bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Microenvironmental Remodeling as a Parameter and Prognostic Factor of Heterogeneous Leukemogenesis in Acute Myelogenous Leukemia
Authors: Kim Jin-A , Shim Jae-Seung , Lee Ga-Young , Yim Hyeon Woo , Kim Tae-Min , Kim Myungshin , Leem Sun-Hee , Lee Jong-Wook , Min Chang-Ki , Oh Il-Hoan
Published: March 2024

Abstract
Acute myelogenous leukemia (AML) is a heterogeneous disorder characterized by clonal proliferation of stem cell-like blasts in bone marrow (BM); however, their unique cellular interaction within the BM microenvironment and its functional significance remain unclear. Here, we assessed the BM microenvironment of AML patients and demonstrate that the leukemia stem cells induce a change in the transcriptional programming of the normal mesenchymal stromal cells (MSC). The modified leukemic niche alters the expressions of cross-talk molecules (i.e., CXCL12 and JAG1) in MSCs to provide a distinct cross-talk between normal and leukemia cells, selectively suppressing normal primitive hematopoietic cells while supporting leukemogenesis and chemoresistance. Of note, AML patients exhibited distinct heterogeneity in the alteration of mesenchymal stroma in BM. The distinct pattern of stromal changes in leukemic BM at initial diagnosis was associated with a heterogeneous posttreatment clinical course with respect to the maintenance of complete remission for 5 to 8 years and early or late relapse. Thus, remodeling of mesenchymal niche by leukemia cells is an intrinsic self-reinforcing process of leukemogenesis that can be a parameter for the heterogeneity in the clinical course of leukemia and hence serve as a potential prognostic factor. Cancer Res; 75(11); 2222–31. ©2015 AACR.
Data from Full-Length Semaphorin-3C Is an Inhibitor of Tumor Lymphangiogenesis and Metastasis
Authors: Mumblat Yelena , Kessler Ofra , Ilan Neta , Neufeld Gera
Published: March 2024

Abstract
Semaphorins play important regulatory roles in diverse processes such as axon guidance, angiogenesis, and immune responses. We find that semaphorin-3C (sema3C) induces the collapse of the cytoskeleton of lymphatic endothelial cells (LEC) in a neuropilin-2-, plexin-D1-, and plexin-A1–dependent manner, while most other semaphorins, including antiangiogenic semaphorins such as sema3A do not. Sema3C is cleaved, like other class-3 semaphorins, by furin-like pro-protein convertases (FPPC). Cleaved sema3C (p65-Sema3C) was unable to induce the collapse of the cytoskeleton of LEC. FPPC are strongly upregulated in tumor cells. In order to examine the effects of full-length sema3C on tumor progression, we therefore generated an active point mutated furin cleavage-resistant sema3C (FR-sema3C). FR-sema3C inhibited potently proliferation of LEC and to a lesser extent proliferation of human umbilical vein–derived endothelial cells. FR-sema3C also inhibited VEGF-C–induced phosphorylation of VEGFR-3, ERK1/2, and AKT. Expression of recombinant FR-sema3C in metastatic, triple-negative LM2-4 breast cancer cells did not affect their migration or proliferation in vitro. However, tumors derived from FR-sema3C–expressing LM2-4 cells implanted in mammary fat pads developed at a slower rate, contained a lower concentration of blood vessels and lymph vessels, and metastasized much less effectively to lymph nodes. Interestingly, p65-Sema3C, but not FR-sema3C, rendered A549 lung cancer cells resistant to serum deprivation, suggesting that previously reported protumorigenic activities of sema3C may be due to p65-Sema3C produced by tumor cells. Our observations suggest that FR-sema3C may be further developed into a novel antitumorigenic drug. Cancer Res; 75(11); 2177–86. ©2015 AACR.
Data from STAT3 Blockade Inhibits Radiation-Induced Malignant Progression in Glioma
Authors: Lau Jasmine , Ilkhanizadeh Shirin , Wang Susan , Miroshnikova Yekaterina A. , Salvatierra Nicolas A. , Wong Robyn A. , Schmidt Christin , Weaver Valerie M. , Weiss William A. , Persson Anders I.
Published: March 2024

Abstract
High grade gliomas (HGG) are classified into four subgroups based on transcriptional signatures and phenotypic characteristics. In particular, the proneural-to-mesenchymal transition (PMT) is associated with increased malignancy, poor prognosis, and disease recurrence, but the underlying causes of PMT are still unclear. In this study, we investigated whether radiotherapy promotes PMT using a genetically engineered mouse model of proneural HGG. We found that cranial ionizing radiation induced robust and durable PMT in tumors. Additionally, we isolated primary proneural HGG cells from mouse and human tumors and demonstrate that radiation induced a sustained cell-intrinsic mesenchymal transition associated with increased invasiveness and resistance to the alkylating agent temozolomide. Expectedly, irradiation-induced PMT was also associated with activation of the STAT3 transcription factor, and the combination of STAT3 blockade using JAK2 inhibitors with radiation abrogated the mesenchymal transition and extended survival of mice. Taken together, our data suggest that clinical JAK2 inhibitors should be tested in conjunction with radiation in patients with proneural HGG as a new strategy for blocking the emergence of therapy-resistant mesenchymal tumors at relapse. Cancer Res; 75(20); 4302–11. ©2015 AACR.
Data from Carbonic Anhydrase Activity Monitored In Vivo by Hyperpolarized 13C-Magnetic Resonance Spectroscopy Demonstrates Its Importance for pH Regulation in Tumors
Authors: Gallagher Ferdia A. , Sladen Helen , Kettunen Mikko I. , Serrao Eva M. , Rodrigues Tiago B. , Wright Alan , Gill Andrew B. , McGuire Sarah , Booth Thomas C. , Boren Joan , McIntyre Alan , Miller Jodi L. , Lee Shen-Han , Honess Davina , Day Sam E. , Hu De-En , Howat William J. , Harris Adrian L. , Brindle Kevin M.
Published: March 2024

