Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Colorectal carcinoma is a major cause of death throughout the Western world. It is increasingly recognized that any reduction in mortality must be achieved through the detection and removal of early and precancerous lesions. The primary attention for such a preventive strategy has been the polypoid adenoma and surveillance studies have shown a significant reduction in the incidence of carcinoma through systematic polypectomy of suspicious lesions. A potential problem with such a program, however, is raised by reports from Japan that some carcinomas seem to arise without a precursor polypoid adenoma, that is de novo. Although the histopathologic findings in such reports seem to clearly support this idea, this concept is not widely accepted in the Western world. We undertook a series of immunohistochemical (p53, bcl-2, Mib-1, E-cadherin, CD44, Stromelysin-3), and microsatellite analysis studies (on 17p (p53), 18q (DCC), 5q (APC), 8p, 2p and 1p), on groups of de novo and ex adenoma carcinomas in order to see if differences between the two groups of lesions exist. The results of these studies demonstrate that de novo carcinomas share several phenotypic and genotypic features with ex adenoma carcinoma (similar CD44 in the carcinomas, similar rates of LOH at APC and DCC loci), but have significantly higher rates of LOH at 17p, p53 over-expression and ST-3 expression indicating that tumor progression in de novo carcinoma is accelerated. These findings should help clarify the concept of de novo carcinoma and contribute to wider recognition of this important clinicopathologic entity.
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PMID:[Are there differences between ex adenoma and de novo colorectal carcinomas?]. 1071 4

Recent advances in the molecular biology has served to unveil the underlying genetic and epigenetic alterations in pituitary adenomas. Three nuclear transcriptional factors, AP-1, CREB, and Pit-1, which are targets of protein kinase C and A, appear to play critical roles in both neoplastic growth and hormone secretion in hormone-producing adenomas. The alteration of G proteins such as Gs and Gi2 is a direct cause of the activation of such transcriptional factors. Autocrine growth factor/cytokine loops also contribute to the augmented signal transductions. Bromocriptine and somatostatin analogs have effects to lower cellular cAMP level through inhibitory G proteins, although the mechanism leading to cellular apoptosis is unknown. On the other hand, most non-functioning adenomas may not have PKC- or PKA-mediated oncogenic mechanisms. Although the loss of Rb and p27Kip1 genes has been demonstrated as a cause of murine pituitary adenomas, the role of tumor suppressor genes for human pituitary adenomas remains elusive. However, potential candidates for the suppressor genes are now emerging. The recently cloned multiple endocrine neoplasia type I gene is one example. Alterations of c-myc/bcl-2, and ras, although rare, appear to be an important cause of the process by which adenoma cells acquire aggressive phenotypes. Further studies on the links between abnormal signal transductions and aberrant tumor suppressor genes will be needed to clarify the whole picture of pituitary oncogenesis.
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PMID:Molecular basis of pituitary oncogenesis. 1072 13

This retrospective study was undertaken to investigate the expression of bcl-2 protein and messenger RNA in colorectal cancer (CRC). Immunohistochemical analysis using a monoclonal mouse antibody to the bcl-2 protein and in situ hybridization using a digoxigenin-labelled bcl-2 cRNA probe were carried out on formalin-fixed and paraffin-embedded specimens from 53 colorectal adenocarcinomas, 27 liver secondaries, and 60 adenomas with various degrees of dysplasia. Normal human tonsil sections were used as positive controls. Expression of bcl-2 protein and of messenger RNA was evaluated semiquantitatively. The expression of bcl-2 protein was gradually and significantly lost during the progression from moderately dysplastic adenoma to primary CRC (moderate/severe dysplasia: Mann-Whitney U-test, p=0.0001; severe dysplasia/primary CRC: p=0.027), whereas the cellular expression of bcl-2 mRNA was gradually increased during the dysplasia/adenoma-carcinoma neoplastic sequence. These observations suggest that in a proportion of colorectal cancer cases, the bcl-2 proto-oncogene expression may be down-regulated at a post-transcriptional level.
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PMID:Evidence for post-transcriptional down-regulation of the apoptosis-related gene bcl-2 in human colorectal cancer. 1076 13

Expression of apoptosis-related proteins, bcl-2, Bax, Fas and Fas ligand (L), in ovarian epithelial neoplasms together with its clinical relevance was examined by immunohistochemistry. They included 36 cases with adenoma, 33 with low potential malignancy (LPM) and 63 with carcinomas. bcl-2 expression was observed in 14 of 36 cases (39%) with adenoma, five of 33 (15%) with LPM (P< 0.05) and 12 of 63 (19%) with carcinoma (P < 0.05). Cases with bcl-2 expression showed more favourable prognosis than those without, but the difference was not statistically significant. There was no difference in frequency of Bax and Fas expression between each histologic category. Fas L expression was observed in one of 36 cases (3%) with adenoma, but in 12 of 33 (36%) with LPM (P < 0.001) and 42 of 63 (67%) with carcinoma (P < 0.0001). In carcinomas, cases expressing Fas L showed a less favourable prognosis than those without (P = 0.02). Density of CD8+ lymphocytes, possibly cytotoxic T-cells, was higher in serous carcinoma with negative Fas L expression than those with positive Fas L expression. These findings suggest that Fas L expressing carcinomas induce apoptosis in infiltrating CTL with Fas expression, and escape from immune surveillance.
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PMID:Expressions of Fas ligand and other apoptosis-related genes and their prognostic significance in epithelial ovarian neoplasms. 1078 May 25

