bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2738: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mediates tumor immune evasion in cholangiocarcinoma
Authors: Loeuillard Emilien , Yang Jingchun , Dong Haidong , Gores Gregory J. , Ilyas Sumera
Published: July 2021

Background and Aims: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a member of the tumor necrosis factor superfamily, is predominantly expressed on immune cells. Although TRAIL biology has garnered considerable interest as a potential anti-cancer strategy, TR agonists have had very limited anti-cancer activity in humans. TRAIL signaling in T cells may also potentially provide an immune checkpoint function as it can inhibit T cell activation and proliferation by interfering with T cell receptor signaling. However, this potential immune checkpoint function of TRAIL has not been examined in cancer biology. Cholangiocarcinoma (CCA), a malignancy of the bile ducts, provides a model to examine the potential immune checkpoint function of TRAIL.

Methods: Using a syngeneic, orthotopic murine model of CCA (PMID: 29464042), murine CCA cells (SB cells) that express both TRAIL and TRAIL receptor (TR) were implanted into livers of WT C57BL/6J and Tr−/− mice. Hence, in this model the host immune cells express TRAIL but not the receptor; they would be capable of inducing TRAIL-mediated apoptosis in CCA cells but would be resistant to potential TRAIL-mediated immunosuppression. After 4 weeks of tumor growth, mice were sacrificed and tumor and immune characterization (via flow cytometry) was conducted.

Results: Implantation of SB cells into Tr−/− mice result in a significant reduction in tumor volumes compared to WT mice. Tumor-bearing Tr−/− mice had a significant infiltration of cytotoxic T lymphocytes (CTLs) (CD45+CD3+CD8+CD11a+) and enhanced CTL effector function. Moreover, Tr−/− mice tumors had a significant decrease in granulocytic and monocytic myeloid-derived suppressor cell (MDSCs) as well as tumor-associated macrophages (TAMs) (CD45+F4/80+CD11b+CD206+) compared to WT mice tumors.

Conclusion: Using a unique syngeneic orthotopic implantation model of murine CCA, we demonstrate that CCA cells expressing TRAIL in a mouse genetically deficient for TR exhibit reduced tumor volumes enhanced CTL infiltration and function, and reduced MDSC and TAM infiltration into the tumors. These data suggest that TRAIL has a potential immune checkpoint function, and targeting TRAIL signaling with consequent augmentation of CTL function maybe a promising therapeutic approach in human cancers.

Citation Format: Emilien Loeuillard, Jingchun Yang, Haidong Dong, Gregory J. Gores, Sumera Ilyas. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mediates tumor immune evasion in cholangiocarcinoma [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 2738.
Abstract 2774: Establishment of in vitro human T cell exhaustion model to enable high throughput target validation for T cell phenotype restoring
Authors: Wang Tienan , Zhang Jie , Wang Zhijun , Li Yingnian , Shi Linghong , Lin Qing
Published: July 2021

Immune surveillance was defined as three phases during tumorigenesis: elimination, equilibrium and escape. During the escape phase, cancer cell acquire a series of mechanism to evade the recognition by immune system, including reduce the function of antigen presenting cells, recruitment of suppressive cells, induce T cell exhaustion etc. The exhaustion phenotype of T cells were frequently observed in various cancer types and exhibit as reduced effector cytokine production, decrease in proliferation and cytolytic activity and overexpression of inhibitory receptors. Restoring T cell exhaustion phenotype become the inspiring filed for cancer therapy and PD1 blocking antibody further encouraging the concept of intervention on T cell exhausted phenotype in tumor microenvironment. In this study, we utilize human primary T cell to establish the in vitro model of T cell exhaustion. Subsequent functional study reveal that the induced exhausted T cell (Tex) display significantly weak response towards dendritic cell activation compare to normal T cell (Tnorm). We take advantage of the model to validate the function of PD1 antibody and demonstrate that blocking of PD1 could partially restore the function of Tex, which suggesting there are still other regulators involved in mediating T cell exhaustion beyond PD1.

Citation Format: Tienan Wang, Jie Zhang, Zhijun Wang, Yingnian Li, Linghong Shi, Qing Lin. Establishment of in vitro human T cell exhaustion model to enable high throughput target validation for T cell phenotype restoring [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 2774.
Abstract 2890: Mitotic inhibitors suppresses tumor formation and metastasis of triple negative breast cancer (TNBC)
Authors: Song Chaeun , Lee SeungBaek
Published: July 2021

Cell division cycle 20 (Cdc20) is the main activator of the anaphase-promoting complex (APC/C) and is essential in mitosis regulation. Recently, several papers reported that Cdc20 is highly conserved in various human cancers such as pancreatic, prostate, and lung cancers yet its relation to breast cancer is unclear. Here, we found that Cdc20 gene was highly expressed in three different TNBC cell lines among the mitosis regulator genes through the National Center for Biotechnology Information (NCBI). High Cdc20 level is positively correlated with metastasis-free patient survival and relapse-free patient survival in breast cancer patient database. We also checked that Cdc20 is highly conserved in all TNBC cell lines compared to other subtypes of breast cancer cell lines and the knockdown of this gene decreased cell growth and invasion in TNBC. Furthermore, we investigated that the mitosis-related small molecule protein kinase inhibitors such as VX-680, ZM447439, BI2536, and apcin also inhibit tumor cell proliferation, migration, and invasion. In conclusion, Cdc20 has an important role in TNBC cell growth and metastasis. Cdc20 might serve as a potential marker of disease progression and as a principal potential therapeutic target. Also, mitosis-related protein kinase inhibitors are additional potential therapy to suppress cancer cell progression and invasion in TNBC effectively.

