bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1225: LNS8801: A novel, enantiomerically pure, small molecule agonist of the G protein-coupled estrogen receptor (GPER) for the treatment of cancer
Authors: Natale Chris , Garyantes Tina , Ridky Todd 
Published: July 2021

Abstract
Women have a lower incidence of and improved clinical outcomes for most cancer types, but the mechanistic basis for this sex difference is unknown. We hypothesized that estrogen signaling may be responsible, despite the fact that many cancer types lack classic nuclear estrogen receptors. The GPER agonist G-1, a racemate, has been demonstrated to have anticancer activities by many independent laboratories, though there are some contradictory findings in the literature. We resolved the enantiomers that compose G-1 and determined that LNS8801 is the sole enantiomer responsible for G-1's anticancer effects. Using CRISPR to deplete GPER, we determined that the anticancer activity of LNS8801 is dependent upon GPER expression within the tumor cells. Previously, we determined that the anticancer mechanism of GPER activation is through a rapid proteasomal degradation of c-Myc. The PRISM screen was performed on LNS8801 at the Broad Institute, and it was determined that this compound has universal anticancer activity across multiple cancer types, consistent with our inhouse data. Sensitivity to LNS8801 was highly correlated with expression of c-Myc target genes, which is consistent with the known mechanism of action. Lineage analysis identified two specific cancer types that were uniformly more sensitive to LNS8801 than other cancer types: diffuse large B-cell lymphoma (DLBCL) and anaplastic large cell lymphoma (ALCL). DLBCL has historically been considered to be highly dependent on c-Myc, which is consistent with the known mechanism of action of LNS8801; however, the identification of ALCL was unexpected. Deeper analysis determined that high expression of anaplastic lymphoma kinase (ALK) fusion genes tightly correlated with sensitivity to LNS8801 in ALCL and other ALK+ cancer types. Using non-small cell lung cancer cell lines engineered to express EML4-ALK, we validated that ALK fusion expression results in increased sensitivity to LNS8801 relative to isogenic controls. This work has identified an enantiomerically pure GPER agonist that has potent activity across many cancer types, with c-Myc-dependent and ALK+ cancer types being enriched for heightened sensitivity.
Citation Format: Chris Natale, Tina Garyantes, Todd Ridky. LNS8801: A novel, enantiomerically pure, small molecule agonist of the G protein-coupled estrogen receptor (GPER) for the treatment of cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1225.
Abstract 1226: Targeting OSCC fitness genes YAP1 and WWTR1 via synergistic killing of CA3 in combination with cisplatin
Authors: Chai Annie Wai Yeeng , Yee Pei San , Yee Shi Mun , Cheong Sok Ching 
Published: July 2021

Abstract
Oral squamous cell carcinoma (OSCC) is one of the most common forms of head and neck cancer, with more than half of the global mortality occurring in Asia. The current treatment regimens for OSCC are of limited benefit to the patients and the development of new targeted therapies is very much needed. In our previous study using genome-wide CRISPR/Cas9 screen to identify the genetic vulnerabilities for OSCC, we have successfully identified two key fitness genes - YAP1 and WWTR1 (TAZ) of the Hippo signaling pathway as potential therapeutic targets for OSCC. We discovered that CRISPR/Cas9-mediated knockout of either YAP1 or WWTR1 in the YAP1- or WWTR1-dependent OSCC cell lines resulted in the down-regulation of pro-proliferative genes such as the CTGF and CYR61. Further, both YAP1 and WWTR1 have separately been implicated as potential mediators of resistance to cisplatin, a common chemotherapy used for the treatment of OSCC patients. Inhibition of the interaction between either YAP1 or WWTR1 with their downstream binding partners, such as the transcription factor, TEAD, has been one of the main focus for therapeutic intervention. However, this has not been examined in the context of OSCC. We, therefore, aim to i) identify and evaluate the anti-proliferative effect of existing YAP1/WWTR1 inhibitors on YAP1/WWTR1-dependent OSCC, ii) evaluate the synergistic effect of combining the YAP1/WWTR1 inhibitors with cisplatin in controlling OSCC growth. We identify two putative inhibitors of YAP/WWTR1/TEAD - Verteporfin and CA3. We show that compared to Verteporfin, the new inhibitor, CA3 exerts a more prominent anti-proliferative effect on the OSCC models that are dependent on either YAP1 or WWTR1, with IC50 in the nanomolar range. We then test the effect of combining CA3 (at 0.5µM and 1µM) with various dosages of cisplatin and demonstrated strong synergistic effects in OSCC across most combinations. We show that CA3 sensitizes OSCC cells to cisplatin at concentrations as low as 0.5µM. Our results further confirm that YAP1/TAZ are important therapeutic targets in OSCC and the treatment of YAP1/TAZ inhibitors could sensitize the OSCC cells to cisplatin. Further investigation is warranted to uncover the mechanism underlying YAP/TAZ-mediated cisplatin sensitivity in OSCC to improve the proportion of OSCC patients who could respond to cisplatin.
