bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5748: Inhibition of tumor growth using exosomes loaded with KRAS siRNA and surface-modified with tumor-targeted proapoptotic peptide
Authors: Kang Li , Jeon Soyeon , Vadevoo Sri Murugan , Kim Sang-Hyun , Lee Byungheon
Published: March 2024

Exosomes are extracellular vesicles naturally secreted by cells and serve as carriers of RNAs and proteins for cell-to-cell communications. KRAS is frequently mutated and plays a vital role in many tumors. Receptor expressed in lymphoid tissue (RELT), also known as tumor necrosis factor receptor superfamily 19-like, is upregulated in certain tumors such as lung and pancreatic tumors and is a potential tumor target. To selectively deliver cytotoxic agents to tumor, we loaded mesenchymal stem cell (MSC)-derived exosomes with a siRNA against KRAS and surface-modified them with the RELTpep-KLA peptide comprising a RELT-binding peptide (CRQTKN, named RELTpep) and proapoptotic peptide (KLAKLAKKLAKLAK, named KLA). Exosomes were isolated from cell culture medium using ultracentrifugation and transfected with the KRAS siRNA using a lipid-based reagent and then surfaced-modified with the RELTpep-KLA using a phospholipid-based membrane anchor. Compared with control peptide-KLA, RELTpep-KLA-targeted MSC-exosomes were more efficiently internalized into A549 lung tumor and Panc-1 pancreatic tumor cells expressing RELT on their surface and exhibited cytotoxicity to these tumor cells. RELTpep-KLA-targeted and KRAS siRNA-loaded MSC-exosomes reduced the phosphorylation of Erk and exhibited an enhanced cytotoxicity in A549 and Panc-1 tumor cells. Moreover, when intravenously injected, they inhibited tumor growth in Balb/c nude mice bearing subcutaneous Panc-1 human tumor xenografts more efficiently than those loaded with control siRNA or modified with control peptide-KLA. These results demonstrate that RELTpep-KLA-targeted MSC-exosomes carrying KRAS siRNA hold a potential for exosome-based targeted therapy against cancer.

Citation Format: Li Kang, Soyeon Jeon, Sri Murugan Vadevoo, Sang-Hyun Kim, Byungheon Lee. Inhibition of tumor growth using exosomes loaded with KRAS siRNA and surface-modified with tumor-targeted proapoptotic peptide [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 5748.
Abstract 5797: Next generation antibody drug conjugates: Multi-payload conjugates targeting multiple mechanisms of cell killing
Authors: Kendall Richard L. , Lobba Marco , Johri Saurabh , Symister Chanez , Trinter Devin , Nguyen Maxwell , Gutierrez Daniel , Brady Samantha , Lau Andrew , Francis Matthew B.
Published: March 2024

Introduction: ADCs have had tremendous impact on patient outcomes in breast cancer and are now second line therapy for stage IV HER2 positive metastatic breast cancer. However, many patients fail to respond or relapse after treatment with ADC therapies due to tumor heterogeneity and resistance to ADC payloads. We are developing next generation ADCs that deliver targeted combination chemotherapies with a single molecule.

Method: CatenaBio has developed a novel system capable of attaching distinct payloads at different sites to the same antibody, enabling the production of highly stable single-molecule targeted combination therapies, Multi-Payload-Conjugates (MPCs), with a well-defined drug-antibody ratio (DAR).

Results: We screened combinations of different payloads targeting several different mechanisms of cell division attached to trastuzumab at different DARs to optimize tumor cell killing. These targeted combination ADCs demonstrated robust killing in both HER2 high and low tumor cell lines. Additionally, these novel MPCs show potent inhibition of tumor growth in a HER2+ xenograft model of cancer.

Conclusion: Antibody Drug Conjugates have revolutionized the treatment of high HER2 positive breast cancer. More recently advances have been made in the design of ADCs to expand indications to include HER2 low as well as HER2 negative patients. Multi-payload Conjugates® offer the next step in ADC design and allow for the combination of multiple mechanisms of action in a single MPC that are highly effective across multiple breast cancer cell lines and HER2 expression levels. These molecules offer the potential to circumvent tumor resistance pathways and deliver deeper and more durable responses.

Citation Format: Richard L. Kendall, Marco Lobba, Saurabh Johri, Chanez Symister, Devin Trinter, Maxwell Nguyen, Daniel Gutierrez, Samantha Brady, Andrew Lau, Matthew B. Francis. Next generation antibody drug conjugates: Multi-payload conjugates targeting multiple mechanisms of cell killing [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 5797.
Abstract 5810: The impact of scaffold, linker, homogeneity and payload selection on the efficacy and tolerability of anti-tubulin ADCs
Authors: Collins Scott D. , Keirstead Natalie , Damelin Marc , Toader Dorin , Ishida Katsu , Kumar Niyanta N. , Lancaster Kelly L. , Catcott Kalli C. , Yau Annika , Bala Mohan , Lowinger Timothy B.
Published: March 2024

