bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A27: Fidelity of a PDX-CR model for bladder cancer
Authors: Mondal Abdul M. , Ma Ai-Hong , Li Guangzhao , Krawczyk Ewa , Jie Lu , Schlegel Richard , Pan Chong-Xian , Liu Xuefeng
Published: August 2020

Current efforts for cancer drug discovery have predominantly been deterred by the lack of appropriate preclinical cancer models that recapitulate the characteristics of this complex disease. Patient-derived xenografts (PDXs) are widely recognized as a more physiologically relevant preclinical model than organoids and standard cell lines, and often resemble the original tumor histology, genetic profile, and gene-expression patterns. Despite these benefits, PDX models are limited by their variable engraftment rate, lack of sustained growth in vitro, low throughput for drug screening, lower amenability to experimental manipulation, and high cost. In this study, we utilized conditional reprogramming (CR) technology to generate four CR cell (CRC) lines from bladder cancer PDXs. The CR cells were then employed to evaluate the genetic status and drug sensitivity and compared with the parental PDX tumors. All the established CRC lines maintained parental mutations and allele frequencies without clonal drift. Moreover, the drug responses of the parental PDX tumors in vivo were retained in the established CRC lines in vitro. Altogether, CR technology offers the ability to generate cell lines and expand PDX cells without compromising fundamental biologic properties of the model, thereby allowing for in vitro use to reduce animal usage, variability, and study cost. Perhaps more importantly, the CR cell lines established here can be used for personalized high-throughput drug screening as well as for studying drug-resistance mechanisms.

Citation Format: Abdul M. Mondal, Ai-Hong Ma, Guangzhao Li, Ewa Krawczyk, Lu Jie, Richard Schlegel, Chong-Xian Pan, Xuefeng Liu. Fidelity of a PDX-CR model for bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr A27.
Abstract B08: MSH2 downregulation induces chemoresistance in bladder cancer
Authors: Goodspeed Andrew E. , Jean Annie , Costello James C.
Published: August 2020

Treatment of muscle-invasive bladder cancer has seen little improvement in three decades. The objective of this study is to identify genes and pathways that associate with cisplatin resistance in bladder cancer. A whole-genome, CRISPR-based screen was performed in the MGHU4 bladder cancer cell line treated with cisplatin to identify genes that mediate resistance to cisplatin. Targeted validation was performed in vitro in another bladder cancer cell line, 253J. MSH2 and MLH1 are prominent components of the mismatch repair. These are the top two genes that have the largest effect on cisplatin resistance according to our synthetic lethal screen. Bladder cancer cells with an MSH2 knockdown are resistant to cisplatin in vitro, in part due to a reduction in apoptosis. MSH2 was also investigated in a publicly available bladder cancer dataset containing 340 bladder cancer patients with treatment, protein, and survival information. Bladder cancer patients with low protein levels of MSH2 have poorer overall survival when treated with cisplatin- or carboplatin-based therapy. If confirmed in follow-up studies, MSH2 protein level may serve as a prospective biomarker of chemotherapy response in this cancer type.

Note: This abstract was not presented at the conference.

Citation Format: Andrew E. Goodspeed, Annie Jean, James C. Costello. MSH2 downregulation induces chemoresistance in bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr B08.
Abstract B12: Acetate metabolism mediated by acetyl-CoA synthetase 2 in cisplatin-resistant bladder cancer
Authors: Wen He , Lee Sujin , Zhu Wei-Guo , Lee Ok-Jun , Yun Seok Joong , Kim Jayoung , Park Sunghyouk
Published: August 2020

Introduction and Objective: Cisplatin is an important chemotherapeutic agent against metastatic bladder cancer, but resistance often limits its usage. With the recent recognition of lipid metabolic alterations in bladder cancers, we studied the metabolic implications of cisplatin resistance using cisplatin-sensitive (T24S) and -resistant (T24R) bladder cancer cells.

Methods: To test whether there should be differences in metabolism and metabolism-associated pathways between cisplatin-sensitive and resistant bladder cancer cells, we applied the live metabolomics approach that we recently developed to isogenic bladder cancer cell lines T24S (cisplatin sensitive) and T24R (cisplatin resistant). The metabolites generated from 13C-glucose tracer were monitored with 2D 1H-13C HSQC NMR in real time.

Results: Real-time live metabolomics revealed that T24R cells consume more glucose, leading to higher production of glucose-derived acetate and fatty acids. Along with the activation of general metabolic regulators, enzymes involved in acetate usage (ACSS2) and fatty acid synthesis (ACC) and a precursor for fatty acid synthesis (acetyl-CoA) were elevated in T24R cells. Consistently, metabolic analysis with 13C isotope revealed that T24R cells preferred glucose to acetate as the exogenous carbon source for the increased fatty acid synthesis, contrary to T24S cells. In addition, ACSS2, rather than the well-established ACLY, was the key enzyme that supplies acetyl-CoA in T24R cells through glucose-derived endogenous acetate. The relevance of ACSS2 in cisplatin resistance was further confirmed by the abrogation of resistance by an ACSS2 inhibitor and, finally, by the higher expression of ACSS2 in the patient tissues with cisplatin resistance.

Conclusions: Our results may help improve the treatment options for chemoresistant bladder cancer patients and provide possible vulnerability targets to overcome the resistance.

