bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Down-regulation of CXCR4 and CD62L in Chronic Lymphocytic Leukemia Cells Is Triggered by B-Cell Receptor Ligation and Associated with Progressive Disease
Authors: Vlad Amalia , Deglesne Pierre-Antoine , Letestu Rémi , Saint-Georges Stéphane , Chevallier Nathalie , Baran-Marszak Fanny , Varin-Blank Nadine , Ajchenbaum-Cymbalista Florence , Ledoux Dominique
Published: March 2024

Abstract
Progressive cases of B-cell chronic lymphocytic leukemia (CLL) are frequently associated with lymphadenopathy, highlighting a critical role for signals emanating from the tumor environment in the accumulation of malignant B cells. We investigated on CLL cells from 30 untreated patients the consequence of B-cell receptor (BCR) triggering on the membrane expression of CXCR4 and CD62L, two surface molecules involved in trafficking and exit of B-lymphocytes from lymph nodes. BCR stimulation promoted a strictly simultaneous down-regulation of CXCR4 and CD62L membrane expression to a variable extent. The variable BCR-dependent decrease of the two proteins was strikingly representative of the heterogeneous capacity of the CLL cells to respond to BCR engagement in a given patient. Functionally, cells down-regulating CXCR4 and CD62L in response to BCR engagement displayed a reduction in both migration toward CXCL12 and adhesion to lymphatic endothelial cells. Remarkably, the ability of CLL cells to respond to BCR ligation was correlated with unfavorable prognostic markers and short progression-free survival. In conclusion, BCR signaling promotes decrease of CXCR4 and CD62L membrane expression in progressive cases only. These results are consistent with the hypothesis that BCR-mediated signaling pathways favor accumulation of a proliferative pool within the lymph nodes of progressive CLL cases. [Cancer Res 2009;69(16):6387–95]
Data from Role of Cyclic AMP Response Element–Binding Protein in Insulin-like Growth Factor-I Receptor Up-regulation by Sex Steroids in Prostate Cancer Cells
Authors: Genua Marco , Pandini Giuseppe , Sisci Diego , Castoria Gabriella , Maggiolini Marcello , Vigneri Riccardo , Belfiore Antonino
Published: March 2024

Abstract
Insulin-like growth factor-I receptor (IGF-IR) overexpression may play a role in prostate cancer progression. We found previously that, in prostate cancer cells, IGF-IR is up-regulated by both androgens and estrogens via a nongenotropic pathway. We now show that, in prostate cancer cells, stimulation with either androgens or estrogens up-regulates IGF-IR by inducing cyclic AMP response element–binding protein (CREB) activation. Both sex steroids phosphorylated CREB at Ser133 in a dose-dependent manner in androgen receptor (AR)–positive LNCaP cells, whereas only estrogens phosphorylated CREB in AR-negative PC3 cells. CREB phosphorylation involved c-Src–dependent extracellular signal-regulated kinase 1/2 activation, but not protein kinase A, protein kinase C, or calmodulin-dependent kinase II, and occurred also in cells transfected with AR or estrogen receptor mutants that do not localize into the nucleus. CREB silencing abrogated IGF-IR up-regulation and promoter activation. We also showed that CREB binds to IGF-IR promoter region and identified the relevant CREB-binding site at the 5′-untranslated region fragment of IGF-IR promoter. In conclusion, we describe a novel mechanism of IGF-IR up-regulation and promoter activity by CREB activation, induced by sex steroids, through a nongenotropic signaling. [Cancer Res 2009;69(18):7270–7]
Data from IFN-Producing Killer Dendritic Cells Are Antigen-Presenting Cells Endowed with T-Cell Cross-Priming Capacity
Authors: Pletneva Maria , Fan Hongni , Park Jang-June , Radojcic Vedran , Jie Chunfa , Yu Yanxing , Chan Camie , Redwood Alec , Pardoll Drew , Housseau Franck
Published: March 2024

Abstract
IFN-producing killer dendritic cells (IKDC) represent a recently discovered cell type in the immune system that possesses a number of functions contributing to innate and adaptive immunity, including production of type 1 and 2 IFNs, interleukin (IL)-12, natural killing, and ultimately antigen presentation to naïve T cells. Here, we compared in vitro and in vivo responses of mouse IKDC, conventional dendritic cells (DC), and natural killer (NK) cells to murine cytomegalovirus infection and found distinct functions among these cell subsets. Upon recognition of infected fibroblasts, IKDC, as well as NK, produced high level of IFN-γ, but unlike NK, IKDC simultaneously produced IL-12p40 and up-regulated MHC class II (MHC-II) and costimulatory molecules. Using MHC-II molecule expression as a phenotypic marker to distinguish activated IKDC from activated NK, we further showed that highly purified MHC-II+ IKDC but not NK cross-present MHC class I–restricted antigens derived from MCMV-infected targets to CD8+ T cells in vitro and in vivo. Our findings emphasize the unique nature of IKDC as a killer antigen-presenting cell directly linking innate and adaptive immunity. [Cancer Res 2009;69(16):6607–14]
Data from Small-Molecule Multidrug Resistance–Associated Protein 1 Inhibitor Reversan Increases the Therapeutic Index of Chemotherapy in Mouse Models of Neuroblastoma
Authors: Burkhart Catherine A. , Watt Fujiko , Murray Jayne , Pajic Marina , Prokvolit Anatoly , Xue Chengyuan , Flemming Claudia , Smith Janice , Purmal Andrei , Isachenko Nadezhda , Komarov Pavel G. , Gurova Katerina V. , Sartorelli Alan C. , Marshall Glenn M. , Norris Murray D. , Gudkov Andrei V. , Haber Michelle
Published: March 2024

Abstract
The multidrug resistance–associated protein 1 (MRP1) has been closely linked to poor treatment response in several cancers, most notably neuroblastoma. Homozygous deletion of the MRP1 gene in primary murine neuroblastoma tumors resulted in increased sensitivity to MRP1 substrate drugs (vincristine, etoposide, and doxorubicin) compared with tumors containing both copies of wild-type MRP1, indicating that MRP1 plays a significant role in the drug resistance in this tumor type and defining this multidrug transporter as a target for pharmacologic suppression. A cell-based readout system was created to functionally determine intracellular accumulation of MRP1 substrates using a p53-responsive reporter as an indicator of drug-induced DNA damage. Screening of small-molecule libraries in this readout system revealed pyrazolopyrimidines as a prominent structural class of potent MRP1 inhibitors. Reversan, the lead compound of this class, increased the efficacy of both vincristine and etoposide in murine models of neuroblastoma (syngeneic and human xenografts). As opposed to the majority of inhibitors of multidrug transporters, Reversan was not toxic by itself nor did it increase the toxicity of chemotherapeutic drug exposure in mice. Therefore, Reversan represents a new class of nontoxic MRP1 inhibitor, which may be clinically useful for the treatment of neuroblastoma and other MRP1-overexpressing drug-refractory tumors by increasing their sensitivity to conventional chemotherapy. [Cancer Res 2009;69(16):6573–80]
Data from Prolonged Cell Cycle Response of HeLa Cells to Low-Level Alkylation Exposure
Authors: Schroering Allen G. , Kothandapani Anbarasi , Patrick Steve M. , Kaliyaperumal Saravanan , Sharma Vishal P. , Williams Kandace J.
Published: March 2024

Abstract
Alkylation chemotherapy has been a long-standing treatment protocol for human neoplasia. N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) is a direct-acting monofunctional alkylator. Temozolomide is a clinical chemotherapeutic equivalent requiring metabolic breakdown to the alkylating agent. Both chemicals have similar mechanistic efficacy against DNA mismatch repair–proficient tumor cells that lack expression of methylguanine methyltransferase. Clinically relevant concentrations of both agents affect replicating cells only after the first cell cycle. This phenomenon has been attributed to replication fork arrest at unrepaired O6-methyldeoxyguanine lesions mispaired with thymine during the first replication cycle. Here, we show, by several different approaches, that MNNG-treated tumor cells do not arrest within the second cell cycle. Instead, the population slowly traverses through mitosis without cytokinesis into a third cell cycle. The peak of both ssDNA and dsDNA breaks occurs at the height of the long mitotic phase. The majority of the population emerges from mitosis as multinucleated cells that subsequently undergo cell death. However, a very small proportion of cells, <1:45,000, survive to form new colonies. Taken together, these results indicate that multinucleation within the third cell cycle, rather than replication fork arrest within the second cell cycle, is the primary trigger for cell death. Importantly, multinucleation and cell death are consistently avoided by a small percentage of the population that continues to divide. This information should prove clinically relevant for the future design of enhanced cancer chemotherapeutics. [Cancer Res 2009;69(15):6307–14]
Data from Cucurbitacin B Induces Apoptosis by Inhibition of the JAK/STAT Pathway and Potentiates Antiproliferative Effects of Gemcitabine on Pancreatic Cancer Cells
Authors: Thoennissen Nils H. , Iwanski Gabriela B. , Doan Ngan B. , Okamoto Ryoko , Lin Patricia , Abbassi Sam , Song Jee Hoon , Yin Dong , Toh Melvin , Xie Wei Dong , Said Jonathan W. , Koeffler H. Phillip
Published: March 2024

Abstract
Pancreatic cancer is an aggressive malignancy that is generally refractory to chemotherapy, thus posing experimental and clinical challenges. In this study, the antiproliferative effect of the triterpenoid compound cucurbitacin B was tested in vitro and in vivo against human pancreatic cancer cells. Dose-response studies showed that the drug inhibited 50% growth of seven pancreatic cancer cell lines at 10−7 mol/L, whereas clonogenic growth was significantly inhibited at 5 × 10−8 mol/L. Cucurbitacin B caused dose- and time-dependent G2-M-phase arrest and apoptosis of pancreatic cancer cells. This was associated with inhibition of activated JAK2, STAT3, and STAT5, increased level of p21WAF1 even in cells with nonfunctional p53, and decrease of expression of cyclin A, cyclin B1, and Bcl-XL with subsequent activation of the caspase cascade. Interestingly, the combination of cucurbitacin B and gemcitabine synergistically potentiated the antiproliferative effects of gemcitabine on pancreatic cancer cells. Moreover, cucurbitacin B decreased the volume of pancreatic tumor xenografts in athymic nude mice by 69.2% (P < 0.01) compared with controls without noticeable drug toxicities. In vivo activation of JAK2/STAT3 was inhibited and expression of Bcl-XL was decreased, whereas caspase-3 and caspase-9 were up-regulated in tumors of drug-treated mice. In conclusion, we showed for the first time that cucurbitacin B has profound in vitro and in vivo antiproliferative effects against human pancreatic cancer cells, and the compound may potentate the antiproliferative effect of the chemotherapeutic agent gemcitabine. Further clinical studies are necessary to confirm our findings in patients with pancreatic cancer. [Cancer Res 2009;69(14):5876–84]
Data from Cell Type–Specific Targeted Mutations of Kras and Pten Document Proliferation Arrest in Granulosa Cells versus Oncogenic Insult to Ovarian Surface Epithelial Cells
Authors: Fan Heng-Yu , Liu Zhilin , Paquet Marilene , Wang Jinrong , Lydon John P. , DeMayo Francesco J. , Richards JoAnne S.
Published: March 2024

