bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1723: Ferroptosis is a novel therapeutic target for RB1 deficient lethal prostate cancer
Authors: Wang Mu-En , Chen Jiaqi , Lu Yi , Wy Jinjin , Ou Jianhong , Asara John , Armstrong Andrew , Wang Qianben , Li Lei , Wang Yuzhuo , Huang Jiaoti , Chen Ming
Published: April 2023

Background: Although the development of next-generation antiandrogens has significantly extended the survival time of patients with metastatic castration-resistant prostate cancer (mCRPC), drug resistance inevitably developed over time. Therefore, the identification of novel therapeutic strategies targeting mCRPC is urgent. RB1 deficiency is a common genetic event and contributes to the development of therapy resistance and poor prognosis in prostate cancer. However, effective therapies against RB1-deficient lethal prostate cancer remain elusive. Here we determined how RB1 regulates the sensitivity of prostate cancer cells to ferroptosis, a form of regulated cell death driven by iron-dependent lipid peroxidation, and whether we can exploit ferroptosis for the treatment of RB1 deficient lethal prostate cancer.

Methods: To determine how RB1 regulates ferroptosis in prostate cancer, we generated RB1 stable knockdown prostate cancer cell lines using lentivirus-delivered shRNAs. We compared cellular sensitivity to ferroptosis and associated lipid peroxidation between control and RB1 stable knockdown prostate cancer cells. Using western blotting, qPCR, and ChIP analyses, we examined the regulation of ferroptosis by RB1. We also evaluated the therapeutic efficacy of ferroptosis inducers in cell-derived xenograft, patient-derived xenograft, and genetically engineered mouse models.

Results: Our studies revealed that RB1 deficiency sensitizes prostate cancer cells to ferroptosis. Mechanistically, we found that the E2F family of transcription factors directly binds and activates the ACSL4 promoter and that RB1 inhibits ferroptosis by suppressing E2F-mediated ACSL4 transcriptional activation. More importantly, our preclinical studies demonstrated that induction of ferroptosis by JKE-1674, a recently discovered ferroptosis inducer, significantly blocks RB1 deficient prostate tumor growth and metastasis, and improves the overall survival of mice in the absence of obvious toxicity.

Conclusions:

Our findings uncover an RB1/E2F/ACSL4 molecular axis that governs ferroptosis and also suggest a new approach to the treatment of RB1-deficient lethal prostate cancer.

Citation Format: Mu-En Wang, Jiaqi Chen, Yi Lu, Jinjin Wy, Jianhong Ou, John Asara, Andrew Armstrong, Qianben Wang, Lei Li, Yuzhuo Wang, Jiaoti Huang, Ming Chen. Ferroptosis is a novel therapeutic target for RB1 deficient lethal prostate 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 1723.
Abstract 1920: Association of type 2 diabetes with overall and site-specific cancer among predominantly low-income Black and White Americans
Authors: Pradhan Pranoti , Wen Wanqing , Zheng Wei
Published: April 2023

Background: Black individuals have the highest cancer incidence rate in the United States compared to White and other populations. Additionally, they are also twice as likely to develop type 2 diabetes (T2D) during their lifetime. Specifically considering the association between diabetes and cancer incidence, both diseases share common modifiable and nonmodifiable risk factors such as, aging, obesity, lack of physical activity, unhealthy diet, excessive alcohol consumption, and smoking. This association could vary between cancer types and race is also a factor which could disproportionately affect this relationship. However, studies on these associations are limited and the impact in terms of risk between the Black and White Americans remains unclear.

Objective: We evaluated the association of T2D with risk of total and 26 site-specific cancers in a large cohort study conducted among predominantly low-income Black and White Americans who have a higher risk of T2D than other populations. Given the previous literature on T2D, cancer, and race, we hypothesized that T2D might be associated with varying risk for cancer.

Methods: For this analysis, we used data from the Southern Community Cohort Study, an on-going prospective cohort study. Enrollment began in 2002 and concluded in 2009, with active follow-up until 2020. Study participants were asked whether they were diagnosed with T2D by physicians at the follow-up interviews and T2D was assessed as a time-varying covariate. Ascertainment of incident cancer was carried out via linkage to state cancer registries. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) after adjusting for confounders.

Results: This study included 81,525 participants (30.2 % (N=24,581) White; 65.9% (N=53,711) Black) of whom 36.2% (N=29,487) were diagnosed with diabetes. Among those with diabetes, 10.3% (N=3,024) were diagnosed with cancer. Individuals with T2D had an elevated risk of several cancers, including pancreatic cancer (HR = 1.52, 95% CI: 1.18-1.96); but a reduced risk of esophageal cancer (HR = 0.55, 95% CI: 0.34-0.89). Some racial differences were found regarding the association of T2D with cancer risk.

Conclusion: We found varying risks between T2D and risk of cancer between White and Black individuals. This highlights the importance of T2D prevention practices to help mitigate the risk of cancer and that further research is necessary to understand this association in minority individuals.

