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

Cyclins are prime cell-cycle regulators central to the control of cell proliferation in eukaryotic cells. The formation of cyclin/cyclin-dependent kinases (CDK) complexes activates the kinases and initiates a cascade of events, which directs cells through the cell cycle. CDK inhibitors (CDKIs) such as p27(kip1) inhibit cyclln-CDK complexes and function as negative regulators of the cell cycle. Previous studies have shown that p27(kip1) is decreased In malignant relative to benign thyroid tumors, but its role and Interaction with other cell cycle regulatory proteins have not been well established In oncocytic lesions of the thyroid. We studied the expression of p27(kip1), cyclins D1 and E, and Ki67 In 20 cases of oncocytic adenoma (AD). 6 cases of oncocytic carcinoma (CA). 8 cases of Hashimoto's thyroiditis (HT). and 9 cases of nodular goiter with oncocytic change (NG) by Immunohistochemlstry. In the latter two lesions only oncocytic cells were evaluated. The positive staining was stratified Into four groups. Statistical analysis was done using the Kruslcal-Wallis one-way analysis of variance test, and, when significant the Dunn multiple-comparisons procedure was used to determine pairwise differences. AllI 20 AD were p27(kip1) posItive, 10 were 4+, 2 were 3+, and the remaining 8 were 1+. In contrast all 6 CA showed 4+ p27(kip1) staining, of the 8 HT 2 were 4+, two 3+, three1+, and I was negative.All 9 NG were p27 positive, 7 showed 4+, one 3+, and one 1+ staining. On pairwise comparison differences in p27(kip1) staining between AD and CA and between HT and CA were statistically significant (p=0.0243 and p=0.0142, respectively). In all but one case Ki67 expression was either very low (<3%) or negative. No significant differences were seen in the expression of cyclin D1 or cyclin E among the groups observed. In conclusion, the increased p27(kip1) expression in malignant oncocytlc tumors relative to benign oncocytic lesions is unlike any other malignant progression reported in the thyroid and other organ systems in the body. This may reflect on the biologic nature of the oncocytic cells of the thyroid and the significance of this finding remains to be established. Proliferative activity as studied by Ki67 immunostalning was not helpful in distinguishing benign from malignant oncocytic tumors.
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PMID:Cell Cycle Regulatory Proteins p27(kip), Cyclins Dl and E and Proliferative Activity in Oncocytic (Hurthle Cell) Lesions of the Thyroid. 1211 57

Dopamine (DA) agonists cause reduction of blood prolactin level and tumor shrinkage in most patients with lactotroph adenoma. Our aim was to investigate the cellular mechanism of tumor shrinkage by determining mitotic, MIB-1, p27, and apoptotic indices, as well as microvessel density (MVD), surface microvessel density (SMD). ploidy, and other nuclear parameters. Surgically removed lactotroph adenomas were selected from 29 patients, of whom 19 were treated with oral bromocriptine (BEC), long-acting injectable BEC (BEC-LAR), or quinagolide and 10 were untreated. In treated adenomas mitotic and MIB-1 indices were lower, whereas the apoptotic indices were not significantly higher compared to untreated adenomas. The decrease in MIB-1 labeling reached significance in adenomas exposed to quinagolide (p<0.05). Aside from the BEC-LAR treated group, wherein p27 expression was significantly reduced (p<0.05), p27 expression did not differ significantly between the treated and untreated groups. MVD density was significantly lower in the treated adenomas, whereas the decrease in SMD did not attain significance. The DNA ploidy and most other nuclear parameters did not differ significantly in the two groups. In conclusion, reduction of mitotic and MIB-1 indices indicates that suppression of cell proliferation contributes to tumor shrinkage, whereas p27 protein expression and apoptosis play no major role in the adenoma involution. Further studies are required to explain the effect of DA agonists on MVD and SMD.
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PMID:Effect of Dopamine Agonists on Lactotroph Adenomas of the Human Pituitary. 1211 58

