Comment

Comment by Dr. Krishna Kumari Challa on Wednesday

Key to the high aggressiveness of pancreatic cancer identified

Pancreatic cancer is one of the most aggressive cancers and has one of the lowest survival rates—only 10% after five years. One of the factors contributing to its aggressiveness is its tumor microenvironment, known as the stroma, which makes up the majority of the tumor mass and consists of a network of proteins and different non-tumor cells. Among these, fibroblasts play a key role, helping tumor cells to grow and increasing their resistance to drugs.

Now, a study  by researchers has identified a new key factor contributing to this feature of pancreatic cancer: a previously unknown function of Galectin-1 protein inside the nuclei of fibroblasts.

This discovery, published in the journal PNAS, offers new insights into the role of these cells in the progression of pancreatic cancer.

The stroma is considered a key component in the aggressive nature of pancreatic cancer, as it interacts with tumor cells, protects them, and hinders the action of drugs. Moreover, stromal cells, particularly fibroblasts, produce substances that support tumor growth and dissemination. 

Until now, fibroblasts were known to secrete Galectin-1, a protein with pro-tumoral properties. This study, however, shows that the molecule is also located inside fibroblasts—specifically in their nuclei—where it plays a key role in gene expression regulation.

The presence of this molecule activates fibroblasts, making them support tumor cell development. The researchers also discovered that Galectin-1 can regulate gene expression in these cells at a highly specific level without altering the DNA sequence, through epigenetic control. One of the genes it regulates is KRAS, which plays a critical role in pancreatic tumors.

This gene is also present in tumor cells in 90% of patients, though in this case it is mutated. It is considered one of the main drivers of uncontrolled growth and tumor aggressiveness.

 The newly discovered functions now pave the way for developing new strategies to tackle this type of tumor.

Judith Vinaixa et al, Nuclear Galectin-1 promotes KRAS -dependent activation of pancreatic cancer stellate cells, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2424051122

Comment by Dr. Krishna Kumari Challa on Wednesday

Researchers resurrect extinct gene in plants with major implications for drug development

Researchers resurrected an extinct plant gene, turning back the evolutionary clock to pave a path forward for the development and discovery of new drugs.

Specifically, the team repaired a defunct gene in the coyote tobacco plant.

In a new paper, they detail their discovery of a previously unknown kind of cyclic peptide, or mini-protein, called nanamin that is easy to bioengineer, making it "a platform with huge potential for drug discovery" . The paper is published in the journal Proceedings of the National Academy of Sciences.

It will provide chemical biologists with other tools to develop new peptide-based cancer treatments, for discovering new antibiotics and also for agricultural applications for defense against pathogens and insects.

Made up of short strings of amino acids, cyclic peptides are very small and almost tailor-made for use in drug development.

Cyclic peptides are much smaller, so it's like a small molecule drug but has the chemical features of a protein. You can also engineer it. We can easily generate a library that produces millions of these peptides that can be used for drug screening.

The researchers  previously discovered that cyclic peptides exist in plants, which brought him to coyote tobacco. As they delved into the genetic code of this plant, they discovered a pseudogene that was no longer functional.

This particular gene had previously encoded the cyclic peptide nanamin in coyote tobacco, but over time, due to adaptive mutations, it had faded away into the evolutionary past. But that didn't stop the researchers.

They found that this gene still existed in related plant species and, using a new method called molecular gene resurrection, cloned the gene and corrected the mutation.

To their surprise, they were able to recover the ancestral function of this gene.

Beyond resurrecting an extinct gene, this research proves the viability of cyclic peptides, and nanamin specifically, as the foundation for a number of novel uses.

Nanamin's size and chemical mutability makes it an asset for discovering new drugs and agriculture.

Elliot M. Suh et al, The emergence and loss of cyclic peptides in Nicotiana illuminate dynamics and mechanisms of plant metabolic evolution, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2425055122

Comment by Dr. Krishna Kumari Challa on Wednesday

NASA experiment shows solar wind might make water on the moon

Scientists have hypothesized since the 1960s that the sun is a source of ingredients that form water on the moon. When a stream of charged particles known as the solar wind smashes into the lunar surface, the idea goes, it triggers a chemical reaction that could make water molecules.

Now, in the most realistic lab simulation of this process yet, NASA-led researchers have confirmed this prediction.

The finding, researchers wrote in the Journal of Geophysical Research: Planets, has implications for NASA's Artemis astronaut operations at the moon's South Pole. A critical resource for exploration, much of the water on the moon is thought to be frozen in permanently shadowed regions at the poles.

Solar wind flows constantly from the sun. It's made largely of protons, which are nuclei of hydrogen atoms that have lost their electrons. Traveling at more than 1 million miles per hour, the solar wind bathes the entire solar system. We see evidence of it on Earth when it lights up our sky in auroral light shows.

