bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Transcriptional Regulation of Estrogen Receptor-α by p53 in Human Breast Cancer Cells
Authors: Shirley Stephanie Harkey , Rundhaug Joyce E. , Tian Jie , Cullinan-Ammann Noirin , Lambertz Isabel , Conti Claudio J. , Fuchs-Young Robin
Published: March 2023

Abstract
Estrogen receptor α (ER) and p53 are critical prognostic indicators in breast cancer. Loss of functional p53 is correlated with poor prognosis, ER negativity, and resistance to antiestrogen treatment. Previously, we found that p53 genotype was correlated with ER expression and response to tamoxifen in mammary tumors arising in mouse mammary tumor virus–Wnt-1 transgenic mice. These results lead us to hypothesize that p53 may regulate ER expression. To test this, MCF-7 cells were treated with doxorubicin or ionizing radiation, both of which stimulated a 5-fold increase in p53 expression. ER expression was also increased 4-fold over a 24-h time frame. In cells treated with small interfering RNA (siRNA) targeting p53, expression of both p53 and ER was significantly reduced (>60%) by 24 h. Induction of ER by DNA-damaging agents was p53 dependent as either ionizing radiation or doxorubicin failed to up-regulate ER after treatment with p53-targeting siRNA. To further investigate whether p53 directly regulates transcription of the ER gene promoter, MCF-7 cells were transiently transfected with a wild-type (WT) p53 expression vector along with a luciferase reporter containing the proximal promoter of ER. In cells transfected with WT p53, transcription from the ER promoter was increased 8-fold. Chromatin immunoprecipitation assays showed that p53 was recruited to the ER promoter along with CARM1, CBP, c-Jun, and Sp1 and that this multifactor complex was formed in a p53-dependent manner. These data show that p53 regulates ER expression through transcriptional control of the ER promoter, accounting for their concordant expression in human breast cancer. [Cancer Res 2009;69(8):3405–14]
Data from 4-1BB Ligand as an Effective Multifunctional Immunomodulator and Antigen Delivery Vehicle for the Development of Therapeutic Cancer Vaccines
Authors: Sharma Rajesh K. , Schabowsky Rich-Henry , Srivastava Abhishek K. , Elpek Kutlu G. , Madireddi Shravan , Zhao Hong , Zhong Zhenping , Miller Robert W. , MacLeod Kathryn J. , Yolcu Esma S. , Shirwan Haval
Published: March 2023

Abstract
Therapeutic subunit vaccines based on tumor-associated antigens (TAA) represent an attractive approach for the treatment of cancer. However, poor immunogenicity of TAAs requires potent adjuvants for therapeutic efficacy. We recently proposed the tumor necrosis factor family costimulatory ligands as potential adjuvants for therapeutic vaccines and, hence, generated a soluble form of 4-1BBL chimeric with streptavidin (SA-4-1BBL) that has pleiotropic effects on cells of innate, adaptive, and regulatory immunity. We herein tested whether these effects can translate into effective cancer immunotherapy when SA-4-1BBL was also used as a vehicle to deliver TAAs in vivo to dendritic cells (DCs) constitutively expressing the 4-1BB receptor. SA-4-1BBL was internalized by DCs upon receptor binding and immunization with biotinylated antigens conjugated to SA-4-1BBL resulted in increased antigen uptake and cross-presentation by DCs, leading to the generation of effective T-cell immune responses. Conjugate vaccines containing human papillomavirus 16 E7 oncoprotein or survivin as a self-TAA had potent therapeutic efficacy against TC-1 cervical and 3LL lung carcinoma tumors, respectively. Therapeutic efficacy of the vaccines was associated with increased CD4+ T and CD8+ T-cell effector and memory responses and higher intratumoral CD8+ T effector/CD4+CD25+Foxp3+ T regulatory cell ratio. Thus, potent pleiotropic immune functions of SA-4-1BBL combined with its ability to serve as a vehicle to increase the delivery of antigens to DCs in vivo endow this molecule with the potential to serve as an effective immunomodulatory component of therapeutic vaccines against cancer and chronic infections. Cancer Res; 70(10); 3945–54. ©2010 AACR.
Data from Identification of the Receptor Tyrosine Kinase c-Met and Its Ligand, Hepatocyte Growth Factor, as Therapeutic Targets in Clear Cell Sarcoma
Authors: Davis Ian J. , McFadden Andrew W. , Zhang Yixiang , Coxon Angela , Burgess Teresa L. , Wagner Andrew J. , Fisher David E.
Published: March 2023

Abstract
Clear cell sarcoma (CCS), a childhood tumor of the tendons and aponeuroses, is uniformly fatal once it has metastasized because of its profound therapeutic resistance. CCS is characterized by production of a chimeric transcription factor, EWS-ATF1, which is formed as the result of a disease-specific chromosomal translocation. EWS-ATF1 activates the melanocyte transcription factor MITF, which in turn activates transcription of c-Met, an oncogenic receptor tyrosine kinase recently shown to be activated in CCS. Based on this connection, we hypothesized that c-Met inhibition may offer a strategy to treat CCS, as an indirect tactic to defeat a transforming pathway downstream of EWS-ATF1. Here, we show that primary CCS and CCS-derived cell lines express c-Met, which is activated in an autocrine fashion by its ligand hepatocyte growth factor (HGF)/scatter factor in some CCS cell lines. c-Met expression is critical for CCS invasion, chemotaxis, and survival. Blocking c-Met activity with a small-molecule inhibitor (SU11274) or a neutralizing antibody to its ligand HGF (AMG 102) significantly reduced CCS cell growth in culture. Similarly, AMG 102 significantly suppressed in vivo tumor growth in an autocrine xenograft model of CCS. Collectively, these findings suggest the HGF:c-Met signaling axis as a candidate therapeutic target to improve clinical management of CCS. Cancer Res; 70(2); 639–45
Data from Haplotype and Cell Proliferation Analyses of Candidate Lung Cancer Susceptibility Genes on Chromosome 15q24-25.1
Authors: Liu Yan , Liu Pengyuan , Wen Weidong , James Michael A. , Wang Yian , Bailey-Wilson Joan E. , Amos Christopher I. , Pinney Susan M. , Yang Ping , de Andrade Mariza , Petersen Gloria M. , Wiest Jonathan S. , Fain Pamela R. , Schwartz Ann G. , Gazdar Adi , Gaba Colette , Rothschild Henry , Mandal Diptasri , Kupert Elena , Lee Juwon , Seminara Daniela , Minna John , Anderson Marshall W. , You Ming
Published: March 2023