Abstract
Carbonic anhydrase buffers tissue pH by catalyzing the rapid interconversion of carbon dioxide (CO2) and bicarbonate (HCO3−). We assessed the functional activity of CAIX in two colorectal tumor models, expressing different levels of the enzyme, by measuring the rate of exchange of hyperpolarized 13C label between bicarbonate (H13CO3−) and carbon dioxide (13CO2), following injection of hyperpolarized H13CO3−, using 13C-magnetic resonance spectroscopy (13C-MRS) magnetization transfer measurements. 31P-MRS measurements of the chemical shift of the pH probe, 3-aminopropylphosphonate, and 13C-MRS measurements of the H13CO3−/13CO2 peak intensity ratio showed that CAIX overexpression lowered extracellular pH in these tumors. However, the 13C measurements overestimated pH due to incomplete equilibration of the hyperpolarized 13C label between the H13CO3− and 13CO2 pools. Paradoxically, tumors overexpressing CAIX showed lower enzyme activity using magnetization transfer measurements, which can be explained by the more acidic extracellular pH in these tumors and the decreased activity of the enzyme at low pH. This explanation was confirmed by administration of bicarbonate in the drinking water, which elevated tumor extracellular pH and restored enzyme activity to control levels. These results suggest that CAIX expression is increased in hypoxia to compensate for the decrease in its activity produced by a low extracellular pH and supports the hypothesis that a major function of CAIX is to lower the extracellular pH. Cancer Res; 75(19); 4109–18. ©2015 AACR.
Data from Tropomodulin 1 Expression Driven by NF-κB Enhances Breast Cancer Growth
Authors: Ito-Kureha Taku , Koshikawa Naohiko , Yamamoto Mizuki , Semba Kentaro , Yamaguchi Noritaka , Yamamoto Tadashi , Seiki Motoharu , Inoue Jun-ichiro
Published: March 2024

Abstract
Triple-negative breast cancers (TNBC), which include the basal-like and claudin-low disease subtypes, are aggressive malignancies for which effective therapeutic targets are lacking. NF-κB activation has an established role in breast malignancy, and it is higher in TNBC than other breast cancer subtypes. On this basis, we hypothesized that proteins derived from NF-κB target genes might be molecular targets for TNBC therapy. In this study, we conducted a microarray-based screen for novel NF-κB–inducible proteins as candidate therapeutic targets, identifying tropomodulin 1 (TMOD1) as a lead candidate. TMOD1 expression was regulated directly by NF-κB and was significantly higher in TNBC than other breast cancer subtypes. TMOD1 elevation is associated with enhanced tumor growth in a mouse tumor xenograft model and in a 3D type I collagen culture. TMOD1-dependent tumor growth was correlated with MMP13 induction, which was mediated by TMOD1-dependent accumulation of β-catenin. Overall, our study highlighted a novel TMOD1-mediated link between NF-κB activation and MMP13 induction, which accounts in part for the NF-κB–dependent malignant phenotype of TNBC. Cancer Res; 75(1); 62–72. ©2014 AACR.
Data from PML/RARα-Regulated miR-181a/b Cluster Targets the Tumor Suppressor RASSF1A in Acute Promyelocytic Leukemia
Authors: Bräuer-Hartmann Daniela , Hartmann Jens-Uwe , Wurm Alexander Arthur , Gerloff Dennis , Katzerke Christiane , Verga Falzacappa Maria Vittoria , Pelicci Pier Giuseppe , Müller-Tidow Carsten , Tenen Daniel G. , Niederwieser Dietger , Behre Gerhard
Published: March 2024

Abstract
In acute promyelocytic leukemia (APL), all-trans retinoic acid (ATRA) treatment induces granulocytic maturation and complete remission of leukemia. microRNAs are known to be critical players in the formation of the leukemic phenotype. In this study, we report downregulation of the miR-181a/b gene cluster in APL blasts and NB4 leukemia cells upon ATRA treatment as a key event in the drug response. We found that miR-181a/b expression was activated by the PML/RARα oncogene in cells and transgenic knock-in mice, an observation confirmed and extended by evidence of enhanced expression of miR-181a/b in APL patient specimens. RNA interference (RNAi)-mediated attenuation of miR-181a/b expression in NB4 cells was sufficient to reduce colony-forming capacity, proliferation, and survival. Mechanistic investigations revealed that miR-181a/b targets the ATRA-regulated tumor suppressor gene RASSF1A by direct binding to its 3′-untranslated region. Enforced expression of miR-181a/b or RNAi-mediated attenuation of RASSF1A inhibited ATRA-induced granulocytic differentiation via regulation of the cell-cycle regulator cyclin D1. Conversely, RASSF1A overexpression enhanced apoptosis. Finally, RASSF1A levels were reduced in PML/RARα knock-in mice and APL patient samples. Taken together, our results define miR-181a and miR-181b as oncomiRs in PML/RARα-associated APL, and they reveal RASSF1A as a pivotal element in the granulocytic differentiation program induced by ATRA in APL. Cancer Res; 75(16); 3411–24. ©2015 AACR.
Data from Neuroendocrine Transdifferentiation in Human Prostate Cancer Cells: An Integrated Approach
Authors: Cerasuolo Marianna , Paris Debora , Iannotti Fabio A. , Melck Dominique , Verde Roberta , Mazzarella Enrico , Motta Andrea , Ligresti Alessia
Published: March 2024

