bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Inducible Nitric Oxide Synthase Drives mTOR Pathway Activation and Proliferation of Human Melanoma by Reversible Nitrosylation of TSC2
Authors: Lopez-Rivera Esther , Jayaraman Padmini , Parikh Falguni , Davies Michael A. , Ekmekcioglu Suhendan , Izadmehr Sudeh , Milton Denái R. , Chipuk Jerry E. , Grimm Elizabeth A. , Estrada Yeriel , Aguirre-Ghiso Julio , Sikora Andrew G.
Published: March 2023

Abstract
Melanoma is one of the cancers of fastest-rising incidence in the world. Inducible nitric oxide synthase (iNOS) is overexpressed in melanoma and other cancers, and previous data suggest that iNOS and nitric oxide (NO) drive survival and proliferation of human melanoma cells. However, specific mechanisms through which this occurs are poorly defined. One candidate is the PI3K–AKT–mTOR pathway, which plays a major role in proliferation, angiogenesis, and metastasis of melanoma and other cancers. We used the chick embryo chorioallantoic membrane (CAM) assay to test the hypothesis that melanoma growth is regulated by iNOS-dependent mTOR pathway activation. Both pharmacologic inhibition and siRNA-mediated gene silencing of iNOS suppressed melanoma proliferation and in vivo growth on the CAM in human melanoma models. This was associated with strong downregulation of mTOR pathway activation by Western blot analysis of p-mTOR, p70 ribosomal S6 kinase (p-P70S6K), p-S6RP, and p-4EBP1. iNOS expression and NO were associated with reversible nitrosylation of tuberous sclerosis complex (TSC) 2, and inhibited dimerization of TSC2 with its inhibitory partner TSC1, enhancing GTPase activity of its target Ras homolog enriched in brain (Rheb), a critical activator of mTOR signaling. Immunohistochemical analysis of tumor specimens from stage III melanoma patients showed a significant correlation between iNOS expression levels and expression of the mTOR pathway members. Exogenously supplied NO was also sufficient to reverse the mTOR pathway inhibition by the B-Raf inhibitor vemurafenib. In summary, covalent modification of TSC2 by iNOS-derived NO is associated with impaired TSC2/TSC1 dimerization, mTOR pathway activation, and proliferation of human melanoma. This model is consistent with the known association of iNOS overexpression and poor prognosis in melanoma and other cancers. Cancer Res; 74(4); 1067–78. ©2014 AACR.
Data from Whole-Genome Sequencing of Asian Lung Cancers: Second-Hand Smoke Unlikely to Be Responsible for Higher Incidence of Lung Cancer among Asian Never-Smokers
Authors: Krishnan Vidhya G. , Ebert Philip J. , Ting Jason C. , Lim Elaine , Wong Swee-Seong , Teo Audrey S.M. , Yue Yong G. , Chua Hui-Hoon , Ma Xiwen , Loh Gary S.L. , Lin Yuhao , Tan Joanna H.J. , Yu Kun , Zhang Shenli , Reinhard Christoph , Tan Daniel S.W. , Peters Brock A. , Lincoln Stephen E. , Ballinger Dennis G. , Laramie Jason M. , Nilsen Geoffrey B. , Barber Thomas D. , Tan Patrick , Hillmer Axel M. , Ng Pauline C.
Published: March 2023

Abstract
Asian nonsmoking populations have a higher incidence of lung cancer compared with their European counterparts. There is a long-standing hypothesis that the increase of lung cancer in Asian never-smokers is due to environmental factors such as second-hand smoke. We analyzed whole-genome sequencing of 30 Asian lung cancers. Unsupervised clustering of mutational signatures separated the patients into two categories of either all the never-smokers or all the smokers or ex-smokers. In addition, nearly one third of the ex-smokers and smokers classified with the never-smoker–like cluster. The somatic variant profiles of Asian lung cancers were similar to that of European origin with G.C>T.A being predominant in smokers. We found EGFR and TP53 to be the most frequently mutated genes with mutations in 50% and 27% of individuals, respectively. Among the 16 never-smokers, 69% had an EGFR mutation compared with 29% of 14 smokers/ex-smokers. Asian never-smokers had lung cancer signatures distinct from the smoker signature and their mutation profiles were similar to European never-smokers. The profiles of Asian and European smokers are also similar. Taken together, these results suggested that the same mutational mechanisms underlie the etiology for both ethnic groups. Thus, the high incidence of lung cancer in Asian never-smokers seems unlikely to be due to second-hand smoke or other carcinogens that cause oxidative DNA damage, implying that routine EGFR testing is warranted in the Asian population regardless of smoking status. Cancer Res; 74(21); 6071–81. ©2014 AACR.
Data from Osteopontin Shapes Immunosuppression in the Metastatic Niche
Authors: Sangaletti Sabina , Tripodo Claudio , Sandri Sara , Torselli Ilaria , Vitali Caterina , Ratti Chiara , Botti Laura , Burocchi Alessia , Porcasi Rossana , Tomirotti Andrea , Colombo Mario P. , Chiodoni Claudia
Published: March 2023

