Tumor Imaging Technique Has Potential as Anti-Cancer Weapon, Mouse Study Shows
Source: Washington University School of Medicine in St. Louis
Summary: According to researchers, a new anti-cancer strategy wields light as a precision weapon. This technique can target and attack cancer cells that have spread deep inside the body.
Traditional cancer-imaging techniques which emit light to locate metastatic tumors can also trigger light-sensitive drugs. In addition, the research shows that when such drugs are packaged into nanoparticles that target lit-up cancer cells, the light-sensitive drug produces toxic free radicals that kill the tumor cells. According to researchers from the Washington University School of Medicine in St. Louis, a new anti-cancer strategy wields light as a precision weapon as this technique can target and attack cancer cells that have spread deep inside the body. They showed that the technique worked effectively in mice with multiple myeloma, a cancer of white blood cells, and aggressive metastatic breast cancer. The team envisions doctors being able to one day use this type of technology to prevent cancer from recurring.The study findings were published in the journal Nature Communications.
The technology harnesses a chemotherapy drug called titanocene. As a chemotherapy agent alone, titanocene has not worked well in clinical trials, even at relatively high doses. But when exposed to the radiation emitted by visible light, titanocene produces reactive particles that are toxic to cells, even at low doses. The team packaged low doses of titanocene inside nanoparticles they targeted to proteins known to sit on the surface of cancer cells. They found that when the nanoparticles make contact with cancer cells, their membranes fuse together, releasing the titanocene into the cells. The investigators then deliver a common cancer imaging agent called fluorodeoxyglucose (FDG), a type of sugar. Energy-hungry cancer cells take up the FDG at high rates, causing tumors to glow in a positron emission tomography (PET) scan. This glow also triggers the titanocene, releasing free radicals and killing the cells.
Senior author Samuel Achilefu said, “We are interested in exploring whether this is something a patient in remission could take once a year for prevention”, “The toxicity appears to be low, so we imagine an outpatient procedure that could involve zapping any cancerous cells, making cancer a chronic condition that could be controlled long-term.”
More Information: Nalinikanth Kotagiri et al, “Radionuclides transform chemotherapeutics into phototherapeutics for precise treatment of disseminated cancer”, Nature Communications (2018). DOI: 10.1038/s41467-017-02758-9