bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from The Inflammasome Component Nlrp3 Impairs Antitumor Vaccine by Enhancing the Accumulation of Tumor-Associated Myeloid-Derived Suppressor Cells
Authors: van Deventer Hendrik W. , Burgents Joseph E. , Wu Qing Ping , Woodford Rita-Marie T. , Brickey W. June , Allen Irving C. , McElvania-Tekippe Erin , Serody Jonathan S. , Ting Jenny P.-Y.
Published: March 2024

Abstract
The inflammasome is a proteolysis complex that generates the active forms of the proinflammatory cytokines interleukin (IL)-1β and IL-18. Inflammasome activation is mediated by NLR proteins that respond to microbial and nonmicrobial stimuli. Among NLRs, NLRP3 senses the widest array of stimuli and enhances adaptive immunity. However, its role in antitumor immunity is unknown. Therefore, we evaluated the function of the NLRP3 inflammasome in the immune response using dendritic cell vaccination against the poorly immunogenic melanoma cell line B16-F10. Vaccination of Nlrp3−/− mice led to a relative 4-fold improvement in survival relative to control animals. Immunity depended on CD8+ T cells and exhibited immune specificity and memory. Increased vaccine efficacy in Nlrp3−/− hosts did not reflect differences in dendritic cells but rather differences in myeloid-derived suppressor cells (MDSC). Although Nlrp3 was expressed in MDSCs, the absence of Nlrp3 did not alter either their functional capacity to inhibit T cells or their presence in peripheral lymphoid tissues. Instead, the absence of Nlrp3 caused a 5-fold reduction in the number of tumor-associated MDSCs found in host mice. Adoptive transfer experiments also showed that Nlrp3−/− MDSCs were less efficient in reaching the tumor site. Depleting MDSCs with an anti–Gr-1 antibody increased the survival of tumor-bearing wild-type mice but not Nlrp3−/− mice. We concluded that Nlrp3 was critical for accumulation of MDSCs in tumors and for inhibition of antitumor T-cell immunity after dendritic cell vaccination. Our findings establish an unexpected role for Nlrp3 in impeding antitumor immune responses, suggesting novel approaches to improve the response to antitumor vaccines by limiting Nlrp3 signaling. Cancer Res; 70(24); 10161–9. ©2010 AACR.
Data from Amiloride Modulates Alternative Splicing in Leukemic Cells and Resensitizes Bcr-AblT315I Mutant Cells to Imatinib
Authors: Chang Wen-Hsin , Liu Ta-Chih , Yang Wen-Kuang , Lee Chien-Chih , Lin Yi-Hsiung , Chen Tsai-Yun , Chang Jan-Gowth
Published: March 2024

Abstract
The antihypertensive drug amiloride is being considered as a tactic to improve cancer therapy including that for chronic myelogenous leukemia. In this study, we show that amiloride modulates the alternative splicing of various cancer genes, including Bcl-x, HIPK3, and BCR/ABL, and that this effect is not mainly related to pH alteration, which is a known effect of the drug. Splice modulation involved various splicing factors, with the phosphorylation state of serine-arginine–rich (SR) proteins also altered during the splicing process. Pretreatment with okadaic acid to inhibit protein phosphatase PP1 reversed partially the phosphorylation levels of SR proteins and also the amiloride-modulated yields of Bcl-xs and HIPK3 U(-) isoforms. Genome-wide detection of alternative splicing further revealed that many other apoptotic genes were regulated by amiloride, including APAF-1, CRK, and SURVIVIN. Various proteins of the Bcl-2 family and MAPK kinases were found to be involved in amiloride-induced apoptosis. Moreover, the effect of amiloride on mRNA levels of Bcl-x was demonstrated to translate to the protein levels. Cotreatment of K562 and BaF3/Bcr-AblT315I cells with amiloride and imatinib induced more loss of cell viability than either agent alone. Our findings suggest that amiloride may offer a potential treatment option for chronic myelogenous leukemia either alone or in combination with imatinib. Cancer Res; 71(2); 383–92. ©2011 AACR.
Data from p38 Kinase Is Crucial for Osteopontin-Induced Furin Expression That Supports Cervical Cancer Progression
Authors: Kumar Vinit , Behera Reeti , Lohite Kirti , Karnik Swapnil , Kundu Gopal C
Published: March 2024

Abstract
p38 kinases activated by growth factors, hormones, and environmental stresses exert diverse functions in regulating normal and malignant cell pathophysiology. Enhanced levels of activated p38 isoforms have been linked with poor prognosis in breast cancer, although the mechanistic basis for this association is poorly understood. In this study, we report that p38 activation in cervical cancer cells is driven by osteopontin (OPN), an extracellular matrix–associated cytokine that drives invasive progression. OPN regulates CD44-mediated p38 phosphorylation that induces NF-κB activation and NF-κB–dependent expression of furin, an extracellular protease implicated in human papilloma virus (HPV) processing that enhances cervical cancer cell motility. OPN induces CD44-mediated MKK3/6 phosphorylation which in turn phosphorylates p38 in these cells. OPN-induced furin expression and cell motility was impeded by blockades to MKK3/6, p38α/β or NF-κB signaling. In a mouse xenograft model of human cervical cancer, tumor growth was enhanced by OPN overexpression and blocked by short hairpin RNA (shRNA)–mediated OPN silencing. Furin overexpression similarly augmented tumor growth in the model, whereas blocking MKK3/6, p38, or furin reduced OPN-induced cervical tumor growth. Analysis of clinical specimens revealed that enhanced expression of OPN, phosphorylated NF-κB, p65, and furin correlated with cervical cancer progression, further strengthening the in vitro and in vivo results. In summary, our findings offer a proof of concept for targeting OPN and its downstream p38 signaling as a novel therapeutic strategy to manage cervical cancer. Cancer Res; 70(24); 10381–91. ©2010 AACR.
Data from Cyclophosphamide Induces Differentiation of Th17 Cells in Cancer Patients
Authors: Viaud Sophie , Flament Caroline , Zoubir Mustapha , Pautier Patricia , LeCesne Axel , Ribrag Vincent , Soria Jean-Charles , Marty Virginie , Vielh Philippe , Robert Caroline , Chaput Nathalie , Zitvogel Laurence
Published: March 2024

