bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 499: Enhancing neoantigen cancer vaccine efficacy with a self-assembling peptide conjugates nanoparticle platform
Authors: Wu Yangfan , Huang Jian-Dong
Published: March 2024

Tumor neoantigens, arising from genomic mutations during cancer cell proliferation, are absent in normal tissues, making them ideal immunotherapy targets. Predicting neoantigen peptide sequences using artificial neural networks (ANNs) like NetMHCpan offers a promising approach to developing personalized peptide cancer vaccines. However, limitations such as low affinity, short half-life, and weak immunogenicity hinder their efficacy. To address these challenges, we propose loading neoantigens into nanoparticles for protection and slow release within the body. We used ANN prediction to determine neoantigen peptide sequences for various cancer cell lines and engineered these peptides by conjugating them with Toll-like receptor 7 agonist (TLR7a) adjuvants, forming a self-assembling peptide conjugates nanoparticle (SPCN) platform. To assess the immunogenicity of the SPCN platform, we conducted enzyme-linked ELISpot assays and evaluated the activation of antigen-presenting cells (APCs) in draining lymph nodes using flow cytometry analysis. The therapeutic efficacy of the SPCN platform was determined by monitoring tumor growth curves in mouse models. The SPCN platform demonstrated broad applicability, carrying different neoantigens in vivo, resulting in robust and safe systemic anti-tumor responses. The SPCN enhanced immunogenicity, stimulating splenocytes to produce more interferon gamma and facilitating efficient absorption by antigen-presenting cells (APCs). Moreover, SPCNs loaded with neoantigens targeted different cancer models, including B16OVA, MB49, and RIL175. In conclusion, our self-assembling peptide conjugates nanoparticle platform enhances APC activation and neoantigen immunogenicity, leading to improved anti-tumor efficacy, offering valuable insights for developing synthetic peptide cancer vaccines.

Citation Format: Yangfan Wu, Jian-Dong Huang. Enhancing neoantigen cancer vaccine efficacy with a self-assembling peptide conjugates nanoparticle platform [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 499.
Abstract 5009: Deciphering anticancer mechanisms of oncolytic virus-loaded stem cells
Authors: Hammad Mohamed , Seth Arun , Yuan Yate-Ching , Ngai Hoi Wa , Mooney Rachael , Lara Jacqueline , Kang Yunyi , Minev Ivelina , Nguyen Duong Hoang , Minev Boris , Santidrian Antonio , Aboody Karen
Published: March 2024

Background: Oncolytic viruses (OVs) selectively trap, replicate, and eradicate tumor cells without endangering healthy cells. However, any virus that enters the body will be found and rendered inactive by our immune system. Therefore, cancer-killing viruses don't function properly when given by themselves. Loading therapeutic viruses into stem cells is a promising solution since they shield the OVs from the immune system until they reach tumor cells and eventually destroy them. Stem cells are potent immunomodulators and, apart from protecting and delivering the cancer-killing viruses may release additional cell factors that may regulate tumor microenvironment favoring the effect of the therapy. In this study, we analyze these factors secreted by clinically relevant stem cells loaded with oncolytic viruses CLD-101 (Neuronova platform) and CLD-201 (Supernova platform)

Method: In our studies, we loaded neural stem cell line (NSCs) with tumor-selective oncolytic adenovirus CRAD-s-PK7 (CLD-101) and adipose-derived stem cells (AD-MSC) with tumor-selective oncolytic adenovirus vaccinia virus CAL1 (CLD-201), and studied their secretome transcriptomic and proteomic profile.

Results: The transcriptomic analysis demonstrated that immunomodulatory cytokines, chemokines, and their receptors are induced after three and twenty-four hours of OV infection. The proteomic analysis of the virus-loaded stem cells revealed a notable distinction from the naive stem cells indicating a potential immunotherapeutic role of the stem cells in addition to the delivery and protection of the OVs.

Conclusions: Our findings suggest that the enhanced therapeutic efficacy of stem cells loaded with OV is, at least partially because of qualitative and quantitative alterations in stem cells' secretome (including immunostimulatory cytokines and chemokines), These findings advance our knowledge of the molecular mechanisms underlying the immunostimulatory role of OV-loaded stem cells and specifically help to understand the mechanism of action of the promising clinical immunotherapies CLD-101 and CLD-201.

Citation Format: Mohamed Hammad, Arun Seth, Yate-Ching Yuan, Hoi Wa Ngai, Rachael Mooney, Jacqueline Lara, Yunyi Kang, Ivelina Minev, Duong Hoang Nguyen, Boris Minev, Antonio Santidrian, Karen Aboody. Deciphering anticancer mechanisms of oncolytic virus-loaded stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5009.
Abstract 5052: Novel drug resistance mechanisms and drug targets in BRAF mutated peritoneal metastasis from colorectal cancer
Authors: Lund-Andersen Christin , Torgunrud Annette , Kanduri Chakravarthi , Dagenborg Vegar J. , Frøysnes Ida S. , Larsen Mette M. , Davidson Ben , Larsen Stein , Flatmark Kjersti
Published: March 2024

Objective: Patients with peritoneal metastasis (PM) from colorectal cancer (CRC) have inferior prognosis and respond poorly to chemotherapy compared to other metastatic locations. This study aims to identify the molecular explanation for the observed clinical behavior and suggest novel treatment strategies in PM-CRC.