Citation Format: He Wen, Sujin Lee, Wei-Guo Zhu, Ok-Jun Lee, Seok Joong Yun, Jayoung Kim, Sunghyouk Park. Acetate metabolism mediated by acetyl-CoA synthetase 2 in cisplatin-resistant bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr B12.
Abstract B14: Epigenetic remodeling of cancer metabolisms in cisplatin-resistant bladder cancer
Authors: Yeon Austin , You Sungyong , Kim Minhyung , Gupta Amit , Park Myung Hee , Weisenberger Daniel , Liang Gangning , Kim Jayoung
Published: August 2020

Introduction and Objective: Alterations in DNA methylation are important epigenetic markers in bladder cancer (BC). These epigenome modifications drive the mechanisms of aggressive chemoresistant BC. Clinicopathologic biomarkers that indicate chemotherapeutic resistance are critical for better assessing treatment strategies for individual patients. Thus, in this study, we aimed to determine whether DNA methylation of certain metabolic enzymes is significantly altered in cisplatin-resistant BC cells.

Methods: To characterize CpG methylation and nucleosome accessibility in cisplatin-resistant BC cells, the Illumina Infinium HM450 DNA methylation assay was performed. Perturbed gene expression was found to be associated with cisplatin resistance, and the biologic roles of spermidine/spermine N1-acetyltransferase (SAT1) and argininosuccinate synthase 1 (ASS1) were further studied using qRT-PCR analysis and various cell biology assays, including Western blot.

Results: ASS1 and SAT1, genes for amino acid and polyamine metabolism catalysts, respectively, were found to be vastly hypermethylated, resulting in greatly downregulated expression. ASS1 expression is of particular interest because prior studies have demonstrated its potential association with BC stage and recurrence. In regard to chemoresistance, we found that aberrant expression or induced stimulation of SAT1 restored cisplatin sensitivity in the cell culture system. We also found that the addition of exogenous arginine deiminase through administration of ADI-PEG 20 (pegylated arginine deiminase) increased ASS1 expression and enhanced cisplatin's apoptotic effects.

Conclusions: Our study demonstrates a novel mechanistic link between the epigenetic perturbation of SAT1 and ASS1 and cancer metabolism in cisplatin-resistant bladder cancer cells. These findings suggest potential utility of SAT1 and ASS1 as predictive biomarkers in resensitizing bladder cancer to chemotherapy and personalizing therapy.

Citation Format: Austin Yeon, Sungyong You, Minhyung Kim, Amit Gupta, Myung Hee Park, Daniel Weisenberger, Gangning Liang, Jayoung Kim. Epigenetic remodeling of cancer metabolisms in cisplatin-resistant bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr B14.
Abstract B20: Characterization of tumor mutational landscape in smokers and nonsmokers with urothelial carcinoma
Authors: Walasek Aleksandra , Almassi Nima , Teo Min Yuen , Funt Samuel , Schultz Nikolaus , Dalbagni Guido , Hu Wenhu , Al-Ahmadie Hikmat , Bajorin Dean F , Rosenberg Jonathan E , Iyer Gopakumar , Bochner Bernard H. , Solit David B. , Pietzak Eugene J.
Published: August 2020

Introduction and Objectives: Smoking is a major risk factor for development of bladder cancer. It has been previously shown that smoking-related and non-smoking-related cancers have characteristic mutational signatures. Hypothesizing that somatic alterations differ between smokers and nonsmokers with urothelial carcinoma, we used next-generation sequencing to evaluate for differences in genomic alterations between these two groups of patients.

Methods: We identified in our prospectively maintained institutional database all patients with urothelial carcinoma whose tumors underwent next-generation sequencing using the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) assay. A panel of genes previously reported by The Cancer Genome Atlas (TCGA) as being commonly mutated in bladder cancer was chosen for analysis.

Results: A total of 1,044 samples from 968 patients were included in the analysis. Seven hundred eighty-five (85%) of the samples represented bladder tumors and 259 (25%) of the samples represented tumors of the upper tract. Patients with smoking history comprised 66% of the cohort. The most frequently altered genes in active or former smokers and never smokers were TERT promoter (55% and 60%), TP53 (43% and 41%), KDM6A (30% and 26%), and FGFR3 (27% and 26%).

Conclusions: Mutational profiling of urothelial tumors in this large cohort of patients showed high incidence of genomic alterations consistent with prior studies. The frequency of alterations in these genes was similar between smokers and nonsmokers. To further understand smoking-related mutational process, we are examining mutational signatures and differences in genomic alterations as a function of smoking intensity exposure.

