Clinical and Translational Oncology

, Volume 16, Issue 11, pp 937–941

The intra-tumor heterogeneity of cell signaling factors in breast cancer: p4E-BP1 and peIF4E are diffusely expressed and are real potential targets

Authors

  • S. Ramon y Cajal
    • Pathology DepartmentVall d’Hebron University Hospital
    • Universitat Autònoma de Barcelona
  • L. De Mattos-Arruda
    • Universitat Autònoma de Barcelona
    • Medical Oncology DepartmentVall d’Hebron Institute of Oncology, Vall d’Hebron University Hospital
  • N. Sonenberg
    • Department of Biochemistry and McGill Cancer CenterMcGill University, Goodman Cancer Centre
  • J. Cortes
    • Medical Oncology DepartmentVall d’Hebron Institute of Oncology, Vall d’Hebron University Hospital
    • Medica Scientia Innovation Research (MedSIR)
    • Pathology DepartmentVall d’Hebron University Hospital
    • Universitat Autònoma de Barcelona
EDUCATIONAL SERIES – BLUE SERIES Advances in Translational Oncology

DOI: 10.1007/s12094-014-1203-9

Cite this article as:
Ramon y Cajal, S., De Mattos-Arruda, L., Sonenberg, N. et al. Clin Transl Oncol (2014) 16: 937. doi:10.1007/s12094-014-1203-9

Abstract

Breast cancers and most malignant tumors are composed of heterogeneous tumor cells both at genetic and morphological levels; intra-tumor heterogeneity can be one underlying cause of therapeutic resistance. Classical studies have focused on analyses of the relationship between primary tumors and metastatic dissemination, and on subclone evolution. However, it should be noted that tumor heterogeneity at the level of protein expression (proteomics) has not been yet studied in depth. The differences in protein expression also can play an important role in elucidating the relationship between intra-tumor heterogeneity and resistance to systemic therapy. In fact, in human tumors there is not always a homogeneous expression of many of the crucial factors involved in cell signaling, such as pMAPK, pAKt, pMTOR, even with constitutive oncogenic alterations upstream, such as HER2, PI3 K. Conversely, two of these factors, peIF4E and p4E-BP1, which are downstream, and control protein translation, show a diffuse and strong protein expression. In summary, most of cell signaling factors show a heterogeneous expression, regardless of oncogenic alterations. Tissue heterogeneity could be driven by local factors, including hypoxia. The fact that the phosphorylation of crucial proteins such as 4E-BP1 and eIF4E is observed homogeneously throughout most tumors and are druggable opens the chance to get real potential targets in cancer therapy.

Keywords

Breast cancerIntra-tumor heterogeneityProteomics

Abbreviations

4E-BP1

4E-binding protein 1

AKT

V-aktmurinethymoma viral oncogene homolog

eIF4E

Eukaryotic translation initiation factor 4E

ERK1/2

Extracellular-signal-regulated kinase

FISH

Fluorescence in situ hybridization

MAPK/ERK

Mitogen-activated protein kinase

mTOR

Mammalian target of rapamycin

PI3K

Phosphoinositide 3-kinase

p

Phosphorylated

S6

Ribosomal protein S6

Supplementary material

12094_2014_1203_MOESM1_ESM.jpg (39 kb)
Supplementary Figure S1. Heterogeneity of cell signaling factors in breast carcinomas: focal vs diffuse cellular expression (JPEG 38 kb)
12094_2014_1203_MOESM2_ESM.doc (38 kb)
Supplementary Table S1. Primary antibodies used (DOC 38 kb)

Copyright information

© Federación de Sociedades Españolas de Oncología (FESEO) 2014