Abstract
The matricellular protein osteopontin (OPN, Spp-1) is widely associated with cancer aggressiveness when produced by tumor cells, but its impact is uncertain when produced by leukocytes in the context of the tumor stroma. In a broad study using Spp1−/− mice along with gene silencing in tumor cells, we obtained evidence of distinct and common activities of OPN when produced by tumor or host cells in a spontaneously metastatic model of breast cancer. Different cellular localization of OPN is associated with its distinct activities, being mainly secreted in tumor cells while intracellular in myeloid cells. OPN produced by tumor cells supported their survival in the blood stream, whereas both tumor- and host-derived OPN, particularly from myeloid cells, rendered the metastatic site more immunosuppressive. Myeloid-derived suppressor cells (MDSC) expanded with tumor progression at both primary and lung metastatic sites. Of the expanded monocytic and granulocytic cell populations of MDSCs, the monocytic subset was the predominant source of OPN. In Spp1−/− mice, the inhibition of lung metastases correlated with the expansion of granulocyte-oriented MDSCs. Notably, monocytic MDSCs in Spp1−/− mice were less suppressive than their wild-type counterparts due to lower expression of arginase-1, IL6, and phospho-Stat3. Moreover, fewer regulatory T cells accumulated at the metastatic site in Spp1−/− mice. Our data find correlation with lung metastases of human mammary carcinomas that are associated with myeloid cells expressing OPN. Overall, our results unveiled novel functions for OPN in shaping local immunosuppression in the lung metastatic niche. Cancer Res; 74(17); 4706–19. ©2014 AACR.
Data from Curative Properties of Noninternalizing Antibody–Drug Conjugates Based on Maytansinoids
Authors: Perrino Elena , Steiner Martina , Krall Nikolaus , Bernardes Gonçalo J.L. , Pretto Francesca , Casi Giulio , Neri Dario
Published: March 2023

Abstract
It is generally thought that the anticancer efficacy of antibody–drug conjugates (ADC) relies on their internalization by cancer cells. However, recent work on an ADC that targets fibronectin in the tumor microenvironment suggests this may not be necessary. The alternatively spliced extra domains A and B (EDA and EDB) of fibronectin offer appealing targets for ADC development, because the antigen is strongly expressed in many solid human tumors and nearly undetectable in normal tissues except for the female reproductive system. In this study, we describe the properties of a set of ADCs based on an antibody targeting the alternatively spliced EDA of fibronectin coupled to one of a set of potent cytotoxic drugs (DM1 or one of two duocarmycin derivatives). The DM1 conjugate SIP(F8)-SS-DM1 mediated potent antitumor activity in mice bearing DM1-sensitive F9 tumors but not DM1-insensitive CT26 tumors. Quantitative biodistribution studies and microscopic analyses confirmed a preferential accumulation of SIP(F8)-SS-DM1 in the subendothelial extracellular matrix of tumors, similar to the pattern observed for unmodified antibody. Notably, we found that treatments were well tolerated at efficacious doses that were fully curative and compatible with pharmaceutical development. Our findings offer a preclinical proof-of-concept for curative ADC targeting the tumor microenvironment that do not rely upon antigen internalization. Cancer Res; 74(9); 2569–78. ©2014 AACR.
Data from Germline Mutations in BAP1 Impair Its Function in DNA Double-Strand Break Repair
Authors: Ismail Ismail Hassan , Davidson Riley , Gagné Jean-Philippe , Xu Zhi Zhong , Poirier Guy G. , Hendzel Michael J.
Published: March 2023

Abstract
The BRCA1-associated deubiquitylase BAP1 is mutated in several cancers, most notably mesothelioma and melanoma, where it is thought to promote oncogenesis. In this study, we present evidence that BAP1 functions as part of the DNA damage response (DDR). We found that BAP1 mediates rapid poly(ADP-ribose)-dependent recruitment of the polycomb deubiquitylase complex PR-DUB to sites of DNA damage. Furthermore, we identified BAP1 as a phosphorylation target for the DDR kinase ATM. Functionally, BAP1 promoted repair of DNA double-strand breaks, enhancing cell survival after DNA damage. Our results highlight the importance of ubiquitin turnover at sites of DNA damage, and they provide a mechanism to account for the tumor-suppressive function of BAP1. Cancer Res; 74(16); 4282–94. ©2014 AACR.
Data from The Transcriptional Regulatory Network of Proneural Glioma Determines the Genetic Alterations Selected during Tumor Progression
Authors: Sonabend Adam M. , Bansal Mukesh , Guarnieri Paolo , Lei Liang , Amendolara Benjamin , Soderquist Craig , Leung Richard , Yun Jonathan , Kennedy Benjamin , Sisti Julia , Bruce Samuel , Bruce Rachel , Shakya Reena , Ludwig Thomas , Rosenfeld Steven , Sims Peter A. , Bruce Jeffrey N. , Califano Andrea , Canoll Peter
Published: March 2023

Abstract
Proneural glioblastoma is defined by an expression pattern resembling that of oligodendrocyte progenitor cells and carries a distinctive set of genetic alterations. Whether there is a functional relationship between the proneural phenotype and the associated genetic alterations is unknown. To evaluate this possible relationship, we performed a longitudinal molecular characterization of tumor progression in a mouse model of proneural glioma. In this setting, the tumors acquired remarkably consistent genetic deletions at late stages of progression, similar to those deleted in human proneural glioblastoma. Further investigations revealed that p53 is a master regulator of the transcriptional network underlying the proneural phenotype. This p53-centric transcriptional network and its associated phenotype were observed at both the early and late stages of progression, and preceded the proneural-specific deletions. Remarkably, deletion of p53 at the time of tumor initiation obviated the acquisition of later deletions, establishing a link between the proneural transcriptional network and the subtype-specific deletions selected during glioma progression. Cancer Res; 74(5); 1440–51. ©2014 AACR.
Data from WEE1 Inhibition Alleviates Resistance to Immune Attack of Tumor Cells Undergoing Epithelial–Mesenchymal Transition
Authors: Hamilton Duane H. , Huang Bruce , Fernando Romaine I. , Tsang Kwong-Yok , Palena Claudia
Published: March 2023