Cyclin A binds to CDK2 and plays critical roles when cells proliferate; staining for Ki67 can monitor the proliferation. The cyclin A expression pattern remains unclear in colorectal carcinogenesis and remote metastasis, however, and no one has reported on the association of its expression with key clinicopathologic factors in primary cancer. p27(kip1) protein-an extremely important inhibitor of CDK2-seems unchanged as colorectal cancers metastasize to the lymph nodes, a result contrary to that seen in gastric and prostatic cancers. To clarify the role of cyclin A in multistage colorectal neoplasms, cyclin A, CDK2, and Ki67 were immunohistochemically stained in 22 normal mucosa, 9 hyperplastic polyps, 61 adenomas, 197 primary carcinomas, 21 lymph node metastases, and 10 hepatic metastases. To clarify the alteration of p27(kip1) during lymphatic invasion, p27(kip1) was also stained in 21 primary cancers and paired lymph node foci. Situated in nuclei, cyclin A expression gradually increased from mild through moderate to severe dysplasia in adenomas and from normal tissue through hyperplasia to adenoma to early carcinoma. Expression was significantly decreased in the hepatic metastases and in the primary cancers showing venous invasion, deep infiltration, lymph node metastasis, mucinous type, advanced stage, or short postoperative survival time. Elevated cyclin A not only was linked with elevated CDK2 in primary cancers, but also was associated with increased Ki67 in both adenomas and primary carcinomas. Lymph node metastases lost more p27(kip1) than primary foci and hepatic lesions. Thus, dysregulation of cyclin A and its control mechanisms may contribute to colorectal carcinogenesis; abatement of overexpression of cyclin A is associated with hepatic metastasis and cancerous invasion. Loss of p27(kip1) may promote lymph node metastasis.
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PMID:Cyclin A correlates with carcinogenesis and metastasis, and p27(kip1) correlates with lymphatic invasion, in colorectal neoplasms. 1239 74

Macrophage migration inhibitory factor (MIF) is an essential regulator of the macrophage responses to endotoxin. MIF also has the ability to override the anti-inflammatory actions of glucocorticoids during an immune response, and is thus an important pro-inflammatory factor. The presence of MIF in cells of the anterior pituitary has been described, and high levels of MIF in other rapidly proliferating tIssues have also been demonstrated. It has been hypothesised that MIF release from these cells is influenced by the hypothalamo-pituitary-adrenal axis, and that ACTH and MIF are released simultaneously to exert counter-regulatory effects on cortisol. However, another intracellular role for MIF has also been suggested as it has been shown that MIF exerts an effect on the inhibitory cell cycle control protein p27 through an interaction with Jab1, a protein implicated in p27 degradation. We studied MIF expression in different normal and adenomatous human pituitary samples using immunohistochemistry and RT-PCR. There was evidence of co-immunoprecipitation of MIF with Jab1, suggesting an interaction of the two proteins. Our results showed that there is increased expression of MIF protein in the nuclei of all pituitary adenomas compared with normal tIssue (P=0.0067), but there was no statistically significant difference in nuclear MIF expression between the different adenoma types. Nuclear MIF expression correlated positively with p27 and its phosphorylated form in normal tIssue (P=0.0028 and P<0.0001); however, this relationship was not seen in the adenoma samples. Cytoplasmic expression of MIF was found to be variable both in normal and adenomatous samples, with no consistent pattern. MIF mRNA was demonstrated to be present in all tumour and normal samples studied. Somatotroph tumours showed higher MIF mRNA expression compared with normal pituitary or other types of adenomas. In conclusion, MIF is expressed in cell nuclei in pituitary adenomas to a greater extent than in normal pituitary tIssue. We speculate that it may play a role in the control of the cell cycle, but whether its higher level in adenomas is a cause or a consequence of the tumorigenic process remains to be clarified.
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PMID:Macrophage migration inhibitory factor expression is increased in pituitary adenoma cell nuclei. 1252 54

We studied 45 patients with typical and 8 with atypical parathyroid adenomas as well as 20 with parathyroid carcinomas. Clinical, pathological, and molecular analyses were conducted on all adenomas. Clinical data were analyzed for 20, histopathologic slides for 16, and tissue specimens for 8 patients with carcinoma. Molecular expression profiles were investigated by immunohistochemistry (IHC) for Ki-67, p53, mdm2, p21, Bcl-2, cyclin D1, and p27 on paraffin-embedded tissues arrayed on tissue microarrays. Trabecular growth and vascular, capsular, and soft-tissue invasion were characteristic of parathyroid carcinomas but not of typical adenomas. No adenomas recurred. Seventy-four percent of carcinomas recurred, most in the neck. Seventy-nine percent of patients with such illness died of disease after an indolent, multiply recurrent course responsive to repeated resections; the 5-year survival rate was 50%. High Ki-67 proliferative index was seen in 2% of adenomas and 25% of carcinomas, whereas p27 expression was present in 80% of adenomas and 18% of carcinomas. The molecular phenotype, p27(+)Bcl-2(+)Ki-67(-)mdm2(+), was observed in 76%, 29%, and 0% of typical and atypical adenomas and carcinomas, respectively. The complexity of molecular phenotypes increased with tumor aggressiveness. Parathyroid carcinoma is an aggressive disease with a propensity for multiple recurrences. It is characterized by capsular, vascular, and soft-tissue invasion. Recurrence portends poor outcome. Molecular markers, Ki-67 and p27, may distinguish parathyroid carcinoma from adenoma. The molecular phenotype, p27(+)Bcl-2(+)Ki-67(-)mdm2(+), appears to be unique to nonmalignant parathyroid tumors, and multimarker phenotypes are more complex in carcinomas.
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PMID:Parathyroid neoplasms: clinical, histopathological, and tissue microarray-based molecular analysis. 1260 67

