Genetic Engineering Publications - GEG Tech top picks

 There is a pervasive sense of hopelessness in these non-small cell lung cancer (NSCLC) patients due to the current lack of treatment options, treatment failure due to drug resistance, and poor survival rates. Chemotherapy resistance is a major challenge in the treatment of NSCLC. Nuclear factor erythroid 2-related factor 2 (NRF2) may be at the root of this resistance. It is a master regulator of hundreds of other genes involved in numerous cytoprotective and metabolic pathways. Under normal physiological conditions, NRF2 protects cells from oxidative stress, toxic attacks and chemotherapy, keeping cells in homeostasis. Cancer cells hijack the NRF2 pathway and disrupt this function. When NRF2 becomes over-expressed and accumulates in the cell, the cell is able to fight off these toxic insults. This is really where the cancer becomes chemoresistant. Advanced patients have much higher levels of NRF2. However, in a paper published last month in Gene Therapy, a research team describes a new anti-cancer strategy that uses CRISPR-Cas9 to eliminate NRF2. The key finding of the study is that CRISPR-based disruption of NRF2 can lead to exon skipping. A dual sgRNA approach to target exon 4 resulted in the deletion of a 103-base-pair fragment, including exonic splice enhancer sequences. 

In this study, the scientists deployed Cpf1 to correct DMD mutations in patient-derived induced pluripotent stem cells (iPSCs) and mdx mice, an animal model of DMD. Cpf1-mediated genomic editing of human iPSCs, either by skipping of an out-of-frame DMD exon or by correcting a nonsense mutation, restored dystrophin expression after differentiation to cardiomyocytes and enhanced contractile function. Similarly, pathophysiological hallmarks of muscular dystrophy were corrected in mdx mice following Cpf1-mediated germline editing. These findings are the first to show the efficiency of Cpf1-mediated correction of genetic mutations in human cells and an animal disease model and represent a significant step toward therapeutic translation of gene editing for correction of DMD.

To restore dystrophin production and myocyte function in patients with Duchenne muscular dystrophy (DMD), several CRISPR strategies have been tried to correct some of the hundreds of thousands of documented mutations in the dystrophin gene (DMD). Among these strategies, researchers at the University of Texas Southwestern Medical Center in Dallas, Texas, have developed a novel CRISPR gene editing strategy for DMD therapy. This was tested in animal and human DMD models where the researchers deleted exon 51 in the DMD gene which disrupted the dystrophin reading frame and generated a premature stop codon in exon 52. The researchers were able to restore the reading frame with both basic and main editing by introducing exon skipping and reframing, respectively, through their "single-swap" ABE strategy, i.e., through editing a single letter in the splice acceptor or donor site can cause exon skipping. The researchers targeted the splice acceptor or splice donor site of exon 50 or 52 and the single nucleotide modification restored dystrophin expression in human cardiomyocytes and contractile function was normalized using master editing. However, one challenge is the high doses required to deliver expression throughout the body.