bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Bcl-2 Family Genetic Profiling Reveals Microenvironment-Specific Determinants of Chemotherapeutic Response
Authors: Pritchard Justin R. , Gilbert Luke A. , Meacham Corbin E. , Ricks Jennifer L. , Jiang Hai , Lauffenburger Douglas A. , Hemann Michael T.
Published: March 2023

Abstract
The Bcl-2 family encompasses a diverse set of apoptotic regulators that are dynamically activated in response to various cell-intrinsic and -extrinsic stimuli. An extensive variety of cell culture experiments have identified effects of growth factors, cytokines, and drugs on Bcl-2 family functions, but in vivo studies have tended to focus on the role of one or two particular members in development and organ homeostasis. Thus, the ability of physiologically relevant contexts to modulate canonical dependencies that are likely to be more complex has yet to be investigated systematically. In this study, we report findings derived from a pool-based shRNA assay that systematically and comprehensively interrogated the functional dependence of leukemia and lymphoma cells upon various Bcl-2 family members across many diverse in vitro and in vivo settings. This approach permitted us to report the first in vivo loss of function screen for modifiers of the response to a front-line chemotherapeutic agent. Notably, our results reveal an unexpected role for the extrinsic death pathway as a tissue-specific modifier of therapeutic response. In particular, our findings show that particular tissue sites of tumor dissemination play critical roles in demarcating the nature and extent of cancer cell vulnerabilities and mechanisms of chemoresistance. Cancer Res; 71(17); 5850–8. ©2011 AACR.
Data from Regulator of G Protein Signaling 6 Mediates Doxorubicin-Induced ATM and p53 Activation by a Reactive Oxygen Species–Dependent Mechanism
Authors: Huang Jie , Yang Jianqi , Maity Biswanath , Mayuzumi Daisuke , Fisher Rory A.
Published: March 2023

Abstract
Doxorubicin (DXR), among the most widely used cancer chemotherapy agents, promotes cancer cell death via activation of ataxia telangiectasia mutated (ATM) and the resultant upregulation of tumor suppressor p53. The exact mechanism by which DXR activates ATM is not fully understood. Here, we discovered a novel role for regulator of G protein signaling 6 (RGS6) in mediating activation of ATM and p53 by DXR. RGS6 was robustly induced by DXR, and genetic loss of RGS6 dramatically impaired DXR-induced activation of ATM and p53, as well as its in vivo apoptotic actions in heart. The ability of RGS6 to promote p53 activation in response to DXR was independent of RGS6 interaction with G proteins but required ATM. RGS6 mediated activation of ATM and p53 by DXR via a reactive oxygen species (ROS)-dependent and DNA damage–independent mechanism. This mechanism represents the primary means by which DXR promotes activation of the ATM–p53 apoptosis pathway that underlies its cytotoxic activity. Our findings contradict the canonical theories that DXR activates ATM primarily by promoting DNA damage either directly or indirectly (via ROS) and that RGS6 function is mediated by its interactions with G proteins. These findings reveal a new mechanism for the chemotherapeutic actions of DXR and identify RGS6 as a novel target for cancer chemotherapy. Cancer Res; 71(20); 6310–9. ©2011 AACR.
Data from Radiosensitization of Human Pancreatic Cancer Cells by MLN4924, an Investigational NEDD8-Activating Enzyme Inhibitor
Authors: Wei Dongping , Li Hua , Yu Jie , Sebolt Jonathan T. , Zhao Lili , Lawrence Theodore S. , Smith Peter G. , Morgan Meredith A. , Sun Yi
Published: March 2023

Abstract
Radiotherapy is used in locally advanced pancreatic cancers in which it can improve survival in combination with gemcitabine. However, prognosis is still poor in this setting in which more effective therapies remain needed. MLN4924 is an investigational small molecule currently in phase I clinical trials. MLN4924 inhibits NAE (NEDD8 Activating Enzyme), a pivotal regulator of the E3 ubiquitin ligase SCF (SKP1, Cullins, and F-box protein), that has been implicated recently in DNA damage and repair. In this study, we provide evidence that MLN4924 can be used as an effective radiosensitizer in pancreatic cancer. Specifically, MLN4924 (20–100 nmol/L) effectively inhibited cullin neddylation and sensitized pancreatic cancer cells to ionizing radiation in vitro with a sensitivity enhancement ratio of approximately 1.5. Mechanistically, MLN4924 treatment stimulated an accumulation of several SCF substrates, including CDT1, WEE1, and NOXA, in parallel with an enhancement of radiation-induced DNA damage, aneuploidy, G2/M phase cell-cycle arrest, and apoptosis. RNAi-mediated knockdown of CDT1 and WEE1 partially abrogated MLN4924-induced aneuploidy, G2/M arrest, and radiosensitization, indicating a causal effect. Furthermore, MLN4924 was an effective radiosensitizer in a mouse xenograft model of human pancreatic cancer. Our findings offer proof-of-concept for use of MLN4924 as a novel class of radiosensitizer for the treatment of pancreatic cancer. Cancer Res; 72(1); 282–93. ©2011 AACR.
Data from Peptide-Conjugated PAMAM Dendrimer as a Universal DNA Vaccine Platform to Target Antigen-Presenting Cells
Authors: Daftarian Pirouz , Kaifer Angel E. , Li Wei , Blomberg Bonnie B. , Frasca Daniela , Roth Felix , Chowdhury Raquibul , Berg Eric A. , Fishman Jordan B. , Al Sayegh Husain A. , Blackwelder Pat , Inverardi Luca , Perez Victor L. , Lemmon Vance , Serafini Paolo
Published: March 2023