Abstract
Recent genome-wide association studies have linked the chromosome 15q24-25.1 locus to nicotine addiction and lung cancer susceptibility. To refine the 15q24-25.1 locus, we performed a haplotype-based association analysis of 194 familial lung cases and 219 cancer-free controls from the Genetic Epidemiology of Lung Cancer Consortium (GELCC) collection, and used proliferation and apoptosis analyses to determine which gene(s) in the 15q24-25.1 locus mediates effects on lung cancer cell growth in vitro. We identified two distinct subregions, hapL (P = 3.20 × 10−6) and hapN (P = 1.51 × 10−6), which were significantly associated with familial lung cancer. hapL encompasses IREB2, LOC123688, and PSMA4, and hapN encompasses the three nicotinic acetylcholine receptor subunit genes CHRNA5, CHRNA3, and CHRNB4. Examination of the genes around hapL revealed that PSMA4 plays a role in promoting cancer cell proliferation. PSMA4 mRNA levels were increased in lung tumors compared with normal lung tissues. Down-regulation of PSMA4 expression decreased proteasome activity and induced apoptosis. Proteasome dysfunction leads to many diseases including cancer, and drugs that inhibit proteasome activity show promise as a form of cancer treatment. Genes around hapN were also investigated, but did not show any direct effect on lung cancer cell proliferation. We concluded that PSMA4 is a strong candidate mediator of lung cancer cell growth, and may directly affect lung cancer susceptibility through its modulation of cell proliferation and apoptosis. [Cancer Res 2009;69(19):7844–50]
Data from CCL2 Blockade Augments Cancer Immunotherapy
Authors: Fridlender Zvi G. , Buchlis George , Kapoor Veena , Cheng Guanjun , Sun Jing , Singhal Sunil , Crisanti M. Cecilia , Wang Liang-Chuan S. , Heitjan Daniel , Snyder Linda A. , Albelda Steven M.
Published: March 2023

Abstract
Altering the immunosuppressive microenvironment that exists within a tumor will likely be necessary for cancer vaccines to trigger an effective antitumor response. Monocyte chemoattractant proteins (such as CCL2) are produced by many tumors and have both direct and indirect immunoinhibitory effects. We hypothesized that CCL2 blockade would reduce immunosuppression and augment vaccine immunotherapy. Anti-murine CCL2/CCL12 monoclonal antibodies were administered in three immunotherapy models: one aimed at the human papillomavirus E7 antigen expressed by a non–small cell lung cancer (NSCLC) line, one targeted to mesothelin expressed by a mesothelioma cell line, and one using an adenovirus-expressing IFN-α to treat a nonimmunogenic NSCLC line. We evaluated the effect of the combination treatment on tumor growth and assessed the mechanism of these changes by evaluating cytotoxic T cells, immunosuppressive cells, and the tumor microenvironment. Administration of anti-CCL2/CCL12 antibodies along with the vaccines markedly augmented efficacy with enhanced reduction in tumor volume and cures of approximately half of the tumors. The combined treatment generated more total intratumoral CD8+ T cells that were more activated and more antitumor antigen–specific, as measured by tetramer evaluation. Another important potential mechanism was reduction in intratumoral T regulatory cells. CCL2 seems to be a key proximal cytokine mediating immunosuppression in tumors. Its blockade augments CD8+ T-cell immune response to tumors elicited by vaccines via multifactorial mechanisms. These observations suggest that combining CCL2 neutralization with vaccines should be considered in future immunotherapy trials. Cancer Res; 70(1); 109–18
Data from Selective Depletion of CD4+CD25+Foxp3+ Regulatory T Cells by Low-Dose Cyclophosphamide Is Explained by Reduced Intracellular ATP Levels
Authors: Zhao Jie , Cao Yuchun , Lei Zhang , Yang Zhuoshun , Zhang Biao , Huang Bo
Published: March 2023

Abstract
CD4+CD25+Foxp3+ regulatory T (Treg) cells have been shown to play important roles in mediating cancer development. Although cyclophosphamide (CY) has shown promise as a drug to selectively target Treg cells with low-dose in vivo, the underlying molecular mechanism remains unclear. In this report, we provide evidence that ATP, the energy molecule and signal element, accounts for the selective depletion of Treg cells by low-dose CY. Relative to conventional T cells or other cell types, ATP levels were much lower in Treg cells. This was due to Treg cells that downregulate one microRNA, miR-142-3p, and upregulate ecto-nucleoside triphosphate diphosphohydrolase CD39. The transfection of miR-142-3p or the blockade of CD39 could increase intracellular ATP levels of Treg cells, consequently decreasing the sensitivity of Treg cells to low-dose CY. On the other hand, the transfection of miR-142-3p inhibitor or the addition of soluble CD39 to the cultured CD4+CD25− T cells resulted in the decrease of intracellular ATP levels and increase of sensitivity of conventional T cells to low-dose CY. Furthermore, we found that the low levels of ATP attenuated the synthesis of glutathione, leading to the decrease of CY detoxification, thus increasing the sensitivity of Treg cells to low-dose CY. Therefore, we here identify a molecular pathway through which low-dose CY selectively ablates Treg cells. Our findings also imply that low levels of ATP are probably related to Treg cell function. Cancer Res; 70(12); 4850–8. ©2010 AACR.
Data from Mechanism of Radiosensitization by the Chk1/2 Inhibitor AZD7762 Involves Abrogation of the G2 Checkpoint and Inhibition of Homologous Recombinational DNA Repair
Authors: Morgan Meredith A. , Parsels Leslie A. , Zhao Lili , Parsels Joshua D. , Davis Mary A. , Hassan Maria C. , Arumugarajah Sankari , Hylander-Gans Linda , Morosini Deborah , Simeone Diane M. , Canman Christine E. , Normolle Daniel P. , Zabludoff Sonya D. , Maybaum Jonathan , Lawrence Theodore S.
Published: March 2023

