bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3241: Targeting the tumor stroma using CAR T-cells
Authors: Ash Sarah , Turrell Frances , Isacke Clare , Lee Steven
Published: September 2020

The majority of breast cancer deaths are due to metastatic disease, thus developing new strategies to target the metastatic cascade is clinically relevant and of scientific importance. Breast cancer metastasis is a multi-step process influenced by many factors, including the tumor microenvironment (TME). Key interactions between the TME and tumor cells have been identified as promoting metastasis, thus presenting novel clinical targets. One such target is endosialin (CD248), a transmembrane glycoprotein which has limited expression in the healthy adult but is strongly upregulated on tumor-associated pericytes and fibroblasts in most solid cancers, including breast cancer. Using endosialin knockout mice, our laboratory has demonstrated that expression of endosialin in the tumor stroma promotes tumor cell intravasation, thereby promoting metastatic dissemination. Endosialin-expressing cells present an interesting target for CAR T-cell therapy, an emerging approach within cancer immunotherapy. Thus far, targeting tumor cells with CAR T-cells has proven challenging in solid neoplasms owing to the harsh, immunosuppressive environment that CAR T-cells encounter. Here, we describe an alternative approach of targeting cells of the microenvironment, which are more accessible to the infiltrating CAR T-cells, to limit breast cancer metastasis. Experiments comparing the effects of endosialin-directed CAR T-cells (Endo3 CARs) and mock- transduced T-cells (mock T-cells) in a spontaneously metastatic BALB/c breast cancer model reveal that Endo3 CAR treatment significantly reduces the number of metastatic deposits in the lungs. Endo3 CARs expand by at least 2-fold in tumor-bearing mice and endosialin staining confirms that Endo3 CAR treatment results in the depletion of endosialin-positive cells in the tumor stroma, without affecting normal tissue. Strikingly, Endo3 CAR treatment also results in significant growth inhibition and necrosis of the primary tumor. However, some evidence of Endo3 CAR T-cell associated toxicity is observed in treated mice, and we are currently testing therapeutic options to minimize these side effects. No off- target activity is observed in parallel experiments with tumor-bearing endosialin knockout mice. In conclusion, these promising results demonstrate that Endo3 CAR T-cell therapy presents a novel approach to limiting breast cancer metastasis via the targeting of activated stromal cells in the tumor microenvironment.

Citation Format: Sarah Ash, Frances Turrell, Clare Isacke, Steven Lee. Targeting the tumor stroma using CAR T-cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3241.
Abstract 3254: MOTO-CARs™: A novel macrophage-based chimeric antigen receptor technology
Authors: Townsend Michelle Hannah , Ewell Zachary D. , Bennion Kelsey A. , Wang Guoying , Skidmore Jonathan , Lum David , Boyer Michael , O'Neill Kim L.
Published: September 2020

We report the development of a novel macrophage-mediated immunotherapy targeting mesothelin-expressing solid tumors. Although the advent of immunotherapy heralded a new era in cancer treatment, it has been accompanied by severe limitations, including antigen escape, cytokine release syndrome (CRS), and the inability to penetrate solid tumors. We sought to ameliorate these issues by developing a macrophage toll-like chimeric antigen receptor (MOTO-CAR™) designed to target and activate upon cancer antigen recognition. Here we show evidence supporting this proof-of-concept MOTO-CAR™ technology in a murine macrophage cell line (RAW 264.7) targeting a mesothelin-expressing, triple-negative, mammary gland squamous carcinoma cell line (HCC-1806). The MOTO-CAR™ construct was transfected into macrophage cells with an average efficiency above 50%. The presence of the chimeric construct was confirmed via mesothelin scFv amplification of isolated mRNA, and the engineered macrophages stably expressed the chimeric receptor for over 7 days, with the highest level of expression approximately 24 hours post transfection. We found that upon exposure to HCC-1806 cells, MOTO-CARs™ are not only effective at eliminating the cancer cells, but also secrete significant levels of TNF-α when compared to mock controls (p= 0.009), indicating activation and polarization to an M1 phenotype upon target recognition. In vitro cytotoxicity assays confirmed that macrophages containing the MOTO-CAR™ construct increasingly targeted and killed HCC-1806 cells when compared to the mock control (p < 0.0001) in three different effector to target ratios. Furthermore, in NSG mice containing HCC-1806-derived xenografts, tumor burdens were significantly lower in mice treated with MOTO-CARs™ when compared to the mock control (p = 0.006). In these models, the MOTO-CARs were administered through the tail vein, which indicates the MOTO-CARs™ can traffic effectively to the tumor site in vivo. Both TLR4 and TLR2 based toll-like receptor signaling domains were evaluated with TLR4 vectors showing higher killing and better efficacy against target cancer cells. Following initial testing in RAW 264.7 macrophages, similar results were observed when MOTO-CARs™ derived from primary human monocytes were co-incubated with the same target cells. These data illustrate the potential for MOTO-CARs™ to be a powerful alternative to current immunotherapies targeting solid tumors.

