Hsp27 (HSPB1): a possible surrogate molecular marker for loss of heterozigocity (LOH) of chromosome 1p in oligodendrogliomas

GISELA N CASTRO, NIUBYS CAYADO-GUTIÉRREZ, VERA L. MONCALERO, PATRICIA LIMA, RODOLFO LUCERO DE ANGELIS, VICTOR CHÁVEZ, F DARÍO CUELLO-CARRIÓN, DANIEL R CIOCCA

Buenos Aires

Workshop; Workshop "Frontiers in BioScience"; 2012

Ministerio de Ciencia, Tecnologia e Innovacion Productiva y Sociedad Max Planck (Alemania)

In oligodendrogliomas, 1p LOH is a predictor of good prognosis and treatment response. In contrast, in uveal melanomas LOH of chromosome 3 has been linked to poor prognosis and down-regulation of Hsp27. In the present study we have analyzed the expression of heat shock proteins (HSPs) to characterize subtypes of gliomas and their histopathologic features, and to correlate with other molecular markers including LOH of 1p. Biopsies from patients with primary gliomas (n=65) were analyzed by immunohistochemistry, CISH and FISH and methylation specific PCR (MSP). Elevated Hsp27 and Hsp70t expression levels were associated with high grade astrocytomas (p=0.0001 and p=0.01 respectively). In grade III oligodendrogliomas the Hsp27 levels were significantly higher (p=0.03). Low MGMT expression was associated with grade II astrocytomas. Elevated -catenin expression was associated with grade III/IV astrocytomas (p=0.003), p53 (+) tumors were more frequently found in grade III/IV astrocytomas (p=0,001). LOH on 1p was associated with oligodendroglial tumours. In addition, a higher Hsp27 expression correlated with LOH of 1p (p=0.017). MSP was successful in only 6 samples. No significant correlations were found for the other markers. In conclusion, in oligodendroglial tumors Hsp27 appeared as a surrogate marker of LOH of 1p which could also help to predict the disease prognosis. In gliomas, p53, Hsp27, Hsp70, MGMT and -catenin correlated with histopathological characteristics suggesting that these markers could predict the disease outcome and the response to treatments.