bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from MYC Acts via the PTEN Tumor Suppressor to Elicit Autoregulation and Genome-Wide Gene Repression by Activation of the Ezh2 Methyltransferase
Authors: Kaur Mandeep , Cole Michael D.
Published: March 2024

Abstract
The control of normal cell growth is a balance between stimulatory and inhibitory signals. MYC is a pleiotropic transcription factor that both activates and represses a broad range of target genes and is indispensable for cell growth. Whereas much is known about gene activation by MYC, there is no established mechanism for the majority of MYC-repressed genes. We report that MYC transcriptionally activates the PTEN tumor suppressor in normal cells to inactivate the phosphoinositide 3-kinase (PI3K) pathway, thus suppressing AKT activation. Suppression of AKT enhances the activity of the EZH2 histone methyltransferase, a subunit of the epigenetic repressor Polycomb Repressive Complex 2 (PRC2), while simultaneously stabilizing the protein. MYC-mediated enhancement in EZH2 protein level and activity results in local and genome-wide elevation in the repressive H3K27me3 histone modification, leading to widespread gene repression including feedback autoregulation of the MYC gene itself. Depletion of either PTEN or EZH2 and inhibition of the PI3K/AKT pathway leads to gene derepression. Importantly, expression of a phospho-defective EZH2 mutant is sufficient to recapitulate nearly half of all MYC-mediated gene repression. We present a novel epigenetic model for MYC-mediated gene repression and propose that PTEN and MYC exist in homeostatic balance to control normal growth, which is disrupted in cancer cells. Cancer Res; 73(2); 695–705. ©2012 AACR.
Data from Differential Contributions of STAT5A and STAT5B to Stress Protection and Tyrosine Kinase Inhibitor Resistance of Chronic Myeloid Leukemia Stem/Progenitor Cells
Authors: Casetti Luana , Martin-Lannerée Séverine , Najjar Imen , Plo Isabelle , Augé Sylvie , Roy Lydia , Chomel Jean-Claude , Lauret Evelyne , Turhan Ali G. , Dusanter-Fourt Isabelle
Published: March 2024

Abstract
STAT5 fulfills essential roles in hematopoietic stem cell (HSC) self-renewal and chronic myeloid leukemia (CML), a prototypical stem cell malignancy. However, the specific contributions of the two related genes STAT5A and STAT5B have not been determined. In this study, we used a RNAi-based strategy to establish participation of these genes to CML disease and persistence following targeted therapy. We showed that STAT5A/STAT5B double-knockdown triggers CML cell apoptosis and suppresses both normal and CML HSC long-term clonogenic potential. STAT5A and STAT5B exhibited similar prosurvival activity, but STAT5A attenuation alone was ineffective at impairing growth of normal and CML CD34+ cells isolated at diagnosis. In contrast, STAT5A attenuation was sufficient to enhance basal oxidative stress and DNA damage of normal CD34+ and CML cells. Furthermore, it weakened the ability to manage exogenous oxidative stress, increased p53 (TRP53)/CHK-2 (CHEK2) stress pathway activation, and enhanced prolyl hydroxylase domain (PHD)-3 (EGLN3) mRNA expression. Only STAT5A and its transactivation domain-deficient mutant STAT5AΔ749 specifically rescued these activities. STAT5A attenuation was also active at inhibiting growth of CML CD34+ cells from patients with acquired resistance to imatinib. Our findings show that STAT5A has a selective role in contributing to stress resistance through unconventional mechanisms, offering new opportunities to eradicate the most primitive and tyrosine kinase inhibitor–resistant CML cells with an additional potential to eradicate persistent stem cell populations. Cancer Res; 73(7); 2052–8. ©2013 AACR.
Data from Therapeutic PD-1 Pathway Blockade Augments with Other Modalities of Immunotherapy T-Cell Function to Prevent Immune Decline in Ovarian Cancer
Authors: Duraiswamy Jaikumar , Freeman Gordon J. , Coukos George
Published: March 2024

Abstract
The tumor microenvironment mediates induction of the immunosuppressive programmed cell death-1 (PD-1) pathway, and targeted interventions against this pathway can help restore antitumor immunity. To gain insight into these responses, we studied the interaction between PD-1 expressed on T cells and its ligands (PD-1:PD-L1, PD-1:PD-L2, and PD-L1:B7.1), expressed on other cells in the tumor microenvironment, using a syngeneic orthotopic mouse model of epithelial ovarian cancer (ID8). Exhaustion of tumor-infiltrating lymphocytes (TIL) correlated with expression of PD-1 ligands by tumor cells and tumor-derived myeloid cells, including tumor-associated macrophages (TAM), dendritic cells, and myeloid-derived suppressor cells (MDSC). When combined with GVAX or FVAX vaccination (consisting of irradiated ID8 cells expressing granulocyte macrophage colony—stimulating factor or FLT3 ligand) and costimulation by agonistic α-4-1BB or TLR 9 ligand, antibody-mediated blockade of PD-1 or PD-L1 triggered rejection of ID8 tumors in 75% of tumor-bearing mice. This therapeutic effect was associated with increased proliferation and function of tumor antigen-specific effector CD8+ T cells, inhibition of suppressive regulatory T cells (Treg) and MDSC, upregulation of effector T-cell signaling molecules, and generation of T memory precursor cells. Overall, PD-1/PD-L1 blockade enhanced the amplitude of tumor immunity by reprogramming suppressive and stimulatory signals that yielded more powerful cancer control. Cancer Res; 73(23); 6900–12. ©2013 AACR.
Data from Durable Adoptive Immunotherapy for Leukemia Produced by Manipulation of Multiple Regulatory Pathways of CD8+ T-Cell Tolerance
Authors: Berrien-Elliott Melissa M. , Jackson Stephanie R. , Meyer Jennifer M. , Rouskey Craig J. , Nguyen Thanh-Long M. , Yagita Hideo , Greenberg Philip D. , DiPaolo Richard J. , Teague Ryan M.
Published: March 2024