Citation Format: Michelle Hannah Townsend, Zachary D. Ewell, Kelsey A. Bennion, Guoying Wang, Jonathan Skidmore, David Lum, Michael Boyer, Kim L. O'Neill. MOTO-CARs™: A novel macrophage-based chimeric antigen receptor technology [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3254.
Abstract 3321: Immunogenic clearance sensitizes cold tumor to PD-1 blockade by enhancing quantity and quality of CD8+ T cells
Authors: Nam Gi-Hoon , Choi Yoonjeong , Kim In-San
Published: September 2020

The effective immune response against cancer requires stepwise events from the release of tumor antigens to T cells' exhibiting cytotoxic effects in the tumor microenvironment (TME). Immunogenic clearance reveals intrinsic tumor antigenicity with immunogenic cell death of the tumor cells and increases priming of T cells with increased phagocytosis activity of professional antigen-presenting cells (pAPCs), therefore, overcome the failure in immune surveillance of cancer caused by immunological ignorance. Here, we investigated the potential strategy to induce immunogenic clearance with immunogenic cell death (ICD) inducers and phagocytosis enhancer. Using anthracyclines, one of the renowned ICD inducers and fasudil, rho-kinase (ROCK) inhibitors that increases phagocytosis activity, reinforced cross-presentation of dendritic cells and cross-priming of CD8+ T cells in secondary lymphoid organ contributes to consecutive infiltration of CD8+ T cells in TME. Inducing the CD8+ T cell immune response, this strategy could surmount the resistance to immune checkpoint blockade of the immunologically cold tumor where little infiltrated T cells exist in the tumor site, which leads not just increased tumor-specific CD8+ T cells, but prolonged survival accompanied with the formation of sustainable CD8+ T cell memory.

Citation Format: Gi-Hoon Nam, Yoonjeong Choi, In-San Kim. Immunogenic clearance sensitizes cold tumor to PD-1 blockade by enhancing quantity and quality of CD8+ T cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3321.
Abstract 3346: Changes of gut microbiota in FAP and UC that might harbor colorectal cancer carcinogenesis
Authors: Bisgin Atil , Hanta Abdullah , Rencuzogullari Ahmet , Boga Ibrahim
Published: September 2020

Inflammatory bowel diseases, Familial adenomatous polyposis(FAP) and colorectal cancer(CRC) are associated with alterations of the intestinal microbiota. However, few data are available on the perpetuation of FAP and Ulcerative Colitis(UC) in relation to microbial dysbiosis. This study evaluated the UC and genetically confirmed FAP patients' gut microbial balance in concordance to clinical outcome. Fecal materials (average mass of 0.54 g) were collected from three FAP and five UC patients to compare with healthy individuals as control group. Genomic materials of microbiota were isolated via QIAamp PowerFecal DNA kit according to manufacturer instructions. Next generation sequencing of 16S rRNA was performed by using QIAseq 16S/ITS panel in Illumina Miseq Platform. Data processing and bioinformatics analysis were performed via CLC Genomic Workbench bioinformatics tool. The comparison between FAP subjects, UC patients and control group revealed an alteration in the intestinal microbial composition. More in details, relative abundance of class levels showing statistical significance differences among FAP, UC and control group was given in Table 1, in which the sample groups are reported in column while class levels are in row. Our preliminary data focused on the explanation of how dysbiosis can lead to inflammation and drive processes together with host genetic profile that leads to colorectal carcinogenesis.

Abundance table of class levels compared between FAP, UC and control groupClass (Aggregated)Cont AbundanceUlc. Col. AbundanceFAP AbundanceActinobacteria65847688013162Alphaproteobacteria899923560Bacilli4806197740237684Bacteroidia13247361374676321973Campylobacteria0730Clostridia748894613039897452Coriobacteriia5684586513543Deltaproteobacteria493780Erysipelotrichia6787833346228289Fusobacteriia18374510Gammaproteobacteria328501859739269883Halanaerobiia27000Kiritimatiellae700Lentisphaeria75400Melainabacteria201100Methanobacteria65600Mollicutes29069949Negativicutes578632230683666Oligosphaeria1700Oxyphotobacteria21150Saccharimonadia048360Stramenopiles200Verrucomicrobiae32065733252

Citation Format: Atil Bisgin, Abdullah Hanta, Ahmet Rencuzogullari, Ibrahim Boga. Changes of gut microbiota in FAP and UC that might harbor colorectal cancer carcinogenesis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3346.
Abstract 3381: Identifying tumor antigen-specific CD4+ T cell dysfunctional states by single cell transcriptomics in immunotherapy-treated cancer patients
Authors: Kozlova Edgar , Eikawa Shingo , Gnjatic Sacha , Losic Bojan
Published: September 2020

Dysfunctional T cell states resulting from continuous exposure to self shared tumor antigens or neoantigens are key to understanding immune mechanisms that prevent proper antitumor immunity. We previously showed that repeated administration of recombinant tumor antigen vaccines without immunological adjuvant emulates a tolerized-like immune response that cannot be rescued even after in vivo re-challenge with adjuvant. We used bulk and single-cell RNA-seq of purified antigen-specific CD4+ T-cells (i.e., the orchestrator of immunity) from 12 ovarian and non-small cell lung cancer patients receiving NY-ESO-1 or MAGE-A3 vaccines with or without adjuvant, over a period of 13 weeks.

First, using bulk RNA-seq data, we derived novel temporal, tolerization CD4+ T cell expression and clonotype evolution signatures using differential expression and VDJ-deconvolution analyses, highlighting significant association with cell cycle and immune activation. Then, we projected these signatures onto several recently published single-cell RNA-seq data profiling exhausted tumor-infiltrating and peripheral blood lymphocytes, finding reasonable predictive power (AUC~0.8) to classify dysfunctional T-cell states that could distinguish exhaustion from tolerance. Next, we characterized in depth the transcriptional profiles and heterogeneity of our antigen-specific CD4+ T-cells pre- and post-treatment at the single-cell level using combined scRNAseq and scTCRseq. Finally, we computationally inferred the regulatory axis of tolerized T-cells by deriving transcription factor signaling networks upstream of gene expression.

