bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Oncogenic Wip1 Phosphatase Is Inhibited by miR-16 in the DNA Damage Signaling Pathway
Authors: Zhang Xinna , Wan Guohui , Mlotshwa Sizolwenkosi , Vance Vicki , Berger Franklin G. , Chen Hexin , Lu Xiongbin
Published: March 2024

Abstract
Wild-type p53-induced phosphatase 1 (Wip1) was identified as an oncogene amplified and overexpressed in several human cancers. Recent evidence suggested that Wip1 is a critical inhibitor in the ATM/ATR-p53 DNA damage signaling pathway. Wip1 dephosphorylates several key DNA damage–responsive proteins and reverses DNA damage–induced cell cycle checkpoints. Previous reports showed that Wip1 was transcriptionally induced by p53 at the early stage of the DNA damage response. To investigate the temporal and functional regulation of Wip1, we identified a microRNA, miR-16, that specifically targets the mRNA of Wip1 and thus negatively regulates the expression level of Wip1. miR-16 itself is induced immediately after DNA damage. Therefore, the increase in Wip1 protein level is significantly postponed compared with that of its mRNA level, preventing a premature inactivation of ATM/ATR signaling and allowing a functional completion of the early DNA damage response. To better understand miR-16 biological functions in the context of cancer cells, we examined its expression in mammary tumor stem cells and found it to be markedly downregulated in mammary tumor stem cells. Overexpression of miR-16 or inhibition of Wip1 suppresses the self-renewal and growth of mouse mammary tumor stem cells and sensitizes MCF-7 human breast cancer cells to the chemotherapeutic drug doxorubicin. Together, our results suggest an important role of miR-16 in the regulation of Wip1 phosphatase in the DNA damage response and mammary tumorigenesis. Cancer Res; 70(18); 7176–86. ©2010 AACR.
Data from A Galectin-3 Ligand Corrects the Impaired Function of Human CD4 and CD8 Tumor-Infiltrating Lymphocytes and Favors Tumor Rejection in Mice
Authors: Demotte Nathalie , Wieërs Grégoire , Van Der Smissen Patrick , Moser Muriel , Schmidt Christopher , Thielemans Kris , Squifflet Jean-Luc , Weynand Birgit , Carrasco Javier , Lurquin Christophe , Courtoy Pierre J. , van der Bruggen Pierre
Published: March 2024

Abstract
Human CD8+ tumor-infiltrating T lymphocytes (TIL), in contrast with CD8+ blood cells, show impaired IFN-γ secretion on ex vivo restimulation. We have attributed the impaired IFN-γ secretion to a decreased mobility of T-cell receptors on trapping in a lattice of glycoproteins clustered by extracellular galectin-3. Indeed, we have previously shown that treatment with N-acetyllactosamine, a galectin ligand, restored this secretion. We strengthened this hypothesis here by showing that CD8+ TIL treated with an anti–galectin-3 antibody had an increased IFN-γ secretion. Moreover, we found that GCS-100, a polysaccharide in clinical development, detached galectin-3 from TIL and boosted cytotoxicity and secretion of different cytokines. Importantly, we observed that not only CD8+ TIL but also CD4+ TIL treated with GCS-100 secreted more IFN-γ on ex vivo restimulation. In tumor-bearing mice vaccinated with a tumor antigen, injections of GCS-100 led to tumor rejection in half of the mice, whereas all control mice died. In nonvaccinated mice, GCS-100 had no effect by itself. These results suggest that a combination of galectin-3 ligands and therapeutic vaccination may induce more tumor regressions in cancer patients than vaccination alone. Cancer Res; 70(19); 7476–88. ©2010 AACR.
Data from Regulation of Insulin-like Growth Factor–Mammalian Target of Rapamycin Signaling by MicroRNA in Childhood Adrenocortical Tumors
Authors: Doghman Mabrouka , Wakil Abeer El , Cardinaud Bruno , Thomas Emilie , Wang Jinling , Zhao Wei , Peralta-Del Valle Maria Helena C. , Figueiredo Bonald C. , Zambetti Gerard P. , Lalli Enzo
Published: March 2024

Abstract
MicroRNAs (miRNAs) act at the posttranscriptional level to control gene expression in virtually every biological process, including oncogenesis. Here, we report the identification of a set of miRNAs that are differentially regulated in childhood adrenocortical tumors (ACT), including miR-99a and miR-100. Functional analysis of these miRNAs in ACT cell lines showed that they coordinately regulate expression of the insulin-like growth factor–mammalian target of rapamycin (mTOR)–raptor signaling pathway through binding sites in their 3′-untranslated regions. In these cells, the active Ser2448-phosphorylated form of mTOR is present only in mitotic cells in association with the mitotic spindle and midbody in the G2-M phases of the cell cycle. Pharmacologic inhibition of mTOR signaling by everolimus greatly reduces tumor cell growth in vitro and in vivo. Our results reveal a novel mechanism of regulation of mTOR signaling by miRNAs, and they lay the groundwork for clinical evaluation of drugs inhibiting the mTOR pathway for treatment of adrenocortical cancer. Cancer Res; 70(11); 4666–75. ©2010 AACR.
Data from PERK–Dependent Regulation of Ceramide Synthase 6 and Thioredoxin Play a Key Role in mda-7/IL-24–Induced Killing of Primary Human Glioblastoma Multiforme Cells
Authors: Yacoub Adly , Hamed Hossein A. , Allegood Jeremy , Mitchell Clint , Spiegel Sarah , Lesniak Maciej S. , Ogretmen Besim , Dash Rupesh , Sarkar Devanand , Broaddus William C. , Grant Steven , Curiel David T. , Fisher Paul B. , Dent Paul
Published: March 2024