Citation Format: Aleksandra Walasek, Nima Almassi, Min Yuen Teo, Samuel Funt, Nikolaus Schultz, Guido Dalbagni, Wenhu Hu, Hikmat Al-Ahmadie, Dean F Bajorin, Jonathan E Rosenberg, Gopakumar Iyer, Bernard H. Bochner, David B. Solit, Eugene J. Pietzak. Characterization of tumor mutational landscape in smokers and nonsmokers with urothelial carcinoma [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr B20.
Abstract B30: A living biomarker from urine to predict drug efficacy and recurrence of bladder cancer
Authors: Liu Xuefeng
Published: August 2020

The culture of cancer cells from urine samples is a simple, noninvasive technique that has the potential to advance the diagnosis, treatment, and monitoring of patients with bladder cancer, and the generation of such urine-derived cultures can provide both genetic and phenotypic data for precision medicine. In this study we collected urine and/or tumor biopsies from 23 bladder cancer patients and used conditional reprogramming (CR) to generate cell cultures from each of these sources. Using this CR technique, the overall success rate of culturing primary bladder cancer cells from the urine of bladder cancer patients was 96% (22/23), with 100% (18/18) of high-grade bladder cancers and 80% (4/5) of low-grade cancers generating cultures. No CR cultures (0/7) were generated from the urine of cancer-free participants. We characterized CR cells at cellular and genetic levels. The therapeutic responses of urine CRCs and tumor CRCs were also distinguishable from different patients and displayed similar patterns if derived from the same patient. This rapid, efficient, and noninvasive method for generating cultures of bladder cancer cells can be used potentially for high-throughput drug screening, predicting patient clinical responses, and monitoring tumor initiation and recurrence.

Citation Format: Xuefeng Liu. A living biomarker from urine to predict drug efficacy and recurrence of bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr B30.
Abstract IA01: The epigenetics of cancer
Authors: Jones Peter A.
Published: August 2020

Human cancers are initiated and maintained by DNA mutations and also by alterations in the cancer epigenome. The interaction between these processes is underscored by the observation that all human cancers contain DNA methylation aberrations and also frequently harbor mutations in genes that modify the epigenome. These include the enzymes that apply and remove methyl groups to and from cytosine, DNMT3A and TET2. Abnormal DNA cytosine methylation has received the most attention in our understanding of its potential to silence tumor suppressor genes and thus to directly contribute to the malignant phenotype. There are now many drugs that can target the epigenome, and I will focus on those that inhibit DNA methylation. It is important that we understand how these drugs elicit responses in patients, and most of the attention to date has centered on their ability to activate genes that are methylated and altered in a cancer relative to the normal tissue. However, a large percentage of the human genome codes for transposable elements, and these are often silenced by DNA methylation. Activation of these transposable elements can give rise to a state of “viral mimicry” in which a cancer cell behaves as though it is infected by an exogenous virus. I will explore how this activation of transposable elements may contribute to an interferon response that leads to apoptosis of cancer cells and to increased visibility to the immune system. Coupling epigenetic therapies with other approaches may be useful in the future in the treatment of cancers, including bladder cancer.

Citation Format: Peter A. Jones. The epigenetics of cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr IA01.
Abstract IA06: A urine assay to triage patients with hematuria for cystoscopy
Authors: van Kessel Kim E.M. , de Jong Joep J. , Ziel-van der Made Angelique C.J. , Roshani Hossain , Haensel Stefan M. , Wolterbeek Josien H. , Boevé Egbert R. , Oomens Eric H.G.M. , van Casteren Niels J. , Krispin Manuel , Boormans Joost L. , Steyerberg Ewout W. , van Criekinge Wim , Zwarthoff Ellen C.
Published: August 2020

Objectives: To assess the accuracy of a previously developed molecular assay to detect bladder cancer in a large prospective cohort of patients referred for hematuria.

Design, Setting and Participants: A urine sample was collected prior to cystoscopy and mutation/methylation status of 6 genes was determined in DNA from urinary cells and combined with age. This existing diagnostic model was validated on this cohort and optimized using logistic regression. Clinical usefulness was determined by the net benefit approach. Main outcome measures: Primary endpoint was the model performance to detect the presence of urothelial cancer, as indicated by the area under the receiver operating characteristic (ROC) curve (AUC). Secondary endpoints were the sensitivity, specificity, and negative predictive value (NPV) of the optimal diagnostic model.

Results: In 838 patients, the mutation/methylation status could be determined for all genes. Urothelial cancer was observed in 112 patients (98/457 in the gross and 14/381 in the microscopic hematuria group). Application of the existing model resulted in an AUC of 0.93. Combining the assay with the type of hematuria resulted in the final optimal model with an AUC of 0.96 (96% sensitivity, 73% specificity, 99% negative predictive value). The assay also detected all six upper tract urothelial tumors that are not visible by cystoscopy. Net benefit analysis showed that the urine test should be preferred over “cystoscopy for all.” Application of the optimal model on patients whose biomarker status was incomplete resulted in the identification of 5 additional tumors. Implementing the urine test as a triage tool could lead to a 53% reduction in cystoscopies.

Conclusions: The urine test detects urothelial cancer with a very high accuracy and is ready for clinical implementation.

Citation Format: Kim E.M. van Kessel, Joep J. de Jong, Angelique C.J. Ziel-van der Made, Hossain Roshani, Stefan M. Haensel, Josien H. Wolterbeek, Egbert R. Boevé, Eric H.G.M. Oomens, Niels J. van Casteren, Manuel Krispin, Joost L. Boormans, Ewout W. Steyerberg, Wim van Criekinge, Ellen C. Zwarthoff. A urine assay to triage patients with hematuria for cystoscopy [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr IA06.
Abstract IA07: Potential benefits of and obstacles to use of urine-based tumor markers
Authors: Lotan Yair
Published: August 2020

