Galectin-3 Cooperates with CD47 to Suppress Phagocytosis and T-cell Immunity in Gastric Cancer Peritoneal Metastases

The peritoneal cavity is a common site of gastric adenocarcinoma (GAC) metastasis. Peritoneal carcinomatosis (PC) is resistant to current therapies and confers poor prognosis, highlighting the need to identify new therapeutic targets. CD47 conveys a "don't eat me" signal to myeloid cells upon binding its receptor signal regulatory protein alpha (SIRPα), which helps tumor cells circumvent macrophage phagocytosis and evade innate immune responses. Previous studies demonstrated that the blockade of CD47 alone results in limited clinical benefits, suggesting that other target(s) might need to be inhibited simultaneously with CD47 to elicit a strong antitumor response. Here, we found that CD47 was highly expressed on malignant PC cells, and elevated CD47 was associated with poor prognosis. Galectin-3 (Gal3) expression correlated with CD47 expression, and coexpression of Gal3 and CD47 was significantly associated with diffuse type, poor differentiation, and tumor relapse. Depletion of Gal3 reduced expression of CD47 through inhibition of c-Myc binding to the CD47 promoter. Furthermore, injection of Gal3-deficient tumor cells into either wild-type and Lgals3-/- mice led to a reduction in M2 macrophages and increased T-cell responses compared with Gal3 wild-type tumor cells, indicating that tumor cell-derived Gal3 plays a more important role in GAC progression and phagocytosis than host-derived Gal3. Dual blockade of Gal3 and CD47 collaboratively suppressed tumor growth, increased phagocytosis, repolarized macrophages, and boosted T-cell immune responses. These data uncovered that Gal3 functions together with CD47 to suppress phagocytosis and orchestrate immunosuppression in GAC with PC, which supports exploring a novel combination therapy targeting Gal3 and CD47.

SIGNIFICANCE

Dual inhibition of CD47 and Gal3 enhances tumor cell phagocytosis and reprograms macrophages to overcome the immunosuppressive microenvironment and suppress tumor growth in peritoneal metastasis of gastric adenocarcinoma.

Evolution of immune and stromal cell states and ecotypes during gastric adenocarcinoma progression

Understanding tumor microenvironment (TME) reprogramming in gastric adenocarcinoma (GAC) progression may uncover novel therapeutic targets. Here, we performed single-cell profiling of precancerous lesions, localized and metastatic GACs, identifying alterations in TME cell states and compositions as GAC progresses. Abundant IgA+ plasma cells exist in the premalignant microenvironment, whereas immunosuppressive myeloid and stromal subsets dominate late-stage GACs. We identified six TME ecotypes (EC1-6). EC1 is exclusive to blood, while EC4, EC5, and EC2 are highly enriched in uninvolved tissues, premalignant lesions, and metastases, respectively. EC3 and EC6, two distinct ecotypes in primary GACs, associate with histopathological and genomic characteristics, and survival outcomes. Extensive stromal remodeling occurs in GAC progression. High SDC2 expression in cancer-associated fibroblasts (CAFs) is linked to aggressive phenotypes and poor survival, and SDC2 overexpression in CAFs contributes to tumor growth. Our study provides a high-resolution GAC TME atlas and underscores potential targets for further investigation.

Abstract 1194: Evolution of immune and stromal cell states during the gastric cancer continuum

Introduction: Gastric adenocarcinoma (GAC), a global health burden, lacks detail understanding of the evolution-driven cellular/molecular programs that lead to GAC tumorigenesis followed by progression/metastases. How the TME is orchestrated by precancerous lesions, primary GAC, and in metastatic niches, when well understood, may propel us into an entirely new dimension with the hopes of novel therapeutics. However, only a few studies have investigated the immune/stromal subtypes of GAC with the limitation of scope, cohort size, and/or depth or mainly focused on the primary GACs. Here, we present an atlas of transcriptionally diverse TME across the full continuum of GAC by including peripheral blood, normal gastric tissues, premalignant lesions, localized, and metastatic GACs.

Methods: We performed a comprehensive single-cell profiling of 68 specimens collected from 43 subjects including a total of 77,392 high-quality cells which revealed 62 unique cell states uncovering varying profiles. We defined alterations in TMEs that underscore initiation of tumorigenesis to eventual progression.

Results: We found a striking preponderance of B lineage cells, primarily the IgA+ plasma cells, in TMEs of the precancerous lesions, whereas 3 immunosuppressive myeloid subsets dominated in advanced GACs. Fractions of GZMK+ effector CD8 T cells and progenitor exhausted CD8 T cells gradually increased as GACs progressed to advanced stages. In addition, our analysis revealed extensive stromal remodeling along the GAC continuum, which may have contributed to enhanced angiogenesis and immune suppressive signaling. The observations in the primary tumors could be validated in an independent scRNA-seq dataset. Notably, we uncovered 3 unique TME interactomes and defined 6 cellular environtypes inhabited by 62 TME cell subsets giving GAC to a novel landscape not yet defined. The two distinct environtypes in GAC primaries are validated in three independent large-scale GAC cohorts, giving credence and definition to previously established histopathological variables, genomic/molecular subtypes and clinical outcomes. The analysis of tumor associated stromal cells discovered SDC2 as an

exploitable target to pursue. SDC2 was abundant in cancer associated fibroblasts (CAFs), and the abundance is validated in 3 independent single-cell GAC cohorts as well as at the protein level. SDC2 expression was significantly higher in advanced (vs. early) stages and diffuse (vs. intestinal) type of GAC, and SDC2 overexpression was associated with shorter survival in all 5 large-scale GAC cohorts. Lastly, we assessed the functional effects of SDC2 expression in CAFs on tumor growth in vivo in xenograft models and found SDC2 overexpression in CAFs contributes to tumor growth.

Conclusion: This study provides an atlas of GAC TMEs from tumorigenesis to advanced GAC that could be further developed for novel therapeutics but also serves as a community resource.

Citation Format: Ruiping Wang, Shumei Song, Jiangjiang Qin, Katsuhiro Yoshimura, Fuduan Peng, Yanshuo Chu, Yuan Li, Yibo Fan, Jiankang Jin, Minghao Dang, Enyu Dai, Guangsheng Pei, Guangchun Han, Yating Li, Deyali Chatterjee, Melissa P. Pizzi, Ailing W. Scott, Ghia Tatlonghari, Xinmiao Yan, Matheus Da Silva Sewastjanow, Ahmed Adel Fouad Abdelhakeem, Pawel K. Mazur, Xiangdong Cheng, Jaffer A. Ajani, Linghua Wang. Evolution of immune and stromal cell states during the gastric cancer continuum [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1194.

A new intronic quantitative PCR method led to the discovery of transformation from human ascites to murine malignancy in a mouse model

Purpose

To establish a fast and accurate detection method for interspecies contaminations in the patient-derived xenograft (PDX) models and cell lines, and to elucidate possible mechanisms if interspecies oncogenic transformation is detected.

Methods

A fast and highly sensitive intronic qPCR method detecting Gapdh intronic genomic copies was developed to quantify if cells were human or murine or a mixture. By this method, we documented that murine stromal cells were abundant in the PDXs; we also authenticated our cell lines to be human or murine.

Results

In one mouse model, GA0825-PDX transformed murine stromal cells into a malignant tumorigenic murine P0825 cell line. We traced the timeline of this transformation and discovered three subpopulations descended from the same GA0825-PDX model: epithelium-like human H0825, fibroblast-like murine M0825, and main passaged murine P0825 displayed differences in tumorigenic capability in vivo. P0825 was the most aggressive and H0825 was weakly tumorigenic. Immunofluorescence (IF) staining revealed that P0825 cells highly expressed several oncogenic and cancer stem cell markers. Whole exosome sequencing (WES) analysis revealed that TP53 mutation in the human ascites IP116-generated GA0825-PDX may have played a role in the human-to-murine oncogenic transformation.

Conclusion

This intronic qPCR is able to quantify human/mouse genomic copies with high sensitivity and within a time frame of a few hours. We are the first to use intronic genomic qPCR for authentication and quantification of biosamples. Human ascites transformed murine stroma into malignancy in a PDX model.

GRK3 is a poor prognosticator and serves as a therapeutic target in advanced gastric adenocarcinoma

Background

G protein-coupled receptor (GPCR) is the most targeted protein family by the FDA-approved drugs. GPCR-kinase 3 (GRK3) is critical for GPCR signaling. Our genomic analysis showed that GRK3 expression correlated with poor prognosis of gastric adenocarcinoma (GAC) patients. However, GRK3’s functions and clinical utility in GAC progression and metastases are unknown.

