bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from DNA Polymerase Eta Prevents Tumor Cell-Cycle Arrest and Cell Death during Recovery from Replication Stress
Authors: Barnes Ryan P. , Tsao Wei-Chung , Moldovan George-Lucian , Eckert Kristin A.
Published: March 2023

Abstract
Neoplastic transformation and genome instability are enhanced by replication stress, conditions that slow or stall DNA replication forks. Consequently, cancer cells require multiple enzymes and checkpoint signaling pathways to mitigate replication stress for their viability and proliferation. Targeting proteins that enhance cancer cell survival during replication stress is a recent approach in clinical strategies, especially when targets produce synthetic lethality. DNA polymerase eta (Pol η) has many key functions in genome stability, particularly for translesion synthesis. Here we demonstrate that endogenous Pol η displays significant protein induction and forms intense foci throughout the nucleus in response to replication stress induced by drugs that do not directly form DNA adducts. During replication stress, Pol η-deficient cells displayed hyperactivation of the ATR replication checkpoint and arrested late in the cell cycle. During recovery from replication stress, Pol η-deficient cells continue to display aberrant phenotypes, including delayed cell-cycle progression, apoptosis, and cell survival. Depletion or inhibition of ATR was synthetically lethal with Pol η deficiency, particularly when tumor cells were treated with replication stress-inducing drugs. Together our data expand knowledge of the cellular environments that increase endogenous Pol η expression beyond DNA damaging agents and demonstrate that Pol η regulation is central to the replication stress response. Because Pol η is aberrantly expressed in several tumor types, our results are critical for developing more effective chemotherapy approaches and identify coinhibition of Pol η and ATR as a potential therapeutic strategy.
Significance:
This study demonstrates that replication stress upregulates Pol η (POLH) in tumor cells and reveals a role for Pol η in tumor cell recovery following replication stress.
Data from Pyruvate Dehydrogenase PDH-E1β Controls Tumor Progression by Altering the Metabolic Status of Cancer Cells
Authors: Yonashiro Ryo , Eguchi Kayoko , Wake Masaki , Takeda Norihiko , Nakayama Koh
Published: March 2023

Abstract
Downregulation of pyruvate dehydrogenase (PDH) is critical for the aberrant preferential activation of glycolysis in cancer cells under normoxic conditions. Phosphorylation-dependent inhibition of PDH is a relevant event in this process, but it is not durable as it relies on PDH kinases that are activated ordinarily under hypoxic conditions. Thus, it remains unclear how PDH is durably downregulated in cancer cells that are not hypoxic. Building on evidence that PDH activity depends on the stability of a multi-protein PDH complex, we found that the PDH-E1β subunit of the PDH complex is downregulated to inhibit PDH activity under conditions of prolonged hypoxia. After restoration of normoxic conditions, reduced expression of PDH-E1β was sustained such that glycolysis remained highly activated. Notably, PDH-E1β silencing in cancer cells produced a metabolic state strongly resembling the Warburg effect, but inhibited tumor growth. Conversely, enforced exogenous expression of PDH-E1β durably increased PDH activity and promoted the malignant growth of breast cancer cells in vivo. Taken together, our results establish the specific mechanism through which PDH acts as an oncogenic factor by tuning glycolytic metabolism in cancer cells.

Significance: This seminal study offers a mechanistic explanation for why glycolysis is aberrantly activated in normoxic cancer cells, offering insights into this long-standing hallmark of cancer termed the Warburg effect. Cancer Res; 78(7); 1592–603. ©2018 AACR.
Data from Radiotherapy and CD40 Activation Separately Augment Immunity to Checkpoint Blockade in Cancer
Authors: Rech Andrew J. , Dada Hannah , Kotzin Jonathan J. , Henao-Mejia Jorge , Minn Andy J. , Twyman-Saint Victor Christina , Vonderheide Robert H.
Published: March 2023

Abstract
Immunotherapy in pancreatic ductal adenocarcinoma (PDA) remains a difficult clinical problem despite success in other disease types with immune checkpoint blockade (ICB) and chimeric antigen receptor T-cell therapy. Mechanisms driving immunosuppression and poor T-cell infiltration in PDA are incompletely understood. Here, we use genetically engineered mouse models of PDA that recapitulate hallmarks of human disease to demonstrate that CD40 pathway activation is required for clinical response to radiotherapy and ICB with αCTLA-4 and αPD-1. The combination of an agonist αCD40 antibody, radiotherapy, and dual ICB eradicated irradiated and unirradiated (i.e., abscopal) tumors, generating long-term immunity. Response required T cells and also short-lived myeloid cells and was dependent on the long noncoding RNA myeloid regulator Morrbid. Using unbiased random forest machine learning, we built unique, contextual signatures for each therapeutic component, revealing that (i) radiotherapy triggers an early proinflammatory stimulus, ablating existing intratumoral T cells and upregulating MHC class I and CD86 on antigen-presenting cells, (ii) αCD40 causes a systemic and intratumoral reorganization of the myeloid compartment, and (iii) ICB increases intratumoral T-cell infiltration and improves the CD8 T-cell:regulatory T-cell ratio. Thus, αCD40 and radiotherapy nonredundantly augment antitumor immunity in PDA, which is otherwise refractory to ICB, providing a clear rationale for clinical evaluation.

