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

The lack of HLA class I antigen expression by the melanoma cell line SK-MEL-33 is caused by a unique lesion in beta 2-microglobulin (beta 2-mu). Sequencing of beta 2-mu mRNA detected a guanosine deletion at position 323 in codon 76 that causes a frameshift with a subsequent introduction of a stop codon at a position 54 base upstream of the normal position of the stop codon in the message. The loss of 18 amino acids and the change of 6 amino acids, including a cysteine at position 80 in the carboxy terminus of beta 2-mu, are likely to cause marked changes in the structure of the polypeptide. The latter may account for the inability of beta 2-mu to associate with HLA class I heavy chains and for its lack of reactivity with the anti-beta 2-mu mAb tested. HLA class I antigen expression on SK-MEL-33 cells was reconstituted after transfection with a wild-type B2m gene, therefore indicating that the abnormality of endogenous B2m gene is the only mechanism underlying lack of HLA class I antigen expression by SK-MEL-33 cells. The guanosine deletion in B2m gene was detected also in the melanoma tissue from which SK-MEL-33 cells had originated. Therefore, the molecular lesion identified in the SK-MEL-33 melanoma cell line is not caused by a mutation acquired during growth in vitro but is likely to reflect a somatic mutation during tumor progression.
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PMID:Lack of HLA class I antigen expression by melanoma cells SK-MEL-33 caused by a reading frameshift in beta 2-microglobulin messenger RNA. 843 69

Polypeptide growth factors contribute to the development and maintenance of normal tissues and are essential for the growth and metastasis of solid tumors. During tumor progression these factors function as autocrine stimulators of tumor cells and/or serve to recruit stromal tissue and blood supply to the expanding tumor. In particular, tumor-induced angiogenesis appears to be significant not only for local tumor growth but also for metastasis to distant organ sites. We purified several years ago the heparin-binding growth factor pleiotrophin (PTN) from the supernatants of human breast cancer cells and demonstrated that PTN can serve as an angiogenesis factor. We found the gene expressed in a number of human tumor cell lines as well as in human tumor tissues. Here we present different approaches to inhibit production and function of this growth factor. Finally we discuss how the experience from this growth factor can be applied to improve our understanding of the role of other factors thought to contribute to tumor angiogenesis.
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PMID:Molecular and pharmacologic targeting of angiogenesis factors--the example of pleiotrophin. 853 64

The CD44 antigen (ECMRIII, Hermes antigen) is a highly glycosylated cell-surface polypeptide involved in diverse cellular functions, including cell adhesion and lymphocyte-homing receptor activity. CD44 is also expressed in vivo by several tumors, including astrocytomas, meningiomas, and colonic adenocarcinomas. In addition, it has been shown that expression of CD44 appears to confer metastatic potential to cell lines derived from certain adenocarcinomas. In the skin, CD44 is normally expressed in epidermal keratinocytes and hair follicular, sebaceous, and eccrine epithelial cells. However, there have been few data with regard to the expression in vivo of CD44 in primary cutaneous neoplasms. Furthermore, there have not been studies in vivo of the possible differential expression of CD44 in primary versus metastatic tumors in the skin. We have examined by immunohistochemistry the expression of CD44 in cutaneous invasive and metastatic squamous cell carcinomas, metastatic adenocarcinomas, and basal cell carcinomas. All invasive and metastatic squamous cell carcinomas, as well as metastatic adenocarcinomas, strongly expressed CD44; however, basal cell carcinomas were nonreactive or showed only focal, minimal reactivity. Adjacent normal skin demonstrated CD44 immunoreactivity throughout the epidermis, including the basal layer. In addition, hair follicles and sebaceous and eccrine glands expressed CD44. The results suggest that expression of CD44 in these cutaneous epithelial tumors is not related to malignant transformation, but instead may be related to tumor progression and the ability to metastasize.
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PMID:Differential expression of CD44 in malignant cutaneous epithelial neoplasms. 859 48

Tissue polypeptide antigen is a differentiation and proliferation marker of non-squamous epithelium and derived neoplasms. No reliable tumor markers are available for bladder cancer. The value of tissue polypeptide antigen was therefore prospectively investigated. The serum tissue polypeptide antigen samples were obtained from 144 newly diagnosed transitional cell carcinoma patients and from 92 patients that were followed after treatment. The normal cut off value was defined at 95 units per liter. Nearly all TaT1 patients had normal TPA values, and 80% of the muscle invasive cancers had normal TPA levels. In those patients where TPA was elevated before treatment its monitoring proved to be a reliable predictor of tumor progression. Tissue polypeptide antigen is a useful marker not for the early detection of bladder cancer but for the monitoring of the efficacy of a treatment.
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PMID:Serum tissue polypeptide antigen (TPA) as tumor marker for bladder cancer. 869 44

