Researchers from University of California, Los Angeles are reporting the development of a new detector that captures circulating tumor cells (CTCs) in whole blood and extracts them individually for further analysis. The microfluidic device features tiny rods that are coated with antibodies of proteins found on CTC’s. After blood passes through, a laser is used to pull CTC’s out of the device for genetic identification of the mutation.
The device is an advancement over an earlier prototype by introducing a new transparent substrate that more efficiently captures CTC’s allowing for blood to be screened quickly from a reasonable sample amount.
From the announcement:
Using the new assay on patients’ blood containing circulating melanoma cells (CMCs), Tseng’s team was able to isolate and preserve single CMCs. Melanoma is a deadly type of skin cancer that is prone to spreading quickly throughout the body. The ability to capture and preserve single CMCs allows doctors to analyze melanoma cells’ DNA structure, determine the genetic characteristics of the patient’s cancer and confirm that the circulating cells remain genetically similar to the tumor they came from.
The preservation of single captured CMCs in this proof-of-concept study also allowed researchers to conduct an analysis — called single-cell genotyping — to find within the cell a specific target (BRAF V600E) for a drug called vemurafenib. BRAF V600E is a mutation in the BRAF protein that appears in approximately 60 percent of melanoma cases. Drugs that inhibit BRAF are able to slow and often reverse the growth of melanoma tumors.
“With this technology, we are getting closer to the goal of a widely clinically applicable liquid biopsy, where we can sample cancer cells by a simple blood draw and understand the genes that allow them to grow,” said Dr. Antoni Ribas, a professor of medicine in the division of hematology–oncology, a Jonsson Cancer Center member and one of Tseng’s key collaborators. “With the NanoVelcro chips, we will be able to better personalize treatments to patients by giving the right treatment to stop what makes that particular cancer grow.”