Significance: Radiotherapy and αCD40 disrupt key links between innate and adaptive immunity, ameliorating resistance to immune checkpoint blockade in pancreatic cancer via multiple cellular mechanisms. Cancer Res; 78(15); 4282–91. ©2018 AACR.
Data from The Tumor Suppressor CIC Directly Regulates MAPK Pathway Genes via Histone Deacetylation
Authors: Weissmann Simon , Cloos Paul A. , Sidoli Simone , Jensen Ole N. , Pollard Steven , Helin Kristian
Published: March 2023

Abstract
Oligodendrogliomas are brain tumors accounting for approximately 10% of all central nervous system cancers. CIC is a transcription factor that is mutated in most patients with oligodendrogliomas; these mutations are believed to be a key oncogenic event in such cancers. Analysis of the Drosophila melanogaster ortholog of CIC, Capicua, indicates that CIC loss phenocopies activation of the EGFR/RAS/MAPK pathway, and studies in mammalian cells have demonstrated a role for CIC in repressing the transcription of the PEA3 subfamily of ETS transcription factors. Here, we address the mechanism by which CIC represses transcription and assess the functional consequences of CIC inactivation. Genome-wide binding patterns of CIC in several cell types revealed that CIC target genes were enriched for MAPK effector genes involved in cell-cycle regulation and proliferation. CIC binding to target genes was abolished by high MAPK activity, which led to their transcriptional activation. CIC interacted with the SIN3 deacetylation complex and, based on our results, we suggest that CIC functions as a transcriptional repressor through the recruitment of histone deacetylases. Independent single amino acid substitutions found in oligodendrogliomas prevented CIC from binding its target genes. Taken together, our results show that CIC is a transcriptional repressor of genes regulated by MAPK signaling, and that ablation of CIC function leads to increased histone acetylation levels and transcription at these genes, ultimately fueling mitogen-independent tumor growth.

Significance: Inactivation of CIC inhibits its direct repression of MAPK pathway genes, leading to their increased expression and mitogen-independent growth.

Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/15/4114/F1.large.jpg. Cancer Res; 78(15); 4114–25. ©2018 AACR.
Data from A Novel Inhibitor Targets Both Wnt Signaling and ATM/p53 in Colorectal Cancer
Authors: Cheng Jiongjia , Dwyer Mary , Okolotowicz Karl J. , Mercola Mark , Cashman John R.
Published: March 2023

Abstract
For 2017, the estimated lifetime risk of developing colorectal cancer was 1 in 22. Even though preventative colonoscopy screening and standard-of-care surgery, radiation, and chemotherapy have decreased the death rate from colorectal cancer, new therapies are needed for metastatic colorectal cancer. Here, we developed a novel small molecule, compound 2, that inhibited proliferation and viability of human colorectal cancer cells (HCT-116, DLD-1, SW480, and 10.1). Compound 2 inhibited cell migration, invasion, and epithelial–mesenchymal transition processes and potently increased cell apoptosis in human colorectal cancer cells. Compound 2 also modulated mitotic stress signaling, leading to both inhibition of Wnt responsiveness and stabilization and activation of p53 to cause cell-cycle arrest. In mouse xenografts, treatment with compound 2 (20 mg/kg/day, i.p.) induced cell death and inhibited tumor growth more than four-fold compared with vehicle at day 34. Neither acute cytotoxicity nor toxicity in animals (up to 1,000 mg/kg, i.p.) were observed for compound 2. To our knowledge, compound 2 is the first reported potent small molecule that inhibits Wnt/β-catenin signaling, activates p53 signaling regardless of p53 mutation status, and binds microtubules without detectable toxicity. Thus, compound 2 offers a novel mechanism of action and a new strategy to treat colorectal cancer.

Significance: These findings identify a potent small molecule that may be therapeutically useful for colon cancer that works by inhibiting Wnt/β-catenin signaling, activating p53, and binding microtubules without detectable toxicity. Cancer Res; 78(17); 5072–83. ©2018 AACR.
Data from miR-590-3p Promotes Ovarian Cancer Growth and Metastasis via a Novel FOXA2–Versican Pathway
Authors: Salem Mohamed , O'Brien Jacob A. , Bernaudo Stefanie , Shawer Heba , Ye Gang , Brkić Jelena , Amleh Asma , Vanderhyden Barbara C. , Refky Basel , Yang Burton B. , Krylov Sergey N. , Peng Chun
Published: March 2023

Abstract
miRNAs play important roles in gene regulation, and their dysregulation is associated with many diseases, including epithelial ovarian cancer (EOC). In this study, we determined the expression and function of miR-590-3p in EOC. miR-590-3p levels were higher in high-grade carcinoma when compared with low-grade or tumors with low malignant potential. Interestingly, plasma levels of miR-590-3p were significantly higher in patients with EOC than in subjects with benign gynecologic disorders. Transient transfection of miR-590-3p mimics or stable transfection of mir-590 increased cell proliferation, migration, and invasion. In vivo studies revealed that mir-590 accelerated tumor growth and metastasis. Using a cDNA microarray, we identified forkhead box A2 (FOXA2) and versican (VCAN) as top downregulated and upregulated genes by mir-590, respectively. miR-590-3p targeted FOXA2 3′ UTR to suppress its expression. In addition, knockdown or knockout of FOXA2 enhanced cell proliferation, migration, and invasion. Overexpression of FOXA2 decreased, whereas knockout of FOXA2 increased VCAN mRNA and protein levels, which was due to direct binding and regulation of the VCAN gene by FOXA2. Interrogation of the TCGA ovarian cancer database revealed a negative relationship between FOXA2 and VCAN mRNA levels in EOC tumors, and high FOXA2/low VCAN mRNA levels in tumors positively correlated with patient survival. Finally, overexpression of FOXA2 or silencing of VCAN reversed the effects of mir-590. These findings demonstrate that miR-590-3p promotes EOC development via a novel FOXA2–VCAN pathway.

Significance: Low FOXA2/high VCAN levels mediate the tumor-promoting effects of miR-590-3p and negatively correlate with ovarian cancer survival. Cancer Res; 78(15); 4175–90. ©2018 AACR.
Data from Specific Targeting of MTAP-Deleted Tumors with a Combination of 2′-Fluoroadenine and 5′-Methylthioadenosine
Authors: Tang Baiqing , Lee Hyung-Ok , An Serim S. , Cai Kathy Q. , Kruger Warren D.
Published: March 2023

Abstract
Homozygous deletion of the methylthioadenosine phosphorylase (MTAP) gene is a frequent event in a wide variety of human cancers and is a possible molecular target for therapy. One potential therapeutic strategy to target MTAP-deleted tumors involves combining toxic purine analogues such as 6′-thioguanine (6TG) or 2′-fluoroadenine (2FA) with the MTAP substrate 5′-deoxy-5′-methylthioadenosine (MTA). The rationale is that excess MTA will protect normal MTAP+ cells from purine analogue toxicity because MTAP catalyzes the conversion of MTA to adenine, which then inhibits the conversion of purine base analogues into nucleotides. However, in MTAP− tumor cells, no protection takes place because adenine is not formed. Here, we examine the effects of 6TG and 2FA in combination with MTA in vitro and in vivo. In vitro, MTA protected against both 6TG and 2FA toxicity in an MTAP-dependent manner, shifting the IC50 concentration by one to three orders of magnitude. However, in mice, MTA protected against toxicity from 2FA but failed to protect against 6TG. Addition of 100 mg/kg MTA to 20 mg/kg 2FA entirely reversed the toxicity of 2FA in a variety of tissues and the treatment was well tolerated by mice. The 2FA+MTA combination inhibited tumor growth of four different MTAP− human tumor cell lines in mouse xenograft models. Our results suggest that 2FA+MTA may be a promising combination for treating MTAP-deleted tumors.

Significance: Loss of MTAP occurs in about 15% of all human cancers; the MTAP protection strategy presented in this study could be very effective in treating these cancers. Cancer Res; 78(15); 4386–95. ©2018 AACR.
Data from miR-193b–Regulated Signaling Networks Serve as Tumor Suppressors in Liposarcoma and Promote Adipogenesis in Adipose-Derived Stem Cells
Authors: Mazzu Ying Z. , Hu Yulan , Soni Rajesh K. , Mojica Kelly M. , Qin Li-Xuan , Agius Phaedra , Waxman Zachary M. , Mihailovic Aleksandra , Socci Nicholas D. , Hendrickson Ronald C. , Tuschl Thomas , Singer Samuel
Published: March 2023

Abstract
Well-differentiated and dedifferentiated liposarcomas (WDLS/DDLS) account for approximately 13% of all soft tissue sarcoma in adults and cause substantial morbidity or mortality in the majority of patients. In this study, we evaluated the functions of miRNA (miR-193b) in liposarcoma in vitro and in vivo. Deep RNA sequencing on 93 WDLS, 145 DDLS, and 12 normal fat samples demonstrated that miR-193b was significantly underexpressed in DDLS compared with normal fat. Reintroduction of miR-193b induced apoptosis in liposarcoma cells and promoted adipogenesis in human adipose-derived stem cells (ASC). Integrative transcriptomic and proteomic analysis of miR-193b–target networks identified novel direct targets, including CRK-like proto-oncogene (CRKL) and focal adhesion kinase (FAK). miR-193b was found to regulate FAK–SRC–CRKL signaling through CRKL and FAK. miR-193b also stimulated reactive oxygen species signaling by targeting the antioxidant methionine sulfoxide reductase A to modulate liposarcoma cell survival and ASC differentiation state. Expression of miR-193b in liposarcoma cells was downregulated by promoter methylation, resulting at least in part from increased expression of the DNA methyltransferase DNMT1 in WDLS/DDLS. In vivo, miR-193b mimetics and FAK inhibitor (PF-562271) each inhibited liposarcoma xenograft growth. In summary, miR-193b not only functions as a tumor suppressor in liposarcoma but also promotes adipogenesis in ASC. Furthermore, this study reveals key tyrosine kinase and DNA methylation pathways in liposarcoma, some with immediate implications for therapeutic exploration. Cancer Res; 77(21); 5728–40. ©2017 AACR.
Data from Genome-Wide Interrogation of Human Cancers Identifies EGLN1 Dependency in Clear Cell Ovarian Cancers
Authors: Price Colles , Gill Stanley , Ho Zandra V. , Davidson Shawn M. , Merkel Erin , McFarland James M. , Leung Lisa , Tang Andrew , Kost-Alimova Maria , Tsherniak Aviad , Jonas Oliver , Vazquez Francisca , Hahn William C.
Published: March 2023

Abstract
We hypothesized that candidate dependencies for which there are small molecules that are either approved or in advanced development for a nononcology indication may represent potential therapeutic targets. To test this hypothesis, we performed genome-scale loss-of-function screens in hundreds of cancer cell lines. We found that knockout of EGLN1, which encodes prolyl hydroxylase domain-containing protein 2 (PHD2), reduced the proliferation of a subset of clear cell ovarian cancer cell lines in vitro. EGLN1-dependent cells exhibited sensitivity to the pan-EGLN inhibitor FG-4592. The response to FG-4592 was reversed by deletion of HIF1A, demonstrating that EGLN1 dependency was related to negative regulation of HIF1A. We also found that ovarian clear cell tumors susceptible to both genetic and pharmacologic inhibition of EGLN1 required intact HIF1A. Collectively, these observations identify EGLN1 as a cancer target with therapeutic potential.
Significance:
These findings reveal a differential dependency of clear cell ovarian cancers on EGLN1, thus identifying EGLN1 as a potential therapeutic target in clear cell ovarian cancer patients.
Data from Exosomes from Glioma-Associated Mesenchymal Stem Cells Increase the Tumorigenicity of Glioma Stem-like Cells via Transfer of miR-1587
Authors: Figueroa Javier , Phillips Lynette M. , Shahar Tal , Hossain Anwar , Gumin Joy , Kim Hoon , Bean Andrew J. , Calin George A. , Fueyo Juan , Walters Edgar T. , Kalluri Raghu , Verhaak Roel G. , Lang Frederick F.
Published: March 2023

