¹The Rudbeck Laboratory, Department of Genetics and Pathology, University Hospital, SE-751 85 Uppsala, Sweden

Correspondence: B Westermark, E-mail: bengt.westermark@genpat.uu.se

Received 14 December 2004; Revised 17 January 2005; Accepted 20 January 2005; Published online 7 March 2005.

Abstract

Retroviral tagging previously identified putative cancer-causing genes in a mouse brain tumor model where a recombinant Moloney murine leukemia virus encoding the platelet-derived growth factor B-chain (MMLV/PDGFB) was intracerebrally injected in newborn mice. In the present study, expression analysis using cDNA arrays revealed several similarities of virus-induced mouse gliomas with human brain tumors. Brain tumors with short latency contained on average 8.0 retroviral insertions and resembled human glioblastoma multiforme (GBM) whereas long-latency gliomas were of lower grade, similar to human oligodendroglioma (OD) and had 2.3 insertions per tumor. Several known and novel genes of tumor progression or cell markers were differentially expressed between OD- and GBM-like tumors. Array and quantitative real-time PCR analysis demonstrated elevated expression similar to Pdgfr of retrovirally tagged genes Abhd2, Ddr1, Fos, Ng2, Ppfibp1, Rad51b and Sulf2 in both glioma types compared to neonatal and adult normal brain. The retrovirally tagged genes Plekhb1, Prex1, Prkg2, Sox10 and 1200004M23Rik were upregulated in the tumors but had a different expression profile than Pdgfr whereas Rap1gap, Gli1, Neurl and Camk2b were downregulated in the tumors. The present study accentuates the proposed role of the retrovirally tagged genes in PDGF-driven gliomagenesis and indicates that insertional mutagenesis can promote glioma progression.