Protein Marker-Dependent Drug Discovery Targeting Breast Cancer Stem Cells

Breast cancer is one of the most common cancers globally. Unfortunately, many patients with breast cancer develop resistance to chemotherapy and tumor recurrence, which is primarily driven by breast cancer stem cells (BCSCs). BCSCs behave like stem cells and can self-renew and differentiate into mature tumor cells, enabling the cancer to regrow and metastasize. Key markers like CD44 and aldehyde dehydrogenase-1 (ALDH1), along with pathways like Wingless-related integration site (Wnt), Notch, and Hedgehog, are critical to regulating this stem-like behavior of BCSCs and, thus, are being investigated as targets for various new therapies. This review summarizes marker-dependent strategies for targeting BCSCs and expands on the challenges for the development of anti-BCSC drugs. We explore cutting-edge approaches like artificial intelligence (AI)-driven drug discovery and urge readers to seriously consider biological clocks and chronotherapy as experimental variables in drug discovery. Collectively, the task of cancer researchers is to overcome the many hurdles targeting BCSCs if we hope to tangibly improve breast cancer treatment outcomes and reduce mortality.