Citation Format: Annie Wai Yeeng Chai, Pei San Yee, Shi Mun Yee, Sok Ching Cheong. Targeting OSCC fitness genes YAP1 and WWTR1 via synergistic killing of CA3 in combination with cisplatin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1226.
Abstract 123: A CRISPR/Cas9-engineered ARID1A-deficient human gastric cancer organoid model reveals essential and non-essential modes of oncogenic transformation
Authors: Lo Yuan-Hung , Kolahi Kevin S. , Du Yuhong , Chang Chiung-Ying , Krokhotin Andrey , Nair Ajay , Sobba Walter D. , Karlsson Kasper , Jones Sunny J. , Longacre Teri A. , Mah Amanda T. , Sockell Alexandra , Seoane Jose A. , Chen Jin , Weissman Jonathan S. , Curtis Christina , Califano Andrea , Fu Haian , Crabtree Gerald R. , Kuo Calvin J. 
Published: July 2021

Abstract
Mutations in ARID1A, encoding a subunit of the BAF chromatin remodeling complex, rank amongst the most common molecular aberrations in human cancer. However, oncogenic consequences of ARID1A mutation in human cells remain poorly defined due to lack of forward human genetic model systems. Here, CRISPR/Cas9 knockout of ARID1A in primary TP53-/- human gastric organoids induced morphologic dysplasia, tumorigenicity and mucinous differentiation but impaired Wnt/β-catenin signaling. Genetic Wnt pathway activation rescued mucinous differentiation, but not hyperproliferation, suggesting alternative essential pathways of ARID1A-mediated transformation. ARID1A loss induced transcriptional regulatory modules characteristic of MSI and EBV subtype human gastric cancer, including FOXM1 regulation of multiple mitotic regulatory genes and BIRC5/survivin. Convergently, high-throughput compound screening indicated selective vulnerability of ARID1A-deficient organoids to BIRC5/survivin inhibition, functionally implicating BIRC5/survivin as an essential mediator of proliferation following initial ARID1A loss. However, CRISPR inactivation of ARID1A in established gastric cancer cell lines did not elicit sensitivity to BIRC5/survivin inhibitors, suggesting that this pathway may be selectively required during the early establishment of tumorigenesis. Overall, we define distinct pathways downstream of oncogenic ARID1A mutation, with non-essential Wnt-inhibited mucinous differentiation in parallel with essential transcriptional FOXM1/BIRC5-stimulated proliferation, indicating the general utility of organoid-based forward genetic cancer analysis in human cells.
Citation Format: Yuan-Hung Lo, Kevin S. Kolahi, Yuhong Du, Chiung-Ying Chang, Andrey Krokhotin, Ajay Nair, Walter D. Sobba, Kasper Karlsson, Sunny J. Jones, Teri A. Longacre, Amanda T. Mah, Alexandra Sockell, Jose A. Seoane, Jin Chen, Jonathan S. Weissman, Christina Curtis, Andrea Califano, Haian Fu, Gerald R. Crabtree, Calvin J. Kuo. A CRISPR/Cas9-engineered ARID1A-deficient human gastric cancer organoid model reveals essential and non-essential modes of oncogenic transformation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 123.