Abstract
The small G-protein KRAS is crucial for mediating gonadotropin-induced events associated with ovulation. However, constitutive expression of KrasG12D in granulosa cells disrupted normal follicle development leading to the persistence of abnormal follicle-like structures containing nonmitotic cells. To determine what factors mediate this potent effect of KrasG12D, gene profiling analyses were done. We also analyzed KrasG12D;Cyp19-Cre and KrasG12;Pgr-Cre mutant mouse models that express Cre prior to or after the initiation of granulosa cell differentiation, respectively. KrasG12D induced cell cycle arrest in granulosa cells of the KrasG12D;Cyp19-Cre mice but not in the KrasG12D;Pgr-Cre mice, documenting the cell context–specific effect of KrasG12D. Expression of KrasG12D silenced the Kras gene, reduced cell cycle activator genes, and impaired the expression of granulosa cell and oocyte-specific genes. Conversely, levels of PTEN and phosphorylated p38 mitogen-activated protein kinase (MAPK) increased markedly in the mutant granulosa cells. Because disrupting Pten in granulosa cells leads to increased proliferation and survival, Pten was disrupted in the KrasG12D mutant mice. The Pten/Kras mutant mice were infertile but lacked granulosa cell tumors. By contrast, the Ptenfl/fl;KrasG12D;Amhr2-Cre mice developed aggressive ovarian surface epithelial cell tumors that did not occur in the Ptenfl/fl;KrasG12D;Cyp19-Cre or Ptenfl/fl;KrasG12D;Pgr-Cre mouse strains. These data document unequivocally that Amhr2-Cre is expressed in and mediates allelic recombination of oncogenic genes in ovarian surface epithelial cells. That KrasG12D/Pten mutant granulosa cells do not transform but rather undergo cell cycle arrest indicates that they resist the oncogenic insults of Kras/Pten by robust self-protecting mechanisms that silence the Kras gene and elevate PTEN and phosphorylated p38 MAPK. [Cancer Res 2009;69(16):6463–72]
Data from Functional Phosphodiesterase 11A Mutations May Modify the Risk of Familial and Bilateral Testicular Germ Cell Tumors
Authors: Horvath Anelia , Korde Larissa , Greene Mark H. , Libe Rossella , Osorio Paulo , Faucz Fabio Rueda , Raffin-Sanson Marie Laure , Tsang Kit Man , Drori-Herishanu Limor , Patronas Yianna , Remmers Elaine F. , Nikita Maria Eleni , Moran Jason , Greene Joseph , Nesterova Maria , Merino Maria , Bertherat Jerome , Stratakis Constantine A.
Published: March 2024

Abstract
Inactivating germline mutations in phosphodiesterase 11A (PDE11A) have been implicated in adrenal tumor susceptibility. PDE11A is highly expressed in endocrine steroidogenic tissues, especially the testis, and mice with inactivated Pde11a exhibit male infertility, a known testicular germ cell tumor (TGCT) risk factor. We sequenced the PDE11A gene-coding region in 95 patients with TGCT from 64 unrelated kindreds. We identified 8 nonsynonymous substitutions in 20 patients from 15 families: four (R52T, F258Y, G291R, and V820M) were newly recognized, three (R804H, R867G, and M878V) were functional variants previously implicated in adrenal tumor predisposition, and one (Y727C) was a known polymorphism. We compared the frequency of these variants in our patients to unrelated controls that had been screened and found negative for any endocrine diseases: only the two previously reported variants, R804H and R867G, known to be frequent in general population, were detected in these controls. The frequency of all PDE11A-gene variants (combined) was significantly higher among patients with TGCT (P = 0.0002), present in 19% of the families of our cohort. Most variants were detected in the general population, but functional studies showed that all these mutations reduced PDE activity, and that PDE11A protein expression was decreased (or absent) in TGCT samples from carriers. This is the first demonstration of the involvement of a PDE gene in TGCT, although the cyclic AMP signaling pathway has been investigated extensively in reproductive organ function and their diseases. In conclusion, we report that PDE11A-inactivating sequence variants may modify the risk of familial and bilateral TGCT. [Cancer Res 2009;69(13):5301–6]
Data from Differentiation-Related Gene-1 Decreases Bim Stability by Proteasome-Mediated Degradation
Authors: Ambrosini Grazia , Seelman Sharon L. , Schwartz Gary K.
Published: March 2024

Abstract
Drg1 was identified as a differentiation-related, putative metastatic suppressor gene in human colon and prostate cancer. Its expression is associated with resistance to irinotecan (CPT-11) therapy in preclinical colorectal cancer models both in vitro and in vivo. However, the functional significance of Drg1 in these processes is unknown. We have shown for the first time that Drg1 directly binds to the BH3-only proapoptotic protein Bim. Depletion of Drg1 by small interfering RNA induced up-regulation of Bim and its accumulation in the mitochondria, which correlated with loss of mitochondrial membrane potential and induction of apoptosis in cells exposed to SN-38. Further analyses revealed that Drg1 promotes degradation of Bim through the Cullin2/ElonginB-CIS ubiquitin-protein ligase complex. Conversely, in the absence of Drg1, Bim was stabilized and bound more abundantly to Hsp70. These results show that Drg1 renders cancer cells more resistant to chemotherapy through enhanced proteasome-mediated Bim degradation. [Cancer Res 2009;69(15):6115–21]
Data from In situ Stimulation of CD40 and Toll-like Receptor 3 Transforms Ovarian Cancer–Infiltrating Dendritic Cells from Immunosuppressive to Immunostimulatory Cells
Authors: Scarlett Uciane K. , Cubillos-Ruiz Juan R. , Nesbeth Yolanda C. , Martinez Diana G. , Engle Xavier , Gewirtz Andrew T. , Ahonen Cory L. , Conejo-Garcia Jose R.
Published: March 2024

