bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Secretion of IL1 by Dedifferentiated Melanoma Cells Inhibits JAK1-STAT3–Driven Actomyosin Contractility of Lymph Node Fibroblastic Reticular Cells
Authors: Rovera Christopher , Berestjuk Ilona , Lecacheur Margaux , Tavernier Cassandre , Diazzi Serena , Pisano Sabrina , Irondelle Marie , Mallavialle Aude , Albrengues Jean , Gaggioli Cédric , Girard Christophe A. , Passeron Thierry , Deckert Marcel , Tartare-Deckert Sophie , Prod'homme Virginie
Published: March 2024

Abstract
Fibroblastic reticular cells (FRC) are immunologically specialized myofibroblasts that control the elasticity of the lymph node, in part through their contractile properties. Swelling of tumor-draining lymph nodes is a hallmark of lymphophilic cancers such as cutaneous melanoma. Melanoma displays high intratumoral heterogeneity with the coexistence of melanoma cells with variable differentiation phenotypes from melanocytic to dedifferentiated states. Factors secreted by melanoma cells promote premetastatic lymph node reprograming and tumor spreading. Elucidating the impact of the melanoma secretome on FRC could help identify approaches to prevent metastasis. Here we show that melanocytic and dedifferentiated melanoma cells differentially impact the FRC contractile phenotype. Factors secreted by dedifferentiated cells, but not by melanocytic cells, strongly inhibited actomyosin-dependent contractile forces of FRC by decreasing the activity of the RHOA–RHO–kinase (ROCK) pathway and the mechano-responsive transcriptional coactivator Yes1 associated transcriptional regulator (YAP). Transcriptional profiling and biochemical analyses indicated that actomyosin cytoskeleton relaxation in FRC is driven by inhibition of the JAK1-STAT3 pathway. This FRC relaxation was associated with increased FRC proliferation and activation and with elevated tumor invasion in vitro. The secretome of dedifferentiated melanoma cells also modulated the biomechanical properties of distant lymph node in premetastatic mouse models. Finally, IL1 produced by dedifferentiated cells was involved in the inhibition of FRC contractility. These data highlight the role of the JAK1-STAT3 and YAP pathways in spontaneous contractility of resting FRC. They also suggest that dedifferentiated melanoma cells specifically target FRC biomechanical properties to favor tumor spreading in the premetastatic lymph node niche. Targeting this remote communication could be an effective strategy to prevent metastatic spread of the disease.
Significance:
Communication between dedifferentiated melanoma cells and lymph node fibroblasts reprograms the biomechanical properties of the premetastatic lymph node niche to promote tumor invasion.

See related commentary by Lund, p. 1692
Data from Neuroblastoma Formation Requires Unconventional CD4 T Cells and Arginase-1–Dependent Myeloid Cells
Authors: Van de Velde Lee-Ann , Allen E. Kaitlynn , Crawford Jeremy Chase , Wilson Taylor L. , Guy Clifford S. , Russier Marion , Zeitler Leonie , Bahrami Armita , Finkelstein David , Pelletier Stephane , Schultz-Cherry Stacey , Thomas Paul G. , Murray Peter J.
Published: March 2024

Abstract
Immune cells regulate tumor growth by mirroring their function as tissue repair organizers in normal tissues. To understand the different facets of immune–tumor collaboration through genetics, spatial transcriptomics, and immunologic manipulation with noninvasive, longitudinal imaging, we generated a penetrant double oncogene–driven autochthonous model of neuroblastoma. Spatial transcriptomic analysis showed that CD4+ and myeloid populations colocalized within the tumor parenchyma, while CD8+ T cells and B cells were peripherally dispersed. Depletion of CD4+ T cells or CCR2+ macrophages, but not B cells, CD8+ T cells, or natural killer (NK) cells, prevented tumor formation. Tumor CD4+ T cells displayed unconventional phenotypes and were clonotypically diverse and antigen independent. Within the myeloid fraction, tumor growth required myeloid cells expressing arginase-1. Overall, these results demonstrate how arginine-metabolizing myeloid cells conspire with pathogenic CD4+ T cells to create permissive conditions for tumor formation, suggesting that these protumorigenic pathways could be disabled by targeting myeloid arginine metabolism.
Significance:
A new model of human neuroblastoma provides ways to track tumor formation and expansion in living animals, allowing identification of CD4+ T-cell and macrophage functions required for oncogenesis.
Data from STINGing Viral Tumors: What We Know from Head and Neck Cancers
Authors: Saulters Emma , Woolley John F. , Varadarajan Shankar , Jones Terence M. , Dahal Lekh N.
Published: March 2024

Abstract
It has now become increasingly clear that viruses, which may not be directly oncogenic, can affect the biology of tumors as well as immune behavior against tumors. This has led to a fundamental question: Should tumors associated with viral infection be considered distinct from those without? Typically, viruses activate the host innate immune responses by stimulating pathogen recognition receptors and DNA-sensing pathways, including the stimulator of interferon genes (STING) pathway. However, regulation of the STING pathway in a virus-associated tumor microenvironment is poorly understood. Human papillomavirus (HPV) infection within a subset of head and neck squamous cell carcinomas (HNSCC) promotes a unique etiology and clinical outcome. For reasons currently not well understood, patients with HPV+ tumors have a better outcome in terms of both overall survival and reduced risk of recurrence compared with HPV− HNSCC. This observation may reflect a greater intrinsic immunogenicity associated with HPV infection, pertaining to innate immune system pathways activated following recognition of viral nucleotides. Here we discuss how HNSCC provides a unique model to study the STING pathway in the context of viral-induced tumor type as well as recent advances in our understanding of this pathway in HSNCC.
Data from The Evolving Genomic Landscape of Esophageal Squamous Cell Carcinoma Under Chemoradiotherapy
Authors: Hirata Hidenari , Niida Atsushi , Kakiuchi Nobuyuki , Uchi Ryutaro , Sugimachi Keishi , Masuda Takaaki , Saito Tomoko , Kageyama Shun-Ichiro , Motomura Yushi , Ito Shuhei , Yoshitake Tadamasa , Tsurumaru Daisuke , Nishimuta Yusuke , Yokoyama Akira , Hasegawa Takanori , Chiba Kenichi , Shiraishi Yuichi , Du Junyan , Miura Fumihito , Morita Masaru , Toh Yasushi , Hirakawa Masakazu , Shioyama Yoshiyuki , Ito Takashi , Akimoto Tetsuo , Miyano Satoru , Shibata Tatsuhiro , Mori Masaki , Suzuki Yutaka , Ogawa Seishi , Ishigami Kousei , Mimori Koshi
Published: March 2024

