bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 275: Harnessing chemerin signaling as a novel therapeutic vulnerability in ccRCC
Authors: Wang Dazhi , Welford Scott , Brugarolas James , Tan Sze K.
Published: April 2023

Clear cell renal cell carcinoma (ccRCC) is the most common and aggressive subtype of kidney cancer, accounting for 70-80% of the cases. While surgical resection of early-stage tumors remains the standard care for patients, advanced ccRCC, metastatic or recurrent, portends a 5-year survival rate of only 12%, primarily due to insensitivity toward conventional chemotherapy. ccRCC is identifiable histologically by its dramatic lipid storage phenotype, similar to adipocytes; yet the role of lipid metabolism in ccRCC is poorly understood. One of the well-established risk factors for ccRCC is obesity and given that adipose tissue is known to produce a variety of pro-adipogenic signaling molecules (called adipokines), we hypothesized that adipokine signaling might be involved in the etiology of ccRCC. We recently identified a pro-tumorigenic adipokine protein, chemerin (RARRES2), that is positively correlated with tumor aggressiveness. Suppression of chemerin via either monoclonal antibody or siRNA led to reduction in lipid storage and significant tumor growth impairment in both in vitro and in vivo models by inducing ferroptosis. We next investigated the signaling mechanisms of chemerin and have found that chemerin drives downstream cellular activities and lipid deposition through either of the two receptors, GPR1 and CMKRL1. We further demonstrated that chemerin signals to both receptors to drive the expression adipose triglyceride lipase (ATGL) that frees up fatty acid from lipid depositions. In addition, Chemerin/CMKLR1 signaling axis further drives the activation of SREBP-mediated lipogenesis pathway. By using a small molecule antagonist specific for CMKRL1, α-NETA, we could suppress ccRCC tumor growth by inhibiting intracellular lipid droplet formation both in vitro and in vivo through the activation of ATGL-mediated lipolysis pathway and suppression of SREBP-mediated lipogenesis pathway. We have therefore shown the possibility of targeting Chemerin/CMKLR1 axis both genetically and pharmacologically to suppress the growth of ccRCC by increasing ferroptosis. Overall, our studies have identified chemerin/CMKLR1 axis as a promising therapeutic target that weakens ccRCC by modulating its lipid metabolic profiles and validated such vulnerability by using a more clinically relevant PDX orthotopic model. Further mechanistic investigations revealed overlapping yet distinct pathways downstream of chemerin that could potentially yield combinational strategies to treat ccRCC patients.

Citation Format: Dazhi Wang, Scott Welford, James Brugarolas, Sze K. Tan. Harnessing chemerin signaling as a novel therapeutic vulnerability in ccRCC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 275.
Abstract 2784: JW-1-283 inhibits melanoma tumor growth via the stabilization of p53 pathway
Authors: Xie Yang , Hartman Kelli , Wu Zhongzhi , Li Wei
Published: April 2023

Melanoma is the most lethal skin cancer, with the increasing incidence in the past decade. Despite the significant advancements in immune therapy and targeted therapy, the overall prognosis for metastatic melanoma remains unsatisfactory. TP53 is a tumor suppressor, but its wildtype is inactivated in about 90% of melanoma. Since activated p53 can promote cancer cell apoptosis and thus effectively inhibit tumor growth and tumor metastasis, reactivation of p53 is considered a promising strategy for cancer therapy. Herein, we report a recently developed small molecule compound, JW-1-283, targeting the interactions between MDM2 E3 ubiquitin-protein ligase and p53 protein. In vitro, JW-1-283 showed potent cytotoxicity against A375 melanoma cell line (IC50 2.2±0.3 μM) which has wildtype p53, but its potency is substantially reduced in two other melanoma cell lines with either p53 mutation (M14) or p53 null (RPMI-7951) status. Treatment with JW-1-283 significantly dose-dependently reduced the stemness in A375 melanoma cells, as indicated by low numbers of colony formation, impaired tumor sphere formation abilities, and inhibition of cancer cell migration. Mechanistically, JW-1-283 disrupts the p53-MDM2 interaction, prevents p53 and MDM2 degradation in the existence of cycloheximide, and induces p38 and p53 phosphorylation in the apoptotic pathway. Genetic knockdown of p38 by siRNA further confirmed that the stabilized p53 could be subsequently phosphorylated by p38, leading to induced apoptosis as well as S phase cell cycle arrest. In vivo, when A375 tumors grown in NSG mice were treated with 7.5 mg/kg of JW-1-283 intraperitoneally every other day for a consecutive of 16 days, significant inhibition of tumor growth was observed, along with decreased tumor cell proliferation, tumor angiogenesis, and enhanced tumor cell apoptosis. In summary, this work provides the initial proof-of-concept of developing the JW-1-283 scaffold as a potential strategy for advanced melanoma, which inhibits tumor growth by activating the p53 signaling pathway.

