bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Tumor-Derived Pericytes Driven by EGFR Mutations Govern the Vascular and Immune Microenvironment of Gliomas
Authors: Segura-Collar Berta , Garranzo-Asensio María , Herranz Beatriz , Hernández-SanMiguel Esther , Cejalvo Teresa , Casas Bárbara S. , Matheu Ander , Pérez-Núñez Ángel , Sepúlveda-Sánchez Juan Manuel , Hernández-Laín Aurelio , Palma Verónica , Gargini Ricardo , Sánchez-Gómez Pilar
Published: March 2023

Abstract
The extraordinary plasticity of glioma cells allows them to contribute to different cellular compartments in tumor vessels, reinforcing the vascular architecture. It was recently revealed that targeting glioma-derived pericytes, which represent a big percentage of the mural cell population in aggressive tumors, increases the permeability of the vessels and improves the efficiency of chemotherapy. However, the molecular determinants of this transdifferentiation process have not been elucidated. Here we show that mutations in EGFR stimulate the capacity of glioma cells to function as pericytes in a BMX- (bone marrow and X-linked) and SOX9-dependent manner. Subsequent activation of platelet-derived growth factor receptor beta in the vessel walls of EGFR-mutant gliomas stabilized the vasculature and facilitated the recruitment of immune cells. These changes in the tumor microenvironment conferred a growth advantage to the tumors but also rendered them sensitive to pericyte-targeting molecules such as ibrutinib or sunitinib. In the absence of EGFR mutations, high-grade gliomas were enriched in blood vessels, but showed a highly disrupted blood–brain barrier due to the decreased BMX/SOX9 activation and pericyte coverage, which led to poor oxygenation, necrosis, and hypoxia. Overall, these findings identify EGFR mutations as key regulators of the glioma-to-pericyte transdifferentiation, highlighting the intricate relationship between the tumor cells and their vascular and immune milieu. Our results lay the foundations for a vascular-dependent stratification of gliomas and suggest different therapeutic vulnerabilities determined by the genetic status of EGFR.
Significance:
This study identifies the EGFR-related mechanisms that govern the capacity of glioma cells to transdifferentiate into pericytes, regulating the vascular and immune phenotypes of the tumors.
Data from Cancer-Associated Fibroblasts in Pancreatic Ductal Adenocarcinoma Determine Response to SLC7A11 Inhibition
Authors: Sharbeen George , McCarroll Joshua A. , Akerman Anouschka , Kopecky Chantal , Youkhana Janet , Kokkinos John , Holst Jeff , Boyer Cyrille , Erkan Mert , Goldstein David , Timpson Paul , Cox Thomas R. , Pereira Brooke A. , Chitty Jessica L. , Fey Sigrid K. , Najumudeen Arafath K. , Campbell Andrew D. , Sansom Owen J. , Ignacio Rosa Mistica C. , Naim Stephanie , Liu Jie , Russia Nelson , Lee Julia , Chou Angela , Johns Amber , Gill Anthony J. , Gonzales-Aloy Estrella , Gebski Val , Guan Yi Fang , Pajic Marina , Turner Nigel , Apte Minoti V. , Davis Thomas P. , Morton Jennifer P. , Haghighi Koroush S. , Kasparian Jorjina , McLean Benjamin J. , Setargew Yordanos F. , Phillips Phoebe A.
Published: March 2023

Abstract
Cancer-associated fibroblasts (CAF) are major contributors to pancreatic ductal adenocarcinoma (PDAC) progression through protumor signaling and the generation of fibrosis, the latter of which creates a physical barrier to drugs. CAF inhibition is thus an ideal component of any therapeutic approach for PDAC. SLC7A11 is a cystine transporter that has been identified as a potential therapeutic target in PDAC cells. However, no prior study has evaluated the role of SLC7A11 in PDAC tumor stroma and its prognostic significance. Here we show that high expression of SLC7A11 in human PDAC tumor stroma, but not tumor cells, is independently prognostic of poorer overall survival. Orthogonal approaches showed that PDAC-derived CAFs are highly dependent on SLC7A11 for cystine uptake and glutathione synthesis and that SLC7A11 inhibition significantly decreases CAF proliferation, reduces their resistance to oxidative stress, and inhibits their ability to remodel collagen and support PDAC cell growth. Importantly, specific ablation of SLC7A11 from the tumor compartment of transgenic mouse PDAC tumors did not affect tumor growth, suggesting the stroma can substantially influence PDAC tumor response to SLC7A11 inhibition. In a mouse orthotopic PDAC model utilizing human PDAC cells and CAFs, stable knockdown of SLC7A11 was required in both cell types to reduce tumor growth, metastatic spread, and intratumoral fibrosis, demonstrating the importance of targeting SLC7A11 in both compartments. Finally, treatment with a nanoparticle gene-silencing drug against SLC7A11, developed by our laboratory, reduced PDAC tumor growth, incidence of metastases, CAF activation, and fibrosis in orthotopic PDAC tumors. Overall, these findings identify an important role of SLC7A11 in PDAC-derived CAFs in supporting tumor growth.
Significance:
This study demonstrates that SLC7A11 in PDAC stromal cells is important for the tumor-promoting activity of CAFs and validates a clinically translatable nanomedicine for therapeutic SLC7A11 inhibition in PDAC.
Data from Multiple Roles of IL6 in Hepatic Injury, Steatosis, and Senescence Aggregate to Suppress Tumorigenesis
Authors: Shriki Anat , Lanton Tali , Sonnenblick Amir , Levkovitch-Siany Orr , Eidelshtein Dana , Abramovitch Rinat , Rosenberg Nofar , Pappo Orit , Elgavish Sharona , Nevo Yuval , Safadi Rifaat , Peled Amnon , Rose-John Stefan , Galun Eithan , Axelrod Jonathan H.
Published: March 2023

Abstract
Hepatocellular carcinoma (HCC) typically develops on a background of chronic hepatitis for which the proinflammatory cytokine IL6 is conventionally considered a crucial driving factor. Paradoxically, IL6 also acts as a hepatoprotective factor in chronic liver injury. Here we used the multidrug-resistant gene 2 knockout (Mdr2−/−) mouse model to elucidate potential roles of IL6 in chronic hepatitis–associated liver cancer. Long-term analysis of three separate IL6/Stat3 signaling–deficient Mdr2−/− strains revealed aggravated liver injury with increased dysplastic nodule formation and significantly accelerated tumorigenesis in all strains. Tumorigenesis in the IL6/Stat3-perturbed models was strongly associated with enhanced macrophage accumulation and hepatosteatosis, phenotypes of nonalcoholic steatohepatitis (NASH), as well as with significant reductions in senescence and the senescence-associated secretory phenotype (SASP) accompanied by increased hepatocyte proliferation. These findings reveal a crucial suppressive role for IL6/Stat3 signaling in chronic hepatitis–associated hepatocarcinogenesis by impeding protumorigenic NASH-associated phenotypes and by reinforcing the antitumorigenic effects of the SASP.
Significance:
These findings describe a context-dependent role of IL6 signaling in hepatocarcinogenesis and predict that increased IL6-neutralizing sgp130 levels in some patients with NASH may herald early HCC development.

See related commentary by Huynh and Ernst, p. 4671
Data from Bladder Tumor Subtype Commitment Occurs in Carcinoma In Situ Driven by Key Signaling Pathways Including ECM Remodeling
Authors: Wullweber Adrian , Strick Reiner , Lange Fabienne , Sikic Danijel , Taubert Helge , Wach Sven , Wullich Bernd , Bertz Simone , Weyerer Veronika , Stoehr Robert , Breyer Johannes , Burger Maximilian , Hartmann Arndt , Strissel Pamela L. , Eckstein Markus
Published: March 2023

Abstract
Basal and luminal subtypes of invasive bladder tumors have significant prognostic and predictive impacts for patients. However, it remains unclear whether tumor subtype commitment occurs in noninvasive urothelial lesions or in carcinoma in situ (CIS) and which gene pathways are important for bladder tumor progression. To understand the timing of this commitment, we used gene expression and protein analysis to create a global overview of 36 separate tissues excised from a whole bladder encompassing urothelium, noninvasive urothelial lesions, CIS, and invasive carcinomas. Additionally investigated were matched CIS, noninvasive urothelial lesions, and muscle-invasive bladder cancers (MIBC) from 22 patients. The final stage of subtype commitment to either a luminal or basal MIBC occurred at the CIS transition. For all tissues combined, hierarchical clustering of subtype gene expression revealed three subtypes: “luminal,” “basal,” and a “luminal p53-/extracellular matrix (ECM)-like” phenotype of ECM-related genes enriched in tumor-associated urothelium, noninvasive urothelial lesions, and CIS, but rarely invasive, carcinomas. A separate cohort of normal urothelium from noncancer patients showed significantly lower expression of ECM-related genes compared with tumor-associated urothelium, noninvasive urothelial lesions, and CIS. A PanCancer Progression Panel of 681 genes unveiled pathways specific for the luminal p53-/ECM-like cluster, for example, ECM remodeling, angiogenesis, epithelial-to-mesenchymal transition, cellular discohesion, cell motility involved in tumor progression, and cell proliferation and oncogenic ERBB2/ERBB3 signaling for invasive carcinomas. In conclusion, this study provides insights into bladder cancer subtype commitment and associated signaling pathways, which could help predict therapy response and enhance our understanding of therapy resistance.
Significance:
This study demonstrates that CIS is the stage of commitment for determining MIBC tumor subtype, which is relevant for patient prognosis and therapy response.
Data from Circulating Small Extracellular Vesicles Activate TYRO3 to Drive Cancer Metastasis and Chemoresistance
Authors: Park Miso , Kim Ji Won , Kim Kyu Min , Kang Seungmin , Kim Wankyu , Kim Jin-Ki , Cho Youngnam , Lee Hyungjae , Baek Moon Chang , Bae Ju-Hyun , Lee Seung Hyun , Jeong Sung Baek , Lim Sung Chul , Jun Dae Won , Cho Sung Yun , Kim Yeonji , Choi Yong June , Kang Keon Wook
Published: March 2023

Abstract
Extracellular vesicles (EV) in the tumor microenvironment have emerged as crucial mediators that promote proliferation, metastasis, and chemoresistance. However, the role of circulating small EVs (csEV) in cancer progression remains poorly understood. In this study, we report that csEV facilitate cancer progression and determine its molecular mechanism. csEVs strongly promoted the migration of cancer cells via interaction with phosphatidylserine of csEVs. Among the three TAM receptors, TYRO3, AXL, and MerTK, TYRO3 mainly interacted with csEVs. csEV-mediated TYRO3 activation promoted migration and metastasis via the epithelial–mesenchymal transition and stimulation of RhoA in invasive cancer cells. Additionally, csEV–TYRO3 interaction induced YAP activation, which led to increased cell proliferation and chemoresistance. Combination treatment with gefitinib and KRCT-6j, a selective TYRO3 inhibitor, significantly reduced tumor volume in xenografts implanted with gefitinib-resistant non–small cell lung cancer cells. The results of this study show that TYRO3 activation by csEVs facilitates cancer cell migration and chemoresistance by activation of RhoA or YAP, indicating that the csEV/TYRO3 interaction may serve as a potential therapeutic target for aggressive cancers in the clinic.
Significance:
These findings demonstrate that circulating extracellular vesicles are a novel driver in migration and survival of aggressive cancer cells via TYRO3 activation.
Data from Transient Competitive Inhibition Bypasses the Binding Site Barrier to Improve Tumor Penetration of Trastuzumab and Enhance T-DM1 Efficacy
Authors: Bordeau Brandon M. , Yang Yujie , Balthasar Joseph P.
Published: March 2023

Abstract
Poor penetration of mAbs in solid tumors is explained, in part, by the binding site barrier hypothesis. Following extravasation, mAbs rapidly bind cellular antigens, leading to the observation that, at subsaturating doses, therapeutic antibody in solid tumors localizes around tumor vasculature. Here we report a unique strategy to overcome the binding site barrier through transient competitive inhibition of antibody–antigen binding. The anti-trastuzumab single domain antibody 1HE was identified through in vitro binding assays as a model inhibitor. Coadministration of 1HE did not alter the plasma pharmacokinetics of trastuzumab or ado-trastuzumab emtansine (T-DM1) in vivo. Administration of 1HE alone was rapidly eliminated with a terminal plasma half-life of 1.2 hours, while coadministrations of 1HE with trastuzumab had a terminal half-life of 56 hours. In mice harboring SKOV3 xenografts, coadministration of 1HE with trastuzumab led to significant increases in both penetration of trastuzumab from vasculature and the percentage of tumor area that stained positive for trastuzumab. 1HE coadministered with a single dose of T-DM1 to NCI-N87 xenograft–bearing mice significantly enhanced T-DM1 efficacy, increasing median survival. These results support the hypothesis that transient competitive inhibition can improve therapeutic antibody distribution in solid tumors and enhance antibody efficacy.
Significance:
This study describes the development of a transient competitive inhibition strategy that enhances the tumor penetration and efficacy of anticancer antibodies.

See related commentary by van Dongen, p. 3956
Data from RNA Splicing Factors SRRM3 and SRRM4 Distinguish Molecular Phenotypes of Castration-Resistant Neuroendocrine Prostate Cancer
Authors: Labrecque Mark P. , Brown Lisha G. , Coleman Ilsa M. , Lakely Bryce , Brady Nicholas J. , Lee John K. , Nguyen Holly M. , Li Dapei , Hanratty Brian , Haffner Michael C. , Rickman David S. , True Lawrence D. , Lin Daniel W. , Lam Hung-Ming , Alumkal Joshi J. , Corey Eva , Nelson Peter S. , Morrissey Colm
Published: March 2023

Abstract
Neuroendocrine (NE) differentiation in metastatic castration-resistant prostate cancer (mCRPC) is an increasingly common clinical feature arising from cellular plasticity. We recently characterized two mCRPC phenotypes with NE features: androgen receptor (AR)-positive NE-positive amphicrine prostate cancer (AMPC) and AR-negative small cell or neuroendocrine prostate cancer (SCNPC). Here, we interrogated the regulation of RE1-silencing transcription factor (REST), a transcriptional repressor of neuronal genes, and elucidated molecular programs driving AMPC and SCNPC biology. Analysis of prostate cancer cell lines, mCRPC specimens, and LuCaP patient-derived xenograft models detected alternative splicing of REST to REST4 and attenuated REST repressor activity in AMPC and SCNPC. The REST locus was also hypermethylated and REST expression was reduced in SCNPC. While serine/arginine repetitive matrix protein 4 (SRRM4) was previously implicated in alternative splicing of REST in mCRPC, we detected SRRM3 expression in REST4-positive, SRRM4-negative AMPC, and SCNPC. In CRPC cell lines, SRRM3 induced alternative splicing of REST to REST4 and exacerbated the expression of REST-repressed genes. Furthermore, SRRM3 and SRRM4 expression defined molecular subsets of AMPC and SCNPC across species and tumor types. Two AMPC phenotypes and three SCNPC phenotypes were characterized, denoted either by REST attenuation and ASCL1 activity or by progressive activation of neuronal transcription factor programs, respectively. These results nominate SRRM3 as the principal REST splicing factor expressed in early NE differentiation and provide a framework to molecularly classify diverse NE phenotypes in mCRPC.
Significance:
This study identifies SRRM3 as a key inducer of cellular plasticity in prostate cancer with neuroendocrine features and delineates distinct neuroendocrine phenotypes to inform therapeutic development and precision medicine applications.
Data from Quantitative Analysis of Tyrosine Phosphorylation from FFPE Tissues Reveals Patient-Specific Signaling Networks
Authors: Kohale Ishwar N. , Burgenske Danielle M. , Mladek Ann C. , Bakken Katrina K. , Kuang Jenevieve , Boughey Judy C. , Wang Liewei , Carter Jodi M. , Haura Eric B. , Goetz Matthew P. , Sarkaria Jann N. , White Forest M.
Published: March 2023

Abstract
Human tissue samples commonly preserved as formalin-fixed paraffin-embedded (FFPE) tissues after diagnostic or surgical procedures in the clinic represent an invaluable source of clinical specimens for in-depth characterization of signaling networks to assess therapeutic options. Tyrosine phosphorylation (pTyr) plays a fundamental role in cellular processes and is commonly dysregulated in cancer but has not been studied to date in FFPE samples. In addition, pTyr analysis that may otherwise inform therapeutic interventions for patients has been limited by the requirement for large amounts of frozen tissue. Here we describe a method for highly sensitive, quantitative analysis of pTyr signaling networks, with hundreds of sites quantified from one to two 10-μm sections of FFPE tissue specimens. A combination of optimized magnetic bead–based sample processing, optimized pTyr enrichment strategies, and tandem mass tag multiplexing enabled in-depth coverage of pTyr signaling networks from small amounts of input material. Phosphotyrosine profiles of flash-frozen and FFPE tissues derived from the same tumors suggested that FFPE tissues preserve pTyr signaling characteristics in patient-derived xenografts and archived clinical specimens. pTyr analysis of FFPE tissue sections from breast cancer tumors as well as lung cancer tumors highlighted patient-specific oncogenic driving kinases, indicating potential targeted therapies for each patient. These data suggest the capability for direct translational insight from pTyr analysis of small amounts of FFPE tumor tissue specimens.
Significance:
This study reports a highly sensitive method utilizing FFPE tissues to identify dysregulated signaling networks in patient tumors, opening the door for direct translational insights from FFPE tumor tissue banks in hospitals.
Data from Phenotypic Heterogeneity and Metastasis of Breast Cancer Cells
Authors: Hapach Lauren A. , Carey Shawn P. , Schwager Samantha C. , Taufalele Paul V. , Wang Wenjun , Mosier Jenna A. , Ortiz-Otero Nerymar , McArdle Tanner J. , Goldblatt Zachary E. , Lampi Marsha C. , Bordeleau Francois , Marshall Jocelyn R. , Richardson Isaac M. , Li Jiahe , King Michael R. , Reinhart-King Cynthia A.
Published: March 2023

Abstract
Although intratumoral genomic heterogeneity can impede cancer research and treatment, less is known about the effects of phenotypic heterogeneities. To investigate the role of cell migration heterogeneities in metastasis, we phenotypically sorted metastatic breast cancer cells into two subpopulations based on migration ability. Although migration is typically considered to be associated with metastasis, when injected orthotopically in vivo, the weakly migratory subpopulation metastasized significantly more than the highly migratory subpopulation. To investigate the mechanism behind this observation, both subpopulations were assessed at each stage of the metastatic cascade, including dissemination from the primary tumor, survival in the circulation, extravasation, and colonization. Although both subpopulations performed each step successfully, weakly migratory cells presented as circulating tumor cell (CTC) clusters in the circulation, suggesting clustering as one potential mechanism behind the increased metastasis of weakly migratory cells. RNA sequencing revealed weakly migratory subpopulations to be more epithelial and highly migratory subpopulations to be more mesenchymal. Depletion of E-cadherin expression from weakly migratory cells abrogated metastasis. Conversely, induction of E-cadherin expression in highly migratory cells increased metastasis. Clinical patient data and blood samples showed that CTC clustering and E-cadherin expression are both associated with worsened patient outcome. This study demonstrates that deconvolving phenotypic heterogeneities can reveal fundamental insights into metastatic progression. More specifically, these results indicate that migratory ability does not necessarily correlate with metastatic potential and that E-cadherin promotes metastasis in phenotypically sorted breast cancer cell subpopulations by enabling CTC clustering.
Significance:
This study employs phenotypic cell sorting for migration to reveal a weakly migratory, highly metastatic breast cancer cell subpopulation regulated by E-cadherin, highlighting the dichotomy between cancer cell migration and metastasis.
Data from Germline and Somatic Genetic Variants in the p53 Pathway Interact to Affect Cancer Risk, Progression, and Drug Response
Authors: Zhang Ping , Kitchen-Smith Isaac , Xiong Lingyun , Stracquadanio Giovanni , Brown Katherine , Richter Philipp H. , Wallace Marsha D. , Bond Elisabeth , Sahgal Natasha , Moore Samantha , Nornes Svanhild , De Val Sarah , Surakhy Mirvat , Sims David , Wang Xuting , Bell Douglas A. , Zeron-Medina Jorge , Jiang Yanyan , Ryan Anderson J. , Selfe Joanna L. , Shipley Janet , Kar Siddhartha , Pharoah Paul D. , Loveday Chey , Jansen Rick , Grochola Lukasz F. , Palles Claire , Protheroe Andrew , Millar Val , Ebner Daniel V. , Pagadala Meghana , Blagden Sarah P. , Maughan Timothy S. , Domingo Enric , Tomlinson Ian , Turnbull Clare , Carter Hannah , Bond Gareth L.
Published: March 2023

Abstract
Insights into oncogenesis derived from cancer susceptibility loci (SNP) hold the potential to facilitate better cancer management and treatment through precision oncology. However, therapeutic insights have thus far been limited by our current lack of understanding regarding both interactions of these loci with somatic cancer driver mutations and their influence on tumorigenesis. For example, although both germline and somatic genetic variation to the p53 tumor suppressor pathway are known to promote tumorigenesis, little is known about the extent to which such variants cooperate to alter pathway activity. Here we hypothesize that cancer risk-associated germline variants interact with somatic TP53 mutational status to modify cancer risk, progression, and response to therapy. Focusing on a cancer risk SNP (rs78378222) with a well-documented ability to directly influence p53 activity as well as integration of germline datasets relating to cancer susceptibility with tumor data capturing somatically-acquired genetic variation provided supportive evidence for this hypothesis. Integration of germline and somatic genetic data enabled identification of a novel entry point for therapeutic manipulation of p53 activities. A cluster of cancer risk SNPs resulted in increased expression of prosurvival p53 target gene KITLG and attenuation of p53-mediated responses to genotoxic therapies, which were reversed by pharmacologic inhibition of the prosurvival c-KIT signal. Together, our results offer evidence of how cancer susceptibility SNPs can interact with cancer driver genes to affect cancer progression and identify novel combinatorial therapies.
Significance:
These results offer evidence of how cancer susceptibility SNPs can interact with cancer driver genes to affect cancer progression and present novel therapeutic targets.
Data from Serine-Threonine Kinase TAO3-Mediated Trafficking of Endosomes Containing the Invadopodia Scaffold TKS5α Promotes Cancer Invasion and Tumor Growth
Authors: Iizuka Shinji , Quintavalle Manuela , Navarro Jose C. , Gribbin Kyle P. , Ardecky Robert J. , Abelman Matthew M. , Ma Chen-Ting , Sergienko Eduard , Zeng Fu-Yue , Pass Ian , Thomas George V. , McWeeney Shannon K. , Hassig Christian A. , Pinkerton Anthony B. , Courtneidge Sara A.
Published: March 2023

Abstract
Invadopodia are actin-based proteolytic membrane protrusions required for invasive behavior and tumor growth. In this study, we used our high-content screening assay to identify kinases whose activity affects invadopodia formation. Among the top hits selected for further analysis was TAO3, an STE20-like kinase of the GCK subfamily. TAO3 was overexpressed in many human cancers and regulated invadopodia formation in melanoma, breast, and bladder cancers. Furthermore, TAO3 catalytic activity facilitated melanoma growth in three-dimensional matrices and in vivo. A novel, potent catalytic inhibitor of TAO3 was developed that inhibited invadopodia formation and function as well as tumor cell extravasation and growth. Treatment with this inhibitor demonstrated that TAO3 activity is required for endosomal trafficking of TKS5α, an obligate invadopodia scaffold protein. A phosphoproteomics screen for TAO3 substrates revealed the dynein subunit protein LIC2 as a relevant substrate. Knockdown of LIC2 or expression of a phosphomimetic form promoted invadopodia formation. Thus, TAO3 is a new therapeutic target with a distinct mechanism of action.
Significance:
An unbiased screening approach identifies TAO3 as a regulator of invadopodia formation and function, supporting clinical development of this class of target.
Data from The Transcription Factor SLUG Uncouples Pancreatic Cancer Progression from the RAF–MEK1/2–ERK1/2 Pathway
Authors: Bilal Faiz , Arenas Enrique J. , Pedersen Kim , Martínez-Sabadell Alex , Nabet Behnam , Guruceaga Elizabeth , Vicent Silvestre , Tabernero Josep , Macarulla Teresa , Arribas Joaquín
Published: March 2023

Abstract
Activating mutations in some isoforms of RAS or RAF are drivers of a substantial proportion of cancers. The main Raf effector, MEK1/2, can be targeted with several highly specific inhibitors. The clinical activity of these inhibitors seems to be mixed, showing efficacy against mutant BRAF-driven tumors but not KRAS-driven tumors, such as pancreatic adenocarcinomas. To improve our understanding of this context-dependent efficacy, we generated pancreatic cancer cells resistant to MEK1/2 inhibition, which were also resistant to KRAS and ERK1/2 inhibitors. Compared with parental cells, inhibitor-resistant cells showed several phenotypic changes including increased metastatic ability in vivo. The transcription factor SLUG, which is known to induce epithelial-to-mesenchymal transition, was identified as the key factor responsible for both resistance to MEK1/2 inhibition and increased metastasis. Slug, but not similar transcription factors, predicted poor prognosis of pancreatic cancer patients and induced the transition to a cellular phenotype in which cell-cycle progression becomes independent of the KRAS–RAF–MEK1/2–ERK1/2 pathway. SLUG was targeted using two independent strategies: (i) inhibition of the MEK5–ERK5 pathway, which is responsible for upregulation of SLUG upon MEK1/2 inhibition, and (ii) direct PROTAC-mediated degradation. Both strategies were efficacious in preclinical pancreatic cancer models, paving the path for the development of more effective therapies against pancreatic cancer.
Significance:
This study demonstrates that SLUG confers resistance to MEK1/2 inhibitors in pancreatic cancer by uncoupling tumor progression from KRAS–RAF–MEK1/2–ERK1/2 signaling, providing new therapeutic opportunities.
Data from Loss-of-Function Mutations in TRAF7 and KLF4 Cooperatively Activate RAS-Like GTPase Signaling and Promote Meningioma Development
Authors: Najm Paul , Zhao Peihua , Steklov Mikhail , Sewduth Raj Nayan , Baietti Maria Francesca , Pandolfi Silvia , Criem Nathan , Lechat Benoit , Maia Teresa Mendes , Van Haver Delphi , Corthout Nikky , Eyckerman Sven , Impens Francis , Sablina Anna A.
Published: March 2023

Abstract
Meningiomas are the most common benign brain tumors. Mutations of the E3 ubiquitin ligase TRAF7 occur in 25% of meningiomas and commonly cooccur with mutations in KLF4, yet the functional link between TRAF7 and KLF4 mutations remains unclear. By generating an in vitro meningioma model derived from primary meningeal cells, we elucidated the cooperative interactions that promote meningioma development. By integrating TRAF7-driven ubiquitinome and proteome alterations in meningeal cells and the TRAF7 interactome, we identified TRAF7 as a proteostatic regulator of RAS-related small GTPases. Meningioma-associated TRAF7 mutations disrupted either its catalytic activity or its interaction with RAS GTPases. TRAF7 loss in meningeal cells altered actin dynamics and promoted anchorage-independent growth by inducing CDC42 and RAS signaling. TRAF deficiency–driven activation of the RAS/MAPK pathway promoted KLF4-dependent transcription that led to upregulation of the tumor-suppressive Semaphorin pathway, a negative regulator of small GTPases. KLF4 loss of function disrupted this negative feedback loop and enhanced mutant TRAF7-mediated cell transformation. Overall, this study provides new mechanistic insights into meningioma development, which could lead to novel treatment strategies.
Significance:
The intricate molecular cross-talk between the ubiquitin ligase TRAF7 and the transcription factor KLF4 provides a first step toward the identification of new therapies for patients with meningioma.
Data from Targeting Epigenetic and Posttranscriptional Gene Regulation by PSF Impairs Hormone Therapy–Refractory Cancer Growth
Authors: Takayama Ken-ichi , Honma Teruki , Suzuki Takashi , Kondoh Yasumitsu , Osada Hiroyuki , Suzuki Yutaka , Yoshida Minoru , Inoue Satoshi
Published: March 2023

