Synthetic introns enable splicing factor mutation-dependent targeting of cancer cells

Nat Biotechnol. 2022 Jul;40(7):1103-1113. doi: 10.1038/s41587-022-01224-2. Epub 2022 Mar 3.


Many cancers carry recurrent, change-of-function mutations affecting RNA splicing factors. Here, we describe a method to harness this abnormal splicing activity to drive splicing factor mutation-dependent gene expression to selectively eliminate tumor cells. We engineered synthetic introns that were efficiently spliced in cancer cells bearing SF3B1 mutations, but unspliced in otherwise isogenic wild-type cells, to yield mutation-dependent protein production. A massively parallel screen of 8,878 introns delineated ideal intronic size and mapped elements underlying mutation-dependent splicing. Synthetic introns enabled mutation-dependent expression of herpes simplex virus-thymidine kinase (HSV-TK) and subsequent ganciclovir (GCV)-mediated killing of SF3B1-mutant leukemia, breast cancer, uveal melanoma and pancreatic cancer cells in vitro, while leaving wild-type cells unaffected. Delivery of synthetic intron-containing HSV-TK constructs to leukemia, breast cancer and uveal melanoma cells and GCV treatment in vivo significantly suppressed the growth of these otherwise lethal xenografts and improved mouse host survival. Synthetic introns provide a means to exploit tumor-specific changes in RNA splicing for cancer gene therapy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antiviral Agents
  • Breast Neoplasms* / genetics
  • Female
  • Ganciclovir / metabolism
  • Ganciclovir / pharmacology
  • Genetic Therapy / methods
  • Humans
  • Introns / genetics
  • Leukemia* / genetics
  • Melanoma* / genetics
  • Melanoma* / therapy
  • Mice
  • Mutation / genetics
  • RNA Splicing Factors / genetics
  • Thymidine Kinase / genetics
  • Thymidine Kinase / metabolism
  • Uveal Neoplasms


  • Antiviral Agents
  • RNA Splicing Factors
  • Thymidine Kinase
  • Ganciclovir

Supplementary concepts

  • Uveal melanoma