Abstract
Esophageal squamous cell carcinoma (ESCC) often recurs after chemoradiotherapy, and the prognosis of ESCC after chemoradiotherapy has not improved over the past few decades. The mutation process in chemoradiotherapy-resistant clones and the functional relevance of genetic alterations remain unclear. To address these problems, we performed whole-exome sequencing of 52 tumor samples from 33 patients with ESCC who received radiotherapy combined with 5-fluorouracil/platinum. In multiregion analyses of pretreatment and locally recurrent lesions from five cases, most driver gene-altered clones remained under chemoradiotherapy selection pressure, while few driver gene alterations were acquired at recurrence. The mutation signatures of recurrent ESCC, including increased deletion frequency and platinum dose-dependent base substitution signatures, were substantially different from those of primary ESCC and reflected the iatrogenic impacts of chemoradiotherapy. Single-region analysis of 28 pretreatment tumors indicated that focal copy-number gain at the MYC locus was significantly associated with poor progression-free survival and overall survival after chemoradiotherapy. MYC gain remained throughout the chemoradiotherapy course and potentially contributes to intrinsic resistance to chemoradiotherapy. Consistent with these findings, MYC copy number and mRNA and protein levels in ESCC cell lines correlated positively with resistance to radiotherapy, and MYC knockdown improved sensitivity to radiotherapy. Overall, these data characterize the clonal evolution process induced by chemoradiotherapy and clinically relevant associations for genetic alterations in ESCC. These findings increase our understanding of therapeutic resistance and support the rationale for precision chemoradiotherapy.
Significance:
Whole-exome sequencing reveals the genetic evolution of ESCC during chemoradiotherapy, highlighting MYC gain in pretreatment tumors as a potential marker of therapy resistance.
Data from Loss of Long Noncoding RNA NXTAR in Prostate Cancer Augments Androgen Receptor Expression and Enzalutamide Resistance
Authors: Ghildiyal Ruchi , Sawant Mithila , Renganathan Arun , Mahajan Kiran , Kim Eric H. , Luo Jingqin , Dang Ha X. , Maher Christopher A. , Feng Felix Y. , Mahajan Nupam P.
Published: March 2024

Abstract
Androgen receptor (AR) signaling continues to play a dominant role in all stages of prostate cancer, including castration-resistant prostate cancers (CRPC) that have developed resistance to second generation AR antagonists such as enzalutamide. In this study, we identified a long noncoding RNA (lncRNA), NXTAR (LOC105373241) that is located convergent with the AR gene and is repressed in human prostate tumors and cell lines. NXTAR bound upstream of the AR promoter and promoted EZH2 recruitment, causing significant loss of AR (and AR-V7) expression. Paradoxically, AR bound the NXTAR promoter, and inhibition of AR by the ACK1/TNK2 small molecule inhibitor (R)-9b excluded AR from the NXTAR promoter. The histone acetyltransferase GCN5 bound and deposited H3K14 acetylation marks, enhancing NXTAR expression. Application of an oligonucleotide derived from NXTAR exon 5 (NXTAR-N5) suppressed AR/AR-V7 expression and prostate cancer cell proliferation, indicating the translational relevance of the negative regulation of AR. In addition, pharmacologic restoration of NXTAR using (R)-9b abrogated enzalutamide-resistant prostate xenograft tumor growth. Overall, this study uncovers a positive feedback loop, wherein NXTAR acts as a novel prostate tumor-suppressing lncRNA by inhibiting AR/AR-V7 expression, which in turn upregulates NXTAR levels, compromising enzalutamide-resistant prostate cancer. The restoration of NXTAR could serve as a new therapeutic modality for patients who have acquired resistance to second generation AR antagonists.
Significance:
This study identifies NXTAR as a tumor suppressive lncRNA that can epigenetically downregulate AR/AR-V7 expression and provides a therapeutic strategy to reinstate NXTAR expression for treating recurrent CRPC.
Data from Characterizing Macrophage Diversity in Metastasis-Bearing Lungs Reveals a Lipid-Associated Macrophage Subset
Authors: Huggins Danielle N. , LaRue Rebecca S. , Wang Ying , Knutson Todd P. , Xu Yingzheng , Williams Jesse W. , Schwertfeger Kathryn L.
Published: March 2024

