Search

Supplementary Figure Legends 1-4

Figure S1. Rationale and readout for the dCAS9-NUT chemical screen. Figure S2. IRBM6 is highly active in vitro and in vivo. Figure S3. IRBM6 induces transcriptional programs leading to growth arrest and differentiation in NC. Figure S4. IRBM6 treatment induces redistribution of BRD4-NUT and H3K27ac.

NUT carcinoma (NC), characterized most commonly by the BRD4-NUTM1 fusion, is a rare, aggressive variant of squamous carcinoma with no effective treatment. BRD4-NUT drives growth and maintains the poorly differentiated state of NC by activating pro-growth genes such as MYC, through the formation of massive, hyperacetylated, superenhancer-like domains termed megadomains. BRD4-NUT–mediated hyperacetylation of chromatin is facilitated by the chromatin-targeting tandem bromodomains of BRD4, combined with NUT, which recruits the histone acetyltransferase, p300. Here, we developed a high-throughput small-molecule screen to identify inhibitors of transcriptional activation by NUT. In this dCAS9-based GFP-reporter assay, the strongest hits were diverse histone deacetylase (HDAC) inhibitors. Two structurally unrelated HDAC inhibitors, panobinostat and the novel compound, IRBM6, both repressed growth and induced differentiation of NC cells in proportion to their inhibition of NUT transcriptional activity. These two compounds repressed transcription of megadomain-associated oncogenic genes, such as MYC and SOX2, while upregulating pro-differentiation, non-megadomain–associated genes, including JUN, FOS, and key cell-cycle regulators, such as CDKN1A. The transcriptional changes correlate with depletion of BRD4-NUT from megadomains, and redistribution of the p300/CBP-associated chromatin acetylation mark, H3K27ac, away from megadomains toward regular enhancer regions previously populated by H3K27ac. In NC xenograft models, we demonstrated that suppression of tumor growth by panobinostat was comparable with that of bromodomain inhibition, and when combined they improved both survival and growth suppression.Implications:The findings provide mechanistic and preclinical rationale for the use of HDAC inhibitors, alone or combined with other agents, in the treatment of NUT carcinoma.

Supplementary Methods

NUT midline carcinoma (NMC) is a rare, aggressive subtype of squamous carcinoma that is driven by the BRD4-NUT fusion oncoprotein. BRD4, a BET protein, binds to chromatin through its two bromodomains, and NUT recruits the p300 histone acetyltransferse (HAT) to activate transcription of oncogenic target genes. BET-selective bromodomain inhibitors have demonstrated on-target activity in patients with NMC, but with limited efficacy. P300, like BRD4, contains a bromodomain. We show that combining selective p300/CBP and BET bromodomain inhibitors, GNE-781 and OTX015, respectively, induces cooperative depletion of MYC and synergistic inhibition of NMC growth. Treatment of NMC cells with the novel dual p300/CBP and BET bromodomain–selective inhibitor, NEO2734, potently inhibits growth and induces differentiation of NMC cells in vitro; findings that correspond with potentiated transcriptional effects from combined BET and p300 bromodomain inhibition. In three disseminated NMC xenograft models, NEO2734 provided greater growth inhibition, with tumor regression and significant survival benefit seen in two of three models, compared with a lead clinical BET inhibitor or “standard” chemotherapy. Our findings provide a strong rationale for clinical study of NEO2734 in patients with NMC. Moreover, the synergistic inhibition of NMC growth by CBP/p300 and BET bromodomain inhibition lays the groundwork for greater mechanistic understanding of the interplay between p300 and BRD4-NUT that drives this cancer.

Supplemental Table S1. Statistical analysis of survival in PER-403 model, full study. Supplemental Table S2. Statistical analysis of survival in 10-15 mouse model, full study. Supplemental Table S3. Statistical analysis of survival in 14169 model, full study.

PDF file - 171KB, Supplementary Fig. S2. NUT is translocated to the NSD3 locus in 1221 cell line as demonstrated by FISH on metaphase spread.