Design: Tumor samples from a Norwegian national cohort of 230 patients undergoing surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) with mitomycin C (MMC) for PM-CRC were subjected to targeted DNA sequencing, and associations between molecular findings and clinical data were analyzed. mRNA sequencing was conducted on a subset of thirty samples to compare gene expression in tumors harboring mutations in the BRAF or KRAS oncogenes and wild-type tumors.

Results: Almost one-third of the patients had mutations in the BRAF oncogene, which were associated with RNF43/R-Spondin aberrations and low expression of negative Wnt regulators (ligand dependent Wnt activation). This molecular profile, with high abundance in PM, could be an underlying mechanism promoting aggressive tumor biology that facilitates metastasis to the peritoneal cavity, and could contribute to the observed poor overall survival of this patient subgroup. BRAF mutations were also associated with gene expression changes in transport solute carrier proteins and drug metabolism enzymes that could influence the efficacy of MMC and irinotecan, commonly used in PM-CRC treatment. BRAF-mutated tumors exhibited increased expression of BTN immune checkpoint molecules, and targeting these checkpoints in addition to ligand dependent Wnt activation could be two novel targeted therapy approaches.

Conclusion: BRAF mutations were associated with particularly poor survival in this cohort, possibly related to altered drug transport and metabolism conferring resistance to MMC and irinotecan. Two potential novel therapeutic approaches were identified, suggesting specific targeting of BTN immune checkpoint molecules and the use of inhibitors to target ligand-dependent Wnt activation.

Citation Format: Christin Lund-Andersen, Annette Torgunrud, Chakravarthi Kanduri, Vegar J. Dagenborg, Ida S. Frøysnes, Mette M. Larsen, Ben Davidson, Stein Larsen, Kjersti Flatmark. Novel drug resistance mechanisms and drug targets in BRAF mutated peritoneal metastasis from colorectal 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 5052.
Abstract 5062: Evaluation of genetic mutations in non-small cell lung cancer patients
Authors: Rothstein Miles , Broughton Phillip , Markalunas Ella , Funkhouser Avery , Allen Lorie , Martin Julie , Edenfield W. Jeffery , Blenda Anna V.
Published: March 2024

Lung cancers represent the second most common cancer and Non-Small Cell Lung Cancer (NSCLC) constitutes 80-85% of all lung cancers. Genes within several cellular pathways have been previously evaluated for their clinical impact in NSCLC. In this investigation, we evaluate genetic mutations found in 50 cancer-critical genes implicated in the signaling pathways RTK/RAS/MAP, TGFβ, PI3K, Wnt, GPCR, p53, JAK/STAT, Notch, and the cell cycle pathway. Some of these mutations have not yet been described or have not been described in NSCLC. The intent of our study is to evaluate these mutations and allow further research into their impact, specifically highlighting mutations that are involved in clinically important pathways.

We evaluated mutations found in 59 NSCLC patients at the Prisma Health Cancer Institute. These mutations are part of 2,800 COSMIC (Catalogue of Somatic Mutations in Cancer) hotspot mutations in 50 cancer-critical genes. Each mutation was investigated further using the ClinVar database to identify whether it had been described in NSCLC or other cancers/conditions, its genetic consequence, pathogenesis, possible variations, and origin.

A total of 73 unique mutations in 59 NSCLC patients were evaluated. Of the 73 mutations, 17 had not been described at all, 40 had been described in other cancers/conditions, and 16 had been previously described in NSCLC. The known mutations’ effects in other cancers/conditions were categorized as pathogenic, likely pathogenic, likely benign, benign, or uncertain. Novel mutations were found in genes that provide a druggable target, help predict treatment response, are under investigation for their ability to predict treatment response or confer additional clinical utility.

Medical management of cancer has benefitted greatly from studies of genetic mutations. Most mutations identified in our patient population had not been described in NSCLC, and a smaller number of those had not been described at all. Further elucidation of these mutations may lead to additional discoveries relevant to NSCLC prognostication and treatment.

Citation Format: Miles Rothstein, Phillip Broughton, Ella Markalunas, Avery Funkhouser, Lorie Allen, Julie Martin, W. Jeffery Edenfield, Anna V. Blenda. Evaluation of genetic mutations in non-small cell lung cancer patients [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 5062.
Abstract 507: HLS-22001 induces G2/M cell cycle arrest and apoptotic cell death via tubulin depolymerization in colon cancer
Authors: Ahn Chi-hyun , Jang Gyu-beom , Kim Chunhwa , Lee Junho , Kim Taewon , Yang Youngeun , Cho Eunji , Kim Minchae , Kim Yun-tai , Han Yong-Hae , Kang Heebum
Published: March 2024

Colorectal cancer (CRC) is one of the main malignant tumors and among the leading cause of death in cancer patients worldwide considering that recurrence and chemotherapeutic drug resistance are highly common in the advanced stage of CRC. Mutations in KRAS and BRAF occur frequently in colorectal cancers, and abnormal cell cycles caused by these mutations affect tumor progression and metastasis. Accordingly, inhibition of cell cycle has been a potential target for colorectal cancers and therefore, we have developed a new lead compound, HLS-22001.

Our studies confirmed that HLS-22001 inhibited the proliferation of several cancer cells and significantly induced G2/M arrest and apoptosis of colon cancer cells and chemotherapy resistant colon cancer cells. The docking model studies showed that HLS-22001 was expected to bind to the colchicine binding site of beta-tubulin, and in fact, as a tubulin inhibitor, it had the effect of inhibiting tubulin dimerization and polymerization in the microtubule dynamics. Consistently, in xenograft mouse model, oral administration of HLS-22001 significantly suppressed tumor weight and volume without acute toxicity in mice.

Collectively, these results suggest further development of HLS-22001 as a novel and promising oral drug for colorectal cancer.

Citation Format: Chi-hyun Ahn, Gyu-beom Jang, Chunhwa Kim, Junho Lee, Taewon Kim, Youngeun Yang, Eunji Cho, Minchae Kim, Yun-tai Kim, Yong-Hae Han, Heebum Kang. HLS-22001 induces G2/M cell cycle arrest and apoptotic cell death via tubulin depolymerization in colon 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 507.
Abstract 5082: Novel TSHR CAR T therapy for targeting oncocytic carcinoma
Authors: Gleba Justyna J. , Alasonyalilar-Demirer Aylin , Pawlush Matthew , Manriquez-Roman Claudia , Siegler Elizabeth L. , Smallridge Robert C. , Zubair Abba , Tun Han W. , Kenderian Saad S. , Copland John A.
Published: March 2024

Oncocytic carcinoma (Hurthle cell carcinoma) has the highest incidence of metastasis among the differentiated thyroid cancers. Metastatic disease is reported at the initial diagnosis in 10-20% of patients and 34% overall. Thyroid-stimulating hormone receptor (TSHR) expression is limited to the thyroid gland. It is abundantly expressed on thyroid tumor cells, making TSHR a compelling target for advanced thyroid cancer diagnostics and therapeutics. We developed a potent anticancer strategy for treating oncocytic carcinoma using a novel thyroid hormone stimulating receptor (TSHR)- targeted (chimeric antigen receptor) CAR T cell therapy. TSHR CAR T was generated by transducing T cells derived from healthy donors. In vitro effector functions (cytotoxicity, proliferation, degranulation) were tested in TSHR+ tumor models, and subsequent in vivo studies using NSG mice were performed to assess anti-tumor activity efficacy. We observed strong anti-tumor activity against metastatic oncocytic carcinoma cell line XCT.UC1 using the TSHR CAR T therapy in vivo. Re-challenging treated mice with XCT.UC1 cells reactivated TSHR CART cells with enhanced proliferation and complete suppression of tumor growth of the newly injected tumor cells. Our work represents a promising strategy to improve treatment outcomes of patients with metastatic oncocytic carcinoma that may provide a durable response.

Citation Format: Justyna J. Gleba, Aylin Alasonyalilar-Demirer, Matthew Pawlush, Claudia Manriquez-Roman, Elizabeth L. Siegler, Robert C. Smallridge, Abba Zubair, Han W. Tun, Saad S. Kenderian, John A. Copland. Novel TSHR CAR T therapy for targeting oncocytic 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 5082.
Abstract 517: 2OHOA-mediated furin inhibition: Disrupting Notch via processing, transcription, and ADAM downregulation
Authors: Rodríguez-Lorca Raquel , Beteta-Göbel Roberto , Roman Ramón , Lladó Victoria , Escribá Pablo V. , Fernández-García Paula
Published: March 2024

Purpose Glioblastomas (GBMs) are highly treatment-resistant and aggressive brain tumors. Herewe assessed the potential of melitherapy to treat GBM, a strategy based on regulating themembrane’s structure and organization to modify aspects of intracellular signaling. In thiscontext, we have evaluated the effects of 2-hydroxyoleic acid (2OHOA) on GBM cells, acompound currently under study in a phase IIB/III clinical trial for newly diagnosed GBMpatients. The current study aims to determine whether 2OHOA modulates the Notch pathway aspart of its antitumoral mechanism, as seen its relevance driving the pathogenesis of GBM.

Methods The effect of 2OHOA was evaluated on different components of the pathway usingseveral methods: W-blot, Q-PCR, and confocal microscopy. The relevance of HES1 in itsmechanism of action was evaluated by its overexpression and pathway activation assays byJagged1. To analyze Notch receptor processing, we performed subcellular fractionation andcolocalization studies. Furin activity was assessed by fluorescence assays measuring its substratecleavage and its binding affinity to 2OHOA was determined by surface plasmon resonance.

