JunB inhibits proliferation and transformation in B-lymphoid cells
2003; Elsevier BV; Volume: 102; Issue: 12 Linguagem: Inglês
10.1182/blood-2003-03-0915
ISSN1528-0020
AutoresAgnieszka Szremska, Lukas Kenner, Eva Weisz, René G. Ott, Emmanuelle Passegué, Michaela Artwohl, Michael Freissmuth, Renate Stoxreiter, Hans-Christian Theussl, Sabina Parzer, Richard Moriggl, Erwin F. Wagner, Veronika Sexl,
Tópico(s)Cytokine Signaling Pathways and Interactions
ResumoThe activator protein 1 (AP-1) member JunB has recently been implicated in leukemogenesis. Here we surveyed human lymphoma samples for expression of JunB and other AP-1 members (c-Jun, c-Fos, Fra1, JunD). JunB was strongly expressed in T-cell lymphomas, but non-Hodgkin B-cell lymphomas do not or only weakly express JunB. We therefore asked whether JunB acted as a negative regulator of B-cell development, proliferation, and transformation. We used transgenic mice that expressed JunB under the control of the ubiquitin C promoter; these displayed increased JunB levels in both B- and T-lymphoid cells. JunB transgenic cells of B-lymphoid, but not of T-lymphoid, origin responded poorly to mitogenic stimuli. Furthermore, JunB transgenic cells were found to be less susceptible to the transforming potential of the Abelson oncogene in vitro. In addition, overexpression of JunB partially protected transgenic mice against the oncogenic challenge in vivo. However, transformed B cells eventually escaped from the inhibitory effect of JunB: the proliferative response was similar in explanted tumor-derived cells from transgenic animals and those from wild-type controls. Our results identify JunB as a novel regulator of B-cell proliferation and transformation.
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