Abstract
Low doses of the alkylating agent cyclophosphamide (CTX) mediate antiangiogenic and immunostimulatory effects, leading to potent tumoricidal activity in association with various immunotherapeutic strategies. Here, we show in rodents and cancer patients that CTX markedly promotes the differentiation of CD4+ T helper 17 (Th17) cells that can be recovered in both blood and tumor beds. However, CTX does not convert regulatory T cells into Th17 cells. Because Th17 are potent inducers of tissue inflammation and autoimmunity, these results suggest impact on the clinical management of various types of malignancies treated with alkylating agents and a potential need to optimize CTX-based immunotherapy in patients. Cancer Res; 71(3); 661–5. ©2010 AACR.
Data from Isoform-Specific Phosphoinositide 3-Kinase Inhibitors Exert Distinct Effects in Solid Tumors
Authors: Edgar Kyle A. , Wallin Jeffrey J. , Berry Megan , Lee Leslie B. , Prior Wei Wei , Sampath Deepak , Friedman Lori S. , Belvin Marcia
Published: March 2024

Abstract
Therapeutic inhibitors are being developed against the phosphoinositide 3-kinase (PI3K) pathway, the deregulation of which drives tumor growth and survival in many cancers. There are eight PI3Ks in mammals divided into three classes. Class IA PI3Ks (p110α, p110β, and p110δ) are critical for cell growth and survival, with the p110α isoform implicated as the most important in carcinomas. In this study, we examined the effects of small-molecule inhibitors of class IA PI3Ks to explore the contributions of different isoforms in cancer cells. Similar responses were seen in cancer cells with wild-type or activated mutant PI3K genes treated with p110α/δ or p110α/β/δ inhibitors in cell viability assays. In contrast, PTEN-negative cell lines tended to be less responsive (4-fold overall) to an inhibitor of p110α/δ versus p110α/β/δ. Combining a p110α/δ inhibitor with a p110β inhibitor resulted in comparable potency to the p110α/β/δ inhibitor. The disparity in efficacy was confirmed in vivo. Pharmacodynamic biomarker analysis revealed that an inhibitor with insufficient potency against the p110β isoform was less effective at inhibiting the PI3K pathway in PTEN-negative tumor xenografts. Our results imply that patients with PTEN-negative tumors may preferentially benefit from treatment with a class I PI3K inhibitor that is capable of inhibiting the p110β isoform. Cancer Res; 70(3); 1164–72
Data from Tyrosine Phosphorylation Profiling Reveals the Signaling Network Characteristics of Basal Breast Cancer Cells
Authors: Hochgräfe Falko , Zhang Luxi , O'Toole Sandra A. , Browne Brigid C. , Pinese Mark , Porta Cubas Ana , Lehrbach Gillian M. , Croucher David R. , Rickwood Danny , Boulghourjian Alice , Shearer Robert , Nair Radhika , Swarbrick Alexander , Faratian Dana , Mullen Peter , Harrison David J. , Biankin Andrew V. , Sutherland Robert L. , Raftery Mark J. , Daly Roger J.
Published: March 2024

Abstract
To identify therapeutic targets and prognostic markers for basal breast cancers, breast cancer cell lines were subjected to mass spectrometry–based profiling of protein tyrosine phosphorylation events. This revealed that luminal and basal breast cancer cells exhibit distinct tyrosine phosphorylation signatures that depend on pathway activation as well as protein expression. Basal breast cancer cells are characterized by elevated tyrosine phosphorylation of Met, Lyn, EphA2, epidermal growth factor receptor (EGFR), and FAK, and Src family kinase (SFK) substrates such as p130Cas. SFKs exert a prominent role in these cells, phosphorylating key regulators of adhesion and migration and promoting tyrosine phosphorylation of the receptor tyrosine kinases EGFR and Met. Consistent with these observations, SFK inhibition attenuated cellular proliferation, survival, and motility. Basal breast cancer cell lines exhibited differential responsiveness to small molecule inhibitors of EGFR and Met that correlated with the degree of target phosphorylation, and reflecting kinase coactivation, inhibiting two types of activated network kinase (e.g., EGFR and SFKs) was more effective than single agent approaches. FAK signaling enhanced both proliferation and invasion, and Lyn was identified as a proinvasive component of the network that is associated with a basal phenotype and poor prognosis in patients with breast cancer. These studies highlight multiple kinases and substrates for further evaluation as therapeutic targets and biomarkers. However, they also indicate that patient stratification based on expression/activation of drug targets, coupled with use of multi-kinase inhibitors or combination therapies, may be required for effective treatment of this breast cancer subgroup. Cancer Res; 70(22); 9391–401. ©2010 AACR.
Data from A Dual PI3K/mTOR Inhibitor, PI-103, Cooperates with Stem Cell–Delivered TRAIL in Experimental Glioma Models
Authors: Bagci-Onder Tugba , Wakimoto Hiroaki , Anderegg Maarten , Cameron Cody , Shah Khalid
Published: March 2024

