Hematopoietic Stem Cell Antigen-1 (Sca-1) Expression in Different Lymphoid Tissues of Female Mice Treated With GnRH Agonist

PROBLEM : Our earlier studies have demonstrated a general suppression of leukocyte maturation upon GnRH agonist treatment in mice and suggested a potential effect at an early stem cell stage of leukocyte development. METHOD : Three-week old Balb/c and C57BL/6 female mice received 50 μlg injections of Lupron depot or placebo. Sequential changes in Sca-1⁺ cells in the bone marrow, thymus, blood and spleen were studied by flow cytometry. RESULTS : In bone marrow, the absolute numbers of Sca-1⁺ cells were significantly decreased at 2 weeks in C57BL/6 mice whereas a decreasing trend was noted in Balb/c mice following agonist administration. Concomitantly, thymocytes expressing Sca-1⁺ cells were significantly increased at 2 weeks in C57BL/6 mice, but were significantly decreased in Balb/c mice. Significant decreases in Sca-1⁺ cells were also observed in spleen and blood in Balb/c mice whereas no significant differences were observed in C57BL/6 mice. CONCLUSIONS : These data suggest GnRH agonists affect hematopoietic stem cell development in mice. The effects observed vary with different genetic backgrounds. In Balb/c mice these effects are more pronounced, and appear to result in the inhibition of stem cell maturation. In contrast, GnRH agonist enhances stem cell maturation in C57BL/6 mice.     

自体甲状腺组织与干细胞移植治疗甲状腺功能减退症的研究进展

不可逆性甲减患者需要终身服用甲状腺激素，对患者的日常工作和生活造成了很大的不便。随着近年来对自体甲状腺组织与干细胞移植研究的进展，有望解决甲减病人终身服药这一问题。自体甲状腺组织移植的动物实验以及人体试验均表明：甲状腺移植物不但能够存活，而且能够发挥作用。最新的胚胎干细胞（Embryonic stemcell，ESC）研究证明，ESC可以分化为甲状腺滤泡细胞。     

Enamel Matrix Serine Proteinase 1: Stage-Specific Expression and Molecular Modeling

Enamel proteins are cleaved by proteinases soon after their secretion by ameloblasts. Intact proteins concentrate in the outer enamel at or near the growing tips of the enamel crystallites while cleavage products accumulate in the deeper enamel. In the transition and early maturation stages there is a dramatic increase in proteolytic activity. This activity, coupled with the diminished secretory and increased reabsorptive functions of ameloblasts, leads to a precipitous fall in the amount of enamel protein in the matrix. Recently we have cloned and characterized an mRNA encoding a tooth-specific serine proteinase designated enamel matrix serine proteinase 1 (EMSP1) [Simmer et al., JDR (1998) 77: 377]. EMSP1 can be detected in the inner enamel during the secretory stage and its activity increases sharply during the transition stage. Stage-specific Northern blot analysis demonstrates this increase is accompanied by a parallel increase in the amount EMSP1 mRNA. A 3-dimensional computer model of EMSP1, based upon the crystal structure of bovine trypsin, has been generated and analyzed. All six disulfide bridges as well as the active site are conserved. Changes in the peptide binding region and the specificity pocket suggest that interaction of the proteinase with protein substrates is altered, potentially causing a shift in substrate specificity. The calcium binding region of trypsin is thoroughly modified suggesting that the calcium independence of EMSP1 activity is due to an inability to bind calcium. The three potential N-linked gly-cosylation sites, N104, N139 and N184, are in surface accessible positions away from the active site.     

Expression and Functions of P-glycoprotein (mdr 1 gene product) in Normal and Malignant Tissues

This paper describes the cellular and tissue distribution of P-glycoprotein (P-GP) (mdrl gene product), the role of P-GP in vivo and immunodiagnosis of multi-drug-resistant cancers. We mainly used MRK 16 monoclonal antibody (MAb) reactive with P-GP. P-GP was found to be expressed very strongly in the adrenal cortex of adults and strongly in the renal tubules of the kidney, capillary blood vessels of the brain, and also in placenta. Interestingly, P-GP was not distributed in fetal and neonatal adrenals, and thus may be closely related to adrenal maturation. A high level of P GP expression was also seen in all cases of functional hormone producing adrenal tumor, one case of insulinoma, two cases of untreated colonic cancer, one case each of untreated lung cancer, gastric cancer and breast cancer, six cases of renal cell carcinoma and 17 cases of bladder cancer. Using flow cytometry and immunocytochemistry, we investigated the reactivity of MRK 16 MAb with peripheral human mononuclear cells (mainly blastic cells and lymphocytes) from 31 patients with leukemia or malignant lymphoma. Reactivity with MRK 16 MAb was observed in five cases. Some cases reflected the prior administration of adriamycin, vincristine and VP 16, which are known to induce P GP expression. P GP MRK 16 protein A-Sepha-rose complex derived from human adrenal possessed marked ATPase activity. These data suggest that P-GP may play a physiological role in the human adrenal. Finally, diagnostic criteria of multi-drug-resistant cancers are presented.     

p27(kip1) and Other Cell-Cycle Protein Expression in Normal and Neoplastic Endocrine Tissues

Endocrine tumors are often diagnostic challenges. Recent studies have suggested that proteins that regulate cell cycle may have diagnostic and prognostic utility in endocrine tumors. p27^{kip 1} (p27) is a cyclin-dependent kinase inhibitor that regulates the transition from the G1 to the S phase of the cell cycle. p27 and other cell-cycle proteins are becoming increasingly important in assessing the biologic behavior of endocrine neoplasms, classifying hyperplastic and neoplastic endocrine tissues, and in the progression of endocrine tumors. p27 appears to separate normal from neoplastic endocrine tissues and, in some cases, benign from malignant endocrine tumors. However, there is overlap in p27 expression among individual cases of benign and malignant tumors, and p27 has only limited prognostic utility in endocrine tumors compared to some epithelial tumors such as breast and prostate neoplasms. Thus, more effective molecular and cellular markers that can be used for diagnostic and prognostic purposes in endocrine pathology are needed.     

Clinical Utility of KAP-1 Expression in Thyroid Lesions

Although there are evidences of the involvement of KAP-1 in other tumors, data on differentiated thyroid carcinomas (DTC) are still lacking. We aimed to evaluate KAP-1 clinical utility in the diagnosis and prognosis of DTC. We used both visual immunohistochemistry and a semiquantitative analysis to evaluate KAP-1 expression in 230 thyroid carcinomas and 131 noncancerous thyroid nodules. There were 43 follicular carcinomas (FC) and 187 papillary thyroid carcinomas (PTC), including 130 classic (CPTC), 4 tall cells (TCPTC), and 53 follicular variants (FVPTC). Patients were followed up for 53.8?±?41 months. They were classified as free-of-disease (142 cases) or poor outcome (25 cases—10 deaths), according to their serum Tg levels and image evidences. KAP-1 was identified in 78 % PTC, 75 % TCPTC, 74 % FC, 72 % FVPTC, 55 % FA, 44 % hyperplasia, and 11 % normal thyroid tissues. A ROC analysis identified malignant nodules with 69 % sensitivity and 75 % specificity, using a cutoff of 73.19. In addition to distinguishing benign from malignant thyroid tissues (p?<?0.0001), KAP-1 expression differentiated CPTC from nodular hyperplasia (p?<?0.0001), CPTC from FA (p?=?0.0028), FVPTC from hyperplasia (p?=?0.0039), and FC from hyperplasia (p?=?0.0025). Furthermore, KAP-1 was more expressed in larger tumors (>4 cm; p?=?0.0038) and in individuals who presented recurrences/metastases (p?=?0.0130). We suggest that KAP-1 may help diagnose thyroid nodules, characterize follicular-patterned thyroid lesions, and identify individuals with poor prognosis.     

