As CRISPR continues to evolve into the laboratory version of a Swiss Army Knife, it’s not surprising that another innovative research team have used the approach in a slick way; in this case to engineer of oncogenic chromosomal rearrangements.
Chromosomal rearrangements, gene fusions, deletions and inversions are classical hallmarks of cancer. These re-arrangements lead to changes in sensitivity towards drugs making them resistant or sensitive. Ectopic expression of fusion oncoproteins using transgenes is widely used. However these fusion oncoproteins are invariably expressed and at non-physiologic levels, thereby making the process and examination laborious and complicated.
Novel genome editing technologies step in to address these key criteria by producing precise genomic changes including oncogenic chromosomal rearrangements. Researchers from Memorial Sloan Kettering Cancer centre, Maddaldo and others use CRISPR/ Cas9 genome editing technology in vivo for the first time to engineer chromosomal rearrangements. The researchers designed a dual small guided RNA (sgRNA)/Cas9 cassette into an adenoviral shuttle vector which was then injected into the lung epithelium of adult mice. They contrived to generate a mouse model of Eml4-Alk driven lung cancer mimicking a subset non-small cell lung cancer (NSCLCs) in humans.
Using this genome editing approach the researchers highlight that
- CRISPR system can faithfully recapitulate oncogenic gene fusions, better than the germ line engineering via transgenesis or homologous recombination strategies.
- This system can be adapted to engineer large deletions, inversions and chromosomal translocations in eukaryotic cells.
- Using adenovirus for delivery the researcher ensured that the vector genome does not integrate with the host genome thereby reducing complexities.
- Since this approach faithfully recapitulated the molecular and biological properties of human ALK+ NSCLCs, the model provides a unique opportunity to dissect the molecular mechanisms that drives the tumour formation, to test the efficacy of targeted therapies and to investigate mechanisms of drug resistance in vivo.
Head on over to Nature, October 2014 and learn more about this latest CRISPR utility.