Advancing Biomarker Research: In Situ Cu Isotope Analysis in Liver Tumors by LA-MC-ICP-MS

Area of Science:

• Biogeochemistry
• Medical Diagnostics
• Analytical Chemistry

Background:

• Stable metal isotopes, particularly copper, are emerging as medical biomarkers for disease detection.
• Understanding isotope fractionation mechanisms in metal metabolism is crucial for disease-related biomarker development.
• Copper isotope variations between healthy and diseased tissues suggest potential for cancer diagnosis.

Purpose of the Study:

• To establish an in situ method for analyzing copper stable isotope fractionation in biological tissues.
• To investigate the underlying processes responsible for isotope fractionation between normal and diseased tissues.
• To assess the potential of copper stable isotopes as biomarkers for liver cancer.

Main Methods:

• Development of an in situ method using laser ablation-multicollector-inductively coupled plasma-mass spectrometry (LA-MC-ICP-MS).
• Creation of gelatin-based bracketing standards and quality control reference materials for accurate laser ablation analysis.
• Application of the developed method to rabbit VX2 liver tumor samples, a model for human hepatocellular carcinoma (HCC).

Main Results:

• The developed LA-MC-ICP-MS method achieved high precision for delta values in both inorganic and biological reference materials.
• Distinct differences in in situ Cu isotope compositions were observed between healthy liver tissue and VX2 tumors.
• Tumorous liver tissue showed an enrichment of heavy 65Cu isotopes compared to healthy tissue, consistent with prior findings.

Conclusions:

• The established in situ LA-MC-ICP-MS method is effective for analyzing copper isotope variations in biological tissues.
• Copper stable isotope analysis reveals a significant isotopic dichotomy between healthy and cancerous liver tissues.
• These findings support the potential of copper stable isotopes as diagnostic biomarkers for liver cancer.