Development of a Doxycycline-inducible Breast Cancer Model to Identify PELP1-induced Pathways that Promote Breast Cancer Invasion
Breast cancer mortality is driven by therapy resistance and metastasis to distant organs. Proline, glutamic acid, and leucine-rich protein 1 (PELP1) is a biomarker of aggressive tumor behavior and exhibits elevated expression levels in about 70% of breast cancers.1 Unpublished preliminary research from the Ostrander lab suggests overexpression of cytoplasmic PELP1 promotes EGF-induced invasion and migration in ER+ breast cancer. To investigate the mechanistic role of PELP1 localization in breast cancer migration and invasion, we have developed a doxycycline (doxy) inducible T47D breast cancer cell line model. In this model, wild-type or cytoplasmic PELP1 expression is induced in the presence of doxycycline. In order to investigate potential upregulated signaling pathways promoting the invasive phenotype, Western blots were performed on T47D-CO pCW cyto cell lysates with PELP1 overexpression treated with EGF due to its previous use as a chemoattractant. Western blot analysis confirmed successful EGF treatment and found the time point of 10 minutes was sufficient to activate the EGFR signaling pathway. Future research will focus on identifying which signaling pathways are upregulated when cytoplasmic PELP1 is overexpressed compared to the wild-type model in the presence of EGF.