Raf-1 Kinase Inhibitory Protein Expression in Thyroid Carcinomas

Raf-1 kinase inhibitory protein (RKIP) has been implicated in several fundamental signal transduction pathways that control cellular growth, differentiation, apoptosis and migration. RKIP is reduced in a variety of human carcinomas, but RKIP expression in thyroid carcinomas has not been analyzed at the protein level. In this study, we examined the immunohistochemical expression of RKIP in various subtypes of thyroid carcinoma. Immunostaining for RKIP was performed on 104 cases of primary thyroid carcinoma (40 papillary, 29 follicular, 11 medullary, 11 poorly differentiated, and 13 anaplastic carcinomas) and 26 cases of nodal metastatic tumor (17 papillary, 4 medullary, and 5 anaplastic carcinomas). Normal thyroid tissue and all cases of follicular, papillary, and medullary carcinomas showed uniform, strong cytoplasmic immunoreactivity for RKIP. With the exception of one case, poorly differentiated carcinomas also revealed strong RKIP expression. In contrast, RKIP expression was completely absent in all anaplastic carcinomas. The transition zone from the differentiated carcinoma component (strong RKIP expression) to the anaplastic carcinoma component (no RKIP expression) demonstrated a completely opposite pattern of RKIP immunoreactivity. This reduction of RKIP expression in anaplastic carcinoma was statistically significant (P?<?0.0001). Additionally, RKIP expression of nodal metastatic tumors corresponded with that of primary tumors: metastatic papillary and medullary carcinomas showed uniform, strong cytoplasmic RKIP immunoreactivity, in contrast, in metastatic anaplastic carcinomas, RKIP expression was completely absent. RKIP expression is significantly reduced in anaplastic thyroid carcinoma as compared to other subtypes of thyroid carcinoma. Further studies are necessary to elucidate the precise mechanism of RKIP action in anaplastic thyroid carcinoma.     

Physiological Relevance of Thyroid Stimulating Hormone and Thyroid Stimulating Hormone Receptor in Tissues other than the Thyroid

Decades of research have provided strong evidence for a reciprocal relationship between the immune system and hormones of the hypothalamus–pituitary–thyroid (HPT) axis. Thyroid stimulating hormone (TSH), in particular, has been shown to have a variety of immune-regulating cytokine-like activities that can influence the outcome of T cell development in the thymus and intestine, and can affect the magnitude of antibody and cell-mediated responses of peripheral lymphocytes. Production of TSH and the expression of the TSH receptor are widely but selectively distributed across many different types of hematopoietic cells in the bone marrow, as well as among subsets of dendritic cells, monocytes and lymphocytes in the spleen and lymph nodes. In addition to their role in immunity, the involvement of TSH-producing hematopoietic cells in the microregulation of thyroid hormone activity represents a novel and potentially important aspect of the TSH-mediated immune-endocrine circuit.     

Thyroid Peroxidase Expression in Diseased Human Thyroid Glands

Histoenzymologic studies of the human thyroid have been restricted to attempts to differentiate benign from malignant tumors and, to our knowledge, there is no systematic study on the distribution and behavior of enzymes for several types of lesions of the thyroid gland. The aim of the present study was to investigate thyroid peroxidase (TPO) expression in diseased thyroids, as well as to study the role of this enzyme as a parameter to define the biological behavior of thyroid lesions. A total of 117 neoplastic and nonneoplastic lesions of the thyroid were evaluated. The expression of TPO was determined by the analysis of at least 200 cells/specimen. A rate of 80% of positive cells was considered a threshold for TPO positivity. TPO expression was detected in all nonneoplastic lesions of thyroid as well as in 78.8% of the adenomas. We also observed positivity for TPO in 20% of malignant lesions. Therefore, these findings do not allow separation of benign and malignant lesions of the thyroid based in the expression of TPO. Presented at the XXI International Congress of the International Academy of Pathology and 12th World Congress of Academic and Environmental Pathology, Budapest, Hungary, 20–25 October 1996.     