Jun activation domain-binding protein 1 (jab1) is known as a coactivator of the AP1 transcription factor. Recent studies have demonstrated that jab1 contributes to carcinoma progression by degrading p27/Kip1 protein. In this study, we immunohistochemically investigated jab1 expression in thyroid neoplasms. jab1 overexpression tended to be frequently observed in follicular carcinoma compared to adenoma. Larger-sized papillary carcinoma overexpressed jab1 in higher incidence than microcarcinomas (1.0 cm or less in maximum diameter). In anaplastic carcinoma, jab1 was more frequently overexpressed than in papillary and follicular carcinomas. An inverse relationship was detected between jab1 overexpression and p27 expression in papillary and anaplastic carcinomas, but not in follicular tumor. These results suggest that jab1 plays a role in the progression of thyroid carcinomas, especially those of aggressive phenotypes, and it may be responsible for p27 degradation in anaplastic and papillary carcinomas.
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PMID:14-3-3 sigma possibly plays a constitutive role in papillary carcinoma, but not in follicular tumor of the thyroid. 1286 Feb 94

Mice with a targeted inactivation of both alleles of the cyclin-dependent kinase inhibitor p27(kip1) developed both small and large intestinal adenomas when fed a control AIN-76A diet. A Western-style diet that is high in fat and phosphate and low in calcium and vitamin D was also able to initiate adenoma formation in wild-type mice. The combination of p27(kip1) inactivation and the Western-style diet was additive in terms of tumor incidence, frequency and size, and in reducing the life span of the mice. The genetic and dietary combination also resulted in development of adenocarcinoma. Tumor formation was linked to a disruption in homeostasis of the intestinal mucosa, involving increased cell proliferation and decreased apoptosis. There was also decreased goblet cell differentiation as assessed by alcian blue staining and expression of the Muc2 gene, especially in mice fed the Western-style diet, although this differentiation lineage was still present as indicated by expression and staining for intestinal trefoil factor. The inactivation of p27(kip1) and the consequent disruption of normal colonic cell maturation in the mucosa were associated with modestly elevated c-myc, cdk4, and cyclin D1 expression. These data establish a fundamental role for p27(kip1) in maintenance of intestinal cell homeostasis and in suppressing tumor formation. The data also emphasize the critical role that dietary factors can have in both tumor initiation and progression through interaction with pathways that normally maintain intestinal homeostasis.
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PMID:Targeted inactivation of p27kip1 is sufficient for large and small intestinal tumorigenesis in the mouse, which can be augmented by a Western-style high-risk diet. 1294 25

Millions of people worldwide suffer goiter, a proliferative disease of the follicular cells of the thyroid that may become neoplastic. Thyroid neoplasms have low proliferative index, low apoptotic index and a high incidence of metastasis. TGF-beta is overexpressed in thyroid follicular tumor cells. To investigate the role of TGF-beta in thyroid tumor progression, we established cultures of human thyrocytes from different proliferative pathologies (Grave's disease, multinodular goiter, follicular adenoma, papillary carcinoma), lymph node metastasis, and a normal thyroid sample. All cultures maintained the thyrocyte phenotype. TGF-beta induced cell-cycle arrest in all cultures, in contrast with results reported for other epithelial tumors. In deprived medium, TGF-beta induced apoptosis in normal thyrocyte cultures and all neoplastic cultures except the metastatic cultures. This apoptosis was mediated by a reduction in p27kip1 levels, inducing cell-cycle initiation. Antisense p27 expression induced apoptosis in the absence of TGF-beta. By contrast, in cells in which p27 was overexpressed, TGF-beta had a survival effect. In growth medium, a net survival effect occurs in neoplastic thyrocytes only, not normal thyrocytes, due to activation of the NF-kappaB survival program. Together, these findings suggest that (a) thyroid neoplasms are due to reduced apoptosis, not increased division, in line with the low proliferative index of these pathologies, and (b) TGF-beta induces apoptosis in normal thyrocytes via p27 reduction, but that in neoplastic thyrocytes this effect is overridden by activation of the NF-kappaB program.
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PMID:TGF-beta-induced apoptosis in human thyrocytes is mediated by p27kip1 reduction and is overridden in neoplastic thyrocytes by NF-kappaB activation. 1458 8

