bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Adipocytes Impair Leukemia Treatment in Mice
Authors: Behan James W. , Yun Jason P. , Proektor Marina P. , Ehsanipour Ehsan A. , Arutyunyan Anna , Moses Ara S. , Avramis Vassilios I. , Louie Stan G. , Butturini Anna , Heisterkamp Nora , Mittelman Steven D.
Published: March 2024

Abstract
Obesity is associated with increased cancer incidence and mortality. We have previously found that obesity in children is associated with a 50% increased recurrence of acute lymphoblastic leukemia (ALL) in high-risk patients. We have therefore developed novel in vivo and in vitro preclinical models to study the mechanism(s) of this association. Obesity increased relapse after monotherapy with vincristine (P = 0.03) in obese mice injected with syngeneic ALL cells. This occurred although the drug was dosed proportionally to body weight, equalizing blood and tissue drug levels. In coculture, 3T3-L1 adipocytes significantly impaired the antileukemia efficacy of vincristine, as well as three other chemotherapies (P < 0.05). Interestingly, this protection was independent of cell-cell contact, and it extended to human leukemia cell lines as well. Adipocytes prevented chemotherapy-induced apoptosis, and this was associated with increased expression of the two prosurvival signals Bcl-2 and Pim-2. These findings highlight the role of the adipocyte in fostering leukemia chemotherapy resistance, and may help explain the increased leukemia relapse rate in obese children and adults. Given the growing prevalence of obesity worldwide, these effects are likely to have increasing importance to cancer treatment. [Cancer Res 2009;69(19):7867–74]
Data from Insulin-like Growth Factor-II Methylation Status in Lymphocyte DNA and Colon Cancer Risk in the Northern Sweden Health and Disease Cohort
Authors: Kaaks Rudolf , Stattin Pär , Villar Stéphanie , Poetsch Anna R. , Dossus Laure , Nieters Alexandra , Riboli Elio , Palmqvist Richard , Hallmans Göran , Plass Christoph , Friesen Marlin D.
Published: March 2024

Abstract
Loss of imprinting (LOI) of the insulin-like growth factor II (IGFII) gene is a frequent phenomenon in colorectal tumor tissues. Previous reports indicated that subjects with colorectal neoplasias show LOI of IGFII in circulating lymphocytes. Furthermore, LOI of IGFII is strongly related to the methylation of a differentially methylated region (DMR) in intron 2 of IGFII, suggesting that the methylation status could serve as a biomarker for early detection. Thus, hypermethylation of this DMR, even at a systemic level, e.g., in lymphocyte DNA, could be used for screening for colon cancer. To validate this, we performed a case-control study of 97 colon cancer cases and 190 age-matched and gender-matched controls, nested within the prospective Northern Sweden Health and Disease Study cohort. Methylation levels of the IGFII-DMR in lymphocyte DNA were measured at two specific CpG sites of the IGFII-DMR using a mass-spectrometric method called short oligonucleotide mass analysis, the measurements of which showed high reproducibility between replicate measurements for the two CpG sites combined and showed almost perfect validity when performed on variable mixtures of methylated and unmethylated standards. Mean fractions of CpG methylation, for the two CpG sites combined, were identical for cases and controls (0.47 and 0.46, respectively; Pdifference = 0.75), and logistic regression analyses showed no relationship between colon cancer risk and quartile levels of CpG methylation. The results from this study population do not support the hypothesis that colon cancer can be predicted from the different degrees of methylation of DMR in the IGFII gene from lymphocyte DNA. [Cancer Res 2009;69(13):5400–5]
Data from Suppression of Nonhomologous End Joining Repair by Overexpression of HMGA2
Authors: Li Angela Y.J. , Boo Lee Ming , Wang Shih-Ya , Lin H. Helen , Wang Clay C.C. , Yen Yun , Chen Benjamin P.C. , Chen David J. , Ann David K.
Published: March 2024

Abstract
Understanding the molecular details associated with aberrant high mobility group A2 (HMGA2) gene expression is key to establishing the mechanism(s) underlying its oncogenic potential and effect on the development of therapeutic strategies. Here, we report the involvement of HMGA2 in impairing DNA-dependent protein kinase (DNA-PK) during the nonhomologous end joining (NHEJ) process. We showed that HMGA2-expressing cells displayed deficiency in overall and precise DNA end-joining repair and accumulated more endogenous DNA damage. Proper and timely activation of DNA-PK, consisting of Ku70, Ku80, and DNA-PKcs subunits, is essential for the repair of DNA double strand breaks (DSB) generated endogenously or by exposure to genotoxins. In cells overexpressing HMGA2, accumulation of histone 2A variant X phosphorylation at Ser-139 (γ-H2AX) was associated with hyperphosphorylation of DNA-PKcs at Thr-2609 and Ser-2056 before and after the induction of DSBs. Also, the steady-state complex of Ku and DNA ends was altered by HMGA2. Microirradiation and real-time imaging in living cells revealed that HMGA2 delayed the release of DNA-PKcs from DSB sites, similar to observations found in DNA-PKcs mutants. Moreover, HMGA2 alone was sufficient to induce chromosomal aberrations, a hallmark of deficiency in NHEJ-mediated DNA repair. In summary, a novel role for HMGA2 to interfere with NHEJ processes was uncovered, implicating HMGA2 in the promotion of genome instability and tumorigenesis. [Cancer Res 2009;69(14):5699–706]
Data from Cyclophosphamide Augments Antitumor Immunity: Studies in an Autochthonous Prostate Cancer Model
Authors: Wada Satoshi , Yoshimura Kiyoshi , Hipkiss Edward L. , Harris Tim J. , Yen Hung-Rong , Goldberg Monica V. , Grosso Joseph F. , Getnet Derese , Demarzo Angelo M. , Netto George J. , Anders Robert , Pardoll Drew M. , Drake Charles G.
Published: March 2024