There are many potential uses of urine-based tumor markers in improving detection and surveillance of bladder cancer. Prior to incorporation of urine markers into clinical care, it is important to demonstrate improved efficacy over standard clinical tools. The main areas where urine markers may improve care is in triaging patients with hematuria who need evaluation, reducing frequency of cystoscopy in patients with low-grade disease, improving detection of high-grade patients, and improving prediction of outcomes in patients with bladder cancer. There are currently limitations in white light cystoscopy, especially in detection of carcinoma in situ (CIS). Also, the most widely used urine marker, cytology, has low sensitivity for detecting low-grade cancer and can miss up to 40% of high-grade bladder cancer. Most urine markers have improved sensitivity over urine cytology but reduced specificity. The prevalence of disease impacts the positive and negative predictive values of these tests. For hematuria, the prevalence of cancer is very low in microhematuria patients; as such, the positive predictive value of urine markers is low. Clinicians need markers to provide clinically useful information by either having a high positive predictive value or high negative predictive value (NPV). In the context of microhematuria, many patients are not adequately evaluated and this can result in delays in diagnosis. A urine marker with a high NPV could reduce need for cystoscopy for low-risk patients and enrich the cohort of patients more likely to have cancer. For surveillance, the sensitivity of urine markers has not been sufficient to replace cystoscopy. It is possible that replacing some cystoscopy procedures by alternating a marker with cystoscopy for patients with low-grade disease may be possible, but trials are needed to demonstrate the safety and efficacy of this approach. In high-grade patients, there is need for improved detection of recurrent tumors, especially CIS, since white light cystoscopy has been shown to miss tumors compared to enhanced cystoscopy. A high-performing urine marker could improve detection, but appropriate studies need to be performed to demonstrate sufficient PPV to justify modifying clinical care. There is also a potential role for using markers to improve management of patients with atypical cytology or cystoscopic findings. They could also improve prediction of outcomes in patients with high-grade disease, especially in those patients treated with intravesical therapies. In order for urine markers to be incorporated into guidelines, it is important to develop appropriate trials to validate their utility. There is also a need to consider overall cost of care and patient perspectives.

Citation Format: Yair Lotan. Potential benefits of and obstacles to use of urine-based tumor markers [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr IA07.
Abstract IA10: Developing rational combination therapy with checkpoint inhibitors
Authors: Tu Megan M. , Lee Francis Y. F. , Jones Robert T. , Kimball Abigail K. , Saravia Elizabeth , Graziano Robert F. , Coleman Brianne , Menard Krista , Yan Jun , Michaud Erin , Chang Han , Abdel-Hafiz Hany A. , Rozhok Andrii I. , Duex Jason E. , Agarwal Neeraj , Chauca-Diaz Ana , Johnson Linda K. , Ng Terry L. , Cambier John C. , Clambey Eric T. , Costello James C. , Korman Alan J. , Theodorescu Dan
Published: August 2020

Targeting antibodies to programmed cell death protein-1 (PD-1) is an effective treatment across multiple cancer types. While a subset of patients receiving these therapies experience favorable responses, many still show disease progression, highlighting the importance of other mechanisms influencing immune responsiveness in these tumors. Therefore, combining therapies that enhance antitumor immunity has been an area of great interest to the entire cancer community. We have recently tackled this challenge in the rapidly evolving field of cancer immunotherapy by using in vivo functional genomics to identify genes whose inhibition potentiates the response to anti-PD-1 immunotherapy. Using an in vivo screening approach with a customized shRNA pooled library, we identified a number of candidates including DDR2 as promising targets for the enhancement of response to anti-PD-1 immunotherapy. In the case of DDR2, using isogenic in vivo murine models across five different tumor histologies—bladder, breast, colon, sarcoma, and melanoma—we show that DDR2 depletion increases sensitivity to anti-PD-1 treatment compared to monotherapy. Combination treatment of tumor-bearing mice with anti-PD-1 and dasatinib, a tyrosine kinase inhibitor of DDR2, also led to tumor load reduction and in some cases, complete clearance. RNAseq and CyTOF analysis revealed higher CD8+ T-cell populations in tumors with DDR2 depletion and those treated with dasatinib when either was combined with anti-PD-1 treatment. Our work provides strong scientific rationale for targeting DDR2 in combination with PD-1 inhibitors. In addition, a number of other potential druggable targets have been identified in our screen that we are currently pursuing.

Citation Format: Megan M. Tu, Francis Y. F. Lee, Robert T. Jones, Abigail K. Kimball, Elizabeth Saravia, Robert F. Graziano, Brianne Coleman, Krista Menard, Jun Yan, Erin Michaud, Han Chang, Hany A. Abdel-Hafiz, Andrii I. Rozhok, Jason E. Duex, Neeraj Agarwal, Ana Chauca-Diaz, Linda K. Johnson, Terry L. Ng, John C. Cambier, Eric T. Clambey, James C. Costello, Alan J. Korman, Dan Theodorescu. Developing rational combination therapy with checkpoint inhibitors [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr IA10.
Abstract IA22: Realizing the potential of targeted therapy in non-muscle invasive bladder cancer
Authors: Black Peter C.
Published: August 2020

