Assessing Breast Cancer Molecular Subtypes Using Extracellular Vesicles' mRNA

Area of Science:

• Biotechnology
• Molecular Biology
• Oncology

Background:

• Extracellular vesicles (EVs) contain RNA cargo reflective of their cell of origin.
• EVs are promising biomarkers for minimally invasive liquid biopsies.
• Precision medicine requires accurate molecular information for treatment guidance.

Purpose of the Study:

• To develop and validate a microfluidic chip for isolating specific EV subpopulations.
• To assess the utility of isolated EV subpopulations for molecular subtyping of breast cancer.
• To evaluate the potential of EV-derived RNA for prognostication.

Main Methods:

• Affinity isolation of EV subpopulations using monoclonal antibodies on a microfluidic chip (EV-MAP).
• Isolation of EV subpopulations EV^EpCAM (epithelial) and EV^FAPα (mesenchymal).
• Analysis of exosomal mRNA (exo-mRNA) using real-time-droplet digital polymerase chain reaction and PAM50 gene expression profiling (exo-PAM50).

Main Results:

• The EV-MAP chip achieved >80% recovery and 99% specificity.
• EV subpopulations (EV^EpCAM and EV^FAPα) isolated from breast cancer patients' plasma yielded specific RNA quantities.
• Profiling of exo-mRNA from EV^EpCAM and EV^FAPα using exo-PAM50 showed 100% concordance with tumor tissue for prognostication.

Conclusions:

• The EV-MAP chip effectively isolates distinct EV subpopulations with high purity and recovery.
• EV subpopulations carry molecular information that accurately reflects tumor tissue characteristics.
• EV-derived RNA profiling holds significant potential for non-invasive breast cancer prognostication and guiding precision medicine.