Supplemental Figure S1: NEO2734 induces differentiation in 10-15 cells. Supplemental Figure S2: Caspase-mediated apoptosis plays a minimal role in the activity of GNE-781, OTX015, or NEO2734. Supplemental Figure S3: BRD4-NUT protein levels decrease slightly upon exposure to NEO2734. Supplemental Figure S4: Global H3K27Ac levels do not change upon exposure to NEO2734. Supplemental Fig. S5. BRD4-NUT foci diminish over time course in TC-797 cells. Images were taken at identical magnification (1000x) with identical exposure settings per stain. Supplemental Figure S6. Dot plots of fold change of gene expression in samples treated with the indicated compound versus that in DMSO-treated samples. Supplemental Figure S7: Proportion of differentially expressed genes overlapping BRD4-NUT megadomains is greater in genes whose expression is downregulated in the presence of p300/CBP and/or BET bromodomain inhibition. Supplemental Figure S8: Tolerability in the full 10-15 mouse xenograft study. Supplemental Figure S9: Cleaved PARP is unchanged, but BRD4-NUT is somewhat depleted in mouse xenograft tumors exposed to NEO2734.

supplemental figures

Supplemental methods

PDF file - 304KB, Supplementary Fig. S4. Among several ET-interacting proteins, only NSD3 is required for the blockade of differentiation in NMC. (A) Quantitative RT-PCR of NSD3, JMJD6, GLTSCR1, and ATAD5 levels 24 h following transfection of siRNAs. (B) Immunoblots of TC-797 lysates 120h following transfection with siRNAs.

PDF file - 213KB, Supplementary Fig. S3. Wild type NSD3 is required for the blockade of differentiation in BRD4-NUT-expressing NMC cells, 8645 and PER-403.

Supplemental Table

Supplemental Table

Supplemental Table

PDF file - 140KB, Supplementary Fig. S1. Karyotype of the 1221 NSD3-NUT-positive cell line.

Purpose:Ewing sarcoma is an aggressive solid tumor malignancy of childhood. Although current treatment regimens cure approximately 70% of patients with localized disease, they are ineffective for most patients with metastases or relapse. New treatment combinations are necessary for these patients.Experimental Design:Ewing sarcoma cells are dependent on focal adhesion kinase (FAK) for growth. To identify candidate treatment combinations for Ewing sarcoma, we performed a small-molecule library screen to identify compounds synergistic with FAK inhibitors in impairing Ewing cell growth. The activity of a top-scoring class of compounds was then validated across multiple Ewing cell lines in vitro and in multiple xenograft models of Ewing sarcoma.Results:Numerous Aurora kinase inhibitors scored as synergistic with FAK inhibition in this screen. We found that Aurora kinase B inhibitors were synergistic across a larger range of concentrations than Aurora kinase A inhibitors when combined with FAK inhibitors in multiple Ewing cell lines. The combination of AZD-1152, an Aurora kinase B–selective inhibitor, and PF-562271 or VS-4718, FAK-selective inhibitors, induced apoptosis in Ewing sarcoma cells at concentrations that had minimal effects on survival when cells were treated with either drug alone. We also found that the combination significantly impaired tumor progression in multiple xenograft models of Ewing sarcoma.Conclusions:FAK and Aurora kinase B inhibitors synergistically impair Ewing sarcoma cell viability and significantly inhibit tumor progression. This study provides preclinical support for the consideration of a clinical trial testing the safety and efficacy of this combination for patients with Ewing sarcoma.

Supplemental Table S7. Reverse Phase Protein Array (RPPA) data. Total protein and phosphorylation levels in untreated and treated A673 and TC32 cells are normalized to total protein levels in each sample.