Antibody-drug conjugates (ADCs) achieve targeted drug delivery to a tumor and have demonstrated clinical success in many tumor types. The properties of an ADC, including its activity and safety profile, can be highly influenced by its characteristics and individual components, commonly viewed as the antibody, payload, linker, and drug-to-antibody ratio (DAR). However, multiple other characteristics can also significantly influence an ADC’s overall drug-like properties, including DAR homogeneity, method of bioconjugation, hydrophilicity, and charge balance. Due to the multiparametric nature of ADC platform optimization, there are few examples in preclinical research, and even fewer in the clinical realm, where comparisons across platforms have been investigated for the same target, both preclinically and clinically, to elucidate how deliberate modifications in molecular design can improve drug-like properties and clinical outcomes. To that end, here we describe the improvements observed in preclinical characteristics, as well as their translational relevance to corresponding clinical characteristics. Two anti-NaPi2b ADCs were produced using two different platforms, XMT-1536 (Dolaflexin platform) and XMT-1592 (Dolasynthen platform), conjugated to the same antibody and employing the same payload. The Dolasynthen platform was deliberately designed, taking into account preclinical and clinical learnings from earlier ADC platforms, to improve both safety and efficacy. In addition, comparisons to clinically approved anti-tubulin ADC platforms are made to provide further context.

Citation Format: Scott D. Collins, Natalie Keirstead, Marc Damelin, Dorin Toader, Katsu Ishida, Niyanta N. Kumar, Kelly L. Lancaster, Kalli C. Catcott, Annika Yau, Mohan Bala, Timothy B. Lowinger. The impact of scaffold, linker, homogeneity and payload selection on the efficacy and tolerability of anti-tubulin ADCs [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 5810.
Abstract 5821: DXC008, a novel STEAP1 antibody-tubulysin analog conjugate with a function linker, demonstrates a potential to broaden therapeutic opportunities for prostate tumors
Authors: Yang Qingliang , Huang Yuanyuan , Jia Junxiang , Guo Huihui , Zhang Lingli , Zhou You , Ye Zhicang , Ye Hangbo , Xu Yifang , Li WenJun , Zhao Zhiyu , Zhao Lingyao , Bai Lu , Zheng Jun , Zhao Robert Y.
Published: March 2024

Six-transmembrane epithelial antigen of the prostate 1 (STEAP1), is a cell surface protein frequently expressed in prostate cancer, with limited expression in non-prostate tissues. A Steap1 antibody called Vandortuzumab conjugated with MMAE (DSTP3086S) was in the clinical phase I trial for treating STEAP1-expressing metastatic castration-resistant prostate cancer and showed acceptable safety at 2.4 mg/kg once every 3 weeks. However, many patients are nonresponsive to DSTP3086S due to low target expression levels and common treatment-related AEs which were caused by MMAE payloads. DXC008 was generated through screening the therapeutical index in vitro of conjugates of an anti-Steap1 antibody with varieties of payloads of tubulysin B analogs through function peptide spacer linkers. The generated DXC008 exhibited not only good affinity for Steap1 but also moderate affinity for Prostate-specific membrane antigen (PSMA) which is as well specifically overexpressed in most prostate cancer with limited expression in normal tissue. DXC008 demonstrated couple tens to a hundred of picomolar concentration (pM) of potency against several prostate tumor cells and over 60% internalization rate within 90 min in vitro. And in vivo it showed very good durable antitumor response as low dose as 1 mg/kg one injection in both high and moderate of both Steap1 and PSMA expression xenograft models. Pharmacokinetic profiles of DXC008 were favorable and the safety of Maximal Tolerable Dose (MTD) was over 120 mg/kg in single injection in mice. DXC008 has been forward to NHP toxicity study and it has potential to be a good STEAP1/PSMA-targeting ADC with a wide therapeutic window for prostate cancers.

Citation Format: Qingliang Yang, Yuanyuan Huang, Junxiang Jia, Huihui Guo, Lingli Zhang, You Zhou, Zhicang Ye, Hangbo Ye, Yifang Xu, WenJun Li, Zhiyu Zhao, Lingyao Zhao, Lu Bai, Jun Zheng, Robert Y. Zhao. DXC008, a novel STEAP1 antibody-tubulysin analog conjugate with a function linker, demonstrates a potential to broaden therapeutic opportunities for prostate 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 5821.
Abstract 5862: Retrotransposable elements mediate the drug-tolerant persistence in claudin-low breast cancer chemo-treatment
Authors: Zhang Zijian , Wang Yiyang , Luo Xinlong , Zhan Xiaomei , Ding Jun , Wu Tao P.
Published: March 2024

The emergence of acquired drug resistance through treatment remains a critical threat to efficient cancer therapies, which most often lead to relapse and metastasis. The development of resistance is an evolutionary adaptation process that heavily depends on tumor heterogeneity (underpinned by cellular plasticity). Therefore, a longitudinal deconvolution of treatment adaptation is critical to uncover the driving-force mechanisms underpinning resistance adaptation. In the clinic, chemotherapy remains the mainstream treatment for TNBC, and one of the primary chemo-agents is doxorubicin. Although the initial responsive rate of doxorubicin-based chemotherapies is up to 70%, it is well recognized that TNBC cells usually generate an adaptive response and result in acquired drug-resistance and multi-drug resistant phenotypes. Although numerous mechanisms of chemo-resistance evolution have been proposed, most of these studies focused on the initial and terminal states, from which we could not deconvolute the adaptation routes and might miss the transient fate-switching events. We hypothesize that the claudin-low TNBC chemo-resistant cells may derive from the early-stage reversible chemo-tolerant persistent state, and early-stage state-switching mediated by epigenetic landscape reprogramming might determine the adaptation through treatment. We developed an in vitro “pulsing-treatment” model to test the hypothesis, which could mimic the clinical treatment and provide therapeutically relevant insights into the acute drug-induced stress response and regrowth. Unexpectedly, we found that the human endogenous retrovirus-like elements (HERVs) show an aberrant bursting in the adaptation. To further interrogate the adaptation, we did the longitudinal single-cell multi-omics sequencing. With a novel bioinformatic workflow, we integrated the HERV’s expression information with protein-coding genes profiling and chromatin accessibility. The preliminary result indicated that a subpopulation of HERV-high cells might transiently mediate the persistence of cancer cells at the early stage of the treatment, which coupled with whole transcriptomic and chromatin landscape reprogramming, and molecular subtype switching. In this study, we employed a new strategy to investigate the longitudinal adaptation route through treatment and uncover a non-canonical element, which shed new light on drug resistance research and novel target screening.

