@misc{oai:repo.qst.go.jp:00070879,
 author = {Bakalova-Zheleva, Rumiana and Zhelev, Zhivko and Kokuryo, Daisuke and Aoki, Ichio and Saga, Tsuneo and et.al and バカロバ ルミアナ and 國領 大介 and 青木 伊知男 and 佐賀 恒夫},
 month = {Sep},
 note = {Background: Redox signalling is crucial for carcinogenesis and tissue redox activity has emerged as an important sensing platform for cancer diagnosis and planning of therapeutic strategy. The cells and tissues of healthy mammalian are characterized by low level of reactive oxygen species (ROS) and some constant (reference) level of reducing equivalents. Increasing of ROS above the critical level provokes genomic instability. Normal cells become malignant. The present study describes universal methodology for direct imaging of tissue redox activity in carcinogenesis, which allows a differentiation of cancer development from normal (healthy) condition. Methods: The experiments were conducted on:
neuroblastoma-bearing, colon cancer-bearing and healthy mice (Balb/c nude). The tissue redox activitywas visualized in vivo by nitroxide-enhanced MRI on anesthetized animals. The method is based on nitroxide redox cycle, coupled with appearance or disappearance of MRI signal. The half-life (t1/2) of
nitroxide-enhanced MRI signal in the respective tissue was used as a diagnostic marker. Results: The study provides direct evidence that healthy and cancer-bearing mammalian are characterized by different tissue redox activity - a basis for cancer diagnostic. The tissues (cancer and normal) of
cancer-bearing mammalian were characterized by long-lived MRI signal (t1/2>14 min), indicating a high oxidative activity. The tissues of healthy organism were characterized by short-lived MRI signal (t1/2=1∼3 min), indicating a high reducing activity. The long-lived nitroxide-enhanced MRI signal in cancer-bearing mice is a result of excessive amounts of superoxide in their tissues (cancer and noncancer).
Conclusions: The high oxidative activity of cancer tissue is a fact despite of the widely accepted opinion that hypoxia develops in solid tumours. Presumably, it is due to abnormal generation of free superoxide instead of using oxygen to maintain normal homeostasis. The study shows that anticancer therapy should solve simultaneously two major problems: to stop proliferation and induce apoptosis in cancer cells, and to protect "normal" tissues of cancer-bearing organism from oxidative damage. There are two therapeutic targets and they are equally important for the success of therapy and survival of the organism. The proposed methodology is applicable in clinical laboratory practice on
isolated biopsy specimens and blood samples for evaluation of the effectiveness of anti-cancer therapy,based on its effect on cellular/tissue redox activity., 2012　World Molecular Imaging Congress},
 title = {Tissue Redox Activity as a Sensing Platform for Magnetic Resonance Imaging of Cancer: Diagnostic and Therapeutic Aspects},
 year = {2012}
}