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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumor cells of a human medullary thyroid carcinoma were isolated and propagated in tissue culture. Several cell lines with different morphology developed from the primary culture, among others a fibroblast-like growing cell line (MTC-F) and a cell line growing as a suspension of single cells and spherical cell clusters (MTC-SK). The MTC-SK cell line was serially propagated for 90 passages, over 3 years. When examined at different times throughout the in vitro period, MTC-SK exhibited properties characteristic of medullary thyroid carcinomas: the cells maintained their epithelioid morphology; endocrine granules were demonstrated in the cytoplasm by electron microscopy; in situ hybridization confirmed the production of calcitonin- and bombesin-mRNA (gastrin releasing peptide); the cells revealed positive immunoreactivity with antibodies to calcitonin, calcitonin gene-related peptide, and bombesin. The in vitro properties of the MTC-SK cells corresponded to the results obtained from the tissue of origin. Cytogenetic studies of the MTC-F cell line revealed a supernumerary metacentric chromosome (20?). In the MTC-SK cell line the predominant findings were terminal chromosomal rearrangements most frequently concerning chromosome 11p, i.e., the locus of the calcitonin and calcitonin gene-related peptide genes and the H-ras oncogene, and a characteristic instability of the centromeric region of chromosome 16 and somatic pairing of the homologous chromosomes 16.
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PMID:Establishment and characterization of continuous cell line MTC-SK derived from a human medullary thyroid carcinoma. 197 48

Medullary carcinoma of the thyroid (MTC) is exceptional in that the hormone calcitonin produced by the tumor cells represents a specific and sensitive tumor marker. Careful screening by serial calcitonin determinations following pentagastrin stimulation allows for the early detection of metastatic disease. We have adopted a method of meticulous modified radical neck dissection to eradicate persistent or recurrent MCT in 11 patients treated over a 15-month period. This surgical approach resulted in potentially curative treatment in two patients. Effective tumor reduction was achieved in another seven. Two patients have persistent or progressive disease despite maximum efforts to eradicate malignant tissue. Follow-up is presently incomplete in one patient. Postoperative complications included recurrent nerve paralysis (n = 3), hypoparathyroidism (n = 2), muscular weakness (n = 2) and Horner's syndrome (n = 3). The majority of nervous complications improved spontaneously. It is concluded that the adopted method of meticulous modified radical neck dissection offers the chance of cure to some patients and results in the removal of substantial tumor mass in the majority of others. Postoperative problems are mostly temporary and are deemed acceptable.
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PMID:New operative strategy in the treatment of metastasizing medullary carcinoma of the thyroid. 197 10

In medium containing low concentrations of serum, rat 13762NF mammary adenocarcinoma cell lines and clones (MTPa and MTC; isolated from the locally growing tumor) of low metastatic potential to lung did not exhibit a growth response to lung-conditioned medium, whereas a highly metastatic cell clone isolated from a spontaneous lung metastasis (MTLn3) did. The major growth-promoting factor for MTLn3 cells from porcine and rat lung-conditioned media was isolated by using a five-step procedure (anion exchange chromatography, Affi-gel blue affinity chromatography, chromatofocusing, size exclusion chromatography, and preparative native gel electrophoresis). The lung-derived factor that stimulated the growth of highly metastatic MTLn3 cells was a glycoprotein of Mr approximately 66,000 (non-reduced) or Mr approximately 72,000 (reduced) and possessed a pI of 6.9-7.0. It preferentially promoted the growth of lung-metastasizing tumor lines over their poorly lung-metastasizing counterparts in three tumor systems: rat 13762NF mammary adenocarcinoma, murine B16 melanoma, and murine RAW117 large-cell lymphoma. The factor's growth-stimulatory affect was inactivated by reduction or exposure to high temperature (95 degrees C). Although the growth factor appears to be glycosylated, its molecular weight was not altered by treatment with the protein-deglycosylating agent, trifluoromethane sulfonic acid. Cleavage of the protein by cyanogen bromide resulted in the formation of five fragments. Malignant cell response to this lung-derived paracrine growth factor may be important in the successful formation of lung metastases.
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PMID:Purification and characterization of a Mr approximately 66,000 lung-derived (paracrine) growth factor that preferentially stimulates the in vitro proliferation of lung-metastasizing tumor cells. 216 61