Abstract
The median survival for patients with locally advanced pancreatic cancer treated with gemcitabine and radiation is approximately 1 year. To develop improved treatment, we have combined a Chk1/2-targeted agent, AZD7762, currently in phase I clinical trials, with gemcitabine and ionizing radiation in preclinical pancreatic tumor models. We found that in vitro AZD7762 alone or in combination with gemcitabine significantly sensitized MiaPaCa-2 cells to radiation. AZD7762 inhibited Chk1 autophosphorylation (S296 Chk1), stabilized Cdc25A, and increased ATR/ATM–mediated Chk1 phosphorylation (S345 Chk1). Radiosensitization by AZD7762 was associated with abrogation of the G2 checkpoint as well as with inhibition of Rad51 focus formation, inhibition of homologous recombination repair, and persistent γ-H2AX expression. AZD7762 was also a radiation sensitizer in multiple tumor xenograft models. In both MiaPaCa-2- and patient-derived xenografts, AZD7762 significantly prolonged the median time required for tumor volume doubling in response to gemcitabine and radiation. Together, our findings suggest that G2 checkpoint abrogation and homologous recombination repair inhibition both contribute to sensitization by Chk1 inhibition. Furthermore, they support the clinical use of AZD7762 in combination with gemcitabine and radiation for patients with locally advanced pancreatic cancer. Cancer Res; 70(12); 4972–81. ©2010 AACR.
Data from BRCA1-Associated Epigenetic Regulation of p73 Mediates an Effector Pathway for Chemosensitivity in Ovarian Carcinoma
Authors: Ibrahim Nageatte , He Lei , Leong Chee-Onn , Xing Deyin , Karlan Beth Y. , Swisher Elizabeth M. , Rueda Bo R. , Orsulic Sandra , Ellisen Leif W.
Published: March 2023

Abstract
The majority of tumors arising in BRCA1 mutation carriers exhibit inactivation of p53, a key effector of cell death after DNA damage. Despite the loss of p53, BRCA1-deficient tumor cells exhibit increased sensitivity to cisplatin, and patients with BRCA1-associated ovarian carcinomas experience improved outcomes with platinum-based chemotherapy compared with sporadic cases. Although it is known that chemosensitivity in BRCA1-associated cancers is associated with unrepaired DNA damage, the specific effector pathway mediating the cellular response to platinum-induced damage in these tumors is poorly understood. Here, we show that the p53-related gene p73, encoding a proapoptotic protein that is linked to chemosensitivity in many settings, is upregulated through a novel epigenetic mechanism in both human and murine models of BRCA1-associated ovarian carcinoma. BRCA1-deficient ovarian carcinoma cells exhibit hypermethylation within a p73 regulatory region, which includes the binding site for the p73 transcriptional repressor ZEB1, leading to the abrogation of ZEB1 binding and increased expression of transactivating p73 isoforms (TAp73). Cisplatin chemotherapy induces TAp73 target genes specifically in BRCA1-deficient cells, and knockdown of TAp73 in these cells causes chemoresistance while having little or no effect on BRCA1-expressing tumor cells. In primary ovarian carcinomas, ZEB1 binding site methylation and TAp73 expression correlate with BRCA1 status and with clinical response. Together, these findings uncover a novel regulatory mechanism that supports the contribution of TAp73 as an important mediator of the response to platinum chemotherapy in a subset of ovarian carcinomas. TAp73 might represent a response predictor and potential therapeutic target for enhancing chemosensitivity in this disease. Cancer Res; 70(18); 7155–65. ©2010 AACR.
Data from Type 1 Insulin-like Growth Factor Receptor Translocates to the Nucleus of Human Tumor Cells
Authors: Aleksic Tamara , Chitnis Meenali M. , Perestenko Olga V. , Gao Shan , Thomas Peter H. , Turner Gareth D. , Protheroe Andrew S. , Howarth Mark , Macaulay Valentine M.
Published: March 2023

Abstract
The type 1 insulin-like growth factor receptor (IGF-1R) is a transmembrane glycoprotein composed of two extracellular α subunits and two β subunits with tyrosine kinase activity. The IGF-1R is frequently upregulated in cancers and signals from the cell surface to promote proliferation and cell survival. Recent attention has focused on the IGF-1R as a target for cancer treatment. Here, we report that the nuclei of human tumor cells contain IGF-1R, detectable using multiple antibodies to α- and β-subunit domains. Cell-surface IGF-1R translocates to the nucleus following clathrin-mediated endocytosis, regulated by IGF levels. The IGF-1R is unusual among transmembrane receptors that undergo nuclear import, in that both α and β subunits traffic to the nucleus. Nuclear IGF-1R is phosphorylated in response to ligand and undergoes IGF-induced interaction with chromatin, suggesting direct engagement in transcriptional regulation. The IGF dependence of these phenomena indicates a requirement for the receptor kinase, and indeed, IGF-1R nuclear import and chromatin binding can be blocked by a novel IGF-1R kinase inhibitor. Nuclear IGF-1R is detectable in primary renal cancer cells, formalin-fixed tumors, preinvasive lesions in the breast, and nonmalignant tissues characterized by a high proliferation rate. In clear cell renal cancer, nuclear IGF-1R is associated with adverse prognosis. Our findings suggest that IGF-1R nuclear import has biological significance, may contribute directly to IGF-1R function, and may influence the efficacy of IGF-1R inhibitory drugs. Cancer Res; 70(16); 6412–9. ©2010 AACR.
Data from Metastasis-Associated Protein 1 and Its Short Form Variant Stimulates Wnt1 Transcription through Promoting Its Derepression from Six3 Corepressor
Authors: Kumar Rakesh , Balasenthil Seetharaman , Manavathi Bramanandam , Rayala Suresh K. , Pakala Suresh B.
Published: March 2023

