Tag: glioblastoma

Categories : CancerTags :

New Way to Assess Immune Checkpoint Effectiveness

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Chromosomes prepared from a malignant glioblastoma visualized by spectral karyotyping (SKY) reveal an enormous degree of chromosomal instability — a hallmark of cancer.
Credit: Thomas Ried, NCI Center for Cancer Research, National Cancer Institute, National Institutes of Health

Researchers have used a new machine learning and protein profiling system to identify vulnerabilities in glioblastomas and to assess immune checkpoint blockade treatment effectiveness.

Neoadjuvant immune checkpoint blockade (ICB) is a promising treatment for melanoma and other cancer types, and has recently been shown to provide a modest survival benefit for patients with recurrent glioblastoma. To improve the treatment efficacy, researchers are looking for vulnerabilities in surgically removed glioblastoma tissues, but this has been difficult due to the vast differences within the tumours and between patients.

To tackle this problem, researchers at Institute for Systems Biology (ISB) and their collaborators developed a new way to study tumours. The method builds mathematical models using machine learning-based image analysis and multiplex spatial protein profiling of microscopic compartments in the tumour.

The team used this approach to analyse and compare tumour tissues gathered from 13 patients with recurrent glioblastoma and 23 patients with high-risk melanoma. Both groups had been treated with neoadjuvant ICB. Using melanoma to guide the interpretation of glioblastoma analyses, they were able to identify the proteins that correlate with tumour-killing T cells, tumour growth, and immune cell-cell interactions.

Co-lead author Dr Yue Lu described the research : “This work reveals similarities shared between glioblastoma and melanoma, immunosuppressive factors that are unique to the glioblastoma microenvironment, and potential co-targets for enhancing the efficacy of neoadjuvant immune checkpoint blockade.”

“This framework can be used to uncover pathophysiological and molecular features that determine the effectiveness of immunotherapies,” added Dr Alphonsus Ng, co-lead author of the paper.

ISB, UCLA and MD Anderson collaborated on the study, the findings of which were published in Nature Communications. Brain cancer represents one of the toughest settings for immunotherapy success. Collaboration between scientists and clinicians provides a great opportunity for improving patient care and achieving a deep understanding of cancer immunotherapy.


“We believe that the integrated biological, clinical and methodological insights derived from comparing two classes of tumors widely seen as at the opposite ends of the spectrum with respect to immunotherapy treatments should be of interest to broad scientific and clinical audiences,” said corresponding author and ISB President, Dr Jim Heath.

Source: PRWeb

Journal information: Yue Lu et al, Resolution of tissue signatures of therapy response in patients with recurrent GBM treated with neoadjuvant anti-PD1, Nature Communications (2021). DOI: 10.1038/s41467-021-24293-4

Categories : CancerTags :

Glioblastoma Induces ‘Stockholm Syndrome’ to Subvert Body’s Defences

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Glioblastoma, an aggressive form of brain cancer, has been found to corrupt immune cells and make the tumour harder to treat.

Most people diagnosed with glioblastoma die in a short period of time after their diagnosis, but some glioblastoma patients see great benefits from chemotherapy and survive beyond expectations. Researchers at the University of Minnesota have revealed the reason for this in a new study published in the Proceedings of the National Academy of Sciences.

“Deciphering the molecular underpinning of these exceptional responses may hold the key to transforming the hope for miracles into the reality of an expected cure for glioblastoma patients,” said lead author Clark C Chen, MD, PhD, Lyle French Chair in Neurosurgery and head of the Department of Neurosurgery at the University of Minnesota Medical School.

Examining the gene expression profiles of glioblastoma samples from approximately 900 glioblastoma patients, the researchers sought to identify unique features associated with exceptional responders, defined as glioblastoma patients who survive more than two years after treatment.

“We utilized different state-of-the-art analytics to study these samples, including methods innovated by Dr. Aaron Sarver, a member of the University of Minnesota Institute of Health Informatics. Impressively, these analytics converged on a single observation, a paucity of microglia and macrophages,” Dr Chen said.

Specialised immune cells, microglia and macrophages act as scavengers, spotting and removing out-of-place cells in healthy brains. They travel to abnormal cancer cell sites to mount a defence, and can form over half the cells in a glioblastoma sample.

“If microglia and macrophages normally fend off cancer cells, more of them should allow the body to better fend off the tumor. So, we expected to see more of them in the exceptional responders; however, we found the contrary,” said Jun Ma, a researcher in the Department of Neurosurgery at the U of M Medical School and a co-first author of this study.

In order to resolve this paradox, the research team then demonstrated that glioblastoma cells can recondition the surrounding microglia and macrophages, corrupting their normal anticancer functions. Where they once fought off cancer growths, these immune cells are now re-programmed by glioblastoma cells to promote tumour growth.

“It is frightening to consider the possibility that cancer cells can ‘brainwash’ our own immune cells and convert them from cells that fight cancer to cells that promote cancer,” said Judith Varner, a co-senior author of the study and professor of pathology at the University of California, San Diego. “Fortunately, we have figured out how glioblastoma cells subvert our immune system and can now reverse this cellular version of the ‘Stockholm syndrome.'”

Stockholm syndrome is characterised as when a captive begins to identify closely with their captors, as well as with their agenda and demands, however there is little evidence for it being a true psychological phenomenon.

