bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transforming Growth Factor-β (TGF-β) and TGF-β–Associated Kinase 1 Are Required for R-Ras–Mediated Transformation of Mammary Epithelial Cells
Authors: Erdogan Mete , Pozzi Ambra , Bhowmick Neil , Moses Harold L. , Zent Roy 
Published: August 2008

AbstractTransforming growth factor-β (TGF-β) cooperates with oncogenic members of the Ras superfamily to promote cellular transformation and tumor progression. Apart from the classic (H-, K-, and N-) Ras GTPases, only the R-Ras subfamily (R-Ras, R-Ras2/TC21, and R-Ras3/M-Ras) has significant oncogenic potential. In this study, we show that oncogenic R-Ras transformation of EpH4 cells requires TGF-β signaling. When murine EpH4 cells were stably transfected with a constitutively active R-Ras(G38V) mutant, they were no longer sensitive to TGF-β–mediated growth inhibition and showed increased proliferation and transformation in response to exogenous TGF-β. R-Ras/EpH4 cells require TGF-β signaling for transformation to occur and they produce significantly elevated levels of endogenous TGF-β, which signals in an autocrine fashion. The effects of TGF-β are independent of Smad2/3 activity and require activation of TGF-β–associated kinase 1 (TAK1) and its downstream effectors c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinase as well as the phosphoinositide 3-kinase/Akt and mammalian target of rapamycin pathways. Thus, TAK1 is a novel link between TGF-β signaling and oncogenic R-Ras in the promotion of tumorigenesis. [Cancer Res 2008;68(15):6224–31]
Neutrophil Gelatinase–Associated Lipocalin: A Novel Suppressor of Invasion and Angiogenesis in Pancreatic Cancer
Authors: Tong Zhimin , Kunnumakkara Ajaikumar B. , Wang Huamin , Matsuo Yoichi , Diagaradjane Parmeswaran , Harikumar Kuzhuvelil B. , Ramachandran Vijaya , Sung Bokyung , Chakraborty Arup , Bresalier Robert S. , Logsdon Craig , Aggarwal Bharat B. , Krishnan Sunil , Guha Sushovan 
Published: August 2008

Abstract
Neutrophil gelatinase–associated lipocalin (NGAL) is a 25-kDa secreted acute phase protein, which is also up-regulated in multiple cancers, including breast, lung, and pancreas. Recently, NGAL has been proposed as an early biomarker in pancreatic cancer (PaCa). However, its biological role in PaCa is unknown. In this study, we examined in vitro and in vivo the functional role of NGAL in PaCa. Well- to moderately differentiated PaCa cells (AsPC-1, BxPC-3, and Capan-2) expressed high levels of NGAL but moderately to poorly differentiated PaCa cells (PANC-1 and MIAPaCa-2) expressed undetectable NGAL levels. Immunohistochemistry of untreated tissue microarray showed specific NGAL staining in resected PaCa specimens (P = 0.0167). Stable NGAL overexpression (MIAPaCa-2 and PANC-1) significantly blocked PaCa cell adhesion and invasion in vitro and vice versa with stable PaCa clones (BxPC-3 and AsPC-1). Moreover, NGAL overexpression reduced focal adhesion kinase (FAK) tyrosine-397 phosphorylation in PaCa cells. Furthermore, NGAL overexpression potently decreased angiogenesis in vitro partly through reduced vascular endothelial growth factor (VEGF) production and vice versa. Stable NGAL overexpression or underexpression had no effect on PaCa cell survival, viability, and response to chemotherapeutic drugs. Finally, MIAPaCa-2 cells overexpressing NGAL reduced tumor volume (P = 0.012), local and distant metastasis (P = 0.002), and angiogenesis (P = 0.05) with no effect on K-67 proliferation index (P &gt; 0.1) in an orthotopic nude mouse PaCa model. Collectively, our results suggest that NGAL reduces adhesion/invasion partly by suppressing FAK activation and inhibits angiogenesis partly by blocking VEGF production in PaCa cells. Thus, NGAL is a potential suppressor of invasion and angiogenesis in advanced PaCa. [Cancer Res 2008;68(15):6100–8]
Kinetic Stabilization of Microtubule Dynamics by Estramustine Is Associated with Tubulin Acetylation, Spindle Abnormalities, and Mitotic Arrest
Authors: Mohan Renu , Panda Dulal 
Published: August 2008

