Real-time analysis of beta- and gamma-catenin mRNA expression in ret/PTC-1 activated and nonactivated thyroid tissues.

Our group has previously demonstrated an association between ret/PTC-1 activation and decreased E-cadherin mRNA levels in papillary thyroid carcinoma. We also observed similarities in the E-cadherin expression profiles of Hashimoto thyroiditis and ret/PTC-1-positive papillary thyroid carcinomas and have hypothesized that ret/PTC-1 activation might cause not only the structural and nuclear peculiarities of PTC but also an immune reaction to thyroid epithelium. The objective of this study was to examine the expression of E-cadherin's ligands, beta- and gamma-catenin, in various thyroid tissue types in the context of ret/PTC-1 positivity using laser capture microdissection and TaqMan (Applied Biosystems, Foster City, CA). One-Step RT-PCR. Beta-catenin mRNA levels were found to be consistently decreased in both papillary and anaplastic carcinomas when compared with a normal/follicular adenoma group. A significant difference in expression levels was observed between papillary and follicular thyroid carcinomas with the latter having elevated mRNA levels of beta-catenin. Gamma-catenin mRNA was decreased in anaplastic carcinomas compared with normal/follicular adenoma groups. A similar expression profile of gamma-catenin as beta-catenin was observed in papillary and follicular carcinomas with the latter once again having higher mRNA levels. These results therefore suggest that although beta- and gamma-catenin may play a role in the progression of thyroid cancer in general, they do not appear to be associated with ret/PTC-1-modulated pathways.     

CK19、CK20在甲状腺乳头状癌诊断中的应用价值

目的：探讨甲状腺癌中CK19、CK20蛋白的表达，提高甲状腺的诊断与鉴别诊断水平。方法：应用免疫组化染色对70例甲状腺癌（15例经典型乳头状癌、34例滤泡型乳头状癌、3例Warthin乳头状癌、2例透明细胞型乳头状癌、例柱状细胞型乳头癌、15例滤泡性癌），10例甲状腺腺瘤、10例结节性甲状腺肿和5例标本甲状腺炎中CK19、CK20的表达进行观察。结果:CK19在甲状腺疾病中的表达：55例乳头状癌中，53例为中、强阳性，2例为弱阳性；15例滤泡性癌中，13例为阴性、弱阳性，2例为中、强阳性，两者之间差异存在显著性（P＜0．05）。各癌旁滤泡、10例滤泡性腺瘤、10例结节性甲状腺肿的滤泡、5例桥本甲状腺炎也主要为阴性、弱阳性，个别为中等阳性。对CK20的表达，各型甲状腺乳头状癌、滤泡性癌、癌旁滤泡及滤泡状癌和乳头状增生、多灶性分布的甲状腺泡型乳头状癌和各种滤泡性病变有帮助，可提高甲状腺良恶性病变诊断的准确率及鉴别诊断水平。CK20对鉴别诊断的帮助不大。     

Presence of immunoreactive corticotropin releasing hormone in thyroid lesions.

