bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5526: Activation of platelet-activating factor (PAF) in high-risk melanoma patients with nodal metastasis
Authors: McMasters Austin , Chariker Julia , Hwang Jae Yeon , Yin Xinmin , Ma Xipeng , Xu Raobo , Zhang Xiang , Park Juw Won , McMasters Kelly M. , Hao Hongying
Published: March 2024

Background: Platelet-activating factor (PAF) is one of the lipid mediators in ultraviolet-induced immunosuppression signaling. Sentinel lymph nodes (SLNs) are the first organs to receive lymphatic drainage via afferent lymphatic channels leading directly from the primary melanoma. In patients with nodal metastasis, it has been shown that the SLN has a profoundly immunotolerant microenvironment. We sought to determine whether lymphatic fluid signals, including PAF, may be involved in modulating the SLN immune microenvironment to favor melanoma metastasis.

Hypothesis: Upregulation of PAF can bind to its receptor on monocytes and activate downstream immunosuppressive chemokines, resulting in an immunosuppressed environment in SLNs that permits nodal metastasis and melanoma progression.

Methods: Lymphatic fluids, plasma samples, and SLN samples were collected from patients undergoing surgical excision of melanoma with SLN biopsy under an IRB-approved protocol. Metabolic analyses were performed on lymphatic fluids from high- versus low-risk patients by two-dimensional liquid chromatography system coupled with mass spectrometry (2D LC-MS). Single cell sequencing was done on single cell suspensions from SLN samples. Protein array was used to compare the cytokine and chemokine levels in plasma samples from high- versus low-risk melanoma patients. We compared two groups: low-risk (no SLN metastasis) and high-risk (with SLN metastasis).

Results: Lymphatic fluid PAF levels were 3-fold greater in high-risk melanoma patients compared with low-risk patients (p=0.0039). Macrophages were identified as the cell type with greatest PTAFR (platelet-activating factor receptor) expression by single cell sequencing. CCL17 levels in plasma samples from high-risk patients were significantly lower than in low-risk patients (p<0.05). These results suggest that increased PAF in lymphatic fluid may bind to PTAFR in SLN macrophages, inhibit chemokines (such as CCL17), and result in an immunosuppressive SLN environment to favor nodal metastasis and melanoma progression.

Conclusion: Lymphatic fluid PAF signaling may contribute to an immunotolerant microenvironment in the SLN that allows nodal metastasis and melanoma progression through downregulation of CCL17. Further studies will investigate whether this pathway can be exploited to therapeutic advantage.

Citation Format: Austin McMasters, Julia Chariker, Jae Yeon Hwang, Xinmin Yin, Xipeng Ma, Raobo Xu, Xiang Zhang, Juw Won Park, Kelly M. McMasters, Hongying Hao. Activation of platelet-activating factor (PAF) in high-risk melanoma patients with nodal metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5526.
Abstract 5531: Loss of csf2(gm-csf) with cisplatin treatment decreases metastasis and improves survival in a hpv positive head and neck cancer murine model
Authors: Ghosh Payal , Welbon Craig , Spanos William C.
Published: March 2024

Granulocyte macrophages colony stimulating factor (GM-CSF) also known as CSF2 is a popular cytokine responsible for homeostasis. According to TCGA databank CSF2 expression upregulated in human HPV+ (Human Papilloma Virus) Head and Neck Small Cell Carcinoma (HNSCC) compared to normal tissue. The mechanism of CSF2 in tumor progression and chemo resistance has not been well studied. Previously, our lab generated a murine model of HPV+ HNSCC that is partially responsive to cisplatin and radiation (like human disease). The role of our study is to evaluate the importance of Csf2 with cisplatin treatment (CT) in HPV + HNSCC in the murine model. Using CRISPR-Cas9 technology we knocked out the expression of the Csf2 ligand in our parental mEERL (murine E6 E7 Ras Luciferase) tumor cell line and implanted both the parental mEERL tumor and the Csf2 KO mEERL tumor in the oral cavity of C57BL6/J mice. When tumors reached a palpable size, we administered Cisplatin (20mg/m2, 3 doses total). We observed slow tumor growth in absence of Csf2 without treatment. On the other hand, we observed tumor regression in both tumor models with cisplatin treatment. Post treatment, mice with Csf2 KO tumors had a significantly prolonged rate of survival. To evaluate the role of Csf2 in the Tumor Microenvironment (TME), we collected the tumors 96 hours post CT and characterized the TME using multicolored flow cytometry. The results showed that post treatment mice with Csf2 KO tumors increased the number of the Natural Killer cell population and a surge of M-MDSC (Ly6Chi) population. The synergistic effect of knocking out Csf2 and cisplatin treatment in our tumor model appears to be driven by chemokine and cytokine changes in the TME. Simultaneously, we observed significantly lower levels of lung metastasis in Csf2 KO tumor bearing mice compared to those with parental mEERL tumors. Whereas we have seen increased metastasis in ipsilateral lymph node of Csf2 KO mice. This metastasis data mimics human disease where many patients have regional lymph node involvement, but few develop distant metastasis. These results indicate that GM-CSF (CSF2) in the TME could be an excellent target that would cause less metastasis and improved overall survival. Further investigations are needed to understand the underlying mechanism of immune response in the absence of CSF2 in the TME.