Supplemental Table S3. Target sequences for shRNAs targeting AURKB expression in the in vivo dependency screen

Supplemental Table S2. Target sequences for shRNAs targeting AURKB expression in the Achilles Project

Supplemental Methods and Figures Supplemental Figure S1. Aurora kinase expression in Ewing sarcoma Supplemental Figure S2. Effects of cell growth on response to AZD-1152 as a function of duration of treatment. Supplemental Figure S3. Aurora kinase and FAK inhibitor combinations are synergistic in Ewing sarcoma cell lines Supplemental Figure S4. Response of Ewing cell lines treated with combinations of Aurora kinase and FAK inhibitors Supplemental Figure S5. Cell cycle and apoptotic effects of Aurora kinase B knock out in Ewing sarcoma cell lines Supplemental Figure S6. PYK2 is poorly expressed in Ewing sarcoma cells Supplemental Figure S7. Zebrafish and Murine studies

Supplemental Table S1. List of compounds in MIPE 4.0 compound library

Supplemental Table S6. Muliple metrics were used to calculate synergy of all compounds tested from MIPE 4.0 library in combination with PF-562271. Highlighted in green are Pan-Aurora Inhibitors, red are Aurora B inhibitors, and blue are Aurora A inhibitors.

Supplemental Table S4. Target sequences for sgRNA guides targeting AURKB, AURKA, and FAK genes

Supplementary Figures 1-2 from Differentiation of NUT Midline Carcinoma by Epigenomic Reprogramming

NUT midline carcinoma (NMC) is a lethal pediatric tumor defined by the presence of BRD-NUT fusion proteins that arrest differentiation. Here we explore the mechanisms underlying the ability of BRD4-NUT to prevent squamous differentiation. In both gain-of and loss-of-expression assays, we find that expression of BRD4-NUT is associated with globally decreased histone acetylation and transcriptional repression. Bulk chromatin acetylation can be restored by treatment of NMC cells with histone deacetylase inhibitors (HDACi), engaging a program of squamous differentiation and arrested growth in vitro that closely mimics the effects of siRNA-mediated attenuation of BRD4-NUT expression. The potential therapeutic utility of HDACi differentiation therapy was established in three different NMC xenograft models, where it produced significant growth inhibition and a survival benefit. Based on these results and translational studies performed with patient-derived primary tumor cells, a child with NMC was treated with the FDA-approved HDAC inhibitor, vorinostat. An objective response was obtained after five weeks of therapy, as determined by positron emission tomography. These findings provide preclinical support for trials of HDACi in patients with NMC. Cancer Res; 71(7); 2686–96. ©2011 AACR.

NUT carcinoma (NC), characterized most commonly by the BRD4-NUTM1 fusion, is a rare, aggressive variant of squamous carcinoma with no effective treatment. BRD4-NUT drives growth and maintains the poorly differentiated state of NC by activating pro-growth genes such as MYC, through the formation of massive, hyperacetylated, superenhancer-like domains termed megadomains. BRD4-NUT–mediated hyperacetylation of chromatin is facilitated by the chromatin-targeting tandem bromodomains of BRD4, combined with NUT, which recruits the histone acetyltransferase, p300. Here, we developed a high-throughput small-molecule screen to identify inhibitors of transcriptional activation by NUT. In this dCAS9-based GFP-reporter assay, the strongest hits were diverse histone deacetylase (HDAC) inhibitors. Two structurally unrelated HDAC inhibitors, panobinostat and the novel compound, IRBM6, both repressed growth and induced differentiation of NC cells in proportion to their inhibition of NUT transcriptional activity. These two compounds repressed transcription of megadomain-associated oncogenic genes, such as MYC and SOX2, while upregulating pro-differentiation, non-megadomain–associated genes, including JUN, FOS, and key cell-cycle regulators, such as CDKN1A. The transcriptional changes correlate with depletion of BRD4-NUT from megadomains, and redistribution of the p300/CBP-associated chromatin acetylation mark, H3K27ac, away from megadomains toward regular enhancer regions previously populated by H3K27ac. In NC xenograft models, we demonstrated that suppression of tumor growth by panobinostat was comparable with that of bromodomain inhibition, and when combined they improved both survival and growth suppression. Implications: The findings provide mechanistic and preclinical rationale for the use of HDAC inhibitors, alone or combined with other agents, in the treatment of NUT carcinoma.

