Our aims were to uncover the role of FAM172A (Family with sequence similarity 172 member A) in the pathogenesis of follicular thyroid carcinoma (FTC) and to evaluate its value in the differential diagnosis between malignant and benign thyroid follicular lesions. FAM172A expression was evaluated by q-PCR, immunoblotting and immunohistochemistry (IHC). The ability of proliferation, migration and invasion of cells were assessed by Cell Counting Kit-8 assay (CCK8), clone-formation and Transwell assays. Nude mouse tumorigenicity assays were used to investigate the role of FAM172A in the pathogenesis of FTC in vivo. The value of FAM172A in the differential diagnosis for FTC was assessed using 120 formalin-fixed paraffin-embedded (FFPE) tissues after the operation and 81 fine-needle aspiration biopsy (FNAB) samples before the operation. FAM172A was highly expressed in FTC tissues and FTC cell lines. Downregulation of FAM172A inhibited the proliferation, invasion and migration of FTC cells through Erk1/2 and JNK pathways. Subcutaneous tumorigenesis in nude mice showed that knockdown of FAM172A inhibited tumor growth and progression in vivo. The FAM172A IHC scores of 3.5 had 92% sensitivity and 63% specificity to separate FTC from benign/borderline thyroid follicular lesions, and 92% sensitivity and 80% specificity to discriminate FTC from benign thyroid follicular lesions in postoperative FFPE samples. The corresponding values were 75 and 78%, and 75 and 89% in preoperative FNA samples, respectively. FAM172A plays an important role in the pathogenesis of FTC through Erk1/2 and JNK pathways. FAM172A may be a potential marker for the preoperative diagnosis of FTC based on the IHC results of thyroid FNAB samples.
Pei-Pei Xu, Su Zeng, Xiao-Tian Xia, Zi-Heng Ye, Mei-Fang Li, Ming-Yun Chen, Tian Xia, Jing-Jing Xu, Qiong Jiao, Liang Liu, Lian-Xi Li, and Ming-Gao Guo
Sandra Lassalle, Véronique Hofman, Marius Ilie, Christelle Bonnetaud, Marie-Pierre Puisségur, Patrick Brest, Céline Loubatier, Nicolas Guevara, Olivier Bordone, Bruno Cardinaud, Kévin Lebrigand, Géraldine Rios, Joseph Santini, Brigitte Franc, Bernard Mari, Abir Al Ghuzlan, Philippe Vielh, Pascal Barbry, and Paul Hofman
The term ‘thyroid tumors of uncertain malignant potential’ (TT-UMP) was coined by surgical pathologists to define well-differentiated tumors (WDT) showing inconclusive morphological evidence of malignancy or benignity. We have analyzed the expression of microRNA (miRNA) in a training set of 42 WDT of different histological subtypes: seven follicular tumors of UMP (FT-UMP), six WDT-UMP, seven follicular thyroid adenomas (FTA), 11 conventional papillary thyroid carcinomas (C-PTC), five follicular variants of PTC (FV-PTC), and six follicular thyroid carcinomas (FTC), which led to the identification of about 40 deregulated miRNAs. A subset of these altered miRNAs was independently validated by qRT-PCR, which included 18 supplementary TT-UMP (eight WDT-UMP and ten FT-UMP). Supervised clustering techniques were used to predict the first 42 samples. Based on the four possible outcomes (FTA, C-PTC, FV-PTC, and FTC), about 80% of FTA and C-PTC and 50% of FV-PTC and FTC samples were correctly assigned. Analysis of the independent set of 18 WDT-UMP by quantitative RT-PCR for the selection of the six most discriminating miRNAs was unable to separate FT-UMP from WDT-UMP, suggesting that the miRNA signature is insufficient in characterizing these two clinical entities. We conclude that considering FT-UMP and WDT-UMP as distinct and specific clinical entities may improve the diagnosis of WDT of the thyroid gland. In this context, a small set of miRNAs (i.e. miR-7, miR-146a, miR-146b, miR-200b, miR-221, and miR-222) appears to be useful, though not sufficient per se, in distinguishing TT-UMP from other WDT of the thyroid gland.
Amandine Berdelou, Livia Lamartina, Michele Klain, Sophie Leboulleux, Martin Schlumberger, and on behalf of the TUTHTYREF Network
Distant metastases from thyroid cancer of follicular origin are uncommon. Treatment includes levothyroxine administration, focal treatment modalities with surgery, external radiation therapy and thermal ablation, and radioiodine in patients with uptake of 131I in their metastases. Two-thirds of distant metastases become refractory to radioiodine at some point, and when there is a significant tumor burden and documented progression on imaging, a treatment with a kinase inhibitor may provide benefits.
