bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Human Cytomegalovirus US28 Found in Glioblastoma Promotes an Invasive and Angiogenic Phenotype
Authors: Soroceanu Liliana , Matlaf Lisa , Bezrookove Vladimir , Harkins Loui , Martinez Roxanne , Greene Mary , Soteropoulos Patricia , Cobbs Charles S.
Published: March 2024

Abstract
Human cytomegalovirus (HCMV) infections are seen often in glioblastoma multiforme (GBM) tumors, but whether the virus contributes to GBM pathogenesis is unclear. In this study, we explored an oncogenic role for the G-protein–coupled receptor-like protein US28 encoded by HCMV that we found to be expressed widely in human GBMs. Immunohistochemical and reverse transcriptase PCR approaches established that US28 was expressed in approximately 60% of human GBM tissues and primary cultures examined. In either uninfected GBM cells or neural progenitor cells, thought to be the GBM precursor cells, HCMV infection or US28 overexpression was sufficient to promote secretion of biologically active VEGF and to activate multiple cellular kinases that promote glioma growth and invasion, including phosphorylated STAT3 (p-STAT3) and endothelial nitric oxide synthase (e-NOS). Consistent with these findings, US28 overexpression increased primary GBM cell invasion in Matrigel. Notably, this invasive phenotype was further enhanced by exposure to CCL5/RANTES, a US28 ligand, associated with poor patient outcome in GBM. Conversely, RNA interference–mediated knockdown of US28 in human glioma cells persistently infected with HCMV led to an inhibition in VEGF expression and glioma cell invasion in response to CCL5 stimulation. Analysis of clinical GBM specimens further revealed that US28 colocalized in situ with several markers of angiogenesis and inflammation, including VEGF, p-STAT3, COX2, and e-NOS. Taken together, our results indicate that US28 expression from HCMV contributes to GBM pathogenesis by inducing an invasive, angiogenic phenotype. In addition, these findings argue that US28–CCL5 paracrine signaling may contribute to glioma progression and suggest that targeting US28 may provide therapeutic benefits in GBM treatment. Cancer Res; 71(21); 6643–53. ©2011 AACR.
Data from Fusion between Intestinal Epithelial Cells and Macrophages in a Cancer Context Results in Nuclear Reprogramming
Authors: Powell Anne E. , Anderson Eric C. , Davies Paige S. , Silk Alain D. , Pelz Carl , Impey Soren , Wong Melissa H.
Published: March 2024

Abstract
The most deadly phase in cancer progression is attributed to the inappropriate acquisition of molecular machinery leading to metastatic transformation and spread of disease to distant organs. Although it is appreciated that metastasis involves epithelial–mesenchymal interplay, the underlying mechanism defining this process is poorly understood. Specifically, how cancer cells evade immune surveillance and gain the ability to navigate the circulatory system remains a focus. One possible mechanism underlying metastatic conversion is fusion between blood-derived immune cells and cancer cells. While this notion is a century old, in vivo evidence that cell fusion occurs within tumors and imparts genetic or physiologic changes remains controversial. We have previously demonstrated in vivo cell fusion between blood cells and intestinal epithelial cells in an injury setting. Here, we hypothesize that immune cells, such as macrophages, fuse with tumor cells imparting metastatic capabilities by transferring their cellular identity. We used parabiosis to introduce fluorescent-labeled bone marrow-derived cells to mice with intestinal tumors, finding that fusion between circulating blood-derived cells and tumor epithelium occurs during the natural course of tumorigenesis. Moreover, we identify the macrophage as a key cellular partner for this process. Interestingly, cell fusion hybrids retain a transcriptome identity characteristic of both parental derivatives, while also expressing a unique subset of transcripts. Our data supports the novel possibility that tumorigenic cell fusion may impart physical behavior attributed to migratory macrophages, including navigation of circulation and immune evasion. As such, cell fusion may represent a promising novel mechanism underlying the metastatic conversion of cancer cells. Cancer Res; 71(4); 1497–505. ©2011 AACR.
Data from Cyclophosphamide Synergizes with Type I Interferons through Systemic Dendritic Cell Reactivation and Induction of Immunogenic Tumor Apoptosis
Authors: Schiavoni Giovanna , Sistigu Antonella , Valentini Mara , Mattei Fabrizio , Sestili Paola , Spadaro Francesca , Sanchez Massimo , Lorenzi Silvia , D'Urso Maria Teresa , Belardelli Filippo , Gabriele Lucia , Proietti Enrico , Bracci Laura
Published: March 2024

Abstract
Successful chemotherapy accounts for both tumor-related factors and host immune response. Compelling evidence suggests that some chemotherapeutic agents can induce an immunogenic type of cell death stimulating tumor-specific immunity. Here, we show that cyclophosphamide (CTX) exerts two types of actions relevant for the induction of antitumor immunity in vivo: (i) effect on dendritic cell (DC) homeostasis, mediated by endogenous type I interferons (IFN-I), leading to the preferential expansion of CD8α+ DC, the main subset involved in the cross-presentation of cell-derived antigens; and (ii) induction of tumor cell death with clear-cut immunogenic features capable of stimulating tumor infiltration, engulfment of tumor apoptotic material, and CD8 T-cell cross-priming by CD8α+ DC. Notably, the antitumor effects of CTX were efficiently amplified by IFN-I, the former providing a source of antigen and a “resetting” of the DC compartment and the latter supplying optimal costimulation for T-cell cross-priming, resulting in the induction of a strong antitumor response and tumor rejection. These results disclose new perspectives for the development of targeted and more effective chemoimmunotherapy treatments of cancer patients. Cancer Res; 71(3); 768–78. ©2010 AACR.
Data from The ΔNp63 Proteins Are Key Allies of BRCA1 in the Prevention of Basal-Like Breast Cancer
Authors: Buckley Niamh E. , Conlon Susan J. , Jirstrom Karin , Kay Elaine W. , Crawford Nyree T. , O'Grady Anthony , Sheehan Katherine , Mc Dade Simon S. , Wang Ching-Wei , McCance Dennis J. , Johnston Patrick G. , Kennedy Richard D. , Harkin D. Paul , Mullan Paul B.
Published: March 2024