Abstract
Estramustine (EM) alone or in combination with other anticancer agents is clinically used for the treatment of hormone refractory prostate cancer. Furthermore, EM has been shown to potently inhibit the proliferation of different types of cancer cells in culture apparently by targeting microtubules; however, the antiproliferative mechanism of action of EM is not clear. In this work, we have shown that EM strongly suppressed the dynamic instability of individual microtubules in MCF-7 cells by reducing the rates of growing and shortening excursions and increasing the time microtubule spent in the pause state. At its half maximal proliferation inhibitory concentration (IC50), EM exerted strong suppressive effects on the dynamics of microtubules in MCF-7 cells without detectably affecting either the organization or the polymerized mass of microtubules. At relatively high concentrations (5 × IC50), EM significantly depolymerized microtubules in the cells. Furthermore, the microtubules were found highly acetylated, supporting the conclusion that they were stabilized by the drug. EM treatment induced spindle abnormalities in MCF-7 cells, and a major population of the arrested mitotic cells was multipolar. EM also perturbed the microtubule-kinetochore interaction, thereby activating the spindle assembly checkpoint and leading to apoptotic cell death. [Cancer Res 2008;68(15):6181–9]
Par-4 Binds to Topoisomerase 1 and Attenuates Its DNA Relaxation Activity
Authors: Goswami Anindya , Qiu Shirley , Dexheimer Thomas S. , Ranganathan Padhma , Burikhanov Ravshan , Pommier Yves , Rangnekar Vivek M. 
Published: August 2008

Abstract
The regulation of DNA relaxation by topoisomerase 1 (TOP1) is essential for DNA replication, transcription, and recombination events. TOP1 activity is elevated in cancer cells, yet the regulatory mechanism restraining its activity is not understood. We present evidence that the tumor suppressor protein prostate apoptosis response-4 (Par-4) directly binds to TOP1 and attenuates its DNA relaxation activity. Unlike camptothecin, which binds at the TOP1-DNA interface to form cleavage complexes, Par-4 interacts with TOP1 via its leucine zipper domain and sequesters TOP1 from the DNA. Par-4 knockdown by RNA interference enhances DNA relaxation and gene transcription activities and promotes cellular transformation in a TOP1-dependent manner. Conversely, attenuation of TOP1 activity either by RNA interference or Par-4 overexpression impedes DNA relaxation, cell cycle progression, and gene transcription activities and inhibits transformation. Collectively, our findings suggest that Par-4 serves as an intracellular repressor of TOP1 catalytic activity and regulates DNA topology to suppress cellular transformation. [Cancer Res 2008;68(15):6190–8]
Loss of Cannabinoid Receptor 1 Accelerates Intestinal Tumor Growth
Authors: Wang Dingzhi , Wang Haibin , Ning Wei , Backlund Michael G. , Dey Sudhansu K. , DuBois Raymond N. 
Published: August 2008

Abstract
Although endocannabinoid signaling is important for certain aspects of gastrointestinal homeostasis, the role of the cannabinoid receptors (CB) in colorectal cancer has not been defined. Here we show that CB1 expression was silenced in human colorectal cancer due to methylation of the CB1 promoter. Our genetic and pharmacologic studies reveal that loss or inhibition of CB1 accelerated intestinal adenoma growth in ApcMin/+ mice whereas activation of CB1 attenuated intestinal tumor growth by inducing cell death via down-regulation of the antiapoptotic factor survivin. This down-regulation of survivin by CB1 is mediated by a cyclic AMP–dependent protein kinase A signaling pathway. These results indicate that the endogenous cannabinoid system may represent a potential therapeutic target for prevention or treatment of colorectal cancer. [Cancer Res 2008;68(15):6468–76]
Antitumor Activity of Immunotoxins with T-Cell Receptor–like Specificity against Human Melanoma Xenografts
Authors: Klechevsky Eynav , Gallegos Michael , Denkberg Galit , Palucka Karolina , Banchereau Jacques , Cohen Cyril , Reiter Yoram 
Published: August 2008

