Side population cells in anaplastic thyroid cancer and normal thyroid

Comparison of studies of cells derived from normal and pathological tissues of the same organ can be fraught with difficulties, particular with cancer where a number of different diseases are considered cancer within the same tissue. In the thyroid, there are 4 main types of cancer, three of which arise from follicular epithelial cells; papillary and follicular which are classified as differentiated, and anaplastic which is classified as undifferentiated.One assay that can be utilised for isolation of cancer stem cells is the side population (SP) assay. However, SP studies have been limited in part due to lack of optimal isolation strategies and in the case of anaplastic thyroid cancer (ATC) are further compounded by lack of access to ATC tumors. We have used thyroid cell lines to determine the optimal conditions to isolate viable SP cells. We then compared SP cells and NSP cells (bulk tumour cells without the SP) of a normal thyroid cell line N-thy ori-3-1 and an anaplastic thyroid cancer cell line SW1736 and showed that both SP cell populations displayed higher levels of stem cell characteristics than the NSP. When we compared SP cells of the N-thy ori-3-1 and the SW1736, the SW1736 SP had a higher colony forming potential, expressed higher levels of stem cell markers and CXCR4 and where more migratory and invasive, invasiveness increasing in response to CXCL12.This is the first report showing functional differences between ATC SP and normal thyroid SP and could lead to the identification of new therapeutic targets to treat ATC.     

Immunohistochemical localization of thyroid hormone in rat thyroid gland.

Direct and indirect immunofluorescence techniques were used to localize the thyroid hormones triidothyronine (T3) and thyroxine (T4) in adult rat thyroid gland. Optimum dilutions of the antisera were established and four tissue fixatives were investigated for usefulness in this technique. Use of antibodies specific for either T3 or T4 resulted in brilliant fluorescence in the colloid pools and apical cytoplasm of follicular cells. In all cases, the adjacent parathyroid gland was devoid of fluorescence. This report demonstrates that these dipeptide hormones can be localized by using immunofluorescence techniques.     

Changes in tight junctions of thyroid epithelium with changes in thyroid activity

The morphology of the tight junction of rat thyroid epithelium was examined in freeze-fractured material fixed in glutaraldehyde and briefly glycerinated. In normal thyroids the overall appearance of this junctional specialization resembled that of other cell types in many respects. Short-term changes in thyroid activity and hypophysectomy for 3 wk did not obviously affect the appearance of tight junctions. Feeding of the goitrogen, thiouracil, which stimulates secretion of thyroid-stimulating hormone, resulted in the appearance of some very narrow and some very wide, tight junctions or sometimes junctions with both wide and narrow regions within the same cell.     

Serum and thyroid tissue lipids in patients with thyroid tumors in euthyroidism

Plasma lipids of 24 euthyroid subjects with thyroid adenoma and non-toxic primary differentiated thyroid carcinoma (papillary and follicular types) were assessed and compared with a similar investigation conducted on 20 normal subjects. A parallel study with thyroid tumor tissues examined the lipid changes which occurred in the same group of patients. These were compared with the picture seen in 5 normal thyroids. The investigations examined the changes in total lipids; total, free and esterified cholesterol; total phospholipids; lecithin; cephalin and sphingomyelin; triglycerides and free fatty acids in both serum and thyroid tissue. Compared with normal subjects, the serum lipids were almost identical except for the concentration of free fatty acids which showed significantly lower values in the group with neoplastic changes. Tissue analysis of the cancerous thyroid however revealed a marked rise in virtually all lipid fractions but the cholesterol seemed to dominate the picture. The differential studies of total phospholipids for thyroid tissue membrane lipids further revealed a significant increase in the lecithin and sphingomyelin components of total phospholipids as well as the esterified cholesterol fraction in thyroid carcinoma. The changes in thyrophospholipids were more marked in females normal thyroids than males. An attempt has been made through evaluation of the results derived from differential lipid studies to elucidate the role of some of the various fractions determined and the possible effect of the changes described on thyroid hormone metabolism.     

