Tag: mRNA

Categories : Neurodegenerative DiseasesTags :

Crafting a ‘Key’ to Cross the Blood-brain Boundary

On By ModernMedia
Source: Pixabay CC0

Researchers led by Michael Mitchell of the University of Pennsylvania are close to gaining access through the blood-brain barrier, a long-standing boundary in biology, by granting molecules a special ‘key’ to gain access.

Their findings, published in the journal Nano Letters, present a model that uses lipid nanoparticles (LNPs) to deliver mRNA, offering new hope for treating conditions like Alzheimer’s disease and seizures.

“Our model performed better at crossing the blood-brain barrier than others and helped us identify organ-specific particles that we later validated in future models,” says Mitchell, associate professor of bioengineering at Penn’s School of Engineering and Applied Science, and senior author on the study.

“It’s an exciting proof of concept that will no doubt inform novel approaches to treating conditions like traumatic brain injury, stroke, and Alzheimer’s.”

Search for the key

To develop the model, Emily Han, a PhD candidate and NSF Graduate Research Fellow in the Mitchell Lab and first author of the paper, explains that it started with a search for the right in vitro screening platform, saying, “I was combing through the literature, most of the platforms I found were limited to a regular 96-well plate, a two-dimensional array that can’t represent both the upper and lower parts of the blood-brain barrier, which correspond to the blood and brain, respectively.”

Han then explored high-throughput transwell systems with both compartments but found they didn’t account for mRNA transfection of the cells, revealing a gap in the development process.

This led her to create a platform capable of measuring mRNA transport from the blood compartment to the brain, as well as transfection of various brain cell types including endothelial cells and neurons.

“I spent months figuring out the optimal conditions for this new in vitro system, including which cell growth conditions and fluorescent reporters to use,” Han explains.

“Once robust, we screened our library of LNPs and tested them on animal models. Seeing the brains express protein as a result of the mRNA we delivered was thrilling and confirmed we were on the right track.”

The team’s platform is poised to significantly advance treatments for neurological disorders.

It’s currently tailored for testing a range of LNPs with brain-targeted peptides, antibodies, and various lipid compositions.

However, it could also deliver other therapeutic agents like siRNA, DNA, proteins, or small molecule drugs directly to the brain after intravenous administration.

What’s more, this approach isn’t limited to the blood-brain barrier as it shows promise for exploring treatments for pregnancy-related diseases by targeting the blood-placental barrier, and for retinal diseases focusing on the blood-retinal barrier.

Next Steps

The team is eager to use this platform to screen new designs and test their effectiveness in different animal models.

They are particularly interested in working with collaborators with advanced animal models of neurological disorders.

“We’re collaborating with researchers at Penn to establish brain disease models,” Han says.

“We’re examining how these LNPs impact mice with various brain conditions, ranging from glioblastoma to traumatic brain injuries. We hope to make inroads towards repairing the blood-brain barrier or target neurons damaged post-injury.”

Source: University of Pennsylvania

Categories : Cancer GeneticsTags :

mRNA Technology Restores Tumour Suppressor Protein in Ovarian Cancer

On By ModernMedia
Photo by Sangharsh Lohakare on Unsplash

Using mRNA technology developed and matured for certain COVID vaccines, researchers have successfully restored the tumour-suppressing p53 protein in mouse models of advanced human ovarian cancer, significantly extending their survival. They report their results in Cancer Communications.

Ovarian cancer is often only detected at an advanced stage and metastases have already formed — usually in the intestines, abdomen or lymph nodes. At such a late stage, only 20 to 30% of all those affected survive the next five years. “Unfortunately, this situation has hardly changed at all over the past two decades,” says Professor Klaus Strebhardt, Director of the Department of Molecular Gynecology and Obstetrics at University Hospital Frankfurt.

In 96% of all ovarian cancer (high-grade) patients, the tumour suppressor gene p53 has mutated and is now non-functional. The gene contains the building instructions for an important protein that normally recognises damage in each cell’s DNA. It then prevents these abnormal cells from proliferating and activates repair mechanisms that rectify the damage.

If this fails, it induces cell death. “In this way, p53 is very effective in preventing carcinogenesis,” explains Strebhardt. “But when it is mutated, this protective mechanism is eradicated.”

