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Recurrent allelic imbalance at the rat Pten locus in DMBA‐induced fibrosarcomas
Author(s) -
Sjöling Åsa,
Samuelson Emma,
Adamovic Tatjana,
Behboudi Afrouz,
Röhme Dan,
Levan Göran
Publication year - 2003
Publication title -
genes, chromosomes and cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.754
H-Index - 119
eISSN - 1098-2264
pISSN - 1045-2257
DOI - 10.1002/gcc.10143
Subject(s) - pten , tensin , biology , allele , genetics , locus (genetics) , exon , cancer research , dmba , tumor suppressor gene , haploinsufficiency , gene , microbiology and biotechnology , carcinogenesis , phenotype , pi3k/akt/mtor pathway , apoptosis
The tumor‐suppressor gene PTEN (phosphatase and tensin homolog) is frequently inactivated in different types of human tumors. Less is known about the involvement of the homologous gene Pten in animal model systems of cancer. By sequencing one of the introns of rat Pten , we found an informative intragenic PCR marker suitable for genetic studies. Through use of this marker, the position of Pten in the genetic linkage map was localized to the distal part of rat chromosome 1 (RNO1) by analysis of F2 progeny from an intercross between inbred strains BN and LE. Subsequently, 22 markers from this region (including the intragenic Pten marker) were used to study the occurrence of allelic imbalance in distal RNO1 in fibrosarcomas that had been induced by DMBA in F1(BN×LE) rats. The analysis revealed that allelic imbalance was common in the vicinity of Pten , and there was loss or reduction of one of the Pten alleles in more than 60% of the fibrosarcomas. DNA sequencing was preformed to investigate whether the Pten allele remaining in the tumors was inactivated by mutation. However, no mutations were detected in the genomic sequence of Pten exons 5 to 9 in any of the fibrosarcomas, and normal mRNA transcripts were expressed in all tumors. Thus, based on the targeted selection for loss of Pten observed in some of these tumors and the absence of inactivation of the remaining allele, we suggest that haploinsufficiency of Pten may be an important factor in rat DMBA‐induced fibrosarcomas. © 2002 Wiley‐Liss, Inc.