Targeted therapies have revolutionized the management of most cancers, but the era of targeted therapy has mostly passed by bladder cancer. Ramicurimab (targeting VEGR) and erdafitinib and infigratinib (both targeting FGFR) have recently provided some reason for optimism that targeted therapies with highly potent inhibitors may yet find a role in advanced bladder cancer. Targeting genomic alterations in FGFR3 holds the most promise, but this molecular event is probably even more relevant in non-muscle invasive bladder cancer (NMIBC), and trials in this space are essential. Similarly, KDMT6a appears to be particularly important in NMIBC, and drugs targeting chromatin modification pathways are likely to be relevant in NMIBC. Novel therapies are also under development that are not specific to an individual cancer's genomic makeup, but instead target specific cancer-related pathways. Such agents include oportuzumab monatox and BC-819. Most clinical trial activity has focused on BCG-unresponsive high-risk NMIBC patients, but this is partly due to the pathway for drug registration, and we are likely to see some of the successful drugs in this disease state move forward to earlier disease states, especially to intermediate-risk patients. These therapies will need to be positioned in the treatment landscape along with other nontargeted intravesical agents such as nadofaragene firadenovec (rAd-IFN) and systemic immune checkpoint blockade.

Citation Format: Peter C. Black. Realizing the potential of targeted therapy in non-muscle invasive bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr IA22.
Abstract PR01: Novel role of ketone body metabolism in acquired gemcitabine resistance
Authors: Rohena-Rivera Krizia , Bhowmick Neil
Published: August 2020

Urinary bladder cancer accounts for 81,000 new cases per year and 4.7% of the new cancer diagnosis in the US. Even though most of the patients suffer from noninvasive lesions, around 70% will recur following surgical intervention. Chemotherapy with gemcitabine in combination with cisplatin is a common treatment option for recurrent disease; however, 60% of the patients will relapse due to resistance. Gemcitabine is a synthetic pyrimidine nucleoside prodrug, without a known mechanism for resistance. In examining mechanisms of resistance, we identified ketone body metabolism to be important. OXCT1, a rate-limiting enzyme in ketone metabolism, was found to be highly associated with bladder cancer death—Hoglund et al, P = 2.3 × 10-3 and TCGA, P = 6.5 × 10-4. We measured the expression of OXCT1 in RT4, UMUC3, T24, and 5637 bladder cancer cell lines and observed that expression correlated with gemcitabine resistance. The generation of gemcitabine resistance of otherwise sensitive 5637 cells (5637GR) resulted in elevation of OXCT1 expression, as well as PGC1a and SIRT1 involved in mitochondrial biogenesis. Conversely, the CRISPR/Cas9 knockout of OXCT1 was able to sensitize inherently resistant UMUC3 and generated 5637GR lines. Given that OXCT1 is a rate-limiting enzyme in ketone metabolism, we evaluated oxygen consumption rate among parental and resistant cells with Seahorse. Surprisingly, resistant cells were found to be metabolically quiescent. We evaluated the role OXCT1 has on cancer stemness through sphere-forming assays (hanging drop and forced floating methods) to reveal that the OXCT1-KO lines had reduced spheres compared to their parental lines. We identified bone morphogenic protein (BMP) signaling to be induced in promoting SOX9 expression, in OXTC1-dependent manner. Gene expression analysis further corroborated the novel role of ketone metabolism in stemness and therapeutic resistance.

This abstract is also being presented as Poster B28.

Citation Format: Krizia Rohena-Rivera, Neil Bhowmick. Novel role of ketone body metabolism in acquired gemcitabine resistance [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr PR01.
Abstract PR05: Similarities in molecular subtypes and subtype immune patterns between naturally occurring canine and human invasive bladder cancer
Authors: Dhawan Deepika , Sommer Breann C. , Ramos-Vara José A. , Hahn Noah M. , Knapp Deborah W.
Published: August 2020

Relevant animal models are needed to study treatment strategies related to the molecular subtypes of bladder cancer and the immune response between these subtypes. The purpose of the study was to characterize the molecular subtypes and immune features in naturally occurring canine invasive urothelial carcinoma (InvUC). Canine InvUC is already known to mimic the human condition in pathologic features, metastatic behavior, and chemotherapy response. Molecular subtyping could further increase the utilization of the canine model. RNA-seq data from canine InvUC (n=56) and normal canine bladder mucosa (n=4) were analyzed using Strand NGS (Strand Genomics, San Francisco, CA). Data were normalized (DESeq, TMM), and DEGs selected (2FC, pcorr <0.05) using DESeq2 and edge R, respectively. Following unsupervised clustering that identified two groups of tumors, supervised clustering was performed in which the data were interrogated using a panel of genes known to classify human bladder cancer subtypes (TCGA), as well as multiple gene panels that classify human bladder cancer as immune hot (infiltrated) or immune cold (noninfiltrated, immune-suppressor features). Infiltrating immune cells were observed in histologic sections with CD3 immunohistochemistry. Distinct luminal (n=28) and basal (n=28) subtypes were identified in the canine InvUC samples, with subclassifications emerging in both subtypes. There was anticipated heterogeneity between the samples, but of the 28 basal tumors, all had hot immune features, with 10 being exceptionally hot. Of the luminal tumors, 22 of 28 were notably immune cold. In conclusion, canine InvUC mimics human invasive bladder cancer in regard to molecular subtypes and immune patterns within subtypes. This expands the value of the canine bladder cancer model and offers opportunities to study strategies for individualized therapy and to develop strategies to enhance the tumor immune environment in order to improve treatment outcomes. Support: NIH/NCI P30CA023168 Supp (Knapp, Ratliff).

