A new genetic tool to label specific genes in human organoids, Researchers have developed a new genetic tool to label specific genes in human organoids or mini organs.
They used a new method called CRISPR-HOT to study how hepatocytes divide and how abnormal cells with too much DNA appear.
By deactivating the TP53 cancer gene, they show that the unstructured abnormal hepatocyte division is more common, which can contribute to the development of cancer.
Organoids are mini organs that can be grown in a laboratory. These small organs grow from a very small piece of tissue, which allows for different organs.
The ability to genetically modify this organoid will strongly support the study of biological processes and disease modeling.
So far, however, the generation of genetically modified human organoids has proven difficult because there is a lack of simple methods for genome technology.
A few years ago, researchers discovered that CRISPR / Cas9, which acts as a small molecular scissors, can cut precisely at certain points in DNA. This new technology has made genetic engineering much easier and simpler. Small wounds in DNA can activate two different repair mechanisms in cells that can also be used by researchers to force cells to fill new pieces of DNA at the wound site. A new genetic tool to label specific genes in human organoids.
One of these methods, known as non-homologous binding, is believed to make mistakes, which is why it is not often used to insert new DNA fragments.
The researchers then used CRISPR-HOT to insert the neon label into human organoid DNA, so that the neon label is attached to the specific gene they want to study.
First, the researchers identified a specific type of cell that is very rare in the intestine: enteroendocrine cells. These cells produce hormones to regulate, for example, glucose levels, food intake and gastric emptying. Because these cells are very rare so it is difficult to learn.
However, with CRISPR-HOT, researchers can easily “paint” these cells in different colors and then easily identify and analyze them.
Second, the researchers drew an organoid from a particular type of cell in the liver, the bile duct cells. With the help of CRISPR-HOT, they visualize keratin, a protein involved in cell skeletons. After looking at this high-resolution keratin in detail, the researchers found their organization in an ultrastructural way.
This keratin also changes expression when cells are specialized or differentiated. Therefore the researchers estimate that CRISPR-HOT can be useful for studying cell fate and cell differentiation.
There are many hepatocytes in the liver that contain two (or more) times the DNA of normal cells. It is not clear how these cells are formed and whether they can separate because of this abnormal amount of DNA.
Older adults contain more of these abnormal hepatocytes, but it is unclear whether they are related to diseases such as cancer. Artegiani and Hendriks used CRISPR-HOT to mark specific components of cell division in the hepatocyte machine and examine the process of cell division. A new genetic tool to label specific genes in human organoids.
In addition, the researchers examined the effects of mutations in the TP53 gene that are common in liver cancer in abnormal cell division in hepatocytes. Without TP53, this abnormal hepatocyte divides more often. This could be one of the ways that TP53 contributes to the development of cancer.
Researchers believe that CRISPR-HOT can be used in many types of human organoids to express all types of genes or cells and to study many developmental problems and diseases.