Abstract
Tumor–stromal communications impact tumorigenesis in ways that are incompletely understood. Here, we show that glioma-associated human mesenchymal stem cells (GA-hMSC), a newly identified stromal component of glioblastoma, release exosomes that increase the proliferation and clonogenicity of tumor-initiating glioma stem-like cells (GSC). This event leads to a significantly greater tumor burden and decreased host survival compared with untreated GSCs in orthotopic xenografts. Analysis of the exosomal content identified miR-1587 as a mediator of the exosomal effects on GSCs, in part via downregulation of the tumor-suppressive nuclear receptor corepressor NCOR1. Our results illuminate the tumor-supporting role for GA-hMSCs by identifying GA-hMSC–derived exosomes in the intercellular transfer of specific miRNA that enhance the aggressiveness of glioblastoma. Cancer Res; 77(21); 5808–19. ©2017 AACR.
Data from miRNA Profiling of Magnetic Nanopore–Isolated Extracellular Vesicles for the Diagnosis of Pancreatic Cancer
Authors: Ko Jina , Bhagwat Neha , Black Taylor , Yee Stephanie S. , Na Young-Ji , Fisher Stephen , Kim Junhyong , Carpenter Erica L. , Stanger Ben Z. , Issadore David
Published: March 2023

Abstract
Improved diagnostics for pancreatic ductal adenocarcinoma (PDAC) to detect the disease at earlier, curative stages and to guide treatments is crucial to progress against this disease. The development of a liquid biopsy for PDAC has proven challenging due to the sparsity and variable phenotypic expression of circulating biomarkers. Here we report methods we developed for isolating specific subsets of extracellular vesicles (EV) from plasma using a novel magnetic nanopore capture technique. In addition, we present a workflow for identifying EV miRNA biomarkers using RNA sequencing and machine-learning algorithms, which we used in combination to classify distinct cancer states. Applying this approach to a mouse model of PDAC, we identified a biomarker panel of 11 EV miRNAs that could distinguish mice with PDAC from either healthy mice or those with precancerous lesions in a training set of n = 27 mice and a user-blinded validation set of n = 57 mice (88% accuracy in a three-way classification). These results provide strong proof-of-concept support for the feasibility of using EV miRNA profiling and machine learning for liquid biopsy.

Significance: These findings present a panel of extracellular vesicle miRNA blood-based biomarkers that can detect pancreatic cancer at a precancerous stage in a transgenic mouse model. Cancer Res; 78(13); 3688–97. ©2018 AACR.
Data from Spliceosome Mutations Induce R Loop-Associated Sensitivity to ATR Inhibition in Myelodysplastic Syndromes
Authors: Nguyen Hai Dang , Leong Wan Yee , Li Weiling , Reddy Pavankumar N.G. , Sullivan Jack D. , Walter Matthew J. , Zou Lee , Graubert Timothy A.
Published: March 2023

Abstract
Heterozygous somatic mutations in spliceosome genes (U2AF1, SF3B1, ZRSR2, or SRSF2) occur in >50% of patients with myelodysplastic syndrome (MDS). These mutations occur early in disease development, suggesting that they contribute to MDS pathogenesis and may represent a unique genetic vulnerability for targeted therapy. Here, we show that RNA splicing perturbation by expression of the U2AF1(S34F) mutant causes accumulation of R loops, a transcription intermediate containing RNA:DNA hybrids and displaced single-stranded DNA, and elicits an ATR response. ATR inhibitors (ATRi) induced DNA damage and cell death in U2AF1(S34F)-expressing cells, and these effects of ATRi were enhanced by splicing modulating compounds. Moreover, ATRi-induced DNA damage was suppressed by overexpression of RNaseH1, an enzyme that specifically removes the RNA in RNA:DNA hybrids, suggesting that the ATRi sensitivity of U2AF1(S34F)-expressing cells arises from R loops. Taken together, our results demonstrate that ATR may represent a novel therapeutic target in patients with MDS carrying the U2AF1(S34F) mutation and potentially other malignancies harboring spliceosome mutations.

Significance: This study provides preclinical evidence that patients with MDS or other myeloid malignancies driven by spliceosome mutations may benefit from ATR inhibition to exploit the R loop–associated vulnerability induced by perturbations in splicing. Cancer Res; 78(18); 5363–74. ©2018 AACR.
Data from Therapeutically Active RIG-I Agonist Induces Immunogenic Tumor Cell Killing in Breast Cancers
Authors: Elion David L. , Jacobson Max E. , Hicks Donna J. , Rahman Bushra , Sanchez Violeta , Gonzales-Ericsson Paula I. , Fedorova Olga , Pyle Anna M. , Wilson John T. , Cook Rebecca S.
Published: March 2023

Abstract
Cancer immunotherapies that remove checkpoint restraints on adaptive immunity are gaining clinical momentum but have not achieved widespread success in breast cancers, a tumor type considered poorly immunogenic and which harbors a decreased presence of tumor-infiltrating lymphocytes. Approaches that activate innate immunity in breast cancer cells and the tumor microenvironment are of increasing interest, based on their ability to induce immunogenic tumor cell death, type I IFNs, and lymphocyte-recruiting chemokines. In agreement with reports in other cancers, we observe loss, downregulation, or mutation of the innate viral nucleotide sensor retinoic acid-inducible gene I (RIG-I/DDX58) in only 1% of clinical breast cancers, suggesting potentially widespread applicability for therapeutic RIG-I agonists that activate innate immunity. This was tested using an engineered RIG-I agonist in a breast cancer cell panel representing each of three major clinical breast cancer subtypes. Treatment with RIG-I agonist resulted in upregulation and mitochondrial localization of RIG-I and activation of proinflammatory transcription factors STAT1 and NF-κB. RIG-I agonist triggered the extrinsic apoptosis pathway and pyroptosis, a highly immunogenic form of cell death in breast cancer cells. RIG-I agonist also induced expression of lymphocyte-recruiting chemokines and type I IFN, confirming that cell death and cytokine modulation occur in a tumor cell–intrinsic manner. Importantly, RIG-I activation in breast tumors increased tumor lymphocytes and decreased tumor growth and metastasis. Overall, these findings demonstrate successful therapeutic delivery of a synthetic RIG-I agonist to induce tumor cell killing and to modulate the tumor microenvironment in vivo.