Abstract
Melanoma differentiation associated gene-7(mda-7) encodes IL-24, a cytokine that can selectively trigger apoptosis in transformed cells. Recombinant mda-7 adenovirus (Ad.mda-7) effectively kills glioma cells, offering a novel gene therapy strategy to address deadly brain tumors. In this study, we defined the proximal mechanisms by which Ad-mda-7 kills glioma cells. Key factors implicated included activation of the endoplasmic reticulum stress kinase protein kinase R–like endoplasmic reticulum kinase (PERK), Ca++ elevation, ceramide generation and reactive oxygen species (ROS) production. PERK inhibition blocked ceramide or dihydroceramide generation, which were critical for Ca++ induction and subsequent ROS formation. Activation of autophagy and cell death relied upon ROS formation, the inhibition of which ablated Ad.mda-7–killing activity. In contrast, inhibiting TRX induced by Ad.MDA-7 enhanced tumor cytotoxicity and improved animal survival in an orthotopic tumor model. Our findings indicate that mda-7/IL-24 induces an endoplasmic reticulum stress response that triggers production of ceramide, Ca2+, and ROS, which in turn promote glioma cell autophagy and cell death. Cancer Res; 70(3); 1120–9
Data from Active Immunotherapy Induces Antibody Responses That Target Tumor Angiogenesis
Authors: Schoenfeld Jonathan , Jinushi Masahisa , Nakazaki Yukoh , Wiener Daniel , Park Joosang , Soiffer Robert , Neuberg Donna , Mihm Martin , Hodi F. Stephen , Dranoff Glenn
Published: March 2024

Abstract
The inhibition of VEGF signaling with antibodies or small molecules achieves clinical benefits in diverse solid malignancies. Nonetheless, therapeutic effects are usually not sustained, and most patients eventually succumb to progressive disease, indicating that antiangiogenic strategies require additional optimization. Vaccination with lethally irradiated, autologous tumor cells engineered to secrete granulocyte‐macrophage colony stimulating factor (GM-CSF) and antibody blockade of cytotoxic T lymphocyte–associated antigen-4 (CTLA-4) trigger a tumor vasculopathy in some long-term responding subjects. These reactions are characterized by disrupted tumor blood vessels in association with lymphocyte and granulocyte infiltrates and zonal areas of ischemic tumor necrosis. However, the mechanisms underlying this immune-mediated destruction of the tumor vasculature remain to be clarified. Here, we show that GM-CSF–secreting tumor cell vaccines and CTLA-4 blockade elicit a functionally important humoral reaction against multiple angiogenic cytokines. Antibodies to angiopoietin-1 and angiopoietin-2 block Tie-2 binding, downstream signaling, endothelial cell tube formation, and macrophage chemotaxis. Antibodies to macrophage inhibitory factor (MIF) attenuate macrophage Tie-2 expression and matrix metalloproteinase-9 (MMP-9) production. Together, these results delineate an immunotherapy-induced host response that broadly targets the angiogenic network in the tumor microenvironment. Cancer Res; 70(24); 10150–60. ©2010 AACR.
Data from Ionizing Radiation Activates the Nrf2 Antioxidant Response
Authors: McDonald J. Tyson , Kim Kwanghee , Norris Andrew J. , Vlashi Erina , Phillips Tiffany M. , Lagadec Chann , Della Donna Lorenza , Ratikan Josephine , Szelag Heather , Hlatky Lynn , McBride William H.
Published: March 2024

Abstract
The transcription factor NF-E2-related factor 2 (Nrf2) binds the antioxidant DNA response element (ARE) to activate important cellular cytoprotective defense systems. Recently several types of cancers have been shown to overexpress Nrf2, but its role in the cellular response to radiation therapy has yet to be fully determined. In this study, we report that single doses of ionizing radiation from 2 to 8 Gy activate ARE-dependent transcription in breast cancer cells in a dose-dependent manner, but only after a delay of five days. Clinically relevant daily dose fractions of radiation also increased ARE-dependent transcription, but again only after five days. Downstream activation of Nrf2-ARE-dependent gene and protein markers, such as heme oxygenase-1, occurred, whereas Nrf2-deficient fibroblasts were incapable of these responses. Compared with wild-type fibroblasts, Nrf2-deficient fibroblasts had relatively high basal levels of reactive oxygen species that increased greatly five days after radiation exposure. Further, in vitro clonogenic survival assays and in vivo sublethal whole body irradiation tests showed that Nrf2 deletion increased radiation sensitivity, whereas Nrf2-inducing drugs did not increase radioresistance. Our results indicate that the Nrf2-ARE pathway is important to maintain resistance to irradiation, but that it operates as a second-tier antioxidant adaptive response system activated by radiation only under specific circumstances, including those that may be highly relevant to tumor response during standard clinical dose-fractionated radiation therapy. Cancer Res; 70(21); 8886–95. ©2010 AACR.
Data from The Phosphoinositide 3-Kinase Regulatory Subunit p85α Can Exert Tumor Suppressor Properties through Negative Regulation of Growth Factor Signaling
Authors: Taniguchi Cullen M. , Winnay Jonathon , Kondo Tatsuya , Bronson Roderick T. , Guimaraes Alexander R. , Alemán José O. , Luo Ji , Stephanopoulos Gregory , Weissleder Ralph , Cantley Lewis C. , Kahn C. Ronald
Published: March 2024

Abstract
Phosphoinositide 3-kinase (PI3K) plays a critical role in tumorigenesis, and the PI3K p85 regulatory subunit exerts both positive and negative effects on signaling. Expression of Pik3r1, the gene encoding p85, is decreased in human prostate, lung, ovarian, bladder, and liver cancers, consistent with the possibility that p85 has tumor suppressor properties. We tested this hypothesis by studying mice with a liver-specific deletion of the Pik3r1 gene. These mice exhibited enhanced insulin and growth factor signaling and progressive changes in hepatic pathology, leading to the development of aggressive hepatocellular carcinomas with pulmonary metastases. Liver tumors that arose exhibited markedly elevated levels of phosphatidylinositol (3,4,5)-trisphosphate, along with Akt activation and decreased PTEN expression, at both the mRNA and protein levels. Together, these results substantiate the concept that the p85 subunit of PI3K has a tumor-suppressive role in the liver and possibly other tissues. Cancer Res; 70(13); 5305–15. ©2010 AACR.
Data from Optical Detection of Buccal Epithelial Nanoarchitectural Alterations in Patients Harboring Lung Cancer: Implications for Screening
Authors: Roy Hemant K. , Subramanian Hariharan , Damania Dhwanil , Hensing Thomas A. , Rom William N. , Pass Harvey I. , Ray Daniel , Rogers Jeremy D. , Bogojevic Andrej , Shah Maitri , Kuzniar Tomasz , Pradhan Prabhakar , Backman Vadim
Published: March 2024