Citation Format: Pranoti Pradhan, Wanqing Wen, Wei Zheng. Association of type 2 diabetes with overall and site-specific cancer among predominantly low-income Black and White Americans [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 1920.
Abstract 1999: Repurposing an antibiotic for breast cancer treatment using liposomes as a delivery system
Authors: Ataide Janaina Artem , Filipczak Nina , Yalamarty Satya Siva Kishan , Mazzola Priscila Gava , Torchilin Vladimir P.
Published: April 2023

Purpose: Scientific community is always searching for alternatives for cancer treatment and promoting drug repurposing is one of the ways. Rifamycin is a well-known antibiotic, that inhibits RNA synthesis and probably can be explored as cytotoxic agent. Thus, our goal was to repurpose rifamycin for breast cancer treatment using liposomes as a delivery system.

Methods: Liposomes were produced by thin-film evaporation method using egg phosphatidylcholine, cholesterol and DOPE-PEG5k (70:25:5, molar ratio). Non-encapsulated drug was removed using dialysis bags and encapsulated drug was directly determined by UV spectrophotometer. Liposomes were characterized regarding size and surface charge by dynamic light scattering. Liposomes were stored at 4°C and 25°C for stability evaluation, monitoring nanoparticles parameters and drug encapsulation. Formulation biocompatibility was evaluated by hemolysis assay. Finally, cytotoxicity of rifamycin SV and liposomes was evaluated in MCF-7 and MDA-MB-231 cell lines.

Results: Blank liposomes (without drug) and rifamycin-loaded liposomes showed size smaller than 100 nm and polydispersity around 0.2, with slightly negative zeta potential. Rifamycin encapsulation in liposomes was 3mg of drug/10mg of lipid films. Both formulations were stable for at least 21 days when stored at 4°C, keeping above 60% of drug encapsulated. In the concentrations tested (0.5mg/mL of drug, 2mg/mL of lipids), liposomes formulation (blank and loaded) and free rifamycin were biocompatible and non-hemolytic, since hemolysis was below 6%. Blank liposomes were not cytotoxic in tested cell lines. Free rifamycin and rifamycin-loaded liposomes demonstrated the IC50 in the same range between 41 and 46 µg/mL in 24h and 48h for both MCF-7 and MDA-MB-231.

Conclusions: Rifamycin was successfully encapsulated in liposomes, leading to a stable, biocompatible, and non-hemolytic formulation. The liposomal rifamycin demonstrated strong cytotoxicity towards cancer cells similar to that of the free drug.

Citation Format: Janaina Artem Ataide, Nina Filipczak, Satya Siva Kishan Yalamarty, Priscila Gava Mazzola, Vladimir P. Torchilin. Repurposing an antibiotic for breast cancer treatment using liposomes as a delivery system [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 1999.
Abstract 20: In vitro and in vivo investigation of tumor treating fields for treatment of spinal metastasis
Authors: Tatsui Claudio Esteves , Ledbetter Daniel , Alvarez-Breckenridge Christopher
Published: April 2023

Introduction: Tumor treating fields (TTF) are used for treatment of glioblastoma. Its utilization for spinal metastasis has never been described. We investigate the anti-mitotic effect of TTF to inhibit the growth of human cancer cells in vitro and in vivo models of spinal metastasis.

Methods: In vitro: human derived osteosarcoma (Krib-luc-1) and lung adenocarcinoma (A549-luc) cells were seeded in 5 × 3mm human demineralized bone grafts kept in culture while treated with 0kHz (control) or 150kHZ of TTF for 14 days. Bioluminescence images (BLI) were obtained at baseline and 14 days. In vivo: Krib-Luc-1 cells were surgically implanted via transperitoneal approach to L3 vertebra in nude mice. Animals were treated with 0kHz or 150kHz for 30 days or until death. BLI were obtained at day 0 and every 7 days. MRI was obtained at day 22. Histological analysis was performed at the end of the experiment. Control and TTF-treated groups were compared with two-tailed t-tests.

Results: In vitro: BLI of the control groups demonstrated 5-fold and 34-fold higher tumor signal (photons/sec) than corresponding 150 kHz TTF treatment groups at 14 days (A549 p=0.0289; KRIB p=0.00895). In vivo: All mice receiving 0 kHz treatment displayed hind limb paralysis by day 30, while mice treated with 150 kHz TTF displayed tail drop or no signs of paralysis. MRI and histology confirmed smaller tumors corroborating to BLI (3.67-fold change in photons/sec) (p=0.0212) when the 150 kHz TTF treatment group was compared to controls.

Conclusions: Application of TTF at 150kHz reduced cellular proliferation in both in vitro and in vivo models of spinal metastasis. This is the first report of utilization of TTF for treatment of bony tumors and represents the first evidence that TTF could become a revolutionary therapy for spinal metastasis.

Citation Format: Claudio Esteves Tatsui, Daniel Ledbetter, Christopher Alvarez-Breckenridge. In vitro and in vivo investigation of tumor treating fields for treatment of spinal metastasis [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 20.
Abstract 2009: Gemcitabine-loaded EGFR aptamer for targeted therapy of lung cancer
Authors: Park Jun Young , Cho Ye Lim , Chae Ju Ri , Kang Won Jun
Published: April 2023

