Abstract 3440: Beta-2 adrenergic receptors role in tumor aggressiveness of MDA-MB-231 breast cancer cells

Breast cancer is the world’s leading cause of cancer mortality among women. Despite advances in both diagnosis and treatment a still large number of women die because of metastatic breast cancer. Research demonstrated a strong link between chronic stress and weakened immune system leaving the body prone to disease like cancer. Indeed, psychological stress has been shown to enhance tumor growth and progression. In addition, stress hormones, such as norepinephrine and epinephrine, are implicated in the growth, invasiveness and metastasis of cancer. Therefore, targeting the beta-adrenergic receptors in cancer chemoprevention may offer new promises for the design of therapeutic strategies. For that reason, we determine the cellular processes involved in beta-2 adrenergic receptor (ADRB2) mediated effects on human breast cancer cells in cultures. We particularly focused on the impact of the inhibition of ADRB2 on cell proliferation, migration and invasion of the triple negative breast cancer cell line MDA-MB-231. In order to determine the effects of loss of expression of the gene, we suppressed ADRB2 by knock down, using CRISPR technology. We also used pharmacologically suppression of ADBR by employing a general beta receptor blocker; propranolol. Cell proliferation, migration and invasion assays were performed to define a degree of aggressiveness to the cells phenotype after the knock down or pharmacological suppression of ADRB2 in comparison to control cells. Also, Western Blot analysis on characteristics proteins of the epithelial-mesenchymal transition (EMT) was used to further characterize the phenotype. PCR Array expression studies were done to analyze modifications of genes expression profile and signaling cascades in the ADRB2 knocked down cells. We found that the knocking down by CRISPR of the ADRB2 receptors or, pharmacologically suppressing ADRB2 reduces proliferation, migration and colony formation of MDA-MB-231 cells. Additionally, ADRB2 knock down increased expression of epithelial proteins (beta-catenin and E-cadherin) while decreased mesenchymal markers (vimentin and N-cadherin). The mRNA expression study using a PCR Array targeting cancer stem cell genes shows that the inhibition of ADRB2 significantly modifies signaling involved in cell movement, invasion, migration and proliferation such as Wnt/beta-catenin signaling, ILK signaling and Notch signaling. Within these signaling pathways, the expression of several genes such as ILK, MAP2K6, GSK3B and JUN seem to be critical as they are under-expressed. These data provide preliminary understanding of the possible connection between the beta-2 adrenergic receptor system and signaling pathways use by the tumor cells to grow and acquire a more aggressive phenotype. Also, some genes are identified as new targets that may be valuable for developing effective treatment of advanced breast cancer. (Supported by NIH grant R01 CA20863201) Citation Format: Benedicte Rousseau, Ananya Tirupathur, Sengottuvelan Murugan, Dipak K. Sarkar. Beta-2 adrenergic receptors role in tumor aggressiveness of MDA-MB-231 breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3440.