Abstract
Tolerizing mechanisms within the host and tumor microenvironment inhibit T-cell effector functions that can control cancer. These mechanisms blunt adoptive immunotherapy with infused T-cells due to a complex array of signals that determine T-cell tolerance, survival, or deletion. Ligation of the negative regulatory receptors CTLA4, PD-1(PDCD1), or LAG3 on T-cells normally hinders their response to antigen through nonredundant biochemical processes that interfere with stimulatory pathways. In this study, we used an established mouse model of T-cell tolerance to define the roles of these inhibitory receptors in regulating CD8+ T-cell tolerance during adoptive immunotherapy to treat leukemia. Blocking CTLA4 and PD-1 in vivo combined to promote survival of transferred T-cells despite powerful deletional signals that mediate Bim (BCL2L11)–dependent apoptosis. However, this dual blockade was not optimal for stimulating effector function by responding T-cells, which required the additional blockade of LAG3 to induce full expansion and allow the acquisition of robust cytolytic activity. Thus, the cooperation of multiple distinct regulatory pathways was needed for the survival and effector differentiation of adoptively transferred tumor-reactive CD8+ T-cells. Our work defines the immune escape pathways in which simultaneous blockade could yield durable immunotherapeutic responses that can eradicate disseminated leukemia. Cancer Res; 73(2); 605–16. ©2012 AACR.
Data from Arkadia Regulates Tumor Metastasis by Modulation of the TGF-β Pathway
Authors: Briones-Orta Marco A. , Levy Laurence , Madsen Chris D. , Das Debipriya , Erker Yigit , Sahai Erik , Hill Caroline S.
Published: March 2024

Abstract
TGF-β can act as a tumor suppressor at early stages of cancer progression and as a tumor promoter at later stages. The E3 ubiquitin ligase Arkadia (RNF111) is a critical component of the TGF-β signaling pathway, being required for a subset of responses, those mediated by Smad3–Smad4 complexes. It acts by mediating ligand-induced degradation of Ski and SnoN (SKIL), which are 2 potent transcriptional repressors. Here, we investigate the role of Arkadia in cancer using model systems to address both potential tumor-suppressive and tumor-promoting roles. Stable reexpression of Arkadia in lung carcinoma NCI-H460 cells, which we show contain a hemizygous nonsense mutation in the Arkadia/RNF111 gene, efficiently restored TGF-β–induced Smad3-dependent transcription, and substantially decreased the ability of these cells to grow in soft agar in vitro. However, it had no effect on tumor growth in vivo in mouse models. Moreover, loss of Arkadia in cancer cell lines and human tumors is rare, arguing against a prominent tumor-suppressive role. In contrast, we have uncovered a potent tumor-promoting function for Arkadia. Using 3 different cancer cell lines whose tumorigenic properties are driven by TGF-β signaling, we show that loss of Arkadia function, either by overexpression of dominant negative Arkadia or by siRNA-induced knockdown, substantially inhibited lung colonization in tail vein injection experiments in immunodeficient mice. Our findings indicate that Arkadia is not critical for regulating tumor growth per se, but is required for the early stages of cancer cell colonization at the sites of metastasis. Cancer Res; 73(6); 1800–10. ©2012 AACR.
Data from A Preclinical Assay for Chemosensitivity in Multiple Myeloma
Authors: Khin Zayar P. , Ribeiro Maria L.C. , Jacobson Timothy , Hazlehurst Lori , Perez Lia , Baz Rachid , Shain Kenneth , Silva Ariosto S.
Published: March 2024

Abstract
Accurate preclinical predictions of the clinical efficacy of experimental cancer drugs are highly desired but often haphazard. Such predictions might be improved by incorporating elements of the tumor microenvironment in preclinical models by providing a more physiological setting. In generating improved xenograft models, it is generally accepted that the use of primary tumors from patients are preferable to clonal tumor cell lines. Here we describe an interdisciplinary platform to study drug response in multiple myeloma, an incurable cancer of the bone marrow. This platform uses microfluidic technology to minimize the number of cells per experiment, while incorporating three-dimensional extracellular matrix and mesenchymal cells derived from the tumor microenvironment. We used sequential imaging and a novel digital imaging analysis algorithm to quantify changes in cell viability. Computational models were used to convert experimental data into dose-exposure–response “surfaces,” which offered predictive utility. Using this platform, we predicted chemosensitivity to bortezomib and melphalan, two clinical multiple myeloma treatments, in three multiple myeloma cell lines and seven patient-derived primary multiple myeloma cell populations. We also demonstrated how this system could be used to investigate environment-mediated drug resistance and drug combinations that target it. This interdisciplinary preclinical assay is capable of generating quantitative data that can be used in computational models of clinical response, demonstrating its utility as a tool to contribute to personalized oncology. Cancer Res; 74(1); 56–67. ©2013 AACR.
Data from Rhythmic Control of the ARF-MDM2 Pathway by ATF4 Underlies Circadian Accumulation of p53 in Malignant Cells
Authors: Horiguchi Michiko , Koyanagi Satoru , Hamdan Ahmed M. , Kakimoto Keisuke , Matsunaga Naoya , Yamashita Chikamasa , Ohdo Shigehiro
Published: March 2024

