A new target has been identified to prevent metastasis in breast cancer.

A study points to the TIM-3 protein as a key factor in breast cancer cells' ability to metastasize. This finding suggests a new therapeutic approach to prevent this process before it develops clinically.

A study led by the Hospital del Mar Research Institute identifies a new way to stop metastasis in breast cancer at the time of diagnosis. micrometastases, when the first cells reach other organs, thus preventing their appearance. The Oncology and Pathology Department of Hospital del Mar also participated in the project, along with researchers from the GEICAM Breast Cancer Research Group.

The work, which publishes Cancer Cell, determines the role of the protein TIM-3 in the most aggressive metastasis-initiating cells, the so-called seeds of metastasis. In these, TIM-3 allows tumor cells suppress the immune system when they reach distant organs, thus ensuring their survival at a critical moment. This very fact makes TIM-3 a unique and specific therapeutic target for this precise moment of the disease.

This stage, that of the arrival to the new organ, is critical, but little known because there are no clinical manifestations nor techniques to investigate it. The team responsible for the work used a mouse model to do so and describe the key role of TIM-3 in the survival of the first tumor cells that seed the affected organs.

"This is a vulnerable phase of the disease, as few cells remain in the area. If we understand what's happening and are able to eradicate them, we will have a great opportunity to prevent clinical metastasis, which is the dangerous phase of the disease," explains the doctor. Toni Celia-Terrassa, lead author of the study and researcher at the GEICAM Group.

Avoiding the immune attack

Cancer cells that survive the journey from the primary tumor use TIM-3 to reconfigure the immune system of the new organ and avoid its attack. This allows them to proliferate and generate a new tumor, the initiation of metastasis, as researchers have seen with cells from various types of breast cancer that have metastasized to the liver.

Furthermore, with a cohort of patients from Hospital del Mar, they were able to verify that those patients with tumors with high levels of TIM-3 had a higher risk of metastasis and a poor prognosis. “Patients who are positive for TIM-3 in the primary tumor have a higher risk of recurrence and metastasis,” says Catalina Rozalén, a predoctoral researcher at the Hospital del Mar Research Institute.

This raises the possibility of using existing drugs that block the action of TIM-3 to prevent the development of new tumors. “Having tools for these high-risk patients, such as those who are TIM-3 positive, may allow us to apply a anti-TIM-3 therapy after surgery to avoid subsequent relapse and prevent metastasis,” says Celià-Terrassa.

This preclinical study indicates that treatment should be applied before metastasis occurs, since once the disease has occurred, it is more difficult to control and TIM-3 loses its relevance. But first, according to the researchers, relevant clinical trials must be conducted.

Source: SINC Agency