New monoclonal antibody halves breast cancer mets to lung in mice

[Lani]

Monoclonal Antibody Promising Against Breast Cancer
By David Douglas

NEW YORK (Reuters Health) Dec 28 - The monoclonal antibody JAA-F11 creates a survival advantage in mice with breast cancer and substantially decreases the development of lung metastasis, according to researchers. JAA-F11 acts against Thomsen-Friedenreich antigen (TF-Ag), which is expressed in many carcinomas.

"TF-Ag was discovered many years ago, but this type of therapy was not possible until monoclonal antibodies were developed," senior investigator Dr. Kate Rittenhouse-Olson told Reuters Health.

"Now we have these promising results because JAAF11 is such a highly specific monoclonal antibody which will selectively bind tumors and not normal tissues that have a related antigen," she said.

In the November issue of Neoplasia, Dr. Rittenhouse-Olson, of the University at Buffalo, New York and colleagues note that JAA-F11 detected the presence of TF-Ag on mouse and human breast tumor cells and significantly inhibited their growth.

JAA-F11 significantly inhibited the adhesion of human or mouse breast tumor cells to endothelial cells, which, as Dr. Rittenhouse-Olson pointed out, "are the cells that line the veins, so it would block a key step in metastasis."

Indeed, the agent also significantly increased the mean survival time of treated mice, while significantly decreasing the amount of visible lung metastasis in mice bearing breast tumors.

Visible lung metastases were reduced from 88% in the control group to 47% in the treatment group. Therefore, Dr. Rittenhouse-Olson added, "53% of treated mice had no visible lung metastasis."

These experiments, she continued, show the success of JAA-F11 passive therapy in this application. "In addition, adhesion of human tumor cells to blood vessel walls is inhibited. This indicates that there is promise for clinical therapy for humans."

This therapy might block further metastasis, Dr. Rittenhouse-Olson concluded, "and if JAA-F11 were linked to a radioactive compound, it may be successful in conjunction with current chemotherapy in decreasing or eliminating the tumor."

Neoplasia 2006;8:939-948.