Abstract
We have recently developed a novel optical technology, partial wave spectroscopic (PWS) microscopy, which is exquisitely sensitive to the nanoarchitectural manifestation of the genetic/epigenetic alterations of field carcinogenesis. Our approach was to screen for lung cancer by assessing the cheek cells based on emerging genetic/epigenetic data which suggests that the buccal epithelium is altered in lung field carcinogenesis. We performed PWS analysis from microscopically normal buccal epithelial brushings from smokers with and without lung cancer (n = 135). The PWS parameter, disorder strength of cell nanoarchitecture (Ld), was markedly (>50%) elevated in patients harboring lung cancer compared with neoplasia-free smokers. The performance characteristic was excellent with an area under the receiver operator characteristic curve of >0.80 and was equivalent for both disease stage (early versus late) and histologies (small cell versus non–small cell lung cancers). An independent data set validated the findings with only a minimal degradation of performance characteristics. Our results offer proof of concept that buccal PWS may potentially herald a minimally intrusive prescreening test that could be integral to the success of lung cancer population screening programs. Cancer Res; 70(20); 7748–54. ©2010 AACR.
Data from Intrinsic Cooperation between p16INK4a and p21Waf1/Cip1 in the Onset of Cellular Senescence and Tumor Suppression In vivo
Authors: Takeuchi Shinji , Takahashi Akiko , Motoi Noriko , Yoshimoto Shin , Tajima Tomoko , Yamakoshi Kimi , Hirao Atsushi , Yanagi Shigeru , Fukami Kiyoko , Ishikawa Yuichi , Sone Saburo , Hara Eiji , Ohtani Naoko
Published: March 2024

Abstract
Although the p16INK4a and p21Waf1/Cip1 cyclin-dependent kinase (CDK) inhibitors are known to play key roles in cellular senescence in vitro, their roles in senescence remain rather poorly understood in vivo. This situation is partly due to the possibility of compensatory effect(s) between p16INK4a and p21Waf1/Cip1 or to the upregulation of functionally related CDK inhibitors. To directly address the cooperative roles of p16INK4a and p21Waf1/Cip1 in senescence in vivo, we generated a mouse line simply lacking both p16INK4a and p21Waf1/Cip1 genes [double-knockout (DKO)]. Mouse embryonic fibroblasts (MEF) derived from DKO mice displayed no evidence of cellular senescence when cultured serially in vitro. Moreover, DKO MEFs readily escaped Ras-induced senescence and overrode contact inhibition in culture. This was not the case in MEFs lacking either p16INK4a or p21Waf1/Cip1, indicating that p16INK4a and p21Waf1/Cip1 play cooperative roles in cellular senescence and contact inhibition in vitro. Notably, we found the DKO mice to be extremely susceptible to 7,12-dimethylbenz(a)anthracene/12-O-tetradecanoylphorbol-13-acetate–induced skin carcinogenesis that involves oncogenic mutation of the H-ras gene. Mechanistic investigations suggested that the high incidence of cancer in DKO mice likely reflected a cooperative effect of increased benign skin tumor formation caused by p21Waf1/Cip1 loss, with increased malignant conversion of benign skin tumors caused by p16INK4a loss. Our findings establish an intrinsic cooperation between p16INK4a and p21Waf1/Cip1 in the onset of cellular senescence and tumor suppression in vivo. Cancer Res; 70(22); 9381–90. ©2010 AACR.
Data from Regulation of Breast Cancer Stem Cell Activity by Signaling through the Notch4 Receptor
Authors: Harrison Hannah , Farnie Gillian , Howell Sacha J. , Rock Rebecca E. , Stylianou Spyros , Brennan Keith R. , Bundred Nigel J. , Clarke Robert B.
Published: March 2024

Abstract
Notch receptor signaling pathways play an important role not only in normal breast development but also in breast cancer development and progression. We assessed the role of Notch receptors in stem cell activity in breast cancer cell lines and nine primary human tumor samples. Stem cells were enriched by selection of anoikis-resistant cells or cells expressing the membrane phenotype ESA+/CD44+/CD24low. Using these breast cancer stem cell populations, we compared the activation status of Notch receptors with the status in luminally differentiated cells, and we evaluated the consequences of pathway inhibition in vitro and in vivo. We found that Notch4 signaling activity was 8-fold higher in stem cell–enriched cell populations compared with differentiated cells, whereas Notch1 signaling activity was 4-fold lower in the stem cell–enriched cell populations. Pharmacologic or genetic inhibition of Notch1 or Notch4 reduced stem cell activity in vitro and reduced tumor formation in vivo, but Notch4 inhibition produced a more robust effect with a complete inhibition of tumor initiation observed. Our findings suggest that Notch4-targeted therapies will be more effective than targeting Notch1 in suppressing breast cancer recurrence, as it is initiated by breast cancer stem cells. Cancer Res; 70(2); 709–18
Data from Hyaluronan Deficiency in Tumor Stroma Impairs Macrophage Trafficking and Tumor Neovascularization
Authors: Kobayashi Nobutaka , Miyoshi Seiji , Mikami Takahide , Koyama Hiroshi , Kitazawa Masato , Takeoka Michiko , Sano Kenji , Amano Jun , Isogai Zenzo , Niida Shumpei , Oguri Kayoko , Okayama Minoru , McDonald John A. , Kimata Koji , Taniguchi Shun'ichiro , Itano Naoki
Published: March 2024

