All About eDNA

If you're a biology student, you've likely discussed the myriad of genetic materials involved in the life cycles of countless types of organisms. mRNA, tRNA, nuclear DNA, mitochondrial DNA are just some of the many kinds of ribonucleic acid that help the world go around, however, one that is likely unfamiliar is eDNA. eDNA, or environmental DNA, is a term used to describe DNA found outside of an organism in an ecosystem. As animals shed, secrete fluids, excrete, and other body functions they almost leave behind a footprint of themselves in the form of eDNA. By collecting this eDNA from the environment, scientists can deduce a variety things about the environment it was collected in. 

An example of how eDNA is collected and used 

Previously, the only way to take count of the number of members of a species in an environment were methods like camera traps and field surveying, but eDNA provides a new method which doesn't require a physical sighting of the animal. Scientists use a complex methods of sample collection and analysis in order to deduce what animals might have been to a given locations. This is most helpful in dense or hard to reach environments like deep rainforests where relying on spotting is difficult and unreliable. eDNA sample collection can quickly provide a wealth of data about these locations, saving time, money and potentially lives. eDNA sampling cannot replace physical spotting yet, but it is nonetheless promising as a future avenue for studying environments. 

Sources: 

https://www.conservation.org/blog/what-on-earth-is-edna

https://www.nature.com/articles/s44358-025-00044-x

A New Cure For Cancer?

In a recent study done by MIT researchers, Senti Bio is engineering immune cells, to be able to distinguish the difference between healthy and cancerous cells. Since proteins that are found on cancer cells, are often also found on healthy ones too, Senti Bio has been developing immune cells to make detecting this protein easier. Former MIT faculty member, Tim Lu said, "Kill anything displaying the cancer target, but spare anything that has this healthy target". 

During the clinical trial, 2 of the 3 patients treated, experienced complete remission. Not even the bone marrow tests were able to detect any cancer cells. Senti Bio leaves hope for cancer patients, their lead clinical trial focused mainly on patients with relapsed or refractory blood cancers. However, they've been partnering with different companies, to perform more trials on patients with liver cancer.

As someone whose father has had two different forms of cancer already, learning about these new immune cells gives me hope. Nobody likes cancer, so knowing that there is a possibility of curing it, I think these new immune cells are an amazing idea. I believe that they're a huge step in the right direction.

Researchers identify DNA changes, biological pathways associated with inherited cancer risk

    A remarkable study headed by Stanford researchers and highlighted by Krista Conger identified over 400 inherited DNA variations that play an important role in cancer risk. Unlike mutations that directly change protein structures, these variations are found in the genome's regulatory regions and influence when and how genes are expressed. The researchers evaluated genetic data from millions of people with 13 prevalent cancer types, discovering around 1,100 genes that are likely implicated in cancer formation. Many of these genes are linked to essential biological mechanisms such as DNA repair, cell migration, and inflammation, providing fresh insights into how hereditary factors contribute to cancers of all sorts.

    This breakthrough has the potential to fundamentally change how we approach cancer risk assessment and prevention. By identifying the genetic variations that govern gene activity, scientists may create more individualized screening tools and potential therapies based on an individual's genetic composition. The discovery also opens up new options for therapeutic research, particularly addressing the inflammatory mechanisms that contribute to cancer formation. As this knowledge becomes more widely used in clinical practice, it has the potential to improve early detection procedures and guide more accurate, preventative healthcare decisions for those with genetic cancer risk.

When Aunt Flo Brings Extra Baggage: The Menstrual Cycle’s Link to Sickle Cell Flare-Ups

    A significant connection between the menstrual cycle and an increase in pain episodes in women with sickle cell disease (SCD) is clarified by new research from the University of Pennsylvania. The study, which was published in Blood Vessels, Thrombosis & Hemostasis, shows that in women with sickle cell disease (SCD), levels of C-reactive protein (CRP), a measure of inflammation, sharply increase during the follicular phase of the menstrual cycle. Painful vaso-occlusive events (VOEs) are more common in these individuals during this phase, which takes place in the early half of the cycle. ​

    The results imply that changes in hormones during the menstrual cycle worsen inflammation, which raises the risk of VOEs. This realization creates opportunities for focused interventions. Hormonal contraceptives that control or suppress menstruation, for example, may lessen these uncomfortable episodes. The authors of the study warn that larger, prospective research is required to confirm these results and investigate efficient management techniques.