Carcinoembryonic antigen (CEA) and nonspecific cross-reacting antigen (NCA) were studied immunohistochemically in formalin-fixed, paraffin-embedded tissues of 73 cases of medullary carcinoma of the thyroid (MTC) using 2 polyclonal antibodies (CEA antisera cross-reactive with or without NCA), 3 monoclonal antibodies recognizing epitopes only on CEA, and one monoclonal antibody against NCA. The staining patterns of the 5 antibodies against CEA in MTCs were not different, and they reacted with 86.3% of all cases. With regard to the effects of fixatives on the staining patterns, samples fixed with formalin or 4% paraformaldehyde demonstrated CEA immunoreactivity in both the cell membrane and cytoplasm. In Bouin-fixed tissue, the immunoreactivity was predominant on the cell membrane, whereas cytoplasmic positivity predominated in alcohol-fixed specimens. Thus the difference in fixatives used in previous studies does not appear to be a major reason for the difference in the reported incidence of CEA-positive MTCs. It is concluded that CEA is still a useful tumor marker for MTC and that it is detectable only in thyroid tumors originating from C cells, as seen in our series. The epitope defined by monoclonal antibody F106-88, present only on NCA, was found in 42.5% of all cases (49.2% of CEA-positive MTCs). The NCA immunoreactivity was located in the tumor cell cytoplasm as globular aggregates, which were also labeled for CEA.
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PMID:Carcinoembryonic antigen and nonspecific cross-reacting antigen in medullary carcinoma of the thyroid. 237 32

The value of radioiodinated metaiodobenzylguanidine (MIBG) in imaging thyroid medullary carcinoma (MTC) was investigated (18 studies) in 12 patients with proven MTC. Calcitonin (CT), carcinoembryonic antigen (CEA) and tissue polypeptide antigen (TPA) were also determined. The patients were divided into two groups. Group I comprised 7 patients who had relapsed; two of them were also studied before total thyroidectomy. In the 2 cases studied before total thyroidectomy 123/131I-MIBG imaged the primary tumor (partially) and the residual tumor involved lobe. The residual/recurrent tumor present in 4 and some of the remote metastases in 3 out of 5 were detected. Group II includes 5 patients studied postoperatively with no evidence of disease. A residual tumor in one of the 2 patients without evidence of disease on the basis of conventional diagnostic modalities but with elevated tumor markers was visualized; the outcome was correctly negative in 3. One patient underwent treatment with 131I-MIBG. A total dose of 27.1 GBq (733 mCi) was given. Relief of pain and partial regression of the lesions was achieved.
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PMID:The possible use of radioiodinated metaiodobenzylguanidine (MIBG) in medullary thyroid carcinoma. 248 94

The ability of malignant cells to respond to growth factor(s) present in or secreted by a distant target organ may be important in tumor metastasis. We used metastatic cell lines and clones of the rat 13762NF mammary adenocarcinoma that show reproducible spontaneous metastatic behavior from the mammary fat pad to regional lymph nodes and lung sites. Whereas poorly lung metastatic MTPa and MTC cells did not grow in response to lung-conditioned medium, highly lung-metastatic MTLn3 cells responded and grew rapidly in lung-conditioned medium. The major growth-promoting factor for MTLn3 cells from porcine and rat lung-conditioned media was purified by using hydroxylapatite affinity and anion exchange chromatography, chromatofocusing, size exclusion chromatography, and preparative native gel electrophoresis. The activity in each of the purification fractions was measured by determining their ability to increase the number of MTLn3 cells in serum-deprived culture. The major component that differentially stimulated the growth of highly metastatic MTLn3 cells was a glycoprotein of Mr approximately 66,000. Under reducing conditions, its apparent Mr was approximately 72,000. This lung-derived mitogen was stable at pH 4.0-9.0, possessed a pI of 6.9-7.0, and preferentially promoted the growth of lung-metastasizing tumor lines over their poorly lung-metastasizing counterparts in rat 13762NF mammary adenocarcinoma and murine B16 melanoma tumor systems. The activity of porcine lung-derived growth factor was not affected by pretreatment with antisera to porcine insulin, human granulocyte-macrophage colony-stimulating factor, human platelet-derived growth factor, or murine epidermal growth factor. It was inactivated by reduction with dithiothreitol or exposure to high temperature (95 degrees C). The results suggest that specific organ-derived growth factors are important in metastatic colonization and organ growth of particular malignant cells.
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PMID:Purification and some properties of a lung-derived growth factor that differentially stimulates the growth of tumor cells metastatic to the lung. 254 64

