Nanoparticle technique reveals cancer treatment effectiveness in 'real time'
Cancer patients could one day be able to know whether their chemotherapy treatment has worked in "real time".
Conventional methods of testing the effectiveness of treatment, such as scans, usually cannot detect whether a tumour is shrinking until a patient has received multiple cycles of therapy.
But experts from the Brigham and Women's Hospital in Boston, Massachusetts, in the United States, have developed an approach which can alert them to the death of cancer cells the moment the drugs being to work.
Using a nanoparticle that delivers cancer therapy and then glows green when cancer cells die, researchers were able to see whether a tumour is resistant or susceptible to chemotherapy or immunotherapy.
The finding, published in The Proceedings Of The National Academy Of Sciences, could one day mean that patients are not given more chemotherapy that does not respond to their cancer.
"Using this approach, the cells light up the moment a cancer drug starts working. We can determine if a cancer therapy is effective within hours of treatment," said Dr Shiladitya Sengupta,a principal investigator in Brigham and Women's Hospital Division of Bioengineering.
"Our long-term goal is to find a way to monitor outcomes very early so that we don't give a chemotherapy drug to patients who are not responding to it."
The technique takes advantage of the fact that when cells die, an enzyme known as caspase is activated. The researchers developed a "reporter element" which glows green when in the presence of this enzyme.
They then tested whether they could use "reporter nanoparticles" to distinguish whether tumours were sensitive to treatment in lab tests.
Using nanoparticles loaded with anti-cancer drugs, the team tested a chemotherapy called paclitaxel, in a pre-clinical model of prostate cancer and an immunotherapy in a pre-clinical model of melanoma.
In the tumours that were sensitive to paclitaxel, there was a 400% increase in fluorescence compared to tumours that were not sensitive to the drug.
The team also saw a significant increase in the fluorescent signal in tumours treated with the immunotherapy after five days.
The researchers now plan to see whether the findings can be tested in humans.