Glioblastoma endothelium drives bevacizumab-induced infiltrative growth via modulation of PLXDC1

Maria Laura Falchetti, Quintino Giorgio D'Alessandris, Simone Pacioni, Mariachiara Buccarelli, Liliana Morgante, Stefano Giannetti, Valentina Lulli, Maurizio Martini, Luigi Maria Larocca, Eliza Vakana, Louis Stancato, Lucia Ricci-Vitiani, Roberto Pallini

Research output: Contribution to journalArticle

Abstract

Bevacizumab, a VEGF-targeting monoclonal antibody, may trigger an infiltrative growth pattern in glioblastoma. We investigated this pattern using both a human specimen and rat models. In the human specimen, a substantial fraction of infiltrating tumor cells were located along perivascular spaces in close relationship with endothelial cells. Brain xenografts of U87MG cells treated with bevacizumab were smaller than controls (p = 0.0055; Student t-test), however, bands of tumor cells spread through the brain farther than controls (p < 0.001; Student t-test). Infiltrating tumor Cells exhibited tropism for vascular structures and propensity to form tubules and niches with endothelial cells. Molecularly, bevacizumab triggered an epithelial to mesenchymal transition with over-expression of the receptor Plexin Domain Containing 1 (PLXDC1). These results were validated using brain xenografts of patient-derived glioma stem-like cells. Enforced expression of PLXDC1 in U87MG cells promoted brain infiltration along perivascular spaces. Importantly, PLXDC1 inhibition prevented perivascular infiltration and significantly increased the survival of bevacizumab-treated rats. Our study indicates that bevacizumab-induced brain infiltration is driven by vascular endothelium and depends on PLXDC1 activation of tumor cells.

Original languageEnglish
JournalInternational Journal of Cancer
DOIs
Publication statusAccepted/In press - Jan 1 2018

Keywords

  • antiangiogenic therapy
  • bevacizumab
  • brain infiltration
  • glioblastoma
  • PLXDC1

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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  • Cite this

    Falchetti, M. L., D'Alessandris, Q. G., Pacioni, S., Buccarelli, M., Morgante, L., Giannetti, S., Lulli, V., Martini, M., Larocca, L. M., Vakana, E., Stancato, L., Ricci-Vitiani, L., & Pallini, R. (Accepted/In press). Glioblastoma endothelium drives bevacizumab-induced infiltrative growth via modulation of PLXDC1. International Journal of Cancer. https://doi.org/10.1002/ijc.31983