Abstract
The sensitivity of cancer cells to chemotherapeutic agents varies according to circadian time. Most chemotherapeutic agents ultimately cause cell death through cell-intrinsic pathways as an indirect consequence of DNA damage. The p53 tumor suppressor gene (TRP53) configures the cell deaths induced by chemotherapeutic agents. In this study, we show that the transcription factor ATF4, a component of the mammalian circadian clock, functions in circadian accumulation of p53 protein in tumor cells. In murine fibroblast tumor cells, ATF4 induced the circadian expression of p19ARF (Cdkn2a). Oscillation of p19ARF interacted in a time-dependent manner with MDM2, a specific ubiquitin ligase of p53, resulting in a rhythmic prevention of its degradation by MDM2. Consequently, the half-life of p53 protein varied in a circadian time-dependent manner without variation in mRNA levels. The p53 protein accumulated during those times when the p19ARF–MDM2 interaction was facilitated. Notably, the ability of the p53 degradation inhibitor nutlin-3 to kill murine fibroblast tumor cells was enhanced when the drug was administered at those times of day during which p53 had accumulated. Taken together, these results suggested that ATF4-mediated regulation of the p19ARF–MDM2 pathway underlies the circadian accumulation of p53 protein in malignant cells. Furthermore, they suggest an explanation for how the sensitivity of cancer cells to chemotherapeutic agents is enhanced at those times of day when p53 protein has accumulated, as a result of circadian processes controlled by ATF4. Cancer Res; 73(8); 2639–49. ©2013 AACR.
Data from Chemotherapy Alters Monocyte Differentiation to Favor Generation of Cancer-Supporting M2 Macrophages in the Tumor Microenvironment
Authors: Dijkgraaf Eveline M. , Heusinkveld Moniek , Tummers Bart , Vogelpoel Lisa T.C. , Goedemans Renske , Jha Veena , Nortier Johan W.R. , Welters Marij J.P. , Kroep Judith R. , van der Burg Sjoerd H.
Published: March 2024

Abstract
Current therapy of gynecologic malignancies consists of platinum-containing chemotherapy. Resistance to therapy is associated with increased levels of interleukin (IL)-6 and prostaglandin E2 (PGE2), 2 inflammatory mediators known to skew differentiation of monocytes to tumor-promoting M2 macrophages. We investigated the impact of cisplatin and carboplatin on 10 different cervical and ovarian cancer cell lines as well as on the ability of the tumor cells to affect the differentiation and function of cocultured monocytes in vitro. Treatment with cisplatin or carboplatin increased the potency of tumor cell lines to induce IL-10–producing M2 macrophages, which displayed increased levels of activated STAT3 due to tumor-produced IL-6 as well as decreased levels of activated STAT1 and STAT6 related to the PGE2 production of tumor cells. Blockade of canonical NF-κB signaling showed that the effect of the chemotherapy was abrogated, preventing the subsequent increased production of PGE2 and/or IL-6 by the tumor cell lines. Treatment with the COX-inhibitor indomethacin and/or the clinical monoclonal antibody against interleukin-6 receptor (IL-6R), tocilizumab, prevented M2-differentiation. Importantly, no correlation existed between the production of PGE2 or IL-6 by cancer cells and their resistance to chemotherapy-induced cell death, indicating that other mechanisms underlie the reported chemoresistance of tumors producing these factors. Our data suggest that a chemotherapy-mediated increase in tumor-promoting M2 macrophages may form an indirect mechanism for chemoresistance. Hence, concomitant therapy with COX inhibitors and/or IL-6R antibodies might increase the clinical effect of platinum-based chemotherapy in otherwise resistant tumors. Cancer Res; 73(8); 2480–92. ©2013 AACR.
Data from Thrombin Drives Tumorigenesis in Colitis-Associated Colon Cancer
Authors: Turpin Brian , Miller Whitney , Rosenfeldt Leah , Kombrinck Keith , Flick Matthew J. , Steinbrecher Kris A. , Harmel-Laws Eleana , Mullins Eric S. , Shaw Maureen , Witte David P. , Revenko Alexey , Monia Brett , Palumbo Joseph S.
Published: March 2024

Abstract
The established association between inflammatory bowel disease and colorectal cancer underscores the importance of inflammation in colon cancer development. On the basis of evidence that hemostatic proteases are powerful modifiers of both inflammatory pathologies and tumor biology, gene-targeted mice carrying low levels of prothrombin were used to directly test the hypothesis that prothrombin contributes to tumor development in colitis-associated colon cancer (CAC). Remarkably, imposing a modest 50% reduction in circulating prothrombin in fII+/− mice, a level that carries no significant bleeding risk, dramatically decreased adenoma formation following an azoxymethane/dextran sodium sulfate challenge. Similar results were obtained with pharmacologic inhibition of prothrombin expression or inhibition of thrombin proteolytic activity. Detailed longitudinal analyses showed that the role of thrombin in tumor development in CAC was temporally associated with the antecedent inflammatory colitis. However, direct studies of the antecedent colitis showed that mice carrying half-normal prothrombin levels were comparable to control mice in mucosal damage, inflammatory cell infiltration, and associated local cytokine levels. These results suggest that thrombin supports early events coupled to inflammation-mediated tumorigenesis in CAC that are distinct from overall inflammation-induced tissue damage and inflammatory cell trafficking. That prothrombin is linked to early events in CAC was strongly inferred by the observation that prothrombin deficiency dramatically reduced the formation of very early, precancerous aberrant crypt foci. Given the importance of inflammation in the development of colon cancer, these studies suggest that therapeutic interventions at the level of hemostatic factors may be an effective means to prevent and/or impede colitis-associated colon cancer progression. Cancer Res; 74(11); 3020–30. ©2014 AACR.
Data from Novel Mechanism of Apoptosis Resistance in Cancer Mediated by Extracellular PAR-4
Authors: Burikhanov Ravshan , Shrestha-Bhattarai Tripti , Qiu Shirley , Shukla Nidhi , Hebbar Nikhil , Lele Subodh M. , Horbinski Craig , Rangnekar Vivek M.
Published: March 2024