Abstract
Despite the importance of stromal cells in tumor progression, our overall understanding of the molecular signals that regulate the complex cellular interactions within tumor stroma is limited. Here, we provide multiple lines of evidence that tumor-associated macrophages (TAM) preferentially traffic to stromal areas formed within tumors in a manner dependent on a hyaluronan (HA)–rich tumor microenvironment. To address the role of stroma-derived HA in macrophage recruitment, we disrupted the HA synthase 2 (Has2) gene in stromal fibroblasts using conditional gene targeting. The Has2 null fibroblasts showed severe impairment in recruiting macrophages when inoculated with tumor cells into nude mice, which shows the contribution of stroma-derived HA in intratumoral macrophage mobilization. Furthermore, a deficiency in stromal HA attenuated tumor angiogenesis and lymphangiogenesis concomitantly with impaired macrophage recruitment. Taken together, our results suggest that stromal HA serves as a microenvironmental signal for the recruitment of TAMs, which are key regulatory cells involved in tumor neovascularization. Cancer Res; 70(18); 7073–83. ©2010 AACR.
Data from Tubulin-Targeting Chemotherapy Impairs Androgen Receptor Activity in Prostate Cancer
Authors: Zhu Meng-Lei , Horbinski Craig M. , Garzotto Mark , Qian David Z. , Beer Tomasz M. , Kyprianou Natasha
Published: March 2024

Abstract
Recent insights into the regulation of the androgen receptor (AR) activity led to novel therapeutic targeting of AR function in prostate cancer patients. Docetaxel is an approved chemotherapy for treatment of castration-resistant prostate cancer; however, the mechanism underlying the action of this tubulin-targeting drug is not fully understood. This study investigates the contribution of microtubules and the cytoskeleton to androgen-mediated signaling and the consequences of their inhibition on AR activity in human prostate cancer. Tissue microarrays from docetaxel-treated and untreated prostate cancer patients were comparatively analyzed for prostate-specific antigen (PSA) and AR immunoreactivity. The AR transcriptional activity was determined in prostate cancer cells in vitro, based on PSA mRNA expression and the androgen response element reporter activity. The interaction of AR with tubulin was examined by immunoprecipitation and immunofluorescence. Treatment of prostate cancer patients with docetaxel led to a significant translocation of AR. In untreated specimens, 50% prostate tumor cells exhibited nuclear accumulation of AR, compared with docetaxel-treated tumors that had significantly depleted nuclear AR (38%), paralleled by an increase in cytosolic AR. AR nuclear localization correlated with PSA expression. In vitro, exposure of prostate cancer cells to paclitaxel (1 μmol/L) or nocodazole (5 μg/mL) inhibited androgen-dependent AR nuclear translocation by targeting AR association with tubulin. Introduction of a truncated AR indicated the requirement of the NH2-terminal domain for AR-tubulin interaction. Our findings show that in addition to blocking cell division, docetaxel impairs AR signaling, evidence that enables new insights into the therapeutic efficacy of microtubule-targeting drugs in prostate cancer. Cancer Res; 70(20); 7992–8002. ©2010 AACR.
Data from Loss of FOXA1/2 Is Essential for the Epithelial-to-Mesenchymal Transition in Pancreatic Cancer
Authors: Song Yan , Washington M. Kay , Crawford Howard C.
Published: March 2024

Abstract
FOXA1 and FOXA2, members of the forkhead transcription factor family, are critical for epithelial differentiation in many endoderm-derived organs, including the pancreas. However, their role in tumor progression is largely unknown. Here, we identified FOXA1 and FOXA2 as important antagonists of the epithelial-to-mesenchymal transition (EMT) in pancreatic ductal adenocarcinoma (PDA) through their positive regulation of E-cadherin and maintenance of the epithelial phenotype. In human PDA samples, FOXA1/2 are expressed in all epithelia from normal to well-differentiated cancer cells, but are lost in undifferentiated cancer cells. In PDA cell lines, FOXA1/2 expression is consistently suppressed in experimental EMT models and RNAi silencing of FOXA1/2 alone is sufficient to induce EMT. Conversely, ectopic FOXA1/2 expression can potently neutralize several EMT-related E-cadherin repressive mechanisms. Finally, ectopic FOXA2 expression could reactivate E-cadherin expression in a PDA cell line with extensive promoter hypermethylation. In fact, demethylation-mediated reactivation of E-cadherin expression in these cells required concurrent reactivation of endogenous FOXA2 expression. We conclude that suppression of FOXA1/2 expression is both necessary and sufficient for EMT during PDA malignant progression. Cancer Res; 70(5); 2115–25
Data from Inhibition of ADP Ribosylation Prevents and Cures Helicobacter-Induced Gastric Preneoplasia
Authors: Toller Isabella M. , Altmeyer Matthias , Kohler Esther , Hottiger Michael O. , Müller Anne
Published: March 2024

Abstract
Gastric adenocarcinoma develops as a consequence of chronic inflammation of the stomach lining that is caused by persistent infection with the bacterium Helicobacter pylori. Gastric carcinogenesis progresses through a sequence of preneoplastic lesions that manifest histologically as atrophic gastritis, intestinal metaplasia, and dysplasia. We show here in several preclinical models of Helicobacter-induced atrophic gastritis, epithelial hyperplasia, and metaplasia that the inhibition of ADP ribosylation by the small-molecule inhibitor PJ34 not only prevents the formation of gastric cancer precursor lesions, but also efficiently reverses preexisting lesions. PJ34 exerts its chemopreventive and therapeutic effects by impairing Helicobacter-specific T-cell priming and TH1 polarization in the gut-draining mesenteric lymph nodes. The subsequent infiltration of pathogenic T cells into the gastric mucosa and the ensuing gastric T cell–driven immunopathology are prevented efficiently by PJ34. Our data indicate that PJ34 directly suppresses T-cell effector functions by blocking the IFN-γ production of mesenteric lymph node T cells ex vivo. Upon exposure to PJ34, purified T cells failed to synthesize ADP-ribose polymers and to activate the transcription of genes encoding IFN-γ, interleukin 2, and the interleukin 2 receptor α chain in response to stimuli such as CD3/CD28 cross-linking or phorbol 12-myristate 13-acetate/ionomycin. The immunosuppressive and chemoprotective effects of PJ34 therefore result from impaired T-cell activation and TH1 polarization, and lead to the protection from preneoplastic gastric immunopathology. In conclusion, ADP-ribosylating enzymes constitute novel targets for the treatment of Helicobacter-associated gastric lesions predisposing infected individuals to gastric cancer and may also hold promise for the treatment of other T cell–driven chronic inflammatory conditions and autoimmune pathologies. Cancer Res; 70(14); 5912–22. ©2010 AACR.
Data from ETS-1 Oncogenic Activity Mediated by Transforming Growth Factor α
Authors: Holterman Chet E. , Franovic Aleksandra , Payette Josianne , Lee Stephen
Published: March 2024