Abstract
Little is known about the origin of basal-like breast cancers, an aggressive disease that is highly similar to BRCA1-mutant breast cancers. p63 family proteins that are structurally related to the p53 suppressor protein are known to function in stem cell regulation and stratified epithelia development in multiple tissues, and p63 expression may be a marker of basal-like breast cancers. Here we report that ΔNp63 isoforms of p63 are transcriptional targets for positive regulation by BRCA1. Our analyses of breast cancer tissue microarrays and BRCA1-modulated breast cancer cell lines do not support earlier reports that p63 is a marker of basal-like or BRCA1 mutant cancers. Nevertheless, we found that BRCA1 interacts with the specific p63 isoform ΔNp63γ along with transcription factor isoforms AP-2α and AP-2γ. BRCA1 required ΔNp63γ and AP-2γ to localize to an intronic enhancer region within the p63 gene to upregulate transcription of the ΔNp63 isoforms. In mammary stem/progenitor cells, siRNA-mediated knockdown of ΔNp63 expression resulted in genomic instability, increased cell proliferation, loss of DNA damage checkpoint control, and impaired growth control. Together, our findings establish that transcriptional upregulation of ΔNp63 proteins is critical for BRCA1 suppressor function and that defects in BRCA1-ΔNp63 signaling are key events in the pathogenesis of basal-like breast cancer. Cancer Res; 71(5); 1933–44. ©2011 AACR.
Data from RNA Helicase DDX5 Is a p53-Independent Target of ARF That Participates in Ribosome Biogenesis
Authors: Saporita Anthony J. , Chang Hsiang-Chun , Winkeler Crystal L. , Apicelli Anthony J. , Kladney Raleigh D. , Wang Jianbo , Townsend R. Reid , Michel Loren S. , Weber Jason D.
Published: March 2024

Abstract
The p19ARF tumor suppressor limits ribosome biogenesis and responds to hyperproliferative signals to activate the p53 checkpoint response. Although its activation of p53 has been well characterized, the role of ARF in restraining nucleolar ribosome production is poorly understood. Here we report the use of a mass spectroscopic analysis to identify protein changes within the nucleoli of Arf-deficient mouse cells. Through this approach, we discovered that ARF limited the nucleolar localization of the RNA helicase DDX5, which promotes the synthesis and maturation of rRNA, ultimately increasing ribosome output and proliferation. ARF inhibited the interaction between DDX5 and nucleophosmin (NPM), preventing association of DDX5 with the rDNA promoter and nuclear pre-ribosomes. In addition, Arf-deficient cells transformed by oncogenic RasV12 were addicted to DDX5, because reduction of DDX5 was sufficient to impair RasV12-driven colony formation in soft agar and tumor growth in mice. Taken together, our findings indicate that DDX5 is a key p53-independent target of the ARF tumor suppressor and is a novel non-oncogene participant in ribosome biogenesis. Cancer Res; 71(21); 6708–17. ©2011 AACR.
Data from Proto-oncogene PBF/PTTG1IP Regulates Thyroid Cell Growth and Represses Radioiodide Treatment
Authors: Read Martin L. , Lewy Greg D. , Fong Jim C.W. , Sharma Neil , Seed Robert I. , Smith Vicki E. , Gentilin Erica , Warfield Adrian , Eggo Margaret C. , Knauf Jeffrey A. , Leadbeater Wendy E. , Watkinson John C. , Franklyn Jayne A. , Boelaert Kristien , McCabe Christopher J.
Published: March 2024

Abstract
Pituitary tumor transforming gene (PTTG)-binding factor (PBF or PTTG1IP) is a little characterized proto-oncogene that has been implicated in the etiology of breast and thyroid tumors. In this study, we created a murine transgenic model to target PBF expression to the thyroid gland (PBF-Tg mice) and found that these mice exhibited normal thyroid function, but a striking enlargement of the thyroid gland associated with hyperplastic and macrofollicular lesions. Expression of the sodium iodide symporter (NIS), a gene essential to the radioiodine ablation of thyroid hyperplasia, neoplasia, and metastasis, was also potently inhibited in PBF-Tg mice. Critically, iodide uptake was repressed in primary thyroid cultures from PBF-Tg mice, which could be rescued by PBF depletion. PBF-Tg thyroids exhibited upregulation of Akt and the TSH receptor (TSHR), each known regulators of thyrocyte proliferation, along with upregulation of the downstream proliferative marker cyclin D1. We extended and confirmed findings from the mouse model by examining PBF expression in human multinodular goiters (MNG), a hyperproliferative thyroid disorder, where PBF and TSHR was strongly upregulated relative to normal thyroid tissue. Furthermore, we showed that depleting PBF in human primary thyrocytes was sufficient to increase radioiodine uptake. Together, our findings indicate that overexpression of PBF causes thyroid cell proliferation, macrofollicular lesions, and hyperplasia, as well as repression of the critical therapeutic route for radioiodide uptake. Cancer Res; 71(19); 6153–64. ©2011 AACR.
Data from The Unfolded Protein Response Induces the Angiogenic Switch in Human Tumor Cells through the PERK/ATF4 Pathway
Authors: Wang Yugang , Alam Goleeta N. , Ning Yu , Visioli Fernanda , Dong Zhihong , Nör Jacques E. , Polverini Peter J.
Published: March 2024

Abstract
Neovascularization is a limiting factor in tumor growth and progression. It is well known that changes in the tumor microenvironment, such as hypoxia and glucose deprivation (GD), can induce VEGF production. However, the mechanism linking GD to tumor growth and angiogenesis is unclear. We hypothesize that GD induces the angiogenic switch in tumors through activation of the unfolded protein response (UPR). We report that UPR activation in human tumors results in elevated expression of proangiogenic mediators and a concomitant decrease in angiogenesis inhibitors. cDNA microarray results showed that GD-induced UPR activation promoted upregulation of a number of proangiogenic mediators (VEGF, FGF-2, IL-6, etc.) and downregulation of several angiogenic inhibitors (THBS1, CXCL14, and CXCL10). In vitro studies revealed that partially blocking UPR signaling by silencing protein kinase RNA–like ER kinase (PERK) or activating transcription factor 4 (ATF4) significantly reduced the production of angiogenesis mediators induced by GD. However, suppressing the alpha subunit of hypoxia-inducible factors had no effect on this process. Chromatin immunoprecipitation (ChIP) confirmed binding of ATF4 to a regulatory site in the VEGF gene. In vivo results confirmed that knockdown of PERK in tumor cells slows down tumor growth and decreases tumor blood vessel density. Collectively, these results show that the PERK/ATF4 arm of UPR mediates the angiogenic switch and is a potential target for antiangiogenic cancer therapy. Cancer Res; 72(20); 5396–406. ©2012 AACR.
Data from Interleukin-10 Ablation Promotes Tumor Development, Growth, and Metastasis
Authors: Tanikawa Takashi , Wilke Cailin Moira , Kryczek Ilona , Chen Grace Y. , Kao John , Núñez Gabriel , Zou Weiping
Published: March 2024

Abstract
Interleukin-10 (IL-10) is a broadly acting immune inhibitory cytokine that is generally thought to support tumor growth. Here we challenge this view with evidence that genetic ablation of IL-10 in the mouse significantly heightens sensitivity to chemical carcinogenesis, growth of transplanted tumors, and formation of metastases. Tumor growth in IL-10–deficient (IL-10−/−) mice was associated with an increased level of myeloid-derived suppressor cells (MDSC) and CD4+Foxp3+ regulatory T (Treg) cells in both the tumor microenvironment and the tumor-draining lymph nodes. IL-10−/− MDSCs express high levels of MHC and IL-1, and they efficiently induced formation of Treg cells. IL-1 signaling blockade reduced tumor growth mediated by IL-10 deficiency, associated with a partial rescue of tumor infiltration and function of effector T cells and a decrease in tumor angiogenesis and tumor infiltration by Treg cells. Taken together, our findings establish that endogenous IL-10 inhibits inflammatory cytokine production and hampers the development of Treg cells and MDSCs, two key components of the immunosuppressive tumor microenvironment, thereby inhibiting tumor development, growth, and metastasis. Cancer Res; 72(2); 420–9. ©2011 AACR.
Data from Genetic Determinants for Promoter Hypermethylation in the Lungs of Smokers: A Candidate Gene-Based Study
Authors: Leng Shuguang , Stidley Christine A. , Liu Yushi , Edlund Christopher K. , Willink Randall P. , Han Younghun , Landi Maria Teresa , Thun Michael , Picchi Maria A. , Bruse Shannon E. , Crowell Richard E. , Van Den Berg David , Caporaso Neil E. , Amos Christopher I. , Siegfried Jill M. , Tesfaigzi Yohannes , Gilliland Frank D. , Belinsky Steven A.
Published: March 2024

Abstract
The detection of tumor suppressor gene promoter methylation in sputum-derived exfoliated cells predicts early lung cancer. Here, we identified genetic determinants for this epigenetic process and examined their biologic effects on gene regulation. A two-stage approach involving discovery and replication was used to assess the association between promoter hypermethylation of a 12-gene panel and common variation in 40 genes involved in carcinogen metabolism, regulation of methylation, and DNA damage response in members of the Lovelace Smokers Cohort (N = 1,434). Molecular validation of three identified variants was conducted using primary bronchial epithelial cells. Association of study-wide significance (P < 8.2 × 10−5) was identified for rs1641511, rs3730859, and rs1883264 in TP53, LIG1, and BIK, respectively. These single-nucleotide polymorphisms (SNP) were significantly associated with altered expression of the corresponding genes in primary bronchial epithelial cells. In addition, rs3730859 in LIG1 was also moderately associated with increased risk for lung cancer among Caucasian smokers. Together, our findings suggest that genetic variation in DNA replication and apoptosis pathways impacts the propensity for gene promoter hypermethylation in the aerodigestive tract of smokers. The incorporation of genetic biomarkers for gene promoter hypermethylation with clinical and somatic markers may improve risk assessment models for lung cancer. Cancer Res; 72(3); 707–15. ©2011 AACR.
Data from Mre11-Dependent Degradation of Stalled DNA Replication Forks Is Prevented by BRCA2 and PARP1
Authors: Ying Songmin , Hamdy Freddie C. , Helleday Thomas
Published: March 2024

Abstract
PARP inhibitors are currently being used in clinical trials to treat BRCA1- or BRCA2-defective tumors, based on the synthetic lethal interaction between PARP1 and BRCA1/2-mediated homologous recombination (HR). However, the molecular mechanisms that drive this synthetic lethality remain unclear. Here, we show increased levels of Mre11, a key component of MRN (Mre11-Rad50-Nbs1) complex that plays a role in the restart of stalled replication forks and enhanced resection at stalled replication forks in BRCA2-deficient cells. BRCA2-deficient cells also showed hypersensitivity to the Mre11 inhibitor mirin. Interestingly, PARP1 activity was required to protect stalled forks from Mre11-dependent degradation. Resistance to PARP inhibition in BRCA2-mutant cells led to reduced levels of Mre11 foci and also rescued their sensitivity to mirin. Taken together, our findings not only show that Mre11 activity is required for the survival of BRCA2 mutant cells but also elucidate roles for both the BRCA2 and PARP1 proteins in protecting stalled replication forks, which offers insight into the molecular mechanisms of the synthetic lethality between BRCA2 and PARP1. Cancer Res; 72(11); 2814–21. ©2012 AACR.
Data from Chronic Autophagy Is a Cellular Adaptation to Tumor Acidic pH Microenvironments
Authors: Wojtkowiak Jonathan W. , Rothberg Jennifer M. , Kumar Virendra , Schramm Karla J. , Haller Edward , Proemsey Joshua B. , Lloyd Mark C. , Sloane Bonnie F. , Gillies Robert J.
Published: March 2024