Abstract
To study the immune response to prostate cancer, we developed an autochthonous animal model based on the transgenic adenocarcinoma of the mouse prostate (TRAMP) mouse in which spontaneously developing tumors express influenza hemagglutinin as a unique, tumor-associated antigen. Our prior studies in these animals showed immunologic tolerance to hemagglutinin, mirroring the clinical situation in patients with cancer who are generally nonresponsive to their disease. We used this physiologically relevant animal model to assess the immunomodulatory effects of cyclophosphamide when administered in combination with an allogeneic, cell-based granulocyte-macrophage colony-stimulating factor–secreting cancer immunotherapy. Through adoptive transfer of prostate/prostate cancer–specific CD8 T cells as well as through studies of the endogenous T-cell repertoire, we found that cyclophosphamide induced a marked augmentation of the antitumor immune response. This effect was strongly dependent on both the dose and the timing of cyclophosphamide administration. Mechanistic studies showed that immune augmentation by cyclophosphamide was associated with a transient depletion of regulatory T cells in the tumor draining lymph nodes but not in the peripheral circulation. Interestingly, we also noted effects on dendritic cell phenotype; low-dose cyclophosphamide was associated with increased expression of dendritic cell maturation markers. Taken together, these data clarify the dose, timing, and mechanism of action by which immunomodulatory cyclophosphamide can be translated to a clinical setting in a combinatorial cancer treatment strategy. [Cancer Res 2009;69(10):4309–18]
Data from Tumor Apoptotic Bodies Inhibit CTL Responses and Antitumor Immunity via Membrane-Bound Transforming Growth Factor-β1 Inducing CD8+ T-Cell Anergy and CD4+ Tr1 Cell Responses
Authors: Xie Yufeng , Bai Ou , Yuan Jinying , Chibbar Rajni , Slattery Karen , Wei Yangdou , Deng Yulin , Xiang Jim
Published: March 2024

Abstract
Tumor cell apoptosis induced by radiation therapy results in apoptotic tumor cells and apparition of membrane blebs termed apoptotic bodies (APB). The immune responses induced by apoptotic tumor cells have been extensively studied. However, the role of APB in modulation of tumor immune responses is elusive. In this study, we induced apoptosis in 90% ovabumin-expressing EG7 tumor cells by in vitro irradiation (9,000 rad) of tumor cells with a subsequent cell culture for 9 hours. APB purified from irradiation-induced apoptotic EG7 cell culture supernatant by differential ultracentrifugation were vesicles with 50 to 90 nm in diameter and expressed apoptosis-specific Annexin V, 14-3-3, and Histone H3. We then investigated its potential modulation in DCOVA–induced T-cell responses and antitumor immunity. We found that EG7-derived APB were tolerogenic and capable of suppressing DCOVA-stimulated CD8+ CTL responses and antitumor immunity via its induction of CD8+ T-cell anergy and type 1 regulatory CD4+ T-cell responses. Analysis of apoptotic tumor cells and APB revealed the expression of membrane-bound transforming growth factor (TGF)-β1 associated with irradiation-induced apoptosis formation, which is a result from activation of transcriptional factor NF-AT specific for TGF-β1 promoters. Our data further elucidate that it is the membrane-bound TGF-β1 expression on APB that contributes to its in vitro antiproliferative effect as shown by using neutralizing TGF-β1–specific antibody. Administration of anti–TGF-β1 antibody in vivo also blocked APB-mediated immune suppression of CD8+ CTL responses and antitumor immunity. Therefore, our study may have great impact in designing a combined radiation therapy with immunotherapy of cancer. [Cancer Res 2009;69(19):7756–66]
Data from AZD1152 Rapidly and Negatively Affects the Growth and Survival of Human Acute Myeloid Leukemia Cells In vitro and In vivo
Authors: Oke Adedayo , Pearce Daniel , Wilkinson Robert W. , Crafter Claire , Odedra Rajesh , Cavenagh Jamie , Fitzgibbon Jude , Lister Andrew T. , Joel Simon , Bonnet Dominique
Published: March 2024

Abstract
Aurora kinases play a critical role in regulating mitosis and cell division, and their overexpression has been implicated in the survival and proliferation of human cancer. In this study, we report the in vitro and in vivo activities of AZD1152, a compound that has selectivity for aurora B kinase, in acute myeloid leukemia (AML) cell lines, primary AML samples, and cord blood cells. AZD1152 exerted antiproliferative or cytotoxic effects in all cell lines studied, inhibited the phosphorylation of histone H3 (pHis H3) on Ser10 in a dose-dependent manner, and resulted in cells with >4N DNA content. THP-1 cells treated with AZD1152 accumulated in a state of polyploidy and showed a senescent response to the drug, in contrast to the apoptotic response seen in other cell lines. Accordingly, AZD1152 profoundly affected the growth of AML cell lines and primary AML in an in vivo xenotransplantation model. However, concentration-dependent effects on cell growth, apoptosis, and cell cycle progression were also observed when human cord blood and primary lineage–negative stem and progenitor cells were analyzed in vitro and in vivo. These data suggest that the inhibition of aurora B kinase may be a useful therapeutic strategy in the treatment of AML and that further exploration of dosing and treatment schedules is warranted in clinical trials. [Cancer Res 2009;69(10):4150–8]
Data from Distinct Concentration-Dependent Effects of the Polo-like Kinase 1–Specific Inhibitor GSK461364A, Including Differential Effect on Apoptosis
Authors: Gilmartin Aidan G. , Bleam Maureen R. , Richter Mark C. , Erskine Symon G. , Kruger Ryan G. , Madden Lenore , Hassler Daniel F. , Smith Gary K. , Gontarek Richard R. , Courtney Mary P. , Sutton David , Diamond Melody A. , Jackson Jeffrey R. , Laquerre Sylvie G.
Published: March 2024