Abstract
Inappropriate expression of Ets-1 is observed in a variety of human cancers, and its forced expression in cultured cells results in transformation, autonomous proliferation, and tumor formation. The basis by which Ets-1 confers autonomous growth, one of the primary hallmarks of cancer cells and a critical component of persistent proliferation, has yet to be fully explained. Using a variety of cancer cell lines, we show that inhibition of Ets-1 blocks tumor formation and cell proliferation in vivo and autonomous growth in culture. A screen of multiple diffusible growth factors revealed that inhibition of Ets-1 results in the specific downregulation of transforming growth factor α (TGFα), the proximal promoter region of which contains multiple ETS family DNA binding sites that can be directly bound and regulated by Ets-1. Notably, rescuing TGFα expression in Ets-1–silenced cells was sufficient to restore tumor cell proliferation in vivo and autonomous growth in culture. These results reveal a previously unrecognized mechanism by which Ets-1 oncogenic activity can be explained in human cancer through its ability to regulate the important cellular mitogen TGFα. Cancer Res; 70(2); 730–40
Data from Interaction with Vascular Endothelium Enhances Survival in Primary Chronic Lymphocytic Leukemia Cells via NF-κB Activation and De novo Gene Transcription
Authors: Buggins Andrea G.S. , Pepper Chris , Patten Piers E.M. , Hewamana Saman , Gohil Satyen , Moorhead Jane , Folarin Najeem'deen , Yallop Deborah , Thomas N. Shaun B. , Mufti Ghulam J. , Fegan Chris , Devereux Stephen
Published: March 2024

Abstract
Chronic lymphocytic leukemia (CLL) cells rapidly undergo apoptosis in vitro, suggesting that the in vivo microenvironment provides crucial antiapoptotic signals. Overexpression of the antiapoptotic proteins Bcl-2 and Mcl-1 is a hallmark of CLL, and their expression is further enhanced in the lymphoid tissues. However, the high levels of Mcl-1 found in peripheral blood samples, coupled with its short half-life, led us to hypothesize that it must be actively maintained in the peripheral circulation. Coculture of CLL cells with human vascular endothelial cells significantly enhanced tumor cell survival, an effect that was not observed with normal B cells. This was associated with elevated levels of the antiapoptotic proteins Bcl-2, Mcl-1, and Bcl-XL and marked increased expression of CD38 and CD49d, both of which are associated with clinically aggressive disease. Because CD38, CD49d, and some Bcl-2 family genes are transcriptional targets for NF-κB, we assessed NF-κB activation following coculture with endothelial cells. DNA binding of the NF-κB subunit Rel A was significantly increased and strongly correlated with changes in transcription of CD38, CD49d, BCL2, MCL1, and BCLXL, effects that were reversed by a peptide inhibitor of Rel A. These effects were not observed following coculture with nonendothelial cell lines. Therefore, CLL cells receive specific survival signals following interaction with endothelial cells mediated through the activation of NF-κB and the induction of downstream target genes. This type of interaction in the peripheral vasculature may explain the constitutive NF-κB activation and the overexpression of Bcl-2 family proteins commonly seen in this disease. Cancer Res; 70(19); 7523–33. ©2010 AACR.
Data from Improved Clinical Outcome in Indolent B-Cell Lymphoma Patients Vaccinated with Autologous Tumor Cells Experiencing Immunogenic Death
Authors: Zappasodi Roberta , Pupa Serenella M. , Ghedini Gaia C. , Bongarzone Italia , Magni Michele , Cabras Antonello D. , Colombo Mario P. , Carlo-Stella Carmelo , Gianni Alessandro M. , Di Nicola Massimo
Published: March 2024

Abstract
Increasing evidence argues that the success of an anticancer treatment may rely on immunoadjuvant side effects including the induction of immunogenic tumor cell death. Based on the assumption that this death mechanism is a similar prerequisite for the efficacy of an active immunotherapy using killed tumor cells, we examined a vaccination strategy using dendritic cells (DC) loaded with apoptotic and necrotic cell bodies derived from autologous tumors. Using this approach, clinical and immunologic responses were achieved in 6 of 18 patients with relapsed indolent non–Hodgkin's lymphoma (NHL). The present report illustrates an impaired ability of the neoplastic cells used to vaccinate nonresponders to undergo immunogenic death on exposure to a cell death protocol based on heat shock, γ-ray, and UVC ray. Interestingly, when compared with doxorubicin, this treatment increased surface translocation of calreticulin and cellular release of high-mobility group box 1 and ATP in histologically distinct NHL cell lines. In contrast, treated lymphoma cells from responders displayed higher amounts of calreticulin and heat shock protein 90 (HSP90) compared with those from nonresponders and boosted the production of specific antibodies when loaded into DCs for vaccination. Accordingly, the extent of calreticulin and HSP90 surface expression in the DC antigenic cargo was significantly associated with the clinical and immunologic responses achieved. Our results indicate that a positive clinical effect is obtained when immunogenically killed autologous neoplastic cells are used for the generation of a DC-based vaccine. Therapeutic improvements may thus be accomplished by circumventing the tumor-impaired ability to undergo immunogenic death and prime the antitumor immune response. Cancer Res; 70(22); 9062–72. ©2010 AACR.
Data from Cutaneous Papillomavirus E6 Proteins Must Interact with p300 and Block p53-Mediated Apoptosis for Cellular Immortalization and Tumorigenesis
Authors: Muench Peter , Probst Sonja , Schuetz Johanna , Leiprecht Natalie , Busch Martin , Wesselborg Sebastian , Stubenrauch Frank , Iftner Thomas
Published: March 2024