Abstract
Prostate cancer is highly sensitive to hormone therapy because androgens are essential for prostate cancer cell growth. However, with the nearly invariable progression of this disease to androgen independence, endocrine therapy ultimately fails to control prostate cancer in most patients. Androgen-independent acquisition may involve neuroendocrine transdifferentiation, but there is little knowledge about this process, which is presently controversial. In this study, we investigated this question in a novel model of human androgen-dependent LNCaP cells cultured for long periods in hormone-deprived conditions. Strikingly, characterization of the neuroendocrine phenotype by transcriptomic, metabolomic, and other statistically integrated analyses showed how hormone-deprived LNCaP cells could transdifferentiate to a nonmalignantneuroendocrine phenotype. Notably, conditioned media from neuroendocrine-like cells affected LNCaP cell proliferation. Predictive in silico models illustrated how after an initial period, when LNCaP cell survival was compromised by an arising population of neuroendocrine-like cells, a sudden trend reversal occurred in which the neuroendocrine-like cells functioned to sustain the remaining androgen-dependent LNCaP cells. Our findings provide direct biologic and molecular support for the concept that neuroendocrine transdifferentiation in prostate cancer cell populations influences the progression to androgen independence. Cancer Res; 75(15); 2975–86. ©2015 AACR.
Data from SYK Is a Candidate Kinase Target for the Treatment of Advanced Prostate Cancer
Authors: Ghotra Veerander P.S. , He Shuning , van der Horst Geertje , Nijhoff Steffen , de Bont Hans , Lekkerkerker Annemarie , Janssen Richard , Jenster Guido , van Leenders Geert J.L.H. , Hoogland A. Marije M. , Verhoef Esther I. , Baranski Zuzanna , Xiong Jiangling , van de Water Bob , van der Pluijm Gabri , Snaar-Jagalska B. Ewa , Danen Erik H.J.
Published: March 2024

Abstract
Improved targeted therapies are needed to combat metastatic prostate cancer. Here, we report the identification of the spleen kinase SYK as a mediator of metastatic dissemination in zebrafish and mouse xenograft models of human prostate cancer. Although SYK has not been implicated previously in this disease, we found that its expression is upregulated in human prostate cancers and associated with malignant progression. RNAi-mediated silencing prevented invasive outgrowth in vitro and bone colonization in vivo, effects that were reversed by wild-type but not kinase-dead SYK expression. In the absence of SYK expression, cell surface levels of the progression-associated adhesion receptors integrin α2β1 and CD44 were diminished. RNAi-mediated silencing of α2β1 phenocopied SYK depletion in vitro and in vivo, suggesting an effector role for α2β1 in this setting. Notably, pharmacologic inhibitors of SYK kinase currently in phase I–II trials for other indications interfered similarly with the invasive growth and dissemination of prostate cancer cells. Our findings offer a mechanistic rationale to reposition SYK kinase inhibitors for evaluation in patients with metastatic prostate cancer. Cancer Res; 75(1); 230–40. ©2014 AACR.
Data from Mast Cells Infiltrating Inflamed or Transformed Gut Alternatively Sustain Mucosal Healing or Tumor Growth
Authors: Rigoni Alice , Bongiovanni Lucia , Burocchi Alessia , Sangaletti Sabina , Danelli Luca , Guarnotta Carla , Lewis Amy , Rizzo Aroldo , Silver Andrew R. , Tripodo Claudio , Colombo Mario P.
Published: March 2024

Abstract
Mast cells (MC) are immune cells located next to the intestinal epithelium with regulatory function in maintaining the homeostasis of the mucosal barrier. We have investigated MC activities in colon inflammation and cancer in mice either wild-type (WT) or MC-deficient (KitW-sh) reconstituted or not with bone marrow-derived MCs. Colitis was chemically induced with dextran sodium sulfate (DSS). Tumors were induced by administering azoxymethane (AOM) intraperitoneally before DSS. Following DSS withdrawal, KitW-sh mice showed reduced weight gain and impaired tissue repair compared with their WT littermates or KitW-sh mice reconstituted with bone marrow-derived MCs. MCs were localized in areas of mucosal healing rather than damaged areas where they degraded IL33, an alarmin released by epithelial cells during tissue damage. KitW-sh mice reconstituted with MC deficient for mouse mast cell protease 4 did not restore normal mucosal healing or reduce efficiently inflammation after DSS withdrawal. In contrast with MCs recruited during inflammation-associated wound healing, MCs adjacent to transformed epithelial cells acquired a protumorigenic profile. In AOM- and DSS-treated WT mice, high MC density correlated with high-grade carcinomas. In similarly treated KitW-sh mice, tumors were less extended and displayed lower histologic grade. Our results indicate that the interaction of MCs with epithelial cells is dependent on the inflammatory stage, and on the activation of the tissue repair program. Selective targeting of MCs for prevention or treatment of inflammation-associated colon cancer should be timely pondered to allow tissue repair at premalignant stages or to reduce aggressiveness at the tumor stage. Cancer Res; 75(18); 3760–70. ©2015 AACR.
Data from Chemotherapeutic Agents Subvert Tumor Immunity by Generating Agonists of Platelet-Activating Factor
Authors: Sahu Ravi P. , Ocana Jesus A. , Harrison Kathleen A. , Ferracini Matheus , Touloukian Christopher E. , Al-Hassani Mohammed , Sun Louis , Loesch Mathew , Murphy Robert C. , Althouse Sandra K. , Perkins Susan M. , Speicher Paul J. , Tyler Douglas S. , Konger Raymond L. , Travers Jeffrey B.
Published: March 2024

Abstract
Oxidative stress suppresses host immunity by generating oxidized lipid agonists of the platelet-activating factor receptor (PAF-R). Because many classical chemotherapeutic drugs induce reactive oxygen species (ROS), we investigated whether these drugs might subvert host immunity by activating PAF-R. Here, we show that PAF-R agonists are produced in melanoma cells by chemotherapy that is administered in vitro, in vivo, or in human subjects. Structural characterization of the PAF-R agonists induced revealed multiple oxidized glycerophosphocholines that are generated nonenzymatically. In a murine model of melanoma, chemotherapeutic administration could augment tumor growth by a PAF-R–dependent process that could be blocked by treatment with antioxidants or COX-2 inhibitors or by depletion of regulatory T cells. Our findings reveal how PAF-R agonists induced by chemotherapy treatment can promote treatment failure. Furthermore, they offer new insights into how to improve the efficacy of chemotherapy by blocking its heretofore unknown impact on PAF-R activation. Cancer Res; 74(23); 7069–78. ©2014 AACR.
Data from ΔNp63α Promotes Breast Cancer Cell Motility through the Selective Activation of Components of the Epithelial-to-Mesenchymal Transition Program
Authors: Dang Tuyen T. , Esparza Matthew A. , Maine Erin A. , Westcott Jill M. , Pearson Gray W.
Published: March 2024

