Microfluidic isolation of cancer-cell-derived microvesicles from hetergeneous extracellular shed vesicle populations

Abstract

Extracellular shed vesicles, including exosomes and microvesicles, are disseminated throughout the body and represent an important conduit of cell communication. Cancer-cell-derived microvesicles have potential as a cancer biomarker as they help shape the tumor microenvironment to promote the growth of the primary tumor and prime the metastatic niche. It is likely that, in cancer cell cultures, the two constituent extracellular shed vesicle subpopulations, observed in dynamic light scattering, represent an exosome population and a cancer-cell-specific microvesicle population and that extracellular shed vesicle size provides information about provenance and cargo. We have designed and implemented a novel microfluidic technology that separates microvesicles, as a function of diameter, from heterogeneous populations of cancer-cell-derived extracellular shed vesicles. We measured cargo carried by the microvesicle subpopulation processed through this microfluidic platform. Such analyses could enable future investigations to more accurately and reliably determine provenance, functional activity, and mechanisms of transformation in cancer.

Microvesicles released from tumor cells disrupt epithelial cell morphology and contractility

“…Interestingly, cells have the ability to release extracellular vesicles that appear to play an important role in the transfer of signaling proteins and cargo to other cells (Al-Nedawi et al, 2009; Al-Nedawi et al, 2008). There are two known types of extracellular vesicles, namely the smaller exosomes (<100nm) and larger microvesicles (MVs) (Santana et al, 2014). While exosomes are produced by a wide variety of cell types, production of significant quantities of MVs appears to be limited to tumor cells (Santana et al, 2014).…”

“…There are two known types of extracellular vesicles, namely the smaller exosomes (<100nm) and larger microvesicles (MVs) (Santana et al, 2014). While exosomes are produced by a wide variety of cell types, production of significant quantities of MVs appears to be limited to tumor cells (Santana et al, 2014). MVs shed by tumor cells can contain ECM components, growth factor receptors, cytoskeletal proteins and signaling molecules as cargo (Antonyak et al, 2011; Grange et al, 2011).…”

Emerging picture of the distinct traits and functions of microvesicles and exosomes

“…Although this size range is larger than that typically reported for exosomes (i.e., ∼30-80 nm in diameter), but smaller than that of most MVs (which are ∼200-1,500 nm in diameter), the finding that the sizes of the different forms of EVs are comparable is particularly noteworthy, given that size has been one of the most common and widely accepted characteristics used to distinguish exosomes from MVs. In fact, this concept has been so entrenched in the EV field that approaches to separate exosomes and MVs based on their size is an extremely active area of research (15,16). Thus, it will be important to see if other cell lines generate exosomes and MVs of overlapping sizes or whether HEK293FT cells are unique in this regard.…”

Decorrelation correction for nanoparticle tracking analysis of dilute polydisperse suspensions in bulk flow

“…For example, the study of small molecule inhibitors that suppress microvesicle production are greatly benefited by accurate size measurements of dilute, polydisperse suspensions [33]. Similarly, microdevices using size-based separation methods to nanoparticle populations for downstream assaying must use accurate cutoff diameters in the design process [49][50][51]. Malvern Inc. recently developed the ability to perform simultaneous nanoparticle size, zeta potential and scattering intensity characterization [52].…”