Analysis of the WNT and Sonic Hedgehog pathways in childhood adrenocortical tumors and its relationship with miRNAs

• Grant number: 11/13807-4
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2012
• End date: March 31, 2015
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Sonir Roberto Rauber Antonini
• Grantee: Sonir Roberto Rauber Antonini
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The incidence of childhood adrenocortical (ACTs) is 10 to 15 higher in Southern Brazil, and it is associated with a germline TP53 mutation (p.R337H). Beta-catenin abnormalities are frequent is adult ACTs and transcriptoma analysis suggested that the Wnt/beta-catenin pathway is activated, and it is associated with poor prognosis in these tumors. The Sonic Hedgehog (SHH) pathway is important in adrenal development and interacts with the Wnt pathway, which appears to be regulated by P53 and miRNAs, among others. Deregulation of these pathways may play an important role in childhood adrenocortical tumorigenesis, but to date, no studies have investigated in a comprehensive way these hypotheses. Objectives: To evaluate the role of canonical and non-canonical Wnt pathways and the SHH pathway in childhood adrenocortical tumorigenesis and their relationship with miRNAs. Patients and Methods: approximately 65 pediatric patients from 2 reference centers will be evaluated. Fetal and childhood adrenal samples will be used as controls. The clinical and biochemical profile as well as the outcome of these patients will be evaluated in relations to molecular abnormalities. The presence of abnormalities in CTNBB1/beta-catenin, TP53 and PRKAR1A genes will be analyzed by direct sequencing. The expression of the SHH, canonical and non-canonical Wnt pathway genes as well as a subset of miRNAs will be assessed by qPCR and immunohistochemistry and/or Western blot. The functional interaction of AXIN1 and miRNA-449 will in vitro assays by over expressing the miRNA. By means of gene silencing assays and methylation studies, we will analyze the putative role of DKK3, a Wnt pathway component, in adrenocortical tumorigenesis. In addition, we will evaluate the functional consequences of CTNNB1 silencing both in normal and tumoral adrenocortical cell lineages. Functional in vitro assays will be performed using immortalized murine (Y1) and human adrenocortical cells (H295R) as well as primary cell cultures from pediatric adrenal tumors. Perspectives: we believe that the results of this work may significantly contribute to improve the knowledge on adrenocortical tumorigenesis and may find putative molecular prognostic markers as well as point to new therapeutical targets research. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

LEAL, LETICIA F.; BUENO, ANA CAROLINA; GOMES, DEBORA C.; ABDUCH, RAFAEL; DE CASTRO, MARGARET; ANTONINI, SONIR R.. Inhibition of the Tcf/beta-catenin complex increases apoptosis and impairs adrenocortical tumor cell proliferation and adrenal steroidogenesis. ONCOTARGET, v. 6, n. 40, p. 43016-43032, DEC 15 2015. (11/13807-4, 11/10512-3)