Abstract
The binding of the papillomavirus E6 protein to E6AP and the induction of p53 degradation are common features of high-risk genital human papillomaviruses (HPV); cutaneous HPVs, on the other hand, lack these capacities. Nevertheless, several cutaneous HPV types of the β-genus, such as HPV38 are associated with tumor formation when combined with genetic predisposition, immunosuppression, or UV exposure. In an animal model system, the cottontail rabbit papillomavirus (CRPV) rapidly induces skin cancer without additional cofactors, and CRPVE6 and E7 immortalize rabbit keratinocytes in vitro. However, CRPVE6 neither interacts with E6AP and p53 nor does it induce p53 degradation. In this study, we show that the interaction of CRPVE6, or HPV38E6, with the histone acetyltransferase p300 is crucial to inhibit the ability of p53 to induce apoptosis. Strikingly, E6 mutants deficient for p300 binding are incapable of preventing p53 acetylation, p53-dependent transcription, and apoptosis induction. Moreover, E6 mutants deficient for p300 binding cannot contribute to HPV38-induced immortalization of human keratinocytes or CRPV-induced tumor formation. Our findings highlight changes in the p53 acetylation status mediated by the viral E6 protein as a crucial requirement in the ability of high-risk cutaneous papillomaviruses to immortalize primary keratinocytes and induce tumors. Cancer Res; 70(17); 6913–24. ©2010 AACR.
Data from Hypoxia Induces Trimethylated H3 Lysine 4 by Inhibition of JARID1A Demethylase
Authors: Zhou Xue , Sun Hong , Chen Haobin , Zavadil Jiri , Kluz Thomas , Arita Adriana , Costa Max
Published: March 2024

Abstract
Histone H3 lysine 4 (H3K4) trimethylation (H3K4me3) at the promoter region of genes has been linked to transcriptional activation. In the present study, we found that hypoxia (1% oxygen) increased H3K4me3 in both normal human bronchial epithelial Beas-2B cells and human lung carcinoma A549 cells. The increase of H3K4me3 from hypoxia was likely caused by the inhibition of H3K4 demethylating activity, as hypoxia still increased H3K4me3 in methionine-deficient medium. Furthermore, an in vitro histone demethylation assay showed that 1% oxygen decreased the activity of H3K4 demethylases in Beas-2B nuclear extracts because ambient oxygen tensions were required for the demethylation reaction to proceed. Hypoxia only minimally increased H3K4me3 in the BEAS-2B cells with knockdown of JARID1A, which is the major histone H3K4 demethylase in this cell line. However, the mRNA and protein levels of JARID1A were not affected by hypoxia. GeneChip and pathway analysis in JARID1A knockdown Beas-2B cells revealed that JARID1A regulates the expression of hundreds of genes involved in different cellular functions, including tumorigenesis. Knocking down of JARID1A increased H3K4me3 at the promoters of HMOX1 and DAF genes. Thus, these results indicate that hypoxia might target JARID1A activity, which in turn increases H3K4me3 at both the global and gene-specific levels, leading to the altered programs of gene expression and tumor progression. Cancer Res; 70(10); 4214–21. ©2010 AACR.
Data from Zoledronic Acid as a New Adjuvant Therapeutic Strategy for Ewing's Sarcoma Patients
Authors: Odri Guillaume A. , Dumoucel Sophie , Picarda Gaëlle , Battaglia Séverine , Lamoureux François , Corradini Nadège , Rousseau Julie , Tirode Franck , Laud Karine , Delattre Olivier , Gouin François , Heymann Dominique , Redini Françoise
Published: March 2024

Abstract
Ewing's sarcoma (ES) is the second most frequent pediatric bone tumor also arising in soft tissues (15% of cases). The prognosis of patients with clinically detectable metastases at diagnosis, not responding to therapy or with disease relapse, is still very poor. Among new therapeutic approaches, bisphosphonates represent promising adjuvant molecules to chemotherapy to limit the osteolytic component of bone tumors and to protect from bone metastases. The combined effects of zoledronic acid and mafosfamide were investigated on cell proliferation, viability, apoptosis, and cell cycle distribution of human ES cell lines differing in their p53 and p16/ink4 status. ES models were developed to reproduce both soft tissue and intraosseous tumor development. Mice were treated with 100 μg/kg zoledronic acid (two or four times per week) and/or ifosfamide (30 mg/kg, one to three cycles of three injections). ES cell lines showed different sensitivities to zoledronic acid and mafosfamide at the cell proliferation level, with no correlation with their molecular status. Both drugs induced cell cycle arrest, but in the S or G2M phase, respectively. In vivo, zoledronic acid had no effect on soft tissue tumor progression, although it dramatically inhibited ES development in bone. When combined with ifosfamide, zoledronic acid exerted synergistic effects in the soft tissue model: Its combination with one cycle of ifosfamide resulted in an inhibitory effect similar to three cycles of ifosfamide alone. This very promising result could allow clinicians to diminish the doses of chemotherapy. Cancer Res; 70(19); 7610–9. ©2010 AACR.
Data from Pathways of Proliferation and Antiapoptosis Driven in Breast Cancer Stem Cells by Stem Cell Protein Piwil2
Authors: Lee Jae Ho , Jung Cornelia , Javadian-Elyaderani Parisa , Schweyer Stefan , Schütte Dorothea , Shoukier Moneef , Karimi-Busheri Feridoun , Weinfeld Michael , Rasouli-Nia Aghdass , Hengstler Jan G. , Mantilla Alejandra , Soleimanpour-Lichaei Hamid Reza , Engel Wolfgang , Robson Craig N. , Nayernia Karim
Published: March 2024