In conclusion, we characterized transcriptional signatures of tumor antigen-specific CD4+ T-cells and derived a specific tolerization profile, distinguishable from exhaustion, and conserved across datasets. Through comprehensive identification of genes and pathways in a human experimental setting for induction of tolerization and exhaustion, these findings provide relevant and promising avenues to reverse dysfunctional CD4+ T cell states.

Citation Format: Edgar Kozlova, Shingo Eikawa, Sacha Gnjatic, Bojan Losic. Identifying tumor antigen-specific CD4+ T cell dysfunctional states by single cell transcriptomics in immunotherapy-treated cancer patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3381.
Abstract 3402: BCAT1 as a druggable target in immuno-oncology
Authors: Papathanassiu Adonia E. , Lodi Francesca , Elkafrawy Hagar , Certo Michelangelo , Vu Hong , Ko Jeong Hun , Behmoaras Jacques , Mauro Claudio , Lambrechts Diether
Published: September 2020

BCAT1, the enzyme responsible for the reversible transamination of leucine in the cytosol, has recently been implicated in the development and growth of various types of cancer. The limited expression of BCAT1 in adult tissues under physiological conditions suggests that the enzyme is a sensible target for drug development. To better understand the role of BCAT1 in cancer, we examined its gene expression at the single cell level (scRNAseq) in specimens obtained from lung, colorectal, breast, and ovarian cancer patients (n=36; >200,000 single cells). In those samples, Bcat1 gene expression was primarily associated with myeloid cells and fibroblasts with the exception of ovarian cancer in which robust Bcat1 presence was also seen in cancer cells. In tumor infiltrating lymphocytes (TILs), enrichment in Bcat1 gene expression was observed in exhausted CD4+ and CD8+ T cells compared to other T cell subtypes; this was independent of the cancer type examined. We speculated that inhibition of BCAT1 in TILs reverses exhaustion and has a therapeutic impact in cancer. In the syngeneic CT26 colon cancer model, combination treatment of a BCAT1 inhibitor (ERG245; ip administration of 5 mg/kg, given at days 7, 8 and 9 after tumor cell inoculation) and an anti-PD1 antibody (ab) (clone RMP1-14; ip administration given at days 7, 11, 14, and 18) led to eradication of established tumors. In the same model, limited treatment of large tumors (average size of ~600 mm3) with ERG245+anti-PD1 ab suppressed tumor growth and increased the frequency of CD8+ T cells expressing Granzyme B and IFNγ by ~50% compared to anti-PD1 monotherapy. Mechanistically, in vitro treatment of newly activated hCD8+ T cells with ERG245 impaired translocation of the lactate transporter MCT1 to the cell surface and increased the levels of intracellular lactate within 30 min of activation leading to upregulation of transcription factor ATF3. ERG245-driven metabolic reprogramming of CD8+ T cells towards an oxidative phenotype (increased OXPHOS) was also observed at 24h of treatment. Withdrawal of ERG245 restored intracellular lactate levels without reversing the metabolic reprogramming of the cells. We propose that these are elements of a mechanism that links temporal inhibition of BCAT1 to the rise of highly energetic CD8+ T cells with increased cytotoxicity and proliferative capacity in vitro and in vivo.

Citation Format: Adonia E. Papathanassiu, Francesca Lodi, Hagar Elkafrawy, Michelangelo Certo, Hong Vu, Jeong Hun Ko, Jacques Behmoaras, Claudio Mauro, Diether Lambrechts. BCAT1 as a druggable target in immuno-oncology [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3402.
Abstract 3426: A synthetic lethality approach to eradicate AML via synergistic activation of pro-apoptotic p53 by MDM2 and BET inhibitors
Authors: Li Sha , Latif Anne , Newcombe Ashley , Gilroy Kathryn , Robertson Neil , Lei Xue , Finlay Darren , Stewart Helen , Barbosa Karina , Higgins Brian , Chevassut Tim , Huang Xu , Copland Mhairi , Keeshan Karen , Deshpande Ani , Adams Peter
Published: September 2020

Acute Myeloid Leukemia (AML) is a typically-lethal molecularly heterogeneous disease, with few broad-spectrum therapeutic targets. Unusually, over 90% of AML patients retain wild type TP53, encoding pro-apoptotic tumor suppressor p53. However, wild-type p53 functions are frequently suppressed by MDM2, an E3 ubiquitin ligase that targets p53 for proteasomal degradation. MDM2 inhibitors (MDM2i), which activate wild-type p53, show encouraging pre-clinical activity, but limited clinical activity. In an effort to find targets that synergize with p53 activation and minimize toxicity via MDM2i, we performed a cell-based synthetic lethal drug screen and a CRISPR viability screen. By integrating the results of these two screens, we found inhibition of BRD4 activates p53 and its target genes. BRD4 (Bromodomain-containing protein 4) is a member of the bromodomain and extraterminal (BET) family proteins, which has typically been reported to activate genes, such as c-MYC, BCL2 and CDK4/6. However, we unexpectedly reveal that BRD4 acts as a transcriptional repressor of p53 target genes. Our combined therapy of MDM2i and BETi is synergistically lethal to human AML cell lines harboring wild type p53 in vitro, against two mouse models of AML in vivo, and against several primary human patient blasts in vitro. Synergistic cell killing was associated with synergistic activation of p53 target genes, and cell killing and p53 target gene expression. Taken together, our data show BRD4 represses p53-mediated transcription activation and apoptosis in AML. Therefore, targetable wild-type p53 and a transcriptional repressor function of BRD4 together represent a potential broad-spectrum synthetic therapeutic vulnerability for AML.

