Tumor-associated macrophages (not tumor cells) are the determinants of photosensitizer tumor localization

摘要

Abstract: The distribution of Photofrin and several other photosensitizers among major cellular populations contained in solid mouse tumors was examined using flow cytometry. Seven tumor models were included in the analysis: sarcomas EMT6, KHT, RIF, FsaR and FsaN, Lewis lung carcinoma and squamous cell carcinoma SCCVII. In all these tumors, the highest photosensitizer levels were found in a subpopulation of tumor associated macrophages consisting of activated cells (as suggested by their increased size, granularity, and the number of interleukin 2 receptors). There was no evidence of selective photosensitizer accumulation in malignant tumor cells. Results consistent with these observations were also obtained with the carcinogen induced squamous cell carcinoma growing in hamster cheek pouch. !11