Lung cancer is the leading cause of cancer-related death in the world and non-small cell lung cancer (NSCLC) is the most common types of the lung cancer. Epidermal growth factor receptor (EGFR) is an attractive therapeutic target due to its high expression in NSCLC. Gemcitabine (Gem) has shown antitumor activity against many kinds of solid tumors, including NSCLC. Aptamers emerged as promising drug delivery vehicles because of their high binding affinity for the target molecules. The objective of this study was to develop the aptamer-drug conjugates using the EGFR-specific aptamer. EGFR aptamers selected by the SELEX process and gemcitabine was internally incorporated into the EGFR aptamer. In vitro binding affinity of EGFR and Gem-loaded EGFR aptamer was evaluated on EGFR-positive A549, H460, H1299 cell lines, as well as EGFR-negative H522 cells using confocal microscopy. To determine whether the Gem-loaded EGFR aptamer was effectively internalized, Z-stack images were acquired after 1 hr incubation of Cy5-conjugated EGFR aptamer at 37°C. The ex vivo biodistribution of Cy7-conjugated EGFR aptamer was investigated in NSCLC xenograft nude mice. To confirm the antiproliferative effects of Gem-loaded EGFR aptamer, the MTT cell proliferation assay was carried out in NSCLC cells. In the confocal image of EGFR-positive cells, Gem-loaded EGFR aptamers were selectively bound to the cell surface, while no aptamer binding was observed in H522 cells. Z-stack imaging showed that internalized Gem-loaded EGFR aptamer accumulated in EGFR-positive cells. The ex vivo biodistribution data showed that the Gem-loaded EGFR aptamer exhibited higher binding in EGFR-positive A549 tumors than scramble EGFR aptamer. A549 cells showed significant reduction in proliferation following treatment with Gem-loaded EGFR aptamer. Our results indicated that Gem-loaded EGFR aptamer has a potential therapeutic agent in EGFR-positive NSCLC therapy.

Citation Format: Jun Young Park, Ye Lim Cho, Ju Ri Chae, Won Jun Kang. Gemcitabine-loaded EGFR aptamer for targeted therapy of 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 2009.
Abstract 2123: Glycine decarboxylase regulates renal carcinoma progression via interferon stimulated gene factor 3-mediated pathway
Authors: Kim Jin Young , Pham Mai Thi Tuyet , Kim Byung Hoon , Seo Ji Hae , Shin Sojin , Ha Eunyoung
Published: April 2023

Glycine decarboxylase (GLDC) is a mitochondrial enzyme that mediates the degradation of glycine as part of the glycine cleavage system; it is implicated as a tumor suppressor in hepatocellular carcinoma but as an oncogene in the lung cancer. Although GLDC expression in the kidney is second highest next to the liver, very little is known as to the role of GLDC in the kidney. Thus, this study was designed to determine the role of GLDC in the renal carcinoma. We found markedly increased expressions of GLDC in patients with renal cell carcinoma (RCC) classified as poor-risk group based on the Memorial Sloan Kettering Cancer Center prognostic model. In vitro studies revealed that cellular proliferation, colony formation, and migration were decreased in GLDC-deficient renal carcinoma cells while those were increased in GLDC-overexpressing renal carcinoma cells. In vivo xenograft studies with GLDC-deficient and -overexpressing cells also revealed that tumor sizes were noticeably decreased in GLDC-deficient cell-injected mice while those were increased in GLDC-overexpressing cell-injected mice. Mechanistically, we found GLDC regulates renal carcinoma progression via interferon (IFN) stimulated gene factor 3 (ISGF3)-mediated pathway. Poly-IC induced mRNA expression of IFN-α more strongly in GLDC-deficient cells. Expressions of IRF9 and STAT2 were increased in GLDC-deficient cells while those were decreased in GLDC-overexpressing cells. Interferon-responsive genes (IFIT1, IFI44, IFI44L, and IFI27) were also regulated by GLDC as evidenced by increased mRNA expressions in GLDC-deficient cells and increased mRNA expressions in GLDC-overexpressing cells. Knock-down of IRF9 and STAT2 in GLDC-deficient cells reversed decreased cellular proliferation, colony formation, and migration. In summary, the data in this study indicates that GLDC regulates renal carcinoma progression via ISFG3-medated pathway and lay a scientific foundation that could support a therapeutic strategy that targets GLDC for the treatment of renal carcinoma.

Citation Format: Jin Young Kim, Mai Thi Tuyet Pham, Byung Hoon Kim, Ji Hae Seo, Sojin Shin, Eunyoung Ha. Glycine decarboxylase regulates renal carcinoma progression via interferon stimulated gene factor 3-mediated 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 2123.
Abstract 2148: Robust detection of somatic genetic alterations in pancreatic cancer ascites
Authors: Kappagantula Rajya L. , Makohon-Moore Alvin P. , Umeda Shigeaki , Karnoub Elias-Ramzey R. , Melchor Jerry P. , Wood Laura D. , Iacobuzio-Donahue Christine A.
Published: April 2023

Introduction: Regardless of the stage at diagnosis most patients with pancreatic ductal adenocarcinoma develop peritoneal disease and some malignant ascites (MA) as well. Prior studies have shown that MA negatively affects overall treatment efficacy and survival. Despite the clinical significance of MA it has not been studied to any great extent.

Methods: We collected MA and matched normal tissue samples at autopsy from 20 PDAC patients who were initially diagnosed at stages IIB to IV. Whole exome or targeted sequencing was previously performed on each PDAC. Each MA sample was centrifuged twice at 4000 RPM first and then at 15000 RPM to separate the cell pellet (CP) from the cell-free ascites fluid. We next extracted DNA from the CP, matched normal tissue, and the cell-free DNA (cfDNA) from the ascites fluid, and all were submitted to the Genomics Core for MSK-IMPACT, a targeted cancer gene panel representing 505 genes.

