ABSTRACT
Glioblastoma (GBM) is the most common and lethal form of brain cancer. Standard of care is surgical resection
followed by treatment with the alkylating agent temozolomide (TMZ). However, two major challenges make GBM
currently untreatable: 1) its diffuse invasion beyond the surgical margin; and 2) TMZ resistance that is tightly
linked to expression of the DNA damage repair protein MGMT. While perivascular niches (PVNs) extending from
the tumor into the surrounding parenchyma are believed to regulate invasion, recurrence, and poor survival, the
majority of animal glioma models are sensitive to TMZ and most do not express MGMT, making it difficult to
assess novel therapeutics in animal models that don’t display TMZ resistance. This Cancer Tissue Engineering
Collaborative project will develop and thoroughly characterize a multidimensional engineered PVN biomaterial,
study pathophysiological processes driving GBM invasion and TMZ resistance, and accelerate the evaluation of
novel TMZ derivatives created to target diffuse GBM cells regardless of MGMT status. We will use advanced
microfluidics to create libraries of miniaturized gelatin hydrogels containing margin-mimetic hyaluronic acid (HA)
and an embedded perivascular network. We also use a novel synthetic pipeline to create TMZ derivatives that
generate alternate DNA modifications that cannot be removed by MGMT that we hypothesize work in an MGMT-
independent fashion. Merging these technologies, we will benchmark an engineered PVN platform formed using
primary brain neurovascular cells for rapid evaluation of GBM invasion, MGMT expression, and TMZ resistance
amenable to analysis of cell lines and patient-derived GBM specimens with disparate MGMT profiles. To do this,
we will first construct and thoroughly characterize an engineered perivascular niche (Aim 1). We will use this
novel biomaterial to benchmark patterns of invasion and MGMT expression in GBM cell lines (Aim 2). Finally,
we will establish predictive efficacy of TMZ variants in an engineered perivascular niche (Aim 3). Together, we
will develop, characterize, and benchmark a tissue engineered PVN to examine the role of microenvironmental
selection pressures in the tumor margin on behaviors related to invasion, MGMT-mediated TMZ resistance,
recurrence, and poor survival. Consistent with score-driving criteria of the CTEC program, we will develop and
thoroughly characterize an engineered PVN biomaterial, show it fits within the continuum of existing cancer
models, use it to examine phenomena underlying the failure to achieve durable survival, and gain actionable
insight regarding novel TMZ derivatives with potential to effectively target GBM cells in the margins independent
of MGMT status.