My name is Louise Laurent, and I’m at the University of California San Diego. The goal of our project for ERCC Stage 2 is to develop a workflow that is easy and generalizable for separating different carrier subtypes from biofluids. I run a translational lab in which our major goals involve bringing new diagnostics to pregnancy diseases, and we are overall working on identifying biomarkers of poor pregnancy outcomes like preeclampsia, or placenta accreta, or preterm birth. Many of these biomarkers that we’re working on are extracellular RNAs, and so at this point what we want to do is to look at the biological function of our candidates and also understand better what kind of carrier subclasses they are being carried in in maternal blood and other biofluids. In my clinical fellowship, I did work on microRNA regulation of pluripotency, so I’d been interested in microRNAs for a long time, and separately in my grad school career, I was involved in studying retroviruses. Close to the time that the
ERCC Stage 1 was being launched, a lot of work in the OB/GYN field was focused on using circulating DNAs for diagnostics for aneuploidy, and so when the opportunity came up to study extracellular RNAs, it was a confluence of all of these different fields and was perfect for our group to start
looking for exRNA biomarkers in the context of pregnancy. As a high-risk obstetrician, I came into this field knowing about lots of multi-analyte assays. So in pregnancy, historically, to identify high-risk pregnancies, pregnancies at high risk for fetal anomaly, or fetal aneuploidy, there had been multi-analyte blood tests, and these included things like proteins and hormones. Along with these, around the time I was starting my training in OB, ultrasound biomarkers were being incorporated as well. So in my background, I was very familiar with using multiple biomarkers of different types. And so at this point, while we haven’t integrated our exRNA candidate biomarkers with other types of molecular and imaging biomarkers, that definitely is on the horizon for our group to explore. In terms of building multi-analyte tools more into the repertoire of things for pregnancy disorders, I think intellectually it will be easy for the clinical field to absorb that concept. They’re already very familiar with it. Logistically, just from history, it has been a barrier towards providing equal access to patients to a lot of these multi-analyte types of markers, especially ones that involve ultrasound as well as a blood test, or blood tests that are taken
at multiple time points. So what our hope is is to, for example, incorporate exRNA biomarkers with protein biomarkers
that are in the same biofluid so that they can be analyzed at the same time more or less in parallel. So in another project that we have that is funded by NICHD we are trying to develop a point of care, miniaturized platform that will both quantify microRNAs and proteins in a biofluid. I think ERCC2, and in particular the carrier subclass group of grant awards, is important because what we’ve learned a lot in ERCC1 is that there is quite a bit
of inter-individual variability in exRNA measurements. From the work of
Aleks Milosavljevic in the group and others, what we have realized is that some of this variability at least can be accounted for by variations in the abundance of different carrier subclasses in a biofluid taken from different individuals, or even from the same individual across time. If we better understand what the component carrier subclasses are in any given sample, we have the possibility of adjusting that and then canceling out some of the noise, and therefore improving the reproducibility of data. It’s a little bit difficult to separate what we learned about exRNA carriers in Stage 1 from where the field was going concurrently at the same time in other groups, but I think during that time, with contribution from groups in ERCC1, we realized that –– or we established better –– that the different carriers had distinct sets of exRNA cargo. We also learned that at least some of these cargo are common between different biofluids. I think we suspect that there are also differences in what a given carrier carries in different biofluids, and I think this is something that we need to explore more in Stage 2 of ERCC. I definitely think that there are things that the investigators who are new to ERCC2 can draw from our experiences from those of us who were in ERCC1. I think something that we learned as a group was how to collaborate in this consortium framework. I think what at least my group learned is that the more we contributed, the more we actually got out of the consortium, and that participation really did drive progress on our own projects in parallel with the collaborative projects that we were executing along with other members of the consortium. We interacted not only on a very technical level –– which we did –– but we also learned a lot about other biological systems and came up with new ideas from different fields that really helped us in many ways see our own system in a new light, including both the strengths and the weaknesses of the system and how to adapt the system to answer questions about exRNAs better.