Título: OCT4/NANOG Expression in cutaneous melanoma. Autores: Jalsi Tacon Arruda; Constanza Thaise Xavier Silva; Alex Cardoso de Souza; Cesar Augusto ...
Código #14346 Título: OCT4/NANOG Expression in cutaneous melanoma Autores: Jalsi Tacon Arruda; Constanza Thaise Xavier Silva; Alex Cardoso de Souza; Cesar Augusto Sam Tiago Vilanova-Costa; Vera Aparecida Saddi; Lídia Andreu Guillo Instituição: Universidade Federal de Goiás, Instituto de Ciências Biológicas, Goiânia, GO, Brasil; Faculdade Araguaia, Goiânia, GO, Brasil; UniEVANGÉLICA – Centro Universitário de Anápolis, GO, Brasil; Pontifícia Universidade Católica de Goiás, Goiânia, GO, Brasil. Resumo do caso: Primary cutaneous melanoma incidence is growing and it appears as a public health problem. Recent evidence suggests a subset of cells within a tumor with "stem-like" characteristics. Cancer stem cells show low proliferative rates, high self-renewing capacity, propensity to differentiate into actively proliferating tumor cells, and resistance to chemotherapy or radiation. OCT4 is an 18-kDa POU-domain transcription factor encoded by the POU5F1 gene. Is involved in the initiation, maintenance, and differentiation of pluripotent and germline cells during normal development. NANOG plays a pivotal role in maintenance of pluripotency and self-renewal in embryonic stem cells. The encoded protein can block embryonic stem cell differentiation and can also autorepress its own expression in differentiating cells. A male patient (CACV) 62 years old, and a female patient (DFP) 83 years old, was admitted to the Araujo Jorge Hospital, in Goiânia, GO, Brazil. CACV with a plantar melanoma (sole) and DFP with a melanoma on the trunk (chest) diagnosed. Both presented lymph node and brain metastasis, and died of melanoma. The diagnosis was made by histological examination of the paraffin sections stained with Haematoxylin – Eosin. Immunohistochemical study for OCT4 and NANOG expression was performed on formalin-fixed, paraffin-embedded tissues. The antibodies the rabbit monoclonal anti-OCT4 antibody and anti-NANOG antibody (Abcam), were used. The tumor infiltrated the subcutaneous fat (Clark's Level V) and showed features of Breslow's high-risk category (CACV with thickness 8mm, DFP with depth 5mm). These patients showed a positive immunostaining expression for both antibodies in nucleus and cytoplasm cell. Ectopic expression of OCT4 or NANOG in somatic cells results in dedifferentiation, malignant transformation and causes dysplasia in epithelial tissue, demonstrating the oncogenic potential of pluripotency genes. Keywords: Cancer stem cells, immunohistochemical, oncogenic potential, proliferating tumor cells. Financiamento: CAPES.