Abstract
Boosting therapeutically relevant immunity against lethal epithelial tumors may require targeting tumor-induced immunosuppression on an individualized basis. Here, we show that, in the ovarian carcinoma microenvironment, CD11c+MHC-II+ dendritic cells spontaneously engulf tumor materials but, rather than enhancing antitumor immunity, suppress T-cell function. In situ costimulation of CD40 and Toll-like receptor (TLR) 3 on tumor-infiltrating dendritic cells decreased their l-arginase activity, enhanced their production of type I IFN and interleukin-12 (p70), augmented their capacity to process antigens, and up-regulated costimulatory molecules in vivo in mice and in vitro in human dissociated tumors. Synergistic CD40/TLR activation also induced the migration of activated dendritic cells to lymphatic locations and promoted their capacity to present antigens. Correspondingly, without exogenous antigen, combined CD40/TLR agonists boosted measurable T-cell–mediated antitumor immunity and induced the rejection of otherwise lethal i.p. ovarian carcinomas. Our results highlight the potential of transforming tumor-infiltrating dendritic cells (the most abundant leukocyte subset in the solid ovarian carcinoma microenvironment) from an immunosuppressive to an immunostimulatory cell type. Combined administration of synergistic CD40 and TLR3 agonists could enhance their individual therapeutic effects against ovarian and other lethal epithelial cancers. [Cancer Res 2009;69(18):7329–37]
Data from Loss of Phosphatase and Tensin Homologue Deleted on Chromosome 10 Engages ErbB3 and Insulin-Like Growth Factor-I Receptor Signaling to Promote Antiestrogen Resistance in Breast Cancer
Authors: Miller Todd W. , Pérez-Torres Marianela , Narasanna Archana , Guix Marta , Stål Olle , Pérez-Tenorio Gizeh , Gonzalez-Angulo Ana M. , Hennessy Bryan T. , Mills Gordon B. , Kennedy J. Phillip , Lindsley Craig W. , Arteaga Carlos L.
Published: March 2024

Abstract
Knockdown of the tumor suppressor phosphatase Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) with shRNA in three estrogen receptor (ER)-positive breast cancer cell lines resulted in increased phosphatidylinositol-3 kinase (PI3K) and AKT activities, resistance to tamoxifen and fulvestrant, and hormone-independent growth. PTEN knockdown induced the up-regulation of ER transcriptional activity in MCF-7 cells but decreased ER protein levels and transcriptional activity in T47D and MDA-361 cells. Tamoxifen and fulvestrant treatment inhibited estradiol-induced ER transcriptional activity in all shPTEN cell lines but did not abrogate the increased cell proliferation induced by PTEN knockdown. PTEN knockdown increased basal and ligand-induced activation of the insulin-like growth factor-I (IGF-I) and ErbB3 receptor tyrosine kinases, and prolonged the association of the p85 PI3K subunit with the IGF-I receptor (IGF-IR) effector insulin receptor substrate-1 and with ErbB3, implicating PTEN in the modulation of signaling upstream of PI3K. Consistent with these data, PTEN levels inversely correlated with levels of tyrosine-phosphorylated IGF-IR in tissue lysate arrays of primary breast cancers. Inhibition of IGF-IR and/or ErbB2-mediated activation of ErbB3 with tyrosine kinase inhibitors restored hormone dependence and the growth inhibitory effect of tamoxifen and fulvestrant on shPTEN cells, suggesting that cotargeting both ER and receptor tyrosine kinase pathways holds promise for the treatment of patients with ER+, PTEN-deficient breast cancers. [Cancer Res 2009;69(10):4192–201]
Data from ADAM23 Negatively Modulates αvβ3 Integrin Activation during Metastasis
Authors: Verbisck Newton V. , Costa Érico T. , Costa Fabrício F. , Cavalher Felícia P. , Costa Michele D.M. , Muras Angelita , Paixão Valéria A. , Moura Ricardo , Granato Mariana F. , Ierardi Daniela F , Machado Tamara , Melo Fabiana , Ribeiro Karina B. , Cunha Isabela W. , Lima Vladmir C.C. , Maciel Maria do Socorro , Carvalho André L. , Soares Fernando F. , Zanata Silvio , Sogayar Mari C. , Chammas Roger , Camargo Anamaria A.
Published: March 2024

Abstract
The ADAM23 gene is frequently silenced in different types of tumors, and, in breast tumors, silencing is correlated with tumor progression, suggesting that it might be associated with the acquisition of a metastatic phenotype. ADAM23 exerts its function mainly through the disintegrin domain, because its metalloprotease domain is inactive. Analysis of ADAM23 binding to integrins has revealed a specific interaction with αvβ3 integrin mediated by the disintegrin domain. Altered expression of αvβ3 integrin has been observed in different types of tumors, and expression of this integrin in the activated form has been shown to promote metastasis formation. Here, we investigated the possibility that interaction between ADAM23 and αvβ3 integrin might negatively modulate αvβ3 activation during metastatic progression. ADAM23 expression was knocked down using short hairpin RNA in the MDA-MB-435 cell line, which has been extensively used as a model for αvβ3 integrin activation. Ablation of ADAM23 enhanced αvβ3 integrin activation by at least 2- to 4-fold and ADAM23 knockdown cells showed enhanced migration and adhesion to classic αvβ3 integrin ligands. Ablation of ADAM23 expression also enhanced pulmonary tumor cell arrest in immunodeficient mice. To complement our findings with clinical evidence, we showed that silencing of ADAM23 gene by DNA promoter hypermethylation in a collection of 94 primary breast tumors was significantly associated with lower distant metastases–free and disease-specific survivals and was an independent prognostic factor for poor disease outcome. Our results strongly support a functional role of ADAM23 during metastatic progression by negatively modulating αvβ3 integrin activation. [Cancer Res 2009;69(13):5546–52]
Data from A “Vascular Normalization Index” as Potential Mechanistic Biomarker to Predict Survival after a Single Dose of Cediranib in Recurrent Glioblastoma Patients
Authors: Sorensen A. Gregory , Batchelor Tracy T. , Zhang Wei-Ting , Chen Poe-Jou , Yeo Priscilla , Wang Meiyun , Jennings Dominique , Wen Patrick Y. , Lahdenranta Johanna , Ancukiewicz Marek , di Tomaso Emmanuelle , Duda Dan G. , Jain Rakesh K.
Published: March 2024

