With more study, the technique could lead to new precision medicine pathology diagnostics and clinical laboratory tests
Researchers at Yale University have devised a new pathology tool that utilizes barcode technology to map the spatial relationships of ribonucleic acid (RNA) and proteins. This will be of interest to histopathologists who are responsible for examining clinical laboratory tissue samples and helping physicians diagnose disease.
Called Patho-DBiT (pathology-compatible deterministic barcoding in tissue), the Yale scientists claim their new tool can completely examine RNA and possibly aid in the diagnoses and treatment of cancer.
The technology, according to a Yale news release, “is unique in that it has microfluidic devices that deliver barcodes into the tissue from two directions creating a unique 2D ‘mosaic’ of pixels, providing spatial information that could be used to inform the creation of patient-specific targeted therapies.”
“It’s the first time we can directly ‘see’ all kinds of RNA species, where they are and what they do, in clinical tissue samples,” said Rong Fan, PhD, Harold Hodgkinson professor of biomedical engineering and pathology at Yale and senior author of the study.
The Yale scientists published their findings in the journal Cell titled, “Spatially Exploring RNA Biology in Archival Formalin-fixed Paraffin-embedded Tissues.”
“I think it’s going to completely transform how we study the biology of humans in the future,” said Rong Fan, PhD (above), Harold Hodgkinson professor of biomedical engineering and pathology at Yale and senior author of the study, in a Yale news release. The discovery could lead to new clinical laboratory screening tests and diagnostics for cancer. (Photo copyright: Yale University.)
More Precise Cancer Diagnoses
“As a physician who has been diagnosing cancer, I was surprised by how much more I can see using this pathology tool,” said Mina Xu, MD, professor of pathology at Yale School of Medicine and one of the authors of the study. “I think this deep molecular dive is going to advance our understanding of tumor biology exponentially. I really look forward to delivering more precise and actionable diagnoses.”
According to the Yale study, the Patho-DBiT tool has many beneficial capabilities. They include:
- Enabling spatial whole transcriptome sequencing in clinical formalin-fixed and paraffin-embedded (FFPE) tissues.
- Allowing spatial co-profiling of gene expression, splicing, and non-coding RNAs.
- Offering genome-wide detection of spatial single nucleotide variant (SNV) distribution to distinguish malignant subclones.
- Dissecting spatiotemporal dynamics of lymphomagenesis at the single-cell level.
FFPE tissue involves the fixation of tissues by utilizing formalin and embedding tissue samples in paraffin wax. This method allows for the long-term preservation of tissue morphology and cellular details and is commonly used in histopathology.
In the past, the RNA within FFPE samples have been susceptible to fragmentation during the paraffin-embedding process and degradation issues. These samples may also experience chemical modifications which could result in resistance to the enzymatic reactions necessary for proper sequencing.
“There are millions of these tissues that have been archived for so many years, but up until now, we didn’t have effective tools to investigate them at spatial level,” said the study’s first author Zhiliang Bai, PhD, a postdoctoral associate in Rong Fan’s lab at Yale. “RNA molecules in these tissues we’re looking at are highly fragmented and traditional methods can’t capture all the important information about them. It’s why we’re very excited about Patho-DBiT.”
Targeted Therapies
The team is encouraged by their research and the future potential for Patho-DBiT. They believe the technology may be useful in creating targeted therapies and helping understand the metamorphosis of low-grade tumors to more aggressive ones. They conceive their tool may assist in developing ways to prevent the progression of cancers.
“It is very exciting that Patho-DBiT-seq is also capable of generating spatial maps of noncoding RNA expression,” said Jun Lu, PhD, associate professor of genetics at Yale and another of the study’s authors. “Noncoding RNAs are often in regions of our genomes that were previously thought of as junk DNA, but now they are recognized as treasured players in biology and diseases such as cancer.”
The research included faculty members from several departments at Yale and was supported by the National Institutes of Health (NIH). The technology is now licensed to biotechnology company AtlasXomics of New Haven, Ct., for further development.
More research and studies are needed to validate the findings of this research, but the Patho-DBiT tool could prove to be useful for the preservation of tissue samples and become essential in the diagnoses and treatment of cancers.
—JP Schlingman