Abstract
DNA-based vaccines hold promise to outperform conventional antigen-based vaccines by virtue of many unique features. However, DNA vaccines have thus far fallen short of expectations, due in part to poor targeting of professional antigen-presenting cells (APC) and low immunogenicity. In this study, we describe a new platform for effective and selective delivery of DNA to APCs in vivo that offers intrinsic immune-enhancing characteristics. This platform is based on conjugation of fifth generation polyamidoamine (G5-PAMAM) dendrimers, a DNA-loading surface, with MHC class II–targeting peptides that can selectively deliver these dendrimers to APCs under conditions that enhance their immune stimulatory potency. DNA conjugated with this platform efficiently transfected murine and human APCs in vitro. Subcutaneous administration of DNA-peptide-dendrimer complexes in vivo preferentially transfected dendritic cells (DC) in the draining lymph nodes, promoted generation of high affinity T cells, and elicited rejection of established tumors. Taken together, our findings show how PAMAM dendrimer complexes can be used for high transfection efficiency and effective targeting of APCs in vivo, conferring properties essential to generate effective DNA vaccines. Cancer Res; 71(24); 7452–62. ©2011 AACR.
Data from PDK1 Attenuation Fails to Prevent Tumor Formation in PTEN-Deficient Transgenic Mouse Models
Authors: Ellwood-Yen Katharine , Keilhack Heike , Kunii Kaiko , Dolinski Brian , Connor Yamicia , Hu Kun , Nagashima Kumiko , O'Hare Erin , Erkul Yusuf , Di Bacco Alessandra , Gargano Diana , Shomer Nirah H. , Angagaw Minilik , Leccese Erica , Andrade Paula , Hurd Melissa , Shin Myung K. , Vogt Thomas F. , Northrup Alan , Bobkova Ekaterina V. , Kasibhatla Shailaja , Bronson Roderick T. , Scott Martin L. , Draetta Giulio , Richon Victoria , Kohl Nancy , Blume-Jensen Peter , Andersen Jannik N. , Kraus Manfred
Published: March 2023

Abstract
PDK1 activates AKT suggesting that PDK1 inhibition might suppress tumor development. However, while PDK1 has been investigated intensively as an oncology target, selective inhibitors suitable for in vivo studies have remained elusive. In this study we present the results of in vivo PDK1 inhibition through a universally applicable RNAi approach for functional drug target validation in oncogenic pathway contexts. This approach, which relies on doxycycline-inducible shRNA expression from the Rosa26 locus, is ideal for functional studies of genes like PDK1 where constitutive mouse models lead to strong developmental phenotypes or embryonic lethality. We achieved more than 90% PDK1 knockdown in vivo, a level sufficient to impact physiological functions resulting in hyperinsulinemia and hyperglycemia. This phenotype was reversible on PDK1 reexpression. Unexpectedly, long-term PDK1 knockdown revealed a lack of potent antitumor efficacy in 3 different mouse models of PTEN-deficient cancer. Thus, despite efficient PDK1 knockdown, inhibition of the PI3K pathway was marginal suggesting that PDK1 was not a rate limiting factor. Ex vivo analysis of pharmacological inhibitors revealed that AKT and mTOR inhibitors undergoing clinical development are more effective than PDK1 inhibitors at blocking activated PI3K pathway signaling. Taken together our findings weaken the widely held expectation that PDK1 represents an appealing oncology target. Cancer Res; 71(8); 3052–65. ©2011 AACR.
Data from Identification of a Tumor Suppressor Relay between the FOXP3 and the Hippo Pathways in Breast and Prostate Cancers
Authors: Li Weiquan , Wang Lizhong , Katoh Hiroto , Liu Runhua , Zheng Pan , Liu Yang
Published: March 2023

Abstract
Defective expression of LATS2, a negative regulator of YAP oncoprotein, has been reported in cancer of prostate, breast, liver, brain, and blood origins. However, no transcriptional regulators for the LATS2 gene have been identified. Here we report that spontaneous mutation of the transcription factor FOXP3 reduces expression of the LATS2 gene in mammary epithelial cells. shRNA-mediated silencing of FOXP3 in normal or malignant mammary epithelial cells of mouse and human origin repressed LATS2 expression and increased YAP protein levels. LATS2 induction required binding of FOXP3 to a specific sequence in the LATS2 promoter, and this interaction contributed to FOXP3-mediated growth inhibition of tumor cells. In support of these results, reduced expression and somatic mutations of FOXP3 correlated strongly with defective LATS2 expression in microdissected prostate cancer tissues. Thus, defective expression of LATS2 is attributable to FOXP3 defects and may be a major independent determinant of YAP protein elevation in cancer. Our findings identify a novel mechanism of LATS2 downregulation in cancer and reveal an important tumor suppressor relay between the FOXP3 and HIPPO pathways which are widely implicated in human cancer. Cancer Res; 71(6); 2162–71. ©2011 AACR.
Data from Functional Cooperation of RKTG with p53 in Tumorigenesis and Epithelial–Mesenchymal Transition
Authors: Jiang Yuhui , Xie Xiaoduo , Li Zhigang , Wang Zheng , Zhang Yixuan , Ling Zhiqiang , Pan Yi , Wang Zhenzhen , Chen Yan
Published: March 2023

