Could testing peptides in urine help diagnose ovarian cancer earlier and save lives? A new study sheds light.
Key Takeaways
Researchers are developing a new ovarian cancer detection technique using nanopore technology. Ovarian cancer only has a 35% survival rate, making early diagnosis critical.
The technique would allow ovarian cancer to be detected through a urine test. The test would enable nanopore sensing to detect cancer-indicating peptides.
A new ovarian cancer detection technique that utilizes nanopore sensing could help improve early diagnosis, according to a press release issued by the Biophysical Society.[]
Ovarian cancer has a 35% survival rate. In patients whose cancer has spread beyond the pelvis, the long-term survival rate drops to 20% or less. Only 20% of ovarian cancers are caught during stages I or II, a critical window for successful treatment. Symptoms can be vague —including bloating, pelvic or abdominal pain, feeling full quickly, or urination urgency or frequency—and hard to catch early on. [][]
Joseph Reiner, PhD, and colleagues at Virginia Commonwealth University want to improve those early diagnosis and survival rates. They found that nanopore sensing technology—designed to detect peptides—could pave the way to a urine-based test for ovarian cancer.
Peptides are found in the urine of patients with ovarian cancer. “[P]eptides play a significant role in biosignaling, both as primary signaling molecules and as effectors after the signal is received. This makes peptides an important biomarker for various diseases, which motivates the development of peptide biosensing,” the team’s research, published in ACS Sensors, explains. Detecting these molecules can be costly and challenging, however.[]
This is where nanopore sensing comes into play: “The basic idea of nanopore sensing involves passing molecules through a tiny pore, or nanopore, and measuring the changes in electrical current or other properties as the molecules move through,” the press release explains. Nanopore sensing may allow clinicians to detect cancer-indicating peptides. In this case, peptides attach to the gold particle, showing a unique current signature.[]
Reiner tells MDLinx that he and his team previously reported on the selective detection of cysteine-containing peptides with a gold-modified nanopore approach, published in ACS Nano. Cysteine is known as a key player in cancer.[][]
“Cysteine is one of the lowest abundance residues in the peptidome, and so it could serve as an ideal target for analyzing clinical samples because our system would be ‘blind’ to many—but not all—of the peptides in a sample, which would simplify analysis,” Reiner explains.
“Working from these results, we decided to demonstrate our approach with ovarian cancer marker peptides in urine. This was motivated by the fact that ovarian cancer is one of the deadliest female reproductive cancers, in part because of the difficulties associated with early detection—and urine is a relatively easy bodily fluid to obtain,” he adds.
The research team’s work made it possible to detect a number of these cancer marker peptides through assessing whether they’ve spiked in urine at high concentrations.
The new method “identified and analyzed 13 peptides, including those derived from LRG‐1, a biomarker found in the urine of ovarian cancer patients,” the press release states.
Nanopore sensing isn’t new, Reiner tells MDLinx. “Nanopore sensing has been an active area of research for the [about the past] 25 years,” he says, noting research efforts in nanopore sensing for DNA sequencing. “This motivates further developments for detecting other types of analyte. Our team has focused on peptide detection, and our approach utilizes gold metallic clusters to improve the detection of peptides with the nanopore sensors.”
The end goal? Reiner’s team hopes to detect ovarian cancer earlier by developing a test that combines with CA‐125 blood tests, transvaginal ultrasound, and analysis of family history.[]
“Our research team is currently focusing on optimizing sample preparation methods. If this approach is going to have real-world applications, it will require the ability to prepare the gold nanoparticles with target peptides outside the nanopore environment, as opposed to delivering the peptides directly onto the nanopore, as was done in this study,” Reiner and research author Gregory Caputo, PhD, of the Department of Chemistry & Biochemistry at Rowan University in Glassboro, NJ, explains to MDLinx.
They plan to focus on refining the preparation as well as demonstrating detection at lower peptide levels. “Our current limit of detection is in the low micromolar range. We will need to get into the nanomolar range in order for this to be workable,” they say. “It's worth noting that our results were from a single nanopore, but we envision this approach scaling up to hundreds or thousands of pores, and we believe this could help reduce the limit of detection for the technique.”
Their hope is that this method will eventually enable clinicians to test for different kinds of cancers and diseases. “It may also be possible to go even further and explore the impact of our approach on the detection of other types of medical conditions (eg, cardiovascular diseases, metabolic conditions, and various infections),” they say.