bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract IA17: Hippo pathway deregulation in cancers
Authors: Dey Anwesha
Published: September 2020

The Hippo signaling pathway is an evolutionarily conserved pathway that plays a key role in the development and homeostasis of tissues and organs. The TEAD family of the transcription factors (TEAD1-4) are the major transcription factors, and YAP/TAZ are the transcription activators/ key effectors of the Hippo pathway. TEADs regulate many biologic processes, including development, tissue homeostasis, and tumorigenesis by regulating target genes involved in cellular proliferation and survival. Amplification or upregulation of YAP/TAZ/TEADs correlates with poor prognosis in cancer patients. While data over the past few years have demonstrated that the pathway is dysregulated in a spectrum of cancers, the underlying molecular mechanisms of regulation and localization are areas of active investigation. One such focus area that I will discuss during my talk is the regulation and localization of TEADs. TEADs contain a highly conserved nuclear localization signal (NLS) embedded in the DNA binding domain (DBD). Overexpression of an NLS mutant TEAD in a Hippo-dependent cancer cell line is dominant negative and suppresses cellular proliferation and tumor growth. Additionally, we have identified physiologic conditions where TEADs are expressed in the cytoplasm and the nucleus. By performing comparative immunoprecipitation-mass spectrometry between WT and NLS mutant TEAD, we found novel interacting partners for cytoplasmic and nuclear TEAD, thus uncovering novel roles for TEADs in cancer.

Citation Format: Anwesha Dey. Hippo pathway deregulation in cancers [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr IA17.
Abstract IA18: Targeting the Hippo pathway for candidate cancer therapy
Authors: Hong Wanjin
Published: September 2020

My lab has been working on the Hippo pathway and its regulators in cancer. Our earlier works defined the oncogenic role of TAZ/WWTR1 and the importance of TEAD in mediating TAZ-driven oncogenesis. We also resolved the crystal structure of YAP-TEAD and Vgll1-TEAD complexes offering the structural basis for their role in the Hippo pathway. Amot proteins, Wbp2, and USP9X were identified to be regulators of the Hippo pathway. Due to the importance of YAP/TAZ-TEAD complex in driving transcriptional program that is implicated in diverse human cancers, targeting TAZ, YAP, TEAD, and their complexes represents an attractive opportunity for novel cancer drug discovery. We recently reported the discovery of a central hydrophobic pocket in the YAP/TAZ-binding domain of TEAD proteins that is targetable by small-molecule inhibitors. Flufenamic acid, a nonsteroidal anti-inflammatory drug (NSAID), was shown to bind to the central pocket of TEAD and modulate its function. Studies from other labs have also shown that this pocket is physiologically occupied by palmitate via autopalmitoylation of TEAD. We therefore developed a target-based, TEAD-palmitate interaction screen that was used to select compounds occupying the palmitate-binding pocket (PBP) in TEADs. Interestingly, we identified some candidates as TEAD-binding compounds that augment YAP/TAZ-TEAD activity. The enhancement of YAP/TAZ-TEAD activity by these compounds accelerates in vivo wound closure in a cutaneous wound-healing mouse model. These results suggest that the class of TEAD-activating compounds could be exploited for use in regenerative medicine, while future search for inhibitors will serve as candidates for cancer drugs.

Citation Format: Wanjin Hong. Targeting the Hippo pathway for candidate cancer therapy [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr IA18.
Abstract IA20: LATS1 and LATS2 suppress breast cancer progression by maintaining cell identity and metabolic state
Authors: Furth Noa , Pateras Ioannis , Rotkopf Ron , Schmitt Ina , Bakaev Deborah , Gershoni Anat , Johnson Randy , Gorgoulis Vassilis , Oren Moshe , Aylon Yael
Published: September 2020

Deregulated activity of the LATS tumor suppressors has broad implications on cellular and tissue homeostasis. We examined the consequences of downregulation of either LATS1 or LATS2 in breast cancer. Consistent with their proposed tumor-suppressive roles, expression of both paralogs is significantly downregulated in human breast cancer, and loss of either paralog accelerated mammary tumorigenesis in mice. However, each paralog had a distinct impact on breast cancer. LATS2 depletion in luminal B tumors resulted in metabolic rewiring, with increased glycolysis and reduced PPARg signaling. Furthermore, pharmacologic activation of PPARg elicited LATS2-dependent death in luminal B-derived cells. In contrast, LATS1 depletion augmented cancer cell plasticity, skewing luminal B tumors towards increased expression of basal-like features, in association with increased resistance to hormone therapy. Hence, these two closely related paralogs play distinct roles in protection against breast cancer; tumors with reduced expression of either LATS1 or LATS2 may rewire signaling networks differently and thus respond differently to anticancer treatments.

Citation Format: Noa Furth, Ioannis Pateras, Ron Rotkopf, Ina Schmitt, Deborah Bakaev, Anat Gershoni, Randy Johnson, Vassilis Gorgoulis, Moshe Oren, Yael Aylon. LATS1 and LATS2 suppress breast cancer progression by maintaining cell identity and metabolic state [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr IA20.
Abstract IA25: Adult deletion of Lats1/2 leads to sarcomatoid renal cell carcinoma
Authors: Reginensi Antoine , Jain Sanjay , Humphreys Benjamin , Shen Jess , Hodzic Didier , Wrana Jeff , McNeill Helen
Published: September 2020

Alterations of the Hippo signaling pathway have been found in patients with sarcomatoid renal cell carcinoma, a highly aggressive kidney disease with rapid progression and poor prognosis. It is unclear whether deregulated Hippo pathway is a primary cause of sarcomatoid cancers. To investigate whether conditional (kidney-specific) Hippo knockout leads to renal cancer development and/or sarcomatoid dedifferentiation, we conditionally inactivated both Lats1 and Lats2 from the adult renal proximal tubule epithelial cells. Mosaic deletion of Lats1 and Lats2 in the adult proximal tubules results in cell-autonomous sarcomatoid renal cell carcinoma ((54%) as early as 8 weeks after gene deletion) and lung metastasis. RNA sequencing of tumors compared to control renal cortices revealed massive transcriptional changes, with 2,292 genes significantly upregulated (FC>2) and 2261 genes significantly downregulated (FCË‚0.5). To visualize the cellular onset and progression of renal defects, we conducted histologic examination at different time points after induction of Lats1/2 deletion. Mutant kidneys displayed tubular atrophy with glomerular cysts. Loss of proximal tubule epithelial markers, and de novo expression of the mesenchymal marker vimentin, indicated that kidney epithelial cells had undergone an epithelial-to-mesenchymal transition (EMT). These studies demonstrate that loss of Lats1/2 rapidly leads to aggressive, metastatic sarcomatoid renal cell carcinoma.

Citation Format: Antoine Reginensi, Sanjay Jain, Benjamin Humphreys, Jess Shen, Didier Hodzic, Jeff Wrana, Helen McNeill. Adult deletion of Lats1/2 leads to sarcomatoid renal cell carcinoma [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr IA25.
Abstract IA26: Oncogenic LncRNA promotes escape from intrinsic Hippo tumor suppression
Authors: Hu Qingsong , Lin Chunru , Yang Liuqing
Published: September 2020

How tumor cells genetically lose antigenicity and evade intrinsic tumor suppression barriers has been uncertain for decades. Here, we report that tissue-specific expression of a human long noncoding RNA LINK-A in mouse mammary gland initiates metastatic breast tumor, which models human basal-like breast cancer morphologically, genetically, transcriptionally, and metabolically. LINK-A expression facilitates crosstalk between PIP3 and inhibitory GPCRs pathways, leading to decreased cAMP level and protein kinase A (PKA)-mediated phosphorylation of E3 ubiquitin ligase TRIM71. This leads to enhanced K48-polyubiquitination-mediated degradation of tumor suppressor MST1 as well as LATS1. Treatment with LINK-A antisense oligonucleotides or Rauwolscine (a Galphai antagonist) stabilizes Hippo tumor suppressor pathway, sensitizing breast tumors to immune checkpoint blockers. PD-1 blockade-resistant TNBC patients exhibited elevated LINK-A and downregulated Hippo tumor suppressors. We demonstrate an lncRNA-dependent escape from intrinsic tumor suppression and immunosurveillance, which provides a regimen of combinational immunotherapy and effective early prevention for TNBC.

Citation Format: Qingsong Hu, Chunru Lin, Liuqing Yang. Oncogenic LncRNA promotes escape from intrinsic Hippo tumor suppression [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr IA26.
Abstract PR01: Regulation of TEAD by p38 MAPK-induced cytoplasmic translocation
Authors: Park Hyun Woo
Published: September 2020

The Hippo pathway controls organ size and tissue homeostasis, with deregulation leading to cancer. The core Hippo components in mammals are composed of the upstream kinases Mst1/2, MAPK4Ks, and Lats1/2. Inactivation of these upstream kinases leads to dephosphorylation, stabilization, nuclear translocation, and thus activation of the major functional transducers of the Hippo pathway, YAP and its paralogue TAZ. YAP/TAZ are transcription coactivators that regulate gene expression primarily through interaction with the TEA domain DNA-binding family of transcription factors (TEAD). The current paradigm for regulation of this pathway centers on phosphorylation-dependent nucleocytoplasmic shuttling of YAP/TAZ through a complex network of upstream components. However, unlike other transcription factors, such as SMAD, NF-kB, NFAT, and STAT, the regulation of TEAD nucleocytoplasmic shuttling has been largely overlooked. In the present study, we show that environmental stress promotes TEAD cytoplasmic translocation via p38 MAPK in a Hippo-independent manner. Importantly, stress-induced TEAD inhibition predominates YAP-activating signals and selectively suppresses YAP-driven cancer cell growth. Our data reveal a mechanism governing TEAD nucleocytoplasmic shuttling and show that TEAD localization is a critical determinant of Hippo signaling output.

This abstract is also being presented as Poster A33.

Citation Format: Hyun Woo Park. Regulation of TEAD by p38 MAPK-induced cytoplasmic translocation [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr PR01.
Abstract PR02: Spatial resets modulate YAP-dependent transcription
Authors: Franklin Matt , Ghosh Raja , Shi Quanming , Liphardt Jan
Published: September 2020

Despite the emergence of YAP as an important regulator of cell proliferation and oncogenesis, a clear picture of the relationship between YAP localization dynamics and downstream transcription is missing. Using live-cell imaging of CRISPR-knockin breast epithelial lines, we show that YAP displays dramatic spatial resets characterized by bulk exit from the nucleus followed by re-entry. These localization resets were upregulated by inhibiting Src-kinase and dampened by Ras transformation. After monolayer wounding, we found that edge-cells exhibited a synchronized localization reset. Lastly, induction of store-operated Ca2+ release and chromatin condensation during mitosis were found to also cause YAP localization resets. We relate these spatiotemporal YAP localization changes to transcriptional outputs from endogenous YAP targets using nascent-transcription reporter-cassette knockins. Maximal transcriptional responses were strictly correlated to the induction of localization resets through targeting Src-kinase, inducing Ca2+ release, and mitosis. By blocking the response to Ca2+ release using a PKC inhibitor, we show that the large transcriptional response is dependent on the ability of YAP to transiently localize to the cytoplasm. We found that Ras transformation, which suppressed YAP localization resets, caused upregulated import and export, reduced overall chromatin binding, and increased target gene expression. Untransformed cells, on the other hand, show relatively high nuclear retention through increased binding and slower nuclear export. This suggests that Ras transformation allows an escape from the compartmentalization-based control shown in untransformed cells. Our results suggest a new perspective on YAP-dependent transcription, revealed through the application of real-time imaging of native YAP dynamics and nascent transcription of YAP target genes.

This abstract is also being presented as Poster A21.

Citation Format: Matt Franklin, Raja Ghosh, Quanming Shi, Jan Liphardt. Spatial resets modulate YAP-dependent transcription [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr PR02.
Abstract PR03: YAP/TAZ requirement in mesenchyme-originated intestinal hamartomatous polyposis
Authors: Cotton Jennifer L. , Dang Kyvan , Li Qi , Johnson Randy L. , Ip Y. Tony , Wu Xu , Mao Junhao
Published: September 2020

Hamartomatous polyposis syndromes (HPS) are rare genetic syndromes, including Peutz-Jeghers syndrome (PJS) and PTEN hamartoma tumor syndrome (Cowden and Bannayan-Riley-Ruvalcaba syndromes), which are caused by germline mutations of STK11 (LKB1) and PTEN genes, respectively. HPS is characterized by the development of hamartomatous polyps in the GI tract; however, the cellular origins and molecular mechanism underlying hamartomatous polyposis remain poorly understood. Here we demonstrate that specific disruption or deletion of Stk11 or Pten in mouse GI mesenchyme, but not in the epithelium, generates hamartomatous polyps histologically resembling GI polyps observed in PJS and Cowden syndrome patients. Genetically, we show that mTOR activity is essential for Pten but not Stk11 deletion-driven hamartomatous polyposis. Furthermore, we show that AMPK1/2 deletion is not able to initiate PJS polyp formation. However, we find significant upregulation of mesenchymal YAP/TAZ activity in PJS polyps and demonstrate that YAP/TAZ in gut mesenchyme are required for Stk11 deletion-induced PJS hamartomatous polyposis. Our studies suggest a mesenchymal origin of GI polyps in HPS and reveal the distinct roles of YAP/TAZ and mTOR in gut mesenchyme during hamartomatous polyposis, which likely have important therapeutic implication for treating these HPSs.

This abstract is also being presented as Poster A06.

Citation Format: Jennifer L. Cotton, Kyvan Dang, Qi Li, Randy L. Johnson, Y. Tony Ip, Xu Wu, Junhao Mao. YAP/TAZ requirement in mesenchyme-originated intestinal hamartomatous polyposis [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr PR03.
Abstract PR04: Integrin-mediated mechano-transduction controls HER2 oncogenic signaling and activation of YAP in breast cancer
Authors: Wang Shimin , Kim Young-Mi , Garippa Ralph , Norton Larry , Giancotti Filippo G.
Published: September 2020

Integrin-mediated adhesion and signaling via focal adhesion kinase is required for mammary tumorigenesis in the PyMT mouse model. Moreover, PTK2 encoding FAK is amplified in a substantial fraction of human breast cancers. We have investigated the mechanism through which integrin signaling controls mammary tumorigenesis and found that integrin-mediated mechano-transduction controls invasive growth in stiff 3D matrices through activation of YAP/TAZ. Mechanistic studies revealed that integrin signaling induces—via activation of FAK and Src family kinases (SFKs) —tyrosine phosphorylation and inactivation of LATS. The ensuing activation of YAP/TAZ is necessary for invasive growth of HER2+ breast cancer cells. Engagement of HER2/HER3 with neuregulin impinges on SFKs to amplify activation of YAP/TAZ in HER2+ breast cancer cells, suggesting that integrin-mediated mechano-transduction functions as a rheostat to regulate HER2 oncogenic signaling. Finally, administration of dasatinib significantly increases the efficacy of HER2 inhibition in the MMTV-Neu mouse model of HER2+ breast cancer. These findings reveal a major mechanism through which the Hippo pathway is disabled in breast cancer and suggest that targeting HER2 and SFKs simultaneously may be a rational strategy in selected cases of breast cancer.

This abstract is also being presented as Poster A22.

Citation Format: Shimin Wang, Young-Mi Kim, Ralph Garippa, Larry Norton, Filippo G. Giancotti. Integrin-mediated mechano-transduction controls HER2 oncogenic signaling and activation of YAP in breast cancer [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr PR04.
Abstract PR05: Genome-wide screening identifies novel YAP modulators
Authors: Elster Dana , Tollot Marie , Schlegelmilch Karin , Ori Alessandro , Rosenwald Andreas , Sahai Erik , von Eyss Björn
Published: September 2020

The transcriptional coactivator YAP is the key downstream effector of the Hippo pathway, which is a central regulator of organ size, stem cell/progenitor cell expansion, and tissue regeneration. Diverse studies have shown the importance of a precise regulation of this pathway and its key downstream regulator YAP for tissue homeostasis. To achieve new insights in the Hippo-independent transcriptional regulation of YAP in breast cancer, we set out to identify new YAP modulators using a genome-wide CRISPR screen and Perturb-Seq. We identified the transcriptional repressor protein Trichorhinophalangeal Syndrome 1 (TRPS1) as a potent repressor of YAP-dependent transactivation, using a genome-wide CRISPR screen. TRPS1 globally regulates YAP-dependent transcription by binding to a large set of joint genomic sites, mainly enhancers. Moreover, TRPS1 antagonizes activating YAP/TEAD complexes by recruiting corepressor complexes to joint sites. Loss of TRPS1 leads to activation of enhancers due to increased H3K27 acetylation and an altered promoter-enhancer interaction landscape. TRPS1 is commonly amplified in breast cancer, suggesting that restrained YAP activity favors tumor growth. Combined, we uncover TRPS1 as an epigenetic regulator of YAP activity in breast cancer. Additionally, we developed a Trps1-deficient mouse line that we will use to test the in vivo role of Trps1 in mammary gland physiology and breast cancer. Furthermore, we combined CRISPR-based gene perturbation with droplet-based single-cell RNA sequencing (Perturb-Seq), to perform a second large-scale analysis on potential YAP modulators. To this end, we used a CRISPR-library containing 158 previously from us in a Bio-ID assay identified YAP interactors. Together, we uncover several novel YAP modulators, contributing to a better understanding of the Hippo-independent transcriptional regulation of YAP.

This abstract is also being presented as Poster B40.

Citation Format: Dana Elster, Marie Tollot, Karin Schlegelmilch, Alessandro Ori, Andreas Rosenwald, Erik Sahai, Björn von Eyss. Genome-wide screening identifies novel YAP modulators [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr PR05.
Abstract PR07: Targeting the Hippo-YAP pathway with small-molecule compounds
Authors: Tang Tracy T. , Konradi Andrei W. , Feng Ying , Peng Xiao , Qiao Sofie , Post Leonard
Published: September 2020

The Hippo-YAP pathway is involved in the regulation of cell proliferation, survival, and cell migration. It functions normally to control tissue regeneration and homeostasis and limit organ size/shape. Genetic alterations of pathway components resulting in YAP activation have been reported in a variety of human malignancies. YAP activity is also linked to resistance to targeted therapies and cancer relapse. Through high-throughput phenotypic screens, we have identified novel classes of small-molecule compounds that target the Hippo-YAP pathway. Using different assays, we determined whether the screen hits specifically inhibit YAP-TEAD transcription activity and examined their effects on YAP phosphorylation, YAP nuclear and cytoplasmic localization, and YAP-TEAD interaction. To map the target points in the Hippo pathway, we analyzed the effects of the compounds in cells deficient for various pathway components. Lead optimization resulted in highly potent inhibitors that block YAP-TEAD transcription activity at single-digit nM, and we have identified the molecular targets of some chemical series. In all, we have discovered different classes of pathway inhibitors: 1) compounds that induce YAP phosphorylation and cytoplasmic translocation, 2) compounds that induce YAP cytoplasmic translocation without affecting its phosphorylation, and 3) compounds that work in the nucleus to block YAP-TEAD transcription activity without affecting YAP phosphorylation or nuclear localization. Examples of a few classes will be presented to illustrate that we now have a way to target the Hippo-YAP pathway that thus far has been undruggable and is dysregulated in many cancers and critically associated with targeted therapy resistance.

This abstract is also being presented as Poster B15.

Citation Format: Tracy T. Tang, Andrei W. Konradi, Ying Feng, Xiao Peng, Sofie Qiao, Leonard Post. Targeting the Hippo-YAP pathway with small-molecule compounds [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr PR07.
Abstract PR08: Systematic pan-cancer analyses of Hippo pathway deregulation in cancer
Authors: Chang Matthew T. , Hagenbeek Thijs J. , Lacap Jennifer , Modrusan Zora , Klijn Christiaan , Dey Anwesha
Published: September 2020

Hippo signaling is a highly conserved, pleiotropic pathway that is recurrently deregulated across many cancers. With large-scale cancer genomics data, several efforts have been undertaken to quantify Hippo pathway activity in an unbiased manner. However, identifying a comprehensive catalog of Hippo pathway genes can be difficult due to the heterogenous nature of the disease and the limitations of any given study. Here we show the high concordance between different methods of quantifying Hippo pathway activity in cancers. Furthermore, we establish a first-principled approach by experimentally deriving a lineage-independent quantification by leveraging the transcriptomic profiles of nearly 900 cell lines from 28 tissue types. We applied these signature(s) to the genomic profiles of over 11,000 primary human cancer patients to identify several statistically significant biomarkers associated with Hippo pathway dysregulation, including NF2 mutations and deletions, SOX2 amplifications, and CDH1 mutations. To further assess therapeutic implications of pathway inhibition, we applied machine learning approaches to predict a tumor’s sensitivity to Hippo pathway inhibition based on its genomic profile, revealing that Hippo pathway inhibition may be a tractable approach in a wide spectrum of cancers.

This abstract is also being presented as Poster B38.

Citation Format: Matthew T. Chang, Thijs J. Hagenbeek, Jennifer Lacap, Zora Modrusan, Christiaan Klijn, Anwesha Dey. Systematic pan-cancer analyses of Hippo pathway deregulation in cancer [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr PR08.
Abstract PR10: Hippo regulates intestinal regeneration by inducing revival stem cells
Authors: Ayyaz Arshad , Wrana Jeff
Published: September 2020

The mechanisms underlying intestinal regeneration and initiation of adenomas have been obscure. Here we profiled the single-cell transcriptomes of regenerating intestines and identify revival stem cells. Revival stem cells are dependent on Yap signaling, are transiently induced by a variety of damage, and are required to reconstitute the intestinal crypt. These studies reveal a unique pathway to regenerate damaged tissues.

This abstract is also being presented as Poster A14.

Citation Format: Arshad Ayyaz, Jeff Wrana. Hippo regulates intestinal regeneration by inducing revival stem cells [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr PR10.
Abstract A02: The feedback loop among miR-449b-3p/ADAM17/NF-κB promotes metastasis in nasopharyngeal carcinoma
Authors: Fei Qian , Du Ming-Yu , Jiang Ning , Yin Li , He Xia
Published: September 2020

Emerging pieces of evidence have proved an important role of miRNAs in tumorigenesis and progression. However, the function of miRNAs in nasopharyngeal carcinoma (NPC) development remains poorly elucidated. Quantitative reverse transcription-polymerase chain was used to detect the expression level of miR-449b-3p in NPC cell lines and tissues. We performed cell viability assay, colony formation, flow cytometric, transwell assay, and wound-healing assay to assess the ability of cell proliferation, apoptosis, invasion, and migration in vitro, respectively. NPC xenograft tumor and lymph node metastatic mice model were conducted to validate the function of miR-449b-3p in vivo. Luciferase reporter assay, ChIP assay, and Western blot analysis were actualized to explore the mechanism underlying the miR-449b-3p on NPC metastasis. Here we showed that miR-449b-3p was downregulated in NPC specimens (p<0.001) and cells (p<0.05), and most of the patients with advanced-stage NPC had an impaired expression of miR-449b-3p, on the contrary, early-stage NPC patients had a high level of miR-449b-3p (p<0.001). Moreover, miR-449b-3p inhibited NPC metastasis both in vitro and in vivo. Further investigation revealed that a disintegrin and metalloproteinase 17 (ADAM17) was the direct target of miR-449b-3p. Rescue experiments suggested that the downregulation of ADAM17 in miR-449b-3p inhibited cells partially reversed the inhibition of cell invasion and migration. We also found that ADAM17 could conversely suppress the promoter activity and expression of miR-449b-3p via inducing NF-κB transcriptional activity. In conclusion, our study provides new insights into the mechanism underlying the invasion and metastasis in NPC. The novel miR-449b-3p/ADAM17/NF-κB feedback loop in NPC could potentially be a target for clinical treatment in NPC.

Citation Format: Qian Fei, Ming-Yu Du, Ning Jiang, Li Yin, Xia He. The feedback loop among miR-449b-3p/ADAM17/NF-κB promotes metastasis in nasopharyngeal carcinoma [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A02.
Abstract A04: Tumor development trajectories for exploring differences between cancer subtypes
Authors: Leshchiner Ignaty , Rosebrock Daniel , Spiro Oliver , Mroz Edmund , Livitz Dimitri , Rocco James W. , Getz Gad
Published: September 2020

We have employed PhylogicNDT, our computational method for timing somatic events and subclonal architecture reconstruction, to explore the association of tumor development trajectory (from normal cell to malignant state) with cancer subtype and genetic landscape. Previous attempts to understand the order of somatic events that lead to the formation of cancers are mostly based on studies of premalignant samples, which are often hard or impossible to obtain due to small size or inaccessible location. Our approach allows us to use information from whole-exome and whole-genome data to computationally reconstruct the order of events preceding malignant transformation of the tissue. We show that this approach yields accurate reconstruction of premalignant events in lung, colorectal, and head and neck cancers based on previous exploration of premalignant lesions. We explored the association between the developmental trajectories, treatment outcome, and survival in several cancer types. PhylogicNDT can be used to infer the order of clonal driver events (including in precancerous stages), subclonal populations of cells and their phylogenetic relationships, and dynamics of cell populations. This methodology will enable a systematic study of tumor initiation and progression across cancer types and therapies.

Citation Format: Ignaty Leshchiner, Daniel Rosebrock, Oliver Spiro, Edmund Mroz, Dimitri Livitz, James W. Rocco, Gad Getz. Tumor development trajectories for exploring differences between cancer subtypes [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A04.
Abstract A10: Treatment of squamous cell carcinoma by alpha radiation-based brachytherapy (Alpha DaRT)
Authors: Mizrachi Aviram , Popovtzer Aron , Rosenfeld Eli , Ben-Hur Ran , Kelson Itzhak , Keisari Yona
Published: September 2020

Objective: The first clinical trial in humans with skin and oral cavity squamous cell carcinoma (SCC) was performed in order to evaluate the effect of a unique intratumoral alpha radiation-based tumor ablation treatment termed Diffusing Alpha-emitters Radiation Therapy (DaRT).

Methods: Radium-224 loaded sources (DaRT seeds) were inserted into solid tumors and released by recoil short-lived alpha-emitting atoms (Rn-220, Po-216, Pb-212, Bi-212, Po-212, Tl-208). These atoms disperse in the tumor and spray it with highly destructive alpha radiation. The decay products diffuse in the tumor mass to a distance of at least 5 mm.

Results: A feasibility and safety clinical study is ongoing and currently 28 patients were treated at the Rabin Medical Center (Israel) and IRST (Italy). Patients with histopathologic confirmed skin or head and neck SCC, and tumor size ≤5 centimeters in the largest diameter, were enrolled. Treatment was delivered based on a CT-simulation pretreatment plan. The seeds (1 cm long and 0.7 mm in diameter), each carrying a dose of 2 μCi, were placed up to 5 millimeters from each other. CT was used in order to confirm the position of the radioactive seeds. Two weeks after implantation the seeds were removed, and six weeks after treatment a CT scan was performed to assess the effect of treatment. Study results are available for 18 cases that were treated per protocol and reached the 30-day follow-up period. Age of the patients ranged from 60 to 102 years (median 80 years). Ten patients had oral cavity SCC and 18 were diagnosed with cutaneous SCC. Thirteen subjects were treated within prior radiation failure fields (radiation dosage >60Gy). All tumors responded to the treatment; 13 tumors exhibited a complete response and five tumors showed partial response. No major toxicity was noted.

Conclusions: In this first feasibility and safety human study we demonstrated that alpha-based treatment (DaRT) resulted in enhanced radiobiologic potential. Furthermore, the treatment was effective against radioresistant SCC tumors without any major side effects.

Citation Format: Aviram Mizrachi, Aron Popovtzer, Eli Rosenfeld, Ran Ben-Hur, Itzhak Kelson, Yona Keisari. Treatment of squamous cell carcinoma by alpha radiation-based brachytherapy (Alpha DaRT) [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A10.
Abstract A22: Patient-derived organoids recapitulate response heterogeneity in head and neck cancer
Authors: King Vincent-Chong Vui , Tracy Erin C. , Baumann Heinz , Hershberger Pamela A , Seshadri Mukund
Published: September 2020

Patient-derived organoids (PDOs) are considered to be a cost-effective, high-throughput preclinical platform for studying cancer biology and evaluating novel therapeutics. While PDOs have been established and characterized for breast, prostate, colon, and pancreatic cancers, PDO models of head and neck squamous cell carcinomas (HNSCC) are limited. To address this paucity, in the present study, we established a panel of PDO models of HNSCC. Five HNSCC samples (3 larynx, 1 tongue, 1 parotid) were procured from donor patients following informed consent and processed to establish organoids. Histologic (H&E) and immunohistochemical evaluation (p16, cytokeratin) was performed along with assessment of PDO response to the alkylating agent, cisplatin, and two tyrosine kinase inhibitors, erlotinib and afatinib. Histologic analyses of established organoids revealed nested cells of squamous cell carcinoma with high N/C ratio similar to donor surgical tumor tissue. Immunohistochemistry revealed strong pan cytokeratin and absence of p16 staining in all samples. Paired PDO and PDX models also successfully retained the squamous histology. Dose-response curves revealed substantial variation in therapeutic profiles of the three agents across the organoid panel. While the IC50 of cisplatin was comparable across the larynx organoids, 2 larynx organoids were sensitive to the two TKIs while one was resistant, exhibiting ~5-fold higher IC50 values. The tongue organoid was relatively sensitive to all agents while the parotid SCC organoid was sensitive to EGFR TKIs but relatively resistant to cisplatin. Collectively, these results demonstrate the ability of organoid models to recapitulate the histologic architecture and response heterogeneity of human HNSCC. Investigation into the molecular profiles of our PDO panel is under way in our laboratory and will enable further development of organoids as a robust platform for evaluation of precision therapeutics against HNSCC.

Citation Format: Vincent-Chong Vui King, Erin C. Tracy, Heinz Baumann, Pamela A Hershberger, Mukund Seshadri. Patient-derived organoids recapitulate response heterogeneity in head and neck cancer [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A22.
Abstract A29: Association of support group attendance with quality-of-life metrics in head and neck cancer patients
Authors: Itamura Kyohei , Lam David , Cameron Brian , Chambers Tamara , Kokot Niels , Maceri Dennis , Sinha Uttam , Swanson Mark , Villegas Brenda
Published: September 2020

Quality of life has emerged as an increasingly prominent metric of interest for those with head and neck cancer during the course of their recovery. Although many factors have been shown to affect quality of life, the effect of support group attendance has been limited and mixed in the head and neck cancer literature. There is still controversy with regard to the efficacy of support groups. This study aims to add to the literature by reporting the association of support group attendance on quality-of-life measures in head and neck cancer patients. Our findings will help with recommendations for implementing support groups into head and neck cancer care. This is a cross-sectional, survey-based study employing the University of Washington head and neck cancer quality-of-life questionnaire. This survey has been previously validated in the literature as an objective quality of life measurement tool for head and neck cancer patients. All study participants are head and neck cancer patients who have received treatment. Study participants were separated into two separate groups: 1) patients who have never attended support group in the past; 2) patients who have utilized support group. Survey scores are compared between the two groups via unpaired Mann-Whitney U test. Patients who attended support group (N=32) compared to those who have not (N=52) showed significantly greater quality-of-life median scores on appearance (support group median score = 75 vs. no support group median score = 50, U=513, p=0.02), activity (75 vs. 50, U=463, p=0.004), recreation (75 vs. 50, U=404, p<0.001), mood (75 vs. 50, U=310, p<0.001), anxiety (100 vs. 30, U=164, p<0.001), and overall sense of quality of life (80 vs. 60, U=365, p<0.001). There were no statistically significant differences between the two groups for scores in pain, swallowing, chewing, speech, shoulder mobility, taste, or recent changes in subjective sense of quality of life. Our data suggest that support group attendance is associated with a higher quality of life specifically related to mental health and social well-being. There was no observable benefit in physical functional recovery with support group attendance. There appear to be psychosocial benefits from incorporating support groups into head and neck cancer rehabilitation.

Citation Format: Kyohei Itamura, David Lam, Brian Cameron, Tamara Chambers, Niels Kokot, Dennis Maceri, Uttam Sinha, Mark Swanson, Brenda Villegas. Association of support group attendance with quality-of-life metrics in head and neck cancer patients [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A29.
Abstract A31: Deregulation of NOTCH 1/NR4A2 signaling axis in head and neck cancer pathogenesis
Authors: Chaudhary Sanjib , Pothuraju Ramesh , Sayed Zafar , Jones Dwight T. , Batra Surinder K. , Macha Muzafar A.
Published: September 2020

Background: Notch1 and its intracellular cytoplasmic domain (NICD) are dysregulated in many solid tumors, including head and neck squamous cell carcinoma (HNSCC), and associated with disease initiation and progression. NICD-mediated upregulation of nuclear receptor related 1 (NURR1/NR4A2) is linked to differentiation/development, homeostasis, and cellular metabolism. However, the role and molecular mechanism(s) of Notch1/NICD- NR4A2 axis in HNSCC pathogenesis are still unknown and need to be investigated.

Methods: The clinicopathologic importance of Notch1 and NR4A2 was investigated using HNSCC patient samples and publicly available databases. NR4A2 was stably knocked out (KO) and Notch1 signaling was blocked using small-molecule inhibitor (PF3084014) in HNSCC cell lines and analyzed for tumorigenic and metastatic potential. We also examined the whole-genome NR4A2 target genes using ChIP sequencing.

Results: Both Notch1 and NR4A2 were highly overexpressed in HNSCC patients. Inhibition of Notch1 signaling or NR4A2 KO significantly decreased the clonogenicity and migratory potential of HNSCC cells. Our ChIP analysis revealed that NR4A2 regulates genes involved in metabolism, hypoxia, cell cycle progression, integrin and Wnt signaling. Interestingly, we observed that NR4A2 regulates stem cell markers including Sox2, Nanog, and CD44 and their expression was drastically reduced upon Notch 1 inhibition.

Conclusion: Targeting Notch1-NR4A2 signaling axis may be crucial for inhibition of cancer stem cell-mediated HNSCC pathogenesis.

Citation Format: Sanjib Chaudhary, Ramesh Pothuraju, Zafar Sayed, Dwight T. Jones, Surinder K. Batra, Muzafar A. Macha. Deregulation of NOTCH 1/NR4A2 signaling axis in head and neck cancer pathogenesis [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A31.
Abstract A34: Effect of microvesicles on metalloproteinases secretion by myoepithelial cells
Authors: Rena Gabriel Bernardo , Teixeira Lucas Novaes , Araújo Vera Cavalcanti , Demasi Ana Paula Dias , Martinez Elizabeth Ferreira
Published: September 2020

In tumorigenesis, not only genetic and epigenetic alterations but also stromal cells and soluble factors in the tumor microenvironment can affect the progression of different neoplasms. In salivary gland tumors derived from the intercalated duct, the myoepithelial (Myo) component modulates the neoplastic phenotype positively. Indeed, in carcinoma ex-pleomorphic adenoma (CXPA) where the malignant component is represented only by epithelial cells, the Myo cells present a role in the progression of this neoplasia. Nevertheless, great interest has been taken in the mechanisms of cellular communication mediated by microvesicles (MV). These structures are secreted by different cells and may induce epigenetic modifications. In malignant neoplasia, MV may affect different stages of carcinogenesis, which comprise the modulation of the extracellular matrix components, including metalloproteinases (MMPs). MMPs 2 and 9 exert an essential role in the epithelial-mesenchymal transition, consequently increasing the potential of migration and invasion of plethora tumors, including CXPA. The present in vitro study aimed to characterize MV derived from malignant neoplastic epithelial cell cultures (CAL27 cells) and their effect on the expression of MMPs in benign Myo cell cultures. Malignant epithelial cells (CAL 27 cell line) were cultured until they reached confluence. Then, the culture medium was collected and the MV were extracted. The Myo cultures, derived from pleomorphic adenomas explants, were exposed to MV from CAL 27 for 24 h. After this period, the secretion of MMPs 2, 9 and their inhibitors, TIMP-1 and TIMP-2, was assayed by means of ELISA. The Myo cultures not exposed to MV were used as control. The results indicated that Myo exposed to MV exhibited a significant increase of MMP-2 and MMP-9 expression (p<0.05) and a reduction in TIMP-2 expression (p<0.05). TIMP-1 expression in Myo cultures was not affected by MV (p>0.05). In conclusion, the data suggest that MV can modulate MMP and their inhibitors’ expression in Myo cell, which may promote extracellular matrix degradation and CXPA invasion.

Citation Format: Gabriel Bernardo Rena, Lucas Novaes Teixeira, Vera Cavalcanti Araújo, Ana Paula Dias Demasi, Elizabeth Ferreira Martinez. Effect of microvesicles on metalloproteinases secretion by myoepithelial cells [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A34.
Abstract A35: Diagnostic performance and timing of post-treatment 18F-FDG PET/CT for head and neck cancer surveillance: A meta-analysis of reported studies
Authors: Wong Erin T. , Dmytriw Adam A. , Yu Eugene , Waldron John , Fazelzad Rouhi , de Almeida John , Veit-Haibach Patrick , O’Sullivan Brian , Xu Wei , Huang Shao Hui
Published: September 2020

Purpose: The aims of this meta-analysis are to evaluate the diagnostic performance and to explore the optimal timing of post-treatment 18F-FDG PET/CT for HNSCC.

Methods: January 2010 to August 2016 was the range for study selection. Subgroup analyses were performed for local/regional failure stratified by treatment-to-scan time interval of ≤3 vs. >3 months.

Results: Twenty-four studies (2,256 patients) were included. Compared to ≤3 months, 18F-FDG PET/CT performed >3 months showed significantly improved sensitivity (87% vs. 60%, p=0.020) and specificity (93% vs. 84%, p<0.001) for identifying local failure and marginally improved sensitivity for regional failure (79% vs. 56%, p=0.100). The specificity for regional failure was equally high for >3 months vs. ≤3 months (95% vs. 97%, p=0.35).

Conclusions: This meta-analysis showed high NPV but modest PPV for post-treatment 18F-FDG PET/CT for local and regional failure. Sensitivity is improved if performed >3 months for local failure and marginally improved for regional failure.

Citation Format: Erin T. Wong, Adam A. Dmytriw, Eugene Yu, John Waldron, Rouhi Fazelzad, John de Almeida, Patrick Veit-Haibach, Brian O’Sullivan, Wei Xu, Shao Hui Huang. Diagnostic performance and timing of post-treatment 18F-FDG PET/CT for head and neck cancer surveillance: A meta-analysis of reported studies [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A35.