New application of the CRISPR-Cas9 system

An effective way to detect cancer has been found

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Molecular biologists from the Netherlands Institute of Cancer Research have tested the effectiveness of a new method for identifying vital genes based on the CRISPR-Cas9 system. It turned out that with the help of CRISPR, you can achieve much better results with a minimum amount of noise. The study was published in the journal Nature Biotechnology (Evers et al., CRISPR knockout screening outperforms shRNA and CRISPRi in identifying essential genes).

To determine which genes are important for cell life or the development of cancerous tumors, scientists are trying to regulate their activity to find out how this will affect the body as a whole. To suppress the functions of genes, the method of RNA interference is usually used, when the gene is inhibited at the stage of transcription, RNA maturation or translation.

RNA interference is carried out using small hairpin-forming RNAs (sRNAs). They are injected into cells using vectors – molecules used to transfer genetic material. The sRNAs are then converted into small interfering RNAs, which bind to the informational RNA and contribute to its cutting. However, this approach has a number of disadvantages, for example, the expression of the gene that is needed is not always suppressed, in addition, inhibition can occur with different effectiveness.

The aim of the researchers was to test the operability of a new method of RNA interference, which uses the CRISPR-Cas9 system, which is a kind of molecular genetic immunity of bacteria. CRISPR are repetitive DNA sequences that are separated by unique spacer regions. These spacers are transcribed to form CRISPR RNAs (sRNAs) that target a specific target– for example, a sequence of foreign DNA belonging to a virus. The SRNA binds to the target, after which the latter is cut by the Cas9 protein.

In a variation of this method, which is called CRISPR interference (CRISPRi), the Cas9 protein is "dead", it does not cut the target, but suppresses the transcription of the desired gene.

Biologists compared the effectiveness of various methods of suppressing gene expression: SRNA, CRISPR and CRISPRi. For the study, the scientists selected 93 genes and monitored their activity in RT-112, a culture of human carcinoma cells. The results showed that the CRISPR method is the best approach to identify important genes, surpassing the SRNA and CRISPRi.

Portal "Eternal youth" http://vechnayamolodost.ru  26.04.2016