Specific expression of cellular oncogenes c-myc and c-myb in T-cell lines established from three types of bovine lymphosarcomas

Abstract

Summary Expression of cellular oncogenes in 3 lymphoid cell lines, BTL-PC3 (BoCD2−, BoCD4−, BoCD8−, BoWC1+), BLS1 (BoCD2+, BoCD4−, BoCD8−, B0WC1+) and BLT2 (BoCD2−, BoCD4−, BoCD8−, BoWC1−), which have been established from calf, skin, and thymic types of lymphosarcomas, respectively, were analyzed by dna-rna (northern blot) hybridization. To determine specific expression of oncogenes involved in malignant transformation of the lymphoid cells, cellular rna was isolated from bovine tumor cell lines, BTL-PC3, BLS1, and BLT2, and from Madin Darby bovine kidney cells used as a control for bovine cell lines. The rna was hybridized against 5 viral oncogene probes (v-jun, v-myc, v-erbB, v-erbA and v-fes), 6 human cellular oncogene probes (N-ras, c-Blym-1 c-erbB-2, c-fos, c-myb and c-abl), human p53 tumor suppressor gene, and bovine LDH-A gene probes. Line BTL-PC3 expressed 2.4-kilobase (kb) c-myc and 4.0- and 3.6-kb c-myb transcripts, and line BLT2 expressed a 3.8-kb c-myb transcript, but line BLS1 expressed no message for the oncogenes tested. Specific transcripts of p53 were found in BTL-PC3 and BLT2 lines, but not in BLS1. Madin Darby bovine kidney cell line expressed multiple cellular oncogenes, c-jun, c-myc, and c-fos, and p53 genes. Southern blot hybridization did not reveal abnormal dna rearrangements associated with the expressed oncogenes (c-myc and c-myb) in the 3 bovine tumor lines. From these results and the immunophenotype of the lymphoid cells, it appeared that c-myb specific mRNA were transcribed more often in immature bovine leukemia T cells (calf and thymic types) than in mature T cells from the skin type.