c-myc expression and transformed phenotypes in hybrid clones between mouse plasmacytoma S194 cells and normal spleen cells or fibroblasts.
Expression of the rearranged c-myc oncogene and transformed phenotypes was investigated in 2 different types of somatic cell hybrid clones between a BALB/c mouse plasmacytoma line (S194) and normal allogeneic spleen cells or fibroblasts. In the parental S194 cells, one allele of the c-myc was rearranged and its 5'-flanking region was partially deleted by recombination with the immunoglobulin C alpha gene. Due to this recombination, S194 cells expressed approximately 20-fold higher than normal spleen or fibroblast levels of c-myc transcripts from the rearranged allele, which are smaller than normal germ-line 2.4-kb c-myc transcripts, but they expressed the same low levels of 2.4-kb c-myc transcripts from the non-rearranged allele as compared with normal spleen cells or fibroblasts. All the hybrid clones retained both the rearranged and the non-rearranged c-myc. The hybrid clones between S194 and normal spleen cells showed transformed phenotypes and expressed the same high levels of rearranged c-myc transcripts and low levels of the non-rearranged c-myc transcripts as the parental S194 cells. On the other hand, the hybrid clones between S194 cells and normal fibroblasts showing non-transformed phenotypes inhibited expression of the rear-ranged c-myc to undetectable levels but expressed the non-rearranged c-myc transcripts at low levels. A hybrid clone between S194 cells and normal fibroblasts showing transformed phenotypes also exhibited the same pattern of c-myc expression as the non-transformed hybrid clones. These results indicate that expression of the rearranged c-myc in S194 mouse plasmacytoma cells is modulated in different ways in different components of cell lineages, although the correlation between the levels of rearranged c-myc transcripts and the transformed phenotypes in the hybrid clones was not absolute.
Laboratory of Molecular Genetics, Hokkaido University School of Medicine, Sapporo, Japan.
T
T
Oikawa
Y
Y
Yuhki
N
N
Kondoh
K
K
Abe
N
N
Yuhki
Y
Y
Ogiso
N
N
Kuzumaki
D000818:Animals; D002471:Cell Transformation, Neoplastic; D002999:Clone Cells / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D005803:Genes, Immunoglobulin; D006822:Hybrid Cells / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D010641:Phenotype; D010954:Plasmacytoma / Q000235:genetics* / Q000473:pathology; D011519:Proto-Oncogenes; D011995:Recombination, Genetic; D013154:Spleen / Q000378:metabolism; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured