Radiation and adjuvant drug-loaded liposomes target glioblastoma stem cells and trigger in-situ immune response

Marco Pizzocri; Francesca Re; Elisabetta Stanzani; Beatrice Formicola; Matteo Tamborini; Eliana Lauranzano; Federica Ungaro; Simona Rodighiero; Maura Francolini; Maria Gregori; Alessandro Perin; Francesco DiMeco; Massimo Masserini; Michela Matteoli; Lorena Passoni

doi:10.1093/noajnl/vdab076

Radiation and adjuvant drug-loaded liposomes target glioblastoma stem cells and trigger in-situ immune response

Neurooncol Adv. 2021 Jun 18;3(1):vdab076. doi: 10.1093/noajnl/vdab076. eCollection 2021 Jan-Dec.

Authors

Marco Pizzocri¹, Francesca Re², Elisabetta Stanzani¹, Beatrice Formicola², Matteo Tamborini^{1

3}, Eliana Lauranzano¹, Federica Ungaro⁴, Simona Rodighiero⁵, Maura Francolini⁶, Maria Gregori², Alessandro Perin⁷, Francesco DiMeco^{7

8

9}, Massimo Masserini², Michela Matteoli^{1

3}, Lorena Passoni¹

Affiliations

¹ IRCCS Humanitas Research Hospital, Laboratory of Pharmacology and Brain Pathology, via Manzoni 56, 20089 Rozzano, Milano, Italy.
² BioNanoMedicine Center NANOMIB, School of Medicine and Surgery, University of Milano-Bicocca, via Raoul Follereau 3, 20854 Vedano al Lambro, Italy.
³ CNR Institute of Neuroscience, Milano, Italy.
⁴ IRCCS Humanitas Research Hospital, Laboratory of Gastrointestinal Immunopathology, via Manzoni 56, 20089 Rozzano, Milan, Italy.
⁵ Fondazione Filarete, Milano, Italy.
⁶ Department of Medical Biotechnology and Translational Medicine, Universita' degli Studi di Milano, Italy.
⁷ Department of Neurological Surgery, Fondazione I.R.C.C.S. Istituto Neurologico "C.Besta" Milano, Italy.
⁸ Department of Pathophysiology and Transplantation, Universita' degli Studi di Milano, Italy.
⁹ Department of Neurological Surgery, Johns Hopkins Medical School, Baltimore, Maryland, USA.

Abstract

Background: The radio- and chemo-resistance of glioblastoma stem-like cells (GSCs), together with their innate tumor-initiating aptitude, make this cell population a crucial target for effective therapies. However, targeting GSCs is hardly difficult and complex, due to the presence of the blood-brain barrier (BBB) and the infiltrative nature of GSCs arousing their dispersion within the brain parenchyma.

Methods: Liposomes (LIPs), surface-decorated with an Apolipoprotein E-modified peptide (mApoE) to enable BBB crossing, were loaded with doxorubicin (DOXO), as paradigm of cytotoxic drug triggering immunogenic cell death (ICD). Patient-derived xenografts (PDXs) obtained by GSC intracranial injection were treated with mApoE-DOXO-LIPs alone or concomitantly with radiation.

Results: Our results indicated that mApoE, through the engagement of the low-density lipoprotein receptor (LDLR), promotes mApoE-DOXO-LIPs transcytosis across the BBB and confers target specificity towards GSCs. Irradiation enhanced LDLR expression on both BBB and GSCs, thus further promoting LIP diffusion and specificity. When administered in combination with radiations, mApoE-DOXO-LIPs caused a significant reduction of in vivo tumor growth due to GSC apoptosis. GSC apoptosis prompted microglia/macrophage phagocytic activity, together with the activation of the antigen-presenting machinery crucially required for anti-tumor adaptive immune response.

Conclusions: Our results advocate for radiotherapy and adjuvant administration of drug-loaded, mApoE-targeted nanovectors as an effective strategy to deliver cytotoxic molecules to GSCs at the surgical tumor margins, the forefront of glioblastoma (GBM) recurrence, circumventing BBB hurdles. DOXO encapsulation proved in situ immune response activation within GBM microenvironment.

Keywords: blood–brain barrier; drug-loaded liposomes; glioblastoma stem cell; immunogenic cell death; radiotherapy.