Abstract
The resistance of glioma cells to a number of antitumor agents and the highly invasive nature of glioma cells that escape the primary tumor mass are key impediments to the eradication of tumors in glioma patients. In this study, we evaluated the therapeutic efficacy of a novel PI3-kinase/mTOR inhibitor, PI-103, in established glioma lines and primary CD133+ glioma-initiating cells and explored the potential of combining PI-103 with stem cell–delivered secretable tumor necrosis factor apoptosis-inducing ligand (S-TRAIL) both in vitro and in orthotopic mouse models of gliomas. We show that PI-103 inhibits proliferation and invasion, causes G0–G1 arrest in cell cycle, and results in significant attenuation of orthotopic tumor growth in vivo. Establishing cocultures of neural stem cells (NSC) and glioma cells, we show that PI-103 augments the response of glioma cells to stem cell–delivered S-TRAIL. Using bimodal optical imaging, we show that when different regimens of systemic PI-103 delivery are combined with NSC-derived S-TRAIL, a significant reduction in tumor volumes is observed compared with PI-103 treatment alone. To our knowledge, this is the first study that reveals the antitumor effect of PI-103 in intracranial gliomas. Our findings offer a preclinical rationale for application of mechanism-based systemically delivered antiproliferative agents and novel stem cell–based proapoptotic therapies to improve treatment of malignant gliomas. Cancer Res; 71(1); 154–63. ©2010 AACR.
Data from FGFR1 Amplification Drives Endocrine Therapy Resistance and Is a Therapeutic Target in Breast Cancer
Authors: Turner Nicholas , Pearson Alex , Sharpe Rachel , Lambros Maryou , Geyer Felipe , Lopez-Garcia Maria A. , Natrajan Rachael , Marchio Caterina , Iorns Elizabeth , Mackay Alan , Gillett Cheryl , Grigoriadis Anita , Tutt Andrew , Reis-Filho Jorge S. , Ashworth Alan
Published: March 2024

Abstract
Amplification of fibroblast growth factor receptor 1 (FGFR1) occurs in ∼10% of breast cancers and is associated with poor prognosis. However, it is uncertain whether overexpression of FGFR1 is causally linked to the poor prognosis of amplified cancers. Here, we show that FGFR1 overexpression is robustly associated with FGFR1 amplification in two independent series of breast cancers. Breast cancer cell lines with FGFR1 overexpression and amplification show enhanced ligand-dependent signaling, with increased activation of the mitogen-activated protein kinase and phosphoinositide 3-kinase–AKT signaling pathways in response to FGF2, but also show basal ligand-independent signaling, and are dependent on FGFR signaling for anchorage-independent growth. FGFR1-amplified cell lines show resistance to 4-hydroxytamoxifen, which is reversed by small interfering RNA silencing of FGFR1, suggesting that FGFR1 overexpression also promotes endocrine therapy resistance. FGFR1 signaling suppresses progesterone receptor (PR) expression in vitro, and likewise, amplified cancers are frequently PR negative, identifying a potential biomarker for FGFR1 activity. Furthermore, we show that amplified cancers have a high proliferative rate assessed by Ki67 staining and that FGFR1 amplification is found in 16% to 27% of luminal B–type breast cancers. Our data suggest that amplification and overexpression of FGFR1 may be a major contributor to poor prognosis in luminal-type breast cancers, driving anchorage-independent proliferation and endocrine therapy resistance. Cancer Res; 70(5); 2085–94
Data from VEGF-PET Imaging Is a Noninvasive Biomarker Showing Differential Changes in the Tumor during Sunitinib Treatment
Authors: Nagengast Wouter B. , Lub-de Hooge Marjolijn N. , Oosting Sjoukje F. , den Dunnen Wilfred F.A. , Warnders Frank-Jan , Brouwers Adrienne H. , de Jong Johan R. , Price Patricia M. , Hollema Harry , Hospers Geke A.P. , Elsinga Philip H. , Hesselink Jan Willem , Gietema Jourik A. , de Vries Elisabeth G.E.
Published: March 2024

Abstract
Non-invasive imaging of angiogenesis could ease the optimization of antiangiogenesis treatments for cancer. In this study, we evaluated the role of VEGF-PET as a biomarker of dynamic angiogenic changes in tumors following treatment with the kinase inhibitor sunitinib. The effects of sunitinib treatment and withdrawal on the tumor was investigated using the new VEGF-PET tracer 89Zr-ranibizumab as well as 18F-FDG PET, and 15O-water PET in mouse xenograft models of human cancer. The obtained imaging results were compared with tumor growth, VEGF plasma levels and immunohistologic analyzes. In contrast to 18F-FDG and 15O-water PET, VEGF-PET demonstrated dynamic changes during sunitinib treatment within the tumor with a strong decline in signal in the tumor center and only minimal reduction in tumor rim, with a pronounced rebound after sunitinib discontinuation. VEGF-PET results corresponded with tumor growth and immunohistochemical vascular- and tumor- markers. Our findings highlight the strengths of VEGF-PET imaging to allow serial analysis of angiogenic changes in different areas within a tumor. Cancer Res; 71(1); 143–53. ©2010 AACR.
Data from A Novel Sialyltransferase Inhibitor Suppresses FAK/Paxillin Signaling and Cancer Angiogenesis and Metastasis Pathways
Authors: Chen Jia-Yang , Tang Yen-An , Huang Sin-Ming , Juan Hsueh-Fen , Wu Li-Wha , Sun Ying-Chieh , Wang Szu-Chi , Wu Kuan-Wei , Balraj Gopula , Chang Tzu-Ting , Li Wen-Shan , Cheng Hung-Chi , Wang Yi-Ching
Published: March 2024

Abstract
Increased sialyltransferase (ST) activity promotes cancer cell metastasis, and overexpression of cell surface sialic acid correlates with poor prognosis in cancer patients. To seek therapies targeting metastasis for cancer treatment, we developed a novel ST inhibitor, Lith-O-Asp, and investigated its antimetastatic and antiangiogenic effects and mechanisms. We found that cells treated with Lith-O-Asp showed a reduction of activity on various ST enzymes by in vitro and cell-based activity analyses. Lith-O-Asp inhibited migration and invasion abilities in various cancer cell lines and showed inhibitory effect on the angiogenic activity of human umbilical vein endothelial cells. Indeed, Lith-O-Asp treatment consequently delayed cancer cell metastasis in experimental and spontaneous metastasis assays in animal models. Importantly, Lith-O-Asp decreased the sialic acid modification of integrin-β1 and inhibited the expression of phospho-FAK, phospho-paxillin, and the matrix metalloprotease (MMP) 2 and MMP9. Lith-O-Asp attenuated the Rho GTPase activity leading to actin dynamic impairment. In addition, 2DE-MS/MS and immunoblotting analyses showed that Lith-O-Asp altered the protein expression level and phosphorylation status of various proteins involved in crucial metastasis and angiogenesis pathways such as vimentin and ribonuclease/angiogenin inhibitor RNH1. Furthermore, Lith-O-Asp treatment significantly inhibited the invasive ability exerted by ectopic overexpression of various ST enzymes catalyzing α-2,6- or α-2,3-sialylation. Our results provide compelling evidence that the potential pan-ST inhibitor, Lith-O-Asp, suppressed cancer cell metastasis likely by inhibiting FAK/paxillin signaling and expressing antiangiogenesis factors. Lith-O-Asp is worthy for further testing as a novel antimetastasis drug for cancer treatment. Cancer Res; 71(2); 473–83. ©2011 AACR.
Data from Id2 Promotes Tumor Cell Migration and Invasion through Transcriptional Repression of Semaphorin 3F
Authors: Coma Silvia , Amin Dhara N. , Shimizu Akio , Lasorella Anna , Iavarone Antonio , Klagsbrun Michael
Published: March 2024