Abstract
Although Wnt1 downstream signaling components have been well studied and activated in human cancer, the pathways that regulate Wnt1 itself have not been explored in depth. Here, we provide gain-of-function, loss-of function, and molecular evidence supporting functional interactions between metastasis-associated protein 1 short-form (MTA1s), metastasis-associated protein 1 (MTA1), and Wnt1 signaling components during mammary gland development and tumorigenesis. Using multiple model systems involving overexpression or knockdown of MTA1s or MTA1, we discovered that MTA1s and MTA1 hyperactivate the Wnt1 pathway due to increased expression of Wnt1 transcription. MTA1s and MTA1 physically interact with Six3 chromatin, a protein product of which is a direct histone deacetylase inhibitor–dependent repressor of Wnt1 transcription. Deletion of the MTA1s and MTA1 allele in murine embryonic fibroblasts resulted in the upregulation of Six3 and downregulation of Wnt signaling. In addition, mammary glands from the MTA1s/MTA1−/− mice exhibited increased recruitment of Six3 corepressor complex to the Wnt1 promoter and inhibition of Wnt1 pathway in mammary glands. These findings identify MTA1s and MTA1 as important upstream modifiers of the Wnt1 transcription, and consequently its functions, by directly inhibiting the transcription of Six3, allowing derepression of Wnt1 transcription. Cancer Res; 70(16); 6649–58. ©2010 AACR.
Data from Definition of microRNAs That Repress Expression of the Tumor Suppressor Gene FOXO1 in Endometrial Cancer
Authors: Myatt Stephen S. , Wang Jun , Monteiro Lara J. , Christian Mark , Ho Ka-Kei , Fusi Luca , Dina Roberto E. , Brosens Jan J. , Ghaem-Maghami Sadaf , Lam Eric W-F.
Published: March 2023

Abstract
Endometrial cancer is the most common malignancy of the lower female reproductive tract. The tumor suppressor FOXO1 is downregulated in endometrial cancer compared with normal endometrium but the underlying mechanisms are not well understood. Using microRNA (miR) target prediction algorithms, we identified several miRs that potentially bind the 3′-untranslated region of FOXO1 transcripts. Expression profiling of normal and malignant endometrial samples by quantitative real-time PCR and Northern blot analysis revealed an inverse correlation between the levels of FOXO1 protein and the abundance of several of the in silico–predicted miRs, suggesting that loss of FOXO1 expression in endometrial cancer may be mediated by miRs. To determine the role of candidate miRs, we used the endometrial cancer cell lines HEC-1B and Ishikawa, which express FOXO1 at high and low levels, respectively. Expression of miR-9, miR-27, miR-96, miR-153, miR-182, miR-183, or miR-186, but not miR-29a, miR-128, miR-152, or miR-486 mimetics in HEC-1B cells was sufficient to significantly reduce the abundance of FOXO1. Conversely, FOXO1 expression was efficiently restored in the Ishikawa cell line upon simultaneous inhibition of miR-9, miR-27, miR-96, miR-153, miR-183, and miR-186. Moreover, induction of FOXO1 in Ishikawa cells by miR inhibitors was accompanied by G1 cell cycle arrest and cell death, and was attenuated by the small interfering RNA–mediated downregulation of FOXO1 expression. Our findings identify several miRs overexpressed in endometrial cancer that function in concert to repress FOXO1 expression. Further, aberrant miR expression results in deregulated cell cycle control and impaired apoptotic responses, and thus, may be central to endometrial tumorigenesis. Cancer Res; 70(1); 367–77
Data from Genome-Wide Mapping of Estrogen Receptor-β–Binding Regions Reveals Extensive Cross-Talk with Transcription Factor Activator Protein-1
Authors: Zhao Chunyan , Gao Hui , Liu Yawen , Papoutsi Zoi , Jaffrey Sadaf , Gustafsson Jan-Åke , Dahlman-Wright Karin
Published: March 2023

Abstract
Estrogen signaling can occur through a nonclassical pathway involving the interaction of estrogen receptors (ER) with other transcription factors such as activator protein-1 (AP-1) and SP-1. However, there is little mechanistic understanding about this pathway, with conflicting results from in vitro investigations. In this study, we applied the ChIP-on-chip approach to identify ERβ-binding sites on a genome-wide scale, identifying 1,457 high-confidence binding sites in ERβ-overexpressing MCF7 breast cancer cells. Genes containing ERβ-binding sites can be regulated by E2. Notably, ∼60% of the genomic regions bound by ERβ contained AP-1–like binding regions and estrogen response element–like sites, suggesting a functional association between AP-1 and ERβ signaling. Chromatin immunoprecipitation (ChIP) analysis confirmed the association of AP-1, which is composed of the oncogenic transcription factors c-Fos and c-Jun, to ERβ-bound DNA regions. Using a re-ChIP assay, we showed co-occupancy of ERβ and AP-1 on chromatin. Short interfering RNA–mediated knockdown of c-Fos or c-Jun expression decreased ERβ recruitment to chromatin, consistent with the role of AP-1 in mediating estrogen signaling in breast cancer cells. Additionally, ERα and ERβ recruitment to AP-1/ERβ target regions exhibited gene-dependent differences in response to antiestrogens. Together, our results broaden insights into ERβ DNA-binding at the genomic level by revealing crosstalk with the AP-1 transcription factor. Cancer Res; 70(12); 5174–83. ©2010 AACR.
Data from Construction and Characterization of Novel, Recombinant Immunotoxins Targeting the Her2/neu Oncogene Product: In vitro and In vivo Studies
Authors: Cao Yu , Marks James D. , Marks John W. , Cheung Lawrence H. , Kim Sehoon , Rosenblum Michael G.
Published: March 2023

