Expression of CD73 and its ecto-5'-nucleotidase activity are elevated in papillary thyroid carcinomas.
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5'-Nucleotidase↗
Biomedical subjects
R Katoh
Publications and source records attributed to R Katoh.
Dye sensitization of nanocrystalline titanium dioxide with square planar platinum(II) diimine dithiolate complexes.
A series of platinum-based sensitizers of the general type Pt(NN)(SS), where NN is 4,4'-dicarboxy-2,2'-bipyridine (dcbpy) or 4,7-dicarboxy-1,10-phenanthroline (dcphen) and SS is ethyl-2-cyano-3,3-dimercaptoacrylate (ecda), quinoxaline-2,3-dithiolate (qdt), 1,2-benzenedithiolate (bdt), or 3,4-toluenedithiolate (tdt), that have various ground-state oxidation potentials has been synthesized and anchored to nanocrystalline titanium dioxide electrodes for light-to-electricity conversion in regenerative photoelectrochemical cells with an I(-)/I(-)(3) acetonitrile electrolyte. The intense mixed-Pt/dithiolate-to-diimine charge-transfer absorption bands in this series could be tuned from 440 to 580 nm by choosing appropriate dithiolate ligands, and the highest occupied molecular orbitals varied by more than 500 mV. Spectrophotometric titration of the Pt(dcphen)(bdt) complex exhibits a ground-state pK(a) value of 3.2 +/- 0.1, which can be assigned to the protonation of the carboxylate group of the dcphen ligand. Binding of Pt(dcbpy)(qdt) to porous nanostructured TiO(2) films was analyzed using the Langmuir adsorption isotherm model, yielding an adsorption equilibrium constant of 4 x 10(5) M(-1). The amount of dye adsorbed at the surface of TiO(2) films was 9.5 x 10(-8) mol/cm(2), which is ca. 50% lower than the full monolayer coverage. The resulting complexes efficiently sensitized TiO(2) over a notably broad spectral range and showed an open-circuit potential of ca. 600 mV with an impressive fill factor of > 0.70, making them attractive candidates for solar energy conversion applications. The visible spectra of the 3,4-toluenedithiol-based sensitizers showed an enhanced red response, but the lower photocurrent efficiency observed for these sensitizers stems in part from a sluggish halide oxidation rate and a fast recombination of injected electrons with the oxidized dye.
Journal Article↗
Expression of vascular endothelial growth factor (VEGF) and VEGF receptor-1 (Flt-1) in Graves disease possibly correlated with increased vascular density.
To evaluate the relation between hypervascularization and vascular endothelial growth factor (VEGF) in the thyroid glands of patients with Graves disease, 19 Graves disease tissues and 6 normal thyroid tissues were studied by immunohistochemistry, in situ hybridization (ISH), and reverse transcriptase-polymerase chain reaction. The mean microvascular densities per follicle and per millimeter of the thyroid follicles' circumferential length in the Graves disease tissues (mean 3.37 and 13.91) were significantly higher than those in the normal thyroid tissues (mean 2.15 and 7.28) (tied P = .0005, P = .0185, and P < .05, respectively). An antibody against VEGF markedly reacted with hyperplastic follicular cells in Graves disease. The intensity was especially strong in the cells covering papillary growth regions containing accumulated microvessels. By ISH, VEGF messenger RNA (mRNA) signals were also detected in the hyperplastic follicular cells in Graves disease tissues and were especially strong in papillary growth regions. The VEGF receptor-1 (Flt-1) protein and mRNA were observed in endothelial cells of all Graves disease tissues. These findings suggest that hypervascularity in Graves disease tissues is related to upregulated VEGF expression in hyperplastic follicles.
Adult↗
Thyroid stimulating hormone downregulates vascular endothelial growth factor expression in FRTL-5 cells.
We studied the regulation of the expression of vascular endothelial growth factor (VEGF) by TSH in monolayer cultures of rat thyroid FRTL-5 cell lines. The VEGF mRNA synthesis was significantly inhibited by TSH as well as dibutyryl cyclic adenosine monophosphate (cAMP) in a dose-dependent manner in FRTL-5 cells. This observation is contrary to previously published results using the thyroid follicular culture system. Our results suggest that the direct effect of TSH/cAMP is to inhibit the VEGF synthesis in monolayer cells.