Abstract
Raf kinase trapping to Golgi (RKTG) is a potential tumor suppressor gene due to its negative roles in regulating Ras/Raf/MEK/ERK (extracellular signal–regulated kinase) pathway and GPCR (G protein–coupled receptor) Gβγ subunit signaling. Interestingly, RKTG-deficient mice are free of tumors, although they are prone to form skin cancer on carcinogen administration. On the other hand, p53 is a well-characterized tumor suppressor gene and p53 heterozygous mice develop sarcoma and other tumors starting from 12 months of age. In RKTG-null mouse embryonic fibroblasts, lypophosphatidic acid (LPA), but not EGF (epidermal growth factor), could stimulate hyperphosphorylation of AKT and GSK3β, accompanied by increases in phosphorylation of p53 at Ser15 and accumulation of p53, as well as its target genes p21 and p16. Spontaneous skin cancer–like tumors were detected in about 25% of RKTG nullizygous and p53 heterozygous mice within 7 months of age. Hyperplasia and epithelial–mesenchymal transition (EMT) were observed in the tumor-overlying epidermis, in which LOH of p53 occurred and EMT features emerged. In p53-mutated A431 epithelial carcinoma cells, knockdown of RKTG led to enhancement of LPA-stimulated AKT and GSK3β phosphorylation, together with increased accumulation of β-catenin and appearance of EMT features that were antagonized by p53 overexpression. In HepG2 epithelial cells, LPA-stimulated AKT phosphorylation and EMT features reached maximum when both RKTG and p53 were simultaneously silenced. In summary, these results not only indicate that RKTG has an in vivo tumor suppressor function to cooperate with p53 in tumorigenesis but also suggest that p53 has an EMT checkpoint function and the loss of this function can combine with loss of RKTG to drive EMT and tumor progression. Cancer Res; 71(8); 2959–68. ©2011 AACR.
Data from 14-3-3σ Exerts Tumor-Suppressor Activity Mediated by Regulation of COP1 Stability
Authors: Su Chun-Hui , Zhao Ruiying , Zhang Fanmao , Qu Changju , Chen Bo , Feng Yin-Hsun , Phan Liem , Chen Jian , Wang Hua , Wang Huamin , Yeung Sai-Ching J. , Lee Mong-Hong
Published: March 2023

Abstract
Constitutive photomorphogenic 1 (COP1) is a p53-targeting E3 ubiquitin ligase that is downregulated by DNA damage through mechanisms that remain obscure. Here, we report that COP1 is not downregulated following DNA damage in 14-3-3σ null cells, implicating 14-3-3σ as a critical regulator in the response of COP1 to DNA damage. We also identified that 14-3-3σ, a p53 target gene product, interacted with COP1 and controlled COP1 protein stability after DNA damage. Mechanistic studies revealed that 14-3-3σ enhanced COP1 self-ubiquitination, thereby preventing COP1-mediated p53 ubiquitination, degradation, and transcriptional repression. In addition, we found that COP1 expression promoted cell proliferation, cell transformation, and tumor progression, manifesting its role in cancer promotion, whereas 14-3-3σ negatively regulated COP1 function and prevented tumor growth in a mouse xenograft model of human cancer. Immunohistochemical analysis of clinical breast and pancreatic cancer specimens demonstrated that COP1 protein levels were inversely correlated with 14-3-3σ protein levels. Together, our findings define a mechanism for posttranslational regulation of COP1 after DNA damage that can explain the correlation between COP1 overexpression and 14-3-3σ downregulation during tumorigenesis. Cancer Res; 71(3); 884–94. ©2010 AACR.
Data from Novel Cryo-Imaging of the Glioma Tumor Microenvironment Reveals Migration and Dispersal Pathways in Vivid Three-Dimensional Detail
Authors: Burden-Gulley Susan M. , Qutaish Mohammed Q. , Sullivant Kristin E. , Lu Hong , Wang Jing , Craig Sonya E.L. , Basilion James P. , Wilson David L. , Brady-Kalnay Susann M.
Published: March 2023

Abstract
Traditional methods of imaging cell migration in the tumor microenvironment include serial sections of xenografts and standard histologic stains. Current molecular imaging techniques suffer from low resolution and difficulty in imaging through the skull. Here we show how computer algorithms can be used to reconstruct images from tissue sections obtained from mouse xenograft models of human glioma and can be rendered into three-dimensional images offering exquisite anatomic detail of tumor cell dispersal. Our findings identify human LN-229 and rodent CNS-1 glioma cells as valid systems to study the highly dispersive nature of glioma tumor cells along blood vessels and white matter tracts in vivo. This novel cryo-imaging technique provides a valuable tool to evaluate therapeutic interventions targeted at limiting tumor cell invasion and dispersal. Cancer Res; 71(17); 5932–40. ©2011 AACR.
Data from Resuscitating Cancer Immunosurveillance: Selective Stimulation of DLL1-Notch Signaling in T cells Rescues T-cell Function and Inhibits Tumor Growth
Authors: Huang Yuhui , Lin Luping , Shanker Anil , Malhotra Anshu , Yang Li , Dikov Mikhail M. , Carbone David P.
Published: March 2023

Abstract
Deficiencies in immune function that accumulate during cancer immunoediting lead to a progressive escape from host immunosurveillance. Therapies that correct or overcome these defects could have a powerful impact on cancer management, but current knowledge of the types and mechanisms of immune escape is still incomplete. Here, we report a novel mechanism of escape from T-cell immunity that is caused by reduction in levels of the Delta family Notch ligands DLL1 and DLL4 in hematopoietic microenvironments. An important mediator of this effect was an elevation in the levels of circulating VEGF. Selective activation of the DLL1-Notch signaling pathway in bone marrow precursors enhanced T-cell activation and inhibited tumor growth. Conversely, tumor growth led to inhibition of Delta family ligand signaling through Notch in the hematopoietic environment, resulting in suppressed T-cell function. Overall, our findings uncover a novel mechanism of tumoral immune escape and suggest that a soluble multivalent form of DLL1 may offer a generalized therapeutic intervention to stimulate T-cell immunity and suppress tumor growth. Cancer Res; 71(19); 6122–31. ©2011 AACR.
Data from Oxygen Is a Master Regulator of the Immunogenicity of Primary Human Glioma Cells
Authors: Olin Michael R. , Andersen Brian M. , Litterman Adam J. , Grogan Patrick T. , Sarver Aaron L. , Robertson Paul T. , Liang Xueqing , Chen Wei , Parney Ian F. , Hunt Matthew A. , Blazar Bruce R. , Ohlfest John R.
Published: March 2023

