UNMC researcher helps create new tool for CRISPR toolbox

UNMC researcher Channabasavaiah Gurumurthy, PhD, MVSC (DVM), contributing to a team from Tokai University, Japan, has co-authored a recent publication in the journal Genome Biology that heralds an exciting new advance in the use of CRISPR technology.

The discovery could become a key contribution toward the use of gene editing in many research fields, leading to developing human therapeutics.

CRISPR, which gave scientists the ability to “cut” individual genes from a genome, revolutionized the research world and won a Nobel Prize.

Then, Easi (Efficient additions with ssDNA inserts)-CRISPR, for which Dr. Gurumurthy was a primary investigator, made the process easy. And then easier.

“CRISPR is a scissors that cuts genes,” Dr. Gurumurthy said. “So in the original CRISPR, it is search, find and cut. But in our case Easi-CRISPR is search, find, cut and insert.”

This allows researchers to generate custom genetically engineered (knock-in) animal models at previously unheard-of rates and significantly lower cost.

When Easi-CRISPR came out in 2017, Paula Turpen, PhD, now-retired director of research resources at UNMC, likened the jump in tech to going from leafing through pages to make corrections with “Wite-Out” on a manual typewriter to simply using Microsoft Word’s “find and replace” feature.

It was an incredible advance for basic research.

But living cells that help with the “insert” step are unpredictable. A cut here could cause another change there. And blanket “find and replace” commands sometimes lead to what Dr. Gurumurthy calls “off-target editing events.” Essentially, that is the unintended consequence of a piece of DNA inserting itself not just where the researcher sent it, but also somewhere else.

“Even though (Easi-CRISPR) is highly accurate, there is a slight chance that there can be missed perfections,” Dr. Gurumurthy said.

Now, “those missed perfections can be identified using the CRISPR-KRISPR method,” Dr. Gurumurthy said.

CRISPR-KRISPR: CRISPR-Knock-ins and Random Inserts Searching PRotocol. As the full name indicates, CRISPR-KRISPR searches for those random inserts, allowing scientists to double-check their work.

Currently, CRISPR-edited genomes that carry this risk are largely used in human trials in cases in which patients are terminally ill and there are few other treatment options.

But CRISPR-KRISPR scans for “missed perfections” to remove them before the edited genome is inserted. And that could open a world of possibilities for human therapeutics.

Dr. Gurumurthy is encouraged that the journal article, already accessed over 2,500 times in just a few weeks, and his explanatory Twitter thread on CRISPR-KRISPR have built buzz in the research world.

“Easi-CRISPR caught on within a couple months, and we are thinking it will be similar to that,” he said.