Time-course effect of estradiol and ERa17p on Early Gene expression in SKBR3 cells

ABSTRACT: ERM-NM-117p is a synthetic peptide corresponding to the sequence P295LMIKRSKKNSLALSLT311 of the estrogen receptor alpha (ERM-NM-1) and initially synthesized to mimic its calmodulin binding site. ERM-NM-117p was subsequently found to elicit estrogenic responses in E2-deprived ERM-NM-1-positive breast cancer cells, increasing proliferation and E2-dependent gene transcription. Surprisingly, in E2-supplemented media, ERM-NM-117p induced apoptosis and modified the actin network, influencing thereby cell motility. Here, we report that ERM-NM-117p induces a massive early (3h) transcriptional activity in breast cancer cell lines SKBR3). Remarkably, about 75% of the significantly modified transcripts were also modified by E2, confirming the pro-estrogenic profile of ERM-NM-117p. The different ER spectra of the used cell lines allowed us to extract a specific ERM-NM-117p signature related to ERM-NM-1 and its variant ERM-NM-136. With respect to ERM-NM-1, the peptide activates nuclear (cell cycle, cell proliferation, nucleic acid and protein synthesis) and extranuclear signaling pathways. In contrast, through ERM-NM-136 it exerts inhibitory events on inflammation and cell cycle and inhibition of EGFR signaling. This is the first work reporting ERM-NM-136 specific transcriptional effects. The fact that a number ERM-NM-117p-induced transcripts is different from those activated by E2 revealed that the apoptosis and actin modifying effects of ERM-NM-117p are independent from the ER-related actions of the peptide. Cells after a 4h incubation with medium containing 10% charcoal stripped FBS were incubated with or without E2 (10-6M) or ERa17p in RPMI 1640 supplemented with 10% charcoal stripped FBS, for 3 hours. Total RNA was isolated using Nucleospin II columns (Macheray-Nagel, Dttren, Germany), according to the manufacturerM-bM-^@M-^Ys instructions. RNA was labeled and hybridized according to the Affymetrix protocol (Affymetrix Gene-Chip Expression Analysis Technical Manual), using the HGU133A plus 2 chip, analyzing a total of 54675 transcripts. Signals were detected by an Affymetrix microarray chip reader.

ORGANISM(S): Homo sapiens

SUBMITTER: George Notas 

PROVIDER: E-GEOD-39719 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress