Virtual Library
Start Your Search
David S Schrump
Author of
-
+
MA20 - Thymic Tumors: From Molecular to Clinical Results and New Challenges in Other Rare Thoracic Tumors (ID 149)
- Event: WCLC 2019
- Type: Mini Oral Session
- Track: Thymoma/Other Thoracic Malignancies
- Presentations: 1
- Now Available
- Moderators:Kazuya Kondo, Edith Michelle Marom
- Coordinates: 9/10/2019, 11:30 - 13:00, San Francisco (2009)
-
+
MA20.01 - Global Quantitative Mass Spectrometry Reveals Potential Novel Actionable Targets in Thymic Epithelial Tumors (TET) (Now Available) (ID 2294)
11:30 - 13:00 | Author(s): David S Schrump
- Abstract
- Presentation
Background
Thymomas (T) and thymic carcinomas (TC), that constitute the thymic epithelial tumors (TETs) are rare epithelial tumors. There are limited treatment options for patients with advanced TETs. The complexity and rarity of the disease hampers the development of effective therapeutics. Next-generation sequencing (NGS) analyses of TETs by the TCGA have confirmed the very low mutational burden and few actionable targets for therapy. Thus, novel strategies are needed for better elucidating the molecular pathways involved in tumor pathogenesis and identification of novel drug targets. Here, we have used quantitative mass spectrometry (MS) to characterize the global proteome and phosphoproteome of TETs with aim of identifying potential actionable drivers in thymomas and thymic carcinomas.
Method
Three-state SILAC quantitative mass spectrometry was used to quantify the global proteomes and phosphoproteomes of two thymoma (IU-TAB1 and T1682) and three thymic carcinoma cell lines (MP57, T1889 and Ty82). 10-plex TMT quantitative proteomics was used to quantify the global proteomes and phosphoproteomes of 54 TET tumors. All tumor tissues were pooled together to make the reference channel and labeled with TMT10-131. Basic RPLC followed by TiO2 enrichment and tandem MS were performed in a Q ExactiveTM HF mass spectrometer. MS data was processed using MaxQuant and Perseus. Protein quantification, normalization and statistical testing for the TMT experiments was done using free R package MSstatsTMT.
Result
We identified 4756 proteins and 5690 phosphosites from TET cell lines. Hierarchical clustering of SILAC ratios of quantitation demonstrated that T1682 and MP57 were more similar to each other than T1889 and Ty82. Several metabolic enzymes (LDHB, GSTP1, and AKR1B1) had higher expression in TC lines, while mitochondrial glutamate carrier SLC25A22 had greater abundance in thymoma lines. Ingenuity pathway analysis revealed that the top enriched canonical pathways associated with the significantly changed proteins in TET included remodeling of epithelial adherens junction, mitochondria dysfunction, and oxidative phosphorylation. RAS signaling pathway was enriched among the significantly changed phosphosites in the thymic MP57 and the B1 thymoma T1682 cells. We further analyzed the proteome and phosphoproteome of 54 TET tumor samples from 28 patients (23 thymoma and 5 thymic carcinoma) undergoing surgery or biopsy using TMT mass spectrometry. In total, 8320 proteins and 17716 phosphosites were identified. Hierarchical clustering of the TMT ratios to the pool for both proteins and phosphosites demonstrated that thymomas and thymic carcinomas clustered separately. Different locations of tumors from the same patient were grouped together. Only a few sites from the thymoma patients clustered in the thymic carcinoma group. GTF2I had higher abundance in thymomas compared to the TCs. MCM complex proteins and solute carrier family proteins had lower abundance and several collagens had higher abundance in TC patients. Several kinases, including PDGFRB, RIOK1, TNIK, and MAP4K4, and the metabolic enzyme glutathione S-transferase (GSTP1) had higher expression in TC patients. Further bioinformatics analysis and validation experiments are currently underway. Sensitivity data to inhibitors of metabolic enzymes and target kinases will be presented.
Conclusion
Global quantitative proteome and phosphoproteome analyses revealed potential novel kinases and metabolic enzymes for targeted therapy of TETs.
Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
-
+
P2.06 - Mesothelioma (ID 170)
- Event: WCLC 2019
- Type: Poster Viewing in the Exhibit Hall
- Track: Mesothelioma
- Presentations: 1
- Now Available
- Moderators:
- Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall
-
+
P2.06-13 - Targeting RAS Signaling in Malignant Mesothelioma (Now Available) (ID 652)
10:15 - 18:15 | Author(s): David S Schrump
- Abstract
Background
Malignant pleural mesothelioma (MPM) is distinguished by molecular features, such as activated and redundant multiple tyrosine kinases signaling via the Ras pathways. Several pharmacologic strategies have been attempted to disrupt this pathogenic axis, but clinically effective agents remain elusive. We propose to leverage microRNA (miRNA) as a potential therapeutic approach, since miRNA can coherently regulate multiple simultaneous gene targets that comprise critical biologic networks.
Method
Our prior miRNA profiling results of human MPM (GSE40345) were cross-referenced with TCGA-Meso data to identify prognostic miRNAs. Both MPM cell lines and tissues (tumors and normal pleura) were assessed using quantitative and functional biologic assays that revealed specific molecular mechanisms of relevant miRNA. In silico algorithms identified downstream gene targets that were verified by 3’-UTR luciferase assay. Murine models of MPM xenografts were used to verify in vitro observations of miRNA effects. Kaplan-Meier assessed outcomes in vivo.
Result
Our analyses showed underexpression of miR-206 by 12-fold in MPM tumors compared to normal pleura. TCGA data (n=74 MPM) indicated worse survival in patients with low miR-206 (25-fold decrease) compared to higher miR-206 expression. We confirmed that miR-206 was significantly underexpressed by qRT-PCR analysis of new, randomly selected MPM tumors versus normal pleurae tissues. In MPM cell lines, ectopic re-expression of miR-206 dramatically suppressed cell proliferation, invasiveness, and growth in soft-agar. Interestingly, we noted several MPM-prognostic genes (p<0.05) regulated by miR-206: KRAS, CDK4, CCND1, and IGF1R. This signaling axis of KRAS/CDK4/CCND1 is important in MPM as it summates well-known dysregulated tyrosine kinase receptors (EGF, IGF-1, VEGF, MET, etc) that are upstream. The KRAS/CDK4/CCND1 axis is associated with cell cycle progression and survival of cancer cells, but is not an easily druggable target. In vitro, miR-206 treatment significantly downregulated KRAS, CDK4 and CCND1 as well upstream target genes such as MET, EGFR, IGF1R and VEGFA. In vivo, miR-206 treatment significantly suppressed MPM tumor growth in subcutaneous and orthotopic xenograft models compared to control. Kaplan-Meier analysis showed that miR-206 treatment improved overall survival.
Conclusion
miR-206 exerts tumor suppressive effects in MPM via inhibition of KRAS/CDK4/CCND1 signaling, which mimics simultaneous blocking of multiple tyrosine kinases. Loss of miR-206 and concomitant overexpression of KRAS, CDK4 and CCND1 formed a novel poor prognosis signature in MPM. Our results indicate that miR-206 is a rational agent to be developed further in preclinical MPM models as a promising therapeutic.
