Abstract
Deep multi-omic analyses to identify targetable pathways in desmoplastic small round cell tumor (DSRCT) with opportunities for clinical intervention.
Author
person
Limin Zhu
OHSU Knight Cancer Institute, Portland, OR
info_outline
Limin Zhu, Jamie Keck, Jayne Stommel, Brett Johnson, Christopher L. Corless, Christopher W. Ryan, Gordon B. Mills, Lara E. Davis
Full text
Authors
person
Limin Zhu
OHSU Knight Cancer Institute, Portland, OR
info_outline
Limin Zhu, Jamie Keck, Jayne Stommel, Brett Johnson, Christopher L. Corless, Christopher W. Ryan, Gordon B. Mills, Lara E. Davis
Organizations
OHSU Knight Cancer Institute, Portland, OR, Oregon Health & Science University, Portland, OR, Knight Cancer Institute, Oregon Health & Science University, Portland, OR
Abstract Disclosures
Research Funding
Other
SMMART Clinical Trials Program
Background:
DSRCT is an extremely rare and highly aggressive soft-tissue sarcoma affecting adolescents and young adults with male predominance. The 5-year overall survival is < 25% despite intensive multi-modality treatment including aggressive surgical resection, radiotherapy, chemotherapy, and targeted therapy. Therefore, more effective and innovative therapeutic options are urgently needed. Recent advances in genomic, epigenomic, proteomic, and immune profiling have uncovered a large number of therapeutic targets that are transforming the field of cancer medicine. This study aimed to identify novel targetable pathways in DSRCT using a deep multi-omics-based platform.
Methods:
Three patients with biopsy proven metastatic DSRCT were enrolled under an IRB-approved observational study within the “Serial Measurements of Molecular and Architectural Responses to Therapy” (SMMART) program at OHSU. Biopsies taken at enrollment were analyzed with targeted DNA sequencing, whole transcriptome sequencing, immunohistochemistry (IHC), NanoString GeoMx digital spatial profiling (DSP) multiplexed proteomics, single cell cyclic immunofluorescence (Cyc-IF), and reverse phase protein array (RPPA).
Results:
Multiple clinically relevant targets were identified, including HER2, androgen receptor (AR), elevated DNA damage response, and MAPK and mTOR signaling pathways. All three DSRCTs expressed HER2: clinical IHC identified HER2 low (1+) to HER2 equivocal (2+) expression; DSP analysis showed high HER2 and phospho-HER2 expression; and HER2 RNA expression was elevated compared to the TCGA sarcoma cohort. Two of the three patients displayed high AR protein expression, assessed by clinical IHC (90-100% positive cells) and DSP (top quartile compared to a 20 mixed-subtype breast cancer cohort). Strong evidence of DNA damage response was demonstrated at both RNA and protein levels, and RPPA revealed high PARP1, PAR, p-ATM, p-RPA32, and RAD51. Within cell signaling pathways, one DSRCT exhibited high total and phospho-ERK1/2 protein across all clinical and exploratory assays, while another patient displayed evidence of elevated mTOR pathway signaling by RPPA.
Conclusions:
Overall, this multi-omic analysis provided new insights into possible therapeutic targets for this rare and difficult to treat sarcoma subtype. Results from this study will be further validated
in vivo
using patient-derived xenograft (PDX) models, providing support for development of multiple early phase trials.
4 organizations
5 drugs
7 targets
Organization
OHSU Knight Cancer Institute, Portland, OROrganization
Portland, OROrganization
Oregon Health & Science UniversityOrganization
Knight Cancer InstituteDrug
HER2 CAR-TDrug
mTOR inhibitorsTarget
androgen receptor (AR)Target
DNA damage responseTarget
ERK1/2Target
HER2 (ERBB2)Target
androgen receptorTarget
MAPKTarget
mTORC1