Methods

We studied GRK3 expression in normal, primary, and metastatic GAC tissues. We identified a novel GRK3 inhibitor, LD2, through a chemical-library screen. Through genetic and pharmacologic modulations of GRK3, a series of functional and molecular studies were performed in vitro and in vivo. Impact of GRK3 on YAP1 and its targets was determined.

Results

GRK3 was overexpressed in GAC tissues compared to normal and was even higher in peritoneal metastases. Overexpression (OE) of GRK3 was significantly associated with shorter survival. Upregulation of GRK3 in GAC cells increased cell invasion, colony formation, and proportion of ALDH1+ cells, while its downregulation reduced these attributes. Further, LD2 potently and specifically inhibited GRK3, but not GRK2, a very similar kinase to GRK3. LD2 highly suppressed GAC cells’ malignant phenotypes in vitro. Mechanistically, GRK3 upregulated YAP1 in GAC tissues and its transcriptional downstream targets: SOX9, Birc5, Cyr61 and CTGF. Knockdown (KD) YAP1 rescued the phenotypes of GRK3 OE in GAC cells. GRK3 OE significantly increased tumor growth but LD2 inhibited tumor growth in the PDX model and dramatically suppressed peritoneal metastases induced by GRK3 OE.

Conclusions

GRK3, a poor prognosticator for survival, conferred aggressive phenotype. Genetic silencing of GRK3 or its inhibitor LD2 blunted GRK3-conferred malignant attributes, suggesting GRK3 as a novel therapeutic target in advanced GAC.

Targeting cancer stem cells with a pan-BCL-2 inhibitor in preclinical and clinical settings in patients with gastroesophageal carcinoma

OBJECTIVE

Gastro-oesophageal cancers (GEC) are resistant to therapy and lead to poor prognosis. The cancer stem cells (CSCs) and antiapoptotic pathways often confer therapy resistance. We sought to elucidate the antitumour action of a BCL-2 inhibitor, AT101 in GEC in vitro, in vivo and in a clinical trial.

METHODS

Extensive preclinical studies in vitro and in vivo were carried out to establish the mechanism action of AT101 on targeting CSCs and antiapoptotic proteins. A pilot clinical trial in patients with GEC was completed with AT-101 added to standard chemoradiation.

RESULTS

Overexpression of BCL-2 and MCL-1 was noted in gastric cancer tissues (GC). AT-101 induced apoptosis, reduced proliferation and tumour sphere formation in MCL-1/BCL-2 high GC cells. Interestingly, AT101 dramatically downregulated genes (YAP-1/Sox9) that control CSCs in GEC cell lines regardless of BCL-2/MCL-1 expression. Addition of docetaxel to AT-101 amplified its antiproliferation and induced apoptosis effects. In vivo studies confirmed the combination of AT101 and docetaxel demonstrated stronger antitumour activity accompanied with significant decrease of CSCs biomarkers (YAP1/SOX9). In a pilot clinical trial, 13 patients with oesophageal cancer (EC) received AT101 orally concurrently with chemoradiation. We observed dramatic clinical complete responses and encouraging overall survival in these patients. Clinical specimen analyses revealed that AT-101 dramatically reduced the expression of CSCs genes in treated EC specimens indicating antitumour activity of AT101 relies more on its anti-CSCs activity.

CONCLUSIONS

Our preclinical and clinical data suggest that AT-101 overcomes resistance by targeting CSCs pathways suggesting a novel mechanism of action of AT101 in patients with GEC.

Patient-derived cell lines and orthotopic mouse model of peritoneal carcinomatosis recapitulate molecular and phenotypic features of human gastric adenocarcinoma

BACKGROUND

Gastric adenocarcinoma with peritoneal carcinomatosis (PC) is therapy resistant and leads to poor survival. To study PC in depth, there is an urgent need to develop representative PC-derived cell lines and metastatic models to study molecular mechanisms of PC and for preclinical screening of new therapies.

METHODS

PC cell lines were developed from patient-derived PC cells. The tumorigenicity and metastatic potential were investigated by subcutaneously (PDXs) and orthotopically. Karyotyping, whole-exome sequencing, RNA-sequencing, and functional studies were performed to molecularly define the cell lines and compare genomic and phenotypic features of PDX and donor PC cells.

RESULTS

We established three PC cell lines (GA0518, GA0804, and GA0825) and characterized them in vitro. The doubling times were 22, 39, and 37 h for GA0518, GA0804, and GA0825, respectively. Expression of cancer stem cell markers (CD44, ALDH1, CD133 and YAP1) and activation of oncogenes varied among the cell lines. All three PC cell lines formed PDXs. Interestingly, all three PC cell lines formed tumors in the patient derived orthotopic (PDO) model and GA0518 cell line consistently produced PC in mice. Moreover, PDXs recapitulated transcriptomic and phenotypic features of the donor PC cells. Finally, these cell lines were suitable for preclinical testing of chemotherapy and target agents in vitro and in vivo.

CONCLUSION

We successfully established three patient-derived PC cell lines and an improved PDO model with high incidence of PC associated with malignant ascites. Thus, these cell lines and metastatic PDO model represent excellent resources for exploring metastatic mechanisms of PC in depth and for target drug screening and validation by interrogating GAC for translational studies.

YAP1 mediates gastric adenocarcinoma peritoneal metastases that are attenuated by YAP1 inhibition

OBJECTIVE

Peritoneal carcinomatosis (PC; malignant ascites or implants) occurs in approximately 45% of advanced gastric adenocarcinoma (GAC) patients and associated with a poor survival. The molecular events leading to PC are unknown. The yes-associated protein 1 (YAP1) oncogene has emerged in many tumour types, but its clinical significance in PC is unclear. Here, we investigated the role of YAP1 in PC and its potential as a therapeutic target.

METHODS

Patient-derived PC cells, patient-derived xenograft (PDX) and patient-derived orthotopic (PDO) models were used to study the function of YAP1 in vitro and in vivo. Immunofluorescence and immunohistochemical staining, RNA sequencing (RNA-Seq) and single-cell RNA-Seq (sc-RNA-Seq) were used to elucidate the expression of YAP1 and PC cell heterogeneity. LentiCRISPR/Cas9 knockout of YAP1 and a YAP1 inhibitor were used to dissect its role in PC metastases.

RESULTS

YAP1 was highly upregulated in PC tumour cells, conferred cancer stem cell (CSC) properties and appeared to be a metastatic driver. Dual staining of YAP1/EpCAM and sc-RNA-Seq revealed that PC tumour cells were highly heterogeneous, YAP1^high PC cells had CSC-like properties and easily formed PDX/PDO tumours but also formed PC in mice, while genetic knockout YAP1 significantly slowed tumour growth and eliminated PC in PDO model. Additionally, pharmacologic inhibition of YAP1 specifically reduced CSC-like properties and suppressed tumour growth in YAP1^high PC cells especially in combination with cytotoxics in vivo PDX model.

CONCLUSIONS

YAP1 is essential for PC that is attenuated by YAP1 inhibition. Our data provide a strong rationale to target YAP1 in clinic for GAC patients with PC.

LncRNA PVT1 Is a Poor Prognosticator and Can Be Targeted by PVT1 Antisense Oligos in Gastric Adenocarcinoma

Gastric adenocarcinoma (GAC) is inherently resistant or becomes resistant to therapy, leading to a poor prognosis. Mounting evidence suggests that lncRNAs can be used as predictive markers and therapeutic targets in the right context. In this study, we determined the role of lncRNA-PVT1 in GAC along with the value of inhibition of PVT1 using antisense oligos (ASOs). RNA scope in situ hybridization was used to analyze PVT1 expression in tumor tissue microarrays (TMAs) of GAC and paired normal tissues from 792 patients. Functional experiments, including colony formation and invasion assays, were performed to evaluate the effects of PVT1 ASO inhibition of PVT1 in vitro; patient-derived xenograft models were used to evaluate the anti-tumor effects of PVT1 ASOs in vivo. LncRNA-PVT1 was upregulated in GACs compared to the matched adjacent normal tissues in the TMA. LncRNA PVT1 expression was positively correlated with larger tumor size, deeper wall invasion, lymph node metastases, and short survival duration. Inhibition of PVT1 using PVT1 ASOs significantly suppressed tumor cell growth and invasion in vitro and in vivo. PVT1 expression was highly associated with poor prognosis in GAC patients and targeting PVT1 using PVT1 ASOs was effective at curtailing tumor cell growth in vitro and in vivo. Thus, PVT1 is a poor prognosticator as well as therapeutic target. Targeting PVT1 using PVT1 ASOs provides a novel therapeutic strategy for GAC.