Abstract
Cancer stem cell studies may improve understanding of tumor pathophysiology and identify more effective strategies for cancer treatment. In a variety of organisms, Piwil2 has been implicated in multiple roles including stem cell self-renewal, RNA silencing, and translational control. In this study, we documented specific expression of the stem cell protein Piwil2 in breast cancer with predominant expression in breast cancer stem cells. In patients who were evaluated, we determined that 90% of invasive carcinomas and 81% of carcinomas in situ exhibited highest expression of Piwil2. In breast cancer cells, Piwil2 silencing suppressed the expression of signal transducer and activator of transcription 3, a pivotal regulator of Bcl-XL and cyclin D1, whose downregulation paralleled a reduction in cell proliferation and survival. Our findings define Piwil2 and its effector signaling pathways as key factors in the proliferation and survival of breast cancer stem cells. Cancer Res; 70(11); 4569–79. ©2010 AACR.
Data from Persistent Activation of the Fyn/ERK Kinase Signaling Axis Mediates Imatinib Resistance in Chronic Myelogenous Leukemia Cells through Upregulation of Intracellular SPARC
Authors: Fenouille Nina , Puissant Alexandre , Dufies Maeva , Robert Guillaume , Jacquel Arnaud , Ohanna Mickaël , Deckert Marcel , Pasquet Jean-Max , Mahon François-Xavier , Cassuto Jill-Patrice , Raynaud Sophie , Tartare-Deckert Sophie , Auberger Patrick
Published: March 2024

Abstract
SPARC is an extracellular matrix protein that exerts pleiotropic effects on extracellular matrix organization, growth factor availability, cell adhesion, differentiation, and immunity in cancer. Chronic myelogenous leukemia (CML) cells resistant to the BCR-ABL inhibitor imatinib (IM-R cells) were found to overexpress SPARC mRNA. In this study, we show that imatinib triggers SPARC accumulation in a variety of tyrosine kinase inhibitor (TKI)–resistant CML cell lines. SPARC silencing in IM-R cells restored imatinib sensitivity, whereas enforced SPARC expression in imatinib-sensitive cells promoted viability as well as protection against imatinib-mediated apoptosis. Notably, we found that the protective effect of SPARC required intracellular retention inside cells. Accordingly, SPARC was not secreted into the culture medium of IM-R cells. Increased SPARC expression was intimately linked to persistent activation of the Fyn/ERK kinase signaling axis. Pharmacologic inhibition of this pathway or siRNA-mediated knockdown of Fyn kinase resensitized IM-R cells to imatinib. In support of our findings, increased levels of SPARC mRNA were documented in blood cells from CML patients after 1 year of imatinib therapy compared with initial diagnosis. Taken together, our results highlight an important role for the Fyn/ERK signaling pathway in imatinib-resistant cells that is driven by accumulation of intracellular SPARC. Cancer Res; 70(23); 9659–70. ©2010 AACR.
Data from The RB-E2F1 Pathway Regulates Autophagy
Authors: Jiang Hong , Martin Vanesa , Gomez-Manzano Candelaria , Johnson David G. , Alonso Marta , White Erin , Xu Jing , McDonnell Timothy J. , Shinojima Naoki , Fueyo Juan
Published: March 2024

Abstract
Autophagy is a protective mechanism that renders cells viable in stressful conditions. Emerging evidence suggests that this cellular process is also a tumor suppressor pathway. Previous studies showed that cyclin-dependent kinase inhibitors (CDKI) induce autophagy. Whether retinoblastoma protein (RB), a key tumor suppressor and downstream target of CDKIs, induces autophagy is not clear. Here, we show that RB triggers autophagy and that the RB activators p16INK4a and p27/kip1 induce autophagy in an RB-dependent manner. RB binding to E2 transcription factor (E2F) is required for autophagy induction and E2F1 antagonizes RB-induced autophagy, leading to apoptosis. Downregulation of E2F1 in cells results in high levels of autophagy. Our findings indicate that RB induces autophagy by repressing E2F1 activity. We speculate that this newly discovered aspect of RB function is relevant to cancer development and therapy. Cancer Res; 70(20); 7882–93. ©2010 AACR.
Data from Estrogen Regulation and Physiopathologic Significance of Alternative Promoters in Breast Cancer
Authors: Dutertre Martin , Gratadou Lise , Dardenne Etienne , Germann Sophie , Samaan Samaan , Lidereau Rosette , Driouch Keltouma , de la Grange Pierre , Auboeuf Didier
Published: March 2024

Abstract
Alternative promoters (AP) occur in >30% protein-coding genes and contribute to proteome diversity. However, large-scale analyses of AP regulation are lacking, and little is known about their potential physiopathologic significance. To better understand the transcriptomic effect of estrogens, which play a major role in breast cancer, we analyzed gene and AP regulation by estradiol in MCF7 cells using pan-genomic exon arrays. We thereby identified novel estrogen-regulated genes (ERG) and determined the regulation of AP-encoded transcripts in 150 regulated genes. In <30% cases, APs were regulated in a similar manner by estradiol, whereas in >70% cases, they were regulated differentially. The patterns of AP regulation correlated with the patterns of estrogen receptor α (ERα) and CCCTC-binding factor (CTCF) binding sites at regulated gene loci. Interestingly, among genes with differentially regulated (DR) APs, we identified cases where estradiol regulated APs in an opposite manner, sometimes without affecting global gene expression levels. This promoter switch was mediated by the DDX5/DDX17 family of ERα coregulators. Finally, genes with DR promoters were preferentially involved in specific processes (e.g., cell structure and motility, and cell cycle). We show, in particular, that isoforms encoded by the NET1 gene APs, which are inversely regulated by estradiol, play distinct roles in cell adhesion and cell cycle regulation and that their expression is differentially associated with prognosis in ER+ breast cancer. Altogether, this study identifies the patterns of AP regulation in ERGs and shows the contribution of AP-encoded isoforms to the estradiol-regulated transcriptome as well as their physiopathologic significance in breast cancer. Cancer Res; 70(9); 3760–70. ©2010 AACR.
Data from A Better Immune Reaction to Erbb-2 Tumors Is Elicited in Mice by DNA Vaccines Encoding Rat/Human Chimeric Proteins
Authors: Quaglino Elena , Mastini Cristina , Amici Augusto , Marchini Cristina , Iezzi Manuela , Lanzardo Stefania , De Giovanni Carla , Montani Maura , Lollini Pier-Luigi , Masucci Giuseppe , Forni Guido , Cavallo Federica
Published: March 2024