Citation Format: Zijian Zhang, Yiyang Wang, Xinlong Luo, Xiaomei Zhan, Jun Ding, Tao P. Wu. Retrotransposable elements mediate the drug-tolerant persistence in claudin-low breast cancer chemo-treatment [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 5862.
Abstract 5871: Unveiling mechanisms of CDK4/6 inhibitor resistance in ER+ breast cancer models with acquired resistance
Authors: Li Bin , Liu Gaoxiang , Ni Ting , Shi Wenting , Gu Qingyang
Published: March 2024

Introduction: Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, including palbociclib, ribociclib, and abemaciclib, have revolutionized the treatment of estrogen receptor-positive (ER+) breast cancer. However, the development of resistance to these inhibitors poses a formidable challenge in the clinical management of ER+ breast cancer. This study aims to explore the common resistance mechanisms in three CDK4/6 inhibitor-resistant models induced by chronic exposure to these agents.

Methods: We developed models of resistance to palbociclib, ribociclib, and abemaciclib by repeatedly exposing murine xenografts to these CDK4/6 inhibitors. Resistance was confirmed through cell viability assays and in vivo tumorigenesis studies. The tumors were sequenced using NGS analyses, and genes of interest were validated through Western blotting and qPCR.

Results: In all resistant models, we identified a common resistant mechanism via NGS analyses, which was characterized by the overexpression of the FAT1, CCNE1, and AR genes. The upregulation of these genes at mRNA and protein levels was confirmed by qPCR analyses and western blotting, respectively. Our data indicate that upregulation of FAT1, CCNE1, and AR genes may play a critical role in mediating resistance to CDK4/6 inhibitors, namely palbociclib, ribociclib, and abemaciclib.

Conclusion: Our investigation uncovered a shared mechanism, characterized by the overexpression of FAT1, CCNE1, and AR genes, that underlay CDK4/6 inhibitors-induced drug resistance in ER+ breast cancer. These findings shed light on the shared pathways that drive CDK4/6 inhibitor resistance and provide insights into potential therapeutic targets for overcoming this resistance in breast cancer patients. Understanding these mechanisms is crucial for the development of more effective treatment strategies for CDK4/6 inhibitor-resistant cancers.

Citation Format: Bin Li, Gaoxiang Liu, Ting Ni, Wenting Shi, Qingyang Gu. Unveiling mechanisms of CDK4/6 inhibitor resistance in ER+ breast cancer models with acquired resistance [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 5871.
Abstract 588: Preclinical evaluation of novel chimeric vesiculovirus mediated expression of proteolytic enzymes targeting two major stromal components of pancreatic ductal adenocarcinoma
Authors: Ferdous Khandoker Usran , Tesfay Mulu Z. , Simoes Camila C. , Cios Aleksandra , Nagalo Bolni Marius
Published: March 2024

The vesiculovirus genus has recently garnered interest as an oncolytic virotherapy for pancreatic ductal adenocarcinoma (PDAC). A new synthetic chimeric vesiculovirus, VMG, demonstrated efficacy and safety against PDAC both in vitro and in vivo. The therapeutic effectiveness of virotherapies against PDAC is often hindered by immunosuppressive factors in the tumor environment, as well as the presence of hyaluronic acid (HA) and collagen (CN), which increase tumor stiffness and interstitial fluid pressure, leading to reduced drug/oncolytic virus and immune cell penetration into tumor. To address this, we engineered VMG viruses incorporating enzymes PH20, collagenase (CNase), and novel proteolytic enzyme SMC, the latter exhibits both PH20 and CNase-like activity. We characterized these modified viruses for their cytotoxicity and performance in vitro. Various PDAC cell lines displayed varied sensitivity to VMG vectors, yet they showed consistent oncolytic effects relative to the parent VMG-GFP virus. Our results revealed no compromise in viral replication or apoptosis-inducing ability after transgene insertion, which is evident as infectious viral progenies were produced to approximately similar level of magnitude of around 108 TCID50/ml in all the cell line tested. Additionally, the VMG-SMC and VMG-hPH20-CNase variants demonstrated notable enzyme activity. To enhance clinical relevance, we utilized an ex vivo live tumor platform, which indicated around 20% tumor cell death using VMG vectors compared to that of the control, signifying tumor viability and virus replicability 72 hours post-infection. Fluorescent imagery highlighted the viruses' ability to spread and express functional enzymes within tumors. In summary, VMG vectors expressing stroma-degrading proteolytic enzymes can effectively express PH20, CNase and SMC enzymes that degrade stromal barrier of HA and CN without interrupting the replicability, performance, and oncolytic characteristics of the VMG vectors. Future research should prioritize the safety of these vectors and their potential to augment neoantigen expression and immune cell infiltration in vivo, which are the hallmarks of antitumor efficacy.