Abstract
With recent approval of the first dendritic cell (DC) vaccine for patient use, many other DC vaccine approaches are now being tested in clinical trials. Many of these DC vaccines employ tumor cell lysates (TL) generated from cells cultured in atmospheric oxygen (∼20% O2) that greatly exceeds levels found in tumors in situ. In this study, we tested the hypothesis that TLs generated from tumor cells cultured under physiologic oxygen (∼5% O2) would be more effective as a source for DC antigens. Gene expression patterns in primary glioma cultures established at 5% O2 more closely paralleled patient tumors in situ and known immunogenic antigens were more highly expressed. DCs treated with TLs generated from primary tumor cells maintained in 5% O2 took up and presented antigens to CD8 T cells more efficiently. Moreover, CD8 T cells primed in this manner exhibited superior tumoricidal activity against target cells cultured in either atmospheric 20% O2 or physiologic 5% O2. Together, these results establish a simple method to greatly improve the effectiveness of DC vaccines in stimulating the production of tumoricidal T cells, with broad implications for many of the DC-based cancer vaccines being developed for clinical application. Cancer Res; 71(21); 6583–9. ©2011 AACR.
Data from Epithelial Junction Opener JO-1 Improves Monoclonal Antibody Therapy of Cancer
Authors: Beyer Ines , van Rensburg Ruan , Strauss Robert , Li ZongYi , Wang Hongjie , Persson Jonas , Yumul Roma , Feng Qinghua , Song Hui , Bartek Jiri , Fender Pascal , Lieber André
Published: March 2023

Abstract
The efficacy of monoclonal antibodies (mAb) used to treat solid tumors is limited by intercellular junctions which tightly link epithelial tumor cells to each another. In this study, we define a small, recombinant adenovirus serotype 3-derived protein, termed junction opener 1 (JO-1), which binds to the epithelial junction protein desmoglein 2 (DSG2). In mouse xenograft models employing Her2/neu- and EGFR-positive human cancer cell lines, JO-1 mediated cleavage of DSG2 dimers and activated intracellular signaling pathways which reduced E-cadherin expression in tight junctions. Notably, JO-1-triggered changes allowed for increased intratumoral penetration of the anti-Her2/neu mAb trastuzumab (Herceptin) and improved access to its target receptor, Her2/neu, which is partly trapped in tight junctions. This effect translated directly into increased therapeutic efficacy of trastuzumab in mouse xenograft models using breast, gastric, and ovarian cancer cells that were Her2/neu-positive. Furthermore, combining JO-1 with the EGFR-targeting mAb cetuximab (Erbitux) greatly improved therapeutic outcomes in a metastatic model of EGFR-positive lung cancer. A combination of JO-1 with an approach that triggered transient degradation of tumor stroma proteins elicited eradication of tumors. Taken together, our findings offer preclinical proof of concept to employ JO-1 in combination with mAb therapy. Cancer Res; 71(22); 7080–90. ©2011 AACR.
Data from Chemotherapeutic Properties of Phospho-Nonsteroidal Anti-Inflammatory Drugs, a New Class of Anticancer Compounds
Authors: Huang Liqun , Mackenzie Gerardo G. , Sun Yu , Ouyang Nengtai , Xie Gang , Vrankova Kvetoslava , Komninou Despina , Rigas Basil
Published: March 2023

Abstract
Nonsteroidal anti-inflammatory drugs (NSAID) exhibit antineoplastic properties, but conventional NSAIDs do not fully meet safety and efficacy criteria for use as anticancer agents. In this study, we evaluated the chemotherapeutic efficacy of 5 novel phospho-NSAIDs, each of which includes in addition to the NSAID moiety a diethylphosphate linked through a butane moiety. All 5 compounds inhibited the growth of human breast, colon, and pancreatic cancer cell lines with micromolar potency. In vivo investigations confirmed the antitumor activity of phospho-aspirin (PA) and phospho-sulindac (PS) in inhibiting tumor growth in established human xenograft models, in which cell proliferation was suppressed and apoptosis enhanced in the absence of detectable animal toxicity. Notably, all of the phospho-NSAIDs tested induced reactive oxygen and nitrogen species in cultured cells, with PA and PS inducing detectable levels of oxidative stress in vivo that were associated positively with apoptosis and negatively with proliferation. Potentially explaining these effects, all of the phospho-NSAIDs tested also inhibited the thioredoxin system and the redox sensitive transcription factor NF-κB. Taken together, our findings show the strong anticancer efficacy and promising safety of phospho-NSAIDs in preclinical models of breast, colon, and pancreatic cancer, suggesting further evaluation as anticancer agents. Cancer Res; 71(24); 7617–27. ©2011 AACR.
Data from Steroid Receptor Coactivator-1 Upregulates Integrin α5 Expression to Promote Breast Cancer Cell Adhesion and Migration
Authors: Qin Li , Chen Xian , Wu Yelin , Feng Zhen , He Tao , Wang Li , Liao Lan , Xu Jianming
Published: March 2023

Abstract
Metastatic breast cancer remains a lethal disease with poorly understood molecular mechanisms. Steroid receptor coactivator-1 (SRC-1 or NCOA1) is overexpressed in a subset of breast cancers with poor prognosis. It potentiates gene expression by serving as a coactivator for nuclear receptors and other transcription factors. We previously reported that SRC-1 promotes breast cancer metastasis without affecting primary mammary tumor formation. Herein, we found that SRC-1 deficiency in mouse and human breast cancer cells substantially reduced cell adhesion and migration capabilities on fibronectin and significantly extended the time of focal adhesion disassembly and reassembly. In agreement with this phenotype, SRC-1 expression positively correlated with integrin α5 (ITGA5) expression in estrogen receptor–negative breast tumors whereas SRC-1 deficiency decreased ITGA5 expression. Furthermore, ITGA5 reduction in SRC-1–deficient/insufficient breast cancer cells or knockdown of ITGA5 in SRC-1–expressing breast cancer cells was associated with a disturbed integrin-mediated signaling. Critical downstream changes included reduced phosphorylation and/or dampened activation of focal adhesion kinase, paxillin, Rac1, and Erk1/2 during cell adhesion. Finally, we found that SRC-1 enhanced ITGA5 promoter activity through an AP-1 (activator protein)–binding site proximal to the transcriptional initiation site; both SRC-1 and c-Jun were recruited to this promoter region in breast cancer cells. These results show that SRC-1 can promote breast cancer metastasis by directly enhancing ITGA5 expression and thus promoting ITGA5-mediated cell adhesion and migration. Therefore, targeting ITGA5 in SRC-1–positive breast cancers may result in inhibition of SRC-1–promoted breast cancer metastasis. Cancer Res; 71(5); 1742–51. ©2011 AACR.
Data from Definition of the Landscape of Promoter DNA Hypomethylation in Liver Cancer
Authors: Stefanska Barbara , Huang Jian , Bhattacharyya Bishnu , Suderman Matthew , Hallett Michael , Han Ze-Guang , Szyf Moshe
Published: March 2023