Abstract
Tumor cell survival relies upon adaptation to the acidic conditions of the tumor microenvironment. To investigate potential acidosis survival mechanisms, we examined the effect of low pH (6.7) on human breast carcinoma cells. Acute low pH exposure reduced proliferation rate, induced a G1 cell cycle arrest, and increased cytoplasmic vacuolization. Gene expression analysis revealed elevated levels of ATG5 and BNIP3 in acid-conditioned cells, suggesting cells exposed to low pH may utilize autophagy as a survival mechanism. In support of this hypothesis, we found that acute low pH stimulated autophagy as defined by an increase in LC3-positive punctate vesicles, double-membrane vacuoles, and decreased phosphorylation of AKT and ribosomal protein S6. Notably, cells exposed to low pH for approximately 3 months restored their proliferative capacity while maintaining the cytoplasmic vacuolated phenotype. Although autophagy is typically transient, elevated autophagy markers were maintained chronically in low pH conditioned cells as visualized by increased protein expression of LC3-II and double-membrane vacuoles. Furthermore, these cells exhibited elevated sensitivity to PI3K-class III inhibition by 3-methyladenine. In mouse tumors, LC3 expression was reduced by systemic treatment with sodium bicarbonate, which raises intratumoral pH. Taken together, these results argue that acidic conditions in the tumor microenvironment promote autophagy, and that chronic autophagy occurs as a survival adaptation in this setting. Cancer Res; 72(16); 3938–47. ©2012 AACR.
Data from CD24 Is an Effector of HIF-1–Driven Primary Tumor Growth and Metastasis
Authors: Thomas Shibu , Harding Michael A. , Smith Steven C. , Overdevest Jonathan B. , Nitz Matthew D. , Frierson Henry F. , Tomlins Scott A. , Kristiansen Glen , Theodorescu Dan
Published: March 2024

Abstract
Hypoxia drives malignant progression in part by promoting accumulation of the oncogenic transcription factor hypoxia inducible factor–1α (HIF-1α) in tumor cells. Tumor aggressiveness also relates to elevation of the cancer stem cell–associated membrane protein CD24, which has been causally implicated in tumor formation and metastasis in experimental models. Here, we link these two elements by showing that hypoxia induces CD24 expression through a functional hypoxia responsive element in the CD24 promoter. HIF-1α overexpression induced CD24 mRNA and protein under normoxic conditions, with this effect traced to a recruitment of endogenous HIF-1α to the CD24 promoter. Short hairpin RNA–mediated attenuation of HIF-1α or CD24 expression reduced cancer cell survival in vitro and in vivo at the levels of primary and metastatic tumor growth. CD24 overexpression in HIF-1α–depleted cancer cells rescued this decrease, whereas HIF-1α overexpression in CD24-depleted cells did not. Analysis of clinical tumor specimens revealed a correlation between HIF-1α and CD24 levels and an association of their coexpression to decreased patient survival. Our results establish a mechanistic linkage between 2 critically important molecules in cancer, identifying CD24 as a critical HIF-1α transcriptional target and biologic effector, strengthening the rationale to target CD24 for cancer therapy. Cancer Res; 72(21); 5600–12. ©2012 AACR.
Data from Kaposi Sarcoma Herpesvirus Promotes Endothelial-to-Mesenchymal Transition through Notch-Dependent Signaling
Authors: Gasperini Paola , Espigol-Frigole Georgina , McCormick Peter J. , Salvucci Ombretta , Maric Dragan , Uldrick Thomas S. , Polizzotto Mark N. , Yarchoan Robert , Tosato Giovanna
Published: March 2024

Abstract
Endothelial-to-mesenchymal transition (EndMT) is now widely considered a pivotal contributor to cancer progression. In this study, we show that the Kaposi's sarcoma (KS)–associated herpesvirus (KSHV) is a sufficient cause of EndMT, potentially helping to explain the aggressiveness of KS that occurs commonly in AIDS patients. Upon KSHV infection, primary dermal microvascular endothelial cells lost expression of endothelial markers and acquired expression of mesenchymal markers, displaying new invasive and migratory properties along with increased survival. KSHV activated Notch-induced transcription factors Slug and ZEB1, and canonical Notch signaling was required for KSHV-induced EndMT. In contrast, KSHV did not utilize the TGFβ signaling pathway, which has also been linked to EndMT. Within KS lesions, KSHV-infected spindle cells displayed features compatible with KSHV-induced EndMT including a complex phenotype of endothelial and mesenchymal properties, Notch activity, and nuclear ZEB1 expression. Our results show that KSHV engages the EndMT program to increase the invasiveness and survival of infected endothelial cells, traits that likely contribute to viral persistence and malignant progression. One important implication of our findings is that therapeutic approaches to disrupt the Notch pathway may offer novel approaches for KS treatment. Cancer Res; 72(5); 1157–69. ©2012 AACR.
Data from Opposing Effects of Pigment Epithelium–Derived Factor on Breast Cancer Cell versus Neuronal Survival: Implication for Brain Metastasis and Metastasis-Induced Brain Damage
Authors: Fitzgerald Daniel P. , Subramanian Preeti , Deshpande Monika , Graves Christian , Gordon Ira , Qian Yongzhen , Snitkovsky Yeva , Liewehr David J. , Steinberg Seth M. , Paltán-Ortiz José D. , Herman Mary M. , Camphausen Kevin , Palmieri Diane , Becerra S. Patricia , Steeg Patricia S.
Published: March 2024

