Poster #024, Charles R. Drew University of Medicine and Science
Mammospheres Cross-Talk with Adipocytes to Induce Epithelial-Mesenchymal Transition
Mentors: Shehla Pervin, PhD
Triple Negative Breast Cancer (TNBC) is an aggressive subtype of breast cancer for which there is no cure. African American women are disproportionately affected; 40% of their breast cancer cases are TNBC. Their tumors are enriched with cancer stem cells that are chemotherapy resistant and undergo epithelial to mesenchymal transition (EMT), a key process in metastasis. During EMT, epithelial cells lose their cell-to-cell adhesion and adopt mesenchymal traits with increased mobility. Therapies targeting breast cancer stem cells have been unsuccessful; consequently, researchers are looking at their interactions with other cells in the microenvironment for treatment opportunities. The purpose of this study is to demonstrate how adipocytes promote a more aggressive phenotype in African American TNBC stem cells and identify key molecular players involved in this interaction. To analyze this interaction, HCC1806 mammospheres were enriched in a low-attachment plate containing the conditioned media from mammospheres co-cultured with adipocytes. A western blot analysis was performed to demonstrate how mammospheres in conditioned media are expressing genes associated with EMT, a key process in metastasis. Further, a scratch assay was utilized to assess cell migration, indicating the transition toward the mesenchymal phenotype associated with metastasis. When HCC1806 mammospheres were cultured in conditioned media they lost the expression of E-Cadherin (an epithelial marker) and upregulated their expression of SLUG (a mesenchymal transcription protein) and SERPINE1 (a gene that promotes metastasis). This data suggests that the mammospheres are losing their attachments and adopting the mesenchymal phenotype associated with metastasis. The Scratch Assay further supports this notion as the mammospheres cultured in conditioned media demonstrated an enhanced migration. The data suggests that mammospheres adopt a mesenchymal phenotype when cultured in conditioned media. RNA sequencing and mass spectrometry will further elucidate the signaling pathways driving this transition and reveal targets for novel treatments.