Malignant rhabdoid tumor is a rare, aggressive, invariably lethal tumor that is resistant to multimodal treatment. In this report, two patients with malignant rhabdoid tumor of the kidney (RTK) are described. The first patient is the first case of RKT with hyperreninemia, and the second case is also the first case with a specific chromosomal abnormality, del 11p13. The first patient presented with hematuria and a mass in the left kidney. Plasma renin, angiotensin, and aldosterone levels were elevated and paralleled the tumor progression. The karyotype of the tumor cells was normal (46,XX). In the second patient, who presented with a mass in the right kidney, the concentration of plasma tissue polypeptide antigen was elevated and paralleled the tumor progression. The karyotype of the tumor cells was 46,XX, del(11)(pter-p13::p12-qter). RTK with a cytogenetic abnormality of del(11p13), which is usually found in aniridia-Wilms' tumor syndrome, has not been known. Both patients died of metastatic disease within 7 months of diagnosis in spite of the multimodal therapy. The clinicopathology of RTK and the differences between Wilms' tumor and RTK raise compelling questions which should be the subject of future studies.
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PMID:Rhabdoid tumor of the kidney: a report of two cases with respective tumor markers and a specific chromosomal abnormality, del(11p13). 869 95

In addition to the classical hormones, the production of numerous polypeptide growth factors, cytokines, vasogenic substances and neuropeptides by pituitary cells has been demonstrated. Expression of the corresponding receptors on pituitary cells enables these factors to influence growth and function of the pituitary by auto- or paracrine mechanisms. Thus, in addition to the external endocrine control of pituitary growth and function, an intrinsic intercellular communication network seems to be involved in the control of pituitary homeostasis. The cell-to-cell communication may be of importance for the pre- and postnatal differentiation of the pituitary, for the regulation of the cellular composition of the gland (by balancing mitosis and apoptosis and controlling angiogenesis) and for the adaption of pituitary function to altered physiological conditions (i.e. stress, pregnancy and diseases). Differences in the expression of or the response to the above-mentioned factors in pituitary adenomas indicate that these substances are of importance for pituitary tumorigenesis. Disturbances of auto-/paracrine mechanisms may not necessarily be involved in the tumor initiation processes, but they may play a crucial role in tumor progression. After the initial transformation, the clonal expansion of the tumor cell is dependent on its ability to escape either from the inhibitory action of growth suppressing factors or to develop an autocrine mechanism that allows autonomous growth. In summary, therefore, this review outlines the potential role of polypeptide growth factors, cytokines and vasogenic peptides as auto-/paracrine-acting substances in normal pituitary and pituitary adenomas.
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PMID:Autocrine and paracrine roles of polypeptide growth factors, cytokines and vasogenic substances in normal and tumorous pituitary function and growth: a review. 898 Jan 50

Physical interaction between the lymphoid high mobility group (HMG)-box architectural transcription factors TCF/LEF and beta-catenin is associated with translocation of the heteromeric complex to the nucleus and regulation of target gene expression. Since formation of molecular complexes among beta-catenin, E-cadherin, p300apc and TCF/LEF depends on balanced expression of these constituents, we investigated the biosynthesis of TCF-1 in colorectal cancer. Here we report detailed analyses of activation and overexpression of lymphoid transcription factor TCF-1 in human colorectal cancer-derived cell lines. Northern blot analyses revealed considerable steady-state expression levels of TCF-1 mRNA of normal size. Genomic rearrangement of the 5' flanking region of the TCF-1 gene was excluded as a cause of ectopic expression. By contrast, CAT-reporter constructs depending on a 515-bp T-cell-regulated TCF-1 genomic upstream region were significantly activated in epithelial tumor cells. RT-PCR analyses revealed a heterogeneic population of mRNA isoforms due to alternative splicing in the TCF-1 gene. On Western blots of colorectal cancer cells, the TCF-1-specific monoclonal antibody 7H3 detected a similar heterogeneous spectrum of TCF-1 specific polypeptide chains. Interestingly, overexpression of TCF-1-specific splice forms correlated with the metastatic behavior of the analyzed cells and with overproduction of lymphoid tyrosine protein kinase p56(lck). We conclude that ectopic expression of the HMG-box factor TCF-1 is associated with late events in tumor progression.
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PMID:Ectopic activation of lymphoid high mobility group-box transcription factor TCF-1 and overexpression in colorectal cancer cells. 925 2