Citation Format: Payal Ghosh, Craig Welbon, William C. Spanos. Loss of csf2(gm-csf) with cisplatin treatment decreases metastasis and improves survival in a hpv positive head and neck cancer murine model [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 5531.
Abstract 5534: Needle biopsy induces pro-metastatic progression and systemic dissemination of estrogen receptor-positive breast cancer cells through the COX-2/PGE2 cascade
Authors: Kameyama Hiroyasu , Leslie Macall , Simmons Reese , Sun Yunguang , Yi Misung , Dondapati Priya , Langenheim John F. , Fung Kar-Ming , Chervoneva Inna , Rui Hallgeir , Tanaka Takemi
Published: March 2024

Breast cancer is the most commonly diagnosed malignancy in the U.S. and over two-thirds of invasive breast cancer cases are diagnosed early stage. However, 15-year survival rates for early-stage breast cancer remain in the range of 70-77%. Mounting evidence showed an increased risk of disease progression and mortality among early-stage breast cancer patients whose surgery was delayed over 60 days after the diagnostic biopsy. Yet, the mechanism(s) underlying the rapidly increased mortality due to delay of surgery after diagnosis remains unknown.

Our cohort analyses of early-stage breast cancer patients reveal the emergence of a significantly rising mortality risk when the biopsy-to-surgery interval was extended beyond 53 days. Additionally, histology of post-biopsy tumors shows prolonged retention of a metastasis-permissive wound stroma dominated by M2-like macrophages capable of promoting cancer cell epithelial-to-mesenchymal transition and angiogenesis by secretion of transforming growth factor beta 1 (TGF-β1) and vascular endothelial growth factor (VEGF). We show that needle biopsy promotes systemic dissemination of cancer cells through a mechanism of sustained activation of the cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) cascade, which favors M2-polarization and its associated pro-metastatic changes, but are abrogated by oral treatment with COX-2 inhibitors in estrogen receptor-positive (ER+) syngeneic mouse tumor models.

Therefore, we conclude that needle biopsy of ER+ breast cancer provokes progressive pro-metastatic changes, which may explain the mortality risk posed by surgery delay after diagnosis. Also, our data may provide a rationale for a pharmacologic strategy to inhibit the COX-2/PGE2 cascade in cases when delay of surgery is unavoidable.

Citation Format: Hiroyasu Kameyama, Macall Leslie, Reese Simmons, Yunguang Sun, Misung Yi, Priya Dondapati, John F. Langenheim, Kar-Ming Fung, Inna Chervoneva, Hallgeir Rui, Takemi Tanaka. Needle biopsy induces pro-metastatic progression and systemic dissemination of estrogen receptor-positive breast cancer cells through the COX-2/PGE2 cascade [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 5534.
Abstract 5540: Single cell multiomic analysis of human brain metastasis reveals conserved dormancy population
Authors: Klotz Remi , Wang Yiru , Sunkara Anu , Attenelo Frank , Yu Min
Published: March 2024

This study explores the complex realm of brain metastasis, pivotal in crafting effective anti-tumor strategies. Leveraging single-cell multi-omics sequencing, we profiled the transcriptomes and chromatin accessibility landscapes of tumor cells and their surrounding microenvironment in human brain metastases that originated from across a spectrum of primary cancers. Our investigations have identified distinct, yet uniformly present, tumor cell subpopulations, each defined by unique gene expression patterns, chromatin accessibility, and the interactions between tumor and stromal cells. Notably, one such subpopulation exhibits a dormancy signature, characterized by enhanced interferon response, oxidative phosphorylation, and upregulated HLA class molecules, alongside alterations in circadian rhythms. Our trajectory analysis charts a course from these dormant cells to rapidly proliferating ones, with notable shifts in circadian rhythm genes, underscoring their potential role in brain metastasis. This aligns with recent findings that disruptions in circadian rhythms can modify stem cell characteristics in glioblastomas. This insight led us to focus on a specific circadian rhythm gene, highly active in the dormant cells and located on the HER2 amplicon—an area linked to high brain metastasis relapse rates in patients. We've developed inducible models for both overexpression and knockdown to scrutinize this gene's impact in her2 positive breast cancer cell lines, examining gene expression and proliferation in vitro. Complementing this, we are conducting spatial transcriptomic analysis to evaluate the microenvironmental regulation of tumor dormancy in human brain metastases. This multi-omics approach reveals a nuanced regulatory landscape of brain metastasis, highlighting a novel and often overlooked factor in metastasis progression and brain tumor relapse: the interplay between circadian rhythms and tumor dormancy. This discovery not only deepens our understanding of brain metastases but also opens potential new avenues for therapeutic interventions.

Citation Format: Remi Klotz, Yiru Wang, Anu Sunkara, Frank Attenelo, Min Yu. Single cell multiomic analysis of human brain metastasis reveals conserved dormancy population [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 5540.
Abstract 5547: Non-invasive monitoring of tumor biomechanics and implications for immunotherapy in HCC
Authors: Cortes Andrea C. , Minamiguchi Kiyoyuki , Kostan Hannah , Stenkamp Maria S. , Anfossi Simone , Fowlkes Natalie Wall , Avritcsher Rony
Published: March 2024