Abstract
Cell identity signals influence the invasive capability of tumor cells, as demonstrated by the selection for programs of epithelial-to-mesenchymal transition (EMT) during malignant progression. Breast cancer cells retain canonical epithelial traits and invade collectively as cohesive groups of cells, but the signaling pathways critical to their invasive capabilities are still incompletely understood. Here we report that the transcription factor ΔNp63α drives the migration of basal-like breast cancer (BLBC) cells by inducing a hybrid mesenchymal/epithelial state. Through a combination of expression analysis and functional testing across multiple BLBC cell populations, we determined that ΔNp63α induces migration by elevating the expression of the EMT program components Slug and Axl. Interestingly, ΔNp63α also increased the expression of miR-205, which can silence ZEB1/2 to prevent the loss of epithelial character caused by EMT induction. In clinical specimens, co-expression of various elements of the ΔNp63α pathway confirmed its implication in motility signaling in BLBC. We observed that activation of the ΔNp63α pathway occurred during the transition from noninvasive ductal carcinoma in situ to invasive breast cancer. Notably, in an orthotopic tumor model, Slug expression was sufficient to induce collective invasion of E-cadherin–expressing BLBC cells. Together, our results illustrate how ΔNp63α can drive breast cancer cell invasion by selectively engaging promigratory components of the EMT program while, in parallel, still promoting the retention of epithelial character. Cancer Res; 75(18); 3925–35. ©2015 AACR.
Data from Anti-CD20 Therapy Acts via FcγRIIIA to Diminish Responsiveness of Human Natural Killer Cells
Authors: Capuano Cristina , Romanelli Maddalena , Pighi Chiara , Cimino Giuseppe , Rago Angela , Molfetta Rosa , Paolini Rossella , Santoni Angela , Galandrini Ricciarda
Published: March 2024

Abstract
Natural killer (NK) immune cells mediate antibody-dependent cellular cytotoxicity (ADCC) by aggregating FcγRIIIA/CD16, contributing significantly to the therapeutic effect of CD20 monoclonal antibodies (mAb). In this study, we show that CD16 ligation on primary human NK cells by the anti-CD20 mAb rituximab or ofatumumab stably impairs the spontaneous cytotoxic response attributable to cross-tolerance of several unrelated NK-activating receptors (including NKG2D, DNAM-1, NKp46, and 2B4). Similar effects were obtained from NK cells isolated from patients with chronic lymphocytic leukemia in an autologous setting. NK cells rendered hyporesponsive in this manner were deficient in the ability of these cross-tolerized receptors to phosphorylate effector signaling molecules critical for NK cytotoxicity, including SLP-76, PLCγ2, and Vav1. These effects were associated with long-lasting recruitment of the tyrosine phosphatase SHP-1 to the CD16 receptor complex. Notably, pharmacologic inhibition of SHP-1 with sodium stibogluconate counteracted CD20 mAb-induced NK hyporesponsiveness, unveiling an unrecognized role for CD16 as a bifunctional receptor capable of engendering long-lasting NK cell inhibitory signals. Our work defines a novel mechanism of immune exhaustion induced by CD20 mAb in human NK cells, with potentially negative implications in CD20 mAb-treated patients where NK cells are partly responsible for clinical efficacy. Cancer Res; 75(19); 4097–108. ©2015 AACR.
Data from Activation Status of the Pregnane X Receptor Influences Vemurafenib Availability in Humanized Mouse Models
Authors: MacLeod A. Kenneth , McLaughlin Lesley A. , Henderson Colin J. , Wolf C. Roland
Published: March 2024

Abstract
Vemurafenib is a revolutionary treatment for melanoma, but the magnitude of therapeutic response is highly variable, and the rapid acquisition of resistance is frequent. Here, we examine how vemurafenib disposition, particularly through cytochrome P450-mediated oxidation pathways, could potentially influence these outcomes using a panel of knockout and transgenic humanized mouse models. We identified CYP3A4 as the major enzyme involved in the metabolism of vemurafenib in in vitro assays with human liver microsomes. However, mice expressing human CYP3A4 did not process vemurafenib to a greater extent than CYP3A4-null animals, suggesting that other pregnane X receptor (PXR)–regulated pathways may contribute more significantly to vemurafenib metabolism in vivo. Activation of PXR, but not of the closely related constitutive androstane receptor, profoundly reduced circulating levels of vemurafenib in humanized mice. This effect was independent of CYP3A4 and was negated by cotreatment with the drug efflux transporter inhibitor elacridar. Finally, vemurafenib strongly induced PXR activity in vitro, but only weakly induced PXR in vivo. Taken together, our findings demonstrate that vemurafenib is unlikely to exhibit a clinically significant interaction with CYP3A4, but that modulation of bioavailability through PXR-mediated regulation of drug transporters (e.g., by other drugs) has the potential to markedly influence systemic exposure and thereby therapeutic outcomes. Cancer Res; 75(21); 4573–81. ©2015 AACR.
Data from Intratumoral Heterogeneity in EGFR-Mutant NSCLC Results in Divergent Resistance Mechanisms in Response to EGFR Tyrosine Kinase Inhibition
Authors: Soucheray Margaret , Capelletti Marzia , Pulido Inés , Kuang Yanan , Paweletz Cloud P. , Becker Jeffrey H. , Kikuchi Eiki , Xu Chunxiao , Patel Tarun B. , Al-shahrour Fatima , Carretero Julián , Wong Kwok-Kin , Jänne Pasi A. , Shapiro Geoffrey I. , Shimamura Takeshi
Published: March 2024