Immunostaining for bcl-2 protein was performed in 27 colorectal adenomas and 108 colorectal adenocarcinomas. The aim of the study was to determine bcl-2 expression in correlation with p53, mdm-2 and Rb expression, with proliferation indices (Ki-67-LI, PCNA-LI) as well as with conventional clinicopathological variables. A higher proportion of adenomas (30.8%) than carcinomas (16.7%) expressed bcl-2 and conversely, a lower proportion of adenomas (7.4%) than carcinomas expressed p53 (57.1%), the difference being statistically significant (p<0.0001). No correlation of bcl-2 expression with p53 expression (parallel or inverse) as well as with the other parameters studied was observed in any tumour. The bcl-2+/p53- subgroup of cancers showed a trend for correlation with negative lymph node status. Our data suggest, that bcl-2 expression may be involved in the early phase of colorectal carcinogenesis regardless of p53 status, while p53 function may be involved in a late stage of the adenoma-carcinoma sequence. P53 is apparently not involved in the regulation of apoptosis in the colorectal neoplasias or perhaps bcl-2 expression, as an early event in colorectal tumours, may occur before changes of p53 take place. Tumours with bcl-2+/p53- immunophenotype are frequently associated with negative lymph node status and seem to have a less aggressive behavior.
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PMID:Bcl-2 expression in colorectal tumours. Correlation with p53, mdm-2, Rb proteins and proliferation indices. 1096 9

The Fas-FasL system seems to mediate thyrocyte death in Hashimoto's thyroiditis. In thyroid cancer, down-regulation of bcl-2 seems to alter apoptosis control. We compared the expression of immunoreactive Fas and FasL in normal thyroid with that of tumors ranging from benign to highly aggressive. Fas is essentially not expressed in normal thyrocytes, whereas FasL is expressed in approximately one-third of cases. Expression of both markers is significantly up-regulated in adenoma and in well-differentiated papillary and follicular carcinoma. In contrast, Fas is suppressed and FasL is strongly reduced in the most aggressive histological variants (poorly differentiated and undifferentiated carcinoma). Immunohistochemistry findings have been confirmed by analysis of Fas-FasL mRNA transcripts. In vitro studies showed that the Fas receptor of thyroid tumor cells was functional, because apoptosis was induced by an agonistic Fas antibody. Fas-expressing and Fas-resistant mammary cell lines were used as specificity controls. Together with our previous data inversely relating bcl-2 expression and thyroid tumor grade, the present findings further indicate that apoptotic pathways are altered in thyroid neoplasia. Thus, the Fas-FasL system may represent a marker of tumor aggressiveness.
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PMID:Suppression of Fas expression and down-regulation of Fas ligand in highly aggressive human thyroid carcinoma. 1100 9

Solitary fibrous tumor is a soft tissue neoplasm initially described in the pleura but subsequently reported in a wide variety of locations. The clinical behavior is usually benign, but the existence of aggressive cases has been documented both in the pleura and in extrapleural sites. In this report clinical and pathologic features of seven solitary fibrous tumors of the thyroid gland are presented. Patients' ages ranged from 43 to 64 years (mean 52 years), and tumor sizes varied from 2 to 6 cm. Grossly, the tumors were white-tan and well circumscribed. Microscopically, there was a variegated, wavy, storiform, hemangiopericytic or desmoid-like arrangement of spindle cells. Trapped thyroid follicles within the tumor and peripheral jagged tumor infiltration among follicles were common. There was immunohistochemical reactivity for CD34, CD99, and bcl-2, and ultrastructural analysis of one tumor was consistent with a fibroblastic lineage. The differential diagnosis included other benign and malignant mesenchymal tumors of the thyroid, spindle cell follicular adenoma, Riedel's thyroiditis, the spindle cell, and paucicellular variants of anaplastic carcinoma, papillary thyroid carcinoma with exuberant nodular fasciitis-like stroma, and the spindle epithelial tumor with thymus-like differentiation. The cumulative data of 13 cases (comprised of the seven present cases and the six previously reported) suggest a benign clinical behavior for thyroid SFT.
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PMID:Solitary fibrous tumor of the thyroid gland: report of seven cases. 1168 60

