Outsmarting chemo-resistant ovarian cancer

Ovarian Tumor Microenvironment
Image Credit: National Cancer Institute

New approach with nanoparticle starves cells of cholesterol and reduces tumor growth by 50%

Treatment with the nanoparticle reduced ovarian tumor growth by more than 50% in human cells and animal models.

Women diagnosed with ovarian cancer may initially respond well to chemotherapy, but the majority of them will develop resistance to treatment and die from the disease.

Now Northwestern Medicine scientists have discovered the Achilles heel of chemotherapy-resistant ovarian cancer — its hunger for cholesterol — and how to sneakily use that to destroy it.

In a new study, scientists first showed that chemotherapy-resistant ovarian cancer cells and tumors are rich in cholesterol due to an increased uptake of it. They then deployed a synthetic nanoparticle that appeared to the cancer cells as a natural one rich in cholesterol. But when the cancer cells bound the fake particle, the mimic actually blocked cholesterol uptake. Additionally, the scientists showed that reducing cholesterol tricked the cancer cells down a cell death pathway. Treatment with the nanoparticle reduced ovarian tumor growth by more than 50% in human cells and animal models.

Anti-diabetic drugs could lower risk of primary and secondary brain cancer

Photo Credit: Tesa Robbins

Diabetic patients who take anti-diabetic drugs - known as glitazones – long term had a lower risk of primary and secondary brain cancer compared with diabetic patients on other medications, new research led by the University of Bristol has found.

The study, published in BMJ Open, suggests these drugs could be repurposed to prevent brain metastasis in cancer patients who are at high risk of secondary cancers, if the current research is supported by future studies.

PPAR- α agonists (fibrates) and PPAR γ agonists (glitazones) drugs are clinically important due to their widespread safe use to treat high cholesterol (hyperlipidemia) and diabetes.  Previous studies have suggested that fibrates and glitazones may have a role in brain tumor prevention. Given the drug's safety and cost, they have the potential to be repurposed to prevent brain cancers and reduce the risk of secondary tumors by stopping tumor growth.

Using primary care records from the UK GP database Clinical Practice Research Datalink (CPRD), which contains data from a network of over 2,000 GPs from more than 670 practices across the UK, the researchers examined if this theory could be supported.

Snakes do it faster, better

An Australian “snake-lizard” (Lialis burtonis).This species shares numerous similarities with snakes, including loss of limbs and highly flexible skull. But it is an entirely different type of reptile. It is, in fact, a gecko, and is only distantly related to snakes. The snake-lizard is a specialized predator of other lizards and thus has a diet that is also more similar to snakes than it is to other lizards. With just two known species, the snake-lizard has undergone very little evolutionary diversification. Snakes, in contrast, have diversified into many hundreds of species in Australia alone.
Photo Credit: Pascal Title, University of Michigan/Stony Brook University.

More than 100 million years ago, the ancestors of the first snakes were small lizards that lived alongside other small, nondescript lizards in the shadow of the dinosaurs.

Then, in a burst of innovation in form and function, the ancestors of snakes evolved legless bodies that could slither across the ground, highly sophisticated chemical detection systems to find and track prey, and flexible skulls that enabled them to swallow large animals.

Those changes set the stage for the spectacular diversification of snakes over the past 66 million years, allowing them to quickly exploit new opportunities that emerged after an asteroid impact wiped out roughly three-quarters of the planet’s plant and animal species.

Air Pollution Hides Increases in Rainfall

Humans have an impact on rainfall through both air pollution and greenhouse gas emissions.
Photo Credit: Patrick Hendry

We know that greenhouse gas emissions like carbon dioxide should increase rainfall. The emissions heat the atmosphere, causing a one-two punch: warmer oceans make it easier for water to evaporate, and warmer air can hold more water vapor, meaning more moisture is available to fall as rain. But for much of the 20th century, that increase in precipitation didn’t clearly show up in the data.