Targeting Hippo coactivator YAP1 through BET bromodomain inhibition in esophageal adenocarcinoma

Hippo/YAP1 signaling is a major regulator of organ size, cancer stemness, and aggressive phenotype. Thus, targeting YAP1 may provide a novel therapeutic strategy for tumors with high YAP1 expression in esophageal cancer (EC). Chromatin immunoprecipitation (ChiP) and quantitative ChiP‐PCR were used to determine the regulation of the chromatin remodeling protein bromodomain‐containing protein 4 (BRD4) on YAP1. The role of the bromodomain and extraterminal motif (BET) inhibitor JQ1, an established BRD4 inhibitor, on inhibition of YAP1 in EC cells was dissected using western blot, immunofluorescence, qPCR, and transient transfection. The antitumor activities of BET inhibitor were further examined by variety of functional assays, cell proliferation (MTS), tumorsphere, and ALDH1+ labeling in vitro and in vivo. Here, we show that BRD4 regulates YAP1 expression and transcription. ChiP assays revealed that BRD4 directly occupies YAP1 promoter and that JQ1 robustly blocks BRD4 binding to the YAP1 promoter. Consequently, JQ1 strongly suppresses constitutive or induced YAP1 expression and transcription in EC cells and YAP1/Tead downstream transcriptional activity. Intriguingly, radiation‐resistant cells that acquire strong cancer stem cell traits and an aggressive phenotype can be effectively suppressed by JQ1 as assessed by cell proliferation, tumorsphere formation, and reduction in the ALDH1+ cells. Moreover, effects of JQ1 are synergistically amplified by the addition of docetaxel in vitro and in vivo. Our results demonstrate that BRD4 is a critical regulator of Hippo/YAP1 signaling and that BRD4 inhibitor JQ1 represents a new class of inhibitor of Hippo/YAP1 signaling, primarily targeting YAP1 high and therapy‐resistant cancer cells enriched with cancer stem cell properties.

PPARδ Interacts with the Hippo Coactivator YAP1 to Promote SOX9 Expression and Gastric Cancer Progression

Despite established functions of PPARδ in lipid metabolism and tumorigenesis, the mechanisms underlying its role in gastric cancer are undefined. Here, we demonstrate that SOX9 was dramatically induced by stably expressing PPARδ and by its agonist GW501516 in human gastric cancer cell lines. PPARδ knockdown in patient-derived gastric cancer cells dramatically reduced SOX9 expression and transcriptional activity, with corresponding decreases in invasion and tumor sphere formation. Mechanistically, PPARδ induced SOX9 transcription through direct interaction with and activation of the Hippo coactivator YAP1. PPARδ-YAP1 interaction occurred via the C-terminal domain of YAP1, and both TEAD- and PPARE-binding sites were required for SOX9 induction. Notably, CRISPR/Cas9-mediated genetic ablation of YAP1 or SOX9 abolished PPARδ-mediated oncogenic functions. Finally, expression of PPARδ, YAP1, and SOX9 were significantly correlated with each other and with poor survival in a large cohort of human gastric cancer tissues. Thus, these findings elucidate a novel mechanism by which PPARδ promotes gastric tumorigenesis through interaction with YAP1 and highlights the PPARδ/YAP1/SOX9 axis as a novel therapeutic target in human gastric cancer. IMPLICATIONS: Our discovery of a new model supports a distinct paradigm for PPARδ and a crucial oncogenic function of PPARδ in gastric cancer through convergence on YAP1/TEAD signaling. Therefore, PPARδ/YAP1/SOX9 axis could be a novel therapeutic target that can be translated into clinics.

An improved strategy for CRISPR/Cas9 gene knockout and subsequent wildtype and mutant gene rescue

A fluorescence marker mOrange was inserted to the popular pLentiCrispr-V2 to create pLentiCrispr-V2-mOrange (V2mO) that contained both a puromycin selection and a fluorescent marker, making viral production and target transduction visible. Lentiviruses packaged with this plasmid and appropriate guide RNAs (gRNAs) successfully knocked out the genes RhoA, Gli1, and Gal3 in human gastric cancer cell lines. Cas9-gRNA editing efficiency could be estimated directly from Sanger electropherograms of short polymerase chain reaction products around the gRNA regions in Cas9-gRNA transduced cells. Single cloning of transduced target cell pools must be performed to establish stable knockout clones. Rescue of wildtype (RhoA and Gal3) and mutant (RhoA.Y42C) genes into knockout cells was successful only when cDNAs, where gRNAs bind, were modified by three nucleotides while the amino acid sequences remained unchanged. Stringent on-target CRISPR/Cas9 editing was observed in Gal3 gene, but not in RhoA gene since RhoA.Y42C already presented a nucleotide change in gRNA5 binding site. In summary, our improved strategy added these advantages: adding visual marker to the popular lentiviral system, monitoring lentiviral production and transduction efficiencies, cell-sorting Cas9+ cells in target cells by fluorescence-activated cell sorting, direct estimation of gene editing efficiency of target cell pools by short PCR electropherograms around gRNA binding sites, and successful rescue of wildtype and mutant genes in knockout cells, overcoming Cas9 editing by modifying cDNAs.

YAP1-Mediated CDK6 Activation Confers Radiation Resistance in Esophageal Cancer - Rationale for the Combination of YAP1 and CDK4/6 Inhibitors in Esophageal Cancer

PURPOSE

Esophageal cancer is a lethal disease that is often resistant to therapy. Alterations of YAP1 and CDK6 are frequent in esophageal cancer. Deregulation of both molecules may be responsible for therapy resistance.

EXPERIMENTAL DESIGN

Expressions of YAP1 and CDK6 were examined in esophageal cancer cells and tissues using immunoblotting and immunohistochemistry. YAP1 expression was induced in esophageal cancer cells to examine YAP1-mediated CDK6 activation and its association with radiation resistance. Pharmacologic and genetic inhibitions of YAP1 and CDK6 were performed to dissect the mechanisms and assess the antitumor effects in vitro and in vivo.

RESULTS

YAP1 expression was positively associated with CDK6 expression in resistant esophageal cancer tissues and cell lines. YAP1 overexpression upregulated CDK6 expression and transcription, and promoted radiation resistance, whereas treatment with the YAP1 inhibitor, CA3, strongly suppressed YAP1 and CDK6 overexpression, reduced Rb phosphorylation, as well as sensitized radiation-resistant/YAP1^high esophageal cancer cells to irradiation. CDK4/6 inhibitor, LEE011, and knock down of CDK6 dramatically inhibited expression of YAP1 and sensitized resistant esophageal cancer cells to irradiation indicating a positive feed-forward regulation of YAP1 by CDK6. In addition, suppression of both the YAP1 and CDK6 pathways by the combination of CA3 and LEE011 significantly reduced esophageal cancer cell growth and cancer stem cell population (ALDH1 ⁺ and CD133 ⁺ ), sensitized cells to irradiation, and showed a strong antitumor effect in vivo against radiation-resistant esophageal cancer cells.

CONCLUSIONS

Our results document that a positive crosstalk between the YAP1 and CDK6 pathways plays an important role in conferring radiation resistance to esophageal cancer cells. Targeting both YAP1 and CDK6 pathways could be a novel therapeutic strategy to overcome resistance in esophageal cancer.

Abstract 288: Genomic profiling of metastatic gastric adenocarcinoma

Objectives: Metastatic gastric adenocarcinoma (mGAC) is highly resistant to therapy and is incurable. Particularly, peritoneal carcinomatosis leads to severe morbidities and short survival. The genome wide approaches have been conducted in primary GAC and have uncovered useful information. However, detailed understanding of mGAC is limited. Thus, we aimed to characterize the genomic landscape of mGAC.

Methods: Thirty-four malignant ascites specimens were prospectively collected from at The University of Texas MD Anderson Cancer Center (Houston, USA) from February 2016. 25 specimens had whole exome sequencing and 30 specimens had RNA sequencing.