Abstract
Polo-like kinase 1 (Plk1) is a conserved serine/threonine kinase that plays an essential role in regulating the many processes involved in mitotic entry and progression. In humans, Plk1 is expressed primarily during late G2 and M phases and, in conjunction with Cdk1/cyclin B1, acts as master regulatory kinases for the myriad protein substrates involved in mitosis. Plk1 overexpression is strongly associated with cancer and has been correlated with poor prognosis in a broad range of human tumor types. We have identified a potent, selective, reversible, ATP-competitive inhibitor of Plk1, GSK461364A, capable of inhibiting cell growth of most proliferating cancer cell lines tested. We observe distinct cell cycle effects of GSK461364A depending on the dose used. The predominant phenotype for cells treated with GSK461364A is prometaphase arrest with characteristic collapsed polar polo spindle. At high concentrations, GSK461364A delays mitotic entry in G2 followed by gradual progression into terminal mitosis; in some cell lines, this correlates with decreased apoptosis. Cell culture growth inhibition by GSK461364A can be cytostatic or cytotoxic but leads to tumor regression in xenograft tumor models under proper dose scheduling. Finally, we describe pharmacodynamic biomarkers of GSK461364A activity (pHH3 and Plk1) that are currently being evaluated in human cancer clinical trials. [Cancer Res 2009;69(17):6969–77]
Data from Combined Inhibition of MEK and Mammalian Target of Rapamycin Abolishes Phosphorylation of Cyclin-Dependent Kinase 4 in Glioblastoma Cell Lines and Prevents Their Proliferation
Authors: Paternot Sabine , Roger Pierre P.
Published: March 2024

Abstract
The Ras/Raf/MEK/extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (mTOR) signaling pathways are aberrantly activated in many tumors, including highly proliferative glioblastomas, but how they are wired with the cell cycle remains imperfectly understood. Inhibitors of MEK/ERK and mTOR pathways are tested as anticancer agents. They are generally considered to induce a G1 cell cycle arrest through down-regulation of D-type cyclins and up-regulation of p27kip1. Here, we examined the effect of targeting mTOR by rapamycin and/or MEK by PD184352 in human glioblastoma cell lines. In combination, these drugs cooperatively and potently inhibited the G1-S transition and retinoblastoma protein phosphorylation. Their cooperation could not be explained by their partial and differential inhibitory effects on cyclin D1 or D3 but instead by their synergistic inhibition of the activating T172 phosphorylation of cyclin-dependent kinase (CDK) 4. This appeared independent of p27 and unrelated to weak modulations of the CDK-activating kinase activity. The T172 phosphorylation of CDK4 thus appears as a crucial node integrating the activity of both MEK/ERK and mTOR pathways. Combined inhibition of both pathways should be considered as a promising strategy for treatment of tumors harboring a deregulated CDK4 activity. [Cancer Res 2009;69(11):4577–81]
Data from Targeted In vivo Imaging of Integrin αvβ6 with an Improved Radiotracer and Its Relevance in a Pancreatic Tumor Model
Authors: Hausner Sven H. , Abbey Craig K. , Bold Richard J. , Gagnon M. Karen , Marik Jan , Marshall John F. , Stanecki Cathy E. , Sutcliffe Julie L.
Published: March 2024

Abstract
The cell surface receptor αvβ6 is epithelial specific, and its expression is tightly regulated; it is low or undetectable in adult tissues but has been shown to be increased in many different cancers, including pancreatic, cervical, lung, and colon cancers. Studies have described αvβ6 as a prognostic biomarker linked to poor survival. We have recently shown the feasibility of imaging αvβ6 in vivo by positron emission tomography (PET) using the peptide [18F]FBA-A20FMDV2. Here, we describe improved αvβ6 imaging agents and test their efficacy in a mouse model with endogenous αvβ6 expression. The modified compounds maintained high affinity for αvβ6 and >1,000-fold selectivity over related integrins (by ELISA) and showed significantly improved αvβ6-dependent binding in cell-based assays (>60% binding versus <10% for [18F]FBA-A20FMDV2). In vivo studies using either a melanoma cell line (transduced αvβ6 expression) or the BxPC-3 human pancreatic carcinoma cell line (endogenous αvβ6 expression) revealed that the modified compounds showed significantly improved tumor retention. This, along with good clearance of nonspecifically bound activity, particularly for the new radiotracer [18F]FBA-PEG28-A20FMDV2, resulted in improved PET imaging. Tumor/pancreas and tumor/blood biodistribution ratios of >23:1 and >47:1, respectively, were achieved at 4 hours. Significantly, [18F]FBA-PEG28-A20FMDV2 was superior to 2-[18F]fluoro-2-deoxy-d-glucose ([18F]FDG) in imaging the BxPC-3 tumors. Pancreatic ductal adenocarcinoma is highly metastatic and current preoperative evaluation of resectability using noninvasive imaging has limited success, with most patients having metastases at time of surgery. The fact that these tumors express αvβ6 suggests that this probe has significant potential for the in vivo detection of this malignancy, thus having important implications for patient care and therapy. [Cancer Res 2009;69(14):5843–50]
Data from RLIP76: A Target for Kidney Cancer Therapy
Authors: Singhal Sharad S. , Singhal Jyotsana , Yadav Sushma , Sahu Mukesh , Awasthi Yogesh C. , Awasthi Sanjay
Published: March 2024

Abstract
RLIP76 is a multifunctional transporter protein that serves as an energy-dependent efflux mechanism for endogenously generated toxic metabolites as well as exogenous toxins, including chemotherapy drugs. Our recent studies in cultured cells, syngeneic animal tumor model, and in xenograft model have shown that RLIP76 serves a major cancer-specific antiapoptotic role in a wide variety of histologic types of cancer, including leukemia, melanoma, colon, lung, prostate, and ovarian cancer. Results of present studies in cell culture and xenograft model of Caki-2 cells show that RLIP76 is an important anticancer for kidney cancer because inhibition of RLIP76 function by antibody or its depletion by small interfering RNA or antisense DNA caused marked and sustained regression of established human kidney xenografts of Caki-2 cells in nude mouse. [Cancer Res 2009;69(10):4244–51]
Data from Inhibition of Tumor Growth Progression by Antiandrogens and mTOR Inhibitor in a Pten-Deficient Mouse Model of Prostate Cancer
Authors: Zhang Weisheng , Zhu Joe , Efferson Clay L. , Ware Chris , Tammam Jennifer , Angagaw Minilik , Laskey Jason , Bettano Kimberly A. , Kasibhatla Shailaja , Reilly John F. , Sur Cyrille , Majumder Pradip K.
Published: March 2024