NUT midline carcinoma (NMC) is a rare, aggressive subtype of squamous carcinoma that is driven by the BRD4-NUT fusion oncoprotein. BRD4, a BET protein, binds to chromatin through its two bromodomains, and NUT recruits the p300 histone acetyltransferse (HAT) to activate transcription of oncogenic target genes. BET-selective bromodomain inhibitors have demonstrated on-target activity in patients with NMC, but with limited efficacy. P300, like BRD4, contains a bromodomain. We show that combining selective p300/CBP and BET bromodomain inhibitors, GNE-781 and OTX015, respectively, induces cooperative depletion of MYC and synergistic inhibition of NMC growth. Treatment of NMC cells with the novel dual p300/CBP and BET bromodomain–selective inhibitor, NEO2734, potently inhibits growth and induces differentiation of NMC cells in vitro; findings that correspond with potentiated transcriptional effects from combined BET and p300 bromodomain inhibition. In three disseminated NMC xenograft models, NEO2734 provided greater growth inhibition, with tumor regression and significant survival benefit seen in two of three models, compared with a lead clinical BET inhibitor or “standard” chemotherapy. Our findings provide a strong rationale for clinical study of NEO2734 in patients with NMC. Moreover, the synergistic inhibition of NMC growth by CBP/p300 and BET bromodomain inhibition lays the groundwork for greater mechanistic understanding of the interplay between p300 and BRD4-NUT that drives this cancer.

NUT midline carcinoma (NMC) is an aggressive type of squamous cell carcinoma that typically harbors BRD4/3-NUT fusion oncogenes which encode chimeric proteins that block differentiation and maintain tumor growth. However, in 30% of cases NUT is fused to yet to be identified non-BRD gene(s). Using RNA sequencing, we identified a novel gene fused to NUT in a NMC cell line (1221), fusing a novel 5′ coding sequence to the NUT gene. Like Brd4/3, this gene encodes a protein that is also involved in epigenetic regulation, and we find that siRNA knockdown of this protein leads to differentiation of the 1221 cells as well as of three BRD4-NUT-positive NMC cell lines. We have established that the novel NUT fusion protein encoded by this translocated gene binds to BRD4. We have mapped the regions of Brd4 and of the novel fusion protein involved in complex formation and are exploring whether association of the novel protein with Brd4 is required for the blockade of differentiation in NMC. Differentiation of TC-797 cells induced by knockdown of BRD4-NUT is abrogated by enforced expression of the novel NUT-fusion gene. Together, these findings identify a novel BRD4-NUT-interacting protein whose expression is required for the maintenance of the undifferentiated state in NMC, and when fused to NUT, is oncogenic and can recapitulate the function of BRD4-NUT to block differentiation. Citation Format: Erica Walsh, Simone Kuhnle, Shaila Rahman, Madeleine Lemieux, Peter Howley, Christopher French. A novel NUT translocation partner binds to BRD4 and is necessary for the blockade of differentiation in NUT midline carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2476. doi:10.1158/1538-7445.AM2014-2476

