TY - JOUR
T1 - Selective roles of E2Fs for ErbB2- and Myc-mediated mammary tumorigenesis
AU - Wu, L.
AU - de Bruin, A.
AU - Wang, H.
AU - Simmons, T.
AU - Cleghorn, W.
AU - Goldenberg, L. E.
AU - Sites, E.
AU - Sandy, A.
AU - Trimboli, A.
AU - Fernandez, S. A.
AU - Eng, C.
AU - Shapiro, C.
AU - Leone, G.
N1 - Funding Information:
We thank L Rawahneh, J Moffitt and N Lovett for technical assistance with histology. We also thank OSUCCC Shared Resources for microarray and nucleic acid. This work was funded by NIH grants to GL (R01CA85619, R01CA82259, R01HD047470, R01 CA121275; P01CA097189). GL is a Pew Charitable Trust Scholar and a Leukemia and Lymphoma Society Scholar.
PY - 2015/1/2
Y1 - 2015/1/2
N2 - Previous studies have demonstrated that cyclin D1, an upstream regulator of the Rb/E2F pathway, is an essential component of the ErbB2/Ras (but not the Wnt/Myc) oncogenic pathway in the mammary epithelium. However, the role of specific E2fs for ErbB2/Ras-mediated mammary tumorigenesis remains unknown. Here, we show that in the majority of mouse and human primary mammary carcinomas with ErbB2/HER2 overexpression, E2f3a is up-regulated, raising the possibility that E2F3a is a critical effector of the ErbB2 oncogenic signaling pathway in the mammary gland. We examined the consequence of ablating individual E2fs in mice on ErbB2-triggered mammary tumorigenesis in comparison to a comparable Myc-driven mammary tumor model. We found that loss of E2f1 or E2f3 led to a significant delay in tumor onset in both oncogenic models, whereas loss of E2f2 accelerated mammary tumorigenesis driven by Myc-overexpression. Furthermore, southern blot analysis of final tumors derived from conditionally deleted E2f3(-/loxP) mammary glands revealed that there is a selection against E2f3(-/-) cells from developing mammary carcinomas, and that such selection pressure is higher in the presence of ErbB2 activation than in the presence of Myc activation. Taken together, our data suggest oncogenic activities of E2F1 and E2F3 in ErbB2- or Myc-triggered mammary tumorigenesis, and a tumor suppressor role of E2F2 in Myc-mediated mammary tumorigenesis.
AB - Previous studies have demonstrated that cyclin D1, an upstream regulator of the Rb/E2F pathway, is an essential component of the ErbB2/Ras (but not the Wnt/Myc) oncogenic pathway in the mammary epithelium. However, the role of specific E2fs for ErbB2/Ras-mediated mammary tumorigenesis remains unknown. Here, we show that in the majority of mouse and human primary mammary carcinomas with ErbB2/HER2 overexpression, E2f3a is up-regulated, raising the possibility that E2F3a is a critical effector of the ErbB2 oncogenic signaling pathway in the mammary gland. We examined the consequence of ablating individual E2fs in mice on ErbB2-triggered mammary tumorigenesis in comparison to a comparable Myc-driven mammary tumor model. We found that loss of E2f1 or E2f3 led to a significant delay in tumor onset in both oncogenic models, whereas loss of E2f2 accelerated mammary tumorigenesis driven by Myc-overexpression. Furthermore, southern blot analysis of final tumors derived from conditionally deleted E2f3(-/loxP) mammary glands revealed that there is a selection against E2f3(-/-) cells from developing mammary carcinomas, and that such selection pressure is higher in the presence of ErbB2 activation than in the presence of Myc activation. Taken together, our data suggest oncogenic activities of E2F1 and E2F3 in ErbB2- or Myc-triggered mammary tumorigenesis, and a tumor suppressor role of E2F2 in Myc-mediated mammary tumorigenesis.
UR - https://www.scopus.com/pages/publications/84964314758
U2 - 10.1038/onc.2013.511
DO - 10.1038/onc.2013.511
M3 - Article
C2 - 24276244
AN - SCOPUS:84964314758
SN - 0950-9232
VL - 34
SP - 119
EP - 128
JO - Oncogene
JF - Oncogene
IS - 1
ER -