Abstract
Early imaging or blood biomarkers of tumor response are desperately needed to customize antiangiogenic therapy for cancer patients. Anti–vascular endothelial growth factor (VEGF) therapy can “normalize” brain tumor vasculature by decreasing vessel diameter and permeability, and thinning the abnormally thick basement membrane. We hypothesized that the extent of vascular normalization will be predictive of outcome of anti-VEGF therapy in glioblastoma. We used advanced magnetic resonance imaging methods to monitor vascular parameters and treatment response in 31 recurrent glioblastoma patients enrolled in a phase II trial of cediranib, an oral pan-VEGF receptor tyrosine kinase inhibitor. We evaluated the correlation between clinical outcome and magnetic resonance imaging–measured changes in vascular permeability/flow (i.e., Ktrans) and in microvessel volume, and the change of circulating collagen IV levels, all after a single dose of cediranib. Here, we show that evaluation of biomarkers as early as after one day of anti-VEGF therapy with cediranib is predictive of response in patients with recurrent glioblastoma. Changes in Ktrans, microvessel volume, and circulating collagen IV correlated with duration of overall survival and/or progression-free survival (P < 0.05). When we combined these three parameters into a “vascular normalization index,” we found that it closely associated with overall survival (ρ = 0.54; P = 0.004) and progression-free survival (ρ = 0.6; P = 0.001). The vascular normalization index described here should be validated in randomized clinical trials. [Cancer Res 2009;69(13):5296–300]
Data from Role of MUTYH and MSH2 in the Control of Oxidative DNA Damage, Genetic Instability, and Tumorigenesis
Authors: Russo Maria Teresa , De Luca Gabriele , Casorelli Ida , Degan Paolo , Molatore Sara , Barone Flavia , Mazzei Filomena , Pannellini Tania , Musiani Piero , Bignami Margherita
Published: March 2024

Abstract
Mismatch repair is the major pathway controlling genetic stability by removing mispairs caused by faulty replication and/or mismatches containing oxidized bases. Thus, inactivation of the Msh2 mismatch repair gene is associated with a mutator phenotype and increased cancer susceptibility. The base excision repair gene Mutyh is also involved in the maintenance of genomic integrity by repairing premutagenic lesions induced by oxidative DNA damage. Because evidence in bacteria suggested that Msh2 and Mutyh repair factors might have some overlapping functions, we investigated the biological consequences of their single and double inactivation in vitro and in vivo. Msh2−/− mouse embryo fibroblasts (MEF) showed a strong mutator phenotype at the hprt gene, whereas Mutyh inactivation was associated with a milder phenotype (2.9 × 10−6 and 3.3 × 10−7 mutation/cell/generation, respectively). The value of 2.7 × 10−6 mutation/cell/generation in Msh2−/−Mutyh−/− MEFs did not differ significantly from Msh2−/− cells. When steady-state levels of DNA 8-oxo-7,8-dihydroguanine (8-oxoG) were measured in MEFs of different genotypes, single gene inactivation resulted in increases similar to those observed in doubly defective cells. In contrast, a synergistic accumulation of 8-oxoG was observed in several organs of Msh2−/−Mutyh−/− animals, suggesting that in vivo Msh2 and Mutyh provide separate repair functions and contribute independently to the control of oxidative DNA damage. Finally, a strong delay in lymphomagenesis was observed in Msh2−/−Mutyh−/− when compared with Msh2−/− animals. The immunophenotype of these tumors indicate that both genotypes develop B-cell lymphoblastic lymphomas displaying microsatellite instability. This suggests that a large fraction of the cancer-prone phenotype of Msh2−/− mice depends on Mutyh activity. [Cancer Res 2009;69(10):4372–9]
Data from Induction of Prostatic Intraepithelial Neoplasia and Modulation of Androgen Receptor by ETS Variant 1/ETS-Related Protein 81
Authors: Shin Sook , Kim Tae-Dong , Jin Fang , van Deursen Jan M. , Dehm Scott M. , Tindall Donald J. , Grande Joseph P. , Munz Jan-Marie , Vasmatzis George , Janknecht Ralf
Published: March 2024

Abstract
ETS variant 1 (ETV1), also known as ETS-related protein 81, is overexpressed in prostate tumors, but whether and how this transcription factor affects tumorigenesis has remained elusive. Here, we show that ETV1 is primarily overexpressed in the most aggressive human prostate tumors. Transgenic ETV1 mice developed prostatic intraepithelial neoplasia as well as hyperplasia/neoplasia in seminal vesicles. Moreover, ETV1 cooperated with the androgen receptor (AR) to bind to the prostate-specific antigen enhancer and stimulate gene transcription. Consistent with its ability to physically interact with AR, ETV1 rendered an ETV1 binding site–driven reporter androgen inducible, and, on the other hand, ETV1 superinduced transcription from an AR binding site on androgen stimulation. In conclusion, our study substantiates that ETV1 overexpression is an underlying cause in the development of prostate and possibly also seminal vesicle cancer. Its interaction with and activation of AR provides a molecular mechanism on how ETV1 exerts its deleterious function. Thus, inhibiting ETV1 or blocking its interaction with AR may represent novel strategies in prostate cancer therapy. [Cancer Res 2009;69(20):8102–10]
Data from Mouse Mammary Tumor Virus p75 and p110 CUX1 Transgenic Mice Develop Mammary Tumors of Various Histologic Types
Authors: Cadieux Chantal , Kedinger Valérie , Yao Lu , Vadnais Charles , Drossos Maria , Paquet Marilène , Nepveu Alain
Published: March 2024

Abstract
The p75 and p110 isoforms of the CUX1 homeodomain protein are overexpressed in breast tumors and cancer cell lines. To assess and compare the ability of these short CUX1 isoforms in driving mammary tumor development, we used site-specific transgenesis into the Hprt locus to generate transgenic mice expressing p75 or p110 CUX1 under the control of the mouse mammary tumor virus-long terminal repeat. We report that mammary tumors developed after a long latency period, and although various histopathologies were observed, the proportion of adenosquamous carcinomas was significantly higher in p75 CUX1 than in p110 CUX1 transgenic mice. Metastasis to the lung was observed in three p75 CUX1 transgenic mice. Comparisons between tumors and adjacent normal mammary glands revealed that transgenes were overexpressed in most but not all tumors, yet in all cases tested, CUX1 DNA binding was increased, suggesting that both higher expression and changes in post-translational modifications can contribute to stimulate transgene activity. Interestingly, higher expression of erbB2 mRNA was seen in most tumors, not only solid carcinomas but also adenosquamous carcinomas, whereas higher expression of various Wnt genes and activation of the β-catenin pathway was observed primarily in adenosquamous carcinomas. Activation of erbB2 expression appeared to represent a cooperating event that occurred independently of CUX1. In contrast, chromatin immunoprecipitation, short hairpin RNA–mediated knockdown, and reporter assays established that CUX1 is involved in the transcriptional regulation of several Wnt genes. Together, these results support the notion that oncogenic activity of CUX1 can facilitate the establishment of a Wnt/β-catenin autocrine loop. [Cancer Res 2009;69(18):7188–97]
Data from CCL5-Mediated Endogenous Antitumor Immunity Elicited by Adoptively Transferred Lymphocytes and Dendritic Cell Depletion
Authors: Nesbeth Yolanda , Scarlett Uciane , Cubillos-Ruiz Juan , Martinez Diana , Engle Xavier , Turk Mary-Jo , Conejo-Garcia Jose R.
Published: March 2024

