bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3175: FAT1 and the immunosuppressive milieu in glioblastoma tumors
Authors: Irshad Khushboo , Srivastava Chitrangda , Malik Nargis , Gupta Yakhlesh , Suri Vaishali , Mahajan Swati , Gupta Deepak , Suri Ashish , Chattopadhyay Parthaprasad , Sinha Subrata , Chosdol Kunzang 
Published: July 2021

Abstract
INTRODUCTION: Glioblastoma tumors harbor an immunosuppressive microenvironment which is sustained by key players such as TGF-β1/2 and IL-10 cytokines; and mediators of the PD-1/PD-L1/2 pathway. Previously, our lab has shown the role of a new gene, FAT1, in promoting gliomagenesis by supporting the production of pro-inflammatory cytokines (IL-1β, IL-6, etc.) in glioma cells. Here, we show a potent role of FAT1 gene in regulation of anti-inflammatory genes in human glioma tumors, cell lines and primary cultures. Our findings indicate an additional way in which FAT1 might contribute to gliomagenesis. METHODS: q-PCR was used to analyse transcript levels of FAT1 and genes of the TGF-β1/2, IL-10 and PD-L1/2 pathways in fresh-frozen glioblastoma samples relative to normal brain RNA. Gene expression correlation was analysed using Spearman's test and semi-supervised clustering. TCGA expression data was extracted to analyse the correlation of FAT1 with anti-inflammatory genes. Primary tumor cultures and cell lines were transfected with FAT1-specific siRNA to check the effect on expression of anti-inflammatory cytokines, as well as effect on migratory properties of monocytes towards FAT1-knockdown tumor cells (supernatants). RESULTS: Significant positive correlation was found between upregulation of FAT1 and that of anti-inflammatory genes in fresh-frozen glioblastoma samples as well as TCGA datasets. Upon siRNA-mediated knockdown of FAT1 in in-vitro glioma cell cultures, we observed decreased anti-inflammatory genes' expression. We also found increased transmigration of monocytes towards the supernatants from siFAT1-transfected cells. CONCLUSION: FAT1 favors the immunosuppressive milieu in glioblastoma by supporting expression of anti-inflammatory genes. This is an emerging role of the new oncogene FAT1 and crucial to our understanding of the contributions of FAT1 to hallmarks of cancer.
FUNDING: SERB Start-Up Grant (DST, India); DHR Young Scientist Scheme (ICMR, India)
Citation Format: Khushboo Irshad, Chitrangda Srivastava, Nargis Malik, Yakhlesh Gupta, Vaishali Suri, Swati Mahajan, Deepak Gupta, Ashish Suri, Parthaprasad Chattopadhyay, Subrata Sinha, Kunzang Chosdol. FAT1 and the immunosuppressive milieu in glioblastoma tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3175.
Abstract 3179: Deconvolving bulk gene expression to chart the immune activity and crosstalk in the tumor microenvironment
Authors: Wang Kun , Patkar Sushant , Lee JooSang , Gertz E. Michael , Robinson Welles , Schischlik Fiorella , Schäffer Alejandro , Ruppin Eytan 
Published: July 2021

