Blockade of a Laminin-411–Notch Axis with CRISPR/Cas9 or a Nanobioconjugate Inhibits Glioblastoma Growth through Tumor-Microenvironment Cross-talk

Abstract

There is an unmet need for the treatment of glioblastoma multiforme (GBM). The extracellular matrix, including laminins, in the tumor microenvironment is important for tumor invasion and progression. In a panel of 226 patient brain glioma samples, we found a clinical correlation between the expression of tumor vascular laminin-411 (a4b1g1) with higher tumor grade and with expression of cancer stem cell (CSC) markers, including Notch pathway members, CD133, Nestin, and c-Myc. Laminin-411 overexpression also correlated with higher recurrence rate and shorter survival of GBM patients. We also showed that depletion of laminin-411 a4 and b1 chains with CRISPR/Cas9 in human GBM cells led to reduced growth of resultant intracranial tumors in mice and significantly increased survival of host animals compared with mice with untreated cells. Inhibition of laminin-411 suppressed Notch pathway in normal and malignant human brain cell types. A nanobioconjugate potentially suitable for clinical use and capable of crossing blood-brain barrier was designed to block laminin-411 expression. Nanobioconjugate treatment of mice carrying intracranial GBM significantly increased animal survival and inhibited multiple CSC markers, including the Notch axis. This study describes an efficient strategy for GBM treatment via targeting a critical component of the tumor microenvironment largely independent of heterogeneous genetic mutations in glioblastoma. Significance: Laminin-411 expression in the glioma microenvironment correlates with Notch and other cancer stem cell markers and can be targeted by a novel, clinically translatable nanobioconjugate to inhibit glioma growth.

Gene silencing of HIF-2α disrupts glioblastoma stem cell phenotype

“…Indeed, a clinical trial is underway utilizing a small molecule HIF-2α inhibitor to teat glioblastoma [7] . Furthermore, as our results indicate a modest additive effect with temozolomide in cell killing and complementary influences on CSC differentiation status, combination therapies that combine chemotherapeutics with HIF-2α silencing or inhibition are an attractive avenue in the pursuit of a therapy that can eradicate the CSCs that drive recurrence of malignant cancers such as glioblastoma [33,34] .…”

Tenascin-c mediated vasculogenic mimicry formation via regulation of MMP2/MMP9 in glioma

“…Dynamic interactions among tumor cells, stromal cells, and the ECM is critical for glioma progression. Overexpression of Laminin-411 correlated with shorter survival of GBM patients and its depletion increased survival of host animals 16 . Integrins involve in the activation of transforming growth factor-β and promote invasiveness, angiogenesis, and maintains cancer cell stemness 17 .…”

Engineering Three-Dimensional Tumor Models to Study Glioma Cancer Stem Cells and Tumor Microenvironment

“…They can trigger downstream signaling for different biological processes including migration, adhesion, proliferation, and survival (Durbeej, 2010 ). In GBM, aberrant overexpression of α4 laminins has been described, and a positive correlation between their expression and tumor grade has been described (Sun et al, 2019 ). Particularly, laminin isoform 8 (α 4 β 1 γ 1 , or laminin 411 according to the new nomenclature) appeared overexpressed on GBM blood vessels and surrounding healthy tissue and was linked to higher recurrence and shorter survival (Ljubimova et al, 2001 ; Lathia et al, 2012 ).…”

“…Particularly, laminin isoform 8 (α 4 β 1 γ 1 , or laminin 411 according to the new nomenclature) appeared overexpressed on GBM blood vessels and surrounding healthy tissue and was linked to higher recurrence and shorter survival (Ljubimova et al, 2001 ; Lathia et al, 2012 ). Furthermore, inhibition of laminin isoform 8 through CRISPR/Cas9 techniques has proven to suppress Notch pathway, rendering decreased intracranial tumor growth and longer survival in a glioma animal model (Sun et al, 2019 ). Lathia et al ( 2012 ) showed that α2 laminins provided by perivascular non-CSCs and endothelial cells (ECs) were critical for GBM CSC maintenance and proliferation, promoting glioma CSC radioresistance through enhancing DNA repair.…”