Abstract
Tumor suppressor PAR-4 acts in part by modulating sensitivity to apoptosis, but the basis for its activity is not fully understood. In this study, we describe a novel mechanism of antiapoptosis by NF-κB, revealing that it can block PAR-4–mediated apoptosis by downregulating trafficking of the PAR-4 receptor GRP78 from the endoplasmic reticulum to the cell surface. Mechanistic investigations revealed that NF-κB mediated this antiapoptotic mechanism by upregulating expression of UACA, a proinflammatory protein in certain disease settings. In clinical specimens of cancer, a strong correlation existed between NF-κB activity and UACA expression, relative to normal tissues. UACA bound to intracellular PAR-4 in diverse cancer cells, where it prevented translocation of GRP78 from the endoplasmic reticulum to the cell surface. This pathway of antiapoptosis could be inhibited by suppressing levels of NF-κB or UACA expression, which enhanced endoplasmic reticulum stress and restored GRP78 trafficking to the cell surface, thereby sensitizing cancer cells to apoptosis by extracellular PAR-4 or GRP78 agonistic antibody. In summary, our results identify a novel intracellular pathway of apoptosis mediated by NF-κB through UACA elevation, which by attenuating endoplasmic reticulum stress and GRP78 translocation to the cell surface can blunt the sensitivity of cancer cells to apoptosis. Cancer Res; 73(2); 1011–9. ©2012 AACR.
Data from CD103 or LFA-1 Engagement at the Immune Synapse between Cytotoxic T Cells and Tumor Cells Promotes Maturation and Regulates T-cell Effector Functions
Authors: Franciszkiewicz Katarzyna , Le Floc'h Audrey , Boutet Marie , Vergnon Isabelle , Schmitt Alain , Mami-Chouaib Fathia
Published: March 2024

Abstract
T-cell adhesion/costimulatory molecules and their cognate receptors on target cells play a major role in T-cell receptor (TCR)–mediated activities. Here, we compared the involvement of CD103 and LFA-1, and their respective ligands, in the maturation of the cytotoxic immune synapse (cIS) and in the activation of CTL effector functions. Our results indicate that cytotoxicity toward cancer cells and, to a lesser extent, cytokine production by specific CTL require, together with TCR engagement, the interaction of either CD103 with E-cadherin or LFA-1 with ICAM-1. Flow-based adhesion assay showed that engagement of CD103 or LFA-1, together with TCR, enhances the strength of the T-cell/target cell interaction. Moreover, electron microscopic analyses showed that integrin-dependent mature cIS (mcIS) displays a cohesive ultrastructure, with tight membrane contacts separated by extensive clefts. In contrast, immature cIS (icIS), which is unable to trigger target cell lysis, is loose, with multiple protrusions in the effector cell membrane. Experiments using confocal microscopy revealed polarized cytokine release and degranulation at the mcIS associated with target cell killing, whereas icIS is characterized by failure of IFN-γ and granzyme B relocalization. Thus, interactive forces between CTL and epithelial tumor cells, mainly regulated by integrin engagement, correlate with maturity and the ultrastructure of the cIS and influence CTL effector functions. These results provide new insights into molecular mechanisms regulating antitumor CTL responses and may lead to the development of more efficient cancer immunotherapy strategies. Cancer Res; 73(2); 617–28. ©2012 AACR.
Data from Dual Inhibition of Bcl-2 and Bcl-xL Strikingly Enhances PI3K Inhibition-Induced Apoptosis in Human Myeloid Leukemia Cells through a GSK3- and Bim-Dependent Mechanism
Authors: Rahmani Mohamed , Aust Mandy Mayo , Attkisson Elisa , Williams David C. , Ferreira-Gonzalez Andrea , Grant Steven
Published: March 2024

Abstract
Effects of concomitant inhibition of the PI3K/AKT/mTOR pathway and Bcl-2/Bcl-xL (BCL2L1) were examined in human myeloid leukemia cells. Tetracycline-inducible Bcl-2 and Bcl-xL dual knockdown sharply increased PI3K/AKT/mTOR inhibitor lethality. Conversely, inducible knockdown or dominant-negative AKT increased, whereas constitutively active AKT reduced lethality of the Bcl-2/Bcl-xL inhibitor ABT-737. Furthermore, PI3K/mTOR inhibitors (e.g., BEZ235 and PI-103) synergistically increased ABT-737–mediated cell death in multiple leukemia cell lines and reduced colony formation in leukemic, but not normal, CD34+ cells. Notably, increased lethality was observed in four of six primary acute myelogenous leukemia (AML) specimens. Responding, but not nonresponding, samples exhibited basal AKT phosphorylation. PI3K/mTOR inhibitors markedly downregulated Mcl-1 but increased Bim binding to Bcl-2/Bcl-xL; the latter effect was abrogated by ABT-737. Combined treatment also markedly diminished Bax/Bak binding to Mcl-1, Bcl-2, or Bcl-xL. Bax, Bak, or Bim (BCL2L11) knockdown or Mcl-1 overexpression significantly diminished regimen-induced apoptosis. Interestingly, pharmacologic inhibition or short hairpin RNA knockdown of GSK3α/β significantly attenuated Mcl-1 downregulation and decreased apoptosis. In a systemic AML xenograft model, dual tetracycline-inducible knockdown of Bcl-2/Bcl-xL sharply increased BEZ235 antileukemic effects. In a subcutaneous xenograft model, BEZ235 and ABT-737 coadministration significantly diminished tumor growth, downregulated Mcl-1, activated caspases, and prolonged survival. Together, these findings suggest that antileukemic synergism between PI3K/AKT/mTOR inhibitors and BH3 mimetics involves multiple mechanisms, including Mcl-1 downregulation, release of Bim from Bcl-2/Bcl-xL as well as Bak and Bax from Mcl-1/Bcl-2/Bcl-xL, and GSK3α/β, culminating in Bax/Bak activation and apoptosis. They also argue that combining PI3K/AKT/mTOR inhibitors with BH3 mimetics warrants attention in AML, particularly in the setting of basal AKT activation and/or addiction. Cancer Res; 73(4); 1340–51. ©2012 AACR.
Data from KLF5 Regulates the Integrity and Oncogenicity of Intestinal Stem Cells
Authors: Nakaya Takeo , Ogawa Seishi , Manabe Ichiro , Tanaka Masami , Sanada Masashi , Sato Toshiro , Taketo Makoto M. , Nakao Kazuki , Clevers Hans , Fukayama Masashi , Kuroda Masahiko , Nagai Ryozo
Published: March 2024