Abstract
Brain metastases are a significant cause of morbidity and mortality for patients with cancer, yet preventative and therapeutic options remain an unmet need. The cytokine pigment epithelium–derived factor (PEDF) is downregulated in resected human brain metastases of breast cancer compared with primary breast tumors, suggesting that restoring its expression might limit metastatic spread. Here, we show that outgrowth of large experimental brain metastases from human 231-BR or murine 4T1-BR breast cancer cells was suppressed by PEDF expression, as supported by in vitro analyses as well as direct intracranial implantation. Notably, the suppressive effects of PEDF were not only rapid but independent of the effects of this factor on angiogenesis. Paralleling its cytotoxic effects on breast cancer cells, PEDF also exerted a prosurvival effect on neurons that shielded the brain from tumor-induced damage, as indicated by a relative 3.5-fold reduction in the number of dying neurons adjacent to tumors expressing PEDF. Our findings establish PEDF as both a metastatic suppressor and a neuroprotectant in the brain, highlighting its role as a double agent in limiting brain metastasis and its local consequences. Cancer Res; 72(1); 144–53. ©2012 AACR.
Data from Alternate Splicing of the p53 Inhibitor HDMX Offers a Superior Prognostic Biomarker than p53 Mutation in Human Cancer
Authors: Lenos Kristiaan , Grawenda Anna M. , Lodder Kirsten , Kuijjer Marieke L. , Teunisse Amina F.A.S. , Repapi Emmanouela , Grochola Lukasz F. , Bartel Frank , Hogendoorn Pancras C.W. , Wuerl Peter , Taubert Helge , Cleton-Jansen Anne-Marie , Bond Gareth L. , Jochemsen Aart G.
Published: March 2024

Abstract
Conventional high-grade osteosarcoma is the most common primary bone malignancy. Although altered expression of the p53 inhibitor HDMX (Mdmx/Mdm4) is associated with cancer risk, progression, and outcome in other tumor types, little is known about its role in osteosarcoma. High expression of the Hdmx splice variant HDMX-S relative to the full-length transcript (the HDMX-S/HDMX-FL ratio) correlates with reduced HDMX protein expression, faster progression, and poorer survival in several cancers. Here, we show that the HDMX-S/HDMX-FL ratio positively correlates with less HDMX protein expression, faster metastatic progression, and a trend to worse overall survival in osteosarcomas. We found that the HDMX-S/HDMX-FL ratio associated with common somatic genetic lesions connected with p53 inhibition, such as p53 mutation and HDM2 overexpression in osteosarcoma cell lines. Interestingly, this finding was not limited to osteosarcomas as we observed similar associations in breast cancer and a variety of other cancer cell lines, as well as in tumors from patients with soft tissue sarcoma. The HDMX-S/HDMX-FL ratio better defined patients with sarcoma with worse survival rates than p53 mutational status. We propose a novel role for alternative splicing of HDMX, whereby it serves as a mechanism by which HDMX protein levels are reduced in cancer cells that have already inhibited p53 activity. Alternative splicing of HDMX could, therefore, serve as a more effective biomarker for p53 pathway attenuation in cancers than p53 gene mutation. Cancer Res; 72(16); 4074–84. ©2012 AACR.
Data from Modulation of Glucose Metabolism by CD44 Contributes to Antioxidant Status and Drug Resistance in Cancer Cells
Authors: Tamada Mayumi , Nagano Osamu , Tateyama Seiji , Ohmura Mitsuyo , Yae Toshifumi , Ishimoto Takatsugu , Sugihara Eiji , Onishi Nobuyuki , Yamamoto Takehiro , Yanagawa Hiroshi , Suematsu Makoto , Saya Hideyuki
Published: March 2024

Abstract
An increased glycolytic flux accompanied by activation of the pentose phosphate pathway (PPP) is implicated in chemoresistance of cancer cells. In this study, we found that CD44, a cell surface marker for cancer stem cells, interacts with pyruvate kinase M2 (PKM2) and thereby enhances the glycolytic phenotype of cancer cells that are either deficient in p53 or exposed to hypoxia. CD44 ablation by RNA interference increased metabolic flux to mitochondrial respiration and concomitantly inhibited entry into glycolysis and the PPP. Such metabolic changes induced by CD44 ablation resulted in marked depletion of cellular reduced glutathione (GSH) and increased the intracellular level of reactive oxygen species in glycolytic cancer cells. Furthermore, CD44 ablation enhanced the effect of chemotherapeutic drugs in p53-deficient or hypoxic cancer cells. Taken together, our findings suggest that metabolic modulation by CD44 is a potential therapeutic target for glycolytic cancer cells that manifest drug resistance. Cancer Res; 72(6); 1438–48. ©2012 AACR.
Data from Mammary Tumor Regression Elicited by Wnt Signaling Inhibitor Requires IGFBP5
Authors: Liu Bob Y. , Soloviev Irina , Huang XiaoDong , Chang Peter , Ernst James A. , Polakis Paul , Sakanaka Chie
Published: March 2024

Abstract
Wnt ligand–driven tumor growth is inhibited by the soluble Wnt inhibitor Fzd8CRD, but the mechanism through which this effect is mediated is unknown. In the MMTV-Wnt1 mouse model, regression of mammary tumors by Fzd8CRD treatment coincides with an acute and strong induction of insulin-like growth factor (IGF)–binding protein IGFBP5, an antagonist of IGF signaling that mediates involution of mammary gland in females after offspring are weaned. In this study, we show that repression of this IGF inhibitory pathway is crucial for Wnt-driven growth of mammary tumors. We found that IGFBP5 regulation was mediated by the β-catenin–dependent Wnt pathway. Wnt, in addition to IGF ligands, facilitated tumor growth by paracrine communication among tumor cells. In addition, Fzd8CRD caused precocious induction of IGFBP5 in normal mammary glands undergoing involution, implying an acceleration of the involution process by inhibition of Wnt signaling. The molecular and phenotypic parallel between tumor regression and mammary gland involution suggests that Wnt-driven mammary tumors use the same growth mechanism as proliferating normal mammary glands. Cancer Res; 72(6); 1568–78. ©2012 AACR.
Data from Activation of Thermogenesis in Brown Adipose Tissue and Dysregulated Lipid Metabolism Associated with Cancer Cachexia in Mice
Authors: Tsoli Maria , Moore Melissa , Burg Dominic , Painter Arran , Taylor Ryland , Lockie Sarah H. , Turner Nigel , Warren Alessandra , Cooney Greg , Oldfield Brian , Clarke Stephen , Robertson Graham
Published: March 2024

