Differential gene expression in meningiomas by microarray and real time PCR with and without 22 deletion

• Grant number: 09/03149-0
• Support Opportunities: Regular Research Grants
• Start date: March 01, 2010
• End date: February 29, 2012
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Carlos Gilberto Carlotti Jr
• Grantee: Carlos Gilberto Carlotti Jr
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Meningiomas are intracranial tumors, originated from the meningothelial cells of the arachnoid, with an annual incidence of 6 per 100,000 people, and are most commonly seen in female adults and after the fifth decade of life. Little is known about the genetic events that are important on the molecular pathology and on the malignant progression of the meningiomas. The most common genetic event found in 60% of the cases is the chromosome 22q deletion. The understanding about the molecular characteristics during the initiation and growth of meningiomas can help to determine targets of molecular therapy. The formation of a brain tumor is a complex process, involving several genetic alterations. The MicroRNAs (miRNAs or miRs) are a class of small non-coding RNA species that regulate gene expression, with a crucial role in the development of cancer and recently the involvement of miRNAs in the pathophysiology of brain cancer has been initiated. Considering that the chromosome 22 deletion is the most frequent alteration in meningioma, the molecular pathways that result in abnormal chromosomal behavior during the progression of this disease are related to a series of complex interactions that need to be characterized, one of them is the possible relationship between this chromosomal alteration and the gene expression. Objective: Evaluate different gene expression between meningiomas grade I that shows chromosome 22 deletion and meningiomas grade I without this deletion. Patients and Methods: For this study it will be used 90 samples of meningiomas grade I. The cases will be selected based on clinical and histopathological diagnosis of grade I meningiomas, according to WHO criteria. Controls will be arachnoid samples obtained from patients submitted to surgery for aneurysm. To determine the deletion of chromosome 22 it will be used Fluorescent In Situ Hybridisation (FISH), followed by global analysis of gene expression by microarrays and subsequent validation of results by real-time PCR. (AU)