Abstract
The tumor microenvironment is a complex mixture of cell-types that interact with each other to affect tumor growth and clinical outcomes. To accelerate the discovery of such interactions, we develop CODEFACS (Confident Deconvolution For All Cell Subsets), a deconvolution tool that infers cell-type-specific gene expression in each sample from bulk expression measurements. We additionally developed LIRICS (Ligand Receptor Interactions between Cell Subsets), a pipeline that analyzes the deconvolved gene expression to further identify clinically relevant ligand-receptor interactions between cell-types. Using 15 benchmark datasets, we first demonstrate that CODEFACS substantially improves our ability to reconstruct cell-type-specific transcriptomes from individual bulk samples compared to the state-of-the-art method, CIBERSORTx. We next analyze the TCGA using CODEFACS and LIRICS to uncover tumor-immunological cell-type-specific interactions that are differentially activate in mismatch repair deficient tumors. This analysis shows that T-cell co-stimulating interactions are associated with higher survival rates in these tumors independent of their mutation burden levels. Finally, using machine learning, we identify key cell-type-specific ligand-receptor interactions that predict patient response to immune checkpoint blockade therapy in melanoma. Taken together, we present and validate a computational framework for analyzing large bulk gene expression datasets at a cell-type specific resolution that has many potential future applications, complementing single cell transcriptomics in a cost-effective manner.
Citation Format: Kun Wang, Sushant Patkar, JooSang Lee, E. Michael Gertz, Welles Robinson, Fiorella Schischlik, Alejandro Schäffer, Eytan Ruppin. Deconvolving bulk gene expression to chart the immune activity and crosstalk in the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3179.
Abstract 3185: Integrin signaling is critical for myeloid-mediated support of T-ALL
Authors: Lyu Aram , Nam Seo Hee , Hu Zicheng , Arasappan Dhivya , Horton Terzah M. , Ehrlich Lauren I. 
Published: July 2021

Abstract
T-cell acute lymphoblastic leukemia (T-ALL) is a malignant transformation of immature T cells. Although T-ALL harbors multiple pro-leukemic genetic alterations, T-ALL blasts require exogenous signals to survive. We recently reported that tumor-associated myeloid cells provide critical support for T-ALL in mouse models and in pediatric patient samples, at least partially through activation of IGF1R signaling. However, IGF1 alone is not sufficient to support T-ALL survival, implicating additional mechanisms in myeloid-mediated T-ALL support. We previously found that T-ALL cells make prolonged and frequent contacts with tumor-associated myeloid cells in live tissue sections; thus, we hypothesized that cell-cell interactions are essential for myeloid-mediated support of T-ALL. Here, we confirm that cell contact is required for myeloid cells to support T-ALL cell survival in vitro. Analysis of transcriptional profiling data revealed enrichment of gene signatures associated with integrin pathways in T-ALL cells relative to healthy T cells, implicating integrin-mediated cell adhesion as a potential mechanism underlying contact-dependent T-ALL support. Blockade of integrin αL ± integrin β1 or their ligands ICAM-1 ± VCAM-1 via antibodies or pharmacologic inhibitors significantly decreased T-ALL survival and reduced activation of IGF1R in T-ALL cells co-cultured with tumor-associated myeloid cells. Consistent with these findings, inhibition of integrins or their ligands in vivo via antibody blockade or genetic manipulation resulted in a significant reduction of T-ALL burden at multiple leukemic sites and prolonged survival. Consistent with mouse models, blockade of integrin-mediated cell adhesion significantly reduced survival of primary pediatric T-ALL cells co-cultured with myeloid cells. Furthermore, analyses of published transcriptomic datasets from pediatric T-ALL patients showed that enrichment of integrin pathways correlates with elevated myeloid gene signatures and poor patient prognosis. Together, our studies demonstrate that tumor-associated myeloid cells promote survival of T-ALL cells by activating integrin signaling, implicating the associated integrins and downstream signals as targets for therapeutic intervention.
Citation Format: Aram Lyu, Seo Hee Nam, Zicheng Hu, Dhivya Arasappan, Terzah M. Horton, Lauren I. Ehrlich. Integrin signaling is critical for myeloid-mediated support of T-ALL [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3185.
Abstract 3186: Differential expression of PD-L1 between primary and metastatic Middle-Eastern epithelial ovarian carcinoma and its clinico-pathological correlation
Authors: Parvathareddy Sandeep K. , Siraj Abdul K. , Annaiyappanaidu Padmanaban , De Vera Felisa , Kong Yan , Qadri Zeeshan , Ahmed Saeeda O. , AlDossari Hassan , Al-Kuraya Khawla S. 
Published: July 2021