Abstract
The Erbb-2 (neu in rat and Her-2 in humans) tyrosine kinase receptor is an oncoantigen (i.e., a tumor-associated molecule directly involved in cancer progression). Because oncoantigens are self-tolerated molecules, to trigger a response circumventing tolerance, we generated two plasmids (RHuT and HuRT) coding for chimeric neu-Her-2 extracellular and transmembrane proteins that are expressed on the cell membrane of the transfected cells and recognized by monoclonal antibodies reacting against neu and Her-2. RHuT encodes a protein in which the 410 NH2-terminal residues are from the neu extracellular domain and the remaining residues from Her-2. Almost symmetrically, HuRT encodes for a protein in which the 390 NH2-terminal residues are from Her-2 and the remainder from neu. The ability of RHuT and HuRT to elicit a protective response to neu and Her-2 in wild-type mice and in transgenic mice tolerant to neu and Her-2 proteins was compared with that of plasmids coding for the fully rat or fully human extracellular and transmembrane domains of the Erbb-2 receptor. In most cases, RHuT and HuRT elicited a stronger response, although this chimeric benefit is markedly modulated by the location of the heterologous moiety in the protein coded by the plasmid, the immune tolerance of the responding mouse, and the kind of Erbb-2 orthologue on the targeted tumor. Cancer Res; 70(7); 2604–12
Data from Identification of Hypermethylated Genes Associated with Cisplatin Resistance in Human Cancers
Authors: Chang Xiaofei , Monitto Constance L. , Demokan Semra , Kim Myoung Sook , Chang Steven S. , Zhong Xiaoli , Califano Joseph A. , Sidransky David
Published: March 2024

Abstract
Cisplatin is among the most widely used cytotoxic anticancer agents in solid tumors; however, the development of secondary resistance remains a major obstacle to clinical efficacy. Treatment-related DNA hypermethylation may play a role in creating drug-resistant phenotypes by inactivating genes that are required for cytotoxicity. We applied a pharmacologic unmasking approach to detect hypermethylated genes whose inactivation contributes to cisplatin resistance. Using three pairs of isogeneic, cisplatin-sensitive, and cisplatin-resistant cell lines derived from two parental cell lines (KB-3-1 and SCC25), we identified several hundred genes that were downregulated in each resistant cell line and reactivated by the DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine. Among them, 30 genes were common to two or more cell lines and/or reported to be downregulated in previous studies. Bisulfite sequencing confirmed that 14 genes were hypermethylated in resistant cell lines but not in the sensitive parental cell lines. Six of 14 genes (SAT, C8orf4, LAMB3, TUBB, G0S2, and MCAM) were cisplatin inducible in sensitive but not in resistant cell lines. Small interfering RNA knockdown of two genes, SAT and S100P, increased cell viability with cisplatin treatment in sensitive parental cell lines. S100P knockdown significantly decreased the S-phase fraction of parental sensitive cell lines and slowed cell proliferation, which was associated with decreased sensitivity to cisplatin. Based on these findings, we conclude that DNA methylation is a frequent event in cells that are chronically exposed to cisplatin and that methylation-induced gene silencing may play a role in the development of resistance to cytotoxic chemotherapeutic agents. Cancer Res; 70(7); 2870–9
Data from Mechanism of Autophagy to Apoptosis Switch Triggered in Prostate Cancer Cells by Antitumor Cytokine Melanoma Differentiation-Associated Gene 7/Interleukin-24
Authors: Bhutia Sujit K. , Dash Rupesh , Das Swadesh K. , Azab Belal , Su Zhao-zhong , Lee Seok-Geun , Grant Steven , Yacoub Adly , Dent Paul , Curiel David T. , Sarkar Devanand , Fisher Paul B.
Published: March 2024

Abstract
Melanoma differentiation-associated gene 7 (mda-7)/interleukin-24 (IL-24) is a unique member of the IL-10 gene family, which displays a broad range of antitumor properties, including induction of cancer-specific apoptosis. Adenoviral-mediated delivery by Ad.mda-7 invokes an endoplasmic reticulum (ER) stress response that is associated with ceramide production and autophagy in some cancer cells. Here, we report that Ad.mda-7–induced ER stress and ceramide production trigger autophagy in human prostate cancer cells, but not in normal prostate epithelial cells, through a canonical signaling pathway that involves Beclin-1, atg5, and hVps34. Autophagy occurs in cancer cells at early times after Ad.mda-7 infection, but a switch to apoptosis occurs by 48 hours after infection. Inhibiting autophagy with 3-methyladenosine increases Ad.mda-7–induced apoptosis, suggesting that autophagy may be initiated first as a cytoprotective mechanism. Inhibiting apoptosis by overexpression of antiapoptotic proteins Bcl-2 or Bcl-xL increased autophagy after Ad.mda-7 infection. During the apoptotic phase, the MDA-7/IL-24 protein physically interacted with Beclin-1 in a manner that could inhibit Beclin-1 function culminating in apoptosis. Conversely, Ad.mda-7 infection elicited calpain-mediated cleavage of the autophagic protein ATG5 in a manner that could facilitate switch to apoptosis. Our findings reveal novel aspects of the interplay between autophagy and apoptosis in prostate cancer cells that underlie the cytotoxic action of mda-7/IL-24, possibly providing new insights in the development of combinatorial therapies for prostate cancer. Cancer Res; 70(9); 3667–76. ©2010 AACR.