bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphatidylinositol 3′-Kinase Activation Leads to Multidrug Resistance Protein-1 Expression and Subsequent Chemoresistance in Advanced Prostate Cancer Cells
Authors: Lee John T. , Steelman Linda S. , McCubrey James A. 
Published: September 2005

Abstract
The development of androgen-independent growth in advanced carcinoma of the prostate (CaP) is associated with poor prognosis and few therapeutic options. Chemotherapeutic drugs offer the afflicted patient palliative benefits, but these are short-lived because of the chemoresistant nature of hormone-refractory prostate cancer. Given the high percentage of CaP patients with mutations in the PTEN tumor suppressor gene, we sought to determine the involvement of the phosphatidylinositol 3′-kinase (PI3K) cascade in the development of CaP drug resistance. PTEN-negative PC3 cells were observed to have increased resistance to both doxorubicin and paclitaxel when compared with PTEN-positive DU145 cells. Furthermore, modulation of PI3K activity with the use of constitutively active and dominant-negative inhibitors was found to affect the ability to CaP cells to respond to chemotoxic treatments. Additionally, inhibition of PI3K with a small molecular weight inhibitor (LY294002) was able to potentiate the antineoplastic activity of both doxorubicin and paclitaxel in CaP cells. Interestingly, multidrug resistance protein-1 (MRP-1) expression, but not MDR-1 (p-glycoprotein), was observed to be induced as a consequence of PI3K activation in these cell types. Inhibition of MRP-1 expression via siRNA was observed to synergistically sensitize CaP cells to chemotoxic drugs while having no appreciable effect on cell growth in the absence of these compounds. Taken together, these data suggest that PI3K activation can lead to the development of chemoresistant cells in prostatic carcinomas through the up-regulation of MRP-1. Thus, inhibition of PI3K activity with concomitant administration of chemotoxic compounds may prove beneficial in preventing the development of drug resistance in patients with hormone-refractory prostate cancer.
Development of Gastric Carcinoma from Intestinal Metaplasia in Cdx2-transgenic Mice
Authors: Mutoh Hiroyuki , Sakurai Shinji , Satoh Kiichi , Tamada Kiichi , Kita Hiroto , Osawa Hiroyuki , Tomiyama Takeshi , Sato Yukihiro , Yamamoto Hironori , Isoda Norio , Yoshida Toru , Ido Kenichi , Sugano Kentaro 
Published: September 2005

Abstract
In the progression of chronic gastritis, gastric mucosal cells deviate from the normal pathway of gastric differentiation to an intestinal phenotype. Many epidemiologic studies have found an association between the formation of intestinal metaplasia and the development of gastric carcinoma. However, there is no direct evidence that shows intestinal metaplasia is a precursor lesion of gastric carcinoma, to date. We periodically examined the intestinal metaplastic mucosa of Cdx2-transgenic mice we have previously generated. Gastric polyps developed from intestinal metaplastic mucosa in all stomachs of Cdx2-transgenic mice examined. These gastric polyps consisted of intestinal-type adenocarcinoma that invaded the submucosa and muscularis propria and occasionally spread into the subserosa. p53 and APC gene mutations were recognized in the adenocarcinomas. The participation of APC and p53 gene mutations in gastric carcinogenesis from the intestinal metaplasia was verified by the Cdx2-transgenic mice, carrying ApcMin mutation or p53 deficiency, that developed gastric polyps much earlier than Cdx2 alone. We successfully showed that long-term intestinal metaplasia induces invasive gastric carcinoma. These results indicate that intestinal metaplasia itself plays a significant role in the genesis and progression of gastric carcinoma.
RNA Interference Targeting Transforming Growth Factor-β Enhances NKG2D-Mediated Antiglioma Immune Response, Inhibits Glioma Cell Migration and Invasiveness, and Abrogates TumorigenicityIn vivo
Authors: Friese Manuel A. , Wischhusen Jörg , Wick Wolfgang , Weiler Markus , Eisele Günter , Steinle Alexander , Weller Michael 
Published: September 2005