Results: The top highly mutated genes in mGAC were TP53, ATM, SYNE2, TTN, CDH11, FAT4/3, KMT2C, FGF23, NCOR1, RP1, CYP2A, and ADAMTS8/9. Compared with mutations in primary GAC (TCGA and TMUCIH), mutations in mGAC shared only 13.7% with TCGA and 10.9% with TMUCIH data. The commonly shared mutations in all three sets were TP53, ATM, FAT4, CDH1, SYNE1, PLEC, PRKDC, and ZFHX3, while unique mutations in mGAC were TTN, SYNE2, ZNF503, PUS7L, PPP2R5C, NBPF12, MROH1, IFNL1, and COL18A1. Furthermore, RNA- sequencing revealed two frequent fusions; 36.7% of samples with C15orf57-CBX3 (t(15;7)) fusion and 10% with SLC35A1-TSHZ2 (t(6;20)). We explored gene signatures in C15orf57-CBX3 fusion subgroup and C15orf57-CBX3 non-fusion subgroup. Gene set enrichment analysis revealed that C15orf57-CBX3 fusion group had enrichment of immune-response related genes, while non-fusion subgroup had enrichment of genes related to the segregation of chromatid, DNA replication, and histone exchange. The clustering analysis of RNA expression using the top 2000 genes with most median absolute deviation identified two subgroups that correlated either with C15orf57-CBX3 fusion or mutations.

Conclusions: We have identified a novel genomic landscape of mGAC, such as unique mutation and fusions. Further studies are needed to gain insights into the mechanism of progression and resistance phenotype of mGAC.

Citation Format: Kazuto Harada, Shumei Song, Yan Xu, Brain D. Bagewell, Melissa P. Pizzi, Jiankang Jin, Ying Wang, Ailing W. Scott, Lang Ma, Fatemeh G. Amlashi, Makoto Kobayashi, Jody V. Vykoukal, Cristina Ivan, Jeannelyn S. Estrella, Sinchita R. Chowdhuri, George A. Calin, Samir Hanash, Ju-Seog Lee, Bin Liu, Jaffer A. Ajani. Genomic profiling of metastatic gastric adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 288.

Galectin-3 expression is prognostic in diffuse type gastric adenocarcinoma, confers aggressive phenotype, and can be targeted by YAP1/BET inhibitors

BACKGROUND

Overexpression of Galectin-3 (Gal-3), a β-galactoside binding protein, has been noted in many tumour types but its functional significance and clinical utility in gastric adenocarcinoma (GAC) are not well known.

METHODS

We studied 184 GAC patients characterised by histologic grade, sub-phenotypes (diffuse vs intestinal), and ethnicity (Asians vs North Americans). Immunohistochemistry was performed to assess the expression of Gal-3 in human GACs and we correlated it to the clinical outcomes. Cell proliferation, invasion, co-immunoprecipitation and kinase activity assays were done in genetically stable Gal-3 overexpressing GC cell lines and the parental counterparts to delineate the mechanisms of action and activity of inhibitors.

RESULTS

Most patients were men, Asian, and had a poorly differentiated GAC. Gal-3 was over-expressed in poorly differentiated (P=0.002) tumours and also in diffuse sub-phenotype (P=0.02). Gal-3 overexpression was associated with shorter overall survival (OS; P=0.026) in all patients. Although, Gal-3 over-expression was not prognostic in the Asian cohort (P=0.337), it was highly prognostic in the North American cohort (P=0.001). In a multivariate analysis, Gal-3 (P=0.001) and N-stage (P=<0.001) were independently prognostic for shorter OS. Mechanistically, Gal-3 induced c-MYC expression through increasing RalA activity and an enhanced YAP1/RalA/RalBP complex to confer an aggressive phenotype. YAP1/BET bromodomain inhibitors reduced Gal-3-mediated aggressive phenotypes in GAC cells.

CONCLUSIONS

Gal-3 is an independent prognostic marker of shorter OS and a novel therapeutic target particularly in diffuse type GAC in North American patients.

A Novel YAP1 Inhibitor Targets CSC-Enriched Radiation-Resistant Cells and Exerts Strong Antitumor Activity in Esophageal Adenocarcinoma

Mounting evidence suggests that the Hippo coactivator Yes-associated protein 1 (YAP1) is a major mediator of cancer stem cell (CSC) properties, tumor progression, and therapy resistance as well as often a terminal node of many oncogenic pathways. Thus, targeting YAP1 may be a novel therapeutic strategy for many types of tumors with high YAP1 expression, including esophageal adenocarcinoma. However, effective YAP1 inhibitors are currently lacking. Here, we identify a small molecule (CA3) that not only has remarkable inhibitory activity on YAP1/Tead transcriptional activity but also demonstrates strong inhibitory effects on esophageal adenocarcinoma cell growth especially on YAP1 high-expressing esophageal adenocarcinoma cells both in vitro and in vivo Remarkably, radiation-resistant cells acquire strong cancer stem cell (CSC) properties and aggressive phenotype, while CA3 can effectively suppress these phenotypes by inhibiting proliferation, inducing apoptosis, reducing tumor sphere formation, and reducing the fraction of ALDH1⁺ cells. Furthermore, CA3, combined with 5-FU, synergistically inhibits esophageal adenocarcinoma cell growth especially in YAP1 high esophageal adenocarcinoma cells. Taken together, these findings demonstrated that CA3 represents a new inhibitor of YAP1 and primarily targets YAP1 high and therapy-resistant esophageal adenocarcinoma cells endowed with CSC properties. Mol Cancer Ther; 17(2); 443-54. ©2017 AACR.

Nuclear expression of Gli-1 is predictive of pathologic complete response to chemoradiation in trimodality treated oesophageal cancer patients

Background:

Predictive biomarkers or signature(s) for oesophageal cancer (OC) patients undergoing preoperative therapy could help administration of effective therapy, avoidance of ineffective ones, and establishment new strategies. Since the hedgehog pathway is often upregulated in OC, we examined its transcriptional factor, Gli-1, which confers therapy resistance, we wanted to assess Gli-1 as a predictive biomarker for chemoradiation response and validate it.

Methods:

Untreated OC tissues from patients who underwent chemoradiation and surgery were assessed for nuclear Gli-1 by immunohistochemistry and labelling indices (LIs) were correlated with pathologic complete response (pathCR) or <pathCR (resistance) and validated in a unique cohort.

Results:

Initial 60 patients formed the discovery set (TDS) and then unique 167 patients formed the validation set (TVS). 16 (27%) patients in TDS and 40 (24%) patients in TVS achieved a pathCR. Nuclear Gli-1 LIs were highly associated with pathCR based on the fitted logistic regression models (P<0.0001) in TDS and TVS. The areas under the curve (AUCs) for receiver-operating characteristics (ROCs) based on a fitted model were 0.813 (fivefold cross validation (0.813) and bootstrap resampling (0.816) for TDS and 0.902 (fivefold cross validation (0.901) and bootstrap resampling (0.902)) for TVS. Our preclinical (including genetic knockdown) studies with FU or radiation resistant cell lines demonstrated that Gli-1 indeed mediates therapy resistance in OC.

Conclusions:

Our validated data in OC show that nuclear Gli-1 LIs are predictive of pathCR after chemoradiation with desirable sensitivity and specificity.

Abstract 5862: YAP1 mediated CDK6 activation confers radiation resistance in esophageal cancer: rationale for the combination of YAP1 and CDK4/6 inhibitors in EC

Background: Esophageal carcinoma (EC) is a lethal disease with high incidence globally and often exist therapy resistance. Alterations (either overexpression or amplification) of YAP1 and CDK4/6 were found frequently in esophageal cancer. Deregulation of these pathways may represent key elements for resistance in esophageal cancer.

Methods: Expression of YAP1 and CDK4/6 were examined in esophageal tumor tissues as well as cell lines using immunohistochemistry and immunoblotting. Inducible YAP1 overexpression in EC cells by lentivirus system was performed to test YAP1 mediated CDK4/6 expression and activation and association with radiation resistance. YAP inhibitor CA3 and CDK4/6 inhibitor Lee001 were used to test their antitumor activities in vitro and in vivo. Cell proliferation assay (MTS), Flow cytometry and immunofluorecence and tumor sphere formation assay were performed to test cell cycle distribution, cancer stem cell (CSC) population maintenance and over growth and therapy resistance.