Abstract
Androgen receptors have been shown to play a critical role in prostate cancer. We used ultrasound imaging techniques to track tumor response to antiandrogen and rapamycin treatment in a prostate-specific Pten-deleted mouse model of cancer. Depletion of androgens by either surgical or chemical castration significantly inhibited tumor growth progression without altering the activation of Akt and mammalian target of rapamycin (mTOR). We also showed for the first time that targeting mTOR along with antiandrogen treatment exhibited additive antitumor effects in vivo when compared with single agents. Our preclinical data suggest that combination of antiandrogens with mTOR inhibitors might be more effective in treating androgen-dependent prostate cancer patients. [Cancer Res 2009;69(18):7466–72]
Data from Basal Subtype and MAPK/ERK Kinase (MEK)-Phosphoinositide 3-Kinase Feedback Signaling Determine Susceptibility of Breast Cancer Cells to MEK Inhibition
Authors: Mirzoeva Olga K. , Das Debopriya , Heiser Laura M. , Bhattacharya Sanchita , Siwak Doris , Gendelman Rina , Bayani Nora , Wang Nicholas J. , Neve Richard M. , Guan Yinghui , Hu Zhi , Knight Zachary , Feiler Heidi S. , Gascard Philippe , Parvin Bahram , Spellman Paul T. , Shokat Kevan M. , Wyrobek Andrew J. , Bissell Mina J. , McCormick Frank , Kuo Wen-Lin , Mills Gordon B. , Gray Joe W. , Korn W. Michael
Published: March 2024

Abstract
Specific inhibitors of mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase (MEK) have been developed that efficiently inhibit the oncogenic RAF-MEK-ERK pathway. We used a systems-based approach to identify breast cancer subtypes particularly susceptible to MEK inhibitors and to understand molecular mechanisms conferring resistance to such compounds. Basal-type breast cancer cells were found to be particularly susceptible to growth inhibition by small-molecule MEK inhibitors. Activation of the phosphatidylinositol 3-kinase (PI3K) pathway in response to MEK inhibition through a negative MEK-epidermal growth factor receptor-PI3K feedback loop was found to limit efficacy. Interruption of this feedback mechanism by targeting MEK and PI3K produced synergistic effects, including induction of apoptosis and, in some cell lines, cell cycle arrest and protection from apoptosis induced by proapoptotic agents. These findings enhance our understanding of the interconnectivity of oncogenic signal transduction circuits and have implications for the design of future clinical trials of MEK inhibitors in breast cancer by guiding patient selection and suggesting rational combination therapies. [Cancer Res 2009;69(2):565–72]
Data from Secretion of Tumor-Specific Antigen by Myeloma Cells Is Required for Cancer Immunosurveillance by CD4+ T Cells
Authors: Corthay Alexandre , Lundin Katrin U. , Lorvik Kristina Berg , Hofgaard Peter O. , Bogen Bjarne
Published: March 2024

Abstract
Tumor-specific CD4+ T cells orchestrate the adaptive immune responses against cancer. We have previously shown that CD4+ T cells recognize MHC class II–negative myeloma cells indirectly by collaborating with tumor-infiltrating macrophages. We, here, hypothesize that this critical step may be dependent on secretion of tumor-specific antigens by cancer cells. This was investigated using T-cell receptor–transgenic mice, in which CD4+ T cells mediate rejection of syngeneic MOPC315 myeloma cells. We analyzed the immune response against myeloma cell variants, which either secrete or retain intracellularly a tumor-specific idiotypic (Id) antigen. Our results reveal that CD4+ T cells helped by macrophages are capable of detecting nonsecreted tumor antigens from MHC class II–negative cancer cells. However, Id secretion was required for successful myeloma immunosurveillance. Antigen secretion resulted in stronger priming of naive myeloma-specific CD4+ T cells in tumor-draining lymph nodes. Secretion of antigen by at least some cancer cells within a tumor was shown to facilitate immunosurveillance. Treatment by local injection of purified tumor-specific antigen successfully enhanced immunity against nonsecreting myeloma cells. Collectively, the data indicate that antigen concentration within the tumor extracellular matrix must reach a certain threshold to allow successful cancer immunosurveillance by CD4+ T cells. [Cancer Res 2009;69(14):5901–7]
Data from Gα12-Mediated Pathway Promotes Invasiveness of Nasopharyngeal Carcinoma by Modulating Actin Cytoskeleton Reorganization
Authors: Liu Shu-Chen , Jen Yee-Min , Jiang Shih Sheng , Chang Junn-Liang , Hsiung Chao A. , Wang Chih-Hung , Juang Jyh-Lyh
Published: March 2024