Abstract
Non–small cell lung cancers (NSCLC) that have developed resistance to EGF receptor (EGFR) tyrosine kinase inhibitor (TKI), including gefitinib and erlotinib, are clinically linked to an epithelial-to-mesenchymal transition (EMT) phenotype. Here, we examined whether modulating EMT maintains the responsiveness of EGFR-mutated NSCLCs to EGFR TKI therapy. Using human NSCLC cell lines harboring mutated EGFR and a transgenic mouse model of lung cancer driven by mutant EGFR (EGFR-Del19-T790M), we demonstrate that EGFR inhibition induces TGFβ secretion followed by SMAD pathway activation, an event that promotes EMT. Chronic exposure of EGFR-mutated NSCLC cells to TGFβ was sufficient to induce EMT and resistance to EGFR TKI treatment. Furthermore, NSCLC HCC4006 cells with acquired resistance to gefitinib were characterized by a mesenchymal phenotype and displayed a higher prevalence of the EGFR T790M mutated allele. Notably, combined inhibition of EGFR and the TGFβ receptor in HCC4006 cells prevented EMT but was not sufficient to prevent acquired gefitinib resistance because of an increased emergence of the EGFR T790M allele compared with cells treated with gefitinib alone. Conversely, another independent NSCLC cell line, PC9, reproducibly developed EGFR T790M mutations as the primary mechanism underlying EGFR TKI resistance, even though the prevalence of the mutant allele was lower than that in HCC4006 cells. Thus, our findings underscore heterogeneity within NSCLC cells lines harboring EGFR kinase domain mutations that give rise to divergent resistance mechanisms in response to treatment and anticipate the complexity of EMT suppression as a therapeutic strategy. Cancer Res; 75(20); 4372–83. ©2015 AACR.
Data from ErbB3–ErbB2 Complexes as a Therapeutic Target in a Subset of Wild-type BRAF/NRAS Cutaneous Melanomas
Authors: Capparelli Claudia , Rosenbaum Sheera , Berman-Booty Lisa D. , Salhi Amel , Gaborit Nadège , Zhan Tingting , Chervoneva Inna , Roszik Jason , Woodman Scott E. , Davies Michael A. , Setiady Yulius Y. , Osman Iman , Yarden Yosef , Aplin Andrew E.
Published: March 2024

Abstract
The treatment options remain limited for patients with melanoma who are wild-type for both BRAF and NRAS (WT/WT). We demonstrate that a subgroup of WT/WT melanomas display high basal phosphorylation of ErbB3 that is associated with autocrine production of the ErbB3 ligand neuregulin-1 (NRG1). In WT/WT melanoma cells displaying high levels of phospho-ErbB3, knockdown of NRG1 reduced cell viability and was associated with decreased phosphorylation of ErbB3, its coreceptor ErbB2, and its downstream target, AKT. Similar effects were observed by targeting ErbB3 with either siRNAs or the neutralizing ErbB3 monoclonal antibodies huHER3-8 and NG33. In addition, pertuzumab-mediated inhibition of ErbB2 heterodimerization decreased AKT phosphorylation, cell growth in vitro, and xenograft growth in vivo. Pertuzumab also potentiated the effects of MEK inhibitor on WT/WT melanoma growth in vitro and in vivo. These findings demonstrate that targeting ErbB3–ErbB2 signaling in a cohort of WT/WT melanomas leads to tumor growth reduction. Together, these studies support the rationale to target the NRG1–ErbB3–ErbB2 axis as a novel treatment strategy in a subset of cutaneous melanomas. Cancer Res; 75(17); 3554–67. ©2015 AACR.
Data from Metabolic Signature Identifies Novel Targets for Drug Resistance in Multiple Myeloma
Authors: Maiso Patricia , Huynh Daisy , Moschetta Michele , Sacco Antonio , Aljawai Yosra , Mishima Yuji , Asara John M. , Roccaro Aldo M. , Kimmelman Alec C. , Ghobrial Irene M.
Published: March 2024

Abstract
Drug resistance remains a major clinical challenge for cancer treatment. Multiple myeloma is an incurable plasma cell cancer selectively localized in the bone marrow. The main cause of resistance in myeloma is the minimal residual disease cells that are resistant to the original therapy, including bortezomib treatment and high-dose melphalan in stem cell transplant. In this study, we demonstrate that altered tumor cell metabolism is essential for the regulation of drug resistance in multiple myeloma cells. We show the unprecedented role of the metabolic phenotype in inducing drug resistance through LDHA and HIF1A in multiple myeloma, and that specific inhibition of LDHA and HIF1A can restore sensitivity to therapeutic agents such as bortezomib and can also inhibit tumor growth induced by altered metabolism. Knockdown of LDHA can restore sensitivity of bortezomib resistance cell lines while gain-of-function studies using LDHA or HIF1A induced resistance in bortezomib-sensitive cell lines. Taken together, these data suggest that HIF1A and LDHA are important targets for hypoxia-driven drug resistance. Novel drugs that regulate metabolic pathways in multiple myeloma, specifically targeting LDHA, can be beneficial to inhibit tumor growth and overcome drug resistance. Cancer Res; 75(10); 2071–82. ©2015 AACR.
Data from HSP90 Supports Tumor Growth and Angiogenesis through PRKD2 Protein Stabilization
Authors: Azoitei Ninel , Diepold Kristina , Brunner Cornelia , Rouhi Arefeh , Genze Felicitas , Becher Alexander , Kestler Hans , van Lint Johan , Chiosis Gabriela , Koren John , Fröhling Stefan , Scholl Claudia , Seufferlein Thomas
Published: March 2024

Abstract
The kinase PRKD2 (protein kinase D) is a crucial regulator of tumor cell-endothelial cell communication in gastrointestinal tumors and glioblastomas, but its mechanistic contributions to malignant development are not understood. Here, we report that the oncogenic chaperone HSP90 binds to and stabilizes PRKD2 in human cancer cells. Pharmacologic inhibition of HSP90 with structurally divergent small molecules currently in clinical development triggered proteasome-dependent degradation of PRKD2, augmenting apoptosis in human cancer cells of various tissue origins. Conversely, ectopic expression of PRKD2 protected cancer cells from the apoptotic effects of HSP90 abrogation, restoring blood vessel formation in two preclinical models of solid tumors. Mechanistic studies revealed that PRKD2 is essential for hypoxia-induced accumulation of hypoxia-inducible factor-1α (HIF1α) and activation of NF-κB in tumor cells. Notably, ectopic expression of PRKD2 was able to partially restore HIF1α and secreted VEGF-A levels in hypoxic cancer cells treated with HSP90 inhibitors. Taken together, our findings indicate that signals from hypoxia and HSP90 pathways are interconnected and funneled by PRKD2 into the NF-κB/VEGF-A signaling axis to promote tumor angiogenesis and tumor growth. Cancer Res; 74(23); 7125–36. ©2014 AACR.
Data from The Neuronal Pentraxin-2 Pathway Is an Unrecognized Target in Human Neuroblastoma, Which Also Offers Prognostic Value in Patients
Authors: Bartolini Alice , Di Paolo Daniela , Noghero Alessio , Murgia Daniele , Sementa Angela R. , Cilli Michele , Pasqualini Renata , Arap Wadih , Bussolino Federico , Ponzoni Mirco , Pastorino Fabio , Marchiò Serena
Published: March 2024

