A Novel Photodynamic Therapy Targeting Cancer Cells and Tumor-Associated Macrophages

作者：Hayashi Noriyuki; Kataoka Hiromi^*; Yano Shigenobu; Tanaka Mamoru; Moriwaki Kazuhiro; Akashi Haruo; Suzuki Shugo; Mori Yoshinori; Kubota Eiji; Tanida Satoshi; Takahashi Satoru; Joh Takashi

来源：Molecular Cancer Therapeutics, 2015, 14(2): 452-460.

DOI：10.1158/1535-7163.MCT-14-0348

Tumor-associated macrophages (TAM) in cancer stroma play important roles for cancer cell growth, invasion, angiogenesis, and metastases. We synthesized a novel photosensitizer, mannose-conjugated chlorin (M-chlorin), designed to bind mannose receptors highly expressed on TAMs. We evaluated the newly available photodynamic therapy (PDT) with M-chlorin against gastric and colon cancer. We evaluated PDT with Mchlorin for in vitro cytotoxicity and apoptosis induction in cancer cells compared with chlorin alone and glucose-conjugated chlorin (G-chlorin). The subcellular localization of M-chlorin was observed by confocal microscopy, and the M-chlorin PDT effects against TAMs including THP-1-induced M2-polarized macrophages were evaluated. Anticancer effects were also investigated in an allograft model where cytotoxic effects against TAMs in the cancer cell stroma were analyzed by immunohistochemistry. M-chlorin PDT strongly induced cell death in cancer cells to almost the same extent as G-chlorin PDT by inducing apoptosis. M-chlorin was incorporated into cancer cells where it localized mainly in lysosomes and endoplasmic reticula. M-chlorin PDT revealed strong cytotoxicity for M2 macrophages induced from THP-1 cell lines, and it induced stronger cytotoxicity than G-chlorin PDT in the allograft model through killing both cancer cells and TAMs in the cancer stroma. The M-chlorin PDT produced strong cytotoxicity against cancer tissue by inducing apoptosis of both cancer cells and TAMs in the cancer stroma. This novel PDT thus stands as a new candidate for very effective, next-generation PDT.

• 出版日期2015-2