Detection of the integrated feline leukemia viruses in a cat lymphoid tumor cell line by fluorescence in situ hybridization.
Feline leukemia virus (FeLV) is a type-C retrovirus associated with lymphoid and hematopoietic malignancies in cats. The FeLV-induced tumors are thought to be caused, at least in part, by somatically acquired insertional mutagenesis in which the integrated provirus may activate a proto-oncogene or disrupt a tumor suppressor gene. This study was undertaken to enumerate and map the acquired proviral insertions in the genome of a feline thymic lymphoma cell line (FT-1) infected with FeLV. Fluorescence in situ hybridization (FISH) combined with tyramide signal amplification was applied on the chromosome specimen of FT-1 cells and normal cat lymphocytes, with an entire FeLV-A genome used as a probe. Specific hybridization signals were detected from only the metaphases of the FT-1 cells, not from those of normal cat lymphocytes. Statistically based on the Poisson's distribution, at least six loci of chromosomal regions, A2p23-p22, B2p15-p14, B4p15-p14, D4q23-q24, E1p14-p13, and E2p13-p12, appeared to be positive for FeLV integration. Consistently, Southern blot hybridization analysis using an FeLV LTR-U3 probe specific for exogenous FeLV showed the integration of at least six FeLV proviral genomes in FT-1 cells. The cytogenetic technique employed here will provide valuable molecular tags to reveal unidentified tumor-associated genes in FeLV-associated tumor cells.
Fujino
Y
Y
Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, 113-8657, Tokyo, Japan.
Satoh
H
H
Hisasue
M
M
Masuda
K
K
Ohno
K
K
Tsujimoto
H
H
D000818:Animals; D015139:Blotting, Southern; D002415:Cats; D045744:Cell Line, Tumor; D002875:Chromosomes / Q000821:virology; D017404:In Situ Hybridization, Fluorescence; D005256:Leukemia Virus, Feline / Q000235:genetics / Q000302:isolation & purification*; D011533:Proviruses / Q000235:genetics / Q000302:isolation & purification; D016662:Virus Integration