Citation Format: Sha Li, Anne Latif, Ashley Newcombe, Kathryn Gilroy, Neil Robertson, Xue Lei, Darren Finlay, Helen Stewart, Karina Barbosa, Brian Higgins, Tim Chevassut, Xu Huang, Mhairi Copland, Karen Keeshan, Ani Deshpande, Peter Adams. A synthetic lethality approach to eradicate AML via synergistic activation of pro-apoptotic p53 by MDM2 and BET inhibitors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3426.
Abstract 3450: Ganglioneuromas are driven by activated AKT and can be therapeutically targeted with mTOR inhibitors
Authors: Tao Ting , Shi Hui , Durbin Adam D. , Wang Meng , Perez-Atayde Antonio R. , London Wendy B. , Gutierrez Alejandro , Lemos Bernardo , Look A. Thomas
Published: September 2020

Peripheral sympathetic nervous system tumors are the most common extra-cranial pediatric tumors in children and include neuroblastoma, ganglioneuroblastoma (intermixed and nodular) and ganglioneuroma. The etiology and molecular pathogenesis of ganglioneuromas remains largely unknown. Surgery is the only effective therapy for ganglioneuroma, which can be challenging due to the location of the tumor and involvement of surrounding structures. Thus, there is need for well tolerated presurgical therapies that could reduce the size and extent of ganglioneuroma, and therefore limit surgical morbidity. Here we found high levels of phosphorylated AKT expressed in 10 of 11 patients with ganglioneuroma, but only in 1 of 15 who had poorly differentiated neuroblastoma (p<0.0001, Fisher's exact test). Consistent with these results, zebrafish transgenic for constitutively activated myr-Akt2 in the sympathetic nervous system were found to develop ganglioneuroma without progression to neuroblastoma. Histopathological analysis and whole-transcriptome sequencing revealed that zebrafish ganglioneuroma highly resembles human ganglioneuroma. Inhibition of the downstream AKT target, mTOR, using sirolimus in zebrafish with ganglioneuroma effectively reduced the tumor burden, providing preclinical evidence for efficacy with this well tolerated drug. Our results implicate activated AKT as a tumorigenic driver in ganglioneuroma. We propose a clinical trial of sirolimus as a means to shrink large ganglioneuromas prior to resection in order to reduce surgical morbidity.

Citation Format: Ting Tao, Hui Shi, Adam D. Durbin, Meng Wang, Antonio R. Perez-Atayde, Wendy B. London, Alejandro Gutierrez, Bernardo Lemos, A. Thomas Look. Ganglioneuromas are driven by activated AKT and can be therapeutically targeted with mTOR inhibitors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3450.
Abstract 3452: Pre-clinical development of next generation selective estrogen receptor degrader - SAR439859
Authors: Sun Fangxian , Cheng Jane , Sullivan Amy , Malkova Natalia , Shomali Maysoun , McManus Jesseca , Levit Mikhail , Bangari Dinesh , El-Ahmad Youssef , Sidhu Sukhvinder , Debussche Laurent , Bouaboula Monsif
Published: September 2020

Abstract: Nearly 70% or more of newly diagnosed cases of breast cancer (BC) are estrogen receptor positive (ER+) where endocrine therapy is a primary treatment. However, substantial evidence describes a continued role of ER signaling in tumor progression, where approximately 40% of patients on endocrine therapy develop resistance that include mutations in ER that drive a constitutively active receptor. SAR439859 is a novel next generation SERD (selective estrogen receptor degrader) with potent antagonist and degradation activity against ER both wild type and mutant and currently evaluated as a single agent and in combination with palbociclib in a Phase I/II clinical trial (NCT03284957). Here we describe the preclinical development of this molecule in multiple xenografts and demonstrated significant anti-tumor efficacy/regression in ER+ BC models including MCF7-ESR1 mutant-Y537S and endocrine therapy resistant patient-derived xenograft tumor models. The molecule also demonstrated strong synergistic activity with CDK4 inhibitor palbociclib. SAR439859 has a favorable safe profile and no uterotrophic activities. Collectively, these results show that SAR439859 is an oral, selective estrogen receptor antagonist and degrader that could provide therapeutic benefit to ER+ breast cancer patients. In conclusion, SAR439859 demonstrates broad anti-tumor activity in ER+ breast cancer cell line/PDX models. Anti-tumor efficacy correlates with PK exposure/PD modulation in target tissue. SAR439859 also has synergistic activity with CDK4 inhibitor Palbociclib.

Citation Format: Fangxian Sun, Jane Cheng, Amy Sullivan, Natalia Malkova, Maysoun Shomali, Jesseca McManus, Mikhail Levit, Dinesh Bangari, Youssef El-Ahmad, Sukhvinder Sidhu, Laurent Debussche, Monsif Bouaboula. Pre-clinical development of next generation selective estrogen receptor degrader - SAR439859 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3452.
Abstract 3493: Interactions between adiponectin pathway polymorphisms and obesity on breast cancer risk among African American postmenopausal women
Authors: Nam Gina E. , Zhang Zuo-Feng , Rao Jianyu , Zhou Hua , Jung Su Yon
Published: September 2020

Purpose: A decreased circulating adiponectin concentration is associated with obesity and an increased breast cancer risk among postmenopausal women. Yet, the interplay between adiponectin-associated genetic variants, obesity, and breast cancer risk is unclear in African American (AA) postmenopausal women. We examined adiponectin pathway polymorphisms for their association with breast cancer risk among AA postmenopausal women. We also explored a gene-environment interaction between adiponectin pathway polymorphisms and obesity for the risk of breast cancer.

Method: Using the Women's Health Initiative SNP Health Association Resource Study, we identified 37 single-nucleotide polymorphisms (SNPs) in relation to the adiponectin pathway. Body-fat distributions were determined using three independent indices including body mass index (BMI), waist-to-hip ratio (WHR), and waist circumference (WC). We used multiple Cox proportional hazards regression models to estimate hazard ratios and 95% confidence intervals (CIs) for the association with breast cancer. Obesity-stratified analysis and tests for the joint effects with the SNPs were conducted.

Results: Of 7,991 AA postmenopausal women, 402 reported of having an invasive breast cancer with a mean follow-up of 14.5 years. The majority were obese, had low WHR (< 0.85), and had high WC (< 88 cm). Of 37 adiponectin pathway-related SNPs, 3 SNPs were significantly associated with breast cancer risk (KCNK9 rs2468677, OR8S1-LALBA rs11168618, and EIF4A2 rs266719). Among women who have under or normal bodyweight, the minor allele GG genotype of NMU rs13434995 had an elevated risk of postmenopausal breast cancer compared to those with the major allele AA genotype. Women who carry the heterozygous TC genotype of OR8S1-LALBA rs11168618 and are obese jointly increased the risk of breast cancer (relative excess risk due to interaction = 0.58, 95% CI = 0.35, 0.80).

Conclusion: Our findings revealed the association between the previously confirmed adiponectin pathway-related SNPs and breast cancer risk among AA postmenopausal women. We also demonstrated that obesity plays an important role as an effect modifier in the relationship between the SNPs and breast cancer, suggesting 1) the potential use of metabolic and genetic biomarkers for identifying a greater risk for breast cancer and 2) support for the research to promote interventions to those with risk genotypes, thus reducing breast cancer risk.

Citation Format: Gina E. Nam, Zuo-Feng Zhang, Jianyu Rao, Hua Zhou, Su Yon Jung. Interactions between adiponectin pathway polymorphisms and obesity on breast cancer risk among African American postmenopausal women [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3493.
Abstract 3502: Do obese patients present with worse breast cancer
Authors: Wang Melinda , Huang Julian , Chagpar Anees
Published: September 2020

Background: Obesity is a known risk factor for breast cancer development; however, it is unclear whether obesity results in worse disease in terms of stage at presentation, receptor profile, and tumor grade. We sought to determine the relationship between obesity and disease status at presentation in patients undergoing mastectomy for breast cancer.

Methods: Medical records of breast cancer patients undergoing mastectomy at our institution between January 2010 and April 2018 were retrospectively reviewed. Patients were separated into obese (BMI ≥ 30) and non-obese (BMI < 30) categories, and compared using non-parametric statistical analyses.

Results: Of the 927 patients in this cohort, 292 (31.3%) were obese. Sociodemographic and clinicopathologic factors of the obese and non-obese patients are shown in the table below. In general, obese patients were more likely to present with node positive disease (27.1% vs. 19.2%, p = 0.008) and positive triple negative status (10.0% vs. 15.4%, p = 0.026). Controlling for the potential confounders of race and insurance status, obesity remained associated with triple negative status (95%CI: 1.04 - 2.46; p = 0.033) and node positive disease (95%CI:1.17 - 2.31; p = 0.004).

Factors associated with obese vs. non-obese mastectomy patientsFactorNot Obese (n = 635)Obese (n = 292)p-valueAge (yrs); median52520.494Race: White: no. (%)506 (79.7%)220 (75.3%)<0.001Race: Black: no. (%)49 (7.7%)52 (17.8%)Race: Asian: no. (%)35 (5.5%)5 (1.7%)Race: Other: no. (%)45 (7.1%)15 (5.1%)Insurance: Uninsured: no. (%)4 (0.6%)1 (0.3%)0.003Insurance: Medicaid: no. (%)63 (9.9%)54 (18.5%)Insurance: Medicare: no. (%)92 (14.5%)40 (13.7%)Insurance: Military: no. (%)11 (1.7%)9 (3.1%)Insurance: Private: no. (%)465 (73.2%)188 (64.4%)Node positive: no. (%)122 (19.2%)79 (27.1%)0.008Multifocality/Multi centricity: no. (%)142 (22.7%)68 (23.4%)0.800Presence of DCIS: no. (%)490 (77.2%)213 (72.9%)0.186Median invasive tumor size (cm)0.500.700.094AJCC Stage: 0: no. (%)217 (34.3%)90 (30.9%)0.073AJCC Stage: I: no. (%)207 (32.8%)78 (26.8%)AJCC Stage: II: no. (%)139 (22.0%)82 (28.2%)AJCC Stage: III: no. (%)65 (10.3%)40 (13.7%)AJCC Stage: IV: no. (%)4 (0.6%)1 (0.3%)ER+: no. (%)505 (79.5%)222 (76.0%)0.425PR+: no. (%)424 (66.8%)194 (66.4%)0.943Her2+: no. (%)95 (15.3%)30 (10.5%)0.111Triple negative: no. (%)62 (10.0%)44 (15.4%)0.026

Conclusion: Obese patients tend to present with more aggressive breast cancer, independent of sociodemographic factors.