Results: We demonstrate that overexpressed YAP1 is positively associated with CDK4/6 expression in resistant tumor tissues and EC cell lines. Overexpression YAP1 by inducible lentivirus system in EC cells up-regulates expression of CDK4/6 at level of its transcription, while knock down YAP1 in JHESO EC cells dramatically decreased CDK6 expression as well as its transcription. CA3, a novel YAP1 inhibitor, was able to decrease activation of CDK4/6 and phosphorylation RB and cell cycle progression induced by YAP1. Interestingly, we found that inducible YAP1 high EC cells are resistant to radiation resistance and CDK6 knockout by Lenti-Crisp sensitize radiation resistant in EC cells induced by YAP1. Further, we demonstrated radiation resistant cells are enriched CSC population and demonstrated increased level of both YAP1 and CDK4/6, while blocking the YAP and CDK4/6 pathway by using their inhibitor CA3 or Lee001 reduced EC cell growth and CSCs properties especially in EC resistant cells. Most importantly, we found combination of Lee001 and CA3 exert a synergistic anticancer effect in radiation resistant EC cells with high YAP1 and CDK4/6 in Vitro and in Vivo.

Conclusions: Our data provide evidence that YAP1 mediated CDK4/6 up-regulation plays an important role in conferring radiation resistance in esophageal cancer cells. Targeting both YAP1 and CDK4/6 may provide novel therapeutic strategies in EC.

Corresponding Authors: Shumei Song, Tel:713-834-6144; Email: ssong@mdanderson.org; or Jaffer A. Ajani, Tel: 713-792-3685; Email: jajani@mdanderson.org

Citation Format: Fan Li, Xiaoquan Dong, Haitao Zhu, Ailing W. Scott, Lang Ma, Jiankang Jin, Jeannelyn Santiano Estrella, Heath Skinner, Randy L. Johnson, Shumei Song, Jaffer A. Ajani. YAP1 mediated CDK6 activation confers radiation resistance in esophageal cancer: rationale for the combination of YAP1 and CDK4/6 inhibitors in EC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5862. doi:10.1158/1538-7445.AM2017-5862

The Hippo Coactivator YAP1 Mediates EGFR Overexpression and Confers Chemoresistance in Esophageal Cancer

PURPOSE

Esophageal cancer is an aggressive malignancy and often resistant to therapy. Overexpression of EGFR has been associated with poor prognosis of patients with esophageal cancer. However, clinical trials using EGFR inhibitors have not provided benefit for patients with esophageal cancer. Failure of EGFR inhibition may be due to crosstalk with other oncogenic pathways.

EXPERIMENTAL DESIGN

In this study, expression of YAP1 and EGFR were examined in EAC-resistant tumor tissues versus sensitive tissues by IHC. Western blot analysis, immunofluorescence, real-time PCR, promoter analysis, site-directed mutagenesis, and in vitro and in vivo functional assays were performed to elucidate the YAP1-mediated EGFR expression and transcription and the relationship with chemoresistance in esophageal cancer.

RESULTS

We demonstrate that Hippo pathway coactivator YAP1 can induce EGFR expression and transcription in multiple cell systems. Both YAP1 and EGFR are overexpressed in resistant esophageal cancer tissues compared with sensitive esophageal cancer tissues. Furthermore, we found that YAP1 increases EGFR expression at the level of transcription requiring an intact TEAD-binding site in the EGFR promoter. Most importantly, exogenous induction of YAP1 induces resistance to 5-fluorouracil and docetaxcel, whereas knockdown of YAP1 sensitizes esophageal cancer cells to these cytotoxics. Verteporfin, a YAP1 inhibitor, effectively inhibits both YAP1 and EGFR expression and sensitizes cells to cytotoxics.

CONCLUSIONS

Our data provide evidence that YAP1 upregulation of EGFR plays an important role in conferring therapy resistance in esophageal cancer cells. Targeting YAP1-EGFR axis may be more efficacious than targeting EGFR alone in esophageal cancer.

Hippo coactivator YAP1 upregulates SOX9 and endows esophageal cancer cells with stem-like properties

Cancer stem cells (CSC) are purported to initiate and maintain tumor growth. Deregulation of normal stem cell signaling may lead to the generation of CSCs; however, the molecular determinants of this process remain poorly understood. Here we show that the transcriptional coactivator YAP1 is a major determinant of CSC properties in nontransformed cells and in esophageal cancer cells by direct upregulation of SOX9. YAP1 regulates the transcription of SOX9 through a conserved TEAD binding site in the SOX9 promoter. Expression of exogenous YAP1 in vitro or inhibition of its upstream negative regulators in vivo results in elevated SOX9 expression accompanied by the acquisition of CSC properties. Conversely, shRNA-mediated knockdown of YAP1 or SOX9 in transformed cells attenuates CSC phenotypes in vitro and tumorigenicity in vivo. The small-molecule inhibitor of YAP1, verteporfin, significantly blocks CSC properties in cells with high YAP1 and a high proportion of ALDH1(+). Our findings identify YAP1-driven SOX9 expression as a critical event in the acquisition of CSC properties, suggesting that YAP1 inhibition may offer an effective means of therapeutically targeting the CSC population.

Metformin sensitizes chemotherapy by targeting cancer stem cells and the mTOR pathway in esophageal cancer

Our clinical study indicates esophageal adenocarcinoma patients on metformin had a better treatment response than those without metformin. However, the effects of metformin and the mechanisms of its action in esophageal cancer (EC) are unclear. EC cell lines were used to assess the effects of metformin alone or in combination with 5-fluorouracil on survival and apoptosis. RPPA proteomic array and immunoblots were used to identify signaling affected by metformin. Standard descriptive statistical methods were used. Reduction in cell survival and induction of apoptosis by metformin were observed in several EC cell lines. The use of metformin in combination with 5-FU significantly sensitized EC cells to the cytotoxic effect of 5-FU. RPPA array demonstrated that metformin decreased various oncogenes including PI3K/mTORsignaling and survival/cancer stem cell-related genes in cells treated with metformin compared with its control. Immunoblots and transcriptional analyses further confirm that metformin downregulated these CSC-related genes and the components of the mTOR pathway in a dose-dependent manner. Sorted ALDH-1+ cell tumor sphere forming capacity was preferentially reduced by metformin. Finally, metformin reduced tumor growth in vivo and when combined with FU, there was synergistic reduction in tumor growth. Metformin inhibits EC cell growth and sensitizes EC cells to 5-FU cytotoxic effects by targeting CSCs and the components of mTOR. The present study supports our previous clinical observations that the use of metformin is beneficial to EC patients. Metformin can complement other therapeutic combinations to effectively treat EC patients.

ALDH-1 expression levels predict response or resistance to preoperative chemoradiation in resectable esophageal cancer patients

PURPOSE

Operable thoracic esophageal/gastroesophageal junction carcinoma (EC) is often treated with chemoradiation and surgery but tumor responses are unpredictable and heterogeneous. We hypothesized that aldehyde dehydrogenase-1 (ALDH-1) could be associated with response.

METHODS

The labeling indices (LIs) of ALDH-1 by immunohistochemistry in untreated tumor specimens were established in EC patients who had chemoradiation and surgery. Univariate logistic regression and 3-fold cross validation were carried out for the training (67% of patients) and validation (33%) sets. Non-clinical experiments in EC cells were performed to generate complimentary data.

RESULTS

Of 167 EC patients analyzed, 40 (24%) had a pathologic complete response (pathCR) and 27 (16%) had an extremely resistant (exCRTR) cancer. The median ALDH-1 LI was 0.2 (range, 0.01-0.85). There was a significant association between pathCR and low ALDH-1 LI (p ≤ 0.001; odds-ratio [OR] = 0.432). The 3-fold cross validation led to a concordance index (C-index) of 0.798 for the fitted model. There was a significant association between exCRTR and high ALDH-1 LI (p ≤ 0.001; OR = 3.782). The 3-fold cross validation led to the C-index of 0.960 for the fitted model. In several cell lines, higher ALDH-1 LIs correlated with resistant/aggressive phenotype. Cells with induced chemotherapy resistance upregulated ALDH-1 and resistance conferring genes (SOX9 and YAP1). Sorted ALDH-1+ cells were more resistant and had an aggressive phenotype in tumor spheres than ALDH-1- cells.

CONCLUSIONS

Our clinical and non-clinical data demonstrate that ALDH-1 LIs are predictive of response to therapy and further research could lead to individualized therapeutic strategies and novel therapeutic targets for EC patients.