Abstract
We use hepatic cellular carcinoma (HCC), one of the most common human cancers, as a model to delineate the landscape of promoter hypomethylation in cancer. Using a combination of methylated DNA immunoprecipitation and hybridization with comprehensive promoter arrays, we have identified approximately 3,700 promoters that are hypomethylated in tumor samples. The hypomethylated promoters appeared in clusters across the genome suggesting that a high-level organization underlies the epigenomic changes in cancer. In normal liver, most hypomethylated promoters showed an intermediate level of methylation and expression, however, high-CpG dense promoters showed the most profound increase in gene expression. The demethylated genes are mainly involved in cell growth, cell adhesion and communication, signal transduction, mobility, and invasion; functions that are essential for cancer progression and metastasis. The DNA methylation inhibitor, 5-aza-2′-deoxycytidine, activated several of the genes that are demethylated and induced in tumors, supporting a causal role for demethylation in activation of these genes. Previous studies suggested that MBD2 was involved in demethylation of specific human breast and prostate cancer genes. Whereas MBD2 depletion in normal liver cells had little or no effect, we found that its depletion in human HCC and adenocarcinoma cells resulted in suppression of cell growth, anchorage-independent growth and invasiveness as well as an increase in promoter methylation and silencing of several of the genes that are hypomethylated in tumors. Taken together, the findings define the potential functional role of hypomethylation in cancer. Cancer Res; 71(17); 5891–903. ©2011 AACR.
Data from Tankyrase and the Canonical Wnt Pathway Protect Lung Cancer Cells from EGFR Inhibition
Authors: Casás-Selves Matias , Kim Jihye , Zhang Zhiyong , Helfrich Barbara A. , Gao Dexiang , Porter Christopher C. , Scarborough Hannah A. , Bunn Paul A. , Chan Daniel C. , Tan Aik Choon , DeGregori James
Published: March 2023

Abstract
Lung cancer is the leading cause of death worldwide. Adenocarcinomas, the most common histologic subtype of non-small cell lung cancer (NSCLC), are frequently associated with activating mutations in the epidermal growth factor receptor (EGFR) gene. Although these patients often respond clinically to the EGFR tyrosine kinase inhibitors erlotinib and gefitinib, relapse inevitably occurs, suggesting the development of escape mechanisms that promote cell survival. Using a loss-of-function, whole genome short hairpin RNA (shRNA) screen, we identified that the canonical Wnt pathway contributes to the maintenance of NSCLC cells during EGFR inhibition, particularly the poly-ADP-ribosylating enzymes tankyrase 1 and 2 that positively regulate canonical Wnt signaling. Inhibition of tankyrase and various other components of the Wnt pathway with shRNAs or small molecules significantly increased the efficacy of EGFR inhibitors both in vitro and in vivo. Our findings therefore reveal a critical role for tankyrase and the canonical Wnt pathway in maintaining lung cancer cells during EGFR inhibition. Targeting the Wnt-tankyrase-β-catenin pathway together with EGFR inhibition may improve clinical outcome in patients with NSCLC. Cancer Res; 72(16); 4154–64. ©2012 AACR.
Data from Metastasis-Associated Protein 1/Nucleosome Remodeling and Histone Deacetylase Complex in Cancer
Authors: Li Da-Qiang , Pakala Suresh B. , Nair Sujit S. , Eswaran Jeyanthy , Kumar Rakesh
Published: March 2023

Abstract
Cancer cells frequently exhibit deregulation of coregulatory molecules to drive the process of growth and metastasis. One such group of ubiquitously expressed coregulators is the metastasis-associated protein (MTA) family, a critical component of the nucleosome remodeling and histone deacetylase (NuRD) complex. MTA1 occupies a special place in cancer biology because of its dual corepressor or coactivator nature and widespread overexpression in human cancers. Here, we highlight recent advances in our understanding of the vital roles of MTA1 on transformation, epithelial–mesenchymal transition, and the functions of key cancer-relevant molecules such as a nexus of multiple oncogenes and tumor suppressors. In addition to its paramount role in oncogenesis, we reveal several new physiologic functions of MTA1 related to DNA damage, inflammatory responses, and infection, in which MTA1 functions as a permissive “gate keeper” for cancer-causing parasites. Further, these discoveries unraveled the versatile multidimensional modes of action of MTA1, which are independent of the NuRD complex and/or transcription. Given the emerging roles of MTA1 in DNA repair, inflammation, and parasitism, we discuss the possibility of MTA1-targeted therapy for use not only in combating cancer but also in other inflammation and pathogen-driven pathologic conditions. Cancer Res; 72(2); 387–94. ©2012 AACR.
Data from CXCR6 Upregulation Contributes to a Proinflammatory Tumor Microenvironment That Drives Metastasis and Poor Patient Outcomes in Hepatocellular Carcinoma
Authors: Gao Qiang , Zhao Ying-Jun , Wang Xiao-Ying , Qiu Shuang-Jian , Shi Ying-Hong , Sun Jian , Yi Yong , Shi Jie-Yi , Shi Guo-Ming , Ding Zhen-Bin , Xiao Yong-Sheng , Zhao Zhong-Hua , Zhou Jian , He Xiang-Huo , Fan Jia
Published: March 2023

