Haura, Eric B.

Abstract Purpose: Preclinical studies in myeloid neoplasms have demonstrated efficacy of bromodomain and extra-terminal protein inhibitors (BETi). However, BETi demonstrates poor single-agent activity in clinical trials. Several studies suggest that combination with other anticancer inhibitors may enhance the efficacy of BETi. Experimental Design: To nominate BETi combination therapies for myeloid neoplasms, we used a chemical screen with therapies currently in clinical cancer development and validated this screen using a panel of myeloid cell line, heterotopic cell line models, and patient-derived xenograft models of disease. We used standard protein and RNA assays to determine the mechanism responsible for synergy in our disease models. Results: We identified PIM inhibitors (PIMi) as therapeutically synergistic with BETi in myeloid leukemia models. Mechanistically, we show that PIM kinase is increased after BETi treatment, and that PIM kinase upregulation is sufficient to induce persistence to BETi and sensitize cells to PIMi. Furthermore, we demonstrate that miR-33a downregulation is the underlying mechanism driving PIM1 upregulation. We also show that GM-CSF hypersensitivity, a hallmark of chronic myelomonocytic leukemia (CMML), represents a molecular signature for sensitivity to combination therapy. Conclusions: Inhibition of PIM kinases is a potential novel strategy for overcoming BETi persistence in myeloid neoplasms. Our data support further clinical investigation of this combination.

Abstract Human tissue samples commonly preserved as formalin-fixed paraffin-embedded (FFPE) tissues after diagnostic or surgical procedures in the clinic represent an invaluable source of clinical specimens for in-depth characterization of signaling networks to assess therapeutic options. Tyrosine phosphorylation (pTyr) plays a fundamental role in cellular processes and is commonly dysregulated in cancer but has not been studied to date in FFPE samples. In addition, pTyr analysis that may otherwise inform therapeutic interventions for patients has been limited by the requirement for large amounts of frozen tissue. Here we describe a method for highly sensitive, quantitative analysis of pTyr signaling networks, with hundreds of sites quantified from one to two 10-μm sections of FFPE tissue specimens. A combination of optimized magnetic bead–based sample processing, optimized pTyr enrichment strategies, and tandem mass tag multiplexing enabled in-depth coverage of pTyr signaling networks from small amounts of input material. Phosphotyrosine profiles of flash-frozen and FFPE tissues derived from the same tumors suggested that FFPE tissues preserve pTyr signaling characteristics in patient-derived xenografts and archived clinical specimens. pTyr analysis of FFPE tissue sections from breast cancer tumors as well as lung cancer tumors highlighted patient-specific oncogenic driving kinases, indicating potential targeted therapies for each patient. These data suggest the capability for direct translational insight from pTyr analysis of small amounts of FFPE tumor tissue specimens. Significance: This study reports a highly sensitive method utilizing FFPE tissues to identify dysregulated signaling networks in patient tumors, opening the door for direct translational insights from FFPE tumor tissue banks in hospitals.

