After graduating from medical school at the University of Tsukuba in Japan, Dr Osuka completed a residency program in Neurosurgery. While he was involved in the treatment of many types of diseases during his residency training, he developed a great interest in malignant brain tumors. Caring for patients with malignant brain tumors gave him first-hand experience with the difficulties of disease control and severe outcome for the patients. These experiences prompted his interest in training in basic research to acquire the skills and knowledge to develop more effective therapies for brain tumors. In parallel with his clinical practice, he started to conduct basic research on brain tumors.
To further improve his basic knowledge about brain tumor biology, he then entered graduate school and joined the laboratory of Dr. Hideyuki Saya at Keio University in Tokyo to train in neuro-oncology research. His dissertation work focused on discovering mechanisms of Glioma stem cell (GSC) resistance to fractionated irradiation. He established an experimental model to study the acquisition of radioresistance in GSCs following sequential in vitro radiotherapy, and revealed a critical role for the IGF1 signaling pathway.
To further his research training in molecular neuro-oncology and gain experience in a different scientific environment, he subsequently joined Dr. Van Meir’s laboratory as a postdoctoral fellow, at the end of 2014. In his laboratory, he have expanded his experience and expertise in molecular biology and brain tumor biology. He conducted two main projects. The first project was to analyze the radioresistance mechanism of GSCs, which was an extension of his dissertation work. He developed additional radioresistance models, including 5 models of human GSCs and one more mouse GSC. By using these models, he found that GSCs can acquire radioresistance by increasing N-cadherin expression, which reduces pro-proliferative Wnt--catenin signaling and Clusterin expression, which is anti-apoptotic. These results are to be published in the Journal of Clinical Investigation (Osuka S. et al, 2021). The second project is to analyze the role of adhesion GPCR BAI1 in the malignancy of glioblastoma and medulloblastoma.
