Binomial mitotic segregation of MYCN-carrying double minutes in neuroblastoma illustrates the role of randomness in oncogene amplification.
Research output: Contribution to journal › Article
BACKGROUND: Amplification of the oncogene MYCN in double minutes (DMs) is a common finding in neuroblastoma (NB). Because DMs lack centromeric sequences it has been unclear how NB cells retain and amplify extrachromosomal MYCN copies during tumour development. PRINCIPAL FINDINGS: We show that MYCN-carrying DMs in NB cells translocate from the nuclear interior to the periphery of the condensing chromatin at transition from interphase to prophase and are preferentially located adjacent to the telomere repeat sequences of the chromosomes throughout cell division. However, DM segregation was not affected by disruption of the telosome nucleoprotein complex and DMs readily migrated from human to murine chromatin in human/mouse cell hybrids, indicating that they do not bind to specific positional elements in human chromosomes. Scoring DM copy-numbers in ana/telophase cells revealed that DM segregation could be closely approximated by a binomial random distribution. Colony-forming assay demonstrated a strong growth-advantage for NB cells with high DM (MYCN) copy-numbers, compared to NB cells with lower copy-numbers. In fact, the overall distribution of DMs in growing NB cell populations could be readily reproduced by a mathematical model assuming binomial segregation at cell division combined with a proliferative advantage for cells with high DM copy-numbers. CONCLUSION: Binomial segregation at cell division explains the high degree of MYCN copy-number variability in NB. Our findings also provide a proof-of-principle for oncogene amplification through creation of genetic diversity by random events followed by Darwinian selection.
|Research areas and keywords||
Subject classification (UKÄ) – MANDATORY
|Publication status||Published - 2008|
The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Islet patophysiology (013212132), Molecular Medicine (013031200), Division of Clinical Genetics (013022003), Mathematics (Faculty of Technology) (011015005), Solid State Physics (011013006)
Related research output
Chromosome dynamics and genomic instablity in neuroblastoma. Three genomic pillars: MYCN amplification, numerical and structural changes.Gisela Lundberg, 2012, Faculty of Medicine, Lund University. 132 p.
Research output: Thesis › Doctoral Thesis (compilation)