bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract D091: The impact of distance to hospital on cervical cancer outcomes
Authors: Park Hyungkyung , Wang Zhixin , Wang Chenguang , Huh Warner , Bae Sejong
Published: September 2020

Objective – To determine the impact of distance on cervical cancer outcomes in addition to identifying potential factors by exploring age-specific differences Methods –Using the National Cancer Database (NCDB) for the years 2004 to 2013, cervical cancer incidence and mortality rates were calculated, and potential factors were investigated by using multivariable logistic regression analysis. Results – A total of 90,076 white and black women (≥20 years old) were diagnosed with cervical cancer from 2004 to 2013 (82.7% and 17.3% respectively). Race, region, insurance, income, facility type, comorbidity, cancer stage, age, and year of diagnosis were significantly associated with cervical cancer mortality. Only cancer stage was significantly associated with mortality for both white and black women across age groups. Race, insurance, facility type, comorbidity, cancer stage, distance to hospital, and age were significantly associated with five-year survival rates. Conclusions – This study confirmed the impact of distance to hospital on five-year survival rates. Both white and black women living more than 50 miles away showed significant lower five-year survival rates than those who lived in less than 10 miles (OR=0.82, 95% CI 0.73 to 0.91; OR=0.59, 95% CI 0.45 to 0.77 respectively).

Citation Format: Hyungkyung Park, Zhixin Wang, Chenguang Wang, Warner Huh, Sejong Bae. The impact of distance to hospital on cervical cancer outcomes [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D091.
Abstract IA25: Using cancer registry data for geospatial and disparity research
Authors: Sherman Recinda
Published: September 2020

This talk will provide an overview on how to use cancer registry data in geospatial analysis. Our national cancer surveillance system comprises a set of international data collection standards overseen by individual state registries. While there are highly detailed geospatial data available from each state registry, not all registries release these data and each have separate data release procedures, regulations, and cost. This presentation will discuss how the cancer surveillance community geocodes cancer incidence data and creates geocoded data quality measures. This presentation will also detail the current area-based social measures available to researchers in the national CiNA (Cancer in North America) cancer incidence dataset. Release procedures and limitations of the data will be described, and the move towards a national geographic dataset for cancer incidence data will be presented.

Citation Format: Recinda Sherman. Using cancer registry data for geospatial and disparity research [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr IA25.
Abstract IA27: Metformin use and pancreatic cancer survival: Are there racial differences?
Authors: Carson Kenneth R. , Toriola Adetunji T. , Luo Suhong , Thomas Theodore , Drake Bettina F. , Chang Su-Hsin , Sanfilippo Kristen M.
Published: September 2020

Background: The effect of metformin use on survival among pancreatic ductal adenocarcinoma (PDAC) patients is controversial. Further, there are no data on African American patients. To address these, we analyzed data from the United States Veterans Health Administration (VHA).

Methods: We performed a population-based retrospective cohort study evaluating survival among 3,811 PDAC patients with pre-existing diabetes mellitus (DM), diagnosed with PDAC within the VHA between 1998 and 2013. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) using multivariable adjusted conventional Cox proportional hazards regression as well as the time-varying Cox proportional hazards regression to control for immortal time bias and confounders. All statistical tests were two-sided.

Results: In multivariable adjusted analyses using the conventional Cox model, there was an artificial survival benefit associated with metformin use: HR= 0.89 (95%CI 0.83-0.98, p-value=0.01). In multivariable adjusted analyses using the time-varying Cox model, metformin use was not associated with survival: HR=1.05 (95%CI 0.92-1.14, p-value=0.28). Results were similar among non-Hispanic white patients: HR=1.05 (95%CI 0.96-1.14, p-value=0.26) and African American patients: HR=1.01 (95%CI 0.86-1.19, p-value=0.88). Among patients who were metformin naïve at the time of PDAC diagnosis (N=1158), metformin use was associated with improved survival in non-Hispanic white: HR=0.78 (95%CI 0.61-0.99, p-value=0.04), but not African American patients: HR=1.20 (95%CI 0.75-1.93, p-value=0.45). The survival benefit among non-Hispanic whites was limited to patients with metastatic disease: HR=0.67 (95%CI 0.44-1.01, p-value=0.055). Among African American patients with metastatic disease, HR was 1.30 (95%CI 0.77-2.53, p-value=0.28). There was an interaction between race and metformin use in patients with metastatic disease (p-interaction=0.05).

Conclusions: Although metformin use was not associated with survival in patients with PDAC, the survival benefit limited to non-Hispanic white patients who were metformin naïve at the time of diagnosis deserves further study in a racially diverse study population.