Abstract
Id proteins (Id1 to Id4) are helix-loop-helix transcription factors that promote metastasis. It was found that Semaphorin 3F (SEMA3F), a potent inhibitor of metastasis, was repressed by Id2. High metastatic human tumor cell lines had relatively high amounts of Id2 and low SEMA3F levels compared with their low metastatic counterparts. No correlation between metastatic potential and expression of the other Id family members was observed. Furthermore, ectopic expression of Id2 in low metastatic tumor cells downregulated SEMA3F and, as a consequence, enhanced their ability to migrate and invade, two requisite steps of metastasis in vivo. Id2 overexpression was driven by the c-myc oncoprotein. SEMA3F was a direct target gene of the E47/Id2 pathway. Two E-box sites, which bind E protein transcription factors including E47, were identified in the promoter region of the SEMA3F gene. E47 directly activated SEMA3F promoter activity and expression and promoted SEMA3F biological activities, including filamentous actin depolymerization, inactivation of RhoA, and inhibition of cell migration. Silencing of SEMA3F inhibited the E47-induced SEMA3F expression and biological activities, confirming that these E47-induced effects were SEMA3F dependent. E47 did not induce expression of the other members of the SEMA3 family. Id2, a dominant-negative inhibitor of E proteins, abrogated the E47-induced SEMA3F expression and biological activities. Thus, high metastatic tumor cells overexpress c-myc, leading to upregulation of Id2 expression; the aberrantly elevated amount of Id2 represses SEMA3F expression and, as a consequence, enhances the ability of tumor cells to migrate and invade. Cancer Res; 70(9); 3823–32. ©2010 AACR.
Data from Zoledronic Acid Reduces Bone Loss and Tumor Growth in an Orthotopic Xenograft Model of Osteolytic Oral Squamous Cell Carcinoma
Authors: Martin Chelsea K. , Werbeck Jillian L. , Thudi Nanda K. , Lanigan Lisa G. , Wolfe Tobie D. , Toribio Ramiro E. , Rosol Thomas J.
Published: March 2024

Abstract
Squamous cell carcinoma (SCC) is the most common form of oral cancer. Destruction and invasion of mandibular and maxillary bone frequently occurs and contributes to morbidity and mortality. We hypothesized that the bisphosphonate drug zoledronic acid (ZOL) would inhibit tumor-induced osteolysis and reduce tumor growth and invasion in a murine xenograft model of bone-invasive oral SCC (OSCC) derived from an osteolytic feline OSCC. Luciferase-expressing OSCC cells (SCCF2Luc) were injected into the perimaxillary subgingiva of nude mice, which were then treated with 100 μg/kg ZOL or vehicle. ZOL treatment reduced tumor growth and prevented loss of bone volume and surface area but had no effect on tumor invasion. Effects on bone were associated with reduced osteolysis and increased periosteal new bone formation. ZOL-mediated inhibition of tumor-induced osteolysis was characterized by reduced numbers of tartrate-resistant acid phosphatase–positive osteoclasts at the tumor-bone interface, where it was associated with osteoclast vacuolar degeneration. The ratio of eroded to total bone surface was not affected by treatment, arguing that ZOL-mediated inhibition of osteolysis was independent of effects on osteoclast activation or initiation of bone resorption. In summary, our results establish that ZOL can reduce OSCC-induced osteolysis and may be valuable as an adjuvant therapy in OSCC to preserve mandibular and maxillary bone volume and function. Cancer Res; 70(21); 8607–16. ©2010 AACR.
Data from Eribulin Induces Irreversible Mitotic Blockade: Implications of Cell-Based Pharmacodynamics for In vivo Efficacy under Intermittent Dosing Conditions
Authors: Towle Murray J. , Salvato Kathleen A. , Wels Bruce F. , Aalfs Kimberley K. , Zheng Wanjun , Seletsky Boris M. , Zhu Xiaojie , Lewis Bryan M. , Kishi Yoshito , Yu Melvin J. , Littlefield Bruce A.
Published: March 2024