Abstract
CXC chemokines and their cognate receptors have been implicated widely in cancer pathogenesis. In this study, we report a critical causal relationship between CXCR6 expression and tumorigenesis in the setting of human hepatocellular carcinoma (HCC). Among the CXC chemokine receptors, only CXCR6 was detected in all the hepatoma cell lines studied. Moreover, in HCC tissue, CXCR6 expression was significantly higher than in noncancerous liver tissues. Reduction of CXCR6 or its ligand CXCL16 in cancer cells reduced cell invasion in vitro and tumor growth, angiogenesis, and metastases in vivo. Importantly, loss of CXCR6 led to reduced Gr-1+ neutrophil infiltration and decreased neoangiogenesis in hepatoma xenografts via inhibition of proinflammatory cytokine production. Clinically, high expression of CXCR6 was an independent predictor of increased recurrence and poor survival in HCCs. Human HCC samples expressing high levels of CXCR6 also contained an increased number of CD66b+ neutrophils and microvessels, and the combination of CXCR6 and neutrophils was a superior predictor of recurrence and survival than either marker used alone. Together, our findings suggest that elevated expression of CXCR6 promotes HCC invasiveness and a protumor inflammatory environment and is associated with poor patient outcome. These results support the concept that inhibition of the CXCR6–CXCL16 pathway may improve prognosis after HCC treatment. Cancer Res; 72(14); 3546–56. ©2012 AACR.
Data from Breast Cancer Cell Uptake of the Inflammatory Mediator Neutrophil Elastase Triggers an Anticancer Adaptive Immune Response
Authors: Mittendorf Elizabeth A. , Alatrash Gheath , Qiao Na , Wu Yun , Sukhumalchandra Pariya , St. John Lisa S. , Philips Anne V. , Xiao Haile , Zhang Mao , Ruisaard Kathryn , Clise-Dwyer Karen , Lu Sijie , Molldrem Jeffrey J.
Published: March 2023

Abstract
There is little understanding of the impact of tumor-associated neutrophils (TAN) on adaptive immunity to tumors. In this study, we report the results of an investigation of the pathobiologic basis for the prognostic significance of neutrophil elastase, a serine protease found in neutrophil granules, in a model of cyclin E (CCNE)–overexpressing breast cancer. We established that neutrophil elastase was expressed by TAN within breast cancer tissues but not by breast cancer cells. Neutrophil elastase modulated killing of breast cancer cells by CTLs specific for CCNE-derived HLA-A2–restricted peptide (ILLDWLMEV). Breast cancer cells exhibited striking antigen-specific uptake of neutrophil elastase from the microenvironment that was independent of neutrophil elastase enzymatic activity. Furthermore, neutrophil elastase uptake increased expression of low molecular weight forms of CCNE and enhanced susceptibility to peptide-specific CTL lysis, suggesting that CCNE peptides are naturally presented on breast cancer cells. Taken together, our findings reveal a previously unknown mechanism of antitumor adaptive immunity that links cancer cell uptake of an inflammatory mediator to an effective cytolytic response against an important breast cancer antigen. Cancer Res; 72(13); 3153–62. ©2012 AACR.
Data from Epithelial Cell Organization Suppresses Myc Function by Attenuating Myc Expression
Authors: Simpson David R. , Yu Min , Zheng Siyuan , Zhao Zhongming , Muthuswamy Senthil K. , Tansey William P.
Published: April 2023

Abstract
c-Myc is an oncogene transcription factor that causes cancer in many settings, including solid tumors that arise in the context of organized tissue structures. Given that disruption of tissue architecture frequently occurs in cancer, there is considerable interest in how cell organization impacts oncogene function. A previous report found that organization of mammary epithelial cells into defined 3-dimensional structures renders them insensitive to the effects of retrovirus-mediated overexpression of Myc, leading to the notion that organization tempers the sensitivity of individual cells to Myc activity. In this article, we report that epithelial cell organization does not profoundly alter Myc activity but, instead, suppresses Myc by modulating its expression. We show that the morphogenesis of mammary epithelial cells into organized acinar structures in vitro is accompanied by widespread changes in gene expression patterns, including a substantial decrease in the expression of Myc. Concomitant with the decrease in endogenous Myc expression, we observe a decrease in transcription from retroviral vectors during morphogenesis and find that Myc transgene expression in acini is much lower than in unorganized cells. This decrease in Myc transgene activity is responsible for the apparent recalcitrance of organized cells to ectopic Myc, as adenovirus-mediated expression of Myc in organized structures potently induces apoptosis. These observations reveal that organization does not alter the inherent response of epithelial cells to Myc and suggest that other tumor suppression mechanisms, apart from structure, antagonize Myc in the development of solid tumors. Cancer Res; 71(11); 3822–30. ©2011 AACR.
Data from β-Catenin/POU5F1/SOX2 Transcription Factor Complex Mediates IGF-I Receptor Signaling and Predicts Poor Prognosis in Lung Adenocarcinoma
Authors: Xu Chuan , Xie Dan , Yu Shi-Cang , Yang Xiao-Jun , He Li-Ru , Yang Jing , Ping Yi-Fang , Wang Bin , Yang Lang , Xu Sen-Lin , Cui Wei , Wang Qing-Liang , Fu Wen-Juan , Liu Qing , Qian Cheng , Cui You-Hong , Rich Jeremy N. , Kung Hsiang-Fu , Zhang Xia , Bian Xiu-Wu
Published: April 2023