Animals↗
Alterations of basement membrane in di-isopropanolnitrosamine-induced carcinogenesis of the rat thyroid gland: an immunohistochemical study.
Alterations of basement membrane (BM) in di-isopropanolnitrosamine (DIPN)-induced carcinogenesis of the rat thyroid gland were examined by means of immunohistochemical localization of collagen type IV (CN-IV), laminin (LN), and fibronectin (FN) in prenodular and nodular thyroid lesions, correlating with the morphogenesis and proliferative activity of these lesions. Adult male rats of the Wistar strain were injected s.c. in the back with DIPN, and the thyroid glands were removed at the 15th and 30th week of treatment. Each of 133 thyroid lesions was histochemically analyzed. The follicular epithelial BM as revealed by CN-IV and LN was discontinued or completely lost during the progression of thyroid lesions from pre-nodular to nodular lesions and finally overt carcinomas. At the same time, the BM of vascular endothelial cells demonstrated a loss of dense capillary networks of follicles, a sinusoidal dilatation and, predominantly in carcinomas, development of interstitial-type blood vessels. However, FN, which was hardly stained in the normal thyroid tissue, was remarkably deposited in the interstitium of invasive carcinomas. These observations strongly suggested that alterations of BM structure play a key role in the morphogenesis of rat thyroid tumors, and that the expression of FN is an important step in the invasive growth of thyroid tumors.
Animals↗
Expression of thyroid transcription factor-1 (TTF-1) in human C cells and medullary thyroid carcinomas.
Thyroid transcription factor-1 (TTF-1) has been known to regulate the transcriptional activity of thyroid-specific genes in thyroid follicular cells. We recently identified TTF-1 mRNA expression in rat thyroid C cells. The current study was undertaken to elucidate how TTF-1 is expressed in human C cells and medullary thyroid carcinomas (MTCs), and how this expression influences the functions and clinical behavior of these cells. By immunohistochemistry, the nuclei of normal and hyperplastic C cells distinctively reacted with antibody against TTF-1, whereas the immunostaining intensity in C cells was rather weak and heterogeneous in comparison with that in follicular cells. Identical TTF-1 immunoreactivity was observed in all 15 MTC specimens examined. The reaction intensity did not depend on tumor patterns or cell features. In nonisotopic in situ hybridization, an antisense riboprobe clearly hybridized the cytoplasms of C cells and MTC cells, which concurrently showed immunohistochemical positivity for calcitonin. Northern blot analysis indicated a marked hybridization with TTF-1 mRNA of approximately 2.3 kb in an MTC specimen. Furthermore, the presence of TTF-1 mRNA was confirmed by reverse transcription polymerase chain reaction (RT-PCR) in the human MTC cell line, TT. Our results suggest that human thyroid C cells and MTC cells express TTF-1 in connection with their functional ability. Therefore, TTF-1 expression can be a functional marker not only for follicular cells and follicular cell tumors but also for C cells and medullary C cell carcinomas.
Adolescent↗
Use of crypt isolation to determine loss of heterozygosity of multiple tumor suppressor genes in colorectal carcinoma.
Analysis of loss of heterozygosity (LOH) is very important in the study of tumor suppressor genes. However, accurate LOH analysis of tumor suppressor genes is difficult because of dilution by contaminating non-tumor DNA. Thus, enrichment of tumor DNA is required to accurately determine LOH of the tumor. We developed a new application of the fluorescent polymerase chain reaction by coupling it with crypt isolation to accurately assess the incidence of LOH of tumor suppressor genes in 45 colorectal carcinomas. LOH was observed at p53 in 26 of 37 tumors (70.3%), at APC in 13 of 35 (37.1%), at DCC in 16 of 25 (64.0%), at NF-2 in 5 of 23 (21.7%), and at nm23 H-1 in 7 of 30 (23.3%). We could clearly determine LOH of these genes because the crypt isolation technique was used. Although the incidence of LOH at each of these loci, as determined by using this technique, was similar to that obtained in previous studies using conventional methods, this method provides a simpler, more accurate way to assess LOH. In addition, the morphology of the samples can be analyzed before genetic analysis.
