Extracellular Vesicle Proteins May Help Predict Breast Cancer Metastasis

Researchers in Singapore and New York have discovered a non-invasive biomarker that could aid with earlier diagnosis of breast cancer metastasis, which is key to successful treatment of the common cancer.

Approximately 2.3 million women globally were diagnosed with breast cancer in 2020—equal to one woman every fourteen seconds. In Singapore, it is the most common cancer among women, and will likely affect one in thirteen women in their lifespan. Although advances in medicine today allow for treatments for early-stage and non-metastatic breast cancer, advanced stage and metastatic breast cancer is considered incurable with current treatment options, with very poor prognosis.

Led by Assistant Professor Minh Le from the Institute for Digital Medicine (WisDM) and Department of Pharmacology at the National University of Singapore’s Yong Loo Lin School of Medicine (NUS Medicine) and Associate Professor Andrew Grimson from the Department of Molecular Biology and Genetics at Cornell University, the research team found that extracellular vesicles (EVs) secreted by tumor cells displayed a high level of protein integrins αv and β1 in patients with locally advanced and metastatic breast cancer.

 “Metastasis is the chief concern for breast cancer patients,” Le says. “The study highlights the potential of integrins αv and β1 as a promising prognostic and therapeutic target for patients with metastatic breast cancer. Our research has opened several doors, and we hope that future work will help develop new ways to assess, monitor and suppress this hallmark of cancer."

The team used an ultra-sensitive protein identification tool to obtain a set of protein expression profiles from the EVs of different metastatic breast cancer cell lines. They discovered that, among many candidate proteins, integrins αv and β1 were consistently overexpressed in EVs of high metastatic background. The team found a high level of integrin αv in samples from patients with stage III or IV breast cancer. “Through the study, we discovered the potential of integrin αv as a new non-invasive biomarker for the early diagnosis of breast cancer metastasis,” adds Associate Professor Victor Lee, Senior Consultant, Department of Pathology, National University Hospital.

According to Grimson, the study offers fundamental insights in the underlying mechanisms of breast cancer metastasis. “In addition to its clinical relevance, the research contributes to recent advances in the EV field, in that there are functionally distinct subsets of EVs, which can now be more readily identified and studied to understand their functions and potential as therapeutic targets in the tumor environment,” he adds.

The findings were published recently in the Journal of Extracellular Vesicles.