bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2615: Preclinical development of a next generation antibody drug conjugate (ADC) targeting cMET for treatment of solid tumors
Authors: Xiao Liang , Lian Wei , Song Shuai , Liu Qigang , Zong Qing , Stann Sasha , Cai Jiaqiang , Xue Tongtong
Published: March 2024

cMET (mesenchymal-epithelial transition factor), which belongs to the MET family, is a type of receptor tyrosine kinase that is expressed on the surfaces of various epithelial cells. The elevation of cMET can promote the development and progression of multiple cancers. cMET- ADCs have shown promising clinical activity with highest cMET levels, indicating tumor cMET levels may be limited for efficacy. YL211, a novel cMET-ADC was developed by leveraging on MediLink’s tumor microenvironment activable linker-payload platform (TMALIN platform), which could release the payload both in the tumor cell and in the tumor microenvironment. YL211 is comprised of an anti-cMET humanized monoclonal antibody conjugated to a novel topoisomerase 1 inhibitor via a protease-cleavable linker. The novel linker-payload and site-specific conjugation of YL211 results in a homogeneous product with a DAR (Drug-to-Antibody Ratio) of 8. Furthermore, the advancement in linker-payload design has facilitated the development of more hydrophilic ADCs, which exhibit minimal impact on the antibody's characteristics while being less prone to aggregation and showcasing lower systematic clearance. Along with release of the payload in the tumor microenvironment extracellularly, upon binding to cMET on tumor cell surfaces, the antigen-ADC complexes are internalized to lysosomal vesicles and subsequently release the toxic payload. The cytotoxic features drive cell cycle arrest, apoptosis, elevation of PARP/caspase 7 expression, as well as cell death and bystander effect. These findings translated in vivo where YL211 showed superior efficacy in causing tumor regressions and good tolerability in both cell lines and patient-derived xenograft (CDX and PDX) mouse models with both low to high cMET expression levels (H358, CR5088, ect.). The in vivo pharmacokinetics in monkeys showed that YL211 is highly stable with less than 0.1% (molar ratio) payload released in circulation. GLP safety evaluations demonstrated good safety profiles and no off-target toxicity in monkeys. These non-clinical data suggest the stability of the linker in circulation as well as efficient release of the payload in tumors with improved therapeutic window. Taken together, preclinical data suggest that YL211 could be a promising treatment strategy for cMET positive cancer patients.

Citation Format: Liang Xiao, Wei Lian, Shuai Song, Qigang Liu, Qing Zong, Sasha Stann, Jiaqiang Cai, Tongtong Xue. Preclinical development of a next generation antibody drug conjugate (ADC) targeting cMET for treatment of solid 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 2615.
Abstract 2639: Combined therapy targeting AR and EZH2 restrains the growth of castration resistant prostate cancer by enhancing antitumor T cell response
Authors: Fischetti Irene , Laura Botti , Sulsenti Roberta , Cancila Valeria , Enriquez Claudia , Ferri Renata , Bregni Marco , Crivelli Filippo , Tripodo Claudio , Colombo Mario P. , Jachetti Elena
Published: March 2024

Castration resistant prostate cancer (CRPC) is a fatal disease. Androgen receptor pathway inhibitors, like enzalutamide, are initially effective but resistance eventually occurs, often associated to the emergence of aggressive neuroendocrine variants (NEPC). Even immunotherapy induced limited results in prostate cancer, governed by an immunosuppressive microenvironment. Therefore, effective therapies are needed. We here investigate in preclinical models a new approach aimed to revert castration resistance and simultaneously turn the immune milieu from “cold” to “hot”, through the combination between enzalutamide and the drug GSK-126, which inhibits the epigenetic modulator EZH2. We show that enzalutamide and GSK-126 can synergize to restrain the growth of CRPC in vitro and in vivo. Moreover, this therapeutic combination efficiently reduced NEPC differentiation, in both subcutaneous and autochthonous in vivo models, increasing the rate of cured mice with regressed lesions. The antitumor efficacy observed in immunocompetent mice bearing subcutaneous syngeneic CRPC tumors was lost in immunodeficient mice, indicating a contribution of immune cells. Additional experiments in the TRAMP spontaneous mouse model revealed that the combination of enzalutamide and GSK-126 significantly induced cytotoxic activity and IFNγ production by tumor-specific CD8+ T cells, otherwise tolerant, and increased IL-17 production by CD4+ T cells. The two drugs did not directly modulate T cell activity in vitro, suggesting the importance of microenvironment accomplices in triggering these effects. These results promote the combined use of enzalutamide and GSK-126 to restrain CRPC growth and NEPC differentiation, and, simultaneously, to awake antitumor T cell response, opening new possibilities for immunotherapy in prostate cancer.

