Glioblastoma cells from different parts of the same tumor behave completely differently — undermining standard drug testing approaches

Glioblastoma cells from different parts of the same tumor behave completely differently — undermining standard drug testing approaches

Glioblastoma (GBM) is the most lethal brain tumor, notorious for resisting treatment. A major reason is intratumoral heterogeneity — different parts of the tumor can be biologically distinct. This study directly characterized this heterogeneity by taking multiple MRI-guided biopsies from different tumor regions in six GBM patients and growing cell cultures from each.

The researchers found that neurosphere cultures derived from different regions of the same tumor showed dramatically divergent phenotypes — different growth rates, drug sensitivities, and ability to accumulate 5-ALA (a fluorescent dye used to visualize cancer cells during surgery). This means that drug screening performed on a single tumor biopsy — the standard approach — likely misses therapeutic vulnerabilities present in other tumor regions, and may overestimate or underestimate drug effectiveness.

The findings reinforce the case for multi-region sampling in GBM clinical trials and suggest that treatment strategies need to account for spatial heterogeneity to be effective.

Key Findings

• Neurosphere cultures from different regions of the same GBM tumor show divergent phenotypes
• Distinct regions varied in proliferative capacity, drug sensitivity, and 5-ALA accumulation
• 40 biopsies from 6 patients and 30 corresponding cultures demonstrated reproducible spatial divergence
• Standard single-biopsy drug screening does not capture the full biological landscape of GBM
• MRI-guided multi-region sampling enabled systematic profiling of spatial tumor heterogeneity

Implications

These results argue strongly for multi-region biopsy approaches in GBM research and potentially clinical trials. Single-biopsy drug screening results should be interpreted cautiously. Future GBM treatment strategies may need to target multiple tumor subpopulations simultaneously to achieve durable responses.

Caveats

Preprint, not peer reviewed. Small cohort (n=6 patients). In vitro neurosphere cultures may not fully reflect in vivo tumor biology. Clinical implications for treatment planning need prospective validation. Summary based on abstract only.

Source: bioRxiv — 2026-04-10