If a cell wants to produce a certain protein, it first makes a transcript of the gene containing the building instructions for it. Such transcripts are called mRNAs. In women with ovarian cancer, the p53 mRNAs are just as defective as the gene from which they were copied.

“We produced an mRNA in the laboratory that contained the blueprint for a normal, non-mutated p53 protein,” says Dr Monika Raab from the Department of Molecular Gynecology and Obstetrics, who conducted many of the key experiments in the study.

“We packed it into small lipid vesicles, known as liposomes, and then tested them first in cultures of various human cancer cell lines. The cells used the artificial mRNA to produce functional p53 protein.”

In the next step, the scientists cultivated ovarian tumours – organoids – from patient cells sourced by the team led by Professor Sven Becker, Director of the Women’s Clinic at University Hospital Frankfurt.

After treatment with the artificial mRNA, the organoids shrank and began to die.

To test whether the artificial mRNA is also effective in organisms and can combat metastases in the abdomen, the researchers implanted human ovarian tumour cells into the ovaries of mice and injected the mRNA liposomes into the animals some time later.

The result was very convincing, says Strebhardt: “With the help of the artificial mRNA, cells in the animals treated produced large quantities of the functional p53 protein, and as a result both the tumours in the ovaries and the metastases disappeared almost completely.”

That the method was so successful is partly due to recent advances in mRNA technology: Normally, mRNA transcripts are very sensitive and degraded by cells within minutes.

However, it is meanwhile possible to prevent this by specifically modifying the molecules.

This extends their lifespan substantially, in this study to up to two weeks.

In addition, the chemical composition of the artificial mRNA is slightly different to that of its natural counterpart.

This prevents the immune system from intervening after the molecule has been injected and from triggering inflammatory responses.

In 2023, the Hungarian scientist Katalin Karikó and her American colleague Drew Weissman were awarded the Nobel Prize in Physiology or Medicine for this discovery.

“Thanks to the development of mRNA vaccines such as those of BioNTech and Moderna, which went into action during the SARS-CoV-2 pandemic, we now also know how to make the molecules even more effective,” explains Strebhardt.

Strebhardt, Raab and Becker are now looking for partners to join the next step of the translational project: testing on patients with ovarian cancer. “What is crucial now is the question of whether we can implement the concept and the results in clinical reality and use our method to help cancer patients,” says Strebhardt. The latest results make him very optimistic that the tide could finally turn in the treatment of ovarian carcinomas. “p53 mRNA is not a normal therapeutic that targets a specific weak point in cancer cells. Instead, we are repairing a natural mechanism that the body normally uses very effectively to suppress carcinogenesis. This is a completely different quality of cancer therapy.”

Source: Goethe University Frankfurt

Categories : CancerTags :

mRNA ‘Trojan Horse’ Tricks Cancer Cells into Self-destruction

On By ModernMedia
Graphical abstract. Credit: Theranostics (2023). DOI: 10.7150/thno.82228

Tel Aviv University researchers have hit upon a novel method of cancer treatment by creating an mRNA ‘Trojan horse’ that instructed cancer cells to produce a toxin lethal to themselves, eventually killing them with a success rate of about 50%. This ground-breaking study was led by PhD student Yasmin Granot-Matok and Prof Dan Peer, a pioneer in the development of RNA therapeutics. The study’s results were published in Theranostics.

Prof Peer explains: “Many bacteria secrete toxins. The most famous of these is probably the botulinum toxin injected in Botox treatments. Another classic treatment technique is chemotherapy, involving the delivery of small molecules through the bloodstream to effectively kill cancer cells. However, chemotherapy has a major downside: it is not selective, and also kills healthy cells. Our idea was to deliver safe mRNA molecules encoded for a bacterial toxin directly to the cancer cells – inducing these cells to actually produce the toxic protein that would later kill them. It’s like placing a Trojan horse inside the cancer cell.”

First, the research team encoded the genetic info of the toxic protein produced by bacteria of the pseudomonas family into mRNA molecules (resembling the procedure in which genetic info of COVID-19’s ‘spike’ protein was encoded into mRNA molecules to create the vaccine). The mRNA molecules were then packaged in lipid nanoparticles developed in Prof Peer’s laboratory and coated with antibodies to ensure they would reach their target, the cancer cells. These particles were injected into the tumours of animal models with melanoma skin cancer. After a single injection, 44–60% of the cancer cells vanished.  

