Estradiol increases IRS-1 gene expression and insulin signaling in breast cancer cells.
This study demonstrates how the potentiating effects of E2 on insulin signaling in ER-positive breast cancer cells are consequent to an enhanced IRS-1 expression [corrected]. It induces an increase of both PI-3K/AKT and ERK1/2 activities. A direct action of E2 in the regulating mouse IRS-1 gene is also investigated in both Chinese hamster ovary and MCF-7 cells that are transfected with mouse IRS-1 regulatory sequences. The authors have reported, for the first time, how E2 induction of IRS-1 mRNA was correlated with a direct positive regulatory role of E2 on the IRS-1 promoter. This effect seems to be not strictly related to the cell type.
Mauro
L
L
Department of Cellular Biology, University of Calabria, Rende, CS, Italy.
Salerno
M
M
Panno
M L
ML
Bellizzi
D
D
Sisci
D
D
Miglietta
A
A
Surmacz
E
E
Andò
S
S
D000704:Analysis of Variance; D001943:Breast Neoplasms; D004958:Estradiol / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007328:Insulin / Q000502:physiology*; D055504:Insulin Receptor Substrate Proteins; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000187:drug effects* / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism
C526292:IRS1 protein, human; D007328:Insulin; D055504:Insulin Receptor Substrate Proteins; C526295:Irs1 protein, mouse; D010750:Phosphoproteins; D012333:RNA, Messenger; D014443:Tyrosine; D004958:Estradiol