Banca de DEFESA: NATÁLIA RODRIGUES SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : NATÁLIA RODRIGUES SILVA
DATE: 30/09/2024
TIME: 08:00
LOCAL: Plataforma Remota
TITLE:

Immunoexpression of Proteins Related to the Hippo Pathway in Papillary Thyroid Carcinomas

KEY WORDS:

Papillary thyroid carcinoma; Hippo signaling pathway; YAP and TEAD proteins.

PAGES: 73
BIG AREA: Ciências da Saúde
AREA: Odontologia
SUMMARY:

Papillary thyroid carcinoma (PTC) is the most common malignant neoplasm in the thyroid gland. Although these lesions typically have an excellent prognosis, some cases exhibit aggressive clinicopathological characteristics, with a high rate of lymph node metastasis and recurrence. Consequently, new molecular biomarkers have been studied to better understand the biological and molecular processes involved in the development and progression of this neoplasm. Among these, the proteins YAP, LATS2, and TEAD, key components of the Hippo Pathway (HP), stand out. This pathway is essential in various biological processes such as organ size control, cellular homeostasis, and tissue regeneration, and is also involved in carcinogenesis when dysregulated. Thus, this study aimed to evaluate the YAP, LATS2, and TEAD proteins in PTCs to assess whether these molecules can influence the biological behavior of these lesions. The sample consisted of 31 cases of PTCs and 5 follicular adenomas (control group), with clinicopathological information correlated to the immunoexpression of YAP-1, LATS-2, and TEAD proteins in these lesions. Immunopositivity was assessed by nuclear positivity and cytoplasmic staining intensity. For nuclear positivity, cases with more than 20% marker expression were considered positive. Regarding intensity, YAP-1 and LATS2 cases were classified as negative (no staining), weak (light brown), or strong (dark brown). Data were statistically analyzed using Pearson's Chi-square and Fisher's Exact tests, with a significance level of 5% (p < 0.05). The immunoexpression analysis showed that all PTC cases (100%) exhibited nuclear positivity for YAP-1. A significant association was also found between strong cytoplasmic YAP-1 expression and PTC cases compared to the control group (p = 0.001). For LATS2, low cytoplasmic expression was observed in most PTC cases (58.1%). TEAD showed higher nuclear positivity (p = 0.029) in PTC cases. No statistically significant associations with clinicopathological data were found. The lower cytoplasmic expression of LATS2 in PTCs suggests that this protein may not regulate YAP, leading to its nuclear translocation. The elevated nuclear expression of YAP and TEAD indicates possible nuclear interaction. Therefore, the cytoplasmic subregulation of LATS2 and the nuclear YAP-TEAD interaction may influence PTC tumorigenesis.

COMMITTEE MEMBERS:
Interna - 2492713 - ERICKA JANINE DANTAS DA SILVEIRA
Externo à Instituição - GUSTAVO PINA GODOY - UFPE
Externo ao Programa - 2885547 - JOABE DOS SANTOS PEREIRA - UFRNPresidente - 1298808 - MARCIA CRISTINA DA COSTA MIGUEL
Externa à Instituição - RANI IANI COSTA GONÇALO - UnP