Abstract
Adoptive transfer of antitumor T cells is a promisingly effective therapy for various cancers, but its effect on endogenous antitumor immune mechanisms remains largely unknown. Here, we show that the administration of naive T cells de novo primed for only 7 days against tumor antigens resulted in the durable rejection of otherwise lethal ovarian cancers when coupled with the depletion of tumor-associated immunosuppressive dendritic cells (DC). Therapeutic activity required tumor antigen specificity and perforin expression by the adoptively transferred T cells, but not IFN-γ production. Importantly, these shortly primed T cells secreted large amounts of CCL5, which was required for their therapeutic benefit. Accordingly, transferred T cells recruited CCR5+ DCs into the tumor, where they showed distinct immunostimulatory attributes. Activated CCR5+ host T cells with antitumor activity also accumulated at tumor locations, and endogenous tumor-specific memory T cells remained elevated after the disappearance of transferred lymphocytes. Therefore, persistent, long-lived antitumor immunity was triggered by the administration of ex vivo activated T cells, but was directly mediated by immune cells of host origin. Our data unveil a CCL5-dependent mechanism of awakening endogenous antitumor immunity triggered by ex vivo expanded T cells, which is augmented by tumor-specific targeting of the cancer microenvironment. [Cancer Res 2009;69(15):6331–8]
Data from Human Papillomavirus E7 Oncoprotein Overrides the Tumor Suppressor Activity of p21Cip1 in Cervical Carcinogenesis
Authors: Shin Myeong-Kyun , Balsitis Scott , Brake Tiffany , Lambert Paul F.
Published: March 2024

Abstract
The E7 oncoprotein of the high-risk human papillomaviruses (HPV) is thought to contribute to cervical carcinogenesis at least in part by abrogating cell cycle regulation. E7 can dysregulate the cell cycle through its interaction with several cellular proteins including the retinoblastoma suppressor protein pRb, as well as the cyclin-dependent kinase inhibitor p21Cip1. Inactivation of pRb in cervical epithelia is not sufficient to explain the ability of E7 to cause cervical cancers in transgenic mice. In the current study, we focused on the role of p21Cip1 in cervical cancer. Cervical disease was significantly increased in p21−/− mice compared with p21+/+ mice, showing that p21Cip1 can function as a tumor suppressor in this tissue. Importantly, the ability of E7 to induce cervical cancers was not significantly enhanced on the p21-null background, consistent with the hypothesis that the ability of E7 to inhibit p21Cip1 contributes to its carcinogenic properties. Further supportive of this hypothesis, cervical carcinogenesis in mice expressing a mutant form of HPV-16 E7, E7CVQ, which fails to inactivate p21Cip1, was significantly reduced compared with that in K14E7WT mice expressing wild-type HPV-16 E7. However, K14E7CVQ mice still displayed heightened levels of cervical carcinogenesis compared with that in nontransgenic mice, indicating that activities of E7 besides its capacity to inactivate p21Cip1 also contribute to cervical carcinogenesis. Taken together, we conclude that p21Cip1 functions as a tumor suppressor in cervical carcinogenesis and that p21Cip1 inactivation by HPV-16 E7 partially contributes to the contribution of E7 to cervical carcinogenesis. [Cancer Res 2009;69(14):5656–63]
Data from Dual Phosphoinositide 3-Kinase/Mammalian Target of Rapamycin Blockade Is an Effective Radiosensitizing Strategy for the Treatment of Non–Small Cell Lung Cancer Harboring K-RAS Mutations
Authors: Konstantinidou Georgia , Bey Erik A. , Rabellino Andrea , Schuster Katja , Maira Michael S. , Gazdar Adi F. , Amici Augusto , Boothman David A. , Scaglioni Pier Paolo
Published: March 2024

Abstract
Non–small cell lung cancer (NSCLC) is a leading cause of cancer-related death worldwide. NSCLC often harbors oncogenic K-RAS mutations that lead to the aberrant activation of several intracellular networks including the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway. Oncogenic K-RAS predicts poor prognosis and resistance to treatment with ionizing radiation (IR). Oncogenic K-Ras expression in the respiratory epithelium is sufficient to initiate NSCLC tumorigenesis, which requires the catalytic subunit of PI3K. Thus, effective inhibition of the PI3K signaling should lead to significant antitumor effects. However, therapy with rapamycin analogues has yielded disappointing results due in part to compensatory up-regulation of AKT. We hypothesized that dual PI3K/mTOR blockade would overcome these limitations. We tested this hypothesis with BEZ235, a novel dual PI3K/mTOR inhibitor that has recently entered clinical development. We found that BEZ235 induces a striking antiproliferative effect both in transgenic mice with oncogenic K-RAS–induced NSCLC and in NSCLC cell lines expressing oncogenic K-RAS. We determined that treatment with BEZ235 was not sufficient to induce apoptosis. However, we found that dual PI3K/mTOR blockade effectively sensitizes NSCLC expressing oncogenic K-RAS to the proapoptotic effects of IR both in vitro and in vivo. We conclude that dual PI3K/mTOR blockade in combination with IR may benefit patients with NSCLC expressing oncogenic K-RAS. These findings may have general applicability in cancer therapy, because aberrant activation of PI3K occurs frequently in human cancer. [Cancer Res 2009;69(19):7644–52]
Data from Mutagenicity and Potential Carcinogenicity of Thiopurine Treatment in Patients with Inflammatory Bowel Disease
Authors: Nguyen Truc , Vacek Pamela M. , O'Neill Patrick , Colletti Richard B. , Finette Barry A.
Published: March 2024