Abstract
The intestinal epithelium maintains homeostasis by a self-renewal process involving resident stem cells, including Lgr5+ crypt-base columnar cells, but core mechanisms and their contributions to intestinal cancer are not fully defined. In this study, we examined a hypothesized role for KLF5, a zinc-finger transcription factor that is critical to maintain the integrity of embryonic and induced pluripotent stem cells, in intestinal stem-cell integrity and cancer in the mouse. Klf5 was indispensable for the integrity and oncogenic transformation of intestinal stem cells. In mice, inducible deletion of Klf5 in Lgr5+ stem cells suppressed their proliferation and survival in a manner associated with nuclear localization of β-catenin (Catnb), generating abnormal apoptotic cells in intestinal crypts. Moreover, production of lethal adenomas and carcinomas by specific expression of an oncogenic mutant of β-catenin in Lgr5+ stem cells was suppressed completely by Klf5 deletion in the same cells. Given that activation of the Wnt/β-catenin pathway is the most frequently altered pathway in human colorectal cancer, our results argue that KLF5 acts as a fundamental core regulator of intestinal oncogenesis at the stem-cell level, and they suggest KLF5 targeting as a rational strategy to eradicate stem-like cells in colorectal cancer. Cancer Res; 74(10); 2882–91. ©2014 AACR.
Data from ΔNp63 Promotes Pediatric Neuroblastoma and Osteosarcoma by Regulating Tumor Angiogenesis
Authors: Bid Hemant K. , Roberts Ryan D. , Cam Maren , Audino Anthony , Kurmasheva Raushan T. , Lin Jiayuh , Houghton Peter J. , Cam Hakan
Published: March 2024

Abstract
The tumor suppressor gene p53 and its family members p63/p73 are critical determinants of tumorigenesis. ΔNp63 is a splice variant of p63, which lacks the N-terminal transactivation domain. It is thought to antagonize p53-, p63-, and p73-dependent translation, thus blocking their tumor suppressor activity. In our studies of the pediatric solid tumors neuroblastoma and osteosarcoma, we find overexpression of ΔNp63; however, there is no correlation of ΔNp63 expression with p53 mutation status. Our data suggest that ΔNp63 itself endows cells with a gain-of-function that leads to malignant transformation, a function independent of any p53 antagonism. Here, we demonstrate that ΔNp63 overexpression, independent of p53, increases secretion of interleukin (IL)-6 and IL-8, leading to elevated phosphorylation of STAT3 (Tyr-705). We show that elevated phosphorylation of STAT3 leads to stabilization of hypoxia-inducible factor 1α (HIF-1α) protein, resulting in VEGF secretion. We also show human clinical data, which suggest a mechanistic role for ΔNp63 in osteosarcoma metastasis. In summary, our studies reveal the mechanism by which ΔNp63, as a master transcription factor, modulates tumor angiogenesis. Cancer Res; 74(1); 320–9. ©2013 AACR.
Data from Low PIP4K2B Expression in Human Breast Tumors Correlates with Reduced Patient Survival: A Role for PIP4K2B in the Regulation of E-Cadherin Expression
Authors: Keune Willem-Jan , Sims Andrew H. , Jones David R. , Bultsma Yvette , Lynch James T. , Jirström Karin , Landberg Goran , Divecha Nullin
Published: March 2024

Abstract
Phosphatidylinositol-5-phosphate (PtdIns5P) 4-kinase β (PIP4K2B) directly regulates the levels of two important phosphoinositide second messengers, PtdIns5P and phosphatidylinositol-(4,5)-bisphosphate [PtdIns(4,5)P2]. PIP4K2B has been linked to the regulation of gene transcription, to TP53 and AKT activation, and to the regulation of cellular reactive oxygen accumulation. However, its role in human tumor development and on patient survival is not known. Here, we have interrogated the expression of PIP4K2B in a cohort (489) of patients with breast tumor using immunohistochemical staining and by a meta-analysis of gene expression profiles from 2,999 breast tumors, both with associated clinical outcome data. Low PIP4K2B expression was associated with increased tumor size, high Nottingham histological grade, Ki67 expression, and distant metastasis, whereas high PIP4K2B expression strongly associated with ERBB2 expression. Kaplan–Meier curves showed that both high and low PIP4K2B expression correlated with poorer patient survival compared with intermediate expression. In normal (MCF10A) and tumor (MCF7) breast epithelial cell lines, mimicking low PIP4K2B expression, using short hairpin RNA interference-mediated knockdown, led to a decrease in the transcription and expression of the tumor suppressor protein E-cadherin (CDH1). In MCF10A cells, knockdown of PIP4K2B enhanced TGF-β–induced epithelial to mesenchymal transition (EMT), a process required during the development of metastasis. Analysis of gene expression datasets confirmed the association between low PIP4K2B and low CDH1expression. Decreased CDH1 expression and enhancement of TGF-β–induced EMT by reduced PIP4K2B expression might, in part, explain the association between low PIP4K2B expression and poor patient survival. Cancer Res; 73(23); 6913–25. ©2013 AACR.
Data from USP22 Regulates Oncogenic Signaling Pathways to Drive Lethal Cancer Progression
Authors: Schrecengost Randy S. , Dean Jeffry L. , Goodwin Jonathan F. , Schiewer Matthew J. , Urban Mark W. , Stanek Timothy J. , Sussman Robyn T. , Hicks Jessica L. , Birbe Ruth C. , Draganova-Tacheva Rossitza A. , Visakorpi Tapio , DeMarzo Angelo M. , McMahon Steven B. , Knudsen Karen E.
Published: March 2024

