Fibrillin expression and localization in various types of carcinomas of the thyroid gland.

Fibrillin is an extracellular matrix (ECM) glycoprotein, a main component of microfibrills, suggested to support cell attachment and to impact cell differentiation and migration. The aim of this study was to investigate fibrillin-1 expression in thyroid carcinomas at mRNA and protein level, since ECM proteins are suggested to be of great importance for the metastatic potential of carcinomas. RNA was extracted from 13 thyroid carcinoma cell lines and RT-PCR analysis with gene-specific primers revealed fibrillin-1 mRNA expression in all cell lines, with highest expression in the follicular carcinoma cell line WRO and lowest expression in the two anaplastic cell lines (APO, FRO). Furthermore, we investigated fibrillin-1 expression by immumohistochemistry in a commercially available tissue microarray including 50 thyroid carcinomas as well as in archival tissue from 33 thyroid carcinomas. Fibrillin-1 demonstrated a cytoplasmic location in the neoplastic cells of almost all carcinomas apart from the follicular ones. The most intense staining was observed in papillary carcinomas with some evidence of a slight increased intensity in advanced stages. Our data indicate that fibrillin-1 is strongly expressed by the neoplastic cells of thyroid carcinomas in different degree in the various histologic types and might be implicated in cell-stroma interaction in terms of signaling, attachment and migration.     

胃动素及其前体mRNA在正常人甲状腺和甲状腺肿瘤组织中表达的研究

目的 探讨胃动素和胃动素前体mRNA基因在正常人甲状腺的表达,比较人甲状腺胃动素前体mRNA基因序列与人小肠胃动素前体mRNA基因序列的异同;观察胃动素活性肽和胃动素前体mRNA在甲状腺肿瘤中的表达,并比较它们在良、恶性甲状腺肿瘤表达的异同及临床意义.方法 采用RT-PCR、Southern杂交和分子克隆等技术,克隆并测定人甲状腺和人小肠黏膜内胃动素前体mRNA基因序列;采用荧光免疫组织化学双染技术、Western印迹和即时荧光定量PCR(real-time PCR),观察胃动素和胃动素前体mRNA在正常甲状腺和甲状腺良、恶性肿瘤组织中表达的异同.结果 (1)正常人甲状腺组织有胃动素和胃动素前体mRNA的表达,且胃动素和降钙素共表达于同一细胞,即甲状腺C细胞;(2)人甲状腺组织内胃动素前体mRNA基因序列与基因库报道的人小肠胃动素前体mRNA基因序列(BC112314,NCBI,美国)完全相同;(3)免疫荧光组织化学、Western印迹以及real-time PCR结果均显示,正常人甲状腺和甲状腺肿瘤组织内均有胃动素和胃动素前体mRNA的表达,其中甲状腺髓样癌和嗜酸性腺瘤胃动素及其前体mRNA的表达高于正常甲状腺组织(均P＜0.05);但甲状腺乳头状癌和滤泡癌胃动素和胃动素前体mRNA的表达则明显降低(均P＜0.05);而结节性甲状腺肿与正常甲状腺组织相比胃动素和胃动素前体mRNA的表达差异均无统计学意义(P＞0.05).结论 人甲状腺组织有胃动素和胃动素前体mRNA的表达,且胃动素主要表达于甲状腺C细胞;人甲状腺组织胃动素前体mRNA基因序列与人小肠胃动素前体mRNA基因序列完全相同;甲状腺髓样癌和嗜酸性腺瘤内胃动素及其前体mRNA的表达明显增高,而甲状腺乳头状癌和滤泡癌内胃动素及其前体mRNA的表达明显降低.提示胃动素可能通过影响甲状腺滤泡旁细胞的分泌活动参与其生理活动的调节,胃动素可能与临床甲状腺髓样癌和甲状腺嗜酸性腺瘤疾病的发生和发展有关.     

Detection of HLA-DR antigens in paraffin-embedded thyroid epithelial cells with a monoclonal antibody.