AbstractIn this study, we have explored the use of Fab-toxin proteins (immunotoxin) to target antigen-specific MHC-peptide complexes of in vitro and in vivo cancer cells. A human phage display library was used to screen for T-cell receptor (TCR)–like antibodies that are highly specific for the peptide melanoma-associated antigen MART-126-35 presented by HLA-A201. We also used previously selected TCR-like antibodies specific for the peptide melanoma-associated antigen gp100280-288 presented by HLA-A201. The recombinant immunotoxin constructs were generated by fusing the targeting Fab fragment to a truncated form of Pseudomonas exotoxin, PE38KDEL. These immunotoxins bound with high affinity to the EBV-transformed JY cell line pulsed with the aforementioned peptides and internalized within 30 min. A significant inhibition of protein synthesis, which resulted in cell death, was detected at 24 h. MART-1–specific and gp100-specific immunotoxins bound and killed HLA-A201 melanoma MART-1+ and gp100+ cell lines that were presented at natural levels but do not bind to HLA-A201− or to HLA-A201+ MART-1− and gp100− cell lines. In severe combined immunodeficient mice, MART-1 and gp100 immunotoxins significantly and discriminately inhibited human melanoma growth. These results show that MHC class I/peptide complexes can serve as a specific target for passive immunotherapy of cancer. [Cancer Res 2008;68(15):6360–7]
Bobel-24 and Derivatives Induce Caspase-Independent Death in Pancreatic Cancer Regardless of Apoptotic Resistance
Authors: Parreño Matilde , Casanova Isolda , Céspedes María Virtudes , Vaqué Jose Pedro , Pavón Miguel Angel , Leon Javier , Mangues Ramon 
Published: August 2008

Abstract
The poor prognosis of pancreatic cancer and poor sensitivity to current therapeutics, associated with resistance to apoptosis, urge the search for new drugs. We previously described the induction of caspase-independent mithochondrial death in leukemia cells by Bobel-24 (AM-24) and derivatives. Here, we explored whether these compounds induce a similar cytotoxicity in human pancreatic carcinoma cell lines (NP18, NP9, NP31, and NP29). Bobel-24 or Bobel-16 induced cytotoxicity and DNA synthesis inhibition in all cell lines and apoptosis in all lines, except for NP9. Caspase and/or poly(ADP-ribose) polymerase-1 (PARP-1) activity inhibition experiments showed that cytotoxicity was mainly induced through apoptosis in NP18 and through a caspase-independent process in NP9. Moreover, in NP29 or NP31 cell lines, both caspase-dependent and caspase-independent cell death mechanisms coexisted. Cell death was associated with reactive oxygen species (ROS) production, mitochondrial depolarization, cytochrome c and apoptosis-inducing factor (AIF) release, AIF nuclear translocation, and lysosomal cathepsin release. Inhibition of ROS production, mitochondrial pore permeability, PARP-1, or phospholipase A2 partially prevented cell death. Moreover, cathepsin B inhibition or down-regulation by small interfering RNA partially blocked cell death. In conclusion, Bobel-24 and derivatives trigger caspase-independent lysosomal and mitochondrial death in all tested human pancreatic cancer lines, irrespective of their degree of apoptotic sensitivity, becoming the only active cytotoxic mechanism in the apoptosis-resistant NP9 line. This mechanism may overcome the resistance to apoptosis observed in pancreatic carcinoma when treated with current genotoxic drugs. [Cancer Res 2008;68(15):6313–23]
Implications of Apurinic/Apyrimidinic Endonuclease in Reactive Oxygen Signaling Response after Cisplatin Treatment of Dorsal Root Ganglion Neurons
Authors: Jiang Yanlin , Guo Chunlu , Vasko Michael R. , Kelley Mark R. 
Published: August 2008

