miRNA – BioQuakes

Currently, many are accustomed to invasive cancer diagnostic methods such as endoscopies, colonoscopies, and mammograms. Driven by the desire to discover new methods, a group of researchers from the American Cancer Society developed an alternative method, which is a significant contribution to cancer detection.

Utilizing CRISPR gene editing as their approach, the group of ACS researchers developed an easy-to-use mechanism for detecting small amounts of cancer in plasma. CRISPR gene editing is a method that scientists and researchers have been using to modify an organism’s DNA. CRISPR gene editing is often done for numerous reasons, such as adding or removing genetic material, creating immune defense systems, and repairing DNA. Their detection method also allows healthcare professionals in diagnostics to decipher between malignant and benign cancer-related molecules that they may discover.

CRISPR Gene-Editing

The first step that the researchers made to develop this approach was to design a CRISPR system that creates a manufactured exosome out of two reporter molecule fragments, which they cut. An exosome is a small vesicle that carries material such as lipids, proteins, and nucleic acids after branching out from a host cell. Exosomes are typically involved in detecting cancerous cells because they provide a glimpse into the host cell they branched out from. Therefore, cancerous cells are shown in their exosomes through biomarkers, like micro RNAs (miRNA). In AP Biology class, microRNAs are described as materials that bind to complementary mRNAs to prevent the translation from occurring. MiRNAs are a recent discovery, identified in 1993. It is now concluded that most gene expression is influenced by them, so the researchers made efficient use of miRNA in their experiment. The two fragments of the reporter molecule came together and interacted with the CRISPR’s materials.

Micro RNA Sequence

The researchers concluded that if the targeted miRNA sequence was evident in the combination, the CRISPR system they made would become activated and cut apart the reporter molecule. The researchers specifically targeted miRNA-21, which is often involved in cancer development. The researchers were able to detect miRNA within a combination of similar sequences and later tested their method on a group of healthy exosomes and cancerous exosomes. Their CRISPR system successfully differentiated between the healthy and cancerous exosomes, which makes this system effective for cancer detection. The researchers are confident that their CRISPR gene editing approach to cancer detection will make diagnosis easier on patients and a more efficient process overall.

We all know stress isn’t always a good thing, but it could be important to especially avoid it at certain points in one’s life. Recently researchers from the University of Lethbridge in Canada investigated the effects of stress on pregnancies and how it can influence pre-term births. It is already known that pre-term births them selves lead to health issues later in life, but there were some new discoveries involving epigenetics.

These researchers studied the length pregnancies of rats, due to the generally small amounts of variation between them, and found something intriguing. They carried out the experiment by first splitting the first generation of rats into “stressed” and “not stressed” groups. What they found was that the daughters of stressed rats had a shorter pregnancy than the daughters of not stressed rats.

This trend continued into the granddaughters of the rats. They also displayed high levels of glucose than the control group, and they weighed less. The stress also compounded, or increased, through generations.

This can all translate into human pregnancies. The researchers believe that the epigenetic changes in the rats is due to microRNA (miRNA) – non-coding RNA molecules that play a role in regulating gene expression. They bind to complementary mRNAs and prevent them from being translated. This is different than what is usual belief with epigenetics which is that epigenomes are affected by DNA methylation of the nucleotide base pairs. Metz, a scientist working on this research states that microRNAs “are important biomarkers of human disease, can be generated by experiences and inherited across generations. We have now shown that maternal stress can generate miRNA modifications with effects across several generations.”

It is very similar to the information found with the generational epigenetic effects of famine in the “Ghost in Our Genes” video that we watched in class.

This research can help determine pre-term births and the causalities that can come along with them. While the research is still not the whole picture, it is another step towards understanding our genetics.

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: miRNA

Cancer Detection Using CRISPR Gene Editing

Can Stress Affect Pregnancies in Later Generations?

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