While epigenetic alterations are widely present in cancers, in the context of genomic instability it has been difficult to determine the degree to which epigenetic alterations serve as primary drivers of tumorigenesis. Cancers initiated by mutation of the SNF5 chromatin remodeling subunit, despite being highly aggressive and lethal, are diploid and genomically stable, making them an ideal model for this purpose. SNF5 is a core subunit of the SWI/SNF chromatin complex and is mutated in the large majority of malignant rhabdoid tumors (MRT), highly lethal cancers that occur in kidney, brain, and soft tissues of young children. Inactivating mutations in SNF5 have also recently been found to occur in a variety of other cancers and mutations in other SWI/SNF subunits occur frequently in ovarian, endometrial, renal, and lung cancers. Given our findings of genomic stability, we hypothesize that the consequences of SNF5 loss are fundamentally epigenetic in nature; that characterization of the epigenetic changes present in our model systems, rather than in cancers with genome instability, will identify those epigenetic alterations capable of driving oncogenic transformation; and lastly that cancers carrying mutations in the SWI/SNF complex can be effectively treated with epigenetically targeted therapies. Analysis of Drosophila mutants suggests that Polycomb and SWI/SNF complexes can serve antagonistic developmental roles. However, the relevance of this relationship to human disease is unclear. Here we have investigated functional relationships between these epigenetic regulators in oncogenic transformation. Mechanistically, we show that loss of the SNF5 tumor suppressor leads to elevated expression of the Polycomb gene EZH2 and that Polycomb targets are broadly H3K27-trimethylated and repressed in SNF5-deficient fibroblasts and cancers. Further, we show antagonism between SNF5 and EZH2 in the regulation of stem cell-associated programs and that Snf5 loss activates those programs. Finally, using conditional mouse models, we show that inactivation of Ezh2 blocks tumor formation driven by Snf5 loss. Collectively, we demonstrate that the rapid onset of tumor formation following SNF5 loss arises due to imbalanced epigenetic antagonism between the SWI/SNF complex and the Polycomb complex PRC2. Our work reveals essential roles for epigenetic modifications during tumor formation and demonstrates that inactivation of EZH2 can have therapeutic efficacy against cancer in vivo. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-237. doi:10.1158/1538-7445.AM2011-LB-237

Tumor vascularization is a critical component of cancer progression, malignancy, and metastasis and hypoxia inducible factor (HIF) is a key regulator of these processes. HIF transcriptional activity regulates numerous pro-angiogenic cytokines that act upon cancer cells and the surrounding tumor stroma to cooperatively stimulate tumor vascularization. HIF is constitutively activated in clear cell renal cell carcinoma (CCRCC), the most lethal and angiogenic type of kidney cancer, due to genetic or functional loss of the HIF-targeting VHL ubiquitin ligase protein. In the absence of VHL-dependent HIF degradation, pharmacologic targeting of HIF may be exploited as a means to suppress HIF-dependent signaling. HIF is also a client protein for Hsp90, a molecular chaperone regulating a number of substrates that support cancer progression. Hsp90 inhibitors possess anti-tumorigenic and anti-angiogenic properties, due in part to their ability to inhibit HIF function. However, clinical trials with the prototypic Hsp90 inhibitor 17-AAG have been unsuccessful in CCRCC and other solid tumors, highlighting the need to further evaluate the role of Hsp90 in CCRCC angiogenic processes and HIF signaling. Approach: We compared the molecular and functional effects of 3 Hsp90 inhibitors, using VHL replaced cells as HIF suppressed controls. We examined the prototypic Hsp90 inhibitor 17-AAG, a newer, more potent totally synthetic small molecule derivative (EC154), and LBH589, an HDAC inhibitor in clinical use that also impairs Hsp90 function. Our assays consisted of analysis of drug effects on 1) genome wide HIF ChIP and RT-PCR 2) cytokine profiles, 3) endothelial cell tubule assays, and 4) limited phospho-proteomic analysis of signaling proteins. Results: These inhibitors exhibit variable suppression of HIF target genes, illustrating the complexity associated with these pathways. Cytokine arrays indicated that while VEGF expression decreased in response to all drugs, a number of proteins unexpectedly increased. In addition, these changes did not always correlate with VHL-dependent HIF suppression. Although Hsp90 inhibitors initiate the destruction of a number of proteins and impact upon numerous signaling cascades, the protein-centric effects of Hsp90 inhibition in cancer cells remain unknown. To explore this, we utilized a commercial phosphoproteome array to examine the effects of Hsp90 inhibition upon the activation status of over 1300 key signaling proteins. Finally, to understand how alterations in these signaling profiles modulate angiogenic potential, conditioned medium from untreated cells, VHL replaced cells, or drug treated cells was evaluated in a tubule assay. Collectively, the results of these studies will further define the role of HIF in CCRCC tumor angiogenesis, add to our understanding of molecular events that contribute to clinical failure of Hsp90 inhibitors, and shed light on alternative approaches for CCRCC treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2391.