First Author | Ciana P | Year | 1997 |
Journal | Oncogene | Volume | 14 |
Issue | 15 | Pages | 1805-10 |
PubMed ID | 9150386 | Mgi Jnum | J:39766 |
Mgi Id | MGI:87115 | Doi | 10.1038/sj.onc.1201015 |
Citation | Ciana P, et al. (1997) Constitutive expression of lymphoma-associated NFKB-2/Lyt-10 proteins is tumorigenic in murine fibroblasts. Oncogene 14(15):1805-10 |
abstractText | The NFKB-2 (Lyt-10) gene codes for an NF-kappa B-related transcription factor containing rel-polyG-ankyrin domains. Rearrangements of the NFKB-2 locus leading to the production of 3prime truncated NFKB-2 proteins are recurrently found in lymphoid neoplasms, particularly cutaneous lymphomas, Such mutant NFKB-2 proteins have lost the ability to repress transcription that is typical of NFKB-2 subunit p52, and function as constitutive transcriptional activators. To verify whether the expression of abnormal NFKB-2 proteins can lead to malignant transformations in mammalian cells, we transfected human lymphoblastoid cell lines and murine fibroblasts (Balb/3T3) with expression vectors carrying the cDNAs coding far normal NFKB-2p52, Lyt-10C alpha or LB40 proteins, which are representative of the abnormal types found in lymphoma cases. The expression of both normal and mutant NFKB-2 proteins has a lethal effect on lymphoblastoid cells and a cytotoxic effect was also observed in murine fibroblasts. The fibroblast cell lines expressing Lyt-10C alpha or LB40, but not those expressing normal MFKB-2p52, were capable of forming colonies in soft agar. The analysis of individual clones revealed that cloning efficiency correlated with the expression levels of the abnormal proteins, Injection of the Lyt-10C alpha-transfected Balb cells in SCID mice led to tumor formation in all of the animals, whereas no tumors were observed in the mice injected with control or NFKB-2p52-transfected cells, thus indicating that abnormal NFKB-2 protein expression is tumorigenic in vivo. Our results show that mutant NFKB-2 proteins can lead to the transformed phenotype, and support the hypothesis that alterations in NFKB-2 genes may play a role in lymphomagenesis. |