Citation Format: Khandoker Usran Ferdous, Mulu Z. Tesfay, Camila C. Simoes, Aleksandra Cios, Bolni Marius Nagalo. Preclinical evaluation of novel chimeric vesiculovirus mediated expression of proteolytic enzymes targeting two major stromal components of pancreatic ductal adenocarcinoma [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 588.
Abstract 5893: Crosstalk between sensory innervation and pancreatic ductal adenocarcinoma
Authors: Wang Kaiyuan , Ni Bo , Wang Xiuchao , Hao Jihui
Published: March 2024

In recent years, a growing body of research has illuminated the integral role of the nervous system in the initiation and progression of cancer, giving rise to the establishment of an emergent field known as cancer neuroscience. Pancreatic ductal adenocarcinoma (PDAC), constituting 90% of pancreatic cancers, manifests as a highly malignant solid tumor characterized by insidious onset, strong invasiveness, and a notable propensity for recurrence or metastasis. Consequently, the 5-year survival rate for PDAC remained dismally low at approximately 10% in 2021. Notably, PDAC is distinguished by perineural invasion (PNI), a phenomenon linked to postoperative recurrence and metastasis. A thorough exploration of the interplay between peripheral innervation and PDAC holds promise for identifying novel targets and therapies to enhance outcomes in PDAC. This study unveils a correlation between PDAC patients exhibiting high calcitonin gene-related peptide-positive (CGRP+) sensory innervation in the tumor microenvironment (TME) and diminished overall survival (OS) and disease-free survival (DFS) compared to those with lower CGRP+ nociceptive innervation. Concurrently, heightened CGRP+ sensory innervation corresponds to increased cancer pain, as assessed by Visual Analog Scale (VAS) scores. Further analysis reveals a negative association between CGRP+ nociceptive nerves and lymphatic metastasis, as well as tumor size in PDAC patients. In a murine PDAC model, the genetic or chemical ablation of CGRP+ sensory neurons significantly impedes disease progression. Additionally, sensory neuron ablation attenuates cancer-induced vesical pain and enhances the locomotor function of mice, suggesting an improvement in overall quality of life. Mechanically, within the TME of PDAC, the secretion of neuropeptides substance P (SP) and CGRP from sensory neurons is elevated, with CGRP exhibiting a more pronounced increase. Furthermore, the expression of the CGRP receptor—receptor activity modifying protein 1 (RAMP1)—surpasses that of the SP receptor in the TME. Subsequent blockade of the CGRP pathway using the RAMP1 antagonist Rimegepant significantly suppresses PDAC progression and alleviates cancer pain, accompanied by improved locomotor function. In summary, sensory innervation actively participates in the progression of PDAC through the secretion of CGRP. Consequently, the inhibition of the CGRP pathway emerges as a potential therapeutic strategy for both PDAC and cancer-induced pain.

Citation Format: Kaiyuan Wang, Bo Ni, Xiuchao Wang, Jihui Hao. Crosstalk between sensory innervation and pancreatic ductal adenocarcinoma [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 5893.
Abstract 5924: RNAi mediated inhibition of beta-catenin demonstrates anti-tumor efficacy and immune microenvironment modulation in preclinical hepatocellular carcinoma models
Authors: Dadali Tulin , Miller Spencer , Saawant Gaurav , Abbott Stephen , Yu Mikyung , Morskaya Svetlana , Lehrich Brandon , Monga Satdarshan , Lau Gloria , Maier Martin , Broom Wendy
Published: March 2024

Hepatocellular carcinoma (HCC) is the fifth most common solid tumor worldwide, and the third most common cause of cancer-related deaths. For the 40% to 50% of HCC patients who are candidates for systemic therapies, the landscape has evolved significantly in the last 10 years, with most recently, immunotherapies such as combination of atezolizumab and bevacizumab emerging as the current first-line systemic therapy for patients with intermediate or advanced disease. However, there are no predictive biomarkers for patients with HCC to enable selection of those most likely to benefit from these therapies and this remains a disease with high unmet medical need. Activation of the WNT pathway via mutational events or indirect pathway activation is implicated in many cancers including up to 50% of HCC patient tumors. High expression of beta-catenin, encoded by the CTNNB1 gene, has been shown to correlate with decreased survival and more rapid disease progression in HCC patients. In addition, WNT/beta-catenin pathway activation has been shown to result in immune exclusion and resistance to immunotherapy in HCC. ALN-BCAT comprises a chemically modified siRNA encapsulated in a lipid nanoparticle formulation which generates robust and highly specific reductions of CTNNB1 mRNA, downstream biomarkers and tumor cell proliferation in in vitro model systems. Anti-tumor activity has been demonstrated in multiple in vivo orthotopic HCC mouse models, in both early and late treatment settings as measured by liver to body weight ratio. Reductions in tumor burden were orthogonally confirmed by histology analysis and shown to be associated with changes in CTNNB1-related biomarkers. Finally, ALN-BCAT treatment results in changes in the tumor microenvironment in a mouse syngeneic HCC model, with increases in CD4+ and CD8+ T cells and reductions in M2 macrophages, consistent with a shift to a more immune stimulatory anti-tumor microenvironment. Here, we demonstrate that ALN-BCAT provides a novel approach to the inhibition of the WNT pathway as a therapeutic approach for treatment of HCC patients and WNT pathway activated tumors.

