Expression of Methylthioadenosine Phosphorylase (MTAP) in Pilocytic Astrocytomas

Autor(es)

Becker, Aline Paixao ^{[1, 2]} ; Scapulatempo-Neto, Cristovam ^[3] ; Menezes, Weder P. ^[1] ; Clara, Carlos ^[4] ; Machado, Helio R. ^[2] ; Oliveira, Ricardo S. ^[2] ; Neder, Luciano ^[2] ; Reis, Rui Manuel ^{[1, 5, 6]}

Afiliação do(s) autor(es)

^[1] Barretos Canc Hosp, Mol Oncol Res Ctr, BR-14784400 Barretos, SP - Brazil

^[2] Univ Sao Paulo, Ribeirao Preto Sch Med, BR-14049 Ribeirao Preto - Brazil

^[3] Barretos Canc Hosp, Dept Pathol, BR-14784400 Barretos, SP - Brazil

^[4] Barretos Canc Hosp, Dept Neurosurg, BR-14784400 Barretos, SP - Brazil

^[5] Univ Minho, Sch Hlth Sci, Life & Hlth Sci Res Inst ICVS, Braga - Portugal

^[6] ICVS 3Bs, PT Govt Associate Lab, Braga - Portugal

• Tipo de documento: Artigo Científico
• Fonte: PATHOBIOLOGY; v. 82, n. 2, p. 84-89, 2015.
• Citações Web of Science: 5

Resumo

Background/Objectives: Pilocytic astrocytomas (PAs) are the most frequent astrocytomas in children and adolescents. Methilthioadenosine phosphorylase (MTAP) is a tumor-suppressor gene, the loss of expression of which is associated with a poor prognosis and better response to specific chemotherapy in leukemia and non-small-cell lung cancer. The expression of MTAP in brain tumors remains largely unknown and its biological role in PA is still unexplored. Our aims were to describe the immunohistochemical MTAP expression in a series of PAs and relate it to the clinicopathological features of the patients. Methods: We assessed MTAP expression on immunohistochemistry in 69 pediatric and adult patients with PA in a tissue microarray platform. Results: Retained expression of MTAP was seen in >85% of the tumors compared to in the nonneoplastic adjacent tissue. Only 3 supratentorial tumors showed a complete loss of MTAP expression. No significant association with clinicopathological features or overall survival of the patients was found. Conclusions: MTAP expression is retained in PAs and is not an outcome predictor for these tumors. Nevertheless, a subset of patients with PAs exhibiting a loss of MTAP could potentially benefit from treatment with specific chemotherapy, especially when lesions are recurrent or surgical resection is not recommended. (C) 2015 S. Karger AG, Basel (AU)

• Processo FAPESP: 12/19590-0 - Perfil mutacional de linhagens primárias de glioblastomas
• Beneficiário: Rui Manuel Vieira Reis
• Modalidade de apoio: Auxílio à Pesquisa - Regular