bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB018: Cloud-based biological domain knowledge derived gene expression classifier to predict the cancer clinical outcome
Authors: Papineni Rao V. , Gupta Seema , Natarajan Aravindan , Papineni Ram , Kasinathan Chandra
Published: July 2021

We report the advances of a cloud-based software utilizing advanced algorithms to identify the molecular cancer drivers and its signal transduction. To test, a classifier based on the NFκB signaling pathway gene expression profiles that predicts the clinical therapeutic response to chemo-radiation therapy of Squamous Cell Carcinomas of the Head and Neck (SCCHN) patients are described here. Expression of HPV16, p16 and 84 NFκB signaling pathway genes were determined using real time RT PCR in SCCHN patient samples and SCCHN cell lines. Gene expression was correlated to chemo-radiation response in cell lines and the model was blindly tested in SCCHN patients to predict their clinical outcome to chemo-radiation. This tool intends to fuse biological domain knowledge by way of integrating disease targets, cell line experiments towards creating a gene expression classifier for clinical outcome. The gene expression-based predicted clinical outcome compared with patients actual observed clinical outcome correctly identified the clinical response in 73% of the cases. Such work will allow design of tailored individualized clinical treatment strategies to target NFκB inhibition using biological modifying agents with or without chemo/radiation therapy. This will help to develop several targets to directly inhibit the NFκB activity or inhibit the downstream pivotal targets. The significance of the classifier would be the ability to use the biologic attributes of a tumor to tailor specific treatment protocols for each individual patient. This would not only spare the chemo-radiation resistant patients the ill effects of the therapy but will also decrease the delay in effective treatment among the resistant patients. The long-term objective is to use such pro-survival driver genes in other cancers; SMAD, TGFβ in pancreatic cancer, and AR in prostate cancer. This tool (MeghaOncomine) intends to fuse biological domain knowledge by way of integrating cancer targets, cell line experiments towards creating a gene expression classifier for clinical outcome.

Citation Format: Rao V. Papineni, Seema Gupta, Aravindan Natarajan, Ram Papineni, Chandra Kasinathan. Cloud-based biological domain knowledge derived gene expression classifier to predict the cancer clinical outcome [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 LB018.
Abstract LB057: Whole exome sequencing of tumor tissue and circulating tumor DNA ingastrointestinal stromal tumors (GIST)
Authors: Coleman Niamh , Abbot Charles , Somaiah Neeta , Piha-Paul Sarina , Pant Shubham , Rodon Jordi , Call S. Greg , Boyle Sean , Meric-Bernstam Funda , Janku Filip
Published: July 2021

Background: The discovery of oncogenic mutations as potential targets for cancer therapy has revolutionized the treatment of GIST and other cancers. However, adaptive resistance ultimately develops in nearly all patients, which emphasizes the need for a more detailed understanding of the underlying molecular profile. Methods: Using the Personalis ImmunoID NeXT Platform® (Personalis, Inc.; Menlo Park, CA), an augmented exome/transcriptome platform and analysis pipeline, we performed whole exome sequencing (WES) and whole transcriptome total RNA sequencing (RNA-Seq) of paired baseline tumor and normal tissue. NeXT Liquid Biopsy™ (Personalis, Inc.) was used for WES of plasma-derived ctDNA from serially collected samples collected at baseline, after 1 month and at progression to experimental systemic therapies in 15 patients with advanced/metastatic GIST. Results: WES of tumor tissue samples from all 15 patients confirmed underlying KIT mutation in all patients. There was large heterogeneity of other molecular alterations, which included therapeutically relevant molecular alterations, such as microsatellite instability-high (MSI-high) in 1 sample. RNA-Seq of tumor tissue revealed recurrent overexpression of GALR2, NY-ESO-1 and other genes involved in cancer progression, angiogenesis and anticancer immunity. Patients with response to systemic therapies demonstrated lower levels of cytolytic activity measured by CYT score in tumor tissue compared to patients without response (P=0.04). KIT mutations were detected in serially collected ctDNA samples from 12 (80%) of 15 patients. Quantity of KIT and other mutant ctDNA dynamically tracked the clonal evolution and clinical course during systemic therapy. Conclusions: Comprehensive genomic profiling (WES and RNA-Seq) of tumor tissue and WES of serially collected ctDNA is feasible and detects underlying druggable KIT mutations and other molecular alterations.

Citation Format: Niamh Coleman, Charles Abbot, Neeta Somaiah, Sarina Piha-Paul, Shubham Pant, Jordi Rodon, S. Greg Call, Sean Boyle, Funda Meric-Bernstam, Filip Janku. Whole exome sequencing of tumor tissue and circulating tumor DNA ingastrointestinal stromal tumors (GIST) [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 LB057.
Abstract LB066: Assessing the safety liability of t-cell bispecific (TCB) antibodies using Ogans-on-Chips technology
Authors: Kerns S. Jordan , Kujala Ville , Kanellias Marianne , Sauld John , Tien-Street William , Grant Heather S. , Karalis Katia A. , Hamilton Geraldine A. , Ewart Lorna , Roth Adrian B. , Moisan Annie , Gjorevski Nikolche
Published: July 2021

T-cell bispecific antibodies (TCBs) are a promising class of immunotherapeutic agents that promote tumor cell killing by physical crosslinking of effector T-cells to target expressing cells.