Abstract
While macrophages are among the most abundant immune cell type found within primary and metastatic mammary tumors, how their complexity and heterogeneity change with metastatic progression remains unknown. Here, macrophages were isolated from the lungs of mice bearing orthotopic mammary tumors for single-cell RNA sequencing (scRNA-seq). Seven distinct macrophage clusters were identified, including populations exhibiting enhanced differential expression of genes related to antigen presentation (H2-Aa, Cd74), cell cycle (Stmn1, Cdk1), and interferon signaling (Isg15, Ifitm3). Interestingly, one cluster demonstrated a profile concordant with lipid-associated macrophages (Lgals3, Trem2). Compared with nontumor-bearing controls, the number of these cells per gram of tissue was significantly increased in lungs from tumor-bearing mice, with the vast majority costaining positively with the alveolar macrophage marker Siglec-F. Enrichment of genes implicated in pathways related to lipid metabolism as well extracellular matrix remodeling and immunosuppression was observed. In addition, these cells displayed reduced capacity for phagocytosis. Collectively, these findings highlight the diversity of macrophages present within metastatic lesions and characterize a lipid-associated macrophage subset previously unidentified in lung metastases.
Significance:
scRNA-seq of macrophages isolated from lung metastases reveals extensive macrophage heterogeneity and identifies a novel subpopulation enriched for genes involved in lipid metabolism, extracellular matrix remodeling, and immunosuppression.
Data from Loss of Integrin-Linked Kinase Sensitizes Breast Cancer to SRC Inhibitors
Authors: Beetham Henry , Griffith Billie G.C. , Murina Olga , Loftus Alexander E.P. , Parry David A. , Temps Carolin , Culley Jayne , Muir Morwenna , Unciti-Broceta Asier , Sims Andrew H. , Byron Adam , Brunton Valerie G.
Published: March 2024

Abstract
SRC is a nonreceptor tyrosine kinase with key roles in breast cancer development and progression. Despite this, SRC tyrosine kinase inhibitors have so far failed to live up to their promise in clinical trials, with poor overall response rates. We aimed to identify possible synergistic gene–drug interactions to discover new rational combination therapies for SRC inhibitors. An unbiased genome-wide CRISPR-Cas9 knockout screen in a model of triple-negative breast cancer revealed that loss of integrin-linked kinase (ILK) and its binding partners α-Parvin and PINCH-1 sensitizes cells to bosutinib, a clinically approved SRC/ABL kinase inhibitor. Sensitivity to bosutinib did not correlate with ABL dependency; instead, bosutinib likely induces these effects by acting as a SRC tyrosine kinase inhibitor. Furthermore, in vitro and in vivo models showed that loss of ILK enhanced sensitivity to eCF506, a novel and highly selective inhibitor of SRC with a unique mode of action. Whole-genome RNA sequencing following bosutinib treatment in ILK knockout cells identified broad changes in the expression of genes regulating cell adhesion and cell–extracellular matrix. Increased sensitivity to SRC inhibition in ILK knockout cells was associated with defective adhesion, resulting in reduced cell number as well as increased G1 arrest and apoptosis. These findings support the potential of ILK loss as an exploitable therapeutic vulnerability in breast cancer, enhancing the effectiveness of clinical SRC inhibitors.
Significance:
A CRISPR-Cas9 screen reveals that loss of integrin-linked kinase synergizes with SRC inhibition, providing a new opportunity for enhancing the clinical effectiveness of SRC inhibitors in breast cancer.
Data from miR-31 Displays Subtype Specificity in Lung Cancer
Authors: Davenport Mackenzie L. , Echols John B. , Silva Austin D. , Anderson Joshua C. , Owens Philip , Yates Clayton , Wei Qing , Harada Shuko , Hurst Douglas R. , Edmonds Mick D.
Published: March 2024

Abstract
miRNA rarely possess pan-oncogenic or tumor-suppressive properties. Most miRNAs function under tissue-specific contexts, acting as either tumor suppressors in one tissue, promoting oncogenesis in another, or having no apparent role in the regulation of processes associated with the hallmarks of cancer. What has been less clear is the role of miRNAs within cell types of the same tissue and the ability within each cell type to contribute to oncogenesis. In this study, we characterize the role of one such tissue-specific miRNA, miR-31, recently identified as the most oncogenic miRNA in lung adenocarcinoma, across the histologic spectrum of human lung cancer. Compared with normal lung tissue, miR-31 was overexpressed in patient lung adenocarcinoma, squamous cell carcinoma, and large-cell neuroendocrine carcinoma, but not small-cell carcinoma or carcinoids. miR-31 promoted tumor growth in mice of xenografted human adenocarcinoma and squamous cell carcinoma cell lines, but not in large- or small-cell carcinoma lines. While miR-31 did not promote primary tumor growth of large- and small-cell carcinoma, it did promote spontaneous metastasis. Mechanistically, miR-31 altered distinct cellular signaling programs within each histologic subtype, resulting in distinct phenotypic differences. This is the first report distinguishing diverse functional roles for this miRNA across the spectrum of lung cancers and suggests that miR-31 has broad clinical value in human lung malignancy.
Significance:
These findings demonstrate the oncogenic properties of miR-31 in specific subtypes of lung cancer and highlight it as a potential therapeutic target in these subtypes.
Data from Ubiquitin-Specific Protease 6 Functions as a Tumor Suppressor in Ewing Sarcoma through Immune Activation
Authors: Henrich Ian C. , Jain Kanika , Young Robert , Quick Laura , Lindsay Jarrett M. , Park Daniel H. , Oliveira Andre M. , Blobel Gerd A. , Chou Margaret M.
Published: March 2024

