Glucocorticoid Receptor-Mediated Engineered Cancer Stem Cell-Led Therapy and Inhibition of Recurrence in Colorectal Cancer

Abstract Dysregulated wnt/β-catenin signaling cascades drive self-renewal, proliferation, differentiation, and therapeutic resistance in cancer stem cells (CSCs), thus contributing to their tumor aggression and poor clinical outcomes. Earlier, we demonstrated that a glucocorticoid receptor (GR)-targeted liposomal formulation carrying dexamethasone (Dex) and the wnt/β-catenin inhibitor FH535 (D1XFH) selectively sensitizes colorectal cancer (CRC) cells and suppresses tumor growth. Herein, we investigate the immuno-therapeutic potential of D1XFH, especially within colorectal CSCs and against tumor recurrence. Our results reveal that D1XFH significantly downregulates CD133 and stemness-associated transcription factors Nanog, Sox2, and Oct4 in CSCs. D1XFH induces selective cytotoxicity by enhancing ROS generation, triggering apoptosis, reducing clonogenic potential, inhibiting cellular migration, and reversing multidrug resistance in CSCs. Co-administration of D1XFH-engineered CSCs and D1XFH into subcutaneous tumor-bearing mice resulted in pronounced tumor regression, accompanied by inhibition of wnt/β-catenin signaling, reversal of EMT, and antitumorigenic immune responses, while improving long-term survival. Additionally, D1XFH treatments post-tumor resection resulted in near-zero tumor recurrence, while zero recurrence was observed even after tumor re-challenge. We observed 250 day long-term survivability with possible resurgence of immune-memory response within tumor-resected, D1XFH-treated mice. Collectively, dual targeting of GR and wnt/β-catenin-driven CSC engineering and immunomodulation is a promising strategy for colorectal cancer therapy.