bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 5245: Anti-CSPG4 CAR-Macrophages synergize with anti-CD47 in melanoma cytotoxicity
Authors: Greiner Daniel , Xue Qian , Waddell Trinity , Roh-Johnson Minna 
Published: March 2024

Abstract
While CAR T-cells have been a success in treating liquid tumors, these successes have not been replicated in solid tumors. There are several reasons for these challenges, including physical matrix barriers and increased tumor antigen heterogeneity in solid tumors. Macrophages are frequently found in melanoma tumors, even in those that have low T-cell infiltrate, suggesting macrophages are well equipped to penetrate the physical barriers surrounding solid tumors. Macrophages are also antigen-presenting cells, thus, if macrophages phagocytose the tumor, they will likely present additional antigens to T-cells, potentially enhancing the adaptive immune response in cancer treatment. Thus, we hypothesized that macrophages expressing chimeric antigen receptors (CAR-Macrophages or CAR-Ms) are able to access solid tumors, phagocytose cancer cells, and subsequently re-educate the tumor immune environment by directly polarizing tumor-associated macrophages and by presenting novel antigens to recruit and educate adaptive immune cells. To test these hypotheses, we generated CAR-Ms with primary human macrophages using an scFV specific to chondroitin sulfate proteoglycan 4 (CSPG4), a highly expressed antigen enriched and specific to melanoma tumors, and an intracellular activation domain to promote phagocytosis. We found that anti-CSPG4 CAR-Ms phagocytosed human melanoma cells at high efficiency, however, this phagocytosis did not result in high levels of melanoma cell cytotoxicity. To improve CAR-M-mediated melanoma cell death engulfment, we blocked the anti-CD47/SIRPα (“don’t eat me”) signaling axis with an anti-CD47 blocking antibody, which resulted in additive effects for phagocytosis, and a robust effect on the melanoma cell killing. Preliminary in vivo xenograft experiments suggest that anti-CSPG4 CAR-Ms alone delay melanoma growth. We are now testing whether combining anti-CD47 and CSPG4 CAR-Ms therapies in vivo can 1) further reduce primary tumor growth and 2) prevent recurrence following surgical resection by treating remnants of the tumor. Our work shows that CSPG4 CAR-M-mediated killing of CSPG4-positive cancer cells is significantly enhanced when in combination with anti-CD47 antibody treatment.
Citation Format: Daniel Greiner, Qian Xue, Trinity Waddell, Minna Roh-Johnson. Anti-CSPG4 CAR-Macrophages synergize with anti-CD47 in melanoma cytotoxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5245.
Abstract 526: Identification of CDK6 binding proteins by proximity labeling reveals novel mechanisms for CDK4/6 inhibitor resistance in breast cancer
Authors: Ting Chung Wei , Zhuang Yong-Ji , Lin Chih-Yi , Yu Chung-Jen , Chao Ta-Chung , Tseng Ling-Ming , Liu Chun-Yu , Tsai Yi-Fang , Huang Chi-Cheng , Lai Jiun-I 
Published: March 2024

Abstract
Breast cancer is one of the most prevalent cancer type in human, and the majority (~70%) is the hormone positive (HR+) subtype. The current frontline treatment of choice in metastatic HR(+) breast cancer is CDK4/6 inhibitors (CDK4/6i) combined with endocrine therapy. Current guidelines recommend CDK4/6i treatment as 1st or 2nd line, as CDK4/6i provides survival benefit and good quality of life. However, resistance eventually emerges, leading to discontinuation of CDK4/6i and switching to subsequent treatment. Investigation of mechanisms to CDK4/6i resistance is an active area of intense research. CDK6 overexpression has been reported as an important mechanism for CDK4/6i resistance by several independent groups. We incidentally discovered a point mutation in the CDK6 protein that abolishes the CDK4/6i resistance conferred by CDK6 overexpression. When treated with CDK4/6i, overexpression of wild type CDK6 did not suppress G1/S, while both non-transfected and overexpression of mutant CDK6 both had similar suppression of G1/S. We hypothesized that a binding partner to CDK6 demonstrated differential binding activity to the mutant which abolished the resistance by CDK6 overexpression. To assess this hypothesis, we performed proximity labeling (PL) by APEX2. Both wild type and mutant CDK6 were cloned into APEX-Flag/V5 vectors with either cytoplasm (NES) or nuclear (NLS) signals. Mass spectrometry following treatment by H2O2 induced biotinylation produced candidate peptides that bound with overexpressed CDK6. We identified leading candidates of differentially binding partners that bound to mutant CDK6. Further experimental validation was performed to confirm physical proximity between CDK6 and the candidate protein. Our research uncovered novel insights to how CDK6 conferred resistance towards CDK4/6i and expands knowledge into further therapeutic development.