Citation Format: Chaeun Song, SeungBaek Lee. Mitotic inhibitors suppresses tumor formation and metastasis of triple negative breast cancer (TNBC) [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 2890.
Abstract 2994: A new ER+Her2- Palbociclib resistant breast cancer PDX model
Authors: Melton Michele , Hyddmark Emma M. , Jiang Hongmei , Bast Athena , Semanik Nicole , Deeds Stacy , Brown Andrew
Published: July 2021

One out of eight women will get breast cancer during their lifetime with over 250000 new cases of invasive breast cancer diagnosed yearly. The majority of breast cancer medicines (94%) were initially approved in the metastatic setting for patients that have been heavily pre-treated and resistant to the standard of care1. Thus, it is crucial that pre-clinical models are representative of this patient population in order for results to be translational. One recently approved class of drugs are the CDK4/6i which increase progression free survival for many patients. However, some tumors are intrinsically resistant, and others develop resistance over time. Hence, there is a need for new pre-clinical models that mimic these resistance features to test new therapies. WHIM81 and WHIM84 are two new ER+Her2- breast cancer PDX models from the Washington University Human in Mouse collection derived from heavily pretreated tumors. WHIM81 was derived from a patient with liver metastasis consistent with breast primary after she received treatment with Palbociclib, first as a monotherapy for 20 days and later in combination with letrozole for 2 months. During treatment, the patient developed the liver metastasis, whereas the WHIM84 model was grafted from a second patient with a bone metastasis prior to the patient seeing Palbociclib, but once she did, the tumor was unresponsive.

In this PDX study, athymic nude mice bearing either WHIM81 or WHIM84 tumors were treated with 3 different concentrations of Palbociclib (10 mg/kg, 25 mg/kg and 75 mg/kg) administered daily for the duration of the experiment and also included an arm with Fulvestrant administered once weekly through a subcutaneous injection of 3 mg/dose. Our results showed that although WHIM81 tumors were responsive to a very high dose of Palbociclib (75 mg/kg), those tumors showed resistance to Palbociclib doses of 10 mg/kg and Palbociclib 25 mg/kg group as well as Fulvestrant, consistent with what was seen in the clinic for the tumor from which this PDX is derived. On the contrary WHIM84, while still showing resistance at the 10 mg/kg dose, was sensitive to treatment with Palbociclib at a dose of 25 mg/kg.

Loss of pRb is an unlikely driver of resistance as WHIM81 retains pRb expression based on the presence of both pRb and phospo-pRb in the tumor. Thus, we believe that WHIM81 will provide a valuable new model to test novel therapies aimed to treat patients with CDK4/6i resistant cancers.

1. Leo and Szucs. (2020). Nature Reviews Drug Discovery. 19, 10.

Citation Format: Michele Melton, Emma M. Hyddmark, Hongmei Jiang, Athena Bast, Nicole Semanik, Stacy Deeds, Andrew Brown. A new ER+Her2- Palbociclib resistant breast cancer PDX model [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 2994.
Abstract 3013: Orthotopic patient-derived xenografts (O-PDX) are effective precision oncology models that can predict therapeutic response, recurrence, and acquired drug resistance
Authors: Nakashima Jonathan , Sperry Jantzen , Carapia Bianca , Yan Deborah , Chin Angelina , Shahsafaei Aliakbar , Chen Joan , Chien Yuan-Hung , Pedros Christophe , Federman Noah , Singh Arun , Eilber Fritz C. , Datnow Brian
Published: July 2021

Patient-derived xenografts provide a functional test system in a living organism, making them the leading assay for precision oncology and drug development. In vivo pharmacology studies are widely performed using subcutaneous implantation; however, due to significant changes in the tumor microenvironment, this methodology falls short of modeling the full complexities of human cancer. We use quantitative magnetic resonance imaging (MRI) to report differences in growth kinetics and pharmacological response between orthotopic and subcutaneous implantation of patient-derived xenografts. We demonstrate that O-PDX models can predict effective treatment strategies for individual patients and forecast tumor recurrence after therapy. Furthermore, we use this approach to develop in vivo models of acquired drug resistance to strategize future treatment options and aid in drug development.