Abstract
The goal of this study was to characterize a series of anti-Her2/neu immunotoxin constructs to identify how different antibodies and linker choices affect the specificity and cytotoxicity of these proteins. We constructed a series of immunotoxins containing either the human single-chain antibody (scFv) C6.5 or the murine scFv e23 fused to the highly toxic recombinant gelonin (rGel) molecule. Based on the flexible GGGGS linker (L), the fusion construct C6.5-L-rGel was compared with e23-L-rGel to evaluate the specific cytotoxic effects against Her2/neu-positive and Her2/neu-negative tumor cells. Both constructs retained the specificity of the original antibody as well as the biological activity of rGel toxin. The two constructs displayed similar cytotoxicity against different carcinoma cells. We additionally introduced the modified linkers TRHRQPRGWEQL (Fpe) and AGNRVRRSVG (Fdt), which contained furin cleavage sites, to determine the effect of these design changes on stability and cell killing efficiency. The introduction of furin cleavage linkers (Fpe or Fdt) into the molecules resulted in dissimilar sensitivity to protease cleavage compared with the constructs containing the L linker, but very similar intracellular rGel release, cytotoxic kinetics, and induction of autophagic cell death in vitro. Xenograft studies with SKOV3 ovarian tumors were done using various C6.5/rGel constructs. C6.5-L-rGel was more efficient in tumor inhibition than constructs containing furin linkers, attributing to a higher stability in vivo of the L version. Therefore, our studies suggest that human C6.5-L-rGel may be an effective novel clinical agent for therapy of patients with Her2/neu-overexpressing malignancies. [Cancer Res 2009;69(23):8987–95]
Data from Characterization of a Novel Mechanism of Genomic Instability Involving the SEI1/SET/NM23H1 Pathway in Esophageal Cancers
Authors: Li Yan , Nie Chang-Jun , Hu Liang , Qin Yanru , Liu Hai-bo , Zeng Ting-Ting , Chen Leilei , Fu Li , Deng Wen , Chen Shu-Peng , Jia Wei-Hua , Zhang Chunyu , Xie Dan , Guan Xin-Yuan
Published: March 2023

Abstract
Amplification of 19q is a frequent genetic alteration in many solid tumors, and SEI1 is a candidate oncogene within the amplified region. Our previous study found that the oncogenic function of SEI1 was associated with chromosome instability. In this study, we report a novel mechanism of genomic instability involving the SEI1-SET-NM23H1 pathway. Overexpression of SEI1 was observed in 57 of 100 of esophageal squamous cell carcinoma cases. Functional study showed that SEI1 had strong tumorigenic ability, and overexpression of SEI1 could induce the genomic instability by increasing micronuclei formation and reducing the number of chromosomes. Further study found that SEI1 was able to upregulate SET expression and subsequently promote the translocation of a small amount of NM23H1 from the cytoplasm to the nucleus. Nuclear NM23H1 can induce DNA damage through its DNA nick activity. Unlike CTL attack, only a small amount of NM23H1 translocated into the nucleus (<10%) induced by the overexpression of SEI1. Further study found that the small amount of NM23H1 only induced minor DNA damage and subsequently increased genomic instability, rather than inducing irreparable DNA damage and initiating apoptosis by CTL attack. Sister chromatid exchange experiment found that the translocation of small amount of NM23H1 into the nucleus induced by the overexpressions of SEI1/SET could increase the frequency of sister chromatid exchange. In addition, overexpression of SEI1 was associated with poor prognosis of esophageal squamous cell carcinoma. Taken together, these findings define a novel mechanism of genomic instability and malignant progression in esophageal cancers, a deadly disease of increasing incidence in developed countries. Cancer Res; 70(14); 5695–705. ©2010 AACR.
Data from Differential Destruction of Stem Cells: Implications for Targeted Cancer Stem Cell Therapy
Authors: Sehl Mary E. , Sinsheimer Janet S. , Zhou Hua , Lange Kenneth L.
Published: March 2023

Abstract
Cancer stem cells represent a novel therapeutic target. The major challenge in targeting leukemic stem cells (LSC) is finding therapies that largely spare normal hematopoietic stem cells (HSC) while eradicating quiescent LSCs. We present a mathematical model to predict how selective a therapy must be to ensure that enough HSCs survive when LSCs have been eradicated. Stem cell population size is modeled as a birth-death process. This permits comparison of LSC and HSC eradication times under therapy and calculation of the number of HSCs at the time of LSC eradication for varied initial population sizes and stem cell death rates. We further investigate the effects of LSC quiescence and resistance mutations on our predictions. From a clinical point of view, our models suggest criteria by which cancer stem cell therapy safety can be assessed. We anticipate that in conjunction with experimental observation of cancer stem cell killing rates, our results will be useful in screening targeted therapies for both hematologic and solid tumor malignancies. [Cancer Res 2009;69(24):9481–9]
Data from The Histone Demethylase JMJD2B Is Regulated by Estrogen Receptor α and Hypoxia, and Is a Key Mediator of Estrogen Induced Growth
Authors: Yang Jun , Jubb Adrian M. , Pike Luke , Buffa Francesca M. , Turley Helen , Baban Dilair , Leek Russell , Gatter Kevin C. , Ragoussis Jiannis , Harris Adrian L.
Published: March 2023

Abstract
Estrogen receptor α (ERα) plays an important role in breast cancer. Upregulation of HIF-1α in ERα-positive cancers suggests that HIF-1α may cooperate with ERα to promote breast cancer progression and consequently affect breast cancer treatment. Here, we show the histone demethylase JMJD2B is regulated by both ERα and HIF-1α, drives breast cancer cell proliferation in normoxia and hypoxia, and epigenetically regulates the expression of cell cycle genes such as CCND1, CCNA1, and WEE1. We also show that JMJD2B and the hypoxia marker CA9 together stratify a subclass of breast cancer patients and predict a worse outcome of these breast cancers. Our findings provide a biological rationale to support the therapeutic targeting of histone demethylases in breast cancer patients. Cancer Res; 70(16); 6456–66. ©2010 AACR.
Data from E2F8 Contributes to Human Hepatocellular Carcinoma via Regulating Cell Proliferation
Authors: Deng Qing , Wang Qun , Zong Wei-Ying , Zheng Da-Li , Wen Yi-Xin , Wang Ke-Sheng , Teng Xiao-Mei , Zhang Xin , Huang Jian , Han Ze-Guang
Published: March 2023