Citation Format: Yang Xie, Kelli Hartman, Zhongzhi Wu, Wei Li. JW-1-283 inhibits melanoma tumor growth via the stabilization of p53 pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2784.
Abstract 2787: Targeting Nrf2 signaling pathway by Keap1-mediated degradation in acquired gemcitabine resistant pancreatic cancer cells
Authors: Lee Sang Kook , Bae Eun Seo , Byun Woong Sub , Ock Chae Won , Kim Won Kyung , Park Hyen Joo
Published: April 2023

Redox status is a main indicator of cancer cell adaptation to chemotherapy. Nuclear factor erythroid 2-related factor 2 (Nrf2) is one of the crucial regulators of redox condition and can affected to drug resistance through redox imbalance. The incidence and mortality of pancreatic cancer (PC) have been gradually increasing globally. Although the first line treatment with anticancer agents improves the disease status, acquired drug resistance is major huddles in the treatment failure. Targeting Nrf2 has been suggested as a promising therapeutic approach for the overcoming drug resistance. In the present study, Nrf2 was found to be upregulated in tumor tissues and gemcitabine-resistant PC cells. In addition, Nrf2 knockdown exhibited to recover gemcitabine sensitivity in the gemcitabine-resistant PC cells. To further validate the role of Nrf2 in gemcitabine-resistant cells, the effects of Nrf2 inhibitor, periplocin, were employed. Periplocin exerted the antiproliferative activities by regulating Nrf2 suppression which leads to the increase of reactive oxygen species generation. Furthermore, the downregulation of Nrf2 by periplocin was correlated to Keap1-mediated protein degradation. Docking simulation also confirmed the binding interaction of Nrf2 and Keap1 by periplocin. These findings suggest that targeting the Nrf2 might be a therapeutic strategy for overcoming acquired gemcitabine PC. Keywords: Pancreatic cancer cell, Gemcitabine resistance, Nuclear factor erythroid-2-related factor 2 (Nrf2), Kelch Like ECH Associated Protein 1 (Keap1), protein degradation

Acknowledgements: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2022R1I1A1A01063346).

Citation Format: Sang Kook Lee, Eun Seo Bae, Woong Sub Byun, Chae Won Ock, Won Kyung Kim, Hyen Joo Park. Targeting Nrf2 signaling pathway by Keap1-mediated degradation in acquired gemcitabine resistant pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2787.
Abstract 2797: Multicenter pharmacokinetic study of pembrolizumab for non-small cell lung cancer in older adults aged over 75 years
Authors: Nakahara Yoshiro , Watanabe Kageaki , Hosomi Yukio , Yamanaka Yuta , Kurata Takayasu , Horinouchi Hidehito , Ohe Yuichiro , Asao Tetsuhiko , Saeki Sho , Tsubata Yukari , Fujita Yu , Konishi Jun Sakakibara , Mizugaki Hidenori , Ohuchi Mayu , Yagishita Shigehiro , Hamada Akinobu
Published: April 2023

Background: Pembrolizumab (Pemb) is a key drug for the treatment of advanced or recurrent non-small cell lung cancer (NSCLC). However, there are limited data on Pemb use in older adults aged >75 years with NSCLC, especially in terms of pharmacokinetics (PK).

Methods: This open-label multicenter observational study aimed to evaluate real-world data on the safety, efficacy, and blood concentrations of Pemb (both monotherapy and combination therapies) in older adults with NSCLC. Blood samples for PK analysis were collected immediately before Pemb administration. Quantitative Pemb concentrations were measured by liquid chromatography-mass spectrometry.

Results: We enrolled 100 patients from July 2019 to September 2020; one patient was excluded due to stage migration. Patient characteristics were as follows: median age, 78 (75-87) years; male/female ratio, 70/29; performance status (PS) 0-1/2-3, 85/14; adenocarcinoma/squamous cell carcinoma/others, 62/25/12; stage I-III/IV/postoperative recurrence (TNM 7th edition), 9/60/30; PD-L1 TPS <1%/1%-49%/≥50%, 12/31/48; and monotherapy/combination therapy, 65/34. The best overall efficacy was CR/PR/SD/PD (7/40/32/20), and the response rate was 47.5%. The median progression-free survival (PFS) and overall survival (OS) were 8.0 and 19.0 months, respectively. The adverse event profile was generally similar to that reported in previous studies. In total, 77 blood samples were collected immediately before the second cycle (C1 trough). Although no clear association between Pemb concentrations and patient background was found, PFS and OS were significantly shortened in the population with low C1 trough, a population characterized by lower PS, high number of metastatic organs at the beginning of treatment, and low blood albumin level.

Conclusion: In older adults aged >75 years with NSCLC and low albumin levels and PS and a high number of metastatic organs, C1 trough of Pemb is reduced and not expected to prolong PFS and OS.

Citation Format: Yoshiro Nakahara, Kageaki Watanabe, Yukio Hosomi, Yuta Yamanaka, Takayasu Kurata, Hidehito Horinouchi, Yuichiro Ohe, Tetsuhiko Asao, Sho Saeki, Yukari Tsubata, Yu Fujita, Jun Sakakibara Konishi, Hidenori Mizugaki, Mayu Ohuchi, Shigehiro Yagishita, Akinobu Hamada. Multicenter pharmacokinetic study of pembrolizumab for non-small cell lung cancer in older adults aged over 75 years [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2797.
Abstract 280: Targeting mRNA pseudouridylation to suppress neuroblastoma metabolism
Authors: Gupta Anamika , Bansal Mohit , Ding Han-Fei
Published: April 2023