Adenocarcinoma, Mucinous↗
Thyroid transcription factor-1 in normal, hyperplastic, and neoplastic follicular thyroid cells examined by immunohistochemistry and nonradioactive in situ hybridization.
Thyroid transcription factor-1 (TTF-1) has been known to regulate the transcriptional activity of thyroid-specific genes. We examined the expression of TTF-1 in non-neoplastic and neoplastic thyroid tissues. By immunohistochemistry, the nuclei of normal and hyperplastic follicular cells strongly reacted with the antibody against TTF-1. Immunohistochemistry also revealed a distinctive nuclear positivity of TTF-1 in all 33 differentiated follicular cell tumors, including 15 follicular adenomas, 5 follicular carcinomas, and 13 papillary carcinomas. No immunoreactions were observed in three of four undifferentiated carcinomas, whereas an isolated and weak nuclear positivity was obtained in one. In normal and hyperplastic tissues, the distribution of TTF-1 was fairly related to that of thyroid-specific proteins thyroglobulin and thyroperoxidase. However, discrepancies in the distribution were observed in tumor tissues. By in situ hybridization, the riboprobe hybridized distinctively with the cytoplasm of neoplastic cells as well as normal follicular cells. Papillary carcinoma cells expressed TTF-1 mRNA in all but two cases, and its expression was also demonstrated in one of four undifferentiated carcinomas. Reverse transcription-polymerase chain reaction confirmed the presence of TTF-1 mRNA in two human undifferentiated carcinoma cell lines, TTA-1 and TTA-2. In conclusion, the investigation of TTF-1 provides useful information on the functional activities and/or differentiation of thyroid tumors and may lead to an increase in our understanding of the biologic nature of thyroid tumors.
Adenoma↗
Incidentally detected liver metastasis of well-differentiated follicular carcinoma of the thyroid, mimicking ectopic thyroid.
A case of incidentally detected liver metastasis of follicular carcinoma of the thyroid, histologically mimicking ectopic thyroid, is described. The patient was a 48-year-old woman. A 2-cm mass was incidentally detected in the left lobe of the liver by abdominal computed tomography (CT) scan. Partial liver resection was performed for diagnosis and treatment. Histologically, the liver nodule was composed of small-to-large follicles containing colloid material. The lining epithelium was flat or cuboidal and showed no cellular or nuclear atypia. Immunohistochemical studies for thyroid-specific proteins, thyroglobulin (Tg), triiodothyronine (T3) and thyroxine (T4), suggested that the nodule was of thyroid origin. Therefore, a differential diagnosis of metastasis of well-differentiated thyroid cancer, ectopic thyroid tissue and teratoma was made. The patient had a history of subtotal thyroidectomy performed 8 years ago due to a thyroid tumor. The original surgical specimens of the thyroid tumor were diagnosed as follicular adenoma. Additional sections of the specimen were reviewed and an area of convincing vascular invasion was found that was suggestive of follicular carcinoma. Subsequent whole-body examination failed to find other metastases. It was determined that the liver tumor was metastasized from well-differentiated follicular carcinoma of the thyroid.
Adenocarcinoma, Follicular↗
Allelic losses of 17p, 5q, and 18q loci in diploid and aneuploid populations of multiploid colorectal carcinomas.