Shear-wave elastography (SWE) is a novel non-invasive technique used to quantify tissue stiffness. This approach can be used to longitudinally monitor tumor biomechanics and holds promise for guiding informed clinical decision-making. This study aims to explore the impact of tumor stiffness, as evaluated by SWE, on the proliferative potential of endothelial, tumor, and immune cells in a preclinical model of hepatocellular carcinoma. Tumor tissue sections from a Buffalo-McA-RH7777 rat HCC tumor model, utilizing a rat hepatoma cell line stably expressing green fluorescent protein genes (fluc/GFP) were selected based on the degree of tumor stiffness assessed by SWE. Nodules were separated based on mean shear wave values (3.05 versus 2.26 m/s) and categorized as stiff or soft, respectively. A 6-color panel was used to assess the percentages of different tumor, immune, and endothelial phenotypes in different areas of the tumor including immune cells (CD45+), endothelial cells (CD34+), green fluorescent protein (GFP), Ki67 (cell proliferation), and class-III intermediate filaments - vimentin. Our findings demonstrated increased expression of vimentin on immune cells (CD45+) within the tumor margin interphase. Stiffer tumors exhibited a higher percentage of CD45 cells co-expressing vimentin compared to softer tumors (P=0.01), whereas softer tumors showed an increased prevalence of CD34+ cells concurrently expressing Ki67 (P=0.01). Same pattern persisted in the tumor margin interphase regarding the proliferation of tumor cells identified by the expression of GFP co-expressing Ki67 (P<0.01). These findings highlight a significant association between tumor mechanical properties and the proliferative activity of endothelial and tumor cells, suggesting a link between tissue stiffness and the regulatory mechanisms associated with cellular proliferation and aggressiveness in HCC. Additionally, the presence of vimentin in immune cells may suggest that stiffer tumors may require enhanced migratory and invasive properties to compensate for changes in tumor mechanics thus potentially influencing immune function.

Citation Format: Andrea C. Cortes, Kiyoyuki Minamiguchi, Hannah Kostan, Maria S. Stenkamp, Simone Anfossi, Natalie Wall Fowlkes, Rony Avritcsher. Non-invasive monitoring of tumor biomechanics and implications for immunotherapy in HCC [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 5547.
Abstract 5550: Crosstalk of estrogen receptor Β with tumor microenvironment signaling explains tumor suppressor actions in TNBC
Authors: Zambo Kristina Diana A. , Nagandla Harika , Cap Kim Cuong , Phillips Aireana , Nikolos Fotis , Qian Wei , Zhou Jianying , Chang Jenny , Thomas Christoforos
Published: March 2024

Triple Negative Breast Cancer (TNBC) is a subtype of breast cancer lacking molecular targets, possessing one of the poorest prognoses of all breast cancers. Recent studies using breast tumor samples show an association between the expression of estrogen receptor β (ERβ) and improved survival of patients with TNBC. ERβ - whose function largely opposes that of oncogenic ERα - is involved in the regulation of many tumor repressive pathways and has lately been observed to partake in immune modulation, thus presenting a promising target for TNBC. Discovering selective ERβ agonists is critical to understanding the potential of activating the receptor as a therapy approach for TNBC. It enables us to elicit estrogen signaling response specific to the tumor suppressive function of the β receptor subtype. We have set out a screening process to test and identify ligands that display the greatest activation and specificity for ERβ as determined by reporter assays and changes in downstream target gene expression. We selected to study in vitro and in vivo the compounds with optimal biological activity to delineate tumor-intrinsic and -extrinsic effects and validate the mechanism of action employing human and mouse cell models that reflect the heterogeneity of the disease. We propose that activation of ERβ decreases the proliferative and metastatic ability of breast cancer cells by altering cellular pathways and crosstalk with immune cells. The results of these studies help lay the groundwork for further research on the clinical potential of ERβ especially in the realm of immunotherapy and treatment of TNBC.

Citation Format: Kristina Diana A. Zambo, Harika Nagandla, Kim Cuong Cap, Aireana Phillips, Fotis Nikolos, Wei Qian, Jianying Zhou, Jenny Chang, Christoforos Thomas. Crosstalk of estrogen receptor Β with tumor microenvironment signaling explains tumor suppressor actions in TNBC [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 5550.
Abstract 5555: Lung squamous cancer cell mTORC2 signaling suppresses antitumor immunity by up-regulation of PSGL-1, a ligand of VISTA/PD-1H checkpoint receptor
Authors: Ngwa Verra M. , Hwang Yoonha , Edwards Deanna N. , Song Wenqiang , Chen Jin
Published: March 2024

Lung squamous cell carcinoma (LUSC) represents 30% of non-small cell lung cancer (NSCLC) cases and has a high mortality rate with limited targeted therapies. Unlike lung adenocarcinoma (LUAD), which has seen advancements in targeted therapies, LUSC has not benefited from similar breakthroughs despite having similar genetic abnormalities. While immune checkpoint inhibitor therapies have shown promise in some LUSC patients, a significant portion does not respond effectively, leaving limited treatment options. In this study, we investigated vulnerabilities in NSCLC and found that a substantial number of LUSC patients have genetic alterations in the PI3K-mTORC2-AKT signaling pathway. By using CRISPR/CAS-9, we showed that disrupting mTORC2 function in LUSC cells reduced glycolysis and lactate secretion, which in turn reduced tumor growth in vivo. Remarkably, the loss of mTORC2 also enhanced the activity of CD4+ and CD8+ T cells within the tumors. To further understand the metabolic and immune changes associated with mTORC2 loss of function, we performed RNA sequencing comparing wild-type (WT) and mTORC2-deficient cells. Our results confirmed a link between mTORC2 and HIF-2α, while regulating PSGL-1, a ligand of the VISTA/PD-1H checkpoint receptor. Furthermore, introducing a stable, non-degradable form of HIF-2α in mTORC2-deficient tumor cells restored PSGL-1 expression in vitro and in vivo. These results suggest that the interaction between PSGL-1 and VISTA plays a role in suppressing the anti-tumor immune response in LUSC tumors. Indeed, anti-VISTA treatment inhibited the growth of LUSC WT tumors in vivo, suggesting that mTORC2 plays a role in regulating PSGL-1 expression in the tumor microenvironment. Together, these data demonstrate that targeting mTORC2 or inhibiting VISTA checkpoint receptor may serve as a potential therapeutic strategy for improving immunotherapy in LUSC.

Citation Format: Verra M. Ngwa, Yoonha Hwang, Deanna N. Edwards, Wenqiang Song, Jin Chen. Lung squamous cancer cell mTORC2 signaling suppresses antitumor immunity by up-regulation of PSGL-1, a ligand of VISTA/PD-1H checkpoint receptor [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 5555.
Abstract 5562: Altered tumor microenvironment in animal model of concomitant GBM and Alzheimer's pathology
Authors: Nascari David , Eghlimi Ryan , Beniwal Angad , Alton Drake , Fryer John , Tran Nhan L.
Published: March 2024

Glioblastoma (GBM) and Alzheimer’s disease (AD) are two devastating central nervous system diagnoses with no known cure. Both diseases are associated with advanced age. The majority of GBM tumors form in the frontal and temporal lobes, two of the brain regions most impacted by amyloid and tau pathology in AD. Females have a higher risk of AD, while males have a higher risk of GBM. Several large case series have established epidemiological evidence that the two diseases are inversely correlated. Nevertheless, it remains unknown whether presence of subclinical amyloid or tau pathology antagonizes the establishment or progression of GBM. The present study sought to characterize GBM growth, progression, and immune response in the setting of concomitant AD pathology using the syngeneic murine GL261 tumor model. To further understand the tumor cell changes that occur in the presence or absence of AD pathology, we engineered GL261 with a dual-tagged vector consisting of RiboTag (to allow for full-length mRNA profiling) and TurboID (to allow for proteomic profiling). GL261 cells were injected intracranially into APPNL-G-F/NL-G-F - MAPThuman/human, APPNL-G-F/+ - MAPThuman/+, and wildtype C57BL/6J mice. Tumors in both wildtype and AD conditions contained ~50% intratumoral myeloid cells (Iba+, P2RY12-). Differential activation of intratumoral myeloid cells will be assessed with immunohistochemistry. Microgliosis (IBA1, P2RY12) and astrogliosis (GFAP) around the tumor in the setting of Alzheimer’s pathology versus normal conditions will be compared. Invasiveness, proliferation, DNA damage (pH2AX), and apoptosis (cleaved PARP, cleaved Caspase 3) will be compared. Tumor cell-specific changes unique to tumors in the AD microenvironment will be assessed transcriptionally with RiboTag profiling as well as proteomically with TurboID purifications. Our preliminary data suggests that the presence of concomitant AD pathology affects GBM growth and progression as well as the immune response to the tumor, and warrants further investigation.

Citation Format: David Nascari, Ryan Eghlimi, Angad Beniwal, Drake Alton, John Fryer, Nhan L. Tran. Altered tumor microenvironment in animal model of concomitant GBM and Alzheimer's pathology [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 5562.
Abstract 5605: Cutibacterium acnes invades prostate epithelial cells to induce BRCAness as a possible pathogen of prostate cancer
Authors: Ashida Shingo , Kawada Chiaki , Tanaka Hiroko , Kurabayashi Atsushi , Yagyu Ken-ichi , Sakamoto Shuji , Maejima Kazuhiro , Miyano Satoru , Daibata Masanori , Nakagawa Hidewaki , Inoue Keiji
Published: March 2024

Abundant evidence suggests that chronic inflammation is linked to prostate cancer and that infection is a possible cause of prostate cancer. However, pathogen of prostate cancer remains to be found. To identify microbiota or pathogens associated with prostate cancer, we investigated the transcriptomes of 20 human prostate cancer tissues. We performed de novo assembly of non-human sequences from RNA-seq data and identified four bacteria as candidate microbiota in the prostate, including Moraxella osloensis, Uncultured chroococcidiopsis, Cutibacterium acnes, and Micrococcus luteus. Among these, C. acnes was detected in 19 of 20 prostate cancer tissue samples by immunohistochemistry. We then analyzed the gene expression profiles of prostate epithelial cells infected in vitro with C. acnes and found significant alterations in homologous recombination (HR) and Fanconi anemia pathway. Notably, electron microscopy showed that C. acnes invaded prostate epithelial cells and localized in perinuclear vesicles, whereas analysis of γH2AX foci and HR assay demonstrated impaired HR repair. In particular, BRCA2 was significantly down-regulated in C. acnes-infected cells. These findings suggest that C. acnes infection in the prostate could lead to HR deficiency and BRCAness which promotes DNA double-strand breaks, thereby increasing the risk of cancer development.