    While previous studies have noted a temporal association between menstruation and VOEs, this research is pioneering in identifying a biological mechanism—elevated CRP levels—that may underpin this relationship .​

Four-Gene Combo Might Predict Lethality Of Stomach Cancer

     A recent article in the U.S. News by Dennis Thompson states that four specific genes have been discovered that could help us understand more about stomach cancer. Testing four different genetic mutations could enable doctors to help find a direct treatment that could aggressively treat conditions, such as surgery or chemotherapy.

    Today, most gastric cancers are treated the same way. Recent research has identified different molecular differences, which may enable scientists to tailor treatment to a specific person's mutation. During this study, they looked at 21 genes in tumors taken from 87 patients who had already undergone chemotherapy. By comparing the genes within the patients, they found that BRCA2, CDH1, RHOA, and TP53 changes were likely to lead to cancer. Researchers are trying to match the findings to establish an affordable test to discover individuals with high-risk patterns. Identifying these patterns could help us lead in the right direction in tumor biology.

A Child Treated with CAR-T Cancer Therapy Is Cancer-Free 18 Years Later

    Roughly eighteen years ago, a four year old girl was diagnosed with a rare nerve cell cancer and had received an infusion of immune cells that were genetically engineered to fight the disease. Since then she has been cancer free, therefore making her the longest surviving patient to have been treated with CAR-T cell therapy. This treatment includes the removal of some of the patients immune cells, and genetically modifying them to target and kill cancer cells before returning them to the body. This is a relatively new type of immunotherapy and is still in clinical stages, but solid tumors have been found to be harder to treat. This is because solid tumors have molecules that can hinder the modified cells, making it hard for the treatment to penetrate the cancer. Solid tumors account for ninety percent of all cancer diagnosed . 

    For part of a clinical study, nineteen children with neuroblastoma were recruited to take part in the CAR-T treatment. In a time period of seven years the children received CAR-T infusions, and unfortunately only seven of the children survived. Researchers at the University of Pennsylvania are now questioning why treatment worked for some and not others, so they are currently taking measures to investigate this. Since this study was done, scientists have modified the CAR-T cells even further to allow them to last longer and locate tumors quicker. The clinical trials on these new CART-T cells are still being ran, but researchers are hopeful that this new modification will result in a higher survival rate.

Sniper DNA: Targeting Antibiotic-Resistant Bacteria

Antibiotic-resistant bacteria are becoming more difficult to prevent due to the overprescription of antibiotics, leading to infection tolerance. Consequently, when antibiotics don’t work, they may die with no other medicine to cure them. For example, E. coli bacteria are resistant to most antibiotics, and even attempting to use “last resort” antibiotics can lead to the bacteria becoming even more resistant than before. E. coli bacteria contain antibiotic resistance from circular DNA called plasmids. In a study, multiple antibiotic-resistant E. coli bacteria were plated with a toxin-containing plasmid, which later killed the antibiotic-resistant bacteria. The article called this plasmid a “precision-guided missile.” Often, the main problem with prescribing antibiotics is that they kill both beneficial and harmful bacteria. However, if these specific missile-like plasmids are utilized, they can work towards killing only the harmful bacteria and save the useful ones. Scientists plan to move forward with the idea of developing precision-based medicines to do precisely this. 

I found this article very interesting because of what we’ve learned about plasmid DNA in class. Future research should explore customizing plasmids to target a broader range of resistant bacteria and the possibility of integrating AI to predict resistance patterns. I hope precision medicine moves beyond theory and into reality before resistance surpasses our ability to respond.

Four-Gene Combo Might Predict Lethality Of Stomach Cancer

    Due to its fast progression and sometimes delayed discovery, stomach cancer continues to rank among the worst tumors worldwide. UTRN, MUC16, CCDC178, and HYDIN are the four genes that have been shown to work together to predict the lethality of stomach cancer, which gives researchers hope.

    Based on these gene changes, researchers created a risk score that allowed them to successfully categorize individuals into low, medium, and high-risk categories. The tumor mutation load was greater and survival rates were higher in the low-risk group. Crucially, this model demonstrated dependability irrespective of disease stage, age, or gender.

    Doctors' ability to evaluate patient prognoses and customize therapy regimens may be significantly enhanced by this genetic characteristic. It is an important step toward more focused and efficient cancer treatment, even though more confirmation is required.