title: Horizontal transmission of clonal cancer cells causes leukemia in soft-shell clams.
abstract: Outbreaks of fatal leukemia-like cancers of marine bivalves throughout the world have led to massive population loss. The cause of the disease is unknown. We recently identified a retrotransposon, Steamer, that is highly expressed and amplified to high copy number in neoplastic cells of soft-shell clams (Mya arenaria). Through analysis of Steamer integration sites, mitochondrial DNA single-nucleotide polymorphisms (SNPs), and polymorphic microsatellite alleles, we show that the genotypes of neoplastic cells do not match those of the host animal. Instead, neoplastic cells from dispersed locations in New York, Maine, and Prince Edward Island (PEI), Canada, all have nearly identical genotypes that differ from those of the host. These results indicate that the cancer is spreading between animals in the marine environment as a clonal transmissible cell derived from a single original clam. Our findings suggest that horizontal transmission of cancer cells is more widespread in nature than previously supposed.
authors: Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
authors: Michael J
authors: MJ
authors: Metzger
authors: Environment Canada, Water Science & Technology Directorate, Burlington, Ontario L7R 4A6, Canada.
authors: Carol
authors: C
authors: Reinisch
authors: Environment Canada, Water Science & Technology Directorate, Burlington, Ontario L7R 4A6, Canada.
authors: James
authors: J
authors: Sherry
authors: Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA. Electronic address: spg1@columbia.edu.
authors: Stephen P
authors: SP
authors: Goff
mesh_terms: D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics; D007938:Leukemia / Q000235:genetics / Q000473:pathology; D018895:Microsatellite Repeats; D049892:Mya / Q000166:cytology* / Q000235:genetics; D018626:Retroelements
chemical_list: D004272:DNA, Mitochondrial; D018626:Retroelements