Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The progression of prostatic adenocarcinoma from localized disease to metastatic carcinoma appears to be a multi-step sequence. The expression of common oncogenes/oncosuppressor genes and the mediating effect of neuroendocrine tumor cells may play a role in this progression. The expression of the more frequently investigated oncogenes/oncosuppressor genes (p53, c-myc, c-erbB-2, bcl-2) and the presence of neuroendocrine cells were assessed in prostatic cancer tissue from patients with localized and metastatic cancer. These oncogenes/oncosuppressor genes were evaluated according to tumor stage and grade and their relationship to one another. Grade was not related to any of the oncogene markers or to the presence of neuroendocrine cells. Advancing stage was associated with a significant increase in p53 expression, while other markers remained constant in all stages. Neuroendocrine cells, p53, c-myc, c-erbB-2 and bcl-2 were rarely co-expressed at any stage of prostate cancer.
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PMID:Immunohistochemical detection of oncogene proteins and neuroendocrine differentiation in different stages of prostate cancer. 853 88

Fifty-eight skin biopsies and three primary internal tumors from patients affected by the rare hereditary disease xeroderma pigmentosum (XP) were studied by an improved PCR-single strand conformation polymorphism analysis to detect the mutations of the tumor suppressor gene p53. The results from cutaneous XP tumors, including 27 squamous cell carcinomas and 6 basal cell carcinomas, show a very high level (86%) of p53 mutations. The analysis of mutations found in XP skin cancers according to the complementation group of the patients shows that tandem CC-->TT transitions are a characteristic of XP-C patients with a frequency much higher in their skin tumors (85%) compared with tumors in XP patients who do not belong to group C (33%). In all XP-C biopsies, mutations were due to replication of unrepaired DNA lesions on the nontranscribed strand of the p53 gene, substantiating the preferential repair in vivo of the transcribed strand of this gene in human tissues. For the first time, we were able to analyze three primary internal tumors (a neuroendocrine tumor of the thyroid, a gastric adenocarcinoma, and a glioma of the brain) of young XP children. All of them contained one mutation on the p53 gene, which were different from the ones found in the XP skin tumors and could have resulted from unrepaired lesions caused by oxidative damage.
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PMID:p53 mutations in skin and internal tumors of xeroderma pigmentosum patients belonging to the complementation group C. 976 70

Mice bred to carry germline Rb and p53 null alleles are associated with a tumor spectrum that overlaps with the inherited multiple endocrine neoplasia-1 (MEN1) and MEN2 syndromes in humans, including medullary thyroid cancer (MTC). To study the genetic basis for these tumors, we microdissected MTC specimens or obtained fresh MTC tissue from nine independent Rb(+/-) p53(+/-) mice, amplified the region of the Ret gene known to be mutated in human MTC, and detected acquired missense Ret mutations in four different mice. These mutations were localized to a group of tandem cysteines which are analogous to activating germline mutations observed in human MEN2A and familial MTC (FMTC). To determine whether the remaining wild type Rb allele was inactivated in these murine MTC samples, we subjected tumor tissue to immunohistochemical staining with an Rb antibody, and demonstrated the absence of RB staining in murine MTC, while normal tissue retained RB nuclear staining. These findings demonstrate the ability of the gene knockout model to recapitulate somatic multi-step tumorigenesis and suggest that the development of a murine neuroendocrine tumor requires mutational dysregulation within both receptor tyrosine kinase and nuclear tumor suppressor gene pathways.
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PMID:RET cooperates with RB/p53 inactivation in a somatic multi-step model for murine thyroid cancer. 979 40

Metastasized neuroendocrine tumors of the gastrointestinal tract and of unknown origin show a highly variable clinical course. Within this group, low-grade and high-grade malignant tumors can be recognized based on the revised classification of neuroendocrine tumors of the lung, pancreas, and gut published by Capella et al in 1995. The present study investigated whether fine-tuning the prediction of prognosis was possible by dividing the group of low-grade malignant tumors of the midgut and of unknown origin into typical and atypical carcinoids by grading them according to the World Health Organization (WHO) classification criteria for neuroendocrine tumors of the lung. Moreover, the prognostic value of immunohistochemical stainings and clinical parameters was evaluated. The study group comprised patients diagnosed between 1983 and 1999 with liver metastases of a neuroendocrine tumor of the midgut n = 40) or of unknown origin (n = 16). As a control for the consistency of grading, 10 patients with metastasized neuroendocrine tumors of the lung also were evaluated. Immunohistochemical stainings for chromogranin A, synaptophysin, Leu 7/CD57, neural cell adhesion molecule/CD56, cytokeratin 8, bcl-2, p53, ki67, and HER2/neu were performed. The clinical parameters age, gender, urinary 5-HIAA level, and presence or absence of the carcinoid syndrome were evaluated. Tumors of the midgut and of unknown origin were evaluated together, because they were clinically similar. In this group of 56 patients, both the Capella and the WHO classification systems recognized the high-grade malignant tumors with a bad prognosis. When the low-grade malignant tumors (Capella) were divided into typical and atypical carcinoids (WHO), no difference in survival was observed, but when the dichotomy into typical and atypical was based on mitotic count alone, the difference became borderline significant (P =.072). Of the immunohistochemical stainings used, synaptophysin, cytokeratin 8, and ki67 had limited prognostic value. Age above 60 was the only clinical parameter of unfavorable prognostic significance. We conclude that high-grade malignant neuroendocrine tumors of the midgut and of unknown origin are recognized by both the Capella classification and the WHO classification of neuroendocrine tumors of the lung. Further subdividing low-grade malignant tumors at this location appears to be of less value than in the lung, but assessing the mitotic activity of these tumors might be of prognostic value.
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PMID:Classification of low-grade neuroendocrine tumors of midgut and unknown origin. 1245 18

The development of adenocarcinoma or carcinoid tumors in atrophic gastritis is widely documented. We report the simultaneous occurrence of gastric adenocarcinoma and carcinoid (composite tumor) in atrophic gastritis, a finding reported only twice before in the literature. This 52-yr-old man with rectal bleeding, epigastric pain, and iron deficiency anemia was noted to have multiple polypoid masses on upper endoscopy. Biopsy revealed features of both adenocarcinoma and carcinoid tumor in a background of atrophic gastritis, leading to a total gastrectomy, lymph node dissection, and liver biopsy. The gastrectomy specimen was characterized by a 6 cm pedunculated polyp and multiple sessile nodular masses between 0.4 and 2.5 cm in the background of a granular mucosa. On microscopic examination, the large polypoid mass corresponded to a well-differentiated adenocarcinoma, intestinal type, infiltrating the wall. The smaller nodules were composed of carcinoid tumors, restricted to the mucosa, or infiltrating the gastric wall. Carcinoid tumor was also seen in the large polypoid mass closely intermingled with adenocarcinoma. The carcinoid tumor metastasized to the liver. Lymph nodes showed both adenocarcinoma and carcinoid tumor. The gastric mucosa was characterized by atrophic gastritis with intestinal metaplasia, neuroendocrine hyperplasia, and microcarcinoids. The adenocarcinoma stained strongly for CK7, CK 20, MIB-1, and focally for chromogranin and synaptophysin. The carcinoid tumor was negative for CK7, CK 20 and MIB-1, and was positive for chromogranin and synaptophysin. Overexpression of p53 was noted only in the adenocarcinoma. Electron microscopy revealed neurosecretory granules in the carcinoid characteristic of a neuroendocrine tumor. Composite tumor can occur in the setting of atrophic gastritis. The findings in this patient reinforce the concept that the epithelial and neuroendocrine cells of the gastrointestinal tract both result from multidirectional differentiation of a primitive cell.
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PMID:Combined adenocarcinoma and carcinoid tumor in atrophic gastritis. 1245 98

Goblet cell carcinoid is a relatively rare neuroendocrine tumor of the vermiform appendix with poorly understood molecular pathogenesis. We studied the clinicopathologic features and genetic alterations, including allelic loss of chromosomes 11q, 16q, and 18q; sequencing of the K-ras, beta-catenin, and DPC4 (SMAD4) genes; and p53 overexpression and loss of DPC4 by immunohistochemistry; in 16 goblet cell carcinoids. We compared the allelic loss in goblet cell carcinoids to those in 18 gastrointestinal carcinoid tumors. For goblet cell carcinoids, appendiceal perforation was the most common (70%, 7/10) clinical presentation. The mean tumor size was 2.0 +/- 1.5 cm (range, 0.4 to 4.5 cm). The tumor invaded to appendiceal serosa in 50% (8/16) of patients, and two patients had metastasis in lymph nodes or adjoining viscera. With mean follow-up of 24 +/- 14 months (median, 23 mo), 1 of 10 patients had died of disease, and 2 others had tumor recurrence. All four patients with metastases, recurrences, and/or death from disease had serosal involvement at presentation (P =.02). Loss of heterozygosity of chromosome 11q was present in 25% of goblet cell carcinoids, 14% of ileal carcinoid tumors, and 9% of nonileal carcinoid tumors; of chromosome 16q in 38%, 29%, and 0 (P =.02); and of chromosome 18q in 56%, 86%, and 9% (P =.002), respectively. No mutations of K-ras, beta-catenin, or DPC4 genes; p53 overexpression; or loss of staining for DPC4 was present in any tumors. These findings suggest that allelic loss of chromosomes 11q, 16q, and 18q in goblet cell carcinoids and ileal carcinoids may have an important role in the pathogenesis of these tumors.
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PMID:Genetic alterations in goblet cell carcinoids of the vermiform appendix and comparison with gastrointestinal carcinoid tumors. 1468 18