Most of the solar particles don't reach the surface of Earth because our planet has a magnetic shield and an atmosphere to deflect them. But the moon has no such protection. As computer models and lab experiments have shown, when protons smash into the moon's surface, which is made of a dusty and rocky material called regolith, they collide with electrons and recombine to form hydrogen atoms.

Then, the hydrogen atoms can migrate through the lunar surface and bond with the abundant oxygen atoms already present in minerals like silica to form hydroxyl (OH) molecules, a component of water, and water (H₂O) molecules themselves.

Scientists have found evidence of both hydroxyl and water molecules in the moon's upper surface, just a few millimeters deep. These molecules leave behind a kind of chemical fingerprint—a noticeable dip in a wavy line on a graph that shows how light interacts with the regolith. With the current tools available, though, it is difficult to tell the difference between hydroxyl and water, so scientists use the term "water" to refer to either one or a mix of both molecules.

Many researchers think the solar wind is the main reason the molecules are there, though other sources like micrometeorite impacts could also help by creating heat and triggering chemical reactions.

Spacecraft measurements had already hinted that the solar wind is the primary driver of water, or its components, at the lunar surface. One key clue, confirmed by Yeo's team's experiment: the moon's water-related spectral signal changes over the course of the day.

In some regions, it's stronger in the cooler morning and fades as the surface heats up, likely because water and hydrogen molecules move around or escape to space. As the surface cools again at night, the signal peaks again. This daily cycle points to an active source—most likely the solar wind—replenishing tiny amounts of water on the moon each day.

Li Hsia Yeo et al, Hydroxylation and Hydrogen Diffusion in Lunar Samples: Spectral Measurements During Proton Irradiation, Journal of Geophysical Research: Planets (2025). DOI: 10.1029/2024JE008334

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Comment by Dr. Krishna Kumari Challa on Wednesday

Children exposed to brain-harming chemicals while sleeping: Scientists urge mattress manufacturers to act

Babies and young children may breathe and absorb plasticizers called phthalates, flame retardants, and other harmful chemicals from their mattresses while they sleep, according to a pair of studies published by the University of Toronto in Environmental Science & Technology and Environmental Science & Technology Letters. These chemicals are linked to neurological and reproductive problems, asthma, hormone disruption, and cancer.

Sleep is vital for brain development, particularly for infants and toddlers. However, this research suggests that many mattresses contain chemicals that can harm kids' brains. 

This is a wake-up call for manufacturers and policymakers to ensure our children's beds are safe and support healthy brain development.

In the first study, researchers measured chemical concentrations in 25 bedrooms of children aged 6 months to 4 years. They detected concerning levels of more than two dozen phthalates, flame retardants, and UV-filters in bedroom air, with the highest levels lurking around the beds. In a companion study, researchers tested 16 newly purchased children's mattresses and confirmed that they are likely the major source of these chemicals in children's sleeping environments. When the researchers simulated a child's body temperature and weight on the mattresses, chemical emissions increased substantially, as much as by several times.

The phthalates and organophosphate ester flame retardants measured in this study are hormone disruptors and are linked to neurological harms, including learning disorders, reduced IQ scores, behavioral problems, and impaired memory. Some are also linked to childhood asthma and cancer. Several UV-filters are hormone disruptors.

Children are uniquely vulnerable to exposure, given that they are still developing, have hand-to-mouth behaviors, and have breathing rates ten times higher than adults. They also have more permeable skin and three times the skin surface area relative to their body weight than adults.

Flame retardants are linked to neurological, reproductive, and hormonal harm as well as cancer, and also have no proven fire-safety benefit as used in mattresses.

Flame retardants have a long history of harming our children's cognitive function and ability to learn. It's concerning that these chemicals are still being found in children's mattresses even though we know they have no proven fire-safety benefit, and aren't needed to comply with flammability standards.

The researchers call for manufacturers to be more vigilant about the chemicals in children's mattresses through testing. Further, stronger regulations on the use of flame retardants and phthalate plasticizers in children's mattresses are needed.

Environmental Science & Technology Letters (2025). DOI: 10.1021/acs.estlett.5c00051

Are Sleeping Children Exposed to Plasticizers, Flame Retardants, and UV-Filters from Their Mattresses?, Environmental Science & Technology (2025). DOI: 10.1021/acs.est.5c03560

Comment by Dr. Krishna Kumari Challa on Wednesday

Heart valve abnormality is associated with malignant arrhythmias, study reveals

People with a certain heart valve abnormality are at increased risk of severe heart rhythm disorders, even after successful valve surgery. This is according to a new study, "Mitral annular disjunction and mitral valve prolapse: long-term risk of ventricular arrhythmias after surgery" , published in the European Heart Journal.

