Gene mutations alter the function of proteins produced by genes, which can lead to diseases such as cancer. Researchers are now using the gene-editing technology CRISPR/Cas 9 in a less common way to generate liver cancer tumors to better understand their underlying genetic mutations.
Genes contain the information needed to make proteins. Splicing is the process of editing copied RNA messages from the information encoded in genes and then using them as blueprints to create specific proteins.
Proteins that are derived from a single gene with very similar functions but different amino acid sequences are called isoforms. Isoform production is the body’s way of specializing the properties of genes or proteins. Different isoforms can lead to the formation of different types of cancer tumors. These tumor subtypes are difficult to create in the laboratory and difficult to study.
To better understand how isoforms lead to the development of different types of liver cancer, a new study uses the gene-editing tool CRISPR/Cas9 to identify different isoforms in different tumor subtypes. We examined how it leads to the occurrence of types.
“Everybody thinks cancer is just one type,” said Semir Beyaz, the study’s corresponding author. “But different isoforms can result in cancer subtypes with different characteristics.”
The researchers used CRISPR/Cas9 to target a single section of the mouse gene CTNNB1. The CTNNB1 gene provides instructions for making a protein called beta-catenin that is involved in the regulation and coordination of cell-cell adhesion and gene transcription.
Previous studies have identified beta-catenin as a potent oncogene, a gene that can transform healthy cells into tumor cells. Mutations in the CTNNB1 gene are associated with various cancers, including liver and colon cancer. Mutations in exon 3 of the CTNNB1 gene (exons are sections of DNA or RNA that encode proteins) are key to the transcription of genes involved in tumorigenesis.
In the current study, researchers hope to clarify how beta-catenin mutations promoted the development of the tumor subtypes of liver cancer, hepatocellular carcinoma (HCC) and hepatoblastoma (HB). I was. HCC is the most common type of liver cancer in adults, accounting for about 90% of all liver cancers, while HB is a rare form of liver cancer that is common in children.
CRISPR/Cas9 technology is commonly used to disrupt gene function by removing part of a DNA sequence (loss of function). But here, for the first time, researchers have used it in gain-of-function studies to create mutations that cause various cancers in mice.
Using CRISPR/Cas9 in this manner stimulated the protein’s activity, which in turn promoted tumor growth. By sequencing the tumor subtypes HCC and HB, the researchers found that CRISPR/Cas9-induced beta-catenin isoforms promote liver tumor subtypes.
“We were able to define the isoforms. [are] It’s associated with different cancer subtypes,” said Beyaz. “It was an amazing discovery for us.”
To confirm that these isoforms induced mutations, the researchers tested whether liver cancer subtypes could be generated in mice without the use of CRISPR. It turns out they can.
This study highlights the potential use of CRISPR/Cas9 for gain-of-function studies and created new methods to model specific liver tumor subtypes. We also demonstrate the role of exon 3 in tumor development and the benefits of targeted exon skipping.
Exon skipping uses mutation-specific antisense oligonucleotides (AONs) (laboratory-made bits of DNA or RNA that can bind to specific RNA molecules) to induce RNA splicing, allowing cells to A treatment that “skips” defective or misaligned exons. .
The researchers hope their findings may guide future research into new therapeutic interventions for cancer.
“Ultimately, what we want to do is find the best model for studying cancer biology and find a cure.
This research journal of pathology.
Source: Cold Spring Harbor Laboratory
