Australian Researchers Reveal Hidden Role of CD47 Protein in Driving Glioblastoma Growth

A team from the University of Adelaide has made a significant breakthrough in understanding glioblastoma, one of the most aggressive and deadly forms of brain cancer. Their research uncovers a previously unrecognized mechanism where the protein CD47 plays a direct role in promoting tumor cell proliferation, migration, and invasion, beyond its known function in evading the immune system. This discovery, published in the Proceedings of the National Academy of Sciences (PNAS) on March 24, 2026, opens new avenues for targeted therapies that could transform treatment outcomes for patients facing this devastating disease.

Glioblastoma multiforme (GBM), as it is formally known, affects around 1,200 Australians annually, with a median survival of just 12-15 months post-diagnosis despite aggressive treatments like surgery, radiation, and chemotherapy. The University of Adelaide's findings highlight how CD47 stabilizes its partner protein ROBO2 by sequestering the E3 ubiquitin ligase ITCH, preventing ROBO2's degradation. This stabilization axis fuels the tumor's relentless advance, correlating with poorer patient survival rates in clinical data.

The Science Behind the CD47-ITCH-ROBO2 Pathway

CD47, a transmembrane protein often overexpressed in cancers, was long appreciated for its 'don't eat me' signal to immune cells via interaction with SIRPα on macrophages. However, the Adelaide team, led by Dr. Nirmal Robinson and including Dr. Ruhi Polara and Professor Stuart Pitson from the Centre for Cancer Biology, demonstrated an immune-independent role. In lab models and patient-derived tissues, CD47 binds ITCH, blocking its ability to tag ROBO2—a receptor involved in cell guidance—for destruction. Elevated ROBO2 then drives oncogenic signaling, enhancing cell motility and growth.

Step-by-step, the process unfolds as follows: first, CD47 expression rises in glioblastoma cells; second, it sequesters ITCH in the cytoplasm; third, unchecked ROBO2 accumulates on the cell surface and activates downstream pathways like SLIT-ROBO signaling; fourth, this cascade promotes epithelial-to-mesenchymal transition (EMT), invasion into surrounding brain tissue, and resistance to apoptosis. Blocking CD47 with antibodies or small molecules disrupted this axis, shrinking tumors and extending survival in mouse xenografts, even in immune-deficient settings.

This mechanism explains why anti-CD47 therapies have shown mixed results in trials—they targeted immune evasion but missed this intrinsic tumor driver. The study's use of CRISPR screening, proteomics, and structural biology provides robust evidence, positioning the CD47-ITCH-ROBO2 pathway as a prime therapeutic target.

University of Adelaide's Centre for Cancer Biology: A Hub for Innovative Research

Housed within the University of Adelaide and SA Pathology, the Centre for Cancer Biology exemplifies Australia's strength in translational oncology. Professor Pitson, a sphingolipid signaling expert, and Dr. Robinson, focusing on cell death pathways, spearheaded this work amid a collaborative environment fostering multi-disciplinary approaches. Their labs leverage advanced tools like mass spectrometry and organoid cultures to bridge basic science and bedside application.

This discovery builds on prior Centre achievements, such as sphingosine-1-phosphate (S1P) research in GBM migration. With over 100 researchers, the Centre secures major funding from NHMRC and Cancer Council SA, underscoring South Australia's role in national cancer research efforts. For aspiring researchers, programs like the university's PhD in molecular oncology offer hands-on training in these cutting-edge techniques.

Glioblastoma in Australia: Statistics and Challenges

In Australia, glioblastoma incidence has risen 2.5% annually over the past decade, linked to aging populations and improved diagnostics. Cancer Australia reports 1,400 new cases yearly, disproportionately affecting males (60%) aged 55-75. Survival remains dismal—5-year rate under 5%—due to the tumor's infiltrative nature, blood-brain barrier, and genetic heterogeneity (e.g., EGFR amplification in 40%, IDH mutations in 10%).

Treatment standard—surgery followed by temozolomide and radiation—yields median progression-free survival of 6.9 months. Recurrence is inevitable, with 90% of patients succumbing within two years. This Adelaide study addresses a key gap: while immunotherapies like checkpoint inhibitors fail in 80% of GBM cases, targeting intrinsic drivers like CD47-ROBO2 could synergize with standards, potentially extending survival by months or years.

Broader Implications for Cancer Therapy and Drug Development

The CD47-ROBO2 insight extends beyond GBM to other ROBO1/2-expressing cancers like breast (30% metastatic cases) and lung. Preclinical data showed CD47 blockade reduced invasion by 60% in organoids. Ongoing trials (e.g., magrolimab, NCT02953509) could be repurposed, combining with ITCH activators or ROBO2 inhibitors.

Challenges include specificity—CD47's normal roles in platelets—and delivery across the blood-brain barrier. Nanoparticle formulations or focused ultrasound, under development at Australian unis like UNSW, offer promise. Economically, GBM costs Australia $500 million yearly in care; novel therapies could save $100 million via extended survival.

Photo by Eriksson Luo on Unsplash

Stakeholder Perspectives: From Patients to Policymakers

Dr. Robinson emphasized, 'This uncovers a non-immune role for CD47, a game-changer for precision medicine.' Patient advocates like Brain Cancer Australia hail it as 'hopeful amid stagnant progress.' Policymakers, via the Medical Research Future Fund ($20 billion allocated), prioritize such uni-led discoveries.

Industry partners, including Spinifex Pharma, eye commercialization. For higher ed, it highlights PhD opportunities in structural biology, with Adelaide offering scholarships up to $35,000/year.

Australian Universities Leading Protein Research

Complementing Adelaide's work, Monash University's AI-designed antimicrobial protein combats superbugs, showcasing novel properties via machine learning. WEHI's TAK1 safety switch enhances immunotherapy efficacy. Doherty Institute decoded KICSTOR-GATOR1 for cell growth control.

These efforts, funded by ARC Discovery Projects ($11M+ in 2026), position Australia as a biotech powerhouse, with exports hitting $5B annually.

Challenges in Translating Discoveries to Clinic

• Funding Gaps: Uni research relies on competitive grants; only 20% success rate.
• Regulatory Hurdles: TGA trials cost $10M+, delaying 5-10 years.
• Talent Shortage: 30% brain drain to US/UK; unis counter with fellowships.
• Ethical Issues: Balancing patient access and trial equity.

Solutions include public-private partnerships like Bio21 Cluster ($1B ecosystem).

Future Outlook: Towards Personalized Brain Cancer Therapies

By 2030, CD47-targeted drugs could enter Phase II trials, integrated with CAR-T cells. AI models from Monash predict protein interactions, accelerating design. Australia's National Brain Cancer Mission ($46M) amplifies uni efforts.

For students, research assistant roles at Adelaide offer entry, linking to /research-assistant-jobs.

Career Opportunities in Australian Cancer Research

Uni labs seek postdocs ($90K+ salary), lecturers, and professors. Platforms like AcademicJobs list 500+ openings, emphasizing protein biochem expertise. Training via HDR programs builds skills in CRISPR, proteomics.

Photo by Martin David on Unsplash

Actionable Insights for Researchers and Students

• Master CRISPR for pathway validation.
• Collaborate via national hubs like AIBN.
• Publish in PNAS/Cell Reports for impact.
• Seek NHMRC fellowships ($1.5M/career).

This discovery exemplifies how uni innovation drives hope against cancer.