The human Class II major histocompatibility (MHC) antigens, or Ia antigens, which are thought to regulate immune cell interaction, can be detected in paraffin-embedded tissues by immunoperoxidase staining with a recently developed monoclonal antibody (LK8D3). HLA-DR antigens were observed in lymphoid tissues, Langerhans cells of the skin, some epithelial cells, and pulmonary alveolar macrophages. The expression of HLA-DR antigens was analyzed in formalin-paraffin sections by immunoperoxidase in 86 normal and abnormal thyroid epithelial tissues. All patients with Hashimoto's disease (8/8) and most patients with Graves' disease (6/8) expressed HLA/DR antigens in the thyroid epithelial cells and in adjacent inflammatory cells. Most papillary carcinomas (12/18), including 3 of 5 follicular variant of papillary thyroid carcinomas, had HLA-DR antigens detected in epithelial cells; whereas medullary thyroid carcinomas (0/5), follicular carcinomas (0/5), and multinodular goiters (0/4) did not have detectable HLA-DR immunoreactivity. A few other thyroid lesions had HLA-DR antigens detected in epithelial cells, including anaplastic carcinomas (2/5), Hurthle-cell tumors (1/16), and thyroid lymphomas (2/2). Monoclonal antibody LK8D3 and two other commercially available monoclonal antibodies against HLA-DR-stained tissues equally well in cryostat sections, but only antibody LK8D3 was effective in formalin-fixed paraffin-embedded tissue sections. These results indicate that epithelial cells from thyroids of patients with autoimmune diseases commonly express HLA-DR antigens. The presence of HLA-DR antigens in most papillary thyroid carcinomas may be helpful diagnostically in cases of follicular variants of papillary carcinomas. The role of HLA-DR expression in autoimmune thyroid disease and in papillary thyroid carcinoma remains to be determined.     

Stage-Specific Embryonic Antigen-1 (SSEA-1) Expression in Thyroid Tissues

Stage-specific embryonic antigen-1 (SSEA-1), also known as CD15, is a member of a cluster of differentiation antigens that have been identified in various normal tissues and in different types of cancers including papillary and medullary thyroid carcinoma. SSEA-1 may be expressed in normal stem cells and cancer stem-like cells. To evaluate the potential diagnostic and prognostic utility of SSEA-1 in thyroid tumors, we analyzed the expression of SSEA-1 in normal and neoplastic thyroid tissues by immunohistochemistry (IHC) using a tissue microarray with 158 different tissue cores. To evaluate the potential utility of SSEA-1 as a surface marker, we also assessed the expression of SSEA-1 in thyroid cell lines by flow cytometric analysis. SSEA-1 immunoreactivity was identified in malignant thyroid follicular epithelial cancers but not in the benign thyroid tissues. Anaplastic thyroid (ATC) (80 %) and conventional papillary thyroid carcinoma (PTC) (60.7 %) showed significantly higher percentage of cases that were SSEA-1 immunoreactive than follicular variant of papillary thyroid carcinoma (FVPTC) (20.6 %) and follicular carcinoma (FCA) (32.1 %). Flow cytometric analysis of cultured thyroid cell lines showed that a small subpopulation of ATC and PTC thyroid tumor cells had SSEA-1 immunoreactivity which may represent thyroid cancer stem-like cells. The ATC cells expressed more SSEA-1 immunoreactive cells than the PTC cell lines. Our findings suggest that expression of SSEA-1 immunoreactivity in thyroid neoplasms was associated with more aggressive thyroid carcinomas. SSEA-1 is a marker that detects malignant thyroid neoplasms in formalin-fixed paraffin-embedded thyroid tissue sections and may be a useful marker for thyroid cancer stem-like cells.     

Diagnostic utility of galectin-3 and CD26/DPPIV as preoperative diagnostic markers for thyroid nodules

The aim of this study was to search for diagnostic markers that could correctly identify thyroid nodular lesions requiring urgent surgical treatment. We investigated whether galectin-3 and dipeptidyl peptidase IV (CD26/DPPIV) could be potential markers for improving the diagnostic accuracy of conventional cytology. Seventy-nine patients with histologically proven thyroid diseases were analyzed. The immunocytochemical staining results showed galectin-3 expression in neoplastic cells of all 37 papillary carcinomas, five of six follicular carcinomas, all three anaplastic carcinomas, one of three medullary carcinomas, and two of 14 follicular adenomas. All 16 adenomatous goiters were negative for galectin-3 immunostaining. On the other hand, all 37 papillary carcinomas, all six follicular carcinomas, and one of three anaplastic carcinomas revealed CD26/DPPIV expression, whereas all three medullary carcinomas were negative. Among benign thyroid lesions, four of 14 follicular adenomas and two of 16 adenomatous goiters exhibited varying degrees of immunoreactivity for CD26/DPPIV. RT-PCR analysis demonstrated overexpression of galectin-3 and CD26/DPPIV mRNAs in all six papillary and all three follicular carcinomas analyzed, whereas the mRNA expressions of these molecules were barely or not detectable in benign thyroid lesions and normal thyroid tissues, except for one case of follicular adenoma. In conclusion, we demonstrate that galectin-3 and CD26/DPPIV were consistently coexpressed at protein and mRNA levels in differentiated thyroid carcinomas. We propose that combined immunostaining for galectin-3 and CD26/DPPIV in the preoperative evaluation of thyroid nodules may play a role in accurate cytodiagnosis.     

