New workflow enhances liquid biopsy detection of triple-negative breast cancer circulating tumor cells, addressing major limitation in current testing methods.
Researchers at Baylor College of Medicine have developed a new approach to detect circulating tumor cells from triple-negative breast cancer using four newly identified protein markers, potentially improving liquid biopsy testing for the most aggressive form of breast cancer.
The study, published in Cancer Research Communications, describes a workflow that captures live circulating tumor cells (CTCs) from blood samples and identifies four surface proteins—AHNAK2, CAVIN1, ODR4, and TRIML2—that specifically mark these cells without appearing on normal blood cells.
Triple-negative breast cancer represents the most aggressive breast cancer type and lacks targeted therapies. The cancer frequently metastasizes through the bloodstream, but tracking CTCs has been challenging due to limited specific markers for identifying these cells in blood samples.
“We developed a new workflow to isolate and analyze live CTCs, focusing first on mouse models of metastatic triple-negative breast cancer and then testing our findings in patient samples,” says Dr Bree M Lege, former graduate student and lead author, in a release.
Enhanced Detection Method
The research team began by capturing live CTCs from blood samples of tumor-bearing mice, separating tumor cells from normal blood cells. They then isolated individual tumor cells and analyzed them using single-cell RNA sequencing to measure gene activity and identify cell-surface proteins present in triple-negative breast cancer CTCs.
The four new markers showed minimal overlap with markers found on normal blood cells, reducing false positive results. When combined, the markers substantially improved detection compared to standard methods.
“The new markers detected cells that standard methods missed. When the four new markers were combined, detection improved substantially,” says corresponding author Chonghui Cheng, MD, PhD, professor of molecular and human genetics and molecular and cellular biology at Baylor, in a release. “Importantly, the new markers on CTCs showed very little overlap with markers on normal blood cells, reducing the risk of false positives.”
Patient Sample Validation
Testing in blood samples from patients with metastatic triple-negative breast cancer showed promising results. Tumor cells that were undetectable using standard markers became clearly visible when researchers applied the new marker combination.
“In these patients, tumor cells were frequently undetectable using standard markers but became clearly visible when we applied the new marker combination,” Cheng says in a release.
The ability to capture live CTCs allows researchers to study genetic expression of tumor cells in detail, potentially helping understand how metastasis occurs and why some tumors resist treatment.
Broader Applications
The newly identified markers also appear in other cancer types, suggesting the strategy could improve CTC detection across multiple cancers beyond triple-negative breast cancer.
The enhanced detection capability could help clinicians monitor disease progression and treatment response more accurately through liquid biopsy testing. Baylor College of Medicine holds a provisional patent on the enhanced detection method.
The research was supported by grants from the Department of Defense, NIH, and CPRIT Cancer Research fellowship, with additional support from core facilities at Baylor College of Medicine.
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