%0 Journal Article
%T Altered Peptidase Activities in Thyroid Neoplasia and Hyperplasia
%A Gorka Larrinaga
%A Lorena Blanco
%A Peio Errarte
%A Maider Beitia
%A BegoŁża Sanz
%A Itxaro Perez
%A Amaia Irazusta
%A Clara E. S¨˘nchez
%A Francisco Santaolalla
%A Leire Andr¨¦s
%A Jos¨¦ I. L¨®pez
%J Disease Markers
%D 2013
%R 10.1155/2013/970736
%X Background. Papillary thyroid carcinoma (PTC), follicular thyroid adenoma (FTA), and thyroid nodular hyperplasia (TNH) are the most frequent diseases of the thyroid gland. Previous studies described the involvement of dipeptidyl-peptidase IV (DPPIV/CD26) in the development of thyroid neoplasia and proposed it as an additional tool in the diagnosis/prognosis of these diseases. However, very little is known about the involvement of other peptidases in neoplastic and hyperplastic processes of this gland. Methods. The catalytic activity of 10 peptidases in a series of 30 PTC, 10 FTA, and 14 TNH was measured fluorimetrically in tumour and nontumour adjacent tissues. Results. The activity of DPPIV/CD26 was markedly higher in PTC than in FTA, TNH, and nontumour tissues. Aspartyl aminopeptidase (AspAP), alanyl aminopeptidase (AlaAP), prolyl endopeptidase, pyroglutamyl peptidase I, and aminopeptidase B activities were significantly increased in thyroid neoplasms when compared to nontumour tissues. AspAP and AlaAP activities were also significantly higher in PTC than in FTA and TNH. Conclusions. These data suggest the involvement of DPPIV/CD26 and some cytosolic peptidases in the neoplastic development of PTC and FTA. Further studies will help to define the possible clinical usefulness of AlaAP and AspAP in the diagnosis/prognosis of thyroid neoplasms. 1. Introduction Solitary and multiple nodules of the thyroid gland are very common in clinical practice, with most of them being benign lesions, either thyroid nodular hyperplasia (TNH) or follicular thyroid adenoma (FTA). Roughly only 5% of thyroid nodules are malignant [1] and 70% of them are papillary thyroid carcinomas (PTC) [2]. The arrival of ultrasound examination to routine practice has discovered a large amount of nonpalpable and clinically silent thyroid nodules. TNH, FTA, and PTC can be distinguished from each other following well-established histopathologic criteria [3]. Interestingly, these lesions are able to be sampled with recognized diagnostic success by sonographically guided fine needle aspiration cytology [1] or by core biopsy [4]. TNH consists of multiple nodules of variable size composed of odd-shaped thyroid follicles with homogeneous bland cytology and partial encapsulation that may reverse and dissapear when the hormonal stimulus ceases. Thyroid hyperfunction is common. FTA usually appears as asymptomatic solitary nodules. This lesion is composed of small size follicles lying in a fibrous, sometimes edematous stroma and shows a well defined fibrous capsule. There is no evidence of vascular
%U http://www.hindawi.com/journals/dm/2013/970736/