Citation Format: Irene Fischetti, Botti Laura, Roberta Sulsenti, Valeria Cancila, Claudia Enriquez, Renata Ferri, Marco Bregni, Filippo Crivelli, Claudio Tripodo, Mario P. Colombo, Elena Jachetti. Combined therapy targeting AR and EZH2 restrains the growth of castration resistant prostate cancer by enhancing antitumor T cell 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 2639.
Abstract 2641: Transcriptional reprogramming of Ewing tumors: gains and losses noted when utilizing immunocompetent in vivo models
Authors: Daley Jessica D. , Mukherjee Elina , Tufino A Carolina , Bao Riyue , Bailey Kelly M.
Published: March 2024

Objective: Ewing sarcoma is an aggressive cancer most frequently diagnosed in adolescents and young adults. Currently, there is a limited understanding of the immunobiology of Ewing sarcoma, including limited pre-clinical studies of immunotherapeutic interventions. This, in part, is due to the historical lack of an immuno-competent murine model. Here, we utilize an immunocompetent, humanized mouse model to investigate the Ewing tumor immune microenvironment. Specifically, we sought to determine the transcriptional differences that occur when comparing human Ewing tumors established in a humanized backdrop versus those developed in an NSG (immuno-deficient) model.

Methods: Human Ewing cell lines (A673, TC32, TC71) and PDX (PSaRC219) were injected orthotopically into humanized or NSG mice. After ~3 weeks, bulk RNA sequencing was performed on tumors utilizing an Illumina Next Generation Sequencer. Tumor single-cell suspensions underwent immunophenotyping by flow cytometry (CyTek Aurora) for the following human markers: CD45, CD3, CD4, CD8, CD56, CD14, CD16, etc.. Peripheral blood was collected, PBMCs isolated, and immunophenotyping was again performed to determine peripheral blood immune cell populations.

Results: Ewing tumors established in humanized mice demonstrate infiltration of human CD45+ cells as well as immune cell sub-populations (CD3+, CD14+, CD56+ cells). Bulk RNA sequencing analysis utilizing unsupervised hierarchal clustering revealed that the transcriptional profile of Ewing tumors generated in humanized vs NSG mice cluster distinctly. Pathway analysis of differentially expressed genes (p <0.05) in Ewing tumors developed in humanized versus NSG mice demonstrates upregulation of pathways including extracellular matrix remodeling, collagen biosynthesis, and Wnt signaling. Notably, transcripts known to be specific to TGFBeta-dependent signaling in Ewing tumors are upregulated in the immune competent model, including TGFB1, FBLN5, and COLEC12.

Conclusion: This work demonstrates the Ewing tumor transcriptional remodeling that occurs when tumors are developed in an immunocompetent in vivo backdrop. Upregulation of several pro-metastatic pathways were noted. Ongoing work focuses on testing drug response differences between Ewing tumors developed in humanized versus NSG backdrops and pursuing immunocompetent Ewing models as a component of preclinical agent testing.

Citation Format: Jessica D. Daley, Elina Mukherjee, A Carolina Tufino, Riyue Bao, Kelly M. Bailey. Transcriptional reprogramming of Ewing tumors: gains and losses noted when utilizing immunocompetent in vivo models [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 2641.
Abstract 2649: A new role for the aryl hydrocarbon receptor (AhR) as a proximal mediator of immune checkpoints (PD-L1/2 and IDO1) in non-small cell lung cancer: Insights into an interferon-induced, LncRNA-and JAK/STAT-mediated signaling pathway
Authors: Lara Brian , Snyder Megan , Wang Zhongyan , Fimbres Jocelyn , Yang Eric , Sherr David H.
Published: March 2024

Non-small cell lung cancer (NSCLC) is the second most common cancer and accounts for ~127,000 deaths/year in the U.S. Its current ~30% five-year survival rate is an improvement from a decade ago thanks in part to the introduction of immune checkpoint inhibitors including PD1- and PD-L1-specific monoclonal antibodies. While PD-1/PD-L1-targeted immunotherapy is effective in many cases, not all patients respond and complete remissions still only occur in a minority of patients. Therefore, a greater understanding of immune checkpoint regulation in human NSCLC is needed. Here, we investigated a novel role for the aryl hydrocarbon receptor (AhR), an environmental carcinogen receptor previously associated with smoking-induced lung cancers, in the regulation of immune checkpoints PD-L1, PD-L2, and IDO1. Computational analyses of existing databases for protein-protein interactions linked to the AhR signaling pathway suggested crosstalk between the AhR, type I and type II Interferon (IFN), and JAK/STAT signaling pathways. AhR deletion from human lung A549 adenocarcinoma cells significantly reduced expression of JAK2, STAT1, STAT2, and the JAK/STAT signaling targets IRF1 and IRF9. Type II IFNγ significantly increased expression of those genes as well as the immune checkpoints IDO1, PD-L1, and PD-L2 in an AhR-dependent fashion. Interestingly, AhR deletion also eliminated IFNγ-mediated induction of a recently described long non-coding RNA, INCR1, which is encoded across the CD274/CD273 locus, and which facilitates JAK2, CD274/PD-L1, and IDO1 translation. Concomitantly, AhR knockout increased baseline expression of an RNA-binding protein, HNRNPH1, known to sequester JAK2 and CD274 mRNA thereby reducing IDO, PD-L1 and PD-L2 expression. Similarly, the AhR was shown to regulate Type I IFNα-mediated induction of STAT1, STAT2, CD274/PD-L1, and CD273/PD-L2. The data indicate that IFN induction of key immune checkpoints in lung adenocarcinoma cells is dependent on the AhR through its control of a conventional JAK/STAT pathway and an unconventional lncRNA (INCR1) and RNA-binding protein (HNRNPH1) pathway.