This abstract is also being presented as Poster A26.

Citation Format: Deepika Dhawan, Breann C. Sommer, José A. Ramos-Vara, Noah M. Hahn, Deborah W. Knapp. Similarities in molecular subtypes and subtype immune patterns between naturally occurring canine and human invasive bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr PR05.
Genetic Variants in One-Carbon Metabolism Pathway Predict Survival Outcomes of Early-Stage Non-Small Cell Lung Cancer
Authors: Do Sook Kyung , Choi Sun Ha , Lee Shin Yup , Choi Jin Eun , Kang Hyo-Gyoung , Hong Mi Jeong , Kim Ji Hyun , Baek Sun Ah , Lee Jang Hyuck , Lee Won Kee , Do Young Woo , Lee Eung Bae , Shin Kyung Min , Jeong Ji Yun , Lee Yong Hoon , Seo Hyewon , Yoo Seung Soo , Lee Jaehee , Cha Seung Ick , Kim Chang Ho , Seok Yangki , Cho Sukki , Jheon Sanghoon , Park Jae Yong
Published: August 2020

Background: This study was conducted to investigate the association between genetic variants in one-carbon metabolism and survival outcomes of surgically resected non-small cell lung cancer (NSCLC). Methods: We genotyped 41 potentially functional variants of 19 key genes in the one-carbon metabolism pathway among 750 NSCLC patients who underwent curative surgery. The association between genetic variants and overall survival (OS)/disease-free survival (DFS) were analyzed. Results: Among the 41 single-nucleotide polymorphisms (SNPs) analyzed, 4 SNPs (MTHFD1L rs6919680T>G and rs3849794T>C, MTR rs2853523C>A, and MTHFR rs4846049G>T) were significantly associated with survival outcomes. MTHFD1L rs6919680T>G and MTR rs2853523C>A were significantly associated with better OS (adjusted hazard ratio [aHR] = 0.73, 95% confidence interval [CI] = 0.54–0.99, p = 0.04) and worse OS (aHR = 2.14, 95% CI = 1.13–4.07, p = 0.02), respectively. MTHFD1L rs3849794T>C and MTHFR rs4846049G>T were significantly associated with worse DFS (aHR = 1.41, 95% CI = 1.08–1.83, p = 0.01; and aHR = 1.97, 95% CI = 1.10–3.53, p = 0.02, respectively). When the patients were divided according to histology, the associations were significant only in squamous cell carcinoma (SCC), but not in adenocarcinoma (AC). In SCC, MTHFD1L rs6919680T>G and MTR rs2853523C>A were significantly associated with better OS (aHR = 0.64, 95% CI = 0.41–1.00, p = 0.05) and worse OS (aHR = 2.77, 95% CI = 1.11–6.91, p = 0.03), respectively, and MTHFD1L rs3849794T>C and MTHFR rs4846049G>T were significantly associated with worse DFS (aHR = 1.73, 95% CI = 1.17–2.56, p = 0.01; and aHR = 2.78, 95% CI = 1.12–6.88, p = 0.03, respectively). Conclusions: Our results suggest that the genetic variants in the one-carbon metabolism pathway could be used as biomarkers for predicting the clinical outcomes of patients with early-stage NSCLC.
Sequential Combination of Cognitive-Behavioral Treatment and Well-Being Therapy in Depressed Patients with Acute Coronary Syndromes: A Randomized Controlled Trial (TREATED-ACS Study)
Authors: Rafanelli Chiara , Gostoli Sara , Buzzichelli Sara , Guidi Jenny , Sirri Laura , Gallo Pamela , Marzola Enrica , Bergerone Serena , De Ferrari Gaetano Maria , Roncuzzi Renzo , Di Pasquale Giuseppe , Abbate-Daga Giovanni , Fava Giovanni A.
Published: August 2020

Introduction: Randomized controlled trials (RCT) of psychotherapeutic interventions have addressed depression and demoralization associated with acute coronary syndromes (ACS). The present trial introduces psychological well-being, an increasingly recognized factor in cardiovascular health, as a therapeutic target. Objective: This study was designed to determine whether the sequential combination of cognitive-behavioral therapy (CBT) and well-being therapy (WBT) may yield more favorable outcomes than an active control group (clinical management; CM) and to identify subgroups of patients at greater risk for cardiac negative outcomes. Methods: This multicenter RCT comparedCBT/WBT sequential combination versus CM, with up to 30 months of follow-up. One hundred consecutive depressed and/or demoralized patients (out of 740 initially screened by cardiologists after a first episode of ACS) were randomized to CBT/WBT associated with lifestyle suggestions (n = 50) and CM (n = 50). The main outcome measures included: severity of depressive symptoms according to the Clinical Interview for Depression, changes in subclinical psychological distress, well-being, and biomarkers, and medical complications and events. Results: CBT/WBT sequential combination was associated with a significant improvement in depressive symptoms compared to CM. In both groups, the benefits persisted at follow-up, even though the differences faded. Treatment was also related to a significant amelioration of biomarkers (platelet count, HDL, and D-dimer), whereas the 2 groups showed similar frequencies of adverse cardiac events. Conclusions: Addressing psychological well-being in the psychotherapeutic approach to ACS patients with depressive symptoms was found to entail important clinical benefits. It is argued that lifestyle changes geared toward cardiovascular health may be facilitated by a personalized approach that targets well-being.
Reelin Amplifies Glycoprotein VI Activation and AlphaIIb Beta3 Integrin Outside-In Signaling via PLC Gamma 2 and Rho GTPases
Authors: Krueger Irena , Gremer Lothar , Mangels Lena , Klier Meike , Jurk Kerstin , Willbold Dieter , Bock Hans H. , Elvers Margitta
Published: August 2020