Abstract
Neuronal pentraxins (NPTX) and their corresponding receptors (NPTXR) have been studied as synapse-associated proteins in the nervous system, but their role in cancer is largely unknown. By applying a multidisciplinary, high-throughput proteomic approach, we have recently identified a peptide ligand motif for targeted drug delivery to neuroblastoma. Here, we report the sequence similarity between this peptide and a conserved portion of the pentraxin domain that is involved in the homo- and hetero-oligomerization of NPTX2 and NPTXR. We show that, in comparison with normal tissues, NPTX2 and NPTXR are overexpressed in vivo in mouse models, as well as in human Schwannian stroma-poor, stage IV neuroblastoma. Both proteins are concentrated in the vicinity of tumor blood vessels, with NPTXR also present on neuroblastic tumor cells. In vivo targeting of NPTX2 and NPTXR with the selected peptide or with specific antibodies reduces tumor burden in orthotopic mouse models of human neuroblastoma. In vitro interference with this ligand/receptor system inhibits the organization of neuroblastoma cells in tumor-like masses in close contact with vascular cells, as well as their adhesion to normal microenvironment-derived cells, suggesting a role in the cross-talk between tumor and normal cells in the early steps of neuroblastoma development. Finally, we show that NPTX2 is a marker of poor prognosis for neuroblastoma patients. Cancer Res; 75(20); 4265–71. ©2015 AACR.
Data from Minor Changes in Expression of the Mismatch Repair Protein MSH2 Exert a Major Impact on Glioblastoma Response to Temozolomide
Authors: McFaline-Figueroa José L. , Braun Christian J. , Stanciu Monica , Nagel Zachary D. , Mazzucato Patrizia , Sangaraju Dewakar , Cerniauskas Edvinas , Barford Kelly , Vargas Amanda , Chen Yimin , Tretyakova Natalia , Lees Jacqueline A. , Hemann Michael T. , White Forest M. , Samson Leona D.
Published: March 2024

Abstract
Glioblastoma (GBM) is often treated with the cytotoxic drug temozolomide, but the disease inevitably recurs in a drug-resistant form after initial treatment. Here, we report that in GBM cells, even a modest decrease in the mismatch repair (MMR) components MSH2 and MSH6 have profound effects on temozolomide sensitivity. RNAi-mediated attenuation of MSH2 and MSH6 showed that such modest decreases provided an unexpectedly strong mechanism of temozolomide resistance. In a mouse xenograft model of human GBM, small changes in MSH2 were sufficient to suppress temozolomide-induced tumor regression. Using The Cancer Genome Atlas to analyze mRNA expression patterns in tumors from temozolomide-treated GBM patients, we found that MSH2 transcripts in primary GBM could predict patient responses to initial temozolomide therapy. In recurrent disease, the absence of microsatellite instability (the standard marker for MMR deficiency) suggests a lack of involvement of MMR in the resistant phenotype of recurrent disease. However, more recent studies reveal that decreased MMR protein levels occur often in recurrent GBM. In accordance with our findings, these reported decreases may constitute a mechanism by which GBM evades temozolomide sensitivity while maintaining microsatellite stability. Overall, our results highlight the powerful effects of MSH2 attenuation as a potent mediator of temozolomide resistance and argue that MMR activity offers a predictive marker for initial therapeutic response to temozolomide treatment. Cancer Res; 75(15); 3127–38. ©2015 AACR.
Data from Targeting Mitochondria with Avocatin B Induces Selective Leukemia Cell Death
Authors: Lee Eric A. , Angka Leonard , Rota Sarah-Grace , Hanlon Thomas , Mitchell Andrew , Hurren Rose , Wang Xiao Ming , Gronda Marcela , Boyaci Ezel , Bojko Barbara , Minden Mark , Sriskanthadevan Shrivani , Datti Alessandro , Wrana Jeffery L. , Edginton Andrea , Pawliszyn Janusz , Joseph Jamie W. , Quadrilatero Joe , Schimmer Aaron D. , Spagnuolo Paul A.
Published: March 2024

Abstract
Treatment regimens for acute myeloid leukemia (AML) continue to offer weak clinical outcomes. Through a high-throughput cell-based screen, we identified avocatin B, a lipid derived from avocado fruit, as a novel compound with cytotoxic activity in AML. Avocatin B reduced human primary AML cell viability without effect on normal peripheral blood stem cells. Functional stem cell assays demonstrated selectivity toward AML progenitor and stem cells without effects on normal hematopoietic stem cells. Mechanistic investigations indicated that cytotoxicity relied on mitochondrial localization, as cells lacking functional mitochondria or CPT1, the enzyme that facilitates mitochondria lipid transport, were insensitive to avocatin B. Furthermore, avocatin B inhibited fatty acid oxidation and decreased NADPH levels, resulting in ROS-dependent leukemia cell death characterized by the release of mitochondrial proteins, apoptosis-inducing factor, and cytochrome c. This study reveals a novel strategy for selective leukemia cell eradication based on a specific difference in mitochondrial function. Cancer Res; 75(12); 2478–88. ©2015 AACR.
Data from Repair versus Checkpoint Functions of BRCA1 Are Differentially Regulated by Site of Chromatin Binding
Authors: Goldstein Michael , Kastan Michael B.
Published: March 2024