Pseudouridylation of mRNA is a common epigenetic modification that reduces RNA conformational flexibility and increases its structural stability and may increase its availability for translation. RNA pseudouridylation is catalyzed by the family of pseudouridine synthases, including dyskerin pseudouridine synthase 1 (DKC1). Here we report the DKC1 gene is a direct transcriptional target of MYCN, which is a major oncogene in driving the development of high-risk neuroblastoma, a childhood cancer with a poor prognosis. The transcriptional upregulation of DKC1 expression in MYCN-amplified cells is of functional significance, as DKC1 depletion by RNA interference inhibits the proliferation of neuroblastoma cell lines. Furthermore, gene expression profiling reveals that DKC1 has a key role in the regulation of amino acid biosynthesis enzymes. Genetic and pharmacological inhibition of DKC1 reduces the expression of ATF4 and its downstream target genes involved in amino acid synthesis and transport. These findings reveal a critical role of DKC1 in sustaining the proliferation of neuroblastoma cells by promoting amino acid metabolism, which could be exploited as a therapeutic strategy against high-risk neuroblastoma.

Citation Format: Anamika Gupta, Mohit Bansal, Han-Fei Ding. Targeting mRNA pseudouridylation to suppress neuroblastoma metabolism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 280.
Abstract 2806: Patient-derived cell-based pharmacogenomic platform to uncover resistance mechanisms and novel therapeutics for advanced lung cancer
Authors: Park Charny , Yu Namhee , Hwang Mihwa , Lee Youngjoo , Song Bo Ram , Kang Eun Hye , Sim Hanna , Ahn Beung-Chul , Hwang Kum Hui , Hong Sehwa , Kim Sunshin , Han Ji-Youn
Published: April 2023

To uncover resistance mechanism and effective drugs for advanced lung cancer patients, we stablished a pharmacogenomic platform using patient-derived cells (PDC). Drug response screening and multi-omics datasets were obtained from lung cancer PDCs (n=102). We interrogated sensitive drugs from variant, gene expression, and clinical profiles. Machine learning approaches were applied to extract molecular target signatures and pathways associated with sensitive drugs. Next, acquired resistance pathways and drug candidates were investigated from patients to receive serial EGFR-TKI treatments. Our PDC model resembled with TCGA genomic profile. Three RNA subtypes were identified from gene expression: (1) MYC, (2) epithelial-to-mesenchymal (EMT), and (3) inflammatory activation. Drugs for mutations and subtypes were extracted. Especially, SCLC harboring both TP53 and RB1 mutations was abundant in RNA subtype 1 and showed sensitivity to cell cycle inhibitors. Among EGFR-TKI treatment groups, Osimertinib resistant group was enriched in EMT-like subtype 2 with vanishing EGFR T790M mutation and activating TGF-β pathway. The group showed sensitivity to YAP/TAZ inhibitor. Our PDC pharmacogenetic platform predict plausible drug candidates and markers for refractory lung cancer patients. We expect further studies for precision medicine by novel analysis and cohort expansion.

Citation Format: Charny Park, Namhee Yu, Mihwa Hwang, Youngjoo Lee, Bo Ram Song, Eun Hye Kang, Hanna Sim, Beung-Chul Ahn, Kum Hui Hwang, Sehwa Hong, Sunshin Kim, Ji-Youn Han. Patient-derived cell-based pharmacogenomic platform to uncover resistance mechanisms and novel therapeutics for advanced lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2806.
Abstract 2811: CDK4/6 inhibition plus radiotherapy enhances anti-tumor immunity in non-small cell lung cancer
Authors: Huang Zhengrong , Luo Jiang , Wang Mengqin , Xie Hongxin , Zeng Yuxin , Yuan Yu , Xiang Wan , Jiang Ziyu , Xie Conghua , Gong Yan
Published: April 2023

Lung cancer is the main cause of cancer-related mortality, of which non-small cell lung cancer (NSCLC) accounts for 85%. Abemaciclib, a selective CDK4/6 inhibitor, enhanced the radiosensitivity of NSCLC in vivo and in vitro and improved the prognosis of advanced NSCLC patients according to a Phase I clinical trial. This study aimed to explore the impact of CDK4/6 inhibition combined with irradiation and immunotherapy on NSCLC. The in vivo xenograft tumor mouse model was used to investigate the synergistic effects of CDK4/6 inhibitor abemaciclib and irradiation together with anti-PD-1 antibodies. The tumor infiltrating lymphocytes (TILs) in tumor microenvironment (TME) were analyzed by flow cytometry. The complete blood count and serum tests were used to determine the safety of this combination therapy. The human phospho-kinase array and dual-luciferase report assay were used to study the regulatory mechanisms of abemaciclib and irradiation combination on PD-L1 transcription in NSCLC cells in vitro. Our results indicated the significantly synergistic effects of abemaciclib, irradiation and anti-PD-1 antibodies on NSCLC growth in vivo, accompanied by increased CD8+ T cell infiltration and decreased regulatory T cells and myeloid-derived suppressor cells (MDSCs), suggesting a strong anti-tumor combination of CDK4/6 inhibition, radiotherapy and immunotherapy. This synergistic effect could be partially impaired by CD8 depletion, and alleviated the anemia and inflammation caused by tumor burden without hepatorenal toxicity. Abemaciclib induced PD-L1 transcription through JNK/c-Jun pathway in vitro, which might elevate PD-L1 expression synergistically with irradiation through TBK1/IRF3 pathway. Our studies suggested that CDK4/6 inhibition plus irradiation enhanced anti-tumor immune responses in NSCLC. Together with immunotherapy, the combination of CDK4/6 inhibitors and radiotherapy could lower the doses of individual treatment, thus alleviating the potential toxicity and side effects of CDK4/6 inhibition and irradiation on normal cells.