Abstract
Eribulin (E7389), a mechanistically unique microtubule inhibitor in phase III clinical trials for cancer, exhibits superior efficacy in vivo relative to the more potent compound ER-076349, a fact not explained by different pharmacokinetic properties. A cell-based pharmacodynamic explanation was suggested by observations that mitotic blockade induced by eribulin, but not ER-076349, is irreversible as measured by a flow cytometric mitotic block reversibility assay employing full dose/response treatment. Cell viability 5 days after drug washout established relationships between mitotic block reversibility and long-term cell survival. Similar results occurred in U937, Jurkat, HL-60, and HeLa cells, ruling out cell type–specific effects. Studies with other tubulin agents suggest that mitotic block reversibility is a quantifiable, compound-specific characteristic of antimitotic agents in general. Bcl-2 phosphorylation patterns parallel eribulin and ER-076349 mitotic block reversibility patterns, suggesting persistent Bcl-2 phosphorylation contributes to long-term cell-viability loss after eribulin's irreversible blockade. Drug uptake and washout/retention studies show that [3H]eribulin accumulates to lower intracellular levels than [3H]ER-076349, yet is retained longer and at higher levels. Similar findings occurred with irreversible vincristine and reversible vinblastine, pointing to persistent cellular retention as a component of irreversibility. Our results suggest that eribulin's in vivo superiority derives from its ability to induce irreversible mitotic blockade, which appears related to persistent drug retention and sustained Bcl-2 phosphorylation. More broadly, our results suggest that compound-specific reversibility characteristics of antimitotic agents contribute to interactions between cell-based pharmacodynamics and in vivo pharmacokinetics that define antitumor efficacy under intermittent dosing conditions. Cancer Res; 71(2); 496–505. ©2011 AACR.
Data from Epigenetic Downregulation of Mitogen-Activated Protein Kinase Phosphatase MKP-2 Relieves Its Growth Suppressive Activity in Glioma Cells
Authors: Waha Anke , Felsberg Jörg , Hartmann Wolfgang , von dem Knesebeck Anna , Mikeska Thomas , Joos Stefan , Wolter Marietta , Koch Arend , Yan Pearlly S. , Endl Elmar , Wiestler Otmar D. , Reifenberger Guido , Pietsch Torsten , Waha Andreas
Published: March 2024

Abstract
Critical tumor suppression pathways in brain tumors have yet to be fully defined. Along with mutational analyses, genome-wide epigenetic investigations may reveal novel suppressor elements. Using differential methylation hybridization, we identified a CpG-rich region of the promoter of the dual-specificity mitogen-activated protein kinase phosphatase-2 gene (DUSP4/MKP-2) that is hypermethylated in gliomas. In 83 astrocytic gliomas and 5 glioma cell lines examined, hypermethylation of the MKP-2 promoter was found to occur relatively more frequently in diffuse or anaplastic astrocytomas and secondary glioblastomas relative to primary glioblastomas. MKP-2 hypermethylation was associated with mutations in TP53 and IDH1, exclusive of EGFR amplification, and with prolonged survival of patients with primary glioblastoma. Expression analysis established that promoter hypermethylation correlated with reduced expression of MKP-2 mRNA and protein. Consistent with a regulatory role, reversing promoter hypermethylation by treating cells with 5-aza-2′-deoxycytidine increased MKP-2 mRNA levels. Furthermore, we found that glioblastoma cell growth was inhibited by overexpression of exogenous MKP-2. Our findings reveal MKP-2 as a common epigenetically silenced gene in glioma, the inactivation of which may play a significant role in glioma development. Cancer Res; 70(4); 1689–99
Data from Therapeutic Targeting of TLR9 Inhibits Cell Growth and Induces Apoptosis in Neuroblastoma
Authors: Brignole Chiara , Marimpietri Danilo , Paolo Daniela Di , Perri Patrizia , Morandi Fabio , Pastorino Fabio , Zorzoli Alessia , Pagnan Gabriella , Loi Monica , Caffa Irene , Erminio Giovanni , Haupt Riccardo , Gambini Claudio , Pistoia Vito , Ponzoni Mirco
Published: March 2024

Abstract
The Toll-like receptor 9 (TLR9) evolved to cope with pathogens, but it is expressed in a variety of tumors for reasons that are unclear. In this study, we report that neuroblastoma (NB) cells express functional TLR9. Liposome-complexed CpG oligonucleotides inhibited the proliferation of TLR9-expressing NB cells and induced caspase-dependent apoptotic cell death. Inhibitory oligonucleotides (iODNs) abrogated these effects. RNA interference reduced TLR9 expression but not to the level where functional responses to CpG were abolished. Compared with free CpG, liposomal formulations of NB-targeted CpG (TL-CpG) significantly prolonged the survival of mice bearing NB tumor xenografts. While CpG alone lacked antitumor efficacy in NOD/SCID/IL2rg−/− mice, TL-CpG retained significant efficacy related to direct effects on tumor cells. TLR9 expression in primary human NB specimens was found to correlate inversely with disease stage. Our findings establish functional expression of TLR9 in NB and suggest that TLR9 may represent a novel theranostic target in this disease. Cancer Res; 70(23); 9816–26. ©2010 AACR.
Data from Antiestrogens Induce Transforming Growth Factor β–Mediated Immunosuppression in Breast Cancer
Authors: Joffroy Christian M. , Buck Miriam B. , Stope Matthias B. , Popp Simone L. , Pfizenmaier Klaus , Knabbe Cornelius
Published: March 2024

Abstract
Antiestrogens are universally used to treat estrogen receptor--positive breast cancer, but relapses occur commonly due to the development of drug resistance. The ability of antiestrogen to induce transforming growth factor β (TGFβ) in breast cancer cells may be relevant to the emergence of resistance, not only at the level of cell autonomous effects of TGFβ on cancer progression but also at the level of its effects on the host immune system. To evaluate the potential role of tumor-derived, antiestrogen-induced TGFβ as an immune suppressor, we established in vitro mixed lymphocyte tumor reactions (MLTR) using MCF-7 cells and peripheral blood mononuclear cells (PBMC), as well as tumor tissue and autologous tumor infiltrating lymphocytes (TIL) obtained from primary breast cancer biopsies. In allogeneic MLTR, antiestrogen-treated MCF-7 cells caused downregulation of the effector molecules granzyme B, perforin, and Fas ligand in CD8+ T cells, and suppressed the generation of cytotoxic effector cells in a TGFβ-dependent manner. Furthermore, we documented induction of regulatory T cells in CD4+ T cells, based on Foxp3 expression and T-cell activation in cocultures. In autologous MLTR, antiestrogen treatment gave rise to enhanced Foxp3 expression of TIL/PBMC and decreased the number of apoptotic tumor cells. These effects were reversed by addition of a TGFβ neutralizing antibody. Our findings offer evidence that antiestrogen induces immunosuppression in the tumor microenvironment, through a TGFβ-dependent mechanism that may contribute to the development of antiestrogen resistance in breast cancer. Cancer Res; 70(4); 1314–22
Data from Constitutively Active Stat3 Enhances Neu-Mediated Migration and Metastasis in Mammary Tumors via Upregulation of Cten
Authors: Barbieri Isaia , Pensa Sara , Pannellini Tania , Quaglino Elena , Maritano Diego , Demaria Marco , Voster Alessandra , Turkson James , Cavallo Federica , Watson Christine J. , Provero Paolo , Musiani Piero , Poli Valeria
Published: March 2024

