Cancer cells. Credit: Dr. Cecil Fox National Cancer InstituteOne potential treatment for mast cell carcinomas is to "mutate" messenger RNA (mRNA), which prevents it from delivering instructions for the production of the gene responsible cell proliferation. Frameshifting is a method that alters the pre-mRNA to make mature mRNA less active and alter any proteins produced by its instructions inert. Frameshifting directed at c-KIT gene in a mouse model reduced the size of mast cells and prevented their infiltration into other parts.Mast cells regulate immune responses. Too many mast cells can lead to a variety of diseases. The most severe are mast cell leukemia, and mast cell sarcoma. The c-KIT gene produces a protein called KIT that is linked to mast cell survival and proliferation. C-KIT mutations may increase mast cell proliferation in multiple organs and lead to mast cell carcinomas."Current treatments to mast cell cancers target signaling through the receptor encoded in the cKIT gene. And the efficacy and effectiveness of current therapies may be negatively affected if c-KIT mutants associated with disease development are present," said Glenn Cruse assistant professor of immunology at North Carolina State University. He is also the corresponding author of this research. We are targeting the gene, not just mutations. We can target the disease if we target the gene driving progression.Cruse used a technique called exon skipping with a group of researchers from NC State (NIH), to create the frameshift mutation.The pre-mRNA is first spliced. It is composed of both non-coding and coding regions, called exons or introns. Once the mature mRNA has been spliced, it delivers the instructions for producing the gene or protein. A stop codon is a short sequence within the mRNA that stops the production of faulty proteins if something goes wrong.Researchers used this technique to their advantage by binding an RNA molecule called an "oligonucleotide" to exon 4 in the c-KIT mRNA. This tricked the splicing protein into believing that the exon was an exon and removed it. The skipped or missing exon causes a frameshift to the reading frame of mRNA. This makes it recognizeable as a mutant and can be removed.Cruse states, "We are changing the message that makes proteinflipping an ‘on’ switch to a 'off' switch." "If you induce mRNA to make a protein that is severely truncated or mutated, your cells will detect that and destroy the message so that no protein is produced."Researchers used the frameshifted cKIT mRNA method to in vitro test mast cell leukemia cells. They found that KIT protein signaling, expression and function had been reduced. Within hours, the cancer cells stopped growing and died. A mouse model showed that tumor growth and infiltration were decreased and tumor cell death was increased when the frameshifted C-KIT mRNA gene was induced.Cruse states that "the other benefit of our technique is the fact it solves degradation evasion." Sometimes, faulty messages can evade degradation and their mutant proteins are produced anyway. However, proteins made by the frameshifted cKIT mRNA protein are inert or non-functional. They cannot do more damage, even if they are produced."This research is published in Molecular Therapy. It was supported by the National Institutes of Health. Douglas Snider, a postdoctoral researcher at NC State, is the first author. Hoth Therapeutics licensed the technology in this paper.Continue readingMore information: Douglas B. Snider and colleagues, Targeting KIT through frameshifting transcripts of mRNA as a therapeutic strategy to combat aggressive mast cell carcinomas, Molecular Therapy (2021). Information from Molecular Therapy Douglas B. Snider et. al. Targeting KIT through frameshifting mRNA transcriptions as a therapeutic strategy to combat aggressive mast cell neoplasms. (2021). DOI: 10.1016/j.ymthe.2021.08.009