17p, 5q, and 18q allelic losses are involved in the pathogenesis and progression of colorectal carcinoma, and DNA aneuploidy in this type of cancer is thought to result from alterations of these chromosomal loci. However, genetic differences between diploid and aneuploid populations of multiploid carcinoma, defined as the coexistence of diploid and aneuploid populations in the same area, remain unclear. The differences in 17p, 5q, and 18q allelic losses between the diploid and aneuploid populations in 24 sporadic DNA multiploid colorectal carcinomas were analyzed by use of crypt isolation coupled with DNA cytometric sorting and polymerase chain reaction assay. 17p Allelic loss was observed in 7 of 22 diploid populations excluding 1 case of microsatellite instability but was found in 21 of 23 aneuploid populations. Although 5q allelic loss was detected in only 3 of 22 diploid populations, 13 of 22 aneuploid populations had 5q allelic loss. Losses of the 18q allele were frequently found in aneuploid populations (15 of 20), although no 18q allelic loss was detected in corresponding diploid populations. 17p Allelic losses may play an important role in the progression from a diploid status to an aneuploid status in a specific subset of colorectal cancer. However, 18q or 5q allelic losses do not appear to precede nor to facilitate the aneuploid clonal divergence of cancer cells. Multiploidy is a useful model to study genetic alterations between diploid and aneuploid populations.
Adult↗
Pendrin, the protein encoded by the Pendred syndrome gene (PDS), is an apical porter of iodide in the thyroid and is regulated by thyroglobulin in FRTL-5 cells.
Pendred syndrome is an autosomal recessive disorder characterized by congenital deafness and thyroid goiter. The thyroid disease typically develops around puberty and is associated with a mild organification defect, characterized by an inappropriate discharge of iodide upon perchlorate stimulation (a positive perchlorate discharge test). The gene (PDS) mutated in Pendred syndrome is expressed in thyroid and encodes a 780-amino acid protein (pendrin) that has recently been shown to function as an iodide/chloride transporter. We sought to establish the location of pendrin in the thyroid and to examine the regulatory network controlling its synthesis. Using peptide-specific antibodies for immunolocalization studies, pendrin was detected in a limited subset of cells within the thyroid follicles, exclusively at the apical membrane of the follicular epithelium. Interestingly, significantly greater amounts of pendrin were encountered in thyroid tissue from patients with Graves' disease. Using a cultured rat thyroid cell line (FRTL-5), PDS expression was found to be significantly induced by low concentrations of thyroglobulin (TG), but not by TSH, sodium iodide, or insulin. This is different from the established effect of TG, more typically a potent suppressor of thyroid-specific gene expression. Together, these results suggest that pendrin is an apical porter of iodide in the thyroid and that the expression and function of both the apical and basal iodide porters are coordinately regulated by follicular TG.
Amino Acid Sequence↗
Autonomic nerve tumour with skeinoid fibres: ultrastructure of skeinoid fibres examined by quick-freezing and deep-etching method.
A case of gastrointestinal autonomic nerve tumour with skeinoid fibres (SFs) of the jejunum in a 79-year-old Japanese man, was examined by the quick-freezing and deep-etching (QF-DE) method. The tumour consisted of spindle cells with immunohistochemical reactions for vimentin, NSE and CD34. Electron microscopically, features of the neural cells of the myenteric plexus were observed. The QF-DE method demonstrated intercellular meshwork structures, consisting of thin filaments (7-15 nm), with granular deposits. Fully developed parts of the deposits formed nodular aggregates composed of irregularly surfaced thick fibrils (30-48 nm) with a tendency to linear arrangement (SFs). We detected many interconnecting thin filaments (ICTFs) between the SFs, which were pre-existing components in the meshwork, avoiding the granular deposits. The focal thickening formed by the connection between SFs and ICTFs revealed a periodicity typical of SFs (33-45 nm). We conclude that SFs are formed by decoration of the granular deposits along pre-existing intercellular meshwork structures.
Abdominal Neoplasms↗
Confocal laser scanning microscopic observation of angioarchitectures in human thyroid neoplasms.
