Distinction between Complete and Partial 1P/19Q Losses in Gliomas: A Novel User-Friendly Approach
A Ariza, C Carrato, MD Lopez, M Domingo-Sabat, MT Lopez, K Beyer. Hospital Germans Trias i Pujol, Autonomous University of Barcelona, Badalona, Barcelona, Spain
Background: Complete loss of both 1p and 19q has been associated with oligodendrogliomas, whereas partial 1p loss has been related to aggressive astrocytomas. However, the two most frequently used methods for 1p and/or 19q loss determination (fluorescent in situ hybridization and microsatellite amplification) focus on 1p34-36 and 19q13 only and are thus unable to accurately distinguish between complete and partial arm losses.
Design: In an attempt to discriminate between the types of arm loss, we used semiquantitative real-time PCR of telomeric and centromeric sequences on 1 p (SPAG17, ATG4), 19q (DPY19L3, RPS9), 1q (PYGO2 and GREM2), and 19p (COPE, FUT3) in a series of 69 astrocytomas and 10 oligodendrogliomas. The deltadeltaCt method was used for relative quantification of PCR products. Conventional LOH study of 1p and 19q by microsatellite amplification was also performed in all cases.
Results: Among astrocytomas, of the 11 instances showing 1p loss and the 12 instances showing 19q loss by microsatellite amplification, our approach demonstrated the loss to be complete for 1p in just 1 instance and for 19q in just 4 instances. In contrast, each of the 10 oligodendrogliomas, all showing both 1p and 19q loss by microsatellite amplification, revealed both complete 1p and complete 19q loss by our method.
Conclusions: The rapid and easy-to-use approach herein described is a useful complementary tool for accurately determinating whether chromosome losses are complete or partial in gliomas. Of practical interest, it abolishes the need for patient's normal tissue or peripheral blood as control.
Tuesday, March 23, 2010 1:45 PM
Platform Session: Section G, Tuesday Afternoon