Abstract
Ewing sarcoma is the second most common pediatric bone cancer, with a 5-year survival rate for metastatic disease of only 20%. Recent work indicates that survival is strongly correlated with high levels of tumor-infiltrating lymphocytes (TIL), whose abundance is associated with IFN-inducible chemokines CXCL10 and CCL5. However, the tumor-intrinsic factors that drive chemokine production and TIL recruitment have not been fully elucidated. We previously showed that ubiquitin-specific protease 6 (USP6) directly deubiquitinates and stabilizes Jak1, thereby inducing an IFN signature in Ewing sarcoma cells. Here, we show that this gene set comprises chemokines associated with immunostimulatory, antitumorigenic functions, including CXCL10 and CCL5. USP6 synergistically enhanced chemokine production in response to exogenous IFN by inducing surface upregulation of IFNAR1 and IFNGR1. USP6-expressing Ewing sarcoma cells stimulated migration of primary human monocytes and T lymphocytes and triggered activation of natural killer (NK) cells in vitro. USP6 inhibited Ewing sarcoma xenograft growth in nude but not NSG mice and was accompanied by increased intratumoral chemokine production and infiltration and activation of NK cells, dendritic cells, and macrophages, consistent with a requirement for innate immune cells in mediating the antitumorigenic effects of USP6. High USP6 expression in patients with Ewing sarcoma was associated with chemokine production, immune infiltration, and improved survival. This work reveals a previously unrecognized tumor-suppressive function for USP6, which engenders an immunostimulatory microenvironment through pleiotropic effects on multiple immune lineages. This further raises the possibility that USP6 activity may be harnessed to create a “hot” tumor microenvironment in immunotherapy.
Significance:
This study reveals a novel tumor-suppressive function for USP6 by inducing an immunostimulatory microenvironment, suggesting that USP6 activity may be exploited to enhance immunotherapy regimens.
Data from Gut Microbiota Condition the Therapeutic Efficacy of Trastuzumab in HER2-Positive Breast Cancer
Authors: Di Modica Martina , Gargari Giorgio , Regondi Viola , Bonizzi Arianna , Arioli Stefania , Belmonte Beatrice , De Cecco Loris , Fasano Elena , Bianchi Francesca , Bertolotti Alessia , Tripodo Claudio , Villani Laura , Corsi Fabio , Guglielmetti Simone , Balsari Andrea , Triulzi Tiziana , Tagliabue Elda
Published: March 2024

Abstract
Emerging evidence indicates that gut microbiota affect the response to anticancer therapies by modulating the host immune system. In this study, we investigated the impact of gut microbiota on immune-mediated trastuzumab antitumor efficacy in preclinical models of HER2-positive breast cancer and in 24 patients with primary HER2-positive breast cancer undergoing trastuzumab-containing neoadjuvant treatment. In mice, the antitumor activity of trastuzumab was impaired by antibiotic administration or fecal microbiota transplantation from antibiotic-treated donors. Modulation of the intestinal microbiota was reflected in tumors by impaired recruitment of CD4+ T cells and granzyme B–positive cells after trastuzumab treatment. Antibiotics caused reductions in dendritic cell (DC) activation and the release of IL12p70 upon trastuzumab treatment, a mechanism that was necessary for trastuzumab effectiveness in our model. In patients, lower α-diversity and lower abundance of Lachnospiraceae, Turicibacteraceae, Bifidobacteriaceae, and Prevotellaceae characterized nonresponsive patients (NR) compared with those who achieved pathologic complete response (R), similar to antibiotic-treated mice. The transfer of fecal microbiota from R and NR into mice bearing HER2-positive breast cancer recapitulated the response to trastuzumab observed in patients. Fecal microbiota β-diversity segregated patients according to response and positively correlated with immune signature related to interferon (IFN) and NO2-IL12 as well as activated CD4+ T cells and activated DCs in tumors. Overall, our data reveal the direct involvement of the gut microbiota in trastuzumab efficacy, suggesting that manipulation of the gut microbiota is an optimal future strategy to achieve a therapeutic effect or to exploit its potential as a biomarker for treatment response.
Significance:
Evidence of gut microbiota involvement in trastuzumab efficacy represents the foundation for new therapeutic strategies aimed at manipulating commensal bacteria to improve response in trastuzumab-resistant patients.

See related commentary by Sharma, p. 1937
Data from BRD4 Regulates Transcription Factor ΔNp63α to Drive a Cancer Stem Cell Phenotype in Squamous Cell Carcinomas
Authors: Fisher Matthew L. , Balinth Seamus , Hwangbo Yon , Wu Caizhi , Ballon Carlos , Wilkinson John E. , Goldberg Gary L. , Mills Alea A.
Published: March 2024

Abstract
Bromodomain containing protein 4 (BRD4) plays a critical role in controlling the expression of genes involved in development and cancer. Inactivation of BRD4 inhibits cancer growth, making it a promising anticancer drug target. The cancer stem cell (CSC) population is a key driver of recurrence and metastasis in patients with cancer. Here we show that cancer stem-like cells can be enriched from squamous cell carcinomas (SCC), and that these cells display an aggressive phenotype with enhanced stem cell marker expression, migration, invasion, and tumor growth. BRD4 is highly elevated in this aggressive subpopulation of cells, and its function is critical for these CSC-like properties. Moreover, BRD4 regulates ΔNp63α, a key transcription factor that is essential for epithelial stem cell function that is often overexpressed in cancers. BRD4 regulates an EZH2/STAT3 complex that leads to increased ΔNp63α-mediated transcription. Targeting BRD4 in human SCC reduces ΔNp63α, leading to inhibition of spheroid formation, migration, invasion, and tumor growth. These studies identify a novel BRD4-regulated signaling network in a subpopulation of cancer stem-like cells, elucidating a possible avenue for effective therapeutic intervention.
Significance:
This study identifies a signaling cascade driven by BRD4 that upregulates ΔNp63α to promote cancer stem-like properties, which has potential therapeutic implications for the treatment of squamous cell carcinomas.
Data from ZIP9 Is a Druggable Determinant of Sex Differences in Melanoma
Authors: Aguirre-Portolés Cristina , Payne Riley , Trautz Aspen , Foskett J. Kevin , Natale Christopher A. , Seykora John T. , Ridky Todd W.
Published: March 2024