Abstract
The E2F family member of transcription factors includes the atypical member E2F8, which has been little studied in cancer. We report that E2F8 is strongly upregulated in human hepatocellular carcinoma (HCC), where it was evidenced to contribute to oncogenesis and progression. Ectopic overexpression of E2F8 promoted cell proliferation, colony formation, and tumorigenicity, whereas E2F8 knockdown inhibited these phenotypes, as documented in Huh-7, Focus, Hep3B, and YY-8103 HCC cell lines. Mechanistic analyses indicated that E2F8 could bind to regulatory elements of cyclin D1, regulating its transcription and promoting accumulation of S-phase cells. Together, our findings suggest that E2F8 contributes to the oncogenic potential of HCC and may constitute a potential therapeutic target in this disease. Cancer Res; 70(2); 782–91
Data from Evaluation of the Proteasome Inhibitor MLN9708 in Preclinical Models of Human Cancer
Authors: Kupperman Erik , Lee Edmund C. , Cao Yueying , Bannerman Bret , Fitzgerald Michael , Berger Allison , Yu Jie , Yang Yu , Hales Paul , Bruzzese Frank , Liu Jane , Blank Jonathan , Garcia Khristofer , Tsu Christopher , Dick Larry , Fleming Paul , Yu Li , Manfredi Mark , Rolfe Mark , Bolen Joe
Published: March 2023

Abstract
The proteasome was validated as an oncology target following the clinical success of VELCADE (bortezomib) for injection for the treatment of multiple myeloma and recurring mantle cell lymphoma. Consequently, severalgroups are pursuing the development of additional small-molecule proteasome inhibitors for both hematologic and solid tumor indications. Here, we describe MLN9708, a selective, orally bioavailable, second-generation proteasome inhibitor that is in phase I clinical development. MLN9708 has a shorter proteasome dissociation half-life and improved pharmacokinetics, pharmacodynamics, and antitumor activity compared with bortezomib. MLN9708 has a larger blood volume distribution at steady state, and analysis of 20S proteasome inhibition and markers of the unfolded protein response confirmed that MLN9708 has greater pharmacodynamic effects in tissues than bortezomib. MLN9708 showed activity in both solid tumor and hematologic preclinical xenograft models, and we found a correlation between greater pharmacodynamic responses and improved antitumor activity. Moreover, antitumor activity was shown via multiple dosing routes, including oral gavage. Taken together, these data support the clinical development of MLN9708 for both hematologic and solid tumor indications. Cancer Res; 70(5); 1970–80
Data from Reduced Levels of IGF-I Mediate Differential Protection of Normal and Cancer Cells in Response to Fasting and Improve Chemotherapeutic Index
Authors: Lee Changhan , Safdie Fernando M. , Raffaghello Lizzia , Wei Min , Madia Federica , Parrella Edoardo , Hwang David , Cohen Pinchas , Bianchi Giovanna , Longo Valter D.
Published: March 2023

Abstract
Inhibitors of the insulin-like growth factor-I (IGF-I) receptor have been widely studied for their ability to enhance the killing of a variety of malignant cells, but whether IGF-I signaling differentially protects the host and cancer cells against chemotherapy is unknown. Starvation can protect mice, but not cancer cells, against high-dose chemotherapy [differential stress resistance (DSR)]. Here, we offer evidence that IGF-I reduction mediates part of the starvation-dependent DSR. A 72-hour fast in mice reduced circulating IGF-I by 70% and increased the level of the IGF-I inhibitor IGFBP-1 by 11-fold. LID mice, with a 70% to 80% reduction in circulating IGF-I levels, were protected against three of four chemotherapy drugs tested. Restoration of IGF-I was sufficient to reverse the protective effect of fasting. Sixty percent of melanoma-bearing LID mice treated with doxorubicin achieved long-term survival whereas all control mice died of either metastases or chemotherapy toxicity. Reducing IGF-I/IGF-I signaling protected primary glia, but not glioma cells, against cyclophosphamide and protected mouse embryonic fibroblasts against doxorubicin. Further, S. cerevisiae lacking homologs of IGF-I signaling proteins were protected against chemotherapy-dependent DNA damage in a manner that could be reversed by expressing a constitutively active form of Ras. We conclude that normal cells and mice can be protected against chemotherapy-dependent damage by reducing circulating IGF-I levels and by a mechanism that involves downregulation of proto-oncogene signals. Cancer Res; 70(4); 1564–72
Data from Targeted Nanoparticles That Deliver a Sustained, Specific Release of Paclitaxel to Irradiated Tumors
Authors: Passarella Ralph J. , Spratt Daniel E. , van der Ende Alice E. , Phillips John G. , Wu Hongmei , Sathiyakumar Vasanth , Zhou Li , Hallahan Dennis E. , Harth Eva , Diaz Roberto
Published: March 2023

Abstract
To capitalize on the response of tumor cells to XRT, we developed a controlled-release nanoparticle drug delivery system using a targeting peptide that recognizes a radiation-induced cell surface receptor. Phage display biopanning identified Gly-Ile-Arg-Leu-Arg-Gly (GIRLRG) as a peptide that selectively recognizes tumors responding to XRT. Membrane protein extracts of irradiated glioma cells identified glucose-regulated protein GRP78 as the receptor target for GIRLRG. Antibodies to GRP78 blocked the binding of GIRLRG in vitro and in vivo. Conjugation of GIRLRG to a sustained-release nanoparticle drug delivery system yielded increased paclitaxel concentration and apoptosis in irradiated breast carcinomas for up to 3 weeks. Compared with controls, a single administration of the GIRLRG-targeted nanoparticle drug delivery system to irradiated tumors delayed the in vivo tumor tripling time by 55 days (P = 0.0001) in MDA-MB-231 and 12 days in GL261 (P < 0.005). This targeting agent combines a novel recombinant peptide with a paclitaxel-encapsulating nanoparticle that specifically targets irradiated tumors, increasing apoptosis and tumor growth delay in a manner superior to known chemotherapy approaches. Cancer Res; 70(11); 4550–9. ©2010 AACR.
Data from Image-Based Chemical Screening Identifies Drug Efflux Inhibitors in Lung Cancer Cells
Authors: Xia Xiaofeng , Yang Jian , Li Fuhai , Li Ying , Zhou Xiaobo , Dai Yue , Wong Stephen T.C.
Published: March 2023