Increased expression of focal adhesion kinase in thyroid cancer: immunohistochemical study

Focal adhesion kinase (FAK) is a tyrosine kinase that is found in cellular structures called focal adhesions. FAK appears to be a key element in signal transduction pathways involved in cell adhesion and locomotion. FAK is overexpressed in various tumors, including tumors derived from regions of the head and neck, colon, breast, prostate, and liver. In this study, we investigated immunohistochemically whether FAK expression was increased in thyroid cancers. FAK staining was not seen in any of the 20 normal thyroid tissues or the 6 nodular hyperplasia specimens. In contrast, FAK staining was observed in all of 17 papillary carcinomas, 9 follicular carcinomas, 8 medullary carcinomas, and 2 anaplastic carcinomas. Nine of 17 follicular adenomas showed FAK immunoreactivity. FAK was not expressed in normal tissue and nodular hyperplasia, but was expressed in some of the follicular adenoma, and all of the follicular, papillary, medullary and anaplastic thyroid carcinoma. This result indicates that the up-regulation of FAK may play a role in the development of thyroid carcinogenesis.     

EGF-receptors in human normal and pathological thyroid tissue

Expression of the epidermal growth factor receptor (EGFR) was studied in cryosections from human thyroid tissues. Normal tissue (4 cases), nodular goitre (12), toxic goitre (9), adenoma (9), follicular carcinoma (1), papillary carcinoma (7) and poorly differentiated carcinoma (1) were used for immunohistochemistry. Northern blot analysis was performed in two nodular goitres, three adenomas, two papillary carcinomas, one follicular carcinoma and the adjacent normal tissue in five cases as well as in two cell lines from anaplastic carcinomas. Epidermal growth factor receptor immunoreactivity was detected in all tissues examined. The amount of EGFR mRNA did not differ between normal and abnormal tissues. However, the EGFR staining was weaker in normal thyroid tissue compared to the adjacent neoplastic areas suggesting an upregulation at the posttranslational level in the latter. A strong staining was also seen in hyperfunctioning thyroid glands. The EGFR location was mainly basal or basolateral in all thyroid tissues with normal histology and in toxic diffuse goitre. Pericellular and sometimes cytoplasmatic staining was seen in neoplastic tissues. In nodular goitre the staining was both basal, lateral and apical and varied in intensity. Our data suggest that a non-polarized location of EGFR probably indicates a loss of the normal epithelial cell polarity and could be interpreted as an early sign of dedifferentiation. Furthermore, a role for the EGFR is proposed, not only in the development of thyroid neoplasias but also in goitre formation.     

TBX2在甲状腺癌组织中的表达及其临床意义

目的:检测TBX2在甲状腺癌组织中的表达,探讨其临床意义。方法:应用RT-PCR方法检测TBX2在9例正常甲状腺、13例甲状腺腺瘤及67例甲状腺癌组织(其中甲状腺乳头状癌28例,甲状腺滤泡癌23例,甲状腺髓样癌14例,甲状腺未分化癌2例)中的表达。结果:TBX2mRNA在甲状腺癌组织中的阳性表达(阳性表达56例,占83.6%)明显高于其在正常甲状腺(阳性表达3例,占33.3%)及甲状腺腺瘤组织(阳性表达6例,占46.2%)中的阳性表达(P<0.05),差异有显著性;TBX2mRNA在甲状腺乳头状癌、甲状腺滤泡癌及甲状腺髓样癌(甲状腺未分化癌例数太少,无统计学意义)组织中的阳性表达强度(相对系数)分别为1.776±0.382、2.627±0.532、2.937±0.481;P<0.05,差异具有显著性。TBX2mRNA在甲状腺癌组织中的阳性表达强度与甲状腺癌组织的分化程度及组织学分型有关。结论:TBX2可能是甲状腺癌发生、发展的促进因子,并有可能成为甲状腺癌临床诊断及预后评估的又一重要参考指标。     

Expression of sodium iodide symporter in benign and malignant human thyroid tissues