Results 2OHOA suppresses both the Notch3 and Notch2 signaling pathways in GBM cell linesusing a two-fold mechanism. Notch3 signaling is abolished by repressing its transcription.Instead, Notch2 pathway is hindered by blocking its first cleavage through the inactivation offurin activity by physical association. Consequently, the Notch2 receptor is retained in the Golgicomplex, preventing its trafficking to the plasma membrane to initiate the signaling cascade.Moreover, overexpression of its target gene, HES1, partially dampened the drug's antiproliferative effect showing the relevance of this pathway in the 2OHOA pharmacologicalefficacy. In addition, considering the levels of Notch intracellular domain (NICD) obtained inJagged1 assays in conjunction with 2OHOA, we evaluated the second cleavage of the Notchprocessing, being also downregulated, as ADAM10 constitutes a furin substrate.

Conclusions These findings elucidate that the antitumoral activity of 2OHOA involves theinhibition of Notch signaling, potentially driven by the direct inhibition of furin. This reveals anovel molecular target for this bioactive lipid in the therapeutic approach to treating GBM.

Citation Format: Raquel Rodríguez-Lorca, Roberto Beteta-Göbel, Ramón Roman, Victoria Lladó, Pablo V. Escribá, Paula Fernández-García. 2OHOA-mediated furin inhibition: Disrupting Notch via processing, transcription, and ADAM downregulation [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 517.
Abstract 5212: Prognostic biomarkers for breast cancer: Metabolic and inflammatory pathways
Authors: McMahon Alexandra N. , Takita Cristiane , Wright Jean L. , Reis Isildinha M. , Lee Eunkyung , Yang George , Hu Jennifer J.
Published: March 2024

Objective: To assess the prognostic significance of molecular biomarkers, particularly metabolic and Inflammatory pathways using samples from a prospective study of breast cancer patients undergoing adjuvant radiotherapy (RT).

Methods: We used ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) for measuring urine metabolites. Following normalization to osmolality, log transformation, and imputation of missing values, we used Welch’s two-sample t-test to identify biochemicals that differed significantly by progression status. We measured pre- and post-RT plasma high-sensitivity C-reactive protein (hsCRP) levels. Progression-free survival (PFS) was calculated from the date of diagnosis to the date of disease progression or last follow-up. Univariable and multivariable Cox proportional hazards regression models assessed the associations between hsCRP and PFS.

Results: In 120 breast cancer patients, carbohydrate metabolism, branch-chain amino acid (BCAA) metabolism, phosphatidylcholine metabolism, arginine metabolism, oxidative stress-related metabolites, androgenic steroids, and nucleotide metabolism had the most notable differences in patients with progression versus progression-free cases. In 488 breast cancer patients, RT significantly increased plasma hsCRP levels, and post-RT hsCRP levels were significantly higher in deceased vs. alive patients (p=0.031). In multivariable models, hsCRP had a prognostic value for all-stage and stage 0-II patients.

Conclusions: In our study of breast cancer patients receiving adjuvant RT, multiple metabolite biomarkers and post-RT plasma CRP levels were associated with a worse prognosis. BCAAs and fatty acids regulate cell metabolism by affecting mitochondrial function and inflammation signals. Thus, our findings suggest a potential role of metabolic and inflammatory pathways in breast cancer prognosis. These molecules may have potential utility as prognostic biomarkers for breast cancer patients undergoing adjuvant RT and targets for intervention.

Keywords: breast cancer, metabolomics, inflammation, prognosis

Citation Format: Alexandra N. McMahon, Cristiane Takita, Jean L. Wright, Isildinha M. Reis, Eunkyung Lee, George Yang, Jennifer J. Hu. Prognostic biomarkers for breast cancer: Metabolic and inflammatory pathways [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 5212.
Abstract 5239: Discovery of AML associated therapeutic targets
Authors: Ibrahim Omar M. , Rettig Michael P. , Jayasinghe Reyka G. , Ding Li , DiPersio John F.
Published: March 2024

Chimeric Antigen Receptor T-cell (CART) immunotherapy has shown significant success in the treatment of hematological malignancies. However, their efficacy in AML is limited due to the disease's genetic diversity and lack of uniform antigen targets. To identify potential AML cell-surface markers, we employed a comprehensive approach that involved the utilization of 3' single-cell RNA sequencing (scRNA-seq), bulk RNA sequencing (RNA-seq), and enhanced whole exome sequencing (eWES). A total of 21 samples were analyzed, comprising 18 distinct AML patients and 3 healthy bone marrow aspirates, serving as controls. We conducted scRNAseq on 21 samples, yielding a total of 185,106 high-quality cells, which were effectively clustered into 38 unbiased groups. Notably, tumor clusters exhibited highest copy number variations and formed separate clusters from other non-tumor immune cells. To uncover key functional pathways, we conducted pathway enrichment analysis comparing tumor cells to non-tumor cells. Our findings demonstrated a significant overrepresentation of cellular processes related to Allograft rejection, IL2/STAT5 signaling, IFN-gamma response and apoptosis. To identify AML specific markers, we performed an unbiased systematic search of the scRNAseq dataset for genes with unique expression patterns in tumor cells compared to the healthy bone marrow controls. Our analysis identified differentially expressed genes, with many genes displaying relative cell and tissue specificity. Notably, among these genes, we unveiled key potential targets with cell surface specificity, including novel markers alongside previously known ones. Noteworthy candidates, such as ADGRE2, CD33, CD123, CLEC12A, and FLT3 and understudied novel markers such as CD86, CSF1R, S100 proteins and VMP1, were prominently expressed, showcasing their potential significance as targets for engineered immunotherapy. To validate and consolidate our discoveries, we conducted a cross-referencing exercise by comparing our scRNAseq data against bulk RNA data from primary human AML samples and cell lines. Bulk global proteomics, flow cytometry-based and CART generation studies are ongoing to confirm our discoveries. Our rigorous computational and experimental approach provides valuable insights into tumor-specific cell surface proteins, which hold promise as potential targets for innovative and precision immunotherapeutic interventions in the realm of AML treatment.