Abstract
RNA-binding protein PSF functions as an epigenetic modifier by interacting with long noncoding RNAs and the corepressor complex. PSF also promotes RNA splicing events to enhance oncogenic signals. In this study, we conducted an in vitro chemical array screen and identified multiple small molecules that interact with PSF. Several molecules inhibited RNA binding by PSF and decreased prostate cancer cell viability. Among these molecules and its derivatives was a promising molecule, No. 10–3 [7,8-dihydroxy-4-(4-methoxyphenyl)chromen-2-one], that was the most effective at blocking PSF RNA-binding ability and suppressing treatment-resistant prostate and breast cancer cell proliferation. Exposure to No. 10–3 inhibited PSF target gene expression at the mRNA level. Treatment with No. 10–3 reversed epigenetically repressed PSF downstream targets, such as cell-cycle inhibitors, at the transcriptional level. Chromatin immunoprecipitation sequencing in prostate cancer cells revealed that No. 10–3 enhances histone acetylation to induce expression of apoptosis as well as cell-cycle inhibitors. Furthermore, No. 10–3 exhibited antitumor efficacy in a hormone therapy–resistant prostate cancer xenograft mouse model, suppressing treatment-resistant tumor growth. Taken together, this study highlights the feasibility of targeting PSF-mediated epigenetic and RNA-splicing activities for the treatment of aggressive cancers.
Significance:
This study identifies small molecules that target PSF–RNA interactions and suppress hormone therapy–refractory cancer growth, suggesting the potential of targeting PSF-mediated gene regulation for cancer treatment.
Data from Inhibition of Jumonji Histone Demethylases Selectively Suppresses HER2+ Breast Leptomeningeal Carcinomatosis Growth via Inhibition of GMCSF Expression
Authors: Bhan Arunoday , Ansari Khairul I. , Chen Mike Y. , Jandial Rahul
Published: March 2023

Abstract
HER2+ breast leptomeningeal carcinomatosis (HER2+ LC) occurs when tumor cells spread to cerebrospinal fluid–containing leptomeninges surrounding the brain and spinal cord, a complication with a dire prognosis. HER2+ LC remains incurable, with few treatment options. Currently, much effort is devoted toward development of therapies that target mutations. However, targeting epigenetic or transcriptional states of HER2+ LC tumors might efficiently target HER2+ LC growth via inhibition of oncogenic signaling; this approach remains promising but is less explored. To test this possibility, we established primary HER2+ LC (Lepto) cell lines from nodular HER2+ LC tissues. These lines are phenotypically CD326+CD49f−, confirming that they are derived from HER2+ LC tumors, and express surface CD44+CD24−, a cancer stem cell (CSC) phenotype. Like CSCs, Lepto lines showed greater drug resistance and more aggressive behavior compared with other HER2+ breast cancer lines in vitro and in vivo. Interestingly, the three Lepto lines overexpressed Jumonji domain–containing histone lysine demethylases KDM4A/4C. Treatment with JIB04, a selective inhibitor of Jumonji demethylases, or genetic loss of function of KDM4A/4C induced apoptosis and cell-cycle arrest and reduced Lepto cell viability, tumorsphere formation, regrowth, and invasion in vitro. JIB04 treatment of patient-derived xenograft mouse models in vivo reduced HER2+ LC tumor growth and prolonged animal survival. Mechanistically, KDM4A/4C inhibition downregulated GMCSF expression and prevented GMCSF-dependent Lepto cell proliferation. Collectively, these results establish KDM4A/4C as a viable therapeutic target in HER2+ LC and spotlight the benefits of targeting the tumorigenic transcriptional network.
Significance:
HER2+ LC tumors overexpress KDM4A/4C and are sensitive to the Jumonji demethylase inhibitor JIB04, which reduces the viability of primary HER2+ LC cells and increases survival in mouse models.
Data from Allosteric Inhibition of HER2 by Moesin-Mimicking Compounds Targets HER2-Positive Cancers and Brain Metastases
Authors: Faure Camille , Djerbi-Bouillié Rym , Domingot Anaïs , Bouzinba-Segard Haniaa , Taouji Saïd , Saidi Yanis , Bernard Sandra , Carallis Floriane , Rothe-Walther Romy , Lenormand Jean-Luc , Chevet Eric , Bourdoulous Sandrine
Published: March 2023

