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Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 11:59am

Breast tumors tunnel into fat cells to fuel up

Scientists caught cancer cells in the act of breaking into fat cells and releasing their fat. The energy heist seems to be critical for the growth of deadly breast cancer. The study appears in Nature Communications.

When triple-negative breast cancer grows, the fat cells around it seem to shrink. Researchers have discovered that the cells of these tumors, which are among the deadliest types of breast cancer, build molecular tunnels, called gap junctions, into nearby fat cells. The tumor cells then send instructions that trigger the fat cells to release stores of energy that could feed the cancer.

Blocking the gap junctions stopped tumors from growing.

The findings have immediate clinical implications. Although no one is yet testing drugs that block gap junctions for breast cancer, there are ongoing clinical trials using these drugs for brain cancer.

Nature Communications (2025). DOI: 10.1038/s41467-025-62486-3

Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 11:52am

What happens in the brain when it learns something new

Memories of significant learning experiences—like the first time a driver gets a speeding ticket—are sharp, compared to the recollection of everyday events—like what someone ate for dinner two weeks ago. That's because the human brain is primed to learn from helpful associations.

Researchers have identified specific neural connections that are especially sensitive to this process of learning about causality. The discovery, while seemingly intuitive, could have widespread implications for understanding how humans learn and inform new ways to address learning challenges.

What's happening inside the brain when experiencing something for the first time—and how it decides if it's meaningful—is the subject of new research which focuses on how memory and learning shape the brain. The study is published in the journal Cell Reports.

 Researchers looked at how the connection between two different types of neurons—cells that transmit information to different parts of the brain—changes in response to new learning experiences. They found that the strength of the connection only changed if an experience was meaningful. These neurons are located in the sensory cortex, a part of the brain that other animals—like cows and dogs—have as well. That means that this finding could have a wider significance and help researchers understand how a broad range of animals learn.

Researchers found this change in the brain if something was useful to learn. If there was nothing to learn, there was no change.

This means that somehow the brain can distinguish whether there is a useful association to make, or there is nothing to learn.

The research shows that the brain is primed to learn new important things and that our brains are very sensitive to things that make sense.

 Eunsol Park et al, Somatostatin neurons detect stimulus-reward contingencies to reduce neocortical inhibition during learning, Cell Reports (2025). DOI: 10.1016/j.celrep.2025.115606

Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 11:41am

Cancer-associated nerve injury can lead to chronic inflammation and immunotherapy resistance

Cancer cells can break down the protective covers around nerves, causing nerve injury that triggers chronic inflammation, leading to immune exhaustion and eventual resistance to immunotherapy, according to new research .

Tumors can sometimes infiltrate the space around nerves and nervous system fibers that are in close proximity, a process known as perineural invasion, which leads to poor prognosis and treatment escalation in various cancer types. 

The study, published today in Nature, underscores the importance of investigating interactions between cancer and the nervous system—a field known as cancer neuroscience. The results suggest that targeting the signaling pathways involved can reverse this inflammation and improve treatment responses.

These findings uncover novel mechanisms by which the immune system and nerves within the tumor microenvironment interact, revealing actionable targets that could transform the way we approach resistance to immunotherapy in patients with cancer.

 Baruch, E.N. et al, Cancer-induced nerve injury promotes resistance to anti-PD-1 therapy, Nature (2025). DOI: 10.1038/s41586-025-09370-8 www.nature.com/articles/s41586-025-09370-8

Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 10:39am

Brain scans reveal action-based organization in people born without hands

Conventional wisdom among neuroscientists suggests that the brain's motor functions are organized around the body, meaning certain brain areas control the hand; others the foot. An emerging alternative theory is that parts of the brain may be organized by the types of action, like reaching or using tools, no matter which body part is used to complete the task.

Researchers  recently set out to understand these theories, because knowing how the brain is organized around function versus body part has profound implications for rehabilitation and a person's return to function following a brain injury.

The findings are published in the Proceedings of the National Academy of Sciences. The work is titled "Action-type mapping principles extend beyond evolutionarily-conserved actions, even in people born without hands."

If motor control is partly based on actions rather than body parts, it's possible the brain can use this flexibility to compensate for the loss of specific limbs.

To gain a deeper understanding of the emerging theory, neuroscientists conducted a novel study with volunteers who were born without hands, and instead use their feet for everyday tasks with and without tools.

