The Human Embryonic Kidney 293T (HEK293T) cell line is a research staple, but for Dr. Marta Popović at the Ruđer Bošković Institute, it represented a critical bottleneck.
Her lab was launching a strategic new investigation into DNA repair, and the entire project hinged on creating a precise foundational mutant model. This cell line wasn't just another experiment; it was the essential baseline against which all future data would be measured. Without it, the new research direction could not begin.
Dr. Marta Popović is a Group Leader at the Ruđer Bošković Institute in Zagreb, Croatia, where she established her lab in 2018. Her research focuses on the mechanisms of DNA-protein crosslink (DPC) repair, investigating how these toxic lesions contribute to cancer, aging, and neurodegeneration. Combining structural biology, cell culture, and in vivo zebrafish models, her work aims to uncover the molecular drivers of genomic instability. Her lab is supported by the Croatian Science Foundation and European Structural and Investment Funds. Popovic Lab website
Why was this specific mutation so critical?
Dr. Popović’s lab investigates DNA-protein crosslinks (DPCs), toxic lesions where proteins become irreversibly trapped on DNA. One of the projects in the lab focuses on SPRTN, a protease that acts as a molecular scalpel to cleave these proteins off the DNA.
To establish this new research direction, Dr. Popović needed to engineer a "hypomorphic" mutant, specifically, a Tyrosine 117 to Cysteine (Y117C) point mutation.
This was not a simple experiment; it was the cornerstone of the entire project. This specific mutation would impair the enzyme's function just enough to study the defects without killing the cell. Without this validated model, the research could not proceed.
What drove the decision to seek external help?
The primary driver was a gap in expertise and time. Dr. Popović’s lab is known for its work with gene editing in zebrafish models, but this new direction required moving into complex knock-in gene editing in human cell culture (HEK293T).
While the scientific vision was clear, the technical infrastructure for knock-in gene editing was missing.
"We work primarily with zebrafish. To establish this method for human cells in-house, it would take six months to a year," Dr. Popović explains. "If you don’t know the method and are still validating, it can take even longer. This is a luxury I didn’t have."
Confronted with a year-long delay to set up a workflow for a single cell line, Dr. Popović faced a hard reality: "Without this [service], I would actually not even pursue this project."
What happened when the target gene had six alleles instead of two?
Once Cytosurge’s CellEDIT team took on the project, an unexpected challenge arose. While standard human cells are diploid (two copies of every gene), the HEK293T are known to have a complex hypotriploid karyotype with variable numbers of individual chromosomes. For the SPRTN gene, the cells carried six alleles instead of the expected two to three alleles.
"I was thinking, 'Oh no, this will be impossible,'" Dr. Popović recalls. "But they managed somehow."
Despite the complexity of targeting six alleles simultaneously, the CellEDIT team delivered. Clone #1 showed that the desired mutation was successfully edited into 5 of the ~6 alleles (82.3% efficiency).
A Transparent Scientific Partnership
What stood out to Dr. Popović was not just the result, but the process, “...the science behind it," she notes. This technical expertise was communicated with a level of clarity that made her feel like a true partner in the process, rather than just a customer. "When they presented how they will do it, I felt involved... Communication was really perfect."
This scientific depth and transparency gave her the confidence to become a vocal advocate for the service: "I would absolutely recommend CellEDIT. Highly recommended."
How is this success fueling future research?
The successful delivery of this cell line did more than just save time; it unlocked the project. The team has validated the cells biochemically, confirming they work exactly as intended. They now have their essential starting point.
With this foundational tool in hand, the lab is ramping up its research. Dr. Popović has already commissioned two new fundamental Knock-In (KI) projects with Cytosurge. These new modifications will build upon the initial success, allowing the lab to investigate other proteins of interest and expand their new human cell platform.
With the "impossible" cell line now in hand, the Popović Lab has successfully launched their new research platform. They have already moved forward with two additional projects, proving that even the most complex genetic hurdles can be overcome with the right partner.
Laying the Foundation: How a Complex Edit Unlocked a New Research Direction
How CellEDIT supported Dr. Marta Popović to establish a new research direction at the Ruđer Bošković Institute