Citation Format: Zhengrong Huang, Jiang Luo, Mengqin Wang, Hongxin Xie, Yuxin Zeng, Yu Yuan, Wan Xiang, Ziyu Jiang, Conghua Xie, Yan Gong. CDK4/6 inhibition plus radiotherapy enhances anti-tumor immunity in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2811.
Abstract 2819: Genome-wide CRISPR screen identifies NANP as a radio-sensitizing target of GBM by regulating NF-κB pathway
Authors: Ding Yingwen , Zhang Ze-Yan , Ezhilarasan Ravesanker , Modrek Aram S. , Karp Jerome , Sulman Erik P.
Published: April 2023

Glioblastoma multiforme (GBM) are the most malignant primary central nervous system tumors. The standard of care for newly diagnosed GBM patients includes surgery followed by combined radiation therapy (RT) and adjuvant temozolomide (TMZ) therapy. However, one of the therapeutic challenges is the inevitable resistance and recurrence after radiotherapy. Glioblastoma stem cells (GSC) are tumor initiating cells for GBM and plays key roles in radio resistance. Thus, we performed a genome-wide CRISPR screen using a radiation resistant GSC to identify potential RT sensitizing targets. We identified 139 potential RT sensitizing targets with a filter for only those genes associated with a greater than 2-fold reduction in representation with a p<0.05. There were 22 genes with a direct function in key DNA double-strand break repair pathways including 5 genes central to non-homologous end-joining (NHEJ1, XLF, PRKDC, DCLRE1C, XRCC4, LIG4), 6 genes involved in homologous recombination (RAD51D, CYREN, ATM, TONSL, BRCA2, RFWD3), and 7 genes central to initial DNA damage sensing (RNF8, RNF168, TP53BP1, RAD17, FOXM1, RAD9A, RAD1). These results are consistent with the crucial role of DNA repair following radiation exposure and demonstrate the success of the screening. Besides that, one of the top hits is NANP (N-acylneuraminate-9-phosphatase), which is involved in sialic acid synthetic pathway. Knocking down of NANP causes more G2/M arrest followed by apoptosis after radiation. γH2A.X staining and comet assay shows more DNA damage in NANP knock down cells after radiation. Transcriptome analysis reveals NANP inhibition restrain mesenchymal status and NF-κB pathway activation. Furthermore, activation of NF-κB pathway could rescue the RT-induced G2/M arrest of NANP knock down cells. TCGA and CGGA dataset shows NANP is highly expressed in GBM patients and patients with NANP high expression have poorer survival. In conclusion, our study identified NANP as a novel radio-sensitizing target for glioblastoma by regulating NF-κB pathway and mesenchymal status of GSCs.

Citation Format: Yingwen Ding, Ze-Yan Zhang, Ravesanker Ezhilarasan, Aram S. Modrek, Jerome Karp, Erik P. Sulman. Genome-wide CRISPR screen identifies NANP as a radio-sensitizing target of GBM by regulating NF-κB pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2819.
Abstract 2830: Fluoxetine mediate radiosensitivity and inhibit metastasis of osteosarcoma cells via RANK/RANKL signaling
Authors: Tan Peggy , Tsai Jai-Jen , Hsu Fei-Ting , Liu Yu-Chiang
Published: April 2023

Osteosarcoma (OS) is most common primary malignant bone tumour OS was flagrantly byaffecting pediatric and young adolescents patients with its outrageous metastatic rate and poorprognosis. It was aggressive in local invasion and further metastasis, especially pulmonarymetastasis. Radiotherapy (RT) was a clinical treatment method that using high-energy ionizingradiation to control tumour growth with low risk and considerably successful rate.Contradictorily, OS was recognized as radio-resistant tumour. Meanwhile, majority of OScases were diagnosed suffering depression and influence patient’s conditions critically. Hence,aim of this prospective study was to identify that combinational therapeutic efficacy ofradiation therapy and fluoxetine (Prozac) through mediating radiosensitivity and inhibitmetastasis of OS cells via RANK/RANKL signaling. OS cell lines U2OS and MG63 were usedin this study. To investigate the cells survival fraction, clonogenic assay were performed. Next,to examine metastasis and invasions of cells wound healing assay and transwell assay werecarried out. Furthermore, TUNEL assay was used to evaluate DNA damage of OS cells.Fluoxetine effectively inhibited the metastasis and invasion ability of OS cells. Thecombinational therapy of fluoxetine and RT successfully decreased the surviving fraction ofOS cells and induced the damage of DNA. Additionally, the protein expression ofRANK/RANKL was markedly suppressed by fluoxetine as illustrated by Western blottingassay. In sum, the combination treatment of radiotherapy with the interrelation of fluoxetinewas showing its potential and consider as new treatment strategy might elevate treatmentefficacy for OS.

