1. Activating mutations in the GNAQ or GNA11 genes occur in approximately 90% of uveal melanoma cases and drive tumor proliferation through downstream signaling pathways. 2. The small GTPase ARF6 is activated by oncogenic GNAQ and plays a key role in orchestrating multiple oncogenic signaling pathways in uveal melanoma cells. 3. Inhibiting ARF6, either through genetic silencing or pharmacological inhibition with the specific ARF6 inhibitor NAV-2729, reduces uveal melanoma cell proliferation in vitro and tumor establishment and growth in vivo, suggesting ARF6 may be a promising molecular target for uveal melanoma treatment.

1. © U N I V E R S I T Y O F U T A H H E A L T H , 2 0 1 8
A Potential Molecular Target for
the Treatment of Uveal Melanoma
Jae Hyuk Yoo, PhD
Department of Internal Medicine
University of Utah Molecular Medicine (U2M2) Program

2. © U N I V E R S I T Y O F U T A H H E A L T H , 2 0 1 8
Before Starting;
- Please, please, please interrupt me at any time, ask questions
http://cutelovelypics.blogspot.com

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http://www.kellogg.umich.edu/theeyeshaveit
• Most common primary ocular
malignancy
• Half of patients will develop
metastases, usually to the liver
• No effective treatments for
metastatic UM
• Mutations in Gαq genes GNAQ or
GNA11 in ~90% of cases
• Genetic landscape of UM recently
characterized
Uveal Melanoma (UM)

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https://1bgubiologylcv.wordpress.com/2018/01/09/the-central-dogma-of-molecular-
biology-and-gene-regulation/
Robertson et al., Cancer Cell, 2017

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Oncogene (accelerator) and Tumor suppressor (brake)
Normal cellCancer cell
Example in UM:
Oncogene: GNAQ/GNA11

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https://www.mycancergenome.org/content/gene/gnaq/
GNAQ/GNA11
- Gq alpha subunit, GTPase protein, and oncogene

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http://tbl.med.yale.edu/cell_communication/reading.php
The GTPase protein regulatory cycle
Activating mutations in GNAQ or GNA11 – constitutively active GNAQ or GNA11

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Signal Pathway (transduction)
Signal Pathway is the process by which a chemical or physical signal
is transmitted through a series of molecular events in a cell

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Targeted Therapy in UM
Yang et al., Ther Adv Med Oncol., 2018
PLC-PKC
MAPKYAP

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GTPase-activating proteins
(GAPs)
Guanine exchange proteins
(GEFs)
ARF6-
GDP
ARF6-
GTP
active
Inactive
ARF6: Small GTPase protein of the Ras superfamily

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The diverse roles of ARF6 on cellular function and behavior
Grossmann et al., Small GTPases, 2016

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Onken et al. Ophthalmology, 2012
Gene expression profile (GEP)
Harbour JW, Methods Mol Biol., 2014

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The Small GTPase ARF6 Stimulates β-Catenin Transcriptional
Activity During WNT5A-Mediated Melanoma Invasion and Metastasis
Grossmann et al., Sci. Signal., 2013

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• Mutations in Gαq genes GNAQ or GNA11 in ~90% of cases.
• The loss of ROBO1 expression is among 12 expression markers
that predict progression to uveal melanoma metastasis
Rationale for study ARF6 in UM

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ARF6 protein levels are increased in human UM
Yoo et al., Cancer Cell, 2016

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What is the role of ARF6 in UM? Can we target ARF6 in UM?
http://www.srimalplantation.com/complete-cure-for-cancer-with-ayurveda/

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ARF6 is activated by oncogenic GNAQ
Yoo et al., Cancer Cell, 2016
(Reducing)
(normal cell)
(Uveal melanoma cells)

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ARF6 is required for uveal melanoma cell
proliferation
Yoo et al., Cancer Cell, 2016
(Reducing) 2D cell culture
3D cell culture
(Reducing)

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ARF6 is an actionable node that orchestrates
oncogenic GNAQ signaling in uveal melanoma
Yoo et al., Cancer Cell, 2016
PLC-PKC
MAPK
YAP

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ARF6 controls GNAQ trafficking between the plasma
membrane and cytosol/cytosolic vesicles
Yoo et al., Cancer Cell, 2016
GNAQ (Green)
Nucleus (Blue)
GNAQ (Green)
Nucleus (Blue)

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Silencing ARF6 reduces uveal melanoma tumorigenesis
Yoo et al., Cancer Cell, 2016
cornea lens
retina
iris
cornea lens
retina
iris
(tumor establishment) (tumor growth)

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What is the role of ARF6 in UM? Can we target ARF6 in UM?
http://www.srimalplantation.com/complete-cure-for-cancer-with-ayurveda/

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NAV-2729 is a specific ARF6 inhibitor
Yoo et al., Cancer Cell, 2016

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NAV-2729 is a specific ARF6 inhibitor
Yoo et al., Cancer Cell, 2016

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NAV-2729 is a specific ARF6 inhibitor
Yoo et al., Cancer Cell, 2016
(tumor establishment) (tumor growth)

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ARF6 is an actionable node that orchestrates
oncogenic GNAQ signaling in uveal melanoma
Yoo et al., Cancer Cell, 2016

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https://www.cytoskeleton.com/about/arf
The function of ARF6 on migration and
invasion of cancer cell

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Steps in
metastasis
McGee et al., EMBO Rep., 2006

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Does ARF6 control UM cell invasion and metastasis?
Silencing of ARF6 inhibits the invasion of uveal melanoma cells
Unpublished data
(Reducing)

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Xenograft model of uveal melanoma metastasis
0 week 5 weeks
Injection with UM cells
and /or NAV-2729
(Daily injection for NAV-2729)
Harvesting samples
No metastasis
https://www.clodrosome.com/animal-injection/

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Xenograft model of uveal melanoma metastasis
0 week 8 weeks
Injection with UM cells Harvesting samples
Metastasis
Retro-orbital injection
Yardeni et al., Lab Anim (NY), 2011
3 week
Start to inject with
NAV-2729 daily

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1. Oncogenic GNAQ/ARF6 is required
for the proliferation of tumor cells.
2. ARF6 is required for UM cell invasion.
3. Oncogenic GNAQ/ARF6 orchestrates
multiple downstream pathways.
4. Reducing ARF6 level or Inhibiting
ARF6 with the drug reduces tumor
establishment and growth.
Summary

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ACKNOWLEDGMENTS
Dean Li
Shannon Odelberg
Allie Grossmann
Weiquan (Wendy) Zhu
Max Shin
Coulson Rich
Lehi Acosta
Aaron Rogers
Lise Sorensen
Jackson Richards
Other members
Collaborators
University of Miami
Bill Harbour
M. D. Anderson Cancer
Center
Scott Woodman
University of Notre Dame
Crislyn D’Souza-Schorey
Navigen Pharmaceuticals
Alan Muller
Daniel Wettstein
Zongzhong Tong
Lab family
Biological family
Wife, JY and AS
Funding
CURE OM Junior Fellowship Award
NIH NCI R01
We want to be Jedi to
fight cancer

34. © U N I V E R S I T Y O F U T A H H E A L T H , 2 0 1 8
A Potential Molecular Target for the Treatment of
Uveal Melanoma