“In our study, the cancer cell produced the toxic protein that eventually killed it,” says Prof Peer. “We used pseudomonas bacteria and the melanoma cancer, but this was only a matter of convenience. Many anaerobic bacteria, especially those that live in the ground, secrete toxins, and most of these toxins can probably be used with our method. This is our ‘recipe’, and we know how to deliver it directly to the target cells with our nanoparticles. When the cancer cell reads the ‘recipe’ at the other end it starts to produce the toxin as if it were the bacteria itself and this self-produced toxin eventually kills it. Thus, with a simple injection to the tumour bed, we can cause cancer cells to ‘commit suicide’, without damaging healthy cells. Moreover, cancer cells cannot develop resistance to our technology as often happens with chemotherapy – because we can always use a different natural toxin.”

Source: Tel Aviv University

Categories : COVIDTags :

Tech Transfer for Local mRNA Vaccine Production

On By ModernMedia

South Africa is planning to make vaccines locally using messenger RNA, the breakthrough technology of the global COVID vaccination effort – and once nearly consigned to the dustbin of medical research history.

The World Health Organization (WHO) and its COVAX partners are working with a South African consortium comprising Biovac, Afrigen Biologics and Vaccines, a network of universities and the Africa Centres for Disease Control and Prevention (CDC) to establish its first COVID mRNA vaccine technology transfer hub.

This follows WHO’s global call for Expression of Interest to establish COVID mRNA vaccine technology transfer hubs to scale up production and access to COVID vaccines. The partners will negotiate details with the South African government and public and private partners both local and international.

South African President Cyril Ramaphosa said: “The COVID pandemic has revealed the full extent of the vaccine gap between developed and developing economies, and how that gap can severely undermine global health security. This landmark initiative is a major advance in the international effort to build vaccine development and manufacturing capacity that will put Africa on a path to self determination. South Africa welcomes the opportunity to host a vaccine technology transfer hub and to build on the capacity and expertise that already exists on the continent to contribute to this effort.”

“This is great news, particularly for Africa, which has the least access to vaccines,” said Dr Tedros Adhanom Ghebreyesus, WHO Director-General. “COVID has highlighted the importance of local production to address health emergencies, strengthen regional health security and expand sustainable access to health products.”

The announcement follows the recent visit to South Africa by French President Emmanuel Macron, who gave his country’s commitment to aiding local vaccine production.

“Today is a great day for Africa. It is also a great day for all those who work towards a more equitable access to health products. I am proud for Biovac and our South African partners to have been selected by WHO, as France has been supporting them for years,” said President Macron. “This initiative is the first of a long list to come, that we will keep supporting, with our partners, united in the belief that acting for global public goods is the fight of the century and that it cannot wait.”

Technology transfer hubs are training facilities where the technology is established at industrial scale and clinical development performed. Interested manufacturers from low- and middle-income countries can receive training and any necessary licences to the technology, assisted by the WHO and partners.

Biovac is a bio-pharmaceutical company resulting from a partnership formed with the South African government in 2003 to establish local vaccine manufacturing capability for the provision of vaccines for national health management and security.

Afrigen Biologics and Vaccines is a biotechnology company focuses on product development, bulk adjuvant manufacturing and supply and distribution of key biologicals to address unmet healthcare needs.

The organisations complement one another, and can each take on different roles within the proposed collaboration: Biovac will be the developer while Afrigen is the manufacturer, with a consortium of universities as academic supporters providing mRNA know-how. Africa CDC will provide technical and regional support.

The South African consortium has existing operating facilities with available capacity and experience in technology transfers. It is also a global hub that can start training technology recipients immediately.

The WHO is speaking to a number of pharmaceutical manufacturers about establishing the hub, though the talks are so far mainly with “smaller companies,” said Soumya Swaminathan, WHO’s chief scientist. “We are having discussions with the larger companies with proven mRNA technology,” she added.

The mRNA vaccines may be produced in South Africa within 9 to 12 months, she said. WHO’s call for expressions of interest has so far generated 28 offers to either provide technology for mRNA vaccines or to host a technology hub or both. 

It is the first time that messenger RNA technology has been used to make vaccines, which has been used by Moderna and Pfizer/BioNTech. They have proven very effective against the original SARS-CoV-2 strains and even against its more recent variants.

Source: World Health Organization