Corticotropin-releasing hormone (CRH) functions as a regulator of the hypothalamic-pituitary-adrenal axis and coordinator of the stress response. Immunoreactive CRH (IrCRH) is also produced in a variety of inflammatory sites, where this peptide acts as a proinflammatory cytokine. To detect CRH in autoimmune thyroid disease as well as in disorders that may be associated with an inflammatory reaction within this gland, we examined immunohistochemically 45 thyroid lesions, including 12 nodular goiters, 9 cases of Hashimoto thyroiditis, 6 follicular adenomas, 4 follicular and 8 papillary carcinomas, 4 Hürthle cell tumors, 1 medullary cancer, and 1 insular thyroid carcinoma. We also examined the presence of IrCRH in the adjacent normal thyroid parenchyma. The avidin-biotin complex method was employed on formalin-fixed, paraffin-embedded tissue, using a highly specific, affinity-purified polyclonal rabbit anti-CRH antibody. Granular cytoplasmic immunostaining of follicular cells was observed in 100% of the cases of Hashimoto thyroiditis, 77% of the neoplasms and 42% of goiters. The intensity of the staining was more pronounced in Hashimoto thyroiditis and Hürthle cell tumors, whereas the remaining lesions exhibited a heterogeneous staining pattern. No IrCRH was observed in the normal thyroid parenchyma. Using a specific radioimmunoassay, the IrCRH in extracts of simple thyroid goiters, papillary carcinomas, and Hürthle cell tumors ranged between 0.031 and 0.224 pmol/g of wet tissue but was undetectable in normal thyroid parenchyma. The IrCRH molecule in the thyroid gland eluted at the same fraction as synthetic rat/human CRH 1-41 in reverse phase high pressure liquid chromatography. We conclude that IrCRH is present in thyroid lesions, predominantly in those related to autoimmune phenomena, suggesting that this neuropeptide may be directly and/or indirectly involved with inflammatory processes taking place in this gland.     

RET oncogene activation in papillary thyroid carcinoma.

The RET proto-oncogene encodes a cell membrane tyrosine-kinase receptor protein whose ligands belong to the glial cell line-derived neurotrophic factor. RET functions as a multicompetent receptor complex that includes alphaGFRs and RET. Somatic rearrangements of RET designated as RET/PTC (from papillary thyroid carcinoma) were identified in papillary thyroid carcinoma before RET was recognized as the susceptibility gene for MEN2. There are now at least at least 15 types of RET/PTC rearrangements involving RET and 10 different genes. RET/PTC1 and RET/PTC3 are by far the most common rearrangements. All of the rearrangements are due to DNA damage and result in the fusion of the RET tyrosine-kinase (RET-TK) domain to the 5'-terminal region of heterologous genes. RET/PTC rearrangements are very common in radiation-induced tumors but have been detected in variable proportions of sporadic (i.e., non-radiation associated) papillary carcinomas. It is estimated that up to approximately half the papillary thyroid carcinomas in the United States and Canada harbor RET/PTC rearrangements, most commonly RET/PTC-1, followed by RET/PTC-3 and occasionally RET/PTC-2. The cause of these rearrangements in sporadic papillary carcinomas is not known, but the close association between their presence and the papillary carcinoma phenotype indicates that they play a causative role in tumor development. The proposed mechanisms of RET/PTC-induced tumorigenesis and the clinical and pathologic implications of RET/PTC activation are discussed.     

BRAF T1799A mutation occurring in a case of malignant struma ovarii

Struma ovarii is an extremely rare tumor that occasionally undergoes malignant transformation. Because struma ovarii is composed of thyroid tissue, it is conceivable that the pathogenetic events involved in thyroid follicular transformation may take place also in struma ovarii. The authors describe a case of a classical variant of papillary thyroid carcinoma arising in a struma ovarii of a 22-year-old female. The tumor was heterozygous for BRAF T1799A mutation. No ret/ PTC-1 or ret/PTC-3 rearrangements were detected. This finding would suggest that malignant struma ovarii is similar histologically and genetically to primary papillary thyroid carcinoma.     

CD98 expression is decreased in papillary carcinoma of the thyroid and Hashimoto’s thyroiditis

Aims: CD98 is a component of the large neutral amino acid transporter (LAT), which is a cell surface amino acid transporter. CD98 also binds to and activates β₁‐integrin, promoting anchorage‐independent growth. CD98 expression is increased in a variety of carcinomas but its distribution in the normal and neoplastic thyroid gland has not been reported. The aim was to examine the immunohistochemical expression of CD98 in normal and diseased thyroid tissue. Methods and results: One hundred and forty thyroid cases were selected from the archives of the Department of Pathology, including normal controls, neoplasms (follicular adenoma, follicular carcinoma and papillary carcinoma) and non‐neoplastic conditions (multinodular goitre, Graves’ disease and Hashimoto’s thyroiditis). Immunohistochemistry for CD98 was performed and each case was scored for proportion of cells and intensity of immunoreactivity. In normal thyroid, there was moderately strong expression of CD98 in the lateral cell membranes of follicular cells. A similar pattern of expression was seen in follicular adenoma, minimally invasive follicular carcinoma, multinodular goitre and Graves’ disease. In most cases of papillary carcinoma and in the inflamed areas of Hashimoto’s thyroiditis, expression of CD98 was decreased. Conclusions: CD98 expression is down‐regulated in thyroid papillary carcinoma; this may relate to the better prognosis associated with many of these tumours.     

