bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4303: Enrichment of nonadherent prostate cancer stem cell populations using simulated microgravity bioreactor
Authors: Khazaw Kezhan , Unlu Sebnem , Dwead Abdulrahman M. , Cinar Bekir
Published: March 2024

Prostate cancer is the most prevalent and the leading cause of cancer-related death among men, particularly African Americans. The cellular and molecular mechanisms contributing to this deadly disease remain largely unknown. As such, there are no effective strategies to treat metastatic cancer and improve patient outcomes. Anchorage-independent growth of circulating prostate tumor cell clusters is essential for developing cancer metastasis. However, there is no model system to study the molecular and functional characteristics of prostate tumor cell clusters reminiscent of the bloodstream in a laboratory setting. In addressing this need, we have established nonadherent LNCaP cell clusters, LN-G2 and LN-G3, under androgen-depleted growth conditions in a simulated microgravity bioreactor called Slow Turning Lateral Vessel (STLV). Our quantitative PCR analysis repeatedly demonstrated that LN-G2 and LN-G3 cell populations expressed high levels of the well-characterized CD44 and CXCR4 cancer stem cell maker, respectively, compared to the LNCaP parental. In addition, our functional analysis indicates that, unlike the LNCaP cell, LN-G2 and LN-G3 cells showed superior clonogenic and growth behaviors in response to androgen depletion and enzalutamide-treatment under adherent monolayer and nonadherent conditions. These observations suggest that cancer stem cell-like cell clusters that survived under microgravitational stress confer distinctive molecular and functional properties associated with superior survival and contribute to castration-resistant prostate cancer. Furthermore, the STLV bioreactor could help enrich cancer stem cell populations and enhance our understanding of the underlying mechanisms of lethal cancer, which may lead to novel therapeutics to improve patient outcomes.

Citation Format: Kezhan Khazaw, Sebnem Unlu, Abdulrahman M. Dwead, Bekir Cinar. Enrichment of nonadherent prostate cancer stem cell populations using simulated microgravity bioreactor [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 4303.
Abstract 4338: A pan-cancer single-cell analysis of intratumoral copy number diversity and evolution
Authors: Ye Hanghui , McDonald Thomas , Sei Emi , Minussi Darlan Conterno , Hu Min , Tang Chenling , Wang Junke , Wang Kaile , Casasent Anna , Chen Hui , Michor Franziska , Navin Nicholas
Published: March 2024

Aneuploidy is a hallmark of human cancers and studies have shown that cancer patients harbor many differences in their copy number aberrations (CNAs) reflecting interpatient heterogeneity (IPH). While IPH has been studied extensively, the intratumoral heterogeneity (ITH) of CNAs within a tumor remains understudied. Here, we conducted a pan-cancer analysis of 94 human tumor samples at single cell genomic resolution, representing seven major cancer types: bladder, breast, colon, glioblastoma, kidney, lung, and ovary. In total, 62,646 aneuploid cells were analyzed by single cell copy number profiling and bulk exome sequencing was performed. In most cancer types, increased subclonal diversity was associated with higher CNA burden, whole genome doubling (WGD) events, and TP53 mutations. In all tumors, our data show that cancer cells share a clonal set of truncal CNAs or mutations, suggesting these tumors evolved from a single ancestral cell. In 18/94 cases we identified subclonal WGD events, which resulted in a higher number of copy number losses after tetraploidization. Macro-spatial sampling showed that increased clonal diversity also correlated with increased spatial geographical diversity. We found that many cancers evolved CNAs in short punctuated bursts of evolution, and that this was not restricted to a specific cancer type. Collectively, these data show that copy number ITH is universally associated with molecular features across these human cancer types.

Citation Format: Hanghui Ye, Thomas McDonald, Emi Sei, Darlan Conterno Minussi, Min Hu, Chenling Tang, Junke Wang, Kaile Wang, Anna Casasent, Hui Chen, Franziska Michor, Nicholas Navin. A pan-cancer single-cell analysis of intratumoral copy number diversity and evolution [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 4338.
Abstract 4448: Effects of adagrasib on cholesterol, lipid and glucose gene expression regulation in tumor xenograft models and patient samples
Authors: Shelton Fabiola , Hoffman Natalie , Trinh David , Helu Xousaen M. , Calinisan Andrew , Hebbert Allan , Yan Larry , Briere David M. , Hover Laura , Fernandez-Benet Julio , Anderes Kenna , Christensen James G. , Hallin Jill , Olson Peter
Published: March 2024

Introduction: Clinically active KRASG12C inhibitors have represented a key research breakthrough and led to novel treatment options for lung, colorectal and other cancer patients harboring this mutation. While treatment with KRASG12C inhibitors are clinically active in the majority of patients, the depth and duration of response is variable and most patients ultimately progress. This variation in therapeutic response highlights the need for a better understanding of drug mechanism of action and the identification of rational combination strategies. Oncogenic KRAS mutations hyperactivate the MAPK pathway, create an immunosuppressive tumor microenvironment, and promote glycolysis even in the presence of oxygen commonly known as the Warburg effect. This altered metabolic state is marked by increased glucose uptake and lactate production, providing necessary substrates for rapid tumor growth.