Shu-Fu Lin, Jen-Der Lin, Chuen Hsueh, Ting-Chao Chou, and Richard J Wong
Activation of cyclin-dependent kinase activity is frequently observed in many human cancers; therefore, cyclin-dependent kinases that promote cell cycle transition and cell proliferation may be potential targets in the treatment of malignancy. The therapeutic effects of roniciclib, a cyclin-dependent kinase inhibitor for papillary and follicular thyroid cancer (designated as well-differentiated thyroid cancer), were investigated in this study. Roniciclib inhibited cell proliferation in two papillary and two follicular thyroid cancer cell lines in a dose-dependent manner. Roniciclib activated caspase-3 activity and induced apoptosis. Cell cycle progression was arrested in the G2/M phase. Roniciclib treatment in vivo retarded the growth of two well-differentiated thyroid tumors in xenograft models in a dose-dependent fashion. Furthermore, the combination of roniciclib with sorafenib was more effective than either single treatment in a follicular thyroid cancer xenograft model. Acceptable safety profiles appeared in animals treated with either roniciclib alone or roniciclib and sorafenib combination therapy. These findings support roniciclib as a potential drug for the treatment of patients with well-differentiated thyroid cancer.
Daphne R Pringle, Zhirong Yin, Audrey A Lee, Parmeet K Manchanda, Lianbo Yu, Alfred F Parlow, David Jarjoura, Krista M D La Perle, and Lawrence S Kirschner
Thyroid cancer is the most common endocrine malignancy in the population, and the incidence of this cancer is increasing at a rapid rate. Although genetic analysis of papillary thyroid cancer (PTC) has identified mutations in a large percentage of patients, the genetic basis of follicular thyroid cancer (FTC) is less certain. Thyroid cancer, including both PTC and FTC, has been observed in patients with the inherited tumor predisposition Carney complex, caused by mutations in PRKAR1A. In order to investigate the role of loss of PRKAR1A in thyroid cancer, we generated a tissue-specific knockout of Prkar1a in the thyroid. We report that the resulting mice are hyperthyroid and developed follicular thyroid neoplasms by 1 year of age, including FTC in over 40% of animals. These thyroid tumors showed a signature of pathway activation different from that observed in other models of thyroid cancer. In vitro cultures of the tumor cells indicated that Prkar1a-null thyrocytes exhibited growth factor independence and suggested possible new therapeutic targets. Overall, this work represents the first report of a genetic mutation known to cause human FTC that exhibits a similar phenotype when modeled in the mouse. In addition to our knowledge of the mechanisms of human follicular thyroid tumorigenesis, this model is highly reproducible and may provide a viable mechanism for the further clinical development of therapies aimed at FTC.
Isabel Amendoeira, Tiago Maia, and Manuel Sobrinho-Simões
The 2017 edition of the WHO book on Classification of Tumours of Endocrine Organs includes a new section entitled ‘Other encapsulated follicular-patterned thyroid tumours’, in which the newly created NIFTP (non-invasive follicular thyroid neoplasm with papillary-like nuclear features) is identified and described in detail. Despite deleting the word ‘carcinoma’ from its name, NIFTP is not a benign tumor either and is best regarded as a neoplasm with ‘very low malignant potential’. The main goal of the introduction of NIFTP category is to prevent overdiagnosis and overtreatment. Sampling constraints, especially when dealing with heterogeneous and/or large nodules, and difficulties in the invasiveness evaluation, are the major weaknesses of the histological characterization of NIFTP. At the cytological level, NIFTP can be separated from classic papillary carcinoma (cPTC) but not from encapsulated, invasive follicular variant PTC. The impact of NIFTP individualization for cytopathology is the drop of rates of malignancy for each Bethesda category in general and for indeterminate categories in particular. The biggest impact will be seen in institutions with a high frequency of FVPTC. The introduction of NIFTP has changed the utility of predictive values of molecular tests because RAS mutations and PAX8-PPARg rearrangements are frequently detected in NIFTP. This turns less promising the application of mutation detection panels as indicators of malignancy and will probably contribute to switch to a rule-out approach of molecular testing. Selection for surgery will go on being determined by a combined detection of clinical, cytological and ultrasound suspicious features.
Denise Zwanziger, Julia Badziong, Saskia Ting, Lars Christian Moeller, Kurt Werner Schmid, Udo Siebolts, Claudia Wickenhauser, Henning Dralle, and Dagmar Fuehrer
CLAUDIN-1 belongs to the family of transmembrane tight junction proteins tightening the paracellular cleft of epithelial cells. In human malignancies, CLAUDIN-1 is often dysregulated and located in subcellular compartments, particularly in the nucleus where it may influence cellular behaviour. Here, we studied CLAUDIN-1 in relation to the biological characteristics of follicular thyroid carcinoma (FTC). CLAUDIN-1 immuno-staining showed loss of membrane expression and increased nuclear CLAUDIN-1 localization in FTC metastases. CLAUDIN-1 function was further investigated in two different follicular thyroid carcinoma cell lines: FTC-133 isolated from a regional lymph node metastasis and FTC-238 derived from a lung metastasis. In both cell lines CLAUDIN-1 expression was demonstrated in the cell nuclei with a significantly higher protein expression in FTC-238 compared to FTC-133 cells. Interestingly, in vitro scratch assay revealed enriched nuclear CLAUDIN-1 expression near the scratch. Furthermore, the increase of the pathogenic character of FTC-133 cells by RASV12 transfection was associated with elevated CLAUDIN-1 expression and enhanced cell migration, invasion and proliferation. Likewise over-expression of nuclear CLAUDIN-1 in FTC-133 cells resulted in increased cell migration and invasion. Conversely, CLAUDIN-1 downregulation in FTC-238 cells by siRNA resulted in decreased cell migration and invasion and was accompanied by reduced phosphoPKC expression. Moreover, activation and inhibition of PKC resulted in CLAUDIN-1 up- and downregulation in FTC cells respectively. These data suggest an impact of CLAUDIN-1 on follicular thyroid carcinoma aggressiveness, which could potentially be influenced by PKC activity.