Differential Expression of miRNAs in Papillary Thyroid Carcinoma Compared to Multinodular Goiter Using Formalin Fixed Paraffin Embedded Tissues

microRNAs (miRNAs) are approximately 22 nt RNAs that negatively regulate target gene expression. Their dysregulation has been implicated in the pathogenesis of a number of human cancers, including papillary thyroid carcinoma (PTC). Whereas previous studies using microarray technologies have largely relied on the ability to procure fresh tissue at the time of surgery to characterize miRNA signatures in PTC, we exploited the ability to procure sufficient miRNA from formalin-fixed paraffin-embedded (FFPE) tissue to describe a series of miRNAs whose expression is dysregulated in PTC compared to benign proliferative multinodular goiter (MNG). We identified 13 miRNAs upregulated and 26 miRNAs downregulated in PTC versus MNG. These include miRNA-21, miRNA-31, miRNA-221, and miRNA-222. Their dysregulation was further validated by real time RT-PCR analysis in an independent set of FFPE tissues. Many of these have previously been described in fresh tissue studies as altered in PTC, confirming the utility of this approach. These results further highlight the applicability of miRNA expression patterns as potential markers of human cancer, and our results suggest that FFPE tissues are suitable resources for such miRNA expression analyses. The ability to utilize FFPE tissue in the molecular characterization of human malignancy will unlock a rich resource for future cancer studies. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

CD26 (Dipeptidyl Aminopeptidase IV) Expression in Normal and Diseased Human Thyroid Glands

The objective of the present study was to investigate CD26 (dipeptidyl aminopeptidase IV) expression in normal and diseased thyroids and its relation to differentiation and cell proliferation. CD 26 was also evaluated as a possible marker of malignancy in thyroid neoplasias. A total of 38 normal thyroids and 117 diseased thyroids (neoplastic and non-neoplastic) were evaluated. CD26 and thyroglobulin (Tg) expression was determined by analyzing at least 200 cells/specimen. A minimum of 500 cells/specimen were counted to calculate the MIB-1-positive cell rate expressed as a percentage of total nucleated epithelial cells. CD26 expression was absent in all thyroids from fetuses and children. Among the adults, 7.1% had CD26 expression only in oncocytic metaplastic areas. In 3 of the 7 elderly subjects, CD26 expression was present in 0.2–90% of epithelial cells. CD26 expression was observed in all diseased thyroids. Since this enzyme is also expressed in benign conditions, it is not useful as a marker of malignancy. There was no relationship between CD26 and Tg expression. The MIB-1-positive cell rate was found to be low for all kinds of thyroid tissues, and when the cell proliferation rate was analyzed according to CD26 expression, a greater cell proliferation rate was found in CD26-positive differentiated (follicular and papillary) carcinomas than in CD26-negative carcinomas. These results demonstrate that expression of this enzyme is related to the proliferative activity of follicular cells.     

Expression of Hepatocyte Growth Factor (HGF) and its Receptor (MET) in Medullary Carcinoma of the Thyroid

The tyrosine kinase receptor encoded by the MET oncogene has the unusual property of mediating the invasive growth of epithelial cells upon binding with the hepatocyte growth factor (HGF). The MET/HGF receptor is known to be overexpressed in thyroid carcinomas originated from follicular cells, but has not been reported in C cell tumors. To investigate the role of HGF and of its receptor (encoded by MET oncogene) in medullary carcinoma of the thyroid (MCT), we studied the expression of HGF and MET in 20 cases by means of different techniques. By RT-PCR, HGF mRNA was found in 10/20 cases, while MET mRNA presence was demonstrated in 8/20, of which 7 also expressed HGF. Northern blot analysis and in situ hybridization were performed in selected cases and confirmed RT-PCR data in some cases, although the lower sensitivity of these procedures did not allow the identification of all RT-PCR positive cases. By immunohistochemistry (using specific monoclonal antibodies) HGF was demonstrated in 8/9 RT-PCR positive cases ald a monoclonal to MET immunostained 5/6 RT-PCR positive cases. All receptor positive cases also expressed the ligand in the same tumor cell population. These findings demonstrate MET and HGF co-expression in a subset of MCT, in which autocrine/paracrine circuits may be active. No correlation was found between HGF/MET expression and clinico-pathological parameters, except for the more common multifocality of HGF/MET positive MCT. Whether the potential activation of MET in MCT is responsible for local invasion and malignant evolution is to be further investigated, especially in multifocal and aggressive tumors.     

