2021/03/09
Keio University School of Medicine
Nippon Medical School
National Cancer Center
National Defense Medical College
Japan Agency for Medical Research and Development
A group of researchers, including Senior Lecturer Takako Hishiki of the Clinical and Translational Research Center at Keio University Hospital; Senior Lecturer Takehiro Yamamoto, Associate Professor Yasuaki Kabe, and Professor Makoto Suematsu of the Department of Biochemistry, School of Medicine; Professor Kazufumi Honda of the Department of Biological Function Control, Graduate School of Medicine, Nippon Medical School; and Division Head Shinsuke Hiraoka of the National Cancer Center Research Institute, has succeeded in the world's first detection of polysulfides (PS), a type of reactive sulfur species, in ovarian cancer tissue removed by surgery, using surface-enhanced Raman scattering imaging. This revealed that in cases with high levels of polysulfides, the effectiveness of postoperative chemotherapy, such as with platinum-based drugs, is reduced, leading to a poor long-term prognosis.
Once ovarian cancer is diagnosed via CT scan or other methods, strong chemotherapy mainly consisting of platinum-based drugs is administered after the bilateral ovaries, fallopian tubes, uterus, and other organs are removed in a procedure known as debulking surgery. In this study, significant variations in the effectiveness of chemotherapy were observed in cases pathologically diagnosed with clear cell carcinoma. Professor Suematsu's research team discovered that: 1) ovarian cancer tissues in refractory cases produce large amounts of PS, a type of reactive sulfur species with cytoprotective effects; 2) unlike other reactive sulfur species, PS has the ability to neutralize the therapeutic effects of platinum-based drugs by inhibiting their DNA cross-linking reaction; and 3) Ambroxol, widely used clinically as an expectorant, can overcome drug resistance in ovarian cancer by degrading PS.
These research findings were published in the online "In Press" version of the Elsevier scientific journal "Redox Biology" on March 2, 2021 (UK time).
Please see below for the full press release.