AbstractPeripheral neuropathy is one of the major side effects of the anticancer drug cisplatin. Although previous work suggests that this neuropathy correlates with formation of DNA adducts in sensory neurons, growing evidence suggests that cisplatin also increases the generation of reactive oxygen species (ROS), which could cause DNA damage. Apurinic/apyrimidinic endonuclease/redox factor-1 (Ape1/Ref-1) is a multifunctional protein involved in DNA base excision repair of oxidative DNA damage and in redox regulation of a number of transcription factors. Therefore, we asked whether altering Ape1 functions would influence cisplatin-induced neurotoxicity. Sensory neurons in culture were exposed to cisplatin for 24 hours and several end points of toxicity were measured, including production of ROS, cell death, apoptosis, and release of the immunoreactive calcitonin gene–related peptide (iCGRP). Reducing expression of Ape1 in neuronal cultures using small interfering RNA (siRNA) enhances cisplatin-induced cell killing, apoptosis, ROS generation, and cisplatin-induced reduction in iCGRP release. Overexpressing wild-type Ape1 attenuates all the toxic effects of cisplatin in cells containing normal endogenous levels of Ape1 and in cells with reduced Ape1 levels after Ape1siRNA treatment. Overexpressing the redox deficient/repair competent C65-Ape1 provides partial rescue, whereas the repair-deficient Ape1 (N226A + R177A) does not protect neurons from cisplatin toxicity. We also observe an increase in phosphorylation of p53 after a decrease in Ape1 levels in sensory neuronal cultures. These results strongly support the notion that Ape1 is a potential translational target such that protecting Ape1 levels and particularly its DNA repair function could reduce peripheral neuropathy in patients undergoing cisplatin treatment. [Cancer Res 2008;68(15):6425–34]
Ugene, a Newly Identified Protein That Is Commonly Overexpressed in Cancer and Binds Uracil DNA Glycosylase
Authors: Guo Chunguang , Zhang Xiaodong , Fink Stephen P. , Platzer Petra , Wilson Keith , Willson James K.V. , Wang Zhenghe , Markowitz Sanford D. 
Published: August 2008

Abstract
Expression microarrays identified a novel transcript, designated as Ugene, whose expression is absent in normal colon and colon adenomas, but that is commonly induced in malignant colon cancers. These findings were validated by real-time PCR and Northern blot analysis in an independent panel of colon cancer cases. In addition, Ugene expression was found to be elevated in many other common cancer types, including breast, lung, uterus, and ovary. Immunofluorescence of V5-tagged Ugene revealed it to have a nuclear localization. In a pull-down assay, uracil DNA glycosylase 2 (UNG2), an important enzyme in the base excision repair (BER) pathway, was identified as a partner protein that binds to Ugene. Coimmunoprecipitation and Western blot analysis confirmed the binding between the endogenous Ugene and UNG2 proteins. Using deletion constructs, we find that Ugene binds to the first 25 amino acids of the UNG2 NH2 terminus. We suggest that Ugene induction in cancer may contribute to the cancer phenotype by interacting with the BER pathway. [Cancer Res 2008;68(15):6118–26]
Loss of Integrin α1β1 Ameliorates Kras-Induced Lung Cancer
Authors: Macias-Perez Ines , Borza Corina , Chen Xiwu , Yan Xuexian , Ibanez Raquel , Mernaugh Glenda , Matrisian Lynn M. , Zent Roy , Pozzi Ambra 
Published: August 2008