Significance: These findings describe the first in vivo delivery of RIG-I mimetics to tumors, demonstrating a potent immunogenic and therapeutic effect in the context of otherwise poorly immunogenic breast cancers. Cancer Res; 78(21); 6183–95. ©2018 AACR.
Data from Sialic Acid Blockade Suppresses Tumor Growth by Enhancing T-cell–Mediated Tumor Immunity
Authors: Büll Christian , Boltje Thomas J. , Balneger Natasja , Weischer Sarah M. , Wassink Melissa , van Gemst Jasper J. , Bloemendal Victor R. , Boon Louis , van der Vlag Johan , Heise Torben , den Brok Martijn H. , Adema Gosse J.
Published: March 2023

Abstract
Sialic acid sugars on the surface of cancer cells have emerged as potent immune modulators that contribute to the immunosuppressive microenvironment and tumor immune evasion. However, the mechanisms by which these sugars modulate antitumor immunity as well as therapeutic strategies directed against them are limited. Here we report that intratumoral injections with a sialic acid mimetic Ac53FaxNeu5Ac block tumor sialic acid expression in vivo and suppress tumor growth in multiple tumor models. Sialic acid blockade had a major impact on the immune cell composition of the tumor, enhancing tumor-infiltrating natural killer cell and CD8+ T-cell numbers while reducing regulatory T-cell and myeloid regulatory cell numbers. Sialic acid blockade enhanced cytotoxic CD8+ T-cell–mediated killing of tumor cells in part by facilitating antigen-specific T-cell–tumor cell clustering. Sialic acid blockade also synergized with adoptive transfer of tumor-specific CD8+ T cells in vivo and enhanced CpG immune adjuvant therapy by increasing dendritic cell activation and subsequent CD8+ T-cell responses. Collectively, these data emphasize the crucial role of sialic acids in tumor immune evasion and provide proof of concept that sialic acid blockade creates an immune-permissive tumor microenvironment for CD8+ T-cell–mediated tumor immunity, either as single treatment or in combination with other immune-based intervention strategies.

Significance: Sialic acid sugars function as important modulators of the immunosuppressive tumor microenvironment that limit potent antitumor immunity.

Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/13/3574/F1.large.jpg. Cancer Res; 78(13); 3574–88. ©2018 AACR.
Data from Evaluation of Explant Responses to STING Ligands: Personalized Immunosurgical Therapy for Head and Neck Squamous Cell Carcinoma
Authors: Baird Jason R. , Bell R. Bryan , Troesch Victoria , Friedman David , Bambina Shelly , Kramer Gwen , Blair Tiffany C. , Medler Terry , Wu Yaping , Sun Zhaoyu , de Gruijl Tanja D. , van de Ven Rieneke , Leidner Rom S. , Crittenden Marka R. , Gough Michael J.
Published: March 2023

Abstract
Surgeons have unique in situ access to tumors enabling them to apply immunotherapies to resection margins as a means to prevent local recurrence. Here, we developed a surgical approach to deliver stimulator of interferon genes (STING) ligands to the site of a purposeful partial tumor resection using a gel-based biomaterial. In a range of head and neck squamous cell carcinoma (HNSCC) murine tumor models, we demonstrate that although control-treated tumors recur locally, tumors treated with STING-loaded biomaterials are cured. The mechanism of tumor control required activation of STING and induction of type I IFN in host cells, not cancer cells, and resulted in CD8 T-cell–mediated cure of residual cancer cells. In addition, we used a novel tumor explant assay to screen individual murine and human HNSCC tumor responses to therapies ex vivo. We then utilized this information to personalize the biomaterial and immunotherapy applied to previously unresponsive tumors in mice. These data demonstrate that explant assays identify the diversity of tumor-specific responses to STING ligands and establish the utility of the explant assay to personalize immunotherapies according to the local response.

Significance: Delivery of immunotherapy directly to resection sites via a gel-based biomaterial prevents locoregional recurrence of head and neck squamous cell carcinoma. Cancer Res; 78(21); 6308–19. ©2018 AACR.
Data from Replication Protein A Availability during DNA Replication Stress Is a Major Determinant of Cisplatin Resistance in Ovarian Cancer Cells
Authors: Bélanger François , Fortier Emile , Dubé Maxime , Lemay Jean-François , Buisson Rémi , Masson Jean-Yves , Elsherbiny Abdelhamid , Costantino Santiago , Carmona Euridice , Mes-Masson Anne-Marie , Wurtele Hugo , Drobetsky Elliot
Published: March 2023

Abstract
Intrinsic and acquired resistance to cisplatin remains a primary hurdle to treatment of high-grade serous ovarian cancer (HGSOC). Cisplatin selectively kills tumor cells by inducing DNA crosslinks that block replicative DNA polymerases. Single-stranded DNA (ssDNA) generated at resulting stalled replication forks (RF) is bound and protected by heterotrimeric replication protein A (RPA), which then serves as a platform for recruitment and activation of replication stress response factors. Cells deficient in this response are characterized by extensive ssDNA formation and excessive RPA recruitment that exhausts the available pool of RPA, which (i) inhibits RPA-dependent processes such as nucleotide excision repair (NER) and (ii) causes catastrophic failure of blocked RF. Here, we investigated the influence of RPA availability on chemosensitivity using a panel of human HGSOC cell lines. Our data revealed a striking correlation among these cell lines between cisplatin sensitivity and the inability to efficiently repair DNA via NER, specifically during S phase. Such defects in NER were attributable to RPA exhaustion arising from aberrant activation of DNA replication origins during replication stress. Reduced RPA availability promoted Mre11-dependent degradation of nascent DNA at stalled RF in cell lines exhibiting elevated sensitivity to cisplatin. Strikingly, defective S-phase NER, RF instability, and cisplatin sensitivity could all be rescued by ectopic overexpression of RPA. Taken together, our findings indicate that RPA exhaustion represents a major determinant of cisplatin sensitivity in HGSOC cell lines.