Results: Pharmacological inhibition of KRASG12C with a potent and selective KRASG12C inhibitor, adagrasib, revealed marked alterations of metabolic gene expression programs in tumor samples collected from mouse xenograft studies and repeat biopsies provided by patients enrolled on adagrasib clinical trials. Upregulation of genes involved in reverse cholesterol transport including ApoE, NR1H3 (LXRa) and ABCA1 was observed across both preclinical tumor xenografts and patient samples following adagrasib treatment. Additionally, decreased expression of Glut1 and low-density lipoprotein receptor (LDLR) genes were also observed in both tumor models and patients suggesting that adagrasib treatment results in an extensive shift in uptake and utilization of cholesterol, lipid, and glucose. The impact of adagrasib treatment on circulating metabolic parameters in tumor xenograft-bearing mice were investigated in follow up studies.

Conclusions: Taken together, these data suggest adagrasib modulates cholesterol efflux, glucose and lipid pathways and alters tumor and systemic metabolic regulation. Additional research may yield a targetable collateral vulnerability and rational combinatorial strategy.

Citation Format: Fabiola Shelton, Natalie Hoffman, David Trinh, Xousaen M. Helu, Andrew Calinisan, Allan Hebbert, Larry Yan, David M. Briere, Laura Hover, Julio Fernandez-Benet, Kenna Anderes, James G. Christensen, Jill Hallin, Peter Olson. Effects of adagrasib on cholesterol, lipid and glucose gene expression regulation in tumor xenograft models and patient samples [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 4448.
Abstract 449: Catabolism of GSH by GGT supports cancer cell survival
Authors: Zocchi Marco , Hecht Castro Medeiros Fabio , Alimohammadi Fatemeh , Tuttle Emily , Asantewaa Gloria , Scales TashJae , Harris Isaac S.
Published: March 2024

Cancer metabolism depends on amino acid sources to fuel tumor growth and drug resistance. Using amino acid restriction to treat tumors can enhance existing therapeutic techniques. The tripeptide Glutathione (GSH), which contains cysteine, glutamate, and glycine, is often considered an antioxidant, and its potential as an amino acid pool has been overlooked. GSH is ubiquitous in the tumor microenvironment and could provide a ready source of amino acids to tumor cells through its catabolism by the enzyme γ-Glutamyl transpeptidase (GGT), which has been shown to cleave GSH and its’ conjugates in the extracellular space. It is unclear if the cleavage of GSH by GGT supports cancers in vivo. We find that inhibiting GGT with the pharmacologic agent GGsTop blocks GSH catabolism and decreases tumor growth. We show that cultured cells can be rescued from a lethal depletion of cystine upon supplementation with GSH or its catabolic product cysteinylglycine, but not under the conditions of GGT inhibition. Through pharmacokinetic methods, we identify a usable systemic dose of GGsTop and show GGT inhibition in tumor tissue. Further, we demonstrate that systemic GGT inhibition in vivo decreases tumor mass and volume. These findings support the hypothesis that GSH catabolism by GGT1 is a non-canonical source of amino acids for tumor metabolism. Understanding GSH catabolism by GGT could elucidate new metabolic pathways in tumors. Inhibiting GSH catabolism could provide new therapeutic approaches to inhibit tumor growth.

Citation Format: Marco Zocchi, Fabio Hecht Castro Medeiros, Fatemeh Alimohammadi, Emily Tuttle, Gloria Asantewaa, TashJae Scales, Isaac S. Harris. Catabolism of GSH by GGT supports cancer cell survival [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 449.
Abstract 4534: HSK40495, a highly selective PARP1 inhibitor with improved hematopoietic safety for the treatment of HRD cancers
Authors: Li Fan , Gou Xiaoli , Chen Lei , Meng Qingyuan , Li Yao , Dong Hongjiao , Tang Pingming , Wang Ju , Yan Pangke
Published: March 2024

It is well known that several PARP inhibitors have been approved for tumors with homologous recombination repair deficiencies (HRD), such as BRCA mutations. However, the common side effect of these inhibitors is hematologic toxicity, which limits their therapeutic index and combination potential with first-line chemotherapies. One possible reason is that currently approved PARP inhibitors do not specifically target PARP1, and might also affect other PARP family members. Recent studies have shown that the synthetic lethality caused by PARP trapping with HRD is mainly dependent on PARP1 inhibition, but not other PARP family members. Accordingly, we developed a selective PARP1 inhibitor that effectively inhibits tumor growth with less hematologic toxicity. HSK40495 is a potent PARP1 inhibitor with highly selectivity of PARP2. HSK40495 inhibited PARP1 enzymatic activity with a single digit nanomolar potency and with greater than 5000-fold selectivity against PARP2 in the protein binding assay. In addition, HSK40495 exhibited potent anti-proliferation activity in both DLD1(BRCA KO) cell and MDA-MB-436 cell, while had minimal effects against BRCA-WT DLD1 cell up to 30 µM in an anti-proliferation assay. In a subcutaneous MDA-MB-436 xenograft tumor model, HSK40495 administered orally once daily achieved excellent tumor growth inhibition of 100% at 3mg/kg. HSK40495 demonstrated significant PARylation inhibition in tumor tissues. Importantly, in CD34+ human bone marrow progenitor cell, HSK40495 showed improved cytotoxicity when compare to first-generation PARP inhibitor, Talazoparib. Meanwhile, in a lineage-specific hematotoxicity assay, HSK40495 exhibited improved cytotoxic safety in the process of differentiation of myeloid, erythroid and megakaryocyte compared with Talazoparib treatment. In summary, HSK40495, a highly selective PARP1inhibitor over other PARP family members, exhibits excellent pharmacological and safety properties, and also has the favorable pharmacokinetics profile in preclinical studies. All these findings suggest that HSK40495 has the great potential to be a promising PARP1 inhibitor for further development in the patients with HRD tumors.