Citation Format: Omar M. Ibrahim, Michael P. Rettig, Reyka G. Jayasinghe, Li Ding, John F. DiPersio. Discovery of AML associated therapeutic targets [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 5239.
Abstract 5265: Targeting mtDNA dynamics enhances immunogenicity and sensitizes KRAS mutant cancers to PD-1 blockade
Authors: Tanaka Kosuke , Adachi Yasuki , Yoshiya Miyuki , Owari Takuya , Yamamori-Morita Tomoko , Ohashi Akihiro , Kobayashi Susumu , Koyama Shohei , Nishikawa Hiroyoshi
Published: March 2024

Mitochondrial DNA (mtDNA) can stimulate an innate immune response that potentiates the efficacy of cancer immunotherapy. However, mtDNA-targeting therapy has not been developed to enhance this innate immune system in specific cancer subtypes efficiently. Here we discover that mtDNA is enriched in KRAS mutant tumors where the DNA sensor machinery cGAS-STING signaling is primed for innate immune activation. Intriguingly, MEK inhibitor induces cytosolic mtDNA release to potently activate the cGAS-STING signaling, which in turn induces PRKN-mediated mitophagy in response to mitochondrial stress in KRAS mutant cancer cells. During the process of mitophagy, PRKN, as an E3 ubiquitin ligase, degrades BAX protein and attenuates mitochondrial pore formation, which is essential for mtDNA efflux upon MEK inhibition. Combined MEK and mitophagy inhibitors efficiently stimulate type I IFNs in both mtDNA- and STING-dependent manners, and this combination enhances the efficacy of PD-1 blockade in Kras mutant murine syngeneic tumors. In the clinic, PRKN is associated with a ‘cold tumor’ phenotype among KRAS mutant tumors. Together, targeting mtDNA dynamics by co-inhibition of MEK and mitophagy represents a promising strategy to convert ‘cold to hot tumor’ in mtDNA-enriched KRAS mutant cancers.

Citation Format: Kosuke Tanaka, Yasuki Adachi, Miyuki Yoshiya, Takuya Owari, Tomoko Yamamori-Morita, Akihiro Ohashi, Susumu Kobayashi, Shohei Koyama, Hiroyoshi Nishikawa. Targeting mtDNA dynamics enhances immunogenicity and sensitizes KRAS mutant cancers to PD-1 blockade [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 5265.
Abstract 529: Investigating the synergistic effect of milciclib and PD0325901 in colorectal cancer therapy
Authors: Pei Xinyu , Nguyen Anh , Neiger Hannah , Wang Wenjia , Bautista William , Wang Lily , Cai Alvan , Gerriets Valerie A. , Cusick John K. , Shi Yihui
Published: March 2024

Milciclib, characterized as a potent nanomolar inhibitor of multiple cyclin-dependent kinases, has recently emerged as a promising therapeutic agent in cancer treatment, particularly with its additional role as a spliceosome modulator. Our recent studies employing RNA sequencing technology revealed a comprehensive profile of Milciclib-induced transcriptional changes in colorectal cancer cells, identifying several key regulated pathways. In light of these findings, we explored a novel therapeutic strategy: combining Milciclib with specific inhibitors targeting pathways upregulated by Milciclib treatment. This hypothesis is based on the rationale that such a combination could exert a synergistic effect. We have assessed the efficacy of this combinational therapy and found that the combination of Milciclib and PD0325901 greatly potentiates the killing of colorectal cancer cells versus either treatment alone. PD0325901 has been extensively studied for its efficacy in targeting the MEK/ERK signaling pathway, a critical pathway in many cancers, including colorectal cancer. To further characterize the underlying molecular mechanisms contributing to the observed synergistic effect, we applied quantitative proteomic analysis of 8107 proteins in human colorectal cancer cells with the treatment of different doses of Milciclib and PD0325901 administered alone, or in combination. Our results demonstrate 49 proteins were significantly decreased in a dose-dependent manner, and that many of these proteins are key players regulating pathways associated with the cell cycle, apoptosis, gene expression, metabolism, WNT signaling, and the MEK/ERK signaling pathway. The discovery of the down-regulation of these proteins and pathways after treatment provides a molecular basis to elucidate the synergistic mechanism underlying Milciclib and PD0325901 combination therapy. In conclusion, our study establishes the combinatorial use of Milciclib and PD0325901 as a potential breakthrough in the treatment of colorectal cancer, offering a promising prospect for enhancing future patient outcomes.

