Alexander Pietras Lab

Thanks to all speakers, including bsky users @winklerlab.bsky.social @claudiakleinman.bsky.social @nelander-lab.bsky.social @gocastelobranco.bsky.social, the Ragnar Söderberg foundation, and co-hosts @remeseiro-lab.bsky.social, @maawim.bsky.social, and Fredrik Swartling.

Had a blast hosting the Brain Tumor Plasticity symposium at the Royal Swedish Academy of Sciences this week! Here's @leilaakkari.bsky.social with an outstanding talk on the evolving brain tumor microenvironment 🤩

Thrilled to share our latest work - we describe a novel and therapeutically relevant mechanism underlying dysregulation of innate immune receptor C5aR1 in the tumour microenvironment. Thanks and congratulations to all authors!

www.nature.com/articles/s41...

To this day, even the strongest treatments fail when the brain’s own healing turns against it. Flunarizine, a migraine drug, may help stop astrocytes from nurturing #glioblastoma back to life.

Read ⤵️

Phenotypic Screening Identifies Flunarizine as an Inhibitor of Radiotherapy-Induced Astrocyte Reactivity with Therapeutic Potential in Glioblastoma Radiotherapy is part of the standard-of-care for glioblastoma, yet tumors invariably recur as incurable lesions post-treatment. Recent studies suggest that radiation-induced astrocyte reactivity foste...

📣 Preprint alert! Happy to share our latest work, in which we identify Flunarizine as an inhibitor of astrocyte reactivity with therapeutic potential in glioblastoma (GBM). Details in 🧵:
www.biorxiv.org/content/10.1...

Phenotypic Screening Identifies Flunarizine as an Inhibitor of Radiotherapy-Induced Astrocyte Reactivity with Therapeutic Potential in Glioblastoma https://www.biorxiv.org/content/10.1101/2025.07.12.664538v1

#Glioblastoma #GBM #AstrocyteReactivity #DrugRepurposing #Radiotherapy #NeuroOncology

…the Swedish Cancer Society, the Swedish Research Council, the Swedish Childhood Cancer Fund, Ollie & Elof Ericssons foundation, the Crafoord foundation, the Swedish Brain Foundation, the Royal Physiographic Society in Lund, Stiftelsen Cancera, @embo.org, and the Fondation Bettencourt-Schueller.

This work was spearheaded by Pauline Jeannot with crucial contributions from collaborators @edinburgh-uni.bsky.social @lundstem.bsky.social @ahleniuslab.bsky.social , and supported by @erc.europa.eu, Mrs. Berta Kamprad's Cancer Foundation, the Ragnar Söderberg Foundation…

Our findings position Flunarizine as a clinically viable repurposed drug to target RT-induced astrocyte reactivity, delaying recurrence in preclinical models.

Importantly, Flunarizine showed no direct cytotoxicity to tumor cells, emphasizing its unique action on the microenvironment rather than the cancer cells themselves.

In preclinical mouse models, combining Flunarizine with RT significantly prolonged survival, reduced fibrosis, and mitigated astrocyte reactivity, specifically targeting the irradiated microenvironment.

Mechanistically, Flunarizine reduced astrocytic activation of TGF-β signaling—a key driver of fibrosis—without directly harming GBM cells.

Flunarizine, an existing migraine medication, emerged as a potent inhibitor of RT-induced astrocyte reactivity, working effectively in vitro and in vivo.

We developed a novel, automated, image-based assay to quantify astrocyte reactivity in human astrocytes and iPSC-derived astrocytes, and screened >1,700 small molecule compounds.

Our goal: Identify compounds that selectively block astrocyte reactivity triggered by radiotherapy, potentially delaying GBM recurrence.

Reactive astrocytes can initially protect brain tissue but, when chronically activated (as seen after radiation), they alter the microenvironment by promoting fibrosis and inflammation.

GBM remains one of the deadliest cancers due to inevitable recurrence after standard treatments, including radiotherapy (RT). We believe that microenvironmental adaptations to RT, including astrocyte reactivity, fosters a tumor-supportive environment.

Phenotypic Screening Identifies Flunarizine as an Inhibitor of Radiotherapy-Induced Astrocyte Reactivity with Therapeutic Potential in Glioblastoma Radiotherapy is part of the standard-of-care for glioblastoma, yet tumors invariably recur as incurable lesions post-treatment. Recent studies suggest that radiation-induced astrocyte reactivity foste...

📣 Preprint alert! Happy to share our latest work, in which we identify Flunarizine as an inhibitor of astrocyte reactivity with therapeutic potential in glioblastoma (GBM). Details in 🧵:
www.biorxiv.org/content/10.1...

🌍 Join us in a supportive, international lab within a vibrant cancer research hub! Strong local bioinformatics community + a high quality of life in the Malmö/Lund region. Great science, great people, great place to live. 💻🧬🏡

📣 New pre-print from the lab:
👉 “Gene regulatory networks linked to GABA signalling emerge as relevant for glioblastoma pathogenesis” #Glioblastoma #GB #GRNs #multiomics #GABA #CancerNeuroscience #ML #GBM

📝 Read the #BioRxiv here:
doi.org/10.1101/2025...

Doctoral Student in Tumor Biology Description of the workplace The research group conducts experimental research on brain tumors and is led by Associate Professor Alexander Pietras. The group consists of a bioinformatician, two postdo

🚨 We’re hiring a bioinformatics-focused PhD student for our ERC-funded project on recurrent GBM! Focus: tumor-supportive microenvironment 🔬 Experience with scRNA-seq, spatial transcriptomics & Python/R a plus. Must be self-motivated & driven. DM for details! Repost=❤️ lu.varbi.com/en/what:job/...

🌍 Join us in a supportive, international lab within a vibrant cancer research hub! Strong local bioinformatics community + a high quality of life in the Malmö/Lund region. Great science, great people, great place to live. 💻🧬🏡

Doctoral Student in Tumor Biology Description of the workplace The research group conducts experimental research on brain tumors and is led by Associate Professor Alexander Pietras. The group consists of a bioinformatician, two postdo

🚨 We’re hiring a bioinformatics-focused PhD student for our ERC-funded project on recurrent GBM! Focus: tumor-supportive microenvironment 🔬 Experience with scRNA-seq, spatial transcriptomics & Python/R a plus. Must be self-motivated & driven. DM for details! Repost=❤️ lu.varbi.com/en/what:job/...

Just a few spots left for this exciting symposium on brain tumor plasticity—grab yours (free of charge!) before they're gone! 🚨

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👋We have 2 amazing projects: A) basic molecular regulation of the LN lymphatic vasculature & B) lymphatic metastasis with new models & human samples describing completely new phenomena - both projects with solid preliminary data to build on. Open for interested postdoctoral scientists 📩

Postdoc in Experimental Oncology - Lund (Stad), Skåne (SE) job with Lund University | 12838990 Lunds universitet, 009999 LUNDS UNIVERSITET, 310000 MED Lund University was founded in 1666 and is repeatedly ranked among the world’s top universi...

Join us for innovative explorations of the tumor microenvironment🔬 Learn cutting-edge technologies and grow in a dynamic environment💡 The postdoc will work alongside a doctoral student from @adaptmet.bsky.social, gaining access to collaborative partners across 🇪🇺.
Apply now👇
tinyurl.com/4mby45hf

Fantastic Leila, congrats!!! Let's celebrate in September if not before 🥳

Thanks for taking the time to come by - great talk and a pleasure hosting you! Fingers crossed for a smooth trip back and a good result from München tonight ⚽