CMML is a lethal myeloid neoplasm with no therapies that improve its dismal prognosis. Inhibition of BET family members has been proposed as a therapeutic strategy based on preclinical data identifying BRD4 as a therapeutic target in acute myeloid leukemia. However, despite potent on-target transcriptional remodeling, early phase clinical trials have demonstrated only modest activity secondary to a variety of resistance mechanisms. In ovarian cancer BET inhibitor (BETi) treated cells, compensatory upregulation and addiction to pro-survival kinase networks have been observed. Given that over 50% of CMML cases have mutations upregulating kinase signaling, we hypothesized that BETi resistance is mediated by these networks in CMML and can be targeted therapeutically. We tested this hypothesis by performing a limited screen of kinase inhibitors alone and in combination with the IC20 of the BETi INCB54329 in 8 human leukemia cell lines. This screen revealed that the IC50 of the PIM inhibitor (PIMi) INCB53914 decreased after co-treatment with BETi in a majority of the leukemia cell lines tested. Synergy was validated chemically in U937, TF1 and SKM1 leukemia cells using other selective inhibitors of BET and PIM. We next assessed the activity of the BET-PIM combination in 14-day colony formation assays with 10 unique CMML bone marrow mononuclear cell (BM-MNCs) patient samples(Fig. 1A). These studies revealed that combination therapy significantly suppressed clonogenicity versus BMNCs treated with vehicle or single drug alone. Finally, this synergy was validated in vivo in 36 patient derived xenografts (PDX) from 3 CMML patients, as manifest by reduced leukemic burden/engraftment in CMML PDX treated with combination therapy(Fig. 1B). To explore the mechanism by which BETi and PIMi therapeutically synergize we treated U937 and SKM1 leukemia cells with INCB54329 and measured mRNA and protein levels for all PIM isoforms. Surprisingly, we identified that PIM1 was increased following treatment with INCB54329, other BETi, or a JQ1-derived PROTAC (Fig. 1C). PIM1 upregulation was also manifest in INCB54329 persistor U937 leukemia cells generated by daily BETi treatment for 6 weeks. Testing across a broader panel of leukemia cell lines revealed an inverse correlation between PIM1 induction and decrease in the IC50 of PIMi following BETi treatment, suggesting PIM1 upregulation confers sensitivity to combination therapy. Consistent with this, isogenic SKM1 leukemia cells engineered to overexpress PIM1 were resistant to INCB54329 and were more sensitive to INCB53914 versus controls cells. Recent studies have demonstrated that inhibitory miRNAs, especially those located near super-enhancers, are suppressed by BET inhibition. Given that several miRNAs are known to control PIM1 expression, we hypothesized that paradoxical PIM1 upregulation following BETi treatment was due to down-regulation of select miRNAs. To test this, we treated our leukemia cell models with broad inhibitors of miRNA activity (i.e., AGO and Dicer inhibitors) and observed a dose dependent increase in PIM1 levels similar to that seen with BET inhibition(Fig. 1Di). Further, integrating public H3K27 CHIP-seq and miRNA super enhancer datasets and using computational prediction algorithms, we identified 6 candidate miRNAs that could regulate PIM1 and were predicted to be controlled by BET inhibitors. Of these, only miR-33a levels were reduced in a dose dependent manner in SKM1 cells by BETi treatment(Fig. 1Dii). This was confirmed by genetically silencing all BET proteins, which suppressed miR-33a levels in SKM1 leukemia cells. Finally, miR-33a mimics (but not control miRNAs) abolished BETi-induced upregulation of PIM1(Fig. 1Diii). Collectively, these studies established BET and PIM inhibition as a novel and potent combination therapy for CMML that is mediated by miR-33a-dependent upregulation of PIM1(Fig. 1E). Disclosures Liu: Incyte Corporation: Employment. Patnaik:Stem Line Pharmaceuticals.: Membership on an entity's Board of Directors or advisory committees. Lancet:Daiichi Sankyo: Consultancy, Other: fees for non-CME/CE services ; Agios, Biopath, Biosight, Boehringer Inglheim, Celator, Celgene, Janssen, Jazz Pharmaceuticals, Karyopharm, Novartis: Consultancy; Pfizer: Consultancy, Research Funding. Komrokji:Novartis: Speakers Bureau; JAZZ: Speakers Bureau; JAZZ: Consultancy; Agios: Consultancy; Incyte: Consultancy; DSI: Consultancy; pfizer: Consultancy; celgene: Consultancy. Epling-Burnette:Incyte Corporation: Research Funding. List:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding. Haura:Incyte Corporation: Research Funding. Reuther:Incyte Corporation: Research Funding. Koblish:Incyte Corporation: Employment.

Abstract Purpose: DNA topoisomerase inhibitors are commonly used for treating small-cell lung cancer (SCLC). Tyrosyl-DNA phosphodiesterase (TDP1) repairs DNA damage caused by this class of drugs and may therefore influence treatment outcome. In this study, we investigated whether common TDP1 single-nucleotide polymorphisms (SNP) are associated with overall survival among SCLC patients. Experimental Design: Two TDP1 SNPs (rs942190 and rs2401863) were analyzed in 890 patients from 10 studies in the International Lung Cancer Consortium (ILCCO). The Kaplan–Meier method and Cox regression analyses were used to evaluate genotype associations with overall mortality at 36 months postdiagnosis, adjusting for age, sex, race, and tumor stage. Results: Patients homozygous for the minor allele (GG) of rs942190 had poorer survival compared with those carrying AA alleles, with a HR of 1.36 [95% confidence interval (CI): 1.08–1.72, P = 0.01), but no association with survival was observed for patients carrying the AG genotype (HR = 1.04, 95% CI, 0.84–1.29, P = 0.72). For rs2401863, patients homozygous for the minor allele (CC) tended to have better survival than patients carrying AA alleles (HR = 0.79; 95% CI, 0.61–1.02, P = 0.07). Results from the Genotype Tissue Expression (GTEx) Project, the Encyclopedia of DNA Elements (ENCODE), and the ePOSSUM web application support the potential function of rs942190. Conclusions: We found the rs942190 GG genotype to be associated with relatively poor survival among SCLC patients. Further investigation is needed to confirm the result and to determine whether this genotype may be a predictive marker for treatment efficacy of DNA topoisomerase inhibitors. Clin Cancer Res; 23(24); 7550–7. ©2017 AACR.

Abstract Background: The efficacy of immunotherapy, including therapeutic strategies capable of modulating innate/adaptive immune resistance, varies greatly across tumor types. As the number of available immunotherapies accelerates, the study of predictive markers by IHC (e.g. PDL1 expression) is under intense investigation. However, staining protocol inconsistency, variation across scoring systems, and subjective interpretation of the immunostaining have produced conflicting results thus far. This work explored the role of Laser Capture Microdissection (LCM) coupled with Reverse Phase Protein Microarray (RPPA) as an alternative high throughput, quantitative, operator independent platform for measuring PDL1 expression across tumor types. Material and Methods: Pure epithelial cells were isolated via LCM from 178 samples including: 72 ovarian cancers (OC), 57 lung adenocarcinomas (LC), 30 metastatic breast cancers (MBC), and 19 pancreatic cancers (PC). PDL1 expression was measured on a continuous scale using quantitative RPPA based analysis. Each tumor type was processed and arrayed independently. Experimental samples and reference standards used for inter-assay normalization were printed in triplicates. Results: PDL1 expression varied greatly across tumor types. LC were characterized by the greatest intra-tumor fold dynamic range (> 35-fold), followed by OC (< 13-fold), MBC (< 4-fold), and PC (< 2-fold). PDL1 expression of 46/57 (80.7%) LC, 17/30 (56.7%) MBC, 6/19 (31.5%) PC, and 20/72 (27.8%) OC was greater than the population median of all tumors combined. Within the LC samples with PDL1 expression equal to the top quartile of the population, 10 (71.4%) were KRAS mutant lesions and 4 (28.6%) were WT tumors. Finally, amongst LC and PC harboring a KRAS mutation, PC showed an overall lower expression of PDL1 with only 2/19 (10.5%) cases been above the population median and none within the top quartile of the population. Conclusions: The LCM-RPPA workflow has the unique ability to capture immune checkpoint expression on a continuous quantitative scale as well as capture its broad dynamic range. Because RPPA is unconstrained by antigen retrieval issues as well as subjectivity of IHC interpretation, this approach may generate more accurate cut-point of therapeutic response prediction. Overall the dynamic range of PDL1 was broader in LC compared to other solid tumors, and LC had a much higher proportion of patients with tumors expressing high levels of PDL1. These quantitative differences may explain therapeutic efficacy of PDL1 inhibition across tumor types. Such speculative hypothesis should be further validated in prospective clinical trials. Finally, these preliminary data suggest that organ specific microenvironments more than specific driving mutations (e.g. KRAS) may strongly influence PDL1 expression in malignant lesions. Citation Format: Elisa Baldelli, Valerie Calvert, K. Alex Hodge, Maria Isabella Sereni, Guido Gambara, Eric B. Haura, Lucio Crino', Bryant Dunetz, Sergio Pecorelli, David J. Perry, Stephen P. Anthony, Nicholas Robert, Donald W. Northfelt, Mohammad Jahanzeb, Emanuel F. Petricoin, Mariaelena Pierobon. Quantitative measurement of PDL1 expression across tumor types using laser capture microdissection and reverse phase protein microarray [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5656. doi:10.1158/1538-7445.AM2017-5656

