Multimodality pH imaging in a mouse dorsal skin fold window chamber model

Area of Science:

• Oncology
• Biomedical Imaging
• Biochemistry

Background:

• Cancer cells upregulate H+ pumps, lowering extracellular pH (pHe).
• Disregulated pHe is linked to tumor metabolism and metastasis.
• pHe measurement offers potential as a cancer diagnostic and therapy monitoring biomarker.

Purpose of the Study:

• To describe a multimodality in-vivo imaging model for pHe in tumors.
• To establish a system for continuous pHe study in the same tissue microenvironment.
• To evaluate optical and MR imaging techniques for pHe measurement.

Main Methods:

• Developed a custom plastic window chamber compatible with optical and MR imaging.
• Utilized SNARF-1 carboxylic acid and confocal microscopy for optical pHe imaging.
• Employed chemical exchange saturation transfer (CEST) with ULTRAVIST for MR pHe imaging.

Main Results:

• Demonstrated a 3-week continuous study capability in a mouse dorsal skin fold window chamber (DSFWC) model.
• Successfully measured pHe using both optical and MR imaging modalities.
• Preliminary evaluation of sodium bicarbonate for reversing tumor acidosis was performed.

Conclusions:

• Multimodality imaging in the DSFWC model enables robust pHe assessment.
• pHe imaging provides a valuable tool for cancer research and potential clinical applications.
• This model supports continuous monitoring for diagnostic and therapeutic evaluations.