Abstract 125: First report of a full spectrum of de novo induced human breast cancer subtypes generated from oncogene-transduced freshly isolated normal human mammary cells
Authors: Tan Susanna , Lefort Sylvain , El-Naggar Amal , Pellacani Davide , Sorensen Poul H. , Eaves Connie 
Published: July 2021

Abstract
Human breast cancers are genetically and biologically heterogeneous with variable responses to current treatments. As an alternative strategy to identify causal and shared mechanisms, we have been exploring the utility of creating de novo models of human breast cancers from freshly isolated, purified subsets of normal human mammary cells that are lentivirally transduced with defined genes of interest and then transplanted subcutaneously in Matrigel into highly immunodeficient adult female Nonobese-diabetic/Rag1-/--IL2Rγc-/- (NRG) mice. In an initial study using this approach, we discovered that forced expression of KRASG12D alone rapidly generates small (growth-arrested), but polyclonal and serially transplantable invasive ductal carcinomas (IDCs) from both normal basal and luminal progenitor subsets of normal human mammary cells. This outcome is neither replaced nor influenced by transduction of the cells with mutant forms of TP53 or PI3KCA (Nguyen et al Nature 2015). More recently, we have found that transduction of these normal human mammary cells with a cDNA encoding a myristylated form of AKT1 (myrAKT1) produces a model of ductal carcinoma in situ (DCIS), whereas forced expression of BMI1, MYC and TP53R273C with KRASG12D (KBMT) rapidly produces large and aggressive tumors within 6 weeks post-transplant, with intermediate outcomes obtained when either MYC or TP53R273C is omitted. Immunohistochemical staining for estrogen, progesterone and epidermal growth factor receptor 2 suggests that the KBMT tumors are triple negative, and that the proportion of proliferating cells in the KBMT tumors is higher than in the tumors induced by just KRASG12D. The latter finding is consistent with the known role of BMI1 as a positive upstream regulator of proliferation via its ability to inhibit expression of p16INK4a, although the relevance of this activity in the KBMT model has yet to be established. At the opposite end of the spectrum, we have also shown that co-induced suppression of Y-Box binding protein-1 (YBX1) expression blocks the in vivo growth of KRASG12D-induced IDCs and its forced increased expression enhances the growth of myrAKT-induced DCIS cells. Taken together, these findings illustrate the advantages of creating and characterizing de novo models of human breast cancers to identify and manipulate pathways that are required for the acquisition of malignant properties.
Citation Format: Susanna Tan, Sylvain Lefort, Amal El-Naggar, Davide Pellacani, Poul H. Sorensen, Connie Eaves. First report of a full spectrum of de novo induced human breast cancer subtypes generated from oncogene-transduced freshly isolated normal human mammary cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 125.
Abstract 1269: Pharmacological targeting of transcription-replication conflict leads to anti-cancer efficacy with minimal side effects in preclinical models
Authors: Gu Long , Li Caroline , Lingeman Robert , Hickey Robert J. , Malkas Linda H. 
Published: July 2021

Abstract
Unchecked growth of cancer cells places simultaneous demands on DNA replication and transcription. Targeting the transcription-replication conflict (TRC), a major source of genome instability, could have important therapeutic implications. However, testing this hypothesis is difficult without agents directly targeting TRC. Here, we report a small molecule ligand (AOH1996) of the replisome component PCNA, which stabilizes interaction between PCNA and the large subunit (rpb1) of RNA polymerase II through the APIM motif, resulting in proteasome-dependent degradation of rpb1 and lethal DNA damages. Orally administrable, AOH1996 suppresses tumor growth without discernable toxicity at more than 10 time the compound's effective dose. In addition, AOH1996 works synergistically with known DNA damage agents to kill cancer cells. These results reveal TRC as cancer-selective vulnerability and demonstrated the therapeutic potential of AOH1996.