The extent of human sodium iodide symporter (hNIS) expression in different kinds of human thyroid cancer tissues and cell lines remains controversial. In this study, polyclonal antibodies to hNIS were used to analyze the expression of symporter protein in benign and malignant human thyroid tissues. Formalin-fixed, paraffin wax-embedded tissue sections were used. Staining was performed using primary polyclonal antibody of rabbit anti-human hNIS diluted in PBS (1:500). Results showed that 2 of 3 normal tissue, 3 of nodular hyperplasia, one follicular adenoma, 3 of 11 papillary thyroid carcinoma, 1 of 5 follicular carcinoma and none of 3 metastatic thyroid epithelial tissue specimens stained positively for hNIS. A higher percentage of positive staining for symporter protein was found in benign thyroid tissues including normal thyroid tissue, nodular hyperplasia, and adenoma (60%). In contrast, papillary and follicular thyroid carcinomas demonstrated lower symporter protein expression (20%). In conclusion, although the number of tissue samples examined in this study was small, hNIS staining found a higher ratio of symporter protein expression in normal and benign thyroid tissues compared with malignant tissues. Determination of the reason for discrepancies in the expression of hNIS in in vivo and in vitro studies will require further investigation.     

Distribution of Leu-7 antigen (HNK-1) in thyroid tumors: its usefulness as a diagnostic marker for follicular and papillary carcinomas.

The reactivity of the anti-Leu-7 monoclonal antibody was tested in 39 neoplastic and nonneoplastic thyroid tissue specimens. These included eight colloid goiters, 14 follicular adenomas, nine papillary carcinomas, five follicular carcinomas, two medullary carcinomas, and one metastatic follicular carcinoma in bone. We observed strong cytoplasmic and/or cell membrane positivity in all follicular and papillary carcinomas, in both primary and metastatic tumors. However, the medullary thyroid carcinomas tested were negative. We also observed weak and only occasional staining with anti-Leu-7 antibody in colloid goiter and follicular adenomas. The staining in the benign thyroid lesions was usually focal, less than 10% of the cells; however, in cases of follicular and papillary carcinomas, both in primary and metastatic tumors, the staining was diffuse and strong. Some of the colloid material in colloid goiters and follicular adenomas showed faint homogenous staining with anti-Leu-7 antibody. Our findings suggest that anti-Leu-7 monoclonal antibody is a marker that may facilitate the differentiation between benign and malignant thyroid lesions, with the exception of medullary carcinoma. In addition, caution should be taken when using this antibody to diagnose metastatic lesions, as other metastatic carcinomas have also been reported to be positive. This antibody should be used in conjunction with a panel of antisera to complement a morphologic diagnosis.     

Role of COX-2, thromboxane A2 synthase, and prostaglandin I2 synthase in papillary thyroid carcinoma growth.

The development of papillary thyroid carcinoma is influenced by many factors including genetic alterations, growth factors, and physical agents such as radiation. Arachidonic acid and its derivatives including prostaglandins (PG) and thromboxane along with the enzymes involved in their synthesis have been shown to influence the growth of various tumors. We analyzed the immunoreactivity for cyclooxygenase-2 (COX-2) and mRNA expression levels of the enzymes COX-2, thromboxane A(2) (TXA(2)) synthase, and PGI(2) synthase by RT-PCR in papillary carcinomas and matching normal tissues to determine the role of these enzymes in the development of papillary thyroid carcinomas. A papillary thyroid carcinoma cell line TPC-1 was also studied in vitro to determine the role of the specific COX-2 inhibitor NS-398 on COX-2 and vascular endothelial growth factor-A, since COX-2 also has a role in regulating tumor angiogenesis. RT-PCR analysis showed significant increases in TXA(2) synthase mRNA levels in papillary thyroid carcinomas compared to normal thyroid tissues. Although COX-2 mRNA levels were generally increased in papillary carcinomas, the differences were not statistically significant. There were no significant differences in PGI(2) synthase mRNA levels. COX-2 protein expression was greater in papillary carcinoma compared to normal thyroid tissues; however, the levels were quite variable. In vitro studies with a COX-2 inhibitor, NS-398, showed inhibition of tumor growth along with increased levels of COX-2 and vascular endothelial growth factor-A mRNA expression. These results indicate that specific enzyme levels in the PG synthesis pathway such as TXA(2) synthase are increased in papillary thyroid carcinomas. COX-2 also has a role in papillary thyroid growth, since a specific inhibitor of COX-2 regulates papillary thyroid carcinoma cell proliferation. These results implicate several enzymes in the synthesis of prostanoids as regulators of thyroid papillary carcinoma proliferation and suggest that increased levels of expression of these enzymes may play a role in the pathogenesis of these tumors.     