Citation Format: Xinyu Pei, Anh Nguyen, Hannah Neiger, Wenjia Wang, William Bautista, Lily Wang, Alvan Cai, Valerie A. Gerriets, John K. Cusick, Yihui Shi. Investigating the synergistic effect of milciclib and PD0325901 in colorectal cancer therapy [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 529.
Abstract 5303: A novel TIGIT and 4-1BB bispecific antibody, ABL112, exhibits potent in vitro and in vivo antitumor activity through dual immune modulation
Authors: Son Wonjun , Lee Yangsoon , Park Yelim , Won Jonghwa
Published: March 2024

T cell immunoreceptor with Ig and ITIM domains (TIGIT) is an immune checkpoint molecule responsible for delivering inhibitory signals that suppress immune activation. Due to its inhibitory role in the immune response, TIGIT has emerged as a potential therapeutic target for various malignancies, with several clinical trials exploring the use of anti-TIGIT blocking antibodies with anti-PD-(L)1 therapies. Recent reports have indicated elevated expression of 4-1BB within intra-tumoral Tregs. Therefore, we hypothesized that a dual targeting approach involving both TIGIT and 4-1BB could effectively enhance intra-tumoral immunity.

ABL112, a First-in-Class bispecific antibody targeting TIGIT and 4-1BB, demonstrated the induction of T cell activation by blocking the TIGIT signaling and TIGIT dependent 4-1BB clustering. By having intact Fc, ABL112 bound to FcγRI and its crosslinking with 4-1BB also induced 4-1BB activation. ABL112 selectively depleted Treg cells but not other T cells in vitro, potentially through antibody-dependent cell-mediated cytotoxicity.

ABL112 demonstrated superior efficacy in tumor regression compared to anti-TIGIT monoclonal antibody across various mouse tumor models. Additionally, combining ABL112 with pembrolizumab significantly inhibited tumor growth better than combining anti-TIGIT monoclonal antibody with pembrolizumab. According to immune cell depletion assay, ABL112-mediated tumor suppressive activity was predominantly driven by CD8+ T cells, with a partial tumor reduction by CD4+ T cell or NK cell depletion. Mice with complete remission (CR) were further protected from the tumor re-challenge after 3 months of cessation of ABL112 treatment, and the proportion of tumor-specific memory T cells in the blood increased, suggesting long-term immunological memory has been established. In conclusion, ABL112 exhibited potent in vitro and in vivo anti-tumor activity through multiple mode of action including TIGIT inhibition and 4-1BB activation. These results strongly suggest that ABL112 is an innovative and promising therapeutic option with the combination of anti-PD-(L)1 therapies for cancer patients.

Citation Format: Wonjun Son, Yangsoon Lee, Yelim Park, Jonghwa Won. A novel TIGIT and 4-1BB bispecific antibody, ABL112, exhibits potent in vitro and in vivo antitumor activity through dual immune modulation [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 5303.
Abstract 5321: Chronic use of tobacco products promotes breast cancer progression through α7 nAChR/STING pathway activation
Authors: Mugisha Samson , Baba Shahnawaz , Labhsetwar Shreyas , Klemke Richard , Desgrosellier Jay
Published: March 2024

Tobacco-use is associated with an increased risk of developing aggressive breast cancer, however the cause remains unclear. While there is a dose-dependent decrease of patients’ overall survival due to tobacco-use, the risk persists even after cessation. Here we show that chronic treatment with of breast cancer cells with low-dose nicotine significantly increases tumorsphere formation, self-renewal and tumor growth, while the acute treatment has little effect. Interestingly, these outcomes were noted even weeks after nicotine treatment was stopped. Mechanistically, this was attributed to α7 nAChR, previously described as an essential regulator of inflammation. In fact, α7 nAChR knock-out prevented activation of the STING antiviral pathway by reducing the nicotine-induced mRNA expression of STING, CCL5, CXCL10 and STAT3. Overall, these findings highlight long-term impact of nicotine on cancer progression through α7 nAChR/STING pathway. This may inform new biomarkers for diagnosis and potential new treatment strategies to combat tobacco-related breast cancers.

Citation Format: Samson Mugisha, Shahnawaz Baba, Shreyas Labhsetwar, Richard Klemke, Jay Desgrosellier. Chronic use of tobacco products promotes breast cancer progression through α7 nAChR/STING pathway 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 5321.
Abstract 5322: Discovery of CRD1601, a potent and selective HPK1 inhibitor with robust in vivo anti-cancer activity
Authors: Banerjee Monali , Shrivastava Ritesh , Pryde David , Middya Sandip , Debnath Sabyasachi , Middya Anindita , Yadav Dharmendra , Rawat Nidhi , Ghosh Rajib , Padaliya Manisha , Basu Sourav , Surya Arjun
Published: March 2024

Background: Haematopoietic Progenitor Kinase (HPK-1, MAP4K1) is a member of the STE20 family of serine/threonine kinases, expressed predominantly in hematopoietic cells. HPK-1 functions as a negative regulator of T-cell and B-cell receptor activation by triggering proteasomal degradation and disrupting signalosome complexes downstream of TCR and BCR. HPK1 inhibition is a novel IO strategy that could combine with existing chemotherapies and immunotherapies.