Expression of p63 in papillary thyroid carcinoma and in Hashimoto's thyroiditis: a pathobiologic link?

p63 proteins are p53 homologs that are postulated to regulate squamous stem cell commitment. An immunohistochemical survey of p63 expression in normal thyroid and in reactive, neoplastic, and inflammatory thyroid disorders was performed. Sections from routinely fixed and processed archival thyroidectomy specimens were pretreated with citric acid, pH 6.0, for antigen retrieval, then incubated overnight with anti-p63 monoclonal antibody 4A4. Slides were stained using a streptavidin-biotin kit and diaminobenzidine as a chromagen, and then were counterstained with hematoxylin. The results showed that p63 expression was negative in normal thyroid tissue, nodular goiters, and oncocytic follicular adenomas. Positivity was rare and weak in follicular adenomas. p63-positive foci were commonly found in Hashimoto's thyroiditis (1 or more foci in 78.8% of cases), but rare in Graves' disease. Twenty-seven of 33 papillary thyroid carcinomas (81.8%) displayed p63-positive foci. Staining was uncommon in follicular carcinomas and rare in medullary carcinomas. One case of insular carcinoma was p63-positive. All squamoid structures were p63-positive; p63-positive structures morphologically consistent with solid cell nests were also identified. Based on the results of this study, we conclude that p63 is commonly expressed in papillary thyroid carcinoma and in Hashimoto's thyroiditis. Given the debated association of papillary thyroid carcinoma with Hashimoto's thyroiditis, it is possible that p63 expression may be a potential pathobiologic link between the two disorders. The finding of p63 in benign squamoid nests supports a possible interrelationship between these structures and both Hashimoto's thyroiditis and papillary carcinoma. The high percentage of papillary carcinomas with p63-positive foci appears to distinguish papillary carcinoma from other neoplasms originating in the thyroid.     

p53, ki-67, galectin-3, HBME-1, 34βE12和CK19在甲状腺乳头状癌中的表达及临床病理意义

 摘要：目的：探讨p53, ki-67, galectin-3, HBME-1, 34βE12和CK-19在甲状腺乳头状癌中的表达及临床病理意义。方法：采用免疫组化检测43例甲状腺乳头状癌、37例结节性甲状腺肿、33例甲状腺腺瘤和17例桥本甲状腺炎中p53, ki-67, galectin-3, HBME-1, 34βE12和CK-19的表达。结果：p53, ki-67, galectin-3, HBME-1, 34βE12和CK-19在甲状腺乳头状癌中的阳性表达例数分别为88.37%、79.07%、88.37%、93.02%、86.05%、95.35%;6种蛋白在甲状腺乳头状癌与结节性甲状腺肿、甲状腺腺瘤和桥本甲状腺炎中的阳性表达率相比较差异均有统计学意义（P<0.01）。结论：联合检测p53, ki-67, galectin-3, HBME-1, 34βE12和CK-19在甲状腺乳头状癌与良性病变的诊断和鉴别诊断中具有重要的价值。     