Abstract
Cancer cachexia/anorexia is a complex syndrome that involves profound metabolic imbalances and is directly implicated as a cause of death in at least 20% to 30% of all cancers. Brown adipose tissue (BAT) plays a key role in thermogenesis and energy balance and potentially contributes to the physiologic perturbations associated with cachexia. In this study, we investigated the impact of cachexia-inducing colorectal tumor on BAT in mice. We found that brown adipocytes were smaller and exhibited profound delipidation in cachectic tumor–bearing mice. Diurnal expression profiling of key regulators of lipid accumulation and fatty acid β-oxidation and their corresponding target genes revealed dramatic molecular changes indicative of active BAT. Increased Ucp1, Pbe, and Cpt1α expression at specific points coincided with higher BAT temperatures during the dark cycle, suggestive of a temporal stimulation of thermogenesis in cachexia. These changes persisted when cachectic mice were acclimatized to 28°C confirming inappropriate stimulation of BAT despite thermoneutrality. Evidence of inflammatory signaling also was observed in the BAT as an energetically wasteful and maladaptive response to anorexia during the development of cachexia. Cancer Res; 72(17); 4372–82. ©2012 AACR.
Data from A Dynamic Inflammatory Cytokine Network in the Human Ovarian Cancer Microenvironment
Authors: Kulbe Hagen , Chakravarty Probir , Leinster D. Andrew , Charles Kellie A. , Kwong Joseph , Thompson Richard G. , Coward Jermaine I. , Schioppa Tiziana , Robinson Stephen C. , Gallagher William M. , Galletta Laura , Salako Michael A. , Smyth John F. , Hagemann Thorsten , Brennan Donal J. , Bowtell David D. , Balkwill Frances R.
Published: March 2024

Abstract
Constitutive production of inflammatory cytokines is a characteristic of many human malignant cell lines; however, the in vitro and in vivo interdependence of these cytokines, and their significance to the human cancer microenvironment, are both poorly understood. Here, we describe for the first time how three key cytokine/chemokine mediators of cancer-related inflammation, TNF, CXCL12, and interleukin 6, are involved in an autocrine cytokine network, the “TNF network,” in human ovarian cancer. We show that this network has paracrine actions on angiogenesis, infiltration of myeloid cells, and NOTCH signaling in both murine xenografts and human ovarian tumor biopsies. Neutralizing antibodies or siRNA to individual members of this TNF network reduced angiogenesis, myeloid cell infiltration, and experimental peritoneal ovarian tumor growth. The dependency of network genes on TNF was shown by their downregulation in tumor cells from patients with advanced ovarian cancer following the infusion of anti-TNF antibodies. Together, the findings define a network of inflammatory cytokine interactions that are crucial to tumor growth and validate this network as a key therapeutic target in ovarian cancer. Cancer Res; 72(1); 66–75. ©2011 AACR.
Data from Mammalian Sterile 20–like Kinase 1 Suppresses Lymphoma Development by Promoting Faithful Chromosome Segregation
Authors: Kim Tae-Shin , Lee Da-Hye , Kim Sang Kyum , Shin So Youn , Seo Eul-Ju , Lim Dae-Sik
Published: March 2024

Abstract
The mammalian Hippo signaling pathway has been implicated in oncogenesis in the context of solid tumors such as hepatocellular carcinoma. Mammalian sterile 20–like kinase 1 (MST1), the core component of the Hippo signaling pathway, is highly expressed in hematopoietic cells. However, its possible impact on tumorigenesis in this setting is unknown. In this study, we provide evidence that Mst1 loss in the mouse enhances chemically and genetically induced lymphoma development by inducing chromosomal instability. Mst1 deficiency increased susceptibility to T-cell acute lymphoblastic leukemia induced by mutagen exposure. Notably, before transformation Mst1−/− normal thymocytes showed no changes in proliferation or apoptosis in vitro and in vivo, but they displayed elevated levels of abnormal mitotic chromosomes and aneuploidy, conditions known to promote tumorigenesis. Mst1−/− mice also showed accelerated formation of spontaneous lymphomas in a p53-deficient background, accompanied by severe aneuploidy. In clinical specimens of lymphoma and leukemia, we documented frequent downregulation of MST1 expression, consistent with our findings. Taken together, our findings reveal a tumor suppressive function of Mst1 based on its ability to prevent chromosomal instability in lymphocytes. Cancer Res; 72(20); 5386–95. ©2012 AACR.
Data from Pocket Proteins Suppress Head and Neck Cancer
Authors: Shin Myeong-Kyun , Pitot Henry C. , Lambert Paul F.
Published: March 2024

Abstract
Head and neck squamous cell carcinomas (HNSCC) is a common cancer in humans long known to be caused by tobacco and alcohol use, but now an increasing percentage of HNSCC is recognized to be caused by the same human papillomaviruses (HPV) that cause cervical and other anogenital cancers. HPV-positive HNSCCs differ remarkably from HPV-negative HNSCCs in their clinical response and molecular properties. From studies in mice, we know that E7 is the dominant HPV oncoprotein in head and neck cancer. E7 is best known for its ability to inactivate pRb, the product of the retinoblastoma tumor susceptibility gene. However, loss of pRb function does not fully account for potency of E7 in causing head and neck cancer. In this study, we characterized the cancer susceptibility of mice deficient in the expression of pRb and either of two related “pocket” proteins, p107 and p130, that are also inactivated by E7. pRb/p107-deficient mice developed head and neck cancer as frequently as do HPV-16 E7 transgenic mice. The head and neck epithelia of the pRb/p107-deficient mice also displayed the same acute phenotypes and biomarker readouts as observed in the epithelia of E7 transgenic mice. Mice deficient for pRb and p130 in their head and neck epithelia showed intermediate acute and tumor phenotypes. We conclude that pRb and p107 act together to efficiently suppress head and neck cancer and are, therefore, highly relevant targets of HPV-16 E7 in its contribution to HPV-positive HNSCC. Cancer Res; 72(5); 1280–9. ©2012 AACR.
Data from Melanoma Cells Inhibit Natural Killer Cell Function by Modulating the Expression of Activating Receptors and Cytolytic Activity
Authors: Pietra Gabriella , Manzini Claudia , Rivara Silvia , Vitale Massimo , Cantoni Claudia , Petretto Andrea , Balsamo Mirna , Conte Romana , Benelli Roberto , Minghelli Simona , Solari Nicola , Gualco Marina , Queirolo Paola , Moretta Lorenzo , Mingari Maria Cristina
Published: March 2024