Citation Format: Tulin Dadali, Spencer Miller, Gaurav Saawant, Stephen Abbott, Mikyung Yu, Svetlana Morskaya, Brandon Lehrich, Satdarshan Monga, Gloria Lau, Martin Maier, Wendy Broom. RNAi mediated inhibition of beta-catenin demonstrates anti-tumor efficacy and immune microenvironment modulation in preclinical hepatocellular carcinoma 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 5924.
Abstract 5980: Cancer therapeutic and prevention strategy targeting mutated mitochondria DNA
Authors: Nagase Hiroki
Published: March 2024

As the energy factory for the cell, the mitochondrion, through its role of ATP production by oxidative phosphorylation, can be regarded as the guardian of well regulated cellular metabolism; the integrity of mitochondrial functions, however, is particularly vulnerable in cancer due to the lack of superstructures such as histone and lamina folds to protect the mitochondrial genome from unintended exposure, which consequently elevates risks of mutation. In cancer, mechanisms responsible for enforcing quality control surveillance for identifying and eliminating defective mitochondria are often poorly regulated, and certain uneliminated mitochondrial DNA (mtDNA) mutations and polymorphisms can be advantageous for the proliferation, progression, and metastasis of tumor cells and disseminated into microenvironment cells through extracellular vesicle and tunnel nano tube. Such pathogenic mtDNA aberrations are likely to increase and frequently be homoplasmic in metastatic cancer cells and, intriguingly, in normal cells in the tumor microenvironments as well. Distinct characteristics of these abnormalities in mtDNA may provide a new path for cancer therapy. We recently tested this hypothesis with a few PIP-TPP conjugates targeting mtDNA mutations to induce mutants reduction in heteoplasmic cells or apoptosis in homoplasmic or near homoplasmic cells in vivo model without major adverse effects. This finding reaffirms the feasibility of such a PIP-TPP-based mtDNA-targeting approach for anticancer therapy as well as perhaps cancer risk prevention. However, the absence of known mtDNA mutation hotspots limits the clinical application of somatic mutation-targeted PIP-TPPs. Thus, we designed CCCh-1005-TPP to selectively target a frequent ATP6 gene variant and often oncogenically homoplasmic in the associated with hypertrophic cardiomyopathy, colon, breast and ovarian cancer risk and found its anticancer effect in mouse xenograft models. Here we study preclinical trial of CCCh-1005-TPP, a promising novel anti-cancer agent for clearing abnormal mtDNA by reactivating mitochondrial quality control surveillance of mitophagy. Given those mechanistic insights may provide a promising therapeutic or maybe preventive approach of the pathogenic mtDNA removal in homoplasmic or heteroplasmic cells. Additional caveat is that this strategy may also use not only for cancer but also many other mitochondria related diseases, such as neurodegenerative, diabetic, renal, muscle and hearing loss diseases as well as aging.

Citation Format: Hiroki Nagase. Cancer therapeutic and prevention strategy targeting mutated mitochondria DNA [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 5980.
Abstract 6055: COOTO-Me (10e) acts as a molecular glue to target NCOR/HDAC3 degradation
Authors: Gong Ping , Huang Min , Li Xin , Wang Haoling , Waxman Samuel , Zhao Linxiang , Jing Yongkui
Published: March 2024

Histone deacetylase 3 (HDAC3) is overexpressed in cancer cells and functions as transcription repression complex with nuclear receptor corepressor (NCOR) to inhibit gene transcription. The pan-HDAC inhibitors have been approved for T-cell lymphoma with evident side effects. The selective HDAC3 inhibitors needs to be developed. Proteolysis-targeting chimera (PROTAC) approach is taken to design HDAC3 degraders with unsolved bioavailability obstacle. We screened small molecules with HDAC3 degradation ability and found two small molecules derived from glycyrrhetinic acid, methyl 2-cyano-3-oxo-18β-olean-1,9(11), 12-trien-30-oate (COOTO, 10e) and methyl 2-cyano-3,12-dioxo-18β-olean-1,9(11)-dien-30-oate (CDODO-Me, 10d), selectively decreased HDAC3 protein with increased acetylation of Histone 3. We explored the mechanism of HDAC3 degradation and found that 10e interrupted the interaction of HDAC3 with NCOR and induced degradation of both HDAC3 and NCOR protein. Biotin labeled 10e shows binding to both HDAC3 and NCOR directly as well as to E3 ligases SIAH2 and ITCH. Mass spectrometry analysis profiling reveals covalent interactions of 10e with multiple cysteine sites of SIAH2 in the binding regions for NCOR and HDAC3. Silencing SIAH2 blocks degradation of HDAC3. N-Acetylcysteine and GSH block the binding of 10e to HDAC3, NCOR and SIAH2. In addition, 10e decreased the levels of c-FLIP protein and increased the levels of NOXA protein leading to apoptosis induction. These data suggest that 10e functions as a molecular glue to attract SIAH2 to HDAC3 and NCOR to cause degradation through covalent binding.