Serrated adenoma of the colorectum is a recently proposed entity characterized by a saw-toothed structure of hyperplastic polyp and cytologic atypia of tubular adenoma. To clarify the role of apoptosis in morphogenesis of serrated adenoma, we investigated apoptotic indices and expression of apoptosis-related antigens in the tumor cells. Thirty-eight serrated adenomas were examined by the nick-end DNA labeling method and immunostained for CD95 (Fas), bcl-2, bax, and p53. Thirty-seven hyperplastic polyps, 48 tubular adenomas, and 16 sections containing normal colonic mucosa were similarly examined for comparison. The apoptotic indices in the upper and middle zones of the crypts of serrated adenomas and hyperplastic polyps were lower than those of normal colon mucosa and tubular adenomas with statistically significant differences. The CD95 expression was diffusely observed throughout the epithelium of normal crypts and tubular adenomas, whereas it was reduced in serrated adenomas and hyperplastic polyps. The bcl-2 expression was confined to the basal crypts in the latter two lesions but was diffuse throughout the neoplastic epithelium in tubular adenomas. The bax expression was increased in serrated adenomas and tubular adenomas but was decreased in hyperplastic polyps. Overexpression of p53 protein was observed in 50% of serrated adenomas, none of hyperplastic polyps, and 14% of tubular adenomas. These findings suggest that inhibition of apoptosis is caused by reduced CD95 expression in serrated adenomas and hyperplastic polyps, which may induce the characteristic saw-toothed structure in these lesions. Based on the similarities and differences between serrated adenoma and hyperplastic polyp observed in the present study, a progression from the latter to the former lesion may be postulated.
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PMID:Apoptosis index and apoptosis-related antigen expression in serrated adenoma of the colorectum: the saw-toothed structure may be related to inhibition of apoptosis. 1181 48

Primary hyperparathyroidism is the clinical result of parathyroid adenoma or hyperplasia, rarely of carcinoma. Clinical, serologic, and radiologic data are unable to discriminate a single parathyroid adenoma from an enlarged hyperplastic gland. Morphologic features also overlap in adenoma and small hyperplastic gland. Studying immunohistochemical expression of fatty acid synthase (FAS), p53, Ki67 and bcl-2, we found that among 21 adenomas 19 (90.5%) were positive for FAS, 12 (57.2%) for Ki67, 11 (52.4%) for p53, and 16 (76.2%) for bcl-2; among 12 hyperplasias, 12 (100%) were positive for FAS, 6 (50%) for KI67, 8 (66.7%) for p53, and 8 (66.7%) for bcl-2. Statistical analysis showed that FAS was associated with parathormone (PTH) (P =.001), Ki67 (P =.01), and p53 (P =.01). Moreover, FAS was associated with hyperplastic (P =.0001) and adenomatous glands (P =.0001). Ki67 was associated with both adenomatous (P =.02) and hyperplastic glands (P =.005). P53 protein were associated only with hyperplastic glands (P =.01). The different occurrence of p53 in parathyroids adenoma and hyperplasia may enable a different management and follow-up of the patients with primary hyperparathyroidism, stratifing them into two groups. The first, with a "false" adenoma having a high risk of relapse, may necessitate exams like serum calcium levels, PTH concentrations, urinary calcium levels for 24 hours, kidney functional tests, and radiology and ultrasound every 3 to 6 months, whereas the second with "true" adenoma, at low risk of relapse, may be checked less frequently with serum calcium levels and PTH concentrations.
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PMID:P53 as a marker of differentiation between hyperplastic and adenomatous parathyroids. 1217 Apr 54

To investigate the effects of apoptosis on colorectal tumorigenesis and its possible biological significance, the apoptotic frequency in primary cultural cell of 9 normal mucosa, 4 adenomas and 9 adenocarcinomas in time period of 2, 12, 24, 48 hour was measured by flow cytometry. The apoptotic cells index (AI) in situ for 15 colorectal normal mucosa, 7 hyperplastic epithelial, 25 adenomas and 77 adenocarcinomas was identified by the terminal deoxynucleotidyl transferasemediated dUTP-biotin nick end labeling technique (TUNEL). Ki-67 proliferate index (KI), wafl and p53 genes were immunostained with ABC method. The results showed that culture related apoptotic incidence was obviously decreased in cultural tumor cell when compared with mucosa cell after 24-48 hour in vitro. There was a directly positive relationship between the spontaneous apoptosis and Ki-67-index in vivo. The well differentiated or early stage lesions with intensive bcl-2 expression were significantly more likely to have low AI and KI. Both mp53 accumulation and wafl depression which mainly related to KI, had no apparent correlation with AI, bcl-2/bax expression and clinicopathological features statistically; elevatory bax/bcl-2 and pervasive wafl depression led to an increasing AI/KI both in adenoma with atypia and in advanced cancer with distant metastasis or embolus, comparatively. The data indicated that the reduction of susceptibility to inductive apoptosis may contribute to the early phase of tumorigenesis, that AI in vivo may reflect proliferative activity, and that bcl family was closely associated with spontaneous apoptosis and biological behavior of human colorectal cancer.
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PMID:[Significance of apoptosis status and apoptosis-associated antigen expression in human colorectal adenocarcinoma sequence]. 1221 55


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