Citation Format: Kenneth R. Carson, Adetunji T. Toriola, Suhong Luo, Theodore Thomas, Bettina F. Drake, Su-Hsin Chang, Kristen M. Sanfilippo. Metformin use and pancreatic cancer survival: Are there racial differences? [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr IA27.
Abstract IA39: Inspiring hope, help, and healing: The hard work and heart work of cancer survivorship
Authors: Brown Jameisha
Published: September 2020

Cancer is the leading cause of disease-related death in children and teens. However, medical milestones advance cancer treatments that help nearly 85% of children diagnosed with cancer live at least five years following diagnosis. Some children are ultimately considered cured. Consequently, there is an increasing interest in childhood cancer survivorship. The current aim is to increase quality of life by decreasing treatment toxicity and proactive surveillance of potential late effects through long-term follow-up. Brown will share her challenges and triumphs experienced from more than 20 years of childhood cancer survivorship, long-term follow-up, and patient and research advocacy.

Citation Format: Jameisha Brown. Inspiring hope, help, and healing: The hard work and heart work of cancer survivorship [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr IA39.
Abstract A03: Generation of primary sarcoma mouse models through CRISPR/Cas9 mediated activation of Yap1
Authors: Huang Jianguo , Xu Eric , Van Mater David , Kirsch David G
Published: September 2020

Soft tissue sarcomas (STSs) are rare heterogeneous cancers arising from diverse connective tissues. Undifferentiated pleomorphic sarcomas (UPSs), the most common sarcomas diagnosed in adult patients, are complex karyotypes of nonspecific genetic alterations. To date, the molecular mechanisms by which UPSs develop in patients are still poorly understood, which hinders precision medicine to treat the disease. Primary UPS mouse model generated by conditional activation of KrasG12D and mutation of Trp53 (KP mouse model) is currently used for studying sarcoma biology, imaging, and preclinical trials. However, Kras mutation is rarely identified in human UPSs. We recently showed that injury can replace KrasG12D to induce primary UPSs in mouse models of conditional mutation of Trp53. Furthermore, our whole-exome sequencing determined Yap1 amplification in some injury-induced sarcomas. Moreover, it is also shown that a subset of human UPSs may be driven by Hippo pathway. In addition, it is reported that activation of mutant Yap1 induced primary rhabdomyosarcomas (RMSs) in mouse models. CRISPR/Cas9-mediated genetic mutation has been applied to rapidly create mouse models of cancers, including sarcoma, with spatial and temporal control. However, rare studies have been performed to investigate whether CRISPR/Cas9-mediated activation of endogenous oncogenes could generate primary cancer models. Thus, we applied CRISPR/Cas9 technology to test whether activation of endogenous Yap1 can induce cell transformation or even generate primary UPSs in mouse models. Our results showed that CRISPR/dCas9-p300-mediated activation of endogenous Yap1 resulted in transformation of KrasG12D immortalized mouse embryonic fibroblasts (MEFs) as well as Trp53 knockout MEFs. Moreover, we are currently applying our recently developed in vivo CRISPR/Cas9 delivery method combined with Sleeping Beauty transposon system to investigate whether we are able to develop primary UPSs in mouse models by activating Yap1. If successful, it will further allow us to perform CRISPR/Cas9-mediated direct in vivo activation screen to identify other oncogene drivers for sarcomagenesis. In conclusion, primary sarcoma mouse models generated by CRISPR/Cas9-mediated activation will be an indispensable platform for studying sarcoma biology and precision medicine.

Citation Format: Jianguo Huang, Eric Xu, David Van Mater, David G Kirsch. Generation of primary sarcoma mouse models through CRISPR/Cas9 mediated activation of Yap1 [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 A03.
Abstract A04: Genetic and pharmacologic inhibition of HES1 reduces YAP1 expression, impairing rhabdomyosarcoma cell growth
Authors: Kovach Alexander R. , Linardic Corinne M.
Published: September 2020

Rhabdomyosarcoma (RMS) is a mesenchymal cancer with skeletal muscle histogenesis and the most common soft-tissue sarcoma of childhood. High-risk patient groups continue to have a poor survival (<30%) and novel therapeutic targets are needed. In our studies of Hippo signaling in RMS, we found that expression of YAP1 in a human myoblast-based model of RMS is permissive for bypass of senescence, tolerance of oncogenic RAS expression, and full transformation to cells able to grow as xenografts mimicking the embryonal variant of RMS (ERMS). In parallel, we found that YAP1 engages in a positive feedback loop with the Notch signaling pathway, suggesting that Notch effectors must impact downstream YAP1. Here we show that shRNA-mediated suppression of the basic helix-loop-helix transcriptional repressor and Notch effector, HES1, inhibits ERMS cell growth in vitro. Mechanistically, HES1 suppression causes decreased levels of YAP1 mRNA and protein, and increased mRNA and protein levels of the cell cycle regulator and tumor suppressor CDKN1C (P57kip2) across three different cell lines. Additionally, HES1 suppression results in cell line-specific increases in the myogenic markers MYOD1, MYOG, and MYF6. Recently, Perron et al. reported that the small molecule JI051 inhibits HES1 by stabilizing its interaction (doi:10.1074/jbc.RA118.002316) with the protein chaperone prohibitin-2, thus sequestering HES1 outside the nucleus. We demonstrate that JI051 inhibits ERMS cell growth in vitro with EC50 values in the low nanomolar range. Preclinical in vivo studies combining HES1 inhibition and YAP1 inhibition are planned, with the hypothesis that their coinhibition could prove effective in mitigating treatment resistance. A full understanding of the relationship between HES1 and YAP1 signaling will be paramount in moving compounds such as JI051 from the laboratory to the clinic.

Citation Format: Alexander R. Kovach, Corinne M. Linardic. Genetic and pharmacologic inhibition of HES1 reduces YAP1 expression, impairing rhabdomyosarcoma cell growth [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 A04.
Abstract A23: Verteporfin as a new treatment paradigm for platinum-resistant ovarian cancer cells
Authors: Gogoi Radhika P. , Dasari Venkata Ramesh
Published: September 2020

Ovarian cancer is the most lethal of the gynecologic malignancies and has poor survival rates due to a combination of diagnosis at advanced stages and disease recurrence due to platinum chemotherapy resistance. It is of utmost importance that novel chemotherapeutic agents are identified to increase or restore chemosensitization to platinum-based chemotherapy. Verteporfin (VP, VisudyneTM) is a benzoporphyrin derivative used for treating adult macular degeneration. Verteporfin has recently been identified as an inhibitor of YAP/TEAD interaction. Yes-associated protein (YAP), the main downstream target of the HIPPO pathway, plays an important role in cell proliferation and apoptosis. We investigated the efficacy of VP alone or in combination with cisplatin (CDDP) or carboplatin (CP) or paclitaxel (Taxol) on two serous ovarian cancer cell lines (OV90, COV504). The effect of VP, CDDP, CP or Taxol was studied either alone or in combination after 72 hours of treatment. Cell viability-based cytotoxicity measurements indicate dose-dependent increase in cytotoxicity for all the drugs. IC50 values of the drugs were calculated based on dose-effect curves using Compusyn software following the Chou-Talalay method. For OV90 cells, the calculated IC50 values were 29.33μM for VP, 2.17μM for cisplatin, 96.21μM for carboplatin, and 89.05μM for paclitaxel. For COV504 cells, the calculated IC50 values were 8.37μM for VP, 1.79μM for cisplatin, 117.23μM for carboplatin, and 7.16μM for paclitaxel. Based on the IC50 values of single agents, we performed cell proliferation assay using VP and CDDP/CP/Taxol in combination. We observed synergistic effects of VP with CDDP/CP/Taxol based on combination index plots. Based on the dose-reduction index (DRI) values of the drugs in combination treatments, we performed cytotoxicity and invasion assays. The combination treatments of these drugs at DRI values induced cytotoxicity and inhibited invasion of cancer cells. To check the chemosensitization of VP in cancer cells, we used cisplatin-resistant ovarian cancer cells, A2780Cis. Similar to ovarian cancer cells, VP effectively inhibited proliferation of A2780Cis cells. Based on these results, we hypothesize that VP is inducing chemosensitivity in platinum resistant ovarian cancer cells and increasing the efficacy of either platin drugs or Taxol. We suggest that our preclinical data in combination with previously available human safety data support the study of VP in combination with platinum in a clinical phase 2 trial of serous ovarian cancer patients.

Note: This abstract was not presented at the conference.

Citation Format: Radhika P. Gogoi, Venkata Ramesh Dasari. Verteporfin as a new treatment paradigm for platinum-resistant ovarian cancer 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 A23.
Abstract A24: Functional annotation of the Hippo somatic mutations in human cancer
Authors: Han Han , Wang Wenqi
Published: September 2020

The Hippo pathway plays a crucial role in organ size control and tissue homeostasis, whose downstream targets YAP and TAZ are frequently activated in various types of human cancers. However, inactivation of this key tumor suppressor pathway in human cancers has not been fully characterized. In this study, we comprehensively annotate the somatic mutations for 23 Hippo core components in The Cancer Genome Atlas, which includes 11,706 patient samples across 32 major human cancer types. To determine the role of these patient-derived mutations in Hippo pathway regulation, we reconstituted each Hippo component mutant into the corresponding knockout (KO) cells and performed an immunofluorescence screen by using YAP cellular localization as a readout. Through it, we identified a number of somatic mutations that are able to suppress Hippo signaling and activate YAP. In addition, we elucidated the underlying mechanism for several identified somatic mutations and revealed novel regulatory mechanisms for the Hippo pathway. Taken together, our study not only systematically profiled the somatic mutations for the Hippo pathway components, but also generated a valuable resource to further characterize of this key signaling pathway in human cancer development.

Citation Format: Han Han, Wenqi Wang. Functional annotation of the Hippo somatic mutations in human 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 A24.
Abstract A35: Regulation of the Hippo signaling pathway through ubiquitin-mediated degradation of TEAD transcription factors
Authors: Lin Eva , Martin Scott , Modrusan Zora , Dey Anwesha , Pham Trang H. , Ho-Lee June , Chang Matt , Lacap Jennifer , Rose Chris , Pham Victoria , Lill Jennie
Published: September 2020

The Hippo pathway is an evolutionarily conserved signaling pathway that plays a key role in the development and homeostasis of tissues and organs. Studies over the past few years have demonstrated that the pathway is deregulated in a spectrum of cancers, making it a promising target for therapeutic intervention. YAP and TAZ, the two important transcriptional coactivators of the Hippo pathway, are highly activated in human cancers. Together with the transcription factor TEAD, the activation is essential for cancer initiation, progression, and metastasis. Regulating protein levels in cancer cells is very critical for their homeostasis, especially for the oncoproteins and tumor suppressors. Several Hippo pathway components including YAP and TAZ have been shown to be targeted for proteasomal degradation via ubiquitination by E3 ligases. Here, we design our studies to characterize the degradation of TEAD transcription factors. YAP and TAZ mainly function via interaction with TEADs as promoters, enhancers, and super-enhancers. Therefore, the level of TEAD proteins is very critical in Hippo-driven tumorigenesis. Thus, understanding how TEAD degradation is regulated can inform future therapeutic strategies.

Citation Format: Eva Lin, Scott Martin, Zora Modrusan, Anwesha Dey, Trang H. Pham, June Ho-Lee, Matt Chang, Jennifer Lacap, Chris Rose, Victoria Pham, Jennie Lill. Regulation of the Hippo signaling pathway through ubiquitin-mediated degradation of TEAD transcription factors [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 A35.
Abstract B05: Investigating the role of STK3/4 kinases in cancer
Authors: Bata Nicole , Limpert Allison , Lambert Lester J. , Chaikuad Apirat , Hansen Malene , Knapp Stefan , Cosford Nicholas D.P.
Published: September 2020

The serine/threonine-protein kinases 3 (STK3, MST2) and 4 (STK4, MST1) are the “core kinase cassette” of the Hippo signaling pathway, directing cell proliferation and differentiation through control of the downstream transcription factors, YAP and TAZ. In cancer, the ability of the Hippo pathway to regulate growth and differentiation provides a potential target for therapeutic intervention. Interestingly, it has been proposed that STK3/4 have a role in autophagy, a cellular, self-degradative process important for generating sources of energy in response to nutrient stress. These functions for STK3/4 are likely to be both cell type and context dependent. For example, we show that knocking down STK3 in prostate tumor cells in vitro decreases proliferation, suggesting that targeting STK3 with small-molecule inhibitors could be effective in the treatment of prostate cancer. However, current chemical probes for STK3/4 are suboptimal with respect to selectivity, potency, and drug-like properties. Better tools are required to obtain a detailed mechanistic understanding of the biologic roles of STK3/4. Thus, we propose to identify small-molecule modulators of STK3 and STK4 that could be used as chemical probes of the Hippo pathway or autophagy and ultimately lead to novel therapies for cancer. With this objective we established an in-house expression of both STK3 and STK4 protein and performed a pilot screen of >90 small molecules against purified STK3/4 using the ADP-Glo in vitro kinase assay. From this pilot screen, we identified nine STK3/4 inhibitors with low nanomolar potency and confirmed these hits as bona fide STK3/4 inhibitors using both protein-thermal shift and enzymatic kinetic assays. In addition, breast tumor cells treated with a selective STK3/4 inhibitor, PF-06447475, showed a concentration-dependent increase in microtubule-associated proteins 1A/1B light chain 3 (LC3) flux. In the future, we plan to further optimize our small-molecule hits and conduct a high-throughput screen to identify novel modulators of STK3/4.

Citation Format: Nicole Bata, Allison Limpert, Lester J. Lambert, Apirat Chaikuad, Malene Hansen, Stefan Knapp, Nicholas D.P. Cosford. Investigating the role of STK3/4 kinases 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 B05.
Abstract B11: Computational insights on the druggability of TEAD YAP-binding domain
Authors: Li Yiping , Zhou Wei , Li Chenglong
Published: September 2020

Transcriptional enhanced associate domain (TEAD) proteins are the downstream effectors of the Hippo signaling pathway that regulate cell proliferation and stem cell functions. The expression of TEAD family is upregulated in many cancer types including pancreatic, colorectal, breast, and prostate cancers, which is correlated with poor survival in patients. Pharmacologic modulators of TEADs could therefore find application in cancer treatment and regenerative medicine. In this presentation, we report our exploration of the TEAD2 Yap-binding domain conformational ensemble and its binding interaction characteristics with peptides and small molecules, using both molecular dynamics simulation and experimental binding studies with FP probes. We carried a series of conventional, cosolvent, and Gaussian-biased MD studies and discovered that the binding subsites II and III possess considerable flexibility as the free energy calculations indicate that multiple low-energy states exist with only about 1.4 Kcal/mol barriers among them. Together with the binding results, our study points to additional “hot spots”/pharmacophores for fresh design of novel small-molecule inhibitors disrupting YAP/TEAD protein-protein interactions.

Note: This abstract was not presented at the conference.

Citation Format: Yiping Li, Wei Zhou, Chenglong Li. Computational insights on the druggability of TEAD YAP-binding domain [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 B11.
Abstract B12: High-throughput screening platform to discover TEAD modulators
Authors: Moon Sungho , Park Hyun Woo
Published: September 2020

The TEAD family of transcription factors play critical roles during development, cell growth, proliferation, regeneration, and tissue homeostasis. TEADs are key downstream transcription factors of the evolutionarily conserved Hippo pathway, which binds Yes-associated protein (YAP) and transcriptional activator with PDZ-binding domain (TAZ) transcriptional coactivators through their transactivation domains. Despite TEAD being the key transducer of the Hippo signaling, most research have been focused on Hippo kinases and YAP/TAZ, whereas the Hippo-dependent and -independent regulators and regulations governing TEAD emerged only recently. Previously, we identified that environmental stress promotes TEAD cytoplasmic translocation via p38 MAPK-dependent, Hippo-independent mechanism, which overrides YAP-driven oncogenic growth in cancer cells. Here, we present a platform for high-throughput screening to identify chemical compounds that modulate TEAD cellular localization and activity. We designed cancer cells stably expressing a TEAD-GFP lentiviral vector and carried out a comprehensive comparative analysis of TEAD4 by GFP-fluorescence, immunoblotting, and transcript activities. Chemical compound screening to discover TEAD modulators will reveal novel anticancer drugs.

Citation Format: Sungho Moon, Hyun Woo Park. High-throughput screening platform to discover TEAD 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 B12.
Abstract B21: Proteomic profiling of tandem affinity purified MAP4K family kinases
Authors: Seo Gayoung , Han Han , Yang Bing , Vargas Rebecca , Chen Yuxuan , Wang Wenqi
Published: September 2020

MAP kinase kinase kinase kinases (MAP4Ks) belong to the mammalian Ste20-like family of serine/threonine kinases and recently have been reported to regulate Hippo pathway via LATS1/2 activation. However, the diverse roles of MAP4Ks in biologic process are still unclear. To identify the MAP4K family kinase interaction network, we employed a tandem affinity purification-mass spectrometry (TAP-MS) approach using SFB tag-conjugated MAP4K1-7. Through a proteomic analysis, we could guess that MAP4K family kinases, especially MAP4K2, may regulate autophagy or interact with striatin-interacting phosphatase and kinase (STRIPAK) components. These results offer a framework for further studies on Hippo pathway and biologic processes involving MAP4Ks.

Note: This abstract was not presented at the conference.

Citation Format: Gayoung Seo, Han Han, Bing Yang, Rebecca Vargas, Yuxuan Chen, Wenqi Wang. Proteomic profiling of tandem affinity purified MAP4K family kinases [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 B21.
Abstract B23: A novel model of neurofibroma that deciphers its developmental origin and susceptibility to modification by the Hippo pathway
Authors: Chen Zhiguo , Mo Juan , Brosseau Jean-Philippe , Shipman Tracey , Wang Yong , Liao Chung-Ping , Cooper Jonathan M. , Allaway Robert J. , Gosline Sara J.C. , Guinney Justin , Carroll Thomas J. , Le Lu Q.
Published: September 2020

The neurocutaneous tumor predisposition disorder neurofibromatosis Type I (NF1) results from deregulation of RAS signaling in the MAPK pathway that leads to a wide spectrum of clinical presentations. Dermal or cutaneous neurofibromas (cNF), a Schwann cell tumor in the skin, affect more than 95% of individuals with NF1 and are a major source of emotional, physical, and social distress as NF1 patients can have thousands of these tumors covering most of their skin. Thus, patients with NF1 often identify these tumors as their greatest burden. To date, there is no available medical treatment for cNF and no known way to prevent them from developing. The major barriers that impede progress in this field are the lack of accurate models of these common cNF tumors for drug evaluation and a limited understanding of their pathogenesis as well as the identity of specific cell of origin that directly gives rise to cNF and signaling pathways essential for tumor development. We take advantage of genetic labeling for cell lineage tracing to identify mouse neural crest Cre lines that are expressed in the subpopulation of Schwann cell lineage that give rise to cNF when NF1 is deleted. We discovered that the Homeobox B7 transcription factor serves as the lineage marker to trace the developmental origin of cNF neoplastic cells that completely recapitulates human neurofibromatosis, generating a novel mouse model that spontaneously develops both cutaneous and plexiform neurofibroma. In addition, we discovered that modulation of the Hippo pathway acts as a modifier that enhances the MAPK pathway activation by NF1 loss to promote neurofibromagenesis, suggesting that dampening the Hippo pathway may serve as part of the comprehensive treatment approach for neurofibroma. This novel mouse model has begun to yield vital clues to neurofibroma pathogenesis and now opens the doors for deciphering the evolution of cNF to identify effective therapies, where none exist today.

Citation Format: Zhiguo Chen, Juan Mo, Jean-Philippe Brosseau, Tracey Shipman, Yong Wang, Chung-Ping Liao, Jonathan M. Cooper, Robert J. Allaway, Sara J.C. Gosline, Justin Guinney, Thomas J. Carroll, Lu Q. Le. A novel model of neurofibroma that deciphers its developmental origin and susceptibility to modification by the Hippo pathway [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 B23.
Abstract B30: Joint control of epidermal cell fate by Yorkie and Bonus
Authors: Zhao Heya , Zhang Can , Moberg Kenneth , Veraksa Alexey
Published: September 2020

Dysregulation of the Hippo pathway results in organ overgrowth and contributes to carcinogenesis in humans. Although the Hippo pathway has been intensively studied for its regulation of cell proliferation and organ growth, its role beyond growth control remains elusive. To explore possible novel functions of the Hippo pathway, we carried out an affinity purification-mass spectrometry (AP-MS) analysis in Drosophila embryos and cultured cells, using transcriptional coactivator Yorkie (Yki, YAP1 homolog) as bait. Prominent groups of identified interactors included all of the core pathway components and known accessory regulators, as well as subunits of RNA polymerase II and components of the Trithorax-related (Trr) complex. Among putative novel interactors we found Bonus (Bon), the Drosophila homolog of the mammalian transcriptional intermediary factor-1/tripartite motif containing (TIF1/TRIM24/TRIM33) family of proteins. Protein interaction between Bon and Yki requires the WW domains in Yki and PPxY motifs in Bon. Interestingly, Bon overexpression leads to formation of epidermal extensions (trichomes) on the surface of adult eyes. This phenotype requires Yki and Scalloped (Sd, TEAD homolog), as well as Bon-Yki interaction. To obtain a mechanistic understanding of this apparent switch towards an epidermal cell fate, we searched for novel genes that may be jointly regulated by Bon and Yki, and identified several candidates based on published ChIP-seq and RNA-seq analyses. These putative target genes are not canonical Hippo pathway effectors, but include factors involved in early eye specification as well as genes controlled by steroid hormone signaling. Loss or gain of function of a subset of these genes modified the trichome phenotype, suggesting that they are under the control of Bon and Yki and are involved in establishing a choice between a “generic” epidermal cell fate and eye field specification. In summary, our study reveals a novel function of the Hippo pathway in the regulation of epidermal cell differentiation. This regulation occurs through the interaction between Yki and Bon as well as their joint transcriptional control of nonclassical target genes. This work broadens our understanding of the Hippo pathway beyond its role in growth control.

Citation Format: Heya Zhao, Can Zhang, Kenneth Moberg, Alexey Veraksa. Joint control of epidermal cell fate by Yorkie and Bonus [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 B30.
Abstract B39: The SWI/SNF complex is a mechanoregulated inhibitor of YAP and TAZ
Authors: Cordenonsi Michelangelo , Chang Lei , Azzolin Luca , Di Biagio Daniele , Zanconato Francesca , Battilana Giusy , Xiccato Romy Lucon , Panciera Tito , Aragona Mariaceleste , Piccolo Stefano
Published: September 2020

Inactivation of ARID1A and other components of the nuclear SWI/SNF protein complex occurs at very high frequencies in a variety of human malignancies, suggesting a widespread role for the SWI/SNF complex in tumor suppression. However, the underlying mechanisms remain poorly understood. Here we show that ARID1A-containing SWI/SNF complex (ARID1A-SWI/SNF) operates as an inhibitor of the pro-oncogenic transcriptional coactivators YAP and TAZ. Using a combination of gain- and loss of-function approaches in several cellular contexts, we show that YAP/TAZ are necessary to induce the effects of the inactivation of the SWI/SNF complex, such as cell proliferation, acquisition of stem cell-like traits, and liver tumorigenesis. We found that YAP/TAZ form a complex with SWI/SNF; this interaction is mediated by ARID1A and is alternative to the association of YAP/TAZ with the DNA-binding platform TEAD. Cellular mechanotransduction regulates the association between ARID1A-SWI/SNF and YAP/TAZ. The inhibitory interaction of ARID1A-SWI/SNF and YAP/TAZ is predominant in cells that experience low mechanical signaling, in which loss of ARID1A rescues the association between YAP/TAZ and TEAD. At high mechanical stress, nuclear F-actin binds to ARID1A-SWI/SNF, thereby preventing the formation of the ARID1A-SWI/SNF-YAP/TAZ complex, in favor of an association between TEAD and YAP/TAZ. We propose that a dual requirement must be met to fully enable the YAP/TAZ responses: promotion of nuclear accumulation of YAP/TAZ, for example, by loss of Hippo signaling, and inhibition of ARID1A-SWI/SNF, which can occur either through genetic inactivation or because of increased cell mechanics. This study offers a molecular framework in which mechanical signals that emerge at the tissue level together with genetic lesions activate YAP/TAZ to induce cell plasticity and tumorigenesis. (Published as Chang et al., Nature 2018.)

Citation Format: Michelangelo Cordenonsi, Lei Chang, Luca Azzolin, Daniele Di Biagio, Francesca Zanconato, Giusy Battilana, Romy Lucon Xiccato, Tito Panciera, Mariaceleste Aragona, Stefano Piccolo. The SWI/SNF complex is a mechanoregulated inhibitor of YAP and TAZ [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 B39.
Abstract IA11: Hippo signaling Is Intrinsically regulated during cell cycle progression
Authors: Yang Yingzi , Kim Wantae , Wang Xiaohui
Published: September 2020

The Hippo-YAP/TAZ signaling pathway plays a pivotal role in growth control during development and regeneration, and its dysregulation is widely implicated in various cancers. Hippo signaling has been recently identified as a major oncosuppressive pathway that plays critical roles in inhibiting hepatocyte proliferation, survival, and hepatocellular carcinoma (HCC) formation. We have found that Hippo/YAP signaling cell-autonomously inhibits HCC proliferation by interacting with Wnt and Notch signaling. We have also found that Hippo/YAP signaling cell-nonautonomously inhibits HCC by shaping its inflammatory microenvironment. To further understand the cellular and molecular mechanisms underlying Hippo signaling regulation, we have found that activities of core Hippo signaling components, LATS kinases and YAP/TAZ transcription factors, are regulated during cell cycle progression by core cell cycle machinery components. Furthermore, we show in Drosophila eye and wing development that cell cycle is required in vivo to regulate Hippo signaling with a conserved mechanism. Cell cycle control of Hippo signaling represents a previously unappreciated and evolutionarily conserved new layer of Hippo signaling regulation.

Citation Format: Yingzi Yang, Wantae Kim, Xiaohui Wang. Hippo signaling Is Intrinsically regulated during cell cycle progression [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 IA11.
Abstract IA15: Growth control and Hippo signaling in the Drosophila abdomen
Authors: Tapon Nicolas
Published: September 2020

To unravel the mechanisms of tissue size determination, we have established quantitative biology tools to study the growth of the Drosophila abdominal histoblasts (HBs), the precursor cells of the adult abdominal epidermis. HBs are organized in nests located in the abdominal segments, surrounded by larval epithelial cells (LECs). HBs are quiescent throughout larval development, then proliferate extensively during abdominal morphogenesis at the pupal stage, replacing the surrounding LECs, which undergo apoptosis. To cover the entire abdominal surface, the HBs undergo eight cell cycles (three synchronous cleavage divisions followed by five asynchronous cycles), then cease proliferating at 31-33hr after puparium formation and differentiate. A major advantage of this system is its amenability to long-term live imaging, allowing us to visualize proliferation/growth of the HBs and death of the LECs. I will present our ongoing work on the role and regulation of Hippo signaling in this system.

Citation Format: Nicolas Tapon. Growth control and Hippo signaling in the Drosophila abdomen [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 IA15.
Abstract IA16: Regulation of SAV1-STRIPAK antagonism by YSK1-dependent phosphorylation
Authors: Luo Xuelian “Sue”
Published: September 2020

The Hippo pathway is critical for tissue homeostasis and tumor suppression in multicellular organisms. Through cell-surface receptors and cytoskeletal complexes, extracellular signals, including cell-cell contact, activate a core kinase cascade formed by the Hippo kinases MST1/2, the NDR family kinases LATS1/2, and the adaptor proteins SAV1 and MOB1. Activated LATS1/2 phosphorylate and prevent the nuclear accumulation of the transcription factors YAP/TAZ. Activation of MST1/2 initiates Hippo signaling and requires trans-autophosphorylation in the T-loop (MST2 T180). We have recently shown that the PP2A complex STRIPAK blocks MST2 activation through feedback inhibition. SAV1 promotes MST2 activation by suppressing STRIPAKSLMAP-mediated dephosphorylation of MST2 pT180. Our preliminary results show that YSK1 (the kinase component of STRIPAK) phosphorylates SAV1 and blocks its ability to inhibit PP2A. We hypothesize that upstream signals impinge on the SAV1-STRIPAK antagonism through YSK1 to regulate MST1/2 activation.

Citation Format: Xuelian “Sue” Luo. Regulation of SAV1-STRIPAK antagonism by YSK1-dependent phosphorylation [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 IA16.
Abstract IA24: YAP in cancer and inflammation
Authors: Wang Guocan , Lu Xin , Chakravarti Deepavali , Kapoor Avnish , Yao Wantong , Ying Haoqiang , Dey Prasenjit , Wu Chiachin , Spring Denise , Hou Pingping , Deng Pingna , Zhao Di , Hu Baoli , Xizeng Mao , Logothesis Christopher , McArthur Michael , Chin Lynda , Wang Alan , Hua Sujun , Xia Hongai , Chu Gerald C , Lim Carol , Vilar Eduardo , Blutt Sarah , DePinho Ronald A.
Published: September 2020