Abstract
Cancer cells with active drug efflux capability are multidrug resistant and pose a significant obstacle for the efficacy of chemotherapy. Moreover, recent evidence suggests that high drug efflux cancer cells (HDECC) may be selectively enriched with stem-like cancer cells, which are believed to be the cause for tumor initiation and recurrence. There is a great need for therapeutic reagents that are capable of eliminating HDECCs. We developed an image-based high-content screening (HCS) system to specifically identify and analyze the HDECC population in lung cancer cells. Using the system, we screened 1,280 pharmacologically active compounds that identified 12 potent HDECC inhibitors. It is shown that these inhibitors are able to overcome multidrug resistance (MDR) and sensitize HDECCs to chemotherapeutic drugs, or directly reduce the tumorigenicity of lung cancer cells possibly by affecting stem-like cancer cells. The HCS system we established provides a new approach for identifying therapeutic reagents overcoming MDR. The compounds identified by the screening may potentially be used as potential adjuvant to improve the efficacy of chemotherapeutic drugs. Cancer Res; 70(19); 7723–33. ©2010 AACR.
Data from Genetic Variants in MicroRNA Biosynthesis Pathways and Binding Sites Modify Ovarian Cancer Risk, Survival, and Treatment Response
Authors: Liang Dong , Meyer Larissa , Chang David W. , Lin Jie , Pu Xia , Ye Yuanqing , Gu Jian , Wu Xifeng , Lu Karen
Published: March 2023

Abstract
MicroRNAs (miRNA) play important roles in tumorigenesis. Genetic variations in miRNA processing genes and miRNA binding sites may affect the biogenesis of miRNA and the regulatory effect of miRNAs to their target genes, hence promoting tumorigenesis. This study analyzed 226 single nucleotide polymorphisms (SNP) in miRNA processing genes and miRNA binding sites in 339 ovarian cancer cases and 349 healthy controls to assess association with cancer risk, overall survival, and treatment response. Thirteen polymorphisms were found to have significant association with risk. The most significant were 2 linked SNPs (r2 = 0.99), rs2740351 and rs7813 in GEMIN4 [odds ratio (OR) = 0.71; 95% confidence interval (CI), 0.57–0.87 and OR = 0.71; 95% CI, 0.57–0.88, respectively]. Unfavorable genotype analysis showed the cumulative effect of these 13 SNPs on risk (P for trend < 0.0001). Potential higher order gene–gene interactions were identified, which categorized patients into different risk groups according to their genotypic signatures. In the clinical outcome study, 24 SNPs exhibited significant association with overall survival and 17 SNPs with treatment response. Notably, patients carrying a rare homozygous genotype of rs1425486 in PDGFC had poorer overall survival [hazard ratio (HR) = 2.69; 95% CI, 1.67–4.33] and worse treatment response (OR = 3.38; 95% CI, 1.39–8.19), compared to carriers of common homozygous and heterozygous genotypes. Unfavorable genotype analyses also showed a strong gene-dosage effect with decreased survival and increased risk of treatment nonresponse in patients with greater number of unfavorable genotypes (P for trend < 0.0001). Taken together, miRNA-related genetic polymorphisms may impact ovarian cancer predisposition and clinical outcome both individually and jointly. Cancer Res; 70(23); 9765–76. ©2010 AACR.
Data from Role of LIM and SH3 Protein 1 (LASP1) in the Metastatic Dissemination of Medulloblastoma
Authors: Traenka Christopher , Remke Marc , Korshunov Andrey , Bender Sebastian , Hielscher Thomas , Northcott Paul A. , Witt Hendrik , Ryzhova Marina , Felsberg Jörg , Benner Axel , Riester Stephanie , Scheurlen Wolfram , Grunewald Thomas G.P. , von Deimling Andreas , Kulozik Andreas E. , Reifenberger Guido , Taylor Michael D. , Lichter Peter , Butt Elke , Pfister Stefan M.
Published: March 2023

Abstract
Medulloblastoma is the most common malignant pediatric brain tumor and is one of the leading causes of cancer-related mortality in children. Treatment failure mainly occurs in children harboring metastatic tumors, which typically carry an isochromosome 17 or gain of 17q, a common hallmark of intermediate and high-risk medulloblastoma. Through mRNA expression profiling, we identified LIM and SH3 protein 1 (LASP1) as one of the most upregulated genes on chromosome 17q in tumors with 17q gain. In an independent validation cohort of 101 medulloblastoma samples, the abundance of LASP1 mRNA was significantly associated with 17q gain, metastatic dissemination, and unfavorable outcome. LASP1 protein expression was analyzed by immunohistochemistry in a large cohort of patients (n = 207), and high protein expression levels were found to be strongly correlated with 17q gain, metastatic dissemination, and inferior overall and progression-free survival. In vitro experiments in medulloblastoma cell lines showed a strong reduction of cell migration, increased adhesion, and decreased proliferation upon LASP1 knockdown by small interfering RNA–mediated silencing, further indicating a functional role for LASP1 in the progression and metastatic dissemination of medulloblastoma. Cancer Res; 70(20); 8003–14. ©2010 AACR.
Data from Chemopreventive Agent 3,3′-Diindolylmethane Selectively Induces Proteasomal Degradation of Class I Histone Deacetylases
Authors: Li Yongming , Li Xia , Guo Bin
Published: March 2023