Abstract
Melanoma and most other cancers occur more frequently and have worse prognosis in males compared with females. Although sex steroids are thought to be involved, classical androgen and estrogen receptors are not detectable in most melanomas. Here we show that testosterone promotes melanoma proliferation by activating ZIP9 (SLC39A9), a zinc transporter that is widely expressed in human melanoma but not intentionally targeted by available therapeutics. This testosterone activity required an influx of zinc, activation of MAPK, and nuclear translocation of YAP. FDA-approved inhibitors of the classical androgen receptor also inhibited ZIP9, thereby antagonizing the protumorigenic effects of testosterone in melanoma. In male mice, androgen receptor inhibitors suppressed growth of ZIP9-expressing melanomas but had no effect on isogenic melanomas lacking ZIP9 or on melanomas in females. These data suggest that ZIP9 might be effectively targeted in melanoma and other cancers by repurposing androgen receptor inhibitors that are currently approved only for prostate cancer.
Significance:
Testosterone signaling through ZIP9 mediates some of the sex differences in melanoma, and drugs that target AR can be repurposed to block ZIP9 and inhibit melanoma in males.
Data from Human Endogenous Retrovirus Type K Promotes Proliferation and Confers Sensitivity to Antiretroviral Drugs in Merlin-Negative Schwannoma and Meningioma
Authors: Maze Emmanuel A. , Agit Bora , Reeves Shona , Hilton David A. , Parkinson David B. , Laraba Liyam , Ercolano Emanuela , Kurian Kathreena M. , Hanemann C. Oliver , Belshaw Robert D. , Ammoun Sylwia
Published: March 2024

Abstract
Deficiency of the tumor suppressor Merlin causes development of schwannoma, meningioma, and ependymoma tumors, which can occur spontaneously or in the hereditary disease neurofibromatosis type 2 (NF2). Merlin mutations are also relevant in a variety of other tumors. Surgery and radiotherapy are current first-line treatments; however, tumors frequently recur with limited treatment options. Here, we use human Merlin-negative schwannoma and meningioma primary cells to investigate the involvement of the endogenous retrovirus HERV-K in tumor development. HERV-K proteins previously implicated in tumorigenesis were overexpressed in schwannoma and all meningioma grades, and disease-associated CRL4DCAF1 and YAP/TEAD pathways were implicated in this overexpression. In normal Schwann cells, ectopic overexpression of HERV-K Env increased proliferation and upregulated expression of c-Jun and pERK1/2, which are key components of known tumorigenic pathways in schwannoma, JNK/c-Jun, and RAS/RAF/MEK/ERK. Furthermore, FDA-approved retroviral protease inhibitors ritonavir, atazanavir, and lopinavir reduced proliferation of schwannoma and grade I meningioma cells. These results identify HERV-K as a critical regulator of progression in Merlin-deficient tumors and offer potential strategies for therapeutic intervention.
Significance:
The endogenous retrovirus HERV-K activates oncogenic signaling pathways and promotes proliferation of Merlin-deficient schwannomas and meningiomas, which can be targeted with antiretroviral drugs and TEAD inhibitors.
Data from Suppression of Endothelial Cell FAK Expression Reduces Pancreatic Ductal Adenocarcinoma Metastasis after Gemcitabine Treatment
Authors: Roy-Luzarraga Marina , Reynolds Louise E. , de Luxán-Delgado Beatriz , Maiques Oscar , Wisniewski Laura , Newport Emma , Rajeeve Vinothini , Drake Rebecca J.G. , Gómez-Escudero Jesús , Richards Frances M. , Weller Céline , Dormann Christof , Meng Ya-Ming , Vermeulen Peter B. , Saur Dieter , Sanz-Moreno Victoria , Wong Ping-Pui , Géraud Cyrill , Cutillas Pedro R. , Hodivala-Dilke Kairbaan
Published: March 2024

Abstract
Despite substantial advances in the treatment of solid cancers, resistance to therapy remains a major obstacle to prolonged progression-free survival. Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers, with a high level of liver metastasis. Primary PDAC is highly hypoxic, and metastases are resistant to first-line treatment, including gemcitabine. Recent studies have indicated that endothelial cell (EC) focal adhesion kinase (FAK) regulates DNA-damaging therapy–induced angiocrine factors and chemosensitivity in primary tumor models. Here, we show that inducible loss of EC-FAK in both orthotopic and spontaneous mouse models of PDAC is not sufficient to affect primary tumor growth but reduces liver and lung metastasis load and improves survival rates in gemcitabine-treated, but not untreated, mice. EC-FAK loss did not affect primary tumor angiogenesis, tumor blood vessel leakage, or early events in metastasis, including the numbers of circulating tumor cells, tumor cell homing, or metastatic seeding. Phosphoproteomics analysis showed a downregulation of the MAPK, RAF, and PAK signaling pathways in gemcitabine-treated FAK-depleted ECs compared with gemcitabine-treated wild-type ECs. Moreover, low levels of EC-FAK correlated with increased survival and reduced relapse in gemcitabine-treated patients with PDAC, supporting the clinical relevance of these findings. Altogether, we have identified a new role of EC-FAK in regulating PDAC metastasis upon gemcitabine treatment that impacts outcome.
Significance:
These findings establish the potential utility of combinatorial endothelial cell FAK targeting together with gemcitabine in future clinical applications to control metastasis in patients with pancreatic ductal adenocarcinoma.
Data from A BRCA1 Coiled-Coil Domain Variant Disrupting PALB2 Interaction Promotes the Development of Mammary Tumors and Confers a Targetable Defect in Homologous Recombination Repair
Authors: Pulver Emilia M. , Mukherjee Chirantani , van de Kamp Gerarda , Roobol Stefan J. , Rother Magdalena B. , van der Gulden Hanneke , de Bruijn Roebi , Lattanzio Maria Valeria , van der Burg Eline , Drenth Anne Paulien , Verkaik Nicole S. , Hahn Kerstin , Klarenbeek Sjoerd , de Korte-Grimmerink Renske , van de Ven Marieke , Pritchard Colin E.J. , Huijbers Ivo J. , Xia Bing , van Gent Dik C. , Essers Jeroen , van Attikum Haico , Ray Chaudhuri Arnab , Bouwman Peter , Jonkers Jos
Published: March 2024

