Protein biomarker validation via proximity ligation assays

Area of Science:

• Biochemistry
• Molecular Biology
• Proteomics

Background:

• Detecting protein biomarkers in blood is crucial for diagnosing diseases, but translation to clinical use is hindered by study size and technological limitations.
• Numerous candidate protein biomarkers are identified annually, yet few reach clinical application due to validation and technological challenges.

Purpose of the Study:

• To explore the potential of proximity ligation assay (PLA) in addressing obstacles in biomarker validation and clinical diagnostics.
• To discuss the requirements for biomarker validation and the role of PLA in meeting these needs.
• To highlight recent technological advancements in PLA, including proximity extension assays and single-cell proteomics.

Main Methods:

• Proximity ligation assay (PLA) for enhanced protein detection specificity and sensitivity.
• Adaptation of PLA for detecting protein complexes, extracellular vesicle proteins, circulating tumor cells, and post-translational modifications.
• Utilizing recombinant affinity reagents for proximity assays.

Main Results:

• PLA demonstrates enhanced specificity, enabling high-performance, large-scale protein analyses with minimal sample consumption and an extended dynamic range.
• The technique is versatile and can be reconfigured for various applications, including detecting protein proximity and multiple modifications on a single protein.
• Recent developments enhance PLA's capabilities, showing promise for single-cell proteomics.

Conclusions:

• PLA is a versatile molecular tool with significant potential to overcome current limitations in biomarker validation and clinical diagnostics.
• The enhanced specificity and flexibility of PLA make it suitable for routine clinical diagnostic needs and advanced proteomic applications.
• Ongoing technological developments position PLA as an increasingly important method in biomarker discovery and validation.