Quantitative nuclear cell image analyses of thyroid tumors from archival material

Sixty-three sections of Feulgen-stained thyroid cell nuclei from paraffin-embedded material, including five multinodular goiters, 10 adenomas, 36 papillary carcinomas, seven follicular carcinomas, and five medullary carcinomas were analyzed by means of the SAMBA 200 (TITN, Grenoble, France) cell image processor. This was done in order to obtain nuclear characteristics of papillary versus follicular carcinomas. The nuclear features were assessed by morphometric, densitometric, and textural parameters. Our preliminary results indicate that the cell nuclei from typical histopathologic specimens of follicular thyroid cancers belong to a larger thyroid cell nuclei population corresponding to the histopathologic family of papillary thyroid cancers. This follicular neoplastic cell nuclei population appears to be quite distinct from the typical medullary neoplastic cell nuclei population which also belongs to the papillary neoplastic cell nuclei population. It appears that there is a specific papillary cell nuclei subpopulation containing typical hypochromatic cell nuclei. We also observed a dramatic increase in nuclear size and hyperchromatism between normal (multinodular goiters) and neoplastic (carcinomas) thyroid tissues, with the benign tissues (adenomas) showing intermediate nuclear characteristics.     

Tissue polypeptide antigen in thyroid tumours of follicular cell origin: an immunohistochemical re-evaluation for diagnostic purposes

Using immunoperoxidase procedures on paraffin sections, we have investigated the distribution pattern of tissue polypeptide antigen (TPA) in follicular adenomas, (20 cases), follicular carcinomas (23 cases), papillary carcinomas (10 cases), anaplastic carcinomas (eight cases) and medullary carcinomas (four cases). Normal thyroid tissue surrounding adenomas was also tested as a control. Our results document positivity for TPA in follicular, papillary and medullary carcinomas, whereas no reactivity was encountered in follicular adenomas and anaplastic carcinomas. These immunohistochemical data were compared with serological levels of TPA and the findings were discordant only for anaplastic carcinomas. We contend that the demonstration of TPA, possible in alcohol- or formalin-fixed tissues, may prove to be of value in the differential diagnosis of thyroid adenomas from carcinomas of follicular cell origin.     

Expression of down stream molecules of RET (p-ERK, p-p38 MAPK, p-JNK and p-AKT) in papillary thyroid carcinomas

To evaluate the roles of 4 putative downstream molecules (ERK, p38 MAPK, JNK and AKT) of the RET signal pathway in the tumorigenesis of papillary carcinomas, the expression patterns of RET and phosphorylated forms of ERK, p38 MAPK, JNK and AKT were evaluated in 115 cases of papillary thyroid carcinomas by 3 mm-core tissue microarray based immunohistochemical staining. The prevalence of RET protein expression was 62.6%. No distinct expression of p-ERK and p-p38 MAPK was demonstrated in tumor cells of papillary carcinomas. All papillary carcinomas except 5 cases expressed nuclear p-JNK and p-JNK expression was increased in tumors compared with paired normal tissues (p < 0.05). There was no difference in the p-JNK expression between RET protein-positive and RET protein-negative papillary carcinomas (p > 0.05). Unequivocal nuclear staining for p-AKT was demonstrated only in 10 cases of papillary carcinomas, and all of them showed focal staining. Our results showing constitutive expression of p-JNK in most cases of surgically excised papillary thyroid carcinomas irrespective of RET protein expression status suggest that JNK activation may play a role in the tumorigenesis or survival of sporadic papillary thyroid carcinoma.     

Aspiration biopsy RNA diagnosis

Recent advances in molecular-based techniques, especially RNA analyses such as differential display, serial analysis of gene expression(SAGE) and DNA arrays, have enabled us to detect the specific changes in mRNA in cancer tissues rapidly and easily. We have established a new method of preoperative molecular-based diagnosis of thyroid carcinomas, one of the most common cancers in females. This technique, Aspiration Biopsy RNA Diagnosis, ABRD, allows us to perform preoperative RNA analysis of the tumors by extracting RNA from tumor cells obtained by fine needle aspiration biopsies(FNABs). For example, by ABRD detection of oncofetal fibronectin or calcitonin mRNA in FNABs, three types of thyroid carcinomas, papillary, anaplastic and medullary carcinomas, were accurately diagnosed preoperatively without the help of cytological or pathological examinations by a skillful pathologist. Further, by real-time monitoring RT-PCR measuring the expression levels of these cancer-specific mRNAs, a fully automated system was established. Because ABRD can be performed without any severe invasion to the patients, in the near future, when more reliable systems of quantitative RNA analysis are developed, ABRD will probably become one of the standard tests for preoperative diagnosis of cancer.     