Citation Format: Shingo Ashida, Chiaki Kawada, Hiroko Tanaka, Atsushi Kurabayashi, Ken-ichi Yagyu, Shuji Sakamoto, Kazuhiro Maejima, Satoru Miyano, Masanori Daibata, Hidewaki Nakagawa, Keiji Inoue. Cutibacterium acnes invades prostate epithelial cells to induce BRCAness as a possible pathogen of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5605.
Abstract 5614: Mechanical regulation of cisplatin-DNA adduct repair in mesenchymal stem cells
Authors: Zavala Anamaria Gabriella , Nikitina Nina , Cantu Crystal , DeLaCruz Dalia , Uzer Gunes
Published: March 2024

This study examined whether loss of mechanotransduction in pluripotent mesenchymal stem cells (MSCs) disrupted repair of bulky DNA adducts, such as those induced by ultraviolet light or cisplatin. MSCs are important for the maintenance and responsiveness of skeletal tissues to environmental mechanical challenges. Beyond regulating proliferative and differentiative capacity of MSCs, emerging evidence suggests that physical activity is associated with improved recovery from DNA damage caused by environmental genotoxic stressors associated with stress and aging. Highlighting the possible crosstalk between DNA repair and bone health, defects in nucleotide excision repair (NER), which removes bulky DNA adducts, are associated with myelosuppression and progeroid aging phenotypes that result in bone defects and lipidodystrophies in mice. Cancer, early aging syndromes, and certain musculoskeletal diseases are associated with disruption of the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex that transduces environmental mechanical signals from the extracellular matrix into the nucleus of a cell. Loss of LINC complex elements is associated with breast cancer progression and poorer prognosis. We hypothesize that LINC-mediated mechanical stimulation into the nucleus is critical for repair of bulky DNA adducts. Our pilot project showed that mechanical stimulation applied in the form of low intensity vibration (LIV) improved NER of cisplatin-induced DNA adducts in cultured MSCs. Our findings show a 20% increase in repair of cisplatin-induced DNA adducts in LIV treated samples compared to non-vibrated samples at 24 hours (P<0.005). We also quantified the effect of LINC complex disruption on cisplatin-induced DNA damage removal. Intact MSCs showed significant adduct removal after 24 hours, while LINC disruption significantly reduced DNA repair (P<0.001). Furthermore, initial experiments suggest that LINC disrupted cells do not arrest at DNA repair checkpoints, therefore, loss of LINC complex may reduce entry into senescence increasing DNA mutagenesis. In conclusion, these findings suggest a novel interaction between mechanical stimulation, the DNA damage response, and LINC complex in DNA repair in multipotent mesenchymal stem cells. Furthermore, we suggest that LINC-mediated mechanical changes associated with LIV treatment may lead to novel therapeutic approaches to combat deleterious musculoskeletal conditions associated with anti-cancer treatments.

Citation Format: Anamaria Gabriella Zavala, Nina Nikitina, Crystal Cantu, Dalia DeLaCruz, Gunes Uzer. Mechanical regulation of cisplatin-DNA adduct repair in mesenchymal 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 5614.
Abstract 5624: Dec2, a circadian rhythm gene facilitates pancreatic cancer dormancy through evasion of antitumor immunity
Authors: Wang Lan , Harris Chris , Prela Orjola , Narrow Wade C. , Carpizo Darren R.
Published: March 2024

Metastatic recurrence following curative intent oncologic surgery is a major clinical problem in patients with pancreatic ductal adenocarcinoma (PDAC). These recurrences are from disseminated tumor cells (DTCs) and can sometimes occur years after surgery indicating that DTCs undergo a period of dormancy. The mechanisms that drive cancer dormancy and its awakening are poorly understood in part due to a lack of animal models that recapitulate dormant tumor cell biology. We created a novel model of PDAC dormancy where mice undergo surgery to remove the primary tumor and are followed for evidence of metastatic recurrence. Dormant DTCs can be isolated from mice without clinical evidence of recurrence for molecular studies. Single cell RNAseq of dormant DTCs detected that the circadian rhythm gene, Dec2 is upregulated. We knocked out (KO) Dec2 from murine pancreatic cancer cells and when implanted into the model we found almost no mice developed metastatic recurrence. When immunodeficient or immunocompetent mice depleted of CD4 and CD8 T cells were used as hosts, we observed no difference in survival in mice engrafted with Dec WT vs. KO cells indicating the survival benefit in the Dec KO group was due to an immune mediated mechanism. We performed a differential expression analysis on bulk RNAseq data comparing the Dec2 WT vs. KO cells and found antigen presentation a top upregulated pathway. We then observed that surface MHC-I was significantly upregulated in Dec2 KO cells as compared to wild type cells. Further mechanistic studies revealed that proteosome activity was significantly higher in Dec2 KO cells and treatment with proteosome inhibitors decreased surface MHCI levels in Dec2 KO cells. Cut and tag experiments revealed that Dec2 binds the promoter of a number of genes that regulate the proteosome. In conclusion, Dec2 promotes cancer dormancy by down regulating cell surface MHCI which facilitates immune evasion.

