CRISPR genes cuts can offer a new way to graph human genomes, In searching for new ways to sequence the human genome and read critical changes in DNA.
Researchers have succeeded in using the CRISPR gene cutting tool to make DNA cuts around long tumor genes that can be used for gathering sequence information.
Report evidence-based experiments with the genome of human cancer cells from cells and tissues.
The researchers say that pairing CRISPR with a device that sequences DNA components from human cancerous tissue is a technique that could one day enable rapid, relatively inexpensive tumor sequencing of patient tumors, optimized selection, and targeted treatment use. very specific and personal genetic changes. CRISPR genes cuts can offer a new way to graph human genomes.
All cancer genomes do not have to be sequenced to tumor sequences in cancer patients, the researchers said.
Conventional genome sequencing requires scientists to make multiple copies of questionable DNA, divide DNA at random into segments, and hand over damaged segments through a computer machine that reads a series of compounds called nucleic acids, consisting of four “bases” that make up The DNA forms are labeled A, C, G and T. Then the scientists look for overlapping areas of overlapping segments and put them together as tiles to form a long section of DNA that forms genes.
In their experiments, Timp and M.D./Ph.D. Timothy Gilpatrick students can skip copies of DNA from conventional CRISPR sequencing to produce target DNA segments isolated from tissue from tissue extracted from a patient’s breast cancer tumor. CRISPR genes cuts can offer a new way to graph human genomes.
The researchers then attached the so-called “sequential adapters” to the ends of the DNA cut by CRISPR.
The adapter acts as a kind of handle that directs DNA into tiny holes or “nanopores” that read the sequence.
By passing DNA through narrow holes, sequencers can make DNA letters based on the unique electrical currents that occur when each chemical letter code glides through a hole.
Among the 10 breast cancer genes the team focuses on, Johns Hopkins scientists can use nanopore sequencing of breast cancer cell lines and tissue samples to detect a type of DNA change called methylation, where chemicals called methyl groups are added to DNA around genes which influences how genes are read. CRISPR genes cuts can offer a new way to graph human genomes.
The researchers found sites with reduced DNA methylation in a gene called keratin 19 (KRT19), which is important for cell structure and skeleton. Previous studies have shown that decreased DNA methylation in KRT19 is associated with tumor spread.
In the breast cancer cell line examined, Johns Hopkins’s team produced an average of 400 “readings” per base, “reading depth” to be a hundred times better than with some conventional sorting devices.
The team was able to produce an average of 100 measurements per region from tissue samples of human breast cancer tumors taken during biopsy.
This is clearly less than what we can do with cell lines, but we must be more careful with DNA from human tissue samples, because it is frozen and thawed several times.
In addition to DNA methylation studies and small mutations, Timp and Gilpatrick sequence genes that are often associated with breast cancer: BRCA1, which spans an area in the genome whose length is more than 80,000 bases.
This gene is very long and we can collect sequences of readings that cross this large and complex region, the researchers said.
Because we can use this technique to sequence very long genes, we might be able to detect large blocks of DNA that we won’t find with more conventional sorting devices.
In addition to its potential to advance patient management, the combination of CRISPR technology and nanopore sequencing, according to Timp, is so deep that scientists can find changes in genes related to new diseases that are specific to alleles (inherited from parents) and not one other person. CRISPR genes cuts can offer a new way to graph human genomes.
Timp and Gilpatrick plan to further refine the CRISPR / nanopore sequencing technique and to test their abilities in other types of tumors.