Citation Format: Brian Lara, Megan Snyder, Zhongyan Wang, Jocelyn Fimbres, Eric Yang, David H. Sherr. A new role for the aryl hydrocarbon receptor (AhR) as a proximal mediator of immune checkpoints (PD-L1/2 and IDO1) in non-small cell lung cancer: Insights into an interferon-induced, LncRNA-and JAK/STAT-mediated signaling pathway [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 2649.
Abstract 2658: The circadian clock modulates cancer immune checkpoint therapy through immune cell trafficking
Authors: Lichterman Jake N. , Srinivasan Tarun , Li Wenling , Sabaeifard Parastoo , Coughlin Laura A. , Poulides Nicole , Hooper Lora V. , Koh Andrew Y.
Published: March 2024

Immune checkpoint inhibitor therapy (ICT) can provide durable remissions for cancer patients with previously incurable malignancies. However, ICT is ineffective for many cancer types, and even those who initially respond may develop ICT resistance and succumb to their cancer. Tumor cell extrinsic factors, termed host factors, have recently emerged as key mediators and biomarkers of ICT response. One intriguing host factor that may influence ICT response is the circadian clock, an evolutionarily conserved transcriptional-translational feedback loop that allows mammalian organisms to adapt to environmental exposures (e.g. light). However, whether “the clock” modulates the ICT anti-tumor immune response is unknown.

Utilizing preclinical mouse models of cancer immunotherapy, we found that ICT efficacy is time-of-day dependent. ICT was most efficacious if ICT was administered at two hours after first light exposure (Zeitgeber time 2, ZT2) and least efficacious at ZT18. Utilizing flow cytometry, bulk cytokine analysis, and single cell RNA sequencing, we characterized the anti-tumor immune response after administering ICT at ZT2 and ZT18. There was an increase in effector granzyme B- and interferon-γ producing CD8+ T-cells in the tumor at ZT2 versus ZT18. This was accompanied by an increase in CD11c+ dendritic cells (DCs) and intratumoral chemokines (e.g. CXCL10) that promote DC/T-cell migration into the tumor microenvironment, and leads to enhanced DC-T-cell priming and anti-tumor immunity. Interestingly, these time-of-day dependent differences in tumor immune cell infiltration were present prior to the administration of ICT. To interrogate the role of the clock in mediating these time-of-day dependent differences, we characterized the response to ICT in mice that lack the core clock gene, BMAL1. Loss of BMAL1 in DCs (BMAL1fl/fl crossed with CD11c-cre) attenuated ICT efficacy, abrogated time-of-day dependent differences in ICT efficacy and dampened anti-tumor immunity. These findings highlight a role for a novel host factor, the circadian clock, in mediating the efficacy of cancer immune checkpoint therapy.

Citation Format: Jake N. Lichterman, Tarun Srinivasan, Wenling Li, Parastoo Sabaeifard, Laura A. Coughlin, Nicole Poulides, Lora V. Hooper, Andrew Y. Koh. The circadian clock modulates cancer immune checkpoint therapy through immune cell trafficking [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 2658.
Abstract 2681: Blockade of SIRPα in glioblastoma cells inhibits mitochondrial fatty acid β-oxidation and increase immune cell mediated cytotoxicity
Authors: Tsai Yu-Ting , Lesser Glenn J. , Soto-Pantoja David R.
Published: March 2024

Glioblastoma (GBM) is the most malignant brain tumor with limited immunotherapeutic options, likely due to significant GBM-associated systemic and intra-tumoral immunosuppression. The binding of SIRPα on myeloid cells to CD47 on cancer cells restricts immuno-phagocytosis against cancer cells. However, less attention has been given to SIRPα is also expressed in cancer cells, and the role of SIRPα on cancer cells is still unclear. Immunohistochemistry (IHC) staining was used to examine the expression of SIRPα in normal brain tissues and GBM. A single-cell database on the Broad Institute Portal was utilized to analyze the SIRPα expression in different cell types. SIRPα antisense morpholino was applied for gene knockdown. Established stable SIRPα overexpressed GBM cell lines were used to examine the mitochondrial function through the Seahorse Mito Stress test. In vitro, immune cell-mediated cytotoxicity was measured by Agilent xCELLigence Real-Time Cell Analysis. Patient biopsies show a 2-fold increase in SIRPα expression in GBM tumors compared to the normal adjacent (n=14-21; p < 0.01). Single-cell RNA-seq data on GBM tumors shows that SIRPα is expressed not only in the myeloid compartment but also in malignant cells. Studies have shown that mitochondrial function and fatty acid β-oxidation (FAO) play a critical role in GBM progression. Respirometry data revealed that blocking SIRPα in murine GBM cell line (CT2A) decreases mitochondrial ATP production. Seahorse Mito Stress test combined with fuel inhibitors showed that SIRPα expression mainly affects the usage of FAO (approximately 50%). In addition, stably, the GFP-tagged SIRPα overexpressed GBM cell line showed an increase of mitochondrial respiration with enhanced FAO ratio compared to the GFP control cell line. These suggested that SIRPα regulates mitochondrial FAO. Studies have shown that tumor-intrinsic FAO confers cell resistance to immune cell-mediated cytotoxicity. Interestingly, by coculturing with microglia, the innate immune population in the brain, our data showed that SIRPα blockade on GBM enhanced microglia-mediated cytotoxicity. Our data showed that targeting SIRPα on GBM may be a prospective therapeutic option by inhibiting FAO in mitochondria and increasing immune cell-mediated cytotoxicity.