According to the literature thyroid nodules are quite rare in the first two decades of life. However, there are some exceptions, relating to areas with an iodine deficiency or affected by radioactive fallout, where the risk of nodules and carcinomas is increased. Therefore, it is a great challenge for the physician to distinguish between benign and malignant lesions preoperatively, and not only in these areas of greater risk. A careful work-up, comprising the patient’s history, clinical examination, laboratory tests, thyroid ultrasound, scintigraphy, fine-needle aspiration biopsy (FNAB) and molecular studies, is mandatory to improve the preoperative diagnosis. The differential diagnosis should also include benign thyroid conditions such as: (i) congenital hypothyroidism due to dyshormonogenesis or ectopy, (ii) thyroid hemiagenesis, (iii) thyroglossal duct cyst, (iv) simple goiter, (v) cystic lesion, (vi) nodular hyperplasia, (vii) follicular adenoma, (viii) Graves’ disease and (ix) Hashimoto thyroiditis, all of which can predispose to the development of thyroid nodules. The majority of thyroid carcinomas derive from the follicular cell (papillary, follicular, insular and undifferentiated (or anaplastic) thyroid carcinoma), whereas medullary thyroid carcinoma derives from calcitonin-producing cells. Inherited forms of thyroid cancer may occur, especially in relation to medullary thyroid carcinoma. FNAB is a critical factor in establishing the preoperative diagnosis. However, we should keep in mind the fact that a conventional cytological evaluation can miss the neoplastic nature of a lesion and the employment of immunocytochemical and molecular studies of aspirates from FNAB can give us a more precise diagnosis of neoplasia in thyroid nodules once they are detected.
Shu-Fu Lin, Jen-Der Lin, Chun-Nan Yeh, Yu-Tung Huang, Ting-Chao Chou, and Richard J Wong
Polo-like kinases (PLKs) are pivotal regulators of cell proliferation and cell survival; therefore, PLKs may be potential targets in the treatment of malignancy. The therapeutic effects of volasertib, a PLKs inhibitor for papillary and follicular thyroid cancer (known as well-differentiated thyroid cancer (WDTC)), were evaluated in this study. Volasertib inhibited cell proliferation in two papillary and two follicular thyroid cancer cell lines in a dose-dependent manner. Volasertib treatment reduced cells in the S phase and increased cells in the G2/M phase. Volasertib activated caspase-3 activity and induced apoptosis. Drug combinations of volasertib and sorafenib showed mostly synergism in four well-differentiated thyroid carcinoma cell lines in vitro. Volasertib treatment in vivo retarded the growth of a papillary thyroid tumor model. Furthermore, the combination of volasertib with sorafenib was more effective than a single treatment of either in a follicular thyroid cancer xenograft model. Promising safety profiles appeared in animals treated with either volasertib alone or volasertib and sorafenib combination therapy. These findings support volasertib as a potential drug for the treatment of patients with WDTC.
D F√ºhrer, A Tannapfel, O Sabri, P Lamesch, and R Paschke
In a 59-year-old patient, thyroid follicular cancer was diagnosed in two right-sided toxic thyroid nodules, which had presented clinically as unilateral thyroid autonomy. In addition, the patient had histologically proven lung metastases of thyroid cancer; however, these failed to exhibit iodine uptake and were resistant to radioiodine treatment. The functional activity of the thyroid nodules prompted us to screen for TSH receptor (TSHR) mutations, and the histological diagnosis of follicular carcinoma led us to search for the PAX8-PPARgamma1 rearrangement and mutations in the ras genes. Each thyroid nodule harboured a different TSHR mutation (large nodule, Asp633Tyr; small nodule, Phe631Ile). Presence of both mutations in one sample suggestive of local invasion of a thyroid carcinoma could not be demonstrated, although several specimens from different nodule locations were screened. Only the wild-type TSHR sequence was identified in the histologically normal left thyroid lobe, and no genetic alterations were found in the other investigated genes. No TSHR mutations were detected in the pulmonary metastases. This is the first case report of a patient with toxic follicular thyroid carcinoma harbouring two different TSHR mutations and presenting with non-functional lung metastases.