Citation Format: Chung Wei Ting, Yong-Ji Zhuang, Chih-Yi Lin, Chung-Jen Yu, Ta-Chung Chao, Ling-Ming Tseng, Chun-Yu Liu, Yi-Fang Tsai, Chi-Cheng Huang, Jiun-I Lai. Identification of CDK6 binding proteins by proximity labeling reveals novel mechanisms for CDK4/6 inhibitor resistance in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 526.
Abstract 5275: Celecoxib and chloroquine enhance the antitumor effect of immune checkpoint blockade therapy, in a syngeneic mouse model for pancreatic cancer
Authors: Moore Jaeger , Chand Dhan , Levey Daniel , Von Hoff Daniel , Han Haiyong 
Published: March 2024

Abstract
Immune checkpoint inhibitors (ICIs) have shown impressive clinical activities in some cancer types, but they have yet to demonstrate any meaningful clinical benefit in patients with pancreatic ductal adenocarcinoma (PDAC) except those with microsatellite instability high (MSI-H) tumors. Several recent studies showed that concomitant use of NSAIDs such as celecoxib by patients with certain cancers could improve the survival benefit of ICI treatment (e.g., Sebastian et al, Clin Lung Cancer, 2023;). Furthermore, autophagy inhibitors such as chloroquine were also reported to sensitize pancreatic tumors to the treatment of ICIs in mouse models for PDAC (Yamamoto, et al, Nature, 2020). We recently reported that the combination of chemotherapy (triple combination of nab-paclitaxel + gemcitabine + cisplatin) and a mouse surrogate of the IFc-enhanced anti-CTLA-4 antibody botensilimab, showed significantly improved antitumor activity in immune competent KPC syngeneic mouse model for PDAC [Tanne, et al, Cancer Res (13_Supplement), 2020]. In this study, we sought to determine whether or not the addition of celecoxib and/or chloroquine further improve the antitumor activity of triple chemotherapy and ICI in the syngeneic KPC model. We first found that celecoxib (30mg/kg P.O. QDx21) significantly enhanced the tumor growth inhibition when added to triple chemotherapy (Gemcitabine 70mg/kg I.P., Cisplatin 4mg/kg I.P., Nab-paclitaxel 25mg/kg I.V. days 1,4 and 7) plus the murine equivalents of botensilimab (100ug I.P. BIW for three weeks) and balstilimab (200ug I.P. BIW for three weeks) (p=0.004, N=10). We then performed a pilot study to assess if adding chloroquine could further improve the activity. While adding chloroquine (60mg/kg I.P. QDx21) alone did not significantly affect tumor growth the addition of both chloroquine and celecoxib greatly improve the tumor growth inhibition compared to just the triple chemotherapy and ICIs (p=0.009, N=5). Overall, our data showed that celecoxib or the combination of celecoxib and chloroquine could substantially sensitize the mouse pancreatic tumors to the treatment of chemotherapy and ICIs. (This work was supported in part by the Seena Magowitz Foundation and the Purple Pansies)
Citation Format: Jaeger Moore, Dhan Chand, Daniel Levey, Daniel Von Hoff, Haiyong Han. Celecoxib and chloroquine enhance the antitumor effect of immune checkpoint blockade therapy, in a syngeneic mouse model for pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5275.
Abstract 528: CDK9 inhibition activates innate immune response in prostate cancer cells
Authors: Yalala Shivani , Gondane Aishwarya , Poulose Ninu , Liang Jing , Mills Ian G. , Itkonen Harri M. 
Published: March 2024

Abstract
Hyper-activation of transcription is frequent in cancer, which often leads to increased sensitivity to compounds targeting the transcriptional kinases, in particular cyclin-dependent kinase 9 (CDK9). However, mechanistic details as to why CDK9 inhibition selectively kills cancer cells remain largely unknown. Here, we report that CDK9 inhibition activates innate immune response through viral mimicry. In MYC over-expressing prostate cancer cells, CDK9 inhibition leads to excessive accumulation of mis-spliced RNA. Double-stranded RNA (dsRNA)-activated kinase can recognize these mis-spliced RNAs, and we show that this kinase is required for the CDK9 inhibitor-induced anti-proliferative effects. Using time-resolved transcriptional profiling (SLAM-seq), targeted proteomics and ChIP-seq, we show that, similar to viral infection, CDK9 inhibition significantly suppresses transcription of most genes but allows selective transcription and translation of certain genes. In particular, CDK9 inhibition activates NFκB-driven cytokine-signaling at the transcriptional- and secretome-levels. Transcriptional signature induced by CDK9 inhibition identifies prostate cancers with high level of genome instability, and we propose that it is possible to induce similar effects using CDK9 inhibitors. In summary, here we show that inhibition of CDK9 activates innate immune response through viral mimicry. In the future, it is important to establish if CDK9 inhibitors can potentiate the effects of immunotherapy against the late-stage prostate cancer, a currently lethal disease.
Citation Format: Shivani Yalala, Aishwarya Gondane, Ninu Poulose, Jing Liang, Ian G. Mills, Harri M. Itkonen. CDK9 inhibition activates innate immune response in prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 528.
Abstract 5297: CLN-619, a clinical stage MICA/B-specific hIgG1 monoclonal antibody, engages multiple immune effector cells to promote anti-tumor activity
Authors: Whalen Kerry A. , Henry Catherine C. , Rakhra Kavya , Meetze Kristan , Michaelson Jennifer S. , Baeuerle Patrick A. 
Published: March 2024

Abstract
CLN-619 is a humanized IgG1 monoclonal antibody that targets MICA and MICB (MICA/B) and is currently in phase 1 clinical development in cancer patients (NCT05117476). MICA/B serve as activating signals on target cells for recognition by the NKG2D receptor, which is expressed on NK cells and a subset of T cell populations. MICA/B expression is induced in response to stressed conditions, thereby enabling NKG2D-mediated elimination of target cells. On NK cells, NKG2D is one of many receptors in the complex network of activating and inhibitory receptors, whereby NKG2D pathway activation results in cytokine production, enhancement of ADCC and target cell death. On CD8 T cells, the NKG2D axis plays a costimulatory role in lowering the threshold for lysis upon TCR engagement, and may also drive direct CD8-mediated killing following prior TCR activation. MICA/B is expressed broadly on a range of solid and hematological malignancies. However, tumor cells evade NKG2D-mediated elimination by shedding MICA/B ligand from the cell surface via proteases present in the tumor microenvironment (TME). CLN-619 functions by binding to MICA/B and preventing shedding, thereby increasing MICA/B cell surface expression to restore the NKG2D-MICA/B axis to promote tumor cell killing by NK cells and T cells. Additionally, CLN-619 can mediate ADCC and ADCP by NK cells and macrophages. In preclinical xenograft models, doses as low as 0.03 mg/kg inhibited tumor outgrowth. We investigated the effects of CLN-619 on a variety of primary immune cells including NK cells, T cells and macrophages. In the evaluation of NK cells, we measured CLN-619 modulation of cytokine production and cytotoxicity in the presence of MICA/B expressing target cells. In addition, we demonstrated the contribution of Fc-mediated functions of CLN-619. In the context of T cells, we explored the requirement of TCR co-stimulation or prior antigen exposure in the activation of the NKG2D pathway by CLN-619. In the context of macrophages, we measured the ability of CLN-619 to mediate ADCP against MICA/B-expressing target cells. These data highlight the potential of CLN-619 to engage multiple immune cell types within the TME, which may lead to greater and broader efficacy compared to IO therapies targeting a single immune cell type.
Citation Format: Kerry A. Whalen, Catherine C. Henry, Kavya Rakhra, Kristan Meetze, Jennifer S. Michaelson, Patrick A. Baeuerle. CLN-619, a clinical stage MICA/B-specific hIgG1 monoclonal antibody, engages multiple immune effector cells to promote anti-tumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5297.
Abstract 530: The effect of cardamonin on PD-L1 expression in triple-negative breast cancer cells
Authors: Mendonca Patricia , Kirpal Bhonessa , Kaur Sukhmandeep , Soliman Karam F. A. 
Published: March 2024

Abstract
Triple-negative breast cancer (TNBC) accounts for about 10% of all breast cancers and does not express estrogen, progesterone, or HER2 receptors. It has an aggressive nature, it is highly metastatic, and because of the lack of therapies, it continues to be a challenge. These cancer cells employ mechanisms to escape the immune system that induce the upregulation of PD-L1 expression, a ligand encoded by the CD274 gene. Because cancer cells tend to produce higher levels of PD-L1 compared to normal cells, therapies that inhibit PD-L1 may be helpful. Evidence also shows that high levels of oxidative stress and inflammation may participate in both the initiation and progression of cancer. Cardamonin, an aromatic enone flavonoid, has displayed an array of pharmacological activities, including modulation of different signaling molecules involved in the development and progression of cancer. This work investigated the cardamonin’s ability to modulate PD-L1 expression and NF-KB in genetically distinct MDA-MB-231 (Caucasian) and MDA-MB-468 (African American) TNBC cell lines. The methodology included cytotoxic assays, ELISA, Real Time-Polymerase Chain Reaction (RT-PCR) assays, and Wes analysis. The results showed that cardamonin treatment caused a dose-dependent decrease in cell viability in both cell lines, ranging from 3.12 µM to 200 µM. The RT-PCR and ELISA data showed that even though IFN-γ stimulated MDA-MB-231 cells showed a higher expression of PD-L1, cardamonin reduced mRNA and protein expression of PD-L1 in both cell lines. As a possible molecular mechanism for PD-L1 inhibition, cardamonin modulated MUC-1, STAT3, and JAK, which are genes that activate the PD1/PD-L1 mechanism. Moreover, data also show that cardamonin modulated NF-KB1 and NF-KB2 genes involved in activating NF-KB signaling. NF-KB is a transcription factor of inflammation and immunity, emerging as a key positive regulator of PD-L1 expression in cancer. Therefore, cardamonin may have the potential utilization as a checkpoint inhibitor that acts by blocking PD-L1 protein, allowing the immune system to recognize and attack the TNBC cancer cells, providing a novel cancer therapy. (Supported by a grant from NIH-NIMHD U54 MD 007582)
Citation Format: Patricia Mendonca, Bhonessa Kirpal, Sukhmandeep Kaur, Karam F. A. Soliman. The effect of cardamonin on PD-L1 expression in triple-negative breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 530.
Abstract 5313: CB307: A dual targeting costimulatory Humabody® VH therapeutic for treating PSMA-positive tumors
Authors: Archer Sophie , Brailey Phillip M. , Song Minjung , Bartlett Phillip D. , Figueiredo Ines , Gurel Bora , Guo Christina , Brucklacher-Waldert Verena , Thompson H. Lorraine , Akinwale Jude , Boyle Samantha E. , Rossant Christine , Birkett Neil R. , Pizzey Julia , Maginn Mark , Legg James , Williams Richard , Johnston Colette M. , Bland-Ward Philip , de Bono Johann S. , Pierce Andrew J. 
Published: March 2024

Abstract
INTRODUCTION: CD137 is a T and NK cell costimulatory receptor involved in consolidating immunological responses. The potent CD137 agonist urelumab has shown clinical promise as a cancer immunotherapeutic but development has been hampered by on-target off-tumour toxicities. A CD137 agonist targeted to the prostate-specific membrane antigen (PSMA), frequently and highly expressed on castration-resistant metastatic prostate cancer (mCRPC) tumour cells, could bring effective immunotherapy to this immunologically challenging to address disease.
EXPERIMENTAL PROCEDURES: We designed and manufactured CB307, a novel half-life extended bispecific costimulatory Humabody® VH therapeutic to elicit CD137 agonism exclusively in a PSMA-high tumour microenvironment (TME). The functional activity of CB307 was assessed in cell-based assays and in syngeneic mouse anti-tumour pharmacology studies. Non-clinical toxicology and toxicokinetic properties of CB307 were assessed in a good laboratory practice (GLP) compliant study in cynomolgus macaques.