Confocal laser scanning microscopy (CLSM) was employed to study the blood vascular system of human thyroid tumors. CLSM observation combined with immunohistochemistry for type IV collagen clearly visualized 3-dimensional images of the microvascular structures. CLSM observation showed that normal thyroid follicles were tightly covered by branching microvessels, whereas microvessels in follicular adenomas were more prominent and more irregular in shape. Microfollicular adenomas showed that neoplastic small follicles were attached to the capillaries and had a "grape-like" appearance. Strikingly well-developed vascular networks were seen in neoplastic follicles of papillary carcinomas. Interestingly, papillae of papillary carcinoma occasionally contained contained aggregated vascular complexes (glomeruloid structure) composed of tortuous, densely packed, and irregularly arranged small vessels. Such aggregated vascular complexes were seen in 5 of 7 papillary carcinoma tissues but not in other histological thyroid tumors. Our findings indicate that the fundamental vascular pattern correlates well with the growth pattern, suggesting an interdependence between parenchyma and stroma characteristic for thyroid tumors. CLSM observation combined with immunohistochemistry may contribute to a better understanding of morphological characteristics of angioarchitecture in human surgical materials.
Adenoma↗
Expression of vascular endothelial growth factor (VEGF) in human thyroid neoplasms.
Vascular endothelial growth factor (VEGF), also known as vascular permeability factor (VPF), is an angiogenic factor that plays important roles in tumor growth. Angiogenesis studies on VEGF deal with various types of malignant tumors, but very little is known about the role or significance of VEGF in human thyroid neoplasms. Therefore, in the current study, we determined whether VEGF is found in normal and neoplastic thyroids and whether its expression is altered in different histological types of thyroid neoplasms. Reverse-transcription polymerase chain reaction (RT-PCR) analysis showed that all specimens of thyroid tumors expressed bands corresponding to 121-, 165-, and 189-amino acid forms of VEGF. Northern blot analysis showed an increase in VEGF mRNA levels in neoplastic tissues in comparison with normal thyroid samples. By nonisotopic in situ hybridization, most of the tumor cells in follicular adenomas expressed VEGF mRNA, whereas VEGF mRNA expression was identified only in epithelium of isolated follicles in normal thyroid tissues. In papillary thyroid carcinomas, an intense labeling with VEGF probe was often found in overlying tumor cells of neoplastic papillae. VEGF expression was distinctly intensified in undifferentiated carcinoma cells that were immediately adjacent to necrotic foci. The immunohistochemical localizations of VEGF protein were comparable to the localization of VEGF mRNA. In conclusion, our results suggest that the histological types of thyroid tumor may determine the vascular pattern through a paracrine mechanism involving VEGF.
Blotting, Northern↗
In vivo expression of thyroid transcription factor-1 RNA and its relation to thyroid function and follicular heterogeneity: identification of follicular thyroglobulin as a feedback suppressor of thyroid transcription factor-1 RNA levels and thyroglobulin synthesis.
We used in situ hybridization to evaluate thyroid transcription factor-1 (TTF-1) RNA expression in individual follicles and related this to thyroglobulin (Tg) synthesis in vivo, as estimated by immunohistochemical analysis. We studied the thyroids of Wistar rats treated with thyroxine (T4) or propylthiouracil (PTU), each of which modulates TSH levels, but affects follicular function and Tg accumulation in the follicular lumen very differently. We show that TTF-1 RNA levels in vivo correlate directly with an increase in the cytoplasmic accumulation of Tg within the cells of individual follicles. Because TTF-1 increases Tg gene expression, RNA levels, and protein synthesis in thyroid cell cultures and because there is no correlation with TSH-increased Tg degradation within the follicular lumen, the increased cytoplasmic accumulation of Tg in vivo is interpreted to reflect TTF-1-increased Tg synthesis. Increases in serum TSH levels in the PTU or T4 treated animals did not always correlate with increases in this measure of increased Tg synthesis; and TSH levels did not always correlate with changes in TTF-1 RNA levels that would be expected to accompany increased Tg synthesis. As one possibility, this suggested there might be a hitherto unrecognized suppressor of TTF-1 RNA levels and TSH-induced Tg synthesis in individual follicles. The immunohistochemical data suggested that this suppressor might be follicular Tg itself. Supporting this possibility, we show that physiological concentrations of highly purified 19S follicular Tg decrease TTF-1 RNA levels in rat FRTL-5 thyroid cells and inhibit the action of TSH to increase Tg synthesis. We therefore suggest that follicular Tg is a feedback autoregulator of thyroid function that can counterregulate TSH actions on thyroid function in vivo and in thyroid cells in culture. We suggest this phenomenon contributes to follicular heterogeneity in vivo.