A new study led by researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) finds that the expected increase in rain has been largely offset by the drying effect of aerosols – emissions like sulfur dioxide that are produced by burning fossil fuels, and commonly thought of as air pollution or smog. The research is published today in the journal Nature Communications.

“This is the first time that we can really understand what’s causing extreme rainfall to change within the continental U.S.,” said Mark Risser, a research scientist at Berkeley Lab and one of the lead authors for the study. He noted that until the 1970s, the expected increases to extreme rainfall were offset by aerosols. But the Clean Air Act caused a drastic reduction in air pollution in the United States. “The aerosol masking was turned off quite suddenly. That means rainfall might ramp up much more quickly than we would have otherwise predicted.”

How bats distinguish different sounds

Seba's short-tailed bat (Carollia perspicillata) filters out important signals from ambient sound and distinguishes between echolocation and communication calls.
Photo Credit: Julio Hechavarría, Goethe University Frankfurt

Bats live in a world of sounds. They use vocalizations both to communicate with their conspecifics and for navigation. For the latter, they emit sounds in the ultrasonic range, which echo and enable them to create an “image" of their surroundings. Neuroscientists at Goethe University Frankfurt have now discovered how Seba's short-tailed bat, a species native to South America, manages to filter out important signals from ambient sound and especially to distinguish between echolocation and communication calls. 

Seba's short-tailed bat (Carollia perspicillata) lives in the subtropical and tropical forests of Central and South America, where it mostly feeds on pepper fruit. The animals spend their days in groups of 10 to 100 individuals in hollow trunks and rocky caverns, and at night they go foraging together. They communicate using sounds that create distinct ambient noise in the colony – like the babble of voices at a lively party. At the same time, the bats also use vocalizations to navigate their surroundings: a phenomenon known as echolocation, for which they emit ultrasonic sounds that reflect off solid surfaces. The animals then assemble these echoes into an “image" of their surroundings. 

Newly discovered brain cells play a key role in right and left turns

Researchers have discovered a new group of neurons in the brainstem which control the right-left circuit.
Graphic Credit: Canva. Courtesy of University of Copenhagen

Researchers have discovered a network of neurons in the brain of mice that help them make right and left turns. In the future, the discovery may be used in treatment for Parkinson’s disease.

Have you ever wondered what happens in the brain when we move to the right or left? Most people don’t; they just do it without thinking about it. But this simple movement is actually controlled by a complex process. 

In a new study, researchers have discovered the missing piece in the complex nerve-network needed for left-right turns. The discovery was made by a research team consisting of Assistant Professor Jared Cregg, Professor Ole Kiehn, and their colleagues from the Department of Neuroscience at the University of Copenhagen. 

In 2020, Ole Kiehn, Jared Creeg and their colleagues identified the ‘brain’s steering wheel’ – a network of neurons in the lower part of the brainstem that commands right- and left- movements when walking. At the time, though, it was not clear to them how this right-left circuit is controlled by other parts of the brain, such as the basal ganglia. 

“We have now discovered a new group of neurons in the brainstem which receives information directly from the basal ganglia and controls the right-left circuit,” Ole Kiehn explains. 

Eventually, this discovery may be able to help people suffering from Parkinson’s disease. The study has been published in the scientific journal Nature Neuroscience.  

RIT researchers highlight the changing connectivity of the Amazon rainforest to global climate

The Amazon rainforest is one of the largest ecosystems in the world, and its climate is changing due to warming and deforestation. Researchers from Rochester Institute of Technology studied the region’s connectivity to the global climate crisis.
Photo Credit: Arın Turkay

The Amazon rainforest is one of the largest ecosystems in the world, and its climate is changing due to warming and deforestation. Researchers from Rochester Institute of Technology studied the region’s connectivity to the global climate crisis.

The Amazon rainforest is a unique region where climatologists have studied the effects of warming and deforestation for decades. With the global climate crisis becoming more evident, a new study is linking the Amazon to climate change around the rest of the world.