Thyroid Peroxidase and Thyroglobulin Expression in Normal Human Thyroid Glands

The objective of the present study was to investigate thyroid peroxidase (TPO) and thyroglobulin (Tg) expression in normal thyroid tissue. Thirty-eight normal thyroids from fetuses(1) children, adults, and elderly subjects were evaluated. TPO and Tg expression was determined by analyzing at least 200 cells/specimen. A value of 80% was considered to be the threshold for TPO positivity. In terms of age, TPO expression occurs in fetuses along with follicle differentiation and is absent in solid follicles. TPO staining was cytoplasmic, and was more intense in the apical membrane in tissue from fetuses, children, and young adults. A perinuclear rang was found in tissue from older adults and from the elderly subjects. There was concomitant TPO and Tg expression in all groups studied. Tg expression was observed in all normal thyroids from all age groups. Tg expression was extremely variable (10-100% of the cells) and fainter than TPO expression.     

Expression of Simple Mucin Type Antigens and Lewis Type 1 and Type 2 Chain Antigens in the Thyroid Gland: An Immunohistochemical Study of Normal Thyroid Tissues,Benign Lesions,and Malignant Tumors

In order to characterize the pattern of expression of carbohydrate structures in several types of thyroid tissues and to evaluate the putative usefulness of the detection of such antigens in diagnostic surgical pathology, we undertook the immunohistochemical study of simple mucin type antigens (T, Tn, and sialyl Tn), Lewis type I antigens (Lewis a, sialyl Lewis a, and Lewis b), and Lewis type 2 related antigens (precursor type 2, H type 2, Lewis x, sialyl Lewis x, and Lewis y) in thyroid samples obtained from 65 patients. The material consisted on paraffin sections of normal thyroid (n = 43), benign lesions (13 goiters/ hyperplastic lesions and 15 adenomas), and malignant tumors (12 follicular carcinomas and 27 papillary carcinomas, 5 of which had lymph node metastases) of the thyroid follicular epithelium. Tn, T, and precursor type 2 antigens were the only antigens that were detected—and very rarely—in normal thyroid. Benign lesions were similar to normal thyroid despite displaying a higher prevalence of immunoreactivity for severa antigens of the three groups. Thyroid carcinomas presented a significantly higher level of expression of all types of simple mucin, Lewis type 1, and Lewis type 2 antigens than the normal thyroid and benign lesions. The expression of sialyl Tn was restricted to malignant tumors, and the expression of sialyl Lewis x was closely associated, though not exclusively, to papillary carcinomas. The immunoreactivity was stronger and the number of positive cases was higher in papillary than in follicular carcinomas. No differences were found between primary tumors and the respective metastases. The existence of distinct patterns of expression of carbohydrate antigens in different types of thyroid lesions points to the usefulness of the detection of some of these antigens in thyroid surgical pathology. The putative role of such antigens in the peculiar metastatic properties of thyroid carcinomas remains unsettled.     

MicroRNA Expression Profiles in Thyroid Tumors

MicroRNAs (miRNAs) constitute a recently identified class of small endogenous noncoding RNAs that act as negative regulators of the protein-coding gene expression and may impact cell differentiation, proliferation and survival, i.e., all fundamental cellular processes implicated in carcinogenesis. miRNA expression is deregulated in many types of human cancers, including thyroid cancer. The purpose of this review is to summarize the existing findings of miRNA deregulation in thyroid tumors and its potential role in thyroid cancer biology and molecular diagnostics.