Acetylated Globotetraose (Ac-Gb4) Suppresses Triple-Negative Breast Cancer Through FAK/AKT Signaling Pathway

Triple-negative breast cancer (TNBC) remains a significant therapeutic challenge due to its unresponsiveness to hormone and HER2-targeted treatments. This study investigated the potential of acetylated globotetraose (Ac-Gb4) as a novel therapeutic approach targeting glycolipid-mediated signaling in breast cancer cells. We synthesized acetylated globotetraose (Gb4) to enhance its membrane permeability while preserving its biological recognition properties. Flow cytometry analysis revealed that Ac-Gb4 treatment significantly decreased SSEA3 and SSEA4 expression in MDA-MB-231 breast cancer cells, which are Globo-H-negative cells. Notably, Ac-Gb4 demonstrated selective cytotoxicity against cancer cells by significantly reducing proliferation and inducing apoptosis in MDA-MB-231 cells while sparing hTERT-HME1 normal breast epithelial cells. Mechanistic studies through Western blot analysis revealed that Ac-Gb4 simultaneously modulated multiple signaling pathways, including FAK cleavage, reduced AKT expression, and increased caspase-3 activation, particularly at the 4 mM concentration. These molecular changes correlated with decreased cancer cell invasion capability in a dose-dependent manner. Our findings demonstrated that Ac-Gb4 effectively targeted breast cancer cells through the modulation of critical signaling pathways involved in cell survival and invasion while maintaining a minimal impact on normal cells. This anti-cancer activity suggests that Ac-Gb4 represents a promising therapeutic candidate for breast cancer treatment, particularly for aggressive subtypes such as TNBC.