Abstract
Aberrant expression of the T-box transcription factor brachyury in human carcinomas drives the phenomenon of epithelial–mesenchymal transition (EMT), a phenotypic modulation that facilitates tumor dissemination and resistance to conventional therapies, including chemotherapy and radiotherapy. By generating isogenic cancer cell lines with various levels of brachyury expression, we demonstrate that high levels of brachyury also significantly reduce the susceptibility of cancer cells to lysis by both antigen-specific T cells and natural killer cells. Our results indicated that resistance of brachyury-high tumor cells to immune-mediated attack was due to inefficient caspase-dependent apoptosis, manifested as inefficient nuclear lamin degradation in the presence of activated effector caspases. We correlated this phenomenon with loss of cell-cycle–dependent kinase 1 (CDK1), which mediates lamin phosphorylation. In support of a causal connection, pretreatment of tumor cells with a specific inhibitor of WEE1, a negative regulator kinase of CDK1, could counter the defective apoptosis of tumor cells expressing high levels of brachyury. Thus, our findings suggested that reconstituting CDK1 activity to threshold levels may be sufficient to restore immunosurveillance of mesenchymal-like cancer cells that have escaped previous immune detection or eradication. Cancer Res; 74(9); 2510–9. ©2014 AACR.
Data from Identification of Alternative Splicing Events Regulated by the Oncogenic Factor SRSF1 in Lung Cancer
Authors: de Miguel Fernando J. , Sharma Ravi D. , Pajares María J. , Montuenga Luis M. , Rubio Angel , Pio Ruben
Published: March 2023

Abstract
Abnormal alternative splicing has been associated with cancer. Genome-wide microarrays can be used to detect differential splicing events. In this study, we have developed ExonPointer, an algorithm that uses data from exon and junction probes to identify annotated cassette exons. We used the algorithm to profile differential splicing events in lung adenocarcinoma A549 cells after downregulation of the oncogenic serine/arginine-rich splicing factor 1 (SRSF1). Data were generated using two different microarray platforms. The PCR-based validation rate of the top 20 ranked genes was 60% and 100%. Functional enrichment analyses found a substantial number of splicing events in genes related to RNA metabolism. These analyses also identified genes associated with cancer and developmental and hereditary disorders, as well as biologic processes such as cell division, apoptosis, and proliferation. Most of the top 20 ranked genes were validated in other adenocarcinoma and squamous cell lung cancer cells, with validation rates of 80% to 95% and 70% to 75%, respectively. Moreover, the analysis allowed us to identify four genes, ATP11C, IQCB1, TUBD1, and proline-rich coiled-coil 2C (PRRC2C), with a significantly different pattern of alternative splicing in primary non–small cell lung tumors compared with normal lung tissue. In the case of PRRC2C, SRSF1 downregulation led to the skipping of an exon overexpressed in primary lung tumors. Specific siRNA downregulation of the exon-containing variant significantly reduced cell growth. In conclusion, using a novel analytical tool, we have identified new splicing events regulated by the oncogenic splicing factor SRSF1 in lung cancer. Cancer Res; 74(4); 1105–15. ©2013 AACR.
Data from Activation of the FGFR–STAT3 Pathway in Breast Cancer Cells Induces a Hyaluronan-Rich Microenvironment That Licenses Tumor Formation
Authors: Bohrer Laura R. , Chuntova Pavlina , Bade Lindsey K. , Beadnell Thomas C. , Leon Ronald P. , Brady Nicholas J. , Ryu Yungil , Goldberg Jodi E. , Schmechel Stephen C. , Koopmeiners Joseph S. , McCarthy James B. , Schwertfeger Kathryn L.
Published: March 2023

Abstract
Aberrant activation of fibroblast growth factor receptors (FGFR) contributes to breast cancer growth, progression, and therapeutic resistance. Because of the complex nature of the FGF/FGFR axis, and the numerous effects of FGFR activation on tumor cells and the surrounding microenvironment, the specific mechanisms through which aberrant FGFR activity contributes to breast cancer are not completely understood. We show here that FGFR activation induces accumulation of hyaluronan within the extracellular matrix and that blocking hyaluronan synthesis decreases proliferation, migration, and therapeutic resistance. Furthermore, FGFR-mediated hyaluronan accumulation requires activation of the STAT3 pathway, which regulates expression of hyaluronan synthase 2 (HAS2) and subsequent hyaluronan synthesis. Using a novel in vivo model of FGFR-dependent tumor growth, we demonstrate that STAT3 inhibition decreases both FGFR-driven tumor growth and hyaluronan levels within the tumor. Finally, our results suggest that combinatorial therapies inhibiting both FGFR activity and hyaluronan synthesis is more effective than targeting either pathway alone and may be a relevant therapeutic approach for breast cancers associated with high levels of FGFR activity. In conclusion, these studies indicate a novel targetable mechanism through which FGFR activation in breast cancer cells induces a protumorigenic microenvironment. Cancer Res; 74(1); 374–86. ©2013 AACR.
Data from Akt1 and Akt3 Exert Opposing Roles in the Regulation of Vascular Tumor Growth
Authors: Phung Thuy L. , Du Wa , Xue Qi , Ayyaswamy Sriram , Gerald Damien , Antonello Zeus , Nhek Sokha , Perruzzi Carole A. , Acevedo Isabel , Ramanna-Valmiki Rajesh , Rodriguez-Waitkus Paul , Enayati Ladan , Hochman Marcelo L. , Lev Dina , Geeganage Sandaruwan , Benjamin Laura E.
Published: March 2023

Abstract
Vascular tumors are endothelial cell neoplasms whose mechanisms of tumorigenesis are poorly understood. Moreover, current therapies, particularly those for malignant lesions, have little beneficial effect on clinical outcomes. In this study, we show that endothelial activation of the Akt1 kinase is sufficient to drive de novo tumor formation. Mechanistic investigations uncovered opposing functions for different Akt isoforms in this regulation, where Akt1 promotes and Akt3 inhibits vascular tumor growth. Akt3 exerted negative effects on tumor endothelial cell growth and migration by inhibiting activation of the translation regulatory kinase S6-Kinase (S6K) through modulation of Rictor expression. S6K in turn acted through a negative feedback loop to restrain Akt3 expression. Conversely, S6K signaling was increased in vascular tumor cells where Akt3 was silenced, and the growth of these tumor cells was inhibited by a novel S6K inhibitor. Overall, our findings offer a preclinical proof of concept for the therapeutic utility of treating vascular tumors, such as angiosarcomas, with S6K inhibitors. Cancer Res; 75(1); 40–50. ©2014 AACR.
Data from Mechanistic Elucidation of the Antitumor Properties of Withaferin A in Breast Cancer
Authors: Nagalingam Arumugam , Kuppusamy Panjamurthy , Singh Shivendra V. , Sharma Dipali , Saxena Neeraj K.
Published: March 2023