Abstract
The transcription factor signal transducer and activator of transcription 3 (STAT3) is constitutively activated in tumors of different origin, but the molecular bases for STAT3 requirement are only partly understood. To evaluate the contribution of enhanced Stat3 activation in a controlled model system, we generated knock-in mice wherein a mutant constitutively active Stat3C allele replaces the endogenous wild-type allele. Stat3C could enhance the tumorigenic power of the rat Neu oncogene in mouse mammary tumor virus (MMTV)–Neu transgenic mice, triggering the production of earlier onset, more invasive mammary tumors. Tumor-derived cell lines displayed higher migration, invasion, and metastatic ability and showed disrupted distribution of cell-cell junction markers mediated by Stat3-dependent overexpression of the COOH terminal tensin-like (Cten) focal adhesion protein, which was also significantly upregulated in Stat3C mammary tumors. Importantly, the proinflammatory cytokine interleukin-6 could mediate Cten induction in MCF10 cells in an exquisitely Stat3-dependent way, showing that Cten upregulation is a feature of inflammation-activated Stat3. In light of the emerging pivotal role of Stat3 in connecting inflammation and cancer, our identification of Cten as a Stat3-dependent mediator of migration provides important new insights into the oncogenic role of Stat3, particularly in the breast. Cancer Res; 70(6); 2558–67
Data from Targeting Cancer Cell Metabolism: The Combination of Metformin and 2-Deoxyglucose Induces p53-Dependent Apoptosis in Prostate Cancer Cells
Authors: Ben Sahra Issam , Laurent Kathiane , Giuliano Sandy , Larbret Frédéric , Ponzio Gilles , Gounon Pierre , Le Marchand-Brustel Yannick , Giorgetti-Peraldi Sophie , Cormont Mireille , Bertolotto Corine , Deckert Marcel , Auberger Patrick , Tanti Jean-François , Bost Frédéric
Published: March 2024

Abstract
Targeting cancer cell metabolism is a new promising strategy to fight cancer. Metformin, a widely used antidiabetic agent, exerts antitumoral and antiproliferative action. In this study, the addition of metformin to 2-deoxyglucose (2DG) inhibited mitochondrial respiration and glycolysis in prostate cancer cells leading to a severe depletion in ATP. The combination of the two drugs was much more harmful for cancer cells than the treatment with metformin or 2DG alone, leading to 96% inhibition of cell viability in LNCaP prostate cancer cells. In contrast, a moderate effect on cell viability was observed in normal prostate epithelial cells. At the cellular level, the combination of metformin and 2DG induced p53-dependent apoptosis via the energy sensor pathway AMP kinase, and the reexpression of a functional p53 in p53-deficient prostate cancer cells restored caspase-3 activity. In addition to apoptosis, the combination of metformin and 2DG arrested prostate cancer cells in G2-M. This G2-M arrest was independent of p53 and correlated with a stronger decrease in cell viability than obtained with either drug. Finally, metformin inhibited 2DG-induced autophagy, decreased beclin 1 expression, and triggered a switch from a survival process to cell death. Our study reinforces the growing interest of metabolic perturbators in cancer therapy and highlights the potential use of the combination of metformin and 2DG as an anticancerous treatment. Cancer Res; 70(6); 2465–75
Data from Induction of DNA Damage-Inducible Gene GADD45β Contributes to Sorafenib-Induced Apoptosis in Hepatocellular Carcinoma Cells
Authors: Ou Da-Liang , Shen Ying-Chun , Yu Sung-Liang , Chen Kuen-Feng , Yeh Pei-Yen , Fan Hsiang-Hsuan , Feng Wen-Chi , Wang Ching-Tzu , Lin Liang-In , Hsu Chiun , Cheng Ann-Lii
Published: March 2024

Abstract
Markers that could accurately predict responses to the general kinase inhibitor sorafenib are needed to better leverage its clinical applications. In this study, we examined a hypothesized role in the drug response for the growth arrest DNA damage-inducible gene 45β (GADD45β), which is commonly underexpressed in hepatocellular carcinoma (HCC) where sorafenib may offer an important new therapeutic option. The anticancer activity of sorafenib-induced GADD45β expression was tested in a panel of HCC cell lines and xenograft models. We found that GADD45β mRNA and protein expression were induced relatively more prominently in HCC cells that were biologically sensitive to sorafenib treatment. GADD45β induction was not found after treatment with either the mitogen-activated protein kinase–extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor U0126 or the Raf inhibitor ZM336372, suggesting that GADD45β induction by sorafenib was independent of Raf/MEK/ERK signaling activity. However, c-Jun NH2-terminal kinase (JNK) kinase activation occurred preferentially in sorafenib-sensitive cells. Small interfering RNA–mediated knockdown of GADD45βor JNK kinase limited the proapoptotic effects of sorafenib in sorafenib-sensitive cells. We defined the −339/−267 region in the GADD45β promoter containing activator protein-1 and SP1-binding sites as a crucial region for GADD45β induction by sorafenib. Together, our findings suggest that GADD45β induction contributes to sorafenib-induced apoptosis in HCC cells, prompting further studies to validate its potential value in predicting sorafenib efficacy. Cancer Res; 70(22); 9309–18. ©2010 AACR.
Data from CpG Island Hypermethylation in Human Astrocytomas
Authors: Wu Xiwei , Rauch Tibor A. , Zhong Xueyan , Bennett William P. , Latif Farida , Krex Dietmar , Pfeifer Gerd P.
Published: March 2024