Abstract
3,3′-Diindolylmethane (DIM) is an anticancer agent that induces cell cycle arrest and apoptosis through unknown mechanisms. Here, we report that DIM can selectively induce proteasome-mediated degradation of class I histone deacetylases (HDAC1, HDAC2, HDAC3, and HDAC8) without affecting the class II HDAC proteins. DIM induced downregulation of class I HDACs in human colon cancer cells in vitro and in vivo in tumor xenografts. HDAC depletion relieved HDAC-mediated transcriptional inhibition of the cyclin-dependent kinase inhibitors p21WAF1 and p27KIP2, significantly increasing their expression and triggering cell cycle arrest in the G2 phase of the cell cycle. Additionally, HDAC depletion was associated with an induction of DNA damage that triggered apoptosis. Our findings indicate that DIM acts to selectively target the degradation of class I HDACs. Cancer Res; 70(2); 646–54
Data from Survivin Enhances Motility of Melanoma Cells by Supporting Akt Activation and α5 Integrin Upregulation
Authors: McKenzie Jodi A. , Liu Tong , Goodson Agnessa G. , Grossman Douglas
Published: March 2023

Abstract
Survivin expression in melanoma is inversely correlated with patient survival. Transgenic mice harboring melanocyte-specific overexpression of survivin exhibit increased susceptibility to UV-induced melanoma and metastatic progression. To understand the mechanistic basis for metastatic progression, we investigated the effects of survivin on the motility of human melanocytes and melanoma cells. We found that survivin overexpression enhanced migration on fibronectin and invasion through Matrigel, whereas survivin knockdown under subapoptotic conditions blocked migration and invasion. In melanocytes, survivin overexpression activated the Akt and mitogen-activated protein kinase pathways. Akt phosphorylation was required for survivin-enhanced migration and invasion, whereas Erk phosphorylation was required only for enhanced invasion. In both melanocytes and melanoma cells, survivin overexpression was associated with upregulation of α5 integrin (fibronectin receptor component), the antibody-mediated blockade or RNA interference-mediated knockdown of which blocked survivin-enhanced migration. Knockdown of α5 integrin did not affect Akt activation, but inhibition of Akt phosphorylation prevented α5 integrin upregulation elicited by survivin overexpression. Together, our results showed that survivin enhanced the migration and invasion of melanocytic cells and suggested that survivin may promote melanoma metastasis by supporting Akt-dependent upregulation of α5 integrin. Cancer Res; 70(20); 7927–37. ©2010 AACR.
Data from PTEN Loss Accelerates KrasG12D-Induced Pancreatic Cancer Development
Authors: Hill Reginald , Calvopina Joseph Hargan , Kim Christine , Wang Ying , Dawson David W. , Donahue Timothy R. , Dry Sarah , Wu Hong
Published: March 2023

Abstract
KRAS mutations are found in ∼90% of human pancreatic ductal adenocarcinomas (PDAC). However, mice genetically engineered to express KrasG12D from its endogenous locus develop PDACs only after a prolonged latency, indicating that other genetic events or pathway alterations are necessary for PDAC progression. The PTEN-controlled phosphatidylinositol 3-kinase (PI3K)/AKT signaling axis is dysregulated in later stages of PDAC. To better elucidate the role of PTEN/PI3K/AKT signaling in KrasG12D-induced PDAC development, we crossed Pten conditional knockout mice (Ptenlox/lox) to mice with conditional activation of KrasG12D. The resulting compound heterozygous mutant mice showed significantly accelerated development of acinar-to-ductal metaplasia (ADM), malignant pancreatic intraepithelial neoplasia (mPanIN), and PDAC within a year. Moreover, all mice with KrasG12D activation and Pten homozygous deletion succumbed to cancer by 3 weeks of age. Our data support a dosage-dependent role for PTEN, and the resulting dysregulation of the PI3K/AKT signaling axis, in both PDAC initiation and progression, and shed additional light on the signaling mechanisms that lead to the development of ADM and subsequent mPanIN and pancreatic cancer. Cancer Res; 70(18); 7114–24. ©2010 AACR.
Data from Astrocyte Elevated Gene-1 Upregulates Matrix Metalloproteinase-9 and Induces Human Glioma Invasion
Authors: Liu Liping , Wu Jueheng , Ying Zhe , Chen Baixue , Han Anjia , Liang Yingjie , Song Libing , Yuan Jie , Li Jun , Li Mengfeng
Published: March 2023

Abstract
The poor prognosis of malignant gliomas is largely attributed to their highly invasive nature. The molecular mechanism underlying the invasiveness of glioma cells, however, remains to be elucidated. The present study found that astrocyte elevated gene-1 (AEG-1) was upregulated in human glioma cell lines and glioma tissues compared with normal astrocytes and brain tissues. AEG-1 was found to be upregulated in 265 of 296 (89.5%) glioma sections, and the AEG-1 expression level significantly correlated with clinicopathologic stages of gliomas. Ectopic expression or short hairpin RNA silencing of AEG-1 significantly enhanced or inhibited, respectively, the invasive ability of glioma cells. At the molecular level, we showed that upregulated AEG-1 in glioma cells interacted with matrix metalloproteinase-9 (MMP-9) promoter and transactivated MMP-9 expression, whereas knockdown of AEG-1 expression reduced the level of MMP-9. Two regions in MMP-9 promoter were found to be involved in the interaction with AEG-1. Suppression of endogenous MMP-9 abrogated the effects of AEG-1 on invasiveness. Consistent with these observations, immunostaining analysis revealed a significant correlation between the expressions of AEG-1 and MMP-9 in a cohort of clinical glioma samples. Moreover, intracranial xenografts of glioma cells engineered to express AEG-1 were highly invasive compared with the parental cells and expressed high level of MMP-9. Collectively, these findings provide evidence that AEG-1 contributes to glioma progression by enhancing MMP-9 transcription and, hence, tumor cell invasiveness, and underscore the importance of AEG-1 in glioma development and progression. Cancer Res; 70(9); 3750–9. ©2010 AACR.