Many common instigators drive the processes of inflammation and carcinogenesis. We have found such a common node in Yap1. In the context of cancer, YAP-TEAD complex is important in modulating the immune microenvironment, such that Yap 1-mediated transcriptional upregulation of CXCL5 by the prostate cancer cells in a PTEN/SMAD4 deficient mouse model leads to the recruitment of MDSCs through the interaction with CXCR2 on them. Depletion of MDSCs or pharmacologic inhibition of CXCR2 leads to impediment of cancer progression. In another well-established pancreatic cancer model (PDAC), Yap1/Tead2 governs escape from mutant Kras (G12D) inhibition through cooperative upregulation of E2F transcription factors to activate a cell cycle and DNA replication program. In the context of inflammation, specifically inflammatory bowel disease, telomere dysfunction is shown to activate pAtm/c-Abl-mediated phosphorylation and stabilization of Yap1 upregulating pro-IL-18, a major proinflammatory factor in IBD. This signaling axis cooperates with the gut microbiome stimulating cytosolic receptors causing activation of caspase-1 cleaving pro-IL-18 into mature IL-18. Epithelial IL-18 leads to recruitment of IFNγ-secreting T cells and other immunocytes provoking classical IBD pathology. Consistent with a role for DNA damage signaling driving IBD, newly diagnosed IBD patient samples exhibited elevated expression of pγH2AX, YAP1, Caspase-1, and IL-18 and significantly reduced telomere lengths. Telomerase reactivation in intestinal epithelium or pharmacologic inhibition of Atm, Yap1, or caspase-1 as well as antibiotic treatment of mice dramatically reduced IL-18 and inflammation. Thus, telomere dysfunction-induced activation of the Atm-Yap1-pro-IL-18 pathway identifies DNA damage signaling as a key instigator and promoter of IBD, illuminating novel therapeutic strategies.

Citation Format: Guocan Wang, Xin Lu, Deepavali Chakravarti, Avnish Kapoor, Wantong Yao, Haoqiang Ying, Prasenjit Dey, Chiachin Wu, Denise Spring, Pingping Hou, Pingna Deng, Di Zhao, Baoli Hu, Mao Xizeng, Christopher Logothesis, Michael McArthur, Lynda Chin, Alan Wang, Sujun Hua, Hongai Xia, Gerald C Chu, Carol Lim, Eduardo Vilar, Sarah Blutt, Ronald A. DePinho. YAP in cancer and inflammation [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 IA24.
Abstract IA29: The Hippo pathway integrates PI3K-Akt signals with mechanical cues to control tissue growth
Authors: Thompson Barry
Published: September 2020

The Hippo signaling pathway restricts cell proliferation in animal tissues by inhibiting YAP (or YAP1) and TAZ (or WWTR1), coactivators of the Scalloped (Sd or TEAD) DNA-binding transcription factor. Drosophila has a 24 single YAP/TAZ homolog named Yorkie (Yki) that can be mechanically regulated during development. Here we show that Yki translocates to the nucleus to drive Sd-mediated cell proliferation in the ovarian follicle cell epithelium in response to mechanical stretching caused by the growth of the germline. Importantly, mechanically induced Yki nuclear translocalization also requires nutritionally induced Insulin/IGF-1 signaling via PI3K, PDK1, and Akt in the follicular epithelium. We find similar results in the developing Drosophila wing, where Yki becomes nuclear in the mechanically stretched cells of the wing pouch during larval feeding, which induces Insulin/IGF-1 signaling, but translocates to the cytoplasm upon cessation of feeding in the third instar stage. Ectopic activation of PI3K or Akt is sufficient to maintain nuclear Yki in the wing disc even after feeding ceases. An Akt phosphorylation site in the Hpo kinase domain is required to attenuate Hpo kinase activity, enabling further inhibition of Hippo signaling by mechanical stimuli to drive Yki activation. Finally, Insulin/IGF-1 signaling also promotes YAP nuclear localization in response to mechanical cues in mammalian skin epithelia. Thus, the Hippo pathway has a physiologic function as an integrator of mechanical and nutritional cues to control cell proliferation and tissue growth in both Drosophila and mammals.

Citation Format: Barry Thompson. The Hippo pathway integrates PI3K-Akt signals with mechanical cues to control tissue growth [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 IA29.
Abstract PR06: Mechanistic insights for TEAD/YAP activation
Authors: Holden Jeffrey K. , Cunningham Christian N.
Published: September 2020

Transcriptional enhanced associate domain (TEAD) transcription factors activate the transcription of cell growth and proliferation genes in the presence of the transcriptional coactivators YAP or TAZ. TEAD proteins consist of two major domains connected by a proline-rich linker: a DNA binding domain and a coactivator binding domain. Although multiple structural models of individual TEAD and YAP domains have been solved, the structures of either the full-length proteins or the heterodimeric complex remain elusive. Characterization of the higher-order architecture of the TEAD:YAP complex is a prerequisite to elucidating the mechanism of Hippo-dependent transcriptional activation and potential therapeutic intervention. To better understand how TEAD and YAP interact, we have successfully been able to express and purify full-length versions of each protein and have used these novel reagents to interrogate their structural interactions using a variety of biophysical and biochemical methodologies in the presence or absence of DNA. Our findings uncover a novel interaction interface between TEAD and YAP that is required to stabilize TEAD in a DNA-binding competent conformation and begin to shed light on the mechanism of TEAD-based transcriptional activation.

This abstract is also being presented as Poster A25.

Citation Format: Jeffrey K. Holden, Christian N. Cunningham. Mechanistic insights for TEAD/YAP activation [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 PR06.