Osteoporosis in thyroid diseases

Thyroid hormones play the essential role in the regulation of metabolism and bone remodeling in physiological conditions and in the course of thyroid dysfunction. Introduction of densitometry to the diagnostics of osteoporosis has made possible the evaluation of influence of both hyperthyroidism and hypothyroidism and their treatment on bone mineral density. Moreover it became possible to estimate the influence of treatment with exogenous thyroid hormones on the skeletal system. Authors presented mechanisms of the thyroid hormones action on bone tissue and analysed current state of knowledge concerning the influence of the thyroxine treatment with replacement and suppressive doses on the bone mineral density. The influence of thyroid hormones on the skeletal system with respect to premenopausal and postmenopausal period was also discussed. Great discrepancies in literature data and its reasons were underlined.     

Trends in thyroid imaging

The master choice for thyroid imaging remains the radioiodine thyroid scan with 123I or 99mTc. 131I has to be reserved for the follow-up of thyroid cancer only. Ultrasound may remain useful in certain situations but it does not integrate as it is the case with the radioisotopic scan together with morphological and functional information.     

Immunohistochemistry of thyroid hormones as a functional parameter in thyroid pathology

The authors study by means of immunoperoxidase method the pattern of thyroglobulin, triiodothyronine and thyroxine distribution in 58 cases of thyroid disorders: 15 euthyroid goiters, 10 Graves' disease, 7 Hashimoto's thyroiditis, 11 folliculo-papillary carcinomas (6 primary tumors and 5 lymph node metastases), 8 follicular carcinomas, 4 anaplastic carcinomas and 3 medullary carcinomas. Thyroglobulin, triiodothyronine and thyroxine were present in most of the thyroid disorders, excepting anaplastic and medullary carcinomas. Thyroglobulin and thyroxine were localized both in the follicular epithelium and in the colloid, whereas triiodothyronine was present especially in the follicular cells. The thyroid hormones distribution in benign lesions is rather similar. In carcinomas, the pattern of thyroglobulin, triiodothyronine and thyroxine is more heterogeneous, but generally the triiodothyronine distribution is similar to that of thyroglobulin. In some carcinomas, triiodothyronine and thyroxine showed a weak or negative immunostaining. The immunoperoxidase method is a valuable tool in the study of functional disturbances in the thyroid pathology and in the diagnosis of thyroid carcinoma metastases as well. Positive thyroid hormones staining clearly indicates the thyroid origin of metastases.     

Stimulation of iodine organification in porcine thyroid cells by thyroid stimulators

Several Graves' sera were simultaneously assessed in a bioassay based on the ability of porcine thyroid cells to organify 125I and in a radioreceptor assay for TSH receptor binding activity. Both assay systems were sensitive to 1 mcU/ml (final concentration) of unlabelled bovine TSH. Six Graves' sera were studied in detail over a wide (0-1.0 mcl sera) dose response range in repeat determinations. Two sera exhibited parallel binding and stimulating. However, two sera revealed significant inhibition of 125I-TSH binding prior to the demonstration of stimulation and the other two sera showed stimulatory capabilities before significant binding was evident. IgG was prepared from one serum by ammonium sulphate precipitation and chromatography on Sepharose 6B and then subjected to preparative isoelectric focusing. The isoelectric distribution of the two activities were found to be identical with major peaks of activity at pl=9.5 and pl=8.5. In summary: 1) each Graves' sera exhibits different dose-response curves with respect to binding and stimulation, 2) at certain concentrations of sera, only binding or stimulation were evident, 3) neither assay was consistently more sensitive for the presence of Graves' immunoglobulins, 4) for one Graves' sera, binding and stimulation could not be separated by isoelectric focusing. These studies would suggest each Graves' immunoglobulin has inherently different characteristics in its interaction with the TSH receptor.     