Abstract
Natural killer (NK) cells play a key role in tumor immune surveillance. However, adoptive immunotherapy protocols using NK cells have shown limited clinical efficacy to date, possibly due to tumor escape mechanisms that inhibit NK cell function. In this study, we analyzed the effect of coculturing melanoma cells and NK cells on their phenotype and function. We found that melanoma cells inhibited the expression of major NK receptors that trigger their immune function, including NKp30, NKp44, and NKG2D, with consequent impairment of NK cell–mediated cytolytic activity against various melanoma cell lines. This inhibitory effect was primarily mediated by indoleamine 2,3-dioxygenase (IDO) and prostaglandin E2 (PGE2). Together, our findings suggest that immunosuppressive barriers erected by tumors greatly hamper the antitumor activity of human NK cells, thereby favoring tumor outgrowth and progression. Cancer Res; 72(6); 1407–15. ©2012 AACR.
Data from Cervical Cancers Require the Continuous Expression of the Human Papillomavirus Type 16 E7 Oncoprotein Even in the Presence of the Viral E6 Oncoprotein
Authors: Jabbar Sean F. , Park Soyeong , Schweizer Johannes , Berard-Bergery Marthe , Pitot Henry C. , Lee Denis , Lambert Paul F.
Published: March 2024

Abstract
High-risk human papillomaviruses (HPV), such as HPV-16, are etiologic agents of a variety of anogenital and oral malignancies, including nearly all cases of cervical cancer. Cervical cancers arising in transgenic mice that express HPV-16 E7 in an inducible manner require the continuous expression of E7 for their maintenance. However, in HPV-associated cancers in vivo, E6 and E7 invariably are coexpressed. In this study, we investigated whether cervical cancers rely on the continuous expression of E7 in the context of constitutively expressed E6. We placed the inducible HPV-16 E7 transgene onto a background in which HPV-16 E6 was constitutively expressed. In transgenic mice with high-grade cervical dysplastic lesions and cervical cancer, repressing the expression of E7 led to the regression of all cancers and the vast majority of high-grade dysplastic lesions. In addition, cervical cancers were occasionally observed in transgenic mice in which E7 was repressed and then reexpressed. Our findings indicate that even in the presence of constitutively expressed E6, the continuous expression of E7 is required for the maintenance of cervical cancers and most precancerous lesions. These data have important implications for the potential clinical use of drugs designed to inhibit the expression and/or function of E7 to treat HPV-associated cancers. Cancer Res; 72(16); 4008–16. ©2012 AACR.
Data from Hedgehog Signaling Inhibition Blocks Growth of Resistant Tumors through Effects on Tumor Microenvironment
Authors: Heller Emanuela , Hurchla Michelle A. , Xiang Jingyu , Su Xinming , Chen Sara , Schneider Jochen , Joeng Kyu-Sang , Vidal Marcos , Goldberg Leah , Deng Hongju , Hornick Mary C. , Prior Julie L. , Piwnica-Worms David , Long Fanxin , Cagan Ross , Weilbaecher Katherine N.
Published: March 2024

Abstract
Hedgehog (Hh) signaling is implicated in bone development and cellular transformation. Here we show that inhibition of Hh pathway activity inhibits tumor growth through effects on the microenvironment. Pharmacologic inhibition of the Hh effector Smoothened (Smo) increased trabecular bone in vivo and inhibited osteoclastogenesis in vitro. In addition, enhanced Hh signaling due to heterozygosity of the Hh inhibitory receptor Patched (Ptch1+/−) increased bone resorption, suggesting direct regulation of osteoclast (OC) activity by the Hh pathway. Ptch1+/− mice had increased bone metastatic and subcutaneous tumor growth, suggesting that increased Hh activation in host cells promoted tumor growth. Subcutaneous growth of Hh-resistant tumor cells was inhibited by LDE225, a novel orally bioavailable SMO antagonist, consistent with effects on tumor microenvironment. Knockdown of the Hh ligand Sonic Hh (SHH) in these cells decreased subcutaneous tumor growth and decreased stromal cell production of interleukin-6, indicating that tumor-derived Hh ligands stimulated tumor growth in a paracrine fashion. Together our findings show that inhibition of the Hh pathway can reduce tumor burden, regardless of tumor Hh responsiveness, through effects on tumor cells, OCs, and stromal cells within the tumor microenvironment. Hh may be a promising therapeutic target for solid cancers and bone metastases. Cancer Res; 72(4); 897–907. ©2011 AACR.
Data from Differential Effects of Polymorphic Alleles of FGF Receptor 4 on Colon Cancer Growth and Metastasis
Authors: Heinzle Christine , Gsur Andrea , Hunjadi Monika , Erdem Zeynep , Gauglhofer Christine , Stättner Stefan , Karner Josef , Klimpfinger Martin , Wrba Friedrich , Reti Andrea , Hegedus Balazs , Baierl Andreas , Grasl-Kraupp Bettina , Holzmann Klaus , Grusch Michael , Berger Walter , Marian Brigitte
Published: March 2024