甲状腺乳头状癌中ret癌基因的表达

目的：观察人甲状腺乳头状癌中ret癌基因的表达。方法：应用RT－PCR技术研究甲状腺乳头状癌新鲜组织中ret癌基因活化形式PTC基因的表达。结果：25例甲状腺乳头状癌中有6例（24％）PTC基因表达阳性,主要分布于Ⅱ级以上肿瘤中;而甲状腺滤泡型癌、甲状腺瘤和正常甲状腺组织吕PTC均为阴性。结论：PTC基因是ret癌基因新的活化形式,ret基因的活化仅限于甲状腺头状癌类型中,可能是乳头状癌的特殊遗传事件,而无PTC基因表达的乳头状癌,其分子发生机制可能与其他基因的遗传性改变有关。因此检测PTC基因可作为判断甲状腺乳头状癌生物学行为的有效参考指标。     

Molecular genetic study comparing follicular variant versus classic papillary thyroid carcinomas: association of N-ras mutation in codon 61 with follicular variant

Although the follicular variant of papillary thyroid carcinoma (FVPTC) has been classified as a papillary cancer based on nuclear features, its follicular growth pattern and potential for hematogenous spread are more characteristic of follicular carcinoma. To gain insight into the biologic nature of FVPTC, we compared genetic alterations characteristic of papillary and follicular thyroid carcinomas in 24 FVPTCs and 26 classic PTC (CPTCs). In FVPTCs, we observed ras mutation in 6 of 24 cases (25%), BRAF mutation in 1 of 13 cases (7.6%), and ret rearrangement in 5 of 12 cases (41.7%). In CPTCs, we found ras mutation in no case, BRAF mutation in 3 of 10 cases (30%), and ret rearrangement in 5 of 11 cases (45%). One FVPTC exhibited simultaneous ras mutation and ret/PTC1 rearrangement, and one CPTC harbored simultaneous BRAF mutation and ret/PTC3 rearrangement. Based on these findings, we concluded that ras mutation correlates with follicular differentiation of thyroid tumors whereas ret activation is associated with papillary nuclei but not with papillary architecture. ret activation is not exclusive of ras or BRAF mutation, whereas ras and BRAF mutations are mutually exclusive. The implications of these results for follicular and papillary carcinogenesis are discussed.     

Molecular profile and clinical-pathologic features of the follicular variant of papillary thyroid carcinoma. An unusually high prevalence of ras mutations

The follicular variant (FV) of papillary thyroid carcinoma is characterized by a follicular growth pattern and cytologic features of papillary carcinoma. ret/PTC rearrangements are common in classic papillary thyroid carcinoma (PTC) and PAX8-PPAR gamma and ras mutations in follicular thyroid carcinoma. Their prevalence in FV has not been established. We studied these genetic alterations and clinical-pathologic features in 30 FV cases and compared those with 46 non-FV papillary carcinomas. FV cases revealed 1 ret/PTC rearrangement (3%) and 13 ras mutations (43%). Non-FV cases harbored 13 ret/PTC (28%) (P = .006) and no ras mutations (P = .0002). No PAX8-PPAR gamma was found in either group. FV cases demonstrated a significantly higher prevalence of tumor encapsulation, angiovascular invasion, and poorly differentiated areas and a lower rate of lymph node metastases. These data indicate that the FV of papillary carcinoma has a distinct set of molecular alterations and is characterized by a high frequency of ras point mutations.     

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.     

Immunohistochemical Demonstration of Epidermal Growth Factor Receptor and Ceruloplasmin in Thyroid Diseases

The expression of epidermal growth factor receptors (EGFR) and ceruloplasmin (CP) in thyroid diseases was investigated by immunohistochemical methods, and the results were compared with the expression of thyroglobulin (TG). Eighty eight surgical specimens of thyroid diseases, including follicular carcinoma (7 cases), papillary carcinoma (20 cases), follicular adenoma (29 cases), adenomatous goiter (10 cases), diffuse hyperplasia (20 cases) and chronic thyroiditis (2 cases), were studied. All cases of follicular carcinoma and 18 cases (90%) of papillary carcinoma expressed the EGFR immunoreaction in the cytoplasm with a moderate to strong staining intensity. A weak immunoreaction for EGFR was noted in some benign thyroid diseases. CP showed various degrees of positivity in all cases of follicular carcinoma and 19 cases (95%) of papillary carcinoma. The benign thyroid lesions were consistently negative for this antigen, not counting one case of Hiirthle cell adenoma. There was a positive correlation between EGFR and CP immunostaining intensity in thyroid carcinomas, representing higher expression of EGFR accompanied by a stronger staining intensity of CP. Except for two cases of papillary carcinoma, all cases showed immunoreaction for TG. The results indicate the enhanced expression of EGFR and CP in thyroid carcinomas. EGFR and CP thus appear to be valuable tools for differential diagnosis between benign and malignant thyroid neoplasms.     

