Hypermethylation of Secreted Frizzled Related Protein 1 gene promoter in different astrocytoma grades

Kafka, Anja and Karin-Kujundžić, Valentina and Šerman, Ljiljana and Bukovac, Anja and Njirić, Niko and Jakovčević, Antonia and Pećina-Šlaus, Nives (2018) Hypermethylation of Secreted Frizzled Related Protein 1 gene promoter in different astrocytoma grades. Croatian Medical Journal, 59 (5). pp. 213-223. ISSN 0353-9504

PDF - Published Version Download (848kB)

Abstract

Aim: To identify the involvement of Secreted Frizzled Related Protein 1 (SFRP1) promoter hypermethylation in different malignancy grades of astrocytoma and assess its association with beta-catenin, lymphoid-enhancer factor 1, and T-cell factor 1. Methods: Twenty-six astrocytoma samples were collected from 2008-2015. Promoter hypermethylation was evaluated by methylation-specific polymerase-chain-reaction and protein expression by immunohistochemistry and stereological analysis. The staining intensity was scored by comparing immunoreactivity with normal tissue and by using 10% and 50% cut-offs. Results: SFRP1 promoter methylation was found in 32% of astrocytomas. The number of hypermethylated samples increased in higher astrocytoma grades and was the highest in glioblastoma (P = 0.042 compared to other astrocytoma grades). There was 45.8% of samples with the lack of or weak expression of SFRP1 protein and 29.2% with strong expression. Samples with methylated promoter expressed significantly less SFRP1 than samples with unmethylated promoter (P = 0.031). Beta-catenin expression levels were elevated. Yet, glioblastomas with unmethylated SFRP1 promoter had significantly less beta-catenin (P = 0.033). Strong expression of lymphoid-enhancer factor 1 was associated to higher astrocytoma grades (P = 0.006). Conclusion: SFRP1 gene was epigenetically silenced in glioblastomas when compared to low astrocytoma grades, which may suggest that the lack of its protein is involved in astrocytoma progression.

Actions (login required)

View Item

Downloads