Knowing whether a therapy is workingeffectively is extremely important when treating cancer. Thatinformation can have a big impact, potentially prompting a change intreatment and improving its outcome. Right now, we don't have amethod of detecting whether a tumor is reacting to medication untilnumerous cycles of therapy have been completed, but research byscientists at Brigham and Women's Hospital (BWH) could change that,with a new nanoparticle treatment providing the information in aslittle as eight hours.
Central to the new nanoparticle tech isan enzyme called caspase, which is activated when cells die. Theresearchers engineered the nanoparticles, which can be loaded withmedication, so that they glow green in the presence of the enzyme.Simply put, the more cells that die as a result of the drugsadministered to the tumor, the brighter the nanoparticles glow.
The cells are designed to startlighting up as soon as the cancer drug begins to work, providing veryfast confirmation – some eight hours in testing – that the chosentreatment is proving effective. If no such reaction is observed, thenit tells the doctors that the therapy is likely not working, givingthem the opportunity to switch to an alternative treatment. Timing iskey when tackling cancer, and the new technology could give doctorsthe chance to switch therapies early enough that it could have a bigimpact on the overall outcome of treatment.
The team tested whether thenanoparticles were able to distinguish between tumors that weresensitive to drugs and those that were drug-resistant. In alaboratory environment, the researchers loaded the nanoparticles withanti-cancer drugs, and tested them on model versions of prostatecancer and a melanoma. In the case of prostate cancer, for which achemotherapeutic agent called paclitaxel was used, the team observedan flourescence increase of 400 percent in tumors that were sensitiveto the treatment. Positive results were also observed with themelanoma tumors.
Those early results are very positive,and strongly indicate that the nanoparticles could be useful forassessing how effective a therapy is on a much shorter time scalethan current treatments, which usually rely on observing the size ofthe tumor. The researchers now plan to tweak the nanoparticles fordirect use in human patients, working to evaluate the safety of themethod prior to potential clinical trials.
"We can determine if a cancer therapyis effective within hours of treatment," said paper co-authorShiladitya Sengupta. "Our long-term goal is to find a way tomonitor outcomes very early so that we don't give a chemotherapy drugto patients who are not responding to it."
Full details of the research arepublished online in The Proceedings of the National Academy of Sciences.
Source: BWH