Circulating neutrophil (PMN) levels can increase in rats bearing subcutaneously growing clones of the 13762NF mammary adenocarcinoma and the level of increase correlates with the metastatic potential of the clone. In rats with poorly metastatic MTC tumors, numbers of circulating PMN did not rise, whereas PMN levels rose 50-fold in rats bearing highly metastatic MTLn3, 12-fold in rats with weakly metastatic MTLn2, and 14-fold in those with moderately metastatic MTF7 tumors. Neutrophilia was caused partly by tumor size, but metastatic potential was a stronger determinant, suggesting that PMNs may play a role in the metastatic process. To determine whether circulating PMNs indeed contribute to cellular metastatic potential, we examined effects of PMN on various aspects of the metastatic process. Experimental metastasis assays involving i.v. co-injections of PMNs yielded a dose-dependent increase in extrapulmonary metastases for MTLn3, but no change in lung colonization potential for any of the clones examined. The change in the metastatic profile was not due to any modification in in vivo distribution of i.v. injected tumor cells or in adhesion to endothelial monolayers in vitro. PMNs also had no effect on in vitro DNA, RNA or protein synthesis and were not cytolytic (E:T 100:1). However, PMNs collected from high-passage MTLn3 tumor-bearing rats had a 50% increase in heparanase and type-IV collagenolytic activity as compared to unstimulated PMNs isolated from normal rats. These results indicate that polymorphonuclear cells may contribute to the metastatic potential of highly metastatic clones from the 13762NF mammary adenocarcinoma cells by assisting in the degradation of basement membrane during extravasation.
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PMID:The role of polymorphonuclear leukocytes (PMN) on the growth and metastatic potential of 13762NF mammary adenocarcinoma cells. 284 49

MTC is characterized by multiple humoral and hormonal manifestations. Although calcitonin is the specific marker of the disease, somatostatin, the pro-opiomelanocortin derived peptides and bombesin--among hormones produced by the tumor--can represent an exacerbation of normal C cells potentialities through genome derepression induced by the cancer. In this paper, the functional polymorphism of princeps tumoral markers and the endocrinological aspects of this neoplasia are reviewed. Molecular biology has been instrumental in discovering new tumoral peptides ("ancestral" CT forms, cryptic peptide and CGRP) and methods of CT detection; therefore, the role of CT could be better evaluated. In addition to its calciotropic role, CT acts also as a neuromodulator on some hypophyseal hormones. Conversely, CT secretion is also regulated by amines and neuropeptides, providing the basis of potential hormonal treatment.
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PMID:[Tumor markers of medullary cancer of the thyroid body. Basic and endocrine aspects]. 290 Jun 20

A case of multiple endocrine neoplasia (MEN) II b syndrome was studied in a 28-year-old Colombian woman. The patient presented initially with medullary carcinoma of the thyroid (MTC), an unusual habitus, numerous mucosal neuromas, and intestinal ganglioneuromatosis. Recurrent medullary carcinoma in the mediastinum produced compression. The tumor mass could not be removed surgically, and the patient died of post-operative complications. At autopsy metastatic MTC was present in the liver, lymph nodes, and lungs. In addition, multiple mucosal neuromas were present in the mouth, nasopharynx, larynx, digestive tract, peri-adrenal fat, and hepatic portal spaces. There was no evidence of pheochromocytoma. Immunofluorescence study of mucosal neuromas showed hyperplasia and hypertrophy of nerves, without evidence of tumor. Kindred screening was negative.
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PMID:Multiple endocrine neoplasia (MEN) type II b: report of a case observed at autopsy with immunohistochemical study of mucosal neuromas. 290 14

Studies with the pyrimido-pyrimidine analogue RA 233 (Rapenton) suggest that its antimetastatic action may not be mediated entirely by inhibition of platelet function. Little is known about its direct effects on tumor cells. We investigated the in vitro effects of RA 233 on clones MTLn3 and MTC of differing metastatic potentials, isolated from the 13762NF rat mammary adenocarcinoma. The results indicated that RA 233 is cytostatic (EC50 of approximately 140 microM and approximately 180 microM for MTLn3 and MTC cells, respectively) rather than cytotoxic by determining changes in viable cell number, thymidine uptake, and incorporation of thymidine and methionine. In both clones RA 233 inhibited cAMP-dependent phosphodiesterase activity and affected cAMP accumulation in intact cells. In contrast, clonal heterogeneity in drug-induced morphological changes, such as vacuole formation and altered organization of cytoskeletal structures, as well as increased tumor cell growth at 50 microM RA 233 was observed between clones MTLn3 and MTC. These data could explain the conflicting results obtained with RA 233 when evaluated as an antimetastatic agent.
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PMID:Direct effects of the pyrimido-pyrimidine derivative RA 233 (Rapenton) on rat 13762NF mammary tumor cell clones in vitro. 302 16


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