Assay Depot invited Dr. Heather Buschman to discuss protein microarrays and the future of biomarker discovery. Dr. Buschman earned her Ph.D. in Molecular Pathology from UC San Diego and is a strong advocate of Open Science.
Imagine this: in a routine blood test, a doctor detects a biomarker that indicates a patient has early-stage pancreatic cancer. A therapeutic is prescribed that specifically targets the molecular underpinnings of the disease. Throughout the treatment course, the doctor monitors the biomarker levels to assess efficacy and adjusts the treatment accordingly. Before long, and without experiencing much in the way of side effects, the patient is in remission.
This is the promise biomarkers hold for clinical diagnostics, prognostics, and personalized medicine—tantalizing especially for conditions that usually aren’t detected early enough for effective treatment, such as pancreatic cancer.
Yet in reality, while some biomarker success has been achieved in other fields, there are very few cancer biomarkers. What’s holding back biomarker discovery?
In a recent Drug Discovery World article, By Dr. Nikolai Schwabe and Katherine Catchpole discuss some of the challenges to finding such biomarkers and argue that protein microarrays are helping to speed up the hunt1.
Challenges to biomarker discovery
One problem facing biomarker hunters is human diversity—a molecule highly elevated in one person’s pancreatic tumor might not appear at all in another’s. And if a biomarker’s detectability or predictive power isn’t reliable for a majority of people, it isn’t all that useful.
If a single, one-size-fits-all biomarker is too much to ask for, researchers need flexible screening technology that can detect multiple molecules and their relative expression levels. Ideally, they could also track the changes throughout disease progression.
Though valuable for many applications, traditional immunoassays, such as ELISAs, aren’t quite up for the task of finding biomarkers, Schwabe and Catchpole say. The costs and labor required to study multiple protein-protein interactions on a large variety of samples are usually prohibitive.
The value of protein microarrays
To pan for biomarker gold in human proteomes, researchers need highly sensitive, higher-throughput assays that can detect multiple proteins using less reagent and sample.
According to the article, transferring assays to sensitive, scaleable platforms such as protein arrays has the potential to improve disease monitoring and ultimately patient care. Protein microarrays use smaller reagent and sample volumes than standard immunoassays. What’s more, protein microarrays can simultaneously detect many thousands of interactions.
While establishing routine array work in-house is typically too expensive, outsourcing to array facilities is an efficient approach. Assay Depot provides a listing of companies with custom array capabilities.
Are you using protein microarrays to find new biomarkers? Share your experiences in the comments below!
1. Schwabe, N. and Catchpole, K. Biomarker discovery – the need for new generation peptideprotein microarrays. Drug Discovery World. Fall 2013.