AbstractTransforming growth factor (TGF)-β is the key molecule implicated in impaired immune function in human patients with malignant gliomas. Here we report that patients with glioblastoma, the most common and lethal type of human glioma, show decreased expression of the activating immunoreceptor NKG2D in CD8+ T and natural killer (NK) cells. TGF-β is responsible for the down-regulation of NKG2D expression in CD8+ T and NK cells mediated by serum and cerebrospinal fluid of glioma patients in vitro. Moreover, TGF-β inhibits the transcription of the NKG2D ligand MICA. Interference with the synthesis of TGF-β1 and TGF-β2 by small interfering RNA technology prevents the down-regulation of NKG2D on immune cells mediated by LNT-229 glioma cell supernatant and strongly enhances MICA expression in the glioma cells and promotes their recognition and lysis by CD8+ T and NK cells. Furthermore, TGF-β silencing results in a less migratory and invasive glioma cell phenotype in vitro. LNT-229 glioma cells deficient in TGF-β exhibit a loss of subcutaneous and orthotopic tumorigenicity in nude mice, and NK cells isolated from these mice show an activated phenotype. RNA interference targeting TGF-β1,2 results in a glioma cell phenotype that is more sensitive to immune cell lysis and less motile in vitro and nontumorigenic in nude mice, strongly confirming TGF-β antagonism as a major therapeutic strategy for the future treatment of malignant gliomas.
Proteolytic Enzymes and Altered Glycosylation Modulate Dystroglycan Function in Carcinoma Cells
Authors: Singh Jarnail , Itahana Yoko , Knight-Krajewski Selena , Kanagawa Motoi , Campbell Kevin P. , Bissell Mina J. , Muschler John 
Published: September 2005

Abstract
Alterations in the basement membrane receptor dystroglycan (DG) are evident in muscular dystrophies and carcinoma cells and characterized by a selective loss or modification of the extracellular α-DG subunit. Defects in posttranslational modifications of DG have been identified in some muscular dystrophies, but the underlying modifications in carcinoma cells have not yet been defined. We reveal here multiple posttranslational modifications that modulate the composition and function of DG in normal epithelial cells and carcinoma cells. We show that α-DG is shed from the cell surface of normal and tumorigenic epithelial cells through a proteolytic mechanism that does not require direct cleavage of either α- or β-DG. Shedding is dependent on metalloprotease activity and the proprotein convertase furin. Surprisingly, furin is also found to directly process α-DG as a proprotein substrate, changing the existing model of DG composition. We also show that the glycosylation of α-DG is altered in invasive carcinoma cells, and this modification causes complete loss of laminin binding properties. Together, these data elucidate several novel events regulating the functional composition of DG and reveal defects that arise during cancer progression, providing direction for efforts to restore this link with the basement membrane in carcinoma cells.
Apoptosis Protease Activator Protein-1 Expression Is Dispensable for Response of Human Melanoma Cells to Distinct Proapoptotic Agents
Authors: Zanon Marina , Piris Adriano , Bersani Ilaria , Vegetti Claudia , Molla Alessandra , Scarito Alessia , Anichini Andrea 
Published: September 2005

AbstractLoss of expression of the apoptosis protease activator protein-1 (APAF-1) in human melanoma is thought to promote resistance to programmed cell death by preventing caspase-9 activation. However, the role of the APAF-1–dependent pathway in apoptosis activated by cellular stress and/or DNA damage has been recently questioned. We investigated APAF-1 expression in a large panel of human melanomas and assessed cellular response to several proapoptotic agents in tumors expressing or lacking APAF-1 protein. In two melanomas with wild-type p53 but with differential expression of APAF-1, treatment with camptothecin, celecoxib, or an nitric oxide synthase inhibitor (1400W) significantly modulated expression of 36 of 96 genes in an apoptosis-specific cDNA macroarray, but APAF-1 mRNA levels were not induced (in APAF-1− cells) nor up-regulated (in APAF-1+ cells), a finding confirmed at the protein level. Treatment with cisplatin, camptothecin, etoposide, betulinic acid, celecoxib, 1400W, and staurosporine promoted enzymatic activity not only of caspases -2, -8, and -3 but also of caspase-9 in both APAF-1+ and APAF-1− tumor cells. Moreover, drug-induced caspase-9 enzymatic activity could be not only partially but significantly reduced by caspase-2, -3, and -8 –specific inhibitors in both APAF-1+ and APAF-1− tumor cells. In response to 1 to 100 μmol/L of cisplatin, camptothecin, or celecoxib, APAF-1+ melanomas (n = 12) did not show significantly increased levels of apoptosis compared with APAF-1− tumors (n = 7), with the exception of enhanced apoptosis in response to a very high dose (100 μmol/L) of etoposide. These results suggest that the response of human melanoma cells to different proapoptotic agents may be independent of their APAF-1 phenotype.
Pancreatic Insulinomas in Multiple Endocrine Neoplasia, Type I Knockout Mice Can Develop in the Absence of Chromosome Instability or Microsatellite Instability
Authors: Scacheri Peter C. , Kennedy Alyssa L. , Chin Koei , Miller Meghan T. , Hodgson J. Graeme , Gray Joe W. , Marx Stephen J. , Spiegel Allen M. , Collins Francis S. 
Published: September 2005