Using fMRI brain scans, the researchers showed that in these individuals, brain areas typically involved in hand tool use are still active—even though the individuals were using their feet, not their hands. This finding is consistent with the same action preference for control participants, who perform the action with either their hands or feet.

They  found that some regions in the brain care about the type of action a person is doing and not whether this action was performed with the hand or with the foot.

It appears this organization can arise without typical motor experience, providing evidence for action-type as a core driving factor in motor organization and development.

Interestingly, this was not true for all brain areas.

The primary motor cortex, which is tightly mapped to the body, did not reorganize for foot-based tool use, even in people who have been using tools with their feet their whole lives. This suggests that some brain areas demonstrate more plasticity than others.

Still, the study reveals a kind of brain organization that goes beyond the body—one that is abstract and action-centered, and that develops even without typical experience.

 Florencia Martinez-Addiego et al, Action-type mapping principles extend beyond evolutionarily conserved actions, even in people born without hands, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2503188122

Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 10:28am

Saharan bacteria shield themselves with biofilms to survive dust storm journeys

How do living bacteria survive on the surface of dust particles carried by desert storms from the Sahara and Egypt to Israel?

Researchers  discovered that these bacteria can form microscopic biofilms over dust particles. These protective structures shield the bacteria from desiccation, extreme radiation, and severe nutrient scarcity during their atmospheric journey.

The research, published in Communications Earth and Environment, contributes to the growing field of atmospheric microbiology. This discipline explores the survival and activity of microorganisms while in the atmosphere, sometimes over thousands of kilometers, and their impact on global cycles, ecosystems, and human health. These processes significantly impact disease patterns, atmospheric CO₂ levels, plant diseases, and even antibiotic resistance dispersal.

In this study, the researchers successfully isolated and cultured bacteria brought in by dust storms under atmospheric conditions, focusing on beneficial Bacillus strains known for their positive applications in agriculture, construction, and medical probiotics.

The team thinks that natural selection during dust storms favors more innovative bacterial strains—a phenomenon that could potentially enhance their practical applications. This study also expands the traditional soil microbiome concept to include airborne microbial communities, broadening the known repertoire of survival strategies among these remarkable organisms.

Naama Lang-Yona et al, Bacillus biofilm formation and niche adaptation shape long-distance transported dust microbial community, Communications Earth & Environment (2025). DOI: 10.1038/s43247-025-02534-4

Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 10:22am

Mitochondria defend cells against infections by competing with pathogens for nutrients

Chronic infections impact a substantial portion of the global population, presenting ongoing challenges to health care systems and compromising patient well-being.

In a new study, researchers have discovered a surprising ally in the fight against infection: the cell's own mitochondria. Best known for providing energy to cells, mitochondria also play a defensive role by competing with pathogens for vital nutrients.

The paper is published in the journal Science.

During infection, mitochondria enter a metabolic tug-of-war with intracellular parasites, like Toxoplasma gondii, battling for access to folate, thereby inhibiting pathogen growth.

This discovery highlights a unique defensive strategy employed by host cells and opens up new possibilities for developing therapies against folate-dependent pathogens, such as Toxoplasma and Plasmodium, which cause toxoplasmosis and malaria respectively.

During infection with the human parasite Toxoplasma gondii, researchers observed the activation of the integrated stress response, which rewires mitochondrial metabolism.

This response enhanced mitochondrial activity, leading to increased demand for folate, a critical nutrient for nucleotide synthesis. Consequently, mitochondria limit the parasite's access to folate, curtailing its growth and proliferation. Mice unable to activate this stress response showed faster parasite growth, confirming the pathway's protective role in vivo.

 Tânia Catarina Medeiros et al, Mitochondria protect against an intracellular pathogen by restricting access to folate, Science (2025). DOI: 10.1126/science.adr6326

Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 9:22am

The team also wants to see if epigenetic noise is amplified for wound healing and tissue repair, and whether or not it can be leveraged to reprogram cells to alternate phenotypes for various clinical contexts, including cancer immunotherapy and treating autoimmunity.

It makes sense that to empower an immune system that uses a random process to recognize virtually any entity in the universe, thymic epithelial cells amplify random noise in the genome to ensure the immune system is focused on pathogens and cancers and not its own tissues. It's fighting fire with fire
Sometimes the random background noise can be just as important as the signal.