EGFR-targeted hybrid plasmonic magnetic nanoparticles synergistically induce autophagy and apoptosis in non-small cell lung cancer cells

BACKGROUND

The epidermal growth factor receptor (EGFR) is overexpressed in 80% of non-small cell lung cancer (NSCLC) and is associated with poor survival. In recent years, EGFR-targeted inhibitors have been tested in the clinic for NSCLC. Despite the emergence of novel therapeutics and their application in cancer therapy, the overall survival rate of lung cancer patients remains 15%. To develop more effective therapies for lung cancer we have combined the anti-EGFR antibody (Clone 225) as a molecular therapeutic with hybrid plasmonic magnetic nanoparticles (NP) and tested on non-small cell lung cancer (NSCLC) cells.

METHODOLOGY/PRINCIPAL FINDINGS

Cell viability was determined by trypan-blue assay. Cellular protein expression was determined by Western blotting. C225-NPs were detected by electron microscopy and confocal microscopy, and EGFR expression using immunocytochemistry. C225-NP exhibited a strong and selective antitumor effect on EGFR-expressing NSCLC cells by inhibiting EGFR-mediated signal transduction and induced autophagy and apoptosis in tumor cells. Optical images showed specificity of interactions between C225-NP and EGFR-expressing NSCLC cells. No binding of C225-NP was observed for EGFR-null NSCLC cells. C225-NP exhibited higher efficiency in induction of cell killing in comparison with the same amount of free C225 antibody in tumor cells with different levels of EGFR expression. Furthermore, in contrast to C225-NP, free C225 antibody did not induce autophagy in cells. However, the therapeutic efficacy of C225-NP gradually approached the level of free antibodies as the amount of C225 antibody conjugated per nanoparticle was decreased. Finally, attaching C225 to NP was important for producing the enhanced tumor cell killing as addition of mixture of free C225 and NP did not demonstrate the same degree of cell killing activity.

CONCLUSIONS/SIGNIFICANCE

We demonstrated for the first time the molecular mechanism of C225-NP induced cytotoxic effects in lung cancer cells that are not characteristic for free molecular therapeutics thus increasing efficacy of therapy against NSCLC.

Abstract 3505: EGFR-targeted hybrid plasmonic magnetic nanoparticles induce autophagy and apoptosis through DNA damage in non-small cell lung cancer cells

Nanoparticles represent a novel class of agents for cancer treatment. In the present study, we examined the effects of epidermal growth factor receptor (EGFR)-targeted hybrid plasmonic magnetic nanoparticles (NP) on non-small cell lung cancer (NSCLC) cells. The nanoparticles (NP) consisted of a paramagnetic iron core that is surrounded by a gold layer and is functionalized with monoclonal anti-EGFR antibody (C225) or control rabbit IgG antibody (IgG). The nanoparticles were tested against a panel of human lung cancer cells that were mutant (HCC827, H1819), wild-type (H1299) or null (H520) for EGFR and compared to EGFR-positive normal fibroblasts (MRC9, WI38) and normal human bronchial epithelial (NHBE) cells. Treatment of tumor cells with C225-NP resulted in a strong and significant inhibitory effect of cell growth compared to normal cells. C225-NP-mediated inhibitory effect was observed only in EGFR-positive tumor cells (HCC827, H1819, H1299) but not in EGFR-null H520 cells. EGFR-mutant cells (HCC827) were the most sensitive to C225-NP. No significant growth inhibitory effects were observed in IgG-NP-treated cells when compared to untreated cells. Molecular analysis showed C225-NP selectively inhibited phosphorylated p-EGFR protein expression and EGFR-mediated signal transduction resulting in induction of autophagy followed by apoptosis. Autophagy occurred as early as twenty-four hours after treatment with an increase in LC3-II content and autophagic vacuoles observed by Western blotting and electron microscopy respectively. Apoptosis as determined by flow cytometry and Western blotting showed an increase in the number of sub-G1 population cells and cleavage of caspase-3 and PARP in C225-NP-treated cells. Optical images determined by dark-field microscopy showed an increase in the concentration of C225-NP bound to EGFR-expressing NSCLC cells but not EGFR-null NSCLC cells. C225-NP exhibited 2-7 fold higher efficiency in induction of cell killing in comparison with the same amount of free C225 antibody. Free C225 antibody did not induce autophagy in cells. Investigation into how C225-NP but not C225 antibody or NP-alone triggers autophagy and initiates apoptosis showed induction of a DNA damage response as evidenced by the formation of γH2AX foci in C225-NP-treated cells. Minimal to no γH2AX foci were observed in cells that were untreated, treated with C225 antibody or NP-alone or treated with IgG-NP. Our data show that EGFR specific NP selectively induced cytotoxic effects in EGFR-expressing lung cancer cells via a novel cell-death mechanism that is not characteristic of the free antibody thus increasing efficacy of therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3505.

Observation of D+ --> etae + nue

Using a 281 pb-1 data sample collected at the psi(3770) resonance with the CLEO-c detector at the Cornell Electron Storage Ring, we report the first observation of D+ --> etae + nue. We also set upper limits for D+ --> eta'e + nue and D + --> varphie + nue that are about 2 orders of magnitude more restrictive than those obtained by previous experiments.

Observation of eta' decays to pi+pi-pi0 and pi+pi-e+e-

Using psi(2S)-->pi;{+}pi;{-}J/psi, J/psi-->gammaeta;{'} events acquired with the CLEO-c detector at the CESR e;{+}e;{-} collider, we make the first observations of the decays eta;{'}-->pi;{+}pi;{-}pi;{0} and eta;{'}-->pi;{+}pi;{-}e;{+}e;{-}, measuring absolute branching fractions (37_{-9};{+11}+/-4)x10;{-4} and (25_{-9};{+12}+/-5)x10;{-4}, respectively. For eta;{'}-->pi;{+}pi;{-}pi;{0}, this result probes the mechanism of isospin violation and the roles of pi;{0}/eta/eta;{'}-mixing and final state rescattering in strong decays. We also set upper limits on branching fractions for eta;{'} decays to pi;{+}pi;{-}micro;{+}micro;{-}, 2(pi;{+}pi;{-}), pi;{+}pi;{-}2pi;{0}, 2(pi;{+}pi;{-})pi;{0}, 3(pi;{+}pi;{-}), and invisible final states.

J/psi and psi(2S) Radiative Transitions to eta_{c}

Using 2.45x10;{7} psi(2S) decays collected with the CLEO-c detector at the Cornell Electron Storage Ring we present the most precise measurements of magnetic dipole transitions in the charmonium system. We measure B(psi(2S)-->gammaeta_{c})=(4.32+/-0.16+/-0.60)x10;{-3}, B(J/psi-->gammaeta_{c})/B(psi(2S)-->gammaeta_{c})=4.59+/-0.23+/-0.64, and B(J/psi-->gammaeta_{c})=(1.98+/-0.09+/-0.30)%. We observe a distortion in the eta_{c} line shape due to the photon-energy dependence of the magnetic dipole transition rate. We find that measurements of the eta_{c} mass are sensitive to the line shape, suggesting an explanation for the discrepancy between measurements of the eta_{c} mass in radiative transitions and other production mechanisms.

Search for lepton flavor violation in upsilon decays

In this Letter, we describe a search for lepton flavor violation (LFV) in the bottomonium system. We search for leptonic decays Upsilon(nS)-->mutau (n=1, 2, and 3) using the data collected with the CLEO III detector. We identify the tau lepton using its leptonic decay nu_{tau}nu[over ]_{e}e and utilize multidimensional likelihood fitting with probability density function shapes measured from independent data samples. We report our estimates of 95% C.L. upper limits on LFV branching fractions of Upsilon mesons. We interpret our results in terms of the exclusion plot for the energy scale of a hypothetical new interaction versus its effective LFV coupling in the framework of effective field theory.

Observation of Upsilon(2S)-->etaUpsilon(1S) and search for related transitions

We report the first observation of Upsilon(2S)-->etaUpsilon(1S), with a branching fraction B=(2.1(-0.6)+0.7(stat)+/-0.3(syst)) x 10(-4) and a statistical significance 5.3sigma. Data were acquired with the CLEO III detector at the CESR e+e(-) symmetric collider. This is the first process observed involving a b-quark spin flip. For related transitions, 90% confidence limits in units of 10(-4) are B(Upsilon(2S)-->pi0Upsilon(1S)) < 1.8, B(Upsilon(3S)-->etaUpsilon(1S)) < 1.8, B(Upsilon(3S)-->pi0Upsilon(1S)) < 0.7, and B(Upsilon(3S)-->pi0Upsilon(2S)) < 5.1.