While TCBs are effective in targeting less-immunogenic tumors, they are subject to safety liabilities in normal tissues, which may express low levels of the target. Preclinical assessment of safety risks is crucial but species differences between human and rodent immune responses necessitate the development of advanced human cell-based models for TCB safety profiling. While conventional killing assays are experimentally tractable, they lack physiological organization and cytoarchitecture and often fail to accurately predict efficacy and off-tumor cytotoxicity. Here, we show the robustness of our Intestine-Chip to capture variability in immune cell activation at physiologically relevant TCB concentrations when immune cells are directly applied to the apical epithelium. With increased confidence in the predictive capabilities of the model, we then confirmed expected regional dependence to gastrointestinal (GI) toxicity of the TCB by showing elevated immune cell activation in the large- versus small-intestine. Further, we have demonstrated vascular recruitment and transmigration of circulating immune cells to the intestinal epithelium to more accurately capture the in vivo mechanisms of TCB-mediated toxicity. Together, these data show that our models are suitable for safety profiling of novel engineered immunotherapies and provide clinically relevant results.

Citation Format: S. Jordan Kerns, Ville Kujala, Marianne Kanellias, John Sauld, William Tien-Street, Heather S. Grant, Katia A. Karalis, Geraldine A. Hamilton, Lorna Ewart, Adrian B. Roth, Annie Moisan, Nikolche Gjorevski. Assessing the safety liability of t-cell bispecific (TCB) antibodies using Ogans-on-Chips technology [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 LB066.
Abstract LB071: Tuning the tumor myeloid microenvironment (TME) by targeting TREM2+ tumor-associated macrophages to overcome resistance to immune checkpoint inhibitors
Authors: Jahchan Nadine S. , Binnewies Mikhail , Pollack Joshua L. , Mehta Ranna , Dash Subhadra , Tun Christine , Lu Erick , Du Xiaoyan , Baker Kevin P. , Reyno Len , Sriram Venkataraman
Published: July 2021

The tumor microenvironment (TME) often contains high levels of suppressive myeloid cells that may contribute to innate checkpoint inhibitor (CPI) resistance. Pionyr's Myeloid Tuning approach involves altering the composition and/or the function of myeloid cells in the TME. To this end, therapeutic targeting of tumor-associated macrophages (TAMs) is a promising strategy to increase CPI response rates in solid tumor indications, as well as to overcome resistance to CPI therapies. Pionyr and others identified the transmembrane protein triggering receptor expressed on myeloid cells-2 (TREM2) as a highly enriched TAMs target. Furthermore, TREM2 mRNA expression negatively correlates with patient survival in a variety of tumor types, supporting the involvement of TAMs in tumor progression. Pionyr developed a lead anti-TREM2 monoclonal antibody (mAb), termed PY314, as well as a murinized version of PY314, termed PY314m. PY314m demonstrated significant anti-tumor activity either as single agent in CPI-sensitive syngeneic tumor models or in combination with anti-PD-1 in CPI-resistant syngeneic tumor models. Mechanistically, PY314m reduced the pro-tumorigenic MHC class II-low, M2-like TAMs, induced pro-inflammatory cytokine production, significant increased CD8+ T cell infiltration into the TME. These findings suggest that PY314 therapy could be used to overcome CPI resistance in humans. To select patients most likely to benefit from PY314 therapy, Pionyr developed a qualitative IHC assay that detects TREM2 expression levels in formalin-fixed, paraffin-embedded human tumor tissues. Screening for TREM2 expression in tumor tissues demonstrated that TREM2+ TAMs were present in multiple solid tumor indications and their number increased with disease grade in a selected set of indications. Ongoing efforts are aimed at better understanding localization of TREM2+ TAMs within the TME, and spatial relationship of the TREM2+ TAMs to other immune cells present in the TME. The TREM2 IHC assay will be used to test our hypothesis that patients with tumors with high level of TREM2+ TAMs are most likely to benefit from PY314 treatment.

Citation Format: Nadine S. Jahchan, Mikhail Binnewies, Joshua L. Pollack, Ranna Mehta, Subhadra Dash, Christine Tun, Erick Lu, Xiaoyan Du, Kevin P. Baker, Len Reyno, Venkataraman Sriram. Tuning the tumor myeloid microenvironment (TME) by targeting TREM2+ tumor-associated macrophages to overcome resistance to 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 LB071.
Abstract LB072: SARS-CoV-2 proteins and anti-COVID-19 drugs induce lytic reactivation of an oncogenic virus
Authors: Qin Zhiqiang , Chen Jungang , Dai Lu , Barrett Lindsey , Post Steven
Published: July 2021

An outbreak of the novel coronavirus SARS-CoV-2, the causative agent of Coronavirus Disease-2019 (COVID-19), a respiratory disease, has infected over 75,000,000 people since the end of 2019, killed over 1,600,000, and caused worldwide social and economic disruption. Because the mechanisms of SARS-CoV-2 infection of host cells and its pathogenesis remain largely unclear, there are currently no antiviral drugs with proven efficacy. Besides severe respiratory and systematic symptoms, several comorbidities increase risk of fatal disease outcome. Therefore, it is required to investigate the impacts of COVID-19 on pre-existing diseases of patients, such as cancer and other infectious diseases. Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of several human cancers, such as Kaposi's sarcoma (KS) and Primary effusion lymphoma (PEL), mostly seen in immunosuppressed patients especially people with HIV infection. In the current study, we for the first time report that SARS-CoV-2 encoded spike (S) and nucleocapsid (N) proteins and some currently used anti-COVID-19 drugs (especially Azithromycin and Nafamostat mesylate) are able to induce lytic reactivation of KSHV from virus infected normal and tumor cells, through manipulation of intracellular signaling pathways. In addition, we found the obvious upregulation of ACE2 expression, the major receptor of SARS-CoV-2, in AIDS-KS tissues, indicating that KSHV may potentially increase SARS-CoV-2 co-infection. Together, our data indicate that those KSHV+ patients especially in endemic areas exposure to COVID-19 or undergoing the treatment may have increased risks to develop these virus-associated cancers, even after they have fully recovered from COVID-19.