Abstract
The molecular mechanisms behind the aggressiveness of nasopharyngeal carcinoma (NPC), a highly invasive and metastatic head and neck malignancy, have not been made clear. In this study investigating these mechanisms, guanine nucleotide-binding protein α12 subunit (Gα12) signaling was found by microarray analysis to be increased in primary NPC cells and NPC-derived cell lines. Using small interfering RNA to knock down Gα12 in NPC cells resulted in a reduction in cell migration and invasion as well as a reversal in fibroblastoid morphology. Using microarray analysis, we also found a reduction in expression of key actin dynamics regulators and several epithelial-to-mesenchymal transition–related genes in Gα12-depleted NPC cells. Knocking down one of those genes, IQ motif containing GTPase activating protein 1, reduced the migration and formation of adherens junctions and reversed the fibroblastoid morphology of NPC cells, as knocking down Gα12 was found to do. Immunohistochemical analysis found NPC tumors to have significantly greater levels of Gα12 protein than the normal basal epithelial cells. Quantitative real-time PCR analysis revealed a significant correlation between Gα12 mRNA levels and NPC lymph node metastasis. Together, our findings support a model in which activation of Gα12 signaling promotes tumorigenesis and progression of NPC by modulating actin cytoskeleton reorganization and expression of epithelial-to-mesenchymal transition–related genes. [Cancer Res 2009;69(15):6122–30]
Data from Increased Manganese Superoxide Dismutase Expression or Treatment with Manganese Porphyrin Potentiates Dexamethasone-Induced Apoptosis in Lymphoma Cells
Authors: Jaramillo Melba C. , Frye Jennifer B. , Crapo James D. , Briehl Margaret M. , Tome Margaret E.
Published: March 2024

Abstract
Glucocorticoid-induced apoptosis is exploited for the treatment of hematologic malignancies. Innate and acquired resistance limits treatment efficacy; however, resistance mechanisms are not well understood. Previously, using WEHI7.2 murine thymic lymphoma cells, we found that increasing the resistance to hydrogen peroxide (H2O2) by catalase transfection or selection for H2O2 resistance caused glucocorticoid resistance. This suggests the possibility that increasing H2O2 sensitivity could sensitize the cells to glucocorticoids. In other cell types, increasing manganese superoxide dismutase (MnSOD) can increase intracellular H2O2. The current study showed that increased expression of MnSOD sensitized WEHI7.2 cells to glucocorticoid-induced apoptosis and H2O2. Treatment of WEHI7.2 cells with the catalytic antioxidant Mn(III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin (MnTE-2-PyP5+), a manganoporphyrin, mimicked the effects of increased MnSOD expression. MnTE-2-PyP5+ also sensitized WEHI7.2 cells to cyclophosphamide and inhibited cell growth; it had no effect on the WEHI7.2 cell response to doxorubicin or vincristine. In primary follicular lymphoma cells, MnTE-2-PyP5+ increased cell death due to dexamethasone. Treatment of H9c2 cardiomyocytes with MnTE-2-PyP5+ inhibited doxorubicin cytotoxicity. The profile of MnTE-2-PyP5+ effects suggests MnTE-2-PyP5+ has potential for use in hematologic malignancies that are treated with glucocorticoids, cyclophosphamide, and doxorubicin. [Cancer Res 2009;69(13):5450–7]
Data from Genetic Inactivation of ADAMTS15 Metalloprotease in Human Colorectal Cancer
Authors: Viloria Cristina G. , Obaya Alvaro J. , Moncada-Pazos Angela , Llamazares María , Astudillo Aurora , Capellá Gabriel , Cal Santiago , López-Otín Carlos
Published: March 2024

Abstract
Matrix metalloproteinases have been traditionally linked to cancer dissemination through their ability to degrade most extracellular matrix components, thus facilitating invasion and metastasis of tumor cells. However, recent functional studies have revealed that some metalloproteases, including several members of the ADAMTS family, also exhibit tumor suppressor properties. In particular, ADAMTS1, ADAMTS9, and ADAMTS18 have been found to be epigenetically silenced in malignant tumors of different sources, suggesting that they may function as tumor suppressor genes. Herein, we show that ADAMTS15 is genetically inactivated in colon cancer. We have performed a mutational analysis of the ADAMTS15 gene in human colorectal carcinomas, with the finding of four mutations in 50 primary tumors and 6 colorectal cancer cell lines. Moreover, functional in vitro and in vivo studies using HCT-116 and SW-620 colorectal cancer cells and severe combined immunodeficient mice have revealed that ADAMTS15 restrains tumor growth and invasion. Furthermore, the presence of ADAMTS15 in human colorectal cancer samples showed a negative correlation with the histopathologic differentiation grade of the corresponding tumors. Collectively, these results provide evidence that extracellular proteases, including ADAMTS15, may be targets of inactivating mutations in human cancer and further validate the concept that secreted metalloproteases may show tumor suppressor properties. [Cancer Res 2009;69(11):4926–34]
Data from Premenopausal Mammographic Density in Relation to Cyclic Variations in Endogenous Sex Hormone Levels, Prolactin, and Insulin-like Growth Factors
Authors: Walker Kate , Fletcher Olivia , Johnson Nichola , Coupland Ben , McCormack Valerie A. , Folkerd Elizabeth , Gibson Lorna , Hillier Stephen G. , Holly Jeff M. , Moss Sue , Dowsett Mitchell , Peto Julian , dos Santos Silva Isabel
Published: March 2024