Abstract
Ovarian cancer (OC) is one of the most common gynecologic cancer, which has the worst prognosis and highest mortality rate. The lack of curative treatment and the high relapse rate, especially in advanced OC, continues to present a clinical challenge, highlighting the need for new therapeutic strategies. This study was conducted to compare the expression of PD-L1 in Middle-Eastern primary epithelial ovarian carcinoma to that in peritoneal metastases and its correlation with clinico-pathological parameters. In total, 194 treatment naïve paired EOC and peritoneal metastases were analyzed by immunohistochemistry for PD-L1 expression. Clinico-pathological information was available for all patients. Significant differences in PD-L1 expression were found between primary EOC and peritoneal metastasis (p &lt; 0.0001). We found discordant tumor cell PD-L1 expression between primary tumors and corresponding peritoneal metastasis in 34% (66/194) of cases. Furthermore, PD-L1 expression in peritoneal metastasis samples was significantly associated with adverse prognostic factors, such as high proliferative index (Ki67) (p = 0.0039) and high histologic grade (p = 0.0330). In conclusion, the heterogeneity of PD-L1 expression in EOC suggests its assessment as a potential biomarker for PD-L1 blockade may require analysis of metastatic lesions.
Citation Format: Sandeep K. Parvathareddy, Abdul K. Siraj, Padmanaban Annaiyappanaidu, Felisa De Vera, Yan Kong, Zeeshan Qadri, Saeeda O. Ahmed, Hassan AlDossari, Khawla S. Al-Kuraya. Differential expression of PD-L1 between primary and metastatic Middle-Eastern epithelial ovarian carcinoma and its clinico-pathological correlation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3186.
Abstract 3198: In vitro exhausted T cell assays
Authors: Janss Thibaut J. , Lamy Juliette , Arnold Johan , Pattijn Sofie 
Published: July 2021

Abstract
The need to better understand the tumor microenvironment (TME) dictates the characterization of the cell types involved, the roles they play and how they respond to treatment. To develop better cancer immunotherapies, in vitro primary immune cell bioassays offer an early assessment of their effects on the various players of the TME. Exhausted T cells were first discovered in LCMV virus infections where chronic stimulation due to remaining virus antigens leads to T cells that stop responding to stimulation and lose their functionality (cytokine secretion and cytotoxic activity). The same phenotype was afterwards found in the tumor microenvironment where a lot of T cells were found to be “anergic”. Reversing their loss of functionality as a therapeutic strategy has made the characterization of these exhausted T cells a priority. Their phenotype is currently defined by an increase in the expression of a specific set of cell surface markers such as PD-1, TIM-3 and LAG-3. As exhaustion builds, the expression of these markers increases while T cell functionality decreases. The loss of functionality is defined by a reduction in cytokine secretion, proliferation, and cytotoxic activity in the presence of an antigen. To evaluate this phenotype in more depth, transcription factors can also be monitored. For example, BLIMP-1 and BATF, which play a role in PD-1 expression, are shown to increase following exhaustion. New therapeutics that can reverse exhausted phenotype lead to a new population of T cells called reinvigorated T cells which possesses high effector activity such as cytotoxicity towards cancer cells. Using primary immune cells, in vitro bioassays were developed to better screen the potential effect of new therapeutics on exhausted T cells. Their ability to reverse the exhausted phenotype and facilitate the anti-tumour immune response can as a result be assessed early in the drug development process.
Citation Format: Thibaut J. Janss, Juliette Lamy, Johan Arnold, Sofie Pattijn. In vitro exhausted T cell assays [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3198.
Abstract 328: Selective fluorogenic probe for rapid detection of cathepsin L activity
Authors: Schleyer Kelton A. , Fetrow Ben , Fatland Peter , Liu Jun , Chaaban Maya , Ma Biwu , Cui Lina 
Published: July 2021