Keywords: Osteosarcoma (OS), Radiotherapy (RT), Fluoxetine, RANK/RANKL

Citation Format: Peggy Tan, Jai-Jen Tsai, Fei-Ting Hsu, Yu-Chiang Liu. Fluoxetine mediate radiosensitivity and inhibit metastasis of osteosarcoma cells via RANK/RANKL signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2830.
Abstract 284: Sigma1 regulates lipid droplet mediated redox homeostasis required for prostate cancer proliferation
Authors: Oyer Halley M. , Steck Alexandra R. , Longen Charles , Venkat Sanjana , Bayrak Konuralp , Munger Eleanor , Fu Dan , Sanders Christina , Myers Justin , Schiewer Matthew , Chen Nan , Mostaghel Elahe , Kim Felix J.
Published: April 2023

Lipid droplets (LDs) are dynamic organelles that serve as hubs of cellular metabolic processes. Emerging evidence shows that LDs also play a critical role in maintaining redox homeostasis and can mitigate lipid oxidative stress. In multiple cancers, including prostate cancer (PCa), LD accumulation is associated with cancer aggressiveness, therapy resistance, and poor clinical outcome. PCa arises as an androgen receptor (AR) driven disease. Among its myriad roles, AR mediates the biosynthesis of LDs, induces autophagy, and modulates cellular oxidative stress in a tightly regulated cycle that promotes cell proliferation. The factors regulating the interplay of these metabolic processes downstream of AR remain unclear. Here, we show that Sigma1/SIGMAR1, a unique ligand-operated scaffolding protein, regulates LD metabolism in PCa cells. Sigma1 inhibition triggers lipophagy, an LD selective form of autophagy, to prevent accumulation of LDs which normally act to sequester toxic levels of reactive oxygen species (ROS). This disrupts the interplay between LDs, autophagy, buffering of oxidative stress and redox homeostasis, and results in the suppression of cell proliferation in vitro and tumor growth in vivo. Consistent with these experimental results, SIGMAR1 transcripts are strongly associated with lipid metabolism and reactive oxygen species pathways in prostate tumors. Altogether, these data reveal a novel, pharmacologically responsive role for Sigma1 in regulating the redox homeostasis required by oncogenic metabolic programs that drive PCa proliferation.

Citation Format: Halley M. Oyer, Alexandra R. Steck, Charles Longen, Sanjana Venkat, Konuralp Bayrak, Eleanor Munger, Dan Fu, Christina Sanders, Justin Myers, Matthew Schiewer, Nan Chen, Elahe Mostaghel, Felix J. Kim. Sigma1 regulates lipid droplet mediated redox homeostasis required for prostate cancer proliferation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 284.
Abstract 2843: RN486, a Bruton’s tyrosine kinase inhibitor, reverses multidrug resistance in ABCG2-overexpressing cancer cells
Authors: Dong Xing-Duo , Lu Qisi , Li Yi-Dong , Teng Qiu-Xu , Lei Zi-Ning , Chen Zhe-Sheng
Published: April 2023

Overcoming ATP-binding cassette subfamily G member 2 (ABCG2)-mediated multidrug resistance (MDR) has attracted the attention of scientists because one of the critical factors leading to MDR is the overexpression of ABCG2. Identification of novel chemotherapeutic reagents as inhibitors of ABCG2 has been considered an effective strategy. RN486, a Bruton’s Tyrosine Kinase (BTK) inhibitor, was discovered to potentially reverse ABCB1-mediated MDR. In this study, we reported that RN486 effectively antagonizes ABCG2-mediated MDR in cancer cells. Non-toxic concentrations of RN486 remarkably increased the sensitivity of ABCG2-overexpressing cancer cells to conventional anticancer drugs mitoxantrone and topotecan. The reversal mechanistic studies showed that RN486 increased the accumulation and decreased the efflux of ABCG2 substrate drug in ABCG2-overexpressing cancer cells. In addition, the inhibitory effect of RN486 on ABCG2-associated ATPase activity was also verified. Docking analysis indicated a strong binding between RN486 and ABCG2 transporter. Meanwhile, the AGCG2 subcellular localization and expression level were not altered by the treatment of RN486. Taken together, our studies suggest that RN486 can antagonize ABCG2-mediated MDR in cancer cells via interacting with ABCG2 and inhibiting the transporting function. RN486 could be potentially used in combination with chemotherapy against ABCG2-mediated MDR in cancers.

Citation Format: Xing-Duo Dong, Qisi Lu, Yi-Dong Li, Qiu-Xu Teng, Zi-Ning Lei, Zhe-Sheng Chen. RN486, a Bruton’s tyrosine kinase inhibitor, reverses multidrug resistance in ABCG2-overexpressing cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2843.
Abstract 2969: Development of a canine PD-L1 antibody and caninized PD-L1 mouse model: an essential translational research tool to raise the success rate of immunotherapy in humans
Authors: Oh Wonkyung , Kim Alyssa , Dhawan Deepika , Kirkham Perry M. , Knapp Deborah W. , Lim Seung-Oe
Published: April 2023