Citation Format: Jonathan Nakashima, Jantzen Sperry, Bianca Carapia, Deborah Yan, Angelina Chin, Aliakbar Shahsafaei, Joan Chen, Yuan-Hung Chien, Christophe Pedros, Noah Federman, Arun Singh, Fritz C. Eilber, Brian Datnow. Orthotopic patient-derived xenografts (O-PDX) are effective precision oncology models that can predict therapeutic response, recurrence, and acquired drug resistance [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 3013.
Abstract 3066: DNA ligase IV inhibitor and X-ray exert a synthetic lethal in loss-of-function p53 cells
Authors: Lin Tingting , Zhou Zhilian , Zhu Lifeng , Fan Yandan , Ding Xiaofen , Sun Yingming
Published: July 2021

The majority of lung cancer patients receive radiotherapy during the treatment process. Dysfunction of DNA ligase IV impaired non-homologous end joining (NHEJ) and sensitized cells to X-ray. p53 regulated DNA damage repair and was mutated in various lung cancer cells. This study aimed to investigate the synergic effects of DNA ligase IV inhibitor SCR-7 and radiation on both wild-type and p53-deficient lung cancer cells. In the p53 wild-type cell, X-ray and SCR-7 triggered G2/M checkpoint, induced BRCA1, RAD18 activation, and promoted PCNA ubiquitination, facilitating homologous recombination (HR) and translesion synthesis (TLS) rather than NHEJ. In p53-deficient cells, SCR-7 and X-ray exerted a synthetic lethal via inducing more DNA damage, muting TLS, and impairing G2/M checkpoint as dysfunction of Cdc2 and Cyclin B1. Moreover, many cells were collapsed in mitosis catastrophe as a large number of disintegrating chromosomes, and apoptosis was significantly increased. Furthermore, the synergic effects of SCR-7 and X-ray were diminished by exogenous p53 overexpression. Therefore, we hypothesized p53 should be a major regulator of HR and TLS activation when HNEJ deficiency. Our studies indicated that patients with a loss function of p53 might benefit from SCR-7 and radiotherapy with fewer side effects.

Citation Format: Tingting Lin, Zhilian Zhou, Lifeng Zhu, Yandan Fan, Xiaofen Ding, Yingming Sun. DNA ligase IV inhibitor and X-ray exert a synthetic lethal in loss-of-function p53 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 3066.
Abstract 3106: Roles of extracellular ATP in inducing cancer stem cell (CSC)-like changes in non-small lung cancer cell line
Authors: Song Jingwen , Chen Xiaozhuo
Published: July 2021

Cancer is a major death-causing disease worldwide, and metastasis, a hallmark of cancer, is associated with up to 90% of all cancer-related deaths. Metastasis requires ATP, and the tumor microenvironment (TME) has much higher concentrations of intratumoral and extracellular ATP (eATP) than healthy tissue, implying that eATP may have potential roles in tumor development and progression. Our previous ATP studies, cited by a Nature Review Cancer paper in 20181 showed that eATP is internalized by cancer cell through macropinocytosis, and it promotes cancer cell growth, survival, and drug resistance. However, how intratumoral eATP plays roles in metastasis remains largely unclear. Our 2019 published results show that eATP promotes cancer migration and invasion, initiates epithelial to mesenchymal transition (EMT), alters expression level of EMT related protein markers such as ZEB1, SNAIL, SLUG in human non-small lung cancer cell (NSCLC) lines2. It has been reported that the EMT and cancer stem cells (CSCs) share some molecular links, but the detailed mechanisms involved are still unknown. Recently, we have found the eATP significantly induces the protein expression level of CSC related makers in A549 cells. We have also found that, after A549 cells were treated with 0.5mM and 0.75mM ATP for 6 and 24 hours, the ATP treated A549 cells were able to show significantly increased colony numbers by soft agar colony formation assay. Based on all these results, we hypothesize that extracellular ATP functions as a messenger, a signal facilitator, an energy molecule, and a transcription cofactor to induce CSC-like features to promote metastasis in NSCLC. RNAseq and metabolomics studies are being used to determine the transcriptional and metabolic changes associated with the ATP induced CSC process in NSCLC. The completion of the study will not only unravel eATP's roles in CSC induction and early steps of tumor metastasis, but also potentially provide novel promising therapeutic targets for inhibiting tumor metastasis.(1) Di Virgilio, F., Sarti, A. C., Falzoni, S., De Marchi, E., & Adinolfi, E. (2018). Extracellular ATP and P2 purinergic signaling in the tumor microenvironment. Nature Reviews Cancer, 18(10), 601-618. (2) Cao, Y., Wang, X., Li, Y., Evers, M., Zhang, H., & Chen, X. (2019). Extracellular and macropinocytosis internalized ATP work together to induce epithelial-mesenchymal transition and other early metastatic activities in lung cancer. Cancer Cell International, 19(1).

Citation Format: Jingwen Song, Xiaozhuo Chen. Roles of extracellular ATP in inducing cancer stem cell (CSC)-like changes in non-small lung cancer cell line [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 3106.
Abstract 3127: A transcriptional lineage tracing approach to unravel crucial gene expression patterns in breast cancer progression
Authors: Roda Niccolò , Hillje Roman , Cheloni Stefano , Gambino Valentina , Blandano Giada , Falvo Paolo , Bertolini Francesco , Pelicci Pier Giuseppe
Published: July 2021

Breast cancer represents a major clinical hurdle, with intra-tumor heterogeneity and metastatic outcome accounting for poor prognosis. Traditionally, its poly-clonal structure was investigated through the genetic barcoding of cells followed by the tracing of the offspring. However, this analysis does not allow a solid investigation of the transcriptional profile associated to clones throughout tumor progression. In this work, we exploited a recently published library of expressed barcodes to perform both clonal and transcriptional tracing in breast cancer by single-cell RNA sequencing. To this aim, human breast cancer cell line MDA-MB-231 was transduced with the above mentioned library and orthotopically transplanted in immune-deficient mice. To analyze our data we generated a pipeline aimed at identifying the barcodes at single-cell level and subsequently sequenced more than 20000 cells in six independent primary tumors. Our clonal distribution analysis strongly suggested that clones within the same tumor possess different growth potential. Furthermore, we found that breast tumors show a transcriptional heterogeneity characterized by two major transcriptional patterns: highly proliferating cells on one side, and stressed and dormant cells on the other. Notably, breast cancer clones were shown to belong to one of these two patterns, therefore suggesting that primary tumors are composed of both proliferative and non-proliferative clones. Interestingly, although the non-proliferative clones outnumbered the proliferative ones, the two different transcriptional patterns do not differ in terms of absolute number of cells. Analyses of breast cancer metastases to lungs and liver revealed that the clones that spread metastases belong to both the transcriptional patterns identified in the primary tumor. Interestingly, the metastatic clones were found to be rare in the primary tumors and shared between the two colonized organs. In addition, metastases recapitulated the same transcriptional heterogeneity of primary tumors, despite being composed of a much lower number of clones. Altogether, these findings represent an intriguing launching pad for the identification of the transcriptional markers whose inhibition may counter the metastatic outcome.

Citation Format: Niccolò Roda, Roman Hillje, Stefano Cheloni, Valentina Gambino, Giada Blandano, Paolo Falvo, Francesco Bertolini, Pier Giuseppe Pelicci. A transcriptional lineage tracing approach to unravel crucial gene expression patterns in breast cancer progression [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 3127.
Abstract 3154: Host and neoplastic cell Axl inhibition impair prostate and breast cancer bone metastasis
Authors: Tanaka Mai , Siemann Dietmar W.
Published: July 2021

Prostate and breast cancers are the most prevalent and the second leading causes of cancer-deaths for men and women in the United States. Cancer survival rates generally worsen significantly with advanced and disseminated disease with nearly 90% of all cancer deaths resulting from metastasis. For breast and prostate cancers, bone is the most common site of metastasis. A key signaling pathway involved in metastatic dissemination of tumor cells is the receptor tyrosine kinase Axl. Axl belongs to the Tyro3, Axl, and MerTK (TAM) subfamily, is expressed in a variety of tumor types, including breast and prostate, and is associated with poor prognosis, metastasis, and outcome. The goal of the present study was to characterize the role of Axl signaling in prostate and breast cancer cell dissemination to bone. This was accomplished using Axl knockdown neoplastic cells, a selective small molecule Axl inhibitor (BGB324), and osteoclast progenitor cells in vitro, as well as intracardiac injection of Axl knockdown tumor cells in vivo. The results showed that Axl inhibition significantly decreases tumor cell migration and invasion in vitro, and suppression of Axl signaling in osteoclast precursor cells reduces the formation of mature osteoclasts. In vivo, Axl knockdown in prostate and breast cancer cells significantly suppressed the formation of neoplastic bone lesions. Taken together our findings indicate that therapeutic targeting of Axl may impair tumor metastasis to the bones through neoplastic and host cell signaling axes.

Citation Format: Mai Tanaka, Dietmar W. Siemann. Host and neoplastic cell Axl inhibition impair prostate and breast cancer bone metastasis [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 3154.
Abstract 3195: Hijacked senescence secretomes as 'immune primers' of antiangiogenic TKI efficacy
Authors: Dolan Melissa , Shi Yuhao , Hill James W. , Mastri Michalis , Vaghi Cristina , Barbi Joseph , Benzekry Sebastien , Ebos John M.
Published: July 2021

VEGF receptor tyrosine kinase inhibitors (VEGFR TKIs) and immune checkpoint inhibitors (ICIs) are approved together as a treatment regimen for multiple metastatic cancers, yet the mechanistic basis for this combinatory benefit remains unclear. Previously we have shown that resistance to VEGFR TKI treatment can transiently hijack the secretory machinery typically associated with senescence - the process of cellular aging. Here we report that these senescence-associated secretory programs can also drive immune cell activation, potentially ‘priming' the tumor for PD-1 pathway inhibition. Using a novel live-cell sorting method based on C12FDG - a substrate for senescence-associated beta-galactosidase activity - we isolated senescence-marker (SM) expressing VEGFR TKI-treated cells for transcriptomic analysis. SM+ cell populations were enriched for senescence, immune, and interferon secretory processes, with a unique gene signature validated using published preclinical and clinical datasets. Notably, SM+ cells were found to be more sensitive to CD8 T-cell mediated tumor inhibition in vivo and ex vivo and be sensitive to PD-L1 blockade and inhibitors of mTOR, a key secretory regulator. Together, these results suggest VEGFR TKI controlled secretory programs contributing to resistance can simultaneously prime the tumor microenvironment for immune cell activation, providing an explanation for improved effects of antiangiogenic and immunotherapy combinations in patients.

Citation Format: Melissa Dolan, Yuhao Shi, James W. Hill, Michalis Mastri, Cristina Vaghi, Joseph Barbi, Sebastien Benzekry, John M. Ebos. Hijacked senescence secretomes as 'immune primers' of antiangiogenic TKI efficacy [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 3195.
Abstract 326: Structural dynamics-based hit generation to disrupt YAP/TAZ-TEAD protein-protein interaction
Authors: Du Lin , Liu Jing , Zeng Qinglong , Xu Ming , Lu Jiting , Zheng Qiangang , Zhu Jidong
Published: July 2021

The Hippo pathway is an evolutionarily conserved pathway involved in developmental biology. The biological functions of Hippo pathway are executed by the downstream transcriptional coactivator YAP/TAZ, which shuttle between the cytoplasm and the nucleus and have to interact with TEADs in nucleus for transcription activation. YAP/TAZ are master transcriptional factors widely activated in human cancers to promote cancer initiation, progression, metastasis and therapy resistance. It has been shown that aberrant YAP/TAZ activation is also associated with the adapted tumor microenvironment (TME) for tumor growth. Dysregulation in Hippo pathway and YAP/TAZ-TEADs transcriptional activity is pervasively associated with various types of cancers, including mesothelioma, squamous cell cancers, liver cancer and lung cancer, making it an attractive target for cancer therapy. Therefore, inhibition of YAP/TAZ oncogenic activity by blocking YAP/TAZ-TEADs interaction is an effective approach for cancer treatment. In this study, we aim to discover small molecule inhibitors that bind to TEADs and disrupt YAP/TAZ-TEADs interaction for cancer therapy. With superposition of all the available crystal structures of four TEAD subtypes in the public database, we found the YAP Ω loop binding site of TEADs is relatively rigid (of backbone atoms), but the side chain flexibility of K289, K265 and V406 in TEAD1 affects the shape of the binding site significantly. Notably, in two TEAD2 structures, e.g. PDB ID: 5dqe and 5dq8, K301 (K274 of TEAD1) adopts an open conformation and accommodates a flufenamic acid to bind in an induced pocket. Using 5dq8 as the protein model, we virtually screened a fragment library, and identified a hit compound that is suitable to combine with flufenamic acid. Interaction between the hit compound and TEAD1 was confirmed by 1D-NMR (STD). Based on the docking poses, we combined the hit and flufenamic acid, designed and synthesized several compounds. Interaction with TEAD1 of the compounds were confirmed by 1D-NMR, SPR and HTRF. Crystal structures of representative compounds confirmed the predicted binding mode in TEAD1. With further medicinal chemistry efforts, we have discovered a series of novel YAP/TAZ-TEAD PPI inhibitors bound at the Ω loop site of TEAD1.

Citation Format: Lin Du, Jing Liu, Qinglong Zeng, Ming Xu, Jiting Lu, Qiangang Zheng, Jidong Zhu. Structural dynamics-based hit generation to disrupt YAP/TAZ-TEAD protein-protein interaction [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 326.
Abstract 329: Targeting an emerging oncogenic biomarker, heparanase
Authors: Cui Lina
Published: July 2021

Heparan sulfate proteoglycans (HSPGs), major components in the extracellular matrix (ECM) of all tissue types, maintain ECM structural integrity and regulate cellular signaling via binding with ECM components and protein ligands such as growth factors and chemokines. Heparanase, the only known enzyme that can cleave the heparan sulfate (HS) side chains of HSPGs, regulates many cellular processes including ECM remodeling and homeostasis of cell-associated HS, and controls the bioavailability and activity of molecules attached to HS. The expression of heparanase is significantly elevated in almost all cancer types, and increased heparanase activity is mostly linked with increased angiogenesis, metastasis, and shortened post-surgery survival. Our research focuses on the development of molecular tools that can target and visualize the spatiotemporal activities of heparanase in both cells and living organisms. We have applied our molecular probes of heparanase towards cancer diagnostics and drug discovery.

Citation Format: Lina Cui. Targeting an emerging oncogenic biomarker, heparanase [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 329.
Abstract 331: Characterization of neoepitope (neoE)-specific T cells from peripheral blood for adoptive neoTCR-T cell therapy for patients with breast cancer (bc) or ovarian cancer (oc)
Authors: Cristea Mihaela , Chmielowski Bartosz , Oh David Y. , Funke Roel P. , Bota Daniela A. , Abedi Mehrdad
Published: July 2021

Introduction: Broad application of neoTCR-T cell therapy involves isolation of mutation-targeted CD8 T cells from the blood of patients with different tumor types. An ultra-sensitive process streamlined for high-throughput capture of neoE-specific T cells from blood is leveraged for producing a fully personalized adoptive T cell therapy for trial participants with BC or OC (NCT03970382).

Methods: Expressed mutations were identified by comparative sequencing of blood cells and tumor tissue. HLA typing was performed with OpiType. Proprietary algorithms were used to predict and prioritize tumor-exclusive neoE-HLA candidates. A library of barcoded HLA-mutational neoantigen complexes was used to interrogate PBMCs from each patient using imPACT Isolation Technology® (Dalmas et al., 2020). NeoTCRs cloned from captured antigen-experienced CD8 T cells were precision genome engineered into healthy donor T cells for functional characterization, including secretion of cytokines and effector molecules (Jacoby et al., 2019; Sennino et al., 2019). Based on pre-specified prioritization criteria, up to 3 actionable neoTCRs were selected for manufacturing the products for each individual.

Results: Six patients (2 BC/4 OC) successfully underwent neoTCR product selection. The median age was 59.5 years (range 38-69). Patients received a median of 5.5 prior regimens for metastatic disease (range 4-9). Median tumor mutational burden (TMB) was 2.7 (range 0.9-13.4). HLA-neoantigen libraries contained a median of 91 snares (range 29-262) and represented 6/6 HLA alleles in 4 patients and 5/6 in the remaining 2. A median of 8.5 distinct neoE-specific T cells (range 5-15) were isolated per patient. Following functional characterization 13 neoTCRs met selection criteria: three patients with 3 TCRs, one with 2 TCRs, and two had a single TCR. The median predicted neoE:HLA affinity of the selected TCRs was 77 nM (range 6.3 - 5866) and the median IFN-g EC50 was 4 ng/mL (range 1-431).

Conclusion: Relevant antigen-experienced, tumor mutation-targeted CD8 T cells were isolated from the blood of heavily pre-treated BC and OC patients with low TMB (<10 mutations/Mb). Correlations between TCR characteristics and clinical and biomarker data are planned. This approach holds potential for broad use in women with BC or OC.

Citation Format: Mihaela Cristea, Bartosz Chmielowski, David Y. Oh, Roel P. Funke, Daniela A. Bota, Mehrdad Abedi. Characterization of neoepitope (neoE)-specific T cells from peripheral blood for adoptive neoTCR-T cell therapy for patients with breast cancer (bc) or ovarian cancer (oc) [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 331.
Abstract 344: Correlative biomarker analyses: Toripalimab plus paclitaxel and carboplatin as neoadjuvant therapy in an open-label, single arm phase 2 trial in locally advanced esophageal squamous carcinoma
Authors: He Wenwu , Peng Lin , Bao Yu , Xiao Wenguang , Fang Qiang , Leng Xuefeng , Yan Jiaxin , Mao Tianqin , Shen Xudong , Huang Depei , Zhang Hushan , She Xueke , Han Yongtao
Published: July 2021

Background: NCT04177797 was an open-label, single arm phase 2 trial in locally advanced esophageal squamous carcinoma (ESCC), which adopted toripalimab, plus paclitaxel and carboplatin as neoadjuvant immunotherapy regimen. Here we report correlative biomarker analyses for all 18 included patients.

Methods: After two cycles of neoadjuvant immunotherapy, sixteen patients underwent surgery and seven of them achieved major pathological response (MPR). Two patients did not receive surgery but their imaging evaluation were both clinical complete response (cCR). We defined MPR or cCR as responders, and others as non-responders.  Peripheral blood, gastroscopic tumor and adjacent normal tissues were collected before the first dose of drug and so did surgery samples. Whole exome sequencing (WES) and RNA-seq were conducted for the pretreatment tissues, and surgery samples were performed for multiplex immunohistochemistry (mIHC) with 5 markers.

Results: In pretreatment tumor tissues, there was no significant difference either in the CD8+ (p=0.19) or CD68+HLA-DR- (p=0.57) density between responders and non-responders. However, CD8+ density increased (p=0.0078) and CD68+HLA-DR- density decreased (p=0.039) significantly in responders after neoadjuvant combined immunotherapy, whereas these two markers did not in non-responders (p=0.13 and p=0.36, respectively). Meanwhile, responders were associated with higher baseline gene expression levels of CXCL 5 (p=0.03) and lower baseline CCL 19 (p=0.017) and UMODL1 (p=0.03).

Conclusions: The mechanism of tumor response may be associated reduction of M2 macrophages and CD8 cells recruitment after combined immunotherapy in locally advanced resectable ESCC.

Citation Format: Wenwu He, Lin Peng, Yu Bao, Wenguang Xiao, Qiang Fang, Xuefeng Leng, Jiaxin Yan, Tianqin Mao, Xudong Shen, Depei Huang, Hushan Zhang, Xueke She, Yongtao Han. Correlative biomarker analyses: Toripalimab plus paclitaxel and carboplatin as neoadjuvant therapy in an open-label, single arm phase 2 trial in locally advanced esophageal squamous carcinoma [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 344.
Abstract 355: Tumor mutational burden, microsatellite instability (MSI) status and mutational frequency of 30 DDR genes in Chinese patients with gastric or gastroesophageal junction (GEJ) cancers with different levels of PD-L1 expression
Authors: Zeng Xiancheng , Liu Xinyi , Huang Mengli
Published: July 2021

Background: Gastric or GEJ cancer with positive PD-L1 expression have been proved a subgroup who can benefit from first-line and second-line therapy of PD-1 inhibitors. Positive PD-L1 expression promises to be the most effective biomarker in gastric/GEJ cancer patients. The results of CheckMate-649 further revealed that patients with PD-L1 CPS≥5 were more favorable to PD-1 inhibitors. On the other hand, high level of tumor mutational burden, MSI-H and mutations in DDR genes had also been identified as biomarkers in setting of immune checkpoint inhibitors in cancers. The difference of genomic features in subgroups with PD-L1 expression level in gastric/GEJ cancers is a question of interest.

Method: 613 cases of Chinese gastric/GEJ cancer patients were included in our analysis. Immunohistochemistry and 381-gene panel next-generation sequencing (NGS) testing had been performed in their tumor tissue specimen. PD-L1 expression level was evaluated by the combined positive score (CPS). Tumor mutational burden and MSI status were evaluated via NGS testing. Somatic and germline mutations in 30 DDR genes had also been analyzed.

Result: 493 out of 613 patients were CPS<1, 54 cases were CPS<5, 64 cases were CPS <49, 16 cases were CPS≥50. The median TMB score of four subgroups were 5.59, 7.26, 7.26 and 8.06 respectively. The proportion of MSI-H patients in four subgroups were 3.25%, 9.26%, 12.5%, and 12.5% respectively. ARID1A and ARTX genes only were detected somatic mutated. There was a negative correlation trend in germline mutational proportion and PD-L1 expression level in some genes, such as MSH2, POLE, POLD1, PALB2 and PTEN. However, the somatic mutational proportion of MSH6, PMS2, POLE genes had a positive correlation trend with PD-L1 expression level.

Conclusion: In Chinese gastric/GEJ cancer population, the TMB level of CPS≥1 subgroup was significantly higher than CPS<1 subgroup. MSI-H patients were enriched in CPS>5 subgroup. In addition, DDR genes had distinct mutational frequency in subgroups with different levels of PD-L1 expression, indicating they impact the immunogenicity of gastric/GEJ cancer through different mechanisms.

Citation Format: Xiancheng Zeng, Xinyi Liu, Mengli Huang. Tumor mutational burden, microsatellite instability (MSI) status and mutational frequency of 30 DDR genes in Chinese patients with gastric or gastroesophageal junction (GEJ) cancers with different levels of PD-L1 expression [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 355.
Abstract 356: Association of LRP1B mutation with tumor mutation burden and survival in bladder cancer patients treated with immune checkpoint inhibitors
Authors: Yang Mengmei , Xie Wenzhuan , Huang Mengli , Wu Peng
Published: July 2021

Background: Bladder cancer is a common genitourinary malignancy worldwide. Immune checkpoint inhibitors(ICIs) including atezolizumab, pembrolizumab, nivolumab have shown durable responses and have been approved by FDA. However ICIs demonstrate antitumor effects only in a fraction of patients, and research exploring the association between gene mutation and clinical benefit is limited. Mutations of LRP1B(The low-density lipoprotein receptor-related protein 1B) are frequently seen in solid tumors and have been reported to be associated with higher tumor mutation burden(TMB) and prolonged survival in NSCLC, melanoma and liver cancer. The association between LRP1B mutation and survival in bladder cancer is unknown.

Methods: The association between LRP1B mutation with TMB was analyzed in bladder cancer patients from the public immunotherapy-treated cohort published by Miao et. al as well as a clinical cohort from 3D Medicines database involving 118 Chinese patients. Wilcoxon test was used for the comparison of TMB. Overall survival(OS) and progression-free survival (PFS) analyses were conducted in the public cohort using Kaplan-Meier curves and log-rank tests. Statistical significance was set at p = 0.05.

Results: 15%(5/33) bladder cancer patients in the public immunotherapy-treated cohort and 18.6% (22/118) patients in the clinical cohort harbored LRP1B mutation. LRP1B mutation is associated with higher TMB in both public cohort(p=0.028) and clinical cohort(p=0.003). Survival analysis in the public cohort demonstrated that LRP1B mutation resulted in significantly longer OS ( 16.8 vs 8.08 months; HR, 0.16; p=0.043) and a increasing trend on PFS without significant difference (15.9 vs 4.1 months; HR, 0.62; P = 0.39) in bladder cancer patients treated with ICIs.

Conclusions: This study shows that LRP1B mutation is relatively common and correlated with higher TMB in bladder cancer. LRP1B mutation may serve as a predictive biomarker of ICI benefit in bladder cancer.

Citation Format: Mengmei Yang, Wenzhuan Xie, Mengli Huang, Peng Wu. Association of LRP1B mutation with tumor mutation burden and survival in bladder cancer patients treated with immune checkpoint inhibitors [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 356.
Abstract 373: Advancing precision oncology by synergizing ddPCR with microdissection
Authors: Johann Donald J. , Shin Ikjae , Peterson Erich , Steliga Mathew , Muesse Jason , Marino Katy , Laun Sarah , Roberge Adam , Weigman Robert , Emmert-Buck Michael , Tangrea Michael
Published: July 2021

Background - The domain of precision oncology includes improving patient treatment outcomes based on the application of advanced molecular profiling methodologies to pathological specimens. To this end, optimal utilization of tumor tissue from diagnostic biopsies is an unmet medical need. This is especially relevant today since precision oncology is a rapidly evolving field where timely tumor genotyping is essential for the indication of many advanced and targeted therapies. National Comprehensive Cancer Network (NCCN) guidelines now mandate molecular testing for clinically actionable targets in certain malignancies. Patients diagnosed with advanced non-small cell lung cancer (NSCLC) are commonly of an older age and have significant co-morbidities. This frequently causes clinical dilemmas regarding the ability to obtain adequate amounts of tissue for tumor genotyping. In these cases, the tumor tissue may have been obtained by an image-guided biopsy, and the diagnosis of NSCLC proper determined via cytology. In certain instances, adequate tissue for tumor genotyping and/or a more advanced mutational analysis to identify oncogenic drivers may not be available.