Citation Format: Lan Wang, Chris Harris, Orjola Prela, Wade C. Narrow, Darren R. Carpizo. Dec2, a circadian rhythm gene facilitates pancreatic cancer dormancy through evasion of antitumor immunity [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 5624.
Abstract 5644: The impact of ATF3, JDP2, FOXR2, NAA10, FOXL2, DDX20, and p14ARF on the transactivation of p53
Authors: Yang William H. , Yang Wei-Hsiung
Published: March 2024

Cancer stands as a formidable health challenge in the 21st century, evoking widespread fear. Presently, the mortality rate associated with cancer in humans ranges from approximately 11% to 25%. Numerous nuclear and cytoplasmic proteins have demonstrated interactions with p53, influencing both its activity and abundance. In our prior, unpublished findings, we established that JDP2 interacts with p53, modulating its activity. Consequently, in the present investigation, we broaden our exploration to identify novel proteins capable of regulating p53 transactivation. First, we found a synergistic effect of ATF3 and JDP2 on p53 transactivation. Moreover, deSUMOylation of ATF3 and dephosphorylation of JDP2 further enhance p53 transactivation. Secondly, FOXR2 (an epigenetically regulated pan-cancer oncogene) and NAA10 (an acetyltransferase) also remarkably increase p53 transactivation in H1299 (p53 null) cells. Thirdly, in addition to MDM2 and MDM4 (MDMX) as p53 negative regulators, we further found that FOXL2 (a transcription factor in steroidogenesis regulation), DDX20 (a transcription factor for embryonic development and ovarian function), and p14ARF (for cell cycle regulation) significantly down-regulate p53 transactivation. Taken together, our preliminary results demonstrate that several transcription factors regulate p53 transactivation and possible p53 stability and/or degradation. This data is presented to substantiate the idea that numerous newly discovered proteins may engage with p53 and control its transactivation.

Citation Format: William H. Yang, Wei-Hsiung Yang. The impact of ATF3, JDP2, FOXR2, NAA10, FOXL2, DDX20, and p14ARF on the transactivation of p53 [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 5644.
Abstract 5649: PRRX1-TOP2A interaction is a malignancy-promoting factor in human malignant peripheral nerve sheath tumors
Authors: Takihira Shota , Nakata Eiji , Yamada Daisuke , Osone Tatsunori , Takao Tomoka , Takarada Takeshi , Hirasawa Akira , Itano Takuto , Fujiwara Tomohiro , Kunisada Toshiyuki , Ozaki Toshifumi
Published: March 2024

Background: Paired related-homeobox 1 (PRRX1) is a transcription factor in the regulation of developmental morphogenetic processes. There is growing evidence that PRRX1 is highly expressed in certain cancers and is critically involved in human survival prognosis. However, the molecular mechanism of PRRX1 in cancer malignancy remains to be elucidated.

Methods: PRRX1 expression in human Malignant peripheral nerve sheath tumors (MPNSTs) samples was detected immunohistochemically to evaluate survival prognosis. MPNST models with PRRX1 gene knockdown or overexpression were constructed in vitro, and the phenotype of MPNST cells was evaluated. Bioinformatics analysis combined with co-immunoprecipitation, mass spectrometry, RNA seq, and structural prediction were used to identify proteins interacting with PRRX1.

Results: High expression of PRRX1 was associated with a poor prognosis for MPNST. PRRX1 knockdown suppressed the tumorigenic potential. PRRX1 overexpressed in MPNSTs directly interacts with topoisomerase 2A (TOP2A) to cooperatively promote epithelial-mesenchymal transition and increase expression of tumor malignancy-related gene sets including mTORC1, KRAS, and SRC signaling pathways. Etoposide, a TOP2A inhibitor used in the treatment of MPNST, may exhibit one of its anticancer effects by inhibiting the PRRX1-TOP2A interaction.

Conclusion: Targeting the PRRX1-TOP2A interaction in malignant tumors with high PRRX1 expression might provide a novel tumor-selective therapeutic strategy.

Significance: MPNST is a malignant tumor with a poor prognosis and still lacks definitive treatment. Our results could hold promise as an alternative therapeutic strategy to inhibit the interaction between PRRX1 and TOP2A, and may improve the prognosis for malignant tumor patients with high expression of PRRX1 and TOP2A such as MPNSTs.

Citation Format: Shota Takihira, Eiji Nakata, Daisuke Yamada, Tatsunori Osone, Tomoka Takao, Takeshi Takarada, Akira Hirasawa, Takuto Itano, Tomohiro Fujiwara, Toshiyuki Kunisada, Toshifumi Ozaki. PRRX1-TOP2A interaction is a malignancy-promoting factor in human malignant peripheral nerve sheath 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 5649.
Abstract 57: Ibrutinib improves chimeric antigen receptor T cell control of leukemia by inhibiting myeloid-derived suppressor cells
Authors: Frost Benjamin F. , Shestova Olga , Shen Feng , Sharpe Chia , Byrd John C. , Gill Saar I.
Published: March 2024

Background: In patients with chronic lymphocytic leukemia (CLL), we and others have shown that the addition of the BTK inhibitor ibrutinib to CART cells increases the rates of durable complete responses. The mechanism for this remains unknown. Lymphodepletion (LD) is considered critical for CART cell therapy success, yet emergency myelopoiesis during recovery from LD may induce a surge of myeloid-derived suppressor cells (MDSC), particularly in patients with advanced cancer. BTK inhibition has been shown to inhibit MDSC function in vitro. We therefore hypothesized that administration of ibrutinib during and following LD could reduce MDSC-mediated suppression of CART cells and thereby improve CART cell outcomes.

Methods: To explore the effects of ibrutinib on human MDSCs, we engineered suppressive monocytes through in vitro culture of CD14+ cells in the presence of IL-6 and GM-CSF. We added ibrutinib to the culture on Days 0-4 and compared the ability of the monocytes to inhibit proliferation of human CAR-T cells. To model CLL treatment with CART in immunocompetent mice, we used the Em-TCL1 adaptive transfer model of CLL. Mice were treated with ibrutinib (I), cyclophosphamide and fludarabine (FC), or ibrutinib + FC (FC+I). MDSCs were isolated from these mice for in vitro function studies. In subsequent experiments mice were also treated with syngeneic CART19 with or without FC or FC+I.