Immune checkpoint blockade therapy, one of the most promising cancer immunotherapies, has shown remarkable clinical impact in multiple cancer types. Despite the recent success of immune checkpoint blockade therapy, the response rates in cancer patients are limited (~20-40%). To improve immune checkpoint blockade therapy, relevant preclinical animal models are an essential component in the development and testing of multiple combination approaches and strategies. Companion dogs naturally develop several types of cancer that in many respects resemble clinical cancer in human patients. Therefore, the canine studies of immuno-oncology drugs are convertible into knowledge that informs and prioritizes new immuno-oncology therapy in humans. The challenge has been, however, that immunotherapeutic antibodies that target canine immune checkpoint molecules, such as canine PD-L1, have not been commercially available. Here, we developed a new canine PD-L1 antibody as an immuno-oncology drug and characterized its functional and biological properties by multiple assays. Furthermore, the therapeutic efficacy of cPD-L1 antibodies was evaluated in our unique caninized PD-L1 mice. Altogether, these in vitro and in vivo data including an initial safety profile in laboratory dogs, support the development of our canine PD-L1 antibody as an immune checkpoint inhibitor for studies in dogs with naturally occurring cancer for translational research. In conclusion, our new therapeutic antibody and caninized PD-L1 mouse model will be an essential translational research tool in raising the success rate of immunotherapy in both dogs and humans.

Citation Format: Wonkyung Oh, Alyssa Kim, Deepika Dhawan, Perry M. Kirkham, Deborah W. Knapp, Seung-Oe Lim. Development of a canine PD-L1 antibody and caninized PD-L1 mouse model: an essential translational research tool to raise the success rate of immunotherapy in humans [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2969.
Abstract 2992: Conserved gene fusion ETV6/RUNX1 displays higher immunogenicity than patient-specific missense mutations within the context of HLA-A*02:01
Authors: Cygan Erin E. , Shah Ravi K. , Kozlik Tanya , Thomas Paul G. , Zamora Anthony E.
Published: April 2023

Tumor-specific antigens can be targeted by T cells and cancer immunotherapies directed against these neoantigens have resulted in regression across several cancer types. Both missense mutations and gene fusions can serve as targets for cytotoxic T cells, but it is unknown whether one of these classes of mutations has unique parameters that make it more immunogenic. This study compares the immunogenicity of patient-specific missense mutations and a conserved gene fusion, ETV6/RUNX1, present in approximately 25% of pediatric B cell acute lymphoblastic leukemia cases to determine which is more effective at inducing CD8+ T cell responses. Utilizing patient HLA haplotype, mutation data obtained from whole-genome and mRNA sequencing, and the online prediction algorithm NetMHCcons, we identified several putative neoepitopes. To experimentally validate these predicted neoantigens, we performed peptide exchange assays with antigen presenting beads to evaluate the efficiency of peptide-HLA interactions and complex formation. To further investigate the immunogenicity of single nucleotide variants (SNVs) compared to the conserved gene fusion ETV6/RUNX1, we assessed peptide-HLA stability by measuring the dissociation of SNV or ETV6/RUNX1 peptides from the HLA binding groove and calculating the corresponding half-life. Higher affinity peptides would have a greater exchange rate than lower affinity peptides and would have a higher stability/half-life; these assays validated that ETV6/RUNX1 has a greater affinity/stability for HLA-A*02:01 compared to any of the patient-specific SNVs evaluated. To determine whether the higher affinity and stability of the fusion peptide was able to induce greater CD8+ T cell responses, we performed co-culture assays using peptide-pulsed artificial antigen presenting cells expressing HLA-A*02:01 and measured CD8+ T cell cytokine secretion and cytotoxicity. Interestingly, while both mutation types were able to activate CD8+ T cells, those targeting the fusion peptides displayed greater polyfunctionality. Additionally, we found a greater frequency of clonally expanded CD8+ T cells targeting fusion peptides using tetramer-binding assays. Overall, our findings suggest fusion neoantigens have greater immunogenicity than missense mutations and may provide better targets for TCR-T cell-based immunotherapies.

Citation Format: Erin E. Cygan, Ravi K. Shah, Tanya Kozlik, Paul G. Thomas, Anthony E. Zamora. Conserved gene fusion ETV6/RUNX1 displays higher immunogenicity than patient-specific missense mutations within the context of HLA-A*02:01 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2992.
Abstract 2999: Hippo signaling pathway regulates cancer-cell-intrinsic MHC-II expression in melanoma
Authors: Gu Shengqing
Published: April 2023

MHC-II is known to be mainly expressed on the surface of antigen-presenting cells (APCs). Nevertheless, increasing evidence suggests that MHC-II is also expressed by solid tumor cancer cells and may be associated with better immunotherapy responses. However, the regulation of MHC-II in cancer cells remain unclear. In this study, we leveraged data mining and experimental validation to elucidate the regulation of MHC-II in cancer cells and its role in modulating the response to immunotherapy. We collated an extensive collection of omics data to examine the cancer-cell-intrinsic MHC-II expression and its association with immunotherapy outcomes. We then tested the functional relevance of cancer-cell-intrinsic MHC-II expression using a syngeneic transplantation model. Finally, we performed data mining to identify pathways potentially involved in the regulation of MHC-II expression, and experimentally validated candidate regulators. Comprehensive meta-analysis of multiomics data from an exhaustive collection of data revealed that MHC-II is heterogeneously expressed in various solid tumors, and its expression is particularly high in melanoma. Using a syngeneic transplantation model, we further established that melanoma cells with high MHC-II responded better to anti-PD-1 treatment. Data mining followed by experimental validation revealed the Hippo signaling pathway as a potential regulator of melanoma MHC-II expression.