Abstract
Withaferin A (WFA) is a steroidal lactone with antitumor effects manifested at multiple levels that are mechanistically obscure. Using a phospho-kinase screening array, we discovered that WFA activated phosphorylation of the S6 kinase RSK (ribosomal S6 kinase) in breast cancer cells. Pursuing this observation, we defined activation of extracellular signal–regulated kinase (ERK)–RSK and ETS-like transcription factor 1 (Elk1)–CHOP (C-EBP homologous protein) kinase pathways in upregulating transcription of the death receptor 5 (DR5). Through this route, WFA acted as an effective DR5 activator capable of potentiating the biologic effects of celecoxib, etoposide, and TRAIL. Accordingly, WFA treatment inhibited breast tumor formation in xenograft and mouse mammary tumor virus (MMTV)-neu mouse models in a manner associated with activation of the ERK/RSK axis, DR5 upregulation, and elevated nuclear accumulation of Elk1 and CHOP. Together, our results offer mechanistic insight into how WFA inhibits breast tumor growth. Cancer Res; 74(9); 2617–29. ©2014 AACR.
Data from MET Signaling in Colon Cancer Stem-like Cells Blunts the Therapeutic Response to EGFR Inhibitors
Authors: Luraghi Paolo , Reato Gigliola , Cipriano Elia , Sassi Francesco , Orzan Francesca , Bigatto Viola , De Bacco Francesca , Menietti Elena , Han May , Rideout William M. , Perera Timothy , Bertotti Andrea , Trusolino Livio , Comoglio Paolo M. , Boccaccio Carla
Published: March 2023

Abstract
Metastatic colorectal cancer remains largely incurable, although in a subset of patients, survival is prolonged by new targeting agents such as anti-EGF receptor (anti-EGFR) antibodies. This disease is believed to be supported by a subpopulation of stem-like cells termed colon cancer–initiating cell (CCIC), which may also confer therapeutic resistance. However, how CCICs respond to EGFR inhibition has not been fully characterized. To explore this question, we systematically generated CCICs through spheroid cultures of patient-derived xenografts of metastatic colorectal cancer. These cultures, termed “xenospheres,” were capable of long-term self-propagation in vitro and phenocopied the original patient tumors in vivo, thus operationally defining CCICs. Xenosphere CCICs retained the genetic determinants for EGFR therapeutic response in vitro and in xenografts; like the original tumors, xenospheres harboring a mutated KRAS gene were resistant to EGFR therapy, whereas those harboring wild-type RAS pathway genes (RASwt) were sensitive. Notably, the effects of EGFR inhibition in sensitive CCICs could be counteracted by cytokines secreted by cancer-associated fibroblasts. In particular, we found that the MET receptor ligand hepatocyte growth factor (HGF) was especially active in supporting in vitro CCIC proliferation and resistance to EGFR inhibition. Ectopic production of human HGF in CCIC xenografts rendered the xenografts susceptible to MET inhibition, which sensitized the response to EGFR therapy. By showing that RASwt CCICs rely on both EGFR and MET signaling, our results offer a strong preclinical proof-of-concept for concurrent targeting of these two pathways in the clinical setting. Cancer Res; 74(6); 1857–69. ©2014 AACR.
Data from TGF-β Modulates Ovarian Cancer Invasion by Upregulating CAF-Derived Versican in the Tumor Microenvironment
Authors: Yeung Tsz-Lun , Leung Cecilia S. , Wong Kwong-Kwok , Samimi Goli , Thompson Melissa S. , Liu Jinsong , Zaid Tarrik M. , Ghosh Sue , Birrer Michael J. , Mok Samuel C.
Published: March 2023

Abstract
TGF-β has limited effects on ovarian cancer cells, but its contributions to ovarian tumor growth might be mediated through elements of the tumor microenvironment. In the present study, we tested the hypothesis that TGF modulates ovarian cancer progression by modulating the contribution of cancer-associated fibroblasts (CAF) that are present in the microenvironment. Transcriptome profiling of microdissected stromal and epithelial components of high-grade serous ovarian tumors and TGF-β–treated normal ovarian fibroblasts identified versican (VCAN) as a key upregulated target gene in CAFs. Functional evaluations in coculture experiments showed that TGF-β enhanced the aggressiveness of ovarian cancer cells by upregulating VCAN in CAFs. VCAN expression was regulated in CAFs through TGF-β receptor type II and SMAD signaling. Upregulated VCAN promoted the motility and invasion of ovarian cancer cells by activating the NF-κB signaling pathway and by upregulating expression of CD44, matrix metalloproteinase-9, and the hyaluronan-mediated motility receptor. Our work identified a TGF-β–inducible gene signature specific to CAFs in advanced high-grade serous ovarian tumors, and showed how TGF-β stimulates ovarian cancer cell motility and invasion by upregulating the CAF-specific gene VCAN. These findings suggest insights to develop or refine strategies for TGF-β–targeted therapy of ovarian cancer. Cancer Res; 73(16); 5016–28. ©2013 AACR.
Data from miR149 Functions as a Tumor Suppressor by Controlling Breast Epithelial Cell Migration and Invasion
Authors: Bischoff Annabell , Huck Bettina , Keller Bettina , Strotbek Michaela , Schmid Simone , Boerries Melanie , Busch Hauke , Müller Dafne , Olayioye Monilola A.
Published: March 2023

