Glioblastoma multiforme (GBM) possesses florid angiogenesis. However, the anti-angiogenic agent, Bevacizumab, did not improve overall survival of GBM patients. For more durable anti-angiogenic treatment, we interrogated resistant mechanisms of GBM against Bevacizumab. Serial orthotopic transplantation of in vivo Bevacizumab-treated GBM cells provoked complete refractoriness to the anti-angiogenic treatment. These tumors were also highly enriched with malignant phenotypes such as invasiveness, epithelial to mesenchymal transition, and stem-like features. Through transcriptome analysis, we identified that Talin1 (TLN1) significantly increased in the refractory GBMs. Inhibition of TLN1 not only attenuated malignant characteristics of GBM cells but also reversed the resistance to the Bevacizumab treatment. These data implicate TLN1 as a novel therapeutic target for GBM to overcome resistance to anti-angiogenic therapies.
Keywords: Talin1; anti-angiogenic therapy; bevacizumab-resistance; glioblastoma multiforme; patient derived xenograft models.