Citation Format: Melinda Wang, Julian Huang, Anees Chagpar. Do obese patients present with worse breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3502.
Abstract 3525: Epidemiology and clinicopathology prognostic factors of TFEB translocation renal cell carcinoma (TBRCC): Analysis of updated pooled database
Authors: Haddad Philip A. , Hammoud Dalia , Gallagher Kevin
Published: September 2020

Renal cell carcinomas harboring the t(6;11) (p21;q12) translocation with a specific Alpha(MALAT1)-TFEB gene fusion is a recognized rare subtype of the Microphthalmia Transcription factor (MiT) family of translocation RCC. TBRCC is an indolent disease that occurs at a younger age. Though it may take on a wide spectrum of morphology, TBRCC has been classically characterized by distinctive biphasic morphology with larger epithelioid cells and smaller cells clustered around eosinophilic spheres formed by basement membrane material. This analysis was conducted to update and expand our existing knowledge of this rare disease. In order to study the demographic characteristics, cytogenetic and molecular signatures, survival, and prognostic factors, we compiled a pooled database of 140 cases. Kaplan-Meier survival curves were constructed. Cox proportional-hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on survival. The median age was 32 (3-78) years with a peak incidence between ages 17 and 30 years. Males and females were afflicted equally. The median overall survival (OS) of the whole group was not reached with more than 78% alive at 10 years. The group's median disease-free survival (DFS) was 96 months. Six percent of this cohort recurred. Among patients who recurred, the median time to recurrence was 24(6-75) months. Sex did not impact OS or DFS. Similarly, the molecular partner of the TFEB gene fusion, Alpha (MALAT1) versus others, did not seem to impact OS or DFS. The presence of necrosis seemed to adversely impact OS (HR:14.3, p<0.0001) and DFS (HR:14.4, p<0.0001). Nuclear grade negatively impacted DFS, the higher the grade the worse the DFS. The presence of eosinophilia, psammoma bodies, and pigmentation did not affect OS or DFS. Similarly, the histologic morphology, biphasic vs others, did not affect OS or DFS. Multivariate analysis revealed older age (HR:1.08, p=0.01) and larger tumor size (HR:10.12, p=0.002) adversely impacted OS. This study presents an updated epidemiologic and clinicopathologic data from a pooled cohort of patients with TBRCC. Age, size, and necrosis were found to adversely impact the OS. However, higher nuclear grade only adversely impacted the cohort's DFS.

Citation Format: Philip A. Haddad, Dalia Hammoud, Kevin Gallagher. Epidemiology and clinicopathology prognostic factors of TFEB translocation renal cell carcinoma (TBRCC): Analysis of updated pooled database [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3525.
Abstract 3534: The study of Lynch syndrome in a special population reveals a strong founder effect and an unusual mutational mechanism in familial adenomatous polyposis
Authors: Siraj Abdul K. , Parvathareddy Sandeep K. , Bu Rong , Masoodi Tariq , Alobaisi Khadija , Alrasheed Maha , Ahmed Saeeda O. , Qadri Zeeshan , Annaiyappanaidu Padmanaban , Benito Allianah , Rala Dionne R. , Al-Kuraya Fowzan , Al-Kuraya Khawla S.
Published: September 2020

Lynch syndrome (LS) is the leading cause of hereditary colorectal cancer (CRC). Germline mutations in DNA mismatch-repair (MMR) genes (MLH1, PMS2, MSH2, and MSH6) are known to cause LS in the heterozygous state. Biallelic mutations in these genes cause mismatch repair cancer syndrome (MMRCS), a very rare childhood cancer syndrome that predisposes to CRC among other cancer types. In this study, we aimed to characterize the mutational landscape of LS in a large CRC cohort (n=1,207) from a population with high rates of consanguinity. The overall contribution of germline mutations in LS gene was comparable to that observed in outbred populations (26/1207). Remarkably, however, we also observed the unusual homozygous occurrence of a founder PMS2 mutation. The homozygous individual presented with massive adenomatous polyposis of the colon at age 8 years, and mutation analysis of multiple polyps revealed the occurrence of multiple independent somatic APC mutations. Our study highlights a previously unrecognized role of LS genes in triggering APC-driven tumors, a phenomenon facilitated by consanguinity.

Citation Format: Abdul K. Siraj, Sandeep K. Parvathareddy, Rong Bu, Tariq Masoodi, Khadija Alobaisi, Maha Alrasheed, Saeeda O. Ahmed, Zeeshan Qadri, Padmanaban Annaiyappanaidu, Allianah Benito, Dionne R. Rala, Fowzan Al-Kuraya, Khawla S. Al-Kuraya. The study of Lynch syndrome in a special population reveals a strong founder effect and an unusual mutational mechanism in familial adenomatous polyposis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3534.
Abstract 3568: Ferroptosis induced by xCT abrogation is dependent on GPX4 protein expression regulated by L-cystine/cysteine metabolism
Authors: Zhang Yanyu , Huang Peng
Published: September 2020

Nutrients in the tumor microenvironment play an essential role in tumor development and proudly impact cancer metabolism. The xCT antiporter, which mediates cellular uptake of L-cystine coupled with glutamate export, has been considered as a promising therapeutic target due in part to its high expression in cancer cells to promote L-cystine uptake as a precursor for glutathione (GSH) synthesis to maintain redox homeostasis. Although inhibition of xCT has been shown to have anticancer effect in multiple models, emerging evidence also reveals that blocking xCT function could confer survival advantages to cancer cells. These opposite observations suggest that xCT inhibition could be a double-edged sword, and its impact on the overall outcome (cancer-inhibitory or tumor-promoting) is likely context-dependent via yet unknown mechanisms. Here, we show that the expression of glutathione peroxidase 4 (GPX4) is a key molecular determinant that decides the cell fate when xCT is suppressed. In cells with low or no expression of GPX4, inhibition of xCT causes severe ROS stress leading to massive cell death via ferroptosis. In contrast, high expression of GPX4 confers cancer cells the ability to escape ROS-induced ferroptosis. Mechanistic study suggests that the intracellular L-cysteine plays a major role in regulating GPX4 protein level, likely via direct binding to GPX4 and stabilize the protein. Pharmacological and genetic disruption of xCT in cancer cells induces dramatic ferroptosis in culture conditions lacking L-cysteine, whereas the presence of L-cysteine in culture or in vivo renders cancer cells resistance to xCT abrogation. Importantly, genetic knockout of xCT by CRISPR/cas9 reduces cancer cell proliferation in culture but promotes tumor growth in vivo, suggesting that the metabolic changes induced by xCT disruption favor cell growth in vivo. Biochemical and molecular analyses show that the in vivo microenvironment containing L-cysteine enables the xCT-disrupted cells to maintain a high GPX4 level, and thus prevents ferroptosis. Furthermore, metabolic flux using U-13C5 glutamine reveals that xCT abrogation leads to intracellular accumulation of more glutamate, which promotes cancer cell survival and proliferation in the low glucose tissue microenvironment in vivo. Our study has identified GPX4 as a key molecule that determines cell fate under metabolic stress induced by xCT suppression, and suggests that modulation of L-cystine/cysteine metabolism might be an effective strategy to overcome ferroptosis-resistant cancer cells.