Abstract
The BRCA1 tumor suppressor gene encodes a multidomain protein for which several functions have been described. These include a key role in homologous recombination repair (HRR) of DNA double-strand breaks, which is shared with two other high-risk hereditary breast cancer suppressors, BRCA2 and PALB2. Although both BRCA1 and BRCA2 interact with PALB2, BRCA1 missense variants affecting its PALB2-interacting coiled-coil domain are considered variants of uncertain clinical significance (VUS). Using genetically engineered mice, we show here that a BRCA1 coiled-coil domain VUS, Brca1 p.L1363P, disrupts the interaction with PALB2 and leads to embryonic lethality. Brca1 p.L1363P led to a similar acceleration in the development of Trp53-deficient mammary tumors as Brca1 loss, but the tumors showed distinct histopathologic features, with more stable DNA copy number profiles in Brca1 p.L1363P tumors. Nevertheless, Brca1 p.L1363P mammary tumors were HRR incompetent and responsive to cisplatin and PARP inhibition. Overall, these results provide the first direct evidence that a BRCA1 missense variant outside of the RING and BRCT domains increases the risk of breast cancer.
Significance:
These findings reveal the importance of a patient-derived BRCA1 coiled-coil domain sequence variant in embryonic development, mammary tumor suppression, and therapy response.

See related commentary by Mishra et al., p. 6080
Data from YAP and β-Catenin Cooperate to Drive Oncogenesis in Basal Breast Cancer
Authors: Quinn Hazel M. , Vogel Regina , Popp Oliver , Mertins Philipp , Lan Linxiang , Messerschmidt Clemens , Landshammer Alexandro , Lisek Kamil , Château-Joubert Sophie , Marangoni Elisabetta , Koren Elle , Fuchs Yaron , Birchmeier Walter
Published: March 2024

Abstract
Targeting cancer stem cells (CSC) can serve as an effective approach toward limiting resistance to therapies. While basal-like (triple-negative) breast cancers encompass cells with CSC features, rational therapies remain poorly established. We show here that the receptor tyrosine kinase Met promotes YAP activity in basal-like breast cancer and find enhanced YAP activity within the CSC population. Interfering with YAP activity delayed basal-like cancer formation, prevented luminal to basal transdifferentiation, and reduced CSC. YAP knockout mammary glands revealed a decrease in β-catenin target genes, suggesting that YAP is required for nuclear β-catenin activity. Mechanistically, nuclear YAP interacted with β-catenin and TEAD4 at gene regulatory elements. Proteomic patient data revealed an upregulation of the YAP signature in basal-like breast cancers. Our findings demonstrate that in basal-like breast cancers, β-catenin activity is dependent on YAP signaling and controls the CSC program. These findings suggest that targeting the YAP/TEAD4/β-catenin complex offers a potential therapeutic strategy for eradicating CSCs in basal-like breast cancers.
Significance:
These findings show that YAP cooperates with β-catenin in basal-like breast cancer to regulate CSCs and that targeting this interaction may be a novel CSC therapy for patients with basal-like breast cancer.
Data from Fat Induces Glucose Metabolism in Nontransformed Liver Cells and Promotes Liver Tumorigenesis
Authors: Broadfield Lindsay A. , Duarte João André Gonçalves , Schmieder Roberta , Broekaert Dorien , Veys Koen , Planque Mélanie , Vriens Kim , Karasawa Yasuaki , Napolitano Francesco , Fujita Suguru , Fujii Masashi , Eto Miki , Holvoet Bryan , Vangoitsenhoven Roman , Fernandez-Garcia Juan , Van Elsen Joke , Dehairs Jonas , Zeng Jia , Dooley James , Rubio Rebeca Alba , van Pelt Jos , Grünewald Thomas G.P. , Liston Adrian , Mathieu Chantal , Deroose Christophe M. , Swinnen Johannes V. , Lambrechts Diether , di Bernardo Diego , Kuroda Shinya , De Bock Katrien , Fendt Sarah-Maria
Published: March 2024

Abstract
Hepatic fat accumulation is associated with diabetes and hepatocellular carcinoma (HCC). Here, we characterize the metabolic response that high-fat availability elicits in livers before disease development. After a short term on a high-fat diet (HFD), otherwise healthy mice showed elevated hepatic glucose uptake and increased glucose contribution to serine and pyruvate carboxylase activity compared with control diet (CD) mice. This glucose phenotype occurred independently from transcriptional or proteomic programming, which identifies increased peroxisomal and lipid metabolism pathways. HFD-fed mice exhibited increased lactate production when challenged with glucose. Consistently, administration of an oral glucose bolus to healthy individuals revealed a correlation between waist circumference and lactate secretion in a human cohort. In vitro, palmitate exposure stimulated production of reactive oxygen species and subsequent glucose uptake and lactate secretion in hepatocytes and liver cancer cells. Furthermore, HFD enhanced the formation of HCC compared with CD in mice exposed to a hepatic carcinogen. Regardless of the dietary background, all murine tumors showed similar alterations in glucose metabolism to those identified in fat exposed nontransformed mouse livers, however, particular lipid species were elevated in HFD tumor and nontumor-bearing HFD liver tissue. These findings suggest that fat can induce glucose-mediated metabolic changes in nontransformed liver cells similar to those found in HCC.
Significance:
With obesity-induced hepatocellular carcinoma on a rising trend, this study shows in normal, nontransformed livers that fat induces glucose metabolism similar to an oncogenic transformation.
Data from Phosphatidylserine Synthase PTDSS1 Shapes the Tumor Lipidome to Maintain Tumor-Promoting Inflammation
Authors: Sekar Divya , Dillmann Christina , Sirait-Fischer Evelyn , Fink Annika F. , Zivkovic Aleksandra , Baum Natalie , Strack Elisabeth , Klatt Stephan , Zukunft Sven , Wallner Stefan , Descot Arnaud , Olesch Catherine , da Silva Priscila , von Knethen Andreas , Schmid Tobias , Grösch Sabine , Savai Rajkumar , Ferreirós Nerea , Fleming Ingrid , Ghosh Sourav , Rothlin Carla V. , Stark Holger , Medyouf Hind , Brüne Bernhard , Weigert Andreas
Published: March 2024

