Potential of [¹¹C](<i>R</i>)-PK11195 PET Imaging for Evaluating Tumor Inflammation: A Murine Mammary Tumor Model

• Main Authors: Aline Morais de Souza (Author), Caroline Cristiano Real (Author), Mara de Souza Junqueira (Author), Larissa Estessi de Souza (Author), Fábio Luiz Navarro Marques (Author), Carlos Alberto Buchpiguel (Author), Roger Chammas (Author), Marcelo Tatit Sapienza (Author), Daniele de Paula Faria (Author)
• Format: Book
• Published: MDPI AG, 2022-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Background: Breast tumor inflammation is an immunological process that occurs mainly by mediation of Tumor-Associated Macrophages (TAM). Aiming for a specific measurement of tumor inflammation, the current study evaluated the potential of Positron Emission Tomography (PET) imaging with [¹¹C](<i>R</i>)-PK11195 to evaluate tumor inflammation in a mammary tumor animal model. Methods: Female Balb/C mice were inoculated with 4T1 cells. The PET imaging with [¹¹C](<i>R</i>)-PK11195 and [¹⁸F]FDG was acquired 3 days, 1 week, and 2 weeks after cell inoculation. Results: The [¹¹C](<i>R</i>)-PK11195 tumor uptake increased from 3 days to 1 week, and decreased at 2 weeks after cell inoculation, as opposed to the [¹⁸F]FDG uptake, which showed a slight decrease in uptake at 1 week and increased uptake at 2 weeks. In the control group, no significant differences occurred in tracer uptake over time. Tumor uptake of both radiopharmaceuticals is more expressed in tumor edge regions, with greater intensity at 2 weeks, as demonstrated by [¹¹C](<i>R</i>)-PK11195 autoradiography and immunofluorescence with TSPO antibodies and CD86 pro-inflammatory phenotype. Conclusion: The [¹¹C](<i>R</i>)-PK11195 was able to identify heterogeneous tumor inflammation in a murine model of breast cancer and the uptake varied according to tumor size. Together with the glycolytic marker [¹⁸F]FDG, molecular imaging with [¹¹C](<i>R</i>)-PK11195 may provide a better characterization of inflammatory responses in cancer.

Item Description

10.3390/pharmaceutics14122715
1999-4923