Results: In vitro generated human MDSC suppressed CART19 function, and this was prevented by pre-treatment of MDSC with ibrutinib. Myeloid cells from the spleens of CLL-bearing mice inhibited syngeneic CART19 function ex vivo regardless of treatment with FC or I alone, but myeloid cells harvested from CLL-bearing mice treated with FC+I lost suppressive function. Finally, mice treated with CART19 after a LD regimen resembling that in our recently reported clinical trial (FC+I) showed a survival advantage over all other groups.

Conclusions: BTK inhibition with ibrutinib prevents myeloid cell suppression of CART cells in vitro in human and murine systems. When combined with lymphodepleting chemotherapy (FC), ibrutinib enhances CART cell control of CLL in vivo, possibly by preventing MDSC-mediated suppression of CART cells.

Citation Format: Benjamin F. Frost, Olga Shestova, Feng Shen, Chia Sharpe, John C. Byrd, Saar I. Gill. Ibrutinib improves chimeric antigen receptor T cell control of leukemia by inhibiting myeloid-derived suppressor 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 57.
Abstract 5727: ISM9682A, a novel and potent KIF18A inhibitor, shows robust antitumor effects against chromosomally unstable cancers
Authors: Zhang Jie , Gao Feng , Zhu Wei , Xu Chenxi , Ding Xiaoyu , Shang Jing , Qiao Junwen , Chen Shan , Cai Xin , Ding Xiao , Bavadekar Supriya , Rao Sujata , Zhang Man , Ren Feng , Zhavoronkov Alex
Published: March 2024

KIF18A belongs to the kinesin-8 subfamily and is a plus-end-directed motor, which regulates kinetochore microtubules dynamics to control mitotic chromosome alignment and spindle tension. Studies have shown that genetic depletion or pharmacological inhibition of KIF18A is a promising therapeutic approach for cancers, exhibiting high chromosomal instability (CIN-high), without having a significant impact on the normal division of euploid cells. Here, we report the discovery and preclinical evaluation of ISM9682A, a novel KIF18A inhibitor with excellent potency and high selectivity. ISM9682A is a potent KIF18A inhibitor with a single-digit nanomolar IC50 value and exhibits high selectivity over other kinesin family members. In addition, ISM9682A demonstrated excellent monotherapy anti-proliferative activity, with single-digit nanomolar IC50 values, in high-grade serous ovarian carcinoma (HGSOC) as well as in triple-negative breast cancer (TNBC) aneuploid cell lines with p53 mutation. Notably, ISM9682A exhibited a prolonged drug-target residence time indicated by both enzymatic and cellular assays. Consistent with the in vitro findings, ISM9682A displayed significant anti-tumor efficacy with a robust pharmacodynamic response (pH3, mitotic marker; γH2AX, DNA damage marker) in OVCAR3 and HCC1806 CDX models in a dose-dependent manner. In addition to its robust biological potency and high selectivity, ISM9682A exhibits favorable drug-like properties, including desirable in vitro ADMET characteristics and excellent in vivo exposure, clearance, as well as good oral bioavailability across multiple preclinical species. Collectively, these findings highlight the potential of ISM9682A as a novel and highly potent KIF18A inhibitor for the treatment of CIN-high cancers.

Citation Format: Jie Zhang, Feng Gao, Wei Zhu, Chenxi Xu, Xiaoyu Ding, Jing Shang, Junwen Qiao, Shan Chen, Xin Cai, Xiao Ding, Supriya Bavadekar, Sujata Rao, Man Zhang, Feng Ren, Alex Zhavoronkov. ISM9682A, a novel and potent KIF18A inhibitor, shows robust antitumor effects against chromosomally unstable 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 5727.
Abstract 5746: Tris(4-methoxyphenyl) methanol conjugates of triptorelin as cell-penetrating anti-cancer prodrugs
Authors: Beni Ryan , Boadi William , Alnakhli Jawzah , Alhamed Samiyah
Published: March 2024

Triptorelin® (TRP) is an anti-cancer drug used for the treatment of a wide range of hormone-responsive cancers, including prostate cancer. The increase in testosterone levels, known as the flare effect, is a major side effect of cancer chemotherapy when TRP is used in a combination regimen. Reports indicate that enhancing the cellular uptake and retention of TRP can improve its biological activity. In this study, TRP conjugates of tris(4-methoxyphenyl) methanol derivatives (TPMs) with optimized hydrophobicity were synthesized by reacting 2-substituted methoxybenzenes with 1,3,5-trioxane, followed by conjugation with TRP and sebacic acid to produce TRP-TPMs derivatives. The hydrophobicity of TRP was optimized by using the appropriate hydrophobic linker attached to the respective TPM to improve cellular uptake. The aim of the current studies was to evaluate the respective antiproliferative effects of the newly synthesized TRP-TPMs, physical mixtures of TPMs and TRP using different cell lines. Our hypothesis was that exposure of cells to TRP-TPMs derivatives can enhance the antiproliferative activities in cells in comparison to respective the physical mixtures and TRP. Antiproliferative studies in human acute lymphoblastic leukemia (CCRF-CEM), human ovarian adenocarcinoma (SK-OV-3), and mouse preadipocytes (3T3-L1) were carried out following exposure to the respective compounds. Our findings indicate that TRP-TPMs conjugates, at a concentration of 50 µM, significantly inhibited cell proliferation in CCRF-CEM, SK-OV-3, and 3T3-L1 cells by 21-37%, 24-73%, and 37-56%, respectively, following 72-hour incubation in comparison to the respective physical mixtures and TRP. Conjugation of TRP with the respective derivative of TPMs enhanced antiproliferative activities in all the cells (with no significant differences in cytotoxicity) compared to the physical mixtures of TPMs and TRP. The findings in the current studies suggest that TRP-TPMs can be used as potential prodrugs, to enhance the cells biological activity, and cellular uptake of TRP.