Citation Format: Zhiqiang Qin, Jungang Chen, Lu Dai, Lindsey Barrett, Steven Post. SARS-CoV-2 proteins and anti-COVID-19 drugs induce lytic reactivation of an oncogenic virus [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 LB072.
Abstract LB077: Adrenergic signaling induces neuroendocrine differentiation of prostate adenocarcinoma cells
Authors: Krishnan Anand , Dwivedi Shubham , Bautista Maricris , Iftikhar Tauqeer
Published: July 2021

Prostate cancer is the leading cancer diagnosed among men worldwide. The prostate cancer-associated mortality is due to the development of aggressive neuroendocrine prostate cancer (NEPC). Unfortunately, there is no effective treatment available for NEPC at present. This is due to the lack of proper understanding of the molecular switch that triggers neuroendocrine changes in prostate adenocarcinoma cells. Recent research demonstrated that peripheral nerves promote prostate cancer progression and metastasis. However, there is no clear understanding of the involvement of sympathetic nerves or their signaling in facilitating NEPC. In this work, we examined the effect of the sympathetic neurotransmitter norepinephrine (NE) in inducing neuroendocrine differentiation (NED) of prostate cancer cells in vitro. We used androgen-sensitive LNCaP and androgen-insensitive DU145 cells for the study. We examined the dose and time-dependent effect of NE in inducing NED-related phenotypic alterations in these cells using bright field and fluorescence imaging. NED-related molecular alterations were assessed using real-time PCR, western bot and immunocytochemistry. We found that NE induces characteristic NEPC morphological changes, such as compact cell bodies and neurite-like extensions, in both DU145 and LNCaP cells. At the mRNA level, NE induced the expression of the NED markers chromogranin B, synaptophysin and βIII tubulin in both cell types. Further immunoblot and immunostaining showed the upregulation of chromogranin B in these cells. We repeated the experiments in growth factor deprived conditions by avoiding fetal bovine serum in the cultures to mimic growth deprivation to prostate cancer cells, which they experience during androgen deprivation therapy. Surprisingly, the NE induced NED changes were more pronounced in the growth factor deprived conditions. Overall, our result indicates the potential of NE in inducing NED in prostate cancer cells and point towards a critical role for this sympathetic neurotransmitter in facilitating the development of NEPC.

Citation Format: Anand Krishnan, Shubham Dwivedi, Maricris Bautista, Tauqeer Iftikhar. Adrenergic signaling induces neuroendocrine differentiation of prostate adenocarcinoma 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 LB077.
Abstract LB093: Incident heart failure among young adult cancer survivors
Authors: Tanaka Yoshihiro , Greenland Phlip , Khan Sadiya , Hibler Elizabeth A.
Published: July 2021

Background: Risk of heart failure (HF) is known to be higher among childhood cancer survivors as well as older adult cancer survivors who may already have cardiovascular disease risk factors. However, the risk of HF among young adult cancer survivors is not known. Aim: To examine incident HF in adult cancer survivors between 18-39 years of age. Methods: We identified patients who were aged 18-39 years when diagnosed with cancer based on the International Classification of Diseases (ICD) 9 and 10 at an integrated multisite single health system (Northwestern Medicine) between January 2000 and January 2019. We stratified by cancer types predominantly linked with anthracycline exposure (leukemia, lymphoma, sarcoma, breast, kidney, and bone cancers) compared with those less likely to have anthracycline exposure. We estimated the cumulative incidence of HF using the Kaplan-Meier method then calculated unadjusted and adjusted hazard ratios (HRs) for incident HF using Cox proportional hazard models. HRs were adjusted for demographic factors and cardiovascular risk factors. Results: Of 12,879 eligible patients, 35% were men and 68% White. The mean age was 31.5±5.7 years. Cardiovascular comorbidities were present in <5% of cancer survivors. During a median follow-up period of 3.4 (IQR, 1.3-7.1) years, 180 incident HF events were observed. Five-year cumulative incidence of HF was significantly higher in those cancer types more likely to have anthracycline exposure compared without (2.5% vs 0.6%, Log-rank p-value <0.01) with an adjusted HR for incident HF of 3.31 (95% confidence of interval 2.36-4.64, p<0.01). Conclusion: While cardiovascular comorbidities and HF are rare in the young adult population, undergoing cancer treatment with anthracycline exposure is associated with significantly higher risk for HF in young adult cancer survivors.

Citation Format: Yoshihiro Tanaka, Phlip Greenland, Sadiya Khan, Elizabeth A. Hibler. Incident heart failure among young adult cancer survivors [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 LB093.
Abstract LB101: Mechanism of the growth inhibitory effect of pemetrexed disodium heptahydrate in human PC9 cells (EGFR exon 19 deletion)
Authors: Mohiuddin Md , Kimura Hideharu , Sone Takashi , Watanabe Satoshi , Matsuoka Hiroki , Saeki Keigo , Terada Nanao , Abo Miki , Kasahara Kazuo
Published: July 2021

Background: Pemetrexed disodium heptahydrate (pemetrexed) in combination with another drug, is recommended for the treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC). However, the mechanisms of its anticancer activities have not yet been analyzed. We examined the in vitro effects of pemetrexed and further elucidated a potential underlying molecular mechanism.Methods: PC9 cells were treated with pemetrexed and then evaluated with a cell viability assay, Giemsa staining, DAPI staining, flow cytometry (FCM), SA-β-Gal staining, and Western blotting.Results: We found that pemetrexed reduced the proliferation of PC9 cells. The cells treated with pemetrexed showed morphological signs of apoptosis. The apoptotic effect of pemetrexed was related to the generation of ROS and the loss of mitochondrial membrane potential. A cell cycle analysis showed that pemetrexed arrested PC9 cells in the G1 phase. Cellular senescence was associated with pRb hyperphosphorylation and the overexpression of CDK. Regarding the molecular mechanism of this apoptosis, pemetrexed can induce the phosphorylation of p53 at ser 15 and ser 46. Moreover, the expression of extrinsic apoptotic pathway proteins, such as Fas/FasL, DR4/TRAIL, and FADD, was elevated after pemetrexed treatment. Conclusion: In addition to apoptosis, pemetrexed can also cause specific adverse reactions, thus providing a new target for reducing lung toxicity.

Citation Format: Md Mohiuddin, Hideharu Kimura, Takashi Sone, Satoshi Watanabe, Hiroki Matsuoka, Keigo Saeki, Nanao Terada, Miki Abo, Kazuo Kasahara. Mechanism of the growth inhibitory effect of pemetrexed disodium heptahydrate in human PC9 cells (EGFR exon 19 deletion) [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 LB101.
Abstract LB115: Blocking p27Kip1phosphorylation with a liposomal:peptide drug induces Reactive Oxygen Species,necroptosis and tumor regression in breast cancer cells
Authors: Blain Stacy Wister , Jilishitz Irina , Quinones Jason L. , Patel Priyank , Chen Grace , Pavetsky Jared , VanInwegen Allison VanInwegen , Schoninger Scott , Jogalekar Manasi P. , Tsiperson Vladislav , Yan Lingyue , Wu Yun , Gottesman Susan R. , Somma Jonathan
Published: July 2021

Resistance to cyclin D-cdk4/6 inhibitors (CDK4/6i) represents an unmet clinical need and is frequently caused by compensatory CDK2 activity. Here we describe a novel strategy to prevent CDK4i resistance by using a therapeutic liposomal:peptide formulation, NP-ALT, to inhibit the tyrosine phosphorylation of p27Kip1(CDKN1B), which in turn inhibits both CDK4/6 and CDK2. We find that NP-ALT blocks proliferation in HR+ breast cancer (BC) cells, as well as CDK4i-resistant cell types, including Triple Negative (TN) BC. The peptide ALT is not as stable in primary mammary epithelium, suggesting that NP-ALT has little effect in non-tumor tissues. In HR+ BC cells specifically, NP-ALT treatment induces ROS and RIPK1-dependent necroptosis. Estrogen signaling and ERα appear required. Significantly, NP-ALT induces necroptosis in MCR7 ESRY537S cells, which contain an ER gain of function mutation frequently detected in metastatic patients, which renders them resistant to endocrine therapy. Here we show that NP-ALT causes necroptosis and tumor regression in treatment naïve, palbociclib-resistant and endocrine-resistant BC cells and xenograft models, demonstrating that p27 is a viable therapeutic target to combat drug resistance. Because the RAS/MAPK axis is the target of many therapies, NP-ALT, with its ability to target p27, can deal with the backend drug resistance seen in the presence of other inhibitors, extending the addressable market of this line of therapy.

Citation Format: Stacy Wister Blain, Irina Jilishitz, Jason L. Quinones, Priyank Patel, Grace Chen, Jared Pavetsky, Allison VanInwegen VanInwegen, Scott Schoninger, Manasi P. Jogalekar, Vladislav Tsiperson, Lingyue Yan, Yun Wu, Susan R. Gottesman, Jonathan Somma. Blocking p27Kip1phosphorylation with a liposomal:peptide drug induces Reactive Oxygen Species,necroptosis and tumor regression in breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB115.
Abstract LB119: VRN08, a Selective Mps1 Kinase Inhibitor Induces Mitotic Catastrophe and Apoptosis Efficiently in Advanced Cancers Including Rb1-Deficient
Authors: Jung Hong Ryul , Kim Yeonsil , Kim Haelee , Kwon Ji-Hye , Seo Dong-hyuk , Son Jung Beom , Kim Nam Doo , Kim Daekwon , Kim Sunghwan
Published: July 2021

Spindle assembly checkpoint (SAC) prevents mis-segregation of chromosome and allows accurate division in mitosis. Mps1 (also known as TTK) is one of the essential kinases for recruitment of SAC proteins after chromosome segregation. Failure of SAC induces chromosome instability, mitotic catastrophe, and ultimately apoptotic cell death and Mps1 is induced or activated in rapidly dividing tumor cells. Therefore, Mps1 has been considered an attractive anti-cancer drug target. VRN081569 is a potent type I kinase inhibitor of Mps1, which stabilizes Mps1 kinase domain in a closed conformation by forming a tight interface with its kinase domain. This structural stabilization appears to increase cellular potency for the induction of aneuploidy and apoptosis (~ 10 nM or less GI50 value). The loss of retinoblastoma tumor suppressor gene (Rb1), which is prevalent in advanced cancers, dysregulates cell cycle and promotes cell division. In particular, the resistance to CDK4/6 inhibitors has been reportedly mediated by loss of the Rb1 gene. We found that Rb1-negative cells express higher level of Mps1 than Rb1-positive cells and VRN081569 efficiently induce apoptosis of Rb1-negative Triple Negative Breast Cancer (TNBC) cell line MDA-MB-468 than Rb1-positive TNBC MDA-MB-231. Especially we confirmed that VRN081569 induces caspase 3/7 activity faster in Rb1-negative cells (~50-fold EC50 of caspase 3/7 activity compared to Rb1-positive cells), and cell cycle analysis has shown that our compound induces a dose-dependent dysregulation of mitosis, resulting in a decrease in the frequency of the G0/G1 phase, and also induces aneuploidy and apoptosis. Finally, we confirmed a combination effects with anti-microtubule agents BCL-2 inhibitor and PARP-1 inhibitor, suggesting that modulation of two different cellular processes may overcome the lack of single agent activity for TNBC.

Citation Format: Hong Ryul Jung, Yeonsil Kim, Haelee Kim, Ji-Hye Kwon, Dong-hyuk Seo, Jung Beom Son, Nam Doo Kim, Daekwon Kim, Sunghwan Kim. VRN08, a Selective Mps1 Kinase Inhibitor Induces Mitotic Catastrophe and Apoptosis Efficiently in Advanced Cancers Including Rb1-Deficient [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 LB119.
Abstract LB134: The rexinoid MSU-42011 enhances dendritic-T cell cross talk in a HER2 positive model of breast cancer
Authors: Leal Ana Sofia , Carapellucci Sarah , Liby Karen T.
Published: July 2021

Breast cancer (BC) was considered an immunologically silent tumor, however recent findings suggest that immune cells present in the tumor microenvironment play important roles in tumor growth. Retinoid X receptors (RXRs) are a subclass of nuclear receptors that act as ligand-dependent transcription factors that regulate a variety of cellular processes including proliferation and differentiation. Rexinoids are synthetic molecules that bind and activate RXRs. Bexarotene (Targretin®) is the only rexinoid approved by the FDA and is used for the treatment of refractory cutaneous T-cell lymphoma. Other more potent rexinoids have been synthesized, such as LG100268 and LG101506, which will not be tested in clinical trials because of intellectual property issues. Because recent studies have suggested that RXRs are involved in immune regulation, we synthesized novel rexinoids and selected MSU-42011 as a lead compound. MMTV-neu mice with tumors approximately 32 mm3 in volume were treated with control diet or MSU-42011 (100 mg/kg diet) for 10 days. Rexinoid treatment significantly (p=0.0069) reduced tumor fold change normalized to initial volume from 8.33 in controls to 4.80 on treatment. Analysis of the tumor by flow cytometry showed no significant differences in the major immune populations, such as T cells, macrophages and dendritic cells. However, expression of PDL1 was increased in CD11c+, MHC-II+ dendritic cells (5484 vs 7140 MFI, p=0.0456), suggesting engaged dendritic cells in activating cytotoxic T cells. To further elucidate the cross talk between dendritic and T cells, cytokines associated with T cell recruitment and activation were analyzed by RT-PCR. Tumor treated with MSU42011 had a 38.5 fold increase in IL12a expression (p=0.011, n=4), and a 20.8 fold increase in CCL9 (p=ns, n=4), suggesting that dendritic cells are actively recruiting and activating T cells. The activation of cytotoxic T cells was confirmed by a 75.5 fold increase in interferon gamma (p=0.0026, n=4) and a decrease of FOXP3 expression (p=ns, n=4). To test if the effects seen in tumor reduction were dependent on the presence of T cells, CD4 and CD8 were depleted. Depletion of CD4 alone, but not CD8, reversed the tumor reduction induced by MSU-42011. These results show that RXR agonists can be used to modulate immune cell populations in the tumor microenvironment, specifically by recruiting and activating dendritic cells that then activate cytotoxic T cells. We thank the Breast Cancer Research Foundation for support of these studies.

Citation Format: Ana Sofia Leal, Sarah Carapellucci, Karen T. Liby. The rexinoid MSU-42011 enhances dendritic-T cell cross talk in a HER2 positive model of breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB134.
Abstract LB139: VRN10, Discovery of Potent Irreversible HER2 Kinase Inhibitors with Intracranial Activity
Authors: Kim Hwan , Lee Younho , Park Jinhee , Lee Youngyi , Choi Jieun , Yoo Jihye , Park Chanmi , Lee Somi , Ko Eunhwa , Son Jung Beom , Choi Hwan Geun , Kim Nam Doo , Kim Daekwon , Kim Sunghwan
Published: July 2021

Human epidermal growth factor receptor 2 (HER2) amplification is one of oncogenic drivers most found in breast cancer but also occurs in multiple other tumor types. Approximately 10-30% of patients with breast cancer develop brain metastases (BCBM), a devastating cause of morbidity and mortality. To address this unmet medical need, VRN10s, brain penetrant, orally bioavailable, and irreversible small molecule inhibitors were designed to target HER2 while sparing EGFR wild type. In biochemical assays VRN10s had low nanomolar potency to inhibit catalytic activity of HER2. In cell viability assays using HER2+ breast and gastric cancer cell lines, VRN10s inhibited proliferation with single-digit nanomolar potency and exhibited an exceptional selectivity for HER2 over EGFR, with an enhancement of > 30-fold. Neuregulin-1 (NRG-1) has been suggested to decrease the anti-tumor activity of HER2 kinase inhibitors by induction of HER3 in brain microenvironment. Two FDA-approved HER2 kinase inhibitors tucatinib and lapatinib are not only less brain permeable, but they also show significantly decreased activity in the presence of NRG-1. However, the addition of NRG-1 did not rescue the proliferation of HER2+ breast cancer cell lines treated with VRN10s. Western blot confirmed that VRN10s inhibit signal transduction downstream of HER2 and HER3 through the AKT and ERK pathways. Inhibition of HER2 is reported to cause cytotoxicity on cardiomyocytes. In spite of potent inhibition of HER2 catalytic inhibition, VRN10s did not show cardiomyocyte cytotoxicity more than other HER2 kinase inhibitors, including tucatinib and neratinib. We confirm VRN10s to have high brain exposure in several preclinical models. Consistent with our in vitro results, potent activity was observed in the xenograft and intracranial models using once daily oral administration with strong tumor growth inhibition. Based on in vitro assay, brain permeability and in vivo efficacy, VRN10s may be promising therapeutic candidates for patients with HER2+ tumors including BCBM.

Citation Format: Hwan Kim, Younho Lee, Jinhee Park, Youngyi Lee, Jieun Choi, Jihye Yoo, Chanmi Park, Somi Lee, Eunhwa Ko, Jung Beom Son, Hwan Geun Choi, Nam Doo Kim, Daekwon Kim, Sunghwan Kim. VRN10, Discovery of Potent Irreversible HER2 Kinase Inhibitors with Intracranial Activity [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 LB139.
Abstract LB140: CNS penetrant, irreversible inhibitors potently inhibit the family of allosteric oncogenic EGFR mutants expressed in GBM and demonstrate efficacy in patient-derived xenograft models
Authors: O'Connor Matthew , Lucas Matt , Romashko Darlene , Rasmussen Sara , Lin Tai-An , Waters Nigel , Fiorenza Raffaele , Wrona Iwona , Chen Deborah , Nicolaides Theodore , Raleigh David R. , Ozawa Tomoko , Trainor George , Arista Luca , Flohr Alexander , Ottaviani Giorgio , Roberts Chris , Buck Elizabeth
Published: July 2021

Oncogenic EGFR mutations occur in approximately 50% of glioblastomas (GBM) and largely reside in the extracellular domain. Prior attempts to reposition current generation EGFR inhibitors to treat GBM likely failed due to poor brain penetration and an inability to potently target the full spectrum of oncogenic mutations. As EGFR oncogenic mutations are found to be co-expressed in many GBMs, it is important that an inhibitor be broadly active against the entire family of relevant EGFR mutants. Additionally, a successful inhibitor would require a pharmacokinetic (PK) profile that allows for sufficient penetration of the blood brain barrier to elicit robust target engagement of the brain tumor. Using these design principles, we designed a series of highly potent molecules exemplified by BDTX-507. This molecule is an irreversible inhibitor of EGFR with antiproliferative IC50's less than 10 nM against the spectrum of GBM-relevant EGFR mutations. PK/PD studies demonstrated sustained pERK suppression exceeding 24 hours following a single QD dose. Furthermore, when dosed in GBM xenografts, including an intracranial Viii PDX (GBM6), robust tumor regressions and improved survival were observed. Emerging from this series were two advanced compounds, BDTX-700 and BDTX-1535, which also demonstrated potent inhibition of the GBM EGFR spectrum, selectivity v. wild-type EGFR, and an excellent CNS PK profile. BDTX-1535 is currently being evaluated in IND-enabling studies for future clinical evaluation in GBM patients.

Citation Format: Matthew O'Connor, Matt Lucas, Darlene Romashko, Sara Rasmussen, Tai-An Lin, Nigel Waters, Raffaele Fiorenza, Iwona Wrona, Deborah Chen, Theodore Nicolaides, David R. Raleigh, Tomoko Ozawa, George Trainor, Luca Arista, Alexander Flohr, Giorgio Ottaviani, Chris Roberts, Elizabeth Buck. CNS penetrant, irreversible inhibitors potently inhibit the family of allosteric oncogenic EGFR mutants expressed in GBM and demonstrate efficacy in patient-derived xenograft models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB140.
Abstract LB166: Evaluation of CAR-T anti-tumor response in a novel immunocompromised NOD-Prkdcem26Cd52Il2rgem26Cd22/NjuCrl mouse model
Authors: Bankoti Rashmi , Joshi Amit , Jorgensen Lasse , Kongsgaard Andreas , Adorno Maddalena , Nicolis di Robilant Benedetta
Published: July 2021

Background: The development of immunocompromised mice revolutionized the field of cancer and stem cell research. Due to the lack of mature B and T lymphocytes, SCID (severe combined immunodeficiency disease) mice are ideal for xenoengraftment of human cells and tissue, including patient-derived tumor cells, hematopoietic stem cells and T cells. Over the years, the SCID models have been implemented to increase the efficiency of engraftment and NSG (NOD-SCID;IL2Rgammanull) has become the most reliable in vivo human cancer model. Here we compared NSG with the novel mouse strain NCG for immune-oncology applications, in particular for CAR-T therapy. NCG (NOD-Prkdcem26Cd52Il2rgem26Cd22/NjuCrl) is a recently developed triple immunodeficient mouse strain, created by sequential CRISPR/Cas9 editing of the PRKDC and IL2rg loci in the NOD/Nju strain. For this purpose, we engrafted NALM-6 and CHLA-55 tumor cell lines and treated them with CD19 and GD2.CAR T cells, respectively. Results: Four different operators generally considered NCG mice to be easier to handle. NCG mice were a bit smaller and have a much smaller spleen compared to age-matched NSG mice. Tumor engraftment was particularly rapid in NCG while the dissemination to organs was comparable. Generally, NCG showed signs of sickness earlier and upon lower tumor burden. When treated with CAR-T cells, in vivo anti-tumor response was comparable, both in a leukemia mouse model (96.6% NSG vs 97.7% NCG) and in a disseminated neuroblastoma model (67.3% NSG vs 57.8% NCG).Conclusion: Our preliminary data show that NCG mice are a suitable immunocompromised host for CAR-T pre-clinical studies.

Citation Format: Rashmi Bankoti, Amit Joshi, Lasse Jorgensen, Andreas Kongsgaard, Maddalena Adorno, Benedetta Nicolis di Robilant. Evaluation of CAR-T anti-tumor response in a novel immunocompromised NOD-Prkdcem26Cd52Il2rgem26Cd22/NjuCrl mouse 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 LB166.
Abstract LB199: Trafficking of Semaphorin4D is regulated by endoplasmic reticulum chaperone GRP78
Authors: Carlos Anthony , Tsai Yuan-Li , Ma Yan , Lee Amy
Published: July 2021

Localization of endoplasmic reticulum (ER) chaperones to the cell surface is an adaptive mechanism for cells to expand the functionality of these proteins in response to stress by activating signaling pathways distinct from their ER functions, thereby impacting cell survival and signaling. In cancer, cell-surface ER chaperones have been reported to regulate oncogenic signaling pathways, proliferation and cell adhesion through interactions with other cell surface proteins. The emerging role of peripheral cell surface GRP78 (csGRP78), traditionally regarded as an ER luminal chaperone, as a multifunctional co-receptor for many different types of cell surface proteins presents novel opportunities for therapeutic interventions. One such cell surface protein is Semaphorin4D (Sema4D). Sema4D was originally discovered as a cell surface cleavable ligand and neuronal axon guidance cue that mobilizes the actin cytoskeleton to facilitate neuronal growth cone homing during development. In cancer, cell surface Sema4D expression is pro-metastatic and pro-angiogenic. Sema4D has been shown to be highly expressed in the breast cancer and epidemiological studies have demonstrated that Sema4D expression in breast cancer patients confers a poor prognosis and high probability of metastatic organotropism. Our recent advances have preliminarily identified a critical role for GRP78 in facilitating Semaphorin4D (Sema4D) trafficking. We show that Sema4D forms a direct protein-protein interaction with GRP78 and that GRP78 may facilitate membrane trafficking of Sema4D to the cell surface, where it exerts pro-angiogenic and metastatic effects. Furthermore, csGRP78 may interact with and facilitate many of the functions of Sema4D. Understanding the conditions by which GRP78 contributes to surface expression of Sema4D and the downstream effects may lead to novel therapeutics that abrogate the effects of Sema4D in cancer and to the elucidation of novel mechanisms by which Sema4D trafficking in cancer is regulated by GRP78.

Citation Format: Anthony Carlos, Yuan-Li Tsai, Yan Ma, Amy Lee. Trafficking of Semaphorin4D is regulated by endoplasmic reticulum chaperone GRP78 [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 LB199.
Abstract LB202: Biphosphorylated Src at Y416/527 is active in triple-negative breast cancer cell lines and a subset of patient samples
Authors: Razorenova Olga V. , Nelson Luke , Wright Heather , Dinh Nguyen , Nguyen Kevin , Heinemann Scott
Published: July 2021

Targeted therapeutics are needed for triple-negative breast cancer (TNBC). In this study, we investigated the activation of Src family of cytoplasmic tyrosine kinases (SFKs) and two SFK substrates: CUB-domain containing protein 1 (CDCP1) and protein kinase C delta (PKCd) in 56 formalin-fixed, paraffin-embedded (FFPE) TNBCs. Expression of SFK phosphorylated at Y416 (SFK_pY416+) in tumor cells was strongly associated with phosphorylation of CDCP1 and PKCd (CDCP1_ pY743+ and PKCd_pY311+), as assessed by immunohistochemistry, indicating increased SFK activity in situ. To enable biochemical analysis, protein extraction from FFPE tissue was optimized. Cleaved CDCP1 isoform (70 kDa) was expressed to a varying degree in all samples but only phosphorylated in TNBC tumor cells that expressed SFK_pY416. Interestingly, active SFK was found to be biphosphorylated (SFK_pY416+/pY527+). Biphosphorylated active SFK was observed more frequently in forkhead box protein A1 (FOXA1)-TNBCs. In addition, in SFK_pY416-samples, FOXA1+ TNBC tended to be SFK_pY527+ (classic inactive SFK), and FOXA1- TNBC tended to be SFK_pY527-(SFK poised for activation). Strong SFK_pY416 staining was also observed in tumor-infiltrating lymphocytes in a subset of TNBCs with high tumor-infiltrating lymphocyte content. This report will facilitate protein biochemical analysis of FFPE tumor samples and justifies the development of therapies targeting the SFK/CDCP1/PKCd pathway for TNBC treatment.

