Complex genomic rearrangement of ALK loci associated with integrated human Epstein-Barr virus in a post-transplant myogenic liver tumor.

Epstein-Barr virus (EBV) is a ubiquitous viral agent, well known to be associated with lymphoid, epithelial, and smooth-muscle malignancies in immunocompromised individuals. This report describes a 10-year-old patient with an EBV-related liver tumor occurring after kidney transplantation. The neoplasm presented a phenotypic spectrum, ranging from a smooth-muscle tumor to an inflammatory pseudotumor (IPT). The neoplastic cells failed to disclose CD21, CD35, or ALK expression, the latter confirmed by reverse-transcription polymerase chain reaction. Cytogenetic analysis revealed a single clonal cell population showing 46,XY,del (2)(p23),der(3)t (2;3)(p23;q29),der(21) t(Y;21)(q12;p13) karyotype. By metaphase FISH analysis, the neoplastic cells demonstrated the presence of two molecularly different but related aberrant clones, one with the loss of one ALK allele and the second with translocation of the 3'end of ALK kinase domain on the der(3) chromosome. Using FISH with an EBV-specific and 3'end ALK DNA probes, a co-localization of the viral DNA and the ALK sequences was found on the der(3) chromosome. Metaphases with loss of rearranged ALK did not show integrated virus; instead, viral particles together with an associated 3'end ALK domain formed an ex-chromosomal, episomal-like type configuration. The interphase study, using dual-color 5'/3' end ALK FISH assay, revealed 30% of nuclei with only one fused signal, confirming the total loss of one ALK allele in the subset of tumor cells. A combined immunofluorescence and FISH study indicated this separate clonal variant to correspond to desmin-positive smooth-muscle cells. In contrast, desmin-negative myofibroblasts showed the presence of both normal and rearranged ALK alleles. Our results indicate that ALK locus may be a target of EBV integration, a hitherto unreported finding. Although the sustained clonal expansion in EBV-related smooth-muscle tumors/IPTs may depend on functions provided by the EBV oncogenic proteins, the tumor phenotype may be further modified by the secondary genomic rearrangements imposed by the virus during and/or after the integration event. In this respect, the observed phenotypic heterogeneity most likely reflects divergence during neoplastic progression, with the subsequent expansion of morphologically and molecularly distinct but cytogenetically related clones.
AuthorsMaria Debiec-Rychter, Romaric Croes, Rita De Vos, Peter Marynen, Tania Roskams, Anne Hagemeijer, Rita Lombaerts, Raf Sciot
JournalThe American journal of pathology (Am J Pathol) Vol. 163 Issue 3 Pg. 913-22 (Sep 2003) ISSN: 0002-9440 [Print] United States
PMID12937132 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't)
Chemical References
  • Protein-Tyrosine Kinases
  • Receptor Protein-Tyrosine Kinases
  • anaplastic lymphoma kinase
  • Child
  • Chromosome Mapping
  • Epstein-Barr Virus Infections (complications, etiology, genetics)
  • Fluorescent Antibody Technique
  • Gene Rearrangement
  • Herpesvirus 4, Human (genetics)
  • Humans
  • In Situ Hybridization, Fluorescence
  • Karyotyping
  • Liver Neoplasms (pathology, virology)
  • Liver Transplantation (adverse effects)
  • Male
  • Microscopy, Electron
  • Protein-Tyrosine Kinases (genetics, metabolism)
  • Receptor Protein-Tyrosine Kinases
  • Reverse Transcriptase Polymerase Chain Reaction
  • Virus Integration

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research network!

Choose Username:
Verify Password: