Protein hampers bladder cancer metastasis

RhoGDI2: The name is awkward, but remember it. That's because the protein may end up being a key to prevent bladder cancer from metastasizing to the lungs, according to new research from the University of Colorado Cancer Center and others.

Usually, as the scientists explain, bladder cancer is generally curable, with 80% reaching a five-year survival rate. But the cancer becomes deadly once the cells start spreading to the lungs, driven by large-scale production of large levels of the protein versican. The protein, in turn, promotes production of macrophages, which help healthy cells survive but also boost production of the cancer cells in other locations, the researchers explain.

Through tests on mice, the team figured out that RhoGDI2, a protein also produced by cancer cells, cuts back on versican production, thereby limiting the cancer cells' ability to spread and then grow in the lungs. In the lab, they verified this by adding RhoGDI2 to tumors, which in turn made them sharply reduce the versican they made--and metastasis went away.

But wait, there's more. Separately, the research team figured out that the protein CCL2 also comes into play. It helps versican attract macrophages, which as we just explained, can spread the cancer. But scientists are already testing drugs to inhibit CCL2 for other indications, so the finding points to another class of drugs that can treat bladder cancer once it spreads.

Pay attention to this one. The researchers must repeat their findings in human clinical trials for the finding to have legs, but it points to enormous potential of giving doctors a way to treat patients with metastatic bladder cancer, something that has been historically very difficult to treat.

Details of the new study are published in the Journal of Clinical Investigation.

- here's the release
- read the study