Scholars at Rochester Institute of Technology have looked at the issue from a mathematical perspective and have reinforced the idea that the Amazon’s climate is very much connected to the global climate system and that the connectivity is reconfiguring.

Mathematical modeling Ph.D. student Adam Giammarese ’21 BS/MS (applied mathematics) and Assistant Professor Nishant Malik recently had their findings published as a featured article in Chaos: An Interdisciplinary Journal of Nonlinear Science. Giammarese began the work as part of RIT’s Research Experience for Undergraduates (REU) program, along with co-author Jacob Brown.

The team used both old and new approaches to climate network analysis for their research, analyzing decades of temperature data.

Mice study suggests metabolic diseases may be driven by gut microbiome, loss of ovarian hormones

Mice that received fecal implants from donors that had their ovaries removed gained more fat mass and had greater expression of liver genes associated with inflammation, Type 2 diabetes, fatty liver disease and atherosclerosis. The findings may shed light on the greater incidence of metabolic dysfunction in postmenopausal women. The team members included, from left: molecular and integrative physiology professor Erik R. Nelson; Kelly Swanson, the director of the Division of Nutritional Sciences and the Kraft Heinz Endowed Professor in Human Nutrition; and animal sciences professor Brett R. Loman.
  Photo Credit: Fred Zwicky

The gut microbiome interacts with the loss of female sex hormones to exacerbate metabolic disease, including weight gain, fat in the liver and the expression of genes linked with inflammation, researchers found in a new rodent study.

The findings, published in the journal Gut Microbes, may shed light on why women are at significantly greater risk of metabolic diseases such as obesity and Type 2 diabetes after menopause, when ovarian production of female sex hormones diminishes.

“Collectively, the findings demonstrate that removal of the ovaries and female hormones led to increased permeability and inflammation of the gut and metabolic organs, and the high-fat diet exacerbated these conditions,” said Kelly S. Swanson, the director of the Division of Nutritional Sciences and the Kraft Heinz Endowed Professor in Human Nutrition at the University of Illinois Urbana-Champaign who is a corresponding author of the paper.  “The results indicated that the gut microbiome responds to changes in female hormones and worsens metabolic dysfunction.”

Stopping the awakening of leukemia stem cells to prevent relapse

Acute Myeloid Leukemia
Image Credit: National Cancer Institute

Why myeloid leukemias start to grow again after chemotherapy has killed the bulk of cancerous cells, and how growth may be blocked by repurposed drugs, may have been solved by new research.

The bone marrow of Acute Myeloid Leukemia (AML) patients contains a rare population of leukemic stem cells (LSCs) that do not grow and, therefore, are not killed by chemotherapy.

However, after treatment, these cells start to grow and produce AML cells, but it has until now been unclear as to what kick-starts this process.

In a new study, published in Nature Communications, experts from Newcastle University, the University of Birmingham and the Princess Maxima Centre of Pediatric oncology, studied single cells from patients with t(8;21) AML to investigate what made the rare LSCs grow.

Graphene research: numerous products, no acute dangers

The "Graphene Flagship" initiative has investigated the effects of graphene (blue) and related materials on health and the environment. Colored scanning electron microscopy
Image Credit: Empa

The largest EU research initiative ever launched has come to a successful end: The Graphene Flagship was officially concluded at the end of last year. Empa researchers were also involved, such as molecular biologist Peter Wick, who was part of the Health and Environment work package from the very beginning – and has just summarized the findings in this area with international colleagues in a comprehensive review article in the specialist journal ACS Nano.

Think big. Despite its research topic, this could well be the motto of the Graphene Flagship, which was launched in 2013: With an overall budget of one billion Euros, it was Europe's largest research initiative to date, alongside the Human Brain Flagship, which was launched at the same time. The same applies to the review article on the effects of graphene and related materials on health and the environment, which Empa researchers Peter Wick and Tina Bürki just published together with 30 international colleagues in the scientific journal ACS Nano; on 57 pages, they summarize the findings on the health and ecological risks of graphene materials, the reference list includes almost 500 original publications.