Results: Results of the first five patients are complete and the remaining are in process. Comparison of the CPs and/or cfDNA to the matched tumor samples indicated 100% concordance for detected variants. However, the somatic alterations of the CP specifically versus the matched cfDNA were divergent in all patients analyzed thus far. Virtually all copy number alterations in all patients were deep deletions (range 66 to 187 cancer genes deleted) affecting multiple DNA repair pathways including homologous recombination deficiency and microsatellite repair.

Conclusions: Samples of MA, when both the cell pellet and cfDNA are sequenced, accurately represent the genetic features of the matched PDAC tissue and may serve as an alternative mode of sampling for precision medicine. Differences in the genetics of the CP versus the cfDNA suggest polyclonality in the peritoneal space. Moreover, the finding of deep deletions in targetable DNA repair pathways suggest a therapeutic vulnerability for exploration. Given that paracentesis is often performed in the palliative setting and may be performed multiple times over the course of a patients’ management, it also offers an opportunity to determine how clonal dynamics in the peritoneal space change over time. Patients with MA have poor overall survival compared to patients without MA so these patients may benefit from this type of tracking which could potentially help with their treatment.

Citation Format: Rajya L. Kappagantula, Alvin P. Makohon-Moore, Shigeaki Umeda, Elias-Ramzey R. Karnoub, Jerry P. Melchor, Laura D. Wood, Christine A. Iacobuzio-Donahue. Robust detection of somatic genetic alterations in pancreatic cancer ascites [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 2148.
Abstract 2428: Cancer stem cells maintain stemness via autocrine activation of the IFN/JAK/STAT signaling pathway
Authors: Li Aidan , Bai Xuetao , Li Na , Cai Shurui , Banerjee Ananya , Lavudi Kousalya , Wang Linzhou , Ge Qianyun , Yang Yajing , Wang Qi-En
Published: April 2023

Interferons (IFNs) and Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) signaling are best known for their roles in immunity. However, recent work has suggested that both IFNs and the JAK/STAT pathways are associated with tumor growth and progression, as well as the maintenance of cancer stem cell (CSC) populations. To better understand the regulation of the CSC population maintenance by the IFN/JAK/STAT signaling pathway, we enriched CSCs from a panel of non-small cell lung cancer (NSCLC) cell lines by using spheroid culture and determined the phosphorylation of STAT1. We found that sphere cells exhibit increased level of pSTAT1-Y701 compared to their corresponding bulk cells. We further determined the expression level of a few interferon-stimulated genes (ISGs) and found that sphere cells possess enhanced expression of ISG54 and ISG56 genes, which are normally induced by type I IFN (IFN-I), as well as IFNA and IFNB. These results indicate that the IFN-I/STAT1 signaling is highly activated in CSCs, which produce and secrete increased amount of IFN-I. To directly show the effect of IFN-I on the stemness of NSCLC cells, we treated NSCLC cells with IFNβ, and found that IFNβ can significantly enhance the expression of SOX2, a stem cell-specific transcription factor; Inhibition of the JAK signaling blocked both basal and IFNβ-induced SOX2 expression. In addition, knockdown of STAT1 also reduced SOX2 expression, indicating that STAT1 activation plays an important role in mediating IFN-induced enhancement of stemness. Finally, the ChIP assay demonstrated that STAT1 protein can bind to the promoter region of the SOX2 gene to serve as a transcription factor. In summary, our results indicate that CSCs produce and secrete IFN-I via their enhanced JAK/STAT1 signaling. The secreted IFN-I can bind to the receptor on the CSCs, further activate their JAK/STAT1 signaling, promoting the expression of SOX2 and maintenance of stemness of CSCs via an autocrine manner.

Citation Format: Aidan Li, Xuetao Bai, Na Li, Shurui Cai, Ananya Banerjee, Kousalya Lavudi, Linzhou Wang, Qianyun Ge, Yajing Yang, Qi-En Wang. Cancer stem cells maintain stemness via autocrine activation of the IFN/JAK/STAT signaling 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 2428.
Abstract 2433: SERPINA12 promotes the tumorigenic capacity of hepatocellular carcinoma stem cells through hyperactivation of AKT/β-catenin signaling
Authors: Yu Huajian , Zhou Lei , Loong Jane Ho-Chun , Lam Ka-Hei , Wong Tin-Lok , Ng Kai-Yu , Tong Man , Ma Victor WS , Wang Yanyan , Zhang Xiang , Lee Terence K , Yun Jing-Ping , Yu Jun , Ma Stephanie
Published: April 2023

