Discovery and validation of protein abundance differences between follicular thyroid neoplasms.

Department of Endocrinology, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
Cancer Research (Impact Factor: 9.28). 04/2008; 68(5):1572-80. DOI: 10.1158/0008-5472.CAN-07-5020
Source: PubMed

ABSTRACT Distinguishing between benign follicular thyroid adenoma (FTA) and malignant follicular thyroid carcinoma (FTC) by cytologic features alone is not possible. Molecular markers may aid distinguishing FTA from FTC in patients with indeterminate cytology. The aim of this study is to define protein abundance differences between FTC from FTA through a discovery (proteomics) and validation (immunohistochemistry) approach. Difference gel electrophoresis (DIGE) and peptide mass fingerprinting were performed on protein extracts from five patients with FTC and compared with six patients with FTA. Individual gel comparisons (i.e., each FTC extract versus FTA pool) were also performed for the five FTC patients. Immunohistochemical validation studies were performed on three of the identified proteins. Based on DIGE images, 680 protein spots were matched on individual gels. Of these, 102 spots showed statistically significant differences in abundance between FTC and FTA in the individual gel analyses and were therefore studied further. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to identify 54 of these protein spots. Three candidates involved in protein folding (heat shock protein gp96, protein disulfide isomerase A3, and calreticulin) were studied by immunohistochemistry. Moderate calreticulin immunohistochemical staining was the best single marker with a high negative predictive value (88%); combining all three markers (any marker less than moderate staining) had the best positive predictive value (75%) while still retaining a good negative predictive value (68%). With DIGE, we identified 54 proteins differentially abundant between FTC and FTA. Three of these were validated by immunohistochemistry. These findings provide further insights into the diagnosis, prognosis, and pathophysiology of follicular-derived thyroid neoplasms.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Preoperative characterization of thyroid follicular lesions is challenging. Fine-needle aspiration specimens cannot differentiate follicular carcinomas from benign follicular neoplasias. Recently, promising markers have been detected using modern molecular techniques. We conducted a retrospective study to confirm the usefulness of immunohistochemical staining for the protein markers, DDIT3, STT3A (ITM1), ARG2 and FAM129A (C1orf24) in separating benign and malignant thyroid follicular lesions. Formalin-fixed, paraffin-embedded thyroid tissue from 30 in-house cases (15 follicular carcinomas and 15 follicular adenomas), as well as 8 follicular carcinomas and 21 follicular adenomas on tissue microarray slides were stained immunohistochemically for DDIT3, STT3A, ARG2 and FAM129A expression. Control tissue consisted of thyroid parenchyma adjacent to the tumors and 11 separate cases of normal thyroid parenchyma. All in-house cases of follicular adenomas, follicular carcinomas and adjacent normal thyroid tissue showed positive immunostaining with anti-DDIT3 and anti-STT3A. Anti-ARG2 and anti-FAM129A polyclonal antibodies showed positive staining in 20 and 60% of in-house follicular adenomas, and 40 and 87% of in-house follicular carcinomas, respectively. Monoclonal anti-FAM129A demonstrated positive staining in 13 and 33% of in-house follicular adenomas and follicular carcinomas, respectively. Polyclonal anti-DDIT3, -STT3A and -FAM129A antibodies showed positive staining in all tissue microarray slides of follicular carcinoma and in 76, 85 and 81% of the follicular adenomas, respectively. Monoclonal anti-STT3A stained 81% of the follicular adenoma cores. Anti-ARG2 stained positive in 13% of follicular carcinomas and 10% of follicular adenomas on the tissue microarray slides. In conclusion, DDIT3, STT3A, ARG2 and FAM129A immunohistochemistry does not appear to be useful in the diagnosis of thyroid follicular neoplasias, as they do not reliably distinguish follicular thyroid carcinoma from follicular thyroid adenoma.
    Modern Pathology 04/2013; 26(4):613-5. DOI:10.1038/modpathol.2013.39 · 6.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The loss of I uptake ability in metastases from differentiated thyroid carcinoma (DTC) is becoming a major obstacle in radioiodine treatment. However, there is no effective way to screen for I uptake ability in metastases. The identification of differentially expressed proteins by serum proteomics may contribute to our understanding of the mechanisms underlying the dedifferentiation of DTC. Serum samples were obtained from papillary thyroid carcinoma patients with non-I-avid lung metastases and I-avid lung metastases. Differential protein analysis was performed using two-dimensional gel electrophoresis. Candidate protein spots showing differences in expression between the two groups were identified by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and were validated by western blotting. We found that afamin is downregulated in the serum of papillary thyroid carcinoma patients with non-I-avid lung metastases. Afamin may be a potential serum biomarker for early screening of I uptake ability in DTC metastases and could therefore be of value in guiding radioiodine treatment decisions.
    Nuclear Medicine Communications 10/2013; 34(12). DOI:10.1097/MNM.0000000000000001 · 1.37 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Thyroid cancer is the most common malignancy of the endocrine system. The diagnosis of thyroid nodules, made by neck examination and ultrasonography, is a common event occurring in over 50% of the patient population over the age of 50. Yet, only 5% of these patients will be diagnosed with cancer. Fine needle aspiration biopsy is the gold standard for diagnosing thyroid nodules. However, 10-15% of these biopsies are inconclusive, ultimately requiring a diagnostic thyroid lobectomy. Consequently, research in thyroid biomarkers has become an area of active interest. In the 40 years since calcitonin was first described as the biomarker for medullary thyroid cancer, new biomarkers in thyroid cancer have been discovered. Advances in genomic and proteomic technologies have defined many of these novel thyroid biomarkers. The purpose of this article is to provide a comprehensive literature review of how these biomarkers have evolved from simple screening tests into a complex array of multiple markers to help predict the malignant potential and genetic signature of thyroid neoplasms.
    06/2010; 2(2):885-912. DOI:10.3390/cancers2020885

Full-text (2 Sources)

Available from
Aug 19, 2014