Abstract
Deregulated molecular signaling pathways are responsible for the altered adhesive, migratory, and invasive properties of cancer cells. The different breast cancer subtypes are characterized by the expression of distinct miRNAs, short non-coding RNAs that posttranscriptionally modulate the expression of entire gene networks. Profiling studies have revealed downregulation of miR149 in basal breast cancer. Here, we show that miR149 expression severely impairs cell spreading, migration, and invasion of basal-like breast cancer cells. We identify signaling molecules, including the small GTPases Rap1a and Rap1b, downstream of integrin receptors as miR149 targets, providing an explanation for the defective Src and Rac activation during cell adhesion and spreading upon miR149 expression. Suppression of cell spreading by miR149 could be rescued, at least in part, by expression of constitutively active Rac. Finally, we demonstrate that increased miR149 levels block lung colonization in vivo. On the basis of our findings, we propose that miR149 downregulation in basal breast cancer facilitates the metastatic dissemination of tumor cells by supporting aberrant Rac activation. Cancer Res; 74(18); 5256–65. ©2014 AACR.
Data from NUP98 Fusion Oncoproteins Promote Aneuploidy by Attenuating the Mitotic Spindle Checkpoint
Authors: Salsi Valentina , Ferrari Silvia , Gorello Paolo , Fantini Sebastian , Chiavolelli Francesca , Mecucci Cristina , Zappavigna Vincenzo
Published: March 2023

Abstract
NUP98 is a recurrent fusion partner in chromosome translocations that cause acute myelogenous leukemia. NUP98, a nucleoporin, and its interaction partner Rae1, have been implicated in the control of chromosome segregation, but their mechanistic contributions to tumorigenesis have been unclear. Here, we show that expression of NUP98 fusion oncoproteins causes mitotic spindle defects and chromosome missegregation, correlating with the capability of NUP98 fusions to cause premature securin degradation and slippage from an unsatisfied spindle assembly checkpoint (SAC). NUP98 fusions, unlike wild-type NUP98, were found to physically interact with the anaphase promoting complex/cyclosome (APC/C)Cdc20 and to displace the BubR1 SAC component, suggesting a possible mechanistic basis for their interference with SAC function. In addition, NUP98 oncoproteins displayed a prolonged half-life in cells. We found that NUP98 stability is controlled by a PEST sequence, absent in NUP98 oncoproteins, whose deletion reproduced the aberrant SAC-interfering activity of NUP98 oncoproteins. Together, our findings suggest that NUP98 oncoproteins predispose myeloid cells to oncogenic transformation or malignant progression by promoting whole chromosome instability. Cancer Res; 74(4); 1079–90. ©2013 AACR.
Data from Activation of the Glutamate Receptor GRM1 Enhances Angiogenic Signaling to Drive Melanoma Progression
Authors: Wen Yu , Li Jiadong , Koo Jasmine , Shin Seung-Shick , Lin Yong , Jeong Byeong-Seon , Mehnert Janice M. , Chen Suzie , Cohen-Sola Karine A. , Goydos James S.
Published: March 2023

Abstract
Glutamate-triggered signal transduction is thought to contribute widely to cancer pathogenesis. In melanoma, overexpression of the metabotropic glutamate receptor (GRM)-1 occurs frequently and its ectopic expression in melanocytes is sufficient for neoplastic transformation. Clinical evaluation of the GRM1 signaling inhibitor riluzole in patients with advanced melanoma has demonstrated tumor regressions that are associated with a suppression of the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathways. Together, these results prompted us to investigate the downstream consequences of GRM1 signaling and its disruption in more detail. We found that melanoma cells with enhanced GRM1 expression generated larger tumors in vivo marked by more abundant blood vessels. Media conditioned by these cells in vitro contained relatively higher concentrations of interleukin-8 and VEGF due to GRM1-mediated activation of the AKT–mTOR–HIF1 pathway. In clinical specimens from patients receiving riluzole, we confirmed an inhibition of MAPK and PI3K/AKT activation in posttreatment as compared with pretreatment tumor specimens, which exhibited a decreased density of blood vessels. Together, our results demonstrate that GRM1 activation triggers proangiogenic signaling in melanoma, offering a mechanistic rationale to design treatment strategies for the most suitable combinatorial use of GRM1 inhibitors in patients. Cancer Res; 74(9); 2499–509. ©2014 AACR.
Data from Adenosine A2A Receptors Intrinsically Regulate CD8+ T Cells in the Tumor Microenvironment
Authors: Cekic Caglar , Linden Joel
Published: March 2023

Abstract
Adenosine A2A receptor (A2AR) blockade enhances innate and adaptive immune responses. However, mouse genetic studies have shown that A2AR deletion does not inhibit the growth of all tumor types. In the current study, we showed that growth rates for ectopic melanoma and bladder tumors are increased in Adora2a−/− mice within 2 weeks of tumor inoculation. A2AR deletion in the host reduced numbers of CD8+ T cells and effector–memory differentiation of all T cells. To examine intrinsic functions in T cells, we generated mice harboring a T-cell–specific deletion of A2AR. In this host strain, tumor-bearing mice displayed increased growth of ectopic melanomas, decreased numbers of tumor-associated T cells, reduced effector–memory differentiation, and reduced antiapoptotic IL7Rα (CD127) expression on antigen-experienced cells. Intratumoral pharmacologic blockade similarly reduced CD8+ T-cell density within tumors in wild-type hosts. We found that A2AR-proficient CD8+ T cells specific for melanoma cells displayed a relative survival advantage in tumors. Thus, abrogating A2AR signaling appeared to reduce IL7R expression, survival, and differentiation of T cells in the tumor microenvironment. One implication of these results is that the antitumor effects of A2AR blockade that can be mediated by activation of cytotoxic T cells may be overcome in some tumor microenvironments as a result of impaired T-cell maintenance and effector–memory differentiation. Thus, our findings imply that the efficacious application of A2AR inhibitors for cancer immunotherapy may require careful dose optimization to prevent activation-induced T-cell death in tumors. Cancer Res; 74(24); 7239–49. ©2014 AACR.
Data from Emergence, Involution, and Progression to Carcinoma of Mutant Clones in Normal Endometrial Tissues
Authors: Mutter George L. , Monte Nicolas M. , Neuberg Donna , Ferenczy Alex , Eng Charis
Published: March 2023