Hepatocellular carcinoma (HCC) is an aggressive disease with a poor clinical outcome. Understanding the mechanisms that drive cancer stemness, which we now know is the root cause of therapy failure and tumor recurrence, is fundamental for designing improved therapeutic strategies. The aim of this study is to identify molecular players specific to CD133+ HCC to better design drugs that can precisely interfere with cancer stem cells (CSCs) but not normal stem cell function. Transcriptome profiling of epithelial-specific ‘normal’ CD133+ cells isolated from fetal and regenerating liver against ‘HCC’ CD133+ cells isolated from proto-oncogene driven and inflammation-associated HCC revealed preferential overexpression of SERPINA12 in HCC but not fetal and regenerating liver cells. SERPINA12 upregulation in HCC is tightly associated with aggressive clinical and stemness features, including survival, tumor stage, cirrhosis, and stemness signatures related to embryonic stem cells, oncogenic dedifferentiation and undifferentiated HCC status. Enrichment of SERPINA12 in HCC is mediated by promoter binding of the well-recognized β-catenin effector TCF7L2 to drive SERPINA12 transcriptional activity. Functional characterization identified a unique and novel role of endogenous SERPINA12 in promoting self-renewal, therapy resistance and metastatic abilities. Mechanistically, SERPINA12 functioned through binding to GRP78, resulting in a hyperactivated AKT/GSK3β/β-catenin signaling cascade, forming a positive feed-forward loop. Intravenous administration of rAVV8-shSERPINA12 sensitized HCC cells to sorafenib and impeded the CSC subset in an immunocompetent HCC mouse model. Collectively, our findings revealed that SERPINA12 is preferentially overexpressed in epithelial HCC CD133+ cells and is a key contributor to HCC initiation and progression by driving an AKT/β-catenin feed-forward loop.

Citation Format: Huajian Yu, Lei Zhou, Jane Ho-Chun Loong, Ka-Hei Lam, Tin-Lok Wong, Kai-Yu Ng, Man Tong, Victor WS Ma, Yanyan Wang, Xiang Zhang, Terence K Lee, Jing-Ping Yun, Jun Yu, Stephanie Ma. SERPINA12 promotes the tumorigenic capacity of hepatocellular carcinoma stem cells through hyperactivation of AKT/β-catenin 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 2433.
Abstract 2435: Single cell spatial analysis identifies regulators of brain tumor initiating cells
Authors: Mirzaei Reza , D’Mello Charlotte , Liu Marina , Nikolic Ana , Kumar Mehul , Visser Frank , Bose Pinaki , Gallo Marco , Yong Wee
Published: April 2023

Glioblastomas (GBMs) are aggressive brain tumors with extensive intratumoral heterogeneity. Here, we used spatial transcriptomics and single-cell ATAC-seq to dissect the transcriptome of distinct anatomical regions of the tumor microenvironment. We identified numerous extracellular matrix (ECM) molecules including biglycan elevated in areas infiltrated with brain tumor-initiating cells (BTICs). Single-cell RNA sequencing showed that the ECM molecules were differentially expressed by cells including injury response versus developmental BTICs. Exogeneous biglycan or overexpression of biglycan resulted in a higher proliferation rate of BTICs, and this was associated mechanistically with LDL receptor-related protein 6 (LRP6) binding and activation of the Wnt/β-catenin pathway. Biglycan-overexpressing BTICs grew to a larger tumor mass and higher mesenchymal phenotypes when implanted intracranially in mice. This study points to the spatial heterogeneity of ECM molecules in the GBM microenvironment and suggests biglycan-LRP6 axis as a therapeutic target to curb GBM growth.

Citation Format: Reza Mirzaei, Charlotte D’Mello, Marina Liu, Ana Nikolic, Mehul Kumar, Frank Visser, Pinaki Bose, Marco Gallo, Wee Yong. Single cell spatial analysis identifies regulators of brain tumor initiating 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 2435.
Abstract 2440: HOTAIR functionality and regulation in ovarian cancer stem cells
Authors: Wang Weini , Zhou Yanchi , Wang Ji , Ozes Ali , O’Hagan Heather M. , Mitra Anirban , Nephew Kenneth P.
Published: April 2023

Ovarian cancer (OC) is the fifth leading cause of cancer-related death among American women. Persistence of OC stem cells (OCSCs) is believed to contribute to resistance to platinum-based chemotherapy and disease relapse. We have previously shown that epigenetic changes in OCSCs play a role in post-therapy OCSC persistence and demonstrated the potential to target OCSC using epigenetic therapies. HOXC transcript antisense RNA (HOTAIR) has been shown to be associated with chemoresistance and overexpressed in high-grade serous OC (HGSOC). HOTAIR interacts with Polycomb Repressive Complex 2 (PRC2) and plays a key role in chromatin remodeling. Because HOTAIR is a known epigenetic regulator of differentiation and developmental genes in OC, we hypothesized that HOTAIR regulates OCSCs and epigenetic targeting HOTAIR will prevent tumor relapse. To produce loss-of-function phenotypes of HOTAIR and investigate the function of this gene, we utilized the paired CRISPR guide RNA design to delete the functional sites of HOTAIR in a panel high grade serous OC cell lines (Kuramochi, OVCAR3) without affecting nearby protein-coding gene. Knockout of HOTAIR re-sensitized OC cells to platinum treatment and significantly decreased (P<0.001) the OCSC population and stemness-related phenotypes, including inhibiting stemness-associated gene expression ALDH1A1, Notch3, Sox9, and PROM1 and in vitro spheroid forming ability under low attachment conditions. Integrated analysis of RNA-seq and ATAC-seq on control and HOTAIR knockout cells revealed HOTAIR altered global chromatin dynamics to change downstream gene expression, particularly, the NF-kB pathway. In xenograft assays using HGSOC cells, combining a HOTAIR inhibitor with an EZH2 inhibitor and chemotherapy significantly decreased in vivo tumor formation and increased mouse survival. In summary, depletion of HOTAIR functionally decreased OCSC phenotypes and malignant potential and reprogrammed HGSOC to a less stem-like phenotype. There is an urgent need to develop new therapeutic strategies to target OCSCs and overcome chemoresistant OC, and the results of this study suggest that targeting HOTAIR in combination with epigenetic therapies may represent a novel therapeutic strategy to prevent tumor relapse in OC.