Abstract
An altered lipidome in tumors may affect not only tumor cells themselves but also their microenvironment. In this study, a lipidomics screen reveals increased amounts of phosphatidylserine (PS), particularly ether-PS (ePS), in murine mammary tumors compared with normal tissue. PS was produced by phosphatidylserine synthase 1 (PTDSS1), and depletion of Ptdss1 from tumor cells in mice reduced ePS levels accompanied by stunted tumor growth and decreased tumor-associated macrophage (TAM) abundance. Ptdss1-deficient tumor cells exposed less PS during apoptosis, which was recognized by the PS receptor MERTK. Mammary tumors in macrophage-specific Mertk−/− mice showed similarly suppressed growth and reduced TAM infiltration. Transcriptomic profiles of TAMs from Ptdss1-knockdown tumors and Mertk−/− TAMs revealed that macrophage proliferation was reduced when the Ptdss1/Mertk pathway was targeted. Moreover, PTDSS1 expression correlated positively with TAM abundance but negatively with breast carcinoma patient survival. PTDSS1 thus may be a target to modify tumor-promoting inflammation.
Significance:
This study shows that inhibiting the production of ether-phosphatidylserine by targeting phosphatidylserine synthase PTDSS1 limits tumor-associated macrophage expansion and breast tumor growth.
Data from Targeting the IRE1α/XBP1 Endoplasmic Reticulum Stress Response Pathway in ARID1A-Mutant Ovarian Cancers
Authors: Zundell Joseph A. , Fukumoto Takeshi , Lin Jianhuang , Fatkhudinov Nail , Nacarelli Timothy , Kossenkov Andrew V. , Liu Qin , Cassel Joel , Hu Chih-Chi Andrew , Wu Shuai , Zhang Rugang
Published: March 2024

Abstract
The SWI/SNF chromatin-remodeling complex is frequently altered in human cancers. For example, the SWI/SNF component ARID1A is mutated in more than 50% of ovarian clear cell carcinomas (OCCC), for which effective treatments are lacking. Here, we report that ARID1A transcriptionally represses the IRE1α–XBP1 axis of the endoplasmic reticulum (ER) stress response, which confers sensitivity to inhibition of the IRE1α–XBP1 pathway in ARID1A-mutant OCCC. ARID1A mutational status correlated with response to inhibition of the IRE1α–XBP1 pathway. In a conditional Arid1aflox/flox/Pik3caH1047R genetic mouse model, Xbp1 knockout significantly improved survival of mice bearing OCCCs. Furthermore, the IRE1α inhibitor B-I09 suppressed the growth of ARID1A-inactivated OCCCs in vivo in orthotopic xenograft, patient-derived xenograft, and the genetic mouse models. Finally, B-I09 synergized with inhibition of HDAC6, a known regulator of the ER stress response, in suppressing the growth of ARID1A-inactivated OCCCs. These studies define the IRE1α−XBP1 axis of the ER stress response as a targetable vulnerability for ARID1A-mutant OCCCs, revealing a promising therapeutic approach for treating ARID1A-mutant ovarian cancers.
Significance:
These findings indicate that pharmacological inhibition of the IRE1α–XBP1 pathway alone or in combination with HDAC6 inhibition represents an urgently needed therapeutic strategy for ARID1A-mutant ovarian cancers.
Data from A Combinatorial CRISPR–Cas9 Screen Identifies Ifenprodil as an Adjunct to Sorafenib for Liver Cancer Treatment
Authors: Xu Feng , Tong Man , Tong Cindy S.W. , Chan Becky K.C. , Chu Hoi Yee , Wong Tin Lok , Fong John H.C. , Cheung Maggie S.H. , Mak Kylie Hin-Man , Pardeshi Lakhansing , Huang Yuanhua , Wong Koon Ho , Choi Gigi C.G. , Ma Stephanie , Wong Alan S.L.
Published: March 2024

Abstract
Systematic testing of existing drugs and their combinations is an attractive strategy to exploit approved drugs for repurposing and identifying the best actionable treatment options. To expedite the search among many possible drug combinations, we designed a combinatorial CRISPR–Cas9 screen to inhibit druggable targets. Coblockade of the N-methyl-d-aspartate receptor (NMDAR) with targets of first-line kinase inhibitors reduced hepatocellular carcinoma (HCC) cell growth. Clinically, HCC patients with low NMDAR1 expression showed better survival. The clinically approved NMDAR antagonist ifenprodil synergized with sorafenib to induce the unfolded protein response, trigger cell-cycle arrest, downregulate genes associated with WNT signaling and stemness, and reduce self-renewal ability of HCC cells. In multiple HCC patient-derived organoids and human tumor xenograft models, the drug combination, but neither single drug alone, markedly reduced tumor-initiating cancer cell frequency. Because ifenprodil has an established safety history for its use as a vasodilator in humans, our findings support the repurposing of this drug as an adjunct for HCC treatment to improve clinical outcome and reduce tumor recurrence. These results also validate an approach for readily discovering actionable combinations for cancer therapy.
Significance:
Combinatorial CRISPR–Cas9 screening identifies actionable targets for HCC therapy, uncovering the potential of combining the clinically approved drugs ifenprodil and sorafenib as a new effective treatment regimen.
Data from NR2F1 Is a Barrier to Dissemination of Early-Stage Breast Cancer Cells
Authors: Rodriguez-Tirado Carolina , Kale Nupura , Carlini Maria J. , Shrivastava Nitisha , Rodrigues Alcina A. , Khalil Bassem D. , Bravo-Cordero Jose Javier , Hong Yan , Alexander Melissa , Ji Jiayi , Behbod Fariba , Sosa Maria Soledad
Published: March 2024