Methods: Curadev used a pharmacophore based approach to discover novel small molecule HPK-1 inhibitors using in vitro enzymatic and phenotypic cellular screens using primary cells. CRD1601, the clinical candidate was selected based on its ability to enhance human T-cell proliferation through the induction of IL2 and IFNγ. Syngeneic tumor models were used to assess anti-tumor activity of selected compounds as a monotherapy or combination therapy.

Results: CRD1601 is a potent HPK1 inhibitor with a single digit nanomolar IC50 value in enzymatic assay and potent cellular activity in the SLP76 assay. A single dose of CRD1601 in mice treated with an anti-CD3 antibody caused systemic enhancement of pro-inflammatory cytokines such as IL2, IFN gamma and reduced pSLP76 levels in the spleen. Further, CRD1601 reversed the immunosuppressive effect of PGE2 and NECA. CRD1601 demonstrated significant single agent activity in murine tumor models while also synergizing with chemotherapy and immunotherapy.

Conclusions: Inhibition of HPK-1 is a promising therapeutic modality that could augment the effects of existing anti-cancer treatments including immunotherapy. CRD1601 is a potent and selective HPK-1 inhibitor with favorable drug like properties that has been selected from a rich portfolio of active compounds and shows promising in vivo activity in tumor models.

Citation Format: Monali Banerjee, Ritesh Shrivastava, David Pryde, Sandip Middya, Sabyasachi Debnath, Anindita Middya, Dharmendra Yadav, Nidhi Rawat, Rajib Ghosh, Manisha Padaliya, Sourav Basu, Arjun Surya. Discovery of CRD1601, a potent and selective HPK1 inhibitor with robust in vivo anti-cancer activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5322.
Abstract 5345: Development and validation of humanized HLA mouse model platforms for preclinical evaluation of novel peptide vaccines
Authors: Niu Zhenlan , Yu Xuan , Shen Zhiyuan , Guo Jing , Lin Qingcong , Xu Hui
Published: March 2024

The human leukocyte antigen (HLA) class I major histocompatibility complex (MHC) plays an integral role in immune surveillance by presenting intracellular antigen peptides on the cell surface, enabling recognition by cytotoxic T cells and subsequent elimination. Harnessing this intrinsic process for cancer immunotherapy is a promising therapeutic strategy; thus, developing preclinical models to evaluate the efficacy of novel peptide vaccines in vivo and ex vivo is critical. Previously, we developed a humanized MHC I mouse model (B-HLA-A2.1 mice), in which we successfully demonstrated efficacy of peptide vaccines as assessed by splenocyte IFN-γ production measured via ELISpot. Here, we provide evidence that B-HLA-A2.1 mice can also mount immune responses to NY-ESO-1 and WT1-Db126 peptides using the same assay. Additionally, immunization with WT1-Db126 at 7, 14, and 21 days prior to tumor inoculation with WT1-expressing MC38 colon cancer cells significantly reduced tumor volume. Additionally, we have generated two new humanized HLA models: B-HLA-A11.1 mice and B-HLA-A24.2 mice. Flow cytometric data demonstrate successful expression of the human HLAs on the cell surface of splenocytes isolated from both strains. Compared to wild-type C57BL/6 mice, analysis of leukocyte and lymphocyte subpopulations in the humanized mice indicates that the CD4/CD8 ratio is altered in favor of CD4+ T cells in both strains, similar to what was observed in B-HLA-A2.1 humanized mice. Despite these observed alterations, B-HLA-A24.2 mice were able to mount an immune response to peptide SART2 93-101, which was measured by splenocyte IFN-γ production. In summary, our data indicate that humanized HLA-A mice provide a powerful preclinical model for in vivo/ex vivo evaluation of novel peptide vaccines.

Citation Format: Zhenlan Niu, Xuan Yu, Zhiyuan Shen, Jing Guo, Qingcong Lin, Hui Xu. Development and validation of humanized HLA mouse model platforms for preclinical evaluation of novel peptide vaccines [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 5345.
Abstract 5370: Tumor-intrinsic cGAS-STING activation promotes anti-tumor inflammatory response in osteosarcoma
Authors: Young Elizabeth "Betsy" Peale , Johnson Christine , Lee Alex G. , Sweet-Cordero Eric Alejandro
Published: March 2024

A “cold” tumor microenvironment (TME) is often seen in patients with osteosarcoma (OS). Genomic instability, characteristic of OS, can stimulate the cGAS-STING pathway and activate the innate immune system. Tumor-intrinsic STING pathway silencing mechanisms can link genomic instability to immune evasion in OS. We hypothesize that dysregulation of the cGAS-STING pathway suppresses an innate immune response to genomic instability and plays a key role in tumor progression through establishing an immunosuppressive TME in OS. Using a novel panel of 11 OS patient-derived cell lines, we have identified two groups in terms of capacity for tumor-intrinsic STING activation, and we aim to unravel the mechanism of STING repression in a subset of OS tumors. To investigate the effects of tumor-intrinsic STING activation on macrophage polarization we employed tumor conditioned media (TCM) assays with murine-derived macrophages and tumor lines treated with cGAS-STING agonism. Tumor-intrinsic STING activation resulted in a significant increase in pro-inflammatory macrophages in a manner dependent on tumor STING. Lastly, we performed bulk RNA seq of OS PDX cell lines treated with STING agonist, defining for the first time the OS-specific STING activation signature. We then evaluated primary patient samples for evidence of this signature by single sample GSEA and performed survival analysis after stratifying samples as high or low for this signature, which demonstrated a significant protective effect of the STING activation signature on progression-free and overall survival. We have defined two subtypes of OS in terms of responsiveness to STING activation and demonstrated that STING activation has a protective effect in the human disease, which is the foundation of current efforts to identify targetable mechanism to reverse STING unresponsiveness and activate immune surveillance in this cancer.