Citation Format: Fan Li, Xiaoli Gou, Lei Chen, Qingyuan Meng, Yao Li, Hongjiao Dong, Pingming Tang, Ju Wang, Pangke Yan. HSK40495, a highly selective PARP1 inhibitor with improved hematopoietic safety for the treatment of HRD cancers [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 4534.
Abstract 46: Mechanisms and impact of bystander killing by CAR T cells
Authors: Chorazeczewski Joanna , Xie Lishi , Chen Xiufen , Wang Sidney , Kline Justin
Published: March 2024

While CD19-directed chimeric antigen receptor (CAR) T cell therapy has improved outcomes of patients with relapsed/refractory diffuse large B cell lymphoma (r/r DLBCL), a majority will suffer disease relapse following CAR T cell infusion. Therefore, understanding mechanisms of CAR T cell killing is critical to enhance therapeutic efficacy. Cytolysis of CAR T cell targets presumably involves recognition of CD19 antigen by the CAR followed by activation of the granzyme/perforin axis. However, bystander elimination of CD19-negative lymphoma cells by CAR T cells has been reported, indicating that an alternative pathway may be required for optimal killing. Through in-depth phenotyping of a large panel of human DLBCLs and in vitro killing assays, we observed that CD19 expression levels on DLBCL cells and vulnerability to CAR T cell killing were weakly correlated. Conversely, cell surface expression of the death receptor, FAS, on DLBCL cells was strongly associated with susceptibility to CAR T cell killing. Although FAS expression across DLBCL cell lines varied, it could be broadly enhanced following exposure to IFNγ. Potent CAR T cell-mediated cytolysis of CD19-negative, Fas-positive murine DLBCL cells required the presence of CD19-positive lymphoma cells in the culture. CRISPR/Cas9 targeting was employed to delete FAS and/or CD19 in isogenic human DLBCL cells to generate CD19+FAS+, CD19+FAS−, CD19−FAS+, and CD19−FAS− subsets, which enabled us to define the extent to which CD19 engagement by the CAR was required to affect killing via FAS. When CAR T cells were co-cultured with equal numbers of the four gene-modified DLBCL cells described above, CD19+FAS+ DLBCL cells were killed most effectively, followed by CD19+FAS− DLBCL cells, and CD19−FAS+ DLBCL cells. Double-negative DLBCL cells were poorly killed. This result suggested that CD19 engagement by the CAR was required for optimal DLBCL cell killing via FAS, and that CD19 and FAS need not necessarily be engaged on the same target cell. Future studies will determine if Fas/FasL interactions can be exploited by overexpression of FasL in CAR T cells and examination of DLBCL killing in vitro and in vivo.

Citation Format: Joanna Chorazeczewski, Lishi Xie, Xiufen Chen, Sidney Wang, Justin Kline. Mechanisms and impact of bystander killing by CAR T 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 46.
Abstract 4621: Dual targeting as an effective therapeutic strategy for malignant brain tumors
Authors: Magnan Elle Y. , Gourishetti Karthik , Thomas Sydney , Bhere Deepak
Published: March 2024

Glioblastoma, a type of brain cancer known for its aggressive nature and resistance to traditional treatments, remains a significant challenge for the medical community. Despite advances in surgical, radiation, and chemotherapy strategies, patients with glioblastoma typically have a poor prognosis, with a median survival time of only 15 months. While temporary symptom relief may be possible for some patients, complete tumor remission is often not achieved. Given the complexity of this disease, effective treatment options for glioblastoma are highly sought after. In this study, we have evaluated the effectiveness of a combinatorial approach using stem cell-derived exosomes enriched with miR-124 cargo paired with viral oncolysis for treating glioblastoma.

Human Umbilical Cord Stem cells (hUCs) are genetically modified with specific miR plasmids, and then cultivated in a specialized medium that has been depleted of exosomes. The exosomes (exo) that contain the target miR are subsequently extracted, purified, quantified, and characterized. These exosomes are then utilized for all subsequent investigations. Using a combination of cell viability assays and microscopy, the overall effect of the exo-miR-124 and oncolytic virus on both established and patient-derived primary GBM cells is analyzed. Additionally, a time course western blot analysis is conducted to comprehend the molecular mechanisms underlying the effects of the miR modification and viral oncolysis on cell proliferation and death pathways. Orthotopic animal models of GBM will be utilized to assess the effects of miR modulation and viral oncolysis in vivo.

Our research has shown that stem cell-derived exosomes are an effective way to deliver microRNA to specific cells, including tumor cells. This is because they can evade the immune system and target cells directly. Our experiments have shown that combining miR modulation paired with viral oncolysis as a promising approach for treating glioblastoma. Specifically, we have found that miR modulation and viral oncolysis can halt tumor cell proliferation in vitro by targeting multiple pathways involved in GBM growth and progression.