Abstract
The product of the Brca1 tumor-suppressor gene is involved in multiple aspects of the cellular DNA damage response (DDR), including activation of cell-cycle arrests and DNA double-stranded break (DSB) repair by homologous recombination. Prior reports demonstrated that BRCA1 recruitment to areas of DNA breakage depended on RAP80 and the RNF8/RNF168 E3 ubiquitin ligases. Here, we extend these findings by showing that RAP80 is only required for the binding of BRCA1 to regions flanking the DSB, whereas BRCA1 binding directly to DNA breaks requires Nijmegen breakage syndrome 1 (NBS1). These differential recruitment mechanisms differentially affect BRCA1 functions: (i) RAP80-dependent recruitment of BRCA1 to chromatin flanking DNA breaks is required for BRCA1 phosphorylation at serine 1387 and 1423 by ATM and, consequently, for the activation of S and G2 checkpoints; and (ii) BRCA1 interaction with NBS1 upon DSB induction results in an NBS1-dependent recruitment of BRCA1 directly to the DNA break and is required for nonhomologous end-joining repair. Together, these findings illustrate that spatially distinct fractions of BRCA1 exist at the DSB site, which are recruited by different mechanisms and execute different functions in the DDR. Cancer Res; 75(13); 2699–707. ©2015 AACR.
Data from Lin28B/Let-7 Regulates Expression of Oct4 and Sox2 and Reprograms Oral Squamous Cell Carcinoma Cells to a Stem-like State
Authors: Chien Chian-Shiu , Wang Mong-Lien , Chu Pen-Yuan , Chang Yuh-Lih , Liu Wei-Hsiu , Yu Cheng-Chia , Lan Yuan-Tzu , Huang Pin-I. , Lee Yi-Yen , Chen Yi-Wei , Lo Wen-Liang , Chiou Shih-Hwa
Published: March 2024

Abstract
Lin28, a key factor for cellular reprogramming and generation of induced pluripotent stem cell (iPSC), makes a critical contribution to tumorigenicity by suppressing Let-7. However, it is unclear whether Lin28 is involved in regulating cancer stem–like cells (CSC), including in oral squamous carcinoma cells (OSCC). In this study, we demonstrate a correlation between high levels of Lin28B, Oct4, and Sox2, and a high percentage of CD44+ALDH1+ CSC in OSCC. Ectopic Lin28B expression in CD44−ALDH1−/OSCC cells was sufficient to enhance Oct4/Sox2 expression and CSC properties, whereas Let7 co-overexpression effectively reversed these phenomena. We identified ARID3B and HMGA2 as downstream effectors of Lin28B/Let7 signaling in regulating endogenous Oct4 and Sox2 expression. Let7 targeted the 3′ untranslated region of ARID3B and HMGA2 and suppressed their expression, whereas ARID3B and HMGA2 increased the transcription of Oct4 and Sox2, respectively, through promoter binding. Chromatin immunoprecipitation assays revealed a direct association between ARID3B and a specific ARID3B-binding sequence in the Oct4 promoter. Notably, by modulating Oct4/Sox2 expression, the Lin28B–Let7 pathway not only regulated stemness properties in OSCC but also determined the efficiency by which normal human oral keratinocytes could be reprogrammed to iPSC. Clinically, a Lin28Bhigh-Let7low expression pattern was highly correlated with high levels of ARID3B, HMGA2, OCT4, and SOX2 expression in OSCC specimens. Taken together, our results show how Lin28B/Let7 regulates key cancer stem–like properties in oral squamous cancers. Cancer Res; 75(12); 2553–65. ©2015 AACR.
Data from CRMP5 Controls Glioblastoma Cell Proliferation and Survival through Notch-Dependent Signaling
Authors: Moutal Aubin , Honnorat Jérôme , Massoma Patrick , Désormeaux Pauline , Bertrand Caroline , Malleval Céline , Watrin Chantal , Chounlamountri Naura , Mayeur Marie-Eve , Besançon Roger , Naudet Nicolas , Magadoux Léa , Khanna Rajesh , Ducray François , Meyronet David , Thomasset Nicole
Published: March 2024

Abstract
Collapsin response mediator protein 5 (CRMP5) belongs to a family of five cytosolic proteins that play a major role in nervous system development. This protein was first described in cancer-induced autoimmune processes, causing neurodegenerative disorders (paraneoplastic neurologic syndromes). CRMP5 expression has been reported to serve as a biomarker for high-grade lung neuroendocrine carcinomas; however, its functional roles have not been examined in any setting of cancer pathophysiology. In this study, we report two different CRMP5 expression patterns observed in human glioblastoma (GBM) biopsies that establish connections between CRMP5 expression, Notch receptor signaling, and GBM cell proliferation. We demonstrated that elevated CRMP5 promotes Notch receptor expression and Akt activation in human tumor cell lines, GBM stem cells, and primary tumor biopsies. We have shown that the high CRMP5 and Notch expression in GBM xenograft is related to stem cells. This suggests that high CRMP5 expression pattern in GBM biopsies encompasses a subset of stem cells. Mechanistically, CRMP5 functioned by hijacking Notch receptors from Itch-dependent lysosomal degradation. Our findings suggest that CRMP5 serves as a major mediator of Notch signaling and Akt activation by controlling the degradation of the Notch receptor, with implications for defining a biomarker signature in GBM that correlates with and may predict patient survival. Cancer Res; 75(17); 3519–28. ©2015 AACR.
Data from G-CSF Promotes Neuroblastoma Tumorigenicity and Metastasis via STAT3-Dependent Cancer Stem Cell Activation
Authors: Agarwal Saurabh , Lakoma Anna , Chen Zaowen , Hicks John , Metelitsa Leonid S. , Kim Eugene S. , Shohet Jason M.
Published: March 2024