Methods - Formalin fixed paraffin embedded (FFPE) specimens were examined using advanced immuno-based laser capture microdissection (LCM), following a formal pathology review. In preparation for droplet digital PCR (ddPCR), DNA was extracted from samples and run with a series of positive and negative controls.

Results - Utilizing lung cancer as an example, an improved genotyping approach for NSCLC solid tumors was developed and tested. The strategy involves optimization of the microdissection process and analysis of a large number of identical target cells from FFPE specimens sharing similar characteristics, in other words, single-cell subtype analysis. Immunostaining status, cell phenotype, and spatial location within a histological section are examples of shared characteristics that can guide cell procurement.

Conclusions - Synergy between microdissection and ddPCR enhances molecular analysis. Demonstrated is a methodology that illustrates genotyping of a solid tumor from a small tissue biopsy sample in a time and cost-efficient manner, using immunohistochemistry directed LCM and ddPCR detection.

Citation Format: Donald J. Johann, Ikjae Shin, Erich Peterson, Mathew Steliga, Jason Muesse, Katy Marino, Sarah Laun, Adam Roberge, Robert Weigman, Michael Emmert-Buck, Michael Tangrea. Advancing precision oncology by synergizing ddPCR with microdissection [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 373.
Abstract 374: NGS based profiling of homologous recombination genes to predict response to platinum-based chemotherapy in NSCLC
Authors: Zhang Linlin , Wang Xin , Song Hui , Meng Fanlu , Yu Guowei , Zhong Diansheng
Published: July 2021

Background: In the era of precision medicine, better response of anti-tumor therapies attribute to detection of specific molecular markers. However, up to the present no validated biomarker for platinum-based chemotherapy could be used in clinic. Next-generation sequencing (NGS) technology has been applied for non-small cell lung cancer (NSCLC) molecular typing for years. Whether analysis of homologous recombination (HR) gene mutations based on NGS results could predict the efficiency of platinum-based therapy in NSCLC is still obscure.

Methods: NGS has been performed for screening homologous recombination (HR) gene mutations, as well as common driver genes in NSCLC, with tumor samples. Advanced or metastatic NSCLC patients receiving platinum-based chemotherapy were included for efficacy analysis.

Results: 129 patients with HR genes information were included for analysis. Among the 129 patients, 55 patients were received platinum-based chemotherapy. The efficiency results showed the objective response rates (ORR) of patients with BRCA1/2 and without BRCA1/2 mutations were 71.4% and 31.3%; and the median progression free survival (PFS) were 7.5 and 5.6 months(p=0.161), respectively. The ORR of patients with and without HR genes mutations were 57.9% and 25.0%; and the median PFS were 8.0 and 5.3 months (p=0.039), respectively.

Conclusions: NGS based profiling of BRCA1/2 and other gene mutations in HR pathways have a promising predictive value for efficacy of platinum-based chemotherapy in advance and metastatic NSCLC.

Citation Format: Linlin Zhang, Xin Wang, Hui Song, Fanlu Meng, Guowei Yu, Diansheng Zhong. NGS based profiling of homologous recombination genes to predict response to platinum-based chemotherapy in NSCLC [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 374.
Abstract 380: WNT signal pathway activation correlates with innate resistant to immune checkpoint therapies in NSCLC
Authors: Ren Dian , Zhang Bo , Liu Renwang , Gong Fuyu , Bai Yuezong , Xie Wenzhuan , Huo Huandong , Zhang Hao , Song Zuoqing
Published: July 2021

Background: Immune checkpoint inhibitors targeting the programmed cell death-1 receptor (PD-1) improve survival in a subset of patients with NSCLC. There are still lots of patients could not reach the clinical benefit, even though with the positive expression of the programmed cell death 1 ligand 1 (PD-L1). Here, we aimed to research the immune resistance mechanism in NSCLC.

Methods: The genomic data and clinical data of the discovery cohort was obtained from The Cancer Genome Atlas (TCGA). The clinical data of validation cohort in NSCLC treated by immunotherapy was retrospective collected. And tissue from patients with NSCLC were performed to whole exome sequencing in a College of American Pathologists-certified and Clinical Laboratory Improvement Amendments-accredited lab.

Results: Activation of WNT signaling was inferred that somatic mutations or somatic copy number alterations in WNT signaling elements including APC, WNT16, AXIN2, WNT4, AXIN1, CTNNB1, BCL9L and SMAD4. Two cohort have been enrolled in this study, the discovery cohort from TCGA, and the validation cohort from the Chinese patients with NSCLC. The frequency of WNT pathway alterations from the TCGA cohort was 16%, and which was represented mutually exclusive molecular subsets. In TCGA cohort, activating alteration WNT signaling were associated with shorter median PFS (18.8 vs 3.9 months, p=0.036, HR=0.24 (0.09-0.68)).

Conclusions: Mutations predicted to activate the WNT pathway were associated with innate resistance to immune checkpoint blockade in NSCLC

Citation Format: Dian Ren, Bo Zhang, Renwang Liu, Fuyu Gong, Yuezong Bai, Wenzhuan Xie, Huandong Huo, Hao Zhang, Zuoqing Song. WNT signal pathway activation correlates with innate resistant to immune checkpoint therapies in NSCLC [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 380.