Kazutaka “Kazu” Sumita, MD, PhD, knows how to meet a challenge. He earned his doctoral and medical degrees at Tokyo Medical & Dental University and then trained to become a brain surgeon. To date, he has performed more than 1,300 surgeries, including a particularly terrifying one. When the Higashi nihon daishinsa –the Great East Japan Earthquake — struck off the Pacific coast of Tōhoku in 2011, triggering the deadly tsunami, Dr. Sumita was performing an endovascular treatment. The lights went out and all power was lost for an hour, but he managed to finish the operation safely and save his patient.
Dr. Sumita, a post-doctoral fellow in the Division of Hematology-Oncology and a researcher at the Brain Tumor Center at the UC Neuroscience Institute and UC Cancer Institute, today faces an equally big challenge: He has been awarded a $50,000 grant — the American Association of Neurological Surgeons (AANS) Section on Tumors/Brainlab International Research Fellowship — to pursue a novel laboratory study of malignant brain tumors. The grant allows a foreign neurosurgeon to perform clinical, translational or basic research in the field of neurosurgical oncology in a clinical and/or laboratory setting within the United States.
Details of Dr. Sumita’s work will be published in a scientific report in a couple of years. He is targeting an energy pathway that enables malignant primary and metastatic brain tumors to grow and spread. More specifically, he is studying phosphoinositide signaling. Phosphoinositide is a cellular messenger that plays a role in controlling cellular activities such as growth and proliferation. Once cells have lost control of phosophoinositide signaling, the risk for disease, particularly cancer, increases.
“We are looking for pathways that are important for the survival of brain cancer cells,” Dr. Sumita said. “We want to identify these pathways so that we can stop the growth of primary brain cancers (such as glioblastoma) as well as metastatic brain tumors. The pathway we are now discovering is a new signaling pathway; it will be a sensational finding, and when we interfere with this pathway, we expect to see a decrease in tumor growth.
“Right now we do not understand how it is happening or what molecular mechanism is making it slow down. The fellowship will enable us to decipher the cause.”
Atsuo Sasaki, PhD, Assistant Professor in the Division of Hematology-Oncology at UC and Dr. Sumita’s scientific mentor, said Dr. Sumita “is likely to discover the central energy status” in cancer cells that have changed from normal brain cells.
“This is an important component of tumor therapy,” he said. “Ideally, we do not want to kill normal cells during treatment, yet this is a major problem with chemotherapy. People suffer side-effects because the therapy also acts on normal tissue. What Dr. Sumita has found is the clue for a brain tumor-specific energy pathway, or energy utilization pathway. We think that this pathway is linked to the phosphoinositide signaling pathway.”
If such a pathway could be targeted with medication, the researchers said, it would give doctors a way to combat cancer cells without harming healthy cells.
Physician-scientists like Dr. Sumita bring a valuable perspective to the study of disease. They can seamlessly introduce the important clinical questions into the laboratory and then test the lab findings in Phase 1 clinical trials. If successful, Phase 1 trials can ultimately lead to a clinically relevant therapy.
“Kazu believes that basic science will help him find a way to cure patients suffering from brain tumors, trauma or neurovascular disease,” Dr. Sasaki said. “During his clinical work he had many patients who suffered from malignant brain tumors. Surgery helps, but it is not a complete solution. He is pursuing this training to find a cure for brain tumors.
“His aspirations are high,” Dr. Sasaki continued. “He is a really dedicated researcher and clinician, and you see him at the lab almost 24-7.”
“We have a great clue,” Dr. Sumita said. “We want to understand this pathway in a year or two. No other researchers are looking at this pathway. We want to be the first.”
— Cindy Starr