Abstract
Cathepsin L (CTL) is a cysteine protease that demonstrates upregulated activity and altered trafficking in various cancers. Its upregulation in many cancers correlates positively with tumor grade while its excessive secretion makes elevated serum levels a possible biomarker for aggressive cancer types. The overlapping substrate specificity of cathepsin family members makes selective detection of activity from a single cathepsin difficult, and CTL activity is particularly difficult to parse from its close homologue CTV and the ubiquitous CTB. This complicates clinical sample assays for CTL activity, which generally rely on simple fluorescent probes lacking specificity for CTL over other cathepsins. We have developed a fluorogenic probe, CTLAP, that is rapidly activated by CTL and displays good selectivity over CTB and CTV, the closest competing analytes for CTL. The novel chemical structure of CTLAP facilitates markedly higher signal generation and improved selectivity for CTL when compared to Z-FR-AMC, the commercial probe commonly used to detect CTL activity in mixed samples. Optimum selectivity for CTL is achieved within 10 min of incubation, suggesting that CTLAP is amenable for rapid detection of CTL, even in the presence of competing cathepsins.
Citation Format: Kelton A. Schleyer, Ben Fetrow, Peter Fatland, Jun Liu, Maya Chaaban, Biwu Ma, Lina Cui. Selective fluorogenic probe for rapid detection of cathepsin L activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 328.
Abstract 337: p16INK4A-deficiency predicts for response to combined HER2 and CDK4/6 inhibition in HER2+ breast cancer brain metastases
Authors: Ni Jing , Kabraji Sheheryar , Xie Shaozhen , Wang Yanzhi , Pan Peichen , He Xiaofang , Liu Zongming , Long Henry , Brown Myles , Winer Eric P. , Dillon Deborah , Lin Nancy , Zhao Jean 
Published: July 2021

Abstract
Approximately 50% of patients with metastatic HER2-positive (HER2+) breast cancer develop brain metastases (BCBMs). To identify predictors of response and resistance to brain-penetrant, small molecule targeted therapies, we performed whole exome sequencing, RNAseq and quantitative immunohistochemistry of HER2+ BCBM tissues from 21 patients. We found that the tumor suppressor p16INK4A (p16) was deficient in the majority of HER2+ BCBMs. Orthotopic HER2+ BCBM patient-derived xenograft (PDX) models with p16 deficiency were resistant to the brain-penetrant HER2 inhibitor, tucatinib or the brain penetrant CDK4/6 inhibitor, abemaciclib, when used as single agents. However, p16-deficiency predicted response to combined tucatinib and abemaciclib in orthotopic HER2+ BCBM PDX models. These data establish the rationale for a biomarker-driven clinical trial of combined CDK4/6- and HER2-targeted agents for patients with HER2+ BCBM.
Citation Format: Jing Ni, Sheheryar Kabraji, Shaozhen Xie, Yanzhi Wang, Peichen Pan, Xiaofang He, Zongming Liu, Henry Long, Myles Brown, Eric P. Winer, Deborah Dillon, Nancy Lin, Jean Zhao. p16INK4A-deficiency predicts for response to combined HER2 and CDK4/6 inhibition in HER2+ breast cancer brain metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 337.
Abstract 348: Development of an RNA based diagnostic panel to the tumor microenvironment to match cancer therapies for colorectal cancer
Authors: Strand-Tibbitts Kristen , Culm-Merdek Kerry , Santps Valerie Chamberlain , Benjamin Laura , Carter Julia , Douglass Larry , Luštrik Roman , Cvitkovič Robert , Ausec Luka , Rosengarten Rafael 
Published: July 2021

