Optical imaging of the peri-tumoral inflammatory response in breast cancer

• Published in: Journal of translational medicine Vol. 7; no. 1; p. 94
• Main Authors: Sista, Akhilesh K, Knebel, Robert J, Tavri, Sidhartha, Johansson, Magnus, DeNardo, David G, Boddington, Sophie E, Kishore, Sirish A, Ansari, Celina, Reinhart, Verena, Coakley, Fergus V, Coussens, Lisa M, Daldrup-Link, Heike E
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 11.11.2009; BioMed Central; BMC
• Subjects: Animals; Breast cancer; Breast Neoplasms - immunology; Breast Neoplasms - pathology; Complications and side effects; Diagnosis; Diagnostic imaging; Female; Fluorescent Dyes - metabolism; Health aspects; Humans; Inflammation; Inflammation - pathology; Mammary Neoplasms, Experimental - immunology; Mammary Neoplasms, Experimental - pathology; Mammary Tumor Virus, Mouse - genetics; Methods; Mice; Mice, Transgenic; Microscopy, Confocal - methods; Microscopy, Fluorescence - methods; Monocytes - cytology; Monocytes - metabolism; Risk factors; United States
• ISSN: 1479-5876; 1479-5876
• DOI: 10.1186/1479-5876-7-94

Peri-tumoral inflammation is a common tumor response that plays a central role in tumor invasion and metastasis, and inflammatory cell recruitment is essential to this process. The purpose of this study was to determine whether injected fluorescently-labeled monocytes accumulate within murine breast tumors and are visible with optical imaging. Murine monocytes were labeled with the fluorescent dye DiD and subsequently injected intravenously into 6 transgenic MMTV-PymT tumor-bearing mice and 6 FVB/n control mice without tumors. Optical imaging (OI) was performed before and after cell injection. Ratios of post-injection to pre-injection fluorescent signal intensity of the tumors (MMTV-PymT mice) and mammary tissue (FVB/n controls) were calculated and statistically compared. MMTV-PymT breast tumors had an average post/pre signal intensity ratio of 1.8+/- 0.2 (range 1.1-2.7). Control mammary tissue had an average post/pre signal intensity ratio of 1.1 +/- 0.1 (range, 0.4 to 1.4). The p-value for the difference between the ratios was less than 0.05. Confocal fluorescence microscopy confirmed the presence of DiD-labeled cells within the breast tumors. Murine monocytes accumulate at the site of breast cancer development in this transgenic model, providing evidence that peri-tumoral inflammatory cell recruitment can be evaluated non-invasively using optical imaging.