Abstract
Increasing evidence suggests that inflammatory cytokines play a critical role in tumor initiation and progression. A cancer stem cell (CSC)-like subpopulation in neuroblastoma is known to be marked by expression of the G-CSF receptor (G-CSFR). Here, we report on the mechanistic contributions of the G-CSFR in neuroblastoma CSCs. Specifically, we demonstrate that the receptor ligand G-CSF selectively activates STAT3 within neuroblastoma CSC subpopulations, promoting their expansion in vitro and in vivo. Exogenous G-CSF enhances tumor growth and metastasis in human xenograft and murine neuroblastoma tumor models. In response to G-CSF, STAT3 acts in a feed-forward loop to transcriptionally activate the G-CSFR and sustain neuroblastoma CSCs. Blockade of this G-CSF–STAT3 signaling loop with either anti-G-CSF antibody or STAT3 inhibitor depleted the CSC subpopulation within tumors, driving correlated tumor growth inhibition, decreased metastasis, and increased chemosensitivity. Taken together, our results define G-CSF as a CSC-activating factor in neuroblastoma, suggest a comprehensive reevaluation of the clinical use of G-CSF in these patients to support white blood cell counts, and suggest that direct targeting of the G-CSF–STAT3 signaling represents a novel therapeutic approach for neuroblastoma. Cancer Res; 75(12); 2566–79. ©2015 AACR.
Data from Quantitative In Vivo Immunohistochemistry of Epidermal Growth Factor Receptor Using a Receptor Concentration Imaging Approach
Authors: Samkoe Kimberley S. , Tichauer Kenneth M. , Gunn Jason R. , Wells Wendy A. , Hasan Tayyaba , Pogue Brian W.
Published: March 2024

Abstract
As receptor-targeted therapeutics become increasingly used in clinical oncology, the ability to quantify protein expression and pharmacokinetics in vivo is imperative to ensure successful individualized treatment plans. Current standards for receptor analysis are performed on extracted tissues. These measurements are static and often physiologically irrelevant; therefore, only a partial picture of available receptors for drug targeting in vivo is provided. Until recently, in vivo measurements were limited by the inability to separate delivery, binding, and retention effects, but this can be circumvented by a dual-tracer approach for referencing the detected signal. We hypothesized that in vivo receptor concentration imaging (RCI) would be superior to ex vivo immunohistochemistry (IHC). Using multiple xenograft tumor models with varying EGFR expression, we determined the EGFR concentration in each model using a novel targeted agent (anti-EGFR affibody-IRDye800CW conjugate) along with a simultaneously delivered reference agent (control affibody-IRDye680RD conjugate). The RCI-calculated in vivo receptor concentration was strongly correlated with ex vivo pathologist-scored IHC and computer-quantified ex vivo immunofluorescence. In contrast, no correlation was observed with ex vivo Western blot analysis or in vitro flow-cytometry assays. Overall, our results argue that in vivo RCI provides a robust measure of receptor expression equivalent to ex vivo immunostaining, with implications for use in noninvasive monitoring of therapy or therapeutic guidance during surgery. Cancer Res; 74(24); 7465–74. ©2014 AACR.
Data from Targeting the MDM2/MDM4 Interaction Interface as a Promising Approach for p53 Reactivation Therapy
Authors: Pellegrino Marsha , Mancini Francesca , Lucà Rossella , Coletti Alice , Giacchè Nicola , Manni Isabella , Arisi Ivan , Florenzano Fulvio , Teveroni Emanuela , Buttarelli Marianna , Fici Laura , Brandi Rossella , Bruno Tiziana , Fanciulli Maurizio , D'Onofrio Mara , Piaggio Giulia , Pellicciari Roberto , Pontecorvi Alfredo , Marine Jean Christophe , Macchiarulo Antonio , Moretti Fabiola
Published: March 2024

Abstract
Restoration of wild-type p53 tumor suppressor function has emerged as an attractive anticancer strategy. Therapeutics targeting the two p53-negative regulators, MDM2 and MDM4, have been developed, but most agents selectively target the ability of only one of these molecules to interact with p53, leaving the other free to operate. Therefore, we developed a method that targets the activity of MDM2 and MDM4 simultaneously based on recent studies indicating that formation of MDM2/MDM4 heterodimer complexes are required for efficient inactivation of p53 function. Using computational and mutagenesis analyses of the heterodimer binding interface, we identified a peptide that mimics the MDM4 C-terminus, competes with endogenous MDM4 for MDM2 binding, and activates p53 function. This peptide induces p53-dependent apoptosis in vitro and reduces tumor growth in vivo. Interestingly, interfering with the MDM2/MDM4 heterodimer specifically activates a p53-dependent oxidative stress response. Consistently, distinct subcellular pools of MDM2/MDM4 complexes were differentially sensitive to the peptide; nuclear MDM2/MDM4 complexes were particularly highly susceptible to the peptide-displacement activity. Taken together, these data identify the MDM2/MDM4 interaction interface as a valuable molecular target for therapeutic reactivation of p53 oncosuppressive function. Cancer Res; 75(21); 4560–72. ©2015 AACR.
Data from Endothelial ALK1 Is a Therapeutic Target to Block Metastatic Dissemination of Breast Cancer
Authors: Cunha Sara I. , Bocci Matteo , Lövrot John , Eleftheriou Nikolas , Roswall Pernilla , Cordero Eugenia , Lindström Linda , Bartoschek Michael , Haller B. Kristian , Pearsall R. Scott , Mulivor Aaron W. , Kumar Ravindra , Larsson Christer , Bergh Jonas , Pietras Kristian
Published: March 2024

Abstract
Exploration of new strategies for the prevention of breast cancer metastasis is justifiably at the center of clinical attention. In this study, we combined a computational biology approach with mechanism-based preclinical trials to identify inhibitors of activin-like receptor kinase (ALK) 1 as effective agents for blocking angiogenesis and metastasis in breast cancer. Pharmacologic targeting of ALK1 provided long-term therapeutic benefit in mouse models of mammary carcinoma, accompanied by strikingly reduced metastatic colonization as a monotherapy or part of combinations with chemotherapy. Gene-expression analysis of breast cancer specimens from a population-based nested case–control study encompassing 768 subjects defined endothelial expression of ALK1 as an independent and highly specific prognostic factor for metastatic manifestation, a finding that was corroborated in an independent clinical cohort. Overall, our results suggest that pharmacologic inhibition of endothelial ALK1 constitutes a tractable strategy for interfering with metastatic dissemination of breast cancer. Cancer Res; 75(12); 2445–56. ©2015 AACR.