Abstract 2742: Small interfering RNA targeting CD24 inhibits proliferation and migration of triple-negative breast cancer cells

Abstract Triple-negative breast cancer (TNBC) is defined as the lack of human epidermal growth factor receptor 2 (HER2), progesterone receptor (PR), and estrogen receptor (ER) expression. TNBC accounts for 10-20% of all cancer cases and is more aggressive than other subtypes of breast cancer. Although chemotherapy is the mainstay of treatment for TNBC, its therapeutic efficacy is limited. Therefore, developing new therapies to address the unmet need of TNBC is urgently needed. CD24 protein is a heavily glycosylated glycosylphosphatidylinositol (GPI)-anchored surface protein. The high expression level of CD24 is observed in a variety of cancers, such as TNBC and ovarian cancer. CD24 plays an important role in tumor growth, invasion, and metastasis of different types of cancers. Besides, overexpression of CD24 in tumors is associated with resistance to chemotherapy agents and targeted therapies. Here, we design four siRNAs targeting different regions of the CD24 mRNA. The silencing activity of the predesigned siRNAs is evaluated by quantitative real-time RT-PCR and western blot. The biological effects of designed siRNAs on human breast cancer cells are investigated by cell proliferation, migration, invasion, cell cycle arrest, and apoptosis. The data demonstrate that the CD24 siRNAs significantly reduce CD24 expressions at both mRNA level and protein level in human TNBC cells. Moreover, silencing of CD24 suppresses breast cancer cell proliferation. Cell cycle assay shows that the anti-proliferation effect of CD24 siRNA is mediated by arresting the cells in the S phase. Furthermore, we reveal that silencing of CD24 inhibits migration and invasion of human breast cancer cells. Significant apoptosis is observed in CD24 siRNA transfected cells compared with the scrambled siRNA group. These data suggest that silencing CD24 using siRNA can be a potential therapeutic strategy for triple-negative breast cancer. Citation Format: Yanli Liu, Kun Cheng. Small interfering RNA targeting CD24 inhibits proliferation and migration of triple-negative breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2742.