Vasostatin, a fragment of calreticulin, was transfected in the BON cell line to evaluate the feasibility of using it for gene therapy in neuroendocrine tumors. Vasostatin transfected cells were subcutaneously inoculated in nude mice. Burkitt lymphoma cell line, CA46, colorectal adenocarcinoma cell line, SW480, as well as endothelial cells PAE and SVEC4 were used for evaluating the function of vasostatin. The results demonstrated that vasostatin transfer caused enhanced malignant behavior of neuroendocrine tumor cell line, BON. Cell adhesion, spreading and cellular invasion were also enhanced in vasostatin-expressing BON cells. Tumor suppressor genes including p53, nm23, Rb and vinculin were down-regulated. Moreover, cell cycle regulatory protein, p27kip1, and cell differentiation-related protein kinase, PKR, were also significantly down-regulated. Furthermore, expression of NKG2D ligands, MICA and MICB, were down-regulated. Mice implanted with vasostatin-expressing BON cells showed an earlier and faster tumor growth compared to wild type. Anti-proliferative effects of vasostatin could not be proven in other cells except in PAE. These results indicated that vasostatin does probably not have a tumor growth inhibitory effect by itself, but rather modulates processes which are necessary for tumor growth. Therefore, one should be very careful when using vasostatin as an anti-tumoral agent in clinical trials, at least for neuroendocrine tumors.
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PMID:Gene transfer of vasostatin, a calreticulin fragment, into neuroendocrine tumor cells results in enhanced malignant behavior. 1629 70

Large cell neuroendocrine carcinoma (LCNEC) is a high-grade malignant neuroendocrine tumor that was first defined in the lungs. There are six previous reports on LCNEC in the gallbladder, comprising three cases combined with another tumor and three pure LCNECs. We describe a tumor combined with LCNEC and adenocarcinoma elements arising in the gallbladder and give a review of the literature. A 68-year-old woman was diagnosed as having gallbladder wall thickening and a hepatic mass. The surgically resected tumor had a dumbbell shape with gallbladder and liver elements. Histological examination revealed LCNEC in the liver and a deep infiltrative portion of the gallbladder, as well as a well-differentiated tubular adenocarcinoma in the mucosa of the gallbladder. The pseudoglandular structures of LCNEC were marked in the transitional area. Immunoreactivities for carcinoembryonic antigen and CA19-9 as well as for chromogranin A and synaptophysin were detected in the LCNEC element. High p53-protein expression and high proliferative activity estimated by Ki-67 positivity were observed in both elements. The results suggest a close relationship between LCNEC and adenocarcinoma, and support the theory that these elements originate from common cancer stem cells.
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PMID:Combined large cell neuroendocrine carcinoma and adenocarcinoma of the gallbladder. 1994 29

We describe a case of duodenal gangliocytic paraganglioma showing lymph node metastasis. A 61-year-old Japanese man underwent pylorus preserving pancreaticoduodenectomy to remove a tumor at the papilla of Vater. The section of the tumor extending from the mucosa to submucosa of the duodenum was sharply demarcated, solid, and white-yellowish. Neither necrosis nor hemorrhage was present. Histological examination confirmed the immunohistochemical identification of three components comprising epithelioid cells, spindle-shaped cells, and ganglion-like cells. Epithelioid cells showed positive reactivity for synaptophysin, somatostatin, and CD56. In contrast, spindle-shaped cells showed positive reactivity for S-100 protein, but not for synaptophysin, somatostatin or CD56. Furthermore, we found lymph node metastasis despite lack of bcl-2 and p53 expression. In addition to the rarity of the tumor, we are describing here the present case suggests the malignant potency of the tumor despite lack of acceptable prognostic indicators for neuroendocrine tumor.
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PMID:Duodenal gangliocytic paraganglioma showing lymph node metastasis: a rare case report. 2044 91

Mechanisms of neuroendocrine tumor (NET) proliferation are poorly understood, and therapies that effectively control NET progression and metastatic disease are limited. We found amplification of a putative oncogene, RABL6A, in primary human pancreatic NETs (PNET) that correlated with high-level RABL6A protein expression. Consistent with those results, stable silencing of RABL6A in cultured BON-1 PNET cells revealed that it is essential for their proliferation and survival. Cells lacking RABL6A predominantly arrested in G1 phase with a moderate mitotic block. Pathway analysis of microarray data suggested activation of the p53 and retinoblastoma (Rb1) tumor-suppressor pathways in the arrested cells. Loss of p53 had no effect on the RABL6A knockdown phenotype, indicating that RABL6A functions independent of p53 in this setting. By comparison, Rb1 inactivation partially restored G1 to S phase progression in RABL6A-knockdown cells, although it was insufficient to override the mitotic arrest and cell death caused by RABL6A loss. Thus, RABL6A promotes G1 progression in PNET cells by inactivating Rb1, an established suppressor of PNET proliferation and development. This work identifies RABL6A as a novel negative regulator of Rb1 that is essential for PNET proliferation and survival. We suggest RABL6A is a new potential biomarker and target for anticancer therapy in PNET patients.
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PMID:RABL6A promotes G1-S phase progression and pancreatic neuroendocrine tumor cell proliferation in an Rb1-dependent manner. 2527 89


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