Abstract
Increasing evidence links deregulation of the ubiquitin-specific proteases 22 (USP22) deubitiquitylase to cancer development and progression in a select group of tumor types, but its specificity and underlying mechanisms of action are not well defined. Here we show that USP22 is a critical promoter of lethal tumor phenotypes that acts by modulating nuclear receptor and oncogenic signaling. In multiple xenograft models of human cancer, modeling of tumor-associated USP22 deregulation demonstrated that USP22 controls androgen receptor accumulation and signaling, and that it enhances expression of critical target genes coregulated by androgen receptor and MYC. USP22 not only reprogrammed androgen receptor function, but was sufficient to induce the transition to therapeutic resistance. Notably, in vivo depletion experiments revealed that USP22 is critical to maintain phenotypes associated with end-stage disease. This was a significant finding given clinical evidence that USP22 is highly deregulated in tumors, which have achieved therapeutic resistance. Taken together, our findings define USP22 as a critical effector of tumor progression, which drives lethal phenotypes, rationalizing this enzyme as an appealing therapeutic target to treat advanced disease. Cancer Res; 74(1); 272–86. ©2013 AACR.
Data from High-Throughput Tyrosine Kinase Activity Profiling Identifies FAK as a Candidate Therapeutic Target in Ewing Sarcoma
Authors: Crompton Brian D. , Carlton Anne L. , Thorner Aaron R. , Christie Amanda L. , Du Jinyan , Calicchio Monica L. , Rivera Miguel N. , Fleming Mark D. , Kohl Nancy E. , Kung Andrew L. , Stegmaier Kimberly
Published: March 2024

Abstract
Limited progress has been made in the treatment of advanced-stage pediatric solid tumors despite the accelerated pace of cancer discovery over the last decade. Tyrosine kinase inhibition is one tractable therapeutic modality for treating human malignancy. However, little is known about the kinases critical to the development or maintenance of many pediatric solid tumors such as Ewing sarcoma. Using a fluorescent, bead-based technology to profile activated tyrosine kinases, we identified focal adhesion kinase (FAK, PTK2) as a candidate target in Ewing sarcoma. FAK is a tyrosine kinase critical for cellular adhesion, growth, and survival. As such, it is a compelling target for cancer-based therapy. In this study, we have shown that FAK is highly phosphorylated in primary Ewing sarcoma tumor samples and that downregulation of FAK by short hairpin RNA and treatment with a FAK-selective kinase inhibitor, PF-562271, impaired growth and colony formation in Ewing sarcoma cell lines. Moreover, treatment of Ewing sarcoma cell lines with PF-562271 induced apoptosis and led to downregulation of AKT/mTOR and CAS activity. Finally, we showed that small-molecule inhibition of FAK attenuated Ewing sarcoma tumor growth in vivo. With FAK inhibitors currently in early-phase clinical trials for adult malignancies, these findings may bear immediate relevance to patients with Ewing sarcoma. Cancer Res; 73(9); 2873–83. ©2013 AACR.
Data from Targeting XRCC1 Deficiency in Breast Cancer for Personalized Therapy
Authors: Sultana Rebeka , Abdel-Fatah Tarek , Abbotts Rachel , Hawkes Claire , Albarakati Nada , Seedhouse Claire , Ball Graham , Chan Stephen , Rakha Emad A. , Ellis Ian O. , Madhusudan Srinivasan
Published: March 2024

Abstract
XRCC1 is a key component of DNA base excision repair, single strand break repair, and backup nonhomologous end-joining pathway. XRCC1 (X-ray repair cross-complementing gene 1) deficiency promotes genomic instability, increases cancer risk, and may have clinical application in breast cancer. We investigated XRCC1 expression in early breast cancers (n = 1,297) and validated in an independent cohort of estrogen receptor (ER)-α–negative breast cancers (n = 281). Preclinically, we evaluated XRCC1-deficient and -proficient Chinese hamster and human cancer cells for synthetic lethality application using double-strand break (DSB) repair inhibitors [KU55933 (ataxia telangectasia–mutated; ATM inhibitor) and NU7441 (DNA-PKcs inhibitor)]. In breast cancer, loss of XRCC1 (16%) was associated with high grade (P < 0.0001), loss of hormone receptors (P < 0.0001), triple-negative (P < 0.0001), and basal-like phenotypes (P = 0.001). Loss of XRCC1 was associated with a two-fold increase in risk of death (P < 0.0001) and independently with poor outcome (P < 0.0001). Preclinically, KU55933 [2-(4-Morpholinyl)-6-(1-thianthrenyl)-4H-pyran-4-one] and NU7441 [8-(4-Dibenzothienyl)-2-(4-morpholinyl)-4H-1-benzopyran-4-one] were synthetically lethal in XRCC1-deficient compared with proficient cells as evidenced by hypersensitivity to DSB repair inhibitors, accumulation of DNA DSBs, G2–M cell-cycle arrest, and induction of apoptosis. This is the first study to show that XRCC1 deficiency in breast cancer results in an aggressive phenotype and that XRCC1 deficiency could also be exploited for a novel synthetic lethality application using DSB repair inhibitors. Cancer Res; 73(5); 1621–34. ©2012 AACR.
Data from De Novo Design of a Tumor-Penetrating Peptide
Authors: Alberici Luca , Roth Lise , Sugahara Kazuki N. , Agemy Lilach , Kotamraju Venkata R. , Teesalu Tambet , Bordignon Claudio , Traversari Catia , Rizzardi Gian-Paolo , Ruoslahti Erkki
Published: March 2024