Citation Format: Weini Wang, Yanchi Zhou, Ji Wang, Ali Ozes, Heather M. O’Hagan, Anirban Mitra, Kenneth P. Nephew. HOTAIR functionality and regulation in ovarian cancer stem 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 2440.
Abstract 2445: PPM1G enhances hepatocellular carcinoma stemness via interacting with YBX1
Authors: Liu Shan , Fang Xiaona , Luo Jie , Huang Jiao , Yang Yuma , Liu Beilei , Huang Jinlin , Wong Ching Ngar , Zhang Baifeng , Gong Lanqi , Ban Liuxian , Yan Qian , Guan Xinyuan
Published: April 2023

PPM1G is a member of protein phosphatase family, marked as Mg2+/Mn2+ dependent 1G. PPM1G protein mainly has three domains: phosphatase domains at both ends and acidic domain (AD) in the middle. It was highly expressed in both embryonic stem cells and hepatocellular carcinoma (HCC) by mRNA-seq data. From pan-cancer view, it was up-regulated in tumor tissue of 24 pan-cancer types and predicted worse overall survival (OS) for 9 cancers. In GSE40267 dataset, PPM1G overexpressed significantly in lung metastasis HCC patients than patients without metastasis. And both from TCGA and ICGC-JP database analysis showed PPM1G was an independent poor prognostic factor for both OS and disease-free survival (DFS) in HCC patients. In vitro, our functional experiments showed that the stemness features such as sphere formation, ALDH assay and atRA (Tretinoin) assay were undermined by knock down (KD) of PPMIG. In HepG2 and 8024 KD cell lines, the tumor capacity of proliferation, cell-cycle, foci-formation, migration invasion and cisplatin induced apoptosis were also impaired. In vivo, KD of PPM1G strongly suppressed the subcutaneous and liver orthotopic tumor formation and lung metastasis and cancer stemness by limited dilution experiment was also significantly weakened. For the mechanism exploration, firstly, GO analysis showed genes highly positive correlated with PPM1G (Spearman R > 0.5) enriched in mRNA splicing. Secondly, YBX1 (role as RNA m5C and m6A reader protein and chemotherapy resistance gene) was screened out by three database (RBP2GO, HiPredict and GEPIA) followed with in vivo CO-IP experiment and immunofluorescence colocalization. The YBX1 expression level was not affected by PPM1G from Western Blot. Lastly, the AD of PPM1G but not the phosphatase domain was interacted with YBX1 by PPM1G cut-off and CO-IP experiments. So, the above evidence proved that PPM1G could interact with YBX1 to promote HCC stemness and tumor growth and metastasis.

Citation Format: Shan Liu, Xiaona Fang, Jie Luo, Jiao Huang, Yuma Yang, Beilei Liu, Jinlin Huang, Ching Ngar Wong, Baifeng Zhang, Lanqi Gong, Liuxian Ban, Qian Yan, Xinyuan Guan. PPM1G enhances hepatocellular carcinoma stemness via interacting with YBX1 [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 2445.
Abstract 2447: XPC suppresses cancer stem cells via inhibiting STAT1-mediated expression of SOX2 in NSCLC
Authors: Li Na , Bai Xuetao , Cai Shurui , Banerjee Ananya , Yang Yajing , Ge Qianyun , Wang Linzhou , Wang Qi-En
Published: April 2023

Xeroderma pigmentosum group C (XPC) is a DNA repair factor mainly involved in nucleotide excision repair but also has functions beyond its role in DNA repair. More than 60% lung adenocarcinoma patients exhibit XPC copy number deletions, and among these patients, low XPC expression is correlated with a poor outcome, indicating that XPC may play a critical role in preventing lung cancer progression. Here, we revealed an inverse relationship between XPC expression and the abundance of cancer stem cell (CSC) subpopulation in non-small cell lung cancer (NSCLC). We demonstrated that knockdown of XPC leads to larger CSC subpopulations in lung cancer cells, while overexpression of XPC can inhibit the stemness properties of these cells. The RNA-seq analysis suggested that XPC can suppress the expression of SOX2, a critical stem cell-specific transcription factor. This finding was further validated in multiple NSCLC cell lines at both mRNA and protein levels. To further investigate the mechanism underlying XPC-mediated suppression of SOX2 expression, we performed quantitative proteomics combined with immuno-affinity purification and found that XPC can interact with STAT1, which is a transcription factor of SOX2. Moreover, XPC can inversely regulate the activation of STAT1 (pSTAT1-Y701), indicating that XPC may suppress SOX2 expression via inhibiting the STAT1 signaling. Taken together, we identified a novel mechanism behind poor outcomes of NSCLC patients with haploinsufficiency XPC. Low level of XPC in lung cancer cells de-represses the activity of STAT1, which further promotes the expression of stem cell-specific gene SOX2 and facilitates the maintenance of CSC subpopulations. Given that CSCs are believed to contribute to tumor progression and chemoresistance, enhanced stemness and expanded CSC populations in XPC haploinsufficiency NSCLC could be responsible for the poor outcome of these patients.