Citation Format: Ryan Beni, William Boadi, Jawzah Alnakhli, Samiyah Alhamed. Tris(4-methoxyphenyl) methanol conjugates of triptorelin as cell-penetrating anti-cancer prodrugs [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 5746.
Abstract 5751: Ultrasound responsive injectable hydrogels for on-demand drug delivery
Authors: Xiang Li , Sener Gulsu , Yildirim Adem
Published: March 2024

In this work, we developed ultrasound-responsive and injectable hydrogels for local and on-demand release of chemotherapeutics to solid tumors. Injectable hydrogels were prepared by using a zwitterionic monomer, sulfobetaine methacrylate (SBMA), without using any crosslinker. Gelation was performed at -20 oC using APS/TEMED as initiator, allowing the formation of strong electrostatic interactions between poly(SBMA) chains to physically crosslink the hydrogels. Monomer and initiator concentrations were carefully optimized to achieve injectable hydrogels with mechanical and thermal stability. To render ultrasound responsivity to the hydrogels, we loaded the hydrogels with hydrophobically (dodecyl) modified mesoporous silica nanoparticles (hMSNs) with sizes around 50 nm. When insonated with low-intensity focused ultrasound (LIUS), the hMSNs incept acoustic cavitation (i.e., growth and collapse of microsized bubbles), which in turn generates mechanical effects in the hydrogels such as shock waves or water jets. We found that loading the hydrogels with hMSN did not affect their injectability, and they remained mechanically stable at 37 °C for more than a week. hMSN-loaded hydrogels demonstrated strong ultrasound responsivity even at low particle concentrations (0.1 mg/mL) and ultrasound powers (25 W, 0.02% duty cycle). Finally, we loaded the hydrogels with a chemotherapy drug, doxorubicin (DOX, 0.2 mg/mL). DOX-loaded hydrogels demonstrated minimal release without LIUS treatment (<20% in a day). Application of LIUS (150 W, 1% duty cycle) for 5 min resulted in almost complete mechanical disintegration of the hydrogels, resulting in a burst DOX release. We also showed that the amount of released DOX could be controlled by tuning the LUIS power and its duration. In summary, we developed injectable hydrogels with strong ultrasound responsivity. These hydrogels hold great promise for local and on-demand drug delivery to solid tumors, which is currently under investigation in our laboratory.

Citation Format: Li Xiang, Gulsu Sener, Adem Yildirim. Ultrasound responsive injectable hydrogels for on-demand drug delivery [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 5751.
Abstract 5754: Targeting miR-92b with peptide-modified liposomes for glioblastoma treatment
Authors: Sánchez-Álvarez Annelis Odette , Valiyeva Fatima , Vivas-Mejia Pablo E.
Published: March 2024

Focusing on enhancing drug delivery to the brain, we aim to optimize a nanocarrier system with a specific focus on glioblastoma (GBM). This involves the utilization of spherical nucleic acids (SNAs) enclosed in peptide-modified liposomes, a configuration previously proven to effectively penetrate the blood-brain barrier (BBB) in a GBM mouse model. Our objective is to enhance the nanocarrier's treatment load by optimizing the attachment of oligonucleotide-modified gold nanoparticles (OMI) to the SNAs. MicroRNAs (miRNAs) play crucial roles in GBM pathogenesis, with miR-92b identified as overexpressed in various cancers, including GBM. Previous research from our lab implicated miR-92b in targeting proteins (FBXW7 & SKP2) in the ubiquitination pathway. RNA sequencing confirmed the significance of these pathways. RNA sequencing of miR-92b inhibition in the U87 GBM cell line revealed impacts on cell cycle, apoptosis, DNA repair, and multiple cancer-related pathways. We successfully modified the gold nanoparticle size from 15 nm to 5 nm, increasing the surface area and improving OMI attachment efficiency from less than 5% to 50%. This alteration significantly enhances drug loading in the nanocarrier, providing a promising platform for clinical applications. Characterization of the optimized peptide-modified liposomes reassured the retention and potential improvement of original features related to nanoparticle size and internalization in cell cultures. Future in vivo experiments, utilizing a GBM mouse model, will assess the therapeutic effect of inhibiting miR-92b using peptide-modified liposomes as a drug delivery system. Our multifaceted approach, involving nanocarrier optimization and miR-92b inhibition, holds promise for developing an effective treatment strategy against GBM. The presented results highlight the potential translational impact of our research in addressing the challenges associated with GBM therapy.

Citation Format: Annelis Odette Sánchez-Álvarez, Fatima Valiyeva, Pablo E. Vivas-Mejia. Targeting miR-92b with peptide-modified liposomes for glioblastoma treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5754.