Citation Format: Elle Y. Magnan, Karthik Gourishetti, Sydney Thomas, Deepak Bhere. Dual targeting as an effective therapeutic strategy for malignant brain 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 4621.
Abstract 4631: Evaluation of the impact of homozygous MTAP truncations on the activity and selectivity of MTA-cooperative PRMT5 inhibitors
Authors: Tonini Matthew R. , Mignault Andre A. , Whittington Douglas A. , Lombardo Steven A. , Shen Binzhang , Stowe Hannah , Yoda Satoshi , Liu Shangtao , Zhang Minjie , Cottrell Kevin M. , Meier Samuel R. , Rego Heidi , Morawiak Jennifer , Hooper Ellen , Yu Yi , DiBenedetto Heather , Crystal Adam S. , Teng  , Briggs Kimberly
Published: March 2024

Homozygous deletion of the MTAP gene occurs in 10-15% of all human cancers. To benefit this large and diverse patient population, MTA-cooperative PRMT5 inhibitors, including TNG908 and TNG462, have been developed to leverage the synthetic lethal relationship between MTAP deletion and PRMT5 inhibition. MTA-cooperative PRMT5 inhibitors selectively bind the PRMT5-MTA complex driving selective inhibition of PRMT5 in MTAP-deleted cancers while sparing normal, MTAP-proficient cells. Our PRMT5 inhibitors are currently in Phase I/II clinical trials (NCT05275478 and NCT05732831), and eligibility is restricted to patients with tumors with confirmed MTAP loss either detected by next-generation sequencing (NGS) or immunohistochemistry.

MTAP gene loss occurs in cancers because of its chromosomal proximity to one of the most common genetically altered tumor suppressor genes, CDKN2A, but the chromosomal 9p breakpoints for the co-deletion are not uniform. Indeed, while clinical NGS testing and preclinical data confirm that homozygous intragenic MTAP breakpoints occur, the functional consequence of any given breakpoint on MTAP enzymatic activity and protein function remains unknown. Given the potential implications for homozygous intragenic MTAP deletions to impact the clinical response to MTA-cooperative PRMT5 inhibitors, we have started to evaluate the loss-of-function phenotype of various MTAP truncations to determine whether they retain MTAP activity. Here, we present our initial functional genomics analysis of this important diagnostic biomarker using in vitro cDNA reconstitution approaches for MTAP activity combined with analysis of PRMT5 inhibitor sensitivity. Ultimately, these data may help refine patient enrollment on clinical trials to drive the maximum benefit for patients with MTAP-deleted cancers.

Citation Format: Matthew R. Tonini, Andre A. Mignault, Douglas A. Whittington, Steven A. Lombardo, Binzhang Shen, Hannah Stowe, Satoshi Yoda, Shangtao Liu, Minjie Zhang, Kevin M. Cottrell, Samuel R. Meier, Heidi Rego, Jennifer Morawiak, Ellen Hooper, Yi Yu, Heather DiBenedetto, Adam S. Crystal, Teng, Kimberly Briggs. Evaluation of the impact of homozygous MTAP truncations on the activity and selectivity of MTA-cooperative PRMT5 inhibitors [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 4631.
Abstract 4635: RNF208: A novel diagnostic and prognostic biomarker for colorectal cancer and key regulator of malignant behavior
Authors: Guo Fangyue , Zhang Shanfeng , Li Pei
Published: March 2024

Background: RNF208, a member of the RING finger protein family, has been implicated in ubiquitin-mediated degradation of Vimentin, regulating invasion in breast cancer, and serves as a prognostic factor in uveal melanoma. However, its diagnostic and prognostic value in colorectal cancer (CRC), as well as its role in regulating malignant behavior in CRC, remains unclear. This study aims to reveal the potential of RNF208 as a diagnostic and prognostic marker for CRC and its function in regulating malignant behavior in CRC through bioinformatics analysis and experimental validation.

Methods: In this study, based on the ExoRbase2.0 human plasma exosome database (CRC=35; Healthy=118) and TCGA-COAD dataset (CRC=478; Healthy=41), we conducted bioinformatics analysis of the transcriptomic differences in plasma exosomes between CRC patients and normal individuals using ExoRbase2.0. Survival data from the TCGA-COAD dataset were integrated to select key molecules for CRC diagnosis and prognosis. Plasma samples from 39 CRC patients and 16 normal individuals were collected from hospital, and exosomes were isolated and purified using a reagent kit. qPCR was employed to validate the levels of RNF208 in plasma exosomes, confirming the results of bioinformatics analysis. Biological behavior was assessed through CCK-8 proliferation assays, flow cytometry experiments, and Transwell migration assays to investigate the relationship between RNF208 and malignant behavior in the HCT116 colorectal cancer cell line.

Results: Bioinformatics analysis revealed a significant correlation between elevated RNF208 expression in plasma exosomes and the incidence of CRC, as well as poor prognosis. The qPCR results from clinical samples further confirmed this correlation, and ROC curves demonstrated high sensitivity and accuracy, suggesting RNF208's potential as a diagnostic and independent prognostic factor for CRC. CCK-8 experiments showed that RNF208 knockdown suppressed proliferation activity in HCT116 cells, flow cytometry indicated that RNF208 knockdown promoted apoptosis in HCT116 cells, and Transwell migration assays demonstrated that RNF208 knockdown inhibited the migration of HCT116 cells.

Conclusion: RNF208 serves as a novel diagnostic and prognostic biomarker for colorectal cancer, promoting the proliferation and migration of colorectal cancer cells and contributing to the further deterioration of the disease.