Citation Format: Yu-Ting Tsai, Glenn J. Lesser, David R. Soto-Pantoja. Blockade of SIRPα in glioblastoma cells inhibits mitochondrial fatty acid β-oxidation and increase immune cell mediated 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 2681.
Abstract 2694: The role of innate lymphoid cells and innate like T cells in hepatocellular carcinoma
Authors: Huang Patrick , Ruf Benjamin , Trehan Rajiv , Soika Dana , Ma Chi , Greten Tim F. , Korangy Firouzeh
Published: March 2024

The major focus of cancer immunotherapy has been on conventional T cells due to their unique recognition of specific peptide antigens. Despite advances in the cancer immunotherapy field, including the use of atezolizumab and bevacizumab as first-line therapy for unresectable hepatocellular carcinoma (HCC), the overall mortality rate of HCC continues to rise. Innate lymphoid cells (ILC) and innate-like T cells (ILTC) are broadly categorized within the innate lymphoid population as playing an important role in inflammation, tissue repair and immune tolerance. Their ability to react rapidly to stimulants in their local tissue environment as well as to recruit and activate a variety of other immune cells makes these cells attractive targets for anti-tumor therapy. However, previous studies looking at ILCs and ILTCs in cancer have revealed both pro- and anti-tumor functions. Furthermore, the complex interplay between these cell populations in the tumor microenvironment is not well understood, particularly over the natural course of tumor development. In this study, we aim to better elucidate the role of ILC and ILTC populations in HCC progression in terms of both their kinetics and role as potential therapeutic targets. We performed hydrodynamic tail vein injections in mice with two different plasmid combinations to alter expression of commonly mutated oncogenes and tumor suppressors in human HCC (MYC;TP53 and MYC;CTNNB1). Histologic analysis of the livers was performed to determine appropriate time points to assess ILC and ILTC populations. We then designed a comprehensive 29-plex spectral flow panel to assess broad kinetic changes in the frequency of ILC, ILTC, and conventional T cell populations. We show that in early time points (4-7 days post-injection) when neoplastic transformation of hepatocytes has already occurred, mucosal-associated invariant T (MAIT) cells, group 1 ILCs, ILC2s, and ILC3s expand in frequency for both tumor models. Cytokine analysis shows a generalized decreased trend across timepoints in effector cytokine production in MAITs and group 1 ILCs, suggesting gradual dysfunction over time. Taken together, these preliminary findings show that ILC and ILTC populations expand early during tumor progression but gradually decrease in functionality with tumor progression.

Citation Format: Patrick Huang, Benjamin Ruf, Rajiv Trehan, Dana Soika, Chi Ma, Tim F. Greten, Firouzeh Korangy. The role of innate lymphoid cells and innate like T cells in hepatocellular carcinoma [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 2694.
Abstract 2755: Characterizing breast cancer cells following immune pruning in mice
Authors: McElduff Sarina , Bronder Daniel , Duran Mercedes , Bakhoum Samuel
Published: March 2024

In cancer patients, metastasis is the leading cause of death. Indeed, primary tumors which are diagnosed early and treated in a timely manner have the highest rate of success. In contrast, metastatic disease and late diagnosis of tumors portend poor outcomes. Thus, understanding the underlying biology and developing novel therapeutic approaches for metastatic cancers is pivotal. Most cancer-based mutational characteristics are tissue-dependent, and cancers with higher mutational load are generally more susceptible to immunotherapy. We observed that poorly metastatic, murine breast cancer cells established a clear phenotypic difference in lung metastasis formation assays. Upon injection of these cells into immune-proficient mice, few, large metastases developed, whereas in immuno-deficient mice, many small metastases grew instead. To determine the molecular features which enable escape under immune editing, we designed the following workflow. We intravenously injected immune-proficient and immune-deficient mice with our poorly metastatic, murine breast cancer cells. As expected, cells readily engrafted in the lungs, causing a significant reduction in survival of immune-deficient mice. Furthermore, liver metastases were observed only in immune-deficient mice. Upon euthanasia, we resected and dissociated both organs. To isolate the tumor cells from these samples, we flow-sorted and subjected them to next-generation sequencing. To elucidate the epigenomic, genomic, and transcriptomic differences between metastases of each background, we performed ATAC, WGS, and RNAseq, respectively. By dissecting the evolutionary mechanisms which allow cancer cells to evade immune detection in metastasis, we can develop targeted immunotherapy strategies to diminish the spread (and lethality) of metastatic cancers. In the future, we plan to examine the descriptive discrepancies between the tissues reared with and without immune pruning in order to put forward innovative therapeutic strategies.