The condition is more common in women and younger patients with valve disorder and can, in the worst case, lead to sudden cardiac arrest.

Mitral annular disjunction, MAD, is a heart abnormality in which the mitral valve attachment "slides." In recent years, the condition has been linked to an increased risk of severe cardiac arrhythmias. Until now, it has not been known whether the risk of arrhythmias disappears if MAD is surgically corrected.

MAD is often associated with a heart disease called mitral valve prolapse, which affects 2.5% of the population and causes one of the heart's valves to leak. This can lead to blood being pumped backward in the heart, causing heart failure and arrhythmias. The disease can cause symptoms such as shortness of breath and palpitations.

In the current study, researchers  investigated the risk of cardiac arrhythmias in 599 patients with mitral valve prolapse who underwent heart surgery at Karolinska University Hospital between 2010 and 2022. Some 16% of the patients also had the cardiac abnormality MAD.

The researchers have been able to show that people with MAD have a significantly higher risk of suffering from ventricular arrhythmias, a dangerous type of heart rhythm disorder that, in the worst case, can lead to cardiac arrest in a subset of patients.

People with MAD were more likely to be female and were on average eight years younger than those without MAD. They also had more extensive mitral valve disease. Although the surgery was successful in correcting MAD, these patients had more than three times the risk of ventricular arrhythmias during five years of follow-up compared to patients without preoperative MAD.

These results show that it is important to closely monitor patients with this condition, even after a successful operation, say the researchers.

The study has led to new hypotheses that the researchers are now investigating further. One hypothesis is that MAD causes permanent changes in the heart muscle over time. Another is that MAD is a sign of an underlying heart muscle disease.

The researchers are now continuing to study scarring in the heart using MRI (magnetic resonance imaging) and analyze tissue samples from the heart muscle.

Bahira Shahim et al, Mitral annular disjunction and mitral valve prolapse: long-term risk of ventricular arrhythmias after surgery, (2025). DOI: 10.1093/eurheartj/ehaf195

Comment by Dr. Krishna Kumari Challa on Wednesday

Abscisic acid was applied to maize roots to chemically induce stomatal closure. Plants exposed to dust laden with PET MPs under these conditions showed significantly lower absorption in leaf tissue, confirming that open stomata are crucial for foliar uptake of airborne MPs.

Plastic particles absorbed through leaves accumulated in measurable quantities across multiple species and sites. Airborne PET and PS entered leaves through stomata and moved along internal pathways to vascular tissues and trichomes.

Concentrations increased with exposure time, environmental levels, and leaf age. Field measurements showed that plastic accumulation in aboveground plant parts exceeds what is typically absorbed through roots.

Widespread detection of plastic polymers and fragments in edible plant parts confirms atmospheric exposure as a significant route of entry into vegetation. As leaves function as a primary source in terrestrial food chains, the presence of accumulated MPs suggests the potential for exposure to multiple layers of the ecosystem.

With plastics around, even vegetarians are not safe!

 Ye Li et al, Leaf absorption contributes to accumulation of microplastics in plants, Nature (2025). DOI: 10.1038/s41586-025-08831-4

Willie Peijnenburg, Airborne microplastics enter plant leaves and end up in our food, Nature (2025). DOI: 10.1038/d41586-025-00909-3

Part 2

Comment by Dr. Krishna Kumari Challa on Wednesday

Airborne microplastics infiltrate plant leaves, raising environmental concerns

Researchers have found that plant leaves can directly absorb microplastics (MPs) from the atmosphere, leading to a widespread presence of plastic polymers in vegetation. Concentrations of polyethylene terephthalate (PET) and polystyrene (PS) were detected in leaves collected from multiple environments, including urban areas and agricultural sites. The study is published in the journal Nature.

Researchers performed field investigations and laboratory simulation experiments to quantify plastic accumulation in plant leaves. Leaf absorption was confirmed as a significant pathway for plastic accumulation in plants, with evidence of translocation into vascular tissue and retention in specialized structures like trichomes.

MPs have been detected throughout terrestrial environments, including soil, water, and air. Laboratory studies have shown that plant roots can absorb MPs, with submicrometer and nanometer-sized particles of PS and polymethylmethacrylate transported upward from the roots of Triticum aestivum, Lactuca sativa, and Arabidopsis thaliana. Root uptake through the apoplastic pathway has been observed, yet translocation to shoots occurs slowly.

Airborne MPs have been measured at concentrations between 0.4 and 2,502 items per cubic meter in urban settings such as Paris, Shanghai, Southern California, and London. Laboratory experiments demonstrated the foliar absorption of nanoparticles including Ag, CuO, TiO₂, and CeO₂.