Precision measurement of the mass of the hc(1P1) state of charmonium

A precision measurement of the mass of the h_{c}(1P1) state of charmonium has been made using a sample of 24.5x10;{6} psi(2S) events produced in e;{+}e;{-} annihilation at the Cornell Electron Storage Ring (CESR). The reaction used was psi(2S)-->pi;{0}h_{c}, pi;{0}-->gammagamma, h_{c}-->gammaeta_{c}, and the reaction products were detected in the CLEO-c detector. Data have been analyzed both for the inclusive reaction and for the exclusive reactions in which eta_{c} decays are reconstructed in 15 hadronic decay channels. Consistent results are obtained in the two analyses. The averaged results of the present measurements are M(h_{c})=3525.28+/-0.19(stat.)+/-0.12(syst.) MeV, and B(psi(2S)-->pi;{0}h_{c})xB(h_{c}-->gammaeta_{c})=(4.19+/-0.32+/-0.45)x10;{-4}. Using the ;{3}P_{J} centroid mass, DeltaM_{hf}(1P) identical withM(chi_{cJ})-M(h_{c})=+0.02+/-0.19+/-0.13 MeV.

Measurement of the eta'-meson mass using J/psi-->gammaeta'

We measure the mass of the eta;{'} meson using psi(2S)-->pi;{+}pi;{-}J/psi, J/psi-->gammaeta;{'} events acquired with the CLEO-c detector operating at the CESR e;{+}e;{-} collider. Using three decay modes, eta;{'}-->rho;{0}gamma, eta;{'}-->pi;{+}pi;{-}eta with eta-->gammagamma, and eta;{'}-->pi;{+}pi;{-}eta with eta-->pi;{+}pi;{-}pi;{0}, we find M_{eta;{'}}=957.793+/-0.054+/-0.036 MeV, in which the uncertainties are statistical and systematic, respectively. This result is consistent with but substantially more precise than the current world average.

Observation of chicJ radiative decays to light vector mesons

Using a total of 2.74 x 10(7) decays of the psi(2S) collected with the CLEO-c detector, we present a study of chi(cJ)-->gammaV, where V=rho(0), omega, phi. The transitions chi(c1)-->gammarho(0 and chi(c1)-->gammaomega are observed with B(chi(c1)-->gammarho(0))=(2.43+/-0.19+/-0.22) x 10(-4) and B(chi(c1)-->gammaomega)=(8.3+/-1.5+/-1.2) x 10(-5). In the chi(c1)-->gammarho(0) transition, the final state meson is dominantly longitudinally polarized. Upper limits on the branching fractions of other chi(cJ) states to light vector mesons are presented.

Search for very light CP-odd Higgs Boson in radiative decays of Upsilon(1S)

We search for a non-SM-like CP-odd Higgs boson (a(1)(0)) decaying to tau(+)tau(-) or mu(+)mu(-) in radiative decays of the Upsilon(1S). No significant signal is found, and upper limits on the product branching ratios are set. Our tau(+)tau(-) results are almost 2 orders of magnitude more stringent than previous upper limits. Our data provide no evidence for a Higgs state with a mass of 214 MeV decaying to mu(+)mu(-), previously proposed as an explanation for 3 Sigma(+)-->pmu(+)mu(-) events observed by the HyperCP experiment. Our results constrain NMSSM models.

Observation of J/psi-->3gamma

We report the first observation of the decay J/psi-->3gamma. The signal has a statistical significance of 6sigma and corresponds to a branching fraction of B(J/psi-->3gamma)=(1.2+/-0.3+/-0.2)x10;{-5}, in which the errors are statistical and systematic, respectively. The measurement uses psi(2S)-->pi;{+}pi;{-}J/psi events acquired with the CLEO-c detector operating at the CESR e;{+}e;{-} collider.

Study of the decays D0-->pi{-}e{+}nu{e}, D{0}-->K{-}e{+}nu{e}, D{+}-->pi{0}e{+}nu{e}, and D{+}-->K0e{+}nu{e}

By using 1.8x10{6} DDpairs, we have measured B(D{0}-->pi{-}e{+}nu{e})=0.299(11)(9)%, B(D{+}-->pi{0}e{+}nu{e})=0.373(22)(13)%, B(D{0}-->K{-}e{+}nu{e})=3.56(3)(9)%, and B(D{+}-->K{0}e{+}nu{e})=8.53(13)(23)% and have studied the q;{2} dependence of the form factors. By combining our results with recent lattice calculations, we obtain |V{cd}|=0.217(9)(4)(23) and |V{cs}|=1.015(10)(11)(106).

Determination of the strong phase in D0-->K+pi- using quantum-correlated measurements

We exploit the quantum coherence between pair-produced D0 and D[over]0 in psi(3770) decays to study charm mixing, which is characterized by the parameters x and y, and to make a first determination of the relative strong phase delta between D0-->K+pi- and D[over]0-->K+pi-. Using 281 pb(-1) of e+e- collision data collected with the CLEO-c detector at Ecm=3.77 GeV, as well as branching fraction input and time-integrated measurements of RM identical with (x2 + y2)/2 and RWS identical with Gamma(D0-->K+pi-)/Gamma(D[over]0-->K+pi-) from other experiments, we find cosdelta=1.03(-0.17)(+0.31)+/-0.06, where the uncertainties are statistical and systematic, respectively. By further including other mixing parameter measurements, we obtain an alternate measurement of cosdelta=1.10+/-0.35+/-0.07, as well as x sindelta=(4.4(-1.8)(+2.7)+/-2.9)x10(-3) and delta=(22(-12-11)(+11+9)) degrees .

First observation of the decay Ds+-->pn

Using e+e--->Ds*-Ds+ data collected near the peak Ds production energy, Ecm=4170 MeV, with the CLEO-c detector, we present the first observation of the decay Ds+-->pn. We measure a branching fraction B(Ds+-->pn)=(1.30+/-0.36(-0.16)+0.12)x10(-3). This is the first observation of a charmed meson decaying into a baryon-antibaryon final state.

Measurement of the absolute branching fraction of Ds+ --> tau+ nutau decay

Using a sample of tagged D(s)(+) decays collected near the D(s)(*+/-)D(s)(-/+) peak production energy in e(+)e(-) collisions with the CLEO-c detector, we study the leptonic decay D(s)(+)-->tau(+)nu(tau) via the decay channel tau(+)-->e(+)nu(e)nu(tau). We measure B(D(s)(+)-->tau(+)nu(tau))=(6.17+/-0.71+/-0.34)%, where the first error is statistical and the second systematic. Combining this result with our measurements of D(s)(+)-->mu(+)nu(mu) and D(s)(+)-->tau(+)nu(tau) (via tau(+)-->pi(+)nu(tau)), we determine f(D(s))=(274+/-10+/-5) MeV.

Absolute measurement of hadronic branching fractions of the Ds+ meson

The branching fractions of D(s)(+/-) meson decays serve to normalize many measurements of processes involving charm quarks. Using 298 pb(-1) of e(+)e(-) collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for eight D(s)(+/-) decays with a double tag technique. In particular we determine the branching fraction B(D(s)(+)-->K(-)K(+}pi(+))=(5.50+/-0.23+/-0.16)%, where the uncertainties are statistical and systematic, respectively. We also provide partial branching fractions for kinematic subsets of the K(-)K(+)pi(+) decay mode.

Comparison of D--> KS0 pi and D--> KL0 pi decay rates

We present measurements of D--> KS0 pi and D--> KL0 pi branching fractions using 281 pb(-1) of psi(3770) data at the CLEO-c experiment. We find that B(D0--> KS0 pi 0) is larger than B(D0--> KL0 pi 0), with an asymmetry of R(D0)=0.108+/-0.025+/-0.024. For B(D+--> KS0 pi+) and B(D+--> KL0 pi+), we observe no measurable difference; the asymmetry is R(D+)=0.022+/-0.016+/-0.018. The D0 asymmetry is consistent with the value based on the U-spin prediction A(D0--> K0 pi 0)/A(D0--> K0 pi 0)=-tan2 theta C, where theta C is the Cabibbo angle.