Abstract
The most utilized targeted therapies in colorectal cancer (CRC) are focused on EGFR inhibition and anti-angiogenesis. In the ~5% of patients with microsatellite instability (MSI-H) or high tumor mutational burden (TMB), checkpoint inhibitors (CPIs) have been approved. Oncxerna has developed an RNA expression-based approach to characterize the ‘dominant' biology of a patient's tumor microenvironment with the diagnostic hypothesis to prospectively pair those patients with therapies and known mechanism of action that directly target these biologies. We developed an RNA-based gene expression panel (TME Panel-1) and machine learning (ML) algorithms to prospectively predict a patient's response to anti-angiogenesis or immune modulators, such as CPIs. In this study, we explore the potential of the TME Panel-1 to identify dominant biologies present in colorectal cancer specimens procured from the Wood-Hudson Cancer Research Lab. Total RNA expression counts from FFPE slides were analyzed with the ML algorithms and used to assign each sample into one of four subgroups. The respective prevalence of the subgroups are similar to those observed in gastric cancer and ovarian cancer samples, suggesting that the TME-Panel 1 has potential to be used to develop pan-tumor diagnostics. We will present these results, correlations with clinical outcomes and other relevant biomarkers for CRC. In summary, we conclude that RNA-based descriptors of biology may be a useful approach to enrich for better response to targeted therapies whose mechanism of action is to modify the TME biology.
Citation Format: Kristen Strand-Tibbitts, Kerry Culm-Merdek, Valerie Chamberlain Santps, Laura Benjamin, Julia Carter, Larry Douglass, Roman Luštrik, Robert Cvitkovič, Luka Ausec, Rafael Rosengarten. Development of an RNA based diagnostic panel to the tumor microenvironment to match cancer therapies for colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 348.
Abstract 360: The dilemma of the current diagnostic tests for MSI in prostate cancer
Authors: Dikoglu Esra , Naizhen Xu , O'Connor Luke P. , Pinto Peter , Merino Maria J. 
Published: July 2021

Abstract
Background:
Understanding the relationship between tumor genomics and the immune response in cancer has gotten more attention with the advance of immunotherapy. Microsatellite instability (MSI) is a molecular marker that provides prognostic and predictive information in many types of tumors including prostate cancer (PC). In PC, MSI-H and dMMR have been reported anywhere from 1% in primary tumors to up to 12% in metastasis. Reliable testing strategies for MSI/MMR status are critical for clinical management of patients with PC. MSI detection methods include PCR based molecular tests, NGS-based MSI detection or immunohistochemical staining (IHC). We observe technical difficulties in our daily practice with current molecular diagnostic tests.
Design:
We examined MMR protein expression (MSH2, MSH6, MLH1, PMS2) and PD-L1 by IHC in 30 PC.
Results:
Among 30 PC tested, 1 tumor (3%) was completely negative for MLH1 and PMS2 and 1 tumor (3%) revealed loss of PMS2 by IHC even though gene panel did not reveal any mutation in PMS2. The PD-L1 IHC was 44% positive, but the single MMR negative biopsy was PD-L1 negative. PD-L1 expression in PC samples did not show correlation with defective MMR expression.
Conclusion:
In our study, controversial results were obtained. Based on our experience; even though many exons of MMR genes are covered with these panels, there are some exons do not get enough coverage to be analyzed. This low coverage problem creates false negative results. There are also pseudogene pairs of these genes, especially PMS2. For some specific regions, even though there is enough coverage it is impossible to know if the pathogenic variant is on the PMS2 or the pseudogene without additional test. This result suffers from false positive results without a confirmatory test. It is also known that 5% to 11% of MSI-H cases demonstrate intact MMR staining and localization (proficient MMR, pMMR) due to retained antigenicity and nonfunctional protein. So far, in regular practice we use MMR analyzing strategies which set up for colon cancer where the tumor is uniform. PC is more complex; most of the time more than one clone is involving.We believe MSI detection for PC requires improvement the technics of detection, robust set up of testing strategy with high sensitivity and specificity, analyzing strategy and training of pathologists. Due to technical difficulties of the detection, we believe that the prevalence of MSI-high/dMMR PC might be higher than reported in the literature so far.
Citation Format: Esra Dikoglu, Xu Naizhen, Luke P. O'Connor, Peter Pinto, Maria J. Merino. The dilemma of the current diagnostic tests for MSI in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 360.