Abstract
Mammographic density is strongly associated with breast cancer risk, and endogenous hormones, which are risk factors for breast cancer, may be involved in the mechanism. This cross-sectional study of 494 premenopausal women is the first to account for cyclic variations in estrogen levels, by measuring urinary estrone glucuronide (E1G) in the periovulatory and luteal phases of the menstrual cycle, and to assess the role of androgens. Computer-assisted density readings were obtained from digitized mammograms. Mean ovulatory E1G level and daily E1G load were both positively associated with percent density before adjustment for body mass index (BMI), with women in the top fourth having 10.2% (95% CI: 2.9%, 18.1%) and 8.9% (1.7%, 16.7%), respectively, higher density than those in the bottom fourth (Ptrend before/after BMI adjustment = 0.006/0.11 and 0.01/0.13, respectively). Neither the peak nor luteal E1G levels were predictive of density after adjustment for E1G levels at other points in the cycle. The plasma androgens testosterone, androstenedione, and dehydroepiandrosterone sulfate were negatively associated with density. In mutually adjusted analyses, density was positively associated with insulin-like growth factor (IGF)-I and negatively with IGF-II (Ptrend = 0.006 for both) but not with IGF binding protein-3. There was also weak evidence of a positive association of prolactin with density. The study supports the hypothesis that endogenous hormones affect density in premenopausal women; in particular, it shows a positive association between estrogen levels and density and suggests that the mean level throughout the cycle is the most biologically relevant measure. Most of these hormone-density associations were attenuated with further adjustment for BMI. [Cancer Res 2009;69(16):6490–99]
Data from Biochemical, Cellular, and In vivo Activity of Novel ATP-Competitive and Selective Inhibitors of the Mammalian Target of Rapamycin
Authors: Yu Ker , Toral-Barza Lourdes , Shi Celine , Zhang Wei-Guo , Lucas Judy , Shor Boris , Kim Jamie , Verheijen Jeroen , Curran Kevin , Malwitz David J. , Cole Derek C. , Ellingboe John , Ayral-Kaloustian Semiramis , Mansour Tarek S. , Gibbons James J. , Abraham Robert T. , Nowak Pawel , Zask Arie
Published: March 2024

Abstract
The mammalian target of rapamycin (mTOR) is centrally involved in cell growth, metabolism, and angiogenesis. While showing clinical efficacy in a subset of tumors, rapamycin and rapalogs are specific and allosteric inhibitors of mTOR complex 1 (mTORC1), but they do not directly inhibit mTOR complex 2 (mTORC2), an emerging player in cancer. Here, we report chemical structure and biological characterization of three pyrazolopyrimidine ATP-competitive mTOR inhibitors, WAY-600, WYE-687, and WYE-354 (IC50, 5–9 nmol/L), with significant selectivity over phosphatidylinositol 3-kinase (PI3K) isofoms (>100-fold). Unlike the rapalogs, these inhibitors acutely blocked substrate phosphorylation by mTORC1 and mTORC2 in vitro and in cells in response to growth factor, amino acids, and hyperactive PI3K/AKT. Unlike the inhibitors of PI3K or dual-pan PI3K/mTOR, cellular inhibition of P-S6K1(T389) and P-AKT(S473) by the pyrazolopyrimidines occurred at significantly lower inhibitor concentrations than those of P-AKT(T308) (PI3K-PDK1 readout), showing mTOR selectivity in cellular setting. mTOR kinase inhibitors reduced AKT downstream function and inhibited proliferation of diverse cancer cell lines. These effects correlated with a strong G1 cell cycle arrest in both the rapamycin-sensitive and rapamycin-resistant cells, selective induction of apoptosis, repression of global protein synthesis, and down-regulation of angiogenic factors. When injected into tumor-bearing mice, WYE-354 inhibited mTORC1 and mTORC2 and displayed robust antitumor activity in PTEN-null tumors. Together, our results highlight mechanistic differentiation between rapalogs and mTOR kinase inhibitors in targeting cancer cell growth and survival and provide support for clinical development of mTOR kinase inhibitors as new cancer therapy. [Cancer Res 2009;69(15):OF6232–9]
Data from Murine Gammaherpesvirus 68 Infection of IFNγ Unresponsive Mice: A Small Animal Model for Gammaherpesvirus-Associated B-Cell Lymphoproliferative Disease
Authors: Lee Katherine S. , Groshong Steve D. , Cool Carlyne D. , Kleinschmidt-DeMasters Bette K. , van Dyk Linda F.
Published: March 2024

Abstract
Gammaherpesviruses are tightly controlled by the host immune response, with gammaherpesvirus-associated malignancies prevalent in immune-suppressed individuals. Previously, infection of IFNγ-unresponsive mice with gammaherpesvirus 68 (γHV68) showed that IFNγ controlled chronic infection, limiting chronic diseases including arteritis and pulmonary fibrosis. Here, we show that γHV68-infected IFNγ receptor–deficient (IFNγR−/−) mice uniformly develop angiocentric inflammatory lesions in the lung. Prolonged infection revealed a range of outcomes, from spontaneous regression to pulmonary lymphoma. By 12 months of infection, 80% of mice had lymphoid hyperplasia or pulmonary lymphoma; 45% of infected mice developed frank tumors between 5 and 12 months postinfection, with some mice showing systemic involvement. Lymphomas were composed of B lymphocytes and contained latently infected cells. Although IFNγR−/− mice control chronic γHV68 infection poorly, both early and late pathologies were indistinguishable between wild-type and reactivation-defective virus infection, indicating that, in contrast with other previously described γHV68-associated pathologies, these chronic diseases were not dependent on the reactivation of latent infection. This distinct combination of latent infection and defined host defect led to a specific and consistent lymphoproliferative disease. Significantly, this mouse model of virus-associated pulmonary B-cell lymphoma closely mimics the full spectrum of human lymphomatoid granulomatosis, an EBV-associated malignancy with no effective treatment. [Cancer Res 2009;69(13):5481–9]
Data from Smad2 and Smad3 Phosphorylated at Both Linker and COOH-Terminal Regions Transmit Malignant TGF-β Signal in Later Stages of Human Colorectal Cancer
Authors: Matsuzaki Koichi , Kitano Chiaki , Murata Miki , Sekimoto Go , Yoshida Katsunori , Uemura Yoshiko , Seki Toshihito , Taketani Shigeru , Fujisawa Jun-ichi , Okazaki Kazuichi
Published: March 2024