Citation Format: Yanyu Zhang, Peng Huang. Ferroptosis induced by xCT abrogation is dependent on GPX4 protein expression regulated by L-cystine/cysteine metabolism [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3568.
Abstract 3579: Pimozide combined with paclitaxel demonstrates a significant antitumor effect in head and neck squamous cell carcinoma
Authors: Nakamura Shintaro , Ozawa Hiroyuki , Yamasaki Juntaro , Okazaki Shogo , Yoshikawa Momoko , Soma Tomoya , Asoda Seiji , Nagano Osamu , Sekimizu Mariko , Saito Shin , Yoshihama Keisuke , Mikoshiba Takuya , Ogawa Kaoru , Saya Hideyuki
Published: September 2020

Background: Head and Neck Squamous Cell Carcinoma (HNSCC) is the sixth most common cancer in the world. Despite the development of various treatments, the five-year survival rate for HNSCC is about 50-60% and has not been improved in recent years. Immune checkpoint inhibitors are promising, but the effect of those is limited. The development of new reagents having different mechanisms against tumor progression is still needed. From the result of drug screening, Pimozide (PMZ), an antipsychotic drug used for the treatment of schizophrenia and chronic psychosis, demonstrated a strong antitumor ability to HNSCC cells expressing high level of CD44v. In this study, we examined the combined effects of PMZ and paclitaxel (PTX) for HNSCC cells.

Methods: Using HNSCC cell lines (FaDu, Detroit562, HSC-2, OSC-19), the antitumor effects of PTX, PMZ, and the combination of PTX and PMZ were evaluated by MTS assay. Moreover, the reactive oxygen species (ROS) expression level under each drug administration was measured by flow cytometry. Moreover, PTX, PMZ (0.45mg/kg), PMZ (1mg/kg), PTX+PMZ were administered to the xenograft model by OSC-19. The tumor was resected after those treatments. The expression of CD44v, ALDH3A1, and NRF2 was evaluated by immunohistochemistry (IHC) of FFPE tissues from those extracted tumors.

Results: PMZ single-agent inhibited tumor growth in various tumor cell lines, and the

antitumor effect was enhanced by concomitant use of PTX. PMZ, which significantly increased ROS of tumor cells, was more effective than PTX in OSC-19, which was a chemoresistant cell line expressing high CD44v. Xenograft model exhibited that tumor growth was suppressed in PTX+PMZ group than in PTX and PMZ single-agent group. IHC staining revealed that PMZ administration restrained CD44v expression, and ALDH3A1 expression markedly decreased in PMZ treated tumors, but not in PTX treated tumors.

Conclusions: PMZ dramatically induced ROS production in tumor cells. These data suggest that aldehyde produced by ROS might suppress HNSCC tumor growth. The results from this study indicated that PMZ could be a novel therapeutic reagent for HNSCC in combination with existing anticancer drugs.

Citation Format: Shintaro Nakamura, Hiroyuki Ozawa, Juntaro Yamasaki, Shogo Okazaki, Momoko Yoshikawa, Tomoya Soma, Seiji Asoda, Osamu Nagano, Mariko Sekimizu, Shin Saito, Keisuke Yoshihama, Takuya Mikoshiba, Kaoru Ogawa, Hideyuki Saya. Pimozide combined with paclitaxel demonstrates a significant antitumor effect in head and neck squamous cell carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3579.
Abstract 3621: Characterization of BRAF mutation in Chinese colorectal cancer patients using next generation sequencing
Authors: Wang Hui , Wu Hao , Zhou Yifan , Zhang Bei , Sun Danpeng , Jiang LIihua , Chen Hui , Bai Yuezong , Zhang Zhe
Published: September 2020

Objective: BRAF alterations were characterized into three classes according to their dependency with upstream gene alterations in activating the MARK signaling pathway, giving clinical doctors clues of inhibitors selection for therapy. However, the characterization of BRAF mutation in Chinese colorectal cancer patients was unknown.

Methods: Colorectum tissue samples were collected from 2155 patients and performed the next generation sequencing (NGS) using a validated commercial panel containing essential genes in RAS-RAF-MARK and PI3K-AKT-mTOR pathways. BRAF mutations were characterized into Class I (kinase-activated, codon 600), II (kinase-activated, non-codon 600) and III (kinase-impaired).

