Heating decreases Stem Cells that drive Tumor Growth
Heated gold nanoshells, now in cancer trials, appear to help kill diseased cells at a previously unreachable root level. In a mouse study, Houston researchers showed that the use of tiny gold-coated particles deliver heat to breast cancer tumors already treated with radiation not only shrank the tumor but also dramatically decreased the population of cancer stem cells.
Cancer stem cells self-renew and drive the growth of tumors.
- Cancer stem cells, only discovered in the 1990s, are the subject of much debate;
- Some researchers think they cause cancer to recur in patients who respond favorably to standard therapy;
- The combination of radiation and nanoshells heated with a near-infrared laser already is being tested in patients with head and neck cancers in trials in Houston and Dallas;
- The trial wasn’t designed to check the effect on cancer stem cells, but it’s possible the technique is working at that level;
- The technique, known as hyperthermia, can only currently be used on superficial cancers (such as head and neck cancers and inflammatory breast cancer) because the technology can’t reach that deep into the body yet;
- The mouse study, which appears in the journal Science Translational Medicine, was triggered by the serendipitous discovery of a Baylor College of Medicine graduate student working with radiation and cancer stem cells;
- M.D. Anderson scientists’ research already had showed hyperthermia delivered through nanoshells disrupts the blood supply to the tumor and enhances radiation’s effectiveness;
- Targets one of the most aggressive and resistant breast tumor types — triple negative breast cancer.
Radiation alone shrank the tumors but left behind a large percentage of cancer stem cells capable of re-growing the tumor.
- But using the nanoshells to send nearly 9 additional degrees Fahrenheit of heat to the tumors reduced the population of stem cells 20 fold;
- There appears to be no harm to healthy tissue;
- Researchers worked with both mice tumors and transplanted human tumors.
The advantage of nanoshells, a specially designed core of material with a thin metal shell a little larger than a molecule, is that the whole body isn’t heated. (HWM and T Ackerman, Houston Chronicle)