Significance: The influence of replication protein A exhaustion on cisplatin sensitivity harbors important implications toward improving therapy of various cancers that initially respond to platinum-based agents but later relapse due to intrinsic or acquired drug resistance. Cancer Res; 78(19); 5561–73. ©2018 AACR.
Data from Targeting the SUMO Pathway Primes All-trans Retinoic Acid–Induced Differentiation of Nonpromyelocytic Acute Myeloid Leukemias
Authors: Baik Hayeon , Boulanger Mathias , Hosseini Mohsen , Kowalczyk Julie , Zaghdoudi Sonia , Salem Tamara , Sarry Jean-Emmanuel , Hicheri Yosr , Cartron Guillaume , Piechaczyk Marc , Bossis Guillaume
Published: March 2023

Abstract
Differentiation therapies using all-trans retinoic acid (ATRA) are highly efficient at treating acute promyelocytic leukemia (APL), a subtype of acute myeloid leukemia (AML). However, their efficacy, if any, is limited in the case of non-APL AML. We report here that inhibition of SUMOylation, a posttranslational modification related to ubiquitination, restores the prodifferentiation and antiproliferative activities of retinoids in non-APL AML. Controlled inhibition of SUMOylation with the pharmacologic inhibitors 2-D08 or anacardic acid, or via overexpression of SENP deSUMOylases, enhanced the ATRA-induced expression of key genes involved in differentiation, proliferation, and apoptosis in non-APL AML cells. This activated ATRA-induced terminal myeloid differentiation and reduced cell proliferation and viability, including in AML cells resistant to chemotherapeutic drugs. Conversely, enhancement of SUMOylation via overexpression of the SUMO-conjugating enzyme Ubc9 dampened expression of ATRA-responsive genes and prevented differentiation. Thus, inhibition of the SUMO pathway is a promising strategy to sensitize patients with non-APL AML to retinoids and improve the treatment of this poor-prognosis cancer.

Significance: SUMOylation silences key ATRA-responsive genes in nonpromyelocytic acute myeloid leukemias. Cancer Res; 78(10); 2601–13. ©2018 AACR.
Data from Optimized Dosing Schedule Based on Circadian Dynamics of Mouse Breast Cancer Stem Cells Improves the Antitumor Effects of Aldehyde Dehydrogenase Inhibitor
Authors: Matsunaga Naoya , Ogino Takashi , Hara Yukinori , Tanaka Takahiro , Koyanagi Satoru , Ohdo Shigehiro
Published: March 2023

Abstract
Although malignant phenotypes of triple-negative breast cancer (TNBC) are subject to circadian alterations, the role of cancer stem cells (CSC) in defining this circadian change remains unclear. CSC are often characterized by high aldehyde dehydrogenase (ALDH) activity, which is associated with the malignancy of cancer cells and is used for identification and isolation of CSC. Here, we show that the population of ALDH-positive cells in a mouse 4T1 breast tumor model exhibits pronounced circadian alterations. Alterations in the number of ALDH-positive cells were generated by time-dependent increases and decreases in the expression of Aldh3a1. Importantly, circadian clock genes were rhythmically expressed in ALDH-negative cells, but not in ALDH-positive cells. Circadian expression of Aldh3a1 in ALDH-positive cells was dependent on the time-dependent release of Wingless-type mmtv integration site family 10a (WNT10a) from ALDH-negative cells. Furthermore, antitumor and antimetastatic effects of ALDH inhibitor N,N-diethylaminobenzaldehyde were enhanced by administration at the time of day when ALDH activity was increased in 4T1 tumor cells. Our findings reveal a new role for the circadian clock within the tumor microenvironment in regulating the circadian dynamics of CSC. These results should enable the development of novel therapeutic strategies for treatment of TNBC with ALDH inhibitors.

Significance: This seminal report reveals that circadian dynamics of CSC are regulated by the tumor microenvironment and provides a proof of principle of its implication for chronotherapy in TNBC. Cancer Res; 78(13); 3698–708. ©2018 AACR.
Data from RAS–MAPK Pathway-Driven Tumor Progression Is Associated with Loss of CIC and Other Genomic Aberrations in Neuroblastoma
Authors: Eleveld Thomas F. , Schild Linda , Koster Jan , Zwijnenburg Danny A. , Alles Lindy K. , Ebus Marli E. , Volckmann Richard , Tijtgat Godelieve A. , van Sluis Peter , Versteeg Rogier , Molenaar Jan J.
Published: March 2023

Abstract
Mutations affecting the RAS–MAPK pathway frequently occur in relapsed neuroblastoma tumors, which suggests that activation of this pathway is associated with a more aggressive phenotype. To explore this hypothesis, we generated several model systems to define a neuroblastoma RAS–MAPK pathway signature. Activation of this pathway in primary tumors indeed correlated with poor survival and was associated with known activating mutations in ALK and other RAS–MAPK pathway genes. Integrative analysis showed that mutations in PHOX2B, CIC, and DMD were also associated with an activated RAS–MAPK pathway. Mutation of PHOX2B and deletion of CIC in neuroblastoma cell lines induced activation of the RAS–MAPK pathway. This activation was independent of phosphorylated ERK in CIC knockout systems. Furthermore, deletion of CIC caused a significant increase in tumor growth in vivo. These results show that the RAS–MAPK pathway is involved in tumor progression and establish CIC as a powerful tumor suppressor that functions downstream of this pathway in neuroblastoma.

