Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This report describes the results of a long term prospective study of 30 women with hyperprolactinemia who were not treated and who underwent yearly clinical, hormonal, and radiographic evaluation for an average of 5.2 yr (range 3-7 yr). At entry into the study 18 women had amenorrhea, 8 had oligomenorrhea, and 4 had regular menstrual periods. The initial mean serum PRL levels did not differ in women grouped according to menstrual function. Nine women (35%) had improvement in clinical symptoms. Serum PRL decreased, and menstrual periods normalized more often in those who initially had oligomenorrhea or regular menstrual periods. In most amenorrheic women serum PRL levels did not decline, and menstrual symptoms did not improve. Six of 30 women had an increase in serum PRL, 14 had no change, and 10 had a decrease, in 6 of whom serum PRL was normal at the last observation. Twenty-seven women had serial radiographic studies. Four (15%) of the 13 women with initially abnormal radiographic findings had normal studies later, 2 had tumor progression, and 7 no change. Four of 14 women who had normal radiographic studies initially developed radiographic evidence of a pituitary tumor, although the radiographic changes were minimal, and no patient developed a macroadenoma or pituitary hypofunction. Increases or decreases in serum PRL did not accurately predict changes in tumor size. Prior estrogen use and previous pregnancies did not increase the likelihood of tumor appearance or enhance tumor growth. The clinical presentation of the patient was an important factor in predicting which patients had a decline in serum PRL and resolution of symptoms. We conclude that patients with hyperprolactinemia are unlikely to have progression of their disease and may, in fact, have clinical and radiographic improvement.
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PMID:The natural history of untreated hyperprolactinemia: a prospective analysis. 291 52

Little is known about the molecular mechanisms of tumor progression in the pituitary. However, animal studies suggest that the Rb gene may be involved in the development of pituitary carcinoma. Pathologic examination of a pituitary tumor that included both benign and malignant components provided insight into this mechanism. Both benign and malignant tumors were immunoreactive for ACTH. The benign adenoma showed strong nuclear immunoreactivity for Rb, however, both the adjacent sellar carcinoma and its metastases were Rb-negative. This study suggests that loss of Rb may in some cases be important in the progression of pituitary adenoma to carcinoma.
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PMID:Loss of Rb expression in an ACTH-secreting pituitary carcinoma. 958 68

Angiogenesis is a key determinant and rate-limiting step in tumor progression and metastatic spread. As pituitary tumor-transforming gene (PTTG) induces basic fibroblast growth factor (bFGF), we tested angiogenesis induced by conditioned medium (CM) derived from NIH-3T3 transfectants overexpressing wild-type human PTTG (WT-hPTTG-CM). We also examined the relationship between PTTG expression and tumor vascularity in a series of human tumors. CM from Wt-hPTTG transfectants induced proliferation, migration, and tube formation of human umbilical vein endothelial cells in vitro. The bFGF concentration in WT-hPTTG-CM was elevated (10.5 +/- 0.56) compared with CM from nontransfected NIH-3T3 cells (3.3 +/- 0.56 pg/mL), and addition of anti-bFGF antibody to CM abrogated these angiogenesis markers (P < 0.01). In vivo, concentrated WT-hPTTG-CM induced chick chorioallantoic membrane spoke-wheel-like appearances. Moreover, CM derived from hPTTG transfectants harboring a point mutation on the C-terminus proline-rich region of PTTG induced weaker angiogenic activity than WT-hPTTG-CM (P < 0.01). Thus, human PTTG induces an angiogenic phenotype in both in vitro and in vivo angiogenesis models, and high PTTG messenger ribonucleic acid is associated with an angiogenic phenotype in human tumors. These PTTG-directed angiogenic actions may be mediated through bFGF, which also contributes to tumor growth.
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PMID:Human pituitary tumor-transforming gene induces angiogenesis. 1115 59

A great deal of knowledge about anterior pituitary development, the pathogenesis of pituitary tumor and pituitary tumor progression has accumulated during the past decade. The role of multiple genes and gene products in pituitary development and the relationship of these genes to postnatal pituitary function and pituitary tumor development are being actively explored. Recent studies indicate that genes important in pituitary development do not contribute to pituitary tumorigenesis. However, mutations and other genetic alterations in these genes often lead to pituitary hypofunction. Many oncogenes and tumor suppressor genes that contribute to pituitary tumorigenesis have been described. There is a growing body of evidence showing that cellular and molecular changes in cyclins and cyclin-dependent kinase inhibitors contribute to pituitary tumorigenesis. Finally, recent comparative genomic hybridization studies show that many more genes that are important in pituitary tumorigenesis and tumor progression have yet to be discovered.
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PMID:Molecular pathology of pituitary adenomas. 1176 28

In recent years, remarkable progress has been made in the understanding of the pathogenesis of pituitary tumors. Pituitary tumors originate from the uncontrolled proliferation of a single transformed cell in which an initiating event has caused a gain of proliferative function. After the initiation, promoting factors cooperate in the clonal expansion. Common oncogenes, such as ras, are only exceptionally involved. The only activating mutations identified so far are gsp mutations causing the constitutive activation of cAMP pathway. However, gsp-positive adenomas are not associated to a more aggressive tumoral phenotype. The oncogenic potential of gsp mutations is limited by a more rapid degradation of the mutant Gs(alpha) with respect to the wild-type protein, and by a faster removal of cAMP due to increased phosphodiesterase activity. Estrogen-inducible gene sequences with transforming properties (pituitary tumor-transforming gene (PTTG)) have been identified in human pituitary tumors. Human pituitary tumor-transforming gene (hPTTG) is involved both in early pituitary tumorigenesis, as it causes in vitro and in vivo transformation acting as a transcription activator, and in tumor progression, as it regulates the production of basic fibroblast growth factor (bFGF), a potent activator of angiogenesis and mitogenesis. Moreover, a role of cyclin D1 in pituitary tumorigenesis is emerging. The allelic loss of loci for unknown oncosuppressor genes are currently under investigation, while an exceedingly limited role for menin gene and RB1 has been demonstrated for sporadic pituitary tumors. Abnormal methylation that predisposing toward genetic instability may favor the allelic loss or the reduced expression of oncosuppressor genes, is also an emerging field of investigation. Several promoting factors, including the excessive action of physiological stimulators, the defective action of inhibitors, the susceptibility to respond to inappropriate stimuli and the locally produced growth factors, help in tumor progression. The study of homeobox genes that intervene in pituitary cell differentiation may help in expanding our knowledge in pituitary tumor cell genealogy.
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PMID:Genesis of pituitary adenomas: state of the art. 1176 37

Estrogens are considered to be critically involved in lactotroph and lactosomatotroph pituitary tumor development. In addition to direct effects, estradiol-induced tumor formation may involve alterations in growth factor and cytokine production. We have studied whether estradiol stimulates the production of the angiogenic vascular endothelial growth factor and the potential tumor progression factor interleukin-6 in 5 lactotroph (LA) and 5 lactosomatotroph (LSA) human pituitary adenoma cell cultures. All tumors secreted heterogenous basal amounts of VEGF (18.0 +/- 1.4 to 425 +/- 26 pg/ml per 24 h) and IL-6 (18.1 +/- 1.5 to 604 +/- 17 pg/ml per 24 h). Estradiol (100 nM) significantly enhanced VEGF release in all LA and LSA cell cultures (47 to 168 % above basal). IL-6 secretion was stimulated in 3 out of 5 LA and in all LSA cell cultures (31 to 287 % above basal). In cell cultures obtained from tumors from which sufficient cells could be isolated, a dose-dependent effect of estradiol (1 to 100 nM) on VEGF and IL-6 production was observed. Stimulation of IL-6 and/or VEGF secretion by estradiol in the majority of human lactotroph and lactosomatotroph adenoma cell cultures studied, suggests that estrogens may contribute to adenoma expansion through the stimulation of these auto-/paracrine-acting adenoma progression factors.
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PMID:Estradiol stimulates vascular endothelial growth factor and interleukin-6 in human lactotroph and lactosomatotroph pituitary adenomas. 1475 67

Galectin-3 (Gal-3), a beta-galactoside-binding protein is expressed in a specific cell-type manner in pituitary tumors. Here we questioned the mechanism of Gal-3 expression in pituitary tumors, by using methylation-specific PCR and DNA sequence analyses to analyze the methylation status of the promoter region of the LGALS3 gene. DNA analysis of a human pituitary tumor, breast carcinoma cell lines, and thyroid carcinoma cell lines showed that in cells expressing Gal-3 protein, the LGALS3 gene was unmethylated, whereas in Gal-3 null cells, the promoter of the LGALS3 gene was methylated. Treatment of cells with 30 mumol/L 5-aza-2'-deoxycytidine induced Gal-3 mRNA and protein expression. Among pituitary tumors, 30% (7/23), mainly in follicle-stimulating hormone/luteinizing hormone-producing (38%) and null cell (57%) adenomas, the promoter of the LGALS3 was found to be methylated and silenced, although prolactin- and adrenocorticotropic hormone-producing tumors, which were unmethylated, expressed the Gal-3 protein. These results show for the first time that Gal-3 expression is regulated in part by promoter methylation in pituitary as well as in other tumors. Because it is functionally involved in cancer progression and metastasis, Gal-3 may serve as a possible therapeutic target in the treatment of pituitary tumors.
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PMID:Effects of DNA methylation on galectin-3 expression in pituitary tumors. 1573 94

The pituitary tumor transforming gene 1 (PTTG1) protein is cell-cycle regulated and is identified as a human securin that inhibits sister chromatid separation and is involved in transformation and tumorigenesis. PTTG1 has very low or undetectable expression in most normal human tissues, but it is abundantly expressed in malignant cell lines and pituitary tumors. In this study, we investigated human PTTG1 expression in 62 hepatocellular carcinoma (HCC) specimens using quantitative real-time reverse transcription polymerase chain reaction analysis. We found that, compared with corresponding noncancerous liver tissues, PTTG1 was remarkably overexpressed in HCCs (PTTG1/beta-actin; 0.443 +/- 0.073 vs. 0.068 +/- 0.007; P < .0001). Furthermore, we found a significant correlation between PTTG1 expression and serum alpha-fetoprotein level (P < .001). Univariate and multivariate analyses revealed that the PTTG1 messenger RNA (mRNA) expression was an independent prognostic factor for disease-free (odds ratio 2.70; P = .037) and overall (odds ratio 5.35; P = .007) survival. Moreover, we discovered a significant relationship between PTTG1 expression and intratumoral microvessel density. Our data supported an important role for PTTG1-mediated upregulation of fibroblast growth factor (FGF)-2, one of angiogenesis and modulation of tumor progression, in hepatocarcinogenesis. In conclusion, PTTG1 might be critically involved in the development of HCCs through the promotion of angiogenesis. PTTG1 is overexpressed in HCC and our results suggest that PTTG1 mRNA expression has prognostic significance for the survival of postoperative patients with HCC.
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PMID:Overexpression of pituitary tumor transforming gene 1 in HCC is associated with angiogenesis and poor prognosis. 1713 95

Pituitary tumor transforming gene (PTTG) is a newly discovered oncogene, and serves as a marker of malignancy grades in several forms of cancer, particularly endocrine malignancies such as pituitary adenomas. PTTG appears also to have a role in the genesis of some types of cancer. Also known as a human form of securin, PTTG is an anaphase inhibitor that prevents premature chromosome separation through inhibition of separase activity; hence, its degradation is required to start anaphase. Through this important function, PTTG participates in several key cellular events such as mitosis, cell cycle progression, DNA repair and apoptosis. The physiological importance of PTTG is indicated by the study of PTTG-null mice that have cell growth abnormalities in testis and pancreatic beta cells. Overexpression of PTTG has been observed in thyroid and colon cancers. In addition, 90% of pituitary adenomas overexpress PTTG, qualifying it as the best available marker for this disease. Although the exact mechanism is unknown, PTTG participates in the pathogenesis of various tumors, including pituitary tumors, by inducing aneuploidy and upregulating FGF-2, a potent mitogenic and angiogenic factor. Various growth factors, nuclear factors and hormones regulate PTTG expression in different tumor cells, which could be important to understand in order to obtain insight into the tumorigenic and tumor progression process. Here, we review the current knowledge of the biological and pathophysiological roles of PTTG.
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PMID:The emerging role of pituitary tumor transforming gene in tumorigenesis. 1680 6

Overexpression of the pituitary tumor-transforming gene (PTTG) has been associated with tumorigenesis. In a mouse model that spontaneously develops follicular thyroid cancer (FTC) with distant metastasis (TRbetaPV mouse), PTTG is overexpressed, similar to human thyroid cancer. To evaluate the role of PTTG in thyroid carcinogenesis, we studied the offspring of TRbetaPV mice with mice lacking PTTG (PTTG(-/-) mice). The thyroids of TRbeta(PV/PV) PTTG(-/-) mice were significantly smaller than TRbeta(PV/PV) mice. Ki-67 staining showed a decrease in thyroid proliferation in TRbeta(PV/PV) PTTG(-/-) mice. Our evaluation of the Rb-E2F pathway, a central mediator of cell growth, found that TRbeta(PV/PV) PTTG(-/-) mice exhibited a decrease in protein levels of phosphorylated Rb along with an elevation of the cdk inhibitor p21. Histological examination documented no difference in FTC occurrence between TRbeta(PV/PV) and TRbeta(PV/PV) PTTG(-/-) mice, which indicates that PTTG removal does not prevent the initiation of FTC. However, TRbeta(PV/PV) PTTG(-/-) mice had a significant decrease in vascular invasion and less development of lung metastasis as they progressively aged. CD31 staining also showed a decrease in vessel density in TRbeta(PV/PV) PTTG(-/-) versus TRbeta(PV/PV) thyroids. Given the decreased vascular invasion in the PTTG knockout mice, we studied genes involved in angiogenesis. Real-time reverse transcription-polymerase chain reaction showed a consistent decrease in pro-angiogenic factors, fibroblast growth factor (FGF2), its receptor FGFR1 and vascular endothelial growth factor. Our results highlight the dual roles of PTTG as a regulator of thyroid growth and contributor to tumor progression. The separation of the pathways regulating cell proliferation, tumor initiation and tumor progression should direct future therapeutic options.
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PMID:The pituitary tumor-transforming gene promotes angiogenesis in a mouse model of follicular thyroid cancer. 1712 11


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