TY - JOUR T1 - Photosensitizer With Illumination Enhances <em>In Vivo</em> Antitumor Effect of Anti-ROBO1 Immunotoxin on Maxillary Sinus Squamous Cell Carcinoma JF - Anticancer Research JO - Anticancer Res SP - 3793 LP - 3799 DO - 10.21873/anticanres.14368 VL - 40 IS - 7 AU - NORIKO KOMATSU AU - MIKU KOMATSU AU - RIUKO OHASHI AU - AKIRA HORII AU - KAZUTO HOSHI AU - TSUYOSHI TAKATO AU - TAKAHIRO ABE AU - TAKAO HAMAKUBO Y1 - 2020/07/01 UR - http://ar.iiarjournals.org/content/40/7/3793.abstract N2 - Background/Aim: Head and neck squamous cell carcinoma (HNSCC) is one of the most common types of cancer worldwide. Our study focused on the axon guidance receptor roundabout guidance receptor 1 (ROBO1) as a target for monoclonal antibody therapy of HNSCC. We previously showed that saporin-conjugated anti-ROBO1 (B5209B) immunotoxin (IT-ROBO1) enhanced cytotoxic effects on HNSCC cells in combination with the photosensitizer aluminum phthalocyanine disulphonate (AlPcS2a) and illumination. We examined the effects of this combination therapy in a mouse xenograft model. Materials and Methods: IT-ROBO1 was intraperitoneally administered to HSQ-89 (derived from Japanese maxillary sinus squamous carcinoma, RCB0789; RIKEN, Tsukuba, Japan) xenografted mice. After 3 days, AlPcS2a was injected subcutaneously around the tumor and the area was illuminated at 650 nm for 30 min. The growth of the tumor was evaluated and the effects on the tumor were examined. Results: Pronounced anti-tumor effects were elicited by the administration of IT-ROBO1 and AlPcS2a with light illumination on tumor size and pathological characteristics. Conclusion: The results showed that photosensitizer treatment with illumination robustly enhanced the antitumor effect of the IT-ROBO1 immunotoxin. ER -