No abstract

An accurate prediction of the intracranial infiltration tendency and drug response of individual Glioblastoma (GBM) cells is essential for personalized prognosis and treatment for this disease. However, the clinical utility of mouse PDOX models remains limited given current technical constraints including difficulty in generating sufficient sample numbers from small tissue samples and a long latency period for results. To overcome these issues, we establish zebrafish GBM xenografts of diverse origin, which can tolerate intracranial engraftment and maintain their unique histological features. Subsequent single cell RNA-seq (scRNA-seq) analysis confirms significant transcriptional identity resemble invading GBM microtumors observed in the proportionally larger brains of model animals and humans. Endothelial scRNA-seq confirms zebrafish blood-brain-barrier is homologous to the mammalian. Finally, we establish a rapid and efficient zebrafish PDOX (zPDOX) model, which can predict long-term outcomes of GBM patients within 20 days. zPDOX provides a novel avenue for precision medicine of GBM, especially for the evaluation of intracranial infiltration tendency and prediction of individual drug sensitivity.

No abstract

The ‘angiogenic switch’ is critical for tumor progression. However, the pathological details and molecular mechanisms remain incompletely characterized. In this study, we established mammal xenografts in zebrafish to visually investigate the first vessel growth (angiogenic switch) in real-time, by inoculating tumor cells into the perivitelline space of live optically transparent Transgenic (flk1:EGFP) zebrafish larvae. Using this model, we found that hypoxia and hypoxia-inducible factor (HIF) signaling were unnecessary for the angiogenic switch, whereas vascular endothelial growth factor A gene (Vegfa) played a crucial role. Mechanistically, transcriptome analysis showed that the angiogenic switch was characterized by inhibition of translation, but not hypoxia. Phosphorylation of eukaryotic translation initiation factor 2 alpha (Eif2α) and the expression of Vegfa were increased in the angiogenic switch microtumors, and 3D tumor spheroids, and puromycin-treated tumor cells. Vegfa overexpression promoted early onset of the angiogenic switch, whereas Vegfa knockout prevented the first tumor vessel from sprouting. Pretreatment of tumor cells with puromycin promoted the angiogenic switch in vivo similarly to Vegfa overexpression, whereas Vegfa knockdown suppressed the increase. This study provides direc and dynamic in vivo evidences that inhibition of translation, but not hypoxia or HIF signaling promotes the angiogenic switch in tumor by increasing Vegfa transcription.