MHC class I expression on prelymphomatous and lymphomatous B-cells is not inhibited by an E mu-myc transgene.
Increased expression of oncogenes from the myc family has been associated with down-regulation of major histocompatibility complex (MHC) class I molecules. In certain models this has been suggested to contribute to tumour progression. Transgenic mice bearing the cellular myc oncogene coupled to the lymphoid-specific immunoglobulin heavy chain enhancer (E mu) develop clonal B lymphoid malignancies early in life. We have asked if expression of such a constitutively activated E mu-myc transgene in BALB/c mice affects MHC class I expression. H-2Kd and Dd expression on prelymphomatous and lymphomatous B-cells as well as newly established pre-B or B lymphoma cell lines derived from E mu-myc transgenic BALB/c mice were analysed. The results reveal no down-regulated or otherwise altered expression of H-2Kd or Dd on any of the cell populations examined. The results are discussed in relation to the myc associated down-regulation of MHC class I molecules observed in other experimental models.
Algarra
I
I
Department of Tumor Biology, Karolinska Institutet, Stockholm, Sweden.
Silva
S
S
Ljunggren
H G
HG
D000818:Animals; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D005805:Genes, MHC Class I; D016259:Genes, myc; D016393:Lymphoma, B-Cell / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D011230:Precancerous Conditions / Q000235:genetics*; D014407:Tumor Cells, Cultured