Citation Format: Long Gu, Caroline Li, Robert Lingeman, Robert J. Hickey, Linda H. Malkas. Pharmacological targeting of transcription-replication conflict leads to anti-cancer efficacy with minimal side effects in preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1269.
Abstract 1289: Conjugation of indomethacin with novel oleanolic acid oximes increases its Nrf2 and NF-κB signaling pathways modulating effect in pancreatic cancer cells
Authors: Baer-Dubowska Wanda , Narozna Maria , Krajka-Kuźniak Violetta , Bednarczyk-Cwynar Barbara 
Published: July 2021

Abstract
Chronic inflammation is a key factor in the etiology of neoplastic diseases, including pancreatic cancer. Nonsteroidal anti-inflammatory drugs (NSAIDs) were approved for the chemoprevention of colon tumors and suggested for pancreas cancers prophylaxis. Anti-inflammatory and anti-tumorigenic activities are also exerted by naturally occurring and synthetic triterpenoids. Coupling of triterpenoid analogues with NSAIDs may enhance this effect and prevent the unfavorable side effects related to NSAIDs long-term use. In this study novel oleanolic acid oxime (OAO) derivatives conjugated with indomethacin (IND) differing in substitution group at position C-17 were evaluated in the context of their possible modulating effect of Nrf2-ARE and NF-κB signaling pathways in pancreatic cancer cells.PSN-1 cells were incubated for 24h with IND and OAO-IND derivatives at the concentrations of 10µM and 20µM selected based on the results of the MTT assay. The activation of Nrf2 and NF-κB was assessed by the evaluation of its translocation into the nucleus and binding to specific DNA sequences by the ELISA assay. Expression of Nrf2, SOD-1, NF-κBp50, NF-κBp65 and COX-2 was evaluated by RT-PCR and Western blot methods.Cell viability was affected mostly by 3-indomethacinoxyiminoolean-12-en-28-oic acid morpholide and 3-indomethacinoxyiminoolean-en-28-oic acid benzyl ester. The level of Nrf2 in the nucleus and binding to ARE sequence was decreased in PSN-1 cells, similarly as was NF-κBp50 and NF-κBp65 binding and nuclear accumulation. As result of diminished activation of these transcription factors decreased expression of SOD-1 and COX-2 i.e. mRNA and protein levels were found. These results indicate that the OAO-IND derivatives, particularly morpholide and benzyl ester conjugates, are more potent suppressors of NF-κB signaling pathway than IND alone. Moreover, conjugation of IND with novel OAO may protect cancer cells against chemoresistance through inhibition of the Nrf2-ARE pathway. Those novel compounds might be considered the potential modulators of hepatocellular carcinoma therapy and chemopreventive agents.
Funding: This work was supported by Polish National Science Centre, grant 2016/21/B/NZ7/01758.
Citation Format: Wanda Baer-Dubowska, Maria Narozna, Violetta Krajka-Kuźniak, Barbara Bednarczyk-Cwynar. Conjugation of indomethacin with novel oleanolic acid oximes increases its Nrf2 and NF-κB signaling pathways modulating effect in pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1289.