Citation Format: Ping Gong, Min Huang, Xin Li, Haoling Wang, Samuel Waxman, Linxiang Zhao, Yongkui Jing. COOTO-Me (10e) acts as a molecular glue to target NCOR/HDAC3 degradation [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 6055.
Abstract 6061: Development of target cell-penetrating scFv conjugate degrader for the selective inhibition of mutant, resistant KRAS cancer
Authors: Yoon Gookjin , Jo Beom Soo , Lee Dong Woo , Yang Jinwook , Park Min-Ho , Seok Sanghui , Lee Jue Yeon , Chung Chong Pyoung , Park Yoon Jeong
Published: March 2024

The activation of mutations in the RAS gene, which is frequently observed in human cancers, induces downstream critical effectors, contributing to tumorigenesis. While attempts to directly target the GTP-bound, activated RAS have shown some success in certain cancer treatments, resistance remains a challenge. Our objective is to develop a cell-penetrating single-chain fragment variable (scFv) degrader that targets mutant KRAS for degradation. The scFv, binding specifically to antigens, can mitigate the side effects of non-specific binding seen with chemical drugs. However, due to the limited cell-penetrating capability of scFv, a delivery carrier is often necessary. In this study, a cancer targeting, and cell-penetrating synthetic peptide (CPP) was developed as a drug delivery carrier and added to the sequence of scFv. To this conjugate, a von Hippel-Lindau (VHL) expressing sequence was added to enable the scFv binding to mutant KRAS, enabling its proteasomal degradation. These conjugates were engineered as a plasmid DNA to be expressed as a protein conjugate in CHO cells. The purity of the scFv-VHL-CPP degrader was confirmed by SDS PAGE. In SPR results, the degrader not only exhibited high binding ability to mutant KRAS but also influenced the proliferation of KRAS mutant cells in cell viability tests. Mutant GTP-bound KRAS was reduced by the KRAS degrader in KRAS mutant cancer cells. The in vivo study further confirmed the degradation of the KRAS, as reflected by the significantly reduced tumor growth. In conclusion, a degrader protein binding to mutant KRAS that consists of cell penetrating peptide, scFv, and VHL is expected to become a new protein anticancer drug especially effective against mutant, resistant KRAS-mediated cancer cells. Especially, the design of the target cell penetrating peptide-scFv-VHL would be served as a platform for the target protein degrader development.

Citation Format: Gookjin Yoon, Beom Soo Jo, Dong Woo Lee, Jinwook Yang, Min-Ho Park, Sanghui Seok, Jue Yeon Lee, Chong Pyoung Chung, Yoon Jeong Park. Development of target cell-penetrating scFv conjugate degrader for the selective inhibition of mutant, resistant KRAS 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 6061.
Abstract 6062: Potent and orally bioavailable BCL6 protein degraders demonstrate efficacy in pre-clinical models of diffuse large B-cell lymphoma (DLBCL)
Authors: Xu Jun , Li Yangguang , Wang Ju , Tang Pingming , Liao Yuting , Zhang Chen , Yan Pangke
Published: March 2024

The B-cell lymphoma 6 (BCL6) transcription repressor protein is a protooncogene especially in diffuse large B-cell lymphoma (DLBCL), conferring survival, protection, and maintenance of lymphoma cells. BCL6 expression in normal B cells contributes to initiation and maintenance of the germinal centers (GC). Somatic mutations of the BCL6 gene including chromosome translocations have been shown to result in the deregulation of BCL6 expression and contributes to a subgroup of poor prognostic double- and triple-hit lymphomas. To solve this unmet clinical need, we have developed highly specific, potent, and orally bioavailable BCL6 protein degrader HSK43608 that demonstrates potent in vitro and in vivo efficacy in multiple pre-clinical DLBCL models. HSK43608 achieves >90% BCL6 degradation at 10 nM and DC50 of <1 nM in the OCI-Ly1 model following 24 hr treatment. Time-course studies showed >90% BCL6 degradation within 1 hr which could be maintained at 24 hrs. Importantly, medicinal chemistry efforts have resulted in the successful development of new-generation IMIDs to improve the oral bioavailability of BCL6 degrader for in vivo treatment. As expected, concentration of HSK43608 in tumor tissue was much higher than that in plasma in the DLBCL xenograft models. This tumor tissue enrichment of HSK43608 achieved >95% BCL6 degradation 48 hr after last dosing and convincing tumor growth inhibition. It is worth noting that BCL6 knockout mice suffer from myocarditis with eosinophils infiltration in heart muscle. The tissue distribution study demonstrated less HSK43608 in heart than in plasma, partially explained why there was no sign of myocarditis with eosinophils infiltration in the heart of the HSK43608 treated mice. Taking advantage of the new IMIDs structure, HSK43608 barely induce the degradation of the first generation IMIDs targets including GSPT1, SALL4, CK1α, Aiolos and Ikaros, indicating its safety. In summary, these results indicate HSK43608 as a potent and orally bioavailable BCL6 degrader and support further development.

