Tissue microarray analysis of eIF4E and its downstream effector proteins in human breast cancer.
BACKGROUND
Eukaryotic initiation factor 4E (eIF4E) is elevated in many cancers and is a prognostic indicator in breast cancer. Many pro-tumorigenic proteins are selectively translated via eIF4E, including c-Myc, cyclin D1, ornithine decarboxylase (ODC), vascular endothelial growth factor (VEGF) and Tousled-like kinase 1B (TLK1B). However, western blot analysis of these factors in human breast cancer has been limited by the availability of fresh frozen tissue and the labor-intensive nature of the multiple assays required. Our goal was to validate whether formalin-fixed, paraffin-embedded tissues arranged in a tissue microarray (TMA) format would be more efficient than the use of fresh-frozen tissue and western blot to test multiple downstream gene products.


RESULTS
Breast tumor TMAs were stained immunohistochemically and quantitated using the ARIOL imaging system. In the TMAs, eIF4E levels correlated strongly with c-Myc, cyclin D1, TLK1B, VEGF, and ODC. Western blot comparisons of eIF4E vs. TLK1B were consistent with the immunohistochemical results. Consistent with our previous western blot results, eIF4E did not correlate with node status, ER, PR, or HER-2/neu.


CONCLUSIONS
We conclude that the TMA technique yields similar results as the western blot technique and can be more efficient and thorough in the evaluation of several products downstream of eIF4E.
Kleiner
Heather E
HE
Dept, of Pharmacology, Toxicology, and Neuroscience, Breast Cancer Focus Group, Feist-Weiller Cancer Center, Shreveport & LSUHSC-Shreveport, Louisiana, LA 71130, USA. hklein@lsuhsc.edu
Krishnan
Prasad
P
Tubbs
Jesse
J
Smith
Mark
M
Meschonat
Carol
C
Shi
Runhua
R
Lowery-Nordberg
Mary
M
Adegboyega
Patrick
P
Unger
Marcia
M
Cardelli
James
J
Chu
Quyen
Q
Mathis
J Michael
JM
Clifford
John
J
De Benedetti
Arrigo
A
Li
Benjamin D L
BD
D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D039561:Eukaryotic Initiation Factor-4E / Q000378:metabolism*; D006801:Humans; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D015398:Signal Transduction; D046888:Tissue Array Analysis
D014408:Biomarkers, Tumor; D039561:Eukaryotic Initiation Factor-4E; D017346:Protein Serine-Threonine Kinases; C425323:TLK1 protein, human