Citation Format: Shengqing Gu. Hippo signaling pathway regulates cancer-cell-intrinsic MHC-II expression in melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2999.
Abstract 3016: Cancers attributable to infectious agents in Italy
Authors: Collatuzzo Giulia , Boffetta Paolo
Published: April 2023

Objectives: The burden of cancer attributable to known risk factors has never been estimated in Italy. This study aimed to provide an evidence-based, consistent assessment of the burden of infection-related cancer in Italy.

Methods: We calculated the proportion of cancers attributable to infectious agents to estimate the burden of infection-related cancer incidence (2020) and mortality (2017). Data on prevalence of infection were mainly derived from cross-sectional surveys among representative sample of Italian population. Data on relative risk were mainly derived from meta-analysis and large-scale studies. Attributable fraction was calculated based on the counterfactual scenario of no exposure to infection. National registries were used to obtain on the number of cancer cases and deaths.

Results: We estimated 7.6% of total cancer deaths occurred in Italy in 2017 were attributable to infections, with higher proportion in men (8.1%) than in women (6.9%). Corresponding figures for incidence in 2020 were 6.9%, 6.1% and 6.5%. Helicobacter pylori (Hp) was the first cause of infection-related cancer deaths, with 3.3% of all cancer deaths and 2.4% of cancer cases followed by Hepatitis C virus (HCV, 1.8% and 1,3%) and Hepatitis B virus (0,9% and 0,6%), Human Papillomavirus 0.6% and 1,0%), Epstein-Barr virus ( 0,3% of both deaths and cases), Human Immunodeficiency Virus (0,9% for both) and Human Herpes Virus- 8 (0,4% and 0,2%).

Conclusions: The burden of cancer attributable to infections was higher in Italy than in other high-income countries in which similar studies were conducted, including the US, due to excess Hp and ACV. Most of the cancer burden related to infections in Italy is due to agents for which common therapies (Hp, HCV) or vaccination (HPV, HBV) are available. Screening prevention policies are needed to control these cancers, which are largely avoidable.

Population attributable fraction (%) of cancer deaths in selected studies, by sex. Sex Italy United States United Kingdom France Men 8.1 3.4 3.1 3.1 Women 6.9 3.3 4.3 4.4

Citation Format: Giulia Collatuzzo, Paolo Boffetta. Cancers attributable to infectious agents in Italy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3016.
Abstract 3018: Demographic and social patterns of average values of inflammatorymarkers in US adults: A 2009-2016 NHANES analysis
Authors: Camacho-Rivera Marlene , Ye Zachary , Haq Raisa , Calixte Rose
Published: April 2023

Several studies report the negative impact of elevated Neutrophil-to-Lymphocyte ratio (NLR) and elevated Platelet-to-Lymphocyte ratio (PLR) on outcomes in many surgical and medical conditions, including cancer. In order to use these inflammatory biomarkers as prognostic factors in disease, a normal value in disease-free individuals must be identified first. This study aims to (1) establish average values of various inflammatory markers using a healthy and nationally representative U.S. adult population and (2) explore heterogeneity in average values by sociodemographic and behavioral risk factors to better specify cut-off points accordingly. The National Health and Nutrition Examination Survey (NHANES) of aggregated cross-sectional data collected from 2009 to 2016 was analyzed; data extracted included markers of systemic inflammation and demographic variables. We excluded participants who were under 20 or had a history of inflammatory diseases such as arthritis and gout. Adjusted linear regression models were used to examine the association between demographic and behavioral characteristics and neutrophil counts, platelet counts, lymphocyte counts, NLR, and PLR. The average NLR is 2.16 and the average PLR is 121.31. Non-Hispanic Black participants have significantly lower mean NLR values (1.78, 95% CI 1.74–1.83 and 2.10, 95% CI 2.04–2.16 respectively) when compared to non-Hispanic Whites (2.27, 95% CI 2.22–2.30–p<0.0001). Participants who reported any no smoking history had significantly lower NLR than subjects who reported any smoking history and higher PLR than current smokers. The average PLR for non-Hispanic blacks is significantly lower compared to non-Hispanic whites. Participants ages 20-29 have significantly lower mean PLR vs. participants in the age groups 30-59, 60-79, and 80 and older. Additionally, current smokers have significantly higher mean PLR compared to those who never smoke. Participants in the obese category also had higher mean PLR compared to normal weight participants. This study provides nationally representative estimates for demographic and behavioral effects on NLR, and PLR, which have been associated with several chronic disease outcomes, suggesting that different cut-off points for inflammatory markers should be set according to social factors.

