Extracellular vesicles in blood: are they viable as diagnostic and predictive tools in breast cancer?

Abstract

Extracellular vesicles (EVs), often described as mini-maps of their cells of origin, are found in the bloodstream and can be rich sources of cargo released from cancer cells. As such, they could be collected through minimally invasive methods and potentially used as biomarkers. However, the relatively complicated methodologies that separate the purest EVs are the least likely to be translated to the clinic, whereas simpler methods are non-selective for EVs. Notwithstanding this, research is underway to identify blood-based EV-associated diagnostic and predictive biomarkers for breast cancer. There is reason to be optimistic that some approaches will yield useful biomarkers. Thus, further studies with larger cohorts of appropriate samples are warranted. Reviews POST SCREEN

Evidence for the Need to Evaluate More Than One Source of Extracellular Vesicles, Rather Than Single or Pooled Samples Only, When Comparing Extracellular Vesicles Separation Methods

“…In cancer, for example, our group was the first to show that EVs can transmit resistance to anti-cancer drugs [28,29]. The potential of EVs, for example, from mesenchymal stem cells (MSCs), as therapeutics and natural drug delivery systems is also of substantial interest [4,25]. Areas in this field that need further attention in our effort toward exploiting the therapeutic potential of EVs, especially those released from cultured mammalian cells, include the EV separation/enrichment step [30,31].…”

“…The EVs' cargo may include proteins, RNAs, DNA, and lipids, and they are often described as mini-maps of their cells of origin. The EVs' bioactive cargo is instrumental in their role in cell-to-cell communication, mediating a broad range of physiological and pathological activities [1][2][3][4][5]. EVs have traditionally been categorized based on size and sub-cellular origin [6], with those derived from multi-vesicular bodies and having a size of approximately 30-150 nm termed exosomes, while those originating by budding/pinching from the cell membrane and typically have a size greater than 150 nm considered to be microvesicles [6,7].…”

Biomarker Reproducibility Challenge: A Review of Non-Nucleotide Biomarker Discovery Protocols from Body Fluids in Breast Cancer Diagnosis

“…In order to reduce vesicle release from blood cells, most procedures suggest using plasma rather than serum [101]. EVs and MVs in cancer biomarker discovery have previously been reviewed in detail [99,101,107,108]. In breast cancer studies focusing on EVs, plasma was used as the main source compared to serum [108], regardless of the type of EV composition.…”

Proteomics profiling identifies extracellular vesicles’ cargo associated with tumour cell induced platelet aggregation

“…Their cargo may include proteins, RNAs, DNA, and lipids, reflecting the content of their cells of origin. Ourselves and other have shown that EVs' bioactive cargo is instrumental in their role in cell-to-cell communication, mediating a broad range of physiological and pathological activities [4][5][6][7][8]. EVs have traditionally been categorised based on sub-cellular origin and size as exosomes and microvesicles/ectosomes [9,10].…”