Detection and Quantitation of Endogenous Membrane-Bound RAS Proteins and KRAS Mutants in Cancer Cell Lines Using...

Area of Science:

• Oncology
• Proteomics
• Molecular Biology

Background:

• RAS proteins regulate cell processes; mutations drive ~30% of cancers.
• KRAS mutants are key targets in RAS-driven cancers.
• Lack of specific antibodies necessitates new methods for RAS analysis.

Purpose of the Study:

• To develop an antibody-free protocol for identifying and quantifying membrane-bound RAS proteins.
• To enable isoform- and mutation-specific analysis of RAS proteins.
• To support anti-cancer drug discovery efforts targeting RAS.

Main Methods:

• Ultracentrifugation to isolate membrane fractions.
• 1D SDS-PAGE for RAS isoform enrichment.
• Bottom-up proteomics (in-gel digestion, HPLC-MS2) for detection and quantitation.

Main Results:

• Successfully detected and relatively quantified wild-type RAS (HRAS, KRAS4A/B, NRAS) and common mutants (G12D, G13D, G12S, G12V).
• Demonstrated the protocol's applicability across multiple cancer cell lines.
• Established a method for analyzing RAS protein concentration changes.

Conclusions:

• The developed 1D-SDS-PAGE-HPLC-MS2 protocol is a simple, antibody-free method for RAS analysis.
• This technique can be automated and applied to drug discovery for RAS-driven cancers.
• Provides a valuable tool for investigating membrane-bound RAS proteins and their mutants.