Abstract 1297: Synthesis and structural analysis on an ionic diphenyltin complex as a potential anticancer agent
Authors: Witter Jade , Song Xueqing , Henry Tajera , Li William 
Published: July 2021

Abstract
Triorganotins are popular among chemists due to their potential biological properties against bacteria, fungi, and cancer cell lines. However, they have limited applications due to their poor water solubility. We hypothesize that solubility can be improved when the complex exhibits partial ionic characteristics. Therefore, it is our research goal to synthesize triphenyltin complexes that possess ionic characteristics. Syntheses of the ionic triphenyltin complex involved the reaction of a diprotic carboxylic acid, with triphenyltin chloride in the presence of di-isopropylamine. However, a tin-carbon cleavage reaction was observed, as IR/NMR spectroscopy and X-ray Crystallography studies showed that an ionic diphenyltin complex was successfully obtained in the reaction. The ionic complex consists of a diphenyltin anionic moiety, two oxalate ligands are observed coordinating to the tin atom in the bidentate mode, and two diisopropylammonium as the counterions. The anionic diphenyltin moieties has a distorted octohedral geometry with two carbons and two oxygens atom occupying the equatorial positions and two oxygen atoms occupying the axial positions. The ionic complex is essentially a 1-D polymer chain through an extensive hydrogen-bonding network between the oxalate groups (OCO) and the N atom from the ammonium cations. Compared to the similar reaction with triphenyltin hydroxide, which resulted in ionic triphenyltin complexes, cleavage of one phenyl group was observed for the first time in the reaction with triphenyltin chloride. Future studies will be focused on the mechanistic studies on the Sn-C cleavage.
Citation Format: Jade Witter, Xueqing Song, Tajera Henry, William Li. Synthesis and structural analysis on an ionic diphenyltin complex as a potential anticancer agent [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1297.
Abstract 1310: Peptide delivery of siRNA in GBM
Authors: Boulos Jessica , Alexander-Bryant Angela 
Published: July 2021

Abstract
Glioblastoma Multiforme (GBM), a grade VI glioma, is an aggressive malignant tumorwith a poor prognosis. With an incidence rate of 3.19 per 100,000, GBM has a median survivalrate of 12-15 months and a five-year survival rate of less than 5%. Typical treatments involvesurgical removal, chemotherapy, and radiation; however, these treatments still result in a lowsurvival rate and can lead to potential harm to healthy cells. Therefore, a new therapeutic isneeded for GBM treatment to improve patient outcomes. RNAi, a naturally found process,utilizes siRNA to target specific mRNA for degradation to inhibit protein translation and hasshown clinical potential for targeting and silencing oncogenes. However, barriers to siRNAdelivery, such as cellular uptake, non-specificity, and lack of endosomal escape hinder clinicaltranslation of RNAi therapeutics. Peptides are a promising carrier for siRNAs and havedemonstrated the potential to overcome barriers to delivery. The purpose of this study is todesign a novel tandem peptide for siRNA delivery, evaluate ability to mediate knockdown of atarget oncogene, and compare the efficacy of the tandem peptide to the individual peptidesalone. The tandem peptide is a novel combination of a fusogenic peptide and a targetingpeptide. STAT3, the target gene, is an oncogene that plays a role in cell proliferation,differentiation, apoptosis, and angiogenesis in GBM. Initial results have confirmed basal expression of EGFR and STAT3 in all three GBM cell lines, LN18, U118, and T98G.Characterization of the fusogenic, targeting, and tandem peptides indicated formation of monodispere nanoparticles with diameters less than 150 nm when complexed with siRNA. Furthermore, gel shift assays were conducted and confirmed that the tandem peptide protectedthe siRNA from degradation in 50% FBS. MTS assays conducted in all three cell lines for eachpeptide confirmed that there was no significant cytotoxicity due to the vehicles alone. Finally, flow cytometry confirmed uptake of the tandem peptide in T98G cell line. Therefore, it ishypothesized that the tandem peptide composed of both fusogenic targeting peptide willenhance cell-specific uptake of STAT3 siRNA into glioblastoma cells for mediating endosomalescape, resulting in more effective gene silencing and associated downstream effects comparedto the fusogenic and targeting peptides alone. Future studies include immunofluorescence for uptake and endosomal escape, knockdown studies (MTS, Western Blot, and qPCR assays), and assays to examine the downstream effect of silencing STAT3, such as migration and invasion assays.
Citation Format: Jessica Boulos, Angela Alexander-Bryant. Peptide delivery of siRNA in GBM [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1310.