Abstract
Multiple endocrine neoplasia, type I (MEN1) is an inherited cancer syndrome characterized by tumors arising primarily in endocrine tissues. The responsible gene acts as a tumor suppressor, and tumors in affected heterozygous individuals occur after inactivation of the wild-type allele. Previous studies have shown that Men1 knockout mice develop multiple pancreatic insulinomas, but this occurs many months after loss of both copies of the Men1 gene. These studies imply that loss of Men1 is not alone sufficient for tumor formation and that additional somatic genetic changes are most likely essential for tumorigenesis. The usual expectation is that such mutations would arise either by a chromosomal instability or microsatellite instability mechanism. In a study of more then a dozen such tumors, using the techniques of array-based comparative genomic hybridization, fluorescent in situ hybridization, loss of heterozygosity analysis using multiple microsatellite markers across the genome, and real time PCR to assess DNA copy number, it appears that many of these full-blown clonal adenomas remain remarkably euploid. Furthermore, the loss of the wild-type Men1 allele in heterozygous Men1 mice occurs by loss and reduplication of the entire mutant-bearing chromosome. Thus, the somatic genetic changes that are postulated to lead to tumorigenesis in a mouse model of MEN1 must be unusually subtle, occurring at either the nucleotide level or through epigenetic mechanisms.
SPRY2 Is an Inhibitor of the Ras/Extracellular Signal-Regulated Kinase Pathway in Melanocytes and Melanoma Cells with Wild-Type
BRAF
but Not with the V599E Mutant
Authors: Tsavachidou Dimitra , Coleman Mathew L. , Athanasiadis Galene , Li Shuixing , Licht Jonathan D. , Olson Michael F. , Weber Barbara L. 
Published: September 2005

Abstract
BRAF mutations result in constitutively active BRAF kinase activity and increased extracellular signal-regulated kinase (ERK) signaling and cell proliferation. Initial studies have shown that BRAF mutations occur at a high frequency in melanocytic nevi and metastatic lesions, but recent data have revealed much lower incidence of these mutations in early-stage melanoma, implying that other factors may contribute to melanoma pathogenesis in a wild-type (WT) BRAF context. To identify such contributing factors, we used microarray gene expression profiling to screen for differences in gene expression between a panel of melanocytic and melanoma cell lines with WT BRAF and a group of melanoma cell lines with the V599E BRAF mutation. We found that SPRY2, an inhibitor homologous to SPRY4, which was previously shown to suppress Ras/ERK signaling via direct binding to Raf-1, had reduced expression in WT BRAF cells. Using small interfering RNA-mediated SPRY2 knockdown, we showed that SPRY2 acts as an inhibitor of ERK signaling in melanocytes and WT BRAF melanoma cells, but not in cell lines with the V599E mutation. We also show that SPRY2 and SPRY4 directly bind WT BRAF but not the V599E and other exon 15 BRAF mutants. These data suggest that SPRY2, an inhibitor of ERK signaling, may be bypassed in melanoma cells either by down-regulation of its expression in WT BRAF cells, or by the presence of the BRAF mutation.
H2-EaDeficiency Is a Risk Factor for Bleomycin-Induced Lung Fibrosis in Mice
Authors: Du Min , Irani Roxanna A. , Stivers David N. , Lee Sang-Joon , Travis Elizabeth L. 
Published: September 2005

AbstractPulmonary fibrosis is a significant complication in cancer patients when treated by radiation, e.g., thoracic malignant diseases, or chemotherapeutic agents. Bleomycin is one of the primary drugs used to treat testicular cancer, but the incidence of significant pulmonary fibrosis limits the dose. It is known that susceptibility to bleomycin-induced pulmonary fibrosis is a heritable trait controlled by multiple genes, none of which, however, are yet known. In this study, we used expression profiling and genetic analysis in mouse models of bleomycin-induced pulmonary fibrosis and identified MHC class II antigen Eα (H2-Ea) as a risk factor for this disease. We found that a loss-of-function deletion in the H2-Ea gene was linked to susceptibility. A functional test of H2-Ea in transgenic mice showed 100% survival in the transgenic mice compared with 53% in C57BL/10J mice and significantly decreased pulmonary fibrosis from 16.42% (C57BL/10J) to 5.76% (transgenic; P = 1.20e−8). These results show that H2-Ea expression protects mice from bleomycin-induced pulmonary fibrosis, which implicates H2-Ea as a candidate susceptibility gene for pulmonary fibrosis.
Liposome-Encapsulated CpG Oligodeoxynucleotides as a Potent Adjuvant for Inducing Type 1 Innate Immunity
Authors: Suzuki Yoshinori , Wakita Daiko , Chamoto Kenji , Narita Yoshinori , Tsuji Takemasa , Takeshima Tsuguhide , Gyobu Hiroshi , Kawarada You , Kondo Satoshi , Akira Shizuo , Katoh Hiroyuki , Ikeda Hiroaki , Nishimura Takashi 
Published: September 2005