Citation Format: Jun Xu, Yangguang Li, Ju Wang, Pingming Tang, Yuting Liao, Chen Zhang, Pangke Yan. Potent and orally bioavailable BCL6 protein degraders demonstrate efficacy in pre-clinical models of diffuse large B-cell lymphoma (DLBCL) [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 6062.
Abstract 6081: DNA integrity and preanalytical handling of endocervical samples for use in liquid biopsy-based diagnostics and monitoring of gynecological cancer
Authors: Lauesgaard Jacob Malchau , Carlsson Therese , Linder Anna , Schumacher Sara , Sundfeldt Karin
Published: March 2024

Background: Liquid biopsies from the gynecological tract can be useful for analysis of cell free DNA (cfDNA) (1, 2, 3). Sampling procedure and optimal preanalytical handling are poorly investigated. In this study, we aimed to evaluate how the profile and integrity of DNA, sampled from the female genital tract, were affected by preanalytical handling.

Methods: Biobanked/archival (stored at -80℃ after 48h at room temperature (RT)) and freshly obtained clinical samples were analyzed together with standardized in vitro samples. Archival and in vitro samples were preserved in methanol-based solution, imitating clinical handling of endocervical samples which are initially stored at RT for 48h before further handling. The fragmentation profile of archival and in vitro samples was analyzed. Time series of in vitro samples at RT and 4℃, with extraction at 6-hour intervals from 0 to 96h, were performed. The fresh clinical samples were collected from the endocervix in methanol-based solution and from the vagina in a solution designed to preserve DNA and placed at 4℃ resp RT. Extraction was performed within 4h and at 48h.

Results: Accumulation of short DNA fragments were observed in the archival samples and in the in vitro samples, indicating that fragmentation was initiated prior to 48h. Time series showed that the quantity of short DNA fragments gradually increased with time at both RT and 4℃ but at a slower rate in 4℃. At RT the percentage of fragments between 100-350bp increased 12-fold (0.39% vs 4.75%, p=0.002). The freshly obtained endocervical samples showed a similar significant increase in short fragments in samples stored at RT compared with samples stored at 4℃ (p= 0.02 for 100-230bp; p= 0.007 for 230-350bp; p= 0.03 for 100-2500bp) at 4h-48h.

Conclusion: Pre-analytical handling of endocervical samples can be optimized. Lowering temperature from RT to 4℃ immediately haltered DNA fragmentation.

Citation Format: Jacob Malchau Lauesgaard, Therese Carlsson, Anna Linder, Sara Schumacher, Karin Sundfeldt. DNA integrity and preanalytical handling of endocervical samples for use in liquid biopsy-based diagnostics and monitoring of gynecological 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 6081.
Abstract 61: A novel immunotherapy for metastatic prostate cancer: A monoclonal antibody that can bind both STEAP1 and STEAP2
Authors: Sheng Minzhi , Thillainadesan Gobi , Sparkes Amanda , Su Boyang , Matus Esther , Wright Jessica , Liu Stanley , Gariepy Jean , Leong Hon S.
Published: March 2024

Prostate cancer (PCa) is the second most prevalent cancer among males, and the 5-year survival rate for patients with metastatic PCa (mPCa) is ~30%. Although significant progress has been made in improving survival in mPCa patients, many of these patients experience relapse or systemic toxicities. Protein expression of prostate-specific membrane antigen (PSMA), a common PCa antigen often targeted in PCa therapy, is unfortunately lost in the later stages of mPCa. In contrast, six transmembrane epithelial antigen of the prostate 1 and 2 (STEAP1 and STEAP2) are both overexpressed in most PCa compared to normal and vital organs and has emerged as a next-generation target in mPCa.

We hypothesize that an antibody that binds to both STEAP1 and STEAP2 via their second extracellular domain (60% homology) could be useful therapeutically. Using an immunogen of this second extracellular domain, we raised several antibody clones that appear to have an affinity towards both STEAP1 and STEAP2 (STEAP1/2). The specificity and affinity of these antibody clones were successfully determined by immunofluorescence, flow cytometry and ELISA. Immunofluorescence results in PCa cell lines and those that overexpress STEAP1 and STEAP2 demonstrate the potential specificity of one clone for human STEAP1 and STEAP2. In addition, ELISA data revealed that the binding affinity of this clone to STEAP1 and STEAP2 is in the low nanomolar and low micromolar range, respectively. This monoclonal STEAP1/2 antibody has been sequenced and will become the basis for future development of immunotherapies thus expanding the therapeutic armamentarium for mPCa.

Citation Format: Minzhi Sheng, Gobi Thillainadesan, Amanda Sparkes, Boyang Su, Esther Matus, Jessica Wright, Stanley Liu, Jean Gariepy, Hon S. Leong. A novel immunotherapy for metastatic prostate cancer: A monoclonal antibody that can bind both STEAP1 and STEAP2 [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 61.
Abstract 6191: Simultaneous prediction of tumor microenvironment biomarkers from pathology slides using multi-task deep regression
Authors: Nahhas Omar S. El , Ligero Marta , Kather Jakob N.
Published: March 2024

Understanding the Tumor Microenvironment (TME) is crucial for tailoring personalized cancer treatments and improving patient outcomes. Using deep learning, we can predict properties of the TME from standard Hematoxylin and Eosin (H&E) stained slides, including specific gene expression signatures. While past models were limited to single signature predictions, we explore the potential of multi-task deep learning to identify multiple biomarkers at once, allowing more complex relationships and interactions to be modeled simultaneously. Our study focuses on the prediction of expression patterns of tumor, stromal, and immune cells in breast cancer (BC).