Animals↗
Thyrotropin prevents apoptosis by promoting cell adhesion and cell cycle progression in FRTL-5 cells.
Apoptosis has been shown to be involved in endocrine tissue homeostasis as well as regression due to hormone deprivation. The goal of this study was to induce apoptosis and to investigate a potential role of TSH as a survival factor in thyroid follicular cells (FRTL-5) in vitro. Our results indicated that FRTL-5 cells underwent anchorage-dependent apoptosis when plated in the absence of serum and hormones, but when the cells became attached to the substrate by addition of TSH in the medium, apoptosis was prevented. The apoptosis was evaluated by positive terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end labeling staining, typical apoptotic bodies by electron microscopy, DNA ladder by gel electrophoresis, and subdiploidy by propidium iodide-stained flow cytometry. TSH was shown to prevent apoptosis and maintain cell viability. cAMP partly mimicked this effect, which was inhibited by a specific inhibitor of protein kinase A, H-89. While investigating the mechanisms of apoptosis, we observed that the phosphorylated focal adhesion kinase was strengthened by TSH. Furthermore, FRTL-5 cells were found to undergo growth arrest in the G1 phase in the absence of TSH, accompanied by an elevated level of cyclin-dependent kinase inhibitor, p27, and a decreased level of cyclin D. In contrast, TSH promoted transition from G1 to S phase by decreasing P27 protein and increasing cyclin D expression. We concluded that in addition to regulating growth and differentiation, TSH may function as a survival factor in thyroid cells by preventing anchorage-dependent apoptosis in FRTL-5 cells partly via the cAMP pathway.
Animals↗
Accumulated basement membrane material in hyalinizing trabecular tumors of the thyroid.
We report here four additional cases of hyalinizing trabecular adenoma of the thyroid and describe the findings of the accumulated basement membrane (BM) material. Focal lumpy depositions of BM material were noted in the stroma of all four tumors and were particularly prominent in two. Antibodies against type IV collagen and laminin strongly immunoreacted with this material, which also showed diastase-resistant periodic acid-Schiff positivity. The ultrastructural findings of accumulated basement membrane was examined in detail. The most striking ultrastructural findings were seen at the periphery of the cell clusters, where the basal aspect of the tumor cells rested on a highly accumulated BM materials displaying mesh-like, fir-branching, or frame-like appearances. Intracytoplasmic BM islands were frequently observed in neoplastic cells. These BM islands were membrane-bounded and focally continuous with the cell surface membrane, suggesting pseudointracytoplasmic depositions of BM material due to marked cytoplasmic infoldings. From the findings, electron microscopic features of accumulated BM material are very characteristic in hyalinizing trabecular adenomas and can be discernible from other histologic types of BM-producing tumors.
Adenoma↗
Immunohistochemical estimations of growth activity to predict biological behavior of pheochromocytomas.
To determine the usefulness of immunohistochemical estimations of growth activity to predict biological behavior of pheochromocytomas (PC), 42 cases of PC (33 adrenal and nine extra-adrenal tumors) were studied by immunohistochemistry using the monoclonal antibody, MIB-1. The mean MIB-1-positive cell rate for all 42 PCs was low (1.4%). The MIB-1-positive cell rates of adrenal PCs were significantly higher in malignant tumors (mean, 3.30%) than in benign tumors (mean, 0.81%) (P = .0184). In extra-adrenal PCs, the difference between benign (mean, 0.44%) and malignant (mean, 5.10%) tumors was also statistically significant (P = .0004). Other clinicopathologic factors, including family history, age, sex, and multiple endocrine neoplasm (MEN) type II status were also examined and were not statistically significant. In conclusion, estimation of the MIB-1-positive cell rate is useful for histologic distinction between benign and malignant pheochromocytomas. Especially, it is important to note that a high MIB-1-positive cell rate (>2%) is highly suggestive of malignancy.
Adolescent↗