Immunohistochemical demonstration of epidermal growth factor receptor and ceruloplasmin in thyroid diseases

The expression of epidermal growth factor receptors (EGFR) and ceruloplasmin (CP) in thyroid diseases was investigated by immunohistochemical methods, and the results were compared with the expression of thyroglobulin (TG). Eighty-eight surgical specimens of thyroid diseases, including follicular carcinoma (7 cases), papillary carcinoma (20 cases), follicular adenoma (29 cases), adenomatous goiter (10 cases), diffuse hyperplasia (20 cases) and chronic thyroiditis (2 cases), were studied. All cases of follicular carcinoma and 18 cases (90%) of papillary carcinoma expressed the EGFR immunoreaction in the cytoplasm with a moderate to strong staining intensity. A weak immunoreaction for EGFR was noted in some benign thyroid diseases. CP showed various degrees of positivity in all cases of follicular carcinoma and 19 cases (95%) of papillary carcinoma. The benign thyroid lesions were consistently negative for this antigen, not counting one case of Hürthle cell adenoma. There was a positive correlation between EGFR and CP immunostaining intensity in thyroid carcinomas, representing higher expression of EGFR accompanied by a stronger staining intensity of CP. Except for two cases of papillary carcinoma, all cases showed immunoreaction for TG. The results indicate the enhanced expression of EGFR and CP in thyroid carcinomas. EGFR and CP thus appear to be valuable tools for differential diagnosis between benign and malignant thyroid neoplasms.     

Pattern of expression of intermediate cytokeratin filaments in the thyroid gland: an immunohistochemical study of simple and stratified epithelial-type cytokeratins

The expression of simple and stratified epithelial-type cytokeratin (CK) intermediate filaments was evaluated by immunohistochemistry in a series of 41 papillary carcinomas, 10 follicular carcinomas, 2 poorly differentiated carcinomas and 34 specimens of normal thyroid parenchyma and lymphocytic thyroiditis. The aim of the study was to establish the CK profile of normal thyroid and thyroid carcinomas in order to clarify the putative application of CK immunostaining in diagnostic surgical pathology, and to evaluate whether the process of neoplastic transformation and tumour progression in the thyroid may be associated with any particular change in CK expression. Normal thyroid strongly expressed simple epithelial-type CKs 7 and 18 and, to a lesser degree, CKs 8 and 19, but did not express stratified epithelial-type CKs. The same pattern was found in lymphocytic thyroiditis, though the CK 19 immunoreactivity was stronger in these lesions than in the normal thyroid. Papillary and follicular thyroid carcinomas shared the expression of simple epithelial-type CKs 7, 8, 18 and 19. Immunoreactivity for CK 19 was frequently stronger and more widely distributed within each particular tumour in papillary than in follicular carcinomas, but it could also be detected, at least focally, in every follicular carcinoma. Strong expression of CK 19 highlighted small foci of papillary carcinoma not easily identifiable by conventional histological examination. Stratified epithelial-type CKs 5/6 and 13 were detected in a high percentage of papillary carcinomas, in contrast to their absence in follicular carcinomas and normal thyroid. The CK pattern was similar in primary and metastatic papillary carcinomas. We conclude that papillary carcinoma of the thyroid presents a distinct CK profile that may be used for diagnostic purposes.