Abstract
The thiopurines azathioprine and 6-mercaptopurine (6-MP) are effective immune modulators and cytotoxic agents extensively used in the treatment of autoimmune diseases, graft rejection, and cancer. There is compelling epidemiologic evidence that thiopurine treatment increases the risk for a variety of tumors by mechanisms that are unclear. We investigated the in vivo mutagenicity of long-term thiopurine treatment by determining the frequency and spectra of somatic mutation events at the hypoxanthine phosphoribosyltransferase (HPRT) locus in peripheral T lymphocytes as well as the prevalence of mutant clonal proliferation in a cross-sectional analysis of data from 119 children and adults with inflammatory bowel disease (IBD). ANOVA and regression were performed to assess relationships among the frequency and spectra of HPRT mutations with disease, duration of illness, duration of treatment, and total therapeutic dose of azathioprine and 6-MP. We observed a significant increase in the frequency of somatic mutations in 56 subjects treated with thiopurines for IBD compared with 63 subjects not treated with thiopurines. This increase was related to both total dose (P < 0.001) and duration of treatment (P < 0.001). Comparative mutation spectra analysis of 1,020 mutant isolates revealed a significant increase in the proportion of all transitions (P < 0.001), particularly G:C to A:T transitions (P < 0.001). Combined analyses of two signatures for mutant clonality, HPRT mutation, and T-cell receptor β CDR3 region unique gene sequence also showed a significant thiopurine-dependent increase in mutant cell clonal proliferation (P < 0.001). These findings provide in vivo evidence for mutation induction as a potential carcinogenic mechanism associated with chronic thiopurine intervention. [Cancer Res 2009;69(17):7004–23]
Data from Characterization of ERG, AR and PTEN Gene Status in Circulating Tumor Cells from Patients with Castration-Resistant Prostate Cancer
Authors: Attard Gerhardt , Swennenhuis Joost F. , Olmos David , Reid Alison H.M. , Vickers Elaine , A'Hern Roger , Levink Rianne , Coumans Frank , Moreira Joana , Riisnaes Ruth , Oommen Nikhil Babu , Hawche George , Jameson Charles , Thompson Emilda , Sipkema Ronald , Carden Craig P. , Parker Christopher , Dearnaley David , Kaye Stan B. , Cooper Colin S. , Molina Arturo , Cox Michael E. , Terstappen Leon W.M.M. , de Bono Johann S.
Published: March 2024

Abstract
Hormone-driven expression of the ERG oncogene after fusion with TMPRSS2 occurs in 30% to 70% of therapy-naive prostate cancers. Its relevance in castration-resistant prostate cancer (CRPC) remains controversial as ERG is not expressed in some TMPRSS2-ERG androgen-independent xenograft models. However, unlike these models, CRPC patients have an increasing prostate-specific antigen, indicating active androgen receptor signaling. Here, we collected blood every month from 89 patients (54 chemotherapy-naive patients and 35 docetaxel-treated patients) treated in phase I/phase II clinical trials of an orally available, highly specific CYP17 inhibitor, abiraterone acetate, that ablates the synthesis of androgens and estrogens that drive TMPRSS2-ERG fusions. We isolated circulating tumor cells (CTC) by anti–epithelial cell adhesion molecule immunomagnetic selection followed by cytokeratin and CD45 immunofluorescence and 4′,6-diamidino-2-phenylindole staining. We used multicolor fluorescence in situ hybridization to show that CRPC CTCs, metastases, and prostate tissue invariably had the same ERG gene status as therapy-naive tumors (n = 31). We then used quantitative reverse transcription–PCR to show that ERG expression was maintained in CRPC. We also observed homogeneity in ERG gene rearrangement status in CTCs (n = 48) in contrast to significant heterogeneity of AR copy number gain and PTEN loss, suggesting that rearrangement of ERG may be an earlier event in prostate carcinogenesis. We finally report a significant association between ERG rearrangements in therapy-naive tumors, CRPCs, and CTCs and magnitude of prostate-specific antigen decline (P = 0.007) in CRPC patients treated with abiraterone acetate. These data confirm that CTCs are malignant in origin and indicate that hormone-regulated expression of ERG persists in CRPC. [Cancer Res 2009;69(7):2912–8]
Data from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck Squamous Cell Carcinoma Promotes Tumor Development and Protects the Tumor from Immune Attack
Authors: Szczepanski Miroslaw J. , Czystowska Malgorzata , Szajnik Marta , Harasymczuk Malgorzata , Boyiadzis Michael , Kruk-Zagajewska Aleksandra , Szyfter Witold , Zeromski Jan , Whiteside Theresa L.
Published: March 2024

Abstract
Toll-like receptors (TLR) expressed on inflammatory cells play a key role in host defense against pathogens, benefiting the host. TLR are also expressed on tumor cells. To evaluate the role of TLR in tumor cells, we investigated TLR4 signaling effects on human head and neck squamous cell carcinoma (HNSCC). Tumor tissues were obtained from 27 patients with laryngeal and 12 with oral cavity cancers. Normal mucosa was obtained from 10 patients with nonneoplastic disorders. Smears for bacteria were taken from all patients during surgery. TLR4 expression in tumors and HNSCC cell lines (PCI-1, PCI-13, and PCI-30) was detected by reverse transcription-PCR and immunohistochemistry. Cell growth, apoptosis, nuclear factor-κB (NF-κB) translocation, and MyD88 and IRAK-4 expression, as well as Akt phosphorylation were measured following tumor cell exposure to the TLR4 ligand lipopolysaccharide (LPS). Tumor cell sensitivity to NK-92–mediated lysis was evaluated in 4-hour 51Cr-release assays. Cytokine levels in HNSCC supernatants were measured in Luminex-based assays. TLR4 was expressed in all tumors, HNSCC cell lines, and normal mucosa. The TLR4 expression intensity correlated with tumor grade. LPS binding to TLR4 on tumor cells enhanced proliferation, activated phosphatidylinositol 3-kinase/Akt pathway, up-regulated IRAK-4 expression, induced nuclear NF-κB translocation, and increased production (P < 0.05) of interleukin (IL)-6, IL-8, vascular endothelial growth factor, and granulocyte macrophage colony-stimulating factor. TLR4 triggering protected tumor cells from lysis mediated by NK-92 cells. TLR4 ligation on tumor cells supports HNSCC progression. [Cancer Res 2009;69(7):3105–13]
Data from ARTEMIS Nuclease Facilitates Apoptotic Chromatin Cleavage
Authors: Britton Sébastien , Frit Philippe , Biard Denis , Salles Bernard , Calsou Patrick
Published: March 2024

