oncogenesis and tumor biology: targeting ascl1 · 2018. 5. 8. · oncogenesis and tumor biology:...
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Oncogenesis and Tumor Biology: Targeting ASCL1
Rahul KolliparaTrisha Savage
KarinePozo
DemetraKelenis
U01 CA213338-01 Developing ASCL1 and NEUROD1 Lineage Oncogene Targeted Therapy
for Small Cell Lung Cancer (PI: Minna)
Jane JohnsonLab
Svetlana EarnestPearl Wichaidit
CourtneyPowell
Melanie CobbLab
John MinnaLab
AidenNguyen
Luc Girard
Kenneth HuffmanMichael Peyton
Adi GazdarLab
Victor Stastny
Major Goal:
To systematically classify SCLCs for their dependency on two key lineage oncogenes, ASCL1 and NeuroD1, and develop therapy targeted at these two transcription factors and their key downstream druggable targets.
U01 CA213338-01 Developing ASCL1 and NEUROD1 Lineage
Oncogene Targeted Therapy for Small Cell Lung Cancer (PI: Minna)
Updating Findings on Lineage Oncogenes ASCL1 and NEUROD1 in
SCLC
Testing ASCL1 and NEUROD1 targets in SCLC cells and xenografts
Identifying a group of transcription factors that cross and auto-regulate one another; testing their requirement for SCLC.
Identifying ASCL1 interacting proteins (co-factors)
Probing the role of ERK and the ERK-ASCL1 axis in SCLC
ASCL1 and NEUROD1 are lineage-specific bHLH transcription factors
• They are transcriptional activators.
• They, or their transcriptional targets, may provide unique, druggable, vulnerabilities in SCLC.
• They are required in multiple neuronal and neuroendocrine lineages during normal development.
• They are not mutated in SCLC but represent lineage-specific TFs required for tumor cell survival.
NEUROD1
ASCL1
ASCL1
NEUROD1
gene
Ascl1-/-
Understanding ASCL1 function in SCLC: New Biomarkers and New Targets
ASCL1 ASCL1
P
PP
Cofactors Regulators
Effectors
SCLC growth
PP
Identifying downstream transcriptional targets of ASCL1 and
NEUROD1 in SCLCDifferentially expressed genes in ASCL1HI and
NEUROD1Hi SCLC models
Potential Targets
ASCL1 or NEUROD1 ChIP-Seq
Associated genes
49394
NEUROD1Targets
571ASCL1 Targets
• Some shared, most distinctBorromeo et al. 2016
In Progress:Drop out screen in SCLC cell lines and in xenografts using an shRNA library with a subset of these targets.
Understanding ASCL1 function in SCLC: New Biomarkers and New Targets
ASCL1 ASCL1
P
PP
Cofactors Regulators
Effectors
SCLC growth
PP
Borromeo et al. 2016
******
Super-enhancers are associated with key cell
lineage genes
A core TF network may co-regulate genes important for tumor biology
ASCL1
NFIB
FOXA2
CANCER GENETARGETS
MYCL
NKX2.1Tumor growth
Is the function of each transcription factor interdependent and necessary for tumorigenesis?
A core TF network may co-regulate genes important for tumor biology
ASCL1 and FOXA2 bind many of the same sites in a SCLC cell line
Johnson Lab, unpublished
ASCL1/FOXA2 bound sites
?
Is each transcription factor interdependent and necessary for tumorigenesis?
ASCL1NFIB
FOXA2NKX2.1
H2107 ASCL1high SCLC cells48 hrs post treatment
Regulatory interactions between a subset of the core TF network
Karine Pozo
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viva
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siRNA
Kd-8
0%
Kd-9
5%
Kd-9
5%
ASCL1 loss is detrimental to SCLC survival
H2107 ASCL1high SCLC cells48 hrs post treatment
Karine Pozo
ASCL1
NFIB
FOXA2
CANCER GENETARGETS
MYCL
NKX2.1Tumor
survival
A core TF network may co-regulate genes important for tumor biology
Identifying ASCL1-cofactors in SCLC
Co-IP Mass Spec from SCLC (H2107)ASCL1
IPIgGIP Nuc Cyto
ASCL1
247 interactors
E12/E47HEBE2.2
Karine PozoMcGovern et al., 2010
ASCL1/PROX1
E15.5 mouselung
NKX2.1PROX1TRIM28CDK2
Understanding ASCL1 function in SCLC: New Biomarkers and Targets
ASCL1 ASCL1
P
PP
Cofactors Regulators
Effectors
SCLC growth
PP
ERK1/2
MEK1/2
SCLC
Growth Factors
ERK in SCLC and an ERK:ASCL1 Axis
• SCLC express relatively low levels of phosphoERK
• SCLC cells (ie H82 and H889) are insensitive to MEK inhibitors
Melanie Cobb Lab
H889
WB: ASCL1
Control +AP + PP2A
ERK1/2
MEK1/2
SCLC
Growth Factors• ASCL1 is phosphorylated and
can be an ERK substrate
• DUSP6 is an ASCL1 targetDUSP6
ASCL1?
H889 H2107 H69 H82 H524 H526 H720
ASCL1
DUSP6
Total ERK
Earnest and Cobb; unpublished
ASCL1 Uses DUSP6 to Set the Amplitude of ERK Signaling
?
Ongoing studies on Lineage Oncogenes ASCL1 and NEUROD1 in
SCLC Testing ASCL1 and NEUROD1 targets in SCLC cells
and xenografts
Identified a TF network; testing requirements for SCLC.
Identified ASCL1 interacting proteins; testing how they modulate ASCL1 activity
Probing the role of ERK and the ERK-ASCL1 axis in SCLC
Acknowledgements
FundingNCI Lung Cancer Spore UTSW
CPRITNCI: U01
Johnson LabTrisha SavageMark BorromeoRahul KolliparaKarine PozoDemetra Kelenis
Melanie Cobb Svetlana EarnestPearl Wichaidit
John MinnaKenneth HuffmanMichael Peyton
Longshan LiAlex AugustynAiden Nguyen
Luc GirardAdi Gazdar
Victor Stastny