Plastic particles have been shown to deposit on plant surfaces, and some studies reported internal accumulation following exposure to high levels of commercial PS models.

At the most polluted sites, concentrations of PET reached tens of thousands of nanograms per gram of dry leaf weight. PS levels followed a similar pattern, with the highest values detected in leaves from the landfill site.

PET and PS were also found in nine leafy vegetables, with open-air crops exhibiting higher levels than greenhouse-grown counterparts. Nano-sized PET and PS were visually confirmed in plant tissue.

Older leaves and outer leaves of vegetables accumulated more plastic than newly grown or inner leaves, suggesting an accumulation over time.

Laboratory exposure of maize to plastic-laden dust resulted in measurable PET absorption in leaf tissue after just one day. PET was not detected in roots or stems under similar root-exposure conditions. Fluorescent and europium-labeled particles enabled visualization of stomatal entry and subsequent migration through the apoplastic pathway.

Part 1

Comment by Dr. Krishna Kumari Challa on Tuesday

Repeated treatment with malaria medication can decrease its effect

In a recently published article in the journal Nature Communications, researchers present results indicating that repeated treatment with piperaquine, an antimalarial drug, can lead to the parasites developing decreased sensitivity to this drug. These findings may impact the use of piperaquine in the future.

Piperaquine is an important antimalarial drug characterized by a long half-life, meaning it remains in the body for several weeks and protects against new infections. This is a key asset of this drug. However, the researchers behind the study have discovered that this advantage can disappear with repeated treatment in areas with high malaria transmission.

The study shows that repeated treatment with dihydroartemisinin-piperaquine can lead to parasites developing drug tolerance by duplicating the plasmepsin 3 (pm3) gene. This allows them to reinfect patients earlier than expected during the expected protective period, reducing piperaquine's effectiveness as a prophylactic medicine.

 Leyre Pernaute-Lau et al, Decreased dihydroartemisinin-piperaquine protection against recurrent malaria associated with Plasmodium falciparum plasmepsin 3 copy number variation in Africa, Nature Communications (2025). DOI: 10.1038/s41467-025-57726-5

Comment by Dr. Krishna Kumari Challa on Tuesday

Modified antibody fragment blocks fertilization, paving way for nonhormonal contraceptive

Current methods of contraception rely on hormones, which can cause side effects such as mood changes, headaches or increased risk of blood clots. Blocking fertilization on the surface of the egg has been proposed as an alternative, but antibodies were deemed unsuitable due to possible immune responses triggered by their Fc region.

A new study  shows how a small antibody fragment can block fertilization by targeting a key protein on the surface of the egg. This discovery brings a nonhormonal contraceptive one step closer to reality. The study has been published in the Proceedings of the National Academy of Sciences.

In the study, the researchers describe how a modified antibody fragment can block fertilization by targeting the protein ZP2 on the surface of the egg. 

This small antibody fragment can block fertilization by targeting ZP2, a key protein in the outer layer of the egg that is involved in both sperm binding and blocking polyspermy.

The researchers have used X-ray crystallography to map the interaction between the antibody IE-3, which is known to prevent fertilization in mice, and ZP2 at the atomic level. A modified, smaller version of the antibody (scFV) was found to be equally effective, blocking fertilization in 100% of IVF tests with mouse eggs. Because it lacks the immune-triggering Fc region of the full antibody, scFV minimizes potential side effects.

Elisa Dioguardi et al, Structural basis of ZP2-targeted female nonhormonal contraception, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2426057122

Comment by Dr. Krishna Kumari Challa on Tuesday

Radiation from CT scans could account for 5% of all cancer cases a year, study suggests

CT can save lives, but its potential harms are often overlooked. CTs expose patients to ionizing radiation—a carcinogen—and it's long been known that the technology carries a higher risk of cancer.

Radiation from CT scans may account for 5% of all cancers annually, according to a new study  that cautions against overusing and overdosing CTs.

The danger is greatest for infants, followed by children and adolescents. But adults are also at risk, since they are the most likely to get scans.

Nearly 103,000 cancers are predicted to result from the 93 million CTs that were performed in 2023 alone. This is three to four times more than previous assessments, the researchers say.

The researchers said some CT scans are unlikely to help patients and are overused, such as those for upper respiratory infections or for headaches without concerning signs or symptoms. They said patients could lower their risk by getting fewer of these scans, or by getting lower-dose scans.

There is currently unacceptable variation in the doses used for CT, with some patients receiving excessive doses. 

JAMA Internal Medicine (2025). jamanetwork.com/journals/jamai … ainternmed.2025.0505

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