Researchers Discover Key to Cancer's Spread

If cancer cells did not metastasize, says Georgia State University's Dr. Zhi-Ren Liu, many tumors would not be deadly.

“Usually in many cases, it does not interfere with normal function," says the Atlanta-based biology professor. "But if you have metastasis, it interferes with multi-organ function and that kills a patient.”

Liu and co-researcher Jenny Yang, a Georgia State biochemist, have discovered they can stop cancers from spreading by disrupting the interaction of two proteins within cells.

Proteins, which act as switches to activate or stop cellular activities — including migration, or metastasis, around the body — are necessary for healing and immune response. But when cancer cells metastasize, the disease can become deadly.

The researchers found that two proteins in particular — p68 and calcium-calmodulin — appear to promote cell migration when interacting. By engineering a peptide that keeps them apart, Yang and Liu discovered they can significantly reduce or prevent the spread of cancerous cells.

According to Liu, their peptide reduced metastasis from primary tumors by 90 percent in mice infected with aggressive human colon and breast cancers.

“The tumor size is much, much smaller," says Liu. "In several cases, we did not see any metastasis at all by the treatment.”

The two Georgia State researchers plan to develop a drug that interferes with the binding of p68 and calmodulin, and look forward to eventually conducting clinical trials with human cancer patients.

Liu and Yang’s discovery of the role of the two proteins in cancer metastasis was published in Nature Communications, Vol. 4, Article number: 1354, on January 15.