AbstractUnmethylated cytosine-phosphorothioate-guanine oligodeoxynucleotides (CpG-ODNs) exhibit potent immunostimulating activity by binding with Toll-like receptor 9 (TLR9) expressed on antigen-presenting cells. Here, we show that CpG-ODN encapsulated in cationic liposomes (CpG-liposomes) improves its incorporation into CD11c+ dendritic cells (DCs) and induces enhanced serum interleukin (IL)-12 levels compared with unmodified CpG-ODN. CpG-liposome potently activated natural killer (NK) cells (84.3%) and NKT cells (48.3%) to produce interferon-γ (IFN-γ), whereas the same dose of unmodified CpG-ODN induced only low numbers of IFN-γ–producing NK cells (12.7%) and NKT cells (1.6%) to produce IFN-γ. In contrast with the NKT cell agonist α-galactosylceramide, which induces both IFN-γ and IL-4 production by NKT cells, CpG-liposome only induced IFN-γ production by NKT cells. Such potent adjuvant activities of CpG-liposome were absent in TLR9-deficient mice, indicating that CpG-liposome was as effective as CpG-ODN in stimulating type 1 innate immunity through TLR9. In addition to TLR9, at least two other factors, IL-12 production by DCs and direct contact between DCs and NK or NKT cells, were essential for inducing type 1 innate immunity by CpG-liposome. Furthermore, ligation of TLR9 by CpG-liposome coencapsulated with ovalbumin (OVA) caused the induction of OVA-specific CTLs, which exhibited potent cytotoxicity against OVA-expressing tumor cells. These results indicate that CpG-liposome alone or combined with tumor antigen protein provides a promising approach for the prevention or therapy of tumors.
Reduced Immunoglobulin E and Allergy among Adults with Glioma Compared with Controls
Authors: Wiemels Joseph L. , Wiencke John K. , Patoka Joseph , Moghadassi Michelle , Chew Terri , McMillan Alex , Miike Rei , Barger Geoffrey , Wrensch Margaret 
Published: September 2005

Abstract
We and others have reported previously that adults with glioma are 1.5- to 4-fold less likely than controls to report a variety of allergic conditions. The consistent nature of this relationship calls for a biological explanation so that preventative or therapeutic modalities can be explored. We enrolled 403 newly diagnosed adult glioma cases in the San Francisco Bay Area over a 3-year period using a population-based cancer registry and 402 age/gender/ethnicity frequency-matched controls identified via random digit dialing. We assessed total, food-specific, and respiratory-specific IgE in available case (n = 228) and control (n = 289) serum samples. IgE levels were associated with gender, age, smoking status, and ethnicity among cases and/or controls. Among the cases, IgE levels were not associated with aspects of glioma therapy including radiation, chemotherapy, or tumor resection. Total IgE levels were lower in cases than controls: age/gender/ethnicity/education/smoking-adjusted odds ratio (OR) for elevated versus normal total IgE was 0.37 [95% confidence interval (CI), 0.22–0.64]. For the food panel, OR was 0.12 (95% CI, 0.04–0.41). For the respiratory panel, OR was 0.76 (95% CI, 0.52–1.1). Among respiratory allergies, late age of onset (&gt;12 years) but not IgE levels defined a group with strong associations with risk (OR, 0.50; 95% CI, 0.33–0.75). These results corroborate and strengthen our findings of an inverse association between allergic reactions and glioma by showing a relationship with a biomarker for allergy and cancer for the first time. Furthermore, the results indicate a complex relationship between allergic disease and glioma risk that varies by allergen and allergic pathology.
Bone Marrow Contribution to Tumor-Associated Myofibroblasts and Fibroblasts
Authors: Direkze Natalie C. , Hodivala-Dilke Kairbaan , Jeffery Rosemary , Hunt Toby , Poulsom Richard , Oukrif Dahmane , Alison Malcolm R. , Wright Nicholas A. 
Published: September 2005