Citation Format: Na Li, Xuetao Bai, Shurui Cai, Ananya Banerjee, Yajing Yang, Qianyun Ge, Linzhou Wang, Qi-En Wang. XPC suppresses cancer stem cells via inhibiting STAT1-mediated expression of SOX2 in NSCLC [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 2447.
Abstract 2451: KRAS activation in gastric cancer stem-like cells promotes tumor angiogenesis and metastasis
Authors: Yoon Changhwan , Lu Jun , Jun Yukyung , Kim Bang- Jin , Till Jacob , Kim Jong Hyun , Keshavjee Sara , Ryeom Sandra , Yoon Sam
Published: April 2023

Our previous work showed that KRAS activation in gastric cancer cells leads to activation of an epithelial-to-mesenchymal transition (EMT) program and generation of cancer stem-like cells (CSCs). Here we analyze how this KRAS activation in gastric CSCs promotes tumor angiogenesis and metastasis. Gastric cancer CSCs were found to secrete pro-angiogenic factors such as vascular endothelial growth factor A (VEGF-A), and inhibition of KRAS markedly reduced secretion of these factors. In a genetically engineered mouse model, gastric tumorigenesis was markedly attenuated when both KRAS and VEGF-A signaling were blocked. In orthotropic implant and experimental metastasis models, silencing of KRAS and VEGF-A using shRNA in gastric CSCs abrogated primary tumor formation, lymph node metastasis, and lung metastasis far greater than individual silencing of KRAS or VEGF-A. Analysis of gastric cancer patient samples using RNA sequencing revealed a clear association between high expression of the gastric CSC marker CD44 and expression of both KRAS and VEGF-A, and high CD44 and VEGF-A expression predicted worse overall survival. In conclusion, KRAS activation in gastric CSCs enhances secretion of pro-angiogenic factors and promotes tumor progression and metastasis.

Citation Format: Changhwan Yoon, Jun Lu, Yukyung Jun, Bang- Jin Kim, Jacob Till, Jong Hyun Kim, Sara Keshavjee, Sandra Ryeom, Sam Yoon. KRAS activation in gastric cancer stem-like cells promotes tumor angiogenesis and metastasis [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 2451.
Abstract 2457: Restoring the balance between WNT and retinoic acid signaling to promote differentiation of cancer stem cells in treatment of colorectal cancer
Authors: Facey Caroline O. B. , Hunsu Victoria O. , Osmond Brian T. , Zhang Chi , Opdenaker Lynn M. , Boman Bruce M.
Published: April 2023

Dysregulated WNT signaling caused by mutation in the APC gene occurs in 80-90% of all colorectal cancer (CRC) cases. Progressive overpopulation of ALDH+ stem cells occurs during development of CRC in familial adenomatous polyposis (FAP) patients. Given that ALDH is a key member of the retinoic acid signaling (RA) pathway, we hypothesize that human CRC is caused by an imbalance between dysregulated WNT and RA signaling. Herein, we aim to restore proper WNT and RA signaling and identify a common link or target to induce differentiation of CSCs along the neuroendocrine cell (NEC) lineage. Accordingly, to determine the effects of restoring wt-APC in APC-mutant HT29 CRC cells, we conducted in vitro experiments to examine Wnt/β-catenin signaling, sensitivity to retinoids, cell proliferation, expression of stem cell markers, quantification of ALDH+ stem cells, and NEC maturation. We utilized Nanostring profiling, TCF reporter assay, western blot, and fluorescence activated cell sorting analyses to ascertain these effects. We found that induction of wt-APC expression decreased WNT/β-catenin signaling and reduced protein expression of WNT-target genes. Notably, inducing wt-APC decreased ATRA-induced expression of the WNT target gene CYP26A1 (by 50%), which is predicted to, in turn, increase RA signaling by lowering degradation of RA. Indeed, inducing wt-APC increased sensitivity of CRC cells to ATRA-induced apoptosis and inhibition of cell proliferation in a dose-dependent manner. Expression of ALDH1A1 decreased (3-fold) with ATRA treatment and inducing wt-APC extended the decrease by an additional 2-fold. Furthermore, upon inducing wt-APC, we found an increase in the protein expression of several NEC markers including CHGA, GLP2R, NSE (ENO2), and SSTR1, and an increased number of GLP2R+ NECs. We also discovered a very highly regulated protein network of 248 proteins and identified a cell signaling mechanism that links the WNT and retinoic acid pathways via CYP26A1. Thus, by inducing wt-APC expression and exogenously activating RA signaling, we found a way to increase differentiation of SCs along the NEC (and other) lineage(s). Translating this strategy in vivo might lead to new, more effective treatments involving retinoids for CRC patients.

Citation Format: Caroline O. B. Facey, Victoria O. Hunsu, Brian T. Osmond, Chi Zhang, Lynn M. Opdenaker, Bruce M. Boman. Restoring the balance between WNT and retinoic acid signaling to promote differentiation of cancer stem cells in treatment of colorectal 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 2457.
Abstract 2462: AXL-WRNIP1 mediated replication stress response aids metastatic latency and relapse
Authors: Marquez-Palencia Mauricio , Malladi Srinivas
Published: April 2023

Metachronous brain metastases, the primary cause of morbidity and mortality in HER2+ breast cancer patients arise from latent residual cells that resist systemic therapies. AXL, a receptor tyrosine kinase, is enriched in metachronous brain metastatic lesions from HER2+ breast cancer patients and in latent metastatic models. In contrast to its known function at the cell surface, AXL is localized to the nucleus and interacts with WRNIP1. Moreover, we show AXL depletion results in an increased replication stress and reduced survival of brain-tropic latent residual and metastatic cells. Furthermore, administration of BGB324 as a neoadjuvant sensitives brain metastatic lesions to targeted therapy. Our findings suggest targeting AXL is a viable option to eradicate residual brain metastatic cells and limit relapses in HER2+ breast cancer patients.