Abstract
Transforming growth factor (TGF)-β initially inhibits growth of mature epithelial cells. Later, however, autocrine TGF-β signaling acts in concert with the Ras pathway to induce a proliferative and invasive phenotype. TGF-β activates not only TGF-β type I receptor (TβRI) but also Ras-associated kinases, which differentially phosphorylate the mediators Smad2 and Smad3 to create distinct phosphorylated forms: COOH-terminally phosphorylated Smad2/3 (pSmad2C and pSmad3C) and both linker and COOH-terminally phosphorylated Smad2/3 (pSmad2L/C and pSmad3L/C). In this study, we investigated actions of pSmad2L/C and pSmad3L/C in cancer progression. TGF-β inhibited cell growth by down-regulating c-Myc oncoprotein through the pSmad2C and pSmad3C pathway; TGF-β signaling, in turn, enhanced cell growth by up-regulating c-Myc through the cyclin-dependent kinase (CDK) 4–dependent pSmad2L/C and pSmad3L/C pathways in cell nuclei. Alternatively, TβRI and c-Jun NH2-terminal kinase (JNK) together created cytoplasmic pSmad2L/C, which entered the nucleus and stimulated cell invasion, partly by up-regulating matrix metalloproteinase-9. In 20 clinical samples, pSmad2L/C and pSmad3L/C showed nuclear localization at invasion fronts of all TGF-β–producing human metastatic colorectal cancers. In vitro kinase assay confirmed that nuclear CDK4 and cytoplasmic JNK obtained from the tumor tissue could phosphorylate Smad2 or Smad3 at their linker regions. We suggest that CDK4, together with JNK, alters tumor-suppressive TGF-β signaling to malignant characteristics in later stages of human colorectal cancer. The linker phosphorylation of Smad2 and Smad3 may represent a target for intervention in human metastatic cancer. [Cancer Res 2009;69(13):5321–30]
Data from Intracellular β-Tubulin/Chaperonin Containing TCP1-β Complex Serves as a Novel Chemotherapeutic Target against Drug-Resistant Tumors
Authors: Lin Yuan-Feng , Tsai Wen-Ping , Liu Hon-Ge , Liang Po-Huang
Published: March 2024

Abstract
In the present study, treatment of HEK-293 cells with the synthetic small molecule N-iodoacetyl-tryptophan (I-Trp) at submicromolar concentrations efficiently induced cell apoptosis as judged from the accumulation of sub-G0 cells and intracellular DNA fragmentation. Activation of all intracellular caspases, except caspase-1, was detected in I-Trp–treated cells. Proteomic analysis revealed that β-tubulin acted as a specific intracellular target of I-Trp. Protein fingerprinting analysis indicated that the Cys354 residue in the peptide fragment TAVCDIPPR of β-tubulin, which is located at the binding interface with chaperonin containing TCP1-β (CCT-β), was alkylated by I-Trp. Moreover, site-directed mutagenesis of Cys354 (Cys-Ala) abolished the incorporation of I-Trp into β-tubulin, suggesting Cys354 is indeed the targeting site of I-Trp. Immunoprecipitation showed that the β-tubulin/CCT-β complex was constitutively formed but disrupted after treatment with I-Trp. Overexpression of the truncated β-tubulin (T351-S364) or treatment with I-Trp or the synthetic peptide Myr-TAVCDIPPRG caused more severe cell apoptosis in multidrug-resistant MES-SA/Dx5 cancer cells due to higher levels of CCT-β relative to wild-type MES-SA cancer cells. Silencing the expression of CCT-β rendered MES-SA/Dx5 cells less sensitive to I-Trp–induced apoptotic cell death. These findings suggest that the β-tubulin/CCT-β complex may serve as an effective chemotherapeutic target for treating clinical tubulin-binding agent-resistant or CCT-β–overexpressing tumors. [Cancer Res 2009;69(17):6879–88]
Data from A Genetic Screen Identifies Topoisomerase 1 as a Regulator of Senescence
Authors: Humbert Nicolas , Martien Sébastien , Augert Arnaud , Da Costa Marco , Mauen Sébastien , Abbadie Corinne , de Launoit Yvan , Gil Jesús , Bernard David
Published: March 2024

Abstract
Normal cell growth can be permanently blocked when cells enter a state known as senescence. This phenomenon can be triggered by various stresses, such as replicative exhaustion, oncogenic stimulation, or oxidative stress. Senescence prevents transmission of aberrant signals to daughter cells and thus prevents irreversible damage that could favor cancer development. To identify new genetic events controlling senescence, we have performed a loss-of-function genetic screen on normal human cells. We report that knockdown of topoisomerase I (Top1) results in an increased replicative potential associated with a decrease in senescence markers and a diminished DNA damage response. In addition, Top1 depletion also favors a bypass of oncogene-induced senescence. Conversely, Top1 constitutive expression induces growth arrest, the appearance of a senescence marker, and an activation of the DNA damage response. Altogether, these results reveal an unanticipated function of Top1 in regulating senescence. [Cancer Res 2009;69(10):4101–6]
Data from In vitro and In vivo Activity of Novel Small-Molecule Inhibitors Targeting the Pleckstrin Homology Domain of Protein Kinase B/AKT
Authors: Moses Sylvestor A. , Ali M. Ahad , Zuohe Song , Du-Cuny Lei , Zhou Li Li , Lemos Robert , Ihle Nathan , Skillman A. Geoffrey , Zhang Shuxing , Mash Eugene A. , Powis Garth , Meuillet Emmanuelle J.
Published: March 2024

Abstract
The phosphatidylinositol 3-kinase/AKT signaling pathway plays a critical role in activating survival and antiapoptotic pathways within cancer cells. Several studies have shown that this pathway is constitutively activated in many different cancer types. The goal of this study was to discover novel compounds that bind to the pleckstrin homology (PH) domain of AKT, thereby inhibiting AKT activation. Using proprietary docking software, 22 potential PH domain inhibitors were identified. Surface plasmon resonance spectroscopy was used to measure the binding of the compounds to the expressed PH domain of AKT followed by an in vitro activity screen in Panc-1 and MiaPaCa-2 pancreatic cancer cell lines. We identified a novel chemical scaffold in several of the compounds that binds selectively to the PH domain of AKT, inducing a decrease in AKT activation and causing apoptosis at low micromolar concentrations. Structural modifications of the scaffold led to compounds with enhanced inhibitory activity in cells. One compound, 4-dodecyl-N-(1,3,4-thiadiazol-2-yl)benzenesulfonamide, inhibited AKT and its downstream targets in cells as well as in pancreatic cancer cell xenografts in immunocompromised mice; it also exhibited good antitumor activity. In summary, a pharmacophore for PH domain inhibitors targeting AKT function was developed. Computer-aided modeling, synthesis, and testing produced novel AKT PH domain inhibitors that exhibit promising preclinical properties. [Cancer Res 2009;69(12):5073–81]
Data from Genome-Wide Linkage Analysis of TMPRSS2-ERG Fusion in Familial Prostate Cancer
Authors: Hofer Matthias D. , Kuefer Rainer , Maier Christiane , Herkommer Kathleen , Perner Sven , Demichelis Francesca , Paiss Thomas , Vogel Walter , Rubin Mark A. , Hoegel Josef
Published: March 2024