Abstract
Sporadic somatic inactivation of genes such as PTEN within histologically normal endometrium (latent precancers) is an early step in endometrial carcinogenesis. We have used clone-specific mutations of PTEN to determine the fate of latent precancers over time in women who do (high risk) and do not (low risk) develop endometrial neoplasia. PTEN immunohistochemistry was performed on 45 occurrences of endometrial neoplasia and their paired antecedent benign biopsies, along with age matched sample pairs from 167 patients who did not develop a neoplasm. When PTEN-deficient cells were present at both time points, DNA sequencing was performed to determine whether they were single or multiple independent events. Loss of PTEN protein in isolated glands was common in the initial normal biopsies of high- and low-risk groups (42% and 27%, respectively, P = 0.066). Protein-deficient glands have a tendency to disappear over time in low-risk women (P = 0.047) and, even when “persistent,” are infrequently (19%, 3/16) confirmed to be the same clone. Similarly, only a small proportion (6.7%, 1/15) of latent precancers seen in high-risk women are the direct progenitors of subsequent neoplasia. There is a high rate of latent precancer turnover in both low- and high-risk patients, with rare long-term persistence of unique clones, which may or may not progress to a histologic lesion. The temporal dynamics of clonal emergence, persistence, and involution are sufficiently complex that in the individual patient, the presence of a latent precancer has an unknown contribution to long-term cancer risk. Cancer Res; 74(10); 2796–802. ©2014 AACR.
Data from Tumor-Derived Osteopontin Suppresses Antitumor Immunity by Promoting Extramedullary Myelopoiesis
Authors: Kim Eun-Kyung , Jeon Insu , Seo Hyungseok , Park Young-Jun , Song Boyeong , Lee Kyoo-A , Jang Yongwoo , Chung Yeonseok , Kang Chang-Yuil
Published: March 2023

Abstract
Extramedullary myelopoiesis occurs commonly in tumor-bearing animals and is known to lead to accumulation of peripheral myeloid-derived suppressor cells (MDSC), which play an important role in immune escape. However, the cellular and molecular mechanisms by which tumors induce extramedullary myelopoiesis are poorly understood. In this study, we found that osteopontin expressed by tumor cells enhances extramedullary myelopoiesis in a CD44-dependent manner through the Erk1/2–MAPK pathway. Osteopontin-mediated extramedullary myelopoiesis was directly associated with increased MDSCs in tumor-bearing hosts. More importantly, osteopontin silencing in tumor cells delayed both tumor growth and extramedullary myelopoiesis, while the same treatment did not affect tumor growth in vitro. Finally, treatment with an antibody against osteopontin inhibited tumor growth and synergized with cell-based immunotherapeutic vaccines in mediating antitumor immunity. Our findings unveil a novel immunosuppressive role for tumor-derived osteopontin and offer a rationale for its therapeutic targeting in cancer treatment. Cancer Res; 74(22); 6705–16. ©2014 AACR.
Data from GPx2 Suppression of H2O2 Stress Links the Formation of Differentiated Tumor Mass to Metastatic Capacity in Colorectal Cancer
Authors: Emmink Benjamin L. , Laoukili Jamila , Kipp Anna P. , Koster Jan , Govaert Klaas M. , Fatrai Szabolcs , Verheem Andre , Steller Ernst J.A. , Brigelius-Flohé Regina , Jimenez Connie R. , Borel Rinkes Inne H.M. , Kranenburg Onno
Published: March 2023

Abstract
Colorectal tumorigenesis is accompanied by the generation of oxidative stress, but how this controls tumor development is poorly understood. Here, we studied how the H2O2-reducing enzyme glutathione peroxidase 2 (GPx2) regulates H2O2 stress and differentiation in patient-derived “colonosphere” cultures. GPx2 silencing caused accumulation of radical oxygen species, sensitization to H2O2-induced apoptosis, and strongly reduced clone- and metastasis-forming capacity. Neutralization of radical oxygen species restored clonogenic capacity. Surprisingly, GPx2-suppressed cells also lacked differentiation potential and formed slow-growing undifferentiated tumors. GPx2 overexpression stimulated multilineage differentiation, proliferation, and tumor growth without reducing the tumor-initiating capacity. Finally, GPx2 expression was inversely correlated with H2O2-stress signatures in human colon tumor cohorts, but positively correlated with differentiation and proliferation. Moreover, high GPx2 expression was associated with early tumor recurrence, particularly in the recently identified aggressive subtype of human colon cancer. We conclude that H2O2 neutralization by GPx2 is essential for maintaining clonogenic and metastatic capacity, but also for the generation of differentiated proliferating tumor mass. The results reveal an unexpected redox-controlled link between tumor mass formation and metastatic capacity. Cancer Res; 74(22); 6717–30. ©2014 AACR.
Data from Myeloid Expression of Adenosine A2A Receptor Suppresses T and NK Cell Responses in the Solid Tumor Microenvironment
Authors: Cekic Caglar , Day Yuan-Ji , Sag Duygu , Linden Joel
Published: March 2023

