New gene can help detect breast cancer early

Washington D.C.: A gene that is known for its ability to repair DNA appears to instead cause breast cancer on mutation, a new study has found.

The gene GT198, whether mutated by genetics and/or environmental factors, has strong potential as both as a way to diagnose breast cancer early and as a new treatment target, said corresponding author Dr. Lan Ko from the Augusta University.

Mutations of the gene are known to be present in both early onset breast and ovarian cancer. Now, scientists have shown that the stem, or progenitor cells, which should ultimately make healthy breast tissue, can also have GT198 mutations that prompt them to instead make a perfect bed for breast cancer.

Their studies were done on an international sampling from 254 cases of breast cancer in pre- and postmenopausal women.

Ko noted that this gene mutation can be in both the blood and the tumor tissue of patients, and in the tissue, it's in high percentages, adding "We believe that once this gene is mutated, it induces the tumor to grow."

GT198, which is also a coactivator of receptors for steroid hormones such as estrogen, is normally regulated by estrogen, Ko said. But once mutated, GT198 can enable tumor production without estrogen. "Regardless of how much hormone you have, it's out-of-control growth," Ko said of the resulting classic, rapid growth of cancer.

"It's a new target in cancer. It's very exciting," said co-author Dr. Nita Maihle, adding "This tells you that all the different types of stromal cells in breast tissue are affected by the GT198 mutation because they all come from a common progenitor cell."

The net effect is a tumorigenic environment filled with what Ko calls inappropriate offspring. "Here is a cause-consequence relationship," she said.

The study is published in the American Journal of Pathology.