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- Hansén Nord, Karolin, et al.
(författare)
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Retained heterodisomy is associated with high gene expression in hyperhaploid inflammatory leiomyosarcoma.
- 2012
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Ingår i: Neoplasia. - : Elsevier BV. - 1522-8002. ; 14:9, s. 807-U156
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Tidskriftsartikel (refereegranskat)abstract
- Inflammatory leiomyosarcoma (ILMS) is a soft tissue tumor that morphologically resembles conventional leiomyosarcoma (LMS) admixed with a prominent inflammatory infiltrate. Genetic data on ILMS are still limited but have suggested that this entity is characterized by hyperhaploidy (24-34 chromosomes). This low chromosome number is otherwise uncommon in neoplasia and has been found only in 0.2% to 0.3% of cytogenetically investigated tumors. Here, three ILMS were investigated using cytogenetic, single-nucleotide polymorphism (SNP) array, and global gene expression analyses. All cases displayed a hyperhaploid origin. Combined with previously reported cases, hyperhaploidy has been found in six of seven cytogenetically investigated ILMS. The copy number distribution of individual chromosomes is clearly nonrandom; the hyperhaploid clones of all six cases displayed disomy for chromosomes 5 and 20, and two copies of chromosomes 18, 21, and 22 were also common. All chromosomes identified as disomic showed a biparental origin by SNP array analysis; whether this is of pathogenetic importance is not known. Compared with conventional LMS, ILMS had a distinct gene expression signature. Furthermore, the number of chromosome copies correlated well with gene expression levels; disomic chromosomes showed higher gene expression levels than monosomic chromosomes, a finding that has not previously been reported for hyperhaploid tumors. Taken together, our findings suggest that disomy for some chromosomes, notably 5 and 20, as well as distorted gene expression achieved through massive loss of other chromosomes are essential features of ILMS.
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