Suppressed decays of D(s)(+) mesons to two pseudoscalar mesons

Using data collected near the D{s}{*+}D{s}{-} peak production energy E_{cm}=4170 MeV by the CLEO-c detector, we study the decays of D{s}{+} mesons to two pseudoscalar mesons. We report on searches for the singly Cabibbo-suppressed D{s}{+} decay modes K{+}eta, K{+}eta', pi{+}K{S}{0}, K{+}pi{0}, and the isospin-forbidden decay mode D{s}{+}-->pi{+}pi{0}. We normalize with respect to the Cabibbo-favored D{s}{+} modes pi{+}eta, pi{+}eta', and K{+}K{S}{0}, and obtain ratios of branching fractions: B(D{s}{+}-->K{+}eta)/B(D{s}{+}-->pi{+}eta)=(8.9+/-1.5+/-0.4)%, B(D{s}{+}-->K{+}eta')/B(D{s}{+}-->pi{+}eta')=(4.2+/-1.3+/-0.3)%, B(D{s}{+}-->pi{+}K{S}{0})/B(D{s}{+}-->K{+}K{S}{0})=(8.2+/-0.9+/-0.2)%, B(D{s}{+}-->K{+}pi{0})/B(D{s}{+}-->K{+}K{S}{0})=(5.5+/-1.3+/-0.7)%, and B(D{s}{+}-->pi{+}pi{0})/B(D{s}{+}-->K{+}K{S}{0})<4.1% at 90% C.L., where the uncertainties are statistical and systematic, respectively.

Evidence for the decay D0-->K(-)pi(+)pi(-)e(+)nu(e)

Using a 281 pb{-1} data sample collected at the psi(3770) with the CLEO-c detector, we present the first absolute branching fraction measurement of the decay D0-->K(-)pi(+)pi(-)e(+)nu(e) at a statistical significance of about 4.0 standard deviations. We find 10 candidates consistent with the decay D0-->K(-)pi(+)pi(-)e(+)nu(e). The probability that a background fluctuation accounts for this signal is less than 4.1 x 10{-5}. We find B(D0-->K(-)pi(+)pi(-)e(+)nu(e)) = [2.8{-1.1}{+1.4}(stat)+/-0.3(syst)]x10{-4}. By restricting the invariant mass of the hadronic system to be consistent with K1(1270), we obtain the product of branching fractions B(D{0}-->K{1}{-}(1270)e{+}nu{e})xB(K1-(1270)-->K{-}pi{+}pi{-})=[2.5{-1.0}{+1.3}(stat)+/-0.2(syst)]x10{-4}. Using B(K1-(1270)-->K{-}pi{+}pi{-})=(33+/-3)%, we obtain B(D{0}-->K{1}{-}(1270)e{+}nu{e})=[7.6{-3.0}{+4.1}(stat)+/-0.6(syst)+/-0.7]x10{-4}. The last error accounts for the uncertainties in the measured K1-(1270)-->K{-}pi{+}pi{-} branching fractions.

Measurement of prominent eta-decay branching fractions

The decay psi(2S) --> etaJ/psi is used to measure, for the first time, all prominent eta-meson branching fractions with the same experiment in the same dataset, thereby providing a consistent treatment of systematics across branching fractions. We present results for eta decays to gamma gamma, pi(+)pi(-)pi(0), 3pi(0), pi(+)pi(-)gamma and e(+)e(-)gamma, accounting for 99.9% of all eta decays. The precision of several of the branching fractions and their ratios is improved. Two channels, pi(+)pi(-)gamma and e(+)e(-)gamma, show results that differ at the level of three standard deviations from those previously determined.

Measurement of the eta-meson mass using psi(2S) --> etaJ/psi

We measure the mass of the eta meson using psi(2S) --> etaJ/psi events acquired with the CLEO-c detector operating at the CESR e(+)e(-) collider. Using the four decay modes eta --> gamma gamma, 3pi(0), pi(+)pi(-)pi(0), and pi(+)pi(-)gamma, we find M(eta) = 547.785 +/- 0.017 +/- 0.057 MeV, in which the first uncertainty is statistical and the second systematic. This result has an uncertainty comparable to the two most precise previous measurements and is consistent with that of NA48, but is inconsistent at the level of 6.5 sigma with the much smaller mass obtained by GEM.

Measurement of the decay constant f(Ds+) using D(s+)-->l+ nu

We measure the decay constant f(Ds+) using the D(s+)-->l+ nu channel, where the l+ designates either a mu+ or a tau+, when the tau+ -->pi+ nu. Using both measurements we find f(Ds+)=274+/-13+/-7 MeV. Combining with our previous determination of f(D+), we compute the ratio f(Ds+)/f(D+)=1.23+/-0.11+/-0.04. We compare with theoretical estimates.

Study of exclusive charmless semileptonic B decays and |Vub|

We study semileptonic B decay to the exclusive charmless states pi, rho/omega, eta, and eta;{'} using the 16 fb(-1) CLEO Upsilon(4S) data sample. We find B(B0-->pi-l+nu)=(1.37+/-0.15stat+/-0.11sys)x10(-4) and B(B0-->rho-l+nu)=(2.93+/-0.37stat+/-0.37sys)x10(-4) and find evidence for B+-->eta'l+nu, with B(B+-->eta'l+nu)=(2.66+/-0.80stat+/-0.56sys)x10(-4). From our B-->pilnu rate for q2>16 GeV2 and lattice QCD, we find |Vub|=(3.6+/0.4stat+/0.2syst-0.4thy+0.6)x10(-3) [corrected]

Precision determination of the D0 mass

A precision measurement of the D0 meson mass has been made using approximately 281 pb(-1) of e+e- annihilation data taken with the CLEO-c detector at the psi(3770) resonance. The exclusive decay D0-->K_{S}phi has been used to obtain M(D0)=1864.847+/-0.150(stat)+/-0.095(syst) MeV. This corresponds to M(D0D*0)=3871.81+/-0.36 MeV, and leads to a well-constrained determination of the binding energy of the proposed D0D*0 molecule X(3872), as Eb=0.6+/-0.6 MeV.

Observation of Upsilon(3S)-->tau+tau- and tests of lepton universality in Upsilon decays

Using data collected with the CLEO III detector at the CESR e+e- collider, we report on a first observation of the decay Upsilon(3S)-->tau+tau-, and precisely measure the ratio of branching fractions of Upsilon(nS), n=1, 2, 3, to tau+tau- and mu+mu- final states, finding agreement with expectations from lepton universality. We derive absolute branching fractions for these decays, and also set a limit on the influence of a low mass CP-odd Higgs boson in the decay of the Upsilon(1S).

Absolute branching fraction measurements for D+ and D0 inclusive semileptonic decays

We present measurements of the inclusive branching fractions for the decays D+-->Xe+ nu(e) and D0-->Xe+ nu(e), using 281 pb(-1) of data collected on the psi(3770) resonance with the CLEO-c detector. We find B(D0-->Xe+ nu(e)) = (6.46+/-0.17+/-0.13)% and B(D+-->Xe+ nu(e)) = (16.13+/-0.20+/-0.33)%. Using the known D meson lifetimes, we obtain the ratio Gamma(D+)sl/Gamma(D0)sl = 0.985+/-0.028+/-0.015, confirming isospin invariance at the level of 3%. The positron momentum spectra from D+ and D0 have consistent shapes.

Observation of Psi(3770)-->gammachi(c1)-->gammagammaJ/Psi

From e(+)e(-) collision data acquired with the CLEO detector at the Cornell Electron Storage Ring, we observe the non-DD(_) decay Psi(3770))-->gammachi(c1) with a statistical significance of 6.6 standard deviations, using the two-photon cascades to J/Psi and J/Psi-->l(+)l(-). We determine sigma(e(=)e(-)-->Psi(3770))xBeta(Psi(3770)-->gammachi(c1))=(18.0 +/- 3.3 +/- 2.5) pb and branching fraction Beta(Psi(3770)-->gammachi(c1)=(2.8 +/- 0.5+/-0.4) x 10(-3). We set 90% C.L. upper limits for the transition to chi(c2) (chi(c0)): sigma x Beta<5.7 pb (<282 pb) and Beta<0.9 x 10(-3) (<44 x 10(-3)). We also determine Gamma(Psi(3770)gammachi(c1))/Gamma(Psi(3770)-->pi(+)pi(-)J/Psi)=1.5 +/- 0.3 +/- 0.3 (>1.0 at 90% C.L.), which bears upon the interpretation of X(3872).