We developed a multi-task transformer-based deep regression model, trained in a weakly-supervised setting, to predict biomarkers in the TME from routine H&E-stained pathology slides of a BC cohort (n=876). The performance was evaluated using Pearson’s correlation coefficient (r) and spatial heatmaps generated via gradient-weighted class activation mapping.

Our model achieved a significant correlation coefficient above 0.40 (p<0.0001) for all predicted TME biomarkers in the holdout test set (n=176). This includes the biomarkers lymphocyte infiltrating signature score (r=0.46, p<0.0001), tumor infiltrating lymphocyte regional fraction (r=0.48, p<0.0001), leukocyte fraction (r=0.43, p<0.0001), stromal fraction (r=0.42, p<0.0001), and tumor cell proliferation (r=0.47, p<0.0001). Notably, the model's heatmaps highlighted the pertinent cells and histological characteristics for its predictions.

These data show that our deep learning model accurately predicts multiple TME biomarkers concurrently from routine pathology slides. This approach offers a promising avenue for cost-effective and efficient biomarker quantification in the TME, with potential applicability across various cancer types.

Citation Format: Omar S. El Nahhas, Marta Ligero, Jakob N. Kather. Simultaneous prediction of tumor microenvironment biomarkers from pathology slides using multi-task deep regression [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 6191.
Abstract 6201: Early-onset CRC, vitamin A deficiency, and stem cell origin of cancer
Authors: Boman Bruce M. , Hunsu Victoria O. , Facey Caroline O.
Published: March 2024

The recent surge in early-onset CRC (EOCRC) has been attributed to a Westernized lifestyle, but the underlying molecular mechanism is largely unknown. In our cancer genetics clinic, we provide care for 10-20 young (<50 age) CRC patients per year. But, only a fraction (~15%) of these young CRC patients are found to have CRC-predisposing germline mutations which doesn’t provide a hereditary factor that can explain EOCRC. Other genetic studies have found that the spectrum of somatic alterations was largely comparable between EOCRC and adult-onset CRC, particularly common are mutations occurring in APC and other members of the WNT pathway. Since a genetic etiology has not turned-up, we are exploring possible lifestyle factors. We hypothesize that vitamin A (retinol) deficiency is a likely etiologic factor because vitamin A is an essential nutrient that is not made by the human body. Thus, young individuals might be prone to any cancer-initiating effects of a vitamin A deficient diet. Indeed, many population-based studies (including ones on well-nourished populations) have reported a high prevalence of vitamin A deficiency in pre-school-aged children. Since APC mutation commonly occurs in early-onset CRCs, we conjecture that vitamin A (retinol) metabolism and APC mutation-induced activation of WNT signaling may be co-factors in promoting EOCRC. Accordingly, we have been investigating whether there is a functional connection between WNT and vitamin A/retinoic acid (RA) signaling, and if APC mutation generates an imbalance in a WNT:RA-linked mechanism that contributes to CRC development by impeding retinoid-induced colonic stem cell (SC) differentiation. We previously reported that RA signaling mainly occurs in aldehyde dehydrogenase-positive (ALDH+) SCs and that APC mutation leads to overpopulation of ALDH+ SCs and incomplete differentiation during CRC development. Thus, our findings suggest that APC mutation attenuates RA signaling in ALDH+ SCs, which might explain how vitamin A deficiency contributes to EOCRC development.

Citation Format: Bruce M. Boman, Victoria O. Hunsu, Caroline O. Facey. Early-onset CRC, vitamin A deficiency, and stem cell origin of 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 6201.
Abstract 6207: Exploring colorectal cancer with ARIA: Biomedical insights
Authors: Nikolic Nevena , Kleinstein Sarah , Radenkovic Jelena , Kovacevic Milan
Published: March 2024

Gaining the promised benefits from the population-scale datasets, both clinical and genomic, is often hindered by the inability to easily access, explore and manipulate such complex data - a difficulty that ARIA was designed to overcome.

In the field of biomedicine, organizations harness extensive datasets, gaining profound insights into patients and participants, thereby unleashing possibilities for accelerating research, especially in the realms of drug development and precision medicine. To facilitate navigation through the intricate landscape of biomedical data, Velsera has innovated ARIA to catalyse efficient and insightful analysis, with a keen emphasis on user-friendliness to ensure accessibility across a diverse professional audience. To demonstrate the practical application of ARIA, we explore genomic and clinical datasets to identify key differences in colorectal cancer progression. CRC, the third most common cancer globally, has unique characteristics in origination and progression from benign to pathogenic. Here we investigate differences between patients with polyps that do and do not progress to CRC, including key environmental factors such as smoking history, inactive lifestyle and obesity in conjunction with their known clinical and genetic risk factors. This exploration into the abilities of ARIA demonstrate the ability to analyse complex datasets combining both clinical and genomics data at a large scale.

For the purpose of this demonstration, a Synthea Dataset, encompassing synthetic clinical and genomic data for 122,011 patients across various age groups, was utilized. This dataset was generated by Velsera specifically for testing ARIA functionalities.

In conclusion, ARIA empowers efficient analysis of complex biomedical datasets, providing a comprehensive understanding of disease mechanisms and facilitating valuable insights.

Citation Format: Nevena Nikolic, Sarah Kleinstein, Jelena Radenkovic, Milan Kovacevic. Exploring colorectal cancer with ARIA: Biomedical insights [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 6207.