New research published in Science Translational Medicine reported the development of a new strategy that they say could detect bladder cancer with more accuracy and sensitivity than standard endoscopy methods. They identified a protein known as CD47 as a molecular imaging target to distinguish bladder cancer from benign tissue. Researchers said “Our motivation is to improve diagnosis of bladder cancer that can better differentiate cancer from noncancer, which is exceedingly challenging at times. Molecular imaging offers the possibility of real-tie cancer detection at the molecular level during diagnostic cytoscopy and tumor resection.”
To improve specificity of imaging the researchers found CD47 that is a protein on a cell’s surface that signals the immune system not to attack the cell and most cells produce it. However, cancer cells make a lot more of it than normal cells. Previous research has shown that blocking the signal from the CD47 of cancer cells allowed the immune system to resume its attack against many types of cancer cells. They developed an anti-CD47 antibody that binds to the cancer cell’s surface and blocks the signal.
The current researchers hypothesized that if it was a good therapeutic target and its also expressed on the surface of the cancer cells, it might be a good imaging target. To test this the added a fluorescent molecule to an antibody that binds to CD47. The modified antibodies were then introduced into intact bladders surgically removed from patients with invasive bladder cancer. After 30 minutes they rinsed the bladder,so only the antibodies that bound to theCD47 protein remained. When the tumor was exposed to fluorescent light, the cancer cells “lit up” whereas normal or inflamed cells did not. They said this “will add to the existing technology and may help avoid unnecessary biopsies.”