Abstract
Cancer stem-like cells (CSLC) are crucial in tumor initiation and progression; however, the underlying mechanism for the self-renewal of cancer cells remains undefined. In the study, immunohistochemical analysis of specimens freshly excised from patients with lung adenocarcinoma showed that high expression of insulin-like growth factor I receptor (IGF-IR) in lung adenocarcinoma cells was positively correlated with the expressions of cancer stem cell markers CD133 and aldehyde dehydrogenase 1 family member A1 (ALDH1A1). IGF-IR activation enhanced POU class 5 homeobox 1 (POU5F1) expression on human lung adenocarcinoma stem-like cells (LACSLC) through PI3K/AKT/GSK3β/β-catenin cascade. POU5F1 could form a novel complex with β-catenin and SOX2 to bind Nanog promoter for transcription to maintain self-renewal of LACSLCs, which was dependent on the functional IGF-IR. Genetic and pharmacologic inhibition of IGF-IR abrogated LACSLC capabilities for self-renewal and tumorigenicity in vitro. In an in vivo xenograft tumor model, knockdown of either IGF-IR or POU5F1 impeded tumorigenic potentials of LACSLCs. By analyzing pathologic specimens excised from 200 patients with lung adenocarcinoma, we found that colocalization of highly expressed IGF-IR with β-catenin and POU5F1 predicted poor prognosis. Taken together, we show that IGF-IR—mediated POU5F1 expression to form a complex with β-catenin and SOX2 is crucial for the self-renewal and oncogenic potentials of LACSLCs, and the integrative clinical detection of the expressions of IGF-IR, β-catenin, and POU5F1 is indicatory for predicting prognosis in the patients of lung adenocarcinoma. Cancer Res; 73(10); 3181–9. ©2013 AACR.
Data from Rab25 Is a Tumor Suppressor Gene with Antiangiogenic and Anti-Invasive Activities in Esophageal Squamous Cell Carcinoma
Authors: Tong Man , Chan Kwok Wah , Bao Jessie Y.J. , Wong Kai Yau , Chen Jin-Na , Kwan Pak Shing , Tang Kwan Ho , Fu Li , Qin Yan-Ru , Lok Si , Guan Xin-Yuan , Ma Stephanie
Published: April 2023

Abstract
Esophageal squamous cell carcinoma (ESCC), the major histologic subtype of esophageal cancer, is a devastating disease characterized by distinctly high incidences and mortality rates. However, there remains limited understanding of molecular events leading to development and progression of the disease, which are of paramount importance to defining biomarkers for diagnosis, prognosis, and personalized treatment. By high-throughout transcriptome sequence profiling of nontumor and ESCC clinical samples, we identified a subset of significantly differentially expressed genes involved in integrin signaling. The Rab25 gene implicated in endocytic recycling of integrins was the only gene in this group significantly downregulated, and its downregulation was confirmed as a frequent event in a second larger cohort of ESCC tumor specimens by quantitative real-time PCR and immunohistochemical analyses. Reduced expression of Rab25 correlated with decreased overall survival and was also documented in ESCC cell lines compared with pooled normal tissues. Demethylation treatment and bisulfite genomic sequencing analyses revealed that downregulation of Rab25 expression in both ESCC cell lines and clinical samples was associated with promoter hypermethylation. Functional studies using lentiviral-based overexpression and suppression systems lent direct support of Rab25 to function as an important tumor suppressor with both anti-invasive and -angiogenic abilities, through a deregulated FAK–Raf–MEK1/2–ERK signaling pathway. Further characterization of Rab25 may provide a prognostic biomarker for ESCC outcome prediction and a novel therapeutic target in ESCC treatment. Cancer Res; 72(22); 6024–35. ©2012 AACR.
Data from Epigenetic Resensitization to Platinum in Ovarian Cancer
Authors: Matei Daniela , Fang Fang , Shen Changyu , Schilder Jeanne , Arnold Alesha , Zeng Yan , Berry William A. , Huang Tim , Nephew Kenneth P.
Published: April 2023

Abstract
Preclinical studies have shown that hypomethylating agents reverse platinum resistance in ovarian cancer. In this phase II clinical trial, based upon the results of our phase I dose defining study, we tested the clinical and biologic activity of low-dose decitabine administered before carboplatin in platinum-resistant ovarian cancer patients. Among 17 patients with heavily pretreated and platinum-resistant ovarian cancer, the regimen induced a 35% objective response rate (RR) and progression-free survival (PFS) of 10.2 months, with nine patients (53%) free of progression at 6 months. Global and gene-specific DNA demethylation was achieved in peripheral blood mononuclear cells and tumors. The number of demethylated genes was greater (P < 0.05) in tumor biopsies from patients with PFS more than 6 versus less than 6 months (311 vs. 244 genes). Pathways enriched at baseline in tumors from patients with PFS more than 6 months included cytokine–cytokine receptor interactions, drug transporters, and mitogen-activated protein kinase, toll-like receptor and Jak-STAT signaling pathways, whereas those enriched in demethylated genes after decitabine treatment included pathways involved in cancer, Wnt signaling, and apoptosis (P < 0.01). Demethylation of MLH1, RASSF1A, HOXA10, and HOXA11 in tumors positively correlated with PFS (P < 0.05). Together, the results of this study suggest that low-dose decitabine altered DNA methylation of genes and cancer pathways, restoring sensitivity to carboplatin in patients with heavily pretreated ovarian cancer and resulting in a high RR and prolonged PFS. Cancer Res; 72(9); 2197–205. ©2012 AACR.
Data from Notch3 Functions as a Tumor Suppressor by Controlling Cellular Senescence
Authors: Cui Hang , Kong Yahui , Xu Mei , Zhang Hong
Published: March 2023