Measurement of thyroid hormone in the rat thyroid gland by radioimmunoassay

The present paper describes (i) a hydrolysis technique with Pronase and leucine aminopeptidase using one rat thyroid gland, resulting in maximum release of thyroid hormones and minimum deiodination, and (ii) a simple and rapid procedure for thyroid hormone radioimmunoassays in thyroid hydrolysates using commercial kits intended for serum thyroid hormone determinations. The procedure is used to determine T4, T3, and rT3 concentrations and hormonal molar ratios in a thyroid gland from a male Wistar rat. The reliability of the method is also studied.     

cMYC expression in thyroid follicular cell-derived carcinomas: a role in thyroid tumorigenesis

Background

cMYC regulates approximately 15% of human genes and is involved in up to 20% of all human cancers. Reports discussing cMYC protein expression in thyroid carcinomas are limited, with controversies pertaining to cMYC expression patterns noted in the literature. The aims of the current study were to clarify patterns and intensities of cMYC expression in follicular cell-derived thyroid carcinomas across a spectrum of cancer morphologies and disease aggressivities, to correlate cMYC with BRAF^V600E expression, and to evaluate the potential role of cMYC in progression of well-differentiated thyroid carcinomas into less well-differentiated carcinomas.

Methods

Immunohistochemical studies using specific monoclonal antibodies for cMYC and BRAF^V600E were performed on tissue microarrays built from follicular cell-derived thyroid carcinomas (25 papillary, 24 follicular, 24 oncocytic variant of follicular, and 21 undifferentiated). In addition, cMYC IHC testing was also performed on whole tissue tumor sections from a subset of patients. Nodular hyperplasia cases were used as non-neoplastic controls. Appropriate positive and negative controls were included.

Results

cMYC was expressed almost exclusively in a nuclear fashion in both thyroid carcinomas and nodular hyperplasias. cMYC expression was weakly positive in both nodular hyperplasias and well-differentiated carcinomas. The majority of undifferentiated carcinomas (UDCs) showed strong nuclear cMYC positivity. PTC cases that were positive for cMYC (6/25) harbored the BRAF ^V600E mutation. A correlation was confirmed between cMYC intensity and tumor size in UDCs. UDC cases that developed out of well-differentiated thyroid carcinomas showed frank overexpression of cMYC in the undifferentiated tumor components.

Conclusions

Our study suggests that nuclear overexpression of cMYC correlates with tumorigenesis / dedifferentiation in follicular cell derived thyroid carcinomas, a concept that has not been shown before on whole tissue sections.

     

甲状腺癌患者血清促甲状腺激素和甲状腺激素表达水平及临床意义

目的:探讨甲状腺癌患者血清促甲状腺激素和甲状腺激素表达水平及临床意义。方法:应用电化学发光方法检测甲状腺癌组、甲状腺良性病变组和正常对照组血清促甲状腺激素(TSH)和甲状腺激素(TT3、FT3、TT4、FT4)水平。结果:①血清TSH在三组中比较有统计学意义(P〈0.001),甲状腺癌组血清TSH水平(3.56±0.93ulU/ml)明显高于甲状腺良性病变组(2.82±0.70ulU/ml)和正常对照组(2.04±0.56ulU/ml);TSH与肿瘤病理分期和肿瘤大小呈正相关(P<0.05)。②血清FT3、FT4水平在三组中有统计学意义(均P〈0.001),甲状腺癌组FT3、FT4水平处于较低水平,二者均明显低于甲状腺良性病变组和正常对照组(P<0.001);FT3与肿瘤病理分期和淋巴结转移呈负相关(P<0.05)。③TT3和TT4水平在三组之间比较均无统计学意义(P>0.05)。结论:高水平TSH可增加甲癌复发的危险性。低甲状腺激素水平在甲状腺癌形成中可能起到一定的作用,因此可以将其作为预测甲癌复发的重要指标之一。