1. THERAPEUTICALLY TARGETING THE HEAT
SHOCK RESPONSE AND REDOX/FYN/C-
CBL SIGNALING IN GLIOBLASTOMA.
Paige Haas
Laboratory of Dr. Mark Noble
2. Glioblastoma multiforme (GBM)
• Most common tumor of the CNS
• Approximate 12 month survival with
multi-modal therapies
• Highly migratory, radio- and
chemo- resistant
• Resistant to proteotoxic stress
• Hypothesis: Down regulation of the heat shock
response with a FDA approved drug will increase
GBM’s sensitivity to chemotherapeutics.
Huge unmet need for novel targeted therapies
Washington University in St. Lewis
School of Medicine
4. The HSR in cancer
• Characteristically up-regulated in cancer
• Increase resistance to proteotoxic stress
• Linked to tumor growth, metastatic potential, and chemo-
resistance
Jego et al, Cancer Letters 2013
13. 0
0.2
0.4
0.6
0.8
1
1.2
Control URMC-07 5uM + Tamoxifen
5uM
Proteinnormalizedtoactin
EGFR
URMC-07 leads to biochemical restoration of
the RFC pathway
p-c-Cbl
c-Cbl
ᵦ-Actin
Control
URMC-07+
Tamoxifen
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Control URMC-07 5uM +
Tamoxifen 5uM
p-c-cbl/c-cblnormalizedto
actin
p-c-Cbl
24 hours
URMC-07+
Tamoxifen
Control
EGFR
ᵦ-Actin
24 hours
14. Summary
• GBM is highly migratory and resistant to proteotoxic
stress
• Over expression of the HSR is linked to these GBM
hallmarks
• URMC-07 down regulates the HSR in GBM, reducing the
cells chemotherapeutic resistance and self renewal
capacity
• URMC-07 biochemically restores another
characteristically dysregulated pathway in GBM, the RFC
pathway
• The HSR and RFC pathway may intersect
15. Continuing Research
• Exploration into the proposed intersection of the
redox/Fyn/c-Cbl pathway and the heat shock
response
• Additional investigation into the effect of URMC-07
on hallmarks of GBM
• Pre-clinical investigation of the therapeutic efficacy
of URMC-07 in a rodent xenograft model of GBM
16. Acknowledgements
• Dr. Mark Noble
• Jennifer Stripay
• Mayer-Pröschel and Pröschel Labs
• University of Rochester
• Department of Biomedical Genetics
Funding: Wilmot Cancer Center Pilot Grant
Editor's Notes
grade IV astrocytoma, most common tumor in the CNS
The minimal progress in clinically treating this disease has created a huge unmet need for novel, targeted therapies in the treatment of glioblastoma multiform.
We will discuss the role of the heat shock response in cancer momentarily, but we’ll begin with a brief introduction to the pathway.
highly conserved chaperone proteins that play essential roles in the response to a wide variety of environmental and physiological insults.
Res. to proteotoxic stress poses a problem in the treatment of cancer, as application of PS is an important mechanism in treatment
We have chosen to look at the effects of a drug we have named URMC-07 in GBM that has been shown to down regulate HSF1.
We have seen evidence that this drug down regulate the HSR in GBM at a molecular level
Western blotting was done on lysates from patient derived glioblastoma cells that were dosed with 5uM URMC-07 with a panel of relevant HS proteins.
…
Having seen the effects of URMC-07 on the HSR at a molecular level, we were interested in identifying the effects of URMC-07 on the viability of these GBM cells.
To investigate this further, we looked into the physiological effects of URMC-07 on these cells by characterizing the drug’s effect on self renewal.
partially due to a population of progenitor cells within the tumor, we hypothesize that URMC-07 has cascading effects on pathways within these sub-populations.
One of which is the redox/fyn/c-cbl pathway which we will discuss in detail momentarily.
As I said before our observations and other work in the field tells us that the heat shock response plays a role in cancer progression, particularly in GBM.
expression driven by receptor tyrosine kinases signal through several downstream cascades, up reg of RTK = over expression of HSR
hypothesize HS complex interacts with a regulator of these RTKs, leading to enhanced chemoresistance and tumor progression.
C-cbl…
Identified in CNS progenitor cells…
RTKs essential in cell cycle regulation and development
physical sequestration of c-Cbl
subsequent overexpression of c-cbl’s downstream targets, which is a major contributing factor in the high proliferative capacity of GBM.
Evidence shows that tumors can engage multiple mechanisms to block c-Cbl function, one of which is physical sequestration by the heat shock response family member heat shock protein-90…
Co-immunoprecipitation reveals a binding event between HSP90 and c-Cbl.
genetic and pharmacological evidence supports the hypothesis that inhibition of HSP90 biochemically restores c-Cbl function and modulates several hallmarks of GBM
We hypothesize that inhibition of the heat shock response at the level of HSF1 (the master regulator of the heat shock response) through use of URMC-07 stands to provide significant anti-cancer effects
BECAUSE of its two pronged effect at the level of c-Cbl activity and its downstream effectors,
targeting the futile cycle of c-cbl modulation and the up-regulation of RTKs and their subsequent transduction pathways.
We have preliminary evidence to support that URMC-07 does just this…
As there is a clear effect of URMC-07 on both the redox/fyn/c-cbl pathway and the heat shock response, we hypothesize there may be an intersection between these two pathways.
genetic perturbation of the redox/fyn/c-cbl pathway and the heat shock response to determine necessity and dependency
hallmarks - the stem cell compartment, mechanisms of chemoresistance like the HSR and mechanisms of cell death.