Abstract
Poor penetration of antitumor drugs into the extravascular tumor tissue is often a major factor limiting the efficacy of cancer treatments. Our group has recently described a strategy to enhance tumor penetration of chemotherapeutic drugs through use of iRGD peptide (CRGDK/RGPDC). This peptide comprises two sequence motifs: RGD, which binds to αvβ3/5 integrins on tumor endothelia and tumor cells, and a cryptic CendR motif (R/KXXR/K-OH). Once integrin binding has brought iRGD to the tumor, the peptide is proteolytically cleaved to expose the cryptic CendR motif. The truncated peptide loses affinity for its primary receptor and binds to neuropilin-1, activating a tissue penetration pathway that delivers the peptide along with attached or co-administered payload into the tumor mass. Here, we describe the design of a new tumor-penetrating peptide based on the current knowledge of homing sequences and internalizing receptors. The tumor-homing motif in the new peptide is the NGR sequence, which binds to endothelial CD13. The NGR sequence was placed in the context of a CendR motif (RNGR), and this sequence was embedded in the iRGD framework. The resulting peptide (CRNGRGPDC, iNGR) homed to tumor vessels and penetrated into tumor tissue more effectively than the standard NGR peptide. iNGR induced greater tumor penetration of coupled nanoparticles and co-administered compounds than NGR. Doxorubicin given together with iNGR was significantly more efficacious than the drug alone. These results show that a tumor-specific, tissue-penetrating peptide can be constructed from known sequence elements. This principle may be useful in designing tissue-penetrating peptides for other diseases. Cancer Res; 73(2); 804–12. ©2012 AACR.
Data from A Chimeric Receptor with NKG2D Specificity Enhances Natural Killer Cell Activation and Killing of Tumor Cells
Authors: Chang Yu-Hsiang , Connolly John , Shimasaki Noriko , Mimura Kousaku , Kono Koji , Campana Dario
Published: March 2024

Abstract
Natural killer (NK) cells rely on surface receptors to distinguish healthy cells from cancer cells. We designed a receptor termed NKG2D-DAP10-CD3ζ that is composed of the NK cell activating molecule NKG2D plus 2 key signaling molecules, DAP10 and CD3ζ, and evaluated its capacity to promote cancer cell killing. Retroviral transduction of NKG2D-DAP10-CD3ζ markedly increased NKG2D surface expression in NK cells, which became consistently more cytotoxic than mock-transduced cells against leukemia and solid tumor cell lines. In contrast, there was no increase in cytotoxicity against nontransformed blood and mesenchymal cells. NKG2D blockade abrogated gains in cytotoxicity to cancer cells. Receptor stimulation triggered signal transduction, secretion of IFN-γ, GM-CSF, IL-13, MIP-1α, MIP-1β, CCL5, and TNF-α, and massive release of cytotoxic granules, which persisted after 48 hours of continuous stimulation. NKG2D-DAP10-CD3ζ–expressing NK cells had considerable antitumor activity in a mouse model of osteosarcoma, whereas activated NK cells were ineffective. Thus, the cytotoxic potential of NK cells against a wide spectrum of tumor subtypes could be markedly enhanced by expression of NKG2D-DAP10-CD3ζ receptors. The development of an electroporation method that permits rapid expression of the receptor in a large number of human NK cells facilitates clinical translation of this NK-based strategy for a generalized cellular therapy that may be useful to treat a wide range of cancers. Cancer Res; 73(6); 1777–86. ©2012 AACR.
Data from Phenotypic Profiling of DPYD Variations Relevant to 5-Fluorouracil Sensitivity Using Real-time Cellular Analysis and In Vitro Measurement of Enzyme Activity
Authors: Offer Steven M. , Wegner Natalie J. , Fossum Croix , Wang Kangsheng , Diasio Robert B.
Published: March 2024

Abstract
In the 45 years since its development, the pyrimidine analog 5-fluorouracil (5-FU) has become an integral component of many cancer treatments, most notably for the management of colorectal cancer. An appreciable fraction of patients who receive 5-FU suffer severe adverse toxicities, which in extreme cases may result in death. Dihydropyrimidine dehydrogenase (DPD, encoded by DPYD) rapidly degrades 85% of administered 5-FU, and as such, limits the amount of drug available for conversion into active metabolites. Clinical studies have suggested that genetic variations in DPYD increase the risk for 5-FU toxicity, however, there is not a clear consensus about which variations are relevant predictors. In the present study, DPYD variants were expressed in mammalian cells, and the enzymatic activity of expressed protein was determined relative to wild-type (WT). Relative sensitivity to 5-FU for cells expressing DPYD variations was also measured. The DPYD*2A variant (exon 14 deletion caused by IVS14+1G>A) was confirmed to be catalytically inactive. Compared with WT, two variants, S534N and C29R, showed significantly higher enzymatic activity. Cells expressing S534N were more resistant to 5-FU–mediated toxicity compared with cells expressing WT DPYD. These findings support the hypothesis that selected DPYD alleles are protective against severe 5-FU toxicity, and, as a consequence, may decrease the effectiveness of 5-FU an antitumor drug in carriers. In addition, this study shows a method that may be useful for phenotyping other genetic variations in pharmacologically relevant pathways. Cancer Res; 73(6); 1958–68. ©2013 AACR.
Data from Regulation of CD4+NKG2D+ Th1 Cells in Patients with Metastatic Melanoma Treated with Sorafenib: Role of IL-15Rα and NKG2D Triggering
Authors: Romero Ana I. , Chaput Nathalie , Poirier-Colame Vichnou , Rusakiewicz Sylvie , Jacquelot Nicolas , Chaba Kariman , Mortier Erwan , Jacques Yannick , Caillat-Zucman Sophie , Flament Caroline , Caignard Anne , Messaoudene Meriem , Aupérin Anne , Vielh Philippe , Dessen Philippe , Porta Camillo , Mateus Christine , Ayyoub Maha , Valmori Danila , Eggermont Alexander , Robert Caroline , Zitvogel Laurence
Published: March 2024