Abstract
Fusion of the 5′-untranslated region of androgen-regulated TMPRSS2 promoter with ETS transcription factor family members is found frequently in prostate cancers, and recent work suggests that the most common TMPRSS2-ERG fusion is associated with an aggressive clinical phenotype compared with fusion-negative prostate cancer. Thus far, analysis of the fusion has been limited to sporadic cases of prostate cancer. In the current study, we explore for an enrichment of TMPRSS2-ERG fusion in familial prostate cancer. TMPRSS2-ERG fusion was identified using a break-apart fluorescence in situ hybridization assay on tissue microarrays. Presence of TMPRSS2-ERG fusion was associated with higher Gleason scores (P = 0.027). Of 75 patients with established history of prostate cancer, we detected the TMPRSS2-ERG fusion in 44 (59%) patients. Almost three quarters (73%) of fusion-positive patients accumulated within 16 specific families whereas only 27% were single fusion-positive cases within one family. Based on reported prevalence rates, we calculated a sibling recurrence risk ratio of up to 18.9. A subset (63%) of families with uniformly TMPRSS2-ERG–positive prostate cancer underwent a genome-wide linkage scan at 500 markers. This revealed several loci located on chromosomes #9, #18, and X that were suggestive of linkage to the TMPRSS2-ERG fusion-positive prostate cancer phenotype with linkage-of-disease scores up to 2.16 and nonparametric linkage scores up to 2.77. This suggests the presence of an inherited susceptibility to developing the TMPRSS2-ERG fusion. Given the association of TMPRSS2-ERG fusion and aggressive prostate cancer, close surveillance of relatives of patients with established fusion-positive prostate cancer or a family history of prostate cancer in general would be warranted. [Cancer Res 2009;69(4):640–6]
Data from Cetuximab/C225-Induced Intracellular Trafficking of Epidermal Growth Factor Receptor
Authors: Liao Hong-Jun , Carpenter Graham
Published: March 2024

Abstract
The monoclonal antibody C225 interacts with the ectodomain of the epidermal growth factor (EGF) receptor (EGFR) to block ligand binding and initiates receptor endocytosis and intracellular trafficking. The data herein show that C225-dependent EGFR trafficking relocalizes the receptor to the endoplasmic reticulum (ER) and nucleus. This mechanism, which also involves interaction of the C225-internalized receptor with the Sec61 translocon within the ER, is, in most respects, analogous to the pathway previously described for EGF-induced trafficking to the ER and nucleus. However, although inhibition of receptor tyrosine kinase activity blocks EGF-induced nuclear localization of the receptor, the same kinase inhibitors stimulate C225-dependent nuclear localization of EGFR in the nucleus. In contrast, the kinase inhibitor Lapatinib fails to stimulate nuclear accumulation of the receptor in C225-treated cells and does not provoke receptor dimerization as do inhibitors that recognize the open conformation of the receptor kinase. This suggests that inhibitor-dependent receptor dimerization may facilitate C225-induced receptor trafficking. [Cancer Res 2009;69(15):6179–83]
Data from Functional Significance of Secreted Frizzled-Related Protein 1 in Metastatic Renal Cell Carcinomas
Authors: Saini Sharanjot , Liu Jan , Yamamura Soichiro , Majid Shahana , Kawakami Kazumori , Hirata Hiroshi , Dahiya Rajvir
Published: March 2024

Abstract
The secreted Frizzled-related protein 1 (SFRP1) is a Wingless-type (Wnt) antagonist that has been associated with various malignancies, including renal cell carcinomas (RCC). However, the functional significance of SFRP1 has never been investigated in metastatic RCC. Here, we investigated the role of this molecule in kidney cancer progression and metastasis. Using Wnt pathway-focused cDNA expression profiling in normal renal, primary RCC, and metastatic RCC cell lines, we identified that SFRP1 is up-regulated in metastatic RCC. SFRP1 overexpression in metastatic RCC was confirmed by immunostaining in renal tissues. We explored the molecular mechanisms underlying SFRP1 up-regulation by analyzing DNA methylation and histone modification patterns on SFRP1 promoter. We found that this gene is unmethylated/hypomethylated and enriched in activating histone modifications in metastatic RCC. To understand the functional significance of SFRP1 overexpression in metastatic RCC with regard to tumorigenesis, we used a small interfering RNA–mediated approach to knockdown the gene and monitored cellular proliferation, apoptosis, and metastatic behavior. Proliferation was unaltered and apoptosis increased on attenuation of SFRP1 expression. Also, SFRP1 depletion decreased the invasive potential of the metastatic RCC cell line, suggesting that the overexpression of this Wnt antagonist may be related to invasiveness and metastatic behavior in RCC. We investigated the molecular basis of the role of SFRP1 in invasion and metastasis and found that matrix metalloproteinase MMP10 is regulated by SFRP1. In conclusion, our data suggest that SFRP1 plays a role in the metastatic potential of RCC. The present findings may be important in the design of treatment modalities for metastatic RCC. [Cancer Res 2009;69(17):6815–22]