RESULTS: CB307 provides effective CD137 agonism in a PSMA-dependent manner, with anti-tumour activity both in vitro and in vivo, and additional activity when combined with checkpoint inhibitors. A validated novel PSMA/CD137 immunohistochemistry (IHC) assay demonstrated a higher prevalence of CD137-postive cells in the PSMA-expressing human mCRPC TME with respect to primary lesions. CB307 did not show substantial toxicity in non-human primates and exhibited a plasma half-life supporting weekly clinical administration.
CONCLUSIONS: CB307 is a first-in-class immunotherapeutic that triggers potent PSMA-dependent T cell activation thereby alleviating toxicological concerns against unrestricted CD137 agonism.
Citation Format: Sophie Archer, Phillip M. Brailey, Minjung Song, Phillip D. Bartlett, Ines Figueiredo, Bora Gurel, Christina Guo, Verena Brucklacher-Waldert, H. Lorraine Thompson, Jude Akinwale, Samantha E. Boyle, Christine Rossant, Neil R. Birkett, Julia Pizzey, Mark Maginn, James Legg, Richard Williams, Colette M. Johnston, Philip Bland-Ward, Johann S. de Bono, Andrew J. Pierce. CB307: A dual targeting costimulatory Humabody® VH therapeutic for treating PSMA-positive tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5313.
Abstract 5316: SM2256: A bispecific conditional CD40 and 4-1BB dual agonist for enhanced solid tumor immune response
Authors: Song Wenjing , Yang Simin , Wei Yi , Lu Shihao , Geng Huiqin , Liu Xiaodan , Zhou Hong , Xie Siyao , Zhang Xing , Zhou Sheila , Liang Yanbin 
Published: March 2024

Abstract
Background: Monoclonal antibodies targeting the co-stimulatory receptors CD137 (4-1BB) and CD40 have displayed encouraging activity against a wide range of solid tumors in preclinical animal models. However, their clinical development as monotherapy has been hindered by dose-related liver toxicity, leading to limited efficacy at safe doses. To address this challenge and bolster tumor-specific immunity by orchestrating the interaction between dendritic cells (DCs) and cytotoxic T cells, we introduce SM2256 - a bispecific conditional CD40 and 4-1BB dual agonist. SM2256 physically bridges DCs and T cells, enhancing T cell priming and reactivation. In preclinical animal studies, SM2256 exhibited both excellent tolerability and potent anti-tumor activity.
Methods: SM2256 was engineered by fusing high-affinity, non-ligand-blocking VHH domains targeting 4-1BB and CD40 to a silenced IgG1 Fc backbone. This fusion resulted in a tetravalent bispecific antibody capable of conditionally activating CD40 and 4-1BB upon mutual receptor binding. We assessed the binding specificity and affinity of SM2256 to human CD40 and 4-1BB using ELISA and flow cytometry. The target-dependent activation of CD40 and 4-1BB was confirmed via reporter assays and co-culture systems using primary DCs and T cells. In vivo safety and anti-tumor efficacy were evaluated in a syngeneic transplantation model using the MC38 cancer cell line in B-h41BB/B-hCD40 double humanized mice.
Results: SM2256 exhibited sub-nanomolar binding affinity to recombinant human and cynomolgus monkey CD40 and 4-1BB, activating 4-1BB-NFκB-luc and CD40-NFκB-luc reporter cell lines at picomolar concentrations in a strictly target-dependent manner. Furthermore, SM2256 physically facilitated the interaction between DCs and T cells, leading to increased expression of DC co-stimulatory ligands and elevated secretion of cytokines by T cells in mixed lymphocyte cultures. In a syngeneic tumor transplantation model, SM2256 significantly restrained the growth of MC38 tumors in B-h41BB/B-hCD40 double humanized mice.
Conclusions: SM2256 is a novel conditional CD40 and 4-1BB dual agonist that demonstrates promising preclinical efficacy against solid tumors while boasting an improved safety profile when compared to existing monoclonal antibodies.
Citation Format: Wenjing Song, Simin Yang, Yi Wei, Shihao Lu, Huiqin Geng, Xiaodan Liu, Hong Zhou, Siyao Xie, Xing Zhang, Sheila Zhou, Yanbin Liang. SM2256: A bispecific conditional CD40 and 4-1BB dual agonist for enhanced solid tumor immune response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5316.