Abstract
Beyond cancer-cell intrinsic factors, the immune status of the host has a prognostic impact on patients with cancer and influences the effects of conventional chemotherapies. Metastatic melanoma is intrinsically immunogenic, thereby facilitating the search for immune biomarkers of clinical responses to cytotoxic agents. Here, we show that a multi-tyrosine kinase inhibitor, sorafenib, upregulates interleukin (IL)-15Rα in vitro and in vivo in patients with melanoma, and in conjunction with natural killer (NK) group 2D (NKG2D) ligands, contributes to the Th1 polarization and accumulation of peripheral CD4+NKG2D+ T cells. Hence, the increase of blood CD4+NKG2D+ T cells after two cycles of sorafenib (combined with temozolomide) was associated with prolonged survival in a prospective phase I/II trial enrolling 63 patients with metastatic melanoma who did not receive vemurafenib nor immune checkpoint–blocking antibodies. In contrast, in metastatic melanoma patients treated with classical treatment modalities, this CD4+NKG2D+ subset failed to correlate with prognosis. These findings indicate that sorafenib may be used as an “adjuvant” molecule capable of inducing or restoring IL-15Rα/IL-15 in tumors expressing MHC class I–related chain A/B (MICA/B) and on circulating monocytes of responding patients, hereby contributing to the bioactivity of NKG2D+ Th1 cells. Cancer Res; 74(1); 68–80. ©2013 AACR.
Data from Transcriptional Profiling of Melanoma Sentinel Nodes Identify Patients with Poor Outcome and Reveal an Association of CD30+ T Lymphocytes with Progression
Authors: Vallacchi Viviana , Vergani Elisabetta , Camisaschi Chiara , Deho Paola , Cabras Antonello D. , Sensi Marialuisa , De Cecco Loris , Bassani Niccolò , Ambrogi Federico , Carbone Antonino , Crippa Federica , Vergani Barbara , Frati Paola , Arienti Flavio , Patuzzo Roberto , Villa Antonello , Biganzoli Elia , Canevari Silvana , Santinami Mario , Castelli Chiara , Rivoltini Licia , Rodolfo Monica
Published: March 2024

Abstract
Sentinel lymph nodes set the stance of the immune system to a localized tumor and are often the first site to be colonized by neoplastic cells that metastasize. To investigate how the presence of neoplastic cells in sentinel lymph nodes may trigger pathways associated with metastatic progression, we analyzed the transcriptional profiles of archival sentinel node biopsy specimens obtained from melanoma patients. Biopsies from positive nodes were selected for comparable tumor infiltration, presence or absence of further regional node metastases, and relapse at 5-year follow-up. Unsupervised analysis of gene expression profiles revealed immune response to be a major gene ontogeny represented. Among genes upregulated in patients with progressing disease, the TNF receptor family member CD30/TNFRSF8 was confirmed in biopsy specimens from an independent group of patients. Immunohistochemical analysis revealed higher numbers of CD30+ lymphocytes in nodes from progressing patients compared with nonprogressing patients. Phenotypic profiling demonstrated that CD30+ lymphocytes comprised a broad population of suppressive or exhausted immune cells, such as CD4+Foxp3+ or PD1+ subpopulations and CD4−CD8− T cells. CD30+ T lymphocytes were increased in peripheral blood lymphocytes of melanoma patients at advanced disease stages. Our findings reinforce the concept that sentinel nodes act as pivotal sites for determining progression patterns, revealing that the presence of CD30+ lymphocytes at those sites associate positively with melanoma progression. Cancer Res; 74(1); 130–40. ©2014 AACR.
Data from Drug–Gene Modeling in Pediatric T-Cell Acute Lymphoblastic Leukemia Highlights Importance of 6-Mercaptopurine for Outcome
Authors: Beesley Alex H. , Firth Martin J. , Anderson Denise , Samuels Amy L. , Ford Jette , Kees Ursula R.
Published: March 2024

Abstract
Patients relapsing with T-cell acute lymphoblastic leukemia (T-ALL) face a dismal outcome. The aim of this study was to identify new markers of drug resistance and clinical response in T-ALL. We measured gene expression and drug sensitivity in 15 pediatric T-ALL cell lines to find signatures predictive of resistance to 10 agents used in therapy. These were used to generate a model for outcome prediction in patient cohorts using microarray data from diagnosis specimens. In three independent T-ALL cohorts, the 10-drug model was able to accurately identify patient outcome, indicating that the in vitro–derived drug–gene profiles were clinically relevant. Importantly, predictions of outcome within each cohort were linked to distinct drugs, suggesting that different mechanisms contribute to relapse. Sulfite oxidase (SUOX) expression and the drug-transporter ABCC1 (MRP1) were linked to thiopurine sensitivity, suggesting novel pathways for targeting resistance. This study advances our understanding of drug resistance in T-ALL and provides new markers for patient stratification. The results suggest potential benefit from the earlier use of 6-mercaptopurine in T-ALL therapy or the development of adjuvants that may sensitize blasts to this drug. The methodology developed in this study could be applied to other cancers to achieve patient stratification at the time of diagnosis. Cancer Res; 73(9); 2749–59. ©2013 AACR.
Data from An Integrated Computational Model of the Bone Microenvironment in Bone-Metastatic Prostate Cancer
Authors: Araujo Arturo , Cook Leah M. , Lynch Conor C. , Basanta David
Published: March 2024

Abstract
Bone metastasis will impact most men with advanced prostate cancer. The vicious cycle of bone degradation and formation driven by metastatic prostate cells in bone yields factors that drive cancer growth. Mechanistic insights into this vicious cycle have suggested new therapeutic opportunities, but complex temporal and cellular interactions in the bone microenvironment make drug development challenging. We have integrated biologic and computational approaches to generate a hybrid cellular automata model of normal bone matrix homeostasis and the prostate cancer-bone microenvironment. The model accurately reproduces the basic multicellular unit bone coupling process, such that introduction of a single prostate cancer cell yields a vicious cycle similar in cellular composition and pathophysiology to models of prostate-to-bone metastasis. Notably, the model revealed distinct phases of osteolytic and osteogenic activity, a critical role for mesenchymal stromal cells in osteogenesis, and temporal changes in cellular composition. To evaluate the robustness of the model, we assessed the effect of established bisphosphonate and anti-RANKL therapies on bone metastases. At approximately 100% efficacy, bisphosphonates inhibited cancer progression while, in contrast with clinical observations in humans, anti-RANKL therapy fully eradicated metastases. Reducing anti-RANKL yielded clinically similar results, suggesting that better targeting or dosing could improve patient survival. Our work establishes a computational model that can be tailored for rapid assessment of experimental therapies and delivery of precision medicine to patients with prostate cancer with bone metastases. Cancer Res; 74(9); 2391–401. ©2014 AACR.