Several polypeptide growth factors stimulate breast cancer growth and may be involved in tumor progression. However, the relative importance of diverse growth factor signaling pathways in the development and maintenance of the neoplastic phenotype is largely unknown. The activation of such growth factor receptors as the insulin-like growth factor I receptor (IGF-I R), erbB-type receptors (erbB Rs) and FGF receptors (FGF Rs) controls the phenotype of a model breast cancer cell line MCF-7. To evaluate the function of 2 post-receptor signaling molecules, insulin receptor substrate-1 (IRS-1) (a major substrate of the IGF-IR) and SHC (a common substrate of tyrosine kinase receptors), we developed several MCF-7-derived cell clones in which the synthesis of either IRS-1 or SHC was blocked by antisense RNA. In MCF-7 cells, down-regulation of IRS-1 by 80-85% strongly suppressed anchorage-dependent and -independent growth and induced apoptotic cell death under growth factor- and estrogen-reduced conditions. The reduction of SHC levels by approximately 50% resulted in the inhibition of monolayer and anchorage-independent growth but did not decrease cell survival. Importantly, cell aggregation and the ability of cells to survive on the extracellular matrix were inhibited in MCF-7/anti-SHC clones, but not in MCF-7/anti-IRS-1 clones. Cell motility toward IGF was not attenuated in any of the tested cell lines, but motility toward EGF was decreased in MCF-7/anti-SHC clones. Our results suggest that in MCF-7 cells: 1) both IRS-1 and SHC are implicated in the control of monolayer and anchorage-independent growth; 2) IRS-1 is critical to support cell survival; 3) SHC is involved in EGF-dependent motility; and 4) normal levels of SHC, but not IRS-1, are necessary for the formation and maintenance of cell-cell interactions.
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PMID:Differential roles of IRS-1 and SHC signaling pathways in breast cancer cells. 931 1

The mutation cluster region in the APC gene defines a region of approximately 660 bp, in which the vast majority of its somatic mutations are found. These mutations disrupt the polypeptide chain, typically eliminating five of the seven repeated sequences of 20 amino acids (aa) each in the central region of the APC protein. To examine the relationship between loss of this structure and loss of function, we constructed APC deletion mutants that progressively truncated the protein across the mutation cluster region. The mutants were tested for their association with beta-catenin and their ability to down-regulate it in SW480 cells. The binding of beta-catenin to APC fragments required the inclusion of only a single 20-aa repeat sequence, whereas down-regulation required the presence of at least three of these repeat sequences, and those including the second repeat exhibited the highest activity. The mutation of three conserved serine residues in the second repeat greatly reduced the activity of an otherwise highly active APC fragment. Thus, the repeated 20-aa sequence is directly implicated in beta-catenin turnover. The elimination of at least five of these seven repeats due to somatic mutations suggests that loss of beta-catenin regulation by APC is selected for during tumor progression.
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PMID:Loss of beta-catenin regulation by the APC tumor suppressor protein correlates with loss of structure due to common somatic mutations of the gene. 937 78

The fibroblast growth factor (FGF) receptor complex is a ubiquitous regulator of development and adult tissue homeostasis that bridges the peri-cellular matrix and the intracellular environment. Diverse members of the FGF polypeptide family, the FGF receptor tyrosine kinase (FGFRTK) family and the FGF receptor heparan sulfate proteoglycan (FGFRHS) family combine to result in active and specific FGFR signal transduction complexes. Regulated alternate splicing and combination of variant subdomains give rise to diversity of FGFRTK monomers. Divalent cations cooperate with the FGFRHS to conformationally restrict FGFRTK trans-phosphorylation, which causes depression of kinase activity and facilitates appropriate activation of the FGFR complex by FGF. Diffusional and conformational molecular models of the oligomeric FGFR complex are presented to explain how different point mutations in the FGFRTK commonly cause craniofacial and skeletal abnormalities of graded severity by graded increases in FGF-independent activity of total FGFR complexes. The role of the FGF family in liver growth and function and in prostate tumor progression is discussed.
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PMID:The heparan sulfate-fibroblast growth factor family: diversity of structure and function. 942 42


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