Objective:

Reelin, a secreted glycoprotein, was originally identified in the central nervous system, where it plays an important role in brain development and maintenance. In the cardiovascular system, reelin plays a role in atherosclerosis by enhancing vascular inflammation and in arterial thrombosis by promoting platelet adhesion, activation, and thrombus formation via APP (amyloid precursor protein) and GP (glycoprotein) Ib. However, the role of reelin in hemostasis and arterial thrombosis is not fully understood to date.

Approach and Results:

In the present study, we analyzed the importance of reelin for cytoskeletal reorganization of platelets and thrombus formation in more detail. Platelets release reelin to amplify alphaIIb beta3 integrin outside-in signaling by promoting platelet adhesion, cytoskeletal reorganization, and clot retraction via activation of Rho GTPases RAC1 (Ras-related C3 botulinum toxin substrate) and RhoA (Ras homolog family member A). Reelin interacts with the collagen receptor GP (glycoprotein) VI with subnanomolar affinity, induces tyrosine phosphorylation in a GPVI-dependent manner, and supports platelet binding to collagen and GPVI-dependent RAC1 activation, PLC gamma 2 (1-phosphatidylinositol-4,5-bisphosphate phosphodiesterase gamma-2) phosphorylation, platelet activation, and aggregation. When GPVI was deleted from the platelet surface by antibody treatment in reelin-deficient mice, thrombus formation was completely abolished after injury of the carotid artery while being only reduced in either GPVI-depleted or reelin-deficient mice.

Conclusions:

Our study identified a novel signaling pathway that involves reelin-induced GPVI activation and alphaIIb beta3 integrin outside-in signaling in platelets. Loss of both, GPVI and reelin, completely prevents stable arterial thrombus formation in vivo suggesting that inhibiting reelin-platelet-interaction might represent a novel strategy to avoid arterial thrombosis in cardiovascular disease.
Systematic Interrogation of Angiogenesis in the Ischemic Mouse Hind Limb
Authors: Lee Jason J. , Arpino John-Michael , Yin Hao , Nong Zengxuan , Szpakowski Alexis , Hashi Abdulaziz A. , Chevalier Jacqueline , O’Neil Caroline , Pickering J. Geoffrey
Published: August 2020

Objective:

There has been little success in translating preclinical studies of mouse hind limb ischemia into benefit for patients with peripheral artery disease. Using systematic strategies, we sought to define the injury and angiogenesis landscapes in mice subjected to hind limb ischemia and ascertain whether published studies to date have used an analysis strategy concordant with these data.

Approach and Results:

Maps of ischemic injury were generated from 22 different hind limb muscles and 33 muscle territories in 12-week-old C57BL/6 mice, based on loss or centralization of myofiber nuclei. Angiogenesis was similarly mapped based on CD (cluster of differentiation) 31–positive capillary content. Only 10 of 33 muscle territories displayed consistent muscle injury, with the distal anterior hind limb muscles most reliably injured. Angiogenesis was patchy and exclusively associated with zones of regenerated muscle (central nuclei). Angiogenesis was not observed in normal appearing muscle, necrotic muscle, or injury border zones. Systematic review of mouse hind limb angiogenesis studies identified 5147 unique publications, of which 509 met eligibility criteria for analysis. Only 7% of these analyzed manuscripts evaluated angiogenesis in distal anterior hind limb muscles and only 15% consistently examined for angiogenesis in zones of muscle regeneration.

Conclusions:

In 12-week C57BL/6 mice, angiogenesis postfemoral artery excision proceeds exclusively in zones of muscle regeneration. Only a minority of studies to date have analyzed angiogenesis in regions of demonstrably regenerating muscle or in high-likelihood territories. Quality assurance standards, informed by the atlas and mapping data herein, could augment data reliability and potentially help translate mouse hind limb ischemia studies to patient care.
Polygenic Contribution to Low-Density Lipoprotein Cholesterol Levels and Cardiovascular Risk in Monogenic Familial Hypercholesterolemia
Authors: Trinder Mark , Paquette Martine , Cermakova Lubomira , Ban Matthew R. , Hegele Robert A. , Baass Alexis , Brunham Liam R.
Published: August 2020

Background:

Familial hypercholesterolemia (FH) is a common autosomal codominant genetic disorder, which causes elevated levels of low-density lipoprotein cholesterol (LDL-C) and increased risk of premature atherosclerotic cardiovascular disease (ASCVD). Even among individuals with monogenic FH, there is substantial interindividual variability in LDL-C levels and risk of ASCVD. We assessed the influence of an LDL-C polygenic score on levels of LDL-C and risk of ASCVD for individuals with monogenic FH.