Citation Format: Sarina McElduff, Daniel Bronder, Mercedes Duran, Samuel Bakhoum. Characterizing breast cancer cells following immune pruning in mice [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 2755.
Abstract 2764: Ubiquitin-specific peptidase 22 controls integrin-dependent cancer cell stemness & metastasis
Authors: Gao Qiong , Liu Kun , Jia Yuzhi , Wei Juncheng , Chaudhuri Shuvam Mohan , Wang Shengnan , Tang Amy , Mani Nikita Lavanya , Iyer Radhika , Cheng Yang , Gao Beixue , Lu Weiyuan , Sun Zhaolin , Liu Huiping , Fang Deyu
Published: March 2024

Integrins play critical roles in connecting the extracellular matrix and actin skeleton for cell adhesion, migration, signal transduction, and gene transcription. While the upregulation of integrins is thought to promote cancer stemness and metastasis, the mechanisms underlying their upregulation in cancer stem cells (CSCs) remain poorly understood. Herein, we show that the death from cancer signature gene, USP22, is essential in maintaining breast cancer cell stemness by promoting the transcription of a group of integrin family members, in particular, integrin β1 (ITGB1). Both genetic and pharmacological inhibition of USP22 largely impaired breast cancer stem cell self-renewal and prevented their metastasis. Reconstitution of Integrin β1 partially rescued USP22-null breast cancer stemness and their metastasis. At the molecular level, USP22 functions as a bona fide deubiquitinase to protect the proteasomal degradation of the forkhead box M1 (FoxM1), a transcription factor for tumoral ITGB1 gene transcription. Importantly, unbiased analysis of the TCGA database revealed a strong positive correlation between USP22 and ITGB1 in more than 90% of human cancer types, implying that USP22 functions as a key factor in maintaining stemness across a broad spectrum of human cancer types possibly through regulating ITGB1. To support this notion, immunohistochemistry staining detected a positive correlation among USP22, FoxM1 and integrin β1 in human breast cancers. Collectively, our study identifies the USP22-FoxM1-integrin β1 signaling axis as critical for cancer stemness and offers a potential target for antitumor therapy.

Citation Format: Qiong Gao, Kun Liu, Yuzhi Jia, Juncheng Wei, Shuvam Mohan Chaudhuri, Shengnan Wang, Amy Tang, Nikita Lavanya Mani, Radhika Iyer, Yang Cheng, Beixue Gao, Weiyuan Lu, Zhaolin Sun, Huiping Liu, Deyu Fang. Ubiquitin-specific peptidase 22 controls integrin-dependent cancer cell stemness & metastasis [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 2764.
Abstract 277: Cancer-associated fibroblasts, educated by tumor cells, differentially facilitate cancer cell invasion in cell-line based human gastric tumoroids
Authors: Hwang Hyun Ju , Lee Saet-Byeol , Kuh Hyo-Jeong
Published: March 2024

Purposes: Gastric cancer can be categorized into two subtypes: intestinal and diffuse. The latter is notorious for frequent peritoneal metastasis, resulting in a poorer prognosis. Cancer-associated fibroblasts (CAFs) in the tumor microenvironment play crucial roles in tumor invasion and metastasis. However, little is known about whether CAFs are associated with the differential progression between the two subtypes of gastric tumors. This study investigated whether differential cancer invasion may be attributed to tumor-specific CAF activation, using a cell-line-based human gastric tumoroid model.

Methods: Heterotypic tumor spheroids (TS) were prepared with human gastric cancer lines of intestinal (MKN28, MKN74) and diffuse type (MKN45, KATO III) mixed with human gastric fibroblasts (HGFs) using a minipillar-array chip previously developed. Invasion phenotype and expression of epithelial-mesenchymal transition (EMT)-related proteins were evaluated in heterotypic TSs. mRNA expression in HGFs isolated from heterotypic TSs was analyzed and compared between the two subtypes.

Results: While both heterotypic TSs displayed increased invasion by HGFs, the diffuse type TS showed a higher level of invasion with individual or amoeboid migration and loose binding of cancer cells with HGF. In contrast, the intestinal type TS showed collective migration and tight binding between cancer cells and HGFs. HGFs in each heterotypic TS exhibited differential morphology, matrix remodeling patterns, and gene expression in a tumor subtype-specific manner. Compared to normal HGFs, HGFs isolated from diffuse heterotypic TS showed enriched expression of cytoskeleton-associated genes and several integrins, whereas those of intestinal heterotypic TS exhibited increased expression levels of inflammatory cytokines.

Conclusions: This study established tumoroid models for human gastric cancer subtypes, intestinal and diffuse, using heterotypic TS culture. Our results suggest that the subtype-specific invasion ability of tumor cells is driven by CAFs that are differentially educated by tumor cells in the tumor microenvironment. Our model not only advances our understanding of CAFs' role in tumor progression but also offers an in vitro model for assessing potential therapeutic targets and drug candidates for human gastric cancers.

Citation Format: Hyun Ju Hwang, Saet-Byeol Lee, Hyo-Jeong Kuh. Cancer-associated fibroblasts, educated by tumor cells, differentially facilitate cancer cell invasion in cell-line based human gastric tumoroids [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 277.
Abstract 278: Investigating the functional role of cancer-associated fibroblasts in the emergence of drug-tolerant persisters in ovarian cancer
Authors: Ng Angel S. , Bui Ngoc , Ailles Laurie
Published: March 2024

