated UKF-NB-2AD169 continued to produce infectious virus in successive subcultures over a period of more than 1 year. Up to 20% of cells expressed viral genes or produced infectious virus after initiation of infection. UKF-NB-2AD169 cells were significantly less sensitive to the cytotoxic agents cisplatinum and etoposide than parental (noninfected) UKF-NB-2 cells. These effects were associated with decreased ability of UKF-NB-2AD169 cells to undergo apoptosis and continuous viral replication. UKF-NB-2AD169 cells showed increased levels of antiapoptosis Bcl-2 protein (up to 12-fold), whereas expression of p53 and c-myc was not changed. Treatment of UKF-NB-2AD169 cells with ganciclovir, abolishing virus production, reestablished sensitivity to chemotherapy, lowered Bcl-2 expression, and facilitated inducibility of apoptosis to the level of the parental cell line. The results demonstrate that persistent HCMV infection confers resistance to cytotoxic agents on neuroectodermal tumor cells and protects from apoptosis, probably due to increased levels of Bcl-2 protein. Hence, it is conceivable that HCMV infection before or during tumorigenesis may contribute in some NB patients to failure of therapy.
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PMID:Persistent human cytomegalovirus infection induces drug resistance and alteration of programmed cell death in human neuroblastoma cells. 944 19

In human neuroblastoma SH-SY5Y cells, S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide (NO)-donor, caused cell death accompanying p53 expression, nucleosomal DNA fragmentation and cell death. In addition, SNAP-induced cell death and DNA fragmentation were enhanced by pretreatment for 4 days with N6,2'-O-dibutyryl cyclic AMP (diBu-cAMP) or staurosporine, while those were not changed by pretreatment with phorbol 12-myristate 13-acetate (PMA). Protein level of Bcl-2 was decreased by pretreatment with diBu-cAMP or staurosporine, and, on the contrary, the level was increased by pretreatment with PMA. However, these pretreatments did not change Bax protein level and SNAP-induced p53 expression. However, SNAP-treatment did not change protein levels of Bcl-2 and Bax. These results suggest that SNAP-induced p53-sensitive apoptosis is enhanced by Bcl-2 reduction, and that Bcl-2 and Bax may act downstream of p53 in SH-SY5Y cells.
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PMID:Nitric oxide donor-induced p53-sensitive cell death is enhanced by Bcl-2 reduction in human neuroblastoma cells. 946 Jul 7

Distinction between benign adrenal cortical proliferative lesions and adrenal cortical carcinoma has been approached by a combination of histological, immunohistochemical, and macroscopical parameters. Modern imaging studies allow detection of small adrenal cortical lesions that may be incorrectly diagnosed. Differentiation between benign and malignant tumors of the adrenal cortex was attempted by microdissection of nine cases of adrenal cortical hyperplasia, 10 cortical adenomas, and 18 adrenal cortical carcinomas with subsequent polymerase chain reaction (PCR) amplification for loss of heterozygosity (LOH) of five microsatellites of putative tumor suppressor gene loci: p53 gene (17p), the neuroblastoma candidate gene (1p), the p16 gene (9p), the von Hippel Lindau gene (3p), and the retinoblastoma gene (13q). None of the hyperplastic lesions or cortical adenomas showed LOH of any of the gene markers used. Conversely, genetic changes were observed in 61% (11 of 18) of the cases of carcinoma. Forty-four percent of the lesions showed LOH for p53 (7 of 16). LOH of 1p, 3p, and 9p were seen in 22%, 22%, and 26%, respectively. LOH of the retinoblastoma gene was seen in 80% or four of five of the informative cases studied. We conclude that LOH studies may be used to distinguish malignant from nonmalignant adrenal cortical proliferations. Relative infrequency of LOH in 3p may furthermore help to differentiate adrenal lesions from clear cell carcinomas of the kidney.
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PMID:Utilization of molecular genetics in the differentiation between adrenal cortical adenomas and carcinomas. 959 77

Genetic alteration of p53, which monitors DNA damage and operates cellular checkpoints, is a major factor in the development of human colorectal carcinoma (CRC). Recently, p73, a novel family member of p53, has been identified and found, like p53, to activate p21Waf1/Cip1 and to induce apoptosis. The p73 gene was mapped at chromosome 1p36.3 which is a region frequently deleted in CRCs and other cancers including neuroblastoma. To assess whether or not p73 is a tumor suppressor gene of CRC, we performed mutational analysis of p73 in 82 colorectal tumor tissues paired with constitutional DNA. Using a microsatellite marker for p73, the loss of heterozygosity (LOH) study was performed and allelic loss of p73 was found in 17% of the CRCs. RT-PCR single strand conformation polymorphism analysis showed no mutation except three polymorphisms in the p73 coding region. In addition, p73 was expressed at higher levels in the CRC tissues than in the normal mucosa or neuroblastoma tissues, though the transcripts were detectable only by the RT-PCR method. Our results suggest that, in CRCs, p73 may not play a role as a tumor suppressor, at least not in a classic Knudson manner.
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PMID:Mutational analysis of the p73 gene localized at chromosome 1p36.3 in colorectal carcinomas. 966 27

Neuroblastoma (NB) cells in vitro are capable of bidirectional transdifferentiation, resulting in two distinct, yet reversible, phenotypes of neuroblastic (N-type) and nonneuronal (S-type) Schwann-like cells. Our previous studies suggested that the wild-type p53 protein is subject to differential regulation in a subset of neuronal cell types. To further test this hypothesis, we compared p53 function in three matched pairs of N- and S-type cell lines, each pair originating from an individual NB tumor. Our data show that although p53 remains cytoplasmically sequestered in a punctate pattern in N-type cells after DNA damage, the protein is diffusely distributed in the S-type cells and is additionally capable of translocating to the nucleus and mediating a biological response to this damage. Our data, therefore, suggest that the p53 protein may be differentially regulated by a neuronal cellular environment and that the sequestration of p53 in NB may be reversible.
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PMID:Differential subcellular p53 localization and function in N- and S-type neuroblastoma cell lines. 969 Jun 22


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