Abstract Introduction: DNA topoisomerase inhibitors (e.g. etoposide, irinotecan, teniposide, topotecan) are commonly used for treating small cell lung cancer (SCLC). Tyrosyl-DNA phosphodiesterase (TDP1) plays a role in repairing DNA damage caused by DNA topoisomerase inhibitors and it is believed to be responsible for resistance to this class of drugs. The purpose of this study was to determine whether common TDP1 polymorphisms are associated with overall survival among SCLC patients. Method: Two common TDP1 SNPs (rs942190 and rs2401863, r2(European)=0.63 and r2(East Asian)=0.26) were analyzed in 898 patients from 10 studies in the International Lung Cancer Consortium, conducted in the U.S., Canada, Japan, Italy, Spain and the United Kingdom. Genotype data were obtained from either the OncoArray Consortium or other existing genome-wide association studies. Cox proportional hazard regression models with robust standard error were used to evaluate genotype associations for overall survival at 36 months post-diagnosis, adjusting for age, sex, race and tumor stage. Results: Patients homozygous for the minor allele (GG) of TDP1 SNP rs942190 were associated with poorer survival compared to those carrying both major alleles (AA), with a hazard ratio (HR) of 1.36 (95% confidence interval (CI): 1.07-1.72, p-value=0.01), but there was no association with survival for patients with the heterozygous genotype (HR=1.02, 95% CI: 0.83-1.27, p-value=0.83). For rs2401863, patients carrying both minor alleles (CC) tended to have better survival than patients carrying AA alleles, but this was within the limits of chance given no significant association (HR=0.79, 95% CI: 0.61-1.02, p-value=0.07). In addition, multi-tissue expression quantitative trait loci (eQTL) analyses from the Genotype-Tissue Expression Project indicated a potential effect of rs942190 on lung tissue, with higher TDP1 gene expression for the GG than AG or AA genotypes. Conclusion: We found that among SCLC patients the TDP1 rs942190 GG genotype was associated with poor overall survival. Further study could determine if this genotype can serve as a predictive marker for the treatment efficacy of DNA topoisomerase inhibitors in SCLC. Citation Format: Pawadee Lohavanichbutr, Lori C. Sakoda, Christopher I. Amos, Susanne M. Arnold, David C. Christiani, Michael P. Davies, John K. Field, Eric B. Haura, Rayjean J. Hung, Takashi Kohno, Maria Teresa Landi, Geoffrey Liu, Yi Liu, Michael W. Marcus, Grainne M. O'Kane, Matthew B. Schabath, Kouya Shiraishi, Stacey A. Slone, Adonina Tardón, Ping Yang, Kazushi Yoshida, Ruyang Zhang, Xuchen Zong, Noel S. Weiss, Chu Chen. Common TDP1 polymorphisms in relation to survival among small cell lung cancer patients in a multicenter study from the International Lung Cancer Consortium [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2248. doi:10.1158/1538-7445.AM2017-2248

Abstract Cigarette smoking is a major risk factor in the development of non–small cell lung cancer (NSCLC), which accounts for 80% of all lung cancers. Nicotine, the major addictive component of tobacco smoke, can induce proliferation, invasion, and epithelial-to-mesenchymal transition (EMT) in NSCLC cell lines and promote metastasis of NSCLC in mice. Here, we demonstrate that the scaffolding protein β-arrestin-1 is necessary for nicotine-mediated induction of mesenchymal genes vimentin and fibronectin as well as EMT regulators ZEB1 and ZEB2. Nicotine induced changes in cell morphology and ablate tight junctions consistent with EMT; β-arrestin-1, but not β-arrestin-2, was required for these changes. β-Arrestin-1 promoted the expression of the mesenchymal genes, as well as ZEB1 and ZEB2, through the mediation of the E2F1 transcription factor; this required Src kinase activity. Stimulation of multiple NSCLC cell lines with nicotine led to enhanced recruitment of β-arrestin-1 and E2F1 on vimentin, fibronectin, and ZEB1 and ZEB2 promoters. Furthermore, there was significantly more β-arrestin-1 and E2F1 associated with these promoters in human NSCLC tumors, and β-arrestin-1 levels correlated with vimentin and fibronectin levels in human NSCLC samples. A549-luciferase cells lacking β-arrestin-1 showed a significantly reduced capacity for tumor growth and metastasis when orthotopically implanted into the lungs of SCID-beige mice. Taken together, these studies reveal a novel role for β-arrestin-1 in the growth and metastasis of NSCLC. Cancer Res; 75(6); 1009–20. ©2015 AACR.