Citation Format: Olga V. Razorenova, Luke Nelson, Heather Wright, Nguyen Dinh, Kevin Nguyen, Scott Heinemann. Biphosphorylated Src at Y416/527 is active in triple-negative breast cancer cell lines and a subset of patient samples [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 LB202.
Abstract LB203: FER regulates endosomal recycling and is a candidate predictor for taxane benefit in breast cancer
Authors: Tavares Sandra , Liv Nalan , Pasolli Milena , Opdam Mark , Ratze Max , Saornil Manuel , Sluimer Lilian , Hengeveld Rutger , van Es Robert , van Werkhoven Erik , Vos Harmjan , Rehmann Holger , Burgering Boudewijn , Oosterkamp Hendrika , Lens Susanne , Klumperman Judith , Linn Sabine , Derksen Patrick
Published: July 2021

To this day, targeted treatment options for patients with triple negative metastatic breast cancer (TNBC) are still virtually absent. Previously, we showed that elevated expression of the tyrosine kinase FER is an independent prognosticator that correlates with poor survival of high-grade and basal/TNBC patients. Here, we show that high FER levels are also associated with improved outcome after adjuvant taxane-based combination chemotherapy, in high-risk, HER2-negative patients. In TNBC cells, we observed a causal relation between high FER levels and sensitivity to taxanes. Our proteomics and mechanistic studies demonstrated that FER regulates endosomal recycling, a microtubule-dependent process that underpins breast cancer cell invasion. Using chemical genetics, we identified DCTN2 as a novel FER substrate. Our work indicates that the DCTN2 tyrosine 6 is essential for tubular recycling domains development in early endosomes and subsequent propagation of TNBC cell invasion in 3D. In conclusion, we show that high FER expression promotes endosomal recycling and represents a candidate predictive marker for benefit of adjuvant taxane-containing chemotherapy in high-risk patients, including TNBC patients.

Citation Format: Sandra Tavares, Nalan Liv, Milena Pasolli, Mark Opdam, Max Ratze, Manuel Saornil, Lilian Sluimer, Rutger Hengeveld, Robert van Es, Erik van Werkhoven, Harmjan Vos, Holger Rehmann, Boudewijn Burgering, Hendrika Oosterkamp, Susanne Lens, Judith Klumperman, Sabine Linn, Patrick Derksen. FER regulates endosomal recycling and is a candidate predictor for taxane benefit in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB203.
Abstract LB210: MicroRNA function is malleable and can be governed by target gene expression levels
Authors: Svoronos Alexander A. , Campbell Stuart G. , Engelman Donald M.
Published: July 2021

MicroRNAs are short, noncoding RNA molecules that reduce the expression of target genes by inhibiting messenger RNA translation and promoting messenger RNA degradation. They are highly dysregulated in cancer, with many microRNAs appearing to have potent oncogenic or tumor suppressive effects. As a result, there exists substantial interest in targeting microRNAs for cancer therapy. However, the literature is filled with conflicting accounts as to whether specific microRNAs are oncogenic or tumor suppressive, with many microRNAs appearing to exhibit entirely opposite functions when placed in different contexts. One explanation for this duality is that individual microRNAs can target tens to hundreds of different genes, many of which may possess opposing functions. Hence, it is likely that the expression levels of the target genes influence whether an individual microRNA will have a net oncogenic or net tumor suppressive effect. To examine this hypothesis, we developed a computational model of miR-125b's effect on the apoptosis pathway. This is an ideal system for examining the expression level hypothesis, as miR-125b is a microRNA that targets several closely interacting pro- and anti-apoptotic members of the pathway, which can be easily modeled as a system of differential equations. From the model, we elucidate a general trend that miR-125b is more pro-apoptotic when its anti-apoptotic targets are overexpressed and/or its pro-apoptotic targets are underexpressed, while it is more anti-apoptotic when its pro-apoptotic targets are overexpressed and/or its anti-apoptotic targets are underexpressed. To examine this experimentally, we switched miR-125b from being tumor suppressive to being oncogenic in cells by modifying the expression levels of one of miR-125b's anti-apoptotic targets. In addition, we observed that treating cells with anticancer drugs can also reverse miR-125b's status as a tumor suppressor. These results have important implications for the use of microRNAs as therapeutic targets in cancer.

Citation Format: Alexander A. Svoronos, Stuart G. Campbell, Donald M. Engelman. MicroRNA function is malleable and can be governed by target gene expression levels [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 LB210.
Abstract LB214: Actin-Like Protein 6A (ACTL6A) Suppresses p21Cip1 Expression to Maintain an Aggressive Mesothelioma Phenotype
Authors: Shrestha Suruchi , Adhikary Gautam , Xu Wen , Friedburg Joseph , Eckert Richard L.
Published: July 2021

Mesothelioma is a fatal asbestos-caused cancer of the mesothelial cells that arises in the pleural and peritoneal cavities in response to asbestos exposure. ACTL6A is an important protein subunit of the SWI/SNF epigenetic regulatory complex but also has independent pro-cancer actions. It is frequently overexpressed in cancer and drives the malignant phenotype; however, it has not been studied in mesothelioma. In the present report, we show that ACTL6A drives mesothelioma cell proliferation, invasion and migration, and that these activities are markedly reduced in ACTL6A knockdown/knockout cells. Moreover, ACTL6A loss is associated with a significant increase in level of the p21Cip1 cyclin-dependent kinase inhibitor. ACTL6A binding to the proximal Sp1 and distal p53 sites on the p21Cip1 gene promoter is associated with reduced p21Cip1 promoter activity, and mRNA and protein level. Similar regulation was observed in cells derived from plural and peritoneal mesothelioma. Moreover, inhibiting the p21Cip1 increase in ACTL6A knockout cells reverses the reduction in cancer phenotype, suggesting the p21Cip1 is an authentic downstream mediator of ACTL6A action. These studies suggest that ACTL6A suppression of p21Cip1 expression contributes to the mesothelioma cell aggressive cancer phenotype and that inhibition of ACTL6A function may be a suitable mesothelioma cancer treatment strategy.

Citation Format: Suruchi Shrestha, Gautam Adhikary, Wen Xu, Joseph Friedburg, Richard L. Eckert. Actin-Like Protein 6A (ACTL6A) Suppresses p21Cip1 Expression to Maintain an Aggressive Mesothelioma Phenotype [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 LB214.