Citation Format: Fangyue Guo, Shanfeng Zhang, Pei Li. RNF208: A novel diagnostic and prognostic biomarker for colorectal cancer and key regulator of malignant behavior [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 4635.
Abstract 4658: Genome wide CRISPR/Cas9 library screening identifies aurora kinase A as a regulator of elraglusib sensitivity in pancreatic cancer
Authors: Ding Li , Maeder Easton , Zhang Cheng , Weiskittel Taylor , Schmitt Daniel , Mazar Andrew , Li Hu , Billadeau Daniel
Published: March 2024

Pancreatic ductal adenocarcinoma (PDAC) is a deadly malignancy with a dismal 5-year survival rate, highlighting the urgent need to improve drug response and overcome primary or acquired (secondary) resistance to conventional chemotherapy. Glycogen synthase kinase 3β (GSK-3β) is a target in PDAC and the GSK-3 inhibitor, elraglusib, has been shown to improve chemosensitivity of PDAC and survival in preclinical cancer models. In addition, data from phase II clinical trials in patients with previously untreated metastatic pancreatic cancer is demonstrating preliminary evidence of clinical benefit in patients receiving a combination of gemcitabine/nab-paclitaxel. While this early evidence is highly encouraging, the biological determinants of elraglusib response are unknown. Using genome wide CRISPR/Cas9 library screening, we identify aurora kinase A (AURKA), an oncogenic kinase with major roles in mitosis, as a critical regulator for elraglusib sensitivity. Elraglusib treatment activates AURKA by inducing a G2/M cell cycle arrest. We show that knocking out AURKA reduces the phosphorylation of polo like kinase 1 (PLK1), arresting cells in mitosis, and leading to mitotic catastrophe and significant apoptosis after elraglusib treatment. Strikingly, the AURKA inhibitor, alisertib, works synergistically with elraglusib to inhibit PDAC cell line growth and induce apoptosis. In summary, our results demonstrate that targeting AURKA is an effective approach to sensitize PDAC tumors to elraglusib.

Citation Format: Li Ding, Easton Maeder, Cheng Zhang, Taylor Weiskittel, Daniel Schmitt, Andrew Mazar, Hu Li, Daniel Billadeau. Genome wide CRISPR/Cas9 library screening identifies aurora kinase A as a regulator of elraglusib sensitivity in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4658.
Abstract 4695: Effect of fully human anti-PTGFRN antibody drug conjugate on head neck cancer cells and patient derived xenografts
Authors: Marquez Jorge , Dong Jianping , Oshimura Mitsuo , Hayashi Jun , Serrero Ginette
Published: March 2024

Prostaglandin F2 Receptor Negative regulator, or PTGFRN, also known as FPRP is a 175 kDa transmembrane protein associated with metastatic characteristics of certain cancer types and a member of the tetraspanin family. PTGFRN expression is undetectable to low in normal tissues whereas it is elevated in several cancers such as head and neck, mesothelioma and medulloblastoma. PTGFRN has also been reported to be upregulated in many different types of cancer, increasingly so in metastatic cancer cells, compared to their non-metastatic counterparts PTGFRN expression has been reported to be a poor prognostic factor for glioblastoma making it a potential novel cancer therapeutic target. We have previously shown that PTGFRN is an internalizable cell surface protein making it suitable for targeting by antibody drug conjugate (ADC). We have developed fully human monoclonal antibodies to PTGFRN by immunizing humanized transgenic TC mice with human PTGFRN. Within 60 days from the start of immunization we were able to select several fully human anti-PTGFRN monoclonal antibodies that were examined by several functional assays that included flow binding, internalization, affinity determination and cell killing as antibody drug conjugates. Several monoclonal antibodies were selected and evaluated for their ability to inhibit tumor formation in several cancers. Selected antibodies were then conjugated to duocarmycin by a cleavable linker. The present study proposed to examine the effect of one such anti-PTGFRN ADC on head and neck cancer cell lines and patient derived xenografts that had been analyzed for their PTGFRN expression by western blot analysis using anti-PTGFRN antibody. Cells lines and PDX that were positive for PTGFRN expression were used to examine the effect of anti-PTGFRN ADC on their in vitro and in vivo proliferation. The data show that anti-PTGFRN ADC inhibits tumor formation in a dose-dependent fashion. These data also establish PTGFRN as cancer druggable target and the selected fully human anti-PTGFRN antibody as an attractive antibody for the development of new antibody drug conjugate in Oncology. These data also emphasize the potential of humanized transgenic TC mice for the development of fully human monoclonal antibodies, thus bypassing the need for humanization and affinity maturation required by other humanized mice or phase display.

