Circulating tumor cells (CTCs) are aggressively being investigated by researchers worldwide to be able to detect a variety of cancers early in their development. The challenge is immense because CTCs are extremely rare, so a practical detector has to be extremely sensitive. Moreover, CTCs are poor biomarkers for brain cancers because they don’t pass through the blood-brain barrier. Microvesicles are bits of cells that exist in blood that were shed somewhere in the body that scientists are only now starting to notice as potential biomarkers for cancer.
To that end, researchers at Massachusetts General Hospital have developed a microfluidic chip that’s used along with handheld nuclear magnetic resonance (NMR) device to detect microvesicles that came off cancer cells.
From the study abstract in Nature Medicine:
Glioblastomas shed large quantities of small, membrane-bound microvesicles into the circulation. Although these hold promise as potential biomarkers of therapeutic response, their identification and quantification remain challenging. Here, we describe a highly sensitive and rapid analytical technique for profiling circulating microvesicles directly from blood samples of patients with glioblastoma. Microvesicles, introduced onto a dedicated microfluidic chip, are labeled with target-specific magnetic nanoparticles and detected by a miniaturized nuclear magnetic resonance system. Compared with current methods, this integrated system has a much higher detection sensitivity and can differentiate glioblastoma multiforme (GBM) microvesicles from nontumor host cell–derived microvesicles. We also show that circulating GBM microvesicles can be used to analyze primary tumor mutations and as a predictive metric of treatment-induced changes. This platform could provide both an early indicator of drug efficacy and a potential molecular stratifier for human clinical trials.
Study in Nature Medicine: Protein typing of circulating microvesicles allows real-time monitoring of glioblastoma therapy