bluuebunny/crossref_metadata_2025_split huggingface dataset:
β-Tubulin Mutations Are Associated with Resistance to 2-Methoxyestradiol in MDA-MB-435 Cancer Cells
Authors: Gökmen-Polar Yesim , Escuin Daniel , Walls Chad D. , Soule Sharon E. , Wang Yuefang , Sanders Kerry L. , LaVallee Theresa M. , Wang Mu , Guenther Brian D. , Giannakakou Paraskevi , Sledge George W. 
Published: October 2005

Abstract
2-Methoxyestradiol is an estradiol metabolite with significant antiproliferative and antiangiogenic activity independent of estrogen receptor status. To identify a molecular basis for acquired 2-methoxyestradiol resistance, we generated a stable 2-methoxyestradiol-resistant (2ME2R) MDA-MB-435 human cancer cell line by stepwise exposure to increasing 2-methoxyestradiol concentrations. 2ME2R cells maintained in the presence of the drug and W435 cells maintained in the absence of the drug showed 32.34- to 40.07-fold resistance to 2-methoxyestradiol. Cross-resistance was observed to Vinca alkaloids, including vincristine, vinorelbine, and vinblastine (4.29- to 6.40-fold), but minimal resistance was seen to colchicine-binding agents including colchicine, colcemid, and AVE8062A (1.72- to 2.86-fold). No resistance was observed to paclitaxel and epothilone B, polymerizing agents (0.89- to 1.14-fold). Genomic sequencing identified two different heterozygous point mutations in the class I (M40) isotype of β-tubulin at amino acids 197 (Dβ197N) and 350 (Kβ350N) in 2ME2R cells. Tandem mass spectrometry confirmed the presence of both wild-type and the mutant β-tubulin in 2ME2R cells at the protein level. Consistently, treatment of parental P435 cells with 2-methoxyestradiol resulted in a dose-dependent depolymerization of microtubules, whereas 2ME2R cells remained unaffected. In contrast, paclitaxel affected both cell lines. In the absence of 2-methoxyestradiol, 2ME2R cells were characterized by an elevated level of detyrosination. Upon 2-methoxyestradiol treatment, levels of acetylated and detyrosinated tubulins decreased in P435 cells, while remaining constant in 2ME2R cells. These results, together with our structure-based modeling, show a tight correlation between the antitubulin and antiproliferative effects of 2-methoxyestradiol, consistent with acquired tubulin mutations contributing to 2-methoxyestradiol resistance.
Radiosensitivity Enhancement by Celecoxib, a Cyclooxygenase (COX)-2 Selective Inhibitor, via COX-2–Dependent Cell Cycle Regulation on Human Cancer Cells Expressing Differential COX-2 Levels
Authors: Shin You Keun , Park Ji Sun , Kim Hyun Seok , Jun Hyun Jung , Kim Gwi Eon , Suh Chang Ok , Yun Yeon Sook , Pyo Hongryull 
Published: October 2005