Abstract
Astrocytomas are common and lethal human brain tumors. We have analyzed the methylation status of over 28,000 CpG islands and 18,000 promoters in normal human brain and in astrocytomas of various grades using the methylated CpG island recovery assay. We identified 6,000 to 7,000 methylated CpG islands in normal human brain. Approximately 5% of the promoter-associated CpG islands in the normal brain are methylated. Promoter CpG island methylation is inversely correlated whereas intragenic methylation is directly correlated with gene expression levels in brain tissue. In astrocytomas, several hundred CpG islands undergo specific hypermethylation relative to normal brain with 428 methylation peaks common to more than 25% of the tumors. Genes involved in brain development and neuronal differentiation, such as BMP4, POU4F3, GDNF, OTX2, NEFM, CNTN4, OTP, SIM1, FYN, EN1, CHAT, GSX2, NKX6-1, PAX6, RAX, and DLX2, were strongly enriched among genes frequently methylated in tumors. There was an overrepresentation of homeobox genes and 31% of the most commonly methylated genes represent targets of the Polycomb complex. We identified several chromosomal loci in which many (sometimes more than 20) consecutive CpG islands were hypermethylated in tumors. Seven such loci were near homeobox genes, including the HOXC and HOXD clusters, and the BARHL2, DLX1, and PITX2 genes. Two other clusters of hypermethylated islands were at sequences of recent gene duplication events. Our analysis offers mechanistic insights into brain neoplasia suggesting that methylation of the genes involved in neuronal differentiation, in cooperation with other oncogenic events, may shift the balance from regulated differentiation towards gliomagenesis. Cancer Res; 70(7); 2718–27
Data from CCT241533 Is a Potent and Selective Inhibitor of CHK2 that Potentiates the Cytotoxicity of PARP Inhibitors
Authors: Anderson Victoria E. , Walton Michael I. , Eve Paul D. , Boxall Katherine J. , Antoni Laurent , Caldwell John J. , Aherne Wynne , Pearl Laurence H. , Oliver Antony W. , Collins Ian , Garrett Michelle D.
Published: March 2024

Abstract
CHK2 is a checkpoint kinase involved in the ATM-mediated response to double-strand DNA breaks. Its potential as a drug target is still unclear, but inhibitors of CHK2 may increase the efficacy of genotoxic cancer therapies in a p53 mutant background by eliminating one of the checkpoints or DNA repair pathways contributing to cellular resistance. We report here the identification and characterization of a novel CHK2 kinase inhibitor, CCT241533. X-ray crystallography confirmed that CCT241533 bound to CHK2 in the ATP pocket. This compound inhibits CHK2 with an IC50 of 3 nmol/L and shows minimal cross-reactivity against a panel of kinases at 1 μmol/L. CCT241533 blocked CHK2 activity in human tumor cell lines in response to DNA damage, as shown by inhibition of CHK2 autophosphorylation at S516, band shift mobility changes, and HDMX degradation. CCT241533 did not potentiate the cytotoxicity of a selection of genotoxic agents in several cell lines. However, this compound significantly potentiates the cytotoxicity of two structurally distinct PARP inhibitors. Clear induction of the pS516 CHK2 signal was seen with a PARP inhibitor alone, and this activation was abolished by CCT241533, implying that the potentiation of PARP inhibitor cell killing by CCT241533 was due to inhibition of CHK2. Consequently, our findings imply that CHK2 inhibitors may exert therapeutic activity in combination with PARP inhibitors. Cancer Res; 71(2); 463–72. ©2011 AACR.
Data from Pharmacologic Inhibition of Cyclin-Dependent Kinases 4 and 6 Arrests the Growth of Glioblastoma Multiforme Intracranial Xenografts
Authors: Michaud Karine , Solomon David A. , Oermann Eric , Kim Jung-Sik , Zhong Wei-Zhu , Prados Michael D. , Ozawa Tomoko , James C. David , Waldman Todd
Published: March 2024

Abstract
Activation of cyclin-dependent kinases 4 and 6 (cdk4/6) occurs in the majority of glioblastoma multiforme (GBM) tumors, and represents a promising molecular target for the development of small molecule inhibitors. In the current study, we investigated the molecular determinants and in vivo response of diverse GBM cell lines and xenografts to PD-0332991, a cdk4/6-specific inhibitor. In vitro testing of PD-0332991 against a panel of GBM cell lines revealed a potent G1 cell cycle arrest and induction of senescence in each of 16 retinoblastoma protein (Rb)–proficient cell lines regardless of other genetic lesions, whereas 5 cell lines with homozygous inactivation of Rb were completely resistant to treatment. Short hairpin RNA depletion of Rb expression conferred resistance of GBM cells to PD-0332991, further demonstrating a requirement of Rb for sensitivity to cdk4/6 inhibition. PD-0332991 was found to efficiently cross the blood-brain barrier and proved highly effective in suppressing the growth of intracranial GBM xenograft tumors, including those that had recurred after initial therapy with temozolomide. Remarkably, no mice receiving PD-0332991 died as a result of disease progression while on therapy. Additionally, the combination of PD-0332991 and radiation therapy resulted in significantly increased survival benefit compared with either therapy alone. In total, our results support clinical trial evaluation of PD-0332991 against newly diagnosed as well as recurrent GBM, and indicate that Rb status is the primary determinant of potential benefit from this therapy. Cancer Res; 70(8); 3228–38. ©2010 AACR.
Data from Cancer Inhibition through Circadian Reprogramming of Tumor Transcriptome with Meal Timing
Authors: Li Xiao-Mei , Delaunay Franck , Dulong Sandrine , Claustrat Bruno , Zampera Sinisa , Fujii Yoshiro , Teboul Michèle , Beau Jacques , Lévi Francis
Published: March 2024