Abstract
A gly388arg polymorphism (rs351855) in the transmembrane domain of the fibroblast growth factor receptor (FGFR4) is associated with increased risk, staging, and metastasis in several different types of cancer. To specifically assess the impact of the polymorphic FGFR4 in colorectal cancer (CRC), we engineered CRC cell lines with distinct endogenous expression patterns to overexpress either the FGFR4gly or FGFR4arg alleles. The biologic analyses revealed an oncogenic importance for both polymorphic alleles, but FGFR4gly was the stronger inducer of tumor growth, whereas FGFR4arg was the stronger inducer of migration. An evaluation of clinical specimens revealed that FGFR4 was upregulated in 20/71 patients independent of gly388arg status. There was no correlation between the presence of an FGFR4arg allele and CRC or polyp risk in 3,471 participants of the CORSA study. However, among 182 patients with CRC, FGFR4arg-carriers had a fivefold higher risk of tumors that were stage II or greater. Together, our results established that both allelic forms of FGFR4 exert an oncogenic impact and may serve equally well as therapeutic targets in CRC. One important implication of our findings is that FGFR4arg-carriers are at a higher risk for more aggressive tumors and therefore may profit from early detection measures. Cancer Res; 72(22); 5767–77. ©2012 AACR.
Data from Adoptive Cell Therapy for Lymphoma with CD4 T Cells Depleted of CD137-Expressing Regulatory T Cells
Authors: Goldstein Matthew J. , Kohrt Holbrook E. , Houot Roch , Varghese Bindu , Lin Jack T. , Swanson Erica , Levy Ronald
Published: March 2024

Abstract
Adoptive immunotherapy with antitumor T cells is a promising novel approach for the treatment of cancer. However, T-cell therapy may be limited by the cotransfer of regulatory T cells (Treg). Here, we explored this hypothesis by using 2 cell surface markers, CD44 and CD137, to isolate antitumor CD4 T cells while excluding Tregs. In a murine model of B-cell lymphoma, only CD137negCD44hi CD4 T cells infiltrated tumor sites and provided protection. Conversely, the population of CD137posCD44hi CD4 T cells consisted primarily of activated Tregs. Notably, this CD137pos Treg population persisted following adoptive transfer and maintained expression of FoxP3 as well as CD137. Moreover, in vitro these CD137pos cells suppressed the proliferation of effector cells in a contact-dependent manner, and in vivo adding the CD137posCD44hi CD4 cells to CD137negCD44hi CD4 cells suppressed the antitumor immune response. Thus, CD137 expression on CD4 T cells defined a population of activated Tregs that greatly limited antitumor immune responses. Consistent with observations in the murine model, human lymphoma biopsies also contained a population of CD137pos CD4 T cells that were predominantly CD25posFoxP3pos Tregs. In conclusion, our findings identify 2 surface markers that can be used to facilitate the enrichment of antitumor CD4 T cells while depleting an inhibitory Treg population. Cancer Res; 72(5); 1239–47. ©2012 AACR.
Data from CD133+ Melanoma Subpopulations Contribute to Perivascular Niche Morphogenesis and Tumorigenicity through Vasculogenic Mimicry
Authors: Lai Chiou-Yan , Schwartz Brian E. , Hsu Mei-Yu
Published: March 2024

Abstract
Tumor cell subpopulations that express cancer stem cell markers such as CD133 (prominin1) or ABCB5 are thought to be crucial for tumor initiation and heterogeneity, but their biological significance in melanoma has been controversial. Here, we report that CD133+ and ABCB5+ subpopulations are colocalized in melanomas in perivascular niches that contain CD144 (VE-cadherin)+ melanoma cells forming vessel-like channels, a phenomenon termed vasculogenic mimicry (VM). RNAi-mediated attenuation of CD133 established its critical function in morphogenesis of these perivascular niches as well as in melanoma tumorigenicity. Niche-associated genes CD144 and ABCB5 were downregulated in tumors derived from CD133 knockdown (KD) melanoma cells compared with controls. CD133KD cells also lacked the ability to form CD144+ VM-like channels in a manner that was associated with a depletion of the ABCB5+ cell subpopulation. Finally, CD133 KD cells exhibited poorer tumor growth in vivo. Taken together, our findings corroborate models in which CD133+/ABCB5+ melanoma cells reside in a complex anastomosing microvascular niche that encompasses CD144+ VM channels as well as authentic endothelial cell-lined blood vessels. Further, they indicate that CD133+ cells act as stem-like cells, which drive tumor growth by promoting VM and the morphogenesis of a specialized perivascular niche in melanoma. Cancer Res; 72(19); 5111–8. ©2012 AACR.
Data from NFAT1 Supports Tumor-induced Anergy of CD4+ T Cells
Authors: Abe Brian T. , Shin Daniel S. , Mocholi Enric , Macian Fernando
Published: March 2024

Abstract
Cancer cells express antigens that elicit T cell-mediated responses, but these responses are limited during malignant progression by the development of immunosuppressive mechanisms in the tumor microenvironment that drive immune escape. T-cell hyporesponsiveness can be caused by clonal anergy or adaptive tolerance, but the pathophysiological roles of these processes in specific tumor contexts has yet to be understood. In CD4+ T cells, clonal anergy occurs when the T-cell receptor is activated in the absence of a costimulatory signal. Here we report that the key T-cell transcription factor NFAT mediates expression of anergy-associated genes in the context of cancer. Specifically, in a murine model of melanoma, we found that cancer cells induced anergy in antigen-specific CD4+ T-cell populations, resulting in defective production of several key effector cytokines. NFAT1 deficiency blunted the induction of anergy in tumor antigen-specific CD4+ T cells, enhancing antitumor responses. These investigations identified tumor-induced T-cell hyporesponsiveness as a form of clonal anergy, and they supported an important role for CD4+ T-cell anergy in driving immune escape. By illustrating the dependence of tumor-induced CD4+ T-cell anergy on NFAT1, our findings open the possibility of targeting this transcription factor to improve the efficacy of cancer immunotherapy or immunochemotherapy. Cancer Res; 72(18); 4642–51. ©2012 AACR.