Abstract
One hallmark of apoptosis is DNA degradation that first appears as high molecular weight fragments followed by extensive internucleosomal fragmentation. During apoptosis, the DNA-dependent protein kinase (DNA-PK) is activated. DNA-PK is involved in the repair of DNA double-strand breaks (DSB) and its catalytic subunit is associated with the nuclease ARTEMIS. Here, we report that, on initiation of apoptosis in human cells by agents causing DNA DSB or by staurosporine or other agents, ARTEMIS binds to apoptotic chromatin together with DNA-PK and other DSB repair proteins. ARTEMIS recruitment to chromatin showed a time and dose dependency. It required DNA-PK protein kinase activity and was blocked by antagonizing the onset of apoptosis with a pan-caspase inhibitor or on overexpression of the antiapoptotic BCL2 protein. In the absence of ARTEMIS, no defect in caspase-3, poly(ADP-ribose) polymerase-1, and XRCC4 cleavage or in H2AX phosphorylation was observed and DNA-PK catalytic subunit was still phosphorylated on S2056 in response to staurosporine. However, DNA fragmentation including high molecular weight fragmentation was delayed in ARTEMIS-deficient cells compared with cells expressing ARTEMIS. In addition, ARTEMIS enhanced the kinetics of MLL gene cleavage at a breakage cluster breakpoint that is frequently translocated in acute or therapy-related leukemias. These results show a facilitating role for ARTEMIS at least in early, site-specific chromosome breakage during apoptosis. [Cancer Res 2009;69(20):8120–6]
Data from Sonic Hedgehog Signaling Pathway Is Activated in ALK-Positive Anaplastic Large Cell Lymphoma
Authors: Singh Rajesh R. , Cho-Vega Jeong Hee , Davuluri Yogesh , Ma Shuguang , Kasbidi Fatan , Milito Cristiane , Lennon Patrick A. , Drakos Elias , Medeiros L. Jeffrey , Luthra Rajyalakshmi , Vega Francisco
Published: March 2024

Abstract
Deregulation of the sonic hedgehog (SHH) signaling pathway has been implicated in several cancers but has not been explored in T-cell lymphomas. Here, we report that the SHH/GLI1 signaling pathway is activated in anaplastic lymphoma kinase (ALK)–positive anaplastic large cell lymphoma (ALCL). We show that SHH, but not its transcriptional effector GLI1, is amplified in ALK+ ALCL tumors and cell lines, and that SHH and GLI1 proteins are highly expressed in ALK+ ALCL tumors and cell lines. We also show that inhibition of SHH/GLI1 signaling with cyclopamine-KAAD, as well as silencing GLI1 gene expression by small interfering (si)RNA, decreased cell viability and clonogenicity of ALK+ ALCL cells. Transfection of wild-type or mutant NPM-ALK into 293T cells showed that only wild-type NPM-ALK increased GLI1 protein levels and activated SHH/GLI1 signaling as shown by increase of CCND2 mRNA levels. Inhibition of ALK tyrosine kinase and phosphatidylinositol 3-kinase (PI3K)/AKT or forced expression of pAKT down-regulated or up-regulated SHH/GLI1 signaling, respectively. Inhibition of GSK3β in 293T cells also increased protein levels of GLI1. In conclusion, the SHH/GLI1 signaling pathway is activated in ALK+ ALCL. SHH/GLI1 activation is the result of SHH gene amplification and is further mediated by NPM-ALK through activation of PI3K/AKT and stabilization of GLI1 protein. There is a positive synergistic effect between the SHH/GLI1 and PI3K/AKT pathways that contributes to the lymphomagenic effect of NPM-ALK. [Cancer Res 2009;69(6):2550–8]
Data from p73 and p63 Sustain Cellular Growth by Transcriptional Activation of Cell Cycle Progression Genes
Authors: Lefkimmiatis Konstantinos , Caratozzolo Mariano Francesco , Merlo Paola , D'Erchia Anna Maria , Navarro Beatriz , Levrero Massimo , Sbisa' Elisabetta , Tullo Apollonia
Published: March 2024

Abstract
Despite extensive studies on the role of tumor suppressor p53 protein and its homologues, p73 and p63, following their overexpression or cellular stress, very little is known about the regulation of the three proteins in cells during physiologic cell cycle progression. We report a role for p73 and p63 in supporting cellular proliferation through the transcriptional activation of the genes involved in G1-S and G2-M progression. We found that in MCF-7 cells, p73 and p63, but not p53, are modulated during the cell cycle with a peak in S phase, and their silencing determines a significant suppression of proliferation compared with the control. Chromatin immunoprecipitation analysis shows that in cycling cells, p73 and p63 are bound to the p53-responsive elements (RE) present in the regulatory region of cell cycle progression genes. On the contrary, when the cells are arrested in G0-G1, p73 detaches from the REs and it is replaced by p53, which represses the expression of these genes. When the cells move in S phase, p73 is recruited again and p53 is displaced or is weakly bound to the REs. These data open new possibilities for understanding the involvement of p73 and p63 in cancer. The elevated concentrations of p73 and p63 found in many cancers could cause the aberrant activation of cell growth progression genes and therefore contribute to cancer initiation or progression under certain conditions. [Cancer Res 2009;69(22):8563–71]