AbstractTo characterize the radiation-enhancing effects on human cancer cells and underlying mechanisms of celecoxib, a cyclooxygenase (COX)-2 selective inhibitor, and to ascertain whether its effects are COX-2 dependent. Clonogenic cytotoxicity assays and radiation survival assays after treatment with celecoxib ± radiation were done on four human cancer cell lines that expressed differential COX-2 levels. Stably COX-2 knocked down or overexpressed cell lines were developed, and clonogenic assays, apoptosis assays, or cell cycle change measurements were conducted after treatment with celecoxib ± radiation. Prostaglandin E2 (PGE2) was applied to medium after treatment with celecoxib ± radiation to determine whether the radiation-enhancing effect associated with celecoxib results from reduced generation of prostaglandin. Celecoxib's radiation-enhancing effect was observed in COX-2–expressing A549 and NCI-H460 cells but was not observed in the COX-2 nonexpressing MCF-7 and HCT-116 cells. Celecoxib's radiation-enhancing effects in A549 cells were shown to disappear after the administration of COX-2 knocked down. In contrast, the HCT-116 cells were radiosensitized by celecoxib after being transfected with COX-2 expression vector. The addition of PGE2 after treatment with celecoxib ± radiation had no significant effects on celecoxib's radiation-enhancing effects in A549 and COX-2 transfected HCT-116 cells. Radiation-induced G2-M arrest was enhanced and sustained in the COX-2–overexpressing cells compared with that seen in COX-2 low-expressing cells. Celecoxib or NS-398 effected no changes or attenuated radiation-induced G2-M arrest in the COX-2–overexpressing cells but further enhanced the radiation-induced G2-M arrest in the COX-2 low-expressing cells. Celecoxib's radiation-enhancing effects seem to occur in a COX-2 expression-dependent manner in the cancer cells. This effect does not seem to be the result of reduced PGE2 generation. Celecoxib may exert an inhibitory effect on enhanced radiation-induced G2-M arrest in the COX-2–overexpressing cells, which may allow the arrested cells to enter mitosis and die after radiation, but may also further enhance radiation-induced G2-M arrest in the COX-2 low-expressing cells, by virtue of another mechanism.
Down-regulation of Integrin α2 Surface Expression by Mutant Epidermal Growth Factor Receptor (EGFRvIII) Induces Aberrant Cell Spreading and Focal Adhesion Formation
Authors: Ning Yan , Zeineldin Reema , Liu Yueying , Rosenberg Martina , Stack M. Sharon , Hudson Laurie G. 
Published: October 2005

Abstract
Elevated expression or activity of the epidermal growth factor receptor (EGFR) is common in ovarian cancer and is associated with poor patient prognosis. A naturally occurring EGFR mutation termed variant III (EGFRvIII) has been detected in many human tumors, including those of the ovary. This mutant receptor does not bind EGF; however, it is constitutively active as detected by receptor dimerization, autophosphorylation, and stimulation of signal transduction cascades. To identify the consequences of EGFRvIII expression in ovarian tumor cells, we introduced EGFRvIII into the epithelial ovarian cancer cell line OVCA 433. The EGFRvIII-transfected cells displayed a motile phenotype, defects in cell spreading, and decreased integrin α2 protein expression as detected by Western blot analysis and flow cytometry. Inhibition of EGFRvIII catalytic activity using the EGFR-selective tyrphostin AG1478 restored integrin α2 expression within 4 to 8 hours after treatment. The modulation of integrin α2 expression corresponded to marked changes in the actin cytoskeleton as detected by redistribution of filamentous-actin. Furthermore, focal adhesions were evident only when EGFRvIII activity was inhibited. Together, these findings suggest that expression of the constitutively active mutant EGFRvIII promotes changes in cell shape and focal adhesion formation, mediated in part through specific modulation of integrin α2 expression and function. We conclude that EGFR-activating mutations, such as EGFRvIII, in ovarian cancer may contribute to a more aggressive disease.
Lysophosphatidic Acid Acyltransferase-β Is a Prognostic Marker and Therapeutic Target in Gynecologic Malignancies
Authors: Springett Gregory M. , Bonham Lynn , Hummer Amanda , Linkov Irina , Misra Dipika , Ma Chia , Pezzoni Gabriella , Di Giovine Stefano , Singer Jack , Kawasaki Hiroaki , Spriggs David , Soslow Robert , Dupont Jakob 
Published: October 2005

Abstract
Lysophosphatidic acid, the substrate for lysophosphatidic acid acyltransferase β (LPAAT-β), is a well-studied autocrine/paracrine signaling molecule that is secreted by ovarian cancer cells and is found at elevated levels in the blood and ascites fluid of women with ovarian cancer. LPAAT-β converts lysophosphatidic acid to phosphatidic acid, which functions as a cofactor in Akt/mTOR and Ras/Raf/Erk pathways. We report that elevated expression of LPAAT-β was associated with reduced survival in ovarian cancer and earlier progression of disease in ovarian and endometrial cancer. Inhibition of LPAAT-β using small interfering RNA or selective inhibitors, CT32521 and CT32228, two small-molecule noncompetitive antagonists representing two different classes of chemical structures, induces apoptosis in human ovarian and endometrial cancer cell lines in vitro at pharmacologically tenable nanomolar concentrations. Inhibition of LPAAT-β also enhanced the survival of mice bearing ovarian tumor xenografts. Cytotoxicity was modulated by diacylglycerol effectors including protein kinase C and CalDAG-GEF1. LPAAT-β was localized to the endoplasmic reticulum and overexpression was associated with redistribution of protein kinase C-α. These findings identify LPAAT-β as a potential prognostic and therapeutic target in ovarian and endometrial cancer.
Fusokine Interleukin-2/Interleukin-18, a Novel Potent Innate and Adaptive Immune Stimulator with Decreased Toxicity
Authors: Acres Bruce , Gantzer Murielle , Remy Christelle , Futin Nicolas , Accart Nathalie , Chaloin Olivier , Hoebeke Johan , Balloul Jean-Marc , Paul Stéphane 
Published: October 2005

AbstractTo redress the immune imbalances created by pathologies such as cancer, it would be beneficial to create novel cytokine molecules, which combine desired cytokine activities with reduced toxicities. Due to their divergent but complementary activities, it is of interest to combine interleukin-2 (IL-2) and IL-18 into one recombinant molecule for immunotherapy. Evaluation of a fusokine protein that combines murine IL-2/IL-18 shows that it is stable, maintains IL-2 and IL-18 bioactivities, has notably reduced IL-2 associated toxicities, and has a novel lymphocyte-stimulating activity. An adeno-viral expression system was used to explore the biology of this “fusokine”. Inclusion of the IL-18 prosequence (proIL-18) increases the expression, secretion, and potency of this fusokine. In vivo gene transfer experiments show that Ad-IL-2/proIL-18 dramatically outdoes Ad-IL-2, Ad-proIL-18, or the combination of both, by inducing high rates of tumor rejection in several murine models. Both innate and adaptive effector mechanisms are required for this antitumor activity.
A Blocking Antibody to Nerve Growth Factor Attenuates Skeletal Pain Induced by Prostate Tumor Cells Growing in Bone
Authors: Halvorson Kyle G. , Kubota Kazufumi , Sevcik Molly A. , Lindsay Theodore H. , Sotillo Julio E. , Ghilardi Joseph R. , Rosol Thomas J. , Boustany Leila , Shelton David L. , Mantyh Patrick W. 
Published: October 2005

AbstractProstate cancer is unique in that bone is often the only clinically detectable site of metastasis. Prostate tumors that have metastasized to bone frequently induce bone pain which can be difficult to fully control as it seems to be driven simultaneously by inflammatory, neuropathic, and tumorigenic mechanisms. As nerve growth factor (NGF) has been shown to modulate inflammatory and some neuropathic pain states in animal models, an NGF-sequestering antibody was administered in a prostate model of bone cancer where significant bone formation and bone destruction occur simultaneously in the mouse femur. Administration of a blocking antibody to NGF produced a significant reduction in both early and late stage bone cancer pain–related behaviors that was greater than or equivalent to that achieved with acute administration of 10 or 30 mg/kg of morphine sulfate. In contrast, this therapy did not influence tumor-induced bone remodeling, osteoblast proliferation, osteoclastogenesis, tumor growth, or markers of sensory or sympathetic innervation in the skin or bone. One rather unique aspect of the sensory innervation of bone, that may partially explain the analgesic efficacy of anti-NGF therapy in relieving prostate cancer–induced bone pain, is that nearly all nerve fibers that innervate the bone express trkA and p75, and these are the receptors through which NGF sensitizes and/or activates nociceptors. The present results suggest that anti-NGF therapy may be effective in reducing pain and enhancing the quality of life in patients with prostate tumor–induced bone cancer pain.
Enhancement of Cancer Radiation Therapy by Use of Adenovirus-Mediated Secretable Glucose-Regulated Protein 94/gp96 Expression
Authors: Liu Shanling , Wang He , Yang Zhonghui , Kon Takashi , Zhu Jiangao , Cao Yiting , Li Fang , Kirkpatrick John , Nicchitta Christopher V. , Li Chuan-Yuan 
Published: October 2005

AbstractTumor-derived glucose-regulated protein 94 (GRP94/gp96) has shown great promise as a tumor vaccine. However, current protein-based approaches require the availability of large quantities of tumor tissue, which are often not possible. In addition, the efficacy of immunotherapy is often not ideal when used alone. In this study, we explored the therapeutic efficacy of a combined GRP94/gp96-based genetic immunotherapy and radiation therapy strategy in the weakly immunogenic and highly metastatic 4T1 murine mammary cancer model. An adenovirus encoding a modified, secretable form of GRP94 gene (AdsGRP94) was constructed and evaluated in various antitumor experiments. Lethally irradiated, virus-infected cells were used as vaccines. Adenoviral vectors were also injected directly into tumors in conjunction with tumor irradiation. Vaccination with lethally irradiated, AdsGRP94-infected 4T1 cells completely prevented subsequent tumor growth from challenge inoculations of as many as 107 cells per mouse. In established tumor models, vaccinations alone had minimal effect on local and metastatic tumor growth. However, when vaccination was combined with radiation therapy and i.t. AdsGRP94 injections, local tumor growth and pulmonary metastasis were markedly inhibited. In some cases, complete tumor regression was observed. In these cases, the mice were resistant to subsequent tumor challenge and remain tumor free up to 10 months after initial therapy. Our results indicate that combined AdsGRP94-based immunotherapy and radiation therapy may be a potentially effective strategy for cancer treatment.
Less Efficient G2-M Checkpoint Is Associated with an Increased Risk of Lung Cancer in African Americans
Authors: Zheng Yun-Ling , Loffredo Christopher A. , Alberg Anthony J. , Yu Zhipeng , Jones Raymond T. , Perlmutter Donna , Enewold Lindsey , Krasna Mark J. , Yung Rex , Shields Peter G. , Harris Curtis C. 
Published: October 2005

AbstractCell cycle checkpoints play critical roles in the maintenance of genomic integrity. The inactivation of checkpoint genes by genetic and epigenetic mechanisms is frequent in all cancer types, as a less-efficient cell cycle control can lead to genetic instability and tumorigenesis. In an on-going case-control study consisting of 216 patients with non–small cell lung cancer, 226 population-based controls, and 114 hospital-based controls, we investigated the relationship of γ-radiation-induced G2-M arrest and lung cancer risk. Peripheral blood lymphocytes were cultured for 90 hours, exposed to 1.0 Gy γ-radiation, and harvested at 3 hours after γ-radiation treatment. γ-Radiation-induced G2-M arrest was measured as the percentage of mitotic cells in untreated cultures minus the percentage of mitotic cells in γ-radiation-treated cultures from the same subject. The mean percentage of γ-radiation-induced G2-M arrest was significantly lower in cases than in population controls (1.18 versus 1.44, P &lt; 0.01) and hospital controls (1.18 versus 1.40, P = 0.01). When dichotomized at the 50th percentile value in combined controls (population and hospital controls), a lower level of γ-radiation-induced G2-M arrest was associated with an increased risk of lung cancer among African Americans after adjusting for baseline mitotic index, age, gender, and pack-years of smoking [adjusted odd ratio (OR), 2.25; 95% confidence interval (95% CI), 0.97-5.20]. A significant trend of an increased risk of lung cancer with a decreased level of G2-M arrest was observed (Ptrend = 0.02) among African Americans, with a lowest-versus-highest quartile adjusted OR of 3.74 (95% CI, 0.98-14.3). This trend was most apparent among African American females (Ptrend &lt; 0.01), with a lowest-versus-highest quartile adjusted OR of 11.75 (95% CI, 1.47-94.04). The results suggest that a less-efficient DNA damage–induced G2-M checkpoint is associated with an increased risk of lung cancer among African Americans. Interestingly, we observed a stronger association of DNA damage–induced G2-M arrest and lung cancer among African Americans when compared with Caucasians. If replicated, these results may provide clues to the exceedingly high lung cancer incidence experienced by African Americans.
Misregulated Wnt/β-Catenin Signaling Leads to Ovarian Granulosa Cell Tumor Development
Authors: Boerboom Derek , Paquet Marilene , Hsieh Minnie , Liu Jinsong , Jamin Soazik P. , Behringer Richard R. , Sirois Jean , Taketo Makoto M. , Richards JoAnne S. 
Published: October 2005

Abstract
Misregulation of the Wnt/β-catenin signaling pathway is a hallmark of several forms of cancer. Components of the Wnt/β-catenin pathway are expressed in ovarian granulosa cells; nevertheless, its potential involvement in granulosa cell tumorigenesis has not been examined. To this end, human (n = 6) and equine (n = 18) granulosa cell tumors (GCT) were analyzed for β-catenin expression by immunohistochemistry. Unlike granulosa cells of normal ovaries, most (15 of 24) GCT samples showed nuclear localization of β-catenin, suggesting that activation of the Wnt/β-catenin pathway plays a role in the etiology of GCT. To confirm this hypothesis, Catnbflox(ex3)/+; Amhr2cre/+ mice that express a dominant stable β-catenin mutant in their granulosa cells were generated. These mice developed follicle-like structures containing disorganized, pleiomorphic granulosa by 6 weeks of age. Even in older mice, these follicle-like lesions grew no larger than the size of antral follicles and contained very few proliferating cells. Similar to corpora lutea, the lesions were highly vascularized, although they did not express the luteinization marker Cyp11a1. Catnbflox(ex3)/+; Amhr2cre/+ females were also found to be severely subfertile, and fewer corpora lutea were found to form in response to exogenous gonadotropin compared with control mice. In older mice, the ovarian lesions often evolved into GCT, indicating that they represent a pretumoral intermediate stage. The GCT in Catnbflox(ex3)/+; Amhr2cre/+ mice featured many histopathologic similarities to the human disease, and prevalence of tumor development attained 57% at 7.5 months of age. Together, these studies show a causal link between misregulated Wnt/β-catenin signaling and GCT development and provide a novel model system for the study of GCT biology.
Epithelial to Mesenchymal Transition Is a Determinant of Sensitivity of Non–Small-Cell Lung Carcinoma Cell Lines and Xenografts to Epidermal Growth Factor Receptor Inhibition
Authors: Thomson Stuart , Buck Elizabeth , Petti Filippo , Griffin Graeme , Brown Eric , Ramnarine Nishal , Iwata Kenneth K. , Gibson Neil , Haley John D. 
Published: October 2005

AbstractTreatment of second- and third-line patients with non–small-cell lung carcinoma (NSCLC) with the epidermal growth factor receptor (EGFR) kinase inhibitor erlotinib significantly increased survival relative to placebo. Whereas patient tumors with EGFR mutations have shown responses to EGFR inhibitors, an exclusive role for mutations in patient survival benefit from EGFR inhibition is unclear. Here we show that wild-type EGFR–containing human NSCLC lines grown both in culture and as xenografts show a range of sensitivities to EGFR inhibition dependent on the degree to which they have undergone an epithelial to mesenchymal transition (EMT). NSCLC lines which express the epithelial cell junction protein E-cadherin showed greater sensitivity to EGFR inhibition in vitro and in xenografts. In contrast, NSCLC lines having undergone EMT, expressing vimentin and/or fibronectin, were insensitive to the growth inhibitory effects of EGFR kinase inhibition in vitro and in xenografts. The differential sensitivity of NSCLC cells with epithelial or mesenchymal phenotypes to EGFR inhibition did not correlate with cell cycle status in vitro or with xenograft growth rates in vivo, or with total EGFR protein levels. Cells sensitive to EGFR inhibition, with an epithelial cell phenotype, did exhibit increased phosphorylation of EGFR and ErbB3 and a marked increase in total ErbB3. The loss of E-cadherin and deregulation of β-catenin associated with EMT have been shown to correlate with poor prognosis in multiple solid tumor types. These data suggest that EMT may be a general biological switch rendering non–small cell lung tumors sensitive or insensitive to EGFR inhibition.
Critical Function for ADAM9 in Mouse Prostate Cancer
Authors: Peduto Lucie , Reuter Victor E. , Shaffer David R. , Scher Howard I. , Blobel Carl P. 
Published: October 2005

