Secondary activation of c-abl may be related to translocation to the nucleolar organizer region in an in vitro cultured rat leukemia cell line (K3D).
Localization of cellular oncogenes (c-onc) near the break points of translocations in tumor cells has indicated involvement of these genes in neoplastic growth. Enhanced transcription of the cellular homolog (c-abl) of the transforming sequence of Abelson murine leukemia virus was observed in K3D, which was one of the cloned cell lines of 7,12-dimethylbenz[a]anthracene-induced rat erythroblastic leukemia. Since the c-abl activation was not observed in the parent cell line (K2D) from which K3D was derived and the latter was different from the former in the presence of a new marker chromosome, t(3;12), this marker may play a role in the expression of c-abl in K3D cells. In contrast to the human c-onc assignments, few rat c-onc assignments have been reported. In situ molecular hybridization studies assigned c-abl to the 3q12 site of the normal chromosome 3 and to the break point of the translocation t(3;12) in K3D cells. Another break point in this translocation chromosome 12p11 involves the nucleolar region, and the 3;12 translocation may involve c-abl and nucleolar cistrons. These results provide evidence of secondary c-onc activation during karyotypic evolution of cloned malignant cells.
Takahashi
R
R
Mihara
K
K
Maeda
S
S
Yamaguchi
T
T
Chen
H L
HL
Aoyama
N
N
Murao
S
S
Hatanaka
M
M
Sugiyama
T
T
D000011:Abelson murine leukemia virus / Q000235:genetics; D000818:Animals; D002460:Cell Line; D002875:Chromosomes / Q000648:ultrastructure; D004273:DNA, Neoplasm / Q000032:analysis; D004274:DNA, Recombinant; D005786:Gene Expression Regulation; D005814:Genes, Viral; D005819:Genetic Markers; D004915:Leukemia, Erythroblastic, Acute / Q000235:genetics*; D007942:Leukemia, Experimental / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D009697:Nucleolus Organizer Region; D009857:Oncogenes; D011519:Proto-Oncogenes; D051381:Rats; D014178:Translocation, Genetic
D004273:DNA, Neoplasm; D004274:DNA, Recombinant; D005819:Genetic Markers