Chemoresistance remains a major clinical challenge for the treatment of high-grade serous ovarian cancer (HGSC), the most lethal gynecologic malignancy. The majority of patients who initially respond to first-line platinum/taxane-based chemotherapy eventually relapse with chemoresistant disease, leading to poor survival outcomes. It is increasingly recognized that cancer cells can enter a reversible drug-tolerant persister (DTP) state through non-genetic mechanisms to evade chemotherapy-induced cytotoxicity prior to the development of chemoresistance. However, how environmental signals and extracellular factors from the tumor microenvironment drive the process remains poorly understood. Cancer-associated fibroblasts (CAFs) are a functionally heterogeneous population of activated fibroblasts. CAFs play a critical role in shaping the tumor microenvironment and tumor behaviors, including promoting tumor growth and mediating therapy resistance. Here, we demonstrated that HGSC cell lines co-cultured with patient-derived FAP-high CAFs, a subpopulation of CAFs previously identified in our lab to be tumor-promoting, significantly increase the formation of DTPs upon prolonged carboplatin treatment compared to the mono-cultured condition. Interestingly, the extracellular matrix (ECM) organization signature is enriched in FAP-high CAFs compared to their FAP-low counterparts, and we found that ECM deposited by FAP-high CAFs also facilitates the emergence of DTPs in HGSC cells. Future work will focus on elucidating the mechanisms by which FAP-high CAFs and the associated ECM promote DTP formation in HGSC cells through transcriptomic and proteomic profiling. This will aid the identification of potential therapeutic vulnerabilities to target cancer cells in the DTP state in FAP-high HGSC patients.

Citation Format: Angel S. Ng, Ngoc Bui, Laurie Ailles. Investigating the functional role of cancer-associated fibroblasts in the emergence of drug-tolerant persisters in ovarian 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 278.
Abstract 2789: NCAPG promotes triple-negative breast cancer stemness by a positive feedback loop with HIF-1α
Authors: Zhang Huimin , Xie Peiling , An Rui
Published: March 2024

Objective: Triple-negative breast cancer (TNBC) is life-threatening because of limited therapies and lack of effective therapeutic targets. NCAPG, an oncogenic marker, might be served as a new target for TNBC treatment. Here, we aimed to elucidate the role of NCAPG played in TNBC and the underlying mechanism.

Design: GEO data was used to investigate the potential targets for TNBC. Patient samples and TCGA data were used to demonstrate the clinical significance. Cell migration, self-renewal ability, chemoresistance and expression of pluripotency factors were tested to detect the stemness of TNBC cells. Immunoprecipitation, ubiquitination assay and chromatin immunoprecipitation assay were utilized to investigate the mutual regulation mechanism of NCAPG and HIF-1α.

Results: NCAPG was significantly overexpressed in TNBC compared with other subtypes of breast cancer and was positively correlated with poor overall survival. Elevated NCAPG expression could enhance cancer stem-like cell properties of TNBC cells. Mechanically, NCAPG positively regulated HIF-1α protein stability by interacting with HIF-1α and competitively abrogating the E3 ligase FBXW7-mediated ubiquitination and degradation towards HIF-1α. NCAPG, as a direct target gene of HIF-1α, could be in turn transcriptionally upregulated by HIF-1α.

Conclusion: NCAPG promotes TNBC stemness by a HIF-1α/NCAPG positive feedback loop. NCAPG is a promising target for TNBC treatment.

Citation Format: Huimin Zhang, Peiling Xie, Rui An. NCAPG promotes triple-negative breast cancer stemness by a positive feedback loop with HIF-1α [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 2789.
Abstract 2791: Establishment of immortalized endometrial cell lines using Sendai virus
Authors: Hikino Kohei , Komatsu Hiroaki , Hichiwa Genki , Kazuki Kanako , Kazuki Yasuhiro , Kugoh Hiroyuki , Okawa Masayo , Ida Yuki , Hosokawa Masayo , Sawada Mayumi , Kudoh Akiko , Sato Shinya , Taniguchi Fuminori
Published: March 2024

Objective: To establish endometrial immortalized cell lines using the Sendai virus and analyze their characteristics.

Methods: The study included patients with benign ovarian tumors and endometrioid carcinoma who had regular menstrual cycles. Endometrial cells were collected and separated into epithelial and non-epithelial cells using flowcytometry (FCM) (CD326 (EpCAM) antibody). Furthermore, the isolated cells were infected with Sendai virus carrying three immortalization genes (Bmi-1, hTERT, and SV40T) to create immortalized cell lines. The cells were characterized as epithelial cells by immunocytochemistry (ICC), and receptor expression was assessed by reverse transcription PCR (RT-PCR) and ICC. Non-epithelial cells from the patients with endometrial carcinoma were evaluated using ICC.

Results: The immortalized cell lines were capable of more than 20 passages. Immortalized endometrial epithelial cells tested positive for anti-Keratin antibodies and negative for anti-Vimentin antibodies by ICC. Additionally, FCM detected these cells as positive for anti-EpCAM antibody, confirming that they were epithelial cells. RT-PCR confirmed mRNA expression of estrogen α-receptor and progesterone receptor after 20 passages and ICC confirmed protein expression of them after 10 passages, establishing an endometrial epithelial immortalized cell line. Non-epithelial cells isolated from patients with endometrial carcinoma tested positive for anti-α-smooth muscle actin and anti-Vimentin antibodies by ICC, indicating their characterization as cancer-associated fibroblasts.

Conclusion: We successfully established an immortalized cell line of endometrial epithelial cells using Sendai virus and generated cancer-associated fibroblasts.