Citation Format: Elizabeth "Betsy" Peale Young, Christine Johnson, Alex G. Lee, Eric Alejandro Sweet-Cordero. Tumor-intrinsic cGAS-STING activation promotes anti-tumor inflammatory response in osteosarcoma [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 5370.
Abstract 5389: Development of T-cell exclusion in melanoma
Authors: Park Ha-Ram , Yang Hee Won , Kim Minah
Published: March 2024

Immune checkpoint inhibitors (ICIs), which prevent immune cell exhaustion and boost an antitumor response, have shown remarkable treatment efficacy in patients with advanced melanoma. However, its efficacy is limited by the emergence of resistance associated with an immunosuppressive tumor microenvironment (TME). The contribution of abnormal tumor vasculature to limited immune cell infiltration into the tumor core has been reported but the mechanisms of its development are still elusive. We analyzed how tumor angiogenesis affects the immune cell exclusion at different time points of primary melanoma using syngeneic murine melanomas. The spatial distribution of various immune cell populations and vascular integrity were analyzed in whole tumor cross-sections via multiplex immunofluorescence staining. We found that the exclusion pattern of CD8+ T cells was less evident with a balanced distribution across the whole tumor regions at the early stage. However, as the tumor grows, there is a pronounced accumulation of CD8+ T cells at the tumor periphery with a conspicuous absence in the core. Tumor blood vessels were structurally uniform and functionally stable in the early developmental tumor but became unstable and leaky as the tumor progressed, which was associated with the development of CD8+ T-cell exclusion. To understand the mechanism underlying vascular regulation of immune exclusion during tumor progression, we will investigate the expression of genes related to tumor angiogenesis using spatial transcriptomic analysis and RNA sequencing of endothelial cells (CD45+CD31-) sorted from the murine melanomas. These results highlight the contribution of spatial tumor vascular destabilization to the T-cell exclusion development, implying the potential of targeting tumor vasculature to enhance immune activation and the therapeutic efficacy of ICI in melanoma.

Citation Format: Ha-Ram Park, Hee Won Yang, Minah Kim. Development of T-cell exclusion in 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 5389.
Abstract 5401: Vasculogenic mimicry: A three-step progress to form lumen-containing and fluid-conducting tubular structures in vitro
Authors: Owen Gareth I. , Santander Nicolle , Mingo Gabriel , Gonzalez Pamela , George Valentina , Babbitt Nicole , Espinioza Alejandra , Vega Isidora , Canales Cristobal , Ibañez Carolina , Gejman Roger , Roa Juan Carlos , Nualart Francisco , Ravasio Andrea , Bertocchi Cristina
Published: March 2024

Introduction: Vasculogenic mimicry (VM) is a clinical phenomenon by which cancer cells can form vessel-like structures in an endothelial-free (CD31-) fashion. VM presence in tumors correlates to poor patient prognosis. In our laboratory we have established an in vitro model where cancer cells from either cell lines or primary culture form lumen-lined and fluid-conducting tubular structures when grown on laminin-rich Matrigel over a four-day period. Given the duration of formation and the complexity of these structures, we hypothesize that VM in vitro is a multistep process, where each stage requires spatio-temporal organization of adhesive proteins, stemness and EMT (suggesting the need for epithelial to mesenchymal transition) signaling.

Methods: Using our in vitro models, we analyzed by siRNA, immunostaining and live cell imaging with Airyscan the distinct phases and the corresponding spatio-temporal organization of selected proteins.

Results: We show that VM in vitro has three distinct phases that are characterized by (1) alignment and migration, (2) contraction, proliferation and bridge formation, and (3) tubular structure closure and lumen formation. These steps require spatio-temporal distribution of ZEB1 and E-cadherin (suggesting gain and loss of epithelial to mesenchymal transition), the presence of Integrin β1 and laminin 111, and the distinct localization of Laminin and CD44.

Conclusion: A better characterization of VM may lead to the identification of a clinically useful marker to predict poor patient prognosis and shed light on a druggable pathway to treat this subgroup of aggressive cancer.

Citation Format: Gareth I. Owen, Nicolle Santander, Gabriel Mingo, Pamela Gonzalez, Valentina George, Nicole Babbitt, Alejandra Espinioza, Isidora Vega, Cristobal Canales, Carolina Ibañez, Roger Gejman, Juan Carlos Roa, Francisco Nualart, Andrea Ravasio, Cristina Bertocchi. Vasculogenic mimicry: A three-step progress to form lumen-containing and fluid-conducting tubular structures in vitro [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 5401.