Significance: This work identifies CIC as a powerful tumor suppressor affecting the RAS-MAPK pathway in neuroblastoma and reinforces the importance of mutation-driven activation of this pathway in cancer. Cancer Res; 78(21); 6297–307. ©2018 AACR.
Data from IFNγ PET Imaging as a Predictive Tool for Monitoring Response to Tumor Immunotherapy
Authors: Gibson Heather M. , McKnight Brooke N. , Malysa Agnes , Dyson Greg , Wiesend Wendy N. , McCarthy Claire E. , Reyes Joyce , Wei Wei-Zen , Viola-Villegas Nerissa T.
Published: March 2023

Abstract
IFNγ is an attractive target for imaging active antitumor immunity due to its function in the T-cell signaling axis. Here, we test an IFNγ immuno-PET (immunoPET) probe for its capacity to identify adaptive immunotherapy response after HER2/neu vaccination in both spontaneous salivary and orthotopic neu+ mouse mammary tumors. IFNγ immunoPET detected elevated cytokine levels in situ after vaccination, which inversely correlated with tumor growth rate, an indicator of response to therapy. In a model of induced T-cell anergy where CD8 T cells infiltrate the tumor, but upregulate PD-1, IFNγ tracer uptake was equivalent to isotype control, illustrating a lack of antitumor T-cell activity. The IFNγ immunoPET tracer detected IFNγ protein sequestered on the surface of tumor cells, likely in complex with the IFNγ receptor, which may explain imaging localization of this soluble factor in vivo. Collectively, we find that the activation status of cytotoxic T cells is annotated by IFNγ immunoPET, with reduced off-target binding to secondary lymphoid tissues compared with imaging total CD3+ tumor-infiltrating lymphocytes. Targeting of soluble cytokines such as IFNγ by PET imaging may provide valuable noninvasive insight into the function of immune cells in situ.

Significance: This study presents a novel approach to monitor therapeutic outcomes via IFNγ-targeted positron emission tomography. Cancer Res; 78(19); 5706–17. ©2018 AACR.
Data from Heterozygosity of Chaperone Grp78 Reduces Intestinal Stem Cell Regeneration Potential and Protects against Adenoma Formation
Authors: van Lidth de Jeude Jooske F. , Spaan Claudia N. , Meijer Bartolomeus J. , Smit Wouter L. , Soeratram Tanya T.D. , Wielenga Mattheus C.B. , Westendorp B. Florien , Lee Amy S. , Meisner Sander , Vermeulen Jacqueline L.M. , Wildenberg Manon E. , van den Brink Gijs R. , Muncan Vanesa , Heijmans Jarom
Published: March 2023

Abstract
Deletion of endoplasmic reticulum resident chaperone Grp78 results in activation of the unfolded protein response and causes rapid depletion of the entire intestinal epithelium. Whether modest reduction of Grp78 may affect stem cell fate without compromising intestinal integrity remains unknown. Here, we employ a model of epithelial-specific, heterozygous Grp78 deletion by use of VillinCreERT2-Rosa26ZsGreen/LacZ-Grp78+/fl mice and organoids. We examine models of irradiation and tumorigenesis, both in vitro and in vivo. Although we observed no phenotypic changes in Grp78 heterozygous mice, Grp78 heterozygous organoid growth was markedly reduced. Irradiation of Grp78 heterozygous mice resulted in less frequent regeneration of crypts compared with nonrecombined (wild-type) mice, exposing reduced capacity for self-renewal upon genotoxic insult. We crossed mice to Apc-mutant animals for adenoma studies and found that adenomagenesis in Apc heterozygous-Grp78 heterozygous mice was reduced compared with Apc heterozygous controls (1.43 vs. 3.33; P < 0.01). In conclusion, epithelium-specific Grp78 heterozygosity compromises epithelial fitness under conditions requiring expansive growth such as adenomagenesis or regeneration after γ-irradiation. These results suggest that Grp78 may be a therapeutic target in prevention of intestinal neoplasms without affecting normal tissue.

Significance: Heterozygous disruption of chaperone protein Grp78 reduces tissue regeneration and expansive growth and protects from tumor formation without affecting intestinal homeostasis. Cancer Res; 78(21); 6098–106. ©2018 AACR.
Data from Targeting PARP1 in XRCC1-Deficient Sporadic Invasive Breast Cancer or Preinvasive Ductal Carcinoma In Situ Induces Synthetic Lethality and Chemoprevention
Authors: Ali Reem , Al-Kawaz Abdulbaqi , Toss Michael S. , Green Andrew R. , Miligy Islam M. , Mesquita Katia A. , Seedhouse Claire , Mirza Sameer , Band Vimla , Rakha Emad A , Madhusudan Srinivasan
Published: March 2023

