TY - JOUR
T1 - The human B-cell lymphoma cell line RC-K8 has multiple genetic alterations that dysregulate the Rel/NF-κB signal transduction pathway
AU - Kalaitzidis, Demetrios
AU - Davis, R. Eric
AU - Rosenwald, Andreas
AU - Staudt, Louis M.
AU - Gilmore, Thomas D.
N1 - Funding Information:
We thank Nancy Rice for anti-REL antisera, Inder Verma for REL and REL-NRG expression plasmids, Keith Brown and Ulrich Siebenlist for IkBa and IKKb constructs, Ulla Hansen for the RSV-Luc plasmid, and Ellen Cahir-McFarland and Elliott Kieff for the EBV-transformed cell line IB4. We thank John Celenza and Dean Tolan for helpful discussions. This work was supported by NIH grant CA47763 (TD Gilmore). D Kalaitzidis was partially supported by NIH Predoctoral Training Grant T32-HD07387.
PY - 2002/12/12
Y1 - 2002/12/12
N2 - The human large B-cell lymphoma cell line RC-K8 has a rearranged REL locus that directs the production of a chimeric protein, termed REL-NRG (Non-Rel Gene). In this study, we show that RC-K8 cells have constitutively nuclear heterodimeric and homodimeric DNA-binding complexes that consist of p50, REL, and REL-NRG. In vitro, IκBα can block the DNA-binding activity of wild-type REL homodimers but not REL-NRG homodimers. In vivo, REL-NRG cannot activate transcription of a κB site reporter plasmid, suggesting that it is a transcription repressing or blocking REL protein. By Western blotting, no IκBα protein can be detected in extracts of RC-K8 cells. The absence of IκBα protein in RC-K8 cells appears to be due to mutations that cause premature termination of translation in three of the four copies of the IKBA gene in RC-K8 cells. Re-expression of wild-type IκBα or a super-repressor form of IκBα in RC-K8 cells is cytotoxic; in contrast, expression of a dominant-negative form of IκB kinase does not affect the growth of RC-K8 cells. By cDNA microarray analysis, a number of previously identified Rel/NF-κB target genes are overexpressed in RC-K8 cells, consistent with there being transcriptionally active REL complexes. Taken together, our results suggest that the growth of RC-K8 cells is dependent on the activity of nuclear wild-type REL dimers, while the contribution of REL-NRG to the transformed state of RC-K8 cells is less clear. Nevertheless, the RC-K8 cell line is the first tumor cell line identified with mutations in genes encoding multiple proteins in the Rel/NF-κB signal transduction pathway.
AB - The human large B-cell lymphoma cell line RC-K8 has a rearranged REL locus that directs the production of a chimeric protein, termed REL-NRG (Non-Rel Gene). In this study, we show that RC-K8 cells have constitutively nuclear heterodimeric and homodimeric DNA-binding complexes that consist of p50, REL, and REL-NRG. In vitro, IκBα can block the DNA-binding activity of wild-type REL homodimers but not REL-NRG homodimers. In vivo, REL-NRG cannot activate transcription of a κB site reporter plasmid, suggesting that it is a transcription repressing or blocking REL protein. By Western blotting, no IκBα protein can be detected in extracts of RC-K8 cells. The absence of IκBα protein in RC-K8 cells appears to be due to mutations that cause premature termination of translation in three of the four copies of the IKBA gene in RC-K8 cells. Re-expression of wild-type IκBα or a super-repressor form of IκBα in RC-K8 cells is cytotoxic; in contrast, expression of a dominant-negative form of IκB kinase does not affect the growth of RC-K8 cells. By cDNA microarray analysis, a number of previously identified Rel/NF-κB target genes are overexpressed in RC-K8 cells, consistent with there being transcriptionally active REL complexes. Taken together, our results suggest that the growth of RC-K8 cells is dependent on the activity of nuclear wild-type REL dimers, while the contribution of REL-NRG to the transformed state of RC-K8 cells is less clear. Nevertheless, the RC-K8 cell line is the first tumor cell line identified with mutations in genes encoding multiple proteins in the Rel/NF-κB signal transduction pathway.
KW - IκB
KW - NF-κB
KW - RC-K8
KW - Rel
KW - Rel-Nrg
KW - c-Rel
UR - http://www.scopus.com/inward/record.url?scp=0037069934&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037069934&partnerID=8YFLogxK
U2 - 10.1038/sj.onc.1206033
DO - 10.1038/sj.onc.1206033
M3 - Article
C2 - 12483529
AN - SCOPUS:0037069934
SN - 0950-9232
VL - 21
SP - 8759
EP - 8768
JO - Oncogene
JF - Oncogene
IS - 57
ER -