Abstract
The collagen IV binding receptor integrin α1β1 has been shown to regulate lung cancer due to its proangiogenic properties; however, it is unclear whether this receptor also plays a direct role in promoting primary lung tumors. To investigate this possibility, integrin α1-null mice were crossed with KrasLA2 mice that carry an oncogenic mutation of the Kras gene (G12D) and develop spontaneous primary tumors with features of non–small cell lung cancer. We provide evidence that KrasLA2/α1-null mice have a decreased incidence of primary lung tumors and longer survival compared with KrasLA2/α1 wild-type controls. Tumors from KrasLA2/α1-null mice were also smaller, less vascularized, and exhibited reduced cell proliferation and increased apoptosis, as determined by proliferating cell nuclear antigen and terminal deoxynucleotidyl-transferase–mediated dUTP nick-end staining, respectively. Moreover, tumors from the KrasLA2/α1-null mice showed diminished extracellular signal-regulated kinase (ERK) but enhanced p38 mitogen-activated protein kinase activation. Primary lung tumor epithelial cells isolated from KrasLA2/α1-null mice showed a significant decrease in anchorage-independent colony formation, collagen-mediated cell proliferation, ERK activation, and, most importantly, tumorigenicity when injected into nude mice compared with KrasLA2/α1 wild-type tumor cells. These results indicate that loss of the integrin α1 subunit decreases the incidence and growth of lung epithelial tumors initiated by oncogenic Kras, suggesting that both Kras and integrin α1β1 cooperate to drive the growth of non–small cell lung cancer in vivo. [Cancer Res 2008;68(15):6127–35]
Synergistic Inhibition of Lung Tumorigenesis by a Combination of Green Tea Polyphenols and Atorvastatin
Authors: Lu Gang , Xiao Hang , You Hui , Lin Yong , Jin Huanyu , Snagaski Blake , Yang Chung S. 
Published: August 2008

Abstract
Purpose: The present study investigated the possible synergistic inhibitory effect of a novel combination of polyphenon E (PPE, a standardized green tea polyphenol preparation) and atorvastatin (trade name Lipitor) in a mouse tumorigenesis model and in human lung cancer H1299 and H460 cell lines.
Experimental Design: Female A/J mice were given two weekly i.p. injections of 4-(methylnitrosaminao)-1-(3-pyridyl)-1-butanone (150 mg/kg total dose); 1 week later, mice were treated with PPE (0.25% or 0.5% in drinking fluid), atorvastatin (200 or 400 ppm in diet), or PPE (0.25%) plus atorvastatin (200 ppm) for 16 weeks. The interaction of these two agents was also studied in human lung cancer H1299 and H460 cells.
Results: The individual agents, PPE or atorvastatin, were not effective in inhibiting lung tumorigenesis. The low-dose combination of PPE and atorvastatin, however, significantly reduced both the tumor multiplicity and tumor burden (by 56% and 55%, respectively, P &lt; 0.05). Isobologram analysis of the interaction of the two agents indicated that the combination synergistically decreased tumor multiplicity (P = 0.0006) and tumor burden (P = 0.0009). The inhibition was associated with enhanced apoptosis and suppressed myeloid cell leukemia 1 (Mcl-1) level in adenoma as determined by immunohistochemistry and Western blots. Treatment with combinations of PPE and atorvastatin also synergistically decreased the number of viable H1299 and H460 cells as determined by isobologram analysis. This synergistic effect was associated with increased apoptosis as determined by the terminal deoxyribonucleotide transferase–mediated nick-end labeling assay. The combination of PPE and atorvastatin was more efficient in reducing the antiapoptotic protein Mcl-1 level and increasing the cleaved caspase-3 and cleaved poly(ADP)-ribose polymerase level than the single-agent treatment.
Conclusions: The present work showed that PPE and atorvastatin synergistically inhibited 4-(methylnitrosaminao)-1-(3-pyridyl)-1-butanone–induced lung tumorigenesis in mice and the growth of lung cancer H1299 and H460 cells, possibly through enhanced apoptosis. The results provide leads for future research on the application of this combination for the prevention and treatment of lung cancer.
The Retinoblastoma Family Member pRb2/p130 Is an Independent Predictor of Survival in Human Soft Tissue Sarcomas
Authors: Masciullo Valeria , Berardengo Ester , Boglione Antonella , Sgambato Alessandro , Bernardi Amelia , Forni Marco , Linari Alessandra , Cito Letizia , Scambia Giovanni , Comandone Alessandro , Giordano Antonio 
Published: August 2008

