Protein-Targeted Glycan Editing on Living Cells Disrupts KRAS Signaling

Area of Science:

• Biochemistry
• Molecular Biology
• Cancer Research

Background:

• KRAS oncogene mutations drive lethal human cancers, necessitating new therapeutic strategies.
• Current KRAS inhibitors are limited, with only one approved for KRAS^G12C mutants.
• Novel approaches to interfere with KRAS signaling pathways are urgently required.

Purpose of the Study:

• To develop a novel strategy for disrupting KRAS signaling by targeting protein glycosylation.
• To investigate the efficacy of a "localized oxidation-coupling" method for protein-specific glycan editing on living cells.
• To explore the potential of manipulating membrane receptor glycosylation to inhibit KRAS activity.

Main Methods:

• Developed a "localized oxidation-coupling" technique for precise glycan editing on cell surfaces.
• Utilized mannotriose to modify terminal galactose/N-acetyl-D-galactosamine epitopes on integrin α_v β₃.
• Assessed the impact of glycan remodeling on galectin-3 binding, KRAS activation, and downstream signaling.

Main Results:

• The glycan remodeling method demonstrated high protein and sugar specificity across different cell types and donor sugars.
• Attachment of mannotriose to integrin α_v β₃ effectively blocked galectin-3 binding.
• Suppression of KRAS activation and downstream signaling pathways was observed, mitigating malignant phenotypes.
• This represents the first successful interference with KRAS activity via membrane receptor glycosylation manipulation.

Conclusions:

• Protein-specific glycan editing is a viable strategy for disrupting KRAS signaling.
• Targeting membrane receptor glycosylation offers a promising new therapeutic avenue for KRAS-driven cancers.
• The developed "localized oxidation-coupling" method provides a versatile tool for glycan manipulation in biological systems.