Differential expression of the oncoproteins c-myc and c-myb in human lymphoproliferative disorders.
Altered regulation of oncogene expression has been described in a variety of hematopoietic malignancies. In this study we analyzed the protein level of c-myc and c-myb in 15 established cell lines derived from lymphopoietic disorders and in 45 samples from patients with acute or chronic lymphatic leukemias. Oncoproteins were assayed by radioimmuno-precipitation with polyclonal rabbit antibodies. In B-cell derived lines, such as Burkitt lymphoma and plasmocytoma lines, we found high amounts of c-myc and no or low amounts of c-myb. In contrast, all T-cell-derived lines revealed high levels of c-myb. In addition, T-lymphoma cell lines of low malignancy also exhibited high levels of c-myc, while T-cell lines of high malignancy (acute T-lymphoblastic leukemias) exhibited moderate levels of c-myc. Of the 45 patient samples analyzed, only three (one B-prolymphocytic and two acute T-lymphoblastic leukemias) contained detectable amounts of myc or myb protein. Corresponding to the results found in established cell lines, the B-cell sample revealed a high level of c-myc but no c-myb, while the T-cell samples revealed high levels of c-myb and no or low levels of c-myc. We therefore conclude that the predominance of c-myc or c-myb expression in malignant lymphoproliferative disorders may be associated to the B-cell or T-cell lineage, respectively. Further, regarding the T-cell lines, there is a possible correlation between cell maturation and the level of c-myc found together with a consistently elevated c-myb.
Siegert
W
W
Medizinische Klinik und Poliklinik, Universitätsklinikum Rudolf Virchow, Berlin, F.R.G.
Beutler
C
C
Langmach
K
K
Keitel
C
C
Schmidt
C A
CA
D002460:Cell Line; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007945:Leukemia, Lymphoid / Q000235:genetics / Q000378:metabolism*; D008223:Lymphoma / Q000032:analysis* / Q000235:genetics; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D020598:Proto-Oncogene Proteins c-myb; D016271:Proto-Oncogene Proteins c-myc; D011519:Proto-Oncogenes; D013601:T-Lymphocytes / Q000032:analysis
D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D016271:Proto-Oncogene Proteins c-myc; D011505:Protein-Tyrosine Kinases