Abstract
Purpose: pRb2/p130, a member of the Retinoblastoma gene family, has been shown to be a powerful prognostic factor in several malignancies. We sought to evaluate pRb2/p130 protein expression and its clinical effect in patients affected with soft tissue sarcomas (STS).
Experimental Design: Expression of pRb2/p130 was evaluated by immunohistochemistry on formalin-fixed, paraffin-embedded sections in 41 STSs. Results obtained were correlated with clinicopathologic variables and disease-free and overall survival (OS) in univariate and multivariate analysis.
Results: Expression of pRb2/p130 was diminished in 25 (61%) tumors, whereas the remaining ones (39%) were classified as high expressors. No correlation between pRb2/p130 expression and clinicopathologic variables was observed. However, a direct relationship between pRb2/p130 expression and clinical outcome of the patients was found in the subgroup of nonmetastatic tumors (n = 31). In univariate analysis, reduced pRb2/p130 expression was a negative prognostic factor and correlated with shorter disease-free survival (P = 0.021) and OS (P = 0.017) survival. In multivariate analysis, reduced pRb2/p130 expression was confirmed to be an independent predictor of shorter OS when considered together with tumor stage and grading (risk ratio, 7.893; confidence interval, 1.618-38.509; P = 0.011).
Conclusions: This study shows for the first time the potential prognostic value of pRb2/130 expression evaluated on formalin-fixed, paraffin-embedded sections in STSs patients. pRb2/p130 immunoreactivity can be used to predict OS in patients with nonmetastatic STSs and, therefore, may represent a new prognostic marker.
A Pilot Study of Consolidative Immunotherapy in Patients with High-Risk Pediatric Sarcomas
Authors: Mackall Crystal L. , Rhee Eunice H. , Read Elizabeth J. , Khuu Hanh M. , Leitman Susan F. , Bernstein Donna , Tesso Merertu , Long Lauren M. , Grindler David , Merino Margret , Kopp William , Tsokos Maria , Berzofsky Jay A. , Helman Lee J. 
Published: August 2008

AbstractPurpose: Patients with metastatic or recurrent Ewing’s sarcoma family of tumors and alveolar rhabdomyosarcoma have &lt;25% 5-year survival in most studies. This study administered a novel immunotherapy regimen aimed at consolidating remission in these patients.Experimental Design: Fifty-two patients with translocation positive, recurrent, or metastatic Ewing’s sarcoma family of tumors or alveolar rhabdomyosarcoma underwent prechemotherapy cell harvest via apheresis for potential receipt of immunotherapy. Following completion of standard multimodal therapy, 30 patients ultimately initiated immunotherapy and were sequentially assigned to three cohorts. All cohorts received autologous T cells, influenza vaccinations, and dendritic cells pulsed with peptides derived from tumor-specific translocation breakpoints and E7, a peptide known to bind HLA-A2. Cohort 1 received moderate-dose recombinant human interleukin-2 (rhIL-2), cohort 2 received low-dose rhIL-2, and cohort 3 did not receive rhIL-2.Results: All immunotherapy recipients generated influenza-specific immune responses, whereas immune responses to the translocation breakpoint peptides occurred in 39%, and only 25% of HLA-A2+ patients developed E7-specific responses. Toxicity was minimal. Intention-to-treat analysis revealed a 31% 5-year overall survival for all patients apheresed (median potential follow-up 7.3 years) with a 43% 5-year overall survival for patients initiating immunotherapy.Conclusions: Consolidative immunotherapy is a scientifically based and clinically practical approach for integrating immunotherapy into a multimodal regimen for chemoresponsive cancer. Patients receiving immunotherapy experienced minimal toxicity and favorable survival. The robust influenza immune responses observed suggest that postchemotherapy immune incompetence will not fundamentally limit this approach. Future studies will seek to increase efficacy by using more immunogenic antigens and more potent dendritic cells.