The aim of the study presented here was to analyze which MCF7 signaling pathways were affected by the placenta. Methods: MCF7-eGFP cells cultured on matrigel with or without placental explants were separated from the placenta

by cell sorting and their mRNA was subjected to microarray analysis. ERa/STAT3/mTOR expression and phosphorylation levels were analyzed in these cells. Results: Trophoblast cells differentiate into extravillous trophoblast cells (EVT) which migrate into the matrigel. The effects (apoptosis/proliferation/detachment) were mainly observed in MCF7 cells that were located near the EVT cells. Microarray results have demonstrated significant changes in genes related to cell adhesion, glycan, breast carcinoma estrogen and JAK-STAT pathways.

Decreased ERa and elevated pmTOR and R428 cost STAT3 proteins detected by immunobloting confirmed our findings at the transcript level. Moreover, promoter analysis of significantly affected genes in this array demonstrated an enrichment of motifs located at the transcription start site that match annotation for ISRE (interferon-stimulated response element), suggesting the activation of interferon (INF) signaling. Conclusion: Our results suggest that the placenta attenuates MCF7 growth in its vicinity by modulating INF/STAT and inducing detachment/migration and apoptosis. Published data demonstrated that the above pathways may indeed stimulate these processes. The involvement of these signaling pathways in buy Fulvestrant cell migration/apoptosis and the fate of the detached MCF7 cells will be further studied. Poster No. 113 Identification of Secretory Stromal Gene Signature of the Ovarian

Anacetrapib Tumor Microenvironment and Implications for Ovarian Cancer Progression Melissa Thompson 1 , Lina Albitar2, Kwong-Kwok Wong1, Michael Birrer3, Samuel Mok1 1 Department of Gynecologic Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA, 2 Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women’s Hospital, Boston, MA, USA, 3 Department of Medicine, Massachusetts General Hospital, Boston, MA, USA The stromal microenvironment provides structural support and myriad signaling cues, which can significantly affect cell growth and development. The tumor-associated stromal microenvironment has been shown to play a key role in many cancers by influencing tumor initiation, invasion and metastasis. Our objective was to identify specific genes that are differentially regulated in the stromal component of high-grade late-stage serous ovarian cancer that may contribute to ovarian cancer progression.