Transcription errors in RNA, though rare and transient, lead to synthesis of defective proteins and RNA mediated regulation. Errors in RNA transcription can cause many human diseases, including those that are age-related.
Researchers at the National Cancer Institute (NCI) and Center for Cancer Research, RNA Biology Laboratory have developed a genetic assay that detects RNA synthesis errors. The new assay can detect the transient errors in transcription as permanent genetic changes. Thus, it has the potential to test the level of transcription error-related toxicity caused by therapeutic compounds and prevent excessively toxic drugs from entering the market.
The assay is based on suppression of a mutation in the Cre recombinase, coupled with a Cre genetic reporter to monitor the activity of the recombinase. The Cre mutation results in an inactive enzyme; errors in RNA transcription of the Cre mutation transiently restores the activity of the enzyme. Additionally, the genetic reporter of Cre activity leads to permanent expression of a yellow fluorescent protein (YFP) and the mouse cell line in the invention assay has both the cre mutation source and cre activatable YFP gene. Activation of the YFP gene allows for the detection of transcription errors following exposure of the cells to compounds or other treatments. For example, exposure of the cells to elevated levels of manganese results in an increase of YFP expressing cells; these results are consistent with in vitro experiments demonstrating manganese can reduce transcription accuracy. The mouse cell lines were derived from transgenic mice allowing for the follow up of results in live mice carrying the assay reporters.
Researchers at the NCI seek licensing partners for the assay which detects errors in RNA synthesis caused by carcinogens or therapeutic candidates.
- Assay to screen against drugs that can potentially cause RNA transcription errors
- Assay to test the level of transcription error-related toxicity caused by therapeutic compounds and carcinogens
- Genetic assay for detecting errors in synthesis at the RNA level
- First of its kind approach to monitoring mRNA synthesis errors and identifying drugs that could potentially increase the rate of transcription errors.
- Proof of principle: Exposure of the cells to elevated levels of manganese results in an increase of YFP expressing cells; these results are consistent with biochemical experiments demonstrating manganese reduces transcription accuracy.
Jeffrey Strathern (NCI), Mary Ernst (NCI), Alison Rattray (NCI)
- U.S. Provisional: U.S. Provisional Patent Application Number 62/480,747, Filed 03 Apr 2017