Citation Format: Jorge Marquez, Jianping Dong, Mitsuo Oshimura, Jun Hayashi, Ginette Serrero. Effect of fully human anti-PTGFRN antibody drug conjugate on head neck cancer cells and patient derived xenografts [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 4695.
Abstract 4712: GPCR panel establishment and application in drug discovery
Authors: Wang Xiaoyan , Sui Ning , Hu Dandan , Zhang Ziwei , Bing Tiejun
Published: March 2024

G protein-coupled receptors (GPCRS) are the largest family of membrane proteins of cell surface receptors. It can be activated by various stimuli and play an important role in various physiological and pathological processes such as cell growth, proliferation, differentiation, metabolism, and homeostasis. Abnormal regulation of GPCR is associated with various human diseases, such as metabolic diseases, cardiovascular diseases, and eye diseases. G protein contains three subunits: α, β, and γ, which form a trimer. When extracellular ligands are bound to GPCRs which activate G protein and GTP phosphorylates Gα subunits, leading to the dissociation of Gα subunits from the trimer and dissociation from the β and γ subunits. In addition, Gα different subtypes of Gαs, Gαi and Gαq have different biological effects after activation, Gas-coupled receptors activate adenylyl cyclase (AC) to increase cAMP. In contrast, Gαi-coupled receptors activated adenylyl cyclase (AC) to inhibit cAMP. Gαq coupled receptors promote phospholipase C (PLC) to produce IP3, and IP3 can increase intracellular Ca2+ concentration. GPCR Panel With high general availability, which provides over 150 GPCR targets, covering wide families like 5-Hydroxytryptamine, adrenoceptors, Acetylcholine, dopamine, glucagon, and opioid receptors and having the selectivity of multiple species. It can conduct similar GPCR poly-link interaction and screening, used to study new GPCR drug development technology, detect the expression properties of GPCR receptors, reveal new GPCR structure and function, and screen GPCR drugs. We also constructed different assay platforms, including cAMP assay, Ca2+ flux assay, IP3 assay, β-arrestin recruitment assay and reporter assay to detect the different second messengers produced by G protein submits and GPCR-mediated multiple signaling pathways. This research constructed stable cell lines expressing GPCRs and provided related assays, which could be used to detect compounds' effects on GPCR targets successfully. In addition, the GPCR panel was applicable to both activating and inhibitory models, and the establishment of this platform provides a powerful tool for drug development of GPCR-related targets.

Citation Format: Xiaoyan Wang, Ning Sui, Dandan Hu, Ziwei Zhang, Tiejun Bing. GPCR panel establishment and application in drug discovery [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 4712.
Abstract 4721: Cell death induction via CB2 receptor and TRPV receptor in cannabichromene (CBC) treated human pancreatic cancer cells
Authors: Hwang Yu-Na , Kim Keun-Cheol
Published: March 2024

Cannabichromene (CBC: C21H3O2, M.W.: 314.46g) is one of the most abundant nonpsychotropic phytocannabinoids extracted from Hemp species (Cannabis sativa), and can extract using either a hexane/florisil extraction method. Phytocannabinoids contain Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiol (CBD), cannabigerol (CBG), cannabichromene (CBC), and other compounds. CBC can cause strong anti-inflammatory effects in animal models of edema through non-CB receptor mechanisms, but there is little pharmacological study in cancer disease models. In this study, we investigated the molecular mechanism on anti-cancer activity of CBC treatment in human pancreatic cancer cells. MTT assay was performed to determine concentrations for inducing pharmacological effects of CBC in human pancreatic cancer cells. FACS and Annexin V/PI staining analysis showed the increase dead cells by CBC treatment, and Western blot analysis also showed the changes in expression of cell death related proteins by CBC. Moreover, CBC treatment increased expression of CB2 receptor and TRPV receptor, but the anti-cancer effect was restored by double inhibition with SR144528 for CB2 receptor and capsazepine for TRPV receptor, respectively. mRNA-seq analysis showed that 1206 genes were upregulated and 1145 genes were down-regulated by CBC treatment, indicating that some of ferroptosis related genes (HMOX1, CHAC1, GPX4 and NFE2L2) were regulated by CBC treatment. qPCR analysis showed that those genes are increased by CBC treatment in time dependent manner. It was also confirmed that HMOX1 protein expression was increased using Western blot analysis. Therefore, we suggest that CBC induces multiple cell death mechanism including ferroptosis via CB2 receptor and TRPV receptor in human pancreatic cancer cells.

Citation Format: Yu-Na Hwang, Keun-Cheol Kim. Cell death induction via CB2 receptor and TRPV receptor in cannabichromene (CBC) treated human pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4721.
Abstract 4725: Phenotypic single-cell analysis of nuclear stress responses in drug-treated prostate cancer cells
Authors: Batnasan Enkhzaya , Kärkkäinen Minttu , Koivukoski Sonja , Ruusuvuori Pekka , Latonen Leena
Published: March 2024

Chemotherapy with anti-cancer drugs aims to stop the growth of cancer cells either by killing them or by stopping them from dividing. The different specificities in inducing cellular damage responses are incompletely understood currently and may underlie the preferential effectiveness of anti-cancer drugs against different types of cancer cells. Better understanding and tools to measure drug-induced phenotypes in vitro may aid in assessing cellular heterogeneity of responses, determining potential effectiveness, estimating amount and types of adverse effects, and predicting likelihood of surviving populations for residual disease. To measure the types and extent of nuclear stress responses to cancer drugs, we studied nuclear organelle, namely nucleolar and Cajal body, phenotypes to drug-induced stress in prostate cancer cells. We utilized organelle-specific markers NPM, Fibrillarin, Coilin, and SMN1 in immunofluorescence staining to determine suitable markers for nuclear organelle stress. We used three different prostate cancer cells lines representing different biological types of advanced prostate cancer (AR positive, AR negative, and expressing AR transcript variant). Based on initial assessments, NPM and coilin immunostaining were selected for automated phenotypic analysis screening for drug effects. Using AI-assisted nuclear segmentation and feature-based single-cell phenotypic analysis, we demonstrated quantitative effects on nuclear morphology, nucleoli, and Cajal bodies with drug treatments. A proof-of-principle study with platinum-based chemotherapeutic agents in clinical use demonstrated heterologous responses to the platinum drugs that are associated with prostate cancer cell types with different AR status. Further, we have defined the corresponding quantitative responses for androgen deprivation therapy (ADT) drugs enzalutamide and bicalutamide in AR-positive prostate cancer cells. Our findings evidence variability of prostate cancer cells’ response to chemotherapy and have implications in future therapy regimen considerations. Furthermore, we have developed a fluorescence light microscopy-based method to assess nuclear stress response phenotypes in prostate cancer cells that can be used for high throughput drug screening.