Results: There were 9031 pathogenic and likely pathogenic somatic mutations were detected in 2137 out of 2155 samples, among which 149 (7.0%), 1048 (48.6%), 82 (3.8%), 2 (0.1%), 8 (0.4%), 362 (16.8%), 90 (4.2%) were found caring BRAF, KRAS, NRAS, HRAS, EGFR, PIK3CA and PTEN mutations, respectively. A total of 19 unique BRAF mutations were detected. The Class I (BRAFV600E), Class II and Class III accounted for 76.0%, 6.7% and 13.3% of all BRAF mutations. Higher incidence of co-occurrence of Class III mutations and RAS mutations were observed in our study, which might be due to their RAS-dependent way in activating downstream signaling pathway. Class III patients might be more sensitive to EGFR inhibitor and receive more benefits from survival than other classes.

Conclusions: In our study, the mutation type, frequency, classification of BRAF mutations and co-occurrence with BRAF and other driver gene mutations were explored in a large cohort of Chinese colorectal cancer patients, which might help to suggest proper therapy methods.

Citation Format: Hui Wang, Hao Wu, Yifan Zhou, Bei Zhang, Danpeng Sun, LIihua Jiang, Hui Chen, Yuezong Bai, Zhe Zhang. Characterization of BRAF mutation in Chinese colorectal cancer patients using next generation sequencing [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3621.
Abstract 3630: Comprehensive integrated HBV DNA profiling in HCC patients with GGH by HBV-targeted NGS and PacBio sequencing analysis
Authors: Kao Yu-Lan , Su Yih-Ping , Tsai Hung-Wen , Su Ih-Jen , Lin Selena , Song Wei , Su Ying-Hsiu
Published: September 2020

Despite current antiviral therapy success in reducing viral load in patients with chronic hepatitis B virus (HBV), persistent viral surface antigen (HBsAg) remains a risk factor of HCC. Recent evidence has shown that integrated HBV can serve as a source for continued viral antigen expression, despite the lack of detectable replication. Given the oncogenicity of pre-S mutant proteins and its expression in type II ground glass hepatocytes (GGH) even in the absence of viral replication, we assessed the likelihood of GGH as a pre-malignant state as compared to other adjacent-to-tumor non-GGH “normal” tissue by investigating the integrity of integrated HBV DNA. We developed a sensitive HBV-targeted NGS and downstream bioinformatics pipeline, ChimericSeq, to identify HBV-host junctions. A pilot study of 10 HBV-HCC patients, each with six micro-dissected FFPE tissue sections (2 tumor, 2 GGH, 2 HBsAg-negative), was subjected to HBV-targeted NGS and ChimericSeq analysis. We identified integrated HBV DNA in 90% of HCC as well as its matched GGH, and identified PreS2 deletions, for instance, deletion at nt. 43-52. Surprisingly, the recurrent insertional driver mutations of TERT, CCNE1, and ABCC13 integration were detected in 9 of 10 (90%) of this GGH/HCC patient cohort. Next we performed PacBio amplicon sequencing of integrated HBV DNA including Pre-S sequences to comprehensively profile the integrity of the integrated HBV DNA, such as insertional mutations or deletion, and mutations across the different frozen tissue sections (tumor, GGH, HBsAg-negative). Our data suggest that HBV integration of cancer driver genes occurs early during course of infection and integrated DNA evolved over time during carcinogenesis. Overall, a sensitive workflow to comprehensively profile integrated HBV DNA in HCC patients enables further investigation of the role of HBV integration during tumorigenesis.

Citation Format: Yu-Lan Kao, Yih-Ping Su, Hung-Wen Tsai, Ih-Jen Su, Selena Lin, Wei Song, Ying-Hsiu Su. Comprehensive integrated HBV DNA profiling in HCC patients with GGH by HBV-targeted NGS and PacBio sequencing analysis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3630.
Abstract 3662: FiTAc-seq: Fixed-Tissue ChIP-seq for H3K27Ac profiling and super-enhancer analysis on FFPE tissues
Authors: Font-Tello Alba , Kesten Nikolas , Xie Yingtian , Taing Len , Bellmunt Joaquim , Brown Myles , Cejas Paloma , Long Henry
Published: September 2020

FiTAc-seq is an epigenetic method for profiling of active enhancers and promoters in FFPE clinical samples. The protocol is optimized to generate high-quality H3K27Ac ChIP-seq maps from FFPE macrodissected or cored tissues within 4 days. We previously developed FiT-seq, a modified ChIP-seq protocol for chromatin profiling in FFPE. FiT-seq produces high-quality chromatin profiles particularly for methylated histone marks but is not optimized to resolve H3K27Ac signal. To overcome this limitation, we have modified the tissue homogenization and sonication steps by replacing the proteinase K digestion applied in FiT-seq with extended heating at 65°C in more stringent detergent conditions and minimizing the sonication step. FiTAc-seq produces high-quality genome wide H3K27Ac profiles, and it is suitable to generate enhancer landscapes and super-enhancer annotation. We demonstrate FiTAc-seq applicability for a wide variety of human tumor types, including bladder cancers, breast cancer brain metastasis, melanomas, pancreatic neuroendocrine tumors and seminomas. The unsupervised hierarchical analyses of both enhancer and super-enhancer only H3K27Ac signal clearly identify clusters according to the different tumor types. Moreover, super-enhancer annotation shows lineage-specific transcription factors for the distinct tumor samples. We demonstrate that FiTAc-seq is a robust method suitable for the epigenetic interrogation of archived FFPE clinical samples. The results generated allow the identification of tissue-specific enhancer and SE landscapes, with potential immediate impact on ongoing basic and translational research.

Citation Format: Alba Font-Tello, Nikolas Kesten, Yingtian Xie, Len Taing, Joaquim Bellmunt, Myles Brown, Paloma Cejas, Henry Long. FiTAc-seq: Fixed-Tissue ChIP-seq for H3K27Ac profiling and super-enhancer analysis on FFPE tissues [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3662.