Methods:

We constructed a weighted LDL-C polygenic score, composed of 28 single-nucleotide variants, for individuals with monogenic FH from the British Columbia FH (n=262); Nutrition, Metabolism and Atherosclerosis Clinic (n=552); and UK Biobank cohorts (n=306). We assessed the association between LDL-C polygenic score with LDL-C levels and ASCVD risk using linear regression and Cox-proportional hazard models, respectively. ASCVD was defined as myocardial infarction, coronary or carotid revascularization, transient ischemic attack, or stroke. The results from individual cohorts were combined in fixed-effect meta-analyses.

Results:

Levels of LDL-C were significantly associated with LDL-C polygenic score in the Nutrition, Metabolism and Atherosclerosis Clinic cohort, UK Biobank cohort, and in the meta-analysis (β [95% CI]=0.13 [0.072–0.19] per a 20% increase in LDL-C polygenic score percentile,
P
<0.0001). Additionally, an elevated LDL-C polygenic score (≥80th percentile) was associated with a trend towards increased ASCVD risk in all 3 cohorts individually. This association was statistically significant in the meta-analysis (hazard ratio [95% CI]=1.48 [1.02–2.14],
P
=0.04).

Conclusions:

Polygenic contributions to LDL-C explain some of the heterogeneity in clinical presentation and ASCVD risk for individuals with FH.
Contrast‐Induced Acute Kidney Injury in Patients Undergoing TAVI Compared With Coronary Interventions
Authors: Venturi Gabriele , Pighi Michele , Pesarini Gabriele , Ferrero Valeria , Lunardi Mattia , Castaldi Gianluca , Setti Martina , Benini Annachiara , Scarsini Roberto , Ribichini Flavio L.
Published: August 2020

Background

Differences in the impact of contrast medium on the development of contrast‐induced acute kidney injury (CI‐AKI) in patients undergoing transcatheter aortic valve implantation (TAVI) or a coronary angiography/percutaneous coronary intervention (CA/PCI) have not been previously investigated.

Methods and Results

Patients treated with TAVI or elective CA/PCI were retrospectively analyzed in terms of baseline and procedural characteristics, including preprocedural and postprocedural kidney function. CI‐AKI was defined as a relative increase in serum creatinine concentration of at least 0.3 mg/dL within 72 hours of contrast‐medium administration compared with baseline. The incidence of CI‐AKI in the TAVI versus CA/PCI group was compared. After the exclusion of patients in dialysis and emergency procedures, 977 patients were analyzed; there were 489 patients who had undergone TAVI (50.1%) and 488 patients who had undergone CA/PCI (49.9%). Patients treated by TAVI were older, presenting a higher rate of anemia and chronic kidney disease (
P
<0.001 for all comparisons). Consistently, they also had a significantly lower glomerular filtration rate and higher serum creatinine concentration (
P
<0.001 for all). However, the occurrence of CI‐AKI was significantly lower in these patients compared with patients treated by a CA/PCI (6.7% versus 14.5%,
P
<0.001). At multivariate analysis, the TAVI procedure had an independent protective effect on CI‐AKI incidence among total population (odds ratio, 0.334; 95% CI, 0.193–0.579;
P
<0.001). This observation was confirmed after propensity score matching among 360 patients (180 by TAVI and 180 by CA/PCI;
P
=0.002).

Conclusions

CI‐AKI occurred less frequently in patients undergoing TAVI than in patients undergoing a CA/PCI, despite a worse‐risk profile. The impact of contrast administration on kidney function in patients who had undergone TAVI may be better tolerated because of the hemodynamic changes following aortic valve replacement.
Reducing ECG Artifact From Left Ventricular Assist Device Electromagnetic Interference
Authors: Loring Zak , Sen Sounok , Black-Maier Eric , Atwater Brett D. , Russell Stuart D. , DeVore Adam D. , Piccini Jonathan P.
Published: August 2020

Background

Left ventricular assist devices (LVADs) generate electromagnetic interference that causes high‐frequency noise artifacts on 12‐lead ECGs. We describe the causes of this interference and potential solutions to aid ECG interpretation in patients with LVAD.

Methods and Results

Waveform data from ECGs performed before and after LVAD implantation were passed through a fast Fourier transform to identify LVAD‐related changes in the spectral profile. ECGs recorded in 9 patients with HeartMate II, HeartMate 3, and HeartWare LVADs were analyzed to identify the LVAD model‐specific spectral patterns. Waveform data were then passed through digital low‐pass and bandstop filters and redisplayed to evaluate the effect of filtering on LVAD‐related electromagnetic interference. The spectral profile of patients with HeartMate II and HeartMate 3 LVADs demonstrated a prominent signal at the device‐specific frequency of impeller rotation. In patients with the HeartMate 3 LVAD, 2 additional peaks were observed at the frequencies equivalent to the LVAD's artificial pulsatility rotational speeds. Patients with HeartWare devices demonstrated a prominent signal peak at a frequency equal to double their LVAD's set rotational speed. Applying a low‐pass filter to a value below the observed frequency peak from the LVAD significantly improved the waveform tracing and quality of the ECG. Applying a speed‐specific bandstop filter to remove the observed LVAD frequency peak also improved the clarity of the ECG without compromising physiological high‐frequency signal components.

Conclusions

LVADs create impeller rotational speed‐specific electromagnetic interference that can be ameliorated by application of low‐pass or bandstop filters to improve ECG clarity.