Abstract
Targeting PARP1 for synthetic lethality is a new strategy for breast cancers harboring germline mutations in BRCA. However, these mutations are rare, and reactivation of BRCA-mediated pathways may result in eventual resistance to PARP1 inhibitor therapy. Alternative synthetic lethality approaches targeting more common sporadic breast cancers and preinvasive ductal carcinoma in situ (DCIS) are desirable. Here we show that downregulation of XRCC1, which interacts with PARP1 and coordinates base excision repair, is an early event in human breast cancer pathogenesis. XRCC1-deficient DCIS were aggressive and associated with increased risk of local recurrence. Human invasive breast cancers deficient in XRCC1 and expressing high PARP1 levels also manifested aggressive features and poor outcome. The PARP1 inhibitor olaparib was synthetically lethal in XRCC1-deficient DCIS and invasive breast cancer cells. We conclude that targeting PARP1 is an attractive strategy for synthetic lethality and chemoprevention in XRCC1-deficient breast cancers, including preinvasive DCIS.
Significance:
These findings show that loss of XRCC1, which is associated with more malignant DCIS, can be exploited by PARP inhibition, suggesting its application as a promising therapeutic and chemoprevention strategy in XRCC1-deficient tumor cells.
Data from Extracorporeal Photochemotherapy Drives Monocyte-to-Dendritic Cell Maturation to Induce Anticancer Immunity
Authors: Ventura Alessandra , Vassall Aaron , Robinson Eve , Filler Renata , Hanlon Douglas , Meeth Katrina , Ezaldein Harib , Girardi Michael , Sobolev Olga , Bosenberg Marcus W. , Edelson Richard L.
Published: March 2023

Abstract
Extracorporeal photochemotherapy (ECP) is a cancer immunotherapy for cutaneous T-cell lymphoma (CTCL) operative in more than 350 centers worldwide. Although its efficacy and favorable safety profile have driven its widespread use, elucidation of its underlying mechanism has been difficult. In this study, we identify the principal contributors to the anticancer immunotherapeutic effects of ECP, with the goal of enhancing potency and broadening applicability to additional malignancies. First, we scaled down the clinical ECP leukocyte-processing device to mouse size. Second, we used that miniaturized device to produce a cellular vaccine that regularly initiated therapeutic antimelanoma immunity. Third, we individually subtracted key factors from either the immunizing inoculum or the treated animal to ascertain their contribution to the in vivo antimelanoma response. Platelet-signaled monocyte-to-dendritic cell (DC) differentiation followed by sorting/processing/presentation of tumor antigens derived from internalized apoptotic tumor cells were absolute requirements. As in clinical ECP, immunogenic cell death of tumor cells was finely titrated by DNA cross-linkage mediated by photoactivated 8-methoxypsoralen (8-MOPA). ECP-induced tumor-loaded DC were effective immunotherapeutic agents only if they were spared exposure to 8-MOPA, indicating that healthy DC are required for ECP. Infusion of responder T cells into naïve tumor-challenged mice established the protective role of stimulated T-cell antitumor immunity. Collectively, these results reveal that selective antitumor effects of ECP are initiated by tumor antigen–loaded, ECP-induced DC, which promote potent collaboration between CD4 and CD8 tumor-specific T cells. These mechanistic insights suggest potential therapeutic applicability of ECP to solid tumors in addition to CTCL.

Significance: These findings identify principal cellular contributors to the anticancer immunotherapeutic impact of ECP and suggest this treatment may be applicable to a broad spectrum of immunogenic malignancies. Cancer Res; 78(14); 4045–58. ©2018 AACR.
Data from VEGFC Antibody Therapy Drives Differentiation of AML
Authors: Kampen Kim R. , Scherpen Frank J.G. , Mahmud Hasan , ter Elst Arja , Mulder André B. , Guryev Victor , Verhagen Han J.M.P. , De Keersmaecker Kim , Smit Linda , Kornblau Steven M. , De Bont Eveline S.J.M.
Published: March 2023

Abstract
High expression of VEGFC predicts adverse prognosis in acute myeloid leukemia (AML). We therefore explored VEGFC-targeting efficacy as an AML therapy using a VEGFC mAb. VEGFC antibody therapy enforced myelocytic differentiation of clonal CD34+ AML blasts. Treatment of CD34+ AML blasts with the antibody reduced expansion potential by 30% to 50% and enhanced differentiation via FOXO3A suppression and inhibition of MAPK/ERK proliferative signals. VEGFC antibody therapy also accelerated leukemia cell differentiation in a systemic humanized AML mouse model. Collectively, these results define a regulatory function of VEGFC in CD34+ AML cell fate decisions via FOXO3A and serve as a new potential differentiation therapy for patients with AML.

Significance: These findings reveal VEGFC targeting as a promising new differentiation therapy in AML. Cancer Res; 78(20); 5940–8. ©2018 AACR.
Data from A Novel Germline Variant in CSF3R Reduces N-Glycosylation and Exerts Potent Oncogenic Effects in Leukemia
Authors: Spiciarich David R. , Oh Stephen T. , Foley Amy , Hughes Seamus B. , Mauro Michael J. , Abdel-Wahab Omar , Press Richard D. , Viner Rosa , Thompson Sarah L. , Chen Qiushi , Azadi Parastoo , Bertozzi Carolyn R. , Maxson Julia E.
Published: March 2023

Abstract
Mutations in the colony-stimulating factor 3 receptor (CSF3R) have been identified in the vast majority of patients with chronic neutrophilic leukemia and are present in other kinds of leukemia, such as acute myeloid leukemia. Here, we studied the function of novel germline variants in CSF3R at amino acid N610. These N610 substitutions were potently oncogenic and activated the receptor independently of its ligand GCSF. These mutations activated the JAK–STAT signaling pathway and conferred sensitivity to JAK inhibitors. Mass spectrometry revealed that the N610 residue is part of a consensus N-linked glycosylation motif in the receptor, usually linked to complex glycans. N610 was also the primary site of sialylation of the receptor. Membrane-proximal N-linked glycosylation was critical for maintaining the ligand dependence of the receptor. Mutation of the N610 site prevented membrane-proximal N-glycosylation of CSF3R, which then drove ligand-independent cellular expansion. Kinase inhibitors blocked growth of cells with an N610 mutation. This study expands the repertoire of oncogenic mutations in CSF3R that are therapeutically targetable and provides insight into the function of glycans in receptor regulation.
Significance:
This study reveals the critical importance of membrane-proximal N-linked glycosylation of CSF3R for the maintenance of ligand dependency in leukemia