A protein known as phosphoinositide-3-kinase gamma isoform (PI3Kγ) could hold the key to cure this cellular “Stockholm syndrome” and possibly glioblastoma. This protein, when activated, is the switch that corrupts their anti-cancer role. Having studied this process for many years, Varner has pioneered drugs that restore the anti-tumour activities of microglia and macrophages.

“In our animal glioblastoma models, treatment with drugs targeting PI3Kγ consistently resulted in impressively durable responses to chemotherapy,” Chen said. “We are eager to translate these findings into a human trial, with the hope of transforming every glioblastoma patient into an exceptional responder.”

Source: Medical Xpress

Journal information: Jie Li et al, PI3Kγ inhibition suppresses microglia/TAM accumulation in glioblastoma microenvironment to promote exceptional temozolomide response, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2009290118

Categories : CancerTags :

Wrapping up Tumours With Micromesh Nets

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An innovative new nanomedicine has been developed that wraps up tumours in a micromesh net, conforming to the surface of tumor masses and efficiently delivering drugs.

The scientists at the IIT (Istituto Italiano di Tecnologia (Italian Institute of Technology) who developed the mesh described it in the journal Nature Nanotechnology.

Brain tumors are rare but they are some of the most aggressive and difficult to treat. In particular, glioblastoma multiforme (GBM), which is a grade 4 glioblastoma has the most severe prognosis: the average survival is just over 12 months and only 5% of the patients survive beyond 5 years.

GBM typically affects men and women between 45 and 75 years of age. Furthermore, unlike other malignancies, there has been no significant diagnostic and therapeutic improvements for this malignancy over the past 30 years. In fact, both the incidence of new cases and the number of deaths has remained practically unchanged. The only therapeutic strategy currently used is based on surgery, which consists of removing a part of the tumor mass and reducing intracranial pressure, followed by radiotherapy and/or chemotherapy.

The biomedical system developed by IIT and its collaborators can play a very important role in the fight against the disease, representing a possible effective alternative to the few pharmacological treatments used to date.

The microMESH is a micrometric-scale polymeric net, made from biodegradable materials and wraps around the tumour mass, enclosing it. In fact, the micrometric thick polymeric fibers are very flexible and are arranged to form regular openings, which are also on the same scale as cancer cells. This unique feature allows the microMESH to achieve a closer interaction with the tumor mass, increasing the therapeutic efficacy.

Its structure consists of two separate compartments in which different drugs can be loaded which are released towards the tumor mass in an independent, precise, and prolonged fashion. Combining different therapies: chemotherapy, nanomedicine, and immunotherapy enables the microMESH to ‘attack’ glioblastoma.

This work has been carried out by a team led by Prof Paolo Decuzzi, head of the IIT Laboratory of Nanotechnology for Precision Medicine, in collaboration with the Neural Stem Cell Biology Laboratory of Dr Rossella Galli at the San Raffaele Hospital in Milan and a team led by Prof Gerald Grant at the Lucile Packard Children’s Hospital of Stanford University.

The group will continue to develop the microMESH by integrating different types of drugs and therapies to tackle other types of tumors. In the short term, their major objective will be to validate the technology on glioblastoma patients.

Source: News-Medical.Net

Journal information: Mascolo, D. D., et al. (2021) Conformable hierarchically engineered polymeric micromeshes enabling combinatorial therapies in brain tumours. Nature Nanotechnology. doi.org/10.1038/s41565-021-00879-3.

Categories : Cancer New Compounds and TreatmentsTags :

Novel Glioblastoma Drug Can Cross The Blood-brain Barrier

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An experimental spherical nucleic acid (SNA) drug was able to penetrate the blood-brain barrier and trigger glioblastoma tumour cell death in an early clinical trial.

Glioblastoma is the most common and aggressive brain tumour, accounting for 16% of cases. It affects 3.2 per 100 000 people, at an average age of 64 years although it can appear at any time.

The new drug, NU-0129, is the first SNA drug developed for systemic use. The SNA groups RNA or DNA around a nanoparticle. A revolutionary new class of drugs, it can be adapted to a number of neurological diseases such as Parkinson’s.

“We showed the drug, NU-0129, even at very small doses, causes tumour cells to undergo what’s called apoptosis or programmed cell death,” said lead investigator Dr Priya Kumthekar, associate professor of neurology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine physician. “It’s a remarkable finding in humans that confirms what we had previously seen in our animal studies.”

The study participants received the drug intravenously prior to surgery to remove the tumour. The researchers team studied the tumours to determine how well the drug crossed the blood-brain barrier and its effect on their cells.

“This unique 3D design has the ability to infiltrate tumor cells to correct the genes inside and make them susceptible for therapy-induced killing,” said senior author Alexander Stegh, an associate professor of neurology at Northwestern.

Unusually, the drug was developed entirely within the university without involving pharmaceutical licensing.
“We want to move the technology forward as quickly as possible because there are patients with a disease with no current cure,” Kumthekar said.

Dr Leon Platanias, director of the Lurie Cancer Center, said, “These exciting findings for the first time support the potential of spherical nucleic acids for drug delivery to brain tumors. They may prove to have important long-term translational implications for the treatment of these tumours.”

Source: Medical Xpress

Journal information: P. Kumthekar el al., “A first-in-human phase 0 clinical study of RNA interference–based spherical nucleic acids in patients with recurrent glioblastoma,” Science Translational Medicine (2021). stm.sciencemag.org/lookup/doi/ … scitranslmed.abb3945