Citation Format: Enkhzaya Batnasan, Minttu Kärkkäinen, Sonja Koivukoski, Pekka Ruusuvuori, Leena Latonen. Phenotypic single-cell analysis of nuclear stress responses in drug-treated prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4725.
Abstract 4737: The combination of the BET inhibitor JQ1 and gemcitabine induces regressions in gemcitabine resistant patient-derived xenograft models of pancreatic cancer
Authors: Miller Aubrey L. , Fehling Samuel C. , Brown Eric Josh , Heard Eric O. , Gamblin Tracy L. , Vance Rebecca B. , Yoon Karina J.
Published: March 2024

Efforts to develop targeted therapies for drug resistant tumors have been relatively unsuccessful. The 5-year survival for patients with advanced pancreatic cancer is ~3%. Gemcitabine is usually combined with nab-paclitaxel as a standard of care for treatment of locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC). However, no chemotherapeutic regimens thus far evaluated have been curative. We developed the first PDAC patient-derived xenograft (PDX) models in which resistance against gemcitabine was acquired in vivo. We used RNA-seq and ingenuity pathway analysis to compare expression profiles of paired parent vs gemcitabine resistant PDX models. This comparison suggested a previously unreported mechanism for gemcitabine resistance, involving aberrations of cholesterol biosynthesis and lipid metabolism pathways. We also made the unexpected observation that gemcitabine-resistant PDAC models derived from primary tumors have high levels of 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), an enzyme essential to cholesterol biosynthesis and rate limiting in ketogenesis. Notably, the BET bromodomain inhibitor JQ1 decreases HMGCS2 levels; and BET inhibitors + gemcitabine exert synergistic cytotoxicity in gemcitabine-resistant PDAC cells. We determined that the BET bromodomain inhibitor JQ1 + gemcitabine induces regressions of two in vivo gemcitabine-resistant tumor models which we developed directly from primary human tumor tissue. These mechanism-based studies suggest that inhibiting HMGCS2 represents a novel approach to therapy for PDAC. We propose that combining gemcitabine with agents that decrease levels of HMGCS2 comprises effective treatment for patients with drug resistant PDAC.

Citation Format: Aubrey L. Miller, Samuel C. Fehling, Eric Josh Brown, Eric O. Heard, Tracy L. Gamblin, Rebecca B. Vance, Karina J. Yoon. The combination of the BET inhibitor JQ1 and gemcitabine induces regressions in gemcitabine resistant patient-derived xenograft models of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4737.
Abstract 4758: Targeting cellular pH as a novel therapeutic strategy in CDK4/6 inhibitor resistant breast cancer
Authors: Scheidemann Erin R. , Demas Diane M. , Shajahan-Haq Ayesha N.
Published: March 2024

Cyclin dependent kinase 4 and 6 inhibitors (CDK4/6i) are part of standard of care therapy in combination with antiestrogens for the treatment of metastatic estrogen receptor positive (ER+) breast cancer. Of the three major CDK4/6i, only ribociclib and abemaciclib, but not palbociclib, have shown significant improvement in overall survival in the clinic. However, resistance to CDK4/6i is prevalent and advanced metastatic ER+ breast cancer remains incurable. Other studies have focused on cell cycle or growth factor alterations in resistant tumors but targeting these pathways have not been clinically validated. Beside inhibiting the cell cycle, CDK4/6i are known to induce lysosomes in sensitive cells but the role of lysosomes in CDK4/6i resistance remains elusive. Recently, we have shown that CDK4/6i resistant breast cancer cells gain metastatic potential relative to sensitive cells and this is potentially due to deregulated lysosomes, which can be targeted with lysosome destabilizers. Here we show that all three CDK4/6i induce rapid lysosomal acidification in sensitive cells, which suggests a role of cellular pH in CDK4/6i-mediated cell death. However, in resistant cells, lysosomal acidification following CDK4/6i treatment was diminished. Therefore, we hypothesize that cellular pH is tightly regulated in CDK4/6i resistant cells and this pathway can be targeted to inhibit cell viability. Interestingly, protein levels of carbonic anhydrase IX (CA9), an important regulator of cellular pH, is significantly elevated in resistant cells. Increased CA9 levels correlate with impaired overall survival in breast and other cancers. Small molecule inhibitor of CA9, S4 or clinical-grade SLC-0111, inhibits growth of resistant cells when combined with CDK4/6i plus antiestrogens. Thus, our study highlights the role of pH changes in CDK4/6i resistant breast cancer and offer therapeutic strategies to treat this incurable disease.