Citation Format: Mauricio Marquez-Palencia, Srinivas Malladi. AXL-WRNIP1 mediated replication stress response aids metastatic latency and relapse [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 2462.
Abstract 2468: Overcoming the leptomeningeal seeding of medulloblastoma by targeting HSP70
Authors: Choi Seung Ah , Ha Saehim , Lee Hee-Young , Kim Joo Whan , Paeng Jin Chul , Phi Ji Hoon
Published: April 2023

Background: Medulloblastoma (MB) is the most common malignant pediatric brain tumor and the development of leptomeningeal dissemination (LM seeding) through the cerebrospinal fluid (CSF) circulation is a major cause of treatment failure. We have previously established the MB LM seeding mouse model. In this study, we aimed to determine molecules that can target seeding (metastatic) cells by analyzing their specific genetic and functional characteristics.

Methods: Seeding and non-seeding cells were isolated and cultured, respectively, and microarray analysis was carried out. Proliferation and wound-healing assays were performed through the HCS system, and viability, migration and adhesion assays were accomplished. In addition, the therapeutic effect of the selected inhibitor was analyzed by region of interest (ROI) analysis of bioluminescence in vivo.

Results: The gene expression and functional characteristics of the successfully obtained seed cells and non-seed cells were compared and analyzed. Differentially expressed genes (DEGs) analysis indicated that heat shock protein 70 (Hsp70) was in the highest rank in seeding cells, and pathway enrichment analysis revealed that the metabolism was the main pathway enriched in seeding cells. Proliferation of seeding cells was slower than that of non-seeding cells, but there was no significant difference in viability. Notably, the wound-healing of seeding cells was delayed, but the adhesion ability on collagen was higher. Among the six HSP70 inhibitors, VER155008 was efficiently sensitive to seeding cells, and suppression of expression of MRP proteins along with HSP70 was also confirmed. In addition, it was observed that the treatment of VER155008 reduced seeding through the spinal cord in vivo.

Conclusion: Our study suggests that VER15008 can be a promising treatment option, targeting LM seeding of MB.

Citation Format: Seung Ah Choi, Saehim Ha, Hee-Young Lee, Joo Whan Kim, Jin Chul Paeng, Ji Hoon Phi. Overcoming the leptomeningeal seeding of medulloblastoma by targeting HSP70 [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 2468.
Abstract 247: Twist pan-cancer synthetic RNA fusion control for assay development
Authors: Cherry Patrick Daniel , Corwin Jason , Fuhrman Kit , Challacombe Jean , Murphy Derek , Toro Esteban
Published: April 2023

Fusion genes are structural variants that arise when the coding region of two previously independent genes become joined together; fusion genes can be a major driving cause of cancer development. Many gene fusion events have been classified as clinically-relevant and are targets for both diagnostic applications, such as TMPRSS2-ERG in prostate cancer, and therapeutic applications, such as CD74-ROS1 and EML4-ALK in non-small cell lung cancer. Given the potential clinical benefits of early detection, there is significant interest in developing highly sensitive and accurate diagnostic assays to detect cancer using these gene fusions as biomarkers. A significant barrier to the development of these diagnostic assays is the lack of a reliable and renewable sample source harboring gene fusions of interest for use in assay development and analytical validation.

Here, we describe the development and performance of a new fusion reference material: the Twist Pan-cancer RNA Fusion Control, a highly-multiplexed positive control designed to be spiked into a selected RNA background or as a stand-alone positive control. The Twist Pan-cancer RNA Fusion Control provides a wide selection of 80+ common and curated cancer targets for analytical validation and assay development. The synthetic RNAs are designed centered around the known and documented fusion sites with 750 nt of RNA 5′- of and 3′- of the fusion junction, suitable for short read sequencing and qPCR experiments. Pooled synthetic fusion RNAs are quantified at known molar ratios, NGS QC’d for uniformity, and ddPCR’d to establish a highly precise pool concentration. Finally, in fusion detection NGS experiments, we observe over a 95% recall rate of fusion events.

The Pan-cancer RNA Fusion Control is designed to serve as a spike-in or stand-alone positive control and specifically pairs well with a clinically-relevant target enrichment (TE) panel within the Twist Targeted Enrichment for Gene Expression solution. This control sample positive for RNA fusions can be applied in both qPCR and NGS workflows to validate panel/probe sets, establish limits of detection, and monitor ongoing assay performance. The Twist Pan-cancer RNA Fusion Control provides a valuable one-stop solution to assay developers seeking reference materials for a wide array of cancer-associated fusion transcripts.

For Research Use Only. Not for use in diagnostic procedures.

Citation Format: Patrick Daniel Cherry, Jason Corwin, Kit Fuhrman, Jean Challacombe, Derek Murphy, Esteban Toro. Twist pan-cancer synthetic RNA fusion control for assay development [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 247.