Abstract
High concentrations of adenosine in tumor microenvironments inhibit antitumor cytotoxic lymphocyte responses. Although T cells express inhibitory adenosine A2A receptors (A2AR) that suppress their activation and inhibit immune killing of tumors, a role for myeloid cell A2ARs in suppressing the immune response to tumors has yet to be investigated. In this study, we show that the growth of transplanted syngeneic B16F10 melanoma or Lewis lung carcinoma cells is slowed in Adora2af/f–LysMCre+/− mice, which selectively lack myeloid A2ARs. Reduced melanoma growth is associated with significant increases in MHCII and IL12 expression in tumor-associated macrophages and with >90% reductions in IL10 expression in tumor-associated macrophages, dendritic cells (DC), and Ly6C+ or Ly6G+ myeloid-derived suppressor cells (MDSC). Myeloid deletion of A2ARs significantly increases CD44 expression on tumor-associated T cells and natural killer (NK) cells. Depletion of CD8+ T cells or NK cells in tumor-bearing mice indicates that both cell types initially contribute to slowing melanoma growth in mice lacking myeloid A2A receptors, but tumor suppression mediated by CD8+ T cells is more persistent. Myeloid-selective A2AR deletion significantly reduces lung metastasis of melanomas that express luciferase (for in vivo tracking) and ovalbumin (as a model antigen). Reduced metastasis is associated with increased numbers and activation of NK cells and antigen-specific CD8+ T cells in lung infiltrates. Overall, the findings indicate that myeloid cell A2ARs have direct myelosuppressive effects that indirectly contribute to the suppression of T cells and NK cells in primary and metastatic tumor microenvironments. The results indicate that tumor-associated myeloid cells, including macrophages, DCs, and MDSCs all express immunosuppressive A2ARs that are potential targets of adenosine receptor blockers to enhance immune killing of tumors. Cancer Res; 74(24); 7250–9. ©2014 AACR.
Data from Ceramide Kinase Promotes Tumor Cell Survival and Mammary Tumor Recurrence
Authors: Payne Ania W. , Pant Dhruv K. , Pan Tien-Chi , Chodosh Lewis A.
Published: March 2023

Abstract
Recurrent breast cancer is typically an incurable disease and, as such, is disproportionately responsible for deaths from this disease. Recurrent breast cancers arise from the pool of disseminated tumor cells (DTC) that survive adjuvant or neoadjuvant therapy, and patients with detectable DTCs following therapy are at substantially increased risk for recurrence. Consequently, the identification of pathways that contribute to the survival of breast cancer cells following therapy could aid in the development of more effective therapies that decrease the burden of residual disease and thereby reduce the risk of breast cancer recurrence. We now report that ceramide kinase (Cerk) is required for mammary tumor recurrence following HER2/neu pathway inhibition and is spontaneously upregulated during tumor recurrence in multiple genetically engineered mouse models for breast cancer. We find that Cerk is rapidly upregulated in tumor cells following HER2/neu downregulation or treatment with Adriamycin and that Cerk is required for tumor cell survival following HER2/neu downregulation. Consistent with our observations in mouse models, analysis of gene expression profiles from more than 2,200 patients revealed that elevated CERK expression is associated with an increased risk of recurrence in women with breast cancer. In addition, although CERK expression is associated with aggressive subtypes of breast cancer, including those that are estrogen receptor–negative, HER2+, basal-like, or high grade, its association with poor clinical outcome is independent of these clinicopathologic variables. Together, our findings identify a functional role for Cerk in breast cancer recurrence and suggest the clinical utility of agents targeted against this prosurvival pathway. Cancer Res; 74(21); 6352–63. ©2014 AACR.
Data from Preclinical Activity of Nanoliposomal Irinotecan Is Governed by Tumor Deposition and Intratumor Prodrug Conversion
Authors: Kalra Ashish V. , Kim Jaeyeon , Klinz Stephan G. , Paz Nancy , Cain Jason , Drummond Daryl C. , Nielsen Ulrik B. , Fitzgerald Jonathan B.
Published: March 2023

Abstract
A major challenge in the clinical use of cytotoxic chemotherapeutics is maximizing efficacy in tumors while sparing normal tissue. Irinotecan is used for colorectal cancer treatment but the extent of its use is limited by toxic side effects. Liposomal delivery systems offer tools to modify pharmacokinetic and safety profiles of cytotoxic drugs. In this study, we defined parameters that maximize the antitumor activity of a nanoliposomal formulation of irinotecan (nal-IRI). In a mouse xenograft model of human colon carcinoma, nal-IRI dosing could achieve higher intratumoral levels of the prodrug irinotecan and its active metabolite SN-38 compared with free irinotecan. For example, nal-IRI administered at doses 5-fold lower than free irinotecan achieved similar intratumoral exposure of SN-38 but with superior antitumor activity. Tumor response and pharmacokinetic modeling identified the duration for which concentrations of SN-38 persisted above a critical intratumoral threshold of 120 nmol/L as determinant for antitumor activity. We identified tumor permeability and carboxylesterase activity needed for prodrug activation as critical factors in achieving longer duration of SN-38 in tumors. Simulations varying tumor permeability and carboxylesterase activity predicted a concave increase in tumor SN-38 duration, which was confirmed experimentally in 13 tumor xenograft models. Tumors in which higher SN-38 duration was achieved displayed more robust growth inhibition compared with tumors with lower SN-38 duration, confirming the importance of this factor in drug response. Overall, our work shows how liposomal encapsulation of irinotecan can safely improve its antitumor activity in preclinical models by enhancing accumulation of its active metabolite within the tumor microenvironment. Cancer Res; 74(23); 7003–13. ©2014 AACR.
Data from In Vivo Regulation of Human Glutathione Transferase GSTP by Chemopreventive Agents
Authors: Henderson Colin J. , McLaren Aileen W. , Wolf C. Roland
Published: March 2023