Citation Format: Erin R. Scheidemann, Diane M. Demas, Ayesha N. Shajahan-Haq. Targeting cellular pH as a novel therapeutic strategy in CDK4/6 inhibitor resistant breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4758.
Abstract 482: Advancing treatment for metastatic triple negative breast cancer: Liposomal oncolytic adenovirus as a novel neoadjuvant therapy
Authors: Shah Jaimin R. , Dong Tao , Phung Abraham , Blair Sarah L. , Aisagbonhi Omonigho , Trogler William C. , Kummel Andrew C.
Published: March 2024

Introduction: Adenovirus type-5 (Ad) is considered a prominent viral vector in cancer therapy due to its modifiability for the selective lysis of cancer cells. However, challenges are posed in Ad delivery to cancers lacking coxsackievirus and adenovirus receptors (CARs). In response to this limitation, Ad-encapsulated DOTAP-folate liposomes were developed, which improved Ad delivery and heightened therapeutic efficacy through membrane fusion and folate receptor-mediated endocytosis.

Methods: The 4T1 mammary carcinoma model, a CAR-negative triple-negative breast cancer (TNBC) cell line (ER-, PR-, HER2-), resistant to adenoviral infection, was utilized for studying the comparative in vitro transduction of green fluorescent protein (GFP)-expressing Ad (Ad-GFP). The study assessed Ad-GFP with and without DOTAP-folate liposomal encapsulation at a multiplicity of infection (MOI) of 50. Additionally, an oncolytic adenovirus, Ad-hTERT, with a human telomerase promoter, underwent liposomal encapsulation. CAR-negative 4T1 GFP-expressing cells and CAR-positive MDA-MB-231-GFP human breast adenocarcinoma TNBC cells were transduced in vitro at MOI 100 with Ad-hTERT, both with and without DOTAP-folate liposomal encapsulation.

Results: CAR-negative 4T1 cells exhibited superior Ad-GFP transduction when encapsulated in DOTAP-folate liposomes, compared to the unencapsulated form (p < 0.001). For oncolytic adenovirus Ad-hTERT, encapsulation resulted in 100% cell lysis within 24 hours in 4T1-GFP cells, contrasting with 13% with unencapsulated Ad-hTERT (P < 0.0001). In CAR-positive MDA-MB-231-GFP TNBC cells, encapsulated Ad-hTERT showed enhanced efficacy, resulting in 100% cell lysis within 24 hours compared to 75% with unencapsulated Ad-hTERT (P < 0.001).

Discussion: DOTAP-folate liposomal encapsulation enhances the efficacy of oncolytic Ad-hTERT in both CAR-negative and CAR-positive TNBC cells, establishing it as an optimal therapy for tumors with CAR heterogeneity. Ongoing in vivo studies with Balb/C immune-competent mice and the 4T1 tumor model will assess the effectiveness of encapsulation through intratumoral administration. This approach may extend the recurrence-free period post-surgical tumor removal.

Citation Format: Jaimin R. Shah, Tao Dong, Abraham Phung, Sarah L. Blair, Omonigho Aisagbonhi, William C. Trogler, Andrew C. Kummel. Advancing treatment for metastatic triple negative breast cancer: Liposomal oncolytic adenovirus as a novel neoadjuvant 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 482.
Abstract 4848: An analysis of black women in the Deep South with triple negative breast cancer and the social determinants of health
Authors: Evans Lauren K. , Jubilee Ivan T. , Lemieux KiTani Parker
Published: March 2024

Background: Triple negative breast cancer (TNBC) has a higher incidence both of diagnosis and mortality among Black women. This research aims to identify specific social determinants of health among African American women in the Deep South with breast cancer. The biological presentation of disease accounts for approximately forty percent of the Experience with the health care providers, access to greenspace, and the quality of infrastructure, such as sidewalks and streetlights evaluate environmental trends associated with the outcomes of Black women in the Deep South who have been diagnosed with TNBC.

Methods: Survey data was derived from the All of Us Research Program Database with inclusion criteria of Black women from Alabama, Georgia, Mississippi, and Louisiana who are 18 or older, born a female, and have been diagnosed with TNBC. Selected questions from the SDoH survey examined infrastructure, interactions with healthcare providers, and perceptions of community dynamics. Participants were identified via the cohort selection tool and further subdivided based on zip codes within the target states. Python was used in Jupyter Notebook to analyze the data the AoURP Workbench, responses were organized according to their corresponding survey questions. Participant responses were then extracted and quantified, facilitating the interpretation of respondents’ answers on a larger scale.

Results: Three hundred and twenty women met the criteria of being born female, being black, being diagnosed with TNBC, and living in the Deep South. Of the topics examined, infrastructure was the area where participants’ feedback indicated the largest socioeconomic deficit. Forty-eight and 49%, respectively. Indicated that did not have access to greenspace nor did not live within 10-15-minute walking distance of a transit stop. Thirty percent reported that their doctor or nurse does not listen to what they are saying.

Conclusion: Quality of life and interaction with members of the health care team associated with poorer health outcomes for Black women in the Deep South. These preliminary results indicate that those diagnosed with TNBC are impacted by the social determinants of health, specifically, proximity to public transportation, quality healthcare, recreational facilities, and infrastructure which suggests that basic needs are not met.

Citation Format: Lauren K. Evans, Ivan T. Jubilee, KiTani Parker Lemieux. An analysis of black women in the Deep South with triple negative breast cancer and the social determinants of health [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 4848.