Abstract
Therapies targeting the tyrosine kinase receptor HER2 have significantly improved survival of patients with HER2+ cancer. However, both de novo and acquired resistance remain a challenge, particularly in the brain metastatic setting. Here we report that, unlike other HER tyrosine kinase receptors, HER2 possesses a binding motif in its cytosolic juxtamembrane region that allows interaction with members of the Ezrin/Radixin/Moesin (ERM) family. Under physiologic conditions, this interaction controls the localization of HER2 in ERM-enriched domains and stabilizes HER2 in a catalytically repressed state. In HER2+ breast cancers, low expression of Moesin correlated with increased HER2 expression. Restoring expression of ERM proteins in HER2+ breast cancer cells was sufficient to revert HER2 activation and inhibit HER2-dependent proliferation. A high-throughput assay recapitulating the HER2–ERM interaction allowed for screening of about 1,500 approved drugs. From this screen, we found Zuclopenthixol, an antipsychotic drug that behaved as a Moesin-mimicking compound, because it directly binds the juxtamembrane region of HER2 and specifically inhibits HER2 activation in HER2+ cancers, as well as activation of oncogenic mutated and truncated forms of HER2. Zuclopenthixol efficiently inhibited HER2+ breast tumor progression in vitro and in vivo and, more importantly, showed significant activity on HER2+ brain tumor progression. Collectively, these data reveal a novel class of allosteric HER2 inhibitors, increasing the number of approaches to consider for intervention on HER2+ breast cancers and brain metastases.
Significance:
This study demonstrates the functional role of Moesin in maintaining HER2 in a catalytically repressed state and provides novel therapeutic approaches targeting HER2+ breast cancers and brain metastasis using Moesin-mimicking compounds.
Data from Cancer-Associated Fibroblasts Promote Aggressive Gastric Cancer Phenotypes via Heat Shock Factor 1–Mediated Secretion of Extracellular Vesicles
Authors: Grunberg Nil , Pevsner-Fischer Meirav , Goshen-Lago Tal , Diment Judith , Stein Yaniv , Lavon Hagar , Mayer Shimrit , Levi-Galibov Oshrat , Friedman Gil , Ofir-Birin Yifat , Syu Li-Jyun , Migliore Cristina , Shimoni Eyal , Stemmer Salomon M. , Brenner Baruch , Dlugosz Andrzej A. , Lyden David , Regev-Rudzki Neta , Ben-Aharon Irit , Scherz-Shouval Ruth
Published: March 2023

Abstract
Gastric cancer is the third most lethal cancer worldwide, and evaluation of the genomic status of gastric cancer cells has not translated into effective prognostic or therapeutic strategies. We therefore hypothesize that outcomes may depend on the tumor microenvironment (TME), in particular, cancer-associated fibroblasts (CAF). However, very little is known about the role of CAFs in gastric cancer. To address this, we mapped the transcriptional landscape of human gastric cancer stroma by microdissection and RNA sequencing of CAFs from patients with gastric cancer. A stromal gene signature was associated with poor disease outcome, and the transcription factor heat shock factor 1 (HSF1) regulated the signature. HSF1 upregulated inhibin subunit beta A and thrombospondin 2, which were secreted in CAF-derived extracellular vesicles to the TME to promote cancer. Together, our work provides the first transcriptional map of human gastric cancer stroma and highlights HSF1 and its transcriptional targets as potential diagnostic and therapeutic targets in the genomically stable tumor microenvironment.
Significance:
This study shows how HSF1 regulates a stromal transcriptional program associated with aggressive gastric cancer and identifies multiple proteins within this program as candidates for therapeutic intervention.
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 2023

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 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 2023

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 2023

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 A Spatial and Functional Interaction of a Heterotetramer Survivin–DNA-PKcs Complex in DNA Damage Response
Authors: Güllülü Ömer , Hehlgans Stephanie , Mayer Benjamin E. , Gößner Ines , Petraki Chrysi , Hoffmann Melanie , Dombrowsky Maximilian J. , Kunzmann Patrick , Hamacher Kay , Strebhardt Klaus , Fokas Emmanouil , Rödel Claus , Münch Christian , Rödel Franz
Published: March 2023

Abstract
Substantial evidence has shown that overexpression of the inhibitor of apoptosis protein (IAP) survivin in human tumors correlates significantly with treatment resistance and poor patient prognosis. Survivin serves as a radiation resistance factor that impacts the DNA damage response by interacting with DNA-dependent protein kinase (DNA-PKcs). However, the complexity, molecular determinants, and functional consequences of this interrelationship remain largely unknown. By applying coimmunoprecipitation and flow cytometry-based Förster resonance energy transfer assays, we demonstrated a direct involvement of the survivin baculovirus IAP repeat domain in the regulation of radiation survival and DNA repair. This survivin-mediated activity required an interaction of residues S20 and W67 with the phosphoinositide 3-kinase (PI3K) domain of DNA-PKcs. In silico molecular docking and dynamics simulation analyses, in vitro kinase assays, and large-scale mass spectrometry suggested a heterotetrameric survivin–DNA-PKcs complex that results in a conformational change within the DNA-PKcs PI3K domain. Overexpression of survivin resulted in enhanced PI3K enzymatic activity and detection of differentially abundant phosphopeptides and proteins implicated in the DNA damage response. The survivin–DNA-PKcs interaction altered the S/T-hydrophobic motif substrate specificity of DNA-PKcs with a predominant usage of S/T-P phosphorylation sites and an increase of DNA-PKcs substrates including Foxo3. These data demonstrate that survivin differentially regulates DNA-PKcs-dependent radiation survival and DNA double-strand break repair via formation of a survivin–DNA-PKcs heterotetrameric complex.
Significance:
These findings provide insight into survivin-mediated regulation of DNA-PKcs kinase and broaden our knowledge of the impact of survivin in modulating the cellular radiation response.

See related commentary by Iliakis, p. 2270