# Mechanism-based drug repurposing and novel treatments for glioblastoma

> **NIH NIH R01** · UNIVERSITY OF ROCHESTER · 2020 · $230,170

## Abstract

This request for supplemental funding represents a direct extension of our NCI-funded research on new
treatments for glioblastoma (GBM). The central hypothesis of our GBM research is that these cells require
inhibition of the c-Cbl ubiquitin ligase (by ßpix) to generate tumors, escape chemotherapy and escape
oxidative stressors. This work has gone so well that we will soon be initiating clinical trials of our new therapies.
 One of the consequences of our GBM research is that we have developed a sophisticated understanding of
the mechanisms by which the inhibitory complex between c-Cbl and ßPix is regulated. Our data indicate that
this complex is formed as a result of increased activation of p21-activated kinases (PAKs), which appears to be
due to increased signaling along the sphingosine-1-phosphate (S1P) pathway.
 As one component of testing whether our understanding of regulation of c-Cbl inhibition is correct, we have
been treating oligodendrocyte progenitor cells (OPCs) with S1P and with the S1P analog FTY720. These
experiments allow us to test whether the inhibitory complex formation is induced by S1P signaling, to better
understand the consequences of c-Cbl inhibition in glial progenitor cells as a complement to understanding the
effects of c-Cbl activation in GBM cells, and to understand the ability of this complex to allow cells to escape
the deleterious effects of oxidative stress (an important component of Alzheimer’s disease (AD).
 As part of our attempts to understand consequences of c-Cbl inhibition, we are analyzing responses to pro-
oxidative stimuli in OPCs with S1P-induced inhibitory complexes or treated with anti-oxidants. The stimulus of
greatest interest, in respect to this supplement, is amyloid-ß(1-42) oligomers, which oxidizes cells and is the
most toxic form of Aß. OPCs are studied due to the extensive myelin damage in AD. Based on our current
understanding, we hypothesized that Aß(1-42) oligomers will activate the redox/Fyn/c-Cbl (RFC) pathway and
cause hyper-activation of c-Cbl in OPCs. This is indeed the case, and activation of the RFC pathway appears
to be critical for Aß toxicity in OPCs. Genetic knockout of Fyn kinase or c-Cbl in OPCs protects against Aß
toxicity and RFC pathway activation, as do anti-oxidants. Aß(1-42) oligomers also activate the RFC pathway in
neurons. We also have confirmed, in studies on other pro-oxidative signals, that generation of the c-Cbl/ßpix
inhibitory complex in OPCs protects cells from the effects of pro-oxidative signals on promoting cell-cycle exit.
 We now seek the opportunity to utilize Aß(1-42) oligomers as an important pro-oxidative insult for analyzing
the consequences of c-Cbl inhibition in glial progenitor cells and neurons, including IPSC-derived OPCs and
neurons that are inherently more vulnerable to Aß due to AD-relevant mutations in presenilin-1 or expression
of apoliprotein E4. At the same time, the experiments we propose will offer a new mechanism of Aß toxicity
that int...

## Key facts

- **NIH application ID:** 10123791
- **Project number:** 3R01CA214066-04S1
- **Recipient organization:** UNIVERSITY OF ROCHESTER
- **Principal Investigator:** MARK D NOBLE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $230,170
- **Award type:** 3
- **Project period:** 2020-04-01 → 2021-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10123791

## Citation

> US National Institutes of Health, RePORTER application 10123791, Mechanism-based drug repurposing and novel treatments for glioblastoma (3R01CA214066-04S1). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10123791. Licensed CC0.

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