Major research interest of Dr. Tanaka is regarding tumor angiogenesis, one of the pivotal pathogenesis of malignant tumors including glioblastoma and therapeutic targets. In the field of basic science, he developed animal models for therapeutics utilizing viral vectors carrying antiangiogenic genes including platelet factor 4, angiostatin, and endostatin.

In the field of neuro-oncology, the innovative work of Dr. Tanaka’s multidisciplinary team has focused on the design and selection of personalized hypervascular malignant glioma treatments based on neuroradiological findings by preoperative administratin of bevacizumab, demonstrating a benefit of surgical radical resection for which hyper-vascular tumor turning into less vascular and decreasing tumor volume and edema. Comparative in situ histological investigation between with or without bevacizumab demonstrated that tumor oxygenation and diminishing of cancer stem cells were induced during effectiveness of bevacizumab, compared with tumors in naïve or recurrence after bevacizumab therapy. In addition, he demonstrated that bevacizumab has an additional benefit for providing immunosupportive tumor microenvironment, which was induced by inhibition of immunosuppressive cells including regulatory T cells and M2-polarized tumor associated macrophages, and immune checkpoint molecules including PD-1 and PD-L1. Those alterations caused induction of cytotoxic T cells, which might accelerate the effectiveness of tumor immunotherapy.