1,721,015 research outputs found
Cooperation between the polyomavirus middle-T-antigen gene and the human c-myc oncogene in a rat thyroid epithelial differentiated cell line: Model of in vitro progression
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Immune response in mice and effects on cells by outer membrane porins from Salmonella typhimurium
No full textTHE ADENOVIRUS E1A GENE BLOCKS THE DIFFERENTIATION OF A THYROID EPITHELIAL-CELL LINE, HOWEVER THE NEOPLASTIC PHENOTYPE IS ACHIEVED ONLY AFTER COOPERATION WITH OTHER ONCOGENES
No full textThe PC Cl 3 cell line is a well characterized epithelial thyroid cell line of Fischer rat origin. This cell line has the peculiarity of retaining in vitro the typical markers of thyroid differentiation (i.e. thyroglobulin synthesis and secretion, iodide uptake and dependence on TSH for growth). The PC Cl 3 cells have been transfected with the E1A gene of Adenovirus 5. The E1A transfected cells, PC E1A, partially lost the dependency on TSH for growth and completely lost the ability to trap iodide and synthesize thyroglobulin; however they did not acquire the typical markers of the neoplastic phenotype. A highly malignant phenotype was achieved after infection of the PC E1A cells with retroviruses carrying the v-raf, v-abl and polyoma virus middle T oncogenes. In contrast, the PC E1A cells transfected with the E1B gene of Adenovirus were not tumorigenic at all, and those infected with retroviruses carrying oncogenes of the ras family displayed a very weak tumorigenic phenotype
A new oncogene in human thyroid papillary carcinomas and their lymph-nodal metastases
No full textUsing DNA transfection analysis1 on NIH3T3 cells2, activated human oncogenes have been isolated from a variety of fresh solid tumours3. Thyroid neoplasias show a wide range of lesions varying from slowly progressive well-differentiated tumours to anaplastic highly malignant neoplasms4. Therefore they represent an attractive model to investigate the role of oncogene activation in different stages of the neoplastic state. Here we report the detection of transforming activity in DNAs extracted from five thyroid papillary carcinomas and two of their respective lymph-nodal metastases. © 1987 Nature Publishing Group
NOREPINEPHRINE AND THYROTROPIN STIMULATION OF [CA++]I IN PC-C-13-A RAT-THYROID EPITHELIAL-CELL LINE - EFFECT OF TRANSFORMATION BY E1A-GENE OF ADENOVIRUS AND POLYOMAVIRUS MIDDLE-T ANTIGEN GENE
No full textThe effect of thyrotropin and norepinephrine on cytosolic calcium levels were evaluated in normal (PC C13) and transformed (PC E1A, PC Py and PC E1APy) rat thyroid epithelial cell lines. A different pattern of response to both norepinephrine and thyrotropin was observed among the distinct cell lines. In PC C13 the cytosolic calcium rise induced by norepinephrine, characterized by an early transient spike followed by a second phase of sustained calcium levels, was greatly enhanced by thyrotropin. The effect of norepinephrine on calcium concentrations was less affected by thyrotropin in PC C13 transformed by the adenovirus E1A oncogene. Conversely, in Polyoma middle-T transformed PC C13 the increase in cytoplasmic calcium was still sensitive to thyrotropin. The most malignant PC E1APy were totally independent of thyrotropin. © 1993
Protein kinase C activities are increased in rat thyroid epithelial cells expressing V-ras genes
No full textBoth cytoplasmic and membrane-bound protein kinase C activities are increased in: Harvey-Sarcoma Virus, infected thyroid epithelial cells. The cytoplasmic kinase C increase is found in the chromatographic fraction eluted at lower salt concentration (100 mM NaCl-S100), while the more acidic protein fraction eluted at higher salt concentration (350 mM NaCl-S350) is virtually absent. Although the cytoplasmic S100 fraction from the control and ras-virus infected cells display a comparable PBt2 binding activity, they are different in the Ca+2-dependence and the TPA down regulation. In addition, the membranes from the control and ras-virus infected cells are different phosphate acceptors in place of the Hl histones. © 1988 Academic Press, Inc
Mitogenic and dedifferentiating effect of the K-fgf/hst oncogene on rat thyroid PC clone 3 epithelial cells.
No full textThe ret proto-oncogene is consistently expressed in human pheochromocytomas and thyroid medullary carcinomas
No full textWe have recently reported the identification of a new oncogene, named PTC, frequently activated in human thyroid papillary carcinomas. This gene is a novel rearranged form of the ret proto-oncogene and we have shown that this rearrangement occurred in vivo as a tumor-specific somatic event. In an effort to further examine the role of this oncogene in human malignancies, we have investigated the expression of the ret oncogene in a number of human tumors. We consistently detected expression of normal-sized transcripts of the ret proto-oncogene in human pheochromocytomas and in human medullary thyroid carcinoimas (MTC), both of familial and sporadic type. Moreover, we showed that ret mRNA levels were increased following (Bu)2cAMP-induced differentiation of a human MTC cell line (TT). Since the ret gene has been mapped on chromosome 10, close to the gene which predisposes patients to the MEN2A syndrome, we suggest that this region of chromosome 10 might be involved in the proliferative and differentiative patterns of these neuroectodermal tissues
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