TY - JOUR
T1 - X-ray-induced lymphomagenesis in Eμ-pim-1 transgenic mice
T2 - An investigation of the co-operating molecular events
AU - Van Der Houven Van Oordt, C. W.
AU - Schouten, T. G.
AU - Van Krieken, J. H.J.M.
AU - Van Dierendonck, J. H.J.
AU - Van Der Eb, A. J.
AU - Breuer, M. L.
N1 - Copyright: Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1998/5
Y1 - 1998/5
N2 - Transgenic mice overexpressing the pim-1 oncogene in their lymphoid compartment display a low incidence of spontaneous T-cell lymphomas, but are highly susceptible to point mutation-inducing genotoxic carcinogens. We show here that total body X-irradiation, which causes mainly chromosomal deletions, rearrangements and amplifications, significantly enhances lymphoma development in Eμ-pim-1 transgenic mice. The X-ray-induced Eμ-pim-1 and nontransgenic lymphomas have a comparable high cell turnover as shown by a relatively high S-phase fraction and a high apoptotic activity. Consistent with previous observations, in 75% of all lymphomas c-myc mRNA levels are 5- to 20-fold higher than in control, non-lymphomatous spleen/thymus. The expression of other oncogenes, which have previously found to be activated in combination with pim-1 in lymphomagenesis, such as gfi-1/pal-1, frat-1 and tiam-1, and also of the mdm-2 and mdm-x oncogenes, appeared not to be affected. Deletions and/or rearrangements of the pl6(INK4A) and p15(INK4B) tumor suppressor genes were seldom observed (in three out of 92 X-ray-induced lymphomas). Strikingly, in addition to the high mRNA levels of the pim-1 transgene, the levels of the endogenous pim-1 transcripts were elevated significantly in 16% of the X-ray-induced Eμ-Pim-1 lymphomas compared with control spleen, even surpassing the level of the pim-1 transgene mRNA by 3- to 5-fold. In combination with previous results, which showed that the lymphoma incidence increased concordantly with higher levels of pim-1, this supports the notion that pim-1 can contribute to lymphomagenesis in a dose-dependent manner.
AB - Transgenic mice overexpressing the pim-1 oncogene in their lymphoid compartment display a low incidence of spontaneous T-cell lymphomas, but are highly susceptible to point mutation-inducing genotoxic carcinogens. We show here that total body X-irradiation, which causes mainly chromosomal deletions, rearrangements and amplifications, significantly enhances lymphoma development in Eμ-pim-1 transgenic mice. The X-ray-induced Eμ-pim-1 and nontransgenic lymphomas have a comparable high cell turnover as shown by a relatively high S-phase fraction and a high apoptotic activity. Consistent with previous observations, in 75% of all lymphomas c-myc mRNA levels are 5- to 20-fold higher than in control, non-lymphomatous spleen/thymus. The expression of other oncogenes, which have previously found to be activated in combination with pim-1 in lymphomagenesis, such as gfi-1/pal-1, frat-1 and tiam-1, and also of the mdm-2 and mdm-x oncogenes, appeared not to be affected. Deletions and/or rearrangements of the pl6(INK4A) and p15(INK4B) tumor suppressor genes were seldom observed (in three out of 92 X-ray-induced lymphomas). Strikingly, in addition to the high mRNA levels of the pim-1 transgene, the levels of the endogenous pim-1 transcripts were elevated significantly in 16% of the X-ray-induced Eμ-Pim-1 lymphomas compared with control spleen, even surpassing the level of the pim-1 transgene mRNA by 3- to 5-fold. In combination with previous results, which showed that the lymphoma incidence increased concordantly with higher levels of pim-1, this supports the notion that pim-1 can contribute to lymphomagenesis in a dose-dependent manner.
UR - http://www.scopus.com/inward/record.url?scp=0031818345&partnerID=8YFLogxK
U2 - https://doi.org/10.1093/carcin/19.5.847
DO - https://doi.org/10.1093/carcin/19.5.847
M3 - Article
C2 - 9635873
SN - 0143-3334
VL - 19
SP - 847
EP - 853
JO - Carcinogenesis
JF - Carcinogenesis
IS - 5
ER -