Abstract
Cancer cells can disseminate during very early and sometimes asymptomatic stages of tumor progression. Though biological barriers to tumorigenesis have been identified and characterized, the mechanisms that limit early dissemination remain largely unknown. We report here that the orphan nuclear receptor nuclear receptor subfamily 2, group F, member 1 (NR2F1)/COUP-TF1 serves as a barrier to early dissemination. NR2F1 expression was decreased in patient ductal carcinoma in situ (DCIS) samples. High-resolution intravital imaging of HER2+ early-stage cancer cells revealed that loss of function of NR2F1 increased in vivo dissemination and was accompanied by decreased E-cadherin expression, activation of wingless-type MMTV integration site family, member 1 (WNT)-dependent β-catenin signaling, disorganized laminin 5 deposition, and increased expression of epithelial–mesenchymal transition (EMT) genes such as twist basic helix-loop-helix transcription factor 1 (TWIST1), zinc finger E-box binding homeobox 1 (ZEB1), and paired related homeobox 1 (PRRX1). Furthermore, downregulation of NR2F1 promoted a hybrid luminal/basal phenotype. NR2F1 expression was positively regulated by p38α signaling and repressed by HER2 and WNT4 pathways. Finally, early cancer cells with NR2F1LOW/PRRX1HIGH staining were observed in DCIS samples. Together, these findings reveal the existence of an inhibitory mechanism of dissemination regulated by NR2F1 in early-stage breast cancer cells.
Significance:
During early stages of breast cancer progression, HER2-mediated suppression of NR2F1 promotes dissemination by inducing EMT and a hybrid luminal/basal-like program.
Data from Quantification of T- and B-cell Immune Receptor Distribution Diversity Characterizes Immune Cell Infiltration and Lymphocyte Heterogeneity in Clear Cell Renal Cell Carcinoma
Authors: Ferrall-Fairbanks Meghan C. , Chakiryan Nicholas H. , Chobrutskiy Boris I. , Kim Youngchul , Teer Jamie K. , Berglund Anders , Mulé James J. , Fournier Michelle , Siegel Erin M. , Dhillon Jasreman , Falasiri Seyed Shayan A. , Arturo Juan F. , Katende Esther N. , Blanck George , Manley Brandon J. , Altrock Philipp M.
Published: March 2024

Abstract
Immune-modulating systemic therapies are often used to treat advanced cancer such as metastatic clear cell renal cell carcinoma (ccRCC). Used alone, sequence-based biomarkers neither accurately capture patient dynamics nor the tumor immune microenvironment. To better understand the tumor ecology of this immune microenvironment, we quantified tumor infiltration across three distinct ccRCC patient tumor cohorts using complementarity determining region-3 (CDR3) sequence recovery counts in tumor-infiltrating lymphocytes and a generalized diversity index (GDI) for CDR3 sequence distributions. GDI can be understood as a curve over a continuum of diversity scales that allows sensitive characterization of distributions to capture sample richness, evenness, and subsampling uncertainty, along with other important metrics that characterize tumor heterogeneity. For example, richness quantified the total unique sequence count, while evenness quantified similarities across sequence frequencies. Significant differences in receptor sequence diversity across gender and race revealed that patients with larger and more clinically aggressive tumors had increased richness of recovered tumoral CDR3 sequences, specifically in those from T-cell receptor alpha and B-cell immunoglobulin lambda light chain. The GDI inflection point (IP) allowed for a novel and robust measure of distribution evenness. High IP values were associated with improved overall survival, suggesting that normal-like sequence distributions lead to better outcomes. These results propose a new quantitative tool that can be used to better characterize patient-specific differences related to immune cell infiltration, and to identify unique characteristics of tumor-infiltrating lymphocyte heterogeneity in ccRCC and other malignancies.
Significance:
Assessment of tumor-infiltrating T-cell and B-cell diversity in renal cell carcinoma advances the understanding of tumor-immune system interactions, linking tumor immune ecology with tumor burden, aggressiveness, and patient survival.

See related commentary by Krishna and Hakimi, p. 764
Data from Neoadjuvant In Situ Immunomodulation Enhances Systemic Antitumor Immunity against Highly Metastatic Tumors
Authors: Oba Takaaki , Kajihara Ryutaro , Yokoi Toshihiro , Repasky Elizabeth A. , Ito Fumito
Published: March 2024

Abstract
Neoadjuvant immunotherapy, given before surgical resection, is a promising approach to develop systemic antitumor immunity for the treatment of high-risk resectable disease. Here, using syngeneic and orthotopic mouse models of triple-negative breast cancer, we have tested the hypothesis that generation of tumor-specific T-cell responses by induction and activation of tumor-residing Batf3-dependent conventional type 1 dendritic cells (cDC1) before resection improves control of distant metastatic disease and survival. Mice bearing highly metastatic orthotopic tumors were treated with a combinatorial in situ immunomodulation (ISIM) regimen comprised of intratumoral administration of Flt3L, local radiotherapy, and in situ TLR3/CD40 stimulations, followed by surgical resection. Neoadjuvant ISIM (neo-ISIM) generated tumor-specific CD8+ T cells that infiltrated into distant nonirradiated metastatic sites, which delayed the progression of lung metastases and improved survival after the resection of primary tumors. The efficacy of neo-ISIM was dependent on de novo adaptive T-cell immunity elicited by Batf3-dependent dendritic cells and was enhanced by increasing dose and fractionation of radiotherapy, and early surgical resection after the completion of neo-ISIM. Importantly, neo-ISIM synergized with programmed cell death protein-1 ligand-1 (PD-L1) blockade to improve control of distant metastases and prolong survival, while removal of tumor-draining lymph nodes abrogated the antimetastatic efficacy of neo-ISIM. Our findings illustrate the therapeutic potential of neoadjuvant multimodal intralesional therapy for the treatment of resectable tumors with high risk of relapse.
Significance:
Neoadjuvant induction and activation of cDC1s in primary tumors enhances systemic antitumor immunity, suppresses metastatic progression, improves survival, and synergizes with anti–PD-L1 therapy.