Viewing a single comment thread. View all comments

chrisdh79 OP t1_jbesegd wrote

From the article: Metastatic breast cancer has no cure and has proven stubbornly resistant to one of the most innovative and promising new cancer treatments: immunotherapy.

Now, researchers at Washington University School of Medicine in St. Louis have identified a way to treat the area surrounding breast tumors that have spread to bone so that such tumors become vulnerable to attack by the body’s immune system. When the researchers boosted the activity of certain immune cells, called T cells and macrophages, these immune cells worked together to clear metastatic breast tumors that had spread to the bones of mice, and continued to eliminate tumor cells that eventually returned.

The study is published March 8 in Cancer Discovery, a journal of the American Association for Cancer Research.

Macrophages are myeloid immune cells that attack cancer cells through the body’s innate immune response to general threats, such as tumors or viruses. Such macrophages further activate T cells by showing the T cells what they should be looking for, thereby harnessing the adaptive immune response as well. In this case, these macrophages present T cells with bits of recognizable tumor — called tumor antigens — from dead cancer cells, and the antigens direct the killing activities of T cells.

“After breast cancer has spread to other parts of the body, it becomes extraordinarily difficult to treat; current therapies can only try to slow it down,” said senior author Sheila A. Stewart, PhD, the Gerty Cori Professor of Cell Biology & Physiology. “About 70% of patients with metastatic breast cancer have tumors that have spread to their bones. Our study suggests we may be able to use two treatments — one to sensitize the myeloid tumor microenvironment to immunotherapy, and one to activate T cells — to target these bone metastases in a way that eliminates the tumor, prevents the cancer from returning and protects against bone loss in the process.”

3