Thymic epithelial cells amplify epigenetic noise to promote immune tolerance, Nature (2025). DOI: 10.1038/s41586-025-09424-x

Part 3

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Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 9:21am

Since such heterogeneity is important, they used a series of single cell sequencing techniques to study gene expression and chromatin structure in individual mTECs, instead of using traditional bulk sequencing tools that average the results over thousands of cells.

Chromatin is the complex of DNA and proteins in the nucleus that packages long stretches of DNA into more compact structures. When chromatin is more loosely packed, or open, genes are more poised to be activated than if it's tightly coiled.

When the researchers analyzed the data, they did not find links between peak levels of chromatin accessibility and the expression of tissue-specific genes. Instead, they saw a lot of accessibility "noise" that gave cells the potential to activate genes solely expressed in other specialized tissues. This "ectopic expression" in turn helped train T cells to discriminate between self and non-self.

Chromatin is usually tightly regulated to sequester regions that encode other cell fates and focus accessibility for regions pertinent for the established cell identity.
In this work context, the researchers found the genomic regions that should be tightly packed were more labile or 'jiggly," allowing more opportunities for factors to access and activate genes specific to different cell types."
The team then tried to understand how this "chromatin noise" is amplified in cells. They found that the activity of the tumor suppressor protein p53, known as "the guardian of the genome," is repressed by mTECs prior to their genome becoming noisy. p53 is usually activated when DNA is damaged and can trigger cell death or stop tumor cell growth.

So, it made sense to the researchers that it would be implicated in a process where epithelial cells promiscuously express genes dedicated to other tissues and organs.
When the researchers genetically engineered p53 activity to be enhanced in mTECs, their chromatin became more stable, epigenetic noise was turned down, and the cells could no longer activate tissue-specific genes. This ultimately resulted in the escape of self-reactive T cells from the thymus to cause multi-organ autoimmune disease.
This suggests that thymic epithelial cells adopt deviant states that should normally trigger p53 activation and cell death.But because p53 is downregulated, the cells survive and facilitate this ectopic gene expression to promote the self/non-self discrimination.
It's a fascinating idea to think that cells are programmed to loosen their grip on genes to give them more freedom to get creative and solve problems like preventing T cells from attacking their own tissues.
The researchers extended their studies and found that epigenetic noise also allows lung cancer to sample more of the genome once p53 is deleted. This activates programs specific to other tissues to develop into more aggressive, malignant states. They hope to continue studying whether other cancer types exploit similar mechanisms for tumorigenesis.
Part 2

Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 9:17am

Epigenetic noise: Unappreciated process helps cells change identity

All cells in the body contain the same DNA, but different cell types express different genes; skin cells express genes for the skin, liver cells express liver genes, and so on. This coordination is crucial to help cells differentiate into their assigned roles, but a new study by researchers shows how cells can randomly "shake up" regions of the genome to express genes normally reserved for other cell types.

The study, "Thymic epithelial cells amplify epigenetic noise to promote immune tolerance," published in Nature, suggests that randomness or variability in the way DNA is packaged can create a kind of "epigenetic noise," enabling cells to take on the identity of different cell types. This flexibility plays an important role in tissue repair and the immune system but can also be exploited for the development of tumors.

The researchers worked with an incredibly resourceful group of cells called medullary thymic epithelial cells (mTECs). These cells are found in the thymus, a small, specialized organ of the immune system located just above the heart. They are one of the few cell types in the body that can express a wide variety of genes and alter their identity to mirror cell types from other tissues.

mTECs play an important role in training the immune system to prevent autoimmunity. They present proteins that are normally expressed only in specialized tissues and organs to T cells developing in the thymus. Then, the T cells that react too strongly to molecules from the body's own cells are purged so they don't later trigger an autoimmune response.

The capability to express almost any gene and alter their identities makes mTECs a great candidate for studying how cells can change their fates.

Each individual cell does not express the entire genome. Instead, they express only a unique subset of the tissue-specific genes at any given snapshot. There's a great deal of heterogeneity, so the researchers thought that it was really important to look cell-by-cell to uncover the mechanisms that allow the activation of each subset of tissue-specific genes.

Part 1

Comment by Dr. Krishna Kumari Challa on August 20, 2025 at 12:09pm

“Logic will get you from A to B.  Imagination will take you everywhere.” –Albert Einstein

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