Citation Format: Kohei Hikino, Hiroaki Komatsu, Genki Hichiwa, Kanako Kazuki, Yasuhiro Kazuki, Hiroyuki Kugoh, Masayo Okawa, Yuki Ida, Masayo Hosokawa, Mayumi Sawada, Akiko Kudoh, Shinya Sato, Fuminori Taniguchi. Establishment of immortalized endometrial cell lines using Sendai virus [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 2791.
Abstract 2807: Distinctive microbiome signatures in colorectal cancer: A comparative metagenomic analysis
Authors: Chen Ziqi , Nie Bei Ning , Luo Bin , Wang Ziliang , Wang Xinyi
Published: March 2024

The human gut microbiome is increasingly recognized for its role in colorectal cancer (CRC) pathogenesis. This study aims to delineate the microbiome characteristics of CRC patients compared to healthy individuals, using a comprehensive metagenomic approach.

We utilized a cohort of 80 CRC patients and an equal number of matched healthy controls. Fecal samples were collected and subjected to in-depth metagenomic sequencing, targeting both structural and functional profiles of the microbiome. Data analysis involved advanced bioinformatics techniques. Key observations were subsequently validated in an independent cohort to bolster the findings.

Our analysis revealed significant alterations in the microbiome composition of CRC patients versus healthy individuals. Notably, there was an increased prevalence of pathogenic bacteria, such as Bacteroides Vulgatus in CRC patients. These bacteria are implicated in promoting inflammation and carcinogenesis. Conversely, there was a noticeable depletion of beneficial microbes like Lactobacillus in the CRC group. Functionally, the microbiome in CRC patients was characterized by enriched pathways related to DNA repair, cell cycle control, and metabolism pathways like Citrate cycle and Galactose metabolism. Validation in an independent cohort confirmed these distinctive microbiomic patterns.

Our study provides compelling evidence of altered microbiome landscapes in CRC patients, highlighting potential roles in disease development and progression. These findings pave the way for further investigation into microbiome-based diagnostics and therapeutic interventions in colorectal cancer.

Citation Format: Ziqi Chen, Bei Ning Nie, Bin Luo, Ziliang Wang, Xinyi Wang. Distinctive microbiome signatures in colorectal cancer: A comparative metagenomic analysis [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 2807.
Abstract 290: The role of tumor stromal topography-regulated genes in modulating the cellular landscape of tumor stroma in breast cancer
Authors: Su Chia-Yi
Published: March 2024

The tumor remodels the surrounding extracellular matrix fibers to become topographically aligned at the tumor front, further facilitating cancer cell migration. Our recent studies show that aligned tumor stromal topography promotes the detachment of breast cancer cells from the main tumor, then, in the following cell migration, upregulating genes such as genes encoding the cytochrome P450 family 1 subfamily A member 1 (CYP1) and inhibitor of DNA binding (ID) proteins. In this study, we further explored the role of topography-regulated genes in modulating the cellular landscape of tumor stroma. By analyzing the correlation of topography-regulated genes with stromal cell infiltration in bioinformatics databases, we found significant positive correlations between the RNA expression levels of most topography-regulated genes and the infiltration levels of cancer-associated fibroblasts and endothelial cells. Notably, the strongest correlation was between the expression level of ID3 and the infiltration levels of cancer-associated fibroblasts (r = 0.509) and endothelial cells (r = 0.506). Additionally, ID3 remained highly expressed in circulating tumor cells but exhibited low expression at distant metastatic sites. These findings suggest that genes regulated by tumor stromal topography, especially ID3, may play a role in neovascularization and fibrosis of the tumor microenvironment and the survival adaptation of cancer cells in circulation, thereby promoting metastasis.

Citation Format: Chia-Yi Su. The role of tumor stromal topography-regulated genes in modulating the cellular landscape of tumor stroma 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 290.
Abstract 2956: Chemotherapy-induced adipocyte senescence triggers bone loss through osteoclast activation
Authors: Raut Ganesh Kumar , Malachowski Taylor , Holt Taylor , Oliveira Renata , Luo Xianmin , Faget Douglas , Ren Qihao , Stewart Sheila
Published: March 2024

Despite breakthroughs in cancer treatment, chemotherapy-induced osteo-toxicity is a major problem that compromises the quality of life and overall survival of cancer patients regardless of cancer type. Recently we demonstrated that chemotherapy-induced senescence drives bone loss by both limiting mineralization of new bone and increasing bone resorption. However, the underlying mechanism of action remains elusive. Therefore, it is critical that we understand the mechanisms that drive these toxicities and develop approaches to mitigate their severity. To establish whether senescent bone resident cells or systemic responses to chemotherapy drove therapy-induced bone loss, we used a vertebral body transplant (vossicle) model. Using this approach, we found that the specific elimination of senescent cells in L4 and L5 donor vossicles (INK-ATTAC) implanted into wildtype mice, protects from chemotherapy-induced bone loss within the vossicles but not the femur of the recipient mice. This demonstrated that chemotherapy-induced senescence in resident bone cells is responsible for bone loss. To determine which bone resident cell(s) underwent senescence in response to chemotherapy and how their gene expression was impacted, we used the p16-CreERT2-tdTomato mouse model and found that chemotherapy triggers senescence in bone marrow adipocytes. Subsequently, we observed that postnatal fat ablation in adipoqCre-inducible DTR transgenic mice (iDTRADQ) prevented chemotherapy-induced bone loss, indicating senescent adipocytes trigger bone loss. Furthermore, we observed chemotherapy-induced bone loss is attributed to RANKL-mediated high osteoclasts activity. Collectively, our data demonstrate that chemotherapy causes senescence in marrow adipocytes which in turn triggers bone loss via RANKL-mediated osteoclasts activation and bone loss can be protected by eliminating senescent cells.