Abstract
Notch signaling regulates a broad spectrum of cell fate decisions and differentiation. Both oncogenic and tumor suppressor functions have been shown for Notch signaling. However, little is known about the underlying mechanisms of its tumor suppressor function. Here, we report that expression of Notch3, a member of Notch family transmembrane receptors, was elevated in human cells during senescence activated by various senescence-inducing stimuli. This upregulation of Notch3 was required for the induction of p21 expression in senescent cells. Downregulation of Notch3 led to a delayed onset of senescence and extended replicative lifespan, whereas adventitious expression of Notch3 was sufficient to activate senescence and p21 expression. The ability of Notch3 to induce senescence and p21 expression was dependent on the canonical Notch singling. Deletion of p21 in cells significantly attenuated Notch3-induced senescence. Furthermore, a significant decrease in Notch3 expression was observed in human tumor cell lines as well as primary human breast cancer and melanoma samples compared with normal tissues. Restoration of Notch3 expression in human tumor cells resulted in inhibition of cell proliferation and activation of senescence. Collectively, our results reveal a novel function of Notch3 in senescence regulation and tumor suppression. Cancer Res; 73(11); 3451–9. ©2013 AACR.
Data from NSD2 Is Recruited through Its PHD Domain to Oncogenic Gene Loci to Drive Multiple Myeloma
Authors: Huang Zheng , Wu Haiping , Chuai Shannon , Xu Fiona , Yan Feng , Englund Nathan , Wang Zhaofu , Zhang Hailong , Fang Ming , Wang Youzhen , Gu Justin , Zhang Man , Yang Teddy , Zhao Kehao , Yu Yanyan , Dai Jingquan , Yi Wei , Zhou Shaolian , Li Qian , Wu Jing , Liu Jun , Wu Xu , Chan Homan , Lu Chris , Atadja Peter , Li En , Wang Yan , Hu Min
Published: March 2023

Abstract
Histone lysine methyltransferase NSD2 (WHSC1/MMSET) is overexpressed frequently in multiple myeloma due to the t(4;14) translocation associated with 15% to 20% of cases of this disease. NSD2 has been found to be involved in myelomagenesis, suggesting it may offer a novel therapeutic target. Here we show that NSD2 methyltransferase activity is crucial for clonogenicity, adherence, and proliferation of multiple myeloma cells on bone marrow stroma in vitro and that NSD2 is required for tumorigenesis of t(4;14)+ but not t(4;14)− multiple myeloma cells in vivo. The PHD domains in NSD2 were important for its cellular activity and biological function through recruiting NSD2 to its oncogenic target genes and driving their transcriptional activation. By strengthening its disease linkage and deepening insights into its mechanism of action, this study provides a strategy to therapeutically target NSD2 in multiple myeloma patients with a t(4;14) translocation. Cancer Res; 73(20); 6277–88. ©2013 AACR.
Data from Proteomic and Lipidomic Signatures of Lipid Metabolism in NASH-Associated Hepatocellular Carcinoma
Authors: Muir Kyle , Hazim Antonious , He Ying , Peyressatre Marion , Kim Do-Young , Song Xiaoling , Beretta Laura
Published: March 2023

Abstract
Nonalcoholic steatohepatitis (NASH) is a common preneoplastic condition of hepatocellular carcinoma (HCC). Mice with hepatocytic deletion of Pten develop NASH and HCC later in life. This model is highly valuable for studies aimed at identifying the molecular mechanism by which metabolic disorders contribute to tumor development. We applied proteomic and lipidomic profiling approaches to Pten-null NASH liver and tumors. Circulating fatty acid composition was also characterized in these mice. The relevance to human NASH and HCC was further validated. This integrative proteomic and lipidomic study from mouse to human and from liver to blood identified the following disease signatures: (i) an HCC signature: upregulated hepatic scd1/scd2, fads2, and acsl5:acsl1 ratio, elevated vaccenic and erucic acids, and reduced margaric and linoleic acids in both liver and plasma; (ii) a NASH signature that correlates with tumor burden: upregulated hepatic elovl6, elevated oleic, adrenic, and osbond acids, and reduced cervonic acid in liver and plasma; and (iii) a NASH signature: reduced hepatic and circulating lignoceric and eicosapentaenoic acids. Altogether, these results show the role of lipid-modifying enzymes converting saturated fatty acids (SFA) to monounsaturated fatty acids (MUFA) in HCC and the importance of an increased ratio of long chain n6-polyunsaturated fatty acids over n3-polyunsaturated fatty acids in NASH and HCC risk. They also highlight the relevance of the Pten-null model for studies related to NASH and HCC and show that circulating lipid metabolome provides a direct read of lipid changes in the liver. Most importantly, novel candidate targets for HCC diagnosis, therapy, risk assessment, and prevention were identified. Cancer Res; 73(15); 4722–31. ©2013 AACR.
Data from BCCIP Suppresses Tumor Initiation but Is Required for Tumor Progression
Authors: Huang Yi-Yuan , Dai Li , Gaines Dakim , Droz-Rosario Roberto , Lu Huimei , Liu Jingmei , Shen Zhiyuan
Published: March 2023

Abstract
Dysfunctions of genome caretaker genes contribute to genomic instability and tumor initiation. Because many of the caretaker genes are also essential for cell viability, permanent loss of function of these genes would prohibit further tumor progression. How essential caretaker genes contribute to tumorigenesis is not fully understood. Here, we report a “hit-and-run” mode of action for an essential caretaker gene in tumorigenesis. Using a BRCA2-interacting protein BCCIP as the platform, we found that a conditional BCCIP knockdown and concomitant p53 deletion caused rapid development of medulloblastomas, which bear a wide spectrum of alterations involving the Sonic Hedgehog (Shh) pathway, consistent with a caretaker responsibility of BCCIP on genomic integrity. Surprisingly, the progressed tumors have spontaneously lost the transgenic BCCIP knockdown cassette and restored BCCIP expression. Thus, a transient downregulation of BCCIP, but not necessarily a permanent mutation, is sufficient to initiate tumorigenesis. After the malignant transformation has been accomplished and autonomous cancer growth has been established, BCCIP reverses its role from a tumor-initiation suppressor to become a requisite for progression. This exemplifies a new type of tumor suppressor, which is distinct from the classical tumor suppressors that are often permanently abrogated during tumorigenesis. It has major implications on how a nonmutagenic or transient regulation of essential caretaker gene contributes to tumorigenesis. We further suggest that BCCIP represents a paradoxical class of modulators for tumorigenesis as a suppressor for initiation but a requisite for progression (SIRP). Cancer Res; 73(23); 7122–33. ©2013 AACR.