MINNEAPOLIS, March 30, 2020 /PRNewswire/ -- Bio-Techne
Corporation (NASDAQ:TECH) today announced researchers from its
Munich-based laboratory, Exosome
Diagnostics, in a paper published in the scientific Journal of
Extracellular Vesicles (JEV) (link), showed that tumor- derived RNA
was not detected in thrombocytes in samples where the tumor RNA was
readily detected in exosomes. This finding holds significant
implications for developers of liquid biopsies for cancer.
The results from this study raise doubts about the commonly held
belief that platelets include abundant tumor RNA that can be used
for tumor specific RNA analysis, a process named Tumor Educated
Platelets (TEPs). This has important implications for the use of
platelets as a potential technology platform for liquid biopsies
that aim to detect or monitor molecules of tumor origin in a
biofluid sample. Such platelet-based strategies have recently been
proposed by other companies and academic labs in the field.
"We wanted to find the most sensitive way to detect tumor
specific RNA and were looking for ways to increase our clinical
sensitivity. In light of previous publications on TEPs, we isolated
RNA from exosomes as well as platelets from the same samples in
hopes of improving the detection. We learned that combining the
sample gave more RNA, but actually decreased the sensitivity for
mutation assays," said Dr. Johan
Skog, Chief Scientific Officer at Exosome Diagnostics, a
Bio-Techne brand. "This finding led to this study quantifying the
amount of tumor specific RNA in the platelets, if any, compared to
other normal RNA". The researchers in this study applied a
sensitive mutation assay but were unable to detect any tumor RNA in
the platelet fraction, even when it was readily detected in the
exosome fraction from the same sample. This casts doubt that
keeping the platelet fraction adds value when looking at single
nucleotide mutations on RNA. "There is plenty of RNA in platelets,"
continued Dr. Skog, "far more than in exosomes… but it does not
come from the tumor."
In this carefully executed study, involving prospective
collection of blood samples from patients with melanoma, whose
tumor tissue had been confirmed to carry the BRAF V600E mutation,
the researchers directly compared the RNA mutation signals
detectable in exosomes to platelets isolated from the same blood
sample. Using an exceptionally sensitive assay for detection of the
BRAF V600E RNA, the mutation could be detected in 10 out of 12
exosome fractions, but not in a single platelet preparation. The
researchers conclude in the article, that based on their findings,
the differences in platelet RNA expression, previously published
between cancer patients and normal healthy controls are unlikely to
be of tumor origin. The researchers further conclude that as a
consequence of their findings, it is recommended for most cases to
remove platelets from a blood specimen for optimal detection of
tumor-derived RNA in extracellular vesicles.
About Bio-Techne Corporation (NASDAQ: TECH)
Contact: David Clair, Senior
Director, Business Development
david.clair@bio-techne.com
612-656-4416
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SOURCE Bio-Techne Corporation