Differential expression of galectin-1 and galectin-3 in thyroid tumors. Potential diagnostic implications.

Carcinoma of the thyroid gland, the most frequently diagnosed endocrine malignancy, is often associated with early regional metastases. With the exception of papillary carcinoma, distinguishing benign from malignant thyroid neoplasms in the absence of metastatic disease is difficult. Recently, the vertebrate lectins galectin-1 and galectin-3 have been implicated in the regulation of cellular growth, differentiation, and malignant transformation of a variety of tissues. To determine whether these galectins have a role in thyroid neoplasia, we analyzed 32 specimens from thyroid malignancies (16 papillary, 7 follicular, 8 medullary carcinomas, and 1 metastasis to lymph node), 10 benign thyroid adenomas, 1 nodular goiter, and 33 specimens from adjacent normal thyroid tissue for the expression of galectin-1 and galectin-3 with immunohistochemical and immunoblotting techniques utilizing anti-galectin antibodies. All thyroid malignancies of epithelial origin (ie, papillary and follicular carcinomas) and a metastatic lymph node from a papillary carcinoma expressed high levels of both galectin-1 and galectin-3. The medullary thyroid carcinomas, which are of parafollicular C cell origin, showed a weaker and variable expression of these galectins. In contrast, neither benign thyroid adenomas nor adjacent normal thyroid tissue expressed galectin-1 or galectin-3. These results suggest that galectin-1 and galectin-3 may be associated with malignant transformation of thyroid epithelium and may potentially serve as markers for distinguishing benign thyroid adenomas from differentiated thyroid carcinomas.     

Expression of prolactin receptor and prolactin in normal and malignant thyroid: A tissue microarray study

Objective There is increasing evidence involving prolactin (PRL) and its receptor (PRLR) in the development of different cancers. The aim of the present study was to investigate the expression of PRLR and PRL in human thyroid tissues. Design and Methods Using tissue microarray (TMA) by immunohistochemical staining, we examined the expression level of PRLR and PRL in 314 specimens from 71 thyroid cancer patients and 15 normal thyroid samples. Results Expression of the PRLR was observed in 93.3% of normal thyroid samples and in 76.1% of all thyroid cancers, while expression of PRL was observed in only 10% of medullary thyroid carcinomas and not at all in the other specimens, whether normal or neoplastic. Moreover, results suggested an overexpression of PRLR in 70% of medullary thyroid carcinomas, whereas 53.3% of poorly differentiated thyroid carcinomas showed a negative pattern of staining (p=0.014 vs normal). Conclusions Present data revealed, for the first time, a widespread expression of PRLR in normal and neoplastic human thyroid tissues as well as a scarce expression of PRL, observed only in a few medullary thyroid carcinomas. Whether the overexpression of PRLR observed in medullary thyroid carcinomas or the underexpression of PRLR observed in poorly differentiated thyroid carcinomas play a contributory role in the oncogenesis of these tumors remains to be determined.     

Molecular-based diagnosis of thyroid carcinomas by detecting cancer-specific mRNAs

Molecular-based diagnosis of thyroid carcinomas can be more easily established by utilizing specific mRNAs that are restrictedly expressed in cancer tissues. In light of this aspect, we searched for cancer-specific mRNAs using sequence specific-differential display(SS-DD) and serial analysis of gene expression(SAGE). By these techniques, we found several mRNAs that efficiently distinguished benign and malignant tissues. Among these, oncofetal fibronectin(onfFN) mRNA was expressed only in thyroid papillary and anaplastic carcinomas and it was considered the most preferable target for molecular-based diagnosis of these carcinomas. In a previous study, we introduced a new method of preoperative diagnosing thyroid carcinomas. This technique, aspiration biopsy-RT-PCR(ABRP), allows us to simultaneously perform cytological and molecular-based diagnoses by extracting RNA from leftover cells within the needle used for fine needle aspiration biopsies(FNABs). ABRP provides both RNA information and cytological diagnosis without further invasion to the patient. We demonstrated that by ABRP detection of onfFN mRNA in FNABs, papillary and anaplastic carcinomas may be accurately diagnosed preoperatively. Further, by real-time monitoring RT-PCR measurement of onfFN mRNA, a fully automated system was established.