Abstract
The role of myofibroblasts in tissue repair and fibrosis is well documented, but the source of these myofibroblasts is unclear. There is evidence of a circulating population of fibrocytes that can home to areas of injury and contribute to myofibroblast populations. Previously, we have shown that the bone marrow is a source of myofibroblasts for many tissues including the gut, lung, and kidney and that this phenomenon is exacerbated by injury. We now show that the bone marrow can contribute to myofibroblast and fibroblast populations in tumor stroma in a mouse model of pancreatic insulinoma. Mice transgenic for the rat insulin promoter II gene linked to the large-T antigen of SV40 (RIPTag) develop solid β-cell tumors of the pancreas. Approximately 25% of myofibroblasts in these pancreatic tumors were donor-derived, and these were concentrated toward the edge of the tumor. Thus, the development of tumor stroma is at least in part a systemic response that may ultimately yield methods of targeting new therapy.
Tumor Cells Fail to
trans
-Induce Telomerase in Human Umbilical Vein Endothelial Cell Cultures
Authors: Pascale Esterina , Reale Graziella Cimino , D’Ambrosio Ettore 
Published: September 2005

Abstract
The shortening of the telomeres that occurs in most somatic cells and untransformed cell cultures is considered a hallmark of cellular senescence. Re-activation of telomerase, which is usually present in immortal cells, avoids telomere shortening and considerably extends the culture life span. Normal human endothelial cells are characterized by an accelerated rate of telomere shortening and reach replicative senescence after a limited number of cell divisions. It has recently been reported that human telomerase reverse transcriptase expression may be strongly up-regulated in human endothelial cells cocultivated with tumor cells. Due to the important implications of this finding on tumor progression, we have extensively analyzed for the presence of telomerase in primary human endothelial cells either cocultivated with tumor cells or grown with tumor-conditioned medium. We found modest, but readily detectable, amounts of telomerase in all human endothelial cell cultures analyzed that disappeared as the cultures approached senescence. Quantitative reverse transcription-PCR also showed a direct correlation between human telomerase reverse transcriptase expression and the proliferative index of the cultures. Nevertheless, we did not find any evidence of induction of telomerase activity by tumor cells in any of the tested conditions. All data indicate that telomerase in human endothelial cells follows an activation program that is strictly associated to the culture growth rate.
The Combination of Genetic Instability and Clonal Expansion Predicts Progression to Esophageal Adenocarcinoma
Authors: Maley Carlo C. , Galipeau Patricia C. , Li Xiaohong , Sanchez Carissa A. , Paulson Thomas G. , Blount Patricia L. , Reid Brian J. 
Published: September 2005

Abstract
There is debate in the literature over the relative importance of genetic instability and clonal expansion during progression to cancer. Barrett’s esophagus is a uniquely suited model to investigate neoplastic progression prospectively because periodic endoscopic biopsy surveillance is recommended for early detection of esophageal adenocarcinoma. We hypothesized that expansion of clones with genetic instability would predict progression to esophageal adenocarcinoma. We measured p16 (CDKN2A/INK4A) lesions (loss of heterozygosity, mutations, and CpG island methylation), p53 (TP53) lesions (loss of heterozygosity, mutation) and ploidy abnormalities (aneuploidy, tetraploidy) within each Barrett’s esophagus segment of a cohort of 267 research participants, who were followed prospectively with cancer as an outcome. We defined the size of a lesion as the fraction of cells with the lesion multiplied by the length of the Barrett’s esophagus segment. A Cox proportional hazards regression indicates that the sizes of clones with p53 loss of heterozygosity (relative risk = 1.27x for an x cm clone; 95% confidence interval, 1.07–1.50) or ploidy abnormalities (relative risk = 1.31x for an x cm clone; 95% confidence interval, 1.07–1.60) predict progression to esophageal adenocarcinoma better than the mere presence of such clones (likelihood ratio test, P &lt; 0.01). Controlling for length of the Barrett’s esophagus segment had little effect. The size of a clone with a p16 lesion is not a significant predictor of esophageal adenocarcinoma when we controlled for p53 loss of heterozygosity status. The combination of clonal expansion and genetic instability is a better predictor of cancer outcome than either alone. This implies that interventions that limit expansion of genetically unstable clones may reduce risk of progression to cancer.