We report here a dialysis patient with secondary hyperparathyroidism who had a history of parathyroidectomy for primary hyperparathyroidism 27 years previously. The patient was a 48-year-old male. In 1974, he was diagnosed as having primary hyperparathyroidism and an adenoma was completely resected in the Department of Urology, Osaka University Hospital. In 1997, he started hemodialysis for chronic renal failure by diabetic nephropathy. Since his intact-PTH was high, we started intravenous vitamin-D pulse therapy, but intact-PTH did not decrease. We could not detect any parathyroid glands by ultrasonography and 201TlCl-99mTcO4-scintigraphy around the thyroid gland. Finally, chest-CT and 99mTc-MIBI scintigraphy revealed a ectopic parathyroid gland in the mediastine, and the ectopic parathyroid gland was successfully resected in July, 2001. In order to distinguish whether the resected ectopic parathyroid gland was due to primary adenoma or secondary hyperplasia, we used an immunohistochemical technique to examine the expression of PRAD1/cyclin D1, Ki67, and p27 and sequence analysis of the MEN1 gene. As a result, the labeling index (LI) of PRAD1/cyclin D1 was 4, LI of Ki67 was 36, and LI of p27 was 257. Moreover, germline-mutation and somatic-mutation of MEN1 gene was not detected. These findings suggested that the resected parathyroid gland was a nodular hyperplasia of secondary hyperparathyroidism. In conclusion, immunohistochemical findings of parathyroid tissue and sequence analysis of MEN1 gene could be useful for the differential diagnosis of primary adenoma and secondary hyperplasia.
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PMID:[A hemodialysis patient with secondary hyperparathyroidism in whom primary parathyroid adenoma was resected 27 years previously]. 1463 67

Multiple genetic and epigenetic alterations in oncogenes, tumour-suppressor genes, cell-cycle regulators, cell adhesion molecules, DNA repair genes and genetic instability as well as telomerase activation are implicated in the multistep process of human stomach carcinogenesis. However, particular combinations of these alterations differ in the two histological types of gastric cancer, indicating that well-differentiated or intestinal-type and poorly differentiated or diffuse-type carcinomas have distinct carcinogenetic pathways. In the multistep process of well-differentiated-type carcinogenesis, the genetic pathway can be divided into three subpathways: an intestinal metaplasia-->adenoma-->carcinoma sequence, an intestinal metaplasia-->carcinoma sequence and de novo. In the multistep process of well-differentiated-type or intestinal-type gastric carcinogenesis, infection with Helicobacter pylori may be a strong trigger for hyperplasia of hTERT-positive 'stem cells' in intestinal metaplasia. Genetic instability and hyperplasia of hTERT-positive stem cells precede replication error at the D1S191 locus, DNA hypermethylation at the D17S5 locus, pS2 loss, RARbeta loss, CD44 abnormal transcripts and p53 mutation, all of which accumulate in at least 30% of incomplete intestinal metaplasias. All of these epigenetic and genetic alterations are common events in intestinal-type gastric cancer. An adenoma-->carcinoma sequence is found in about 20% of gastric adenomas with APC mutations. In addition to these events, p53 mutation and loss of heterozygosity (LOH), reduced p27 expression, cyclin E expression and the presence of c-met 6.0-kb transcripts allow malignant transformation from the above precancerous lesions to intestinal-type gastric cancer. DCC loss, APC mutations, 1q LOH, p27 loss, reduced tumour growth factor (TGF)-beta type I receptor expression, reduced nm23 expression and c-erbB gene amplification are frequently associated with an advanced stage of intestinal-type gastric cancer. The de-novo pathway for carcinogenesis of well-differentiated gastric cancer involves LOH and abnormal expression of the p73 gene that is responsible for the development of foveolar-type gastric cancers with pS2 expression. On the other hand, LOH at chromosome 17p, mutation or LOH of p53 and mutation or loss of E-cadherin are preferentially involved in the development of poorly differentiated gastric cancers. In addition to these changes, gene amplification of K-sam, and c-met and p27 loss as well as reduced nm23 obviously confer progression, metastasis and diffusely productive fibrosis. Mixed gastric carcinomas composed of well-differentiated and poorly differentiated components exhibit some but not all of the molecular events described so far for each of the two types of gastric cancer. Besides these genetic and epigenetic events, well-differentiated and poorly differentiated gastric cancers also organize different patterns of interplay between cancer cells and stromal cells through the growth factor/cytokine receptor system, which plays an important role in cell growth, apoptosis, morphogenesis, angiogenesis, progression and metastasis. Meta-analysis of epidemiological studies and animal models show that both intestinal and diffuse types of gastric cancer are equally associated with H. pylori infection. However, H. pylori infection may play a role only in the initial steps of gastric carcinogenesis. Differences in H. pylori strain, patient age, exogenous or endogenous carcinogens and genetic factors such as DNA polymorphism and genetic instability may be implicated in two distinct major genetic pathways for gastric carcinogenesis.
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PMID:Genetic pathways of two types of gastric cancer. 1505 5


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