Abstract
Relatively little progress has been made in determining the in vivo regulation of glutathione S-transferase P (GSTP), particularly the human enzyme hGSTP1, despite being identified as a significant factor in carcinogenesis and development of drug resistance in tumor cell lines. Here, we report the characterization of a transgenic reporter mouse that reveals how hGSTP1 is regulated in vivo by chemopreventive agents. Basal expression was found in crypts and villi of the small and large intestine, bronchiolar epithelial cells, the epidermis and hair follicles, gall bladder epithelium, choroid plexus, and biliary epithelium. Expression was induced in different tissues by the antioxidant chemopreventive agents ethoxyquin and butylated hydroxyanisole. However, genetic deletion of the Nrf2 transcription factor, which directs central genetic programs of detoxification and protection against oxidative stress, increased rather than attenuated GSTP1 expression. In vitro investigations with mouse embryonic fibroblasts revealed factors, in addition to Nrf2, that control the expression of GSTP1, offering further insights into regulation. The new reporter mouse described here provides a useful tool to gain deeper insights into the mechanisms of action of chemopreventive compounds and other environmental agents. Cancer Res; 74(16); 4378–87. ©2014 AACR.
Data from Pancreatic Cancer–Specific Cell Death Induced In Vivo by Cytoplasmic-Delivered Polyinosine–Polycytidylic Acid
Authors: Bhoopathi Praveen , Quinn Bridget A. , Gui Qin , Shen Xue-Ning , Grossman Steven R. , Das Swadesh K. , Sarkar Devanand , Fisher Paul B. , Emdad Luni
Published: March 2023

Abstract
Polyinosine–polycytidylic acid [pIC] is a synthetic dsRNA that acts as an immune agonist of TLR3 and RLR to activate dendritic and natural killer cells that can kill tumor cells. pIC can also trigger apoptosis in pancreatic ductal adenocarcinoma cells (PDAC) but its mechanism of action is obscure. In this study, we investigated the potential therapeutic activity of a formulation of pIC with polyethylenimine ([pIC]PEI) in PDAC and investigated its mechanism of action. [pIC]PEI stimulated apoptosis in PDAC cells without affecting normal pancreatic epithelial cells. Mechanistically, [pIC]PEI repressed XIAP and survivin expression and activated an immune response by inducing MDA-5, RIG-I, and NOXA. Phosphorylation of AKT was inhibited by [pIC]PEI in PDAC, and this event was critical for stimulating apoptosis through XIAP and survivin degradation. In vivo administration of [pIC]PEI inhibited tumor growth via AKT-mediated XIAP degradation in both subcutaneous and quasi-orthotopic models of PDAC. Taken together, these results offer a preclinical proof-of-concept for the evaluation of [pIC]PEI as an immunochemotherapy to treat pancreatic cancer. Cancer Res; 74(21); 6224–35. ©2014 AACR.
Data from Oncogene Pathway Activation in Mammary Tumors Dictates FDG-PET Uptake
Authors: Alvarez James V. , Belka George K. , Pan Tien-Chi , Chen Chien-Chung , Blankemeyer Eric , Alavi Abass , Karp Joel S. , Chodosh Lewis A.
Published: March 2023

Abstract
Increased glucose utilization is a hallmark of human cancer that is used to image tumors clinically. In this widely used application, glucose uptake by tumors is monitored by positron emission tomography of the labeled glucose analogue 2[18F]fluoro-2-deoxy-d-glucose (FDG). Despite its widespread clinical use, the cellular and molecular mechanisms that determine FDG uptake—and that underlie the heterogeneity observed across cancers—remain poorly understood. In this study, we compared FDG uptake in mammary tumors driven by the Akt1, c-MYC, HER2/neu, Wnt1, or H-Ras oncogenes in genetically engineered mice, correlating it to tumor growth, cell proliferation, and expression levels of gene involved in key steps of glycolytic metabolism. We found that FDG uptake by tumors was dictated principally by the driver oncogene and was not independently associated with tumor growth or cellular proliferation. Oncogene downregulation resulted in a rapid decrease in FDG uptake, preceding effects on tumor regression, irrespective of the baseline level of uptake. FDG uptake correlated positively with expression of hexokinase-2 (HK2) and hypoxia-inducible factor-1α (HIF1α) and associated negatively with PFK-2b expression and p-AMPK. The correlation between HK2 and FDG uptake was independent of all variables tested, including the initiating oncogene, suggesting that HK2 is an independent predictor of FDG uptake. In contrast, expression of Glut1 was correlated with FDG uptake only in tumors driven by Akt or HER2/neu. Together, these results demonstrate that the oncogenic pathway activated within a tumor is a primary determinant of its FDG uptake, mediated by key glycolytic enzymes, and provide a framework to interpret effects on this key parameter in clinical imaging. Cancer Res; 74(24); 7583–98. ©2014 AACR.
Data from Identification of Oncogenic and Drug-Sensitizing Mutations in the Extracellular Domain of FGFR2
Authors: Tanizaki Junko , Ercan Dalia , Capelletti Marzia , Dodge Michael , Xu Chunxiao , Bahcall Magda , Tricker Erin M. , Butaney Mohit , Calles Antonio , Sholl Lynette M. , Hammerman Peter S. , Oxnard Geoffrey R. , Wong Kwok-Kin , Jänne Pasi A.
Published: March 2023

Abstract
The discovery of oncogenic driver mutations and the subsequent developments in targeted therapies have led to improved outcomes for subsets of lung cancer patients. The identification of additional oncogenic and drug-sensitive alterations may similarly lead to new therapeutic approaches for lung cancer. We identify and characterize novel FGFR2 extracellular domain insertion mutations and demonstrate that they are both oncogenic and sensitive to inhibition by FGFR kinase inhibitors. We demonstrate that the mechanism of FGFR2 activation and subsequent transformation is mediated by ligand-independent dimerization and activation of FGFR2 kinase activity. Both FGFR2-mutant forms are predominantly located in the endoplasmic reticulum and Golgi but nevertheless can activate downstream signaling pathways through their interactions with fibroblast growth factor receptor substrate 2 (FRS2). Our findings provide a rationale for therapeutically targeting this unique subset of FGFR2-mutant cancers as well as insight into their oncogenic mechanisms. Cancer Res; 75(15); 3139–46. ©2015 AACR.