AVALIAÇÃO DA EXPRESSÃO GÊNICA DE P300 E CITED-1 EM CARCINOMAS PAPILÍFEROS DE TIREÓIDE

Abstract

Thhyroid cancer is the most common malignant neoplasm of the endocrine system and accounts for the majority of deaths reported among these tumors. Papillary thyroid carcinoma (PTC) is the most common histological type, accounting for 85% of all thyroid cancers. The expression of two important genes, CITED-1 and P300, involved in the regulation of several transcriptional factors, has been shown in several tumors; however, to date, no studies have been found in the literature that elucidated the role of P300 and CITED-1 in PTC. The present study aimed to evaluate the expression of the messenger RNA (mRNA) of P300 and CITED-1 in PTC using reverse transcription and real-time quantitative PCR. P300 expression was similar in both tissues, normal (median = 0.052, IIQ = 0.094) and tumor (median = 0.041, IIQ = 0.048) (p = 0.481). In relation to the expression of CITED-1, expression was higher in tumor tissues (median = 0.780, IIQ = 0.881) compared to normal tissues (median = 0.017, IIQ = 0.086) (p <0.0001). Significant association was observed between CITED-1 expression and tumor size, however no association was evidenced between P300 expression and histopathological characteristics of the tumors. P300 is described as a molecule associated with the regulation of CITED-1 and several other genes. CITED-1 is a transcription-specific cofactor, which may explain its overexpression in the tumors evaluated. CITED-1 hyperexpression in PTC suggests that this gene is a candidate for integrating the PTC biomarkers profile, and the fact that CITED-1 is associated with tumor size in later stage tumors may turn it an important candidate as a therapeutic target for these tumors.