Abstract
Circadian disruption accelerates cancer progression, whereas circadian reinforcement could halt it. Mice with P03 pancreatic adenocarcinoma (n = 77) were synchronized and fed ad libitum (AL) or with meal timing (MT) from Zeitgeber time (ZT) 2 to ZT6 with normal or fat diet. Tumor gene expression profiling was determined with DNA microarrays at endogenous circadian time (CT) 4 and CT16. Circadian mRNA expression patterns were determined for clock genes Rev-erbα, Per2, and Bmal1, cellular stress genes Hspa8 and Cirbp, and cyclin A2 gene Ccna2 in liver and tumor. The 24-hour patterns in telemetered rest-activity and body temperature and plasma corticosterone and insulin-like growth factor-I (IGF-I) were assessed. We showed that MT inhibited cancer growth by ∼40% as compared with AL (P = 0.011) irrespective of calorie intake. Clock gene transcription remained arrhythmic in tumors irrespective of feeding schedule or diet. Yet, MT upregulated or downregulated the expression of 423 tumor genes, according to CT. Moreover, 36 genes involved in cellular stress, cell cycle, and metabolism were upregulated at one CT and downregulated 12 h apart. MT induced >10-fold circadian expression of Hspa8, Cirbp, and Ccna2 in tumors. Corticosterone or IGF-I patterns played no role in tumor growth inhibition. In contrast, MT consistently doubled the circadian amplitude of body temperature. Peak and trough respectively corresponded to peak expressions of Hspa8 and Cirbp in tumors. The reinforcement of the host circadian timing system with MT induced 24-hour rhythmic expression of critical genes in clock-deficient tumors, which translated into cancer growth inhibition. Targeting circadian clocks represents a novel potential challenge for cancer therapeutics. Cancer Res; 70(8); 3351–60. ©2010 AACR.
Data from Transcription Factor NF-Y Induces Apoptosis in Cells Expressing Wild-Type p53 through E2F1 Upregulation and p53 Activation
Authors: Gurtner Aymone , Fuschi Paola , Martelli Fabio , Manni Isabella , Artuso Simona , Simonte Giacoma , Ambrosino Valeria , Antonini Annalisa , Folgiero Valentina , Falcioni Rita , Sacchi Ada , Piaggio Giulia
Published: March 2024

Abstract
The CCAAT-binding transcription factor NF-Y plays a central role in regulating cellular proliferation by controlling the expression of genes required for cell-cycle progression such as cyclin A, cyclin B1, cyclin B2, cdc25A, cdc25C, and cdk1. Here we show that unrestricted NF-Y activity leads to apoptosis in an E2F1- and wild-type p53 (wtp53)-dependent manner. Unrestricted NF-Y activity induced an increase in E2F1 mRNA and protein levels. Furthermore, NF-Y directly bound the E2F1 promoter and this correlated with the appearance of open chromatin marks. The ability of NF-Y to induce apoptosis was impaired in cells lacking E2F1 and wtp53. Moreover, NF-Y overexpression elicited phosphorylation of wt p53Ser18 in an E2F1-dependent manner. Our findings establish that NF-Y acts upstream of E2F1 in p53-mediated apoptosis. Cancer Res; 70(23); 9711–20. ©2010 AACR.
Data from Breast Cancer Stem Cells Are Regulated by Mesenchymal Stem Cells through Cytokine Networks
Authors: Liu Suling , Ginestier Christophe , Ou Sing J. , Clouthier Shawn G. , Patel Shivani H. , Monville Florence , Korkaya Hasan , Heath Amber , Dutcher Julie , Kleer Celina G. , Jung Younghun , Dontu Gabriela , Taichman Russell , Wicha Max S.
Published: March 2024

Abstract
We have used in vitro and mouse xenograft models to examine the interaction between breast cancer stem cells (CSC) and bone marrow–derived mesenchymal stem cells (MSC). We show that both of these cell populations are organized in a cellular hierarchy in which primitive aldehyde dehydrogenase expressing mesenchymal cells regulate breast CSCs through cytokine loops involving IL6 and CXCL7. In NOD/SCID mice, labeled MSCs introduced into the tibia traffic to sites of growing breast tumor xenografts where they accelerated tumor growth by increasing the breast CSC population. With immunochemistry, we identified MSC–CSC niches in these tumor xenografts as well as in frozen sections from primary human breast cancers. Bone marrow–derived MSCs may accelerate human breast tumor growth by generating cytokine networks that regulate the CSC population. Cancer Res; 71(2); 614–24. ©2011 AACR.
Data from General Transcription Factor Binding at CpG Islands in Normal Cells Correlates with Resistance to De novo DNA Methylation in Cancer Cells
Authors: Gebhard Claudia , Benner Chris , Ehrich Mathias , Schwarzfischer Lucia , Schilling Elmar , Klug Maja , Dietmaier Wolfgang , Thiede Christian , Holler Ernst , Andreesen Reinhard , Rehli Michael
Published: March 2024

Abstract
Aberrant DNA methylation at CpG islands is thought to contribute to cancer initiation and progression, but mechanisms that establish and maintain DNA methylation status during tumorigenesis or normal development remain poorly understood. In this study, we used methyl-CpG immunoprecipitation to generate comparative DNA methylation profiles of healthy and malignant cells (acute leukemia and colorectal carcinoma) for human CpG islands across the genome. While searching for sequence patterns that characterize DNA methylation states, we discovered several nonredundant sequences in CpG islands that were resistant to aberrant de novo methylation in cancer and that resembled consensus binding sites for general transcription factors (TF). Comparing methylation profiles with global CpG island binding data for specific protein 1, nuclear respiratory factor 1, and yin-yang 1 revealed that their DNA binding activity in normal blood cells correlated strictly with an absence of de novo methylation in cancer. In addition, global evidence showed that binding of any of these TFs to their consensus motif depended on their co-occurrence with neighboring consensus motifs. In summary, our results had two major implications. First, they pointed to a major role for cooperative binding of TFs in maintaining the unmethylated status of CpG islands in health and disease. Second, our results suggest that the majority of de novo methylated CpG islands are characterized by the lack of sequence motif combinations and the absence of activating TF binding. Cancer Res; 70(4); 1398–407