Abstract
ADAM9 is a membrane-anchored metalloprotease that is markedly up-regulated in several human carcinomas. Here, we show that ADAM9 is similarly up-regulated in mouse models for prostate, breast, and intestinal carcinoma. To assess whether ADAM9 is critical for the pathogenesis of prostate carcinoma, one of the most common cancers in men, we evaluated how loss of ADAM9 affects tumorigenesis in W10 mice, a mouse model for this disease. In the absence of ADAM9, most tumors in 50-week-old W10 mice were well differentiated, whereas littermate controls expressing wild-type ADAM9 had predominantly poorly differentiated, and in some cases significantly larger, tumors. Moreover, gain-of-function experiments in which ADAM9 was overexpressed in mouse prostate epithelium resulted in significant abnormalities, including epithelial hyperplasia at 4 to 6 months of age, and prostatic intraepithelial neoplasia after 1 year. A potential underlying mechanism for the role of ADAM9 in prostate cancer emerged from cell-based assays: ADAM9 can cleave and release epidermal growth factor and FGFR2iiib from cells, both of which have pivotal functions in the pathogenesis of this disease. Taken together, these results suggest that ADAM9 contributes to the pathogenesis of prostate cancer and potentially also other carcinomas, raising the possibility that ADAM9 might be a good target for antitumor drugs.
Bovine Herpesvirus 4 Induces Apoptosis of Human Carcinoma Cell Lines In vitro and In vivo
Authors: Gillet Laurent , Dewals Benjamin , Farnir Frédéric , de Leval Laurence , Vanderplasschen Alain 
Published: October 2005

Abstract
The idea of using oncolytic viruses for the treatment of cancers was proposed a century ago. During the last two decades, viruses able to replicate specifically in cancer cells and to induce their lysis were identified and were genetically modified to improve their viro-oncolytic properties. More recently, a new approach consisting of inducing selective apoptosis in cancer cells through viral infection has been proposed; this approach has been called viro-oncoapoptosis. In the present study, we report the property of bovine herpesvirus-4 (BoHV-4) to induce, in vitro and in vivo, apoptosis of some human carcinomas. This conclusion relies on the following observations: (a) In vitro, BoHV-4 infection induced apoptosis of A549 and OVCAR carcinoma cell lines in a time- and dose-dependent manner. (b) Apoptosis was induced by the expression of an immediate-early or an early BoHV-4 gene, but did not require viral replication. (c) Cell treatment with caspase inhibitors showed that apoptosis induced by BoHV-4 relied mainly on caspase-10 activation. (d) Infection of cocultures of A549 or OVCAR cells mixed with human 293 cells (in which BoHV-4 does not induce apoptosis) showed that BoHV-4 specifically eradicated A549 or OVCAR cancer cells from the cocultures. (e) Finally, in vivo experiments done with nude mice showed that BoHV-4 intratumoral injections reduced drastically the growth of preestablished A549 xenografts. Taken together, these results suggest that BoHV-4 may have potential as a viro-oncoapoptotic agent for the treatment of some human carcinomas. Moreover, further identification of BoHV-4 proapoptotic gene(s) and the cellular pathways targeted by this or these gene(s) could lead to the design of new cancer therapeutic strategies.