Citation Format: Marlene Camacho-Rivera, Zachary Ye, Raisa Haq, Rose Calixte. Demographic and social patterns of average values of inflammatorymarkers in US adults: A 2009-2016 NHANES analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3018.
Abstract 304: Micronuclei in circulating stromal cells correlates with PD-L1 expression and predicts progression in metastatic breast cancer
Authors: Kasabwala Dimpal M. , Cristofanilli Massimo , Alpaugh R. Katherine , Chumsri Saranya , Reduzzi Carolina , Tang Cha-Mei , Lapidus Rena G. , Priore Giuseppe Del , Williams William V. , Adams Daniel L.
Published: April 2023

Background: Micronuclei (MN) are a result of biological DNA repair mechanisms which form due to internal chromosomal aberrations indicating sub-clonal cancer populations with higher cell survivability and drug therapy resistance. MN are often observed as small fragments of nucleic acids excised from a primary nucleus in Circulating Stomal Cells (CStCs) in response to DNA damage. CStCs with damaged DNA undergoing repair mechanisms, such as those that form MN, are likely to have upregulated expression of programmed cell death ligand (PD-L1) which can be abnormally high on cancer cells that have high mutational burdens. We evaluated CStCs in metastatic breast cancer (mBC) patients for presence of MN and the cell's PD-L1 expression, to determine its prognostic significance to clinical outcomes.

Methods: We enumerated MN formation in CStCs in a prospective pilot study using n=76 mBC patients starting new lines of treatment. Whole peripheral blood (7.5mL) was procured and filtered for CStCs and then stained for PD-L1. DAPI was used to identify MN, defined by small (<3 µm) DAPI+ circular formations within the cytoplasm, separate from the primary nucleus. We compared number of MN to PD-L1 expression of all cells, and the MN presence to all available clinical variables. Patients’ progression-free survival (PFS) and overall survival (OS) hazard ratios (HRs) were analyzed by censored univariate analysis based on RECIST v1.1 over two-years.

Results: MN were identified in 62% (n=46/76) of CStCs and MN positive CStCs had a significantly higher PD-L1 expression than MN negative CStCs (p=0.0082). A linear relationship between increasing MN number and higher PDL-1 expression within cells was identified, R=0.9411. Further, presence of MN with in CStCs was significantly prognostic for worse PFS (HR=2.62 95%CI 1.50-4.59, p=0.0012) and worse OS (HR= 3.07 95%CI 1.56-6.03, p = 0.002) over 24 months.

Conclusion: MN formations in mBC are observable biomarkers of an underlying repair mechanism which suggest the survivability of sub-clonal cancer populations associated with more aggressive cancer subtypes with worsening progression rates. Further studies to evaluate the effect of PD-1 immunotherapies in MN positive patients is ongoing.

Citation Format: Dimpal M. Kasabwala, Massimo Cristofanilli, R. Katherine Alpaugh, Saranya Chumsri, Carolina Reduzzi, Cha-Mei Tang, Rena G. Lapidus, Giuseppe Del Priore, William V. Williams, Daniel L. Adams. Micronuclei in circulating stromal cells correlates with PD-L1 expression and predicts progression in metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 304.
Abstract 3046: Association of XRCC1 Arg194Trp polymorphism and XPD Lys751Gln polymorphism with biochemical parameters, severity and risk of prostate cancer in Bangladesh Population
Authors: Ahmed Nafisa , Islam MD. Ariful , Hossain M. Mahboob , Kabir Yearul
Published: April 2023

a)To evaluate the association between x-ray cross-complementing gene 1 (XRCC1) polymorphism Arg194Gln and xeroderma pigmentosum group D (XPD) polymorphism Lys751Gln with severity and risk of prostate cancer as well as with biochemical parameters of prostate cancer patients in Bangladesh population.

b) Blood samples and data were collected from 132 prostate cancer patients and 135 healthy controls among Bangladesh population. Genotype analysis was done by the PCR-RFLP method. Statistical analysis was performed using GraphPad Prism 9.4.1 software.

c) Only the recessive model, that is, carrying two copies of the XRCC1 194 codon Trp allele was positively associated with prostate cancer, with an OR of 7.50 (95% CI, 1.227-85.12; p=0.035). No association was found between the XPD variants with prostate cancer risk. Keeping the wild type and heterozygous genotype as a reference, the combined effects of the XRCC1 codon 194 Arg/Arg and the XPD codon 751 Gln/Gln genotype were found to be significantly associated with prostate cancer risk with an OR of 3.25 (95% CI, 1.39-8.20; p=0.006).

XRCC1 194 Trp/Trp genotype was significantly associated with obstructive features, such as hematuria and creatinine levels of the prostate cancer patients (P<0.05). Moreover, the homozygous mutant Gln/Gln genotype of XPD gene was also significantly associated with creatinine levels in prostate cancer patients. No association was found between any of the variants of XRCC1 and XPD with invasiveness, tumor grade, prostate ultrasound scan results, digital rectal examination, Urine R/E or Prostate Specific Antigen (PSA) results (P>0.05).

d) Only the XRCC1 codon 194 Trp allele showed a modest association with prostate cancer risk with an 8.19-fold increased risk when two copies of the allele were present. When both alleles- XRCC1 codon 194 and XPD codon 751 Gln -were present in their homozygous states, the risk for prostate cancer increased by 3.2-folds. Our results showed a significant association between XRCC1 194 Trp/Trp with obstructive features and and levels of creatinine in prostate cancer patients of Bangladeshi men.

Citation Format: Nafisa Ahmed, MD. Ariful Islam, M. Mahboob Hossain, Yearul Kabir. Association of XRCC1 Arg194Trp polymorphism and XPD Lys751Gln polymorphism with biochemical parameters, severity and risk of prostate cancer in Bangladesh Population [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3046.