Citation Format: Ganesh Kumar Raut, Taylor Malachowski, Taylor Holt, Renata Oliveira, Xianmin Luo, Douglas Faget, Qihao Ren, Sheila Stewart. Chemotherapy-induced adipocyte senescence triggers bone loss through osteoclast activation [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 2956.
Abstract 2980: Exploiting the selenoproteome in uveal melanoma
Authors: Sanders Alyssa , Cunanan Camille , Hartsough Edward
Published: March 2024

Uveal melanoma (UM) is a common intraocular malignancy arising from GNAQ/GNA11 mutations in uveal tract melanocytes. Although primary UM is treatable by radiation and enucleation, half of patients will develop liver metastasis. Unfortunately, patients with metastatic UM have a poor prognosis of approximately one-year - underscoring metastatic UM as one of the deadliest cancers. A strong prognostic indicator for UM liver metastases is a deletion or inactivation of the deubiquitinase BAP1, yet its specific role in disease progression is unclear. Intriguingly, upon BAP1 loss of function, the cysteine importer SLC7A11 is up regulated. Imported cysteine can be converted into glutathione serving as a cofactor for antioxidant enzymes like GPX4, a selenoprotein (SeP). SePs are a protein family characterized by having at least one selenocysteine - a selenium (Se) containing amino acid. Interestingly, the liver serves as a major hub for Se transport via Selenoprotein P (SEPP). The selenocysteine rich SEPP is secreted by hepatocytes and catabolized in recipient cells facilitating synthesis of de novo SeP. Here we hypothesize that mutant BAP1 UM utilizes the liver’s Se rich microenvironment to augment selenoproteome expression to stave off oxidative stress. Using publicly available datasets, we found patients with mutant BAP1 UM have increased expression of antioxidants proteins and genes associated with SeP expression. In a panel of BAP1 expressing and deficient UM cells, we found that BAP1 deficient cells have increased expression of SePs, suggesting a predisposition to resist oxidative stress. In the presence of exogenous Se, UM cell lines upregulate SeP expression indicating the importance of selenium availability for SeP expression. In addition, a hepatocyte cell line, and an ex vivo liver slice co-culture model was used to confirm that SEPP was produced in the liver slices and was associated with increased SeP expression in UM cells. Furthermore, we found that BAP1 null UM cells were more susceptible to GPX4 inhibition compared to wild type cells, suggesting a reliance on SeP expression. Taken together, these findings suggest that the liver associated selenoproteome expression may underpin an oxidative stress-associated therapeutic vulnerability in UM liver metastases.

Citation Format: Alyssa Sanders, Camille Cunanan, Edward Hartsough. Exploiting the selenoproteome in uveal melanoma [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 2980.
Abstract 2988: TUG1 exosomal lncRNA sponges let-7 miRNA family members and advances prostate cancer
Authors: Marima Rahaba Makgotso , Mbeje Mandisa , Kandhavelu Jeyalakshmi , Penny Clement , Dlamini Zodwa
Published: March 2024

Exosomal long-non coding RNAs (lncRNAs) play an important role in cancer progression and have potential prognostic biomarker potential in several cancers including prostate cancer (PCa). Taurine-upregulated gene 1 (TUG1) is an oncogenic lncRNA overexpressed in PCa. This exosomal lncRNA has been reported to promote PCa migration, invasion and Epithelial-Mesenchymal Transition (EMT). However, TUG1 PCa prognostic mechanisms remain to be elucidated. This study aimed to profile differentially expressed lncRNAs in PCa high-grade tumor cells (PC-3) cells compared to low-grade PCa tumor cells (LNCaP). This was achieved by using a 384-well plate of PCa lncRNA gene panel. A human lncRNA database, LncSEA and other bioinformatics tools were used for annotation and enrichment analysis. RT-qPCR was used to confirm the gene array data. Up or down-regulation of ±2 and p <0.05 were considered significant. Forty two (42%) percent and 14% of lncRNAs were shown to be up and downregulated, respectively. Notably, TUG1 was shown to be upregulated in PC-3 cells from PCR array and RT-qPCR results. Bioinformatics analysis revealed that TUG1 is involved in several cancer hallmarks including apoptosis evasion, migration, invasion and EMT. Furthermore, lncRNA/miRNA complexes regulate a series of oncogenic signaling pathways and this study demonstrated that TUG1 sponges the let-7 miRNA family members (a highly conserved tumor suppressor miRNA family) and promotes PCa progression. Precise mechanisms of TUG1/let-7 axis in PCa prognosis need to be largely elucidated as this may hold potential to understanding lncRNA/miRNA-mediated PCa progression and thus be targeted for novel therapeutics.

Citation Format: Rahaba Makgotso Marima, Mandisa Mbeje, Jeyalakshmi Kandhavelu, Clement Penny, Zodwa Dlamini. TUG1 exosomal lncRNA sponges let-7 miRNA family members and advances prostate 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 2988.